linux/drivers/firmware/dmi-id.c
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   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
  15struct 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
  22static 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)         \
  38static struct dmi_device_attribute sys_dmi_##_name##_attr =     \
  39        DMI_ATTR(_name, _mode, sys_dmi_field_show, _field);
  40
  41DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor,          0444, DMI_BIOS_VENDOR);
  42DEFINE_DMI_ATTR_WITH_SHOW(bios_version,         0444, DMI_BIOS_VERSION);
  43DEFINE_DMI_ATTR_WITH_SHOW(bios_date,            0444, DMI_BIOS_DATE);
  44DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor,           0444, DMI_SYS_VENDOR);
  45DEFINE_DMI_ATTR_WITH_SHOW(product_name,         0444, DMI_PRODUCT_NAME);
  46DEFINE_DMI_ATTR_WITH_SHOW(product_version,      0444, DMI_PRODUCT_VERSION);
  47DEFINE_DMI_ATTR_WITH_SHOW(product_serial,       0400, DMI_PRODUCT_SERIAL);
  48DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,         0400, DMI_PRODUCT_UUID);
  49DEFINE_DMI_ATTR_WITH_SHOW(product_sku,          0444, DMI_PRODUCT_SKU);
  50DEFINE_DMI_ATTR_WITH_SHOW(product_family,       0444, DMI_PRODUCT_FAMILY);
  51DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,         0444, DMI_BOARD_VENDOR);
  52DEFINE_DMI_ATTR_WITH_SHOW(board_name,           0444, DMI_BOARD_NAME);
  53DEFINE_DMI_ATTR_WITH_SHOW(board_version,        0444, DMI_BOARD_VERSION);
  54DEFINE_DMI_ATTR_WITH_SHOW(board_serial,         0400, DMI_BOARD_SERIAL);
  55DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag,      0444, DMI_BOARD_ASSET_TAG);
  56DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor,       0444, DMI_CHASSIS_VENDOR);
  57DEFINE_DMI_ATTR_WITH_SHOW(chassis_type,         0444, DMI_CHASSIS_TYPE);
  58DEFINE_DMI_ATTR_WITH_SHOW(chassis_version,      0444, DMI_CHASSIS_VERSION);
  59DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial,       0400, DMI_CHASSIS_SERIAL);
  60DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag,    0444, DMI_CHASSIS_ASSET_TAG);
  61
  62static 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
  72static 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
 125static 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
 135static struct device_attribute sys_dmi_modalias_attr =
 136        __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL);
 137
 138static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2];
 139
 140static struct attribute_group sys_dmi_attribute_group = {
 141        .attrs = sys_dmi_attributes,
 142};
 143
 144static const struct attribute_group* sys_dmi_attribute_groups[] = {
 145        &sys_dmi_attribute_group,
 146        NULL
 147};
 148
 149static 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
 163static struct class dmi_class = {
 164        .name = "dmi",
 165        .dev_release = (void(*)(struct device *)) kfree,
 166        .dev_uevent = dmi_dev_uevent,
 167};
 168
 169static 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! */
 179static 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
 210static 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
 239fail_put_dmi_dev:
 240        put_device(dmi_dev);
 241
 242fail_class_unregister:
 243        class_unregister(&dmi_class);
 244
 245        return ret;
 246}
 247
 248arch_initcall(dmi_id_init);
 249