Fix SDEI state machine issue during reboot process

hulk inclusion
category: bugfix
bugzilla: https://atomgit.com/openeuler/kernel/issues/8325

--------------------------------

Add sdei event status check in sdei pm notifier, If event is already
unregistered, don't do disable/enable in pm notifier. In this way, we
can prevent incorrect state transitions, e.g., disabling or enabling
after unregistering.

Fixes: c8f96adca7fa ("arm64/watchdog: fix watchdog failure in low power scenarios")
Signed-off-by: Bowen You <youbowen2@huawei.com>
(cherry picked from commit 4f1e47d2241d253a802be3e0f5288626a590bec5)
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: Bowen You

arch/arm64/kernel/watchdog_sdei.c

@@ -114,9 +114,27 @@ static int sdei_watchdog_pm_notifier(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
 	int rv = 0;
+	u64 result;
 
 	WARN_ON_ONCE(preemptible());
 
+	/*
+	 * Judge event status before disable or enable to prevent
+	 * incorrect state transitions, e.g., disabling after
+	 * unregistering.
+	 */
+	rv = sdei_api_event_status(sdei_watchdog_event_num, &result);
+	if (rv)
+		goto error;
+	if (!result)
+		goto success;
+
+	/*
+	 * After powering on/off the LPI (Low Power Idle),
+	 * the enable function must be called to enable the
+	 * EL3 Secure Timer, ensuring proper handling of
+	 * secure timer functionality.
+	 */
 	switch (action) {
 	case CPU_PM_ENTER:
 		if (per_cpu(sdei_usr_en, smp_processor_id()))
@@ -131,9 +149,10 @@ static int sdei_watchdog_pm_notifier(struct notifier_block *nb,
 		return NOTIFY_DONE;
 	}
 
+error:
 	if (rv)
 		return notifier_from_errno(rv);
-
+success:
 	return NOTIFY_OK;
 }