/* * 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 #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 int atomic_cmpxchg(atomic_t *v, int old, int new) { int ret; unsigned long flags; local_irq_save(flags); ret = v->counter; if (likely(ret == old)) v->counter = new; local_irq_restore(flags); return ret; } #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) static inline int atomic_add_unless(atomic_t *v, int a, int u) { int ret; unsigned long flags; local_irq_save(flags); ret = v->counter; if (ret != u) v->counter += a; local_irq_restore(flags); return ret != u; } #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) 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() #include <asm-generic/atomic.h> #endif #endif