linux/drivers/base/firmware_class.c
Stephen Boyd a098ecd2fa firmware: support loading into a pre-allocated buffer
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

This creates needless memory pressure and delays loading because we have
to copy from kernel memory to somewhere else.  Let's add a
request_firmware_into_buf() API that allows drivers to request firmware
be loaded directly into a pre-allocated buffer.  This skips the
intermediate step of allocating a buffer in kernel memory to hold the
firmware image while it's read from the filesystem.  It also requires
that drivers know how much memory they'll require before requesting the
firmware and negates any benefits of firmware caching because the
firmware layer doesn't manage the buffer lifetime.

For a 16MB buffer, about half the time is spent performing a memcpy from
the buffer to the final resting place.  I see loading times go from
0.081171 seconds to 0.047696 seconds after applying this patch.  Plus
the vmalloc pressure is reduced.

This is based on a patch from Vikram Mulukutla on codeaurora.org:
  https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.18/commit/drivers/base/firmware_class.c?h=rel/msm-3.18&id=0a328c5f6cd999f5c591f172216835636f39bcb5

Link: http://lkml.kernel.org/r/20160607164741.31849-4-stephen.boyd@linaro.org
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Vikram Mulukutla <markivx@codeaurora.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:10 -04:00

1776 lines
42 KiB
C

/*
* firmware_class.c - Multi purpose firmware loading support
*
* Copyright (c) 2003 Manuel Estrada Sainz
*
* Please see Documentation/firmware_class/ for more information.
*
*/
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/highmem.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/reboot.h>
#include <linux/security.h>
#include <generated/utsrelease.h>
#include "base.h"
MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");
/* Builtin firmware support */
#ifdef CONFIG_FW_LOADER
extern struct builtin_fw __start_builtin_fw[];
extern struct builtin_fw __end_builtin_fw[];
static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
void *buf, size_t size)
{
struct builtin_fw *b_fw;
for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
if (strcmp(name, b_fw->name) == 0) {
fw->size = b_fw->size;
fw->data = b_fw->data;
if (buf && fw->size <= size)
memcpy(buf, fw->data, fw->size);
return true;
}
}
return false;
}
static bool fw_is_builtin_firmware(const struct firmware *fw)
{
struct builtin_fw *b_fw;
for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
if (fw->data == b_fw->data)
return true;
return false;
}
#else /* Module case - no builtin firmware support */
static inline bool fw_get_builtin_firmware(struct firmware *fw,
const char *name, void *buf,
size_t size)
{
return false;
}
static inline bool fw_is_builtin_firmware(const struct firmware *fw)
{
return false;
}
#endif
enum {
FW_STATUS_LOADING,
FW_STATUS_DONE,
FW_STATUS_ABORT,
};
static int loading_timeout = 60; /* In seconds */
static inline long firmware_loading_timeout(void)
{
return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
}
/* firmware behavior options */
#define FW_OPT_UEVENT (1U << 0)
#define FW_OPT_NOWAIT (1U << 1)
#ifdef CONFIG_FW_LOADER_USER_HELPER
#define FW_OPT_USERHELPER (1U << 2)
#else
#define FW_OPT_USERHELPER 0
#endif
#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
#define FW_OPT_FALLBACK FW_OPT_USERHELPER
#else
#define FW_OPT_FALLBACK 0
#endif
#define FW_OPT_NO_WARN (1U << 3)
#define FW_OPT_NOCACHE (1U << 4)
struct firmware_cache {
/* firmware_buf instance will be added into the below list */
spinlock_t lock;
struct list_head head;
int state;
#ifdef CONFIG_PM_SLEEP
/*
* Names of firmware images which have been cached successfully
* will be added into the below list so that device uncache
* helper can trace which firmware images have been cached
* before.
*/
spinlock_t name_lock;
struct list_head fw_names;
struct delayed_work work;
struct notifier_block pm_notify;
#endif
};
struct firmware_buf {
struct kref ref;
struct list_head list;
struct completion completion;
struct firmware_cache *fwc;
unsigned long status;
void *data;
size_t size;
size_t allocated_size;
#ifdef CONFIG_FW_LOADER_USER_HELPER
bool is_paged_buf;
bool need_uevent;
struct page **pages;
int nr_pages;
int page_array_size;
struct list_head pending_list;
#endif
const char *fw_id;
};
struct fw_cache_entry {
struct list_head list;
const char *name;
};
struct fw_name_devm {
unsigned long magic;
const char *name;
};
#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
#define FW_LOADER_NO_CACHE 0
#define FW_LOADER_START_CACHE 1
static int fw_cache_piggyback_on_request(const char *name);
/* fw_lock could be moved to 'struct firmware_priv' but since it is just
* guarding for corner cases a global lock should be OK */
static DEFINE_MUTEX(fw_lock);
static struct firmware_cache fw_cache;
static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
struct firmware_cache *fwc,
void *dbuf, size_t size)
{
struct firmware_buf *buf;
buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
if (!buf)
return NULL;
buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
if (!buf->fw_id) {
kfree(buf);
return NULL;
}
kref_init(&buf->ref);
buf->fwc = fwc;
buf->data = dbuf;
buf->allocated_size = size;
init_completion(&buf->completion);
#ifdef CONFIG_FW_LOADER_USER_HELPER
INIT_LIST_HEAD(&buf->pending_list);
#endif
pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
return buf;
}
static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
{
struct firmware_buf *tmp;
struct firmware_cache *fwc = &fw_cache;
list_for_each_entry(tmp, &fwc->head, list)
if (!strcmp(tmp->fw_id, fw_name))
return tmp;
return NULL;
}
static int fw_lookup_and_allocate_buf(const char *fw_name,
struct firmware_cache *fwc,
struct firmware_buf **buf, void *dbuf,
size_t size)
{
struct firmware_buf *tmp;
spin_lock(&fwc->lock);
tmp = __fw_lookup_buf(fw_name);
if (tmp) {
kref_get(&tmp->ref);
spin_unlock(&fwc->lock);
*buf = tmp;
return 1;
}
tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size);
if (tmp)
list_add(&tmp->list, &fwc->head);
spin_unlock(&fwc->lock);
*buf = tmp;
return tmp ? 0 : -ENOMEM;
}
static void __fw_free_buf(struct kref *ref)
__releases(&fwc->lock)
{
struct firmware_buf *buf = to_fwbuf(ref);
struct firmware_cache *fwc = buf->fwc;
pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
__func__, buf->fw_id, buf, buf->data,
(unsigned int)buf->size);
list_del(&buf->list);
spin_unlock(&fwc->lock);
#ifdef CONFIG_FW_LOADER_USER_HELPER
if (buf->is_paged_buf) {
int i;
vunmap(buf->data);
for (i = 0; i < buf->nr_pages; i++)
__free_page(buf->pages[i]);
vfree(buf->pages);
} else
#endif
if (!buf->allocated_size)
vfree(buf->data);
kfree_const(buf->fw_id);
kfree(buf);
}
static void fw_free_buf(struct firmware_buf *buf)
{
struct firmware_cache *fwc = buf->fwc;
spin_lock(&fwc->lock);
if (!kref_put(&buf->ref, __fw_free_buf))
spin_unlock(&fwc->lock);
}
/* direct firmware loading support */
static char fw_path_para[256];
static const char * const fw_path[] = {
fw_path_para,
"/lib/firmware/updates/" UTS_RELEASE,
"/lib/firmware/updates",
"/lib/firmware/" UTS_RELEASE,
"/lib/firmware"
};
/*
* Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
* from kernel command line because firmware_class is generally built in
* kernel instead of module.
*/
module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
static void fw_finish_direct_load(struct device *device,
struct firmware_buf *buf)
{
mutex_lock(&fw_lock);
set_bit(FW_STATUS_DONE, &buf->status);
complete_all(&buf->completion);
mutex_unlock(&fw_lock);
}
static int
fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
{
loff_t size;
int i, len;
int rc = -ENOENT;
char *path;
enum kernel_read_file_id id = READING_FIRMWARE;
size_t msize = INT_MAX;
/* Already populated data member means we're loading into a buffer */
if (buf->data) {
id = READING_FIRMWARE_PREALLOC_BUFFER;
msize = buf->allocated_size;
}
path = __getname();
if (!path)
return -ENOMEM;
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
/* skip the unset customized path */
if (!fw_path[i][0])
continue;
len = snprintf(path, PATH_MAX, "%s/%s",
fw_path[i], buf->fw_id);
if (len >= PATH_MAX) {
rc = -ENAMETOOLONG;
break;
}
buf->size = 0;
rc = kernel_read_file_from_path(path, &buf->data, &size, msize,
id);
if (rc) {
if (rc == -ENOENT)
dev_dbg(device, "loading %s failed with error %d\n",
path, rc);
else
dev_warn(device, "loading %s failed with error %d\n",
path, rc);
continue;
}
dev_dbg(device, "direct-loading %s\n", buf->fw_id);
buf->size = size;
fw_finish_direct_load(device, buf);
break;
}
__putname(path);
return rc;
}
/* firmware holds the ownership of pages */
static void firmware_free_data(const struct firmware *fw)
{
/* Loaded directly? */
if (!fw->priv) {
vfree(fw->data);
return;
}
fw_free_buf(fw->priv);
}
/* store the pages buffer info firmware from buf */
static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
{
fw->priv = buf;
#ifdef CONFIG_FW_LOADER_USER_HELPER
fw->pages = buf->pages;
#endif
fw->size = buf->size;
fw->data = buf->data;
pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
__func__, buf->fw_id, buf, buf->data,
(unsigned int)buf->size);
}
#ifdef CONFIG_PM_SLEEP
static void fw_name_devm_release(struct device *dev, void *res)
{
struct fw_name_devm *fwn = res;
if (fwn->magic == (unsigned long)&fw_cache)
pr_debug("%s: fw_name-%s devm-%p released\n",
__func__, fwn->name, res);
kfree_const(fwn->name);
}
static int fw_devm_match(struct device *dev, void *res,
void *match_data)
{
struct fw_name_devm *fwn = res;
return (fwn->magic == (unsigned long)&fw_cache) &&
!strcmp(fwn->name, match_data);
}
static struct fw_name_devm *fw_find_devm_name(struct device *dev,
const char *name)
{
struct fw_name_devm *fwn;
fwn = devres_find(dev, fw_name_devm_release,
fw_devm_match, (void *)name);
return fwn;
}
/* add firmware name into devres list */
static int fw_add_devm_name(struct device *dev, const char *name)
{
struct fw_name_devm *fwn;
fwn = fw_find_devm_name(dev, name);
if (fwn)
return 1;
fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
GFP_KERNEL);
if (!fwn)
return -ENOMEM;
fwn->name = kstrdup_const(name, GFP_KERNEL);
if (!fwn->name) {
devres_free(fwn);
return -ENOMEM;
}
fwn->magic = (unsigned long)&fw_cache;
devres_add(dev, fwn);
return 0;
}
#else
static int fw_add_devm_name(struct device *dev, const char *name)
{
return 0;
}
#endif
/*
* user-mode helper code
*/
#ifdef CONFIG_FW_LOADER_USER_HELPER
struct firmware_priv {
bool nowait;
struct device dev;
struct firmware_buf *buf;
struct firmware *fw;
};
static struct firmware_priv *to_firmware_priv(struct device *dev)
{
return container_of(dev, struct firmware_priv, dev);
}
static void __fw_load_abort(struct firmware_buf *buf)
{
/*
* There is a small window in which user can write to 'loading'
* between loading done and disappearance of 'loading'
*/
if (test_bit(FW_STATUS_DONE, &buf->status))
return;
list_del_init(&buf->pending_list);
set_bit(FW_STATUS_ABORT, &buf->status);
complete_all(&buf->completion);
}
static void fw_load_abort(struct firmware_priv *fw_priv)
{
struct firmware_buf *buf = fw_priv->buf;
__fw_load_abort(buf);
/* avoid user action after loading abort */
fw_priv->buf = NULL;
}
#define is_fw_load_aborted(buf) \
test_bit(FW_STATUS_ABORT, &(buf)->status)
static LIST_HEAD(pending_fw_head);
/* reboot notifier for avoid deadlock with usermode_lock */
static int fw_shutdown_notify(struct notifier_block *unused1,
unsigned long unused2, void *unused3)
{
mutex_lock(&fw_lock);
while (!list_empty(&pending_fw_head))
__fw_load_abort(list_first_entry(&pending_fw_head,
struct firmware_buf,
pending_list));
mutex_unlock(&fw_lock);
return NOTIFY_DONE;
}
static struct notifier_block fw_shutdown_nb = {
.notifier_call = fw_shutdown_notify,
};
static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", loading_timeout);
}
/**
* firmware_timeout_store - set number of seconds to wait for firmware
* @class: device class pointer
* @attr: device attribute pointer
* @buf: buffer to scan for timeout value
* @count: number of bytes in @buf
*
* Sets the number of seconds to wait for the firmware. Once
* this expires an error will be returned to the driver and no
* firmware will be provided.
*
* Note: zero means 'wait forever'.
**/
static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
const char *buf, size_t count)
{
loading_timeout = simple_strtol(buf, NULL, 10);
if (loading_timeout < 0)
loading_timeout = 0;
return count;
}
static struct class_attribute firmware_class_attrs[] = {
__ATTR_RW(timeout),
__ATTR_NULL
};
static void fw_dev_release(struct device *dev)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
kfree(fw_priv);
}
static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
{
if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
return -ENOMEM;
if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
return -ENOMEM;
if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
return -ENOMEM;
return 0;
}
static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
int err = 0;
mutex_lock(&fw_lock);
if (fw_priv->buf)
err = do_firmware_uevent(fw_priv, env);
mutex_unlock(&fw_lock);
return err;
}
static struct class firmware_class = {
.name = "firmware",
.class_attrs = firmware_class_attrs,
.dev_uevent = firmware_uevent,
.dev_release = fw_dev_release,
};
static ssize_t firmware_loading_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
int loading = 0;
mutex_lock(&fw_lock);
if (fw_priv->buf)
loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
mutex_unlock(&fw_lock);
return sprintf(buf, "%d\n", loading);
}
/* Some architectures don't have PAGE_KERNEL_RO */
#ifndef PAGE_KERNEL_RO
#define PAGE_KERNEL_RO PAGE_KERNEL
#endif
/* one pages buffer should be mapped/unmapped only once */
static int fw_map_pages_buf(struct firmware_buf *buf)
{
if (!buf->is_paged_buf)
return 0;
vunmap(buf->data);
buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
if (!buf->data)
return -ENOMEM;
return 0;
}
/**
* firmware_loading_store - set value in the 'loading' control file
* @dev: device pointer
* @attr: device attribute pointer
* @buf: buffer to scan for loading control value
* @count: number of bytes in @buf
*
* The relevant values are:
*
* 1: Start a load, discarding any previous partial load.
* 0: Conclude the load and hand the data to the driver code.
* -1: Conclude the load with an error and discard any written data.
**/
static ssize_t firmware_loading_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware_buf *fw_buf;
ssize_t written = count;
int loading = simple_strtol(buf, NULL, 10);
int i;
mutex_lock(&fw_lock);
fw_buf = fw_priv->buf;
if (!fw_buf)
goto out;
switch (loading) {
case 1:
/* discarding any previous partial load */
if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
for (i = 0; i < fw_buf->nr_pages; i++)
__free_page(fw_buf->pages[i]);
vfree(fw_buf->pages);
fw_buf->pages = NULL;
fw_buf->page_array_size = 0;
fw_buf->nr_pages = 0;
set_bit(FW_STATUS_LOADING, &fw_buf->status);
}
break;
case 0:
if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
int rc;
set_bit(FW_STATUS_DONE, &fw_buf->status);
clear_bit(FW_STATUS_LOADING, &fw_buf->status);
/*
* Several loading requests may be pending on
* one same firmware buf, so let all requests
* see the mapped 'buf->data' once the loading
* is completed.
* */
rc = fw_map_pages_buf(fw_buf);
if (rc)
dev_err(dev, "%s: map pages failed\n",
__func__);
else
rc = security_kernel_post_read_file(NULL,
fw_buf->data, fw_buf->size,
READING_FIRMWARE);
/*
* Same logic as fw_load_abort, only the DONE bit
* is ignored and we set ABORT only on failure.
*/
list_del_init(&fw_buf->pending_list);
if (rc) {
set_bit(FW_STATUS_ABORT, &fw_buf->status);
written = rc;
}
complete_all(&fw_buf->completion);
break;
}
/* fallthrough */
default:
dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
/* fallthrough */
case -1:
fw_load_abort(fw_priv);
break;
}
out:
mutex_unlock(&fw_lock);
return written;
}
static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
loff_t offset, size_t count, bool read)
{
if (read)
memcpy(buffer, buf->data + offset, count);
else
memcpy(buf->data + offset, buffer, count);
}
static void firmware_rw(struct firmware_buf *buf, char *buffer,
loff_t offset, size_t count, bool read)
{
while (count) {
void *page_data;
int page_nr = offset >> PAGE_SHIFT;
int page_ofs = offset & (PAGE_SIZE-1);
int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
page_data = kmap(buf->pages[page_nr]);
if (read)
memcpy(buffer, page_data + page_ofs, page_cnt);
else
memcpy(page_data + page_ofs, buffer, page_cnt);
kunmap(buf->pages[page_nr]);
buffer += page_cnt;
offset += page_cnt;
count -= page_cnt;
}
}
static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t offset, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware_buf *buf;
ssize_t ret_count;
mutex_lock(&fw_lock);
buf = fw_priv->buf;
if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
ret_count = -ENODEV;
goto out;
}
if (offset > buf->size) {
ret_count = 0;
goto out;
}
if (count > buf->size - offset)
count = buf->size - offset;
ret_count = count;
if (buf->data)
firmware_rw_buf(buf, buffer, offset, count, true);
else
firmware_rw(buf, buffer, offset, count, true);
out:
mutex_unlock(&fw_lock);
return ret_count;
}
static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
{
struct firmware_buf *buf = fw_priv->buf;
int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
/* If the array of pages is too small, grow it... */
if (buf->page_array_size < pages_needed) {
int new_array_size = max(pages_needed,
buf->page_array_size * 2);
struct page **new_pages;
new_pages = vmalloc(new_array_size * sizeof(void *));
if (!new_pages) {
fw_load_abort(fw_priv);
return -ENOMEM;
}
memcpy(new_pages, buf->pages,
buf->page_array_size * sizeof(void *));
memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
(new_array_size - buf->page_array_size));
vfree(buf->pages);
buf->pages = new_pages;
buf->page_array_size = new_array_size;
}
while (buf->nr_pages < pages_needed) {
buf->pages[buf->nr_pages] =
alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
if (!buf->pages[buf->nr_pages]) {
fw_load_abort(fw_priv);
return -ENOMEM;
}
buf->nr_pages++;
}
return 0;
}
/**
* firmware_data_write - write method for firmware
* @filp: open sysfs file
* @kobj: kobject for the device
* @bin_attr: bin_attr structure
* @buffer: buffer being written
* @offset: buffer offset for write in total data store area
* @count: buffer size
*
* Data written to the 'data' attribute will be later handed to
* the driver as a firmware image.
**/
static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t offset, size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware_buf *buf;
ssize_t retval;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
mutex_lock(&fw_lock);
buf = fw_priv->buf;
if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
retval = -ENODEV;
goto out;
}
if (buf->data) {
if (offset + count > buf->allocated_size) {
retval = -ENOMEM;
goto out;
}
firmware_rw_buf(buf, buffer, offset, count, false);
retval = count;
} else {
retval = fw_realloc_buffer(fw_priv, offset + count);
if (retval)
goto out;
retval = count;
firmware_rw(buf, buffer, offset, count, false);
}
buf->size = max_t(size_t, offset + count, buf->size);
out:
mutex_unlock(&fw_lock);
return retval;
}
static struct bin_attribute firmware_attr_data = {
.attr = { .name = "data", .mode = 0644 },
.size = 0,
.read = firmware_data_read,
.write = firmware_data_write,
};
static struct attribute *fw_dev_attrs[] = {
&dev_attr_loading.attr,
NULL
};
static struct bin_attribute *fw_dev_bin_attrs[] = {
&firmware_attr_data,
NULL
};
static const struct attribute_group fw_dev_attr_group = {
.attrs = fw_dev_attrs,
.bin_attrs = fw_dev_bin_attrs,
};
static const struct attribute_group *fw_dev_attr_groups[] = {
&fw_dev_attr_group,
NULL
};
static struct firmware_priv *
fw_create_instance(struct firmware *firmware, const char *fw_name,
struct device *device, unsigned int opt_flags)
{
struct firmware_priv *fw_priv;
struct device *f_dev;
fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
if (!fw_priv) {
fw_priv = ERR_PTR(-ENOMEM);
goto exit;
}
fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
fw_priv->fw = firmware;
f_dev = &fw_priv->dev;
device_initialize(f_dev);
dev_set_name(f_dev, "%s", fw_name);
f_dev->parent = device;
f_dev->class = &firmware_class;
f_dev->groups = fw_dev_attr_groups;
exit:
return fw_priv;
}
/* load a firmware via user helper */
static int _request_firmware_load(struct firmware_priv *fw_priv,
unsigned int opt_flags, long timeout)
{
int retval = 0;
struct device *f_dev = &fw_priv->dev;
struct firmware_buf *buf = fw_priv->buf;
/* fall back on userspace loading */
if (!buf->data)
buf->is_paged_buf = true;
dev_set_uevent_suppress(f_dev, true);
retval = device_add(f_dev);
if (retval) {
dev_err(f_dev, "%s: device_register failed\n", __func__);
goto err_put_dev;
}
mutex_lock(&fw_lock);
list_add(&buf->pending_list, &pending_fw_head);
mutex_unlock(&fw_lock);
if (opt_flags & FW_OPT_UEVENT) {
buf->need_uevent = true;
dev_set_uevent_suppress(f_dev, false);
dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
} else {
timeout = MAX_JIFFY_OFFSET;
}
retval = wait_for_completion_interruptible_timeout(&buf->completion,
timeout);
if (retval == -ERESTARTSYS || !retval) {
mutex_lock(&fw_lock);
fw_load_abort(fw_priv);
mutex_unlock(&fw_lock);
} else if (retval > 0) {
retval = 0;
}
if (is_fw_load_aborted(buf))
retval = -EAGAIN;
else if (buf->is_paged_buf && !buf->data)
retval = -ENOMEM;
device_del(f_dev);
err_put_dev:
put_device(f_dev);
return retval;
}
static int fw_load_from_user_helper(struct firmware *firmware,
const char *name, struct device *device,
unsigned int opt_flags, long timeout)
{
struct firmware_priv *fw_priv;
fw_priv = fw_create_instance(firmware, name, device, opt_flags);
if (IS_ERR(fw_priv))
return PTR_ERR(fw_priv);
fw_priv->buf = firmware->priv;
return _request_firmware_load(fw_priv, opt_flags, timeout);
}
#ifdef CONFIG_PM_SLEEP
/* kill pending requests without uevent to avoid blocking suspend */
static void kill_requests_without_uevent(void)
{
struct firmware_buf *buf;
struct firmware_buf *next;
mutex_lock(&fw_lock);
list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
if (!buf->need_uevent)
__fw_load_abort(buf);
}
mutex_unlock(&fw_lock);
}
#endif
#else /* CONFIG_FW_LOADER_USER_HELPER */
static inline int
fw_load_from_user_helper(struct firmware *firmware, const char *name,
struct device *device, unsigned int opt_flags,
long timeout)
{
return -ENOENT;
}
/* No abort during direct loading */
#define is_fw_load_aborted(buf) false
#ifdef CONFIG_PM_SLEEP
static inline void kill_requests_without_uevent(void) { }
#endif
#endif /* CONFIG_FW_LOADER_USER_HELPER */
/* wait until the shared firmware_buf becomes ready (or error) */
static int sync_cached_firmware_buf(struct firmware_buf *buf)
{
int ret = 0;
mutex_lock(&fw_lock);
while (!test_bit(FW_STATUS_DONE, &buf->status)) {
if (is_fw_load_aborted(buf)) {
ret = -ENOENT;
break;
}
mutex_unlock(&fw_lock);
ret = wait_for_completion_interruptible(&buf->completion);
mutex_lock(&fw_lock);
}
mutex_unlock(&fw_lock);
return ret;
}
/* prepare firmware and firmware_buf structs;
* return 0 if a firmware is already assigned, 1 if need to load one,
* or a negative error code
*/
static int
_request_firmware_prepare(struct firmware **firmware_p, const char *name,
struct device *device, void *dbuf, size_t size)
{
struct firmware *firmware;
struct firmware_buf *buf;
int ret;
*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
if (!firmware) {
dev_err(device, "%s: kmalloc(struct firmware) failed\n",
__func__);
return -ENOMEM;
}
if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
dev_dbg(device, "using built-in %s\n", name);
return 0; /* assigned */
}
ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
/*
* bind with 'buf' now to avoid warning in failure path
* of requesting firmware.
*/
firmware->priv = buf;
if (ret > 0) {
ret = sync_cached_firmware_buf(buf);
if (!ret) {
fw_set_page_data(buf, firmware);
return 0; /* assigned */
}
}
if (ret < 0)
return ret;
return 1; /* need to load */
}
static int assign_firmware_buf(struct firmware *fw, struct device *device,
unsigned int opt_flags)
{
struct firmware_buf *buf = fw->priv;
mutex_lock(&fw_lock);
if (!buf->size || is_fw_load_aborted(buf)) {
mutex_unlock(&fw_lock);
return -ENOENT;
}
/*
* add firmware name into devres list so that we can auto cache
* and uncache firmware for device.
*
* device may has been deleted already, but the problem
* should be fixed in devres or driver core.
*/
/* don't cache firmware handled without uevent */
if (device && (opt_flags & FW_OPT_UEVENT) &&
!(opt_flags & FW_OPT_NOCACHE))
fw_add_devm_name(device, buf->fw_id);
/*
* After caching firmware image is started, let it piggyback
* on request firmware.
*/
if (!(opt_flags & FW_OPT_NOCACHE) &&
buf->fwc->state == FW_LOADER_START_CACHE) {
if (fw_cache_piggyback_on_request(buf->fw_id))
kref_get(&buf->ref);
}
/* pass the pages buffer to driver at the last minute */
fw_set_page_data(buf, fw);
mutex_unlock(&fw_lock);
return 0;
}
/* called from request_firmware() and request_firmware_work_func() */
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size,
unsigned int opt_flags)
{
struct firmware *fw = NULL;
long timeout;
int ret;
if (!firmware_p)
return -EINVAL;
if (!name || name[0] == '\0') {
ret = -EINVAL;
goto out;
}
ret = _request_firmware_prepare(&fw, name, device, buf, size);
if (ret <= 0) /* error or already assigned */
goto out;
ret = 0;
timeout = firmware_loading_timeout();
if (opt_flags & FW_OPT_NOWAIT) {
timeout = usermodehelper_read_lock_wait(timeout);
if (!timeout) {
dev_dbg(device, "firmware: %s loading timed out\n",
name);
ret = -EBUSY;
goto out;
}
} else {
ret = usermodehelper_read_trylock();
if (WARN_ON(ret)) {
dev_err(device, "firmware: %s will not be loaded\n",
name);
goto out;
}
}
ret = fw_get_filesystem_firmware(device, fw->priv);
if (ret) {
if (!(opt_flags & FW_OPT_NO_WARN))
dev_warn(device,
"Direct firmware load for %s failed with error %d\n",
name, ret);
if (opt_flags & FW_OPT_USERHELPER) {
dev_warn(device, "Falling back to user helper\n");
ret = fw_load_from_user_helper(fw, name, device,
opt_flags, timeout);
}
}
if (!ret)
ret = assign_firmware_buf(fw, device, opt_flags);
usermodehelper_read_unlock();
out:
if (ret < 0) {
release_firmware(fw);
fw = NULL;
}
*firmware_p = fw;
return ret;
}
/**
* request_firmware: - send firmware request and wait for it
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* @firmware_p will be used to return a firmware image by the name
* of @name for device @device.
*
* Should be called from user context where sleeping is allowed.
*
* @name will be used as $FIRMWARE in the uevent environment and
* should be distinctive enough not to be confused with any other
* firmware image for this or any other device.
*
* Caller must hold the reference count of @device.
*
* The function can be called safely inside device's suspend and
* resume callback.
**/
int
request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device)
{
int ret;
/* Need to pin this module until return */
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, NULL, 0,
FW_OPT_UEVENT | FW_OPT_FALLBACK);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware);
/**
* request_firmware_direct: - load firmware directly without usermode helper
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* This function works pretty much like request_firmware(), but this doesn't
* fall back to usermode helper even if the firmware couldn't be loaded
* directly from fs. Hence it's useful for loading optional firmwares, which
* aren't always present, without extra long timeouts of udev.
**/
int request_firmware_direct(const struct firmware **firmware_p,
const char *name, struct device *device)
{
int ret;
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, NULL, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL_GPL(request_firmware_direct);
/**
* request_firmware_into_buf - load firmware into a previously allocated buffer
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded and DMA region allocated
* @buf: address of buffer to load firmware into
* @size: size of buffer
*
* This function works pretty much like request_firmware(), but it doesn't
* allocate a buffer to hold the firmware data. Instead, the firmware
* is loaded directly into the buffer pointed to by @buf and the @firmware_p
* data member is pointed at @buf.
*
* This function doesn't cache firmware either.
*/
int
request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size)
{
int ret;
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, buf, size,
FW_OPT_UEVENT | FW_OPT_FALLBACK |
FW_OPT_NOCACHE);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware_into_buf);
/**
* release_firmware: - release the resource associated with a firmware image
* @fw: firmware resource to release
**/
void release_firmware(const struct firmware *fw)
{
if (fw) {
if (!fw_is_builtin_firmware(fw))
firmware_free_data(fw);
kfree(fw);
}
}
EXPORT_SYMBOL(release_firmware);
/* Async support */
struct firmware_work {
struct work_struct work;
struct module *module;
const char *name;
struct device *device;
void *context;
void (*cont)(const struct firmware *fw, void *context);
unsigned int opt_flags;
};
static void request_firmware_work_func(struct work_struct *work)
{
struct firmware_work *fw_work;
const struct firmware *fw;
fw_work = container_of(work, struct firmware_work, work);
_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
fw_work->opt_flags);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */
module_put(fw_work->module);
kfree_const(fw_work->name);
kfree(fw_work);
}
/**
* request_firmware_nowait - asynchronous version of request_firmware
* @module: module requesting the firmware
* @uevent: sends uevent to copy the firmware image if this flag
* is non-zero else the firmware copy must be done manually.
* @name: name of firmware file
* @device: device for which firmware is being loaded
* @gfp: allocation flags
* @context: will be passed over to @cont, and
* @fw may be %NULL if firmware request fails.
* @cont: function will be called asynchronously when the firmware
* request is over.
*
* Caller must hold the reference count of @device.
*
* Asynchronous variant of request_firmware() for user contexts:
* - sleep for as small periods as possible since it may
* increase kernel boot time of built-in device drivers
* requesting firmware in their ->probe() methods, if
* @gfp is GFP_KERNEL.
*
* - can't sleep at all if @gfp is GFP_ATOMIC.
**/
int
request_firmware_nowait(
struct module *module, bool uevent,
const char *name, struct device *device, gfp_t gfp, void *context,
void (*cont)(const struct firmware *fw, void *context))
{
struct firmware_work *fw_work;
fw_work = kzalloc(sizeof(struct firmware_work), gfp);
if (!fw_work)
return -ENOMEM;
fw_work->module = module;
fw_work->name = kstrdup_const(name, gfp);
if (!fw_work->name) {
kfree(fw_work);
return -ENOMEM;
}
fw_work->device = device;
fw_work->context = context;
fw_work->cont = cont;
fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
if (!try_module_get(module)) {
kfree_const(fw_work->name);
kfree(fw_work);
return -EFAULT;
}
get_device(fw_work->device);
INIT_WORK(&fw_work->work, request_firmware_work_func);
schedule_work(&fw_work->work);
return 0;
}
EXPORT_SYMBOL(request_firmware_nowait);
#ifdef CONFIG_PM_SLEEP
static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
/**
* cache_firmware - cache one firmware image in kernel memory space
* @fw_name: the firmware image name
*
* Cache firmware in kernel memory so that drivers can use it when
* system isn't ready for them to request firmware image from userspace.
* Once it returns successfully, driver can use request_firmware or its
* nowait version to get the cached firmware without any interacting
* with userspace
*
* Return 0 if the firmware image has been cached successfully
* Return !0 otherwise
*
*/
static int cache_firmware(const char *fw_name)
{
int ret;
const struct firmware *fw;
pr_debug("%s: %s\n", __func__, fw_name);
ret = request_firmware(&fw, fw_name, NULL);
if (!ret)
kfree(fw);
pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
return ret;
}
static struct firmware_buf *fw_lookup_buf(const char *fw_name)
{
struct firmware_buf *tmp;
struct firmware_cache *fwc = &fw_cache;
spin_lock(&fwc->lock);
tmp = __fw_lookup_buf(fw_name);
spin_unlock(&fwc->lock);
return tmp;
}
/**
* uncache_firmware - remove one cached firmware image
* @fw_name: the firmware image name
*
* Uncache one firmware image which has been cached successfully
* before.
*
* Return 0 if the firmware cache has been removed successfully
* Return !0 otherwise
*
*/
static int uncache_firmware(const char *fw_name)
{
struct firmware_buf *buf;
struct firmware fw;
pr_debug("%s: %s\n", __func__, fw_name);
if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
return 0;
buf = fw_lookup_buf(fw_name);
if (buf) {
fw_free_buf(buf);
return 0;
}
return -EINVAL;
}
static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
{
struct fw_cache_entry *fce;
fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
if (!fce)
goto exit;
fce->name = kstrdup_const(name, GFP_ATOMIC);
if (!fce->name) {
kfree(fce);
fce = NULL;
goto exit;
}
exit:
return fce;
}
static int __fw_entry_found(const char *name)
{
struct firmware_cache *fwc = &fw_cache;
struct fw_cache_entry *fce;
list_for_each_entry(fce, &fwc->fw_names, list) {
if (!strcmp(fce->name, name))
return 1;
}
return 0;
}
static int fw_cache_piggyback_on_request(const char *name)
{
struct firmware_cache *fwc = &fw_cache;
struct fw_cache_entry *fce;
int ret = 0;
spin_lock(&fwc->name_lock);
if (__fw_entry_found(name))
goto found;
fce = alloc_fw_cache_entry(name);
if (fce) {
ret = 1;
list_add(&fce->list, &fwc->fw_names);
pr_debug("%s: fw: %s\n", __func__, name);
}
found:
spin_unlock(&fwc->name_lock);
return ret;
}
static void free_fw_cache_entry(struct fw_cache_entry *fce)
{
kfree_const(fce->name);
kfree(fce);
}
static void __async_dev_cache_fw_image(void *fw_entry,
async_cookie_t cookie)
{
struct fw_cache_entry *fce = fw_entry;
struct firmware_cache *fwc = &fw_cache;
int ret;
ret = cache_firmware(fce->name);
if (ret) {
spin_lock(&fwc->name_lock);
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
free_fw_cache_entry(fce);
}
}
/* called with dev->devres_lock held */
static void dev_create_fw_entry(struct device *dev, void *res,
void *data)
{
struct fw_name_devm *fwn = res;
const char *fw_name = fwn->name;
struct list_head *head = data;
struct fw_cache_entry *fce;
fce = alloc_fw_cache_entry(fw_name);
if (fce)
list_add(&fce->list, head);
}
static int devm_name_match(struct device *dev, void *res,
void *match_data)
{
struct fw_name_devm *fwn = res;
return (fwn->magic == (unsigned long)match_data);
}
static void dev_cache_fw_image(struct device *dev, void *data)
{
LIST_HEAD(todo);
struct fw_cache_entry *fce;
struct fw_cache_entry *fce_next;
struct firmware_cache *fwc = &fw_cache;
devres_for_each_res(dev, fw_name_devm_release,
devm_name_match, &fw_cache,
dev_create_fw_entry, &todo);
list_for_each_entry_safe(fce, fce_next, &todo, list) {
list_del(&fce->list);
spin_lock(&fwc->name_lock);
/* only one cache entry for one firmware */
if (!__fw_entry_found(fce->name)) {
list_add(&fce->list, &fwc->fw_names);
} else {
free_fw_cache_entry(fce);
fce = NULL;
}
spin_unlock(&fwc->name_lock);
if (fce)
async_schedule_domain(__async_dev_cache_fw_image,
(void *)fce,
&fw_cache_domain);
}
}
static void __device_uncache_fw_images(void)
{
struct firmware_cache *fwc = &fw_cache;
struct fw_cache_entry *fce;
spin_lock(&fwc->name_lock);
while (!list_empty(&fwc->fw_names)) {
fce = list_entry(fwc->fw_names.next,
struct fw_cache_entry, list);
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
uncache_firmware(fce->name);
free_fw_cache_entry(fce);
spin_lock(&fwc->name_lock);
}
spin_unlock(&fwc->name_lock);
}
/**
* device_cache_fw_images - cache devices' firmware
*
* If one device called request_firmware or its nowait version
* successfully before, the firmware names are recored into the
* device's devres link list, so device_cache_fw_images can call
* cache_firmware() to cache these firmwares for the device,
* then the device driver can load its firmwares easily at
* time when system is not ready to complete loading firmware.
*/
static void device_cache_fw_images(void)
{
struct firmware_cache *fwc = &fw_cache;
int old_timeout;
DEFINE_WAIT(wait);
pr_debug("%s\n", __func__);
/* cancel uncache work */
cancel_delayed_work_sync(&fwc->work);
/*
* use small loading timeout for caching devices' firmware
* because all these firmware images have been loaded
* successfully at lease once, also system is ready for
* completing firmware loading now. The maximum size of
* firmware in current distributions is about 2M bytes,
* so 10 secs should be enough.
*/
old_timeout = loading_timeout;
loading_timeout = 10;
mutex_lock(&fw_lock);
fwc->state = FW_LOADER_START_CACHE;
dpm_for_each_dev(NULL, dev_cache_fw_image);
mutex_unlock(&fw_lock);
/* wait for completion of caching firmware for all devices */
async_synchronize_full_domain(&fw_cache_domain);
loading_timeout = old_timeout;
}
/**
* device_uncache_fw_images - uncache devices' firmware
*
* uncache all firmwares which have been cached successfully
* by device_uncache_fw_images earlier
*/
static void device_uncache_fw_images(void)
{
pr_debug("%s\n", __func__);
__device_uncache_fw_images();
}
static void device_uncache_fw_images_work(struct work_struct *work)
{
device_uncache_fw_images();
}
/**
* device_uncache_fw_images_delay - uncache devices firmwares
* @delay: number of milliseconds to delay uncache device firmwares
*
* uncache all devices's firmwares which has been cached successfully
* by device_cache_fw_images after @delay milliseconds.
*/
static void device_uncache_fw_images_delay(unsigned long delay)
{
queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
msecs_to_jiffies(delay));
}
static int fw_pm_notify(struct notifier_block *notify_block,
unsigned long mode, void *unused)
{
switch (mode) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
case PM_RESTORE_PREPARE:
kill_requests_without_uevent();
device_cache_fw_images();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
case PM_POST_RESTORE:
/*
* In case that system sleep failed and syscore_suspend is
* not called.
*/
mutex_lock(&fw_lock);
fw_cache.state = FW_LOADER_NO_CACHE;
mutex_unlock(&fw_lock);
device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
break;
}
return 0;
}
/* stop caching firmware once syscore_suspend is reached */
static int fw_suspend(void)
{
fw_cache.state = FW_LOADER_NO_CACHE;
return 0;
}
static struct syscore_ops fw_syscore_ops = {
.suspend = fw_suspend,
};
#else
static int fw_cache_piggyback_on_request(const char *name)
{
return 0;
}
#endif
static void __init fw_cache_init(void)
{
spin_lock_init(&fw_cache.lock);
INIT_LIST_HEAD(&fw_cache.head);
fw_cache.state = FW_LOADER_NO_CACHE;
#ifdef CONFIG_PM_SLEEP
spin_lock_init(&fw_cache.name_lock);
INIT_LIST_HEAD(&fw_cache.fw_names);
INIT_DELAYED_WORK(&fw_cache.work,
device_uncache_fw_images_work);
fw_cache.pm_notify.notifier_call = fw_pm_notify;
register_pm_notifier(&fw_cache.pm_notify);
register_syscore_ops(&fw_syscore_ops);
#endif
}
static int __init firmware_class_init(void)
{
fw_cache_init();
#ifdef CONFIG_FW_LOADER_USER_HELPER
register_reboot_notifier(&fw_shutdown_nb);
return class_register(&firmware_class);
#else
return 0;
#endif
}
static void __exit firmware_class_exit(void)
{
#ifdef CONFIG_PM_SLEEP
unregister_syscore_ops(&fw_syscore_ops);
unregister_pm_notifier(&fw_cache.pm_notify);
#endif
#ifdef CONFIG_FW_LOADER_USER_HELPER
unregister_reboot_notifier(&fw_shutdown_nb);
class_unregister(&firmware_class);
#endif
}
fs_initcall(firmware_class_init);
module_exit(firmware_class_exit);