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Message-Id: <1345460657-24093-2-git-send-email-ming.lei@canonical.com>
Date: Mon, 20 Aug 2012 19:04:16 +0800
From: Ming Lei <ming.lei@...onical.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-kernel@...r.kernel.org, Ming Lei <ming.lei@...onical.com>
Subject: [PATCH 2/3] firmware loader: let caching firmware piggyback on loading firmware
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@...onical.com>
---
drivers/base/firmware_class.c | 83 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 74 insertions(+), 9 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index edc88bc..95f6851 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -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);
}
--
1.7.9.5
--
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