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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// 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