1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Export SMBIOS/DMI info via sysfs to userspace 4 * 5 * Copyright 2007, Lennart Poettering 6 */ 7 8 #include <linux/module.h> 9 #include <linux/kernel.h> 10 #include <linux/init.h> 11 #include <linux/dmi.h> 12 #include <linux/device.h> 13 #include <linux/slab.h> 14 15 struct dmi_device_attribute{ 16 struct device_attribute dev_attr; 17 int field; 18 }; 19 #define to_dmi_dev_attr(_dev_attr) \ 20 container_of(_dev_attr, struct dmi_device_attribute, dev_attr) 21 22 static ssize_t sys_dmi_field_show(struct device *dev, 23 struct device_attribute *attr, 24 char *page) 25 { 26 int field = to_dmi_dev_attr(attr)->field; 27 ssize_t len; 28 len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field)); 29 page[len-1] = '\n'; 30 return len; 31 } 32 33 #define DMI_ATTR(_name, _mode, _show, _field) \ 34 { .dev_attr = __ATTR(_name, _mode, _show, NULL), \ 35 .field = _field } 36 37 #define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field) \ 38 static struct dmi_device_attribute sys_dmi_##_name##_attr = \ 39 DMI_ATTR(_name, _mode, sys_dmi_field_show, _field); 40 41 DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor, 0444, DMI_BIOS_VENDOR); 42 DEFINE_DMI_ATTR_WITH_SHOW(bios_version, 0444, DMI_BIOS_VERSION); 43 DEFINE_DMI_ATTR_WITH_SHOW(bios_date, 0444, DMI_BIOS_DATE); 44 DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor, 0444, DMI_SYS_VENDOR); 45 DEFINE_DMI_ATTR_WITH_SHOW(bios_release, 0444, DMI_BIOS_RELEASE); 46 DEFINE_DMI_ATTR_WITH_SHOW(ec_firmware_release, 0444, DMI_EC_FIRMWARE_RELEASE); 47 DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME); 48 DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION); 49 DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL); 50 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID); 51 DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU); 52 DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY); 53 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR); 54 DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME); 55 DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION); 56 DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL); 57 DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG); 58 DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR); 59 DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE); 60 DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION); 61 DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL); 62 DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG); 63 64 static void ascii_filter(char *d, const char *s) 65 { 66 /* Filter out characters we don't want to see in the modalias string */ 67 for (; *s; s++) 68 if (*s > ' ' && *s < 127 && *s != ':') 69 *(d++) = *s; 70 71 *d = 0; 72 } 73 74 static ssize_t get_modalias(char *buffer, size_t buffer_size) 75 { 76 /* 77 * Note new fields need to be added at the end to keep compatibility 78 * with udev's hwdb which does matches on "`cat dmi/id/modalias`*". 79 */ 80 static const struct mafield { 81 const char *prefix; 82 int field; 83 } fields[] = { 84 { "bvn", DMI_BIOS_VENDOR }, 85 { "bvr", DMI_BIOS_VERSION }, 86 { "bd", DMI_BIOS_DATE }, 87 { "br", DMI_BIOS_RELEASE }, 88 { "efr", DMI_EC_FIRMWARE_RELEASE }, 89 { "svn", DMI_SYS_VENDOR }, 90 { "pn", DMI_PRODUCT_NAME }, 91 { "pvr", DMI_PRODUCT_VERSION }, 92 { "rvn", DMI_BOARD_VENDOR }, 93 { "rn", DMI_BOARD_NAME }, 94 { "rvr", DMI_BOARD_VERSION }, 95 { "cvn", DMI_CHASSIS_VENDOR }, 96 { "ct", DMI_CHASSIS_TYPE }, 97 { "cvr", DMI_CHASSIS_VERSION }, 98 { "sku", DMI_PRODUCT_SKU }, 99 { NULL, DMI_NONE } 100 }; 101 102 ssize_t l, left; 103 char *p; 104 const struct mafield *f; 105 106 strcpy(buffer, "dmi"); 107 p = buffer + 3; left = buffer_size - 4; 108 109 for (f = fields; f->prefix && left > 0; f++) { 110 const char *c; 111 char *t; 112 113 c = dmi_get_system_info(f->field); 114 if (!c) 115 continue; 116 117 t = kmalloc(strlen(c) + 1, GFP_KERNEL); 118 if (!t) 119 break; 120 ascii_filter(t, c); 121 l = scnprintf(p, left, ":%s%s", f->prefix, t); 122 kfree(t); 123 124 p += l; 125 left -= l; 126 } 127 128 p[0] = ':'; 129 p[1] = 0; 130 131 return p - buffer + 1; 132 } 133 134 static ssize_t sys_dmi_modalias_show(struct device *dev, 135 struct device_attribute *attr, char *page) 136 { 137 ssize_t r; 138 r = get_modalias(page, PAGE_SIZE-1); 139 page[r] = '\n'; 140 page[r+1] = 0; 141 return r+1; 142 } 143 144 static struct device_attribute sys_dmi_modalias_attr = 145 __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL); 146 147 static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2]; 148 149 static struct attribute_group sys_dmi_attribute_group = { 150 .attrs = sys_dmi_attributes, 151 }; 152 153 static const struct attribute_group* sys_dmi_attribute_groups[] = { 154 &sys_dmi_attribute_group, 155 NULL 156 }; 157 158 static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env) 159 { 160 ssize_t len; 161 162 if (add_uevent_var(env, "MODALIAS=")) 163 return -ENOMEM; 164 len = get_modalias(&env->buf[env->buflen - 1], 165 sizeof(env->buf) - env->buflen); 166 if (len >= (sizeof(env->buf) - env->buflen)) 167 return -ENOMEM; 168 env->buflen += len; 169 return 0; 170 } 171 172 static struct class dmi_class = { 173 .name = "dmi", 174 .dev_release = (void(*)(struct device *)) kfree, 175 .dev_uevent = dmi_dev_uevent, 176 }; 177 178 static struct device *dmi_dev; 179 180 /* Initialization */ 181 182 #define ADD_DMI_ATTR(_name, _field) \ 183 if (dmi_get_system_info(_field)) \ 184 sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr; 185 186 /* In a separate function to keep gcc 3.2 happy - do NOT merge this in 187 dmi_id_init! */ 188 static void __init dmi_id_init_attr_table(void) 189 { 190 int i; 191 192 /* Not necessarily all DMI fields are available on all 193 * systems, hence let's built an attribute table of just 194 * what's available */ 195 i = 0; 196 ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR); 197 ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION); 198 ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE); 199 ADD_DMI_ATTR(bios_release, DMI_BIOS_RELEASE); 200 ADD_DMI_ATTR(ec_firmware_release, DMI_EC_FIRMWARE_RELEASE); 201 ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR); 202 ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME); 203 ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION); 204 ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL); 205 ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID); 206 ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); 207 ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU); 208 ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR); 209 ADD_DMI_ATTR(board_name, DMI_BOARD_NAME); 210 ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION); 211 ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL); 212 ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG); 213 ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR); 214 ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE); 215 ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION); 216 ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL); 217 ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG); 218 sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr; 219 } 220 221 static int __init dmi_id_init(void) 222 { 223 int ret; 224 225 if (!dmi_available) 226 return -ENODEV; 227 228 dmi_id_init_attr_table(); 229 230 ret = class_register(&dmi_class); 231 if (ret) 232 return ret; 233 234 dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL); 235 if (!dmi_dev) { 236 ret = -ENOMEM; 237 goto fail_class_unregister; 238 } 239 240 dmi_dev->class = &dmi_class; 241 dev_set_name(dmi_dev, "id"); 242 dmi_dev->groups = sys_dmi_attribute_groups; 243 244 ret = device_register(dmi_dev); 245 if (ret) 246 goto fail_put_dmi_dev; 247 248 return 0; 249 250 fail_put_dmi_dev: 251 put_device(dmi_dev); 252 253 fail_class_unregister: 254 class_unregister(&dmi_class); 255 256 return ret; 257 } 258 259 arch_initcall(dmi_id_init); 260