power: wakeup_reason: make log function work in interrupt context

If log_suspend_abort_reason called in interrupt context, the spinlock
may deadlock.
With https://lkml.org/lkml/2014/9/1/404, wakeup mechanism changed, so
log_suspend_abort_reason can be placed in interrupt context to retrieve
the abort reasons.

Bug: 32371978
Change-Id: I6902770e54b663d21b47289daec19401fc0dbed4

kernel/power/wakeup_reason.c

@@ -436,12 +436,13 @@ bool log_possible_wakeup_reason(int irq,
 void log_suspend_abort_reason(const char *fmt, ...)
 {
 	va_list args;
+	unsigned long flags;
 
-	spin_lock(&resume_reason_lock);
+	spin_lock_irqsave(&resume_reason_lock, flags);
 
 	//Suspend abort reason has already been logged.
 	if (suspend_abort) {
-		spin_unlock(&resume_reason_lock);
+		spin_unlock_irqrestore(&resume_reason_lock, flags);
 		return;
 	}
 
@@ -450,7 +451,7 @@ void log_suspend_abort_reason(const char *fmt, ...)
 	vsnprintf(abort_reason, MAX_SUSPEND_ABORT_LEN, fmt, args);
 	va_end(args);
 
-	spin_unlock(&resume_reason_lock);
+	spin_unlock_irqrestore(&resume_reason_lock, flags);
 }
 
 static bool match_node(struct wakeup_irq_node *n, void *_p)
@@ -462,9 +463,10 @@ static bool match_node(struct wakeup_irq_node *n, void *_p)
 int check_wakeup_reason(int irq)
 {
 	bool found;
-	spin_lock(&resume_reason_lock);
+	unsigned long flags;
+	spin_lock_irqsave(&resume_reason_lock, flags);
 	found = !walk_irq_node_tree(base_irq_nodes, match_node, &irq);
-	spin_unlock(&resume_reason_lock);
+	spin_unlock_irqrestore(&resume_reason_lock, flags);
 	return found;
 }
 
@@ -544,11 +546,12 @@ void clear_wakeup_reasons(void)
 static int wakeup_reason_pm_event(struct notifier_block *notifier,
 		unsigned long pm_event, void *unused)
 {
+	unsigned long flags;
 	switch (pm_event) {
 	case PM_SUSPEND_PREPARE:
-		spin_lock(&resume_reason_lock);
+		spin_lock_irqsave(&resume_reason_lock, flags);
 		suspend_abort = false;
-		spin_unlock(&resume_reason_lock);
+		spin_unlock_irqrestore(&resume_reason_lock, flags);
 		/* monotonic time since boot */
 		last_monotime = ktime_get();
 		/* monotonic time since boot including the time spent in suspend */