Since 536fa402221f ("compiler: Allow 1- and 2-byte smp_load_acquire()
and smp_store_release()"), smp_store_release supports byte accesses, so
use that in writer unlock and remove the conditional macro override.
Reviewed-by: Waiman Long <Waiman.Long@xxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
---
arch/x86/include/asm/qrwlock.h | 10 ----------
include/asm-generic/qrwlock.h | 9 +--------
2 files changed, 1 insertion(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/qrwlock.h b/arch/x86/include/asm/qrwlock.h
index a8810bf135ab..c537cbb038a7 100644
--- a/arch/x86/include/asm/qrwlock.h
+++ b/arch/x86/include/asm/qrwlock.h
@@ -2,16 +2,6 @@
#define _ASM_X86_QRWLOCK_H
#include <asm-generic/qrwlock_types.h>
-
-#ifndef CONFIG_X86_PPRO_FENCE
-#define queued_write_unlock queued_write_unlock
-static inline void queued_write_unlock(struct qrwlock *lock)
-{
- barrier();
- ACCESS_ONCE(*(u8 *)&lock->cnts) = 0;
-}
-#endif
-
#include <asm-generic/qrwlock.h>
#endif /* _ASM_X86_QRWLOCK_H */
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index deb9e8b0eb9e..eb673dde8879 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -134,21 +134,14 @@ static inline void queued_read_unlock(struct qrwlock *lock)
atomic_sub(_QR_BIAS, &lock->cnts);
}
-#ifndef queued_write_unlock
/**
* queued_write_unlock - release write lock of a queue rwlock
* @lock : Pointer to queue rwlock structure
*/
static inline void queued_write_unlock(struct qrwlock *lock)
{
- /*
- * If the writer field is atomic, it can be cleared directly.
- * Otherwise, an atomic subtraction will be used to clear it.
- */
- smp_mb__before_atomic();
- atomic_sub(_QW_LOCKED, &lock->cnts);
+ smp_store_release((u8 *)&lock->cnts, 0);
}
-#endif
/*
* Remapping rwlock architecture specific functions to the corresponding
--
2.1.4
--
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