From: Stephen Hemminger Date: Thu, 7 Dec 2006 04:34:35 +0000 (-0800) Subject: [PATCH] convert pm_sem to a mutex X-Git-Tag: v2.6.20-rc1~145^2^2~272 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a6d70980602e6f1869ebcdcbfaf55a0a5941583e;p=linux-2.6 [PATCH] convert pm_sem to a mutex The power management semaphore is only used as mutex, so convert it. [akpm@osdl.org: fix rotten bug] Signed-off-by: Stephen Hemminger Acked-by: Ingo Molnar Acked-by: Pavel Machek Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 53b3b57c02..08d9e7aac0 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -213,10 +213,10 @@ static int software_resume(void) { int error; - down(&pm_sem); + mutex_lock(&pm_mutex); if (!swsusp_resume_device) { if (!strlen(resume_file)) { - up(&pm_sem); + mutex_unlock(&pm_mutex); return -ENOENT; } swsusp_resume_device = name_to_dev_t(resume_file); @@ -231,7 +231,7 @@ static int software_resume(void) * FIXME: If noresume is specified, we need to find the partition * and reset it back to normal swap space. */ - up(&pm_sem); + mutex_unlock(&pm_mutex); return 0; } @@ -275,7 +275,7 @@ static int software_resume(void) unprepare_processes(); Done: /* For success case, the suspend path will release the lock */ - up(&pm_sem); + mutex_unlock(&pm_mutex); pr_debug("PM: Resume from disk failed.\n"); return 0; } @@ -336,7 +336,7 @@ static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n) p = memchr(buf, '\n', n); len = p ? p - buf : n; - down(&pm_sem); + mutex_lock(&pm_mutex); for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) { if (!strncmp(buf, pm_disk_modes[i], len)) { mode = i; @@ -360,7 +360,7 @@ static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n) pr_debug("PM: suspend-to-disk mode set to '%s'\n", pm_disk_modes[mode]); - up(&pm_sem); + mutex_unlock(&pm_mutex); return error ? error : n; } @@ -385,9 +385,9 @@ static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n) if (maj != MAJOR(res) || min != MINOR(res)) goto out; - down(&pm_sem); + mutex_lock(&pm_mutex); swsusp_resume_device = res; - up(&pm_sem); + mutex_unlock(&pm_mutex); printk("Attempting manual resume\n"); noresume = 0; software_resume(); diff --git a/kernel/power/main.c b/kernel/power/main.c index 6096c71b18..751157b789 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -25,7 +25,7 @@ /*This is just an arbitrary number */ #define FREE_PAGE_NUMBER (100) -DECLARE_MUTEX(pm_sem); +DEFINE_MUTEX(pm_mutex); struct pm_ops *pm_ops; suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN; @@ -37,9 +37,9 @@ suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN; void pm_set_ops(struct pm_ops * ops) { - down(&pm_sem); + mutex_lock(&pm_mutex); pm_ops = ops; - up(&pm_sem); + mutex_unlock(&pm_mutex); } @@ -183,7 +183,7 @@ static int enter_state(suspend_state_t state) if (!valid_state(state)) return -ENODEV; - if (down_trylock(&pm_sem)) + if (!mutex_trylock(&pm_mutex)) return -EBUSY; if (state == PM_SUSPEND_DISK) { @@ -201,7 +201,7 @@ static int enter_state(suspend_state_t state) pr_debug("PM: Finishing wakeup.\n"); suspend_finish(state); Unlock: - up(&pm_sem); + mutex_unlock(&pm_mutex); return error; } diff --git a/kernel/power/power.h b/kernel/power/power.h index 3afa5dbe6b..eb461b816b 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -22,7 +22,9 @@ static inline int pm_suspend_disk(void) return -EPERM; } #endif -extern struct semaphore pm_sem; + +extern struct mutex pm_mutex; + #define power_attr(_name) \ static struct subsys_attribute _name##_attr = { \ .attr = { \ diff --git a/kernel/power/user.c b/kernel/power/user.c index 26c66941c0..905dc269c3 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -79,10 +79,10 @@ static int snapshot_release(struct inode *inode, struct file *filp) free_all_swap_pages(data->swap, data->bitmap); free_bitmap(data->bitmap); if (data->frozen) { - down(&pm_sem); + mutex_lock(&pm_mutex); thaw_processes(); enable_nonboot_cpus(); - up(&pm_sem); + mutex_unlock(&pm_mutex); } atomic_inc(&device_available); return 0; @@ -144,7 +144,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, case SNAPSHOT_FREEZE: if (data->frozen) break; - down(&pm_sem); + mutex_lock(&pm_mutex); error = disable_nonboot_cpus(); if (!error) { error = freeze_processes(); @@ -154,7 +154,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, error = -EBUSY; } } - up(&pm_sem); + mutex_unlock(&pm_mutex); if (!error) data->frozen = 1; break; @@ -162,10 +162,10 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, case SNAPSHOT_UNFREEZE: if (!data->frozen) break; - down(&pm_sem); + mutex_lock(&pm_mutex); thaw_processes(); enable_nonboot_cpus(); - up(&pm_sem); + mutex_unlock(&pm_mutex); data->frozen = 0; break; @@ -174,7 +174,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, error = -EPERM; break; } - down(&pm_sem); + mutex_lock(&pm_mutex); /* Free memory before shutting down devices. */ error = swsusp_shrink_memory(); if (!error) { @@ -187,7 +187,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, } resume_console(); } - up(&pm_sem); + mutex_unlock(&pm_mutex); if (!error) error = put_user(in_suspend, (unsigned int __user *)arg); if (!error) @@ -201,7 +201,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, error = -EPERM; break; } - down(&pm_sem); + mutex_lock(&pm_mutex); pm_prepare_console(); suspend_console(); error = device_suspend(PMSG_PRETHAW); @@ -211,7 +211,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, } resume_console(); pm_restore_console(); - up(&pm_sem); + mutex_unlock(&pm_mutex); break; case SNAPSHOT_FREE: @@ -286,7 +286,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, break; } - if (down_trylock(&pm_sem)) { + if (!mutex_trylock(&pm_mutex)) { error = -EBUSY; break; } @@ -314,7 +314,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, pm_ops->finish(PM_SUSPEND_MEM); OutS3: - up(&pm_sem); + mutex_unlock(&pm_mutex); break; case SNAPSHOT_PMOPS: