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Diffstat (limited to 'include/asm-sh/atomic.h')
-rw-r--r-- | include/asm-sh/atomic.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/include/asm-sh/atomic.h b/include/asm-sh/atomic.h new file mode 100644 index 000000000000..3c4f805da1ac --- /dev/null +++ b/include/asm-sh/atomic.h @@ -0,0 +1,114 @@ +#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 <asm/system.h> + +/* + * To get proper branch prediction for the main line, we must branch + * forward to code at the end of this object's .text section, then + * branch back to restart the operation. + */ + +static __inline__ void atomic_add(int i, atomic_t * v) +{ + unsigned long flags; + + local_irq_save(flags); + *(long *)v += i; + local_irq_restore(flags); +} + +static __inline__ void atomic_sub(int i, atomic_t *v) +{ + unsigned long flags; + + local_irq_save(flags); + *(long *)v -= i; + local_irq_restore(flags); +} + +static __inline__ int atomic_add_return(int i, atomic_t * v) +{ + unsigned long temp, flags; + + local_irq_save(flags); + temp = *(long *)v; + temp += i; + *(long *)v = temp; + local_irq_restore(flags); + + return temp; +} + +#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) + +static __inline__ int atomic_sub_return(int i, atomic_t * v) +{ + unsigned long temp, flags; + + local_irq_save(flags); + temp = *(long *)v; + temp -= i; + *(long *)v = temp; + local_irq_restore(flags); + + return temp; +} + +#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)) + +static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v) +{ + unsigned long flags; + + local_irq_save(flags); + *(long *)v &= ~mask; + local_irq_restore(flags); +} + +static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v) +{ + unsigned long flags; + + local_irq_save(flags); + *(long *)v |= mask; + local_irq_restore(flags); +} + +/* 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() + +#endif /* __ASM_SH_ATOMIC_H */ |