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[PATCH] mutex: some cleanups

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Turn some macros into inline functions and add proper type checking as
well as being more readable.  Also a minor comment adjustment.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Nicolas Pitre 2006-03-31 02:32:13 -08:00 committed by Linus Torvalds
parent a58e00e7da
commit e358c1a2c4
2 changed files with 33 additions and 30 deletions
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30
include/asm-generic/mutex-dec.h
View File

@ -17,13 +17,14 @@
* it wasn't 1 originally. This function MUST leave the value lower than * it wasn't 1 originally. This function MUST leave the value lower than
* 1 even when the "1" assertion wasn't true. * 1 even when the "1" assertion wasn't true.
*/ */
#define __mutex_fastpath_lock(count, fail_fn) \ static inline void
do { \ __mutex_fastpath_lock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))
if (unlikely(atomic_dec_return(count) < 0)) \ {
fail_fn(count); \ if (unlikely(atomic_dec_return(count) < 0))
else \ fail_fn(count);
smp_mb(); \ else
} while (0) smp_mb();
}
/** /**
* __mutex_fastpath_lock_retval - try to take the lock by moving the count * __mutex_fastpath_lock_retval - try to take the lock by moving the count
@ -36,7 +37,7 @@ do { \
* or anything the slow path function returns. * or anything the slow path function returns.
*/ */
static inline int static inline int
__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) __mutex_fastpath_lock_retval(atomic_t *count, fastcall int (*fail_fn)(atomic_t *))
{ {
if (unlikely(atomic_dec_return(count) < 0)) if (unlikely(atomic_dec_return(count) < 0))
return fail_fn(count); return fail_fn(count);
@ -59,12 +60,13 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
* __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs * __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs
* to return 0 otherwise. * to return 0 otherwise.
*/ */
#define __mutex_fastpath_unlock(count, fail_fn) \ static inline void
do { \ __mutex_fastpath_unlock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))
smp_mb(); \ {
if (unlikely(atomic_inc_return(count) <= 0)) \ smp_mb();
fail_fn(count); \ if (unlikely(atomic_inc_return(count) <= 0))
} while (0) fail_fn(count);
}
#define __mutex_slowpath_needs_to_unlock() 1 #define __mutex_slowpath_needs_to_unlock() 1

33
include/asm-generic/mutex-xchg.h
View File

@ -3,7 +3,7 @@
* *
* Generic implementation of the mutex fastpath, based on xchg(). * Generic implementation of the mutex fastpath, based on xchg().
* *
* NOTE: An xchg based implementation is less optimal than an atomic * NOTE: An xchg based implementation might be less optimal than an atomic
* decrement/increment based implementation. If your architecture * decrement/increment based implementation. If your architecture
* has a reasonable atomic dec/inc then you should probably use * has a reasonable atomic dec/inc then you should probably use
* asm-generic/mutex-dec.h instead, or you could open-code an * asm-generic/mutex-dec.h instead, or you could open-code an
@ -22,14 +22,14 @@
* wasn't 1 originally. This function MUST leave the value lower than 1 * wasn't 1 originally. This function MUST leave the value lower than 1
* even when the "1" assertion wasn't true. * even when the "1" assertion wasn't true.
*/ */
#define __mutex_fastpath_lock(count, fail_fn) \ static inline void
do { \ __mutex_fastpath_lock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))
if (unlikely(atomic_xchg(count, 0) != 1)) \ {
fail_fn(count); \ if (unlikely(atomic_xchg(count, 0) != 1))
else \ fail_fn(count);
smp_mb(); \ else
} while (0) smp_mb();
}
/** /**
* __mutex_fastpath_lock_retval - try to take the lock by moving the count * __mutex_fastpath_lock_retval - try to take the lock by moving the count
@ -42,7 +42,7 @@ do { \
* or anything the slow path function returns * or anything the slow path function returns
*/ */
static inline int static inline int
__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) __mutex_fastpath_lock_retval(atomic_t *count, fastcall int (*fail_fn)(atomic_t *))
{ {
if (unlikely(atomic_xchg(count, 0) != 1)) if (unlikely(atomic_xchg(count, 0) != 1))
return fail_fn(count); return fail_fn(count);
@ -64,12 +64,13 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
* __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs * __mutex_slowpath_needs_to_unlock() macro needs to return 1, it needs
* to return 0 otherwise. * to return 0 otherwise.
*/ */
#define __mutex_fastpath_unlock(count, fail_fn) \ static inline void
do { \ __mutex_fastpath_unlock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))
smp_mb(); \ {
if (unlikely(atomic_xchg(count, 1) != 0)) \ smp_mb();
fail_fn(count); \ if (unlikely(atomic_xchg(count, 1) != 0))
} while (0) fail_fn(count);
}
#define __mutex_slowpath_needs_to_unlock() 0 #define __mutex_slowpath_needs_to_unlock() 0