From 4bf236a3330e97d275e5848420f7e31948fef07a Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 5 Jan 2018 09:19:08 -0800 Subject: PM / sleep: Make lock/unlock_system_sleep() available to kernel modules Since pm_mutex is not exported using lock/unlock_system_sleep() from inside a kernel module causes a "pm_mutex undefined" linker error. Hence move lock/unlock_system_sleep() into kernel/power/main.c and export these. Signed-off-by: Bart Van Assche Signed-off-by: Rafael J. Wysocki --- include/linux/suspend.h | 28 ++-------------------------- kernel/power/main.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 26 deletions(-) diff --git a/include/linux/suspend.h b/include/linux/suspend.h index d60b0f5c38d5..cc22a24516d6 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -443,32 +443,8 @@ extern bool pm_save_wakeup_count(unsigned int count); extern void pm_wakep_autosleep_enabled(bool set); extern void pm_print_active_wakeup_sources(void); -static inline void lock_system_sleep(void) -{ - current->flags |= PF_FREEZER_SKIP; - mutex_lock(&pm_mutex); -} - -static inline void unlock_system_sleep(void) -{ - /* - * Don't use freezer_count() because we don't want the call to - * try_to_freeze() here. - * - * Reason: - * Fundamentally, we just don't need it, because freezing condition - * doesn't come into effect until we release the pm_mutex lock, - * since the freezer always works with pm_mutex held. - * - * More importantly, in the case of hibernation, - * unlock_system_sleep() gets called in snapshot_read() and - * snapshot_write() when the freezing condition is still in effect. - * Which means, if we use try_to_freeze() here, it would make them - * enter the refrigerator, thus causing hibernation to lockup. - */ - current->flags &= ~PF_FREEZER_SKIP; - mutex_unlock(&pm_mutex); -} +extern void lock_system_sleep(void); +extern void unlock_system_sleep(void); #else /* !CONFIG_PM_SLEEP */ diff --git a/kernel/power/main.c b/kernel/power/main.c index 3a2ca9066583..705c2366dafe 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -22,6 +22,35 @@ DEFINE_MUTEX(pm_mutex); #ifdef CONFIG_PM_SLEEP +void lock_system_sleep(void) +{ + current->flags |= PF_FREEZER_SKIP; + mutex_lock(&pm_mutex); +} +EXPORT_SYMBOL_GPL(lock_system_sleep); + +void unlock_system_sleep(void) +{ + /* + * Don't use freezer_count() because we don't want the call to + * try_to_freeze() here. + * + * Reason: + * Fundamentally, we just don't need it, because freezing condition + * doesn't come into effect until we release the pm_mutex lock, + * since the freezer always works with pm_mutex held. + * + * More importantly, in the case of hibernation, + * unlock_system_sleep() gets called in snapshot_read() and + * snapshot_write() when the freezing condition is still in effect. + * Which means, if we use try_to_freeze() here, it would make them + * enter the refrigerator, thus causing hibernation to lockup. + */ + current->flags &= ~PF_FREEZER_SKIP; + mutex_unlock(&pm_mutex); +} +EXPORT_SYMBOL_GPL(unlock_system_sleep); + /* Routines for PM-transition notifications */ static BLOCKING_NOTIFIER_HEAD(pm_chain_head); -- cgit