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firmware loader: let caching firmware piggyback on loading firmware

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After starting caching firmware, there is still some time left
before devices are suspended, during the period, request_firmware
or its nowait version may still be triggered by the below situations
to load firmware images which can't be cached during suspend/resume
cycle.

	- new devices added
	- driver bind
	- or device open kind of things

This patch utilizes the piggyback trick to cache firmware for
this kind of situation: just increase the firmware buf's reference
count and add the fw name entry into cache entry list after starting
caching firmware and before syscore_suspend() is called.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ming Lei 2012-08-20 19:04:16 +08:00 committed by Greg Kroah-Hartman
parent ef40bb1bd0
commit ac39b3ea73
1 changed files with 74 additions and 9 deletions
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83
drivers/base/firmware_class.c
View File

@ -25,6 +25,7 @@
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include "base.h"
@ -105,6 +106,8 @@ struct firmware_cache {
spinlock_t name_lock;
struct list_head fw_names;
int state;
wait_queue_head_t wait_queue;
int cnt;
struct delayed_work work;
@ -146,6 +149,11 @@ struct fw_name_devm {
#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);
@ -741,6 +749,7 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
int retval = 0;
struct device *f_dev = &fw_priv->dev;
struct firmware_buf *buf = fw_priv->buf;
struct firmware_cache *fwc = &fw_cache;
dev_set_uevent_suppress(f_dev, true);
@ -796,6 +805,15 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
if (!retval)
retval = fw_map_pages_buf(buf);
/*
* After caching firmware image is started, let it piggyback
* on request firmware.
*/
if (!retval && 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_priv->fw);
@ -1041,6 +1059,29 @@ exit:
return fce;
}
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);
list_for_each_entry(fce, &fwc->fw_names, list) {
if (!strcmp(fce->name, 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(fce);
@ -1054,17 +1095,14 @@ static void __async_dev_cache_fw_image(void *fw_entry,
int ret;
ret = cache_firmware(fce->name);
if (ret)
goto free;
if (ret) {
spin_lock(&fwc->name_lock);
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
spin_lock(&fwc->name_lock);
list_add(&fce->list, &fwc->fw_names);
spin_unlock(&fwc->name_lock);
goto drop_ref;
free_fw_cache_entry(fce);
}
free:
free_fw_cache_entry(fce);
drop_ref:
spin_lock(&fwc->name_lock);
fwc->cnt--;
spin_unlock(&fwc->name_lock);
@ -1109,6 +1147,7 @@ static void dev_cache_fw_image(struct device *dev, void *data)
spin_lock(&fwc->name_lock);
fwc->cnt++;
list_add(&fce->list, &fwc->fw_names);
spin_unlock(&fwc->name_lock);
async_schedule(__async_dev_cache_fw_image, (void *)fce);
@ -1164,7 +1203,10 @@ static void device_cache_fw_images(void)
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 */
spin_lock(&fwc->name_lock);
@ -1229,6 +1271,14 @@ static int fw_pm_notify(struct notifier_block *notify_block,
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;
}
@ -1243,6 +1293,17 @@ static int fw_pm_notify(struct notifier_block *notify_block,
}
#endif
/* 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,
};
static void __init fw_cache_init(void)
{
spin_lock_init(&fw_cache.lock);
@ -1251,6 +1312,7 @@ static void __init fw_cache_init(void)
spin_lock_init(&fw_cache.name_lock);
INIT_LIST_HEAD(&fw_cache.fw_names);
fw_cache.cnt = 0;
fw_cache.state = FW_LOADER_NO_CACHE;
init_waitqueue_head(&fw_cache.wait_queue);
INIT_DELAYED_WORK(&fw_cache.work,
@ -1258,6 +1320,8 @@ static void __init fw_cache_init(void)
fw_cache.pm_notify.notifier_call = fw_pm_notify;
register_pm_notifier(&fw_cache.pm_notify);
register_syscore_ops(&fw_syscore_ops);
}
static int __init firmware_class_init(void)
@ -1268,6 +1332,7 @@ static int __init firmware_class_init(void)
static void __exit firmware_class_exit(void)
{
unregister_syscore_ops(&fw_syscore_ops);
unregister_pm_notifier(&fw_cache.pm_notify);
class_unregister(&firmware_class);
}