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 13 #define ATOMIC_INIT(i) { (i) } 14 #define ATOMIC64_INIT(i) { (i) } 15 16 #define atomic_read(v) (*(volatile int *)&(v)->counter) 17 #define atomic64_read(v) (*(volatile long *)&(v)->counter) 18 19 #define atomic_set(v, i) (((v)->counter) = i) 20 #define atomic64_set(v, i) (((v)->counter) = i) 21 22 extern void atomic_add(int, atomic_t *); 23 extern void atomic64_add(long, atomic64_t *); 24 extern void atomic_sub(int, atomic_t *); 25 extern void atomic64_sub(long, atomic64_t *); 26 27 extern int atomic_add_ret(int, atomic_t *); 28 extern long atomic64_add_ret(long, atomic64_t *); 29 extern int atomic_sub_ret(int, atomic_t *); 30 extern long atomic64_sub_ret(long, atomic64_t *); 31 32 #define atomic_dec_return(v) atomic_sub_ret(1, v) 33 #define atomic64_dec_return(v) atomic64_sub_ret(1, v) 34 35 #define atomic_inc_return(v) atomic_add_ret(1, v) 36 #define atomic64_inc_return(v) atomic64_add_ret(1, v) 37 38 #define atomic_sub_return(i, v) atomic_sub_ret(i, v) 39 #define atomic64_sub_return(i, v) atomic64_sub_ret(i, v) 40 41 #define atomic_add_return(i, v) atomic_add_ret(i, v) 42 #define atomic64_add_return(i, v) atomic64_add_ret(i, v) 43 44 /* 45 * atomic_inc_and_test - increment and test 46 * @v: pointer of type atomic_t 47 * 48 * Atomically increments @v by 1 49 * and returns true if the result is zero, or false for all 50 * other cases. 51 */ 52 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) 53 #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) 54 55 #define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0) 56 #define atomic64_sub_and_test(i, v) (atomic64_sub_ret(i, v) == 0) 57 58 #define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0) 59 #define atomic64_dec_and_test(v) (atomic64_sub_ret(1, v) == 0) 60 61 #define atomic_inc(v) atomic_add(1, v) 62 #define atomic64_inc(v) atomic64_add(1, v) 63 64 #define atomic_dec(v) atomic_sub(1, v) 65 #define atomic64_dec(v) atomic64_sub(1, v) 66 67 #define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0) 68 #define atomic64_add_negative(i, v) (atomic64_add_ret(i, v) < 0) 69 70 #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) 71 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 72 73 static inline int __atomic_add_unless(atomic_t *v, int a, int u) 74 { 75 int c, old; 76 c = atomic_read(v); 77 for (;;) { 78 if (unlikely(c == (u))) 79 break; 80 old = atomic_cmpxchg((v), c, c + (a)); 81 if (likely(old == c)) 82 break; 83 c = old; 84 } 85 return c; 86 } 87 88 #define atomic64_cmpxchg(v, o, n) \ 89 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n))) 90 #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) 91 92 static inline long atomic64_add_unless(atomic64_t *v, long a, long u) 93 { 94 long c, old; 95 c = atomic64_read(v); 96 for (;;) { 97 if (unlikely(c == (u))) 98 break; 99 old = atomic64_cmpxchg((v), c, c + (a)); 100 if (likely(old == c)) 101 break; 102 c = old; 103 } 104 return c != (u); 105 } 106 107 #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) 108 109 extern long atomic64_dec_if_positive(atomic64_t *v); 110 111 /* Atomic operations are already serializing */ 112 #define smp_mb__before_atomic_dec() barrier() 113 #define smp_mb__after_atomic_dec() barrier() 114 #define smp_mb__before_atomic_inc() barrier() 115 #define smp_mb__after_atomic_inc() barrier() 116 117 #endif /* !(__ARCH_SPARC64_ATOMIC__) */ 118