| wdenk | bb2d927 | 2003-06-25 22:26:29 +0000 | [diff] [blame] | 1 | /* |
| 2 | * linux/include/asm-arm/atomic.h |
| 3 | * |
| 4 | * Copyright (c) 1996 Russell King. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * Changelog: |
| 11 | * 27-06-1996 RMK Created |
| 12 | * 13-04-1997 RMK Made functions atomic! |
| 13 | * 07-12-1997 RMK Upgraded for v2.1. |
| 14 | * 26-08-1998 PJB Added #ifdef __KERNEL__ |
| 15 | */ |
| 16 | #ifndef __ASM_ARM_ATOMIC_H |
| 17 | #define __ASM_ARM_ATOMIC_H |
| 18 | |
| 19 | #include <linux/config.h> |
| 20 | |
| 21 | #ifdef CONFIG_SMP |
| 22 | #error SMP not supported |
| 23 | #endif |
| 24 | |
| 25 | typedef struct { volatile int counter; } atomic_t; |
| 26 | |
| 27 | #define ATOMIC_INIT(i) { (i) } |
| 28 | |
| 29 | #ifdef __KERNEL__ |
| 30 | #include <asm/proc/system.h> |
| 31 | |
| 32 | #define atomic_read(v) ((v)->counter) |
| 33 | #define atomic_set(v,i) (((v)->counter) = (i)) |
| 34 | |
| 35 | static inline void atomic_add(int i, volatile atomic_t *v) |
| 36 | { |
| 37 | unsigned long flags; |
| 38 | |
| 39 | local_irq_save(flags); |
| 40 | v->counter += i; |
| 41 | local_irq_restore(flags); |
| 42 | } |
| 43 | |
| 44 | static inline void atomic_sub(int i, volatile atomic_t *v) |
| 45 | { |
| 46 | unsigned long flags; |
| 47 | |
| 48 | local_irq_save(flags); |
| 49 | v->counter -= i; |
| 50 | local_irq_restore(flags); |
| 51 | } |
| 52 | |
| 53 | static inline void atomic_inc(volatile atomic_t *v) |
| 54 | { |
| 55 | unsigned long flags; |
| 56 | |
| 57 | local_irq_save(flags); |
| 58 | v->counter += 1; |
| 59 | local_irq_restore(flags); |
| 60 | } |
| 61 | |
| 62 | static inline void atomic_dec(volatile atomic_t *v) |
| 63 | { |
| 64 | unsigned long flags; |
| 65 | |
| 66 | local_irq_save(flags); |
| 67 | v->counter -= 1; |
| 68 | local_irq_restore(flags); |
| 69 | } |
| 70 | |
| 71 | static inline int atomic_dec_and_test(volatile atomic_t *v) |
| 72 | { |
| 73 | unsigned long flags; |
| 74 | int val; |
| 75 | |
| 76 | local_irq_save(flags); |
| 77 | val = v->counter; |
| 78 | v->counter = val -= 1; |
| 79 | local_irq_restore(flags); |
| 80 | |
| 81 | return val == 0; |
| 82 | } |
| 83 | |
| 84 | static inline int atomic_add_negative(int i, volatile atomic_t *v) |
| 85 | { |
| 86 | unsigned long flags; |
| 87 | int val; |
| 88 | |
| 89 | local_irq_save(flags); |
| 90 | val = v->counter; |
| 91 | v->counter = val += i; |
| 92 | local_irq_restore(flags); |
| 93 | |
| 94 | return val < 0; |
| 95 | } |
| 96 | |
| 97 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
| 98 | { |
| 99 | unsigned long flags; |
| 100 | |
| 101 | local_irq_save(flags); |
| 102 | *addr &= ~mask; |
| 103 | local_irq_restore(flags); |
| 104 | } |
| 105 | |
| 106 | /* Atomic operations are already serializing on ARM */ |
| 107 | #define smp_mb__before_atomic_dec() barrier() |
| 108 | #define smp_mb__after_atomic_dec() barrier() |
| 109 | #define smp_mb__before_atomic_inc() barrier() |
| 110 | #define smp_mb__after_atomic_inc() barrier() |
| 111 | |
| 112 | #endif |
| 113 | #endif |