PCIe ASPM: forcedly -> forcibly
[linux-2.6.git] / drivers / pci / pci-label.c
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/wiki/index.php/Oss/libnetdevname 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 <acpi/acpi_bus.h>
33 #include "pci.h"
34
35 #define DEVICE_LABEL_DSM        0x07
36
37 #ifndef CONFIG_DMI
38
39 static inline int
40 pci_create_smbiosname_file(struct pci_dev *pdev)
41 {
42         return -1;
43 }
44
45 static inline void
46 pci_remove_smbiosname_file(struct pci_dev *pdev)
47 {
48 }
49
50 #else
51
52 enum smbios_attr_enum {
53         SMBIOS_ATTR_NONE = 0,
54         SMBIOS_ATTR_LABEL_SHOW,
55         SMBIOS_ATTR_INSTANCE_SHOW,
56 };
57
58 static mode_t
59 find_smbios_instance_string(struct pci_dev *pdev, char *buf,
60                             enum smbios_attr_enum attribute)
61 {
62         const struct dmi_device *dmi;
63         struct dmi_dev_onboard *donboard;
64         int bus;
65         int devfn;
66
67         bus = pdev->bus->number;
68         devfn = pdev->devfn;
69
70         dmi = NULL;
71         while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
72                                       NULL, dmi)) != NULL) {
73                 donboard = dmi->device_data;
74                 if (donboard && donboard->bus == bus &&
75                                         donboard->devfn == devfn) {
76                         if (buf) {
77                                 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
78                                         return scnprintf(buf, PAGE_SIZE,
79                                                          "%d\n",
80                                                          donboard->instance);
81                                 else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
82                                         return scnprintf(buf, PAGE_SIZE,
83                                                          "%s\n",
84                                                          dmi->name);
85                         }
86                         return strlen(dmi->name);
87                 }
88         }
89         return 0;
90 }
91
92 static mode_t
93 smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
94                              int n)
95 {
96         struct device *dev;
97         struct pci_dev *pdev;
98
99         dev = container_of(kobj, struct device, kobj);
100         pdev = to_pci_dev(dev);
101
102         return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
103                                            S_IRUGO : 0;
104 }
105
106 static ssize_t
107 smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
108 {
109         struct pci_dev *pdev;
110         pdev = to_pci_dev(dev);
111
112         return find_smbios_instance_string(pdev, buf,
113                                            SMBIOS_ATTR_LABEL_SHOW);
114 }
115
116 static ssize_t
117 smbiosinstance_show(struct device *dev,
118                     struct device_attribute *attr, char *buf)
119 {
120         struct pci_dev *pdev;
121         pdev = to_pci_dev(dev);
122
123         return find_smbios_instance_string(pdev, buf,
124                                            SMBIOS_ATTR_INSTANCE_SHOW);
125 }
126
127 static struct device_attribute smbios_attr_label = {
128         .attr = {.name = "label", .mode = 0444},
129         .show = smbioslabel_show,
130 };
131
132 static struct device_attribute smbios_attr_instance = {
133         .attr = {.name = "index", .mode = 0444},
134         .show = smbiosinstance_show,
135 };
136
137 static struct attribute *smbios_attributes[] = {
138         &smbios_attr_label.attr,
139         &smbios_attr_instance.attr,
140         NULL,
141 };
142
143 static struct attribute_group smbios_attr_group = {
144         .attrs = smbios_attributes,
145         .is_visible = smbios_instance_string_exist,
146 };
147
148 static int
149 pci_create_smbiosname_file(struct pci_dev *pdev)
150 {
151         return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
152 }
153
154 static void
155 pci_remove_smbiosname_file(struct pci_dev *pdev)
156 {
157         sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
158 }
159
160 #endif
161
162 #ifndef CONFIG_ACPI
163
164 static inline int
165 pci_create_acpi_index_label_files(struct pci_dev *pdev)
166 {
167         return -1;
168 }
169
170 static inline int
171 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
172 {
173         return -1;
174 }
175
176 static inline bool
177 device_has_dsm(struct device *dev)
178 {
179         return false;
180 }
181
182 #else
183
184 static const char device_label_dsm_uuid[] = {
185         0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
186         0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
187 };
188
189 enum acpi_attr_enum {
190         ACPI_ATTR_NONE = 0,
191         ACPI_ATTR_LABEL_SHOW,
192         ACPI_ATTR_INDEX_SHOW,
193 };
194
195 static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
196 {
197         int len;
198         len = utf16s_to_utf8s((const wchar_t *)obj->
199                               package.elements[1].string.pointer,
200                               obj->package.elements[1].string.length,
201                               UTF16_LITTLE_ENDIAN,
202                               buf, PAGE_SIZE);
203         buf[len] = '\n';
204 }
205
206 static int
207 dsm_get_label(acpi_handle handle, int func,
208               struct acpi_buffer *output,
209               char *buf, enum acpi_attr_enum attribute)
210 {
211         struct acpi_object_list input;
212         union acpi_object params[4];
213         union acpi_object *obj;
214         int len = 0;
215
216         int err;
217
218         input.count = 4;
219         input.pointer = params;
220         params[0].type = ACPI_TYPE_BUFFER;
221         params[0].buffer.length = sizeof(device_label_dsm_uuid);
222         params[0].buffer.pointer = (char *)device_label_dsm_uuid;
223         params[1].type = ACPI_TYPE_INTEGER;
224         params[1].integer.value = 0x02;
225         params[2].type = ACPI_TYPE_INTEGER;
226         params[2].integer.value = func;
227         params[3].type = ACPI_TYPE_PACKAGE;
228         params[3].package.count = 0;
229         params[3].package.elements = NULL;
230
231         err = acpi_evaluate_object(handle, "_DSM", &input, output);
232         if (err)
233                 return -1;
234
235         obj = (union acpi_object *)output->pointer;
236
237         switch (obj->type) {
238         case ACPI_TYPE_PACKAGE:
239                 if (obj->package.count != 2)
240                         break;
241                 len = obj->package.elements[0].integer.value;
242                 if (buf) {
243                         if (attribute == ACPI_ATTR_INDEX_SHOW)
244                                 scnprintf(buf, PAGE_SIZE, "%llu\n",
245                                 obj->package.elements[0].integer.value);
246                         else if (attribute == ACPI_ATTR_LABEL_SHOW)
247                                 dsm_label_utf16s_to_utf8s(obj, buf);
248                         kfree(output->pointer);
249                         return strlen(buf);
250                 }
251                 kfree(output->pointer);
252                 return len;
253         break;
254         default:
255                 kfree(output->pointer);
256         }
257         return -1;
258 }
259
260 static bool
261 device_has_dsm(struct device *dev)
262 {
263         acpi_handle handle;
264         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
265
266         handle = DEVICE_ACPI_HANDLE(dev);
267
268         if (!handle)
269                 return FALSE;
270
271         if (dsm_get_label(handle, DEVICE_LABEL_DSM, &output, NULL,
272                           ACPI_ATTR_NONE) > 0)
273                 return TRUE;
274
275         return FALSE;
276 }
277
278 static mode_t
279 acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
280 {
281         struct device *dev;
282
283         dev = container_of(kobj, struct device, kobj);
284
285         if (device_has_dsm(dev))
286                 return S_IRUGO;
287
288         return 0;
289 }
290
291 static ssize_t
292 acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
293 {
294         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
295         acpi_handle handle;
296         int length;
297
298         handle = DEVICE_ACPI_HANDLE(dev);
299
300         if (!handle)
301                 return -1;
302
303         length = dsm_get_label(handle, DEVICE_LABEL_DSM,
304                                &output, buf, ACPI_ATTR_LABEL_SHOW);
305
306         if (length < 1)
307                 return -1;
308
309         return length;
310 }
311
312 static ssize_t
313 acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
314 {
315         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
316         acpi_handle handle;
317         int length;
318
319         handle = DEVICE_ACPI_HANDLE(dev);
320
321         if (!handle)
322                 return -1;
323
324         length = dsm_get_label(handle, DEVICE_LABEL_DSM,
325                                &output, buf, ACPI_ATTR_INDEX_SHOW);
326
327         if (length < 0)
328                 return -1;
329
330         return length;
331
332 }
333
334 static struct device_attribute acpi_attr_label = {
335         .attr = {.name = "label", .mode = 0444},
336         .show = acpilabel_show,
337 };
338
339 static struct device_attribute acpi_attr_index = {
340         .attr = {.name = "acpi_index", .mode = 0444},
341         .show = acpiindex_show,
342 };
343
344 static struct attribute *acpi_attributes[] = {
345         &acpi_attr_label.attr,
346         &acpi_attr_index.attr,
347         NULL,
348 };
349
350 static struct attribute_group acpi_attr_group = {
351         .attrs = acpi_attributes,
352         .is_visible = acpi_index_string_exist,
353 };
354
355 static int
356 pci_create_acpi_index_label_files(struct pci_dev *pdev)
357 {
358         return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
359 }
360
361 static int
362 pci_remove_acpi_index_label_files(struct pci_dev *pdev)
363 {
364         sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
365         return 0;
366 }
367 #endif
368
369 void pci_create_firmware_label_files(struct pci_dev *pdev)
370 {
371         if (device_has_dsm(&pdev->dev))
372                 pci_create_acpi_index_label_files(pdev);
373         else
374                 pci_create_smbiosname_file(pdev);
375 }
376
377 void pci_remove_firmware_label_files(struct pci_dev *pdev)
378 {
379         if (device_has_dsm(&pdev->dev))
380                 pci_remove_acpi_index_label_files(pdev);
381         else
382                 pci_remove_smbiosname_file(pdev);
383 }