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