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 <bart.vanassche@wdc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 2 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 */