PCI: export SMBIOS provided firmware instance and label to sysfs

This patch exports SMBIOS provided firmware instance and label of
onboard PCI devices to sysfs.  New files are:
  /sys/bus/pci/devices/.../label which contains the firmware name for
the device in question, and
  /sys/bus/pci/devices/.../index which contains the firmware device type
instance for the given device.

Signed-off-by: Jordan Hargrave <jordan_hargrave@dell.com>
Signed-off-by: Narendra K <narendra_k@dell.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

4 files changed, 160 insertions, 0 deletions

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 0b51857fbaf7..dc1aa0922868 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -55,6 +55,9 @@ obj-$(CONFIG_MICROBLAZE) += setup-bus.o
 #
 obj-$(CONFIG_ACPI)    += pci-acpi.o
 
+# SMBIOS provided firmware instance and labels
+obj-$(CONFIG_DMI)    += pci-label.o
+
 # Cardbus & CompactPCI use setup-bus
 obj-$(CONFIG_HOTPLUG) += setup-bus.o
 
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
new file mode 100644
index 000000000000..111500e86f94
--- /dev/null
+++ b/drivers/pci/pci-label.c
@@ -0,0 +1,143 @@
+/*
+ * Purpose: Export the firmware instance and label associated with
+ * a pci device to sysfs
+ * Copyright (C) 2010 Dell Inc.
+ * by Narendra K <Narendra_K@dell.com>,
+ * Jordan Hargrave <Jordan_Hargrave@dell.com>
+ *
+ * SMBIOS defines type 41 for onboard pci devices. This code retrieves
+ * the instance number and string from the type 41 record and exports
+ * it to sysfs.
+ *
+ * Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
+ * information.
+ */
+
+#include <linux/dmi.h>
+#include <linux/sysfs.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include "pci.h"
+
+enum smbios_attr_enum {
+        SMBIOS_ATTR_NONE = 0,
+        SMBIOS_ATTR_LABEL_SHOW,
+        SMBIOS_ATTR_INSTANCE_SHOW,
+};
+
+static mode_t
+find_smbios_instance_string(struct pci_dev *pdev, char *buf,
+                            enum smbios_attr_enum attribute)
+{
+        const struct dmi_device *dmi;
+        struct dmi_dev_onboard *donboard;
+        int bus;
+        int devfn;
+
+        bus = pdev->bus->number;
+        devfn = pdev->devfn;
+
+        dmi = NULL;
+        while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
+                                      NULL, dmi)) != NULL) {
+                donboard = dmi->device_data;
+                if (donboard && donboard->bus == bus &&
+                                        donboard->devfn == devfn) {
+                        if (buf) {
+                                if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
+                                        return scnprintf(buf, PAGE_SIZE,
+                                                         "%d\n",
+                                                         donboard->instance);
+                                else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
+                                        return scnprintf(buf, PAGE_SIZE,
+                                                         "%s\n",
+                                                         dmi->name);
+                        }
+                        return strlen(dmi->name);
+                }
+        }
+        return 0;
+}
+
+static mode_t
+smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
+                             int n)
+{
+        struct device *dev;
+        struct pci_dev *pdev;
+
+        dev = container_of(kobj, struct device, kobj);
+        pdev = to_pci_dev(dev);
+
+        return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
+                                           S_IRUGO : 0;
+}
+
+static ssize_t
+smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct pci_dev *pdev;
+        pdev = to_pci_dev(dev);
+
+        return find_smbios_instance_string(pdev, buf,
+                                           SMBIOS_ATTR_LABEL_SHOW);
+}
+
+static ssize_t
+smbiosinstance_show(struct device *dev,
+                    struct device_attribute *attr, char *buf)
+{
+        struct pci_dev *pdev;
+        pdev = to_pci_dev(dev);
+
+        return find_smbios_instance_string(pdev, buf,
+                                           SMBIOS_ATTR_INSTANCE_SHOW);
+}
+
+static struct device_attribute smbios_attr_label = {
+        .attr = {.name = "label", .mode = 0444, .owner = THIS_MODULE},
+        .show = smbioslabel_show,
+};
+
+static struct device_attribute smbios_attr_instance = {
+        .attr = {.name = "index", .mode = 0444, .owner = THIS_MODULE},
+        .show = smbiosinstance_show,
+};
+
+static struct attribute *smbios_attributes[] = {
+        &smbios_attr_label.attr,
+        &smbios_attr_instance.attr,
+        NULL,
+};
+
+static struct attribute_group smbios_attr_group = {
+        .attrs = smbios_attributes,
+        .is_visible = smbios_instance_string_exist,
+};
+
+static int
+pci_create_smbiosname_file(struct pci_dev *pdev)
+{
+        if (!sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group))
+                return 0;
+        return -ENODEV;
+}
+
+static void
+pci_remove_smbiosname_file(struct pci_dev *pdev)
+{
+        sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
+}
+
+void pci_create_firmware_label_files(struct pci_dev *pdev)
+{
+        if (!pci_create_smbiosname_file(pdev))
+                ;
+}
+
+void pci_remove_firmware_label_files(struct pci_dev *pdev)
+{
+        pci_remove_smbiosname_file(pdev);
+}
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index f7692dc531e4..b5a7d9bfcb24 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1165,6 +1165,8 @@ int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
         if (retval)
                 goto err_vga_file;
 
+        pci_create_firmware_label_files(pdev);
+
         return 0;
 
 err_vga_file:
@@ -1232,6 +1234,9 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
                 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
                 kfree(pdev->rom_attr);
         }
+
+        pci_remove_firmware_label_files(pdev);
+
 }
 
 static int __init pci_sysfs_init(void)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f8077b3c8c8c..d930338e0922 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -11,6 +11,15 @@
 extern int pci_uevent(struct device *dev, struct kobj_uevent_env *env);
 extern int pci_create_sysfs_dev_files(struct pci_dev *pdev);
 extern void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
+#ifndef CONFIG_DMI
+static inline void pci_create_firmware_label_files(struct pci_dev *pdev)
+{ return 0; }
+static inline void pci_remove_firmware_label_files(struct pci_dev *pdev)
+{ return 0; }
+#else
+extern void pci_create_firmware_label_files(struct pci_dev *pdev);
+extern void pci_remove_firmware_label_files(struct pci_dev *pdev);
+#endif
 extern void pci_cleanup_rom(struct pci_dev *dev);
 #ifdef HAVE_PCI_MMAP
 extern int pci_mmap_fits(struct pci_dev *pdev, int resno,