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-rw-r--r--include/asm-generic/qrwlock.h12
-rw-r--r--include/asm-generic/qrwlock_types.h15
-rw-r--r--kernel/locking/qrwlock.c26
3 files changed, 16 insertions, 37 deletions
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 50925327b0a8..02c0a768e6b0 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -129,22 +129,12 @@ static inline void queued_read_unlock(struct qrwlock *lock)
}
/**
- * __qrwlock_write_byte - retrieve the write byte address of a queue rwlock
- * @lock : Pointer to queue rwlock structure
- * Return: the write byte address of a queue rwlock
- */
-static inline u8 *__qrwlock_write_byte(struct qrwlock *lock)
-{
- return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN);
-}
-
-/**
* 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)
{
- smp_store_release(__qrwlock_write_byte(lock), 0);
+ smp_store_release(&lock->wmode, 0);
}
/*
diff --git a/include/asm-generic/qrwlock_types.h b/include/asm-generic/qrwlock_types.h
index 0abc6b6062fb..507f2dc51bba 100644
--- a/include/asm-generic/qrwlock_types.h
+++ b/include/asm-generic/qrwlock_types.h
@@ -9,12 +9,23 @@
*/
typedef struct qrwlock {
- atomic_t cnts;
+ union {
+ atomic_t cnts;
+ struct {
+#ifdef __LITTLE_ENDIAN
+ u8 wmode; /* Writer mode */
+ u8 rcnts[3]; /* Reader counts */
+#else
+ u8 rcnts[3]; /* Reader counts */
+ u8 wmode; /* Writer mode */
+#endif
+ };
+ };
arch_spinlock_t wait_lock;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { \
- .cnts = ATOMIC_INIT(0), \
+ { .cnts = ATOMIC_INIT(0), }, \
.wait_lock = __ARCH_SPIN_LOCK_UNLOCKED, \
}
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index 2655f26ec882..1af791e37348 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -23,26 +23,6 @@
#include <linux/spinlock.h>
#include <asm/qrwlock.h>
-/*
- * This internal data structure is used for optimizing access to some of
- * the subfields within the atomic_t cnts.
- */
-struct __qrwlock {
- union {
- atomic_t cnts;
- struct {
-#ifdef __LITTLE_ENDIAN
- u8 wmode; /* Writer mode */
- u8 rcnts[3]; /* Reader counts */
-#else
- u8 rcnts[3]; /* Reader counts */
- u8 wmode; /* Writer mode */
-#endif
- };
- };
- arch_spinlock_t lock;
-};
-
/**
* rspin_until_writer_unlock - inc reader count & spin until writer is gone
* @lock : Pointer to queue rwlock structure
@@ -125,10 +105,8 @@ void queued_write_lock_slowpath(struct qrwlock *lock)
* or wait for a previous writer to go away.
*/
for (;;) {
- struct __qrwlock *l = (struct __qrwlock *)lock;
-
- if (!READ_ONCE(l->wmode) &&
- (cmpxchg_relaxed(&l->wmode, 0, _QW_WAITING) == 0))
+ if (!READ_ONCE(lock->wmode) &&
+ (cmpxchg_relaxed(&lock->wmode, 0, _QW_WAITING) == 0))
break;
cpu_relax();