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 <Narendra_K@dell.com>,
6 * Jordan Hargrave <Jordan_Hargrave@dell.com>
7 *
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
13 * sysfs.
14 *
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
17 * it to sysfs.
18 *
19 * Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
20 * information.
21 */
22
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>
32 #include <acpi/acpi_bus.h>
33 #include "pci.h"
34
35 #define DEVICE_LABEL_DSM 0x07
36
37 #ifndef CONFIG_DMI
38
39 static inline int
pci_create_smbiosname_file(struct pci_dev * pdev)40 pci_create_smbiosname_file(struct pci_dev *pdev)
41 {
42 return -1;
43 }
44
45 static inline void
pci_remove_smbiosname_file(struct pci_dev * pdev)46 pci_remove_smbiosname_file(struct pci_dev *pdev)
47 {
48 }
49
50 #else
51
52 enum smbios_attr_enum {
53 SMBIOS_ATTR_NONE = 0,
54 SMBIOS_ATTR_LABEL_SHOW,
55 SMBIOS_ATTR_INSTANCE_SHOW,
56 };
57
58 static mode_t
find_smbios_instance_string(struct pci_dev * pdev,char * buf,enum smbios_attr_enum attribute)59 find_smbios_instance_string(struct pci_dev *pdev, char *buf,
60 enum smbios_attr_enum attribute)
61 {
62 const struct dmi_device *dmi;
63 struct dmi_dev_onboard *donboard;
64 int bus;
65 int devfn;
66
67 bus = pdev->bus->number;
68 devfn = pdev->devfn;
69
70 dmi = NULL;
71 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
72 NULL, dmi)) != NULL) {
73 donboard = dmi->device_data;
74 if (donboard && donboard->bus == bus &&
75 donboard->devfn == devfn) {
76 if (buf) {
77 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
78 return scnprintf(buf, PAGE_SIZE,
79 "%d\n",
80 donboard->instance);
81 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
82 return scnprintf(buf, PAGE_SIZE,
83 "%s\n",
84 dmi->name);
85 }
86 return strlen(dmi->name);
87 }
88 }
89 return 0;
90 }
91
92 static mode_t
smbios_instance_string_exist(struct kobject * kobj,struct attribute * attr,int n)93 smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
94 int n)
95 {
96 struct device *dev;
97 struct pci_dev *pdev;
98
99 dev = container_of(kobj, struct device, kobj);
100 pdev = to_pci_dev(dev);
101
102 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
103 S_IRUGO : 0;
104 }
105
106 static ssize_t
smbioslabel_show(struct device * dev,struct device_attribute * attr,char * buf)107 smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
108 {
109 struct pci_dev *pdev;
110 pdev = to_pci_dev(dev);
111
112 return find_smbios_instance_string(pdev, buf,
113 SMBIOS_ATTR_LABEL_SHOW);
114 }
115
116 static ssize_t
smbiosinstance_show(struct device * dev,struct device_attribute * attr,char * buf)117 smbiosinstance_show(struct device *dev,
118 struct device_attribute *attr, char *buf)
119 {
120 struct pci_dev *pdev;
121 pdev = to_pci_dev(dev);
122
123 return find_smbios_instance_string(pdev, buf,
124 SMBIOS_ATTR_INSTANCE_SHOW);
125 }
126
127 static struct device_attribute smbios_attr_label = {
128 .attr = {.name = "label", .mode = 0444},
129 .show = smbioslabel_show,
130 };
131
132 static struct device_attribute smbios_attr_instance = {
133 .attr = {.name = "index", .mode = 0444},
134 .show = smbiosinstance_show,
135 };
136
137 static struct attribute *smbios_attributes[] = {
138 &smbios_attr_label.attr,
139 &smbios_attr_instance.attr,
140 NULL,
141 };
142
143 static struct attribute_group smbios_attr_group = {
144 .attrs = smbios_attributes,
145 .is_visible = smbios_instance_string_exist,
146 };
147
148 static int
pci_create_smbiosname_file(struct pci_dev * pdev)149 pci_create_smbiosname_file(struct pci_dev *pdev)
150 {
151 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
152 }
153
154 static void
pci_remove_smbiosname_file(struct pci_dev * pdev)155 pci_remove_smbiosname_file(struct pci_dev *pdev)
156 {
157 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
158 }
159
160 #endif
161
162 #ifndef CONFIG_ACPI
163
164 static inline int
pci_create_acpi_index_label_files(struct pci_dev * pdev)165 pci_create_acpi_index_label_files(struct pci_dev *pdev)
166 {
167 return -1;
168 }
169
170 static inline int
pci_remove_acpi_index_label_files(struct pci_dev * pdev)171 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
172 {
173 return -1;
174 }
175
176 static inline bool
device_has_dsm(struct device * dev)177 device_has_dsm(struct device *dev)
178 {
179 return false;
180 }
181
182 #else
183
184 static const char device_label_dsm_uuid[] = {
185 0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
186 0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
187 };
188
189 enum acpi_attr_enum {
190 ACPI_ATTR_NONE = 0,
191 ACPI_ATTR_LABEL_SHOW,
192 ACPI_ATTR_INDEX_SHOW,
193 };
194
dsm_label_utf16s_to_utf8s(union acpi_object * obj,char * buf)195 static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
196 {
197 int len;
198 len = utf16s_to_utf8s((const wchar_t *)obj->
199 package.elements[1].string.pointer,
200 obj->package.elements[1].string.length,
201 UTF16_LITTLE_ENDIAN,
202 buf, PAGE_SIZE);
203 buf[len] = '\n';
204 }
205
206 static int
dsm_get_label(acpi_handle handle,int func,struct acpi_buffer * output,char * buf,enum acpi_attr_enum attribute)207 dsm_get_label(acpi_handle handle, int func,
208 struct acpi_buffer *output,
209 char *buf, enum acpi_attr_enum attribute)
210 {
211 struct acpi_object_list input;
212 union acpi_object params[4];
213 union acpi_object *obj;
214 int len = 0;
215
216 int err;
217
218 input.count = 4;
219 input.pointer = params;
220 params[0].type = ACPI_TYPE_BUFFER;
221 params[0].buffer.length = sizeof(device_label_dsm_uuid);
222 params[0].buffer.pointer = (char *)device_label_dsm_uuid;
223 params[1].type = ACPI_TYPE_INTEGER;
224 params[1].integer.value = 0x02;
225 params[2].type = ACPI_TYPE_INTEGER;
226 params[2].integer.value = func;
227 params[3].type = ACPI_TYPE_PACKAGE;
228 params[3].package.count = 0;
229 params[3].package.elements = NULL;
230
231 err = acpi_evaluate_object(handle, "_DSM", &input, output);
232 if (err)
233 return -1;
234
235 obj = (union acpi_object *)output->pointer;
236
237 switch (obj->type) {
238 case ACPI_TYPE_PACKAGE:
239 if (obj->package.count != 2)
240 break;
241 len = obj->package.elements[0].integer.value;
242 if (buf) {
243 if (attribute == ACPI_ATTR_INDEX_SHOW)
244 scnprintf(buf, PAGE_SIZE, "%llu\n",
245 obj->package.elements[0].integer.value);
246 else if (attribute == ACPI_ATTR_LABEL_SHOW)
247 dsm_label_utf16s_to_utf8s(obj, buf);
248 kfree(output->pointer);
249 return strlen(buf);
250 }
251 kfree(output->pointer);
252 return len;
253 break;
254 default:
255 kfree(output->pointer);
256 }
257 return -1;
258 }
259
260 static bool
device_has_dsm(struct device * dev)261 device_has_dsm(struct device *dev)
262 {
263 acpi_handle handle;
264 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
265
266 handle = DEVICE_ACPI_HANDLE(dev);
267
268 if (!handle)
269 return FALSE;
270
271 if (dsm_get_label(handle, DEVICE_LABEL_DSM, &output, NULL,
272 ACPI_ATTR_NONE) > 0)
273 return TRUE;
274
275 return FALSE;
276 }
277
278 static mode_t
acpi_index_string_exist(struct kobject * kobj,struct attribute * attr,int n)279 acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
280 {
281 struct device *dev;
282
283 dev = container_of(kobj, struct device, kobj);
284
285 if (device_has_dsm(dev))
286 return S_IRUGO;
287
288 return 0;
289 }
290
291 static ssize_t
acpilabel_show(struct device * dev,struct device_attribute * attr,char * buf)292 acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
293 {
294 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
295 acpi_handle handle;
296 int length;
297
298 handle = DEVICE_ACPI_HANDLE(dev);
299
300 if (!handle)
301 return -1;
302
303 length = dsm_get_label(handle, DEVICE_LABEL_DSM,
304 &output, buf, ACPI_ATTR_LABEL_SHOW);
305
306 if (length < 1)
307 return -1;
308
309 return length;
310 }
311
312 static ssize_t
acpiindex_show(struct device * dev,struct device_attribute * attr,char * buf)313 acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
314 {
315 struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
316 acpi_handle handle;
317 int length;
318
319 handle = DEVICE_ACPI_HANDLE(dev);
320
321 if (!handle)
322 return -1;
323
324 length = dsm_get_label(handle, DEVICE_LABEL_DSM,
325 &output, buf, ACPI_ATTR_INDEX_SHOW);
326
327 if (length < 0)
328 return -1;
329
330 return length;
331
332 }
333
334 static struct device_attribute acpi_attr_label = {
335 .attr = {.name = "label", .mode = 0444},
336 .show = acpilabel_show,
337 };
338
339 static struct device_attribute acpi_attr_index = {
340 .attr = {.name = "acpi_index", .mode = 0444},
341 .show = acpiindex_show,
342 };
343
344 static struct attribute *acpi_attributes[] = {
345 &acpi_attr_label.attr,
346 &acpi_attr_index.attr,
347 NULL,
348 };
349
350 static struct attribute_group acpi_attr_group = {
351 .attrs = acpi_attributes,
352 .is_visible = acpi_index_string_exist,
353 };
354
355 static int
pci_create_acpi_index_label_files(struct pci_dev * pdev)356 pci_create_acpi_index_label_files(struct pci_dev *pdev)
357 {
358 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
359 }
360
361 static int
pci_remove_acpi_index_label_files(struct pci_dev * pdev)362 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
363 {
364 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
365 return 0;
366 }
367 #endif
368
pci_create_firmware_label_files(struct pci_dev * pdev)369 void pci_create_firmware_label_files(struct pci_dev *pdev)
370 {
371 if (device_has_dsm(&pdev->dev))
372 pci_create_acpi_index_label_files(pdev);
373 else
374 pci_create_smbiosname_file(pdev);
375 }
376
pci_remove_firmware_label_files(struct pci_dev * pdev)377 void pci_remove_firmware_label_files(struct pci_dev *pdev)
378 {
379 if (device_has_dsm(&pdev->dev))
380 pci_remove_acpi_index_label_files(pdev);
381 else
382 pci_remove_smbiosname_file(pdev);
383 }
384