1 /* atomic.h: Thankfully the V9 is at least reasonable for this 2 * stuff. 3 * 4 * Copyright (C) 1996, 1997, 2000, 2012 David S. Miller (davem@redhat.com) 5 */ 6 7 #ifndef __ARCH_SPARC64_ATOMIC__ 8 #define __ARCH_SPARC64_ATOMIC__ 9 10 #include <linux/types.h> 11 #include <asm/cmpxchg.h> 12 #include <asm/barrier.h> 13 14 #define ATOMIC_INIT(i) { (i) } 15 #define ATOMIC64_INIT(i) { (i) } 16 17 #define atomic_read(v) ACCESS_ONCE((v)->counter) 18 #define atomic64_read(v) ACCESS_ONCE((v)->counter) 19 20 #define atomic_set(v, i) (((v)->counter) = i) 21 #define atomic64_set(v, i) (((v)->counter) = i) 22 23 #define ATOMIC_OP(op) \ 24 void atomic_##op(int, atomic_t *); \ 25 void atomic64_##op(long, atomic64_t *); 26 27 #define ATOMIC_OP_RETURN(op) \ 28 int atomic_##op##_return(int, atomic_t *); \ 29 long atomic64_##op##_return(long, atomic64_t *); 30 31 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) 32 33 ATOMIC_OPS(add) 34 ATOMIC_OPS(sub) 35 36 #undef ATOMIC_OPS 37 #undef ATOMIC_OP_RETURN 38 #undef ATOMIC_OP 39 40 #define atomic_dec_return(v) atomic_sub_return(1, v) 41 #define atomic64_dec_return(v) atomic64_sub_return(1, v) 42 43 #define atomic_inc_return(v) atomic_add_return(1, v) 44 #define atomic64_inc_return(v) atomic64_add_return(1, v) 45 46 /* 47 * atomic_inc_and_test - increment and test 48 * @v: pointer of type atomic_t 49 * 50 * Atomically increments @v by 1 51 * and returns true if the result is zero, or false for all 52 * other cases. 53 */ 54 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) 55 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) 56 57 #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) 58 #define atomic64_sub_and_test(i, v) (atomic64_sub_return(i, v) == 0) 59 60 #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) 61 #define atomic64_dec_and_test(v) (atomic64_sub_return(1, v) == 0) 62 63 #define atomic_inc(v) atomic_add(1, v) 64 #define atomic64_inc(v) atomic64_add(1, v) 65 66 #define atomic_dec(v) atomic_sub(1, v) 67 #define atomic64_dec(v) atomic64_sub(1, v) 68 69 #define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0) 70 #define atomic64_add_negative(i, v) (atomic64_add_return(i, v) < 0) 71 72 #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) 73 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 74 75 static inline int __atomic_add_unless(atomic_t *v, int a, int u) 76 { 77 int c, old; 78 c = atomic_read(v); 79 for (;;) { 80 if (unlikely(c == (u))) 81 break; 82 old = atomic_cmpxchg((v), c, c + (a)); 83 if (likely(old == c)) 84 break; 85 c = old; 86 } 87 return c; 88 } 89 90 #define atomic64_cmpxchg(v, o, n) \ 91 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) 92 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) 93 94 static inline long atomic64_add_unless(atomic64_t *v, long a, long u) 95 { 96 long c, old; 97 c = atomic64_read(v); 98 for (;;) { 99 if (unlikely(c == (u))) 100 break; 101 old = atomic64_cmpxchg((v), c, c + (a)); 102 if (likely(old == c)) 103 break; 104 c = old; 105 } 106 return c != (u); 107 } 108 109 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 110 111 long atomic64_dec_if_positive(atomic64_t *v); 112 113 #endif /* !(__ARCH_SPARC64_ATOMIC__) */ 114