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 | ||
1017275d KW |
36 | static bool device_has_acpi_name(struct device *dev) |
37 | { | |
38 | #ifdef CONFIG_ACPI | |
362fb766 | 39 | acpi_handle handle = ACPI_HANDLE(dev); |
1017275d | 40 | |
1017275d KW |
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 | ||
4c859804 | 51 | #ifdef CONFIG_DMI |
911e1c9b N |
52 | enum smbios_attr_enum { |
53 | SMBIOS_ATTR_NONE = 0, | |
54 | SMBIOS_ATTR_LABEL_SHOW, | |
55 | SMBIOS_ATTR_INSTANCE_SHOW, | |
56 | }; | |
57 | ||
3c78bc61 RD |
58 | static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf, |
59 | enum smbios_attr_enum attribute) | |
911e1c9b N |
60 | { |
61 | const struct dmi_device *dmi; | |
62 | struct dmi_dev_onboard *donboard; | |
362fb766 KW |
63 | int domain_nr = pci_domain_nr(pdev->bus); |
64 | int bus = pdev->bus->number; | |
65 | int devfn = pdev->devfn; | |
911e1c9b N |
66 | |
67 | dmi = NULL; | |
68 | while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, | |
69 | NULL, dmi)) != NULL) { | |
70 | donboard = dmi->device_data; | |
6c51c82c SP |
71 | if (donboard && donboard->segment == domain_nr && |
72 | donboard->bus == bus && | |
73 | donboard->devfn == devfn) { | |
911e1c9b N |
74 | if (buf) { |
75 | if (attribute == SMBIOS_ATTR_INSTANCE_SHOW) | |
ad025f8e KW |
76 | return sysfs_emit(buf, "%d\n", |
77 | donboard->instance); | |
911e1c9b | 78 | else if (attribute == SMBIOS_ATTR_LABEL_SHOW) |
ad025f8e KW |
79 | return sysfs_emit(buf, "%s\n", |
80 | dmi->name); | |
911e1c9b N |
81 | } |
82 | return strlen(dmi->name); | |
83 | } | |
84 | } | |
85 | return 0; | |
86 | } | |
87 | ||
4dd7dfa1 KW |
88 | static ssize_t smbios_label_show(struct device *dev, |
89 | struct device_attribute *attr, char *buf) | |
911e1c9b | 90 | { |
362fb766 | 91 | struct pci_dev *pdev = to_pci_dev(dev); |
911e1c9b N |
92 | |
93 | return find_smbios_instance_string(pdev, buf, | |
94 | SMBIOS_ATTR_LABEL_SHOW); | |
95 | } | |
4dd7dfa1 KW |
96 | static struct device_attribute dev_attr_smbios_label = __ATTR(label, 0444, |
97 | smbios_label_show, NULL); | |
911e1c9b | 98 | |
4dd7dfa1 KW |
99 | static ssize_t index_show(struct device *dev, struct device_attribute *attr, |
100 | char *buf) | |
911e1c9b | 101 | { |
362fb766 | 102 | struct pci_dev *pdev = to_pci_dev(dev); |
911e1c9b N |
103 | |
104 | return find_smbios_instance_string(pdev, buf, | |
105 | SMBIOS_ATTR_INSTANCE_SHOW); | |
106 | } | |
4dd7dfa1 | 107 | static DEVICE_ATTR_RO(index); |
911e1c9b | 108 | |
4dd7dfa1 KW |
109 | static struct attribute *smbios_attrs[] = { |
110 | &dev_attr_smbios_label.attr, | |
111 | &dev_attr_index.attr, | |
911e1c9b N |
112 | NULL, |
113 | }; | |
114 | ||
df1af7cb KW |
115 | static 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 | ||
506140f9 | 130 | const struct attribute_group pci_dev_smbios_attr_group = { |
4dd7dfa1 KW |
131 | .attrs = smbios_attrs, |
132 | .is_visible = smbios_attr_is_visible, | |
911e1c9b | 133 | }; |
4c859804 | 134 | #endif |
07eefe1c | 135 | |
4c859804 | 136 | #ifdef CONFIG_ACPI |
6058989b | 137 | enum acpi_attr_enum { |
6058989b ND |
138 | ACPI_ATTR_LABEL_SHOW, |
139 | ACPI_ATTR_INDEX_SHOW, | |
140 | }; | |
141 | ||
316ae330 | 142 | static int dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) |
6058989b ND |
143 | { |
144 | int len; | |
316ae330 | 145 | |
dcfa9be8 SG |
146 | len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, |
147 | obj->buffer.length, | |
6058989b | 148 | UTF16_LITTLE_ENDIAN, |
bdcdaa13 | 149 | buf, PAGE_SIZE - 1); |
316ae330 KW |
150 | buf[len++] = '\n'; |
151 | ||
152 | return len; | |
6058989b ND |
153 | } |
154 | ||
3c78bc61 RD |
155 | static int dsm_get_label(struct device *dev, char *buf, |
156 | enum acpi_attr_enum attr) | |
6058989b | 157 | { |
362fb766 | 158 | acpi_handle handle = ACPI_HANDLE(dev); |
1d0fcef7 | 159 | union acpi_object *obj, *tmp; |
316ae330 | 160 | int len = 0; |
1d0fcef7 | 161 | |
1d0fcef7 | 162 | if (!handle) |
6058989b ND |
163 | return -1; |
164 | ||
94116f81 | 165 | obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2, |
3910ebac | 166 | DSM_PCI_DEVICE_NAME, NULL); |
1d0fcef7 JL |
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 && | |
dcfa9be8 SG |
173 | (tmp[1].type == ACPI_TYPE_STRING || |
174 | tmp[1].type == ACPI_TYPE_BUFFER)) { | |
2fc59fe2 JL |
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 | */ | |
dcfa9be8 | 180 | if (attr == ACPI_ATTR_INDEX_SHOW) { |
f8cf6e51 | 181 | len = sysfs_emit(buf, "%llu\n", tmp->integer.value); |
dcfa9be8 SG |
182 | } else if (attr == ACPI_ATTR_LABEL_SHOW) { |
183 | if (tmp[1].type == ACPI_TYPE_STRING) | |
f8cf6e51 KW |
184 | len = sysfs_emit(buf, "%s\n", |
185 | tmp[1].string.pointer); | |
dcfa9be8 | 186 | else if (tmp[1].type == ACPI_TYPE_BUFFER) |
316ae330 | 187 | len = dsm_label_utf16s_to_utf8s(tmp + 1, buf); |
dcfa9be8 | 188 | } |
6058989b | 189 | } |
54e5bb46 | 190 | |
1d0fcef7 | 191 | ACPI_FREE(obj); |
54e5bb46 | 192 | |
316ae330 | 193 | return len > 0 ? len : -1; |
6058989b ND |
194 | } |
195 | ||
2ed64941 KW |
196 | static ssize_t label_show(struct device *dev, struct device_attribute *attr, |
197 | char *buf) | |
6058989b | 198 | { |
1d0fcef7 | 199 | return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW); |
6058989b | 200 | } |
2ed64941 | 201 | static DEVICE_ATTR_RO(label); |
6058989b | 202 | |
2ed64941 | 203 | static ssize_t acpi_index_show(struct device *dev, |
3c78bc61 | 204 | struct device_attribute *attr, char *buf) |
6058989b | 205 | { |
1d0fcef7 | 206 | return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW); |
6058989b | 207 | } |
2ed64941 | 208 | static DEVICE_ATTR_RO(acpi_index); |
6058989b | 209 | |
2ed64941 KW |
210 | static struct attribute *acpi_attrs[] = { |
211 | &dev_attr_label.attr, | |
212 | &dev_attr_acpi_index.attr, | |
6058989b ND |
213 | NULL, |
214 | }; | |
215 | ||
df1af7cb KW |
216 | static 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 | ||
506140f9 | 227 | const struct attribute_group pci_dev_acpi_attr_group = { |
2ed64941 KW |
228 | .attrs = acpi_attrs, |
229 | .is_visible = acpi_attr_is_visible, | |
6058989b | 230 | }; |
6058989b | 231 | #endif |