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1da177e4 LT |
1 | #ifndef __ASM_SH_ATOMIC_H |
2 | #define __ASM_SH_ATOMIC_H | |
3 | ||
4 | /* | |
5 | * Atomic operations that C can't guarantee us. Useful for | |
6 | * resource counting etc.. | |
7 | * | |
8 | */ | |
9 | ||
ea435467 MW |
10 | #include <linux/compiler.h> |
11 | #include <linux/types.h> | |
e839ca52 | 12 | #include <asm/cmpxchg.h> |
603228bc | 13 | #include <asm/barrier.h> |
1da177e4 | 14 | |
ec2ccd88 | 15 | #define ATOMIC_INIT(i) { (i) } |
1da177e4 | 16 | |
f3d46f9d | 17 | #define atomic_read(v) (*(volatile int *)&(v)->counter) |
1da177e4 LT |
18 | #define atomic_set(v,i) ((v)->counter = (i)) |
19 | ||
1efe4ce3 SM |
20 | #if defined(CONFIG_GUSA_RB) |
21 | #include <asm/atomic-grb.h> | |
22 | #elif defined(CONFIG_CPU_SH4A) | |
ec723fbe | 23 | #include <asm/atomic-llsc.h> |
781125ca | 24 | #else |
ec723fbe | 25 | #include <asm/atomic-irq.h> |
781125ca | 26 | #endif |
1da177e4 LT |
27 | |
28 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | |
8c0b8139 PM |
29 | #define atomic_dec_return(v) atomic_sub_return(1, (v)) |
30 | #define atomic_inc_return(v) atomic_add_return(1, (v)) | |
31 | #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) | |
32 | #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) | |
33 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
1da177e4 | 34 | |
8c0b8139 PM |
35 | #define atomic_inc(v) atomic_add(1, (v)) |
36 | #define atomic_dec(v) atomic_sub(1, (v)) | |
1da177e4 | 37 | |
8c0b8139 PM |
38 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
39 | #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) | |
40 | ||
41 | /** | |
f24219b4 | 42 | * __atomic_add_unless - add unless the number is a given value |
1da177e4 | 43 | * @v: pointer of type atomic_t |
8c0b8139 PM |
44 | * @a: the amount to add to v... |
45 | * @u: ...unless v is equal to u. | |
1da177e4 | 46 | * |
8c0b8139 | 47 | * Atomically adds @a to @v, so long as it was not @u. |
f24219b4 | 48 | * Returns the old value of @v. |
1da177e4 | 49 | */ |
f24219b4 | 50 | static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
8426e1f6 | 51 | { |
8c0b8139 PM |
52 | int c, old; |
53 | c = atomic_read(v); | |
54 | for (;;) { | |
55 | if (unlikely(c == (u))) | |
56 | break; | |
57 | old = atomic_cmpxchg((v), c, c + (a)); | |
58 | if (likely(old == c)) | |
59 | break; | |
60 | c = old; | |
61 | } | |
62 | ||
f24219b4 | 63 | return c; |
8426e1f6 | 64 | } |
8426e1f6 | 65 | |
1da177e4 | 66 | #endif /* __ASM_SH_ATOMIC_H */ |