diff options
Diffstat (limited to 'include/asm-arm/atomic.h')
-rw-r--r-- | include/asm-arm/atomic.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h index 2885972b0855..75b802719723 100644 --- a/include/asm-arm/atomic.h +++ b/include/asm-arm/atomic.h | |||
@@ -80,6 +80,23 @@ static inline int atomic_sub_return(int i, atomic_t *v) | |||
80 | return result; | 80 | return result; |
81 | } | 81 | } |
82 | 82 | ||
83 | static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new) | ||
84 | { | ||
85 | u32 oldval, res; | ||
86 | |||
87 | do { | ||
88 | __asm__ __volatile__("@ atomic_cmpxchg\n" | ||
89 | "ldrex %1, [%2]\n" | ||
90 | "teq %1, %3\n" | ||
91 | "strexeq %0, %4, [%2]\n" | ||
92 | : "=&r" (res), "=&r" (oldval) | ||
93 | : "r" (&ptr->counter), "Ir" (old), "r" (new) | ||
94 | : "cc"); | ||
95 | } while (res); | ||
96 | |||
97 | return oldval; | ||
98 | } | ||
99 | |||
83 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | 100 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
84 | { | 101 | { |
85 | unsigned long tmp, tmp2; | 102 | unsigned long tmp, tmp2; |
@@ -131,6 +148,20 @@ static inline int atomic_sub_return(int i, atomic_t *v) | |||
131 | return val; | 148 | return val; |
132 | } | 149 | } |
133 | 150 | ||
151 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) | ||
152 | { | ||
153 | int ret; | ||
154 | unsigned long flags; | ||
155 | |||
156 | local_irq_save(flags); | ||
157 | ret = v->counter; | ||
158 | if (likely(ret == old)) | ||
159 | v->counter = new; | ||
160 | local_irq_restore(flags); | ||
161 | |||
162 | return ret; | ||
163 | } | ||
164 | |||
134 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | 165 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
135 | { | 166 | { |
136 | unsigned long flags; | 167 | unsigned long flags; |
@@ -142,6 +173,17 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | |||
142 | 173 | ||
143 | #endif /* __LINUX_ARM_ARCH__ */ | 174 | #endif /* __LINUX_ARM_ARCH__ */ |
144 | 175 | ||
176 | static inline int atomic_add_unless(atomic_t *v, int a, int u) | ||
177 | { | ||
178 | int c, old; | ||
179 | |||
180 | c = atomic_read(v); | ||
181 | while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c) | ||
182 | c = old; | ||
183 | return c != u; | ||
184 | } | ||
185 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) | ||
186 | |||
145 | #define atomic_add(i, v) (void) atomic_add_return(i, v) | 187 | #define atomic_add(i, v) (void) atomic_add_return(i, v) |
146 | #define atomic_inc(v) (void) atomic_add_return(1, v) | 188 | #define atomic_inc(v) (void) atomic_add_return(1, v) |
147 | #define atomic_sub(i, v) (void) atomic_sub_return(i, v) | 189 | #define atomic_sub(i, v) (void) atomic_sub_return(i, v) |