Linux kernel documentation tree maintained by Jonathan Corbet http://mirrors.hust.edu.cn/git/lwn.git/atom?h=docs-5.2a 2019-03-16T20:05:32+00:00 2019-03-16T20:05:32+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-16T20:05:32+00:00 urn:sha1:f67e3fb4891287b8248ebb3320f794b9f5e782d4 Pull device-dax updates from Dan Williams: "New device-dax infrastructure to allow persistent memory and other "reserved" / performance differentiated memories, to be assigned to the core-mm as "System RAM". Some users want to use persistent memory as additional volatile memory. They are willing to cope with potential performance differences, for example between DRAM and 3D Xpoint, and want to use typical Linux memory management apis rather than a userspace memory allocator layered over an mmap() of a dax file. The administration model is to decide how much Persistent Memory (pmem) to use as System RAM, create a device-dax-mode namespace of that size, and then assign it to the core-mm. The rationale for device-dax is that it is a generic memory-mapping driver that can be layered over any "special purpose" memory, not just pmem. On subsequent boots udev rules can be used to restore the memory assignment. One implication of using pmem as RAM is that mlock() no longer keeps data off persistent media. For this reason it is recommended to enable NVDIMM Security (previously merged for 5.0) to encrypt pmem contents at rest. We considered making this recommendation an actively enforced requirement, but in the end decided to leave it as a distribution / administrator policy to allow for emulation and test environments that lack security capable NVDIMMs. Summary: - Replace the /sys/class/dax device model with /sys/bus/dax, and include a compat driver so distributions can opt-in to the new ABI. - Allow for an alternative driver for the device-dax address-range - Introduce the 'kmem' driver to hotplug / assign a device-dax address-range to the core-mm. - Arrange for the device-dax target-node to be onlined so that the newly added memory range can be uniquely referenced by numa apis" NOTE! I'm not entirely happy with the whole "PMEM as RAM" model because we currently have special - and very annoying rules in the kernel about accessing PMEM only with the "MC safe" accessors, because machine checks inside the regular repeat string copy functions can be fatal in some (not described) circumstances. And apparently the PMEM modules can cause that a lot more than regular RAM. The argument is that this happens because PMEM doesn't necessarily get scrubbed at boot like RAM does, but that is planned to be added for the user space tooling. Quoting Dan from another email: "The exposure can be reduced in the volatile-RAM case by scanning for and clearing errors before it is onlined as RAM. The userspace tooling for that can be in place before v5.1-final. There's also runtime notifications of errors via acpi_nfit_uc_error_notify() from background scrubbers on the DIMM devices. With that mechanism the kernel could proactively clear newly discovered poison in the volatile case, but that would be additional development more suitable for v5.2. I understand the concern, and the need to highlight this issue by tapping the brakes on feature development, but I don't see PMEM as RAM making the situation worse when the exposure is also there via DAX in the PMEM case. Volatile-RAM is arguably a safer use case since it's possible to repair pages where the persistent case needs active application coordination" * tag 'devdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: "Hotplug" persistent memory for use like normal RAM mm/resource: Let walk_system_ram_range() search child resources mm/memory-hotplug: Allow memory resources to be children mm/resource: Move HMM pr_debug() deeper into resource code mm/resource: Return real error codes from walk failures device-dax: Add a 'modalias' attribute to DAX 'bus' devices device-dax: Add a 'target_node' attribute device-dax: Auto-bind device after successful new_id acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node device-dax: Add /sys/class/dax backwards compatibility device-dax: Add support for a dax override driver device-dax: Move resource pinning+mapping into the common driver device-dax: Introduce bus + driver model device-dax: Start defining a dax bus model device-dax: Remove multi-resource infrastructure device-dax: Kill dax_region base device-dax: Kill dax_region ida 2019-03-14T17:48:14+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-14T17:48:14+00:00 urn:sha1:3b319ee220a8795406852a897299dbdfc1b09911 Pull more ACPI updates from Rafael Wysocki: "These fix a couple of issues and do some cleanups on top of the previous ACPI changes for 5.1-rc1. Specifics: - Fix a crash caused by unloading an SSDT overlay (Andy Shevchenko) - Prevent user space from getting confusing error values on failing ACPI sysfs accesses (Rafael Wysocki) - Simplify leaf node detection in the PPTT parsing code by using a new flag defined in ACPI 6.3 (Jeremy Linton) - Add missing "static" in some places in the ACPI configfs code (Andy Shevchenko) - Fix acpidbg tool path in the ACPI documentation (Flavio Suligoi)" * tag 'acpi-5.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: sysfs: Prevent get_status() from returning acpi_status ACPI / device_sysfs: Avoid OF modalias creation for removed device ACPI / configfs: Mark local data structures static ACPI / configfs: Mark local functions static ACPI: tables: Simplify PPTT leaf node detection ACPI: Documentation: Fix path for acpidbg tool 2019-03-14T15:46:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-14T15:46:17+00:00 urn:sha1:dc2535be1fd547fbd56aff091370280007b0a1af Pull clk subsystem updates from Stephen Boyd: "We have a fairly balanced mix of clk driver updates and clk framework updates this time around. It's the usual pile of new drivers for new hardware out there and the normal small fixes and updates, but then we have some core framework changes too. In the core framework, we introduce support for a clk_get_optional() API to get clks that may not always be populated and a way to devm manage clkdev lookups registered by provider drivers. We also do some refactoring to simplify the interface between clkdev and the common clk framework so we can reuse the DT parsing and clk_get() path in provider drivers in the future. This work will continue in the next few cycles while we convert how providers specify clk parents. On the driver side, the biggest part of the dirstat is the Amlogic clk driver that got support for the G12A SoC. It dominates with almost half the overall diff, while the second largest part of the diff is in the i.MX clk driver that gained support for imx8mm SoCs. After that, we have the Actions Semiconductor and Qualcomm drivers rounding out the big part of the dirstat because they both got new hardware support for SoCs. The rest is just various updates and non-critical fixes for existing drivers. Core: - Convert a few clk bindings to JSON schema format - Add a {devm_}clk_get_optional() API - Add devm_clk_hw_register_clkdev() API to manage clkdev lookups - Start rewriting clk parent registration and supporting device links by moving around code that supports clk_get() and DT parsing of the 'clocks' property New Drivers: - Add Qualcomm MSM8998 RPM managed clks - IPA clk support on Qualcomm RPMh clk controllers - Actions Semi S500 SoC clk support - Support for fixed rate clks populated from an MMIO register - Add RPC (QSPI/HyperFLASH) clocks on Renesas R-Car V3H - Add TMU (timer) clocks on Renesas RZ/G2E - Add Amlogic G12A Always-On Clock Controller - Add 32k clock generation for Amlogic AXG - Add support for the Mali GPU clocks on Amlogic Meson8 - Add Amlogic G12A EE clock controller driver - Add missing CANFD clocks on Renesas RZ/G2M and RZ/G2E - Add i.MX8MM SoC clk driver support Removed Drivers: - Remove clps711x driver as the board support is gone Updates: - 3rd ECO fix for Mediatek MT2712 SoCs - Updates for Qualcomm MSM8998 GCC clks - Random static analysis fixes for clk drivers - Support for sleeping gpios in the clk-gpio type - Minor fixes for STM32MP1 clk driver (parents, critical flag, etc.) - Split LCDC into two clks on the Marvell MMP2 SoC - Various DT of_node refcount fixes - Get rid of CLK_IS_BASIC from TI code (yay!) - TI Autoidle clk support - Fix Amlogic Meson8 APB clock ID name - Claim input clocks through DT for Amlogic AXG and GXBB - Correct the DU (display unit) parent clock on Renesas RZ/G2E - Exynos5433 IMEM CMU crypto clk support (SlimSS) - Fix for the PLL-MIPI on the Allwinner A23 - Fix Rockchip rk3328 PLL rate calculation - Add SET_RATE_PARENT flag on display clk of Rockhip rk3066 - i.MX SCU clk driver clk_set_parent() and cpufreq support" * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (150 commits) dt-bindings: clock: imx8mq: Fix numbering overlaps and gaps clk: ti: clkctrl: Fix clkdm_name regression for TI_CLK_CLKCTRL_COMPAT clk: fixup default index for of_clk_get_by_name() clk: Move of_clk_*() APIs into clk.c from clkdev.c clk: Inform the core about consumer devices clk: Introduce of_clk_get_hw_from_clkspec() clk: core: clarify the check for runtime PM clk: Combine __clk_get() and __clk_create_clk() clk: imx8mq: add GPIO clocks to clock tree clk: mediatek: correct cpu clock name for MT8173 SoC clk: imx: Refactor entire sccg pll clk clk: imx: scu: add cpu frequency scaling support clk: mediatek: Mark bus and DRAM related clocks as critical clk: mediatek: Add flags to mtk_gate clk: mediatek: Add MUX_FLAGS macro clk: qcom: gcc-sdm845: Define parent of PCIe PIPE clocks clk: ingenic: Remove set but not used variable 'enable' clk: at91: programmable: remove unneeded register read clk: mediatek: using CLK_MUX_ROUND_CLOSEST for the clock of dpi1_sel clk: mediatek: add MUX_GATE_FLAGS_2 ... 2019-03-14T09:54:28+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2019-03-14T09:54:28+00:00 urn:sha1:b6e88119f1edcdc1fa3fd3a168310ac2d433a873 * acpi-tables: ACPI: tables: Simplify PPTT leaf node detection * acpi-debug: ACPI: sysfs: Prevent get_status() from returning acpi_status * acpi-doc: ACPI: Documentation: Fix path for acpidbg tool * acpi-misc: ACPI / configfs: Mark local data structures static ACPI / configfs: Mark local functions static 2019-03-13T16:41:18+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-13T16:41:18+00:00 urn:sha1:5ea6718b1f1bb58825426e19a21cdba47075a954 Pull libnvdimm updates from Dan Williams: "The bulk of this has been in -next since before the merge window opened, with no known collisions / issues reported. The only detail worth noting, outside the summary below, is that the "libnvdimm-start-pad" topic has been truncated to just cleanups and small fixes. The full topic branch would have doubled down on hacks around the "section alignment" limitation of the core-mm, instead effort is now being spent to address that root issue in the memory hotplug implementation for v5.2. - Fix nfit-bus command submission regression - Support retrieval of short-ARS results if the ARS state is "requires continuation", and even if the "no_init_ars" module parameter is specified - Allow busy-polling of the kernel ARS state by allowing root to reset the exponential back-off timer - Filter potentially stale ARS results by tracking query-ARS relative to the previous start-ARS - Enhance dax_device alignment checks - Add support for the Hyper-V family of device-specific-methods (DSMs) - Add several fixes and workarounds for Hyper-V compatibility - Fix support to cache the dirty-shutdown-count at init" * tag 'libnvdimm-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (25 commits) libnvdimm/namespace: Clean up holder_class_store() libnvdimm/of_pmem: Fix platform_no_drv_owner.cocci warnings acpi/nfit: Update NFIT flags error message libnvdimm/btt: Fix LBA masking during 'free list' population libnvdimm/btt: Remove unnecessary code in btt_freelist_init libnvdimm/pfn: Remove dax_label_reserve dax: Check the end of the block-device capacity with dax_direct_access() nfit/ars: Avoid stale ARS results nfit/ars: Allow root to busy-poll the ARS state machine nfit/ars: Introduce scrub_flags nfit/ars: Remove ars_start_flags nfit/ars: Attempt short-ARS even in the no_init_ars case nfit/ars: Attempt a short-ARS whenever the ARS state is idle at boot acpi/nfit: Require opt-in for read-only label configurations libnvdimm/pmem: Honor force_raw for legacy pmem regions libnvdimm/pfn: Account for PAGE_SIZE > info-block-size in nd_pfn_init() libnvdimm: Fix altmap reservation size calculation libnvdimm, pfn: Fix over-trim in trim_pfn_device() acpi/nfit: Fix bus command validation libnvdimm/dimm: Add a no-BLK quirk based on NVDIMM family ... 2019-03-12T09:34:58+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2019-03-12T09:30:29+00:00 urn:sha1:3fd16d70166194dd0bf0f7a555779a42ee267223 The return value of get_status() is passed to user space on errors, so it should not return acpi_status values then. Make it return error values that are meaningful for user space instead. This also makes a Clang warning regarding the initialization of a local variable in get_status() go away. Reported-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 2019-03-12T08:56:18+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2019-03-11T16:41:03+00:00 urn:sha1:f16eb8a4b096514ac06fb25bf599dcc792899b3d If SSDT overlay is loaded via ConfigFS and then unloaded the device, we would like to have OF modalias for, already gone. Thus, acpi_get_name() returns no allocated buffer for such case and kernel crashes afterwards: ACPI: Host-directed Dynamic ACPI Table Unload ads7950 spi-PRP0001:00: Dropping the link to regulator.0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 #PF error: [normal kernel read fault] PGD 80000000070d6067 P4D 80000000070d6067 PUD 70d0067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 40 Comm: kworker/u4:2 Not tainted 5.0.0+ #96 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 Workqueue: kacpi_hotplug acpi_device_del_work_fn RIP: 0010:create_of_modalias.isra.1+0x4c/0x150 Code: 00 00 48 89 44 24 18 31 c0 48 8d 54 24 08 48 c7 44 24 10 00 00 00 00 48 c7 44 24 08 ff ff ff ff e8 7a b0 03 00 48 8b 4c 24 10 <0f> b6 01 84 c0 74 27 48 c7 c7 00 09 f4 a5 0f b6 f0 8d 50 20 f6 04 RSP: 0000:ffffa51040297c10 EFLAGS: 00010246 RAX: 0000000000001001 RBX: 0000000000000785 RCX: 0000000000000000 RDX: 0000000000001001 RSI: 0000000000000286 RDI: ffffa2163dc042e0 RBP: ffffa216062b1196 R08: 0000000000001001 R09: ffffa21639873000 R10: ffffffffa606761d R11: 0000000000000001 R12: ffffa21639873218 R13: ffffa2163deb5060 R14: ffffa216063d1010 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa2163e000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000007114000 CR4: 00000000001006f0 Call Trace: __acpi_device_uevent_modalias+0xb0/0x100 spi_uevent+0xd/0x40 ... In order to fix above let create_of_modalias() check the status returned by acpi_get_name() and bail out in case of failure. Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Link: https://bugzilla.kernel.org/show_bug.cgi?id=201381 Reported-by: Ferry Toth <fntoth@gmail.com> Tested-by: Ferry Toth<fntoth@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: 4.1+ <stable@vger.kernel.org> # 4.1+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 2019-03-12T08:50:56+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2019-03-11T14:04:30+00:00 urn:sha1:bf567dd38993a51e4f13d1806985e9aa596f2519 There is no need to have non-static local data structures. otherwise sparse is not happy: CHECK drivers/acpi/acpi_configfs.c drivers/acpi/acpi_configfs.c:100:31: warning: symbol 'acpi_table_bin_attrs' was not declared. Should it be static? drivers/acpi/acpi_configfs.c:196:27: warning: symbol 'acpi_table_attrs' was not declared. Should it be static? drivers/acpi/acpi_configfs.c:236:34: warning: symbol 'acpi_table_group_ops' was not declared. Should it be static? Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 2019-03-12T08:50:56+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2019-03-11T14:04:29+00:00 urn:sha1:c62c15a92455bc60e9ab4d01b6c047a74dd42c5e There is no need to have non-static local functions. otherwise compiler is not happy: CC [M] drivers/acpi/acpi_configfs.o drivers/acpi/acpi_configfs.c:105:9: warning: no previous prototype for ‘acpi_table_signature_show’ [-Wmissing-prototypes] ssize_t acpi_table_signature_show(struct config_item *cfg, char *str) ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/acpi/acpi_configfs.c:115:9: warning: no previous prototype for ‘acpi_table_length_show’ [-Wmissing-prototypes] ssize_t acpi_table_length_show(struct config_item *cfg, char *str) ^~~~~~~~~~~~~~~~~~~~~~ ... Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 2019-03-11T19:37:55+00:00 Dan Williams dan.j.williams@intel.com 2019-03-11T19:37:55+00:00 urn:sha1:4083014e32699af04a8e6eaa4855b08dba36a47a Merge several updates to the ARS implementation. Highlights include: * Support retrieval of short-ARS results if the ARS state is "requires continuation", and even if the "no_init_ars" module parameter is specified. * Allow busy-polling of the kernel ARS state by allowing root to reset the exponential back-off timer. * Filter potentially stale ARS results by tracking query-ARS relative to the previous start-ARS.