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 <Narendra_K@dell.com>,
6 * Jordan Hargrave <Jordan_Hargrave@dell.com>
8 * PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
9 * PCI or PCI Express Device Under Operating Systems) defines an instance
10 * number and string name. This code retrieves them and exports them to sysfs.
11 * If the system firmware does not provide the ACPI _DSM (Device Specific
12 * Method), then the SMBIOS type 41 instance number and string is exported to
15 * SMBIOS defines type 41 for onboard pci devices. This code retrieves
16 * the instance number and string from the type 41 record and exports
19 * Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
23 #include <linux/dmi.h>
24 #include <linux/sysfs.h>
25 #include <linux/pci.h>
26 #include <linux/pci_ids.h>
27 #include <linux/module.h>
28 #include <linux/device.h>
29 #include <linux/nls.h>
30 #include <linux/acpi.h>
31 #include <linux/pci-acpi.h>
34 #define DEVICE_LABEL_DSM 0x07
39 pci_create_smbiosname_file(struct pci_dev *pdev)
45 pci_remove_smbiosname_file(struct pci_dev *pdev)
51 enum smbios_attr_enum {
53 SMBIOS_ATTR_LABEL_SHOW,
54 SMBIOS_ATTR_INSTANCE_SHOW,
58 find_smbios_instance_string(struct pci_dev *pdev, char *buf,
59 enum smbios_attr_enum attribute)
61 const struct dmi_device *dmi;
62 struct dmi_dev_onboard *donboard;
66 bus = pdev->bus->number;
70 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
71 NULL, dmi)) != NULL) {
72 donboard = dmi->device_data;
73 if (donboard && donboard->bus == bus &&
74 donboard->devfn == devfn) {
76 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
77 return scnprintf(buf, PAGE_SIZE,
80 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
81 return scnprintf(buf, PAGE_SIZE,
85 return strlen(dmi->name);
92 smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
98 dev = container_of(kobj, struct device, kobj);
99 pdev = to_pci_dev(dev);
101 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
106 smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
108 struct pci_dev *pdev;
109 pdev = to_pci_dev(dev);
111 return find_smbios_instance_string(pdev, buf,
112 SMBIOS_ATTR_LABEL_SHOW);
116 smbiosinstance_show(struct device *dev,
117 struct device_attribute *attr, char *buf)
119 struct pci_dev *pdev;
120 pdev = to_pci_dev(dev);
122 return find_smbios_instance_string(pdev, buf,
123 SMBIOS_ATTR_INSTANCE_SHOW);
126 static struct device_attribute smbios_attr_label = {
127 .attr = {.name = "label", .mode = 0444},
128 .show = smbioslabel_show,
131 static struct device_attribute smbios_attr_instance = {
132 .attr = {.name = "index", .mode = 0444},
133 .show = smbiosinstance_show,
136 static struct attribute *smbios_attributes[] = {
137 &smbios_attr_label.attr,
138 &smbios_attr_instance.attr,
142 static struct attribute_group smbios_attr_group = {
143 .attrs = smbios_attributes,
144 .is_visible = smbios_instance_string_exist,
148 pci_create_smbiosname_file(struct pci_dev *pdev)
150 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
154 pci_remove_smbiosname_file(struct pci_dev *pdev)
156 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
164 pci_create_acpi_index_label_files(struct pci_dev *pdev)
170 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
176 device_has_dsm(struct device *dev)
183 static const char device_label_dsm_uuid[] = {
184 0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
185 0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
188 enum acpi_attr_enum {
189 ACPI_ATTR_LABEL_SHOW,
190 ACPI_ATTR_INDEX_SHOW,
193 static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
196 len = utf16s_to_utf8s((const wchar_t *)obj->string.pointer,
204 dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr)
207 union acpi_object *obj, *tmp;
210 handle = ACPI_HANDLE(dev);
214 obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2,
215 DEVICE_LABEL_DSM, NULL);
219 tmp = obj->package.elements;
220 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
221 tmp[0].type == ACPI_TYPE_INTEGER &&
222 tmp[1].type == ACPI_TYPE_STRING) {
224 * The second string element is optional even when
225 * this _DSM is implemented; when not implemented,
226 * this entry must return a null string.
228 if (attr == ACPI_ATTR_INDEX_SHOW)
229 scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value);
230 else if (attr == ACPI_ATTR_LABEL_SHOW)
231 dsm_label_utf16s_to_utf8s(tmp + 1, buf);
232 len = strlen(buf) > 0 ? strlen(buf) : -1;
241 device_has_dsm(struct device *dev)
245 handle = ACPI_HANDLE(dev);
249 return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2,
250 1 << DEVICE_LABEL_DSM);
254 acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
258 dev = container_of(kobj, struct device, kobj);
260 if (device_has_dsm(dev))
267 acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
269 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
273 acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
275 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
278 static struct device_attribute acpi_attr_label = {
279 .attr = {.name = "label", .mode = 0444},
280 .show = acpilabel_show,
283 static struct device_attribute acpi_attr_index = {
284 .attr = {.name = "acpi_index", .mode = 0444},
285 .show = acpiindex_show,
288 static struct attribute *acpi_attributes[] = {
289 &acpi_attr_label.attr,
290 &acpi_attr_index.attr,
294 static struct attribute_group acpi_attr_group = {
295 .attrs = acpi_attributes,
296 .is_visible = acpi_index_string_exist,
300 pci_create_acpi_index_label_files(struct pci_dev *pdev)
302 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
306 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
308 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
313 void pci_create_firmware_label_files(struct pci_dev *pdev)
315 if (device_has_dsm(&pdev->dev))
316 pci_create_acpi_index_label_files(pdev);
318 pci_create_smbiosname_file(pdev);
321 void pci_remove_firmware_label_files(struct pci_dev *pdev)
323 if (device_has_dsm(&pdev->dev))
324 pci_remove_acpi_index_label_files(pdev);
326 pci_remove_smbiosname_file(pdev);