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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/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}