Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
911e1c9b | 2 | /* |
df62ab5e BH |
3 | * Export the firmware instance and label associated with a PCI device to |
4 | * sysfs | |
5 | * | |
911e1c9b N |
6 | * Copyright (C) 2010 Dell Inc. |
7 | * by Narendra K <Narendra_K@dell.com>, | |
8 | * Jordan Hargrave <Jordan_Hargrave@dell.com> | |
9 | * | |
6058989b ND |
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 | * | |
911e1c9b N |
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 | * | |
7ecd4a81 | 21 | * Please see https://linux.dell.com/files/biosdevname/ for more |
911e1c9b N |
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> | |
6058989b ND |
31 | #include <linux/nls.h> |
32 | #include <linux/acpi.h> | |
33 | #include <linux/pci-acpi.h> | |
911e1c9b N |
34 | #include "pci.h" |
35 | ||
4c859804 | 36 | #ifdef CONFIG_DMI |
911e1c9b N |
37 | enum smbios_attr_enum { |
38 | SMBIOS_ATTR_NONE = 0, | |
39 | SMBIOS_ATTR_LABEL_SHOW, | |
40 | SMBIOS_ATTR_INSTANCE_SHOW, | |
41 | }; | |
42 | ||
3c78bc61 RD |
43 | static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf, |
44 | enum smbios_attr_enum attribute) | |
911e1c9b N |
45 | { |
46 | const struct dmi_device *dmi; | |
47 | struct dmi_dev_onboard *donboard; | |
6c51c82c | 48 | int domain_nr; |
911e1c9b N |
49 | int bus; |
50 | int devfn; | |
51 | ||
6c51c82c | 52 | domain_nr = pci_domain_nr(pdev->bus); |
911e1c9b N |
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; | |
6c51c82c SP |
60 | if (donboard && donboard->segment == domain_nr && |
61 | donboard->bus == bus && | |
62 | donboard->devfn == devfn) { | |
911e1c9b N |
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 | ||
3c78bc61 RD |
79 | static umode_t smbios_instance_string_exist(struct kobject *kobj, |
80 | struct attribute *attr, int n) | |
911e1c9b N |
81 | { |
82 | struct device *dev; | |
83 | struct pci_dev *pdev; | |
84 | ||
554a6037 | 85 | dev = kobj_to_dev(kobj); |
911e1c9b N |
86 | pdev = to_pci_dev(dev); |
87 | ||
88 | return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ? | |
89 | S_IRUGO : 0; | |
90 | } | |
91 | ||
3c78bc61 RD |
92 | static ssize_t smbioslabel_show(struct device *dev, |
93 | struct device_attribute *attr, char *buf) | |
911e1c9b N |
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 | ||
3c78bc61 RD |
102 | static ssize_t smbiosinstance_show(struct device *dev, |
103 | struct device_attribute *attr, char *buf) | |
911e1c9b N |
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 | ||
112 | static struct device_attribute smbios_attr_label = { | |
763e9db9 | 113 | .attr = {.name = "label", .mode = 0444}, |
911e1c9b N |
114 | .show = smbioslabel_show, |
115 | }; | |
116 | ||
117 | static struct device_attribute smbios_attr_instance = { | |
763e9db9 | 118 | .attr = {.name = "index", .mode = 0444}, |
911e1c9b N |
119 | .show = smbiosinstance_show, |
120 | }; | |
121 | ||
122 | static struct attribute *smbios_attributes[] = { | |
123 | &smbios_attr_label.attr, | |
124 | &smbios_attr_instance.attr, | |
125 | NULL, | |
126 | }; | |
127 | ||
f4841285 | 128 | static const struct attribute_group smbios_attr_group = { |
911e1c9b N |
129 | .attrs = smbios_attributes, |
130 | .is_visible = smbios_instance_string_exist, | |
131 | }; | |
132 | ||
3c78bc61 | 133 | static int pci_create_smbiosname_file(struct pci_dev *pdev) |
911e1c9b | 134 | { |
6058989b | 135 | return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group); |
911e1c9b N |
136 | } |
137 | ||
3c78bc61 | 138 | static void pci_remove_smbiosname_file(struct pci_dev *pdev) |
911e1c9b N |
139 | { |
140 | sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group); | |
141 | } | |
4c859804 | 142 | #else |
3c78bc61 | 143 | static inline int pci_create_smbiosname_file(struct pci_dev *pdev) |
6058989b ND |
144 | { |
145 | return -1; | |
146 | } | |
147 | ||
3c78bc61 | 148 | static inline void pci_remove_smbiosname_file(struct pci_dev *pdev) |
07eefe1c | 149 | { |
07eefe1c | 150 | } |
4c859804 | 151 | #endif |
07eefe1c | 152 | |
4c859804 | 153 | #ifdef CONFIG_ACPI |
6058989b | 154 | enum acpi_attr_enum { |
6058989b ND |
155 | ACPI_ATTR_LABEL_SHOW, |
156 | ACPI_ATTR_INDEX_SHOW, | |
157 | }; | |
158 | ||
159 | static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) | |
160 | { | |
161 | int len; | |
dcfa9be8 SG |
162 | len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, |
163 | obj->buffer.length, | |
6058989b ND |
164 | UTF16_LITTLE_ENDIAN, |
165 | buf, PAGE_SIZE); | |
166 | buf[len] = '\n'; | |
167 | } | |
168 | ||
3c78bc61 RD |
169 | static int dsm_get_label(struct device *dev, char *buf, |
170 | enum acpi_attr_enum attr) | |
6058989b | 171 | { |
1d0fcef7 JL |
172 | acpi_handle handle; |
173 | union acpi_object *obj, *tmp; | |
174 | int len = -1; | |
175 | ||
176 | handle = ACPI_HANDLE(dev); | |
177 | if (!handle) | |
6058989b ND |
178 | return -1; |
179 | ||
94116f81 | 180 | obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2, |
3910ebac | 181 | DSM_PCI_DEVICE_NAME, NULL); |
1d0fcef7 JL |
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 && | |
dcfa9be8 SG |
188 | (tmp[1].type == ACPI_TYPE_STRING || |
189 | tmp[1].type == ACPI_TYPE_BUFFER)) { | |
2fc59fe2 JL |
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 | */ | |
dcfa9be8 | 195 | if (attr == ACPI_ATTR_INDEX_SHOW) { |
2fc59fe2 | 196 | scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); |
dcfa9be8 SG |
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 | } | |
2fc59fe2 | 204 | len = strlen(buf) > 0 ? strlen(buf) : -1; |
6058989b | 205 | } |
54e5bb46 | 206 | |
1d0fcef7 | 207 | ACPI_FREE(obj); |
54e5bb46 | 208 | |
1d0fcef7 | 209 | return len; |
6058989b ND |
210 | } |
211 | ||
3c78bc61 | 212 | static bool device_has_dsm(struct device *dev) |
6058989b ND |
213 | { |
214 | acpi_handle handle; | |
6058989b | 215 | |
3a83f992 | 216 | handle = ACPI_HANDLE(dev); |
6058989b | 217 | if (!handle) |
2fc59fe2 | 218 | return false; |
6058989b | 219 | |
94116f81 | 220 | return !!acpi_check_dsm(handle, &pci_acpi_dsm_guid, 0x2, |
3910ebac | 221 | 1 << DSM_PCI_DEVICE_NAME); |
6058989b ND |
222 | } |
223 | ||
3c78bc61 RD |
224 | static umode_t acpi_index_string_exist(struct kobject *kobj, |
225 | struct attribute *attr, int n) | |
6058989b ND |
226 | { |
227 | struct device *dev; | |
228 | ||
554a6037 | 229 | dev = kobj_to_dev(kobj); |
6058989b ND |
230 | |
231 | if (device_has_dsm(dev)) | |
232 | return S_IRUGO; | |
233 | ||
234 | return 0; | |
235 | } | |
236 | ||
3c78bc61 RD |
237 | static ssize_t acpilabel_show(struct device *dev, |
238 | struct device_attribute *attr, char *buf) | |
6058989b | 239 | { |
1d0fcef7 | 240 | return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW); |
6058989b ND |
241 | } |
242 | ||
3c78bc61 RD |
243 | static ssize_t acpiindex_show(struct device *dev, |
244 | struct device_attribute *attr, char *buf) | |
6058989b | 245 | { |
1d0fcef7 | 246 | return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW); |
6058989b ND |
247 | } |
248 | ||
249 | static struct device_attribute acpi_attr_label = { | |
250 | .attr = {.name = "label", .mode = 0444}, | |
251 | .show = acpilabel_show, | |
252 | }; | |
253 | ||
254 | static struct device_attribute acpi_attr_index = { | |
255 | .attr = {.name = "acpi_index", .mode = 0444}, | |
256 | .show = acpiindex_show, | |
257 | }; | |
258 | ||
259 | static struct attribute *acpi_attributes[] = { | |
260 | &acpi_attr_label.attr, | |
261 | &acpi_attr_index.attr, | |
262 | NULL, | |
263 | }; | |
264 | ||
f4841285 | 265 | static const struct attribute_group acpi_attr_group = { |
6058989b ND |
266 | .attrs = acpi_attributes, |
267 | .is_visible = acpi_index_string_exist, | |
268 | }; | |
269 | ||
3c78bc61 | 270 | static int pci_create_acpi_index_label_files(struct pci_dev *pdev) |
6058989b ND |
271 | { |
272 | return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group); | |
273 | } | |
274 | ||
3c78bc61 | 275 | static int pci_remove_acpi_index_label_files(struct pci_dev *pdev) |
6058989b ND |
276 | { |
277 | sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group); | |
278 | return 0; | |
279 | } | |
4c859804 | 280 | #else |
3c78bc61 | 281 | static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev) |
4c859804 BH |
282 | { |
283 | return -1; | |
284 | } | |
285 | ||
3c78bc61 | 286 | static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev) |
4c859804 BH |
287 | { |
288 | return -1; | |
289 | } | |
290 | ||
3c78bc61 | 291 | static inline bool device_has_dsm(struct device *dev) |
4c859804 BH |
292 | { |
293 | return false; | |
294 | } | |
6058989b ND |
295 | #endif |
296 | ||
911e1c9b N |
297 | void pci_create_firmware_label_files(struct pci_dev *pdev) |
298 | { | |
6058989b ND |
299 | if (device_has_dsm(&pdev->dev)) |
300 | pci_create_acpi_index_label_files(pdev); | |
301 | else | |
302 | pci_create_smbiosname_file(pdev); | |
911e1c9b N |
303 | } |
304 | ||
305 | void pci_remove_firmware_label_files(struct pci_dev *pdev) | |
306 | { | |
6058989b ND |
307 | if (device_has_dsm(&pdev->dev)) |
308 | pci_remove_acpi_index_label_files(pdev); | |
309 | else | |
310 | pci_remove_smbiosname_file(pdev); | |
911e1c9b | 311 | } |