drivers/firmware/dmi-sysfs.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * dmi-sysfs.c
0004  *
0005  * This module exports the DMI tables read-only to userspace through the
0006  * sysfs file system.
0007  *
0008  * Data is currently found below
0009  *    /sys/firmware/dmi/...
0010  *
0011  * DMI attributes are presented in attribute files with names
0012  * formatted using %d-%d, so that the first integer indicates the
0013  * structure type (0-255), and the second field is the instance of that
0014  * entry.
0015  *
0016  * Copyright 2011 Google, Inc.
0017  */
0018
0019 #include <linux/kernel.h>
0020 #include <linux/init.h>
0021 #include <linux/module.h>
0022 #include <linux/types.h>
0023 #include <linux/kobject.h>
0024 #include <linux/dmi.h>
0025 #include <linux/capability.h>
0026 #include <linux/slab.h>
0027 #include <linux/list.h>
0028 #include <linux/io.h>
0029 #include <asm/dmi.h>
0030
0031 #define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we consider
0032                   the top entry type is only 8 bits */
0033
0034 struct dmi_sysfs_entry {
0035     struct dmi_header dh;
0036     struct kobject kobj;
0037     int instance;
0038     int position;
0039     struct list_head list;
0040     struct kobject *child;
0041 };
0042
0043 /*
0044  * Global list of dmi_sysfs_entry.  Even though this should only be
0045  * manipulated at setup and teardown, the lazy nature of the kobject
0046  * system means we get lazy removes.
0047  */
0048 static LIST_HEAD(entry_list);
0049 static DEFINE_SPINLOCK(entry_list_lock);
0050
0051 /* dmi_sysfs_attribute - Top level attribute. used by all entries. */
0052 struct dmi_sysfs_attribute {
0053     struct attribute attr;
0054     ssize_t (*show)(struct dmi_sysfs_entry *entry, char *buf);
0055 };
0056
0057 #define DMI_SYSFS_ATTR(_entry, _name) \
0058 struct dmi_sysfs_attribute dmi_sysfs_attr_##_entry##_##_name = { \
0059     .attr = {.name = __stringify(_name), .mode = 0400}, \
0060     .show = dmi_sysfs_##_entry##_##_name, \
0061 }
0062
0063 /*
0064  * dmi_sysfs_mapped_attribute - Attribute where we require the entry be
0065  * mapped in.  Use in conjunction with dmi_sysfs_specialize_attr_ops.
0066  */
0067 struct dmi_sysfs_mapped_attribute {
0068     struct attribute attr;
0069     ssize_t (*show)(struct dmi_sysfs_entry *entry,
0070             const struct dmi_header *dh,
0071             char *buf);
0072 };
0073
0074 #define DMI_SYSFS_MAPPED_ATTR(_entry, _name) \
0075 struct dmi_sysfs_mapped_attribute dmi_sysfs_attr_##_entry##_##_name = { \
0076     .attr = {.name = __stringify(_name), .mode = 0400}, \
0077     .show = dmi_sysfs_##_entry##_##_name, \
0078 }
0079
0080 /*************************************************
0081  * Generic DMI entry support.
0082  *************************************************/
0083 static void dmi_entry_free(struct kobject *kobj)
0084 {
0085     kfree(kobj);
0086 }
0087
0088 static struct dmi_sysfs_entry *to_entry(struct kobject *kobj)
0089 {
0090     return container_of(kobj, struct dmi_sysfs_entry, kobj);
0091 }
0092
0093 static struct dmi_sysfs_attribute *to_attr(struct attribute *attr)
0094 {
0095     return container_of(attr, struct dmi_sysfs_attribute, attr);
0096 }
0097
0098 static ssize_t dmi_sysfs_attr_show(struct kobject *kobj,
0099                    struct attribute *_attr, char *buf)
0100 {
0101     struct dmi_sysfs_entry *entry = to_entry(kobj);
0102     struct dmi_sysfs_attribute *attr = to_attr(_attr);
0103
0104     /* DMI stuff is only ever admin visible */
0105     if (!capable(CAP_SYS_ADMIN))
0106         return -EACCES;
0107
0108     return attr->show(entry, buf);
0109 }
0110
0111 static const struct sysfs_ops dmi_sysfs_attr_ops = {
0112     .show = dmi_sysfs_attr_show,
0113 };
0114
0115 typedef ssize_t (*dmi_callback)(struct dmi_sysfs_entry *,
0116                 const struct dmi_header *dh, void *);
0117
0118 struct find_dmi_data {
0119     struct dmi_sysfs_entry  *entry;
0120     dmi_callback        callback;
0121     void            *private;
0122     int         instance_countdown;
0123     ssize_t         ret;
0124 };
0125
0126 static void find_dmi_entry_helper(const struct dmi_header *dh,
0127                   void *_data)
0128 {
0129     struct find_dmi_data *data = _data;
0130     struct dmi_sysfs_entry *entry = data->entry;
0131
0132     /* Is this the entry we want? */
0133     if (dh->type != entry->dh.type)
0134         return;
0135
0136     if (data->instance_countdown != 0) {
0137         /* try the next instance? */
0138         data->instance_countdown--;
0139         return;
0140     }
0141
0142     /*
0143      * Don't ever revisit the instance.  Short circuit later
0144      * instances by letting the instance_countdown run negative
0145      */
0146     data->instance_countdown--;
0147
0148     /* Found the entry */
0149     data->ret = data->callback(entry, dh, data->private);
0150 }
0151
0152 /* State for passing the read parameters through dmi_find_entry() */
0153 struct dmi_read_state {
0154     char *buf;
0155     loff_t pos;
0156     size_t count;
0157 };
0158
0159 static ssize_t find_dmi_entry(struct dmi_sysfs_entry *entry,
0160                   dmi_callback callback, void *private)
0161 {
0162     struct find_dmi_data data = {
0163         .entry = entry,
0164         .callback = callback,
0165         .private = private,
0166         .instance_countdown = entry->instance,
0167         .ret = -EIO,  /* To signal the entry disappeared */
0168     };
0169     int ret;
0170
0171     ret = dmi_walk(find_dmi_entry_helper, &data);
0172     /* This shouldn't happen, but just in case. */
0173     if (ret)
0174         return -EINVAL;
0175     return data.ret;
0176 }
0177
0178 /*
0179  * Calculate and return the byte length of the dmi entry identified by
0180  * dh.  This includes both the formatted portion as well as the
0181  * unformatted string space, including the two trailing nul characters.
0182  */
0183 static size_t dmi_entry_length(const struct dmi_header *dh)
0184 {
0185     const char *p = (const char *)dh;
0186
0187     p += dh->length;
0188
0189     while (p[0] || p[1])
0190         p++;
0191
0192     return 2 + p - (const char *)dh;
0193 }
0194
0195 /*************************************************
0196  * Support bits for specialized DMI entry support
0197  *************************************************/
0198 struct dmi_entry_attr_show_data {
0199     struct attribute *attr;
0200     char *buf;
0201 };
0202
0203 static ssize_t dmi_entry_attr_show_helper(struct dmi_sysfs_entry *entry,
0204                       const struct dmi_header *dh,
0205                       void *_data)
0206 {
0207     struct dmi_entry_attr_show_data *data = _data;
0208     struct dmi_sysfs_mapped_attribute *attr;
0209
0210     attr = container_of(data->attr,
0211                 struct dmi_sysfs_mapped_attribute, attr);
0212     return attr->show(entry, dh, data->buf);
0213 }
0214
0215 static ssize_t dmi_entry_attr_show(struct kobject *kobj,
0216                    struct attribute *attr,
0217                    char *buf)
0218 {
0219     struct dmi_entry_attr_show_data data = {
0220         .attr = attr,
0221         .buf  = buf,
0222     };
0223     /* Find the entry according to our parent and call the
0224      * normalized show method hanging off of the attribute */
0225     return find_dmi_entry(to_entry(kobj->parent),
0226                   dmi_entry_attr_show_helper, &data);
0227 }
0228
0229 static const struct sysfs_ops dmi_sysfs_specialize_attr_ops = {
0230     .show = dmi_entry_attr_show,
0231 };
0232
0233 /*************************************************
0234  * Specialized DMI entry support.
0235  *************************************************/
0236
0237 /*** Type 15 - System Event Table ***/
0238
0239 #define DMI_SEL_ACCESS_METHOD_IO8   0x00
0240 #define DMI_SEL_ACCESS_METHOD_IO2x8 0x01
0241 #define DMI_SEL_ACCESS_METHOD_IO16  0x02
0242 #define DMI_SEL_ACCESS_METHOD_PHYS32    0x03
0243 #define DMI_SEL_ACCESS_METHOD_GPNV  0x04
0244
0245 struct dmi_system_event_log {
0246     struct dmi_header header;
0247     u16 area_length;
0248     u16 header_start_offset;
0249     u16 data_start_offset;
0250     u8  access_method;
0251     u8  status;
0252     u32 change_token;
0253     union {
0254         struct {
0255             u16 index_addr;
0256             u16 data_addr;
0257         } io;
0258         u32 phys_addr32;
0259         u16 gpnv_handle;
0260         u32 access_method_address;
0261     };
0262     u8  header_format;
0263     u8  type_descriptors_supported_count;
0264     u8  per_log_type_descriptor_length;
0265     u8  supported_log_type_descriptos[];
0266 } __packed;
0267
0268 #define DMI_SYSFS_SEL_FIELD(_field) \
0269 static ssize_t dmi_sysfs_sel_##_field(struct dmi_sysfs_entry *entry, \
0270                       const struct dmi_header *dh, \
0271                       char *buf) \
0272 { \
0273     struct dmi_system_event_log sel; \
0274     if (sizeof(sel) > dmi_entry_length(dh)) \
0275         return -EIO; \
0276     memcpy(&sel, dh, sizeof(sel)); \
0277     return sprintf(buf, "%u\n", sel._field); \
0278 } \
0279 static DMI_SYSFS_MAPPED_ATTR(sel, _field)
0280
0281 DMI_SYSFS_SEL_FIELD(area_length);
0282 DMI_SYSFS_SEL_FIELD(header_start_offset);
0283 DMI_SYSFS_SEL_FIELD(data_start_offset);
0284 DMI_SYSFS_SEL_FIELD(access_method);
0285 DMI_SYSFS_SEL_FIELD(status);
0286 DMI_SYSFS_SEL_FIELD(change_token);
0287 DMI_SYSFS_SEL_FIELD(access_method_address);
0288 DMI_SYSFS_SEL_FIELD(header_format);
0289 DMI_SYSFS_SEL_FIELD(type_descriptors_supported_count);
0290 DMI_SYSFS_SEL_FIELD(per_log_type_descriptor_length);
0291
0292 static struct attribute *dmi_sysfs_sel_attrs[] = {
0293     &dmi_sysfs_attr_sel_area_length.attr,
0294     &dmi_sysfs_attr_sel_header_start_offset.attr,
0295     &dmi_sysfs_attr_sel_data_start_offset.attr,
0296     &dmi_sysfs_attr_sel_access_method.attr,
0297     &dmi_sysfs_attr_sel_status.attr,
0298     &dmi_sysfs_attr_sel_change_token.attr,
0299     &dmi_sysfs_attr_sel_access_method_address.attr,
0300     &dmi_sysfs_attr_sel_header_format.attr,
0301     &dmi_sysfs_attr_sel_type_descriptors_supported_count.attr,
0302     &dmi_sysfs_attr_sel_per_log_type_descriptor_length.attr,
0303     NULL,
0304 };
0305 ATTRIBUTE_GROUPS(dmi_sysfs_sel);
0306
0307 static struct kobj_type dmi_system_event_log_ktype = {
0308     .release = dmi_entry_free,
0309     .sysfs_ops = &dmi_sysfs_specialize_attr_ops,
0310     .default_groups = dmi_sysfs_sel_groups,
0311 };
0312
0313 typedef u8 (*sel_io_reader)(const struct dmi_system_event_log *sel,
0314                 loff_t offset);
0315
0316 static DEFINE_MUTEX(io_port_lock);
0317
0318 static u8 read_sel_8bit_indexed_io(const struct dmi_system_event_log *sel,
0319                    loff_t offset)
0320 {
0321     u8 ret;
0322
0323     mutex_lock(&io_port_lock);
0324     outb((u8)offset, sel->io.index_addr);
0325     ret = inb(sel->io.data_addr);
0326     mutex_unlock(&io_port_lock);
0327     return ret;
0328 }
0329
0330 static u8 read_sel_2x8bit_indexed_io(const struct dmi_system_event_log *sel,
0331                      loff_t offset)
0332 {
0333     u8 ret;
0334
0335     mutex_lock(&io_port_lock);
0336     outb((u8)offset, sel->io.index_addr);
0337     outb((u8)(offset >> 8), sel->io.index_addr + 1);
0338     ret = inb(sel->io.data_addr);
0339     mutex_unlock(&io_port_lock);
0340     return ret;
0341 }
0342
0343 static u8 read_sel_16bit_indexed_io(const struct dmi_system_event_log *sel,
0344                     loff_t offset)
0345 {
0346     u8 ret;
0347
0348     mutex_lock(&io_port_lock);
0349     outw((u16)offset, sel->io.index_addr);
0350     ret = inb(sel->io.data_addr);
0351     mutex_unlock(&io_port_lock);
0352     return ret;
0353 }
0354
0355 static sel_io_reader sel_io_readers[] = {
0356     [DMI_SEL_ACCESS_METHOD_IO8] = read_sel_8bit_indexed_io,
0357     [DMI_SEL_ACCESS_METHOD_IO2x8]   = read_sel_2x8bit_indexed_io,
0358     [DMI_SEL_ACCESS_METHOD_IO16]    = read_sel_16bit_indexed_io,
0359 };
0360
0361 static ssize_t dmi_sel_raw_read_io(struct dmi_sysfs_entry *entry,
0362                    const struct dmi_system_event_log *sel,
0363                    char *buf, loff_t pos, size_t count)
0364 {
0365     ssize_t wrote = 0;
0366
0367     sel_io_reader io_reader = sel_io_readers[sel->access_method];
0368
0369     while (count && pos < sel->area_length) {
0370         count--;
0371         *(buf++) = io_reader(sel, pos++);
0372         wrote++;
0373     }
0374
0375     return wrote;
0376 }
0377
0378 static ssize_t dmi_sel_raw_read_phys32(struct dmi_sysfs_entry *entry,
0379                        const struct dmi_system_event_log *sel,
0380                        char *buf, loff_t pos, size_t count)
0381 {
0382     u8 __iomem *mapped;
0383     ssize_t wrote = 0;
0384
0385     mapped = dmi_remap(sel->access_method_address, sel->area_length);
0386     if (!mapped)
0387         return -EIO;
0388
0389     while (count && pos < sel->area_length) {
0390         count--;
0391         *(buf++) = readb(mapped + pos++);
0392         wrote++;
0393     }
0394
0395     dmi_unmap(mapped);
0396     return wrote;
0397 }
0398
0399 static ssize_t dmi_sel_raw_read_helper(struct dmi_sysfs_entry *entry,
0400                        const struct dmi_header *dh,
0401                        void *_state)
0402 {
0403     struct dmi_read_state *state = _state;
0404     struct dmi_system_event_log sel;
0405
0406     if (sizeof(sel) > dmi_entry_length(dh))
0407         return -EIO;
0408
0409     memcpy(&sel, dh, sizeof(sel));
0410
0411     switch (sel.access_method) {
0412     case DMI_SEL_ACCESS_METHOD_IO8:
0413     case DMI_SEL_ACCESS_METHOD_IO2x8:
0414     case DMI_SEL_ACCESS_METHOD_IO16:
0415         return dmi_sel_raw_read_io(entry, &sel, state->buf,
0416                        state->pos, state->count);
0417     case DMI_SEL_ACCESS_METHOD_PHYS32:
0418         return dmi_sel_raw_read_phys32(entry, &sel, state->buf,
0419                            state->pos, state->count);
0420     case DMI_SEL_ACCESS_METHOD_GPNV:
0421         pr_info("dmi-sysfs: GPNV support missing.\n");
0422         return -EIO;
0423     default:
0424         pr_info("dmi-sysfs: Unknown access method %02x\n",
0425             sel.access_method);
0426         return -EIO;
0427     }
0428 }
0429
0430 static ssize_t dmi_sel_raw_read(struct file *filp, struct kobject *kobj,
0431                 struct bin_attribute *bin_attr,
0432                 char *buf, loff_t pos, size_t count)
0433 {
0434     struct dmi_sysfs_entry *entry = to_entry(kobj->parent);
0435     struct dmi_read_state state = {
0436         .buf = buf,
0437         .pos = pos,
0438         .count = count,
0439     };
0440
0441     return find_dmi_entry(entry, dmi_sel_raw_read_helper, &state);
0442 }
0443
0444 static struct bin_attribute dmi_sel_raw_attr = {
0445     .attr = {.name = "raw_event_log", .mode = 0400},
0446     .read = dmi_sel_raw_read,
0447 };
0448
0449 static int dmi_system_event_log(struct dmi_sysfs_entry *entry)
0450 {
0451     int ret;
0452
0453     entry->child = kzalloc(sizeof(*entry->child), GFP_KERNEL);
0454     if (!entry->child)
0455         return -ENOMEM;
0456     ret = kobject_init_and_add(entry->child,
0457                    &dmi_system_event_log_ktype,
0458                    &entry->kobj,
0459                    "system_event_log");
0460     if (ret)
0461         goto out_free;
0462
0463     ret = sysfs_create_bin_file(entry->child, &dmi_sel_raw_attr);
0464     if (ret)
0465         goto out_del;
0466
0467     return 0;
0468
0469 out_del:
0470     kobject_del(entry->child);
0471 out_free:
0472     kfree(entry->child);
0473     return ret;
0474 }
0475
0476 /*************************************************
0477  * Generic DMI entry support.
0478  *************************************************/
0479
0480 static ssize_t dmi_sysfs_entry_length(struct dmi_sysfs_entry *entry, char *buf)
0481 {
0482     return sprintf(buf, "%d\n", entry->dh.length);
0483 }
0484
0485 static ssize_t dmi_sysfs_entry_handle(struct dmi_sysfs_entry *entry, char *buf)
0486 {
0487     return sprintf(buf, "%d\n", entry->dh.handle);
0488 }
0489
0490 static ssize_t dmi_sysfs_entry_type(struct dmi_sysfs_entry *entry, char *buf)
0491 {
0492     return sprintf(buf, "%d\n", entry->dh.type);
0493 }
0494
0495 static ssize_t dmi_sysfs_entry_instance(struct dmi_sysfs_entry *entry,
0496                     char *buf)
0497 {
0498     return sprintf(buf, "%d\n", entry->instance);
0499 }
0500
0501 static ssize_t dmi_sysfs_entry_position(struct dmi_sysfs_entry *entry,
0502                     char *buf)
0503 {
0504     return sprintf(buf, "%d\n", entry->position);
0505 }
0506
0507 static DMI_SYSFS_ATTR(entry, length);
0508 static DMI_SYSFS_ATTR(entry, handle);
0509 static DMI_SYSFS_ATTR(entry, type);
0510 static DMI_SYSFS_ATTR(entry, instance);
0511 static DMI_SYSFS_ATTR(entry, position);
0512
0513 static struct attribute *dmi_sysfs_entry_attrs[] = {
0514     &dmi_sysfs_attr_entry_length.attr,
0515     &dmi_sysfs_attr_entry_handle.attr,
0516     &dmi_sysfs_attr_entry_type.attr,
0517     &dmi_sysfs_attr_entry_instance.attr,
0518     &dmi_sysfs_attr_entry_position.attr,
0519     NULL,
0520 };
0521 ATTRIBUTE_GROUPS(dmi_sysfs_entry);
0522
0523 static ssize_t dmi_entry_raw_read_helper(struct dmi_sysfs_entry *entry,
0524                      const struct dmi_header *dh,
0525                      void *_state)
0526 {
0527     struct dmi_read_state *state = _state;
0528     size_t entry_length;
0529
0530     entry_length = dmi_entry_length(dh);
0531
0532     return memory_read_from_buffer(state->buf, state->count,
0533                        &state->pos, dh, entry_length);
0534 }
0535
0536 static ssize_t dmi_entry_raw_read(struct file *filp,
0537                   struct kobject *kobj,
0538                   struct bin_attribute *bin_attr,
0539                   char *buf, loff_t pos, size_t count)
0540 {
0541     struct dmi_sysfs_entry *entry = to_entry(kobj);
0542     struct dmi_read_state state = {
0543         .buf = buf,
0544         .pos = pos,
0545         .count = count,
0546     };
0547
0548     return find_dmi_entry(entry, dmi_entry_raw_read_helper, &state);
0549 }
0550
0551 static const struct bin_attribute dmi_entry_raw_attr = {
0552     .attr = {.name = "raw", .mode = 0400},
0553     .read = dmi_entry_raw_read,
0554 };
0555
0556 static void dmi_sysfs_entry_release(struct kobject *kobj)
0557 {
0558     struct dmi_sysfs_entry *entry = to_entry(kobj);
0559
0560     spin_lock(&entry_list_lock);
0561     list_del(&entry->list);
0562     spin_unlock(&entry_list_lock);
0563     kfree(entry);
0564 }
0565
0566 static struct kobj_type dmi_sysfs_entry_ktype = {
0567     .release = dmi_sysfs_entry_release,
0568     .sysfs_ops = &dmi_sysfs_attr_ops,
0569     .default_groups = dmi_sysfs_entry_groups,
0570 };
0571
0572 static struct kset *dmi_kset;
0573
0574 /* Global count of all instances seen.  Only for setup */
0575 static int __initdata instance_counts[MAX_ENTRY_TYPE + 1];
0576
0577 /* Global positional count of all entries seen.  Only for setup */
0578 static int __initdata position_count;
0579
0580 static void __init dmi_sysfs_register_handle(const struct dmi_header *dh,
0581                          void *_ret)
0582 {
0583     struct dmi_sysfs_entry *entry;
0584     int *ret = _ret;
0585
0586     /* If a previous entry saw an error, short circuit */
0587     if (*ret)
0588         return;
0589
0590     /* Allocate and register a new entry into the entries set */
0591     entry = kzalloc(sizeof(*entry), GFP_KERNEL);
0592     if (!entry) {
0593         *ret = -ENOMEM;
0594         return;
0595     }
0596
0597     /* Set the key */
0598     memcpy(&entry->dh, dh, sizeof(*dh));
0599     entry->instance = instance_counts[dh->type]++;
0600     entry->position = position_count++;
0601
0602     entry->kobj.kset = dmi_kset;
0603     *ret = kobject_init_and_add(&entry->kobj, &dmi_sysfs_entry_ktype, NULL,
0604                     "%d-%d", dh->type, entry->instance);
0605
0606     if (*ret) {
0607         kobject_put(&entry->kobj);
0608         return;
0609     }
0610
0611     /* Thread on the global list for cleanup */
0612     spin_lock(&entry_list_lock);
0613     list_add_tail(&entry->list, &entry_list);
0614     spin_unlock(&entry_list_lock);
0615
0616     /* Handle specializations by type */
0617     switch (dh->type) {
0618     case DMI_ENTRY_SYSTEM_EVENT_LOG:
0619         *ret = dmi_system_event_log(entry);
0620         break;
0621     default:
0622         /* No specialization */
0623         break;
0624     }
0625     if (*ret)
0626         goto out_err;
0627
0628     /* Create the raw binary file to access the entry */
0629     *ret = sysfs_create_bin_file(&entry->kobj, &dmi_entry_raw_attr);
0630     if (*ret)
0631         goto out_err;
0632
0633     return;
0634 out_err:
0635     kobject_put(entry->child);
0636     kobject_put(&entry->kobj);
0637     return;
0638 }
0639
0640 static void cleanup_entry_list(void)
0641 {
0642     struct dmi_sysfs_entry *entry, *next;
0643
0644     /* No locks, we are on our way out */
0645     list_for_each_entry_safe(entry, next, &entry_list, list) {
0646         kobject_put(entry->child);
0647         kobject_put(&entry->kobj);
0648     }
0649 }
0650
0651 static int __init dmi_sysfs_init(void)
0652 {
0653     int error;
0654     int val;
0655
0656     if (!dmi_kobj) {
0657         pr_debug("dmi-sysfs: dmi entry is absent.\n");
0658         error = -ENODATA;
0659         goto err;
0660     }
0661
0662     dmi_kset = kset_create_and_add("entries", NULL, dmi_kobj);
0663     if (!dmi_kset) {
0664         error = -ENOMEM;
0665         goto err;
0666     }
0667
0668     val = 0;
0669     error = dmi_walk(dmi_sysfs_register_handle, &val);
0670     if (error)
0671         goto err;
0672     if (val) {
0673         error = val;
0674         goto err;
0675     }
0676
0677     pr_debug("dmi-sysfs: loaded.\n");
0678
0679     return 0;
0680 err:
0681     cleanup_entry_list();
0682     kset_unregister(dmi_kset);
0683     return error;
0684 }
0685
0686 /* clean up everything. */
0687 static void __exit dmi_sysfs_exit(void)
0688 {
0689     pr_debug("dmi-sysfs: unloading.\n");
0690     cleanup_entry_list();
0691     kset_unregister(dmi_kset);
0692 }
0693
0694 module_init(dmi_sysfs_init);
0695 module_exit(dmi_sysfs_exit);
0696
0697 MODULE_AUTHOR("Mike Waychison <mikew@google.com>");
0698 MODULE_DESCRIPTION("DMI sysfs support");
0699 MODULE_LICENSE("GPL");