diff options
Diffstat (limited to 'kernel/arch/metag/include/asm/atomic_lock1.h')
-rw-r--r-- | kernel/arch/metag/include/asm/atomic_lock1.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/kernel/arch/metag/include/asm/atomic_lock1.h b/kernel/arch/metag/include/asm/atomic_lock1.h new file mode 100644 index 000000000..f5d5898c1 --- /dev/null +++ b/kernel/arch/metag/include/asm/atomic_lock1.h @@ -0,0 +1,146 @@ +#ifndef __ASM_METAG_ATOMIC_LOCK1_H +#define __ASM_METAG_ATOMIC_LOCK1_H + +#define ATOMIC_INIT(i) { (i) } + +#include <linux/compiler.h> + +#include <asm/barrier.h> +#include <asm/global_lock.h> + +static inline int atomic_read(const atomic_t *v) +{ + return (v)->counter; +} + +/* + * atomic_set needs to be take the lock to protect atomic_add_unless from a + * possible race, as it reads the counter twice: + * + * CPU0 CPU1 + * atomic_add_unless(1, 0) + * ret = v->counter (non-zero) + * if (ret != u) v->counter = 0 + * v->counter += 1 (counter set to 1) + * + * Making atomic_set take the lock ensures that ordering and logical + * consistency is preserved. + */ +static inline int atomic_set(atomic_t *v, int i) +{ + unsigned long flags; + + __global_lock1(flags); + fence(); + v->counter = i; + __global_unlock1(flags); + return i; +} + +#define ATOMIC_OP(op, c_op) \ +static inline void atomic_##op(int i, atomic_t *v) \ +{ \ + unsigned long flags; \ + \ + __global_lock1(flags); \ + fence(); \ + v->counter c_op i; \ + __global_unlock1(flags); \ +} \ + +#define ATOMIC_OP_RETURN(op, c_op) \ +static inline int atomic_##op##_return(int i, atomic_t *v) \ +{ \ + unsigned long result; \ + unsigned long flags; \ + \ + __global_lock1(flags); \ + result = v->counter; \ + result c_op i; \ + fence(); \ + v->counter = result; \ + __global_unlock1(flags); \ + \ + return result; \ +} + +#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op) + +ATOMIC_OPS(add, +=) +ATOMIC_OPS(sub, -=) + +#undef ATOMIC_OPS +#undef ATOMIC_OP_RETURN +#undef ATOMIC_OP + +static inline void atomic_clear_mask(unsigned int mask, atomic_t *v) +{ + unsigned long flags; + + __global_lock1(flags); + fence(); + v->counter &= ~mask; + __global_unlock1(flags); +} + +static inline void atomic_set_mask(unsigned int mask, atomic_t *v) +{ + unsigned long flags; + + __global_lock1(flags); + fence(); + v->counter |= mask; + __global_unlock1(flags); +} + +static inline int atomic_cmpxchg(atomic_t *v, int old, int new) +{ + int ret; + unsigned long flags; + + __global_lock1(flags); + ret = v->counter; + if (ret == old) { + fence(); + v->counter = new; + } + __global_unlock1(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; + + __global_lock1(flags); + ret = v->counter; + if (ret != u) { + fence(); + v->counter += a; + } + __global_unlock1(flags); + + return ret; +} + +static inline int atomic_sub_if_positive(int i, atomic_t *v) +{ + int ret; + unsigned long flags; + + __global_lock1(flags); + ret = v->counter - 1; + if (ret >= 0) { + fence(); + v->counter = ret; + } + __global_unlock1(flags); + + return ret; +} + +#endif /* __ASM_METAG_ATOMIC_LOCK1_H */ |