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 typedef struct { volatile int counter; } atomic_t; 11 12 #define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) 13 14 #define atomic_read(v) ((v)->counter) 15 #define atomic_set(v,i) ((v)->counter = (i)) 16 17 #include <linux/compiler.h> 18 #include <asm/system.h> 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_add_negative(a, v) (atomic_add_return((a), (v)) < 0) 29 30 #define atomic_dec_return(v) atomic_sub_return(1,(v)) 31 #define atomic_inc_return(v) atomic_add_return(1,(v)) 32 33 /* 34 * atomic_inc_and_test - increment and test 35 * @v: pointer of type atomic_t 36 * 37 * Atomically increments @v by 1 38 * and returns true if the result is zero, or false for all 39 * other cases. 40 */ 41 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) 42 43 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) 44 #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) 45 46 #define atomic_inc(v) atomic_add(1,(v)) 47 #define atomic_dec(v) atomic_sub(1,(v)) 48 49 #ifndef CONFIG_GUSA_RB 50 static inline int atomic_cmpxchg(atomic_t *v, int old, int new) 51 { 52 int ret; 53 unsigned long flags; 54 55 local_irq_save(flags); 56 ret = v->counter; 57 if (likely(ret == old)) 58 v->counter = new; 59 local_irq_restore(flags); 60 61 return ret; 62 } 63 64 static inline int atomic_add_unless(atomic_t *v, int a, int u) 65 { 66 int ret; 67 unsigned long flags; 68 69 local_irq_save(flags); 70 ret = v->counter; 71 if (ret != u) 72 v->counter += a; 73 local_irq_restore(flags); 74 75 return ret != u; 76 } 77 #endif 78 79 #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) 80 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 81 82 /* Atomic operations are already serializing on SH */ 83 #define smp_mb__before_atomic_dec() barrier() 84 #define smp_mb__after_atomic_dec() barrier() 85 #define smp_mb__before_atomic_inc() barrier() 86 #define smp_mb__after_atomic_inc() barrier() 87 88 #include <asm-generic/atomic.h> 89 #endif /* __ASM_SH_ATOMIC_H */ 90