| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 90 | static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) |
| 91 | { |
| 92 | unsigned long flags; |
| 93 | |
| 94 | local_irq_save(flags); |
| 95 | *(long *)v &= ~mask; |
| 96 | local_irq_restore(flags); |
| 97 | } |
| 98 | |
| 99 | static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v) |
| 100 | { |
| 101 | unsigned long flags; |
| 102 | |
| 103 | local_irq_save(flags); |
| 104 | *(long *)v |= mask; |
| 105 | local_irq_restore(flags); |
| 106 | } |
| 107 | |
| 108 | /* Atomic operations are already serializing on SH */ |
| 109 | #define smp_mb__before_atomic_dec() barrier() |
| 110 | #define smp_mb__after_atomic_dec() barrier() |
| 111 | #define smp_mb__before_atomic_inc() barrier() |
| 112 | #define smp_mb__after_atomic_inc() barrier() |
| 113 | |
| 114 | #endif /* __ASM_SH_ATOMIC_H */ |