Commit e358c1a2 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Linus Torvalds
Browse files

[PATCH] mutex: some cleanups 



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: default avatarNicolas Pitre <nico@cam.org>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent a58e00e7

include/asm-generic/mutex-dec.h

+16 −14
Original line number Diff line number Diff line
@@ -17,13 +17,14 @@ 
 * it wasn't 1 originally. This function MUST leave the value lower than

 * 1 even when the "1" assertion wasn't true.

 */

#define __mutex_fastpath_lock(count, fail_fn)				\

do {									\

	if (unlikely(atomic_dec_return(count) < 0))			\

		fail_fn(count);						\

	else								\

		smp_mb();						\

} while (0)

static inline void

__mutex_fastpath_lock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))

{

	if (unlikely(atomic_dec_return(count) < 0))

		fail_fn(count);

	else

		smp_mb();

}



/**

 *  __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.

 */

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))

		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

 * to return 0 otherwise.

 */

#define __mutex_fastpath_unlock(count, fail_fn)				\

do {									\

	smp_mb();							\

	if (unlikely(atomic_inc_return(count) <= 0))			\

		fail_fn(count);						\

} while (0)

static inline void

__mutex_fastpath_unlock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))

{

	smp_mb();

	if (unlikely(atomic_inc_return(count) <= 0))

		fail_fn(count);

}



#define __mutex_slowpath_needs_to_unlock()		1

include/asm-generic/mutex-xchg.h

+17 −16
Original line number Diff line number Diff line
@@ -3,7 +3,7 @@ 
 *

 * 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

 *       has a reasonable atomic dec/inc then you should probably use

 *	 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

 * even when the "1" assertion wasn't true.

 */

#define __mutex_fastpath_lock(count, fail_fn)				\

do {									\

	if (unlikely(atomic_xchg(count, 0) != 1))			\

		fail_fn(count);						\

	else								\

		smp_mb();						\

} while (0)



static inline void

__mutex_fastpath_lock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))

{

	if (unlikely(atomic_xchg(count, 0) != 1))

		fail_fn(count);

	else

		smp_mb();

}



/**

 *  __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

 */

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))

		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

 * to return 0 otherwise.

 */

#define __mutex_fastpath_unlock(count, fail_fn)				\

do {									\

	smp_mb();							\

	if (unlikely(atomic_xchg(count, 1) != 0))			\

		fail_fn(count);						\

} while (0)

static inline void

__mutex_fastpath_unlock(atomic_t *count, fastcall void (*fail_fn)(atomic_t *))

{

	smp_mb();

	if (unlikely(atomic_xchg(count, 1) != 0))

		fail_fn(count);

}



#define __mutex_slowpath_needs_to_unlock()		0

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