PM: hibernate: Incorporate concurrency handling
Hibernation concurrency handling is currently delegated to user.c,
where it's also used for regulating the access to the snapshot device.
In the prospective of making user.c a separate configuration option,
such mutual exclusion is brought into hibernate.c and made available
through accessor helpers hereby introduced.
Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 30bd28d..02ec716 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -67,6 +67,18 @@ bool freezer_test_done;
static const struct platform_hibernation_ops *hibernation_ops;
+static atomic_t hibernate_atomic = ATOMIC_INIT(1);
+
+bool hibernate_acquire(void)
+{
+ return atomic_add_unless(&hibernate_atomic, -1, 0);
+}
+
+void hibernate_release(void)
+{
+ atomic_inc(&hibernate_atomic);
+}
+
bool hibernation_available(void)
{
return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
@@ -704,7 +716,7 @@ int hibernate(void)
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
- if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ if (!hibernate_acquire()) {
error = -EBUSY;
goto Unlock;
}
@@ -775,7 +787,7 @@ int hibernate(void)
Exit:
__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
pm_restore_console();
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
Unlock:
unlock_system_sleep();
pr_info("hibernation exit\n");
@@ -880,7 +892,7 @@ static int software_resume(void)
goto Unlock;
/* The snapshot device should not be opened while we're running */
- if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ if (!hibernate_acquire()) {
error = -EBUSY;
swsusp_close(FMODE_READ);
goto Unlock;
@@ -911,7 +923,7 @@ static int software_resume(void)
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
pm_restore_console();
pr_info("resume failed (%d)\n", error);
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&system_transition_mutex);