| /* |
| * linux/include/asm-arm/atomic.h |
| * |
| * Copyright (c) 1996 Russell King. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * Changelog: |
| * 27-06-1996 RMK Created |
| * 13-04-1997 RMK Made functions atomic! |
| * 07-12-1997 RMK Upgraded for v2.1. |
| * 26-08-1998 PJB Added #ifdef __KERNEL__ |
| */ |
| #ifndef __ASM_ARM_ATOMIC_H |
| #define __ASM_ARM_ATOMIC_H |
| |
| #include <linux/config.h> |
| |
| #ifdef CONFIG_SMP |
| #error SMP not supported |
| #endif |
| |
| typedef struct { volatile int counter; } atomic_t; |
| |
| #define ATOMIC_INIT(i) { (i) } |
| |
| #ifdef __KERNEL__ |
| #include <asm/proc/system.h> |
| |
| #define atomic_read(v) ((v)->counter) |
| #define atomic_set(v,i) (((v)->counter) = (i)) |
| |
| static __inline__ void atomic_add(int i, volatile atomic_t *v) |
| { |
| unsigned long flags; |
| |
| __save_flags_cli(flags); |
| v->counter += i; |
| __restore_flags(flags); |
| } |
| |
| static __inline__ void atomic_sub(int i, volatile atomic_t *v) |
| { |
| unsigned long flags; |
| |
| __save_flags_cli(flags); |
| v->counter -= i; |
| __restore_flags(flags); |
| } |
| |
| static __inline__ void atomic_inc(volatile atomic_t *v) |
| { |
| unsigned long flags; |
| |
| __save_flags_cli(flags); |
| v->counter += 1; |
| __restore_flags(flags); |
| } |
| |
| static __inline__ void atomic_dec(volatile atomic_t *v) |
| { |
| unsigned long flags; |
| |
| __save_flags_cli(flags); |
| v->counter -= 1; |
| __restore_flags(flags); |
| } |
| |
| static __inline__ int atomic_dec_and_test(volatile atomic_t *v) |
| { |
| unsigned long flags; |
| int result; |
| |
| __save_flags_cli(flags); |
| v->counter -= 1; |
| result = (v->counter == 0); |
| __restore_flags(flags); |
| |
| return result; |
| } |
| |
| static inline int atomic_add_negative(int i, volatile atomic_t *v) |
| { |
| unsigned long flags; |
| int result; |
| |
| __save_flags_cli(flags); |
| v->counter += i; |
| result = (v->counter < 0); |
| __restore_flags(flags); |
| |
| return result; |
| } |
| |
| static __inline__ void atomic_clear_mask(unsigned long mask, unsigned long *addr) |
| { |
| unsigned long flags; |
| |
| __save_flags_cli(flags); |
| *addr &= ~mask; |
| __restore_flags(flags); |
| } |
| |
| /* Atomic operations are already serializing on ARM */ |
| #define smp_mb__before_atomic_dec() barrier() |
| #define smp_mb__after_atomic_dec() barrier() |
| #define smp_mb__before_atomic_inc() barrier() |
| #define smp_mb__after_atomic_inc() barrier() |
| |
| #endif |
| #endif |