.. SPDX-License-Identifier: GPL-2.0

===================
PCI Test User Guide
===================

:Author: Kishon Vijay Abraham I <kishon@ti.com>

This document is a guide to help users use pci-epf-test function driver
and pci_endpoint_test host driver for testing PCI. The list of steps to
be followed in the host side and EP side is given below.

Endpoint Device
===============

Endpoint Controller Devices
---------------------------

To find the list of endpoint controller devices in the system::

	# ls /sys/class/pci_epc/
	  51000000.pcie_ep

If PCI_ENDPOINT_CONFIGFS is enabled::

	# ls /sys/kernel/config/pci_ep/controllers
	  51000000.pcie_ep


Endpoint Function Drivers
-------------------------

To find the list of endpoint function drivers in the system::

	# ls /sys/bus/pci-epf/drivers
	  pci_epf_test

If PCI_ENDPOINT_CONFIGFS is enabled::

	# ls /sys/kernel/config/pci_ep/functions
	  pci_epf_test


Creating pci-epf-test Device
----------------------------

PCI endpoint function device can be created using the configfs. To create
pci-epf-test device, the following commands can be used::

	# mount -t configfs none /sys/kernel/config
	# cd /sys/kernel/config/pci_ep/
	# mkdir functions/pci_epf_test/func1

The "mkdir func1" above creates the pci-epf-test function device that will
be probed by pci_epf_test driver.

The PCI endpoint framework populates the directory with the following
configurable fields::

	# ls functions/pci_epf_test/func1
	  baseclass_code	interrupt_pin	progif_code	subsys_id
	  cache_line_size	msi_interrupts	revid		subsys_vendorid
	  deviceid          	msix_interrupts	subclass_code	vendorid

The PCI endpoint function driver populates these entries with default values
when the device is bound to the driver. The pci-epf-test driver populates
vendorid with 0xffff and interrupt_pin with 0x0001::

	# cat functions/pci_epf_test/func1/vendorid
	  0xffff
	# cat functions/pci_epf_test/func1/interrupt_pin
	  0x0001


Configuring pci-epf-test Device
-------------------------------

The user can configure the pci-epf-test device using configfs entry. In order
to change the vendorid and the number of MSI interrupts used by the function
device, the following commands can be used::

	# echo 0x104c > functions/pci_epf_test/func1/vendorid
	# echo 0xb500 > functions/pci_epf_test/func1/deviceid
	# echo 32 > functions/pci_epf_test/func1/msi_interrupts
	# echo 2048 > functions/pci_epf_test/func1/msix_interrupts

By default, pci-epf-test uses the following BAR sizes::

	# grep . functions/pci_epf_test/func1/pci_epf_test.0/bar?_size
	  functions/pci_epf_test/func1/pci_epf_test.0/bar0_size:131072
	  functions/pci_epf_test/func1/pci_epf_test.0/bar1_size:131072
	  functions/pci_epf_test/func1/pci_epf_test.0/bar2_size:131072
	  functions/pci_epf_test/func1/pci_epf_test.0/bar3_size:131072
	  functions/pci_epf_test/func1/pci_epf_test.0/bar4_size:131072
	  functions/pci_epf_test/func1/pci_epf_test.0/bar5_size:1048576

The user can override a default value using e.g.::
	# echo 1048576 > functions/pci_epf_test/func1/pci_epf_test.0/bar1_size

Overriding the default BAR sizes can only be done before binding the
pci-epf-test device to a PCI endpoint controller driver.

Note: Some endpoint controllers might have fixed-size BARs or reserved BARs;
for such controllers, the corresponding BAR size in configfs will be ignored.


Binding pci-epf-test Device to EP Controller
--------------------------------------------

In order for the endpoint function device to be useful, it has to be bound to
a PCI endpoint controller driver. Use the configfs to bind the function
device to one of the controller driver present in the system::

	# ln -s functions/pci_epf_test/func1 controllers/51000000.pcie_ep/

Once the above step is completed, the PCI endpoint is 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'::

	# echo 1 > controllers/51000000.pcie_ep/start


RootComplex Device
==================

lspci Output
------------

Note that the devices listed here correspond to the value populated in 1.4
above::

	00:00.0 PCI bridge: Texas Instruments Device 8888 (rev 01)
	01:00.0 Unassigned class [ff00]: Texas Instruments Device b500


Using Endpoint Test function Device
-----------------------------------

Kselftest added in tools/testing/selftests/pci_endpoint can be used to run all
the default PCI endpoint tests. To build the Kselftest for PCI endpoint
subsystem, the following commands should be used::

	# cd <kernel-dir>
	# make -C tools/testing/selftests/pci_endpoint

or if you desire to compile and install in your system::

	# cd <kernel-dir>
	# make -C tools/testing/selftests/pci_endpoint INSTALL_PATH=/usr/bin install

The test will be located in <rootfs>/usr/bin/

Kselftest Output
~~~~~~~~~~~~~~~~
::

	# pci_endpoint_test
	TAP version 13
	1..16
	# Starting 16 tests from 9 test cases.
	#  RUN           pci_ep_bar.BAR0.BAR_TEST ...
	#            OK  pci_ep_bar.BAR0.BAR_TEST
	ok 1 pci_ep_bar.BAR0.BAR_TEST
	#  RUN           pci_ep_bar.BAR1.BAR_TEST ...
	#            OK  pci_ep_bar.BAR1.BAR_TEST
	ok 2 pci_ep_bar.BAR1.BAR_TEST
	#  RUN           pci_ep_bar.BAR2.BAR_TEST ...
	#            OK  pci_ep_bar.BAR2.BAR_TEST
	ok 3 pci_ep_bar.BAR2.BAR_TEST
	#  RUN           pci_ep_bar.BAR3.BAR_TEST ...
	#            OK  pci_ep_bar.BAR3.BAR_TEST
	ok 4 pci_ep_bar.BAR3.BAR_TEST
	#  RUN           pci_ep_bar.BAR4.BAR_TEST ...
	#            OK  pci_ep_bar.BAR4.BAR_TEST
	ok 5 pci_ep_bar.BAR4.BAR_TEST
	#  RUN           pci_ep_bar.BAR5.BAR_TEST ...
	#            OK  pci_ep_bar.BAR5.BAR_TEST
	ok 6 pci_ep_bar.BAR5.BAR_TEST
	#  RUN           pci_ep_basic.CONSECUTIVE_BAR_TEST ...
	#            OK  pci_ep_basic.CONSECUTIVE_BAR_TEST
	ok 7 pci_ep_basic.CONSECUTIVE_BAR_TEST
	#  RUN           pci_ep_basic.LEGACY_IRQ_TEST ...
	#            OK  pci_ep_basic.LEGACY_IRQ_TEST
	ok 8 pci_ep_basic.LEGACY_IRQ_TEST
	#  RUN           pci_ep_basic.MSI_TEST ...
	#            OK  pci_ep_basic.MSI_TEST
	ok 9 pci_ep_basic.MSI_TEST
	#  RUN           pci_ep_basic.MSIX_TEST ...
	#            OK  pci_ep_basic.MSIX_TEST
	ok 10 pci_ep_basic.MSIX_TEST
	#  RUN           pci_ep_data_transfer.memcpy.READ_TEST ...
	#            OK  pci_ep_data_transfer.memcpy.READ_TEST
	ok 11 pci_ep_data_transfer.memcpy.READ_TEST
	#  RUN           pci_ep_data_transfer.memcpy.WRITE_TEST ...
	#            OK  pci_ep_data_transfer.memcpy.WRITE_TEST
	ok 12 pci_ep_data_transfer.memcpy.WRITE_TEST
	#  RUN           pci_ep_data_transfer.memcpy.COPY_TEST ...
	#            OK  pci_ep_data_transfer.memcpy.COPY_TEST
	ok 13 pci_ep_data_transfer.memcpy.COPY_TEST
	#  RUN           pci_ep_data_transfer.dma.READ_TEST ...
	#            OK  pci_ep_data_transfer.dma.READ_TEST
	ok 14 pci_ep_data_transfer.dma.READ_TEST
	#  RUN           pci_ep_data_transfer.dma.WRITE_TEST ...
	#            OK  pci_ep_data_transfer.dma.WRITE_TEST
	ok 15 pci_ep_data_transfer.dma.WRITE_TEST
	#  RUN           pci_ep_data_transfer.dma.COPY_TEST ...
	#            OK  pci_ep_data_transfer.dma.COPY_TEST
	ok 16 pci_ep_data_transfer.dma.COPY_TEST
	# PASSED: 16 / 16 tests passed.
	# Totals: pass:16 fail:0 xfail:0 xpass:0 skip:0 error:0


Testcase 16 (pci_ep_data_transfer.dma.COPY_TEST) will fail for most of the DMA
capable endpoint controllers due to the absence of the MEMCPY over DMA. For such
controllers, it is advisable to skip this testcase using this
command::

	# pci_endpoint_test -f pci_ep_bar -f pci_ep_basic -v memcpy -T COPY_TEST -v dma

Kselftest EP Doorbell
~~~~~~~~~~~~~~~~~~~~~

If the Endpoint MSI controller is used for the doorbell usecase, run below
command for testing it:

	# pci_endpoint_test -f pcie_ep_doorbell

	# Starting 1 tests from 1 test cases.
	#  RUN           pcie_ep_doorbell.DOORBELL_TEST ...
	#            OK  pcie_ep_doorbell.DOORBELL_TEST
	ok 1 pcie_ep_doorbell.DOORBELL_TEST
	# PASSED: 1 / 1 tests passed.
	# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0