4 files changed, 913 insertions, 138 deletions

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index e710424b59ea..3c56afc5eb1b 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -113,6 +113,17 @@ config DMIID
           information from userspace through /sys/class/dmi/id/ or if you want
           DMI-based module auto-loading.
 
+config DMI_SYSFS
+        tristate "DMI table support in sysfs"
+        depends on SYSFS && DMI
+        default n
+        help
+          Say Y or M here to enable the exporting of the raw DMI table
+          data via sysfs.  This is useful for consuming the data without
+          requiring any access to /dev/mem at all.  Tables are found
+          under /sys/firmware/dmi when this option is enabled and
+          loaded.
+
 config ISCSI_IBFT_FIND
         bool "iSCSI Boot Firmware Table Attributes"
         depends on X86
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 1c3c17343dbe..20c17fca1232 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -2,6 +2,7 @@
 # Makefile for the linux kernel.
 #
 obj-$(CONFIG_DMI)               += dmi_scan.o
+obj-$(CONFIG_DMI_SYSFS)         += dmi-sysfs.o
 obj-$(CONFIG_EDD)               += edd.o
 obj-$(CONFIG_EFI_VARS)          += efivars.o
 obj-$(CONFIG_EFI_PCDP)          += pcdp.o
diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
new file mode 100644
index 000000000000..eb26d62e5188
--- /dev/null
+++ b/drivers/firmware/dmi-sysfs.c
@@ -0,0 +1,696 @@
+/*
+ * dmi-sysfs.c
+ *
+ * This module exports the DMI tables read-only to userspace through the
+ * sysfs file system.
+ *
+ * Data is currently found below
+ *    /sys/firmware/dmi/...
+ *
+ * DMI attributes are presented in attribute files with names
+ * formatted using %d-%d, so that the first integer indicates the
+ * structure type (0-255), and the second field is the instance of that
+ * entry.
+ *
+ * Copyright 2011 Google, Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kobject.h>
+#include <linux/dmi.h>
+#include <linux/capability.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/io.h>
+
+#define MAX_ENTRY_TYPE 255 /* Most of these aren't used, but we consider
+                              the top entry type is only 8 bits */
+
+struct dmi_sysfs_entry {
+        struct dmi_header dh;
+        struct kobject kobj;
+        int instance;
+        int position;
+        struct list_head list;
+        struct kobject *child;
+};
+
+/*
+ * Global list of dmi_sysfs_entry.  Even though this should only be
+ * manipulated at setup and teardown, the lazy nature of the kobject
+ * system means we get lazy removes.
+ */
+static LIST_HEAD(entry_list);
+static DEFINE_SPINLOCK(entry_list_lock);
+
+/* dmi_sysfs_attribute - Top level attribute. used by all entries. */
+struct dmi_sysfs_attribute {
+        struct attribute attr;
+        ssize_t (*show)(struct dmi_sysfs_entry *entry, char *buf);
+};
+
+#define DMI_SYSFS_ATTR(_entry, _name) \
+struct dmi_sysfs_attribute dmi_sysfs_attr_##_entry##_##_name = { \
+        .attr = {.name = __stringify(_name), .mode = 0400}, \
+        .show = dmi_sysfs_##_entry##_##_name, \
+}
+
+/*
+ * dmi_sysfs_mapped_attribute - Attribute where we require the entry be
+ * mapped in.  Use in conjunction with dmi_sysfs_specialize_attr_ops.
+ */
+struct dmi_sysfs_mapped_attribute {
+        struct attribute attr;
+        ssize_t (*show)(struct dmi_sysfs_entry *entry,
+                        const struct dmi_header *dh,
+                        char *buf);
+};
+
+#define DMI_SYSFS_MAPPED_ATTR(_entry, _name) \
+struct dmi_sysfs_mapped_attribute dmi_sysfs_attr_##_entry##_##_name = { \
+        .attr = {.name = __stringify(_name), .mode = 0400}, \
+        .show = dmi_sysfs_##_entry##_##_name, \
+}
+
+/*************************************************
+ * Generic DMI entry support.
+ *************************************************/
+static void dmi_entry_free(struct kobject *kobj)
+{
+        kfree(kobj);
+}
+
+static struct dmi_sysfs_entry *to_entry(struct kobject *kobj)
+{
+        return container_of(kobj, struct dmi_sysfs_entry, kobj);
+}
+
+static struct dmi_sysfs_attribute *to_attr(struct attribute *attr)
+{
+        return container_of(attr, struct dmi_sysfs_attribute, attr);
+}
+
+static ssize_t dmi_sysfs_attr_show(struct kobject *kobj,
+                                   struct attribute *_attr, char *buf)
+{
+        struct dmi_sysfs_entry *entry = to_entry(kobj);
+        struct dmi_sysfs_attribute *attr = to_attr(_attr);
+
+        /* DMI stuff is only ever admin visible */
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
+        return attr->show(entry, buf);
+}
+
+static const struct sysfs_ops dmi_sysfs_attr_ops = {
+        .show = dmi_sysfs_attr_show,
+};
+
+typedef ssize_t (*dmi_callback)(struct dmi_sysfs_entry *,
+                                const struct dmi_header *dh, void *);
+
+struct find_dmi_data {
+        struct dmi_sysfs_entry  *entry;
+        dmi_callback            callback;
+        void                    *private;
+        int                     instance_countdown;
+        ssize_t                 ret;
+};
+
+static void find_dmi_entry_helper(const struct dmi_header *dh,
+                                  void *_data)
+{
+        struct find_dmi_data *data = _data;
+        struct dmi_sysfs_entry *entry = data->entry;
+
+        /* Is this the entry we want? */
+        if (dh->type != entry->dh.type)
+                return;
+
+        if (data->instance_countdown != 0) {
+                /* try the next instance? */
+                data->instance_countdown--;
+                return;
+        }
+
+        /*
+         * Don't ever revisit the instance.  Short circuit later
+         * instances by letting the instance_countdown run negative
+         */
+        data->instance_countdown--;
+
+        /* Found the entry */
+        data->ret = data->callback(entry, dh, data->private);
+}
+
+/* State for passing the read parameters through dmi_find_entry() */
+struct dmi_read_state {
+        char *buf;
+        loff_t pos;
+        size_t count;
+};
+
+static ssize_t find_dmi_entry(struct dmi_sysfs_entry *entry,
+                              dmi_callback callback, void *private)
+{
+        struct find_dmi_data data = {
+                .entry = entry,
+                .callback = callback,
+                .private = private,
+                .instance_countdown = entry->instance,
+                .ret = -EIO,  /* To signal the entry disappeared */
+        };
+        int ret;
+
+        ret = dmi_walk(find_dmi_entry_helper, &data);
+        /* This shouldn't happen, but just in case. */
+        if (ret)
+                return -EINVAL;
+        return data.ret;
+}
+
+/*
+ * Calculate and return the byte length of the dmi entry identified by
+ * dh.  This includes both the formatted portion as well as the
+ * unformatted string space, including the two trailing nul characters.
+ */
+static size_t dmi_entry_length(const struct dmi_header *dh)
+{
+        const char *p = (const char *)dh;
+
+        p += dh->length;
+
+        while (p[0] || p[1])
+                p++;
+
+        return 2 + p - (const char *)dh;
+}
+
+/*************************************************
+ * Support bits for specialized DMI entry support
+ *************************************************/
+struct dmi_entry_attr_show_data {
+        struct attribute *attr;
+        char *buf;
+};
+
+static ssize_t dmi_entry_attr_show_helper(struct dmi_sysfs_entry *entry,
+                                          const struct dmi_header *dh,
+                                          void *_data)
+{
+        struct dmi_entry_attr_show_data *data = _data;
+        struct dmi_sysfs_mapped_attribute *attr;
+
+        attr = container_of(data->attr,
+                            struct dmi_sysfs_mapped_attribute, attr);
+        return attr->show(entry, dh, data->buf);
+}
+
+static ssize_t dmi_entry_attr_show(struct kobject *kobj,
+                                   struct attribute *attr,
+                                   char *buf)
+{
+        struct dmi_entry_attr_show_data data = {
+                .attr = attr,
+                .buf  = buf,
+        };
+        /* Find the entry according to our parent and call the
+         * normalized show method hanging off of the attribute */
+        return find_dmi_entry(to_entry(kobj->parent),
+                              dmi_entry_attr_show_helper, &data);
+}
+
+static const struct sysfs_ops dmi_sysfs_specialize_attr_ops = {
+        .show = dmi_entry_attr_show,
+};
+
+/*************************************************
+ * Specialized DMI entry support.
+ *************************************************/
+
+/*** Type 15 - System Event Table ***/
+
+#define DMI_SEL_ACCESS_METHOD_IO8       0x00
+#define DMI_SEL_ACCESS_METHOD_IO2x8     0x01
+#define DMI_SEL_ACCESS_METHOD_IO16      0x02
+#define DMI_SEL_ACCESS_METHOD_PHYS32    0x03
+#define DMI_SEL_ACCESS_METHOD_GPNV      0x04
+
+struct dmi_system_event_log {
+        struct dmi_header header;
+        u16     area_length;
+        u16     header_start_offset;
+        u16     data_start_offset;
+        u8      access_method;
+        u8      status;
+        u32     change_token;
+        union {
+                struct {
+                        u16 index_addr;
+                        u16 data_addr;
+                } io;
+                u32     phys_addr32;
+                u16     gpnv_handle;
+                u32     access_method_address;
+        };
+        u8      header_format;
+        u8      type_descriptors_supported_count;
+        u8      per_log_type_descriptor_length;
+        u8      supported_log_type_descriptos[0];
+} __packed;
+
+#define DMI_SYSFS_SEL_FIELD(_field) \
+static ssize_t dmi_sysfs_sel_##_field(struct dmi_sysfs_entry *entry, \
+                                      const struct dmi_header *dh, \
+                                      char *buf) \
+{ \
+        struct dmi_system_event_log sel; \
+        if (sizeof(sel) > dmi_entry_length(dh)) \
+                return -EIO; \
+        memcpy(&sel, dh, sizeof(sel)); \
+        return sprintf(buf, "%u\n", sel._field); \
+} \
+static DMI_SYSFS_MAPPED_ATTR(sel, _field)
+
+DMI_SYSFS_SEL_FIELD(area_length);
+DMI_SYSFS_SEL_FIELD(header_start_offset);
+DMI_SYSFS_SEL_FIELD(data_start_offset);
+DMI_SYSFS_SEL_FIELD(access_method);
+DMI_SYSFS_SEL_FIELD(status);
+DMI_SYSFS_SEL_FIELD(change_token);
+DMI_SYSFS_SEL_FIELD(access_method_address);
+DMI_SYSFS_SEL_FIELD(header_format);
+DMI_SYSFS_SEL_FIELD(type_descriptors_supported_count);
+DMI_SYSFS_SEL_FIELD(per_log_type_descriptor_length);
+
+static struct attribute *dmi_sysfs_sel_attrs[] = {
+        &dmi_sysfs_attr_sel_area_length.attr,
+        &dmi_sysfs_attr_sel_header_start_offset.attr,
+        &dmi_sysfs_attr_sel_data_start_offset.attr,
+        &dmi_sysfs_attr_sel_access_method.attr,
+        &dmi_sysfs_attr_sel_status.attr,
+        &dmi_sysfs_attr_sel_change_token.attr,
+        &dmi_sysfs_attr_sel_access_method_address.attr,
+        &dmi_sysfs_attr_sel_header_format.attr,
+        &dmi_sysfs_attr_sel_type_descriptors_supported_count.attr,
+        &dmi_sysfs_attr_sel_per_log_type_descriptor_length.attr,
+        NULL,
+};
+
+
+static struct kobj_type dmi_system_event_log_ktype = {
+        .release = dmi_entry_free,
+        .sysfs_ops = &dmi_sysfs_specialize_attr_ops,
+        .default_attrs = dmi_sysfs_sel_attrs,
+};
+
+typedef u8 (*sel_io_reader)(const struct dmi_system_event_log *sel,
+                            loff_t offset);
+
+static DEFINE_MUTEX(io_port_lock);
+
+static u8 read_sel_8bit_indexed_io(const struct dmi_system_event_log *sel,
+                                   loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outb((u8)offset, sel->io.index_addr);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static u8 read_sel_2x8bit_indexed_io(const struct dmi_system_event_log *sel,
+                                     loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outb((u8)offset, sel->io.index_addr);
+        outb((u8)(offset >> 8), sel->io.index_addr + 1);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static u8 read_sel_16bit_indexed_io(const struct dmi_system_event_log *sel,
+                                    loff_t offset)
+{
+        u8 ret;
+
+        mutex_lock(&io_port_lock);
+        outw((u16)offset, sel->io.index_addr);
+        ret = inb(sel->io.data_addr);
+        mutex_unlock(&io_port_lock);
+        return ret;
+}
+
+static sel_io_reader sel_io_readers[] = {
+        [DMI_SEL_ACCESS_METHOD_IO8]     = read_sel_8bit_indexed_io,
+        [DMI_SEL_ACCESS_METHOD_IO2x8]   = read_sel_2x8bit_indexed_io,
+        [DMI_SEL_ACCESS_METHOD_IO16]    = read_sel_16bit_indexed_io,
+};
+
+static ssize_t dmi_sel_raw_read_io(struct dmi_sysfs_entry *entry,
+                                   const struct dmi_system_event_log *sel,
+                                   char *buf, loff_t pos, size_t count)
+{
+        ssize_t wrote = 0;
+
+        sel_io_reader io_reader = sel_io_readers[sel->access_method];
+
+        while (count && pos < sel->area_length) {
+                count--;
+                *(buf++) = io_reader(sel, pos++);
+                wrote++;
+        }
+
+        return wrote;
+}
+
+static ssize_t dmi_sel_raw_read_phys32(struct dmi_sysfs_entry *entry,
+                                       const struct dmi_system_event_log *sel,
+                                       char *buf, loff_t pos, size_t count)
+{
+        u8 __iomem *mapped;
+        ssize_t wrote = 0;
+
+        mapped = ioremap(sel->access_method_address, sel->area_length);
+        if (!mapped)
+                return -EIO;
+
+        while (count && pos < sel->area_length) {
+                count--;
+                *(buf++) = readb(mapped + pos++);
+                wrote++;
+        }
+
+        iounmap(mapped);
+        return wrote;
+}
+
+static ssize_t dmi_sel_raw_read_helper(struct dmi_sysfs_entry *entry,
+                                       const struct dmi_header *dh,
+                                       void *_state)
+{
+        struct dmi_read_state *state = _state;
+        struct dmi_system_event_log sel;
+
+        if (sizeof(sel) > dmi_entry_length(dh))
+                return -EIO;
+
+        memcpy(&sel, dh, sizeof(sel));
+
+        switch (sel.access_method) {
+        case DMI_SEL_ACCESS_METHOD_IO8:
+        case DMI_SEL_ACCESS_METHOD_IO2x8:
+        case DMI_SEL_ACCESS_METHOD_IO16:
+                return dmi_sel_raw_read_io(entry, &sel, state->buf,
+                                           state->pos, state->count);
+        case DMI_SEL_ACCESS_METHOD_PHYS32:
+                return dmi_sel_raw_read_phys32(entry, &sel, state->buf,
+                                               state->pos, state->count);
+        case DMI_SEL_ACCESS_METHOD_GPNV:
+                pr_info("dmi-sysfs: GPNV support missing.\n");
+                return -EIO;
+        default:
+                pr_info("dmi-sysfs: Unknown access method %02x\n",
+                        sel.access_method);
+                return -EIO;
+        }
+}
+
+static ssize_t dmi_sel_raw_read(struct file *filp, struct kobject *kobj,
+                                struct bin_attribute *bin_attr,
+                                char *buf, loff_t pos, size_t count)
+{
+        struct dmi_sysfs_entry *entry = to_entry(kobj->parent);
+        struct dmi_read_state state = {
+                .buf = buf,
+                .pos = pos,
+                .count = count,
+        };
+
+        return find_dmi_entry(entry, dmi_sel_raw_read_helper, &state);
+}
+
+static struct bin_attribute dmi_sel_raw_attr = {
+        .attr = {.name = "raw_event_log", .mode = 0400},
+        .read = dmi_sel_raw_read,
+};
+
+static int dmi_system_event_log(struct dmi_sysfs_entry *entry)
+{
+        int ret;
+
+        entry->child = kzalloc(sizeof(*entry->child), GFP_KERNEL);
+        if (!entry->child)
+                return -ENOMEM;
+        ret = kobject_init_and_add(entry->child,
+                                   &dmi_system_event_log_ktype,
+                                   &entry->kobj,
+                                   "system_event_log");
+        if (ret)
+                goto out_free;
+
+        ret = sysfs_create_bin_file(entry->child, &dmi_sel_raw_attr);
+        if (ret)
+                goto out_del;
+
+        return 0;
+
+out_del:
+        kobject_del(entry->child);
+out_free:
+        kfree(entry->child);
+        return ret;
+}
+
+/*************************************************
+ * Generic DMI entry support.
+ *************************************************/
+
+static ssize_t dmi_sysfs_entry_length(struct dmi_sysfs_entry *entry, char *buf)
+{
+        return sprintf(buf, "%d\n", entry->dh.length);
+}
+
+static ssize_t dmi_sysfs_entry_handle(struct dmi_sysfs_entry *entry, char *buf)
+{
+        return sprintf(buf, "%d\n", entry->dh.handle);
+}
+
+static ssize_t dmi_sysfs_entry_type(struct dmi_sysfs_entry *entry, char *buf)
+{
+        return sprintf(buf, "%d\n", entry->dh.type);
+}
+
+static ssize_t dmi_sysfs_entry_instance(struct dmi_sysfs_entry *entry,
+                                        char *buf)
+{
+        return sprintf(buf, "%d\n", entry->instance);
+}
+
+static ssize_t dmi_sysfs_entry_position(struct dmi_sysfs_entry *entry,
+                                        char *buf)
+{
+        return sprintf(buf, "%d\n", entry->position);
+}
+
+static DMI_SYSFS_ATTR(entry, length);
+static DMI_SYSFS_ATTR(entry, handle);
+static DMI_SYSFS_ATTR(entry, type);
+static DMI_SYSFS_ATTR(entry, instance);
+static DMI_SYSFS_ATTR(entry, position);
+
+static struct attribute *dmi_sysfs_entry_attrs[] = {
+        &dmi_sysfs_attr_entry_length.attr,
+        &dmi_sysfs_attr_entry_handle.attr,
+        &dmi_sysfs_attr_entry_type.attr,
+        &dmi_sysfs_attr_entry_instance.attr,
+        &dmi_sysfs_attr_entry_position.attr,
+        NULL,
+};
+
+static ssize_t dmi_entry_raw_read_helper(struct dmi_sysfs_entry *entry,
+                                         const struct dmi_header *dh,
+                                         void *_state)
+{
+        struct dmi_read_state *state = _state;
+        size_t entry_length;
+
+        entry_length = dmi_entry_length(dh);
+
+        return memory_read_from_buffer(state->buf, state->count,
+                                       &state->pos, dh, entry_length);
+}
+
+static ssize_t dmi_entry_raw_read(struct file *filp,
+                                  struct kobject *kobj,
+                                  struct bin_attribute *bin_attr,
+                                  char *buf, loff_t pos, size_t count)
+{
+        struct dmi_sysfs_entry *entry = to_entry(kobj);
+        struct dmi_read_state state = {
+                .buf = buf,
+                .pos = pos,
+                .count = count,
+        };
+
+        return find_dmi_entry(entry, dmi_entry_raw_read_helper, &state);
+}
+
+static const struct bin_attribute dmi_entry_raw_attr = {
+        .attr = {.name = "raw", .mode = 0400},
+        .read = dmi_entry_raw_read,
+};
+
+static void dmi_sysfs_entry_release(struct kobject *kobj)
+{
+        struct dmi_sysfs_entry *entry = to_entry(kobj);
+        sysfs_remove_bin_file(&entry->kobj, &dmi_entry_raw_attr);
+        spin_lock(&entry_list_lock);
+        list_del(&entry->list);
+        spin_unlock(&entry_list_lock);
+        kfree(entry);
+}
+
+static struct kobj_type dmi_sysfs_entry_ktype = {
+        .release = dmi_sysfs_entry_release,
+        .sysfs_ops = &dmi_sysfs_attr_ops,
+        .default_attrs = dmi_sysfs_entry_attrs,
+};
+
+static struct kobject *dmi_kobj;
+static struct kset *dmi_kset;
+
+/* Global count of all instances seen.  Only for setup */
+static int __initdata instance_counts[MAX_ENTRY_TYPE + 1];
+
+/* Global positional count of all entries seen.  Only for setup */
+static int __initdata position_count;
+
+static void __init dmi_sysfs_register_handle(const struct dmi_header *dh,
+                                             void *_ret)
+{
+        struct dmi_sysfs_entry *entry;
+        int *ret = _ret;
+
+        /* If a previous entry saw an error, short circuit */
+        if (*ret)
+                return;
+
+        /* Allocate and register a new entry into the entries set */
+        entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+        if (!entry) {
+                *ret = -ENOMEM;
+                return;
+        }
+
+        /* Set the key */
+        memcpy(&entry->dh, dh, sizeof(*dh));
+        entry->instance = instance_counts[dh->type]++;
+        entry->position = position_count++;
+
+        entry->kobj.kset = dmi_kset;
+        *ret = kobject_init_and_add(&entry->kobj, &dmi_sysfs_entry_ktype, NULL,
+                                    "%d-%d", dh->type, entry->instance);
+
+        if (*ret) {
+                kfree(entry);
+                return;
+        }
+
+        /* Thread on the global list for cleanup */
+        spin_lock(&entry_list_lock);
+        list_add_tail(&entry->list, &entry_list);
+        spin_unlock(&entry_list_lock);
+
+        /* Handle specializations by type */
+        switch (dh->type) {
+        case DMI_ENTRY_SYSTEM_EVENT_LOG:
+                *ret = dmi_system_event_log(entry);
+                break;
+        default:
+                /* No specialization */
+                break;
+        }
+        if (*ret)
+                goto out_err;
+
+        /* Create the raw binary file to access the entry */
+        *ret = sysfs_create_bin_file(&entry->kobj, &dmi_entry_raw_attr);
+        if (*ret)
+                goto out_err;
+
+        return;
+out_err:
+        kobject_put(entry->child);
+        kobject_put(&entry->kobj);
+        return;
+}
+
+static void cleanup_entry_list(void)
+{
+        struct dmi_sysfs_entry *entry, *next;
+
+        /* No locks, we are on our way out */
+        list_for_each_entry_safe(entry, next, &entry_list, list) {
+                kobject_put(entry->child);
+                kobject_put(&entry->kobj);
+        }
+}
+
+static int __init dmi_sysfs_init(void)
+{
+        int error = -ENOMEM;
+        int val;
+
+        /* Set up our directory */
+        dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
+        if (!dmi_kobj)
+                goto err;
+
+        dmi_kset = kset_create_and_add("entries", NULL, dmi_kobj);
+        if (!dmi_kset)
+                goto err;
+
+        val = 0;
+        error = dmi_walk(dmi_sysfs_register_handle, &val);
+        if (error)
+                goto err;
+        if (val) {
+                error = val;
+                goto err;
+        }
+
+        pr_debug("dmi-sysfs: loaded.\n");
+
+        return 0;
+err:
+        cleanup_entry_list();
+        kset_unregister(dmi_kset);
+        kobject_put(dmi_kobj);
+        return error;
+}
+
+/* clean up everything. */
+static void __exit dmi_sysfs_exit(void)
+{
+        pr_debug("dmi-sysfs: unloading.\n");
+        cleanup_entry_list();
+        kset_unregister(dmi_kset);
+        kobject_put(dmi_kobj);
+}
+
+module_init(dmi_sysfs_init);
+module_exit(dmi_sysfs_exit);
+
+MODULE_AUTHOR("Mike Waychison <mikew@google.com>");
+MODULE_DESCRIPTION("DMI sysfs support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index 2a62ec6390e0..ff0c373e3bbf 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -90,17 +90,6 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION(EFIVARS_VERSION);
 
 /*
- * efivars_lock protects two things:
- * 1) efivar_list - adds, removals, reads, writes
- * 2) efi.[gs]et_variable() calls.
- * It must not be held when creating sysfs entries or calling kmalloc.
- * efi.get_next_variable() is only called from efivars_init(),
- * which is protected by the BKL, so that path is safe.
- */
-static DEFINE_SPINLOCK(efivars_lock);
-static LIST_HEAD(efivar_list);
-
-/*
  * The maximum size of VariableName + Data = 1024
  * Therefore, it's reasonable to save that much
  * space in each part of the structure,
@@ -118,6 +107,7 @@ struct efi_variable {
 
 
 struct efivar_entry {
+        struct efivars *efivars;
         struct efi_variable var;
         struct list_head list;
         struct kobject kobj;
@@ -144,9 +134,10 @@ struct efivar_attribute efivar_attr_##_name = { \
  * Prototype for sysfs creation function
  */
 static int
-efivar_create_sysfs_entry(unsigned long variable_name_size,
-                                efi_char16_t *variable_name,
-                                efi_guid_t *vendor_guid);
+efivar_create_sysfs_entry(struct efivars *efivars,
+                          unsigned long variable_name_size,
+                          efi_char16_t *variable_name,
+                          efi_guid_t *vendor_guid);
 
 /* Return the number of unicode characters in data */
 static unsigned long
@@ -170,18 +161,18 @@ utf8_strsize(efi_char16_t *data, unsigned long maxlength)
 }
 
 static efi_status_t
-get_var_data(struct efi_variable *var)
+get_var_data(struct efivars *efivars, struct efi_variable *var)
 {
         efi_status_t status;
 
-        spin_lock(&efivars_lock);
+        spin_lock(&efivars->lock);
         var->DataSize = 1024;
-        status = efi.get_variable(var->VariableName,
-                                &var->VendorGuid,
-                                &var->Attributes,
-                                &var->DataSize,
-                                var->Data);
-        spin_unlock(&efivars_lock);
+        status = efivars->ops->get_variable(var->VariableName,
+                                            &var->VendorGuid,
+                                            &var->Attributes,
+                                            &var->DataSize,
+                                            var->Data);
+        spin_unlock(&efivars->lock);
         if (status != EFI_SUCCESS) {
                 printk(KERN_WARNING "efivars: get_variable() failed 0x%lx!\n",
                         status);
@@ -215,7 +206,7 @@ efivar_attr_read(struct efivar_entry *entry, char *buf)
         if (!entry || !buf)
                 return -EINVAL;
 
-        status = get_var_data(var);
+        status = get_var_data(entry->efivars, var);
         if (status != EFI_SUCCESS)
                 return -EIO;
 
@@ -238,7 +229,7 @@ efivar_size_read(struct efivar_entry *entry, char *buf)
         if (!entry || !buf)
                 return -EINVAL;
 
-        status = get_var_data(var);
+        status = get_var_data(entry->efivars, var);
         if (status != EFI_SUCCESS)
                 return -EIO;
 
@@ -255,7 +246,7 @@ efivar_data_read(struct efivar_entry *entry, char *buf)
         if (!entry || !buf)
                 return -EINVAL;
 
-        status = get_var_data(var);
+        status = get_var_data(entry->efivars, var);
         if (status != EFI_SUCCESS)
                 return -EIO;
 
@@ -270,6 +261,7 @@ static ssize_t
 efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
 {
         struct efi_variable *new_var, *var = &entry->var;
+        struct efivars *efivars = entry->efivars;
         efi_status_t status = EFI_NOT_FOUND;
 
         if (count != sizeof(struct efi_variable))
@@ -291,14 +283,14 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
                 return -EINVAL;
         }
 
-        spin_lock(&efivars_lock);
-        status = efi.set_variable(new_var->VariableName,
-                                        &new_var->VendorGuid,
-                                        new_var->Attributes,
-                                        new_var->DataSize,
-                                        new_var->Data);
+        spin_lock(&efivars->lock);
+        status = efivars->ops->set_variable(new_var->VariableName,
+                                            &new_var->VendorGuid,
+                                            new_var->Attributes,
+                                            new_var->DataSize,
+                                            new_var->Data);
 
-        spin_unlock(&efivars_lock);
+        spin_unlock(&efivars->lock);
 
         if (status != EFI_SUCCESS) {
                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
@@ -319,7 +311,7 @@ efivar_show_raw(struct efivar_entry *entry, char *buf)
         if (!entry || !buf)
                 return 0;
 
-        status = get_var_data(var);
+        status = get_var_data(entry->efivars, var);
         if (status != EFI_SUCCESS)
                 return -EIO;
 
@@ -407,6 +399,7 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
                              char *buf, loff_t pos, size_t count)
 {
         struct efi_variable *new_var = (struct efi_variable *)buf;
+        struct efivars *efivars = bin_attr->private;
         struct efivar_entry *search_efivar, *n;
         unsigned long strsize1, strsize2;
         efi_status_t status = EFI_NOT_FOUND;
@@ -415,12 +408,12 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
-        spin_lock(&efivars_lock);
+        spin_lock(&efivars->lock);
 
         /*
          * Does this variable already exist?
          */
-        list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
+        list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
                 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
                 strsize2 = utf8_strsize(new_var->VariableName, 1024);
                 if (strsize1 == strsize2 &&
@@ -433,28 +426,31 @@ static ssize_t efivar_create(struct file *filp, struct kobject *kobj,
                 }
         }
         if (found) {
-                spin_unlock(&efivars_lock);
+                spin_unlock(&efivars->lock);
                 return -EINVAL;
         }
 
         /* now *really* create the variable via EFI */
-        status = efi.set_variable(new_var->VariableName,
-                        &new_var->VendorGuid,
-                        new_var->Attributes,
-                        new_var->DataSize,
-                        new_var->Data);
+        status = efivars->ops->set_variable(new_var->VariableName,
+                                            &new_var->VendorGuid,
+                                            new_var->Attributes,
+                                            new_var->DataSize,
+                                            new_var->Data);
 
         if (status != EFI_SUCCESS) {
                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
                         status);
-                spin_unlock(&efivars_lock);
+                spin_unlock(&efivars->lock);
                 return -EIO;
         }
-        spin_unlock(&efivars_lock);
+        spin_unlock(&efivars->lock);
 
         /* Create the entry in sysfs.  Locking is not required here */
-        status = efivar_create_sysfs_entry(utf8_strsize(new_var->VariableName,
-                        1024), new_var->VariableName, &new_var->VendorGuid);
+        status = efivar_create_sysfs_entry(efivars,
+                                           utf8_strsize(new_var->VariableName,
+                                                        1024),
+                                           new_var->VariableName,
+                                           &new_var->VendorGuid);
         if (status) {
                 printk(KERN_WARNING "efivars: variable created, but sysfs entry wasn't.\n");
         }
@@ -466,6 +462,7 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
                              char *buf, loff_t pos, size_t count)
 {
         struct efi_variable *del_var = (struct efi_variable *)buf;
+        struct efivars *efivars = bin_attr->private;
         struct efivar_entry *search_efivar, *n;
         unsigned long strsize1, strsize2;
         efi_status_t status = EFI_NOT_FOUND;
@@ -474,12 +471,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
 
-        spin_lock(&efivars_lock);
+        spin_lock(&efivars->lock);
 
         /*
          * Does this variable already exist?
          */
-        list_for_each_entry_safe(search_efivar, n, &efivar_list, list) {
+        list_for_each_entry_safe(search_efivar, n, &efivars->list, list) {
                 strsize1 = utf8_strsize(search_efivar->var.VariableName, 1024);
                 strsize2 = utf8_strsize(del_var->VariableName, 1024);
                 if (strsize1 == strsize2 &&
@@ -492,44 +489,34 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
                 }
         }
         if (!found) {
-                spin_unlock(&efivars_lock);
+                spin_unlock(&efivars->lock);
                 return -EINVAL;
         }
         /* force the Attributes/DataSize to 0 to ensure deletion */
         del_var->Attributes = 0;
         del_var->DataSize = 0;
 
-        status = efi.set_variable(del_var->VariableName,
-                        &del_var->VendorGuid,
-                        del_var->Attributes,
-                        del_var->DataSize,
-                        del_var->Data);
+        status = efivars->ops->set_variable(del_var->VariableName,
+                                            &del_var->VendorGuid,
+                                            del_var->Attributes,
+                                            del_var->DataSize,
+                                            del_var->Data);
 
         if (status != EFI_SUCCESS) {
                 printk(KERN_WARNING "efivars: set_variable() failed: status=%lx\n",
                         status);
-                spin_unlock(&efivars_lock);
+                spin_unlock(&efivars->lock);
                 return -EIO;
         }
         list_del(&search_efivar->list);
         /* We need to release this lock before unregistering. */
-        spin_unlock(&efivars_lock);
+        spin_unlock(&efivars->lock);
         efivar_unregister(search_efivar);
 
         /* It's dead Jim.... */
         return count;
 }
 
-static struct bin_attribute var_subsys_attr_new_var = {
-        .attr = {.name = "new_var", .mode = 0200},
-        .write = efivar_create,
-};
-
-static struct bin_attribute var_subsys_attr_del_var = {
-        .attr = {.name = "del_var", .mode = 0200},
-        .write = efivar_delete,
-};
-
 /*
  * Let's not leave out systab information that snuck into
  * the efivars driver
@@ -572,8 +559,6 @@ static struct attribute_group efi_subsys_attr_group = {
         .attrs = efi_subsys_attrs,
 };
 
-
-static struct kset *vars_kset;
 static struct kobject *efi_kobj;
 
 /*
@@ -582,13 +567,14 @@ static struct kobject *efi_kobj;
  *    variable_name_size = number of bytes required to hold
  *                         variable_name (not counting the NULL
  *                         character at the end.
- *    efivars_lock is not held on entry or exit.
+ *    efivars->lock is not held on entry or exit.
  * Returns 1 on failure, 0 on success
  */
 static int
-efivar_create_sysfs_entry(unsigned long variable_name_size,
-                        efi_char16_t *variable_name,
-                        efi_guid_t *vendor_guid)
+efivar_create_sysfs_entry(struct efivars *efivars,
+                          unsigned long variable_name_size,
+                          efi_char16_t *variable_name,
+                          efi_guid_t *vendor_guid)
 {
         int i, short_name_size = variable_name_size / sizeof(efi_char16_t) + 38;
         char *short_name;
@@ -603,6 +589,7 @@ efivar_create_sysfs_entry(unsigned long variable_name_size,
                 return 1;
         }
 
+        new_efivar->efivars = efivars;
         memcpy(new_efivar->var.VariableName, variable_name,
                 variable_name_size);
         memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));
@@ -618,7 +605,7 @@ efivar_create_sysfs_entry(unsigned long variable_name_size,
         *(short_name + strlen(short_name)) = '-';
         efi_guid_unparse(vendor_guid, short_name + strlen(short_name));
 
-        new_efivar->kobj.kset = vars_kset;
+        new_efivar->kobj.kset = efivars->kset;
         i = kobject_init_and_add(&new_efivar->kobj, &efivar_ktype, NULL,
                                  "%s", short_name);
         if (i) {
@@ -631,22 +618,95 @@ efivar_create_sysfs_entry(unsigned long variable_name_size,
         kfree(short_name);
         short_name = NULL;
 
-        spin_lock(&efivars_lock);
-        list_add(&new_efivar->list, &efivar_list);
-        spin_unlock(&efivars_lock);
+        spin_lock(&efivars->lock);
+        list_add(&new_efivar->list, &efivars->list);
+        spin_unlock(&efivars->lock);
 
         return 0;
 }
-/*
- * For now we register the efi subsystem with the firmware subsystem
- * and the vars subsystem with the efi subsystem.  In the future, it
- * might make sense to split off the efi subsystem into its own
- * driver, but for now only efivars will register with it, so just
- * include it here.
- */
 
-static int __init
-efivars_init(void)
+static int
+create_efivars_bin_attributes(struct efivars *efivars)
+{
+        struct bin_attribute *attr;
+        int error;
+
+        /* new_var */
+        attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+        if (!attr)
+                return -ENOMEM;
+
+        attr->attr.name = "new_var";
+        attr->attr.mode = 0200;
+        attr->write = efivar_create;
+        attr->private = efivars;
+        efivars->new_var = attr;
+
+        /* del_var */
+        attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+        if (!attr) {
+                error = -ENOMEM;
+                goto out_free;
+        }
+        attr->attr.name = "del_var";
+        attr->attr.mode = 0200;
+        attr->write = efivar_delete;
+        attr->private = efivars;
+        efivars->del_var = attr;
+
+        sysfs_bin_attr_init(efivars->new_var);
+        sysfs_bin_attr_init(efivars->del_var);
+
+        /* Register */
+        error = sysfs_create_bin_file(&efivars->kset->kobj,
+                                      efivars->new_var);
+        if (error) {
+                printk(KERN_ERR "efivars: unable to create new_var sysfs file"
+                        " due to error %d\n", error);
+                goto out_free;
+        }
+        error = sysfs_create_bin_file(&efivars->kset->kobj,
+                                      efivars->del_var);
+        if (error) {
+                printk(KERN_ERR "efivars: unable to create del_var sysfs file"
+                        " due to error %d\n", error);
+                sysfs_remove_bin_file(&efivars->kset->kobj,
+                                      efivars->new_var);
+                goto out_free;
+        }
+
+        return 0;
+out_free:
+        kfree(efivars->new_var);
+        efivars->new_var = NULL;
+        kfree(efivars->new_var);
+        efivars->new_var = NULL;
+        return error;
+}
+
+void unregister_efivars(struct efivars *efivars)
+{
+        struct efivar_entry *entry, *n;
+
+        list_for_each_entry_safe(entry, n, &efivars->list, list) {
+                spin_lock(&efivars->lock);
+                list_del(&entry->list);
+                spin_unlock(&efivars->lock);
+                efivar_unregister(entry);
+        }
+        if (efivars->new_var)
+                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->new_var);
+        if (efivars->del_var)
+                sysfs_remove_bin_file(&efivars->kset->kobj, efivars->del_var);
+        kfree(efivars->new_var);
+        kfree(efivars->del_var);
+        kset_unregister(efivars->kset);
+}
+EXPORT_SYMBOL_GPL(unregister_efivars);
+
+int register_efivars(struct efivars *efivars,
+                     const struct efivar_operations *ops,
+                     struct kobject *parent_kobj)
 {
         efi_status_t status = EFI_NOT_FOUND;
         efi_guid_t vendor_guid;
@@ -654,31 +714,21 @@ efivars_init(void)
         unsigned long variable_name_size = 1024;
         int error = 0;
 
-        if (!efi_enabled)
-                return -ENODEV;
-
         variable_name = kzalloc(variable_name_size, GFP_KERNEL);
         if (!variable_name) {
                 printk(KERN_ERR "efivars: Memory allocation failed.\n");
                 return -ENOMEM;
         }
 
-        printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
-               EFIVARS_DATE);
+        spin_lock_init(&efivars->lock);
+        INIT_LIST_HEAD(&efivars->list);
+        efivars->ops = ops;
 
-        /* For now we'll register the efi directory at /sys/firmware/efi */
-        efi_kobj = kobject_create_and_add("efi", firmware_kobj);
-        if (!efi_kobj) {
-                printk(KERN_ERR "efivars: Firmware registration failed.\n");
-                error = -ENOMEM;
-                goto out_free;
-        }
-
-        vars_kset = kset_create_and_add("vars", NULL, efi_kobj);
-        if (!vars_kset) {
+        efivars->kset = kset_create_and_add("vars", NULL, parent_kobj);
+        if (!efivars->kset) {
                 printk(KERN_ERR "efivars: Subsystem registration failed.\n");
                 error = -ENOMEM;
-                goto out_firmware_unregister;
+                goto out;
         }
 
         /*
@@ -689,14 +739,15 @@ efivars_init(void)
         do {
                 variable_name_size = 1024;
 
-                status = efi.get_next_variable(&variable_name_size,
+                status = ops->get_next_variable(&variable_name_size,
                                                 variable_name,
                                                 &vendor_guid);
                 switch (status) {
                 case EFI_SUCCESS:
-                        efivar_create_sysfs_entry(variable_name_size,
-                                                        variable_name,
-                                                        &vendor_guid);
+                        efivar_create_sysfs_entry(efivars,
+                                                  variable_name_size,
+                                                  variable_name,
+                                                  &vendor_guid);
                         break;
                 case EFI_NOT_FOUND:
                         break;
@@ -708,35 +759,60 @@ efivars_init(void)
                 }
         } while (status != EFI_NOT_FOUND);
 
-        /*
-         * Now add attributes to allow creation of new vars
-         * and deletion of existing ones...
-         */
-        error = sysfs_create_bin_file(&vars_kset->kobj,
-                                      &var_subsys_attr_new_var);
-        if (error)
-                printk(KERN_ERR "efivars: unable to create new_var sysfs file"
-                        " due to error %d\n", error);
-        error = sysfs_create_bin_file(&vars_kset->kobj,
-                                      &var_subsys_attr_del_var);
+        error = create_efivars_bin_attributes(efivars);
         if (error)
-                printk(KERN_ERR "efivars: unable to create del_var sysfs file"
-                        " due to error %d\n", error);
+                unregister_efivars(efivars);
 
-        /* Don't forget the systab entry */
-        error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
-        if (error)
-                printk(KERN_ERR "efivars: Sysfs attribute export failed with error %d.\n", error);
-        else
-                goto out_free;
+out:
+        kfree(variable_name);
 
-        kset_unregister(vars_kset);
+        return error;
+}
+EXPORT_SYMBOL_GPL(register_efivars);
 
-out_firmware_unregister:
-        kobject_put(efi_kobj);
+static struct efivars __efivars;
+static struct efivar_operations ops;
 
-out_free:
-        kfree(variable_name);
+/*
+ * For now we register the efi subsystem with the firmware subsystem
+ * and the vars subsystem with the efi subsystem.  In the future, it
+ * might make sense to split off the efi subsystem into its own
+ * driver, but for now only efivars will register with it, so just
+ * include it here.
+ */
+
+static int __init
+efivars_init(void)
+{
+        int error = 0;
+
+        printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
+               EFIVARS_DATE);
+
+        if (!efi_enabled)
+                return 0;
+
+        /* For now we'll register the efi directory at /sys/firmware/efi */
+        efi_kobj = kobject_create_and_add("efi", firmware_kobj);
+        if (!efi_kobj) {
+                printk(KERN_ERR "efivars: Firmware registration failed.\n");
+                return -ENOMEM;
+        }
+
+        ops.get_variable = efi.get_variable;
+        ops.set_variable = efi.set_variable;
+        ops.get_next_variable = efi.get_next_variable;
+        error = register_efivars(&__efivars, &ops, efi_kobj);
+
+        /* Don't forget the systab entry */
+        error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
+        if (error) {
+                printk(KERN_ERR
+                       "efivars: Sysfs attribute export failed with error %d.\n",
+                       error);
+                unregister_efivars(&__efivars);
+                kobject_put(efi_kobj);
+        }
 
         return error;
 }
@@ -744,16 +820,7 @@ out_free:
 static void __exit
 efivars_exit(void)
 {
-        struct efivar_entry *entry, *n;
-
-        list_for_each_entry_safe(entry, n, &efivar_list, list) {
-                spin_lock(&efivars_lock);
-                list_del(&entry->list);
-                spin_unlock(&efivars_lock);
-                efivar_unregister(entry);
-        }
-
-        kset_unregister(vars_kset);
+        unregister_efivars(&__efivars);
         kobject_put(efi_kobj);
 }