qcacmn: check wrap around in BEFORE_UNLOCK

1 Add protection for wrap around of jiffies.
2 fix assign issue from uint32_t to uint64_t.

Change-Id: Idbd3604d0cb985d08aa82e3b1d7f32fa6be8c3ef
CRs-Fixed: 2864737

qdf/inc/qdf_lock.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2021 The Linux Foundation. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
@@ -138,8 +138,15 @@ do { \
 /* max_hold_time in US */
 #define BEFORE_UNLOCK(lock, max_hold_time) \
 do {\
-	uint64_t held_time = qdf_get_log_timestamp_lightweight() - \
-		lock->stats.last_acquired; \
+	uint64_t BEFORE_UNLOCK_time;  \
+	uint64_t held_time;  \
+	BEFORE_UNLOCK_time = qdf_get_log_timestamp_lightweight(); \
+\
+	if (unlikely(BEFORE_UNLOCK_time < lock->stats.last_acquired)) \
+		held_time = 0; \
+	else \
+		held_time = BEFORE_UNLOCK_time - lock->stats.last_acquired; \
+\
 	lock->stats.held_time += held_time; \
 \
 	if (held_time > lock->stats.max_held_time) \

qdf/inc/qdf_time.h

@@ -553,7 +553,15 @@ static inline uint64_t qdf_get_log_timestamp_lightweight(void)
 {
 	uint64_t timestamp_us;
 
-	timestamp_us = __qdf_system_ticks_to_msecs(qdf_system_ticks()) * 1000;
+	/* explicitly change to uint64_t, otherwise it will assign
+	 * uint32_t to timestamp_us, which lose high 32bits.
+	 * on 64bit platform, it will only use low 32bits jiffies in
+	 * jiffies_to_msecs.
+	 * eg: HZ=250, it will overflow every (0xffff ffff<<2==0x3fff ffff)
+	 * ticks. it is 1193 hours.
+	 */
+	timestamp_us =
+	(uint64_t)__qdf_system_ticks_to_msecs(qdf_system_ticks()) * 1000;
 	return timestamp_us;
 }
 #endif /* end of MSM_PLATFORM */