diff options
Diffstat (limited to 'Documentation')
92 files changed, 3070 insertions, 2495 deletions
diff --git a/Documentation/ABI/stable/sysfs-class-tpm b/Documentation/ABI/stable/sysfs-class-tpm index 9f790eebb5d2..c0e23830f56a 100644 --- a/Documentation/ABI/stable/sysfs-class-tpm +++ b/Documentation/ABI/stable/sysfs-class-tpm @@ -116,7 +116,7 @@ Description: The "pubek" property will return the TPM's public endorsement owner's authorization. Since the TPM driver doesn't store any secrets, it can't authorize its own request for the pubek, making it unaccessible. The public endorsement key is gener- - ated at TPM menufacture time and exists for the life of the + ated at TPM manufacture time and exists for the life of the chip. Example output: @@ -163,7 +163,7 @@ Date: April 2006 KernelVersion: 2.6.17 Contact: tpmdd-devel@lists.sf.net Description: The "temp_deactivated" property returns a '1' if the chip has - been temporarily dectivated, usually until the next power + been temporarily deactivated, usually until the next power cycle. Whether a warm boot (reboot) will clear a TPM chip from a temp_deactivated state is platform specific. diff --git a/Documentation/ABI/stable/sysfs-firmware-opal-elog b/Documentation/ABI/stable/sysfs-firmware-opal-elog index e1f3058f5954..2536434d49d0 100644 --- a/Documentation/ABI/stable/sysfs-firmware-opal-elog +++ b/Documentation/ABI/stable/sysfs-firmware-opal-elog @@ -57,4 +57,4 @@ Description: Shortly after acknowledging it, the log entry will be removed from sysfs. Reading this file will list the supported - operations (curently just acknowledge).
\ No newline at end of file + operations (currently just acknowledge). diff --git a/Documentation/ABI/testing/sysfs-class-power b/Documentation/ABI/testing/sysfs-class-power index 369d2a2d7d3e..fa05719f9981 100644 --- a/Documentation/ABI/testing/sysfs-class-power +++ b/Documentation/ABI/testing/sysfs-class-power @@ -74,3 +74,61 @@ Description: Valid values: - 0 - 70 (minutes), step by 10 (rounded down) + +What: /sys/class/power_supply/bq24257-charger/ovp_voltage +Date: October 2015 +KernelVersion: 4.4.0 +Contact: Andreas Dannenberg <dannenberg@ti.com> +Description: + This entry configures the overvoltage protection feature of bq24257- + type charger devices. This feature protects the device and other + components against damage from overvoltage on the input supply. See + device datasheet for details. + + Valid values: + - 6000000, 6500000, 7000000, 8000000, 9000000, 9500000, 10000000, + 10500000 (all uV) + +What: /sys/class/power_supply/bq24257-charger/in_dpm_voltage +Date: October 2015 +KernelVersion: 4.4.0 +Contact: Andreas Dannenberg <dannenberg@ti.com> +Description: + This entry configures the input dynamic power path management voltage of + bq24257-type charger devices. Once the supply drops to the configured + voltage, the input current limit is reduced down to prevent the further + drop of the supply. When the IC enters this mode, the charge current is + lower than the set value. See device datasheet for details. + + Valid values: + - 4200000, 4280000, 4360000, 4440000, 4520000, 4600000, 4680000, + 4760000 (all uV) + +What: /sys/class/power_supply/bq24257-charger/high_impedance_enable +Date: October 2015 +KernelVersion: 4.4.0 +Contact: Andreas Dannenberg <dannenberg@ti.com> +Description: + This entry allows enabling the high-impedance mode of bq24257-type + charger devices. If enabled, it places the charger IC into low power + standby mode with the switch mode controller disabled. When disabled, + the charger operates normally. See device datasheet for details. + + Valid values: + - 1: enabled + - 0: disabled + +What: /sys/class/power_supply/bq24257-charger/sysoff_enable +Date: October 2015 +KernelVersion: 4.4.0 +Contact: Andreas Dannenberg <dannenberg@ti.com> +Description: + This entry allows enabling the sysoff mode of bq24257-type charger + devices. If enabled and the input is removed, the internal battery FET + is turned off in order to reduce the leakage from the BAT pin to less + than 1uA. Note that on some devices/systems this disconnects the battery + from the system. See device datasheet for details. + + Valid values: + - 1: enabled + - 0: disabled diff --git a/Documentation/ABI/testing/sysfs-driver-ppi b/Documentation/ABI/testing/sysfs-driver-ppi index 7d1435bc976c..9921ef285899 100644 --- a/Documentation/ABI/testing/sysfs-driver-ppi +++ b/Documentation/ABI/testing/sysfs-driver-ppi @@ -1,4 +1,4 @@ -What: /sys/devices/pnp0/<bus-num>/ppi/ +What: /sys/class/tpm/tpmX/ppi/ Date: August 2012 Kernel Version: 3.6 Contact: xiaoyan.zhang@intel.com @@ -8,9 +8,14 @@ Description: folder makes sense. The folder path can be got by command 'find /sys/ -name 'pcrs''. For the detail information of PPI, please refer to the PPI specification from + http://www.trustedcomputinggroup.org/ -What: /sys/devices/pnp0/<bus-num>/ppi/version + In Linux 4.2 ppi was moved to the character device directory. + A symlink from tpmX/device/ppi to tpmX/ppi to provide backwards + compatibility. + +What: /sys/class/tpm/tpmX/ppi/version Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: @@ -18,7 +23,7 @@ Description: platform. This file is readonly. -What: /sys/devices/pnp0/<bus-num>/ppi/request +What: /sys/class/tpm/tpmX/ppi/request Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: @@ -28,7 +33,7 @@ Description: integer value range from 1 to 160, and 0 means no request. This file can be read and written. -What: /sys/devices/pnp0/00:<bus-num>/ppi/response +What: /sys/class/tpm/tpmX/ppi/response Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: @@ -37,7 +42,7 @@ Description: : <response description>". This file is readonly. -What: /sys/devices/pnp0/<bus-num>/ppi/transition_action +What: /sys/class/tpm/tpmX/ppi/transition_action Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: @@ -47,7 +52,7 @@ Description: description>". This file is readonly. -What: /sys/devices/pnp0/<bus-num>/ppi/tcg_operations +What: /sys/class/tpm/tpmX/ppi/tcg_operations Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: @@ -58,7 +63,7 @@ Description: This attribute is only supported by PPI version 1.2+. This file is readonly. -What: /sys/devices/pnp0/<bus-num>/ppi/vs_operations +What: /sys/class/tpm/tpmX/ppi/vs_operations Date: August 2012 Contact: xiaoyan.zhang@intel.com Description: diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 2c4cc42006e8..0345f2d1c727 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -80,3 +80,15 @@ Date: February 2015 Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> Description: Controls the trimming rate in batch mode. + +What: /sys/fs/f2fs/<disk>/cp_interval +Date: October 2015 +Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> +Description: + Controls the checkpoint timing. + +What: /sys/fs/f2fs/<disk>/ra_nid_pages +Date: October 2015 +Contact: "Chao Yu" <chao2.yu@samsung.com> +Description: + Controls the count of nid pages to be readaheaded. diff --git a/Documentation/Changes b/Documentation/Changes index f447f0516f07..ec97b77c8b00 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -44,6 +44,7 @@ o grub 0.93 # grub --version || grub-insta o mcelog 0.6 # mcelog --version o iptables 1.4.2 # iptables -V o openssl & libcrypto 1.0.0 # openssl version +o bc 1.06.95 # bc --version Kernel compilation diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index 55b70b903ead..d69b3fc64e14 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -681,6 +681,11 @@ or: as appropriate. +PLEASE NOTE: The 'nents' argument to dma_sync_sg_for_cpu() and + dma_sync_sg_for_device() must be the same passed to + dma_map_sg(). It is _NOT_ the count returned by + dma_map_sg(). + After the last DMA transfer call one of the DMA unmap routines dma_unmap_{single,sg}(). If you don't touch the data from the first dma_map_*() call till dma_unmap_*(), then you don't have to call the diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index edccacd4f048..8d065d6ec956 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -340,7 +340,7 @@ accessed sg->address and sg->length as shown above. void dma_unmap_sg(struct device *dev, struct scatterlist *sg, - int nhwentries, enum dma_data_direction direction) + int nents, enum dma_data_direction direction) Unmap the previously mapped scatter/gather list. All the parameters must be the same as those and passed in to the scatter/gather mapping @@ -356,10 +356,10 @@ void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction) void -dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, +dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction direction) void -dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, +dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction direction) Synchronise a single contiguous or scatter/gather mapping for the CPU diff --git a/Documentation/DocBook/.gitignore b/Documentation/DocBook/.gitignore index 7ebd5465d927..e05da3f7aa21 100644 --- a/Documentation/DocBook/.gitignore +++ b/Documentation/DocBook/.gitignore @@ -11,5 +11,7 @@ *.png *.gif *.svg +*.proc +*.db media-indices.tmpl media-entities.tmpl diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 93eff64387cd..d2544961b67a 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -69,6 +69,12 @@ installmandocs: mandocs KERNELDOCXMLREF = $(srctree)/scripts/kernel-doc-xml-ref KERNELDOC = $(srctree)/scripts/kernel-doc DOCPROC = $(objtree)/scripts/docproc +CHECK_LC_CTYPE = $(objtree)/scripts/check-lc_ctype + +# Use a fixed encoding - UTF-8 if the C library has support built-in +# or ASCII if not +LC_CTYPE := $(call try-run, LC_CTYPE=C.UTF-8 $(CHECK_LC_CTYPE),C.UTF-8,C) +export LC_CTYPE XMLTOFLAGS = -m $(srctree)/$(src)/stylesheet.xsl XMLTOFLAGS += --skip-validation diff --git a/Documentation/DocBook/device-drivers.tmpl b/Documentation/DocBook/device-drivers.tmpl index 1d6008d51b55..42a2d8593e39 100644 --- a/Documentation/DocBook/device-drivers.tmpl +++ b/Documentation/DocBook/device-drivers.tmpl @@ -221,6 +221,9 @@ X!Isound/sound_firmware.c <title>Media Devices</title> <sect1><title>Video2Linux devices</title> +!Iinclude/media/tuner.h +!Iinclude/media/tuner-types.h +!Iinclude/media/tveeprom.h !Iinclude/media/v4l2-async.h !Iinclude/media/v4l2-ctrls.h !Iinclude/media/v4l2-dv-timings.h @@ -231,6 +234,7 @@ X!Isound/sound_firmware.c !Iinclude/media/v4l2-of.h !Iinclude/media/v4l2-subdev.h !Iinclude/media/videobuf2-core.h +!Iinclude/media/videobuf2-v4l2.h !Iinclude/media/videobuf2-memops.h </sect1> <sect1><title>Digital TV (DVB) devices</title> @@ -239,15 +243,82 @@ X!Isound/sound_firmware.c !Idrivers/media/dvb-core/dvb_math.h !Idrivers/media/dvb-core/dvb_ringbuffer.h !Idrivers/media/dvb-core/dvbdev.h - </sect1> - <sect1><title>Remote Controller devices</title> + <sect1><title>Digital TV Demux API</title> + <para>The kernel demux API defines a driver-internal interface for + registering low-level, hardware specific driver to a hardware + independent demux layer. It is only of interest for Digital TV + device driver writers. The header file for this API is named + <constant>demux.h</constant> and located in + <constant>drivers/media/dvb-core</constant>.</para> + + <para>The demux API should be implemented for each demux in the + system. It is used to select the TS source of a demux and to manage + the demux resources. When the demux client allocates a resource via + the demux API, it receives a pointer to the API of that + resource.</para> + <para>Each demux receives its TS input from a DVB front-end or from + memory, as set via this demux API. In a system with more than one + front-end, the API can be used to select one of the DVB front-ends + as a TS source for a demux, unless this is fixed in the HW platform. + The demux API only controls front-ends regarding to their connections + with demuxes; the APIs used to set the other front-end parameters, + such as tuning, are not defined in this document.</para> + <para>The functions that implement the abstract interface demux should + be defined static or module private and registered to the Demux + core for external access. It is not necessary to implement every + function in the struct <constant>dmx_demux</constant>. For example, + a demux interface might support Section filtering, but not PES + filtering. The API client is expected to check the value of any + function pointer before calling the function: the value of NULL means + that the “function is not available”.</para> + <para>Whenever the functions of the demux API modify shared data, + the possibilities of lost update and race condition problems should + be addressed, e.g. by protecting parts of code with mutexes.</para> + <para>Note that functions called from a bottom half context must not + sleep. Even a simple memory allocation without using GFP_ATOMIC can + result in a kernel thread being put to sleep if swapping is needed. + For example, the Linux kernel calls the functions of a network device + interface from a bottom half context. Thus, if a demux API function + is called from network device code, the function must not sleep. + </para> + </sect1> + + <section id="demux_callback_api"> + <title>Demux Callback API</title> + <para>This kernel-space API comprises the callback functions that + deliver filtered data to the demux client. Unlike the other DVB + kABIs, these functions are provided by the client and called from + the demux code.</para> + <para>The function pointers of this abstract interface are not + packed into a structure as in the other demux APIs, because the + callback functions are registered and used independent of each + other. As an example, it is possible for the API client to provide + several callback functions for receiving TS packets and no + callbacks for PES packets or sections.</para> + <para>The functions that implement the callback API need not be + re-entrant: when a demux driver calls one of these functions, + the driver is not allowed to call the function again before + the original call returns. If a callback is triggered by a + hardware interrupt, it is recommended to use the Linux + “bottom half” mechanism or start a tasklet instead of + making the callback function call directly from a hardware + interrupt.</para> + <para>This mechanism is implemented by + <link linkend='API-dmx-ts-cb'>dmx_ts_cb()</link> and + <link linkend='API-dmx-section-cb'>dmx_section_cb()</link>.</para> + </section> + +!Idrivers/media/dvb-core/demux.h + </sect1> + <sect1><title>Remote Controller devices</title> !Iinclude/media/rc-core.h - </sect1> - <sect1><title>Media Controller devices</title> +!Iinclude/media/lirc_dev.h + </sect1> + <sect1><title>Media Controller devices</title> !Iinclude/media/media-device.h !Iinclude/media/media-devnode.h !Iinclude/media/media-entity.h - </sect1> + </sect1> </chapter> diff --git a/Documentation/DocBook/media/dvb/dvbapi.xml b/Documentation/DocBook/media/dvb/dvbapi.xml index 858fd7d17104..8576481e20ae 100644 --- a/Documentation/DocBook/media/dvb/dvbapi.xml +++ b/Documentation/DocBook/media/dvb/dvbapi.xml @@ -125,9 +125,6 @@ Added ISDB-T test originally written by Patrick Boettcher &sub-audio; </section> </chapter> - <chapter id="dvb_kdapi"> - &sub-kdapi; - </chapter> <chapter id="dvb_examples"> &sub-examples; </chapter> diff --git a/Documentation/DocBook/media/dvb/kdapi.xml b/Documentation/DocBook/media/dvb/kdapi.xml deleted file mode 100644 index 68bcd33a82c3..000000000000 --- a/Documentation/DocBook/media/dvb/kdapi.xml +++ /dev/null @@ -1,2309 +0,0 @@ -<title>Kernel Demux API</title> -<para>The kernel demux API defines a driver-internal interface for registering low-level, -hardware specific driver to a hardware independent demux layer. It is only of interest for -DVB device driver writers. The header file for this API is named <constant>demux.h</constant> and located in -<constant>">drivers/media/dvb-core</constant>. -</para> -<para>Maintainer note: This section must be reviewed. It is probably out of date. -</para> - -<section id="kernel_demux_data_types"> -<title>Kernel Demux Data Types</title> - - -<section id="dmx_success_t"> -<title>dmx_success_t</title> - <programlisting> - typedef enum { - DMX_OK = 0, /⋆ Received Ok ⋆/ - DMX_LENGTH_ERROR, /⋆ Incorrect length ⋆/ - DMX_OVERRUN_ERROR, /⋆ Receiver ring buffer overrun ⋆/ - DMX_CRC_ERROR, /⋆ Incorrect CRC ⋆/ - DMX_FRAME_ERROR, /⋆ Frame alignment error ⋆/ - DMX_FIFO_ERROR, /⋆ Receiver FIFO overrun ⋆/ - DMX_MISSED_ERROR /⋆ Receiver missed packet ⋆/ - } dmx_success_t; -</programlisting> - -</section> -<section id="ts_filter_types"> -<title>TS filter types</title> - <programlisting> - /⋆--------------------------------------------------------------------------⋆/ - /⋆ TS packet reception ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - /⋆ TS filter type for set_type() ⋆/ - - #define TS_PACKET 1 /⋆ send TS packets (188 bytes) to callback (default) ⋆/ - #define TS_PAYLOAD_ONLY 2 /⋆ in case TS_PACKET is set, only send the TS - payload (<=184 bytes per packet) to callback ⋆/ - #define TS_DECODER 4 /⋆ send stream to built-in decoder (if present) ⋆/ -</programlisting> - -</section> -<section id="dmx_ts_pes_t"> -<title>dmx_ts_pes_t</title> -<para>The structure -</para> -<programlisting> - typedef enum - { - DMX_TS_PES_AUDIO, /⋆ also send packets to audio decoder (if it exists) ⋆/ - DMX_TS_PES_VIDEO, /⋆ ... ⋆/ - DMX_TS_PES_TELETEXT, - DMX_TS_PES_SUBTITLE, - DMX_TS_PES_PCR, - DMX_TS_PES_OTHER, - } dmx_ts_pes_t; -</programlisting> -<para>describes the PES type for filters which write to a built-in decoder. The correspond (and -should be kept identical) to the types in the demux device. -</para> -<programlisting> - struct dmx_ts_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_ts_feed_s⋆ feed, - __u16 pid, - size_t callback_length, - size_t circular_buffer_size, - int descramble, - struct timespec timeout); - int (⋆start_filtering) (struct dmx_ts_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_ts_feed_s⋆ feed); - int (⋆set_type) (struct dmx_ts_feed_s⋆ feed, - int type, - dmx_ts_pes_t pes_type); - }; - - typedef struct dmx_ts_feed_s dmx_ts_feed_t; -</programlisting> - <programlisting> - /⋆--------------------------------------------------------------------------⋆/ - /⋆ PES packet reception (not supported yet) ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef struct dmx_pes_filter_s { - struct dmx_pes_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - } dmx_pes_filter_t; -</programlisting> - <programlisting> - typedef struct dmx_pes_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_pes_feed_s⋆ feed, - __u16 pid, - size_t circular_buffer_size, - int descramble, - struct timespec timeout); - int (⋆start_filtering) (struct dmx_pes_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_pes_feed_s⋆ feed); - int (⋆allocate_filter) (struct dmx_pes_feed_s⋆ feed, - dmx_pes_filter_t⋆⋆ filter); - int (⋆release_filter) (struct dmx_pes_feed_s⋆ feed, - dmx_pes_filter_t⋆ filter); - } dmx_pes_feed_t; -</programlisting> - <programlisting> - typedef struct { - __u8 filter_value [DMX_MAX_FILTER_SIZE]; - __u8 filter_mask [DMX_MAX_FILTER_SIZE]; - struct dmx_section_feed_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - } dmx_section_filter_t; -</programlisting> - <programlisting> - struct dmx_section_feed_s { - int is_filtering; /⋆ Set to non-zero when filtering in progress ⋆/ - struct dmx_demux_s⋆ parent; /⋆ Back-pointer ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int (⋆set) (struct dmx_section_feed_s⋆ feed, - __u16 pid, - size_t circular_buffer_size, - int descramble, - int check_crc); - int (⋆allocate_filter) (struct dmx_section_feed_s⋆ feed, - dmx_section_filter_t⋆⋆ filter); - int (⋆release_filter) (struct dmx_section_feed_s⋆ feed, - dmx_section_filter_t⋆ filter); - int (⋆start_filtering) (struct dmx_section_feed_s⋆ feed); - int (⋆stop_filtering) (struct dmx_section_feed_s⋆ feed); - }; - typedef struct dmx_section_feed_s dmx_section_feed_t; - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ Callback functions ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef int (⋆dmx_ts_cb) ( __u8 ⋆ buffer1, - size_t buffer1_length, - __u8 ⋆ buffer2, - size_t buffer2_length, - dmx_ts_feed_t⋆ source, - dmx_success_t success); - - typedef int (⋆dmx_section_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_section_filter_t ⋆ source, - dmx_success_t success); - - typedef int (⋆dmx_pes_cb) ( __u8 ⋆ buffer1, - size_t buffer1_len, - __u8 ⋆ buffer2, - size_t buffer2_len, - dmx_pes_filter_t⋆ source, - dmx_success_t success); - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ DVB Front-End ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - typedef enum { - DMX_OTHER_FE = 0, - DMX_SATELLITE_FE, - DMX_CABLE_FE, - DMX_TERRESTRIAL_FE, - DMX_LVDS_FE, - DMX_ASI_FE, /⋆ DVB-ASI interface ⋆/ - DMX_MEMORY_FE - } dmx_frontend_source_t; - - typedef struct { - /⋆ The following char⋆ fields point to NULL terminated strings ⋆/ - char⋆ id; /⋆ Unique front-end identifier ⋆/ - char⋆ vendor; /⋆ Name of the front-end vendor ⋆/ - char⋆ model; /⋆ Name of the front-end model ⋆/ - struct list_head connectivity_list; /⋆ List of front-ends that can - be connected to a particular - demux ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - dmx_frontend_source_t source; - } dmx_frontend_t; - - /⋆--------------------------------------------------------------------------⋆/ - /⋆ MPEG-2 TS Demux ⋆/ - /⋆--------------------------------------------------------------------------⋆/ - - /⋆ - ⋆ Flags OR'ed in the capabilites field of struct dmx_demux_s. - ⋆/ - - #define DMX_TS_FILTERING 1 - #define DMX_PES_FILTERING 2 - #define DMX_SECTION_FILTERING 4 - #define DMX_MEMORY_BASED_FILTERING 8 /⋆ write() available ⋆/ - #define DMX_CRC_CHECKING 16 - #define DMX_TS_DESCRAMBLING 32 - #define DMX_SECTION_PAYLOAD_DESCRAMBLING 64 - #define DMX_MAC_ADDRESS_DESCRAMBLING 128 -</programlisting> - -</section> -<section id="demux_demux_t"> -<title>demux_demux_t</title> - <programlisting> - /⋆ - ⋆ DMX_FE_ENTRY(): Casts elements in the list of registered - ⋆ front-ends from the generic type struct list_head - ⋆ to the type ⋆ dmx_frontend_t - ⋆. - ⋆/ - - #define DMX_FE_ENTRY(list) list_entry(list, dmx_frontend_t, connectivity_list) - - struct dmx_demux_s { - /⋆ The following char⋆ fields point to NULL terminated strings ⋆/ - char⋆ id; /⋆ Unique demux identifier ⋆/ - char⋆ vendor; /⋆ Name of the demux vendor ⋆/ - char⋆ model; /⋆ Name of the demux model ⋆/ - __u32 capabilities; /⋆ Bitfield of capability flags ⋆/ - dmx_frontend_t⋆ frontend; /⋆ Front-end connected to the demux ⋆/ - struct list_head reg_list; /⋆ List of registered demuxes ⋆/ - void⋆ priv; /⋆ Pointer to private data of the API client ⋆/ - int users; /⋆ Number of users ⋆/ - int (⋆open) (struct dmx_demux_s⋆ demux); - int (⋆close) (struct dmx_demux_s⋆ demux); - int (⋆write) (struct dmx_demux_s⋆ demux, const char⋆ buf, size_t count); - int (⋆allocate_ts_feed) (struct dmx_demux_s⋆ demux, - dmx_ts_feed_t⋆⋆ feed, - dmx_ts_cb callback); - int (⋆release_ts_feed) (struct dmx_demux_s⋆ demux, - dmx_ts_feed_t⋆ feed); - int (⋆allocate_pes_feed) (struct dmx_demux_s⋆ demux, - dmx_pes_feed_t⋆⋆ feed, - dmx_pes_cb callback); - int (⋆release_pes_feed) (struct dmx_demux_s⋆ demux, - dmx_pes_feed_t⋆ feed); - int (⋆allocate_section_feed) (struct dmx_demux_s⋆ demux, - dmx_section_feed_t⋆⋆ feed, - dmx_section_cb callback); - int (⋆release_section_feed) (struct dmx_demux_s⋆ demux, - dmx_section_feed_t⋆ feed); - int (⋆descramble_mac_address) (struct dmx_demux_s⋆ demux, - __u8⋆ buffer1, - size_t buffer1_length, - __u8⋆ buffer2, - size_t buffer2_length, - __u16 pid); - int (⋆descramble_section_payload) (struct dmx_demux_s⋆ demux, - __u8⋆ buffer1, - size_t buffer1_length, - __u8⋆ buffer2, size_t buffer2_length, - __u16 pid); - int (⋆add_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - int (⋆remove_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - struct list_head⋆ (⋆get_frontends) (struct dmx_demux_s⋆ demux); - int (⋆connect_frontend) (struct dmx_demux_s⋆ demux, - dmx_frontend_t⋆ frontend); - int (⋆disconnect_frontend) (struct dmx_demux_s⋆ demux); - - - /⋆ added because js cannot keep track of these himself ⋆/ - int (⋆get_pes_pids) (struct dmx_demux_s⋆ demux, __u16 ⋆pids); - }; - typedef struct dmx_demux_s dmx_demux_t; -</programlisting> - -</section> -<section id="demux_directory"> -<title>Demux directory</title> - <programlisting> - /⋆ - ⋆ DMX_DIR_ENTRY(): Casts elements in the list of registered - ⋆ demuxes from the generic type struct list_head⋆ to the type dmx_demux_t - ⋆. - ⋆/ - - #define DMX_DIR_ENTRY(list) list_entry(list, dmx_demux_t, reg_list) - - int dmx_register_demux (dmx_demux_t⋆ demux); - int dmx_unregister_demux (dmx_demux_t⋆ demux); - struct list_head⋆ dmx_get_demuxes (void); -</programlisting> - </section></section> -<section id="demux_directory_api"> -<title>Demux Directory API</title> -<para>The demux directory is a Linux kernel-wide facility for registering and accessing the -MPEG-2 TS demuxes in the system. Run-time registering and unregistering of demux drivers -is possible using this API. -</para> -<para>All demux drivers in the directory implement the abstract interface dmx_demux_t. -</para> - -<section -role="subsection"><title>dmx_register_demux()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function makes a demux driver interface available to the Linux kernel. It is - usually called by the init_module() function of the kernel module that contains - the demux driver. The caller of this function is responsible for allocating - dynamic or static memory for the demux structure and for initializing its fields - before calling this function. The memory allocated for the demux structure - must not be freed before calling dmx_unregister_demux(),</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_register_demux ( dmx_demux_t ⋆demux )</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux structure.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EEXIST</para> -</entry><entry - align="char"> -<para>A demux with the same value of the id field already stored - in the directory.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSPC</para> -</entry><entry - align="char"> -<para>No space left in the directory.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_unregister_demux()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function is called to indicate that the given demux interface is no - longer available. The caller of this function is responsible for freeing the - memory of the demux structure, if it was dynamically allocated before calling - dmx_register_demux(). The cleanup_module() function of the kernel module - that contains the demux driver should call this function. Note that this function - fails if the demux is currently in use, i.e., release_demux() has not been called - for the interface.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_unregister_demux ( dmx_demux_t ⋆demux )</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux structure which is to be - unregistered.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>ENODEV</para> -</entry><entry - align="char"> -<para>The specified demux is not registered in the demux - directory.</para> -</entry> - </row><row><entry - align="char"> -<para>EBUSY</para> -</entry><entry - align="char"> -<para>The specified demux is currently in use.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_get_demuxes()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Provides the caller with the list of registered demux interfaces, using the - standard list structure defined in the include file linux/list.h. The include file - demux.h defines the macro DMX_DIR_ENTRY() for converting an element of - the generic type struct list_head* to the type dmx_demux_t*. The caller must - not free the memory of any of the elements obtained via this function call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>struct list_head ⋆dmx_get_demuxes ()</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>none</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>struct list_head *</para> -</entry><entry - align="char"> -<para>A list of demux interfaces, or NULL in the case of an - empty list.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="demux_api"> -<title>Demux API</title> -<para>The demux API should be implemented for each demux in the system. It is used to select -the TS source of a demux and to manage the demux resources. When the demux -client allocates a resource via the demux API, it receives a pointer to the API of that -resource. -</para> -<para>Each demux receives its TS input from a DVB front-end or from memory, as set via the -demux API. In a system with more than one front-end, the API can be used to select one of -the DVB front-ends as a TS source for a demux, unless this is fixed in the HW platform. The -demux API only controls front-ends regarding their connections with demuxes; the APIs -used to set the other front-end parameters, such as tuning, are not defined in this -document. -</para> -<para>The functions that implement the abstract interface demux should be defined static or -module private and registered to the Demux Directory for external access. It is not necessary -to implement every function in the demux_t struct, however (for example, a demux interface -might support Section filtering, but not TS or PES filtering). The API client is expected to -check the value of any function pointer before calling the function: the value of NULL means -“function not available”. -</para> -<para>Whenever the functions of the demux API modify shared data, the possibilities of lost -update and race condition problems should be addressed, e.g. by protecting parts of code with -mutexes. This is especially important on multi-processor hosts. -</para> -<para>Note that functions called from a bottom half context must not sleep, at least in the 2.2.x -kernels. Even a simple memory allocation can result in a kernel thread being put to sleep if -swapping is needed. For example, the Linux kernel calls the functions of a network device -interface from a bottom half context. Thus, if a demux API function is called from network -device code, the function must not sleep. -</para> - - -<section id="kdapi_fopen"> -<title>open()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function reserves the demux for use by the caller and, if necessary, - initializes the demux. When the demux is no longer needed, the function close() - should be called. It should be possible for multiple clients to access the demux - at the same time. Thus, the function implementation should increment the - demux usage count when open() is called and decrement it when close() is - called.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int open ( demux_t⋆ demux );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EUSERS</para> -</entry><entry - align="char"> -<para>Maximum usage count reached.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> -<section id="kdapi_fclose"> -<title>close()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function reserves the demux for use by the caller and, if necessary, - initializes the demux. When the demux is no longer needed, the function close() - should be called. It should be possible for multiple clients to access the demux - at the same time. Thus, the function implementation should increment the - demux usage count when open() is called and decrement it when close() is - called.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int close(demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENODEV</para> -</entry><entry - align="char"> -<para>The demux was not in use.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> -<section id="kdapi_fwrite"> -<title>write()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function provides the demux driver with a memory buffer containing TS - packets. Instead of receiving TS packets from the DVB front-end, the demux - driver software will read packets from memory. Any clients of this demux - with active TS, PES or Section filters will receive filtered data via the Demux - callback API (see 0). The function returns when all the data in the buffer has - been consumed by the demux. Demux hardware typically cannot read TS from - memory. If this is the case, memory-based filtering has to be implemented - entirely in software.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int write(demux_t⋆ demux, const char⋆ buf, size_t - count);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>const char* buf</para> -</entry><entry - align="char"> -<para>Pointer to the TS data in kernel-space memory.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t length</para> -</entry><entry - align="char"> -<para>Length of the TS data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_ts_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Allocates a new TS feed, which is used to filter the TS packets carrying a - certain PID. The TS feed normally corresponds to a hardware PID filter on the - demux chip.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_ts_feed(dmx_demux_t⋆ demux, - dmx_ts_feed_t⋆⋆ feed, dmx_ts_cb callback);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t** - feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_cb callback</para> -</entry><entry - align="char"> -<para>Pointer to the callback function for passing received TS - packet</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>No more TS feeds available.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_ts_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Releases the resources allocated with allocate_ts_feed(). Any filtering in - progress on the TS feed should be stopped before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_ts_feed(dmx_demux_t⋆ demux, - dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t* demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_section_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Allocates a new section feed, i.e. a demux resource for filtering and receiving - sections. On platforms with hardware support for section filtering, a section - feed is directly mapped to the demux HW. On other platforms, TS packets are - first PID filtered in hardware and a hardware section filter then emulated in - software. The caller obtains an API pointer of type dmx_section_feed_t as an - out parameter. Using this API the caller can set filtering parameters and start - receiving sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_section_feed(dmx_demux_t⋆ demux, - dmx_section_feed_t ⋆⋆feed, dmx_section_cb callback);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_feed_t - **feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_cb - callback</para> -</entry><entry - align="char"> -<para>Pointer to the callback function for passing received - sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>No more section feeds available.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>The command is not implemented.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_section_feed()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Releases the resources allocated with allocate_section_feed(), including - allocated filters. Any filtering in progress on the section feed should be stopped - before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_section_feed(dmx_demux_t⋆ demux, - dmx_section_feed_t ⋆feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>demux_t *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_feed_t - *feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>descramble_mac_address()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function runs a descrambling algorithm on the destination MAC - address field of a DVB Datagram Section, replacing the original address - with its un-encrypted version. Otherwise, the description on the function - descramble_section_payload() applies also to this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int descramble_mac_address(dmx_demux_t⋆ demux, __u8 - ⋆buffer1, size_t buffer1_length, __u8 ⋆buffer2, - size_t buffer2_length, __u16 pid);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t - *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the first byte of the section.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the section data, or NULL. The - pointer has a non-NULL value if the section wraps past - the end of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>The PID on which the section was received. Useful - for obtaining the descrambling key, e.g. from a DVB - Common Access facility.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>descramble_section_payload()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function runs a descrambling algorithm on the payload of a DVB - Datagram Section, replacing the original payload with its un-encrypted - version. The function will be called from the demux API implementation; - the API client need not call this function directly. Section-level scrambling - algorithms are currently standardized only for DVB-RCC (return channel - over 2-directional cable TV network) systems. For all other DVB networks, - encryption schemes are likely to be proprietary to each data broadcaster. Thus, - it is expected that this function pointer will have the value of NULL (i.e., - function not available) in most demux API implementations. Nevertheless, it - should be possible to use the function pointer as a hook for dynamically adding - a “plug-in” descrambling facility to a demux driver.</para> -</entry> - </row><row><entry - align="char"> -<para>While this function is not needed with hardware-based section descrambling, - the descramble_section_payload function pointer can be used to override the - default hardware-based descrambling algorithm: if the function pointer has a - non-NULL value, the corresponding function should be used instead of any - descrambling hardware.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int descramble_section_payload(dmx_demux_t⋆ demux, - __u8 ⋆buffer1, size_t buffer1_length, __u8 ⋆buffer2, - size_t buffer2_length, __u16 pid);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t - *demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the first byte of the section.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8 *buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the section data, or NULL. The - pointer has a non-NULL value if the section wraps past - the end of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the section data, including headers and CRC, - in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>The PID on which the section was received. Useful - for obtaining the descrambling key, e.g. from a DVB - Common Access facility.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>add_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Registers a connectivity between a demux and a front-end, i.e., indicates that - the demux can be connected via a call to connect_frontend() to use the given - front-end as a TS source. The client of this function has to allocate dynamic or - static memory for the frontend structure and initialize its fields before calling - this function. This function is normally called during the driver initialization. - The caller must not free the memory of the frontend struct before successfully - calling remove_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int add_frontend(dmx_demux_t ⋆demux, dmx_frontend_t - ⋆frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EEXIST</para> -</entry><entry - align="char"> -<para>A front-end with the same value of the id field already - registered.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINUSE</para> -</entry><entry - align="char"> -<para>The demux is in use.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>No more front-ends can be added.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>remove_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Indicates that the given front-end, registered by a call to add_frontend(), can - no longer be connected as a TS source by this demux. The function should be - called when a front-end driver or a demux driver is removed from the system. - If the front-end is in use, the function fails with the return value of -EBUSY. - After successfully calling this function, the caller can free the memory of - the frontend struct if it was dynamically allocated before the add_frontend() - operation.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int remove_frontend(dmx_demux_t⋆ demux, - dmx_frontend_t⋆ frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>The front-end is in use, i.e. a call to connect_frontend() - has not been followed by a call to disconnect_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>get_frontends()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Provides the APIs of the front-ends that have been registered for this demux. - Any of the front-ends obtained with this call can be used as a parameter for - connect_frontend().</para> -</entry> - </row><row><entry - align="char"> -<para>The include file demux.h contains the macro DMX_FE_ENTRY() for - converting an element of the generic type struct list_head* to the type - dmx_frontend_t*. The caller must not free the memory of any of the elements - obtained via this function call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>struct list_head⋆ get_frontends(dmx_demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t*</para> -</entry><entry - align="char"> -<para>A list of front-end interfaces, or NULL in the case of an - empty list.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>connect_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Connects the TS output of the front-end to the input of the demux. A demux - can only be connected to a front-end registered to the demux with the function - add_frontend().</para> -</entry> - </row><row><entry - align="char"> -<para>It may or may not be possible to connect multiple demuxes to the same - front-end, depending on the capabilities of the HW platform. When not used, - the front-end should be released by calling disconnect_frontend().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int connect_frontend(dmx_demux_t⋆ demux, - dmx_frontend_t⋆ frontend);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_frontend_t* - frontend</para> -</entry><entry - align="char"> -<para>Pointer to the front-end instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row><row><entry - align="char"> -<para>-EBUSY</para> -</entry><entry - align="char"> -<para>The front-end is in use.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>disconnect_frontend()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Disconnects the demux and a front-end previously connected by a - connect_frontend() call.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int disconnect_frontend(dmx_demux_t⋆ demux);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_demux_t* - demux</para> -</entry><entry - align="char"> -<para>Pointer to the demux API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="demux_callback_api"> -<title>Demux Callback API</title> -<para>This kernel-space API comprises the callback functions that deliver filtered data to the -demux client. Unlike the other APIs, these API functions are provided by the client and called -from the demux code. -</para> -<para>The function pointers of this abstract interface are not packed into a structure as in the -other demux APIs, because the callback functions are registered and used independent -of each other. As an example, it is possible for the API client to provide several -callback functions for receiving TS packets and no callbacks for PES packets or -sections. -</para> -<para>The functions that implement the callback API need not be re-entrant: when a demux -driver calls one of these functions, the driver is not allowed to call the function again before -the original call returns. If a callback is triggered by a hardware interrupt, it is recommended -to use the Linux “bottom half” mechanism or start a tasklet instead of making the callback -function call directly from a hardware interrupt. -</para> - -<section -role="subsection"><title>dmx_ts_cb()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function, provided by the client of the demux API, is called from the - demux code. The function is only called when filtering on this TS feed has - been enabled using the start_filtering() function.</para> -</entry> - </row><row><entry - align="char"> -<para>Any TS packets that match the filter settings are copied to a circular buffer. The - filtered TS packets are delivered to the client using this callback function. The - size of the circular buffer is controlled by the circular_buffer_size parameter - of the set() function in the TS Feed API. It is expected that the buffer1 and - buffer2 callback parameters point to addresses within the circular buffer, but - other implementations are also possible. Note that the called party should not - try to free the memory the buffer1 and buffer2 parameters point to.</para> -</entry> - </row><row><entry - align="char"> -<para>When this function is called, the buffer1 parameter typically points to the - start of the first undelivered TS packet within a circular buffer. The buffer2 - buffer parameter is normally NULL, except when the received TS packets have - crossed the last address of the circular buffer and ”wrapped” to the beginning - of the buffer. In the latter case the buffer1 parameter would contain an address - within the circular buffer, while the buffer2 parameter would contain the first - address of the circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>The number of bytes delivered with this function (i.e. buffer1_length + - buffer2_length) is usually equal to the value of callback_length parameter - given in the set() function, with one exception: if a timeout occurs before - receiving callback_length bytes of TS data, any undelivered packets are - immediately delivered to the client by calling this function. The timeout - duration is controlled by the set() function in the TS Feed API.</para> -</entry> - </row><row><entry - align="char"> -<para>If a TS packet is received with errors that could not be fixed by the TS-level - forward error correction (FEC), the Transport_error_indicator flag of the TS - packet header should be set. The TS packet should not be discarded, as - the error can possibly be corrected by a higher layer protocol. If the called - party is slow in processing the callback, it is possible that the circular buffer - eventually fills up. If this happens, the demux driver should discard any TS - packets received while the buffer is full. The error should be indicated to the - client on the next callback by setting the success parameter to the value of - DMX_OVERRUN_ERROR.</para> -</entry> - </row><row><entry - align="char"> -<para>The type of data returned to the callback can be selected by the new - function int (*set_type) (struct dmx_ts_feed_s* feed, int type, dmx_ts_pes_t - pes_type) which is part of the dmx_ts_feed_s struct (also cf. to the - include file ost/demux.h) The type parameter decides if the raw TS packet - (TS_PACKET) or just the payload (TS_PACKET—TS_PAYLOAD_ONLY) - should be returned. If additionally the TS_DECODER bit is set the stream - will also be sent to the hardware MPEG decoder. In this case, the second - flag decides as what kind of data the stream should be interpreted. The - possible choices are one of DMX_TS_PES_AUDIO, DMX_TS_PES_VIDEO, - DMX_TS_PES_TELETEXT, DMX_TS_PES_SUBTITLE, - DMX_TS_PES_PCR, or DMX_TS_PES_OTHER.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_ts_cb(__u8⋆ buffer1, size_t buffer1_length, - __u8⋆ buffer2, size_t buffer2_length, dmx_ts_feed_t⋆ - source, dmx_success_t success);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>__u8* buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the start of the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the TS data in buffer1.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the filtered TS packets, or NULL.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the TS data in buffer2.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_ts_feed_t* - source</para> -</entry><entry - align="char"> -<para>Indicates which TS feed is the source of the callback.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_success_t - success</para> -</entry><entry - align="char"> -<para>Indicates if there was an error in TS reception.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>Continue filtering.</para> -</entry> - </row><row><entry - align="char"> -<para>-1</para> -</entry><entry - align="char"> -<para>Stop filtering - has the same effect as a call to - stop_filtering() on the TS Feed API.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>dmx_section_cb()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function, provided by the client of the demux API, is called from the - demux code. The function is only called when filtering of sections has been - enabled using the function start_filtering() of the section feed API. When the - demux driver has received a complete section that matches at least one section - filter, the client is notified via this callback function. Normally this function is - called for each received section; however, it is also possible to deliver multiple - sections with one callback, for example when the system load is high. If an - error occurs while receiving a section, this function should be called with - the corresponding error type set in the success field, whether or not there is - data to deliver. The Section Feed implementation should maintain a circular - buffer for received sections. However, this is not necessary if the Section Feed - API is implemented as a client of the TS Feed API, because the TS Feed - implementation then buffers the received data. The size of the circular buffer - can be configured using the set() function in the Section Feed API. If there - is no room in the circular buffer when a new section is received, the section - must be discarded. If this happens, the value of the success parameter should - be DMX_OVERRUN_ERROR on the next callback.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int dmx_section_cb(__u8⋆ buffer1, size_t - buffer1_length, __u8⋆ buffer2, size_t - buffer2_length, dmx_section_filter_t⋆ source, - dmx_success_t success);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>__u8* buffer1</para> -</entry><entry - align="char"> -<para>Pointer to the start of the filtered section, e.g. within the - circular buffer of the demux driver.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer1_length</para> -</entry><entry - align="char"> -<para>Length of the filtered section data in buffer1, including - headers and CRC.</para> -</entry> - </row><row><entry - align="char"> -<para>__u8* buffer2</para> -</entry><entry - align="char"> -<para>Pointer to the tail of the filtered section data, or NULL. - Useful to handle the wrapping of a circular buffer.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t buffer2_length</para> -</entry><entry - align="char"> -<para>Length of the filtered section data in buffer2, including - headers and CRC.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t* - filter</para> -</entry><entry - align="char"> -<para>Indicates the filter that triggered the callback.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_success_t - success</para> -</entry><entry - align="char"> -<para>Indicates if there was an error in section reception.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>Continue filtering.</para> -</entry> - </row><row><entry - align="char"> -<para>-1</para> -</entry><entry - align="char"> -<para>Stop filtering - has the same effect as a call to - stop_filtering() on the Section Feed API.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="ts_feed_api"> -<title>TS Feed API</title> -<para>A TS feed is typically mapped to a hardware PID filter on the demux chip. -Using this API, the client can set the filtering properties to start/stop filtering TS -packets on a particular TS feed. The API is defined as an abstract interface of the type -dmx_ts_feed_t. -</para> -<para>The functions that implement the interface should be defined static or module private. The -client can get the handle of a TS feed API by calling the function allocate_ts_feed() in the -demux API. -</para> - -<section -role="subsection"><title>set()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function sets the parameters of a TS feed. Any filtering in progress on the - TS feed must be stopped before calling this function.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int set ( dmx_ts_feed_t⋆ feed, __u16 pid, size_t - callback_length, size_t circular_buffer_size, int - descramble, struct timespec timeout);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>PID value to filter. Only the TS packets carrying the - specified PID will be passed to the API client.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - callback_length</para> -</entry><entry - align="char"> -<para>Number of bytes to deliver with each call to the - dmx_ts_cb() callback function. The value of this - parameter should be a multiple of 188.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - circular_buffer_size</para> -</entry><entry - align="char"> -<para>Size of the circular buffer for the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>int descramble</para> -</entry><entry - align="char"> -<para>If non-zero, descramble the filtered TS packets.</para> -</entry> - </row><row><entry - align="char"> -<para>struct timespec - timeout</para> -</entry><entry - align="char"> -<para>Maximum time to wait before delivering received TS - packets to the client.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>Not enough memory for the requested buffer size.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available for TS.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>start_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Starts filtering TS packets on this TS feed, according to its settings. The PID - value to filter can be set by the API client. All matching TS packets are - delivered asynchronously to the client, using the callback function registered - with allocate_ts_feed().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int start_filtering(dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>stop_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Stops filtering TS packets on this TS feed.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int stop_filtering(dmx_ts_feed_t⋆ feed);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_ts_feed_t* feed</para> -</entry><entry - align="char"> -<para>Pointer to the TS feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - </section></section> -<section id="section_feed_api"> -<title>Section Feed API</title> -<para>A section feed is a resource consisting of a PID filter and a set of section filters. Using this -API, the client can set the properties of a section feed and to start/stop filtering. The API is -defined as an abstract interface of the type dmx_section_feed_t. The functions that implement -the interface should be defined static or module private. The client can get the handle of -a section feed API by calling the function allocate_section_feed() in the demux -API. -</para> -<para>On demux platforms that provide section filtering in hardware, the Section Feed API -implementation provides a software wrapper for the demux hardware. Other platforms may -support only PID filtering in hardware, requiring that TS packets are converted to sections in -software. In the latter case the Section Feed API implementation can be a client of the TS -Feed API. -</para> - -</section> -<section id="kdapi_set"> -<title>set()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function sets the parameters of a section feed. Any filtering in progress on - the section feed must be stopped before calling this function. If descrambling - is enabled, the payload_scrambling_control and address_scrambling_control - fields of received DVB datagram sections should be observed. If either one is - non-zero, the section should be descrambled either in hardware or using the - functions descramble_mac_address() and descramble_section_payload() of the - demux API. Note that according to the MPEG-2 Systems specification, only - the payloads of private sections can be scrambled while the rest of the section - data must be sent in the clear.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int set(dmx_section_feed_t⋆ feed, __u16 pid, size_t - circular_buffer_size, int descramble, int - check_crc);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>__u16 pid</para> -</entry><entry - align="char"> -<para>PID value to filter; only the TS packets carrying the - specified PID will be accepted.</para> -</entry> - </row><row><entry - align="char"> -<para>size_t - circular_buffer_size</para> -</entry><entry - align="char"> -<para>Size of the circular buffer for filtered sections.</para> -</entry> - </row><row><entry - align="char"> -<para>int descramble</para> -</entry><entry - align="char"> -<para>If non-zero, descramble any sections that are scrambled.</para> -</entry> - </row><row><entry - align="char"> -<para>int check_crc</para> -</entry><entry - align="char"> -<para>If non-zero, check the CRC values of filtered sections.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOMEM</para> -</entry><entry - align="char"> -<para>Not enough memory for the requested buffer size.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSYS</para> -</entry><entry - align="char"> -<para>No descrambling facility available for sections.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameters.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>allocate_filter()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function is used to allocate a section filter on the demux. It should only be - called when no filtering is in progress on this section feed. If a filter cannot be - allocated, the function fails with -ENOSPC. See in section ?? for the format of - the section filter.</para> -</entry> - </row><row><entry - align="char"> -<para>The bitfields filter_mask and filter_value should only be modified when no - filtering is in progress on this section feed. filter_mask controls which bits of - filter_value are compared with the section headers/payload. On a binary value - of 1 in filter_mask, the corresponding bits are compared. The filter only accepts - sections that are equal to filter_value in all the tested bit positions. Any changes - to the values of filter_mask and filter_value are guaranteed to take effect only - when the start_filtering() function is called next time. The parent pointer in - the struct is initialized by the API implementation to the value of the feed - parameter. The priv pointer is not used by the API implementation, and can - thus be freely utilized by the caller of this function. Any data pointed to by the - priv pointer is available to the recipient of the dmx_section_cb() function call.</para> -</entry> - </row><row><entry - align="char"> -<para>While the maximum section filter length (DMX_MAX_FILTER_SIZE) is - currently set at 16 bytes, hardware filters of that size are not available on all - platforms. Therefore, section filtering will often take place first in hardware, - followed by filtering in software for the header bytes that were not covered - by a hardware filter. The filter_mask field can be checked to determine how - many bytes of the section filter are actually used, and if the hardware filter will - suffice. Additionally, software-only section filters can optionally be allocated - to clients when all hardware section filters are in use. Note that on most demux - hardware it is not possible to filter on the section_length field of the section - header – thus this field is ignored, even though it is included in filter_value and - filter_mask fields.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int allocate_filter(dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆⋆ filter);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t** - filter</para> -</entry><entry - align="char"> -<para>Pointer to the allocated filter.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENOSPC</para> -</entry><entry - align="char"> -<para>No filters of given type and length available.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameters.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>release_filter()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>This function releases all the resources of a previously allocated section filter. - The function should not be called while filtering is in progress on this section - feed. After calling this function, the caller should not try to dereference the - filter pointer.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int release_filter ( dmx_section_feed_t⋆ feed, - dmx_section_filter_t⋆ filter);</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row><row><entry - align="char"> -<para>dmx_section_filter_t* - filter</para> -</entry><entry - align="char"> -<para>I/O Pointer to the instance data of a section filter.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-ENODEV</para> -</entry><entry - align="char"> -<para>No such filter allocated.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>start_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Starts filtering sections on this section feed, according to its settings. Sections - are first filtered based on their PID and then matched with the section - filters allocated for this feed. If the section matches the PID filter and - at least one section filter, it is delivered to the API client. The section - is delivered asynchronously using the callback function registered with - allocate_section_feed().</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int start_filtering ( dmx_section_feed_t⋆ feed );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section><section -role="subsection"><title>stop_filtering()</title> -<para>DESCRIPTION -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>Stops filtering sections on this section feed. Note that any changes to the - filtering parameters (filter_value, filter_mask, etc.) should only be made when - filtering is stopped.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>SYNOPSIS -</para> -<informaltable><tgroup cols="1"><tbody><row><entry - align="char"> -<para>int stop_filtering ( dmx_section_feed_t⋆ feed );</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>PARAMETERS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>dmx_section_feed_t* - feed</para> -</entry><entry - align="char"> -<para>Pointer to the section feed API and instance data.</para> -</entry> - </row></tbody></tgroup></informaltable> -<para>RETURNS -</para> -<informaltable><tgroup cols="2"><tbody><row><entry - align="char"> -<para>0</para> -</entry><entry - align="char"> -<para>The function was completed without errors.</para> -</entry> - </row><row><entry - align="char"> -<para>-EINVAL</para> -</entry><entry - align="char"> -<para>Bad parameter.</para> -</entry> - </row></tbody></tgroup></informaltable> - -</section> diff --git a/Documentation/DocBook/media/v4l/biblio.xml b/Documentation/DocBook/media/v4l/biblio.xml index fdee6b3f3eca..9beb30f0071b 100644 --- a/Documentation/DocBook/media/v4l/biblio.xml +++ b/Documentation/DocBook/media/v4l/biblio.xml @@ -177,6 +177,24 @@ Signal - NTSC for Studio Applications"</title> 1125-Line High-Definition Production"</title> </biblioentry> + <biblioentry id="smpte431"> + <abbrev>SMPTE RP 431-2</abbrev> + <authorgroup> + <corpauthor>Society of Motion Picture and Television Engineers +(<ulink url="http://www.smpte.org">http://www.smpte.org</ulink>)</corpauthor> + </authorgroup> + <title>SMPTE RP 431-2:2011 "D-Cinema Quality - Reference Projector and Environment"</title> + </biblioentry> + + <biblioentry id="smpte2084"> + <abbrev>SMPTE ST 2084</abbrev> + <authorgroup> + <corpauthor>Society of Motion Picture and Television Engineers +(<ulink url="http://www.smpte.org">http://www.smpte.org</ulink>)</corpauthor> + </authorgroup> + <title>SMPTE ST 2084:2014 "High Dynamic Range Electro-Optical Transfer Function of Master Reference Displays"</title> + </biblioentry> + <biblioentry id="srgb"> <abbrev>sRGB</abbrev> <authorgroup> diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index a0aef85d33c1..5701a08ed792 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2591,6 +2591,26 @@ and &v4l2-mbus-framefmt;. </orderedlist> </section> + <section> + <title>V4L2 in Linux 4.4</title> + <orderedlist> + <listitem> + <para>Renamed <constant>V4L2_TUNER_ADC</constant> to +<constant>V4L2_TUNER_SDR</constant>. The use of +<constant>V4L2_TUNER_ADC</constant> is deprecated now. + </para> + </listitem> + <listitem> + <para>Added <constant>V4L2_CID_RF_TUNER_RF_GAIN</constant> +RF Tuner control.</para> + </listitem> + <listitem> + <para>Added transmitter support for Software Defined Radio (SDR) +Interface.</para> + </listitem> + </orderedlist> + </section> + <section id="other"> <title>Relation of V4L2 to other Linux multimedia APIs</title> diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index 33aece541880..f13a429093f1 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -5418,6 +5418,18 @@ set. Unit is in Hz. The range and step are driver-specific.</entry> <entry spanname="descr">Enables/disables IF automatic gain control (AGC)</entry> </row> <row> + <entry spanname="id"><constant>V4L2_CID_RF_TUNER_RF_GAIN</constant> </entry> + <entry>integer</entry> + </row> + <row> + <entry spanname="descr">The RF amplifier is the very first +amplifier on the receiver signal path, just right after the antenna input. +The difference between the LNA gain and the RF gain in this document is that +the LNA gain is integrated in the tuner chip while the RF gain is a separate +chip. There may be both RF and LNA gain controls in the same device. +The range and step are driver-specific.</entry> + </row> + <row> <entry spanname="id"><constant>V4L2_CID_RF_TUNER_LNA_GAIN</constant> </entry> <entry>integer</entry> </row> @@ -5425,6 +5437,8 @@ set. Unit is in Hz. The range and step are driver-specific.</entry> <entry spanname="descr">LNA (low noise amplifier) gain is first gain stage on the RF tuner signal path. It is located very close to tuner antenna input. Used when <constant>V4L2_CID_RF_TUNER_LNA_GAIN_AUTO</constant> is not set. +See <constant>V4L2_CID_RF_TUNER_RF_GAIN</constant> to understand how RF gain +and LNA gain differs from the each others. The range and step are driver-specific.</entry> </row> <row> diff --git a/Documentation/DocBook/media/v4l/dev-sdr.xml b/Documentation/DocBook/media/v4l/dev-sdr.xml index f8903568a243..a659771f7b7c 100644 --- a/Documentation/DocBook/media/v4l/dev-sdr.xml +++ b/Documentation/DocBook/media/v4l/dev-sdr.xml @@ -28,6 +28,16 @@ Devices supporting the SDR receiver interface set the <structfield>capabilities</structfield> field of &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device has an Analog to Digital Converter (ADC), which is a mandatory element for the SDR receiver. + </para> + <para> +Devices supporting the SDR transmitter interface set the +<constant>V4L2_CAP_SDR_OUTPUT</constant> and +<constant>V4L2_CAP_MODULATOR</constant> flag in the +<structfield>capabilities</structfield> field of &v4l2-capability; +returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device has an +Digital to Analog Converter (DAC), which is a mandatory element for the SDR transmitter. + </para> + <para> At least one of the read/write, streaming or asynchronous I/O methods must be supported. </para> @@ -39,15 +49,16 @@ be supported. <para> SDR devices can support <link linkend="control">controls</link>, and must support the <link linkend="tuner">tuner</link> ioctls. Tuner ioctls are used -for setting the ADC sampling rate (sampling frequency) and the possible RF tuner -frequency. +for setting the ADC/DAC sampling rate (sampling frequency) and the possible +radio frequency (RF). </para> <para> -The <constant>V4L2_TUNER_ADC</constant> tuner type is used for ADC tuners, and -the <constant>V4L2_TUNER_RF</constant> tuner type is used for RF tuners. The -tuner index of the RF tuner (if any) must always follow the ADC tuner index. -Normally the ADC tuner is #0 and the RF tuner is #1. +The <constant>V4L2_TUNER_SDR</constant> tuner type is used for setting SDR +device ADC/DAC frequency, and the <constant>V4L2_TUNER_RF</constant> +tuner type is used for setting radio frequency. +The tuner index of the RF tuner (if any) must always follow the SDR tuner index. +Normally the SDR tuner is #0 and the RF tuner is #1. </para> <para> @@ -59,9 +70,9 @@ The &VIDIOC-S-HW-FREQ-SEEK; ioctl is not supported. <title>Data Format Negotiation</title> <para> -The SDR capture device uses the <link linkend="format">format</link> ioctls to -select the capture format. Both the sampling resolution and the data streaming -format are bound to that selectable format. In addition to the basic +The SDR device uses the <link linkend="format">format</link> ioctls to +select the capture and output format. Both the sampling resolution and the data +streaming format are bound to that selectable format. In addition to the basic <link linkend="format">format</link> ioctls, the &VIDIOC-ENUM-FMT; ioctl must be supported as well. </para> @@ -69,7 +80,8 @@ must be supported as well. <para> To use the <link linkend="format">format</link> ioctls applications set the <structfield>type</structfield> field of a &v4l2-format; to -<constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant> and use the &v4l2-sdr-format; +<constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant> or +<constant>V4L2_BUF_TYPE_SDR_OUTPUT</constant> and use the &v4l2-sdr-format; <structfield>sdr</structfield> member of the <structfield>fmt</structfield> union as needed per the desired operation. Currently there is two fields, <structfield>pixelformat</structfield> and diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 7bbc2a48911e..da654031ef3f 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -1006,8 +1006,14 @@ must set this to 0.</entry> <row> <entry><constant>V4L2_BUF_TYPE_SDR_CAPTURE</constant></entry> <entry>11</entry> - <entry>Buffer for Software Defined Radio (SDR), see <xref - linkend="sdr" />.</entry> + <entry>Buffer for Software Defined Radio (SDR) capture stream, see + <xref linkend="sdr" />.</entry> + </row> + <row> + <entry><constant>V4L2_BUF_TYPE_SDR_OUTPUT</constant></entry> + <entry>12</entry> + <entry>Buffer for Software Defined Radio (SDR) output stream, see + <xref linkend="sdr" />.</entry> </row> </tbody> </tgroup> diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml index 965ea916784a..d871245d2973 100644 --- a/Documentation/DocBook/media/v4l/pixfmt.xml +++ b/Documentation/DocBook/media/v4l/pixfmt.xml @@ -540,6 +540,10 @@ colorspaces except for BT.2020 which uses limited range R'G'B' quantization.</pa <entry>See <xref linkend="col-bt2020" />.</entry> </row> <row> + <entry><constant>V4L2_COLORSPACE_DCI_P3</constant></entry> + <entry>See <xref linkend="col-dcip3" />.</entry> + </row> + <row> <entry><constant>V4L2_COLORSPACE_SMPTE240M</constant></entry> <entry>See <xref linkend="col-smpte-240m" />.</entry> </row> @@ -601,6 +605,14 @@ colorspaces except for BT.2020 which uses limited range R'G'B' quantization.</pa <entry><constant>V4L2_XFER_FUNC_NONE</constant></entry> <entry>Do not use a transfer function (i.e. use linear RGB values).</entry> </row> + <row> + <entry><constant>V4L2_XFER_FUNC_DCI_P3</constant></entry> + <entry>Use the DCI-P3 transfer function.</entry> + </row> + <row> + <entry><constant>V4L2_XFER_FUNC_SMPTE2084</constant></entry> + <entry>Use the SMPTE 2084 transfer function.</entry> + </row> </tbody> </tgroup> </table> @@ -1154,6 +1166,68 @@ clamped to the range [-0.5…0.5]. The Y'CbCr quantization is limited range clamped to the range [-0.5…0.5]. The Yc'CbcCrc quantization is limited range.</para> </section> + <section id="col-dcip3"> + <title>Colorspace DCI-P3 (<constant>V4L2_COLORSPACE_DCI_P3</constant>)</title> + <para>The <xref linkend="smpte431" /> standard defines the colorspace used by cinema +projectors that use the DCI-P3 colorspace. +The default transfer function is <constant>V4L2_XFER_FUNC_DCI_P3</constant>. +The default Y'CbCr encoding is <constant>V4L2_YCBCR_ENC_709</constant>. Note that this +colorspace does not specify a Y'CbCr encoding since it is not meant to be encoded +to Y'CbCr. So this default Y'CbCr encoding was picked because it is the HDTV +encoding. The default Y'CbCr quantization is limited range. The chromaticities of +the primary colors and the white reference are:</para> + <table frame="none"> + <title>DCI-P3 Chromaticities</title> + <tgroup cols="3" align="left"> + &cs-str; + <thead> + <row> + <entry>Color</entry> + <entry>x</entry> + <entry>y</entry> + </row> + </thead> + <tbody valign="top"> + <row> + <entry>Red</entry> + <entry>0.6800</entry> + <entry>0.3200</entry> + </row> + <row> + <entry>Green</entry> + <entry>0.2650</entry> + <entry>0.6900</entry> + </row> + <row> + <entry>Blue</entry> + <entry>0.1500</entry> + <entry>0.0600</entry> + </row> + <row> + <entry>White Reference</entry> + <entry>0.3140</entry> + <entry>0.3510</entry> + </row> + </tbody> + </tgroup> + </table> + <variablelist> + <varlistentry> + <term>Transfer function:</term> + <listitem> + <para>L' = L<superscript>1/2.6</superscript></para> + </listitem> + </varlistentry> + <varlistentry> + <term>Inverse Transfer function:</term> + <listitem> + <para>L = L'<superscript>2.6</superscript></para> + </listitem> + </varlistentry> + </variablelist> + <para>Y'CbCr encoding is not specified. V4L2 defaults to Rec. 709.</para> + </section> + <section id="col-smpte-240m"> <title>Colorspace SMPTE 240M (<constant>V4L2_COLORSPACE_SMPTE240M</constant>)</title> <para>The <xref linkend="smpte240m" /> standard was an interim standard used during @@ -1402,6 +1476,41 @@ and <constant>V4L2_QUANTIZATION_FULL_RANGE</constant>.</para> </section> + <section> + <title>Detailed Transfer Function Descriptions</title> + <section id="xf-smpte-2084"> + <title>Transfer Function SMPTE 2084 (<constant>V4L2_XFER_FUNC_SMPTE2084</constant>)</title> + <para>The <xref linkend="smpte2084" /> standard defines the transfer function used by +High Dynamic Range content.</para> + <variablelist> + <varlistentry> + <term>Constants:</term> + <listitem> + <para>m1 = (2610 / 4096) / 4</para> + <para>m2 = (2523 / 4096) * 128</para> + <para>c1 = 3424 / 4096</para> + <para>c2 = (2413 / 4096) * 32</para> + <para>c3 = (2392 / 4096) * 32</para> + </listitem> + </varlistentry> + <varlistentry> + <term>Transfer function:</term> + <listitem> + <para>L' = ((c1 + c2 * L<superscript>m1</superscript>) / (1 + c3 * L<superscript>m1</superscript>))<superscript>m2</superscript></para> + </listitem> + </varlistentry> + </variablelist> + <variablelist> + <varlistentry> + <term>Inverse Transfer function:</term> + <listitem> + <para>L = (max(L'<superscript>1/m2</superscript> - c1, 0) / (c2 - c3 * L'<superscript>1/m2</superscript>))<superscript>1/m1</superscript></para> + </listitem> + </varlistentry> + </variablelist> + </section> + </section> + <section id="pixfmt-indexed"> <title>Indexed Format</title> @@ -1623,7 +1732,7 @@ extended control <constant>V4L2_CID_MPEG_STREAM_TYPE</constant>, see <section id="sdr-formats"> <title>SDR Formats</title> - <para>These formats are used for <link linkend="sdr">SDR Capture</link> + <para>These formats are used for <link linkend="sdr">SDR</link> interface only.</para> &sub-sdr-cu08; diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index e98caa1c39bd..7e61643358de 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -151,9 +151,18 @@ Rubli, Andy Walls, Muralidharan Karicheri, Mauro Carvalho Chehab, structs, ioctls) must be noted in more detail in the history chapter (compat.xml), along with the possible impact on existing drivers and applications. --> + <revision> + <revnumber>4.4</revnumber> + <date>2015-05-26</date> + <authorinitials>ap</authorinitials> + <revremark>Renamed V4L2_TUNER_ADC to V4L2_TUNER_SDR. +Added V4L2_CID_RF_TUNER_RF_GAIN control. +Added transmitter support for Software Defined Radio (SDR) Interface. + </revremark> + </revision> <revision> - <revnumber>3.21</revnumber> + <revnumber>4.1</revnumber> <date>2015-02-13</date> <authorinitials>mcc</authorinitials> <revremark>Fix documentation for media controller device nodes and add support for DVB device nodes. @@ -557,7 +566,7 @@ and discussions on the V4L mailing list.</revremark> </partinfo> <title>Video for Linux Two API Specification</title> - <subtitle>Revision 3.19</subtitle> + <subtitle>Revision 4.4</subtitle> <chapter id="common"> &sub-common; diff --git a/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml b/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml index fc1d4625a78c..70a4a08e9404 100644 --- a/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml +++ b/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml @@ -130,7 +130,7 @@ encoding will continue until the end of the current <wordasword>Group Of Pictures</wordasword>, otherwise encoding will stop immediately. When the encoder is already stopped, this command does nothing. mem2mem encoders will send a <constant>V4L2_EVENT_EOS</constant> event -when the last frame has been decoded and all frames are ready to be dequeued and +when the last frame has been encoded and all frames are ready to be dequeued and will set the <constant>V4L2_BUF_FLAG_LAST</constant> buffer flag on the last buffer of the capture queue to indicate there will be no new buffers produced to dequeue. This buffer may be empty, indicated by the driver setting the diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml index c5bdbfcc42b3..842536aae8b4 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml @@ -200,6 +200,13 @@ Valid if this control is of type <constant>V4L2_CTRL_TYPE_U16</constant>.</entry </row> <row> <entry></entry> + <entry>__u32 *</entry> + <entry><structfield>p_u32</structfield></entry> + <entry>A pointer to a matrix control of unsigned 32-bit values. +Valid if this control is of type <constant>V4L2_CTRL_TYPE_U32</constant>.</entry> + </row> + <row> + <entry></entry> <entry>void *</entry> <entry><structfield>ptr</structfield></entry> <entry>A pointer to a compound type which can be an N-dimensional array and/or a diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml index 4fe19a7a9a31..ffcb448251f0 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml @@ -175,7 +175,7 @@ capture and output devices.</entry> <entry>&v4l2-sdr-format;</entry> <entry><structfield>sdr</structfield></entry> <entry>Definition of a data format, see -<xref linkend="pixfmt" />, used by SDR capture devices.</entry> +<xref linkend="pixfmt" />, used by SDR capture and output devices.</entry> </row> <row> <entry></entry> diff --git a/Documentation/DocBook/media/v4l/vidioc-g-modulator.xml b/Documentation/DocBook/media/v4l/vidioc-g-modulator.xml index 7068b599a00d..96e17b344c5d 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-modulator.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-modulator.xml @@ -78,6 +78,12 @@ different audio modulation if the request cannot be satisfied. However this is a write-only ioctl, it does not return the actual audio modulation selected.</para> + <para><link linkend="sdr">SDR</link> specific modulator types are +<constant>V4L2_TUNER_SDR</constant> and <constant>V4L2_TUNER_RF</constant>. +For SDR devices <structfield>txsubchans</structfield> field must be +initialized to zero. +The term 'modulator' means SDR transmitter in this context.</para> + <para>To change the radio frequency the &VIDIOC-S-FREQUENCY; ioctl is available.</para> @@ -140,7 +146,13 @@ indicator, for example a stereo pilot tone.</entry> </row> <row> <entry>__u32</entry> - <entry><structfield>reserved</structfield>[4]</entry> + <entry><structfield>type</structfield></entry> + <entry spanname="hspan">Type of the modulator, see <xref + linkend="v4l2-tuner-type" />.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved</structfield>[3]</entry> <entry>Reserved for future extensions. Drivers and applications must set the array to zero.</entry> </row> diff --git a/Documentation/DocBook/media/v4l/vidioc-g-tuner.xml b/Documentation/DocBook/media/v4l/vidioc-g-tuner.xml index b0d865933da6..459b7e561f3c 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-tuner.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-tuner.xml @@ -80,6 +80,12 @@ if the requested mode is invalid or unsupported. Since this is a <!-- FIXME -->write-only ioctl, it does not return the actually selected audio mode.</para> + <para><link linkend="sdr">SDR</link> specific tuner types are +<constant>V4L2_TUNER_SDR</constant> and <constant>V4L2_TUNER_RF</constant>. +For SDR devices <structfield>audmode</structfield> field must be +initialized to zero. +The term 'tuner' means SDR receiver in this context.</para> + <para>To change the radio frequency the &VIDIOC-S-FREQUENCY; ioctl is available.</para> @@ -261,6 +267,16 @@ applications must set the array to zero.</entry> <entry>2</entry> <entry></entry> </row> + <row> + <entry><constant>V4L2_TUNER_SDR</constant></entry> + <entry>4</entry> + <entry></entry> + </row> + <row> + <entry><constant>V4L2_TUNER_RF</constant></entry> + <entry>5</entry> + <entry></entry> + </row> </tbody> </tgroup> </table> diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml b/Documentation/DocBook/media/v4l/vidioc-querycap.xml index 20fda75a012d..cd82148dedd7 100644 --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml @@ -308,6 +308,12 @@ modulator programming see fields.</entry> </row> <row> + <entry><constant>V4L2_CAP_SDR_OUTPUT</constant></entry> + <entry>0x00400000</entry> + <entry>The device supports the +<link linkend="sdr">SDR Output</link> interface.</entry> + </row> + <row> <entry><constant>V4L2_CAP_READWRITE</constant></entry> <entry>0x01000000</entry> <entry>The device supports the <link diff --git a/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml b/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml index 6ec39c698baf..55b7582cf314 100644 --- a/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml +++ b/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml @@ -101,8 +101,9 @@ prematurely end the enumeration).</para></footnote></para> next supported non-compound control, or <errorcode>EINVAL</errorcode> if there is none. In addition, the <constant>V4L2_CTRL_FLAG_NEXT_COMPOUND</constant> flag can be specified to enumerate all compound controls (i.e. controls -with type ≥ <constant>V4L2_CTRL_COMPOUND_TYPES</constant>). Specify both -<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> and +with type ≥ <constant>V4L2_CTRL_COMPOUND_TYPES</constant> and/or array +control, in other words controls that contain more than one value). +Specify both <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> and <constant>V4L2_CTRL_FLAG_NEXT_COMPOUND</constant> in order to enumerate all controls, compound or not. Drivers which do not support these flags yet always return <errorcode>EINVAL</errorcode>.</para> @@ -422,7 +423,7 @@ the array to zero.</entry> <entry>any</entry> <entry>An integer-valued control ranging from minimum to maximum inclusive. The step value indicates the increment between -values which are actually different on the hardware.</entry> +values.</entry> </row> <row> <entry><constant>V4L2_CTRL_TYPE_BOOLEAN</constant></entry> @@ -518,7 +519,7 @@ Older drivers which do not support this feature return an <entry>any</entry> <entry>An unsigned 8-bit valued control ranging from minimum to maximum inclusive. The step value indicates the increment between -values which are actually different on the hardware. +values. </entry> </row> <row> @@ -528,7 +529,17 @@ values which are actually different on the hardware. <entry>any</entry> <entry>An unsigned 16-bit valued control ranging from minimum to maximum inclusive. The step value indicates the increment between -values which are actually different on the hardware. +values. +</entry> + </row> + <row> + <entry><constant>V4L2_CTRL_TYPE_U32</constant></entry> + <entry>any</entry> + <entry>any</entry> + <entry>any</entry> + <entry>An unsigned 32-bit valued control ranging from minimum to +maximum inclusive. The step value indicates the increment between +values. </entry> </row> </tbody> diff --git a/Documentation/DocBook/media_api.tmpl b/Documentation/DocBook/media_api.tmpl index f3f5fe5b64c9..92037033f5eb 100644 --- a/Documentation/DocBook/media_api.tmpl +++ b/Documentation/DocBook/media_api.tmpl @@ -38,7 +38,7 @@ <title>LINUX MEDIA INFRASTRUCTURE API</title> <copyright> - <year>2009-2014</year> + <year>2009-2015</year> <holder>LinuxTV Developers</holder> </copyright> diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches index fd89b04d34f0..4710e4afef19 100644 --- a/Documentation/SubmittingPatches +++ b/Documentation/SubmittingPatches @@ -659,8 +659,8 @@ succinct and descriptive, but that is what a well-written summary should do. The "summary phrase" may be prefixed by tags enclosed in square -brackets: "Subject: [PATCH tag] <summary phrase>". The tags are not -considered part of the summary phrase, but describe how the patch +brackets: "Subject: [PATCH <tag>...] <summary phrase>". The tags are +not considered part of the summary phrase, but describe how the patch should be treated. Common tags might include a version descriptor if the multiple versions of the patch have been sent out in response to comments (i.e., "v1, v2, v3"), or "RFC" to indicate a request for @@ -672,8 +672,8 @@ the patch series. A couple of example Subjects: - Subject: [patch 2/5] ext2: improve scalability of bitmap searching - Subject: [PATCHv2 001/207] x86: fix eflags tracking + Subject: [PATCH 2/5] ext2: improve scalability of bitmap searching + Subject: [PATCH v2 01/27] x86: fix eflags tracking The "from" line must be the very first line in the message body, and has the form: diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 62435bb25266..5bda5031c83d 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -14,8 +14,43 @@ Statistics for individual zram devices are exported through sysfs nodes at * Usage +There are several ways to configure and manage zram device(-s): +a) using zram and zram_control sysfs attributes +b) using zramctl utility, provided by util-linux (util-linux@vger.kernel.org). + +In this document we will describe only 'manual' zram configuration steps, +IOW, zram and zram_control sysfs attributes. + +In order to get a better idea about zramctl please consult util-linux +documentation, zramctl man-page or `zramctl --help'. Please be informed +that zram maintainers do not develop/maintain util-linux or zramctl, should +you have any questions please contact util-linux@vger.kernel.org + Following shows a typical sequence of steps for using zram. +WARNING +======= +For the sake of simplicity we skip error checking parts in most of the +examples below. However, it is your sole responsibility to handle errors. + +zram sysfs attributes always return negative values in case of errors. +The list of possible return codes: +-EBUSY -- an attempt to modify an attribute that cannot be changed once +the device has been initialised. Please reset device first; +-ENOMEM -- zram was not able to allocate enough memory to fulfil your +needs; +-EINVAL -- invalid input has been provided. + +If you use 'echo', the returned value that is changed by 'echo' utility, +and, in general case, something like: + + echo 3 > /sys/block/zram0/max_comp_streams + if [ $? -ne 0 ]; + handle_error + fi + +should suffice. + 1) Load Module: modprobe zram num_devices=4 This creates 4 devices: /dev/zram{0,1,2,3} @@ -47,7 +82,7 @@ max_comp_streams adjustment. 3) Select compression algorithm Using comp_algorithm device attribute one can see available and - currently selected (shown in square brackets) compression algortithms, + currently selected (shown in square brackets) compression algorithms, change selected compression algorithm (once the device is initialised there is no way to change compression algorithm). @@ -119,7 +154,7 @@ execute 8) Stats: Per-device statistics are exported as various nodes under /sys/block/zram<id>/ -A brief description of exported device attritbutes. For more details please +A brief description of exported device attributes. For more details please read Documentation/ABI/testing/sysfs-block-zram. Name access description @@ -140,8 +175,9 @@ zero_pages RO the number of zero filled pages written to this disk orig_data_size RO uncompressed size of data stored in this disk compr_data_size RO compressed size of data stored in this disk mem_used_total RO the amount of memory allocated for this disk -mem_used_max RW the maximum amount memory zram have consumed to - store compressed data +mem_used_max RW the maximum amount of memory zram have consumed to + store the data (to reset this counter to the actual + current value, write 1 to this attribute) mem_limit RW the maximum amount of memory ZRAM can use to store the compressed data pages_compacted RO the number of pages freed during compaction diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt index 12686bec37b9..52fa9f353342 100644 --- a/Documentation/cgroups/blkio-controller.txt +++ b/Documentation/cgroups/blkio-controller.txt @@ -59,7 +59,7 @@ cgroups. Here is what you can do. - At macro level, first dd should finish first. To get more precise data, keep on looking at (with the help of script), at blkio.disk_time and blkio.disk_sectors files of both test1 and test2 groups. This will tell how - much disk time (in milli seconds), each group got and how many secotors each + much disk time (in milliseconds), each group got and how many sectors each group dispatched to the disk. We provide fairness in terms of disk time, so ideally io.disk_time of cgroups should be in proportion to the weight. diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index f935fac1e73b..c6256ae9885b 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -637,6 +637,10 @@ void exit(struct task_struct *task) Called during task exit. +void free(struct task_struct *task) + +Called when the task_struct is freed. + void bind(struct cgroup *root) (cgroup_mutex held by caller) diff --git a/Documentation/cgroups/freezer-subsystem.txt b/Documentation/cgroups/freezer-subsystem.txt index c96a72cbb30a..e831cb2b8394 100644 --- a/Documentation/cgroups/freezer-subsystem.txt +++ b/Documentation/cgroups/freezer-subsystem.txt @@ -50,7 +50,7 @@ being frozen. This allows the bash example above and gdb to run as expected. The cgroup freezer is hierarchical. Freezing a cgroup freezes all -tasks beloning to the cgroup and all its descendant cgroups. Each +tasks belonging to the cgroup and all its descendant cgroups. Each cgroup has its own state (self-state) and the state inherited from the parent (parent-state). Iff both states are THAWED, the cgroup is THAWED. diff --git a/Documentation/cgroups/unified-hierarchy.txt b/Documentation/cgroups/unified-hierarchy.txt index e0975c2cf03d..781b1d475bcf 100644 --- a/Documentation/cgroups/unified-hierarchy.txt +++ b/Documentation/cgroups/unified-hierarchy.txt @@ -107,12 +107,6 @@ root of unified hierarchy can be bound to other hierarchies. This allows mixing unified hierarchy with the traditional multiple hierarchies in a fully backward compatible way. -For development purposes, the following boot parameter makes all -controllers to appear on the unified hierarchy whether supported or -not. - - cgroup__DEVEL__legacy_files_on_dfl - A controller can be moved across hierarchies only after the controller is no longer referenced in its current hierarchy. Because per-cgroup controller states are destroyed asynchronously and controllers may @@ -341,11 +335,11 @@ is riddled with issues. unnecessarily complicated and probably done this way because event delivery itself was expensive. -Unified hierarchy implements an interface file "cgroup.populated" -which can be used to monitor whether the cgroup's subhierarchy has -tasks in it or not. Its value is 0 if there is no task in the cgroup -and its descendants; otherwise, 1. poll and [id]notify events are -triggered when the value changes. +Unified hierarchy implements "populated" field in "cgroup.events" +interface file which can be used to monitor whether the cgroup's +subhierarchy has tasks in it or not. Its value is 0 if there is no +task in the cgroup and its descendants; otherwise, 1. poll and +[id]notify events are triggered when the value changes. This is significantly lighter and simpler and trivially allows delegating management of subhierarchy - subhierarchy monitoring can @@ -374,6 +368,10 @@ supported and the interface files "release_agent" and - The "cgroup.clone_children" file is removed. +- /proc/PID/cgroup keeps reporting the cgroup that a zombie belonged + to before exiting. If the cgroup is removed before the zombie is + reaped, " (deleted)" is appeneded to the path. + 5-3. Controller File Conventions @@ -435,6 +433,11 @@ may be specified in any order and not all pairs have to be specified. the first entry in the file. Specific entries can use "default" as its value to indicate inheritance of the default value. +- For events which are not very high frequency, an interface file + "events" should be created which lists event key value pairs. + Whenever a notifiable event happens, file modified event should be + generated on the file. + 5-4. Per-Controller Changes @@ -491,7 +494,7 @@ may be specified in any order and not all pairs have to be specified. ${R|W}BPS are read/write bytes per second and ${R|W}IOPS are read/write IOs per second. "max" indicates no limit. Writing to the file follows the same format but the individual - settings may be ommitted or specified in any order. + settings may be omitted or specified in any order. This file is available only on non-root cgroups. diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt index b7675904a747..8c07e0ea6bc0 100644 --- a/Documentation/crypto/asymmetric-keys.txt +++ b/Documentation/crypto/asymmetric-keys.txt @@ -186,7 +186,7 @@ and looks like the following: const struct public_key_signature *sig); }; -Asymmetric keys point to this with their type_data[0] member. +Asymmetric keys point to this with their payload[asym_subtype] member. The owner and name fields should be set to the owning module and the name of the subtype. Currently, the name is only used for print statements. @@ -269,8 +269,7 @@ mandatory: struct key_preparsed_payload { char *description; - void *type_data[2]; - void *payload; + void *payload[4]; const void *data; size_t datalen; size_t quotalen; @@ -283,16 +282,18 @@ mandatory: not theirs. If the parser is happy with the blob, it should propose a description for - the key and attach it to ->description, ->type_data[0] should be set to - point to the subtype to be used, ->payload should be set to point to the - initialised data for that subtype, ->type_data[1] should point to a hex - fingerprint and quotalen should be updated to indicate how much quota this - key should account for. - - When clearing up, the data attached to ->type_data[1] and ->description - will be kfree()'d and the data attached to ->payload will be passed to the - subtype's ->destroy() method to be disposed of. A module reference for - the subtype pointed to by ->type_data[0] will be put. + the key and attach it to ->description, ->payload[asym_subtype] should be + set to point to the subtype to be used, ->payload[asym_crypto] should be + set to point to the initialised data for that subtype, + ->payload[asym_key_ids] should point to one or more hex fingerprints and + quotalen should be updated to indicate how much quota this key should + account for. + + When clearing up, the data attached to ->payload[asym_key_ids] and + ->description will be kfree()'d and the data attached to + ->payload[asm_crypto] will be passed to the subtype's ->destroy() method + to be disposed of. A module reference for the subtype pointed to by + ->payload[asym_subtype] will be put. If the data format is not recognised, -EBADMSG should be returned. If it diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,imgsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,imgsys.txt new file mode 100644 index 000000000000..b1f2ce17dff8 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,imgsys.txt @@ -0,0 +1,22 @@ +Mediatek imgsys controller +============================ + +The Mediatek imgsys controller provides various clocks to the system. + +Required Properties: + +- compatible: Should be: + - "mediatek,mt8173-imgsys", "syscon" +- #clock-cells: Must be 1 + +The imgsys controller uses the common clk binding from +Documentation/devicetree/bindings/clock/clock-bindings.txt +The available clocks are defined in dt-bindings/clock/mt*-clk.h. + +Example: + +imgsys: clock-controller@15000000 { + compatible = "mediatek,mt8173-imgsys", "syscon"; + reg = <0 0x15000000 0 0x1000>; + #clock-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt new file mode 100644 index 000000000000..4385946eadef --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.txt @@ -0,0 +1,22 @@ +Mediatek mmsys controller +============================ + +The Mediatek mmsys controller provides various clocks to the system. + +Required Properties: + +- compatible: Should be: + - "mediatek,mt8173-mmsys", "syscon" +- #clock-cells: Must be 1 + +The mmsys controller uses the common clk binding from +Documentation/devicetree/bindings/clock/clock-bindings.txt +The available clocks are defined in dt-bindings/clock/mt*-clk.h. + +Example: + +mmsys: clock-controller@14000000 { + compatible = "mediatek,mt8173-mmsys", "syscon"; + reg = <0 0x14000000 0 0x1000>; + #clock-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,vdecsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vdecsys.txt new file mode 100644 index 000000000000..1faacf1c1b25 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vdecsys.txt @@ -0,0 +1,22 @@ +Mediatek vdecsys controller +============================ + +The Mediatek vdecsys controller provides various clocks to the system. + +Required Properties: + +- compatible: Should be: + - "mediatek,mt8173-vdecsys", "syscon" +- #clock-cells: Must be 1 + +The vdecsys controller uses the common clk binding from +Documentation/devicetree/bindings/clock/clock-bindings.txt +The available clocks are defined in dt-bindings/clock/mt*-clk.h. + +Example: + +vdecsys: clock-controller@16000000 { + compatible = "mediatek,mt8173-vdecsys", "syscon"; + reg = <0 0x16000000 0 0x1000>; + #clock-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencltsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencltsys.txt new file mode 100644 index 000000000000..3cc299fd7857 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencltsys.txt @@ -0,0 +1,22 @@ +Mediatek vencltsys controller +============================ + +The Mediatek vencltsys controller provides various clocks to the system. + +Required Properties: + +- compatible: Should be: + - "mediatek,mt8173-vencltsys", "syscon" +- #clock-cells: Must be 1 + +The vencltsys controller uses the common clk binding from +Documentation/devicetree/bindings/clock/clock-bindings.txt +The available clocks are defined in dt-bindings/clock/mt*-clk.h. + +Example: + +vencltsys: clock-controller@19000000 { + compatible = "mediatek,mt8173-vencltsys", "syscon"; + reg = <0 0x19000000 0 0x1000>; + #clock-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencsys.txt b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencsys.txt new file mode 100644 index 000000000000..5bb2866a2b50 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,vencsys.txt @@ -0,0 +1,22 @@ +Mediatek vencsys controller +============================ + +The Mediatek vencsys controller provides various clocks to the system. + +Required Properties: + +- compatible: Should be: + - "mediatek,mt8173-vencsys", "syscon" +- #clock-cells: Must be 1 + +The vencsys controller uses the common clk binding from +Documentation/devicetree/bindings/clock/clock-bindings.txt +The available clocks are defined in dt-bindings/clock/mt*-clk.h. + +Example: + +vencsys: clock-controller@18000000 { + compatible = "mediatek,mt8173-vencsys", "syscon"; + reg = <0 0x18000000 0 0x1000>; + #clock-cells = <1>; +}; diff --git a/Documentation/devicetree/bindings/ata/ahci-fsl-qoriq.txt b/Documentation/devicetree/bindings/ata/ahci-fsl-qoriq.txt new file mode 100644 index 000000000000..032a7606b862 --- /dev/null +++ b/Documentation/devicetree/bindings/ata/ahci-fsl-qoriq.txt @@ -0,0 +1,21 @@ +Binding for Freescale QorIQ AHCI SATA Controller + +Required properties: + - reg: Physical base address and size of the controller's register area. + - compatible: Compatibility string. Must be 'fsl,<chip>-ahci', where + chip could be ls1021a, ls2080a, ls1043a etc. + - clocks: Input clock specifier. Refer to common clock bindings. + - interrupts: Interrupt specifier. Refer to interrupt binding. + +Optional properties: + - dma-coherent: Enable AHCI coherent DMA operation. + - reg-names: register area names when there are more than 1 register area. + +Examples: + sata@3200000 { + compatible = "fsl,ls1021a-ahci"; + reg = <0x0 0x3200000 0x0 0x10000>; + interrupts = <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&platform_clk 1>; + dma-coherent; + }; diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt index a2321819e7f5..c2340eeeb97f 100644 --- a/Documentation/devicetree/bindings/ata/ahci-platform.txt +++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt @@ -16,8 +16,6 @@ Required properties: - "snps,dwc-ahci" - "snps,exynos5440-ahci" - "snps,spear-ahci" - - "fsl,qoriq-ahci" : for qoriq series socs which include ls1021, ls2085, etc. - - "fsl,<chip>-ahci" : chip could be ls1021, ls2085 etc. - "generic-ahci" - interrupts : <interrupt mapping for SATA IRQ> - reg : <registers mapping> diff --git a/Documentation/devicetree/bindings/clock/at91-clock.txt b/Documentation/devicetree/bindings/clock/at91-clock.txt index 5ba6450693b9..181bc8ac4e3a 100644 --- a/Documentation/devicetree/bindings/clock/at91-clock.txt +++ b/Documentation/devicetree/bindings/clock/at91-clock.txt @@ -77,6 +77,9 @@ Required properties: "atmel,sama5d4-clk-h32mx": at91 h32mx clock + "atmel,sama5d2-clk-generated": + at91 generated clock + Required properties for SCKC node: - reg : defines the IO memory reserved for the SCKC. - #size-cells : shall be 0 (reg is used to encode clk id). @@ -461,3 +464,35 @@ For example: compatible = "atmel,sama5d4-clk-h32mx"; clocks = <&mck>; }; + +Required properties for generated clocks: +- #size-cells : shall be 0 (reg is used to encode clk id). +- #address-cells : shall be 1 (reg is used to encode clk id). +- clocks : shall be the generated clock source phandles. + e.g. clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>, <&audio_pll_pmc>; +- name: device tree node describing a specific generated clock. + * #clock-cells : from common clock binding; shall be set to 0. + * reg: peripheral id. See Atmel's datasheets to get a full + list of peripheral ids. + * atmel,clk-output-range : minimum and maximum clock frequency + (two u32 fields). + +For example: + gck { + compatible = "atmel,sama5d2-clk-generated"; + #address-cells = <1>; + #size-cells = <0>; + clocks = <&clk32k>, <&main>, <&plladiv>, <&utmi>, <&mck>, <&audio_pll_pmc>; + + tcb0_gclk: tcb0_gclk { + #clock-cells = <0>; + reg = <35>; + atmel,clk-output-range = <0 83000000>; + }; + + pwm_gclk: pwm_gclk { + #clock-cells = <0>; + reg = <38>; + atmel,clk-output-range = <0 83000000>; + }; + }; diff --git a/Documentation/devicetree/bindings/clock/brcm,bcm2835-cprman.txt b/Documentation/devicetree/bindings/clock/brcm,bcm2835-cprman.txt new file mode 100644 index 000000000000..e56a1df3a9d3 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/brcm,bcm2835-cprman.txt @@ -0,0 +1,45 @@ +Broadcom BCM2835 CPRMAN clocks + +This binding uses the common clock binding: + Documentation/devicetree/bindings/clock/clock-bindings.txt + +The CPRMAN clock controller generates clocks in the audio power domain +of the BCM2835. There is a level of PLLs deriving from an external +oscillator, a level of PLL dividers that produce channels off of the +few PLLs, and a level of mostly-generic clock generators sourcing from +the PLL channels. Most other hardware components source from the +clock generators, but a few (like the ARM or HDMI) will source from +the PLL dividers directly. + +Required properties: +- compatible: Should be "brcm,bcm2835-cprman" +- #clock-cells: Should be <1>. The permitted clock-specifier values can be + found in include/dt-bindings/clock/bcm2835.h +- reg: Specifies base physical address and size of the registers +- clocks: The external oscillator clock phandle + +Example: + + clk_osc: clock@3 { + compatible = "fixed-clock"; + reg = <3>; + #clock-cells = <0>; + clock-output-names = "osc"; + clock-frequency = <19200000>; + }; + + clocks: cprman@7e101000 { + compatible = "brcm,bcm2835-cprman"; + #clock-cells = <1>; + reg = <0x7e101000 0x2000>; + clocks = <&clk_osc>; + }; + + i2c0: i2c@7e205000 { + compatible = "brcm,bcm2835-i2c"; + reg = <0x7e205000 0x1000>; + interrupts = <2 21>; + clocks = <&clocks BCM2835_CLOCK_VPU>; + #address-cells = <1>; + #size-cells = <0>; + }; diff --git a/Documentation/devicetree/bindings/clock/brcm,iproc-clocks.txt b/Documentation/devicetree/bindings/clock/brcm,iproc-clocks.txt index da8d9bb5751c..ede65a55e21b 100644 --- a/Documentation/devicetree/bindings/clock/brcm,iproc-clocks.txt +++ b/Documentation/devicetree/bindings/clock/brcm,iproc-clocks.txt @@ -130,3 +130,81 @@ These clock IDs are defined in: ch3_unused mipipll 4 BCM_CYGNUS_MIPIPLL_CH3_UNUSED ch4_unused mipipll 5 BCM_CYGNUS_MIPIPLL_CH4_UNUSED ch5_unused mipipll 6 BCM_CYGNUS_MIPIPLL_CH5_UNUSED + +Northstar and Northstar Plus +------ +PLL and leaf clock compatible strings for Northstar and Northstar Plus are: + "brcm,nsp-armpll" + "brcm,nsp-genpll" + "brcm,nsp-lcpll0" + +The following table defines the set of PLL/clock index and ID for Northstar and +Northstar Plus. These clock IDs are defined in: + "include/dt-bindings/clock/bcm-nsp.h" + + Clock Source Index ID + --- ----- ----- --------- + crystal N/A N/A N/A + + armpll crystal N/A N/A + + genpll crystal 0 BCM_NSP_GENPLL + phy genpll 1 BCM_NSP_GENPLL_PHY_CLK + ethernetclk genpll 2 BCM_NSP_GENPLL_ENET_SW_CLK + usbclk genpll 3 BCM_NSP_GENPLL_USB_PHY_REF_CLK + iprocfast genpll 4 BCM_NSP_GENPLL_IPROCFAST_CLK + sata1 genpll 5 BCM_NSP_GENPLL_SATA1_CLK + sata2 genpll 6 BCM_NSP_GENPLL_SATA2_CLK + + lcpll0 crystal 0 BCM_NSP_LCPLL0 + pcie_phy lcpll0 1 BCM_NSP_LCPLL0_PCIE_PHY_REF_CLK + sdio lcpll0 2 BCM_NSP_LCPLL0_SDIO_CLK + ddr_phy lcpll0 3 BCM_NSP_LCPLL0_DDR_PHY_CLK + +Northstar 2 +----------- +PLL and leaf clock compatible strings for Northstar 2 are: + "brcm,ns2-genpll-scr" + "brcm,ns2-genpll-sw" + "brcm,ns2-lcpll-ddr" + "brcm,ns2-lcpll-ports" + +The following table defines the set of PLL/clock index and ID for Northstar 2. +These clock IDs are defined in: + "include/dt-bindings/clock/bcm-ns2.h" + + Clock Source Index ID + --- ----- ----- --------- + crystal N/A N/A N/A + + genpll_scr crystal 0 BCM_NS2_GENPLL_SCR + scr genpll_scr 1 BCM_NS2_GENPLL_SCR_SCR_CLK + fs genpll_scr 2 BCM_NS2_GENPLL_SCR_FS_CLK + audio_ref genpll_scr 3 BCM_NS2_GENPLL_SCR_AUDIO_CLK + ch3_unused genpll_scr 4 BCM_NS2_GENPLL_SCR_CH3_UNUSED + ch4_unused genpll_scr 5 BCM_NS2_GENPLL_SCR_CH4_UNUSED + ch5_unused genpll_scr 6 BCM_NS2_GENPLL_SCR_CH5_UNUSED + + genpll_sw crystal 0 BCM_NS2_GENPLL_SW + rpe genpll_sw 1 BCM_NS2_GENPLL_SW_RPE_CLK + 250 genpll_sw 2 BCM_NS2_GENPLL_SW_250_CLK + nic genpll_sw 3 BCM_NS2_GENPLL_SW_NIC_CLK + chimp genpll_sw 4 BCM_NS2_GENPLL_SW_CHIMP_CLK + port genpll_sw 5 BCM_NS2_GENPLL_SW_PORT_CLK + sdio genpll_sw 6 BCM_NS2_GENPLL_SW_SDIO_CLK + + lcpll_ddr crystal 0 BCM_NS2_LCPLL_DDR + pcie_sata_usb lcpll_ddr 1 BCM_NS2_LCPLL_DDR_PCIE_SATA_USB_CLK + ddr lcpll_ddr 2 BCM_NS2_LCPLL_DDR_DDR_CLK + ch2_unused lcpll_ddr 3 BCM_NS2_LCPLL_DDR_CH2_UNUSED + ch3_unused lcpll_ddr 4 BCM_NS2_LCPLL_DDR_CH3_UNUSED + ch4_unused lcpll_ddr 5 BCM_NS2_LCPLL_DDR_CH4_UNUSED + ch5_unused lcpll_ddr 6 BCM_NS2_LCPLL_DDR_CH5_UNUSED + + lcpll_ports crystal 0 BCM_NS2_LCPLL_PORTS + wan lcpll_ports 1 BCM_NS2_LCPLL_PORTS_WAN_CLK + rgmii lcpll_ports 2 BCM_NS2_LCPLL_PORTS_RGMII_CLK + ch2_unused lcpll_ports 3 BCM_NS2_LCPLL_PORTS_CH2_UNUSED + ch3_unused lcpll_ports 4 BCM_NS2_LCPLL_PORTS_CH3_UNUSED + ch4_unused lcpll_ports 5 BCM_NS2_LCPLL_PORTS_CH4_UNUSED + ch5_unused lcpll_ports 6 BCM_NS2_LCPLL_PORTS_CH5_UNUSED diff --git a/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt index 5ddb68418655..38dcf0370143 100644 --- a/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt +++ b/Documentation/devicetree/bindings/clock/renesas,cpg-div6-clocks.txt @@ -1,7 +1,7 @@ * Renesas CPG DIV6 Clock The CPG DIV6 clocks are variable factor clocks provided by the Clock Pulse -Generator (CPG). They clock input is divided by a configurable factor from 1 +Generator (CPG). Their clock input is divided by a configurable factor from 1 to 64. Required Properties: diff --git a/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt b/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt new file mode 100644 index 000000000000..59297d34b208 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/renesas,cpg-mssr.txt @@ -0,0 +1,69 @@ +* Renesas Clock Pulse Generator / Module Standby and Software Reset + +On Renesas ARM SoCs (SH/R-Mobile, R-Car, RZ), the CPG (Clock Pulse Generator) +and MSSR (Module Standby and Software Reset) blocks are intimately connected, +and share the same register block. + +They provide the following functionalities: + - The CPG block generates various core clocks, + - The MSSR block provides two functions: + 1. Module Standby, providing a Clock Domain to control the clock supply + to individual SoC devices, + 2. Reset Control, to perform a software reset of individual SoC devices. + +Required Properties: + - compatible: Must be one of: + - "renesas,r8a7795-cpg-mssr" for the r8a7795 SoC + + - reg: Base address and length of the memory resource used by the CPG/MSSR + block + + - clocks: References to external parent clocks, one entry for each entry in + clock-names + - clock-names: List of external parent clock names. Valid names are: + - "extal" (r8a7795) + - "extalr" (r8a7795) + + - #clock-cells: Must be 2 + - For CPG core clocks, the two clock specifier cells must be "CPG_CORE" + and a core clock reference, as defined in + <dt-bindings/clock/*-cpg-mssr.h>. + - For module clocks, the two clock specifier cells must be "CPG_MOD" and + a module number, as defined in the datasheet. + + - #power-domain-cells: Must be 0 + - SoC devices that are part of the CPG/MSSR Clock Domain and can be + power-managed through Module Standby should refer to the CPG device + node in their "power-domains" property, as documented by the generic PM + Domain bindings in + Documentation/devicetree/bindings/power/power_domain.txt. + + +Examples +-------- + + - CPG device node: + + cpg: clock-controller@e6150000 { + compatible = "renesas,r8a7795-cpg-mssr"; + reg = <0 0xe6150000 0 0x1000>; + clocks = <&extal_clk>, <&extalr_clk>; + clock-names = "extal", "extalr"; + #clock-cells = <2>; + #power-domain-cells = <0>; + }; + + + - CPG/MSSR Clock Domain member device node: + + scif2: serial@e6e88000 { + compatible = "renesas,scif-r8a7795", "renesas,scif"; + reg = <0 0xe6e88000 0 64>; + interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&cpg CPG_MOD 310>; + clock-names = "sci_ick"; + dmas = <&dmac1 0x13>, <&dmac1 0x12>; + dma-names = "tx", "rx"; + power-domains = <&cpg>; + status = "disabled"; + }; diff --git a/Documentation/devicetree/bindings/clock/silabs,si514.txt b/Documentation/devicetree/bindings/clock/silabs,si514.txt new file mode 100644 index 000000000000..ea1a9dbc63b6 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/silabs,si514.txt @@ -0,0 +1,24 @@ +Binding for Silicon Labs 514 programmable I2C clock generator. + +Reference +This binding uses the common clock binding[1]. Details about the device can be +found in the datasheet[2]. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt +[2] Si514 datasheet + http://www.silabs.com/Support%20Documents/TechnicalDocs/si514.pdf + +Required properties: + - compatible: Shall be "silabs,si514" + - reg: I2C device address. + - #clock-cells: From common clock bindings: Shall be 0. + +Optional properties: + - clock-output-names: From common clock bindings. Recommended to be "si514". + +Example: + si514: clock-generator@55 { + reg = <0x55>; + #clock-cells = <0>; + compatible = "silabs,si514"; + }; diff --git a/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt b/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt index d8b168ebd5f1..844b3a0976bf 100644 --- a/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt +++ b/Documentation/devicetree/bindings/clock/st/st,clkgen-pll.txt @@ -23,6 +23,7 @@ Required properties: "st,stih407-plls-c32-a9", "st,clkgen-plls-c32" "sst,plls-c32-cx_0", "st,clkgen-plls-c32" "sst,plls-c32-cx_1", "st,clkgen-plls-c32" + "st,stih418-plls-c28-a9", "st,clkgen-plls-c32" "st,stih415-gpu-pll-c32", "st,clkgengpu-pll-c32" "st,stih416-gpu-pll-c32", "st,clkgengpu-pll-c32" diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt index 3443e0f838df..947863acc2d4 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt @@ -36,5 +36,24 @@ the PCIe specification. NOTE: this only applies to the SMMU itself, not masters connected upstream of the SMMU. +- msi-parent : See the generic MSI binding described in + devicetree/bindings/interrupt-controller/msi.txt + for a description of the msi-parent property. + - hisilicon,broken-prefetch-cmd : Avoid sending CMD_PREFETCH_* commands to the SMMU. + +** Example + + smmu@2b400000 { + compatible = "arm,smmu-v3"; + reg = <0x0 0x2b400000 0x0 0x20000>; + interrupts = <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>, + <GIC_SPI 75 IRQ_TYPE_EDGE_RISING>, + <GIC_SPI 77 IRQ_TYPE_EDGE_RISING>, + <GIC_SPI 79 IRQ_TYPE_EDGE_RISING>; + interrupt-names = "eventq", "priq", "cmdq-sync", "gerror"; + dma-coherent; + #iommu-cells = <0>; + msi-parent = <&its 0xff0000>; + }; diff --git a/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt b/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt index 869699925fd5..4bd10dd881b8 100644 --- a/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt +++ b/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt @@ -4,6 +4,7 @@ Required properties: - compatible : Should be one of, "ti,omap2-iommu" for OMAP2/OMAP3 IOMMU instances "ti,omap4-iommu" for OMAP4/OMAP5 IOMMU instances + "ti,dra7-dsp-iommu" for DRA7xx DSP IOMMU instances "ti,dra7-iommu" for DRA7xx IOMMU instances - ti,hwmods : Name of the hwmod associated with the IOMMU instance - reg : Address space for the configuration registers @@ -19,6 +20,13 @@ Optional properties: Should be either 8 or 32 (default: 32) - ti,iommu-bus-err-back : Indicates the IOMMU instance supports throwing back a bus error response on MMU faults. +- ti,syscon-mmuconfig : Should be a pair of the phandle to the DSP_SYSTEM + syscon node that contains the additional control + register for enabling the MMU, and the MMU instance + number (0-indexed) within the sub-system. This property + is required for DSP IOMMU instances on DRA7xx SoCs. The + instance number should be 0 for DSP MDMA MMUs and 1 for + DSP EDMA MMUs. Example: /* OMAP3 ISP MMU */ @@ -30,3 +38,22 @@ Example: ti,hwmods = "mmu_isp"; ti,#tlb-entries = <8>; }; + + /* DRA74x DSP2 MMUs */ + mmu0_dsp2: mmu@41501000 { + compatible = "ti,dra7-dsp-iommu"; + reg = <0x41501000 0x100>; + interrupts = <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>; + ti,hwmods = "mmu0_dsp2"; + #iommu-cells = <0>; + ti,syscon-mmuconfig = <&dsp2_system 0x0>; + }; + + mmu1_dsp2: mmu@41502000 { + compatible = "ti,dra7-dsp-iommu"; + reg = <0x41502000 0x100>; + interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>; + ti,hwmods = "mmu1_dsp2"; + #iommu-cells = <0>; + ti,syscon-mmuconfig = <&dsp2_system 0x1>; + }; diff --git a/Documentation/devicetree/bindings/media/exynos-jpeg-codec.txt b/Documentation/devicetree/bindings/media/exynos-jpeg-codec.txt index 4ef45636ebde..38941db23dd2 100644 --- a/Documentation/devicetree/bindings/media/exynos-jpeg-codec.txt +++ b/Documentation/devicetree/bindings/media/exynos-jpeg-codec.txt @@ -4,7 +4,8 @@ Required properties: - compatible : should be one of: "samsung,s5pv210-jpeg", "samsung,exynos4210-jpeg", - "samsung,exynos3250-jpeg", "samsung,exynos5420-jpeg"; + "samsung,exynos3250-jpeg", "samsung,exynos5420-jpeg", + "samsung,exynos5433-jpeg"; - reg : address and length of the JPEG codec IP register set; - interrupts : specifies the JPEG codec IP interrupt; - clock-names : should contain: diff --git a/Documentation/devicetree/bindings/mfd/axp20x.txt b/Documentation/devicetree/bindings/mfd/axp20x.txt index 41811223e5be..a474359dd206 100644 --- a/Documentation/devicetree/bindings/mfd/axp20x.txt +++ b/Documentation/devicetree/bindings/mfd/axp20x.txt @@ -60,8 +60,8 @@ DCDC2 : DC-DC buck : vin2-supply DCDC3 : DC-DC buck : vin3-supply DCDC4 : DC-DC buck : vin4-supply DCDC5 : DC-DC buck : vin5-supply -DC1SW : On/Off Switch : dcdc1-supply : DCDC1 secondary output -DC5LDO : LDO : dcdc5-supply : input from DCDC5 +DC1SW : On/Off Switch : : DCDC1 secondary output +DC5LDO : LDO : : input from DCDC5 ALDO1 : LDO : aldoin-supply : shared supply ALDO2 : LDO : aldoin-supply : shared supply ALDO3 : LDO : aldoin-supply : shared supply diff --git a/Documentation/devicetree/bindings/power/bq24257.txt b/Documentation/devicetree/bindings/power/bq24257.txt index 5c9d3940d07c..d693702c9c1e 100644 --- a/Documentation/devicetree/bindings/power/bq24257.txt +++ b/Documentation/devicetree/bindings/power/bq24257.txt @@ -1,21 +1,64 @@ -Binding for TI bq24257 Li-Ion Charger +Binding for TI bq24250/bq24251/bq24257 Li-Ion Charger Required properties: - compatible: Should contain one of the following: + * "ti,bq24250" + * "ti,bq24251" * "ti,bq24257" -- reg: integer, i2c address of the device. +- reg: integer, i2c address of the device. +- interrupt-parent: Should be the phandle for the interrupt controller. Use in + conjunction with "interrupts". +- interrupts: Interrupt mapping for GPIO IRQ (configure for both edges). Use in + conjunction with "interrupt-parent". - ti,battery-regulation-voltage: integer, maximum charging voltage in uV. -- ti,charge-current: integer, maximum charging current in uA. -- ti,termination-current: integer, charge will be terminated when current in - constant-voltage phase drops below this value (in uA). +- ti,charge-current: integer, maximum charging current in uA. +- ti,termination-current: integer, charge will be terminated when current in + constant-voltage phase drops below this value (in uA). + +Optional properties: +- pg-gpios: GPIO used for connecting the bq2425x device PG (Power Good) pin. + This pin is not available on all devices however it should be used if + possible as this is the recommended way to obtain the charger's input PG + state. If this pin is not specified a software-based approach for PG + detection is used. +- ti,current-limit: The maximum current to be drawn from the charger's input + (in uA). If this property is not specified, the input limit current is + set automatically using USB D+/D- signal based charger type detection. + If the hardware does not support the D+/D- based detection, a default + of 500,000 is used (=500mA) instead. +- ti,ovp-voltage: Configures the over voltage protection voltage (in uV). If + not specified a default of 6,5000,000 (=6.5V) is used. +- ti,in-dpm-voltage: Configures the threshold input voltage for the dynamic + power path management (in uV). If not specified a default of 4,360,000 + (=4.36V) is used. Example: bq24257 { compatible = "ti,bq24257"; reg = <0x6a>; + interrupt-parent = <&gpio1>; + interrupts = <16 IRQ_TYPE_EDGE_BOTH>; + + pg-gpios = <&gpio1 28 GPIO_ACTIVE_HIGH>; ti,battery-regulation-voltage = <4200000>; ti,charge-current = <1000000>; ti,termination-current = <50000>; }; + +Example: + +bq24250 { + compatible = "ti,bq24250"; + reg = <0x6a>; + interrupt-parent = <&gpio1>; + interrupts = <16 IRQ_TYPE_EDGE_BOTH>; + + ti,battery-regulation-voltage = <4200000>; + ti,charge-current = <500000>; + ti,termination-current = <50000>; + ti,current-limit = <900000>; + ti,ovp-voltage = <9500000>; + ti,in-dpm-voltage = <4440000>; +}; diff --git a/Documentation/devicetree/bindings/power_supply/axp20x_usb_power.txt b/Documentation/devicetree/bindings/power_supply/axp20x_usb_power.txt new file mode 100644 index 000000000000..862f4a49dc49 --- /dev/null +++ b/Documentation/devicetree/bindings/power_supply/axp20x_usb_power.txt @@ -0,0 +1,34 @@ +AXP20x USB power supply + +Required Properties: +-compatible: "x-powers,axp202-usb-power-supply" + +This node is a subnode of the axp20x PMIC. + +Example: + +axp209: pmic@34 { + compatible = "x-powers,axp209"; + reg = <0x34>; + interrupt-parent = <&nmi_intc>; + interrupts = <0 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells = <1>; + + regulators { + x-powers,dcdc-freq = <1500>; + + vdd_cpu: dcdc2 { + regulator-always-on; + regulator-min-microvolt = <1000000>; + regulator-max-microvolt = <1450000>; + regulator-name = "vdd-cpu"; + }; + + ... + }; + + usb-power-supply: usb-power-supply { + compatible = "x-powers,axp202-usb-power-supply"; + }; +}; diff --git a/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt b/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt new file mode 100644 index 000000000000..65b88fac854b --- /dev/null +++ b/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt @@ -0,0 +1,131 @@ +Qualcomm Switch-Mode Battery Charger and Boost + +PROPERTIES +- compatible: + Usage: required + Value type: <stringlist> + Description: Must be one of: + - "qcom,pm8941-charger" + +- reg: + Usage: required + Value type: <prop-encoded-array> + Description: Base address of registers for SMBB block + +- interrupts: + Usage: required + Value type: <prop-encoded-array> + Description: The format of the specifier is defined by the binding document + describing the node's interrupt parent. Must contain one + specifier for each of the following interrupts, in order: + - charge done + - charge fast mode + - charge trickle mode + - battery temperature ok + - battery present + - charger disconnected + - USB-in valid + - DC-in valid + +- interrupt-names: + Usage: required + Value type: <stringlist> + Description: Must contain the following list, strictly ordered: + "chg-done", + "chg-fast", + "chg-trkl", + "bat-temp-ok", + "bat-present", + "chg-gone", + "usb-valid", + "dc-valid" + +- qcom,fast-charge-current-limit: + Usage: optional (default: 1A, or pre-configured value) + Value type: <u32>; uA; range [100mA : 3A] + Description: Maximum charge current; May be clamped to safety limits. + +- qcom,fast-charge-low-threshold-voltage: + Usage: optional (default: 3.2V, or pre-configured value) + Value type: <u32>; uV; range [2.1V : 3.6V] + Description: Battery voltage limit above which fast charging may operate; + Below this value linear or switch-mode auto-trickle-charging + will operate. + +- qcom,fast-charge-high-threshold-voltage: + Usage: optional (default: 4.2V, or pre-configured value) + Value type: <u32>; uV; range [3.24V : 5V] + Description: Battery voltage limit below which fast charging may operate; + The fast charger will attempt to charge the battery to this + voltage. May be clamped to safety limits. + +- qcom,fast-charge-safe-voltage: + Usage: optional (default: 4.2V, or pre-configured value) + Value type: <u32>; uV; range [3.24V : 5V] + Description: Maximum safe battery voltage; May be pre-set by bootloader, in + which case, setting this will harmlessly fail. The property + 'fast-charge-high-watermark' will be clamped by this value. + +- qcom,fast-charge-safe-current: + Usage: optional (default: 1A, or pre-configured value) + Value type: <u32>; uA; range [100mA : 3A] + Description: Maximum safe battery charge current; May pre-set by bootloader, + in which case, setting this will harmlessly fail. The property + 'qcom,fast-charge-current-limit' will be clamped by this value. + +- qcom,auto-recharge-threshold-voltage: + Usage: optional (default: 4.1V, or pre-configured value) + Value type: <u32>; uV; range [3.24V : 5V] + Description: Battery voltage limit below which auto-recharge functionality + will restart charging after end-of-charge; The high cutoff + limit for auto-recharge is 5% above this value. + +- qcom,minimum-input-voltage: + Usage: optional (default: 4.3V, or pre-configured value) + Value type: <u32>; uV; range [4.2V : 9.6V] + Description: Input voltage level above which charging may operate + +- qcom,dc-current-limit: + Usage: optional (default: 100mA, or pre-configured value) + Value type: <u32>; uA; range [100mA : 2.5A] + Description: Default DC charge current limit + +- qcom,disable-dc: + Usage: optional (default: false) + Value type: boolean: <u32> or <empty> + Description: Disable DC charger + +- qcom,jeita-extended-temp-range: + Usage: optional (default: false) + Value type: boolean: <u32> or <empty> + Description: Enable JEITA extended temperature range; This does *not* + adjust the maximum charge voltage or current in the extended + temperature range. It only allows charging when the battery + is in the extended temperature range. Voltage/current + regulation must be done externally to fully comply with + the JEITA safety guidelines if this flag is set. + +EXAMPLE +charger@1000 { + compatible = "qcom,pm8941-charger"; + reg = <0x1000 0x700>; + interrupts = <0x0 0x10 7 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x10 5 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x10 4 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x12 1 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x12 0 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x13 2 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x13 1 IRQ_TYPE_EDGE_BOTH>, + <0x0 0x14 1 IRQ_TYPE_EDGE_BOTH>; + interrupt-names = "chg-done", + "chg-fast", + "chg-trkl", + "bat-temp-ok", + "bat-present", + "chg-gone", + "usb-valid", + "dc-valid"; + + qcom,fast-charge-current-limit = <1000000>; + qcom,dc-charge-current-limit = <1000000>; +}; diff --git a/Documentation/devicetree/bindings/power_supply/tps65217_charger.txt b/Documentation/devicetree/bindings/power_supply/tps65217_charger.txt new file mode 100644 index 000000000000..98d131acee95 --- /dev/null +++ b/Documentation/devicetree/bindings/power_supply/tps65217_charger.txt @@ -0,0 +1,12 @@ +TPS65217 Charger + +Required Properties: +-compatible: "ti,tps65217-charger" + +This node is a subnode of the tps65217 PMIC. + +Example: + + tps65217-charger { + compatible = "ti,tps65090-charger"; + }; diff --git a/Documentation/devicetree/bindings/regulator/act8865-regulator.txt b/Documentation/devicetree/bindings/regulator/act8865-regulator.txt index e91485d11241..6067d9830d07 100644 --- a/Documentation/devicetree/bindings/regulator/act8865-regulator.txt +++ b/Documentation/devicetree/bindings/regulator/act8865-regulator.txt @@ -8,6 +8,8 @@ Required properties: Optional properties: - system-power-controller: Telling whether or not this pmic is controlling the system power. See Documentation/devicetree/bindings/power/power-controller.txt . +- active-semi,vsel-high: Indicates the VSEL pin is high. + If this property is missing, assume the VSEL pin is low(0). Optional input supply properties: - for act8600: @@ -49,6 +51,7 @@ Example: pmic: act8865@5b { compatible = "active-semi,act8865"; reg = <0x5b>; + active-semi,vsel-high; status = "disabled"; regulators { diff --git a/Documentation/devicetree/bindings/regulator/anatop-regulator.txt b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt index 758eae24082a..37c4ea076f88 100644 --- a/Documentation/devicetree/bindings/regulator/anatop-regulator.txt +++ b/Documentation/devicetree/bindings/regulator/anatop-regulator.txt @@ -13,6 +13,7 @@ Optional properties: - anatop-delay-reg-offset: Anatop MFD step time register offset - anatop-delay-bit-shift: Bit shift for the step time register - anatop-delay-bit-width: Number of bits used in the step time register +- vin-supply: The supply for this regulator Any property defined as part of the core regulator binding, defined in regulator.txt, can also be used. diff --git a/Documentation/devicetree/bindings/regulator/arizona-regulator.txt b/Documentation/devicetree/bindings/regulator/arizona-regulator.txt new file mode 100644 index 000000000000..443564d7784f --- /dev/null +++ b/Documentation/devicetree/bindings/regulator/arizona-regulator.txt @@ -0,0 +1,17 @@ +Cirrus Logic Arizona class audio SoCs + +These devices are audio SoCs with extensive digital capabilities and a range +of analogue I/O. + +This document lists regulator specific bindings, see the primary binding +document: + ../mfd/arizona.txt + +Optional properties: + - wlf,ldoena : GPIO specifier for the GPIO controlling LDOENA + +Optional subnodes: + - ldo1 : Initial data for the LDO1 regulator, as covered in + Documentation/devicetree/bindings/regulator/regulator.txt + - micvdd : Initial data for the MICVDD regulator, as covered in + Documentation/devicetree/bindings/regulator/regulator.txt diff --git a/Documentation/devicetree/bindings/regulator/max77802.txt b/Documentation/devicetree/bindings/regulator/max77802.txt index 79e5476444f7..09d796ed48be 100644 --- a/Documentation/devicetree/bindings/regulator/max77802.txt +++ b/Documentation/devicetree/bindings/regulator/max77802.txt @@ -8,7 +8,28 @@ regulators that can be controlled over I2C. Following properties should be present in main device node of the MFD chip. -Optional node: +Optional properties: +- inb1-supply: The input supply for BUCK1 +- inb2-supply: The input supply for BUCK2 +- inb3-supply: The input supply for BUCK3 +- inb4-supply: The input supply for BUCK4 +- inb5-supply: The input supply for BUCK5 +- inb6-supply: The input supply for BUCK6 +- inb7-supply: The input supply for BUCK7 +- inb8-supply: The input supply for BUCK8 +- inb9-supply: The input supply for BUCK9 +- inb10-supply: The input supply for BUCK10 +- inl1-supply: The input supply for LDO8 and LDO15 +- inl2-supply: The input supply for LDO17, LDO27, LDO30 and LDO35 +- inl3-supply: The input supply for LDO3, LDO5, LDO6 and LDO7 +- inl4-supply: The input supply for LDO10, LDO11, LDO13 and LDO14 +- inl5-supply: The input supply for LDO9 and LDO19 +- inl6-supply: The input supply for LDO4, LDO21, LDO24 and LDO33 +- inl7-supply: The input supply for LDO18, LDO20, LDO28 and LDO29 +- inl9-supply: The input supply for LDO12, LDO23, LDO25, LDO26, LDO32 and LDO34 +- inl10-supply: The input supply for LDO1 and LDO2 + +Optional nodes: - regulators : The regulators of max77802 have to be instantiated under subnode named "regulators" using the following format. @@ -58,6 +79,8 @@ Example: #address-cells = <1>; #size-cells = <0>; + inb1-supply = <&parent_reg>; + regulators { ldo1_reg: LDO1 { regulator-name = "vdd_1v0"; diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 24bd422cecd5..1d112fc456aa 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -11,6 +11,7 @@ Optional properties: - regulator-always-on: boolean, regulator should never be disabled - regulator-boot-on: bootloader/firmware enabled regulator - regulator-allow-bypass: allow the regulator to go into bypass mode +- regulator-allow-set-load: allow the regulator performance level to be configured - <name>-supply: phandle to the parent supply/regulator node - regulator-ramp-delay: ramp delay for regulator(in uV/uS) For hardware which supports disabling ramp rate, it should be explicitly diff --git a/Documentation/devicetree/bindings/regulator/tps65023.txt b/Documentation/devicetree/bindings/regulator/tps65023.txt new file mode 100644 index 000000000000..a4714e4da370 --- /dev/null +++ b/Documentation/devicetree/bindings/regulator/tps65023.txt @@ -0,0 +1,60 @@ +TPS65023 family of regulators + +Required properties: +- compatible: Must be one of the following. + "ti,tps65020", + "ti,tps65021", + "ti,tps65023", +- reg: I2C slave address +- regulators: list of regulators provided by this controller, must be named + after their hardware counterparts: VDCDC[1-3] and LDO[1-2] +- regulators: This is the list of child nodes that specify the regulator + initialization data for defined regulators. The definition for each of + these nodes is defined using the standard binding for regulators found at + Documentation/devicetree/bindings/regulator/regulator.txt. + +Each regulator is defined using the standard binding for regulators. + +Example: + + tps65023@48 { + compatible = "ti,tps65023"; + reg = <0x48>; + + regulators { + VDCDC1 { + regulator-name = "vdd_mpu"; + regulator-always-on; + regulator-min-microvolt = <1200000>; + regulator-max-microvolt = <1200000>; + }; + + VDCDC2 { + regulator-name = "vdd_core"; + regulator-always-on; + regulator-min-microvolt = <3300000>; + regulator-max-microvolt = <3300000>; + }; + + VDCDC3 { + regulator-name = "vdd_io"; + regulator-always-on; + regulator-min-microvolt = <1800000>; + regulator-max-microvolt = <1800000>; + }; + + LDO1 { + regulator-name = "vdd_usb18"; + regulator-always-on; + regulator-min-microvolt = <1800000>; + regulator-max-microvolt = <1800000>; + }; + + LDO2 { + regulator-name = "vdd_usb33"; + regulator-always-on; + regulator-min-microvolt = <3300000>; + regulator-max-microvolt = <3300000>; + }; + }; + }; diff --git a/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt b/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt new file mode 100644 index 000000000000..9887b0724759 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/brcm,bcm2835-aux-spi.txt @@ -0,0 +1,38 @@ +Broadcom BCM2835 auxiliar SPI1/2 controller + +The BCM2835 contains two forms of SPI master controller, one known simply as +SPI0, and the other known as the "Universal SPI Master"; part of the +auxiliary block. This binding applies to the SPI1/2 controller. + +Required properties: +- compatible: Should be "brcm,bcm2835-aux-spi". +- reg: Should contain register location and length for the spi block +- interrupts: Should contain shared interrupt of the aux block +- clocks: The clock feeding the SPI controller - needs to + point to the auxiliar clock driver of the bcm2835, + as this clock will enable the output gate for the specific + clock. +- cs-gpios: the cs-gpios (native cs is NOT supported) + see also spi-bus.txt + +Example: + +spi1@7e215080 { + compatible = "brcm,bcm2835-aux-spi"; + reg = <0x7e215080 0x40>; + interrupts = <1 29>; + clocks = <&aux_clocks BCM2835_AUX_CLOCK_SPI1>; + #address-cells = <1>; + #size-cells = <0>; + cs-gpios = <&gpio 18>, <&gpio 17>, <&gpio 16>; +}; + +spi2@7e2150c0 { + compatible = "brcm,bcm2835-aux-spi"; + reg = <0x7e2150c0 0x40>; + interrupts = <1 29>; + clocks = <&aux_clocks BCM2835_AUX_CLOCK_SPI2>; + #address-cells = <1>; + #size-cells = <0>; + cs-gpios = <&gpio 43>, <&gpio 44>, <&gpio 45>; +}; diff --git a/Documentation/devicetree/bindings/spi/spi-mt65xx.txt b/Documentation/devicetree/bindings/spi/spi-mt65xx.txt index 6160ffbcb3d3..ce363c923f44 100644 --- a/Documentation/devicetree/bindings/spi/spi-mt65xx.txt +++ b/Documentation/devicetree/bindings/spi/spi-mt65xx.txt @@ -29,8 +29,11 @@ Required properties: muxes clock, and "spi-clk" for the clock gate. Optional properties: +-cs-gpios: see spi-bus.txt, only required for MT8173. + - mediatek,pad-select: specify which pins group(ck/mi/mo/cs) spi - controller used, this value should be 0~3, only required for MT8173. + controller used. This is a array, the element value should be 0~3, + only required for MT8173. 0: specify GPIO69,70,71,72 for spi pins. 1: specify GPIO102,103,104,105 for spi pins. 2: specify GPIO128,129,130,131 for spi pins. @@ -49,7 +52,7 @@ spi: spi@1100a000 { <&topckgen CLK_TOP_SPI_SEL>, <&pericfg CLK_PERI_SPI0>; clock-names = "parent-clk", "sel-clk", "spi-clk"; - - mediatek,pad-select = <0>; + cs-gpios = <&pio 105 GPIO_ACTIVE_LOW>, <&pio 72 GPIO_ACTIVE_LOW>; + mediatek,pad-select = <1>, <0>; status = "disabled"; }; diff --git a/Documentation/email-clients.txt b/Documentation/email-clients.txt index 3fa450881ecb..aba85b39a400 100644 --- a/Documentation/email-clients.txt +++ b/Documentation/email-clients.txt @@ -220,7 +220,7 @@ to coerce it into behaving. Compose dialog. Please note that "external editor" requires that your editor must not - fork, or in other words, the editor must not return before closing. + fork, or in other words, the editor must not return before closing. You may have to pass additional flags or change the settings of your editor. Most notably if you are using gvim then you must pass the -f option to gvim by putting "/usr/bin/gvim -f" (if the binary is in diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index e2d5105b7214..b102b436563e 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -102,7 +102,8 @@ background_gc=%s Turn on/off cleaning operations, namely garbage collection, triggered in background when I/O subsystem is idle. If background_gc=on, it will turn on the garbage collection and if background_gc=off, garbage collection - will be truned off. + will be truned off. If background_gc=sync, it will turn + on synchronous garbage collection running in background. Default value for this option is on. So garbage collection is on by default. disable_roll_forward Disable the roll-forward recovery routine diff --git a/Documentation/filesystems/path-lookup.md b/Documentation/filesystems/path-lookup.md new file mode 100644 index 000000000000..1b39e084a2b2 --- /dev/null +++ b/Documentation/filesystems/path-lookup.md @@ -0,0 +1,1297 @@ +<head> +<style> p { max-width:50em} ol, ul {max-width: 40em}</style> +</head> + +Pathname lookup in Linux. +========================= + +This write-up is based on three articles published at lwn.net: + +- <https://lwn.net/Articles/649115/> Pathname lookup in Linux +- <https://lwn.net/Articles/649729/> RCU-walk: faster pathname lookup in Linux +- <https://lwn.net/Articles/650786/> A walk among the symlinks + +Written by Neil Brown with help from Al Viro and Jon Corbet. + +Introduction +------------ + +The most obvious aspect of pathname lookup, which very little +exploration is needed to discover, is that it is complex. There are +many rules, special cases, and implementation alternatives that all +combine to confuse the unwary reader. Computer science has long been +acquainted with such complexity and has tools to help manage it. One +tool that we will make extensive use of is "divide and conquer". For +the early parts of the analysis we will divide off symlinks - leaving +them until the final part. Well before we get to symlinks we have +another major division based on the VFS's approach to locking which +will allow us to review "REF-walk" and "RCU-walk" separately. But we +are getting ahead of ourselves. There are some important low level +distinctions we need to clarify first. + +There are two sorts of ... +-------------------------- + +[`openat()`]: http://man7.org/linux/man-pages/man2/openat.2.html + +Pathnames (sometimes "file names"), used to identify objects in the +filesystem, will be familiar to most readers. They contain two sorts +of elements: "slashes" that are sequences of one or more "`/`" +characters, and "components" that are sequences of one or more +non-"`/`" characters. These form two kinds of paths. Those that +start with slashes are "absolute" and start from the filesystem root. +The others are "relative" and start from the current directory, or +from some other location specified by a file descriptor given to a +"xxx`at`" system call such as "[`openat()`]". + +[`execveat()`]: http://man7.org/linux/man-pages/man2/execveat.2.html + +It is tempting to describe the second kind as starting with a +component, but that isn't always accurate: a pathname can lack both +slashes and components, it can be empty, in other words. This is +generally forbidden in POSIX, but some of those "xxx`at`" system calls +in Linux permit it when the `AT_EMPTY_PATH` flag is given. For +example, if you have an open file descriptor on an executable file you +can execute it by calling [`execveat()`] passing the file descriptor, +an empty path, and the `AT_EMPTY_PATH` flag. + +These paths can be divided into two sections: the final component and +everything else. The "everything else" is the easy bit. In all cases +it must identify a directory that already exists, otherwise an error +such as `ENOENT` or `ENOTDIR` will be reported. + +The final component is not so simple. Not only do different system +calls interpret it quite differently (e.g. some create it, some do +not), but it might not even exist: neither the empty pathname nor the +pathname that is just slashes have a final component. If it does +exist, it could be "`.`" or "`..`" which are handled quite differently +from other components. + +[POSIX]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_12 + +If a pathname ends with a slash, such as "`/tmp/foo/`" it might be +tempting to consider that to have an empty final component. In many +ways that would lead to correct results, but not always. In +particular, `mkdir()` and `rmdir()` each create or remove a directory named +by the final component, and they are required to work with pathnames +ending in "`/`". According to [POSIX] + +> A pathname that contains at least one non- <slash> character and +> that ends with one or more trailing <slash> characters shall not +> be resolved successfully unless the last pathname component before +> the trailing <slash> characters names an existing directory or a +> directory entry that is to be created for a directory immediately +> after the pathname is resolved. + +The Linux pathname walking code (mostly in `fs/namei.c`) deals with +all of these issues: breaking the path into components, handling the +"everything else" quite separately from the final component, and +checking that the trailing slash is not used where it isn't +permitted. It also addresses the important issue of concurrent +access. + +While one process is looking up a pathname, another might be making +changes that affect that lookup. One fairly extreme case is that if +"a/b" were renamed to "a/c/b" while another process were looking up +"a/b/..", that process might successfully resolve on "a/c". +Most races are much more subtle, and a big part of the task of +pathname lookup is to prevent them from having damaging effects. Many +of the possible races are seen most clearly in the context of the +"dcache" and an understanding of that is central to understanding +pathname lookup. + +More than just a cache. +----------------------- + +The "dcache" caches information about names in each filesystem to +make them quickly available for lookup. Each entry (known as a +"dentry") contains three significant fields: a component name, a +pointer to a parent dentry, and a pointer to the "inode" which +contains further information about the object in that parent with +the given name. The inode pointer can be `NULL` indicating that the +name doesn't exist in the parent. While there can be linkage in the +dentry of a directory to the dentries of the children, that linkage is +not used for pathname lookup, and so will not be considered here. + +The dcache has a number of uses apart from accelerating lookup. One +that will be particularly relevant is that it is closely integrated +with the mount table that records which filesystem is mounted where. +What the mount table actually stores is which dentry is mounted on top +of which other dentry. + +When considering the dcache, we have another of our "two types" +distinctions: there are two types of filesystems. + +Some filesystems ensure that the information in the dcache is always +completely accurate (though not necessarily complete). This can allow +the VFS to determine if a particular file does or doesn't exist +without checking with the filesystem, and means that the VFS can +protect the filesystem against certain races and other problems. +These are typically "local" filesystems such as ext3, XFS, and Btrfs. + +Other filesystems don't provide that guarantee because they cannot. +These are typically filesystems that are shared across a network, +whether remote filesystems like NFS and 9P, or cluster filesystems +like ocfs2 or cephfs. These filesystems allow the VFS to revalidate +cached information, and must provide their own protection against +awkward races. The VFS can detect these filesystems by the +`DCACHE_OP_REVALIDATE` flag being set in the dentry. + +REF-walk: simple concurrency management with refcounts and spinlocks +-------------------------------------------------------------------- + +With all of those divisions carefully classified, we can now start +looking at the actual process of walking along a path. In particular +we will start with the handling of the "everything else" part of a +pathname, and focus on the "REF-walk" approach to concurrency +management. This code is found in the `link_path_walk()` function, if +you ignore all the places that only run when "`LOOKUP_RCU`" +(indicating the use of RCU-walk) is set. + +[Meet the Lockers]: https://lwn.net/Articles/453685/ + +REF-walk is fairly heavy-handed with locks and reference counts. Not +as heavy-handed as in the old "big kernel lock" days, but certainly not +afraid of taking a lock when one is needed. It uses a variety of +different concurrency controls. A background understanding of the +various primitives is assumed, or can be gleaned from elsewhere such +as in [Meet the Lockers]. + +The locking mechanisms used by REF-walk include: + +### dentry->d_lockref ### + +This uses the lockref primitive to provide both a spinlock and a +reference count. The special-sauce of this primitive is that the +conceptual sequence "lock; inc_ref; unlock;" can often be performed +with a single atomic memory operation. + +Holding a reference on a dentry ensures that the dentry won't suddenly +be freed and used for something else, so the values in various fields +will behave as expected. It also protects the `->d_inode` reference +to the inode to some extent. + +The association between a dentry and its inode is fairly permanent. +For example, when a file is renamed, the dentry and inode move +together to the new location. When a file is created the dentry will +initially be negative (i.e. `d_inode` is `NULL`), and will be assigned +to the new inode as part of the act of creation. + +When a file is deleted, this can be reflected in the cache either by +setting `d_inode` to `NULL`, or by removing it from the hash table +(described shortly) used to look up the name in the parent directory. +If the dentry is still in use the second option is used as it is +perfectly legal to keep using an open file after it has been deleted +and having the dentry around helps. If the dentry is not otherwise in +use (i.e. if the refcount in `d_lockref` is one), only then will +`d_inode` be set to `NULL`. Doing it this way is more efficient for a +very common case. + +So as long as a counted reference is held to a dentry, a non-`NULL` `->d_inode` +value will never be changed. + +### dentry->d_lock ### + +`d_lock` is a synonym for the spinlock that is part of `d_lockref` above. +For our purposes, holding this lock protects against the dentry being +renamed or unlinked. In particular, its parent (`d_parent`), and its +name (`d_name`) cannot be changed, and it cannot be removed from the +dentry hash table. + +When looking for a name in a directory, REF-walk takes `d_lock` on +each candidate dentry that it finds in the hash table and then checks +that the parent and name are correct. So it doesn't lock the parent +while searching in the cache; it only locks children. + +When looking for the parent for a given name (to handle "`..`"), +REF-walk can take `d_lock` to get a stable reference to `d_parent`, +but it first tries a more lightweight approach. As seen in +`dget_parent()`, if a reference can be claimed on the parent, and if +subsequently `d_parent` can be seen to have not changed, then there is +no need to actually take the lock on the child. + +### rename_lock ### + +Looking up a given name in a given directory involves computing a hash +from the two values (the name and the dentry of the directory), +accessing that slot in a hash table, and searching the linked list +that is found there. + +When a dentry is renamed, the name and the parent dentry can both +change so the hash will almost certainly change too. This would move the +dentry to a different chain in the hash table. If a filename search +happened to be looking at a dentry that was moved in this way, +it might end up continuing the search down the wrong chain, +and so miss out on part of the correct chain. + +The name-lookup process (`d_lookup()`) does _not_ try to prevent this +from happening, but only to detect when it happens. +`rename_lock` is a seqlock that is updated whenever any dentry is +renamed. If `d_lookup` finds that a rename happened while it +unsuccessfully scanned a chain in the hash table, it simply tries +again. + +### inode->i_mutex ### + +`i_mutex` is a mutex that serializes all changes to a particular +directory. This ensures that, for example, an `unlink()` and a `rename()` +cannot both happen at the same time. It also keeps the directory +stable while the filesystem is asked to look up a name that is not +currently in the dcache. + +This has a complementary role to that of `d_lock`: `i_mutex` on a +directory protects all of the names in that directory, while `d_lock` +on a name protects just one name in a directory. Most changes to the +dcache hold `i_mutex` on the relevant directory inode and briefly take +`d_lock` on one or more the dentries while the change happens. One +exception is when idle dentries are removed from the dcache due to +memory pressure. This uses `d_lock`, but `i_mutex` plays no role. + +The mutex affects pathname lookup in two distinct ways. Firstly it +serializes lookup of a name in a directory. `walk_component()` uses +`lookup_fast()` first which, in turn, checks to see if the name is in the cache, +using only `d_lock` locking. If the name isn't found, then `walk_component()` +falls back to `lookup_slow()` which takes `i_mutex`, checks again that +the name isn't in the cache, and then calls in to the filesystem to get a +definitive answer. A new dentry will be added to the cache regardless of +the result. + +Secondly, when pathname lookup reaches the final component, it will +sometimes need to take `i_mutex` before performing the last lookup so +that the required exclusion can be achieved. How path lookup chooses +to take, or not take, `i_mutex` is one of the +issues addressed in a subsequent section. + +### mnt->mnt_count ### + +`mnt_count` is a per-CPU reference counter on "`mount`" structures. +Per-CPU here means that incrementing the count is cheap as it only +uses CPU-local memory, but checking if the count is zero is expensive as +it needs to check with every CPU. Taking a `mnt_count` reference +prevents the mount structure from disappearing as the result of regular +unmount operations, but does not prevent a "lazy" unmount. So holding +`mnt_count` doesn't ensure that the mount remains in the namespace and, +in particular, doesn't stabilize the link to the mounted-on dentry. It +does, however, ensure that the `mount` data structure remains coherent, +and it provides a reference to the root dentry of the mounted +filesystem. So a reference through `->mnt_count` provides a stable +reference to the mounted dentry, but not the mounted-on dentry. + +### mount_lock ### + +`mount_lock` is a global seqlock, a bit like `rename_lock`. It can be used to +check if any change has been made to any mount points. + +While walking down the tree (away from the root) this lock is used when +crossing a mount point to check that the crossing was safe. That is, +the value in the seqlock is read, then the code finds the mount that +is mounted on the current directory, if there is one, and increments +the `mnt_count`. Finally the value in `mount_lock` is checked against +the old value. If there is no change, then the crossing was safe. If there +was a change, the `mnt_count` is decremented and the whole process is +retried. + +When walking up the tree (towards the root) by following a ".." link, +a little more care is needed. In this case the seqlock (which +contains both a counter and a spinlock) is fully locked to prevent +any changes to any mount points while stepping up. This locking is +needed to stabilize the link to the mounted-on dentry, which the +refcount on the mount itself doesn't ensure. + +### RCU ### + +Finally the global (but extremely lightweight) RCU read lock is held +from time to time to ensure certain data structures don't get freed +unexpectedly. + +In particular it is held while scanning chains in the dcache hash +table, and the mount point hash table. + +Bringing it together with `struct nameidata` +-------------------------------------------- + +[First edition Unix]: http://minnie.tuhs.org/cgi-bin/utree.pl?file=V1/u2.s + +Throughout the process of walking a path, the current status is stored +in a `struct nameidata`, "namei" being the traditional name - dating +all the way back to [First Edition Unix] - of the function that +converts a "name" to an "inode". `struct nameidata` contains (among +other fields): + +### `struct path path` ### + +A `path` contains a `struct vfsmount` (which is +embedded in a `struct mount`) and a `struct dentry`. Together these +record the current status of the walk. They start out referring to the +starting point (the current working directory, the root directory, or some other +directory identified by a file descriptor), and are updated on each +step. A reference through `d_lockref` and `mnt_count` is always +held. + +### `struct qstr last` ### + +This is a string together with a length (i.e. _not_ `nul` terminated) +that is the "next" component in the pathname. + +### `int last_type` ### + +This is one of `LAST_NORM`, `LAST_ROOT`, `LAST_DOT`, `LAST_DOTDOT`, or +`LAST_BIND`. The `last` field is only valid if the type is +`LAST_NORM`. `LAST_BIND` is used when following a symlink and no +components of the symlink have been processed yet. Others should be +fairly self-explanatory. + +### `struct path root` ### + +This is used to hold a reference to the effective root of the +filesystem. Often that reference won't be needed, so this field is +only assigned the first time it is used, or when a non-standard root +is requested. Keeping a reference in the `nameidata` ensures that +only one root is in effect for the entire path walk, even if it races +with a `chroot()` system call. + +The root is needed when either of two conditions holds: (1) either the +pathname or a symbolic link starts with a "'/'", or (2) a "`..`" +component is being handled, since "`..`" from the root must always stay +at the root. The value used is usually the current root directory of +the calling process. An alternate root can be provided as when +`sysctl()` calls `file_open_root()`, and when NFSv4 or Btrfs call +`mount_subtree()`. In each case a pathname is being looked up in a very +specific part of the filesystem, and the lookup must not be allowed to +escape that subtree. It works a bit like a local `chroot()`. + +Ignoring the handling of symbolic links, we can now describe the +"`link_path_walk()`" function, which handles the lookup of everything +except the final component as: + +> Given a path (`name`) and a nameidata structure (`nd`), check that the +> current directory has execute permission and then advance `name` +> over one component while updating `last_type` and `last`. If that +> was the final component, then return, otherwise call +> `walk_component()` and repeat from the top. + +`walk_component()` is even easier. If the component is `LAST_DOTS`, +it calls `handle_dots()` which does the necessary locking as already +described. If it finds a `LAST_NORM` component it first calls +"`lookup_fast()`" which only looks in the dcache, but will ask the +filesystem to revalidate the result if it is that sort of filesystem. +If that doesn't get a good result, it calls "`lookup_slow()`" which +takes the `i_mutex`, rechecks the cache, and then asks the filesystem +to find a definitive answer. Each of these will call +`follow_managed()` (as described below) to handle any mount points. + +In the absence of symbolic links, `walk_component()` creates a new +`struct path` containing a counted reference to the new dentry and a +reference to the new `vfsmount` which is only counted if it is +different from the previous `vfsmount`. It then calls +`path_to_nameidata()` to install the new `struct path` in the +`struct nameidata` and drop the unneeded references. + +This "hand-over-hand" sequencing of getting a reference to the new +dentry before dropping the reference to the previous dentry may +seem obvious, but is worth pointing out so that we will recognize its +analogue in the "RCU-walk" version. + +Handling the final component. +----------------------------- + +`link_path_walk()` only walks as far as setting `nd->last` and +`nd->last_type` to refer to the final component of the path. It does +not call `walk_component()` that last time. Handling that final +component remains for the caller to sort out. Those callers are +`path_lookupat()`, `path_parentat()`, `path_mountpoint()` and +`path_openat()` each of which handles the differing requirements of +different system calls. + +`path_parentat()` is clearly the simplest - it just wraps a little bit +of housekeeping around `link_path_walk()` and returns the parent +directory and final component to the caller. The caller will be either +aiming to create a name (via `filename_create()`) or remove or rename +a name (in which case `user_path_parent()` is used). They will use +`i_mutex` to exclude other changes while they validate and then +perform their operation. + +`path_lookupat()` is nearly as simple - it is used when an existing +object is wanted such as by `stat()` or `chmod()`. It essentially just +calls `walk_component()` on the final component through a call to +`lookup_last()`. `path_lookupat()` returns just the final dentry. + +`path_mountpoint()` handles the special case of unmounting which must +not try to revalidate the mounted filesystem. It effectively +contains, through a call to `mountpoint_last()`, an alternate +implementation of `lookup_slow()` which skips that step. This is +important when unmounting a filesystem that is inaccessible, such as +one provided by a dead NFS server. + +Finally `path_openat()` is used for the `open()` system call; it +contains, in support functions starting with "`do_last()`", all the +complexity needed to handle the different subtleties of O_CREAT (with +or without O_EXCL), final "`/`" characters, and trailing symbolic +links. We will revisit this in the final part of this series, which +focuses on those symbolic links. "`do_last()`" will sometimes, but +not always, take `i_mutex`, depending on what it finds. + +Each of these, or the functions which call them, need to be alert to +the possibility that the final component is not `LAST_NORM`. If the +goal of the lookup is to create something, then any value for +`last_type` other than `LAST_NORM` will result in an error. For +example if `path_parentat()` reports `LAST_DOTDOT`, then the caller +won't try to create that name. They also check for trailing slashes +by testing `last.name[last.len]`. If there is any character beyond +the final component, it must be a trailing slash. + +Revalidation and automounts +--------------------------- + +Apart from symbolic links, there are only two parts of the "REF-walk" +process not yet covered. One is the handling of stale cache entries +and the other is automounts. + +On filesystems that require it, the lookup routines will call the +`->d_revalidate()` dentry method to ensure that the cached information +is current. This will often confirm validity or update a few details +from a server. In some cases it may find that there has been change +further up the path and that something that was thought to be valid +previously isn't really. When this happens the lookup of the whole +path is aborted and retried with the "`LOOKUP_REVAL`" flag set. This +forces revalidation to be more thorough. We will see more details of +this retry process in the next article. + +Automount points are locations in the filesystem where an attempt to +lookup a name can trigger changes to how that lookup should be +handled, in particular by mounting a filesystem there. These are +covered in greater detail in autofs4.txt in the Linux documentation +tree, but a few notes specifically related to path lookup are in order +here. + +The Linux VFS has a concept of "managed" dentries which is reflected +in function names such as "`follow_managed()`". There are three +potentially interesting things about these dentries corresponding +to three different flags that might be set in `dentry->d_flags`: + +### `DCACHE_MANAGE_TRANSIT` ### + +If this flag has been set, then the filesystem has requested that the +`d_manage()` dentry operation be called before handling any possible +mount point. This can perform two particular services: + +It can block to avoid races. If an automount point is being +unmounted, the `d_manage()` function will usually wait for that +process to complete before letting the new lookup proceed and possibly +trigger a new automount. + +It can selectively allow only some processes to transit through a +mount point. When a server process is managing automounts, it may +need to access a directory without triggering normal automount +processing. That server process can identify itself to the `autofs` +filesystem, which will then give it a special pass through +`d_manage()` by returning `-EISDIR`. + +### `DCACHE_MOUNTED` ### + +This flag is set on every dentry that is mounted on. As Linux +supports multiple filesystem namespaces, it is possible that the +dentry may not be mounted on in *this* namespace, just in some +other. So this flag is seen as a hint, not a promise. + +If this flag is set, and `d_manage()` didn't return `-EISDIR`, +`lookup_mnt()` is called to examine the mount hash table (honoring the +`mount_lock` described earlier) and possibly return a new `vfsmount` +and a new `dentry` (both with counted references). + +### `DCACHE_NEED_AUTOMOUNT` ### + +If `d_manage()` allowed us to get this far, and `lookup_mnt()` didn't +find a mount point, then this flag causes the `d_automount()` dentry +operation to be called. + +The `d_automount()` operation can be arbitrarily complex and may +communicate with server processes etc. but it should ultimately either +report that there was an error, that there was nothing to mount, or +should provide an updated `struct path` with new `dentry` and `vfsmount`. + +In the latter case, `finish_automount()` will be called to safely +install the new mount point into the mount table. + +There is no new locking of import here and it is important that no +locks (only counted references) are held over this processing due to +the very real possibility of extended delays. +This will become more important next time when we examine RCU-walk +which is particularly sensitive to delays. + +RCU-walk - faster pathname lookup in Linux +========================================== + +RCU-walk is another algorithm for performing pathname lookup in Linux. +It is in many ways similar to REF-walk and the two share quite a bit +of code. The significant difference in RCU-walk is how it allows for +the possibility of concurrent access. + +We noted that REF-walk is complex because there are numerous details +and special cases. RCU-walk reduces this complexity by simply +refusing to handle a number of cases -- it instead falls back to +REF-walk. The difficulty with RCU-walk comes from a different +direction: unfamiliarity. The locking rules when depending on RCU are +quite different from traditional locking, so we will spend a little extra +time when we come to those. + +Clear demarcation of roles +-------------------------- + +The easiest way to manage concurrency is to forcibly stop any other +thread from changing the data structures that a given thread is +looking at. In cases where no other thread would even think of +changing the data and lots of different threads want to read at the +same time, this can be very costly. Even when using locks that permit +multiple concurrent readers, the simple act of updating the count of +the number of current readers can impose an unwanted cost. So the +goal when reading a shared data structure that no other process is +changing is to avoid writing anything to memory at all. Take no +locks, increment no counts, leave no footprints. + +The REF-walk mechanism already described certainly doesn't follow this +principle, but then it is really designed to work when there may well +be other threads modifying the data. RCU-walk, in contrast, is +designed for the common situation where there are lots of frequent +readers and only occasional writers. This may not be common in all +parts of the filesystem tree, but in many parts it will be. For the +other parts it is important that RCU-walk can quickly fall back to +using REF-walk. + +Pathname lookup always starts in RCU-walk mode but only remains there +as long as what it is looking for is in the cache and is stable. It +dances lightly down the cached filesystem image, leaving no footprints +and carefully watching where it is, to be sure it doesn't trip. If it +notices that something has changed or is changing, or if something +isn't in the cache, then it tries to stop gracefully and switch to +REF-walk. + +This stopping requires getting a counted reference on the current +`vfsmount` and `dentry`, and ensuring that these are still valid - +that a path walk with REF-walk would have found the same entries. +This is an invariant that RCU-walk must guarantee. It can only make +decisions, such as selecting the next step, that are decisions which +REF-walk could also have made if it were walking down the tree at the +same time. If the graceful stop succeeds, the rest of the path is +processed with the reliable, if slightly sluggish, REF-walk. If +RCU-walk finds it cannot stop gracefully, it simply gives up and +restarts from the top with REF-walk. + +This pattern of "try RCU-walk, if that fails try REF-walk" can be +clearly seen in functions like `filename_lookup()`, +`filename_parentat()`, `filename_mountpoint()`, +`do_filp_open()`, and `do_file_open_root()`. These five +correspond roughly to the four `path_`* functions we met earlier, +each of which calls `link_path_walk()`. The `path_*` functions are +called using different mode flags until a mode is found which works. +They are first called with `LOOKUP_RCU` set to request "RCU-walk". If +that fails with the error `ECHILD` they are called again with no +special flag to request "REF-walk". If either of those report the +error `ESTALE` a final attempt is made with `LOOKUP_REVAL` set (and no +`LOOKUP_RCU`) to ensure that entries found in the cache are forcibly +revalidated - normally entries are only revalidated if the filesystem +determines that they are too old to trust. + +The `LOOKUP_RCU` attempt may drop that flag internally and switch to +REF-walk, but will never then try to switch back to RCU-walk. Places +that trip up RCU-walk are much more likely to be near the leaves and +so it is very unlikely that there will be much, if any, benefit from +switching back. + +RCU and seqlocks: fast and light +-------------------------------- + +RCU is, unsurprisingly, critical to RCU-walk mode. The +`rcu_read_lock()` is held for the entire time that RCU-walk is walking +down a path. The particular guarantee it provides is that the key +data structures - dentries, inodes, super_blocks, and mounts - will +not be freed while the lock is held. They might be unlinked or +invalidated in one way or another, but the memory will not be +repurposed so values in various fields will still be meaningful. This +is the only guarantee that RCU provides; everything else is done using +seqlocks. + +As we saw above, REF-walk holds a counted reference to the current +dentry and the current vfsmount, and does not release those references +before taking references to the "next" dentry or vfsmount. It also +sometimes takes the `d_lock` spinlock. These references and locks are +taken to prevent certain changes from happening. RCU-walk must not +take those references or locks and so cannot prevent such changes. +Instead, it checks to see if a change has been made, and aborts or +retries if it has. + +To preserve the invariant mentioned above (that RCU-walk may only make +decisions that REF-walk could have made), it must make the checks at +or near the same places that REF-walk holds the references. So, when +REF-walk increments a reference count or takes a spinlock, RCU-walk +samples the status of a seqlock using `read_seqcount_begin()` or a +similar function. When REF-walk decrements the count or drops the +lock, RCU-walk checks if the sampled status is still valid using +`read_seqcount_retry()` or similar. + +However, there is a little bit more to seqlocks than that. If +RCU-walk accesses two different fields in a seqlock-protected +structure, or accesses the same field twice, there is no a priori +guarantee of any consistency between those accesses. When consistency +is needed - which it usually is - RCU-walk must take a copy and then +use `read_seqcount_retry()` to validate that copy. + +`read_seqcount_retry()` not only checks the sequence number, but also +imposes a memory barrier so that no memory-read instruction from +*before* the call can be delayed until *after* the call, either by the +CPU or by the compiler. A simple example of this can be seen in +`slow_dentry_cmp()` which, for filesystems which do not use simple +byte-wise name equality, calls into the filesystem to compare a name +against a dentry. The length and name pointer are copied into local +variables, then `read_seqcount_retry()` is called to confirm the two +are consistent, and only then is `->d_compare()` called. When +standard filename comparison is used, `dentry_cmp()` is called +instead. Notably it does _not_ use `read_seqcount_retry()`, but +instead has a large comment explaining why the consistency guarantee +isn't necessary. A subsequent `read_seqcount_retry()` will be +sufficient to catch any problem that could occur at this point. + +With that little refresher on seqlocks out of the way we can look at +the bigger picture of how RCU-walk uses seqlocks. + +### `mount_lock` and `nd->m_seq` ### + +We already met the `mount_lock` seqlock when REF-walk used it to +ensure that crossing a mount point is performed safely. RCU-walk uses +it for that too, but for quite a bit more. + +Instead of taking a counted reference to each `vfsmount` as it +descends the tree, RCU-walk samples the state of `mount_lock` at the +start of the walk and stores this initial sequence number in the +`struct nameidata` in the `m_seq` field. This one lock and one +sequence number are used to validate all accesses to all `vfsmounts`, +and all mount point crossings. As changes to the mount table are +relatively rare, it is reasonable to fall back on REF-walk any time +that any "mount" or "unmount" happens. + +`m_seq` is checked (using `read_seqretry()`) at the end of an RCU-walk +sequence, whether switching to REF-walk for the rest of the path or +when the end of the path is reached. It is also checked when stepping +down over a mount point (in `__follow_mount_rcu()`) or up (in +`follow_dotdot_rcu()`). If it is ever found to have changed, the +whole RCU-walk sequence is aborted and the path is processed again by +REF-walk. + +If RCU-walk finds that `mount_lock` hasn't changed then it can be sure +that, had REF-walk taken counted references on each vfsmount, the +results would have been the same. This ensures the invariant holds, +at least for vfsmount structures. + +### `dentry->d_seq` and `nd->seq`. ### + +In place of taking a count or lock on `d_reflock`, RCU-walk samples +the per-dentry `d_seq` seqlock, and stores the sequence number in the +`seq` field of the nameidata structure, so `nd->seq` should always be +the current sequence number of `nd->dentry`. This number needs to be +revalidated after copying, and before using, the name, parent, or +inode of the dentry. + +The handling of the name we have already looked at, and the parent is +only accessed in `follow_dotdot_rcu()` which fairly trivially follows +the required pattern, though it does so for three different cases. + +When not at a mount point, `d_parent` is followed and its `d_seq` is +collected. When we are at a mount point, we instead follow the +`mnt->mnt_mountpoint` link to get a new dentry and collect its +`d_seq`. Then, after finally finding a `d_parent` to follow, we must +check if we have landed on a mount point and, if so, must find that +mount point and follow the `mnt->mnt_root` link. This would imply a +somewhat unusual, but certainly possible, circumstance where the +starting point of the path lookup was in part of the filesystem that +was mounted on, and so not visible from the root. + +The inode pointer, stored in `->d_inode`, is a little more +interesting. The inode will always need to be accessed at least +twice, once to determine if it is NULL and once to verify access +permissions. Symlink handling requires a validated inode pointer too. +Rather than revalidating on each access, a copy is made on the first +access and it is stored in the `inode` field of `nameidata` from where +it can be safely accessed without further validation. + +`lookup_fast()` is the only lookup routine that is used in RCU-mode, +`lookup_slow()` being too slow and requiring locks. It is in +`lookup_fast()` that we find the important "hand over hand" tracking +of the current dentry. + +The current `dentry` and current `seq` number are passed to +`__d_lookup_rcu()` which, on success, returns a new `dentry` and a +new `seq` number. `lookup_fast()` then copies the inode pointer and +revalidates the new `seq` number. It then validates the old `dentry` +with the old `seq` number one last time and only then continues. This +process of getting the `seq` number of the new dentry and then +checking the `seq` number of the old exactly mirrors the process of +getting a counted reference to the new dentry before dropping that for +the old dentry which we saw in REF-walk. + +### No `inode->i_mutex` or even `rename_lock` ### + +A mutex is a fairly heavyweight lock that can only be taken when it is +permissible to sleep. As `rcu_read_lock()` forbids sleeping, +`inode->i_mutex` plays no role in RCU-walk. If some other thread does +take `i_mutex` and modifies the directory in a way that RCU-walk needs +to notice, the result will be either that RCU-walk fails to find the +dentry that it is looking for, or it will find a dentry which +`read_seqretry()` won't validate. In either case it will drop down to +REF-walk mode which can take whatever locks are needed. + +Though `rename_lock` could be used by RCU-walk as it doesn't require +any sleeping, RCU-walk doesn't bother. REF-walk uses `rename_lock` to +protect against the possibility of hash chains in the dcache changing +while they are being searched. This can result in failing to find +something that actually is there. When RCU-walk fails to find +something in the dentry cache, whether it is really there or not, it +already drops down to REF-walk and tries again with appropriate +locking. This neatly handles all cases, so adding extra checks on +rename_lock would bring no significant value. + +`unlazy walk()` and `complete_walk()` +------------------------------------- + +That "dropping down to REF-walk" typically involves a call to +`unlazy_walk()`, so named because "RCU-walk" is also sometimes +referred to as "lazy walk". `unlazy_walk()` is called when +following the path down to the current vfsmount/dentry pair seems to +have proceeded successfully, but the next step is problematic. This +can happen if the next name cannot be found in the dcache, if +permission checking or name revalidation couldn't be achieved while +the `rcu_read_lock()` is held (which forbids sleeping), if an +automount point is found, or in a couple of cases involving symlinks. +It is also called from `complete_walk()` when the lookup has reached +the final component, or the very end of the path, depending on which +particular flavor of lookup is used. + +Other reasons for dropping out of RCU-walk that do not trigger a call +to `unlazy_walk()` are when some inconsistency is found that cannot be +handled immediately, such as `mount_lock` or one of the `d_seq` +seqlocks reporting a change. In these cases the relevant function +will return `-ECHILD` which will percolate up until it triggers a new +attempt from the top using REF-walk. + +For those cases where `unlazy_walk()` is an option, it essentially +takes a reference on each of the pointers that it holds (vfsmount, +dentry, and possibly some symbolic links) and then verifies that the +relevant seqlocks have not been changed. If there have been changes, +it, too, aborts with `-ECHILD`, otherwise the transition to REF-walk +has been a success and the lookup process continues. + +Taking a reference on those pointers is not quite as simple as just +incrementing a counter. That works to take a second reference if you +already have one (often indirectly through another object), but it +isn't sufficient if you don't actually have a counted reference at +all. For `dentry->d_lockref`, it is safe to increment the reference +counter to get a reference unless it has been explicitly marked as +"dead" which involves setting the counter to `-128`. +`lockref_get_not_dead()` achieves this. + +For `mnt->mnt_count` it is safe to take a reference as long as +`mount_lock` is then used to validate the reference. If that +validation fails, it may *not* be safe to just drop that reference in +the standard way of calling `mnt_put()` - an unmount may have +progressed too far. So the code in `legitimize_mnt()`, when it +finds that the reference it got might not be safe, checks the +`MNT_SYNC_UMOUNT` flag to determine if a simple `mnt_put()` is +correct, or if it should just decrement the count and pretend none of +this ever happened. + +Taking care in filesystems +--------------------------- + +RCU-walk depends almost entirely on cached information and often will +not call into the filesystem at all. However there are two places, +besides the already-mentioned component-name comparison, where the +file system might be included in RCU-walk, and it must know to be +careful. + +If the filesystem has non-standard permission-checking requirements - +such as a networked filesystem which may need to check with the server +- the `i_op->permission` interface might be called during RCU-walk. +In this case an extra "`MAY_NOT_BLOCK`" flag is passed so that it +knows not to sleep, but to return `-ECHILD` if it cannot complete +promptly. `i_op->permission` is given the inode pointer, not the +dentry, so it doesn't need to worry about further consistency checks. +However if it accesses any other filesystem data structures, it must +ensure they are safe to be accessed with only the `rcu_read_lock()` +held. This typically means they must be freed using `kfree_rcu()` or +similar. + +[`READ_ONCE()`]: https://lwn.net/Articles/624126/ + +If the filesystem may need to revalidate dcache entries, then +`d_op->d_revalidate` may be called in RCU-walk too. This interface +*is* passed the dentry but does not have access to the `inode` or the +`seq` number from the `nameidata`, so it needs to be extra careful +when accessing fields in the dentry. This "extra care" typically +involves using `ACCESS_ONCE()` or the newer [`READ_ONCE()`] to access +fields, and verifying the result is not NULL before using it. This +pattern can be see in `nfs_lookup_revalidate()`. + +A pair of patterns +------------------ + +In various places in the details of REF-walk and RCU-walk, and also in +the big picture, there are a couple of related patterns that are worth +being aware of. + +The first is "try quickly and check, if that fails try slowly". We +can see that in the high-level approach of first trying RCU-walk and +then trying REF-walk, and in places where `unlazy_walk()` is used to +switch to REF-walk for the rest of the path. We also saw it earlier +in `dget_parent()` when following a "`..`" link. It tries a quick way +to get a reference, then falls back to taking locks if needed. + +The second pattern is "try quickly and check, if that fails try +again - repeatedly". This is seen with the use of `rename_lock` and +`mount_lock` in REF-walk. RCU-walk doesn't make use of this pattern - +if anything goes wrong it is much safer to just abort and try a more +sedate approach. + +The emphasis here is "try quickly and check". It should probably be +"try quickly _and carefully,_ then check". The fact that checking is +needed is a reminder that the system is dynamic and only a limited +number of things are safe at all. The most likely cause of errors in +this whole process is assuming something is safe when in reality it +isn't. Careful consideration of what exactly guarantees the safety of +each access is sometimes necessary. + +A walk among the symlinks +========================= + +There are several basic issues that we will examine to understand the +handling of symbolic links: the symlink stack, together with cache +lifetimes, will help us understand the overall recursive handling of +symlinks and lead to the special care needed for the final component. +Then a consideration of access-time updates and summary of the various +flags controlling lookup will finish the story. + +The symlink stack +----------------- + +There are only two sorts of filesystem objects that can usefully +appear in a path prior to the final component: directories and symlinks. +Handling directories is quite straightforward: the new directory +simply becomes the starting point at which to interpret the next +component on the path. Handling symbolic links requires a bit more +work. + +Conceptually, symbolic links could be handled by editing the path. If +a component name refers to a symbolic link, then that component is +replaced by the body of the link and, if that body starts with a '/', +then all preceding parts of the path are discarded. This is what the +"`readlink -f`" command does, though it also edits out "`.`" and +"`..`" components. + +Directly editing the path string is not really necessary when looking +up a path, and discarding early components is pointless as they aren't +looked at anyway. Keeping track of all remaining components is +important, but they can of course be kept separately; there is no need +to concatenate them. As one symlink may easily refer to another, +which in turn can refer to a third, we may need to keep the remaining +components of several paths, each to be processed when the preceding +ones are completed. These path remnants are kept on a stack of +limited size. + +There are two reasons for placing limits on how many symlinks can +occur in a single path lookup. The most obvious is to avoid loops. +If a symlink referred to itself either directly or through +intermediaries, then following the symlink can never complete +successfully - the error `ELOOP` must be returned. Loops can be +detected without imposing limits, but limits are the simplest solution +and, given the second reason for restriction, quite sufficient. + +[outlined recently]: http://thread.gmane.org/gmane.linux.kernel/1934390/focus=1934550 + +The second reason was [outlined recently] by Linus: + +> Because it's a latency and DoS issue too. We need to react well to +> true loops, but also to "very deep" non-loops. It's not about memory +> use, it's about users triggering unreasonable CPU resources. + +Linux imposes a limit on the length of any pathname: `PATH_MAX`, which +is 4096. There are a number of reasons for this limit; not letting the +kernel spend too much time on just one path is one of them. With +symbolic links you can effectively generate much longer paths so some +sort of limit is needed for the same reason. Linux imposes a limit of +at most 40 symlinks in any one path lookup. It previously imposed a +further limit of eight on the maximum depth of recursion, but that was +raised to 40 when a separate stack was implemented, so there is now +just the one limit. + +The `nameidata` structure that we met in an earlier article contains a +small stack that can be used to store the remaining part of up to two +symlinks. In many cases this will be sufficient. If it isn't, a +separate stack is allocated with room for 40 symlinks. Pathname +lookup will never exceed that stack as, once the 40th symlink is +detected, an error is returned. + +It might seem that the name remnants are all that needs to be stored on +this stack, but we need a bit more. To see that, we need to move on to +cache lifetimes. + +Storage and lifetime of cached symlinks +--------------------------------------- + +Like other filesystem resources, such as inodes and directory +entries, symlinks are cached by Linux to avoid repeated costly access +to external storage. It is particularly important for RCU-walk to be +able to find and temporarily hold onto these cached entries, so that +it doesn't need to drop down into REF-walk. + +[object-oriented design pattern]: https://lwn.net/Articles/446317/ + +While each filesystem is free to make its own choice, symlinks are +typically stored in one of two places. Short symlinks are often +stored directly in the inode. When a filesystem allocates a `struct +inode` it typically allocates extra space to store private data (a +common [object-oriented design pattern] in the kernel). This will +sometimes include space for a symlink. The other common location is +in the page cache, which normally stores the content of files. The +pathname in a symlink can be seen as the content of that symlink and +can easily be stored in the page cache just like file content. + +When neither of these is suitable, the next most likely scenario is +that the filesystem will allocate some temporary memory and copy or +construct the symlink content into that memory whenever it is needed. + +When the symlink is stored in the inode, it has the same lifetime as +the inode which, itself, is protected by RCU or by a counted reference +on the dentry. This means that the mechanisms that pathname lookup +uses to access the dcache and icache (inode cache) safely are quite +sufficient for accessing some cached symlinks safely. In these cases, +the `i_link` pointer in the inode is set to point to wherever the +symlink is stored and it can be accessed directly whenever needed. + +When the symlink is stored in the page cache or elsewhere, the +situation is not so straightforward. A reference on a dentry or even +on an inode does not imply any reference on cached pages of that +inode, and even an `rcu_read_lock()` is not sufficient to ensure that +a page will not disappear. So for these symlinks the pathname lookup +code needs to ask the filesystem to provide a stable reference and, +significantly, needs to release that reference when it is finished +with it. + +Taking a reference to a cache page is often possible even in RCU-walk +mode. It does require making changes to memory, which is best avoided, +but that isn't necessarily a big cost and it is better than dropping +out of RCU-walk mode completely. Even filesystems that allocate +space to copy the symlink into can use `GFP_ATOMIC` to often successfully +allocate memory without the need to drop out of RCU-walk. If a +filesystem cannot successfully get a reference in RCU-walk mode, it +must return `-ECHILD` and `unlazy_walk()` will be called to return to +REF-walk mode in which the filesystem is allowed to sleep. + +The place for all this to happen is the `i_op->follow_link()` inode +method. In the present mainline code this is never actually called in +RCU-walk mode as the rewrite is not quite complete. It is likely that +in a future release this method will be passed an `inode` pointer when +called in RCU-walk mode so it both (1) knows to be careful, and (2) has the +validated pointer. Much like the `i_op->permission()` method we +looked at previously, `->follow_link()` would need to be careful that +all the data structures it references are safe to be accessed while +holding no counted reference, only the RCU lock. Though getting a +reference with `->follow_link()` is not yet done in RCU-walk mode, the +code is ready to release the reference when that does happen. + +This need to drop the reference to a symlink adds significant +complexity. It requires a reference to the inode so that the +`i_op->put_link()` inode operation can be called. In REF-walk, that +reference is kept implicitly through a reference to the dentry, so +keeping the `struct path` of the symlink is easiest. For RCU-walk, +the pointer to the inode is kept separately. To allow switching from +RCU-walk back to REF-walk in the middle of processing nested symlinks +we also need the seq number for the dentry so we can confirm that +switching back was safe. + +Finally, when providing a reference to a symlink, the filesystem also +provides an opaque "cookie" that must be passed to `->put_link()` so that it +knows what to free. This might be the allocated memory area, or a +pointer to the `struct page` in the page cache, or something else +completely. Only the filesystem knows what it is. + +In order for the reference to each symlink to be dropped when the walk completes, +whether in RCU-walk or REF-walk, the symlink stack needs to contain, +along with the path remnants: + +- the `struct path` to provide a reference to the inode in REF-walk +- the `struct inode *` to provide a reference to the inode in RCU-walk +- the `seq` to allow the path to be safely switched from RCU-walk to REF-walk +- the `cookie` that tells `->put_path()` what to put. + +This means that each entry in the symlink stack needs to hold five +pointers and an integer instead of just one pointer (the path +remnant). On a 64-bit system, this is about 40 bytes per entry; +with 40 entries it adds up to 1600 bytes total, which is less than +half a page. So it might seem like a lot, but is by no means +excessive. + +Note that, in a given stack frame, the path remnant (`name`) is not +part of the symlink that the other fields refer to. It is the remnant +to be followed once that symlink has been fully parsed. + +Following the symlink +--------------------- + +The main loop in `link_path_walk()` iterates seamlessly over all +components in the path and all of the non-final symlinks. As symlinks +are processed, the `name` pointer is adjusted to point to a new +symlink, or is restored from the stack, so that much of the loop +doesn't need to notice. Getting this `name` variable on and off the +stack is very straightforward; pushing and popping the references is +a little more complex. + +When a symlink is found, `walk_component()` returns the value `1` +(`0` is returned for any other sort of success, and a negative number +is, as usual, an error indicator). This causes `get_link()` to be +called; it then gets the link from the filesystem. Providing that +operation is successful, the old path `name` is placed on the stack, +and the new value is used as the `name` for a while. When the end of +the path is found (i.e. `*name` is `'\0'`) the old `name` is restored +off the stack and path walking continues. + +Pushing and popping the reference pointers (inode, cookie, etc.) is more +complex in part because of the desire to handle tail recursion. When +the last component of a symlink itself points to a symlink, we +want to pop the symlink-just-completed off the stack before pushing +the symlink-just-found to avoid leaving empty path remnants that would +just get in the way. + +It is most convenient to push the new symlink references onto the +stack in `walk_component()` immediately when the symlink is found; +`walk_component()` is also the last piece of code that needs to look at the +old symlink as it walks that last component. So it is quite +convenient for `walk_component()` to release the old symlink and pop +the references just before pushing the reference information for the +new symlink. It is guided in this by two flags; `WALK_GET`, which +gives it permission to follow a symlink if it finds one, and +`WALK_PUT`, which tells it to release the current symlink after it has been +followed. `WALK_PUT` is tested first, leading to a call to +`put_link()`. `WALK_GET` is tested subsequently (by +`should_follow_link()`) leading to a call to `pick_link()` which sets +up the stack frame. + +### Symlinks with no final component ### + +A pair of special-case symlinks deserve a little further explanation. +Both result in a new `struct path` (with mount and dentry) being set +up in the `nameidata`, and result in `get_link()` returning `NULL`. + +The more obvious case is a symlink to "`/`". All symlinks starting +with "`/`" are detected in `get_link()` which resets the `nameidata` +to point to the effective filesystem root. If the symlink only +contains "`/`" then there is nothing more to do, no components at all, +so `NULL` is returned to indicate that the symlink can be released and +the stack frame discarded. + +The other case involves things in `/proc` that look like symlinks but +aren't really. + +> $ ls -l /proc/self/fd/1 +> lrwx------ 1 neilb neilb 64 Jun 13 10:19 /proc/self/fd/1 -> /dev/pts/4 + +Every open file descriptor in any process is represented in `/proc` by +something that looks like a symlink. It is really a reference to the +target file, not just the name of it. When you `readlink` these +objects you get a name that might refer to the same file - unless it +has been unlinked or mounted over. When `walk_component()` follows +one of these, the `->follow_link()` method in "procfs" doesn't return +a string name, but instead calls `nd_jump_link()` which updates the +`nameidata` in place to point to that target. `->follow_link()` then +returns `NULL`. Again there is no final component and `get_link()` +reports this by leaving the `last_type` field of `nameidata` as +`LAST_BIND`. + +Following the symlink in the final component +-------------------------------------------- + +All this leads to `link_path_walk()` walking down every component, and +following all symbolic links it finds, until it reaches the final +component. This is just returned in the `last` field of `nameidata`. +For some callers, this is all they need; they want to create that +`last` name if it doesn't exist or give an error if it does. Other +callers will want to follow a symlink if one is found, and possibly +apply special handling to the last component of that symlink, rather +than just the last component of the original file name. These callers +potentially need to call `link_path_walk()` again and again on +successive symlinks until one is found that doesn't point to another +symlink. + +This case is handled by the relevant caller of `link_path_walk()`, such as +`path_lookupat()` using a loop that calls `link_path_walk()`, and then +handles the final component. If the final component is a symlink +that needs to be followed, then `trailing_symlink()` is called to set +things up properly and the loop repeats, calling `link_path_walk()` +again. This could loop as many as 40 times if the last component of +each symlink is another symlink. + +The various functions that examine the final component and possibly +report that it is a symlink are `lookup_last()`, `mountpoint_last()` +and `do_last()`, each of which use the same convention as +`walk_component()` of returning `1` if a symlink was found that needs +to be followed. + +Of these, `do_last()` is the most interesting as it is used for +opening a file. Part of `do_last()` runs with `i_mutex` held and this +part is in a separate function: `lookup_open()`. + +Explaining `do_last()` completely is beyond the scope of this article, +but a few highlights should help those interested in exploring the +code. + +1. Rather than just finding the target file, `do_last()` needs to open + it. If the file was found in the dcache, then `vfs_open()` is used for + this. If not, then `lookup_open()` will either call `atomic_open()` (if + the filesystem provides it) to combine the final lookup with the open, or + will perform the separate `lookup_real()` and `vfs_create()` steps + directly. In the later case the actual "open" of this newly found or + created file will be performed by `vfs_open()`, just as if the name + were found in the dcache. + +2. `vfs_open()` can fail with `-EOPENSTALE` if the cached information + wasn't quite current enough. Rather than restarting the lookup from + the top with `LOOKUP_REVAL` set, `lookup_open()` is called instead, + giving the filesystem a chance to resolve small inconsistencies. + If that doesn't work, only then is the lookup restarted from the top. + +3. An open with O_CREAT **does** follow a symlink in the final component, + unlike other creation system calls (like `mkdir`). So the sequence: + + > ln -s bar /tmp/foo + > echo hello > /tmp/foo + + will create a file called `/tmp/bar`. This is not permitted if + `O_EXCL` is set but otherwise is handled for an O_CREAT open much + like for a non-creating open: `should_follow_link()` returns `1`, and + so does `do_last()` so that `trailing_symlink()` gets called and the + open process continues on the symlink that was found. + +Updating the access time +------------------------ + +We previously said of RCU-walk that it would "take no locks, increment +no counts, leave no footprints." We have since seen that some +"footprints" can be needed when handling symlinks as a counted +reference (or even a memory allocation) may be needed. But these +footprints are best kept to a minimum. + +One other place where walking down a symlink can involve leaving +footprints in a way that doesn't affect directories is in updating access times. +In Unix (and Linux) every filesystem object has a "last accessed +time", or "`atime`". Passing through a directory to access a file +within is not considered to be an access for the purposes of +`atime`; only listing the contents of a directory can update its `atime`. +Symlinks are different it seems. Both reading a symlink (with `readlink()`) +and looking up a symlink on the way to some other destination can +update the atime on that symlink. + +[clearest statement]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_08 + +It is not clear why this is the case; POSIX has little to say on the +subject. The [clearest statement] is that, if a particular implementation +updates a timestamp in a place not specified by POSIX, this must be +documented "except that any changes caused by pathname resolution need +not be documented". This seems to imply that POSIX doesn't really +care about access-time updates during pathname lookup. + +[Linux 1.3.87]: https://git.kernel.org/cgit/linux/kernel/git/history/history.git/diff/fs/ext2/symlink.c?id=f806c6db77b8eaa6e00dcfb6b567706feae8dbb8 + +An examination of history shows that prior to [Linux 1.3.87], the ext2 +filesystem, at least, didn't update atime when following a link. +Unfortunately we have no record of why that behavior was changed. + +In any case, access time must now be updated and that operation can be +quite complex. Trying to stay in RCU-walk while doing it is best +avoided. Fortunately it is often permitted to skip the `atime` +update. Because `atime` updates cause performance problems in various +areas, Linux supports the `relatime` mount option, which generally +limits the updates of `atime` to once per day on files that aren't +being changed (and symlinks never change once created). Even without +`relatime`, many filesystems record `atime` with a one-second +granularity, so only one update per second is required. + +It is easy to test if an `atime` update is needed while in RCU-walk +mode and, if it isn't, the update can be skipped and RCU-walk mode +continues. Only when an `atime` update is actually required does the +path walk drop down to REF-walk. All of this is handled in the +`get_link()` function. + +A few flags +----------- + +A suitable way to wrap up this tour of pathname walking is to list +the various flags that can be stored in the `nameidata` to guide the +lookup process. Many of these are only meaningful on the final +component, others reflect the current state of the pathname lookup. +And then there is `LOOKUP_EMPTY`, which doesn't fit conceptually with +the others. If this is not set, an empty pathname causes an error +very early on. If it is set, empty pathnames are not considered to be +an error. + +### Global state flags ### + +We have already met two global state flags: `LOOKUP_RCU` and +`LOOKUP_REVAL`. These select between one of three overall approaches +to lookup: RCU-walk, REF-walk, and REF-walk with forced revalidation. + +`LOOKUP_PARENT` indicates that the final component hasn't been reached +yet. This is primarily used to tell the audit subsystem the full +context of a particular access being audited. + +`LOOKUP_ROOT` indicates that the `root` field in the `nameidata` was +provided by the caller, so it shouldn't be released when it is no +longer needed. + +`LOOKUP_JUMPED` means that the current dentry was chosen not because +it had the right name but for some other reason. This happens when +following "`..`", following a symlink to `/`, crossing a mount point +or accessing a "`/proc/$PID/fd/$FD`" symlink. In this case the +filesystem has not been asked to revalidate the name (with +`d_revalidate()`). In such cases the inode may still need to be +revalidated, so `d_op->d_weak_revalidate()` is called if +`LOOKUP_JUMPED` is set when the look completes - which may be at the +final component or, when creating, unlinking, or renaming, at the penultimate component. + +### Final-component flags ### + +Some of these flags are only set when the final component is being +considered. Others are only checked for when considering that final +component. + +`LOOKUP_AUTOMOUNT` ensures that, if the final component is an automount +point, then the mount is triggered. Some operations would trigger it +anyway, but operations like `stat()` deliberately don't. `statfs()` +needs to trigger the mount but otherwise behaves a lot like `stat()`, so +it sets `LOOKUP_AUTOMOUNT`, as does "`quotactl()`" and the handling of +"`mount --bind`". + +`LOOKUP_FOLLOW` has a similar function to `LOOKUP_AUTOMOUNT` but for +symlinks. Some system calls set or clear it implicitly, while +others have API flags such as `AT_SYMLINK_FOLLOW` and +`UMOUNT_NOFOLLOW` to control it. Its effect is similar to +`WALK_GET` that we already met, but it is used in a different way. + +`LOOKUP_DIRECTORY` insists that the final component is a directory. +Various callers set this and it is also set when the final component +is found to be followed by a slash. + +Finally `LOOKUP_OPEN`, `LOOKUP_CREATE`, `LOOKUP_EXCL`, and +`LOOKUP_RENAME_TARGET` are not used directly by the VFS but are made +available to the filesystem and particularly the `->d_revalidate()` +method. A filesystem can choose not to bother revalidating too hard +if it knows that it will be asked to open or create the file soon. +These flags were previously useful for `->lookup()` too but with the +introduction of `->atomic_open()` they are less relevant there. + +End of the road +--------------- + +Despite its complexity, all this pathname lookup code appears to be +in good shape - various parts are certainly easier to understand now +than even a couple of releases ago. But that doesn't mean it is +"finished". As already mentioned, RCU-walk currently only follows +symlinks that are stored in the inode so, while it handles many ext4 +symlinks, it doesn't help with NFS, XFS, or Btrfs. That support +is not likely to be long delayed. diff --git a/Documentation/filesystems/path-lookup.txt b/Documentation/filesystems/path-lookup.txt index 3571667c7105..9b8930f589d9 100644 --- a/Documentation/filesystems/path-lookup.txt +++ b/Documentation/filesystems/path-lookup.txt @@ -379,4 +379,4 @@ Papers and other documentation on dcache locking 2. http://lse.sourceforge.net/locking/dcache/dcache.html - +3. path-lookup.md in this directory. diff --git a/Documentation/filesystems/sysfs-tagging.txt b/Documentation/filesystems/sysfs-tagging.txt index eb843e49c5a3..c7c8e6438958 100644 --- a/Documentation/filesystems/sysfs-tagging.txt +++ b/Documentation/filesystems/sysfs-tagging.txt @@ -17,13 +17,13 @@ the sysfs directory entries we ensure that we don't have conflicts in the directories and applications only see a limited set of the network devices. -Each sysfs directory entry may be tagged with zero or one -namespaces. A sysfs_dirent is augmented with a void *s_ns. If a -directory entry is tagged, then sysfs_dirent->s_flags will have a -flag between KOBJ_NS_TYPE_NONE and KOBJ_NS_TYPES, and s_ns will -point to the namespace to which it belongs. +Each sysfs directory entry may be tagged with a namespace via the +void *ns member of its kernfs_node. If a directory entry is tagged, +then kernfs_node->flags will have a flag between KOBJ_NS_TYPE_NONE +and KOBJ_NS_TYPES, and ns will point to the namespace to which it +belongs. -Each sysfs superblock's sysfs_super_info contains an array void +Each sysfs superblock's kernfs_super_info contains an array void *ns[KOBJ_NS_TYPES]. When a task in a tagging namespace kobj_nstype first mounts sysfs, a new superblock is created. It will be differentiated from other sysfs mounts by having its @@ -31,7 +31,7 @@ s_fs_info->ns[kobj_nstype] set to the new namespace. Note that through bind mounting and mounts propagation, a task can easily view the contents of other namespaces' sysfs mounts. Therefore, when a namespace exits, it will call kobj_ns_exit() to invalidate any -sysfs_dirent->s_ns pointers pointing to it. +kernfs_node->ns pointers pointing to it. Users of this interface: - define a type in the kobj_ns_type enumeration. diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index 9494afb9476a..24da7b32c489 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -40,7 +40,7 @@ ancestors of object hierarchies; i.e. the subsystems the objects belong to. Sysfs internally stores a pointer to the kobject that implements a -directory in the sysfs_dirent object associated with the directory. In +directory in the kernfs_node object associated with the directory. In the past this kobject pointer has been used by sysfs to do reference counting directly on the kobject whenever the file is opened or closed. With the current sysfs implementation the kobject reference count is @@ -191,9 +191,10 @@ implementations: be called again, rearmed, to fill the buffer. - On write(2), sysfs expects the entire buffer to be passed during the - first write. Sysfs then passes the entire buffer to the store() - method. - + first write. Sysfs then passes the entire buffer to the store() method. + A terminating null is added after the data on stores. This makes + functions like sysfs_streq() safe to use. + When writing sysfs files, userspace processes should first read the entire file, modify the values it wishes to change, then write the entire buffer back. diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt index f59c43b6411b..3092178628c4 100644 --- a/Documentation/gpio/board.txt +++ b/Documentation/gpio/board.txt @@ -21,8 +21,8 @@ exact way to do it depends on the GPIO controller providing the GPIOs, see the device tree bindings for your controller. GPIOs mappings are defined in the consumer device's node, in a property named -either <function>-gpios or <function>-gpio, where <function> is the function -the driver will request through gpiod_get(). For example: +<function>-gpios, where <function> is the function the driver will request +through gpiod_get(). For example: foo_device { compatible = "acme,foo"; @@ -31,9 +31,13 @@ the driver will request through gpiod_get(). For example: <&gpio 16 GPIO_ACTIVE_HIGH>, /* green */ <&gpio 17 GPIO_ACTIVE_HIGH>; /* blue */ - power-gpio = <&gpio 1 GPIO_ACTIVE_LOW>; + power-gpios = <&gpio 1 GPIO_ACTIVE_LOW>; }; +Properties named <function>-gpio are also considered valid and old bindings use +it but are only supported for compatibility reasons and should not be used for +newer bindings since it has been deprecated. + This property will make GPIOs 15, 16 and 17 available to the driver under the "led" function, and GPIO 1 as the "power" GPIO: diff --git a/Documentation/gpio/sysfs.txt b/Documentation/gpio/sysfs.txt index 0700b55637f5..aeab01aa4d00 100644 --- a/Documentation/gpio/sysfs.txt +++ b/Documentation/gpio/sysfs.txt @@ -20,14 +20,14 @@ userspace GPIO can be used to determine system configuration data that standard kernels won't know about. And for some tasks, simple userspace GPIO drivers could be all that the system really needs. -DO NOT ABUSE SYFS TO CONTROL HARDWARE THAT HAS PROPER KERNEL DRIVERS. +DO NOT ABUSE SYSFS TO CONTROL HARDWARE THAT HAS PROPER KERNEL DRIVERS. PLEASE READ THE DOCUMENT NAMED "drivers-on-gpio.txt" IN THIS DOCUMENTATION DIRECTORY TO AVOID REINVENTING KERNEL WHEELS IN USERSPACE. I MEAN IT. REALLY. Paths in Sysfs -------------- -There are three kinds of entry in /sys/class/gpio: +There are three kinds of entries in /sys/class/gpio: - Control interfaces used to get userspace control over GPIOs; @@ -106,7 +106,7 @@ read-only attributes: "label" ... provided for diagnostics (not always unique) - "ngpio" ... how many GPIOs this manges (N to N + ngpio - 1) + "ngpio" ... how many GPIOs this manages (N to N + ngpio - 1) Board documentation should in most cases cover what GPIOs are used for what purposes. However, those numbers are not always stable; GPIOs on diff --git a/Documentation/kernel-docs.txt b/Documentation/kernel-docs.txt index eda1eb1451a0..08913361e054 100644 --- a/Documentation/kernel-docs.txt +++ b/Documentation/kernel-docs.txt @@ -696,18 +696,18 @@ Memory related patches, HOWTOs, links, mm developers... Don't miss it if you are interested in memory management development! - * Name: "Kernel Newbies IRC Channel" + * Name: "Kernel Newbies IRC Channel and Website" URL: http://www.kernelnewbies.org Keywords: IRC, newbies, channel, asking doubts. - Description: #kernelnewbies on irc.openprojects.net. From the web - page: "#kernelnewbies is an IRC network dedicated to the 'newbie' + Description: #kernelnewbies on irc.oftc.net. + #kernelnewbies is an IRC network dedicated to the 'newbie' kernel hacker. The audience mostly consists of people who are learning about the kernel, working on kernel projects or professional kernel hackers that want to help less seasoned kernel - people. [...] #kernelnewbies is on the Open Projects IRC Network, - try irc.openprojects.net or irc.<country>.openprojects.net as your - server and then /join #kernelnewbies". It also hosts articles, - documents, FAQs... + people. + #kernelnewbies is on the OFTC IRC Network. + Try irc.oftc.net as your server and then /join #kernelnewbies. + The kernelnewbies website also hosts articles, documents, FAQs... * Name: "linux-kernel mailing list archives and search engines" URL: http://vger.kernel.org/vger-lists.html diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 0231f4508abe..84c0214b64a7 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -790,8 +790,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. is passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb - requires at least 64M+32K low memory. Kernel would - try to allocate 72M below 4G automatically. + requires at least 64M+32K low memory, also enough extra + low memory is needed to make sure DMA buffers for 32-bit + devices won't run out. Kernel would try to allocate at + at least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. @@ -972,6 +974,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. earlycon= [KNL] Output early console device and options. + When used with no options, the early console is + determined by the stdout-path property in device + tree's chosen node. + cdns,<addr> Start an early, polled-mode console on a cadence serial port at the specified address. The cadence serial port @@ -1584,6 +1590,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nosid disable Source ID checking no_x2apic_optout BIOS x2APIC opt-out request will be ignored + nopost disable Interrupt Posting iomem= Disable strict checking of access to MMIO memory strict regions from userspace. @@ -2345,11 +2352,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels Format: [panic,][nopanic,][num] Valid num: 0 or 1 - 0 - turn nmi_watchdog off - 1 - turn nmi_watchdog on + 0 - turn hardlockup detector in nmi_watchdog off + 1 - turn hardlockup detector in nmi_watchdog on When panic is specified, panic when an NMI watchdog timeout occurs (or 'nopanic' to override the opposite - default). + default). To disable both hard and soft lockup detectors, + please see 'nowatchdog'. This is useful when you use a panic=... timeout and need the box quickly up again. diff --git a/Documentation/kselftest.txt b/Documentation/kselftest.txt index a87d840bacfe..9bbbcdc598d9 100644 --- a/Documentation/kselftest.txt +++ b/Documentation/kselftest.txt @@ -54,6 +54,22 @@ To run the hotplug tests: - note that some tests will require root privileges. +Install selftests +================= + +You can use kselftest_install.sh tool installs selftests in default +location which is tools/testing/selftests/kselftest or an user specified +location. + +To install selftests in default location: + $ cd tools/testing/selftests + $ ./kselftest_install.sh + +To install selftests in an user specified location: + $ cd tools/testing/selftests + $ ./kselftest_install.sh install_dir + + Contributing new tests ====================== diff --git a/Documentation/misc-devices/apds990x.txt b/Documentation/misc-devices/apds990x.txt index d5408cade32f..454d95d623b3 100644 --- a/Documentation/misc-devices/apds990x.txt +++ b/Documentation/misc-devices/apds990x.txt @@ -30,7 +30,7 @@ lead to false interrupt, but that doesn't harm. ALS contains 4 different gain steps. Driver automatically selects suitable gain step. After each measurement, reliability of the results -is estimated and new measurement is trigged if necessary. +is estimated and new measurement is triggered if necessary. Platform data can provide tuned values to the conversion formulas if values are known. Otherwise plain sensor default values are used. diff --git a/Documentation/misc-devices/isl29003 b/Documentation/misc-devices/isl29003 index c4ff5f38e010..80b952fd32ff 100644 --- a/Documentation/misc-devices/isl29003 +++ b/Documentation/misc-devices/isl29003 @@ -29,7 +29,7 @@ Detection The ISL29003 does not have an ID register which could be used to identify it, so the detection routine will just try to read from the configured I2C -addess and consider the device to be present as soon as it ACKs the +address and consider the device to be present as soon as it ACKs the transfer. diff --git a/Documentation/misc-devices/max6875 b/Documentation/misc-devices/max6875 index 1e89ee3ccc1b..2f2bd0b17b5d 100644 --- a/Documentation/misc-devices/max6875 +++ b/Documentation/misc-devices/max6875 @@ -22,7 +22,7 @@ At reset, the MAX6875 reads the configuration EEPROM into its configuration registers. The chip then begins to operate according to the values in the registers. -The Maxim MAX6874 is a similar, mostly compatible device, with more intputs +The Maxim MAX6874 is a similar, mostly compatible device, with more inputs and outputs: vin gpi vout MAX6874 6 4 8 diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index fd1a1aad49a9..4636b94518da 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -1018,25 +1018,34 @@ solution for a couple of reasons: $ ip link set can0 type can help Usage: ip link set DEVICE type can - [ bitrate BITRATE [ sample-point SAMPLE-POINT] ] | - [ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1 - phase-seg2 PHASE-SEG2 [ sjw SJW ] ] - - [ loopback { on | off } ] - [ listen-only { on | off } ] - [ triple-sampling { on | off } ] - - [ restart-ms TIME-MS ] - [ restart ] - - Where: BITRATE := { 1..1000000 } - SAMPLE-POINT := { 0.000..0.999 } - TQ := { NUMBER } - PROP-SEG := { 1..8 } - PHASE-SEG1 := { 1..8 } - PHASE-SEG2 := { 1..8 } - SJW := { 1..4 } - RESTART-MS := { 0 | NUMBER } + [ bitrate BITRATE [ sample-point SAMPLE-POINT] ] | + [ tq TQ prop-seg PROP_SEG phase-seg1 PHASE-SEG1 + phase-seg2 PHASE-SEG2 [ sjw SJW ] ] + + [ dbitrate BITRATE [ dsample-point SAMPLE-POINT] ] | + [ dtq TQ dprop-seg PROP_SEG dphase-seg1 PHASE-SEG1 + dphase-seg2 PHASE-SEG2 [ dsjw SJW ] ] + + [ loopback { on | off } ] + [ listen-only { on | off } ] + [ triple-sampling { on | off } ] + [ one-shot { on | off } ] + [ berr-reporting { on | off } ] + [ fd { on | off } ] + [ fd-non-iso { on | off } ] + [ presume-ack { on | off } ] + + [ restart-ms TIME-MS ] + [ restart ] + + Where: BITRATE := { 1..1000000 } + SAMPLE-POINT := { 0.000..0.999 } + TQ := { NUMBER } + PROP-SEG := { 1..8 } + PHASE-SEG1 := { 1..8 } + PHASE-SEG2 := { 1..8 } + SJW := { 1..4 } + RESTART-MS := { 0 | NUMBER } - Display CAN device details and statistics: @@ -1178,7 +1187,55 @@ solution for a couple of reasons: The CAN device MTU can be retrieved e.g. with a SIOCGIFMTU ioctl() syscall. N.B. CAN FD capable devices can also handle and send legacy CAN frames. - FIXME: Add details about the CAN FD controller configuration when available. + When configuring CAN FD capable CAN controllers an additional 'data' bitrate + has to be set. This bitrate for the data phase of the CAN FD frame has to be + at least the bitrate which was configured for the arbitration phase. This + second bitrate is specified analogue to the first bitrate but the bitrate + setting keywords for the 'data' bitrate start with 'd' e.g. dbitrate, + dsample-point, dsjw or dtq and similar settings. When a data bitrate is set + within the configuration process the controller option "fd on" can be + specified to enable the CAN FD mode in the CAN controller. This controller + option also switches the device MTU to 72 (CANFD_MTU). + + The first CAN FD specification presented as whitepaper at the International + CAN Conference 2012 needed to be improved for data integrity reasons. + Therefore two CAN FD implementations have to be distinguished today: + + - ISO compliant: The ISO 11898-1:2015 CAN FD implementation (default) + - non-ISO compliant: The CAN FD implementation following the 2012 whitepaper + + Finally there are three types of CAN FD controllers: + + 1. ISO compliant (fixed) + 2. non-ISO compliant (fixed, like the M_CAN IP core v3.0.1 in m_can.c) + 3. ISO/non-ISO CAN FD controllers (switchable, like the PEAK PCAN-USB FD) + + The current ISO/non-ISO mode is announced by the CAN controller driver via + netlink and displayed by the 'ip' tool (controller option FD-NON-ISO). + The ISO/non-ISO-mode can be altered by setting 'fd-non-iso {on|off}' for + switchable CAN FD controllers only. + + Example configuring 500 kbit/s arbitration bitrate and 4 Mbit/s data bitrate: + + $ ip link set can0 up type can bitrate 500000 sample-point 0.75 \ + dbitrate 4000000 dsample-point 0.8 fd on + $ ip -details link show can0 + 5: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 72 qdisc pfifo_fast state UNKNOWN \ + mode DEFAULT group default qlen 10 + link/can promiscuity 0 + can <FD> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 + bitrate 500000 sample-point 0.750 + tq 50 prop-seg 14 phase-seg1 15 phase-seg2 10 sjw 1 + pcan_usb_pro_fd: tseg1 1..64 tseg2 1..16 sjw 1..16 brp 1..1024 \ + brp-inc 1 + dbitrate 4000000 dsample-point 0.800 + dtq 12 dprop-seg 7 dphase-seg1 8 dphase-seg2 4 dsjw 1 + pcan_usb_pro_fd: dtseg1 1..16 dtseg2 1..8 dsjw 1..4 dbrp 1..1024 \ + dbrp-inc 1 + clock 80000000 + + Example when 'fd-non-iso on' is added on this switchable CAN FD adapter: + can <FD,FD-NON-ISO> state ERROR-ACTIVE (berr-counter tx 0 rx 0) restart-ms 0 6.7 Supported CAN hardware diff --git a/Documentation/rbtree.txt b/Documentation/rbtree.txt index 39873ef41bf9..b9d9cc57be18 100644 --- a/Documentation/rbtree.txt +++ b/Documentation/rbtree.txt @@ -203,7 +203,7 @@ functions with the user provided augmentation callback when inserting and erasing nodes. C files implementing augmented rbtree manipulation must include -<linux/rbtree_augmented.h> instead of <linus/rbtree.h>. Note that +<linux/rbtree_augmented.h> instead of <linux/rbtree.h>. Note that linux/rbtree_augmented.h exposes some rbtree implementations details you are not expected to rely on; please stick to the documented APIs there and do not include <linux/rbtree_augmented.h> from header files diff --git a/Documentation/security/Smack.txt b/Documentation/security/Smack.txt index 5e6d07fbed07..945cc633d883 100644 --- a/Documentation/security/Smack.txt +++ b/Documentation/security/Smack.txt @@ -255,6 +255,16 @@ unconfined the access permitted if it wouldn't be otherwise. Note that this is dangerous and can ruin the proper labeling of your system. It should never be used in production. +relabel-self + This interface contains a list of labels to which the process can + transition to, by writing to /proc/self/attr/current. + Normally a process can change its own label to any legal value, but only + if it has CAP_MAC_ADMIN. This interface allows a process without + CAP_MAC_ADMIN to relabel itself to one of labels from predefined list. + A process without CAP_MAC_ADMIN can change its label only once. When it + does, this list will be cleared. + The values are set by writing the desired labels, separated + by spaces, to the file or cleared by writing "-" to the file. If you are using the smackload utility you can add access rules in /etc/smack/accesses. They take the form: diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt index c9e7f4f223a5..8c183873b2b7 100644 --- a/Documentation/security/keys.txt +++ b/Documentation/security/keys.txt @@ -1049,12 +1049,12 @@ search a specific keyring, so using keyrings in this way is of limited utility. NOTES ON ACCESSING PAYLOAD CONTENTS =================================== -The simplest payload is just a number in key->payload.value. In this case, -there's no need to indulge in RCU or locking when accessing the payload. +The simplest payload is just data stored in key->payload directly. In this +case, there's no need to indulge in RCU or locking when accessing the payload. -More complex payload contents must be allocated and a pointer to them set in -key->payload.data. One of the following ways must be selected to access the -data: +More complex payload contents must be allocated and pointers to them set in the +key->payload.data[] array. One of the following ways must be selected to +access the data: (1) Unmodifiable key type. @@ -1092,6 +1092,13 @@ data: the payload. key->datalen cannot be relied upon to be consistent with the payload just dereferenced if the key's semaphore is not held. + Note that key->payload.data[0] has a shadow that is marked for __rcu + usage. This is called key->payload.rcu_data0. The following accessors + wrap the RCU calls to this element: + + rcu_assign_keypointer(struct key *key, void *data); + void *rcu_dereference_key(struct key *key); + =================== DEFINING A KEY TYPE @@ -1143,8 +1150,7 @@ The structure has a number of fields, some of which are mandatory: struct key_preparsed_payload { char *description; - void *type_data[2]; - void *payload; + union key_payload payload; const void *data; size_t datalen; size_t quotalen; @@ -1160,10 +1166,9 @@ The structure has a number of fields, some of which are mandatory: attached as a string to the description field. This will be used for the key description if the caller of add_key() passes NULL or "". - The method can attach anything it likes to type_data[] and payload. These - are merely passed along to the instantiate() or update() operations. If - set, the expiry time will be applied to the key if it is instantiated from - this data. + The method can attach anything it likes to payload. This is merely passed + along to the instantiate() or update() operations. If set, the expiry + time will be applied to the key if it is instantiated from this data. The method should return 0 if successful or a negative error code otherwise. @@ -1172,11 +1177,10 @@ The structure has a number of fields, some of which are mandatory: (*) void (*free_preparse)(struct key_preparsed_payload *prep); This method is only required if the preparse() method is provided, - otherwise it is unused. It cleans up anything attached to the - description, type_data and payload fields of the key_preparsed_payload - struct as filled in by the preparse() method. It will always be called - after preparse() returns successfully, even if instantiate() or update() - succeed. + otherwise it is unused. It cleans up anything attached to the description + and payload fields of the key_preparsed_payload struct as filled in by the + preparse() method. It will always be called after preparse() returns + successfully, even if instantiate() or update() succeed. (*) int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); @@ -1197,6 +1201,11 @@ The structure has a number of fields, some of which are mandatory: It is safe to sleep in this method. + generic_key_instantiate() is provided to simply copy the data from + prep->payload.data[] to key->payload.data[], with RCU-safe assignment on + the first element. It will then clear prep->payload.data[] so that the + free_preparse method doesn't release the data. + (*) int (*update)(struct key *key, const void *data, size_t datalen); diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134 index f4b395bdc090..282102014bb9 100644 --- a/Documentation/video4linux/CARDLIST.saa7134 +++ b/Documentation/video4linux/CARDLIST.saa7134 @@ -193,3 +193,4 @@ 192 -> AverMedia AverTV Satellite Hybrid+FM A706 [1461:2055] 193 -> WIS Voyager or compatible [1905:7007] 194 -> AverMedia AverTV/505 [1461:a10a] +195 -> Leadtek Winfast TV2100 FM [107d:6f3a] diff --git a/Documentation/video4linux/v4l2-pci-skeleton.c b/Documentation/video4linux/v4l2-pci-skeleton.c index 9c80c090e92d..95ae82860092 100644 --- a/Documentation/video4linux/v4l2-pci-skeleton.c +++ b/Documentation/video4linux/v4l2-pci-skeleton.c @@ -37,6 +37,7 @@ #include <media/v4l2-dv-timings.h> #include <media/v4l2-ctrls.h> #include <media/v4l2-event.h> +#include <media/videobuf2-v4l2.h> #include <media/videobuf2-dma-contig.h> MODULE_DESCRIPTION("V4L2 PCI Skeleton Driver"); @@ -162,10 +163,11 @@ static irqreturn_t skeleton_irq(int irq, void *dev_id) * minimum number: many DMA engines need a minimum of 2 buffers in the * queue and you need to have another available for userspace processing. */ -static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt, +static int queue_setup(struct vb2_queue *vq, const void *parg, unsigned int *nbuffers, unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[]) { + const struct v4l2_format *fmt = parg; struct skeleton *skel = vb2_get_drv_priv(vq); skel->field = skel->format.field; diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index d9ecceea5a02..092ee9fbaf2b 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -401,10 +401,9 @@ Capability: basic Architectures: x86, ppc, mips Type: vcpu ioctl Parameters: struct kvm_interrupt (in) -Returns: 0 on success, -1 on error +Returns: 0 on success, negative on failure. -Queues a hardware interrupt vector to be injected. This is only -useful if in-kernel local APIC or equivalent is not used. +Queues a hardware interrupt vector to be injected. /* for KVM_INTERRUPT */ struct kvm_interrupt { @@ -414,7 +413,14 @@ struct kvm_interrupt { X86: -Note 'irq' is an interrupt vector, not an interrupt pin or line. +Returns: 0 on success, + -EEXIST if an interrupt is already enqueued + -EINVAL the the irq number is invalid + -ENXIO if the PIC is in the kernel + -EFAULT if the pointer is invalid + +Note 'irq' is an interrupt vector, not an interrupt pin or line. This +ioctl is useful if the in-kernel PIC is not used. PPC: @@ -1598,7 +1604,7 @@ provided event instead of triggering an exit. struct kvm_ioeventfd { __u64 datamatch; __u64 addr; /* legal pio/mmio address */ - __u32 len; /* 1, 2, 4, or 8 bytes */ + __u32 len; /* 0, 1, 2, 4, or 8 bytes */ __s32 fd; __u32 flags; __u8 pad[36]; @@ -1621,6 +1627,10 @@ to the registered address is equal to datamatch in struct kvm_ioeventfd. For virtio-ccw devices, addr contains the subchannel id and datamatch the virtqueue index. +With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and +the kernel will ignore the length of guest write and may get a faster vmexit. +The speedup may only apply to specific architectures, but the ioeventfd will +work anyway. 4.60 KVM_DIRTY_TLB @@ -1774,7 +1784,7 @@ has been called, this interface is completely emulated within the kernel. To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the following algorithm: - - pause the vpcu + - pause the vcpu - read the local APIC's state (KVM_GET_LAPIC) - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) - if so, issue KVM_NMI @@ -2798,7 +2808,7 @@ Returns: = 0 on success, < 0 on generic error (e.g. -EFAULT or -ENOMEM), > 0 if an exception occurred while walking the page tables -Read or write data from/to the logical (virtual) memory of a VPCU. +Read or write data from/to the logical (virtual) memory of a VCPU. Parameters are specified via the following structure: @@ -3309,6 +3319,18 @@ Valid values for 'type' are: to ignore the request, or to gather VM memory core dump and/or reset/shutdown of the VM. + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; + +Indicates that the VCPU's in-kernel local APIC received an EOI for a +level-triggered IOAPIC interrupt. This exit only triggers when the +IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); +the userspace IOAPIC should process the EOI and retrigger the interrupt if +it is still asserted. Vector is the LAPIC interrupt vector for which the +EOI was received. + /* Fix the size of the union. */ char padding[256]; }; @@ -3627,6 +3649,26 @@ struct { KVM handlers should exit to userspace with rc = -EREMOTE. +7.5 KVM_CAP_SPLIT_IRQCHIP + +Architectures: x86 +Parameters: args[0] - number of routes reserved for userspace IOAPICs +Returns: 0 on success, -1 on error + +Create a local apic for each processor in the kernel. This can be used +instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the +IOAPIC and PIC (and also the PIT, even though this has to be enabled +separately). + +This capability also enables in kernel routing of interrupt requests; +when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are +used in the IRQ routing table. The first args[0] MSI routes are reserved +for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, +a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. + +Fails if VCPU has already been created, or if the irqchip is already in the +kernel (i.e. KVM_CREATE_IRQCHIP has already been called). + 8. Other capabilities. ---------------------- diff --git a/Documentation/virtual/kvm/arm/vgic-mapped-irqs.txt b/Documentation/virtual/kvm/arm/vgic-mapped-irqs.txt new file mode 100644 index 000000000000..38bca2835278 --- /dev/null +++ b/Documentation/virtual/kvm/arm/vgic-mapped-irqs.txt @@ -0,0 +1,187 @@ +KVM/ARM VGIC Forwarded Physical Interrupts +========================================== + +The KVM/ARM code implements software support for the ARM Generic +Interrupt Controller's (GIC's) hardware support for virtualization by +allowing software to inject virtual interrupts to a VM, which the guest +OS sees as regular interrupts. The code is famously known as the VGIC. + +Some of these virtual interrupts, however, correspond to physical +interrupts from real physical devices. One example could be the +architected timer, which itself supports virtualization, and therefore +lets a guest OS program the hardware device directly to raise an +interrupt at some point in time. When such an interrupt is raised, the +host OS initially handles the interrupt and must somehow signal this +event as a virtual interrupt to the guest. Another example could be a +passthrough device, where the physical interrupts are initially handled +by the host, but the device driver for the device lives in the guest OS +and KVM must therefore somehow inject a virtual interrupt on behalf of +the physical one to the guest OS. + +These virtual interrupts corresponding to a physical interrupt on the +host are called forwarded physical interrupts, but are also sometimes +referred to as 'virtualized physical interrupts' and 'mapped interrupts'. + +Forwarded physical interrupts are handled slightly differently compared +to virtual interrupts generated purely by a software emulated device. + + +The HW bit +---------- +Virtual interrupts are signalled to the guest by programming the List +Registers (LRs) on the GIC before running a VCPU. The LR is programmed +with the virtual IRQ number and the state of the interrupt (Pending, +Active, or Pending+Active). When the guest ACKs and EOIs a virtual +interrupt, the LR state moves from Pending to Active, and finally to +inactive. + +The LRs include an extra bit, called the HW bit. When this bit is set, +KVM must also program an additional field in the LR, the physical IRQ +number, to link the virtual with the physical IRQ. + +When the HW bit is set, KVM must EITHER set the Pending OR the Active +bit, never both at the same time. + +Setting the HW bit causes the hardware to deactivate the physical +interrupt on the physical distributor when the guest deactivates the +corresponding virtual interrupt. + + +Forwarded Physical Interrupts Life Cycle +---------------------------------------- + +The state of forwarded physical interrupts is managed in the following way: + + - The physical interrupt is acked by the host, and becomes active on + the physical distributor (*). + - KVM sets the LR.Pending bit, because this is the only way the GICV + interface is going to present it to the guest. + - LR.Pending will stay set as long as the guest has not acked the interrupt. + - LR.Pending transitions to LR.Active on the guest read of the IAR, as + expected. + - On guest EOI, the *physical distributor* active bit gets cleared, + but the LR.Active is left untouched (set). + - KVM clears the LR on VM exits when the physical distributor + active state has been cleared. + +(*): The host handling is slightly more complicated. For some forwarded +interrupts (shared), KVM directly sets the active state on the physical +distributor before entering the guest, because the interrupt is never actually +handled on the host (see details on the timer as an example below). For other +forwarded interrupts (non-shared) the host does not deactivate the interrupt +when the host ISR completes, but leaves the interrupt active until the guest +deactivates it. Leaving the interrupt active is allowed, because Linux +configures the physical GIC with EOIMode=1, which causes EOI operations to +perform a priority drop allowing the GIC to receive other interrupts of the +default priority. + + +Forwarded Edge and Level Triggered PPIs and SPIs +------------------------------------------------ +Forwarded physical interrupts injected should always be active on the +physical distributor when injected to a guest. + +Level-triggered interrupts will keep the interrupt line to the GIC +asserted, typically until the guest programs the device to deassert the +line. This means that the interrupt will remain pending on the physical +distributor until the guest has reprogrammed the device. Since we +always run the VM with interrupts enabled on the CPU, a pending +interrupt will exit the guest as soon as we switch into the guest, +preventing the guest from ever making progress as the process repeats +over and over. Therefore, the active state on the physical distributor +must be set when entering the guest, preventing the GIC from forwarding +the pending interrupt to the CPU. As soon as the guest deactivates the +interrupt, the physical line is sampled by the hardware again and the host +takes a new interrupt if and only if the physical line is still asserted. + +Edge-triggered interrupts do not exhibit the same problem with +preventing guest execution that level-triggered interrupts do. One +option is to not use HW bit at all, and inject edge-triggered interrupts +from a physical device as pure virtual interrupts. But that would +potentially slow down handling of the interrupt in the guest, because a +physical interrupt occurring in the middle of the guest ISR would +preempt the guest for the host to handle the interrupt. Additionally, +if you configure the system to handle interrupts on a separate physical +core from that running your VCPU, you still have to interrupt the VCPU +to queue the pending state onto the LR, even though the guest won't use +this information until the guest ISR completes. Therefore, the HW +bit should always be set for forwarded edge-triggered interrupts. With +the HW bit set, the virtual interrupt is injected and additional +physical interrupts occurring before the guest deactivates the interrupt +simply mark the state on the physical distributor as Pending+Active. As +soon as the guest deactivates the interrupt, the host takes another +interrupt if and only if there was a physical interrupt between injecting +the forwarded interrupt to the guest and the guest deactivating the +interrupt. + +Consequently, whenever we schedule a VCPU with one or more LRs with the +HW bit set, the interrupt must also be active on the physical +distributor. + + +Forwarded LPIs +-------------- +LPIs, introduced in GICv3, are always edge-triggered and do not have an +active state. They become pending when a device signal them, and as +soon as they are acked by the CPU, they are inactive again. + +It therefore doesn't make sense, and is not supported, to set the HW bit +for physical LPIs that are forwarded to a VM as virtual interrupts, +typically virtual SPIs. + +For LPIs, there is no other choice than to preempt the VCPU thread if +necessary, and queue the pending state onto the LR. + + +Putting It Together: The Architected Timer +------------------------------------------ +The architected timer is a device that signals interrupts with level +triggered semantics. The timer hardware is directly accessed by VCPUs +which program the timer to fire at some point in time. Each VCPU on a +system programs the timer to fire at different times, and therefore the +hardware is multiplexed between multiple VCPUs. This is implemented by +context-switching the timer state along with each VCPU thread. + +However, this means that a scenario like the following is entirely +possible, and in fact, typical: + +1. KVM runs the VCPU +2. The guest programs the time to fire in T+100 +3. The guest is idle and calls WFI (wait-for-interrupts) +4. The hardware traps to the host +5. KVM stores the timer state to memory and disables the hardware timer +6. KVM schedules a soft timer to fire in T+(100 - time since step 2) +7. KVM puts the VCPU thread to sleep (on a waitqueue) +8. The soft timer fires, waking up the VCPU thread +9. KVM reprograms the timer hardware with the VCPU's values +10. KVM marks the timer interrupt as active on the physical distributor +11. KVM injects a forwarded physical interrupt to the guest +12. KVM runs the VCPU + +Notice that KVM injects a forwarded physical interrupt in step 11 without +the corresponding interrupt having actually fired on the host. That is +exactly why we mark the timer interrupt as active in step 10, because +the active state on the physical distributor is part of the state +belonging to the timer hardware, which is context-switched along with +the VCPU thread. + +If the guest does not idle because it is busy, the flow looks like this +instead: + +1. KVM runs the VCPU +2. The guest programs the time to fire in T+100 +4. At T+100 the timer fires and a physical IRQ causes the VM to exit + (note that this initially only traps to EL2 and does not run the host ISR + until KVM has returned to the host). +5. With interrupts still disabled on the CPU coming back from the guest, KVM + stores the virtual timer state to memory and disables the virtual hw timer. +6. KVM looks at the timer state (in memory) and injects a forwarded physical + interrupt because it concludes the timer has expired. +7. KVM marks the timer interrupt as active on the physical distributor +7. KVM enables the timer, enables interrupts, and runs the VCPU + +Notice that again the forwarded physical interrupt is injected to the +guest without having actually been handled on the host. In this case it +is because the physical interrupt is never actually seen by the host because the +timer is disabled upon guest return, and the virtual forwarded interrupt is +injected on the KVM guest entry path. diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt index 3fb905429e8a..59541d49e15c 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt @@ -44,28 +44,29 @@ Groups: Attributes: The attr field of kvm_device_attr encodes two values: bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | - values: | reserved | cpu id | offset | + values: | reserved | vcpu_index | offset | All distributor regs are (rw, 32-bit) The offset is relative to the "Distributor base address" as defined in the GICv2 specs. Getting or setting such a register has the same effect as - reading or writing the register on the actual hardware from the cpu - specified with cpu id field. Note that most distributor fields are not - banked, but return the same value regardless of the cpu id used to access - the register. + reading or writing the register on the actual hardware from the cpu whose + index is specified with the vcpu_index field. Note that most distributor + fields are not banked, but return the same value regardless of the + vcpu_index used to access the register. Limitations: - Priorities are not implemented, and registers are RAZ/WI - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2. Errors: - -ENODEV: Getting or setting this register is not yet supported + -ENXIO: Getting or setting this register is not yet supported -EBUSY: One or more VCPUs are running + -EINVAL: Invalid vcpu_index supplied KVM_DEV_ARM_VGIC_GRP_CPU_REGS Attributes: The attr field of kvm_device_attr encodes two values: bits: | 63 .... 40 | 39 .. 32 | 31 .... 0 | - values: | reserved | cpu id | offset | + values: | reserved | vcpu_index | offset | All CPU interface regs are (rw, 32-bit) @@ -91,8 +92,9 @@ Groups: - Priorities are not implemented, and registers are RAZ/WI - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2. Errors: - -ENODEV: Getting or setting this register is not yet supported + -ENXIO: Getting or setting this register is not yet supported -EBUSY: One or more VCPUs are running + -EINVAL: Invalid vcpu_index supplied KVM_DEV_ARM_VGIC_GRP_NR_IRQS Attributes: diff --git a/Documentation/virtual/kvm/devices/vm.txt b/Documentation/virtual/kvm/devices/vm.txt index 5542c4641a3c..2d09d1ed86d0 100644 --- a/Documentation/virtual/kvm/devices/vm.txt +++ b/Documentation/virtual/kvm/devices/vm.txt @@ -74,7 +74,7 @@ struct kvm_s390_vm_cpu_processor { KVM does not enforce or limit the cpu model data in any form. Take the information retrieved by means of KVM_S390_VM_CPU_MACHINE as hint for reasonable configuration -setups. Instruction interceptions triggered by additionally set facilitiy bits that +setups. Instruction interceptions triggered by additionally set facility bits that are not handled by KVM need to by imlemented in the VM driver code. Parameters: address of buffer to store/set the processor related cpu diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index d68af4dc3006..19f94a6b9bb0 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -166,3 +166,15 @@ Comment: The srcu read lock must be held while accessing memslots (e.g. MMIO/PIO address->device structure mapping (kvm->buses). The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu if it is needed by multiple functions. + +Name: blocked_vcpu_on_cpu_lock +Type: spinlock_t +Arch: x86 +Protects: blocked_vcpu_on_cpu +Comment: This is a per-CPU lock and it is used for VT-d posted-interrupts. + When VT-d posted-interrupts is supported and the VM has assigned + devices, we put the blocked vCPU on the list blocked_vcpu_on_cpu + protected by blocked_vcpu_on_cpu_lock, when VT-d hardware issues + wakeup notification event since external interrupts from the + assigned devices happens, we will find the vCPU on the list to + wakeup. diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt index 319560646f32..e26115ce4258 100644 --- a/Documentation/virtual/kvm/ppc-pv.txt +++ b/Documentation/virtual/kvm/ppc-pv.txt @@ -110,7 +110,7 @@ Flags are passed to the host in the low 12 bits of the Effective Address. The following flags are currently available for a guest to expose: - MAGIC_PAGE_FLAG_NOT_MAPPED_NX Guest handles NX bits correclty wrt magic page + MAGIC_PAGE_FLAG_NOT_MAPPED_NX Guest handles NX bits correctly wrt magic page MSR bits ======== diff --git a/Documentation/zh_CN/filesystems/sysfs.txt b/Documentation/zh_CN/filesystems/sysfs.txt index e230eaa33122..7d3b05edb8ce 100644 --- a/Documentation/zh_CN/filesystems/sysfs.txt +++ b/Documentation/zh_CN/filesystems/sysfs.txt @@ -61,7 +61,7 @@ Documentation/kobject.txt 文档以获得更多关于 kobject 接口的 内核的对象层次到用户空间。sysfs 中的顶层目录代表着内核对象层次的 共同祖先；例如：某些对象属于某个子系统。 -Sysfs 在与其目录关联的 sysfs_dirent 对象中内部保存一个指向实现 +Sysfs 在与其目录关联的 kernfs_node 对象中内部保存一个指向实现 目录的 kobject 的指针。以前，这个 kobject 指针被 sysfs 直接用于 kobject 文件打开和关闭的引用计数。而现在的 sysfs 实现中，kobject 引用计数只能通过 sysfs_schedule_callback() 函数直接修改。 |