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 "pci.h" 33 34 #define DEVICE_LABEL_DSM 0x07 35 36 #ifdef CONFIG_DMI 37 enum smbios_attr_enum { 38 SMBIOS_ATTR_NONE = 0, 39 SMBIOS_ATTR_LABEL_SHOW, 40 SMBIOS_ATTR_INSTANCE_SHOW, 41 }; 42 43 static size_t 44 find_smbios_instance_string(struct pci_dev *pdev, char *buf, 45 enum smbios_attr_enum attribute) 46 { 47 const struct dmi_device *dmi; 48 struct dmi_dev_onboard *donboard; 49 int bus; 50 int devfn; 51 52 bus = pdev->bus->number; 53 devfn = pdev->devfn; 54 55 dmi = NULL; 56 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, 57 NULL, dmi)) != NULL) { 58 donboard = dmi->device_data; 59 if (donboard && donboard->bus == bus && 60 donboard->devfn == devfn) { 61 if (buf) { 62 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW) 63 return scnprintf(buf, PAGE_SIZE, 64 "%d\n", 65 donboard->instance); 66 else if (attribute == SMBIOS_ATTR_LABEL_SHOW) 67 return scnprintf(buf, PAGE_SIZE, 68 "%s\n", 69 dmi->name); 70 } 71 return strlen(dmi->name); 72 } 73 } 74 return 0; 75 } 76 77 static umode_t 78 smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr, 79 int n) 80 { 81 struct device *dev; 82 struct pci_dev *pdev; 83 84 dev = container_of(kobj, struct device, kobj); 85 pdev = to_pci_dev(dev); 86 87 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ? 88 S_IRUGO : 0; 89 } 90 91 static ssize_t 92 smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf) 93 { 94 struct pci_dev *pdev; 95 pdev = to_pci_dev(dev); 96 97 return find_smbios_instance_string(pdev, buf, 98 SMBIOS_ATTR_LABEL_SHOW); 99 } 100 101 static ssize_t 102 smbiosinstance_show(struct device *dev, 103 struct device_attribute *attr, char *buf) 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 = { 113 .attr = {.name = "label", .mode = 0444}, 114 .show = smbioslabel_show, 115 }; 116 117 static struct device_attribute smbios_attr_instance = { 118 .attr = {.name = "index", .mode = 0444}, 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 }; 127 128 static struct attribute_group smbios_attr_group = { 129 .attrs = smbios_attributes, 130 .is_visible = smbios_instance_string_exist, 131 }; 132 133 static int 134 pci_create_smbiosname_file(struct pci_dev *pdev) 135 { 136 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group); 137 } 138 139 static void 140 pci_remove_smbiosname_file(struct pci_dev *pdev) 141 { 142 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group); 143 } 144 #else 145 static inline int 146 pci_create_smbiosname_file(struct pci_dev *pdev) 147 { 148 return -1; 149 } 150 151 static inline void 152 pci_remove_smbiosname_file(struct pci_dev *pdev) 153 { 154 } 155 #endif 156 157 #ifdef CONFIG_ACPI 158 static const char device_label_dsm_uuid[] = { 159 0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D, 160 0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D 161 }; 162 163 enum acpi_attr_enum { 164 ACPI_ATTR_LABEL_SHOW, 165 ACPI_ATTR_INDEX_SHOW, 166 }; 167 168 static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) 169 { 170 int len; 171 len = utf16s_to_utf8s((const wchar_t *)obj->string.pointer, 172 obj->string.length, 173 UTF16_LITTLE_ENDIAN, 174 buf, PAGE_SIZE); 175 buf[len] = '\n'; 176 } 177 178 static int 179 dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr) 180 { 181 acpi_handle handle; 182 union acpi_object *obj, *tmp; 183 int len = -1; 184 185 handle = ACPI_HANDLE(dev); 186 if (!handle) 187 return -1; 188 189 obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2, 190 DEVICE_LABEL_DSM, NULL); 191 if (!obj) 192 return -1; 193 194 tmp = obj->package.elements; 195 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 && 196 tmp[0].type == ACPI_TYPE_INTEGER && 197 tmp[1].type == ACPI_TYPE_STRING) { 198 /* 199 * The second string element is optional even when 200 * this _DSM is implemented; when not implemented, 201 * this entry must return a null string. 202 */ 203 if (attr == ACPI_ATTR_INDEX_SHOW) 204 scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); 205 else if (attr == ACPI_ATTR_LABEL_SHOW) 206 dsm_label_utf16s_to_utf8s(tmp + 1, buf); 207 len = strlen(buf) > 0 ? strlen(buf) : -1; 208 } 209 210 ACPI_FREE(obj); 211 212 return len; 213 } 214 215 static bool 216 device_has_dsm(struct device *dev) 217 { 218 acpi_handle handle; 219 220 handle = ACPI_HANDLE(dev); 221 if (!handle) 222 return false; 223 224 return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2, 225 1 << DEVICE_LABEL_DSM); 226 } 227 228 static umode_t 229 acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n) 230 { 231 struct device *dev; 232 233 dev = container_of(kobj, struct device, kobj); 234 235 if (device_has_dsm(dev)) 236 return S_IRUGO; 237 238 return 0; 239 } 240 241 static ssize_t 242 acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf) 243 { 244 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW); 245 } 246 247 static ssize_t 248 acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf) 249 { 250 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW); 251 } 252 253 static struct device_attribute acpi_attr_label = { 254 .attr = {.name = "label", .mode = 0444}, 255 .show = acpilabel_show, 256 }; 257 258 static struct device_attribute acpi_attr_index = { 259 .attr = {.name = "acpi_index", .mode = 0444}, 260 .show = acpiindex_show, 261 }; 262 263 static struct attribute *acpi_attributes[] = { 264 &acpi_attr_label.attr, 265 &acpi_attr_index.attr, 266 NULL, 267 }; 268 269 static struct attribute_group acpi_attr_group = { 270 .attrs = acpi_attributes, 271 .is_visible = acpi_index_string_exist, 272 }; 273 274 static int 275 pci_create_acpi_index_label_files(struct pci_dev *pdev) 276 { 277 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group); 278 } 279 280 static int 281 pci_remove_acpi_index_label_files(struct pci_dev *pdev) 282 { 283 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group); 284 return 0; 285 } 286 #else 287 static inline int 288 pci_create_acpi_index_label_files(struct pci_dev *pdev) 289 { 290 return -1; 291 } 292 293 static inline int 294 pci_remove_acpi_index_label_files(struct pci_dev *pdev) 295 { 296 return -1; 297 } 298 299 static inline bool 300 device_has_dsm(struct device *dev) 301 { 302 return false; 303 } 304 #endif 305 306 void pci_create_firmware_label_files(struct pci_dev *pdev) 307 { 308 if (device_has_dsm(&pdev->dev)) 309 pci_create_acpi_index_label_files(pdev); 310 else 311 pci_create_smbiosname_file(pdev); 312 } 313 314 void pci_remove_firmware_label_files(struct pci_dev *pdev) 315 { 316 if (device_has_dsm(&pdev->dev)) 317 pci_remove_acpi_index_label_files(pdev); 318 else 319 pci_remove_smbiosname_file(pdev); 320 } 321