diff options
-rw-r--r-- | include/asm-generic/mutex-dec.h | 26 | ||||
-rw-r--r-- | include/asm-generic/mutex-xchg.h | 9 |
2 files changed, 3 insertions, 32 deletions
diff --git a/include/asm-generic/mutex-dec.h b/include/asm-generic/mutex-dec.h index ed108be6743f..f104af7cf437 100644 --- a/include/asm-generic/mutex-dec.h +++ b/include/asm-generic/mutex-dec.h | |||
@@ -22,8 +22,6 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) | |||
22 | { | 22 | { |
23 | if (unlikely(atomic_dec_return(count) < 0)) | 23 | if (unlikely(atomic_dec_return(count) < 0)) |
24 | fail_fn(count); | 24 | fail_fn(count); |
25 | else | ||
26 | smp_mb(); | ||
27 | } | 25 | } |
28 | 26 | ||
29 | /** | 27 | /** |
@@ -41,10 +39,7 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) | |||
41 | { | 39 | { |
42 | if (unlikely(atomic_dec_return(count) < 0)) | 40 | if (unlikely(atomic_dec_return(count) < 0)) |
43 | return fail_fn(count); | 41 | return fail_fn(count); |
44 | else { | 42 | return 0; |
45 | smp_mb(); | ||
46 | return 0; | ||
47 | } | ||
48 | } | 43 | } |
49 | 44 | ||
50 | /** | 45 | /** |
@@ -63,7 +58,6 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) | |||
63 | static inline void | 58 | static inline void |
64 | __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) | 59 | __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) |
65 | { | 60 | { |
66 | smp_mb(); | ||
67 | if (unlikely(atomic_inc_return(count) <= 0)) | 61 | if (unlikely(atomic_inc_return(count) <= 0)) |
68 | fail_fn(count); | 62 | fail_fn(count); |
69 | } | 63 | } |
@@ -88,25 +82,9 @@ __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) | |||
88 | static inline int | 82 | static inline int |
89 | __mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) | 83 | __mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) |
90 | { | 84 | { |
91 | /* | 85 | if (likely(atomic_cmpxchg(count, 1, 0) == 1)) |
92 | * We have two variants here. The cmpxchg based one is the best one | ||
93 | * because it never induce a false contention state. It is included | ||
94 | * here because architectures using the inc/dec algorithms over the | ||
95 | * xchg ones are much more likely to support cmpxchg natively. | ||
96 | * | ||
97 | * If not we fall back to the spinlock based variant - that is | ||
98 | * just as efficient (and simpler) as a 'destructive' probing of | ||
99 | * the mutex state would be. | ||
100 | */ | ||
101 | #ifdef __HAVE_ARCH_CMPXCHG | ||
102 | if (likely(atomic_cmpxchg(count, 1, 0) == 1)) { | ||
103 | smp_mb(); | ||
104 | return 1; | 86 | return 1; |
105 | } | ||
106 | return 0; | 87 | return 0; |
107 | #else | ||
108 | return fail_fn(count); | ||
109 | #endif | ||
110 | } | 88 | } |
111 | 89 | ||
112 | #endif | 90 | #endif |
diff --git a/include/asm-generic/mutex-xchg.h b/include/asm-generic/mutex-xchg.h index 7b9cd2cbfebe..580a6d35c700 100644 --- a/include/asm-generic/mutex-xchg.h +++ b/include/asm-generic/mutex-xchg.h | |||
@@ -27,8 +27,6 @@ __mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) | |||
27 | { | 27 | { |
28 | if (unlikely(atomic_xchg(count, 0) != 1)) | 28 | if (unlikely(atomic_xchg(count, 0) != 1)) |
29 | fail_fn(count); | 29 | fail_fn(count); |
30 | else | ||
31 | smp_mb(); | ||
32 | } | 30 | } |
33 | 31 | ||
34 | /** | 32 | /** |
@@ -46,10 +44,7 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) | |||
46 | { | 44 | { |
47 | if (unlikely(atomic_xchg(count, 0) != 1)) | 45 | if (unlikely(atomic_xchg(count, 0) != 1)) |
48 | return fail_fn(count); | 46 | return fail_fn(count); |
49 | else { | 47 | return 0; |
50 | smp_mb(); | ||
51 | return 0; | ||
52 | } | ||
53 | } | 48 | } |
54 | 49 | ||
55 | /** | 50 | /** |
@@ -67,7 +62,6 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) | |||
67 | static inline void | 62 | static inline void |
68 | __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) | 63 | __mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) |
69 | { | 64 | { |
70 | smp_mb(); | ||
71 | if (unlikely(atomic_xchg(count, 1) != 0)) | 65 | if (unlikely(atomic_xchg(count, 1) != 0)) |
72 | fail_fn(count); | 66 | fail_fn(count); |
73 | } | 67 | } |
@@ -110,7 +104,6 @@ __mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) | |||
110 | if (prev < 0) | 104 | if (prev < 0) |
111 | prev = 0; | 105 | prev = 0; |
112 | } | 106 | } |
113 | smp_mb(); | ||
114 | 107 | ||
115 | return prev; | 108 | return prev; |
116 | } | 109 | } |