projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
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 <asm/system.h> | |
| 18 | ||
| 19 | /* | |
| 20 | * To get proper branch prediction for the main line, we must branch | |
| 21 | * forward to code at the end of this object's .text section, then | |
| 22 | * branch back to restart the operation. | |
| 23 | */ | |
| 24 | ||
| 25 | static __inline__ void atomic_add(int i, atomic_t * v) | |
| 26 | { | |
| 27 | unsigned long flags; | |
| 28 | ||
| 29 | local_irq_save(flags); | |
| 30 | *(long *)v += i; | |
| 31 | local_irq_restore(flags); | |
| 32 | } | |
| 33 | ||
| 34 | static __inline__ void atomic_sub(int i, atomic_t *v) | |
| 35 | { | |
| 36 | unsigned long flags; | |
| 37 | ||
| 38 | local_irq_save(flags); | |
| 39 | *(long *)v -= i; | |
| 40 | local_irq_restore(flags); | |
| 41 | } | |
| 42 | ||
| 43 | static __inline__ int atomic_add_return(int i, atomic_t * v) | |
| 44 | { | |
| 45 | unsigned long temp, flags; | |
| 46 | ||
| 47 | local_irq_save(flags); | |
| 48 | temp = *(long *)v; | |
| 49 | temp += i; | |
| 50 | *(long *)v = temp; | |
| 51 | local_irq_restore(flags); | |
| 52 | ||
| 53 | return temp; | |
| 54 | } | |
| 55 | ||
| 56 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | |
| 57 | ||
| 58 | static __inline__ int atomic_sub_return(int i, atomic_t * v) | |
| 59 | { | |
| 60 | unsigned long temp, flags; | |
| 61 | ||
| 62 | local_irq_save(flags); | |
| 63 | temp = *(long *)v; | |
| 64 | temp -= i; | |
| 65 | *(long *)v = temp; | |
| 66 | local_irq_restore(flags); | |
| 67 | ||
| 68 | return temp; | |
| 69 | } | |
| 70 | ||
| 71 | #define atomic_dec_return(v) atomic_sub_return(1,(v)) | |
| 72 | #define atomic_inc_return(v) atomic_add_return(1,(v)) | |
| 73 | ||
| 74 | /* | |
| 75 | * atomic_inc_and_test - increment and test | |
| 76 | * @v: pointer of type atomic_t | |
| 77 | * | |
| 78 | * Atomically increments @v by 1 | |
| 79 | * and returns true if the result is zero, or false for all | |
| 80 | * other cases. | |
| 81 | */ | |
| 82 | #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) | |
| 83 | ||
| 84 | #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) | |
| 85 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
| 86 | ||
| 87 | #define atomic_inc(v) atomic_add(1,(v)) | |
| 88 | #define atomic_dec(v) atomic_sub(1,(v)) | |
| 89 | ||
| 4a6dae6d NP |
90 | static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
| 91 | { | |
| 92 | int ret; | |
| 93 | unsigned long flags; | |
| 94 | ||
| 95 | local_irq_save(flags); | |
| 96 | ret = v->counter; | |
| 97 | if (likely(ret == old)) | |
| 98 | v->counter = new; | |
| 99 | local_irq_restore(flags); | |
| 100 | ||
| 101 | return ret; | |
| 102 | } | |
| 103 | ||
| 8426e1f6 NP |
104 | static inline int atomic_add_unless(atomic_t *v, int a, int u) |
| 105 | { | |
| 106 | int ret; | |
| 107 | unsigned long flags; | |
| 108 | ||
| 109 | local_irq_save(flags); | |
| 110 | ret = v->counter; | |
| 111 | if (ret != u) | |
| 112 | v->counter += a; | |
| 113 | local_irq_restore(flags); | |
| 114 | ||
| 115 | return ret != u; | |
| 116 | } | |
| 117 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) | |
| 118 | ||
| 1da177e4 LT |
119 | static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) |
| 120 | { | |
| 121 | unsigned long flags; | |
| 122 | ||
| 123 | local_irq_save(flags); | |
| 124 | *(long *)v &= ~mask; | |
| 125 | local_irq_restore(flags); | |
| 126 | } | |
| 127 | ||
| 128 | static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v) | |
| 129 | { | |
| 130 | unsigned long flags; | |
| 131 | ||
| 132 | local_irq_save(flags); | |
| 133 | *(long *)v |= mask; | |
| 134 | local_irq_restore(flags); | |
| 135 | } | |
| 136 | ||
| 137 | /* Atomic operations are already serializing on SH */ | |
| 138 | #define smp_mb__before_atomic_dec() barrier() | |
| 139 | #define smp_mb__after_atomic_dec() barrier() | |
| 140 | #define smp_mb__before_atomic_inc() barrier() | |
| 141 | #define smp_mb__after_atomic_inc() barrier() | |
| 142 | ||
| 143 | #endif /* __ASM_SH_ATOMIC_H */ |