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 find_smbios_instance_string(struct pci_dev *pdev, char *buf, 44 enum smbios_attr_enum attribute) 45 { 46 const struct dmi_device *dmi; 47 struct dmi_dev_onboard *donboard; 48 int bus; 49 int devfn; 50 51 bus = pdev->bus->number; 52 devfn = pdev->devfn; 53 54 dmi = NULL; 55 while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, 56 NULL, dmi)) != NULL) { 57 donboard = dmi->device_data; 58 if (donboard && donboard->bus == bus && 59 donboard->devfn == devfn) { 60 if (buf) { 61 if (attribute == SMBIOS_ATTR_INSTANCE_SHOW) 62 return scnprintf(buf, PAGE_SIZE, 63 "%d\n", 64 donboard->instance); 65 else if (attribute == SMBIOS_ATTR_LABEL_SHOW) 66 return scnprintf(buf, PAGE_SIZE, 67 "%s\n", 68 dmi->name); 69 } 70 return strlen(dmi->name); 71 } 72 } 73 return 0; 74 } 75 76 static umode_t smbios_instance_string_exist(struct kobject *kobj, 77 struct attribute *attr, int n) 78 { 79 struct device *dev; 80 struct pci_dev *pdev; 81 82 dev = container_of(kobj, struct device, kobj); 83 pdev = to_pci_dev(dev); 84 85 return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ? 86 S_IRUGO : 0; 87 } 88 89 static ssize_t smbioslabel_show(struct device *dev, 90 struct device_attribute *attr, char *buf) 91 { 92 struct pci_dev *pdev; 93 pdev = to_pci_dev(dev); 94 95 return find_smbios_instance_string(pdev, buf, 96 SMBIOS_ATTR_LABEL_SHOW); 97 } 98 99 static ssize_t smbiosinstance_show(struct device *dev, 100 struct device_attribute *attr, char *buf) 101 { 102 struct pci_dev *pdev; 103 pdev = to_pci_dev(dev); 104 105 return find_smbios_instance_string(pdev, buf, 106 SMBIOS_ATTR_INSTANCE_SHOW); 107 } 108 109 static struct device_attribute smbios_attr_label = { 110 .attr = {.name = "label", .mode = 0444}, 111 .show = smbioslabel_show, 112 }; 113 114 static struct device_attribute smbios_attr_instance = { 115 .attr = {.name = "index", .mode = 0444}, 116 .show = smbiosinstance_show, 117 }; 118 119 static struct attribute *smbios_attributes[] = { 120 &smbios_attr_label.attr, 121 &smbios_attr_instance.attr, 122 NULL, 123 }; 124 125 static struct attribute_group smbios_attr_group = { 126 .attrs = smbios_attributes, 127 .is_visible = smbios_instance_string_exist, 128 }; 129 130 static int pci_create_smbiosname_file(struct pci_dev *pdev) 131 { 132 return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group); 133 } 134 135 static void pci_remove_smbiosname_file(struct pci_dev *pdev) 136 { 137 sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group); 138 } 139 #else 140 static inline int pci_create_smbiosname_file(struct pci_dev *pdev) 141 { 142 return -1; 143 } 144 145 static inline void pci_remove_smbiosname_file(struct pci_dev *pdev) 146 { 147 } 148 #endif 149 150 #ifdef CONFIG_ACPI 151 static const char device_label_dsm_uuid[] = { 152 0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D, 153 0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D 154 }; 155 156 enum acpi_attr_enum { 157 ACPI_ATTR_LABEL_SHOW, 158 ACPI_ATTR_INDEX_SHOW, 159 }; 160 161 static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) 162 { 163 int len; 164 len = utf16s_to_utf8s((const wchar_t *)obj->string.pointer, 165 obj->string.length, 166 UTF16_LITTLE_ENDIAN, 167 buf, PAGE_SIZE); 168 buf[len] = '\n'; 169 } 170 171 static int dsm_get_label(struct device *dev, char *buf, 172 enum acpi_attr_enum attr) 173 { 174 acpi_handle handle; 175 union acpi_object *obj, *tmp; 176 int len = -1; 177 178 handle = ACPI_HANDLE(dev); 179 if (!handle) 180 return -1; 181 182 obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2, 183 DEVICE_LABEL_DSM, NULL); 184 if (!obj) 185 return -1; 186 187 tmp = obj->package.elements; 188 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 && 189 tmp[0].type == ACPI_TYPE_INTEGER && 190 tmp[1].type == ACPI_TYPE_STRING) { 191 /* 192 * The second string element is optional even when 193 * this _DSM is implemented; when not implemented, 194 * this entry must return a null string. 195 */ 196 if (attr == ACPI_ATTR_INDEX_SHOW) 197 scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); 198 else if (attr == ACPI_ATTR_LABEL_SHOW) 199 dsm_label_utf16s_to_utf8s(tmp + 1, buf); 200 len = strlen(buf) > 0 ? strlen(buf) : -1; 201 } 202 203 ACPI_FREE(obj); 204 205 return len; 206 } 207 208 static bool device_has_dsm(struct device *dev) 209 { 210 acpi_handle handle; 211 212 handle = ACPI_HANDLE(dev); 213 if (!handle) 214 return false; 215 216 return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2, 217 1 << DEVICE_LABEL_DSM); 218 } 219 220 static umode_t acpi_index_string_exist(struct kobject *kobj, 221 struct attribute *attr, int n) 222 { 223 struct device *dev; 224 225 dev = container_of(kobj, struct device, kobj); 226 227 if (device_has_dsm(dev)) 228 return S_IRUGO; 229 230 return 0; 231 } 232 233 static ssize_t acpilabel_show(struct device *dev, 234 struct device_attribute *attr, char *buf) 235 { 236 return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW); 237 } 238 239 static ssize_t acpiindex_show(struct device *dev, 240 struct device_attribute *attr, char *buf) 241 { 242 return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW); 243 } 244 245 static struct device_attribute acpi_attr_label = { 246 .attr = {.name = "label", .mode = 0444}, 247 .show = acpilabel_show, 248 }; 249 250 static struct device_attribute acpi_attr_index = { 251 .attr = {.name = "acpi_index", .mode = 0444}, 252 .show = acpiindex_show, 253 }; 254 255 static struct attribute *acpi_attributes[] = { 256 &acpi_attr_label.attr, 257 &acpi_attr_index.attr, 258 NULL, 259 }; 260 261 static struct attribute_group acpi_attr_group = { 262 .attrs = acpi_attributes, 263 .is_visible = acpi_index_string_exist, 264 }; 265 266 static int pci_create_acpi_index_label_files(struct pci_dev *pdev) 267 { 268 return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group); 269 } 270 271 static int pci_remove_acpi_index_label_files(struct pci_dev *pdev) 272 { 273 sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group); 274 return 0; 275 } 276 #else 277 static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev) 278 { 279 return -1; 280 } 281 282 static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev) 283 { 284 return -1; 285 } 286 287 static inline bool device_has_dsm(struct device *dev) 288 { 289 return false; 290 } 291 #endif 292 293 void pci_create_firmware_label_files(struct pci_dev *pdev) 294 { 295 if (device_has_dsm(&pdev->dev)) 296 pci_create_acpi_index_label_files(pdev); 297 else 298 pci_create_smbiosname_file(pdev); 299 } 300 301 void pci_remove_firmware_label_files(struct pci_dev *pdev) 302 { 303 if (device_has_dsm(&pdev->dev)) 304 pci_remove_acpi_index_label_files(pdev); 305 else 306 pci_remove_smbiosname_file(pdev); 307 } 308