9.5. PCI Test User Guide — The Linux Kernel 5.11.11-gnu-2-64 documentation

# 9.5. 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.

## 9.5.1. Endpoint Device

### 9.5.1.1. 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

### 9.5.1.2. 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

### 9.5.1.3. 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

### 9.5.1.4. 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 16 > functions/pci_epf_test/func1/msi_interrupts
    # echo 8 > functions/pci_epf_test/func1/msix_interrupts

### 9.5.1.5. 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.

### 9.5.1.6. 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

## 9.5.2. RootComplex Device

### 9.5.2.1. 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

### 9.5.2.2. Using Endpoint Test function Device

pcitest.sh added in tools/pci/ can be used to run all the default PCI endpoint tests. To compile this tool the following commands should be used:

    # cd <kernel-dir>
    # make -C tools/pci

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

    # cd <kernel-dir>
    # make -C tools/pci install

The tool and script will be located in <rootfs>/usr/bin/

#### 9.5.2.2.1. pcitest.sh Output

    # pcitest.sh
    BAR tests

    BAR0:           OKAY
    BAR1:           OKAY
    BAR2:           OKAY
    BAR3:           OKAY
    BAR4:           NOT OKAY
    BAR5:           NOT OKAY

    Interrupt tests

    SET IRQ TYPE TO LEGACY:         OKAY
    LEGACY IRQ:     NOT OKAY
    SET IRQ TYPE TO MSI:            OKAY
    MSI1:           OKAY
    MSI2:           OKAY
    MSI3:           OKAY
    MSI4:           OKAY
    MSI5:           OKAY
    MSI6:           OKAY
    MSI7:           OKAY
    MSI8:           OKAY
    MSI9:           OKAY
    MSI10:          OKAY
    MSI11:          OKAY
    MSI12:          OKAY
    MSI13:          OKAY
    MSI14:          OKAY
    MSI15:          OKAY
    MSI16:          OKAY
    MSI17:          NOT OKAY
    MSI18:          NOT OKAY
    MSI19:          NOT OKAY
    MSI20:          NOT OKAY
    MSI21:          NOT OKAY
    MSI22:          NOT OKAY
    MSI23:          NOT OKAY
    MSI24:          NOT OKAY
    MSI25:          NOT OKAY
    MSI26:          NOT OKAY
    MSI27:          NOT OKAY
    MSI28:          NOT OKAY
    MSI29:          NOT OKAY
    MSI30:          NOT OKAY
    MSI31:          NOT OKAY
    MSI32:          NOT OKAY
    SET IRQ TYPE TO MSI-X:          OKAY
    MSI-X1:         OKAY
    MSI-X2:         OKAY
    MSI-X3:         OKAY
    MSI-X4:         OKAY
    MSI-X5:         OKAY
    MSI-X6:         OKAY
    MSI-X7:         OKAY
    MSI-X8:         OKAY
    MSI-X9:         NOT OKAY
    MSI-X10:        NOT OKAY
    MSI-X11:        NOT OKAY
    MSI-X12:        NOT OKAY
    MSI-X13:        NOT OKAY
    MSI-X14:        NOT OKAY
    MSI-X15:        NOT OKAY
    MSI-X16:        NOT OKAY
    [...]
    MSI-X2047:      NOT OKAY
    MSI-X2048:      NOT OKAY

    Read Tests

    SET IRQ TYPE TO MSI:            OKAY
    READ (      1 bytes):           OKAY
    READ (   1024 bytes):           OKAY
    READ (   1025 bytes):           OKAY
    READ (1024000 bytes):           OKAY
    READ (1024001 bytes):           OKAY

    Write Tests

    WRITE (      1 bytes):          OKAY
    WRITE (   1024 bytes):          OKAY
    WRITE (   1025 bytes):          OKAY
    WRITE (1024000 bytes):          OKAY
    WRITE (1024001 bytes):          OKAY

    Copy Tests

    COPY (      1 bytes):           OKAY
    COPY (   1024 bytes):           OKAY
    COPY (   1025 bytes):           OKAY
    COPY (1024000 bytes):           OKAY
    COPY (1024001 bytes):           OKAY