1 files changed, 27 insertions, 7 deletions
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index f4a59f5631e4..5278d0560a4a 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -71,10 +71,16 @@ static DEFINE_MUTEX(hwspinlock_tree_lock);
  * This function attempts to lock an hwspinlock, and will immediately
  * fail if the hwspinlock is already taken.
  *
- * Upon a successful return from this function, preemption (and possibly
- * interrupts) is disabled, so the caller must not sleep, and is advised to
- * release the hwspinlock as soon as possible. This is required in order to
- * minimize remote cores polling on the hardware interconnect.
+ * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine
+ * of getting hardware lock with mutex or spinlock. Since in some scenarios,
+ * user need some time-consuming or sleepable operations under the hardware
+ * lock, they need one sleepable lock (like mutex) to protect the operations.
+ *
+ * If the mode is not HWLOCK_RAW, upon a successful return from this function,
+ * preemption (and possibly interrupts) is disabled, so the caller must not
+ * sleep, and is advised to release the hwspinlock as soon as possible. This is
+ * required in order to minimize remote cores polling on the hardware
+ * interconnect.
  *
  * The user decides whether local interrupts are disabled or not, and if yes,
  * whether he wants their previous state to be saved. It is up to the user
@@ -113,6 +119,9 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
 	case HWLOCK_IRQ:
 		ret = spin_trylock_irq(&hwlock->lock);
 		break;
+	case HWLOCK_RAW:
+		ret = 1;
+		break;
 	default:
 		ret = spin_trylock(&hwlock->lock);
 		break;
@@ -134,6 +143,9 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
 		case HWLOCK_IRQ:
 			spin_unlock_irq(&hwlock->lock);
 			break;
+		case HWLOCK_RAW:
+			/* Nothing to do */
+			break;
 		default:
 			spin_unlock(&hwlock->lock);
 			break;
@@ -170,9 +182,14 @@ EXPORT_SYMBOL_GPL(__hwspin_trylock);
  * is already taken, the function will busy loop waiting for it to
  * be released, but give up after @timeout msecs have elapsed.
  *
- * Upon a successful return from this function, preemption is disabled
- * (and possibly local interrupts, too), so the caller must not sleep,
- * and is advised to release the hwspinlock as soon as possible.
+ * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine
+ * of getting hardware lock with mutex or spinlock. Since in some scenarios,
+ * user need some time-consuming or sleepable operations under the hardware
+ * lock, they need one sleepable lock (like mutex) to protect the operations.
+ *
+ * If the mode is not HWLOCK_RAW, upon a successful return from this function,
+ * preemption is disabled (and possibly local interrupts, too), so the caller
+ * must not sleep, and is advised to release the hwspinlock as soon as possible.
  * This is required in order to minimize remote cores polling on the
  * hardware interconnect.
  *
@@ -266,6 +283,9 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags)
 	case HWLOCK_IRQ:
 		spin_unlock_irq(&hwlock->lock);
 		break;
+	case HWLOCK_RAW:
+		/* Nothing to do */
+		break;
 	default:
 		spin_unlock(&hwlock->lock);
 		break;