diff options
Diffstat (limited to 'include/asm-arm26/atomic.h')
-rw-r--r-- | include/asm-arm26/atomic.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/include/asm-arm26/atomic.h b/include/asm-arm26/atomic.h new file mode 100644 index 000000000000..4a88235c0e76 --- /dev/null +++ b/include/asm-arm26/atomic.h @@ -0,0 +1,93 @@ +/* + * linux/include/asm-arm26/atomic.h + * + * Copyright (c) 1996 Russell King. + * Modified for arm26 by Ian Molton + * + * 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: + * 25-11-2004 IM Updated for 2.6.9 + * 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__ + * + * FIXME - its probably worth seeing what these compile into... + */ +#ifndef __ASM_ARM_ATOMIC_H +#define __ASM_ARM_ATOMIC_H + +#include <linux/config.h> + +#ifdef CONFIG_SMP +#error SMP is NOT supported +#endif + +typedef struct { volatile int counter; } atomic_t; + +#define ATOMIC_INIT(i) { (i) } + +#ifdef __KERNEL__ +#include <asm/system.h> + +#define atomic_read(v) ((v)->counter) +#define atomic_set(v,i) (((v)->counter) = (i)) + +static inline int atomic_add_return(int i, atomic_t *v) +{ + unsigned long flags; + int val; + + local_irq_save(flags); + val = v->counter; + v->counter = val += i; + local_irq_restore(flags); + + return val; +} + +static inline int atomic_sub_return(int i, atomic_t *v) +{ + unsigned long flags; + int val; + + local_irq_save(flags); + val = v->counter; + v->counter = val -= i; + local_irq_restore(flags); + + return val; +} + +static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +{ + unsigned long flags; + + local_irq_save(flags); + *addr &= ~mask; + local_irq_restore(flags); +} + +#define atomic_add(i, v) (void) atomic_add_return(i, v) +#define atomic_inc(v) (void) atomic_add_return(1, v) +#define atomic_sub(i, v) (void) atomic_sub_return(i, v) +#define atomic_dec(v) (void) atomic_sub_return(1, v) + +#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) +#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) +#define atomic_inc_return(v) (atomic_add_return(1, v)) +#define atomic_dec_return(v) (atomic_sub_return(1, v)) + +#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) + +/* Atomic operations are already serializing on ARM26 */ +#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 |