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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - include/asm-sh/atomic.h
1 #ifndef __ASM_SH_ATOMIC_H
2 #define __ASM_SH_ATOMIC_H
5 * Atomic operations that C can't guarantee us. Useful for
6 * resource counting etc..
10 typedef struct { volatile int counter
; } atomic_t
;
12 #define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
14 #define atomic_read(v) ((v)->counter)
15 #define atomic_set(v,i) ((v)->counter = (i))
17 #include <asm/system.h>
20 * To get proper branch prediction for the main line, we must branch
21 * forward to code at the end of this object's .text section, then
22 * branch back to restart the operation.
25 static __inline__
void atomic_add(int i
, atomic_t
* v
)
29 local_irq_save(flags
);
31 local_irq_restore(flags
);
34 static __inline__
void atomic_sub(int i
, atomic_t
*v
)
38 local_irq_save(flags
);
40 local_irq_restore(flags
);
43 static __inline__
int atomic_add_return(int i
, atomic_t
* v
)
45 unsigned long temp
, flags
;
47 local_irq_save(flags
);
51 local_irq_restore(flags
);
56 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
58 static __inline__
int atomic_sub_return(int i
, atomic_t
* v
)
60 unsigned long temp
, flags
;
62 local_irq_save(flags
);
66 local_irq_restore(flags
);
71 #define atomic_dec_return(v) atomic_sub_return(1,(v))
72 #define atomic_inc_return(v) atomic_add_return(1,(v))
75 * atomic_inc_and_test - increment and test
76 * @v: pointer of type atomic_t
78 * Atomically increments @v by 1
79 * and returns true if the result is zero, or false for all
82 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
84 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
85 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
87 #define atomic_inc(v) atomic_add(1,(v))
88 #define atomic_dec(v) atomic_sub(1,(v))
90 static inline int atomic_cmpxchg(atomic_t
*v
, int old
, int new)
95 local_irq_save(flags
);
97 if (likely(ret
== old
))
99 local_irq_restore(flags
);
104 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
106 static inline int atomic_add_unless(atomic_t
*v
, int a
, int u
)
111 local_irq_save(flags
);
115 local_irq_restore(flags
);
119 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
121 static __inline__
void atomic_clear_mask(unsigned int mask
, atomic_t
*v
)
125 local_irq_save(flags
);
127 local_irq_restore(flags
);
130 static __inline__
void atomic_set_mask(unsigned int mask
, atomic_t
*v
)
134 local_irq_save(flags
);
136 local_irq_restore(flags
);
139 /* Atomic operations are already serializing on SH */
140 #define smp_mb__before_atomic_dec() barrier()
141 #define smp_mb__after_atomic_dec() barrier()
142 #define smp_mb__before_atomic_inc() barrier()
143 #define smp_mb__after_atomic_inc() barrier()
145 #include <asm-generic/atomic.h>
146 #endif /* __ASM_SH_ATOMIC_H */