1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
new file mode 100644
index 00000000..edaed6f4
--- /dev/null
+++ b/drivers/pci/pci-label.c
@@ -0,0 +1,383 @@
+/*
+ * 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>
+ *
+ * PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
+ * PCI or PCI Express Device Under Operating Systems) defines an instance
+ * number and string name. This code retrieves them and exports them to sysfs.
+ * If the system firmware does not provide the ACPI _DSM (Device Specific
+ * Method), then the SMBIOS type 41 instance number and string is exported to
+ * sysfs.
+ *
+ * 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 <linux/nls.h>
+#include <linux/acpi.h>
+#include <linux/pci-acpi.h>
+#include <acpi/acpi_bus.h>
+#include "pci.h"
+
+#define	DEVICE_LABEL_DSM	0x07
+
+#ifndef CONFIG_DMI
+
+static inline int
+pci_create_smbiosname_file(struct pci_dev *pdev)
+{
+	return -1;
+}
+
+static inline void
+pci_remove_smbiosname_file(struct pci_dev *pdev)
+{
+}
+
+#else
+
+enum smbios_attr_enum {
+	SMBIOS_ATTR_NONE = 0,
+	SMBIOS_ATTR_LABEL_SHOW,
+	SMBIOS_ATTR_INSTANCE_SHOW,
+};
+
+static size_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 umode_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},
+	.show = smbioslabel_show,
+};
+
+static struct device_attribute smbios_attr_instance = {
+	.attr = {.name = "index", .mode = 0444},
+	.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)
+{
+	return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
+}
+
+static void
+pci_remove_smbiosname_file(struct pci_dev *pdev)
+{
+	sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
+}
+
+#endif
+
+#ifndef CONFIG_ACPI
+
+static inline int
+pci_create_acpi_index_label_files(struct pci_dev *pdev)
+{
+	return -1;
+}
+
+static inline int
+pci_remove_acpi_index_label_files(struct pci_dev *pdev)
+{
+	return -1;
+}
+
+static inline bool
+device_has_dsm(struct device *dev)
+{
+	return false;
+}
+
+#else
+
+static const char device_label_dsm_uuid[] = {
+	0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
+	0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
+};
+
+enum acpi_attr_enum {
+	ACPI_ATTR_NONE = 0,
+	ACPI_ATTR_LABEL_SHOW,
+	ACPI_ATTR_INDEX_SHOW,
+};
+
+static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
+{
+	int len;
+	len = utf16s_to_utf8s((const wchar_t *)obj->
+			      package.elements[1].string.pointer,
+			      obj->package.elements[1].string.length,
+			      UTF16_LITTLE_ENDIAN,
+			      buf, PAGE_SIZE);
+	buf[len] = '\n';
+}
+
+static int
+dsm_get_label(acpi_handle handle, int func,
+	      struct acpi_buffer *output,
+	      char *buf, enum acpi_attr_enum attribute)
+{
+	struct acpi_object_list input;
+	union acpi_object params[4];
+	union acpi_object *obj;
+	int len = 0;
+
+	int err;
+
+	input.count = 4;
+	input.pointer = params;
+	params[0].type = ACPI_TYPE_BUFFER;
+	params[0].buffer.length = sizeof(device_label_dsm_uuid);
+	params[0].buffer.pointer = (char *)device_label_dsm_uuid;
+	params[1].type = ACPI_TYPE_INTEGER;
+	params[1].integer.value = 0x02;
+	params[2].type = ACPI_TYPE_INTEGER;
+	params[2].integer.value = func;
+	params[3].type = ACPI_TYPE_PACKAGE;
+	params[3].package.count = 0;
+	params[3].package.elements = NULL;
+
+	err = acpi_evaluate_object(handle, "_DSM", &input, output);
+	if (err)
+		return -1;
+
+	obj = (union acpi_object *)output->pointer;
+
+	switch (obj->type) {
+	case ACPI_TYPE_PACKAGE:
+		if (obj->package.count != 2)
+			break;
+		len = obj->package.elements[0].integer.value;
+		if (buf) {
+			if (attribute == ACPI_ATTR_INDEX_SHOW)
+				scnprintf(buf, PAGE_SIZE, "%llu\n",
+				obj->package.elements[0].integer.value);
+			else if (attribute == ACPI_ATTR_LABEL_SHOW)
+				dsm_label_utf16s_to_utf8s(obj, buf);
+			kfree(output->pointer);
+			return strlen(buf);
+		}
+		kfree(output->pointer);
+		return len;
+	break;
+	default:
+		kfree(output->pointer);
+	}
+	return -1;
+}
+
+static bool
+device_has_dsm(struct device *dev)
+{
+	acpi_handle handle;
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+
+	handle = DEVICE_ACPI_HANDLE(dev);
+
+	if (!handle)
+		return FALSE;
+
+	if (dsm_get_label(handle, DEVICE_LABEL_DSM, &output, NULL,
+			  ACPI_ATTR_NONE) > 0)
+		return TRUE;
+
+	return FALSE;
+}
+
+static umode_t
+acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct device *dev;
+
+	dev = container_of(kobj, struct device, kobj);
+
+	if (device_has_dsm(dev))
+		return S_IRUGO;
+
+	return 0;
+}
+
+static ssize_t
+acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_handle handle;
+	int length;
+
+	handle = DEVICE_ACPI_HANDLE(dev);
+
+	if (!handle)
+		return -1;
+
+	length = dsm_get_label(handle, DEVICE_LABEL_DSM,
+			       &output, buf, ACPI_ATTR_LABEL_SHOW);
+
+	if (length < 1)
+		return -1;
+
+	return length;
+}
+
+static ssize_t
+acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_handle handle;
+	int length;
+
+	handle = DEVICE_ACPI_HANDLE(dev);
+
+	if (!handle)
+		return -1;
+
+	length = dsm_get_label(handle, DEVICE_LABEL_DSM,
+			       &output, buf, ACPI_ATTR_INDEX_SHOW);
+
+	if (length < 0)
+		return -1;
+
+	return length;
+
+}
+
+static struct device_attribute acpi_attr_label = {
+	.attr = {.name = "label", .mode = 0444},
+	.show = acpilabel_show,
+};
+
+static struct device_attribute acpi_attr_index = {
+	.attr = {.name = "acpi_index", .mode = 0444},
+	.show = acpiindex_show,
+};
+
+static struct attribute *acpi_attributes[] = {
+	&acpi_attr_label.attr,
+	&acpi_attr_index.attr,
+	NULL,
+};
+
+static struct attribute_group acpi_attr_group = {
+	.attrs = acpi_attributes,
+	.is_visible = acpi_index_string_exist,
+};
+
+static int
+pci_create_acpi_index_label_files(struct pci_dev *pdev)
+{
+	return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
+}
+
+static int
+pci_remove_acpi_index_label_files(struct pci_dev *pdev)
+{
+	sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
+	return 0;
+}
+#endif
+
+void pci_create_firmware_label_files(struct pci_dev *pdev)
+{
+	if (device_has_dsm(&pdev->dev))
+		pci_create_acpi_index_label_files(pdev);
+	else
+		pci_create_smbiosname_file(pdev);
+}
+
+void pci_remove_firmware_label_files(struct pci_dev *pdev)
+{
+	if (device_has_dsm(&pdev->dev))
+		pci_remove_acpi_index_label_files(pdev);
+	else
+		pci_remove_smbiosname_file(pdev);
+}