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 14 #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) 15 16 #define atomic_read(v) (*(volatile int *)&(v)->counter) 17 #define atomic_set(v,i) ((v)->counter = (i)) 18 19 #if defined(CONFIG_GUSA_RB) 20 #include <asm/atomic-grb.h> 21 #elif defined(CONFIG_CPU_SH4A) 22 #include <asm/atomic-llsc.h> 23 #else 24 #include <asm/atomic-irq.h> 25 #endif 26 27 #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 28 #define atomic_dec_return(v) atomic_sub_return(1, (v)) 29 #define atomic_inc_return(v) atomic_add_return(1, (v)) 30 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) 31 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 32 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 33 34 #define atomic_inc(v) atomic_add(1, (v)) 35 #define atomic_dec(v) atomic_sub(1, (v)) 36 37 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 38 #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) 39 40 /** 41 * __atomic_add_unless - add unless the number is a given value 42 * @v: pointer of type atomic_t 43 * @a: the amount to add to v... 44 * @u: ...unless v is equal to u. 45 * 46 * Atomically adds @a to @v, so long as it was not @u. 47 * Returns the old value of @v. 48 */ 49 static inline int __atomic_add_unless(atomic_t *v, int a, int u) 50 { 51 int c, old; 52 c = atomic_read(v); 53 for (;;) { 54 if (unlikely(c == (u))) 55 break; 56 old = atomic_cmpxchg((v), c, c + (a)); 57 if (likely(old == c)) 58 break; 59 c = old; 60 } 61 62 return c; 63 } 64 65 #define smp_mb__before_atomic_dec() smp_mb() 66 #define smp_mb__after_atomic_dec() smp_mb() 67 #define smp_mb__before_atomic_inc() smp_mb() 68 #define smp_mb__after_atomic_inc() smp_mb() 69 70 #endif /* __ASM_SH_ATOMIC_H */ 71