Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | #ifdef CONFIG_DMI |
| 35 | enum smbios_attr_enum { |
| 36 | SMBIOS_ATTR_NONE = 0, |
| 37 | SMBIOS_ATTR_LABEL_SHOW, |
| 38 | SMBIOS_ATTR_INSTANCE_SHOW, |
| 39 | }; |
| 40 | |
| 41 | static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf, |
| 42 | enum smbios_attr_enum attribute) |
| 43 | { |
| 44 | const struct dmi_device *dmi; |
| 45 | struct dmi_dev_onboard *donboard; |
| 46 | int bus; |
| 47 | int devfn; |
| 48 | |
| 49 | bus = pdev->bus->number; |
| 50 | devfn = pdev->devfn; |
| 51 | |
| 52 | dmi = NULL; |
| 53 | while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD, |
| 54 | NULL, dmi)) != NULL) { |
| 55 | donboard = dmi->device_data; |
| 56 | if (donboard && donboard->bus == bus && |
| 57 | donboard->devfn == devfn) { |
| 58 | if (buf) { |
| 59 | if (attribute == SMBIOS_ATTR_INSTANCE_SHOW) |
| 60 | return scnprintf(buf, PAGE_SIZE, |
| 61 | "%d\n", |
| 62 | donboard->instance); |
| 63 | else if (attribute == SMBIOS_ATTR_LABEL_SHOW) |
| 64 | return scnprintf(buf, PAGE_SIZE, |
| 65 | "%s\n", |
| 66 | dmi->name); |
| 67 | } |
| 68 | return strlen(dmi->name); |
| 69 | } |
| 70 | } |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | static umode_t smbios_instance_string_exist(struct kobject *kobj, |
| 75 | struct attribute *attr, int n) |
| 76 | { |
| 77 | struct device *dev; |
| 78 | struct pci_dev *pdev; |
| 79 | |
| 80 | dev = container_of(kobj, struct device, kobj); |
| 81 | pdev = to_pci_dev(dev); |
| 82 | |
| 83 | return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ? |
| 84 | S_IRUGO : 0; |
| 85 | } |
| 86 | |
| 87 | static ssize_t smbioslabel_show(struct device *dev, |
| 88 | struct device_attribute *attr, char *buf) |
| 89 | { |
| 90 | struct pci_dev *pdev; |
| 91 | pdev = to_pci_dev(dev); |
| 92 | |
| 93 | return find_smbios_instance_string(pdev, buf, |
| 94 | SMBIOS_ATTR_LABEL_SHOW); |
| 95 | } |
| 96 | |
| 97 | static ssize_t smbiosinstance_show(struct device *dev, |
| 98 | struct device_attribute *attr, char *buf) |
| 99 | { |
| 100 | struct pci_dev *pdev; |
| 101 | pdev = to_pci_dev(dev); |
| 102 | |
| 103 | return find_smbios_instance_string(pdev, buf, |
| 104 | SMBIOS_ATTR_INSTANCE_SHOW); |
| 105 | } |
| 106 | |
| 107 | static struct device_attribute smbios_attr_label = { |
| 108 | .attr = {.name = "label", .mode = 0444}, |
| 109 | .show = smbioslabel_show, |
| 110 | }; |
| 111 | |
| 112 | static struct device_attribute smbios_attr_instance = { |
| 113 | .attr = {.name = "index", .mode = 0444}, |
| 114 | .show = smbiosinstance_show, |
| 115 | }; |
| 116 | |
| 117 | static struct attribute *smbios_attributes[] = { |
| 118 | &smbios_attr_label.attr, |
| 119 | &smbios_attr_instance.attr, |
| 120 | NULL, |
| 121 | }; |
| 122 | |
| 123 | static struct attribute_group smbios_attr_group = { |
| 124 | .attrs = smbios_attributes, |
| 125 | .is_visible = smbios_instance_string_exist, |
| 126 | }; |
| 127 | |
| 128 | static int pci_create_smbiosname_file(struct pci_dev *pdev) |
| 129 | { |
| 130 | return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group); |
| 131 | } |
| 132 | |
| 133 | static void pci_remove_smbiosname_file(struct pci_dev *pdev) |
| 134 | { |
| 135 | sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group); |
| 136 | } |
| 137 | #else |
| 138 | static inline int pci_create_smbiosname_file(struct pci_dev *pdev) |
| 139 | { |
| 140 | return -1; |
| 141 | } |
| 142 | |
| 143 | static inline void pci_remove_smbiosname_file(struct pci_dev *pdev) |
| 144 | { |
| 145 | } |
| 146 | #endif |
| 147 | |
| 148 | #ifdef CONFIG_ACPI |
| 149 | enum acpi_attr_enum { |
| 150 | ACPI_ATTR_LABEL_SHOW, |
| 151 | ACPI_ATTR_INDEX_SHOW, |
| 152 | }; |
| 153 | |
| 154 | static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) |
| 155 | { |
| 156 | int len; |
| 157 | len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, |
| 158 | obj->buffer.length, |
| 159 | UTF16_LITTLE_ENDIAN, |
| 160 | buf, PAGE_SIZE); |
| 161 | buf[len] = '\n'; |
| 162 | } |
| 163 | |
| 164 | static int dsm_get_label(struct device *dev, char *buf, |
| 165 | enum acpi_attr_enum attr) |
| 166 | { |
| 167 | acpi_handle handle; |
| 168 | union acpi_object *obj, *tmp; |
| 169 | int len = -1; |
| 170 | |
| 171 | handle = ACPI_HANDLE(dev); |
| 172 | if (!handle) |
| 173 | return -1; |
| 174 | |
| 175 | obj = acpi_evaluate_dsm(handle, pci_acpi_dsm_uuid, 0x2, |
| 176 | DEVICE_LABEL_DSM, NULL); |
| 177 | if (!obj) |
| 178 | return -1; |
| 179 | |
| 180 | tmp = obj->package.elements; |
| 181 | if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 && |
| 182 | tmp[0].type == ACPI_TYPE_INTEGER && |
| 183 | (tmp[1].type == ACPI_TYPE_STRING || |
| 184 | tmp[1].type == ACPI_TYPE_BUFFER)) { |
| 185 | /* |
| 186 | * The second string element is optional even when |
| 187 | * this _DSM is implemented; when not implemented, |
| 188 | * this entry must return a null string. |
| 189 | */ |
| 190 | if (attr == ACPI_ATTR_INDEX_SHOW) { |
| 191 | scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); |
| 192 | } else if (attr == ACPI_ATTR_LABEL_SHOW) { |
| 193 | if (tmp[1].type == ACPI_TYPE_STRING) |
| 194 | scnprintf(buf, PAGE_SIZE, "%s\n", |
| 195 | tmp[1].string.pointer); |
| 196 | else if (tmp[1].type == ACPI_TYPE_BUFFER) |
| 197 | dsm_label_utf16s_to_utf8s(tmp + 1, buf); |
| 198 | } |
| 199 | len = strlen(buf) > 0 ? strlen(buf) : -1; |
| 200 | } |
| 201 | |
| 202 | ACPI_FREE(obj); |
| 203 | |
| 204 | return len; |
| 205 | } |
| 206 | |
| 207 | static bool device_has_dsm(struct device *dev) |
| 208 | { |
| 209 | acpi_handle handle; |
| 210 | |
| 211 | handle = ACPI_HANDLE(dev); |
| 212 | if (!handle) |
| 213 | return false; |
| 214 | |
| 215 | return !!acpi_check_dsm(handle, pci_acpi_dsm_uuid, 0x2, |
| 216 | 1 << DEVICE_LABEL_DSM); |
| 217 | } |
| 218 | |
| 219 | static umode_t acpi_index_string_exist(struct kobject *kobj, |
| 220 | struct attribute *attr, int n) |
| 221 | { |
| 222 | struct device *dev; |
| 223 | |
| 224 | dev = container_of(kobj, struct device, kobj); |
| 225 | |
| 226 | if (device_has_dsm(dev)) |
| 227 | return S_IRUGO; |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | static ssize_t acpilabel_show(struct device *dev, |
| 233 | struct device_attribute *attr, char *buf) |
| 234 | { |
| 235 | return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW); |
| 236 | } |
| 237 | |
| 238 | static ssize_t acpiindex_show(struct device *dev, |
| 239 | struct device_attribute *attr, char *buf) |
| 240 | { |
| 241 | return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW); |
| 242 | } |
| 243 | |
| 244 | static struct device_attribute acpi_attr_label = { |
| 245 | .attr = {.name = "label", .mode = 0444}, |
| 246 | .show = acpilabel_show, |
| 247 | }; |
| 248 | |
| 249 | static struct device_attribute acpi_attr_index = { |
| 250 | .attr = {.name = "acpi_index", .mode = 0444}, |
| 251 | .show = acpiindex_show, |
| 252 | }; |
| 253 | |
| 254 | static struct attribute *acpi_attributes[] = { |
| 255 | &acpi_attr_label.attr, |
| 256 | &acpi_attr_index.attr, |
| 257 | NULL, |
| 258 | }; |
| 259 | |
| 260 | static struct attribute_group acpi_attr_group = { |
| 261 | .attrs = acpi_attributes, |
| 262 | .is_visible = acpi_index_string_exist, |
| 263 | }; |
| 264 | |
| 265 | static int pci_create_acpi_index_label_files(struct pci_dev *pdev) |
| 266 | { |
| 267 | return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group); |
| 268 | } |
| 269 | |
| 270 | static int pci_remove_acpi_index_label_files(struct pci_dev *pdev) |
| 271 | { |
| 272 | sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group); |
| 273 | return 0; |
| 274 | } |
| 275 | #else |
| 276 | static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev) |
| 277 | { |
| 278 | return -1; |
| 279 | } |
| 280 | |
| 281 | static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev) |
| 282 | { |
| 283 | return -1; |
| 284 | } |
| 285 | |
| 286 | static inline bool device_has_dsm(struct device *dev) |
| 287 | { |
| 288 | return false; |
| 289 | } |
| 290 | #endif |
| 291 | |
| 292 | void pci_create_firmware_label_files(struct pci_dev *pdev) |
| 293 | { |
| 294 | if (device_has_dsm(&pdev->dev)) |
| 295 | pci_create_acpi_index_label_files(pdev); |
| 296 | else |
| 297 | pci_create_smbiosname_file(pdev); |
| 298 | } |
| 299 | |
| 300 | void pci_remove_firmware_label_files(struct pci_dev *pdev) |
| 301 | { |
| 302 | if (device_has_dsm(&pdev->dev)) |
| 303 | pci_remove_acpi_index_label_files(pdev); |
| 304 | else |
| 305 | pci_remove_smbiosname_file(pdev); |
| 306 | } |