drivers/firmware/dmi-id.c

   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(product_name,         0444, DMI_PRODUCT_NAME);
  46 DEFINE_DMI_ATTR_WITH_SHOW(product_version,      0444, DMI_PRODUCT_VERSION);
  47 DEFINE_DMI_ATTR_WITH_SHOW(product_serial,       0400, DMI_PRODUCT_SERIAL);
  48 DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,         0400, DMI_PRODUCT_UUID);
  49 DEFINE_DMI_ATTR_WITH_SHOW(product_sku,          0444, DMI_PRODUCT_SKU);
  50 DEFINE_DMI_ATTR_WITH_SHOW(product_family,       0444, DMI_PRODUCT_FAMILY);
  51 DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,         0444, DMI_BOARD_VENDOR);
  52 DEFINE_DMI_ATTR_WITH_SHOW(board_name,           0444, DMI_BOARD_NAME);
  53 DEFINE_DMI_ATTR_WITH_SHOW(board_version,        0444, DMI_BOARD_VERSION);
  54 DEFINE_DMI_ATTR_WITH_SHOW(board_serial,         0400, DMI_BOARD_SERIAL);
  55 DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag,      0444, DMI_BOARD_ASSET_TAG);
  56 DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor,       0444, DMI_CHASSIS_VENDOR);
  57 DEFINE_DMI_ATTR_WITH_SHOW(chassis_type,         0444, DMI_CHASSIS_TYPE);
  58 DEFINE_DMI_ATTR_WITH_SHOW(chassis_version,      0444, DMI_CHASSIS_VERSION);
  59 DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial,       0400, DMI_CHASSIS_SERIAL);
  60 DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag,    0444, DMI_CHASSIS_ASSET_TAG);
  61
  62 static void ascii_filter(char *d, const char *s)
  63 {
  64         /* Filter out characters we don't want to see in the modalias string */
  65         for (; *s; s++)
  66                 if (*s > ' ' && *s < 127 && *s != ':')
  67                         *(d++) = *s;
  68
  69         *d = 0;
  70 }
  71
  72 static ssize_t get_modalias(char *buffer, size_t buffer_size)
  73 {
  74         static const struct mafield {
  75                 const char *prefix;
  76                 int field;
  77         } fields[] = {
  78                 { "bvn", DMI_BIOS_VENDOR },
  79                 { "bvr", DMI_BIOS_VERSION },
  80                 { "bd",  DMI_BIOS_DATE },
  81                 { "svn", DMI_SYS_VENDOR },
  82                 { "pn",  DMI_PRODUCT_NAME },
  83                 { "pvr", DMI_PRODUCT_VERSION },
  84                 { "rvn", DMI_BOARD_VENDOR },
  85                 { "rn",  DMI_BOARD_NAME },
  86                 { "rvr", DMI_BOARD_VERSION },
  87                 { "cvn", DMI_CHASSIS_VENDOR },
  88                 { "ct",  DMI_CHASSIS_TYPE },
  89                 { "cvr", DMI_CHASSIS_VERSION },
  90                 { NULL,  DMI_NONE }
  91         };
  92
  93         ssize_t l, left;
  94         char *p;
  95         const struct mafield *f;
  96
  97         strcpy(buffer, "dmi");
  98         p = buffer + 3; left = buffer_size - 4;
  99
 100         for (f = fields; f->prefix && left > 0; f++) {
 101                 const char *c;
 102                 char *t;
 103
 104                 c = dmi_get_system_info(f->field);
 105                 if (!c)
 106                         continue;
 107
 108                 t = kmalloc(strlen(c) + 1, GFP_KERNEL);
 109                 if (!t)
 110                         break;
 111                 ascii_filter(t, c);
 112                 l = scnprintf(p, left, ":%s%s", f->prefix, t);
 113                 kfree(t);
 114
 115                 p += l;
 116                 left -= l;
 117         }
 118
 119         p[0] = ':';
 120         p[1] = 0;
 121
 122         return p - buffer + 1;
 123 }
 124
 125 static ssize_t sys_dmi_modalias_show(struct device *dev,
 126                                      struct device_attribute *attr, char *page)
 127 {
 128         ssize_t r;
 129         r = get_modalias(page, PAGE_SIZE-1);
 130         page[r] = '\n';
 131         page[r+1] = 0;
 132         return r+1;
 133 }
 134
 135 static struct device_attribute sys_dmi_modalias_attr =
 136         __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
 137
 138 static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
 139
 140 static struct attribute_group sys_dmi_attribute_group = {
 141         .attrs = sys_dmi_attributes,
 142 };
 143
 144 static const struct attribute_group* sys_dmi_attribute_groups[] = {
 145         &sys_dmi_attribute_group,
 146         NULL
 147 };
 148
 149 static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 150 {
 151         ssize_t len;
 152
 153         if (add_uevent_var(env, "MODALIAS="))
 154                 return -ENOMEM;
 155         len = get_modalias(&env->buf[env->buflen - 1],
 156                            sizeof(env->buf) - env->buflen);
 157         if (len >= (sizeof(env->buf) - env->buflen))
 158                 return -ENOMEM;
 159         env->buflen += len;
 160         return 0;
 161 }
 162
 163 static struct class dmi_class = {
 164         .name = "dmi",
 165         .dev_release = (void(*)(struct device *)) kfree,
 166         .dev_uevent = dmi_dev_uevent,
 167 };
 168
 169 static struct device *dmi_dev;
 170
 171 /* Initialization */
 172
 173 #define ADD_DMI_ATTR(_name, _field) \
 174         if (dmi_get_system_info(_field)) \
 175                 sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr;
 176
 177 /* In a separate function to keep gcc 3.2 happy - do NOT merge this in
 178    dmi_id_init! */
 179 static void __init dmi_id_init_attr_table(void)
 180 {
 181         int i;
 182
 183         /* Not necessarily all DMI fields are available on all
 184          * systems, hence let's built an attribute table of just
 185          * what's available */
 186         i = 0;
 187         ADD_DMI_ATTR(bios_vendor,       DMI_BIOS_VENDOR);
 188         ADD_DMI_ATTR(bios_version,      DMI_BIOS_VERSION);
 189         ADD_DMI_ATTR(bios_date,         DMI_BIOS_DATE);
 190         ADD_DMI_ATTR(sys_vendor,        DMI_SYS_VENDOR);
 191         ADD_DMI_ATTR(product_name,      DMI_PRODUCT_NAME);
 192         ADD_DMI_ATTR(product_version,   DMI_PRODUCT_VERSION);
 193         ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
 194         ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
 195         ADD_DMI_ATTR(product_family,    DMI_PRODUCT_FAMILY);
 196         ADD_DMI_ATTR(product_sku,       DMI_PRODUCT_SKU);
 197         ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
 198         ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
 199         ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);
 200         ADD_DMI_ATTR(board_serial,      DMI_BOARD_SERIAL);
 201         ADD_DMI_ATTR(board_asset_tag,   DMI_BOARD_ASSET_TAG);
 202         ADD_DMI_ATTR(chassis_vendor,    DMI_CHASSIS_VENDOR);
 203         ADD_DMI_ATTR(chassis_type,      DMI_CHASSIS_TYPE);
 204         ADD_DMI_ATTR(chassis_version,   DMI_CHASSIS_VERSION);
 205         ADD_DMI_ATTR(chassis_serial,    DMI_CHASSIS_SERIAL);
 206         ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG);
 207         sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr;
 208 }
 209
 210 static int __init dmi_id_init(void)
 211 {
 212         int ret;
 213
 214         if (!dmi_available)
 215                 return -ENODEV;
 216
 217         dmi_id_init_attr_table();
 218
 219         ret = class_register(&dmi_class);
 220         if (ret)
 221                 return ret;
 222
 223         dmi_dev = kzalloc(sizeof(*dmi_dev), GFP_KERNEL);
 224         if (!dmi_dev) {
 225                 ret = -ENOMEM;
 226                 goto fail_class_unregister;
 227         }
 228
 229         dmi_dev->class = &dmi_class;
 230         dev_set_name(dmi_dev, "id");
 231         dmi_dev->groups = sys_dmi_attribute_groups;
 232
 233         ret = device_register(dmi_dev);
 234         if (ret)
 235                 goto fail_put_dmi_dev;
 236
 237         return 0;
 238
 239 fail_put_dmi_dev:
 240         put_device(dmi_dev);
 241
 242 fail_class_unregister:
 243         class_unregister(&dmi_class);
 244
 245         return ret;
 246 }
 247
 248 arch_initcall(dmi_id_init);