linux/drivers/base/firmware_class.c
Luis R. Rodriguez 191e885a2e firmware: fix NULL pointer dereference in __fw_load_abort()
Since commit 5d47ec02c3 ("firmware: Correct handling of
fw_state_wait() return value") fw_load_abort() could be called twice and
lead us to a kernel crash. This happens only when the firmware fallback
mechanism (regular or custom) is used. The fallback mechanism exposes a
sysfs interface for userspace to upload a file and notify the kernel
when the file is loaded and ready, or to cancel an upload by echo'ing -1
into on the loading file:

echo -n "-1" > /sys/$DEVPATH/loading

This will call fw_load_abort(). Some distributions actually have a udev
rule in place to *always* immediately cancel all firmware fallback
mechanism requests (Debian), they have:

  $ cat /lib/udev/rules.d/50-firmware.rules
  # stub for immediately telling the kernel that userspace firmware loading
  # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y
  SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1

Distributions with this udev rule would run into this crash only if the
fallback mechanism is used. Since most distributions disable by default
using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK),
this would typicaly mean only 2 drivers which *require* the fallback
mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and
the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling
CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more
exposed to this crash.

The crash happens because after commit 5b02962494 ("firmware: do not
use fw_lock for fw_state protection") and subsequent fix commit
5d47ec02c3 ("firmware: Correct handling of fw_state_wait() return
value") a race can happen between this cancelation and the firmware
fw_state_wait_timeout() being woken up after a state change with which
fw_load_abort() as that calls swake_up(). Upon error
fw_state_wait_timeout() will also again call fw_load_abort() and trigger
a null reference.

At first glance we could just fix this with a !buf check on
fw_load_abort() before accessing buf->fw_st, however there is a logical
issue in having a state machine used for the fallback mechanism and
preventing access from it once we abort as its inside the buf
(buf->fw_st).

The firmware_class.c code is setting the buf to NULL to annotate an
abort has occurred. Replace this mechanism by simply using the state
check instead. All the other code in place already uses similar checks
for aborting as well so no further changes are needed.

An oops can be reproduced with the new fw_fallback.sh fallback mechanism
cancellation test. Either cancelling the fallback mechanism or the
custom fallback mechanism triggers a crash.

mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware
(git::20170111-fw-fixes)$ sudo ./fw_fallback.sh

./fw_fallback.sh: timeout works
./fw_fallback.sh: firmware comparison works
./fw_fallback.sh: fallback mechanism works

[ this then sits here when it is trying the cancellation test ]

Kernel log:

test_firmware: loading 'nope-test-firmware.bin'
misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2
misc test_firmware: Falling back to user helper
BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: _request_firmware+0xa27/0xad0
PGD 0

Oops: 0000 [#1] SMP
Modules linked in: test_firmware(E) ... etc ...
CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G        W E   4.10.0-rc3-next-20170111+ #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000
RIP: 0010:_request_firmware+0xa27/0xad0
RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246
RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000
RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000
RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000
R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480
R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8
FS:  00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0
Call Trace:
 request_firmware+0x37/0x50
 trigger_request_store+0x79/0xd0 [test_firmware]
 dev_attr_store+0x18/0x30
 sysfs_kf_write+0x37/0x40
 kernfs_fop_write+0x110/0x1a0
 __vfs_write+0x37/0x160
 ? _cond_resched+0x1a/0x50
 vfs_write+0xb5/0x1a0
 SyS_write+0x55/0xc0
 ? trace_do_page_fault+0x37/0xd0
 entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f8603f49620
RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620
RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001
RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336
R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80
R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950
Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff
ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b
45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00
RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10
CR2: 0000000000000038
---[ end trace 6d94ac339c133e6f ]---

Fixes: 5d47ec02c3 ("firmware: Correct handling of fw_state_wait() return value")
Reported-and-Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reported-and-Tested-by: Patrick Bruenn <p.bruenn@beckhoff.com>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
CC: <stable@vger.kernel.org>    [3.10+]
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-27 09:19:48 +01:00

1811 lines
43 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 <linux/swait.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 {
FW_STATUS_UNKNOWN,
FW_STATUS_LOADING,
FW_STATUS_DONE,
FW_STATUS_ABORTED,
};
static int loading_timeout = 60; /* In seconds */
static inline long firmware_loading_timeout(void)
{
return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
}
/*
* Concurrent request_firmware() for the same firmware need to be
* serialized. struct fw_state is simple state machine which hold the
* state of the firmware loading.
*/
struct fw_state {
struct swait_queue_head wq;
enum fw_status status;
};
static void fw_state_init(struct fw_state *fw_st)
{
init_swait_queue_head(&fw_st->wq);
fw_st->status = FW_STATUS_UNKNOWN;
}
static inline bool __fw_state_is_done(enum fw_status status)
{
return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED;
}
static int __fw_state_wait_common(struct fw_state *fw_st, long timeout)
{
long ret;
ret = swait_event_interruptible_timeout(fw_st->wq,
__fw_state_is_done(READ_ONCE(fw_st->status)),
timeout);
if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
return -ENOENT;
if (!ret)
return -ETIMEDOUT;
return ret < 0 ? ret : 0;
}
static void __fw_state_set(struct fw_state *fw_st,
enum fw_status status)
{
WRITE_ONCE(fw_st->status, status);
if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
swake_up(&fw_st->wq);
}
#define fw_state_start(fw_st) \
__fw_state_set(fw_st, FW_STATUS_LOADING)
#define fw_state_done(fw_st) \
__fw_state_set(fw_st, FW_STATUS_DONE)
#define fw_state_wait(fw_st) \
__fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT)
#ifndef CONFIG_FW_LOADER_USER_HELPER
#define fw_state_is_aborted(fw_st) false
#else /* CONFIG_FW_LOADER_USER_HELPER */
static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
{
return fw_st->status == status;
}
#define fw_state_aborted(fw_st) \
__fw_state_set(fw_st, FW_STATUS_ABORTED)
#define fw_state_is_done(fw_st) \
__fw_state_check(fw_st, FW_STATUS_DONE)
#define fw_state_is_loading(fw_st) \
__fw_state_check(fw_st, FW_STATUS_LOADING)
#define fw_state_is_aborted(fw_st) \
__fw_state_check(fw_st, FW_STATUS_ABORTED)
#define fw_state_wait_timeout(fw_st, timeout) \
__fw_state_wait_common(fw_st, timeout)
#endif /* CONFIG_FW_LOADER_USER_HELPER */
/* 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 firmware_cache *fwc;
struct fw_state fw_st;
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;
fw_state_init(&buf->fw_st);
#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 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_state_done(&buf->fw_st);
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 (fw_state_is_done(&buf->fw_st))
return;
list_del_init(&buf->pending_list);
fw_state_aborted(&buf->fw_st);
}
static void fw_load_abort(struct firmware_priv *fw_priv)
{
struct firmware_buf *buf = fw_priv->buf;
__fw_load_abort(buf);
}
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 CLASS_ATTR_RW(timeout);
static struct attribute *firmware_class_attrs[] = {
&class_attr_timeout.attr,
NULL,
};
ATTRIBUTE_GROUPS(firmware_class);
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_groups = firmware_class_groups,
.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 = fw_state_is_loading(&fw_priv->buf->fw_st);
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_state_is_aborted(&fw_buf->fw_st))
goto out;
switch (loading) {
case 1:
/* discarding any previous partial load */
if (!fw_state_is_done(&fw_buf->fw_st)) {
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;
fw_state_start(&fw_buf->fw_st);
}
break;
case 0:
if (fw_state_is_loading(&fw_buf->fw_st)) {
int rc;
/*
* 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) {
fw_state_aborted(&fw_buf->fw_st);
written = rc;
} else {
fw_state_done(&fw_buf->fw_st);
}
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 || fw_state_is_done(&buf->fw_st)) {
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 || fw_state_is_done(&buf->fw_st)) {
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 = fw_state_wait_timeout(&buf->fw_st, timeout);
if (retval < 0) {
mutex_lock(&fw_lock);
fw_load_abort(fw_priv);
mutex_unlock(&fw_lock);
}
if (fw_state_is_aborted(&buf->fw_st))
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;
}
#ifdef CONFIG_PM_SLEEP
static inline void kill_requests_without_uevent(void) { }
#endif
#endif /* CONFIG_FW_LOADER_USER_HELPER */
/* 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 = fw_state_wait(&buf->fw_st);
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 || fw_state_is_aborted(&buf->fw_st)) {
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);