如何为 PCIe UIO 设备创建基于序列号的符号链接？

Question 1

我也找到了第二个问题的答案。我创建了一个显示 PCIe 设备序列号的简单应用程序。它可用于替换lspci帮助程序脚本中的调用。它还消除了输出格式的更改lspci导致先前解决方案无效的风险。来源：

/*
  Simple application displaying the PCIe Device Serial Number
  Written by Wojciech M. Zabolotny ([email protected] or [email protected])
  2021.05.23
  This code is heavily based on the examples provided in the pciutils package
  https://github.com/pciutils/pciutils therefore I release it under the same
  license: GNU GENERAL PUBLIC LICENSE Version 2, June 1991
  
  You may compile it with:
    gcc -o pcidsn pcidsn.c -lpci
*/

#include <stdio.h>
#include <pci/pci.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>

void __attribute__((noreturn))
die(char *msg, ...)
{
    va_list args;

    va_start(args, msg);
    fprintf(stderr, "pcisdn: ");
    vfprintf(stderr, msg, args);
    fputc('\n', stderr);
    exit(1);
}

int main(int argc, char * argv[])
{
    struct pci_access *pacc;
    struct pci_filter filter;
    struct pci_dev *dev;
    struct pci_cap *pdsn;
    unsigned int c;
    char namebuf[1024], *name;
    char * msg = NULL;
    pacc = pci_alloc();     /* Get the pci_access structure */
    pacc->error = die;
    pci_filter_init(pacc,&filter);
    if (msg=pci_filter_parse_slot(&filter,argv[1])) {
        die("Wrong slot definition: %s",msg);
    };
    pci_init(pacc);     /* Initialize the PCI library */

    pci_scan_bus(pacc);     /* We want to get the list of devices */
    for (dev=pacc->devices; dev; dev=dev->next) /* Iterate over all devices */
    {
        if(pci_filter_match(&filter,dev)) { /* Select only our slot */
            pdsn = pci_find_cap(dev, PCI_EXT_CAP_ID_DSN, PCI_CAP_EXTENDED);
            if(pdsn) {
                uint32_t lw = pci_read_long(dev, pdsn->addr+4);
                uint32_t hw = pci_read_long(dev, pdsn->addr+8);
                printf("%8.8lx%8.8lx\n",hw,lw);
            }
        }
    }
    pci_cleanup(pacc);      /* Close everything */
    return 0;
}

可以编译为

gcc -o pcidsn pcidsn.c -lpci

生成的应用程序应该可以通过系统路径获得。/opt/bin/uio_namer然后应将帮助程序脚本修改为：

#!/bin/sh
set -e
SLOTNAME=`basename \`readlink /sys/${DEVPATH}/device\``
DSNCAP=`pcidsn ${SLOTNAME}`
echo daq/${DSNCAP##*" "}

udev 规则/etc/udev/rules.d/30-daq.rules可能如前所述：

SUBSYSTEM=="uio"  ACTION=="add" ATTRS{vendor}=="0xabba" ATTRS{device}=="0x3342" PROGRAM="/opt/bin/uio_namer" SYMLINK="%c"

Answer

我也找到了第二个问题的答案。我创建了一个显示 PCIe 设备序列号的简单应用程序。它可用于替换lspci帮助程序脚本中的调用。它还消除了输出格式的更改lspci导致先前解决方案无效的风险。来源：

/*
  Simple application displaying the PCIe Device Serial Number
  Written by Wojciech M. Zabolotny ([email protected] or [email protected])
  2021.05.23
  This code is heavily based on the examples provided in the pciutils package
  https://github.com/pciutils/pciutils therefore I release it under the same
  license: GNU GENERAL PUBLIC LICENSE Version 2, June 1991
  
  You may compile it with:
    gcc -o pcidsn pcidsn.c -lpci
*/

#include <stdio.h>
#include <pci/pci.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>

void __attribute__((noreturn))
die(char *msg, ...)
{
    va_list args;

    va_start(args, msg);
    fprintf(stderr, "pcisdn: ");
    vfprintf(stderr, msg, args);
    fputc('\n', stderr);
    exit(1);
}

int main(int argc, char * argv[])
{
    struct pci_access *pacc;
    struct pci_filter filter;
    struct pci_dev *dev;
    struct pci_cap *pdsn;
    unsigned int c;
    char namebuf[1024], *name;
    char * msg = NULL;
    pacc = pci_alloc();     /* Get the pci_access structure */
    pacc->error = die;
    pci_filter_init(pacc,&filter);
    if (msg=pci_filter_parse_slot(&filter,argv[1])) {
        die("Wrong slot definition: %s",msg);
    };
    pci_init(pacc);     /* Initialize the PCI library */

    pci_scan_bus(pacc);     /* We want to get the list of devices */
    for (dev=pacc->devices; dev; dev=dev->next) /* Iterate over all devices */
    {
        if(pci_filter_match(&filter,dev)) { /* Select only our slot */
            pdsn = pci_find_cap(dev, PCI_EXT_CAP_ID_DSN, PCI_CAP_EXTENDED);
            if(pdsn) {
                uint32_t lw = pci_read_long(dev, pdsn->addr+4);
                uint32_t hw = pci_read_long(dev, pdsn->addr+8);
                printf("%8.8lx%8.8lx\n",hw,lw);
            }
        }
    }
    pci_cleanup(pacc);      /* Close everything */
    return 0;
}

可以编译为

gcc -o pcidsn pcidsn.c -lpci

生成的应用程序应该可以通过系统路径获得。/opt/bin/uio_namer然后应将帮助程序脚本修改为：

#!/bin/sh
set -e
SLOTNAME=`basename \`readlink /sys/${DEVPATH}/device\``
DSNCAP=`pcidsn ${SLOTNAME}`
echo daq/${DSNCAP##*" "}

udev 规则/etc/udev/rules.d/30-daq.rules可能如前所述：

SUBSYSTEM=="uio"  ACTION=="add" ATTRS{vendor}=="0xabba" ATTRS{device}=="0x3342" PROGRAM="/opt/bin/uio_namer" SYMLINK="%c"

Question 2

我已经找到了第一个问题的答案。在http://reactivated.net/writing_udev_rules.html有一个说法：

ATTRS - 匹配设备的 sysfs 属性，或任何父设备的 sysfs 属性

因此 PCI 供应商和设备属性的规则也可能与父设备匹配。

udev 规则/etc/udev/rules.d/30-daq.rules可以修改为：

SUBSYSTEM=="uio"  ACTION=="add" ATTRS{vendor}=="0xabba" ATTRS{device}=="0x3342" PROGRAM="/opt/bin/uio_namer" SYMLINK="%c"

辅助脚本/opt/bin/uio_namer可以简化为：

#!/bin/sh
SLOTNAME=`basename \`readlink /sys/${DEVPATH}/device\``
DSNCAP=`lspci -vvv -s ${SLOTNAME} | grep "Device Serial Number" `
echo daq/${DSNCAP##*" "}

Answer