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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Export the firmware instance and label associated with a PCI device to
4 * sysfs
5 *
6 * Copyright (C) 2010 Dell Inc.
7 * by Narendra K <Narendra_K@dell.com>,
8 * Jordan Hargrave <Jordan_Hargrave@dell.com>
9 *
10 * PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
11 * PCI or PCI Express Device Under Operating Systems) defines an instance
12 * number and string name. This code retrieves them and exports them to sysfs.
13 * If the system firmware does not provide the ACPI _DSM (Device Specific
14 * Method), then the SMBIOS type 41 instance number and string is exported to
15 * sysfs.
16 *
17 * SMBIOS defines type 41 for onboard pci devices. This code retrieves
18 * the instance number and string from the type 41 record and exports
19 * it to sysfs.
20 *
21 * Please see https://linux.dell.com/files/biosdevname/ for more
22 * information.
23 */
24
25#include <linux/dmi.h>
26#include <linux/sysfs.h>
27#include <linux/pci.h>
28#include <linux/pci_ids.h>
29#include <linux/module.h>
30#include <linux/device.h>
31#include <linux/nls.h>
32#include <linux/acpi.h>
33#include <linux/pci-acpi.h>
34#include "pci.h"
35
36static bool device_has_acpi_name(struct device *dev)
37{
38#ifdef CONFIG_ACPI
39 acpi_handle handle = ACPI_HANDLE(dev);
40
41 if (!handle)
42 return false;
43
44 return acpi_check_dsm(handle, &pci_acpi_dsm_guid, 0x2,
45 1 << DSM_PCI_DEVICE_NAME);
46#else
47 return false;
48#endif
49}
50
51#ifdef CONFIG_DMI
52enum smbios_attr_enum {
53 SMBIOS_ATTR_NONE = 0,
54 SMBIOS_ATTR_LABEL_SHOW,
55 SMBIOS_ATTR_INSTANCE_SHOW,
56};
57
58static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf,
59 enum smbios_attr_enum attribute)
60{
61 const struct dmi_device *dmi;
62 struct dmi_dev_onboard *donboard;
63 int domain_nr = pci_domain_nr(pdev->bus);
64 int bus = pdev->bus->number;
65 int devfn = pdev->devfn;
66
67 dmi = NULL;
68 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
69 NULL, dmi)) != NULL) {
70 donboard = dmi->device_data;
71 if (donboard && donboard->segment == domain_nr &&
72 donboard->bus == bus &&
73 donboard->devfn == devfn) {
74 if (buf) {
75 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
76 return sysfs_emit(buf, "%d\n",
77 donboard->instance);
78 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
79 return sysfs_emit(buf, "%s\n",
80 dmi->name);
81 }
82 return strlen(dmi->name);
83 }
84 }
85 return 0;
86}
87
88static ssize_t smbios_label_show(struct device *dev,
89 struct device_attribute *attr, char *buf)
90{
91 struct pci_dev *pdev = to_pci_dev(dev);
92
93 return find_smbios_instance_string(pdev, buf,
94 SMBIOS_ATTR_LABEL_SHOW);
95}
96static struct device_attribute dev_attr_smbios_label = __ATTR(label, 0444,
97 smbios_label_show, NULL);
98
99static ssize_t index_show(struct device *dev, struct device_attribute *attr,
100 char *buf)
101{
102 struct pci_dev *pdev = to_pci_dev(dev);
103
104 return find_smbios_instance_string(pdev, buf,
105 SMBIOS_ATTR_INSTANCE_SHOW);
106}
107static DEVICE_ATTR_RO(index);
108
109static struct attribute *smbios_attrs[] = {
110 &dev_attr_smbios_label.attr,
111 &dev_attr_index.attr,
112 NULL,
113};
114
115static umode_t smbios_attr_is_visible(struct kobject *kobj, struct attribute *a,
116 int n)
117{
118 struct device *dev = kobj_to_dev(kobj);
119 struct pci_dev *pdev = to_pci_dev(dev);
120
121 if (device_has_acpi_name(dev))
122 return 0;
123
124 if (!find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE))
125 return 0;
126
127 return a->mode;
128}
129
130const struct attribute_group pci_dev_smbios_attr_group = {
131 .attrs = smbios_attrs,
132 .is_visible = smbios_attr_is_visible,
133};
134#endif
135
136#ifdef CONFIG_ACPI
137enum acpi_attr_enum {
138 ACPI_ATTR_LABEL_SHOW,
139 ACPI_ATTR_INDEX_SHOW,
140};
141
142static int dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
143{
144 int len;
145
146 len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer,
147 obj->buffer.length,
148 UTF16_LITTLE_ENDIAN,
149 buf, PAGE_SIZE - 1);
150 buf[len++] = '\n';
151
152 return len;
153}
154
155static int dsm_get_label(struct device *dev, char *buf,
156 enum acpi_attr_enum attr)
157{
158 acpi_handle handle = ACPI_HANDLE(dev);
159 union acpi_object *obj, *tmp;
160 int len = 0;
161
162 if (!handle)
163 return -1;
164
165 obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2,
166 DSM_PCI_DEVICE_NAME, NULL);
167 if (!obj)
168 return -1;
169
170 tmp = obj->package.elements;
171 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
172 tmp[0].type == ACPI_TYPE_INTEGER &&
173 (tmp[1].type == ACPI_TYPE_STRING ||
174 tmp[1].type == ACPI_TYPE_BUFFER)) {
175 /*
176 * The second string element is optional even when
177 * this _DSM is implemented; when not implemented,
178 * this entry must return a null string.
179 */
180 if (attr == ACPI_ATTR_INDEX_SHOW) {
181 len = sysfs_emit(buf, "%llu\n", tmp->integer.value);
182 } else if (attr == ACPI_ATTR_LABEL_SHOW) {
183 if (tmp[1].type == ACPI_TYPE_STRING)
184 len = sysfs_emit(buf, "%s\n",
185 tmp[1].string.pointer);
186 else if (tmp[1].type == ACPI_TYPE_BUFFER)
187 len = dsm_label_utf16s_to_utf8s(tmp + 1, buf);
188 }
189 }
190
191 ACPI_FREE(obj);
192
193 return len > 0 ? len : -1;
194}
195
196static ssize_t label_show(struct device *dev, struct device_attribute *attr,
197 char *buf)
198{
199 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
200}
201static DEVICE_ATTR_RO(label);
202
203static ssize_t acpi_index_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
207}
208static DEVICE_ATTR_RO(acpi_index);
209
210static struct attribute *acpi_attrs[] = {
211 &dev_attr_label.attr,
212 &dev_attr_acpi_index.attr,
213 NULL,
214};
215
216static umode_t acpi_attr_is_visible(struct kobject *kobj, struct attribute *a,
217 int n)
218{
219 struct device *dev = kobj_to_dev(kobj);
220
221 if (!device_has_acpi_name(dev))
222 return 0;
223
224 return a->mode;
225}
226
227const struct attribute_group pci_dev_acpi_attr_group = {
228 .attrs = acpi_attrs,
229 .is_visible = acpi_attr_is_visible,
230};
231#endif
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
39static inline int
40pci_create_smbiosname_file(struct pci_dev *pdev)
41{
42 return -1;
43}
44
45static inline void
46pci_remove_smbiosname_file(struct pci_dev *pdev)
47{
48}
49
50#else
51
52enum smbios_attr_enum {
53 SMBIOS_ATTR_NONE = 0,
54 SMBIOS_ATTR_LABEL_SHOW,
55 SMBIOS_ATTR_INSTANCE_SHOW,
56};
57
58static size_t
59find_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
92static mode_t
93smbios_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
106static ssize_t
107smbioslabel_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
116static ssize_t
117smbiosinstance_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
127static struct device_attribute smbios_attr_label = {
128 .attr = {.name = "label", .mode = 0444},
129 .show = smbioslabel_show,
130};
131
132static struct device_attribute smbios_attr_instance = {
133 .attr = {.name = "index", .mode = 0444},
134 .show = smbiosinstance_show,
135};
136
137static struct attribute *smbios_attributes[] = {
138 &smbios_attr_label.attr,
139 &smbios_attr_instance.attr,
140 NULL,
141};
142
143static struct attribute_group smbios_attr_group = {
144 .attrs = smbios_attributes,
145 .is_visible = smbios_instance_string_exist,
146};
147
148static int
149pci_create_smbiosname_file(struct pci_dev *pdev)
150{
151 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
152}
153
154static void
155pci_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
164static inline int
165pci_create_acpi_index_label_files(struct pci_dev *pdev)
166{
167 return -1;
168}
169
170static inline int
171pci_remove_acpi_index_label_files(struct pci_dev *pdev)
172{
173 return -1;
174}
175
176static inline bool
177device_has_dsm(struct device *dev)
178{
179 return false;
180}
181
182#else
183
184static 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
189enum acpi_attr_enum {
190 ACPI_ATTR_NONE = 0,
191 ACPI_ATTR_LABEL_SHOW,
192 ACPI_ATTR_INDEX_SHOW,
193};
194
195static 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
206static int
207dsm_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
260static bool
261device_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
278static mode_t
279acpi_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
291static ssize_t
292acpilabel_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
312static ssize_t
313acpiindex_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
334static struct device_attribute acpi_attr_label = {
335 .attr = {.name = "label", .mode = 0444},
336 .show = acpilabel_show,
337};
338
339static struct device_attribute acpi_attr_index = {
340 .attr = {.name = "acpi_index", .mode = 0444},
341 .show = acpiindex_show,
342};
343
344static struct attribute *acpi_attributes[] = {
345 &acpi_attr_label.attr,
346 &acpi_attr_index.attr,
347 NULL,
348};
349
350static struct attribute_group acpi_attr_group = {
351 .attrs = acpi_attributes,
352 .is_visible = acpi_index_string_exist,
353};
354
355static int
356pci_create_acpi_index_label_files(struct pci_dev *pdev)
357{
358 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
359}
360
361static int
362pci_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
369void 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
377void 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}