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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/files/biosdevname/ 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 "pci.h"
33
34#ifdef CONFIG_DMI
35enum smbios_attr_enum {
36 SMBIOS_ATTR_NONE = 0,
37 SMBIOS_ATTR_LABEL_SHOW,
38 SMBIOS_ATTR_INSTANCE_SHOW,
39};
40
41static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf,
42 enum smbios_attr_enum attribute)
43{
44 const struct dmi_device *dmi;
45 struct dmi_dev_onboard *donboard;
46 int bus;
47 int devfn;
48
49 bus = pdev->bus->number;
50 devfn = pdev->devfn;
51
52 dmi = NULL;
53 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
54 NULL, dmi)) != NULL) {
55 donboard = dmi->device_data;
56 if (donboard && donboard->bus == bus &&
57 donboard->devfn == devfn) {
58 if (buf) {
59 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
60 return scnprintf(buf, PAGE_SIZE,
61 "%d\n",
62 donboard->instance);
63 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
64 return scnprintf(buf, PAGE_SIZE,
65 "%s\n",
66 dmi->name);
67 }
68 return strlen(dmi->name);
69 }
70 }
71 return 0;
72}
73
74static umode_t smbios_instance_string_exist(struct kobject *kobj,
75 struct attribute *attr, int n)
76{
77 struct device *dev;
78 struct pci_dev *pdev;
79
80 dev = kobj_to_dev(kobj);
81 pdev = to_pci_dev(dev);
82
83 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
84 S_IRUGO : 0;
85}
86
87static ssize_t smbioslabel_show(struct device *dev,
88 struct device_attribute *attr, char *buf)
89{
90 struct pci_dev *pdev;
91 pdev = to_pci_dev(dev);
92
93 return find_smbios_instance_string(pdev, buf,
94 SMBIOS_ATTR_LABEL_SHOW);
95}
96
97static ssize_t smbiosinstance_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
99{
100 struct pci_dev *pdev;
101 pdev = to_pci_dev(dev);
102
103 return find_smbios_instance_string(pdev, buf,
104 SMBIOS_ATTR_INSTANCE_SHOW);
105}
106
107static struct device_attribute smbios_attr_label = {
108 .attr = {.name = "label", .mode = 0444},
109 .show = smbioslabel_show,
110};
111
112static struct device_attribute smbios_attr_instance = {
113 .attr = {.name = "index", .mode = 0444},
114 .show = smbiosinstance_show,
115};
116
117static struct attribute *smbios_attributes[] = {
118 &smbios_attr_label.attr,
119 &smbios_attr_instance.attr,
120 NULL,
121};
122
123static struct attribute_group smbios_attr_group = {
124 .attrs = smbios_attributes,
125 .is_visible = smbios_instance_string_exist,
126};
127
128static int pci_create_smbiosname_file(struct pci_dev *pdev)
129{
130 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
131}
132
133static void pci_remove_smbiosname_file(struct pci_dev *pdev)
134{
135 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
136}
137#else
138static inline int pci_create_smbiosname_file(struct pci_dev *pdev)
139{
140 return -1;
141}
142
143static inline void pci_remove_smbiosname_file(struct pci_dev *pdev)
144{
145}
146#endif
147
148#ifdef CONFIG_ACPI
149enum acpi_attr_enum {
150 ACPI_ATTR_LABEL_SHOW,
151 ACPI_ATTR_INDEX_SHOW,
152};
153
154static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
155{
156 int len;
157 len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer,
158 obj->buffer.length,
159 UTF16_LITTLE_ENDIAN,
160 buf, PAGE_SIZE);
161 buf[len] = '\n';
162}
163
164static int dsm_get_label(struct device *dev, char *buf,
165 enum acpi_attr_enum attr)
166{
167 acpi_handle handle;
168 union acpi_object *obj, *tmp;
169 int len = -1;
170
171 handle = ACPI_HANDLE(dev);
172 if (!handle)
173 return -1;
174
175 obj = acpi_evaluate_dsm(handle, pci_acpi_dsm_uuid, 0x2,
176 DEVICE_LABEL_DSM, NULL);
177 if (!obj)
178 return -1;
179
180 tmp = obj->package.elements;
181 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
182 tmp[0].type == ACPI_TYPE_INTEGER &&
183 (tmp[1].type == ACPI_TYPE_STRING ||
184 tmp[1].type == ACPI_TYPE_BUFFER)) {
185 /*
186 * The second string element is optional even when
187 * this _DSM is implemented; when not implemented,
188 * this entry must return a null string.
189 */
190 if (attr == ACPI_ATTR_INDEX_SHOW) {
191 scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value);
192 } else if (attr == ACPI_ATTR_LABEL_SHOW) {
193 if (tmp[1].type == ACPI_TYPE_STRING)
194 scnprintf(buf, PAGE_SIZE, "%s\n",
195 tmp[1].string.pointer);
196 else if (tmp[1].type == ACPI_TYPE_BUFFER)
197 dsm_label_utf16s_to_utf8s(tmp + 1, buf);
198 }
199 len = strlen(buf) > 0 ? strlen(buf) : -1;
200 }
201
202 ACPI_FREE(obj);
203
204 return len;
205}
206
207static bool device_has_dsm(struct device *dev)
208{
209 acpi_handle handle;
210
211 handle = ACPI_HANDLE(dev);
212 if (!handle)
213 return false;
214
215 return !!acpi_check_dsm(handle, pci_acpi_dsm_uuid, 0x2,
216 1 << DEVICE_LABEL_DSM);
217}
218
219static umode_t acpi_index_string_exist(struct kobject *kobj,
220 struct attribute *attr, int n)
221{
222 struct device *dev;
223
224 dev = kobj_to_dev(kobj);
225
226 if (device_has_dsm(dev))
227 return S_IRUGO;
228
229 return 0;
230}
231
232static ssize_t acpilabel_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
234{
235 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
236}
237
238static ssize_t acpiindex_show(struct device *dev,
239 struct device_attribute *attr, char *buf)
240{
241 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
242}
243
244static struct device_attribute acpi_attr_label = {
245 .attr = {.name = "label", .mode = 0444},
246 .show = acpilabel_show,
247};
248
249static struct device_attribute acpi_attr_index = {
250 .attr = {.name = "acpi_index", .mode = 0444},
251 .show = acpiindex_show,
252};
253
254static struct attribute *acpi_attributes[] = {
255 &acpi_attr_label.attr,
256 &acpi_attr_index.attr,
257 NULL,
258};
259
260static struct attribute_group acpi_attr_group = {
261 .attrs = acpi_attributes,
262 .is_visible = acpi_index_string_exist,
263};
264
265static int pci_create_acpi_index_label_files(struct pci_dev *pdev)
266{
267 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
268}
269
270static int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
271{
272 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
273 return 0;
274}
275#else
276static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev)
277{
278 return -1;
279}
280
281static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
282{
283 return -1;
284}
285
286static inline bool device_has_dsm(struct device *dev)
287{
288 return false;
289}
290#endif
291
292void pci_create_firmware_label_files(struct pci_dev *pdev)
293{
294 if (device_has_dsm(&pdev->dev))
295 pci_create_acpi_index_label_files(pdev);
296 else
297 pci_create_smbiosname_file(pdev);
298}
299
300void pci_remove_firmware_label_files(struct pci_dev *pdev)
301{
302 if (device_has_dsm(&pdev->dev))
303 pci_remove_acpi_index_label_files(pdev);
304 else
305 pci_remove_smbiosname_file(pdev);
306}
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
36#ifdef CONFIG_DMI
37enum smbios_attr_enum {
38 SMBIOS_ATTR_NONE = 0,
39 SMBIOS_ATTR_LABEL_SHOW,
40 SMBIOS_ATTR_INSTANCE_SHOW,
41};
42
43static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf,
44 enum smbios_attr_enum attribute)
45{
46 const struct dmi_device *dmi;
47 struct dmi_dev_onboard *donboard;
48 int domain_nr;
49 int bus;
50 int devfn;
51
52 domain_nr = pci_domain_nr(pdev->bus);
53 bus = pdev->bus->number;
54 devfn = pdev->devfn;
55
56 dmi = NULL;
57 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
58 NULL, dmi)) != NULL) {
59 donboard = dmi->device_data;
60 if (donboard && donboard->segment == domain_nr &&
61 donboard->bus == bus &&
62 donboard->devfn == devfn) {
63 if (buf) {
64 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
65 return scnprintf(buf, PAGE_SIZE,
66 "%d\n",
67 donboard->instance);
68 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
69 return scnprintf(buf, PAGE_SIZE,
70 "%s\n",
71 dmi->name);
72 }
73 return strlen(dmi->name);
74 }
75 }
76 return 0;
77}
78
79static umode_t smbios_instance_string_exist(struct kobject *kobj,
80 struct attribute *attr, int n)
81{
82 struct device *dev;
83 struct pci_dev *pdev;
84
85 dev = kobj_to_dev(kobj);
86 pdev = to_pci_dev(dev);
87
88 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
89 S_IRUGO : 0;
90}
91
92static ssize_t smbioslabel_show(struct device *dev,
93 struct device_attribute *attr, char *buf)
94{
95 struct pci_dev *pdev;
96 pdev = to_pci_dev(dev);
97
98 return find_smbios_instance_string(pdev, buf,
99 SMBIOS_ATTR_LABEL_SHOW);
100}
101
102static ssize_t smbiosinstance_show(struct device *dev,
103 struct device_attribute *attr, char *buf)
104{
105 struct pci_dev *pdev;
106 pdev = to_pci_dev(dev);
107
108 return find_smbios_instance_string(pdev, buf,
109 SMBIOS_ATTR_INSTANCE_SHOW);
110}
111
112static struct device_attribute smbios_attr_label = {
113 .attr = {.name = "label", .mode = 0444},
114 .show = smbioslabel_show,
115};
116
117static struct device_attribute smbios_attr_instance = {
118 .attr = {.name = "index", .mode = 0444},
119 .show = smbiosinstance_show,
120};
121
122static struct attribute *smbios_attributes[] = {
123 &smbios_attr_label.attr,
124 &smbios_attr_instance.attr,
125 NULL,
126};
127
128static const struct attribute_group smbios_attr_group = {
129 .attrs = smbios_attributes,
130 .is_visible = smbios_instance_string_exist,
131};
132
133static int pci_create_smbiosname_file(struct pci_dev *pdev)
134{
135 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
136}
137
138static void pci_remove_smbiosname_file(struct pci_dev *pdev)
139{
140 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
141}
142#else
143static inline int pci_create_smbiosname_file(struct pci_dev *pdev)
144{
145 return -1;
146}
147
148static inline void pci_remove_smbiosname_file(struct pci_dev *pdev)
149{
150}
151#endif
152
153#ifdef CONFIG_ACPI
154enum acpi_attr_enum {
155 ACPI_ATTR_LABEL_SHOW,
156 ACPI_ATTR_INDEX_SHOW,
157};
158
159static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
160{
161 int len;
162 len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer,
163 obj->buffer.length,
164 UTF16_LITTLE_ENDIAN,
165 buf, PAGE_SIZE);
166 buf[len] = '\n';
167}
168
169static int dsm_get_label(struct device *dev, char *buf,
170 enum acpi_attr_enum attr)
171{
172 acpi_handle handle;
173 union acpi_object *obj, *tmp;
174 int len = -1;
175
176 handle = ACPI_HANDLE(dev);
177 if (!handle)
178 return -1;
179
180 obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2,
181 DSM_PCI_DEVICE_NAME, NULL);
182 if (!obj)
183 return -1;
184
185 tmp = obj->package.elements;
186 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
187 tmp[0].type == ACPI_TYPE_INTEGER &&
188 (tmp[1].type == ACPI_TYPE_STRING ||
189 tmp[1].type == ACPI_TYPE_BUFFER)) {
190 /*
191 * The second string element is optional even when
192 * this _DSM is implemented; when not implemented,
193 * this entry must return a null string.
194 */
195 if (attr == ACPI_ATTR_INDEX_SHOW) {
196 scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value);
197 } else if (attr == ACPI_ATTR_LABEL_SHOW) {
198 if (tmp[1].type == ACPI_TYPE_STRING)
199 scnprintf(buf, PAGE_SIZE, "%s\n",
200 tmp[1].string.pointer);
201 else if (tmp[1].type == ACPI_TYPE_BUFFER)
202 dsm_label_utf16s_to_utf8s(tmp + 1, buf);
203 }
204 len = strlen(buf) > 0 ? strlen(buf) : -1;
205 }
206
207 ACPI_FREE(obj);
208
209 return len;
210}
211
212static bool device_has_dsm(struct device *dev)
213{
214 acpi_handle handle;
215
216 handle = ACPI_HANDLE(dev);
217 if (!handle)
218 return false;
219
220 return !!acpi_check_dsm(handle, &pci_acpi_dsm_guid, 0x2,
221 1 << DSM_PCI_DEVICE_NAME);
222}
223
224static umode_t acpi_index_string_exist(struct kobject *kobj,
225 struct attribute *attr, int n)
226{
227 struct device *dev;
228
229 dev = kobj_to_dev(kobj);
230
231 if (device_has_dsm(dev))
232 return S_IRUGO;
233
234 return 0;
235}
236
237static ssize_t acpilabel_show(struct device *dev,
238 struct device_attribute *attr, char *buf)
239{
240 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
241}
242
243static ssize_t acpiindex_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
245{
246 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
247}
248
249static struct device_attribute acpi_attr_label = {
250 .attr = {.name = "label", .mode = 0444},
251 .show = acpilabel_show,
252};
253
254static struct device_attribute acpi_attr_index = {
255 .attr = {.name = "acpi_index", .mode = 0444},
256 .show = acpiindex_show,
257};
258
259static struct attribute *acpi_attributes[] = {
260 &acpi_attr_label.attr,
261 &acpi_attr_index.attr,
262 NULL,
263};
264
265static const struct attribute_group acpi_attr_group = {
266 .attrs = acpi_attributes,
267 .is_visible = acpi_index_string_exist,
268};
269
270static int pci_create_acpi_index_label_files(struct pci_dev *pdev)
271{
272 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
273}
274
275static int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
276{
277 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
278 return 0;
279}
280#else
281static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev)
282{
283 return -1;
284}
285
286static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
287{
288 return -1;
289}
290
291static inline bool device_has_dsm(struct device *dev)
292{
293 return false;
294}
295#endif
296
297void pci_create_firmware_label_files(struct pci_dev *pdev)
298{
299 if (device_has_dsm(&pdev->dev))
300 pci_create_acpi_index_label_files(pdev);
301 else
302 pci_create_smbiosname_file(pdev);
303}
304
305void pci_remove_firmware_label_files(struct pci_dev *pdev)
306{
307 if (device_has_dsm(&pdev->dev))
308 pci_remove_acpi_index_label_files(pdev);
309 else
310 pci_remove_smbiosname_file(pdev);
311}