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-rw-r--r--include/asm-generic/qrwlock.h27
1 files changed, 25 insertions, 2 deletions
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 54a8e65e18b6..7d026bf27713 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -25,7 +25,20 @@
25#include <asm-generic/qrwlock_types.h> 25#include <asm-generic/qrwlock_types.h>
26 26
27/* 27/*
28 * Writer states & reader shift and bias 28 * Writer states & reader shift and bias.
29 *
30 * | +0 | +1 | +2 | +3 |
31 * ----+----+----+----+----+
32 * LE | 78 | 56 | 34 | 12 | 0x12345678
33 * ----+----+----+----+----+
34 * | wr | rd |
35 * +----+----+----+----+
36 *
37 * ----+----+----+----+----+
38 * BE | 12 | 34 | 56 | 78 | 0x12345678
39 * ----+----+----+----+----+
40 * | rd | wr |
41 * +----+----+----+----+
29 */ 42 */
30#define _QW_WAITING 1 /* A writer is waiting */ 43#define _QW_WAITING 1 /* A writer is waiting */
31#define _QW_LOCKED 0xff /* A writer holds the lock */ 44#define _QW_LOCKED 0xff /* A writer holds the lock */
@@ -134,12 +147,22 @@ static inline void queued_read_unlock(struct qrwlock *lock)
134} 147}
135 148
136/** 149/**
150 * __qrwlock_write_byte - retrieve the write byte address of a queue rwlock
151 * @lock : Pointer to queue rwlock structure
152 * Return: the write byte address of a queue rwlock
153 */
154static inline u8 *__qrwlock_write_byte(struct qrwlock *lock)
155{
156 return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN);
157}
158
159/**
137 * queued_write_unlock - release write lock of a queue rwlock 160 * queued_write_unlock - release write lock of a queue rwlock
138 * @lock : Pointer to queue rwlock structure 161 * @lock : Pointer to queue rwlock structure
139 */ 162 */
140static inline void queued_write_unlock(struct qrwlock *lock) 163static inline void queued_write_unlock(struct qrwlock *lock)
141{ 164{
142 smp_store_release((u8 *)&lock->cnts, 0); 165 smp_store_release(__qrwlock_write_byte(lock), 0);
143} 166}
144 167
145/* 168/*