Thread (78 messages) 78 messages, 4 authors, 2022-11-10

Re: [PATCH 01/17] powerpc/qspinlock: powerpc qspinlock implementation

From: Jordan Niethe <hidden>
Date: 2022-11-10 00:36:25

On Thu, 2022-07-28 at 16:31 +1000, Nicholas Piggin wrote:
<snip>
-#define queued_spin_lock queued_spin_lock
 
-static inline void queued_spin_unlock(struct qspinlock *lock)
+static __always_inline int queued_spin_trylock(struct qspinlock *lock)
 {
-	if (!IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) || !is_shared_processor())
-		smp_store_release(&lock->locked, 0);
-	else
-		__pv_queued_spin_unlock(lock);
+	if (atomic_cmpxchg_acquire(&lock->val, 0, 1) == 0)
+		return 1;
+	return 0;
optional style nit: return (atomic_cmpxchg_acquire(&lock->val, 0, 1) == 0);

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