diff options
Diffstat (limited to 'arch/sh/include/asm/atomic.h')
-rw-r--r-- | arch/sh/include/asm/atomic.h | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h new file mode 100644 index 0000000..c043ef0 --- /dev/null +++ b/arch/sh/include/asm/atomic.h @@ -0,0 +1,89 @@ +#ifndef __ASM_SH_ATOMIC_H +#define __ASM_SH_ATOMIC_H + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + * + */ + +typedef struct { volatile int counter; } atomic_t; + +#define ATOMIC_INIT(i) ( (atomic_t) { (i) } ) + +#define atomic_read(v) ((v)->counter) +#define atomic_set(v,i) ((v)->counter = (i)) + +#include <linux/compiler.h> +#include <asm/system.h> + +#if defined(CONFIG_GUSA_RB) +#include <asm/atomic-grb.h> +#elif defined(CONFIG_CPU_SH4A) +#include <asm/atomic-llsc.h> +#else +#include <asm/atomic-irq.h> +#endif + +#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) + +#define atomic_dec_return(v) atomic_sub_return(1,(v)) +#define atomic_inc_return(v) atomic_add_return(1,(v)) + +/* + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) + +#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) +#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) + +#define atomic_inc(v) atomic_add(1,(v)) +#define atomic_dec(v) atomic_sub(1,(v)) + +#ifndef CONFIG_GUSA_RB +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; +} + +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; +} +#endif + +#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +/* Atomic operations are already serializing on SH */ +#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 /* __ASM_SH_ATOMIC_H */ |