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>

Documentation/ABI/testing/sysfs-bus-pci

@@ -139,3 +139,30 @@ Contact:	linux-pci@vger.kernel.org
 Description:
 		This symbolic link points to the PCI hotplug controller driver
 		module that manages the hotplug slot.
+
+What:		/sys/bus/pci/devices/.../label
+Date:		July 2010
+Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
+Description:
+		Reading this attribute will provide the firmware
+		given name(SMBIOS type 41 string) of the PCI device.
+		The attribute will be created only if the firmware
+		has given a name to the PCI device.
+Users:
+		Userspace applications interested in knowing the
+		firmware assigned name of the PCI device.
+
+What:		/sys/bus/pci/devices/.../index
+Date:		July 2010
+Contact:	Narendra K <narendra_k@dell.com>, linux-bugs@dell.com
+Description:
+		Reading this attribute will provide the firmware
+		given instance(SMBIOS type 41 device type instance)
+		of the PCI device. The attribute will be created
+		only if the firmware has given a device type instance
+		to the PCI device.
+Users:
+		Userspace applications interested in knowing the
+		firmware assigned device type instance of the PCI
+		device that can help in understanding the firmware
+		intended order of the PCI device.

drivers/firmware/dmi_scan.c

@@ -277,6 +277,29 @@ static void __init dmi_save_ipmi_device(const struct dmi_header *dm)
 	list_add_tail(&dev->list, &dmi_devices);
 }
 
+static void __init dmi_save_dev_onboard(int instance, int segment, int bus,
+					int devfn, const char *name)
+{
+	struct dmi_dev_onboard *onboard_dev;
+
+	onboard_dev = dmi_alloc(sizeof(*onboard_dev) + strlen(name) + 1);
+	if (!onboard_dev) {
+		printk(KERN_ERR "dmi_save_dev_onboard: out of memory.\n");
+		return;
+	}
+	onboard_dev->instance = instance;
+	onboard_dev->segment = segment;
+	onboard_dev->bus = bus;
+	onboard_dev->devfn = devfn;
+
+	strcpy((char *)&onboard_dev[1], name);
+	onboard_dev->dev.type = DMI_DEV_TYPE_DEV_ONBOARD;
+	onboard_dev->dev.name = (char *)&onboard_dev[1];
+	onboard_dev->dev.device_data = onboard_dev;
+
+	list_add(&onboard_dev->dev.list, &dmi_devices);
+}
+
 static void __init dmi_save_extended_devices(const struct dmi_header *dm)
 {
 	const u8 *d = (u8*) dm + 5;
@@ -285,6 +308,8 @@ static void __init dmi_save_extended_devices(const struct dmi_header *dm)
 	if ((*d & 0x80) == 0)
 		return;
 
+	dmi_save_dev_onboard(*(d+1), *(u16 *)(d+2), *(d+4), *(d+5),
+			     dmi_string_nosave(dm, *(d-1)));
 	dmi_save_one_device(*d & 0x7f, dmi_string_nosave(dm, *(d - 1)));
 }
 

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
 

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);
+}

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)

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,

include/linux/dmi.h

@@ -20,6 +20,7 @@ enum dmi_device_type {
 	DMI_DEV_TYPE_SAS,
 	DMI_DEV_TYPE_IPMI = -1,
 	DMI_DEV_TYPE_OEM_STRING = -2,
+	DMI_DEV_TYPE_DEV_ONBOARD = -3,
 };
 
 struct dmi_header {
@@ -37,6 +38,14 @@ struct dmi_device {
 
 #ifdef CONFIG_DMI
 
+struct dmi_dev_onboard {
+	struct dmi_device dev;
+	int instance;
+	int segment;
+	int bus;
+	int devfn;
+};
+
 extern int dmi_check_system(const struct dmi_system_id *list);
 const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list);
 extern const char * dmi_get_system_info(int field);