drivers/pci/pci-label.c

   1 /*
   2  * Purpose: Export the firmware instance and label associated with
   3  * a pci device to sysfs
   4  * Copyright (C) 2010 Dell Inc.
   5  * by Narendra K <[email protected]>,
   6  * Jordan Hargrave <[email protected]>
   7  *
   8  * SMBIOS defines type 41 for onboard pci devices. This code retrieves
   9  * the instance number and string from the type 41 record and exports
  10  * it to sysfs.
  11  *
  12  * Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
  13  * information.
  14  */
  15
  16 #include <linux/dmi.h>
  17 #include <linux/sysfs.h>
  18 #include <linux/pci.h>
  19 #include <linux/pci_ids.h>
  20 #include <linux/module.h>
  21 #include <linux/device.h>
  22 #include "pci.h"
  23
  24 enum smbios_attr_enum {
  25         SMBIOS_ATTR_NONE = 0,
  26         SMBIOS_ATTR_LABEL_SHOW,
  27         SMBIOS_ATTR_INSTANCE_SHOW,
  28 };
  29
  30 static mode_t
  31 find_smbios_instance_string(struct pci_dev *pdev, char *buf,
  32                             enum smbios_attr_enum attribute)
  33 {
  34         const struct dmi_device *dmi;
  35         struct dmi_dev_onboard *donboard;
  36         int bus;
  37         int devfn;
  38
  39         bus = pdev->bus->number;
  40         devfn = pdev->devfn;
  41
  42         dmi = NULL;
  43         while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
  44                                       NULL, dmi)) != NULL) {
  45                 donboard = dmi->device_data;
  46                 if (donboard && donboard->bus == bus &&
  47                                         donboard->devfn == devfn) {
  48                         if (buf) {
  49                                 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
  50                                         return scnprintf(buf, PAGE_SIZE,
  51                                                          "%d\n",
  52                                                          donboard->instance);
  53                                 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
  54                                         return scnprintf(buf, PAGE_SIZE,
  55                                                          "%s\n",
  56                                                          dmi->name);
  57                         }
  58                         return strlen(dmi->name);
  59                 }
  60         }
  61         return 0;
  62 }
  63
  64 static mode_t
  65 smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
  66                              int n)
  67 {
  68         struct device *dev;
  69         struct pci_dev *pdev;
  70
  71         dev = container_of(kobj, struct device, kobj);
  72         pdev = to_pci_dev(dev);
  73
  74         return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
  75                                            S_IRUGO : 0;
  76 }
  77
  78 static ssize_t
  79 smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
  80 {
  81         struct pci_dev *pdev;
  82         pdev = to_pci_dev(dev);
  83
  84         return find_smbios_instance_string(pdev, buf,
  85                                            SMBIOS_ATTR_LABEL_SHOW);
  86 }
  87
  88 static ssize_t
  89 smbiosinstance_show(struct device *dev,
  90                     struct device_attribute *attr, char *buf)
  91 {
  92         struct pci_dev *pdev;
  93         pdev = to_pci_dev(dev);
  94
  95         return find_smbios_instance_string(pdev, buf,
  96                                            SMBIOS_ATTR_INSTANCE_SHOW);
  97 }
  98
  99 static struct device_attribute smbios_attr_label = {
 100         .attr = {.name = "label", .mode = 0444},
 101         .show = smbioslabel_show,
 102 };
 103
 104 static struct device_attribute smbios_attr_instance = {
 105         .attr = {.name = "index", .mode = 0444},
 106         .show = smbiosinstance_show,
 107 };
 108
 109 static struct attribute *smbios_attributes[] = {
 110         &smbios_attr_label.attr,
 111         &smbios_attr_instance.attr,
 112         NULL,
 113 };
 114
 115 static struct attribute_group smbios_attr_group = {
 116         .attrs = smbios_attributes,
 117         .is_visible = smbios_instance_string_exist,
 118 };
 119
 120 static int
 121 pci_create_smbiosname_file(struct pci_dev *pdev)
 122 {
 123         if (!sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group))
 124                 return 0;
 125         return -ENODEV;
 126 }
 127
 128 static void
 129 pci_remove_smbiosname_file(struct pci_dev *pdev)
 130 {
 131         sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
 132 }
 133
 134 void pci_create_firmware_label_files(struct pci_dev *pdev)
 135 {
 136         if (!pci_create_smbiosname_file(pdev))
 137                 ;
 138 }
 139
 140 void pci_remove_firmware_label_files(struct pci_dev *pdev)
 141 {
 142         pci_remove_smbiosname_file(pdev);
 143 }