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 10 #include <linux/compiler.h> 11 #include <linux/types.h> 12 #include <asm/cmpxchg.h> 13 #include <asm/barrier.h> 14 15 #define ATOMIC_INIT(i) { (i) } 16 17 #define atomic_read(v) READ_ONCE((v)->counter) 18 #define atomic_set(v,i) WRITE_ONCE((v)->counter, (i)) 19 20 #if defined(CONFIG_GUSA_RB) 21 #include <asm/atomic-grb.h> 22 #elif defined(CONFIG_CPU_SH4A) 23 #include <asm/atomic-llsc.h> 24 #else 25 #include <asm/atomic-irq.h> 26 #endif 27 28 #define atomic_fetch_or atomic_fetch_or 29 30 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 31 #define atomic_dec_return(v) atomic_sub_return(1, (v)) 32 #define atomic_inc_return(v) atomic_add_return(1, (v)) 33 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) 34 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 35 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 36 37 #define atomic_inc(v) atomic_add(1, (v)) 38 #define atomic_dec(v) atomic_sub(1, (v)) 39 40 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 41 #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) 42 43 /** 44 * __atomic_add_unless - add unless the number is a given value 45 * @v: pointer of type atomic_t 46 * @a: the amount to add to v... 47 * @u: ...unless v is equal to u. 48 * 49 * Atomically adds @a to @v, so long as it was not @u. 50 * Returns the old value of @v. 51 */ 52 static inline int __atomic_add_unless(atomic_t *v, int a, int u) 53 { 54 int c, old; 55 c = atomic_read(v); 56 for (;;) { 57 if (unlikely(c == (u))) 58 break; 59 old = atomic_cmpxchg((v), c, c + (a)); 60 if (likely(old == c)) 61 break; 62 c = old; 63 } 64 65 return c; 66 } 67 68 #endif /* __ASM_SH_ATOMIC_H */ 69