diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-13 14:00:45 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-13 14:00:45 -0700 |
commit | a976835fdb312590ee5c085567a4e2b06da7ac33 (patch) | |
tree | 7367f1318b0dce800fd74e6bf1f09bd0cde08035 /Documentation/PCI | |
parent | 9872e4a8734c68b78e8782e4f7f49e22cd6e9463 (diff) | |
parent | e4fe2a2fc423cb51bfd36c14f95f3ca1d279ca92 (diff) | |
download | lwn-a976835fdb312590ee5c085567a4e2b06da7ac33.tar.gz lwn-a976835fdb312590ee5c085567a4e2b06da7ac33.zip |
Merge tag 'ntb-5.20' of https://github.com/jonmason/ntb
Pull NTB updates from Jon Mason:
"Non-Transparent Bridge updates.
Fix of heap data and clang warnings, support for a new Intel NTB
device, and NTB EndPoint Function (EPF) support and the various fixes
for that"
* tag 'ntb-5.20' of https://github.com/jonmason/ntb:
MAINTAINERS: add PCI Endpoint NTB drivers to NTB files
NTB: EPF: Tidy up some bounds checks
NTB: EPF: Fix error code in epf_ntb_bind()
PCI: endpoint: pci-epf-vntb: reduce several globals to statics
PCI: endpoint: pci-epf-vntb: fix error handle in epf_ntb_mw_bar_init()
PCI: endpoint: Fix Kconfig dependency
NTB: EPF: set pointer addr to null using NULL rather than 0
Documentation: PCI: extend subheading underline for "lspci output" section
Documentation: PCI: Use code-block block for scratchpad registers diagram
Documentation: PCI: Add specification for the PCI vNTB function device
PCI: endpoint: Support NTB transfer between RC and EP
NTB: epf: Allow more flexibility in the memory BAR map method
PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address
ntb: intel: add GNR support for Intel PCIe gen5 NTB
NTB: ntb_tool: uninitialized heap data in tool_fn_write()
ntb: idt: fix clang -Wformat warnings
Diffstat (limited to 'Documentation/PCI')
-rw-r--r-- | Documentation/PCI/endpoint/index.rst | 2 | ||||
-rw-r--r-- | Documentation/PCI/endpoint/pci-vntb-function.rst | 129 | ||||
-rw-r--r-- | Documentation/PCI/endpoint/pci-vntb-howto.rst | 167 |
3 files changed, 298 insertions, 0 deletions
diff --git a/Documentation/PCI/endpoint/index.rst b/Documentation/PCI/endpoint/index.rst index 38ea1f604b6d..4d2333e7ae06 100644 --- a/Documentation/PCI/endpoint/index.rst +++ b/Documentation/PCI/endpoint/index.rst @@ -13,6 +13,8 @@ PCI Endpoint Framework pci-test-howto pci-ntb-function pci-ntb-howto + pci-vntb-function + pci-vntb-howto function/binding/pci-test function/binding/pci-ntb diff --git a/Documentation/PCI/endpoint/pci-vntb-function.rst b/Documentation/PCI/endpoint/pci-vntb-function.rst new file mode 100644 index 000000000000..0c51f53ab972 --- /dev/null +++ b/Documentation/PCI/endpoint/pci-vntb-function.rst @@ -0,0 +1,129 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +PCI vNTB Function +================= + +:Author: Frank Li <Frank.Li@nxp.com> + +The difference between PCI NTB function and PCI vNTB function is + +PCI NTB function need at two endpoint instances and connect HOST1 +and HOST2. + +PCI vNTB function only use one host and one endpoint(EP), use NTB +connect EP and PCI host + +.. code-block:: text + + + +------------+ +---------------------------------------+ + | | | | + +------------+ | +--------------+ + | NTB | | | NTB | + | NetDev | | | NetDev | + +------------+ | +--------------+ + | NTB | | | NTB | + | Transfer | | | Transfer | + +------------+ | +--------------+ + | | | | | + | PCI NTB | | | | + | EPF | | | | + | Driver | | | PCI Virtual | + | | +---------------+ | NTB Driver | + | | | PCI EP NTB |<------>| | + | | | FN Driver | | | + +------------+ +---------------+ +--------------+ + | | | | | | + | PCI BUS | <-----> | PCI EP BUS | | Virtual PCI | + | | PCI | | | BUS | + +------------+ +---------------+--------+--------------+ + PCI RC PCI EP + +Constructs used for Implementing vNTB +===================================== + + 1) Config Region + 2) Self Scratchpad Registers + 3) Peer Scratchpad Registers + 4) Doorbell (DB) Registers + 5) Memory Window (MW) + + +Config Region: +-------------- + +It is same as PCI NTB Function driver + +Scratchpad Registers: +--------------------- + +It is appended after Config region. + +.. code-block:: text + + + +--------------------------------------------------+ Base + | | + | | + | | + | Common Config Register | + | | + | | + | | + +-----------------------+--------------------------+ Base + span_offset + | | | + | Peer Span Space | Span Space | + | | | + | | | + +-----------------------+--------------------------+ Base + span_offset + | | | + span_count * 4 + | | | + | Span Space | Peer Span Space | + | | | + +-----------------------+--------------------------+ + Virtual PCI Pcie Endpoint + NTB Driver NTB Driver + + +Doorbell Registers: +------------------- + + Doorbell Registers are used by the hosts to interrupt each other. + +Memory Window: +-------------- + + Actual transfer of data between the two hosts will happen using the + memory window. + +Modeling Constructs: +==================== + +32-bit BARs. + +====== =============== +BAR NO CONSTRUCTS USED +====== =============== +BAR0 Config Region +BAR1 Doorbell +BAR2 Memory Window 1 +BAR3 Memory Window 2 +BAR4 Memory Window 3 +BAR5 Memory Window 4 +====== =============== + +64-bit BARs. + +====== =============================== +BAR NO CONSTRUCTS USED +====== =============================== +BAR0 Config Region + Scratchpad +BAR1 +BAR2 Doorbell +BAR3 +BAR4 Memory Window 1 +BAR5 +====== =============================== + + diff --git a/Documentation/PCI/endpoint/pci-vntb-howto.rst b/Documentation/PCI/endpoint/pci-vntb-howto.rst new file mode 100644 index 000000000000..4ab8e4a26d4b --- /dev/null +++ b/Documentation/PCI/endpoint/pci-vntb-howto.rst @@ -0,0 +1,167 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=================================================================== +PCI Non-Transparent Bridge (NTB) Endpoint Function (EPF) User Guide +=================================================================== + +:Author: Frank Li <Frank.Li@nxp.com> + +This document is a guide to help users use pci-epf-vntb function driver +and ntb_hw_epf host driver for NTB functionality. The list of steps to +be followed in the host side and EP side is given below. For the hardware +configuration and internals of NTB using configurable endpoints see +Documentation/PCI/endpoint/pci-vntb-function.rst + +Endpoint Device +=============== + +Endpoint Controller Devices +--------------------------- + +To find the list of endpoint controller devices in the system:: + + # ls /sys/class/pci_epc/ + 5f010000.pcie_ep + +If PCI_ENDPOINT_CONFIGFS is enabled:: + + # ls /sys/kernel/config/pci_ep/controllers + 5f010000.pcie_ep + +Endpoint Function Drivers +------------------------- + +To find the list of endpoint function drivers in the system:: + + # ls /sys/bus/pci-epf/drivers + pci_epf_ntb pci_epf_test pci_epf_vntb + +If PCI_ENDPOINT_CONFIGFS is enabled:: + + # ls /sys/kernel/config/pci_ep/functions + pci_epf_ntb pci_epf_test pci_epf_vntb + + +Creating pci-epf-vntb Device +---------------------------- + +PCI endpoint function device can be created using the configfs. To create +pci-epf-vntb device, the following commands can be used:: + + # mount -t configfs none /sys/kernel/config + # cd /sys/kernel/config/pci_ep/ + # mkdir functions/pci_epf_vntb/func1 + +The "mkdir func1" above creates the pci-epf-ntb function device that will +be probed by pci_epf_vntb driver. + +The PCI endpoint framework populates the directory with the following +configurable fields:: + + # ls functions/pci_epf_ntb/func1 + baseclass_code deviceid msi_interrupts pci-epf-ntb.0 + progif_code secondary subsys_id vendorid + cache_line_size interrupt_pin msix_interrupts primary + revid subclass_code subsys_vendor_id + +The PCI endpoint function driver populates these entries with default values +when the device is bound to the driver. The pci-epf-vntb driver populates +vendorid with 0xffff and interrupt_pin with 0x0001:: + + # cat functions/pci_epf_vntb/func1/vendorid + 0xffff + # cat functions/pci_epf_vntb/func1/interrupt_pin + 0x0001 + + +Configuring pci-epf-vntb Device +------------------------------- + +The user can configure the pci-epf-vntb device using its configfs entry. In order +to change the vendorid and the deviceid, the following +commands can be used:: + + # echo 0x1957 > functions/pci_epf_vntb/func1/vendorid + # echo 0x0809 > functions/pci_epf_vntb/func1/deviceid + +In order to configure NTB specific attributes, a new sub-directory to func1 +should be created:: + + # mkdir functions/pci_epf_vntb/func1/pci_epf_vntb.0/ + +The NTB function driver will populate this directory with various attributes +that can be configured by the user:: + + # ls functions/pci_epf_vntb/func1/pci_epf_vntb.0/ + db_count mw1 mw2 mw3 mw4 num_mws + spad_count + +A sample configuration for NTB function is given below:: + + # echo 4 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/db_count + # echo 128 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/spad_count + # echo 1 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/num_mws + # echo 0x100000 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/mw1 + +A sample configuration for virtual NTB driver for virutal PCI bus:: + + # echo 0x1957 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_vid + # echo 0x080A > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vntb_pid + # echo 0x10 > functions/pci_epf_vntb/func1/pci_epf_vntb.0/vbus_number + +Binding pci-epf-ntb Device to EP Controller +-------------------------------------------- + +NTB function device should be attached to PCI endpoint controllers +connected to the host. + + # ln -s controllers/5f010000.pcie_ep functions/pci-epf-ntb/func1/primary + +Once the above step is completed, the PCI endpoint controllers are ready to +establish a link with the host. + + +Start the Link +-------------- + +In order for the endpoint device to establish a link with the host, the _start_ +field should be populated with '1'. For NTB, both the PCI endpoint controllers +should establish link with the host (imx8 don't need this steps):: + + # echo 1 > controllers/5f010000.pcie_ep/start + +RootComplex Device +================== + +lspci Output at Host side +------------------------- + +Note that the devices listed here correspond to the values populated in +"Creating pci-epf-ntb Device" section above:: + + # lspci + 00:00.0 PCI bridge: Freescale Semiconductor Inc Device 0000 (rev 01) + 01:00.0 RAM memory: Freescale Semiconductor Inc Device 0809 + +Endpoint Device / Virtual PCI bus +================================= + +lspci Output at EP Side / Virtual PCI bus +----------------------------------------- + +Note that the devices listed here correspond to the values populated in +"Creating pci-epf-ntb Device" section above:: + + # lspci + 10:00.0 Unassigned class [ffff]: Dawicontrol Computersysteme GmbH Device 1234 (rev ff) + +Using ntb_hw_epf Device +----------------------- + +The host side software follows the standard NTB software architecture in Linux. +All the existing client side NTB utilities like NTB Transport Client and NTB +Netdev, NTB Ping Pong Test Client and NTB Tool Test Client can be used with NTB +function device. + +For more information on NTB see +:doc:`Non-Transparent Bridge <../../driver-api/ntb>` |