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#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 READ_ONCE((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, -=)
ATOMIC_OP(and, &=)
ATOMIC_OP(or, |=)
ATOMIC_OP(xor, ^=)
#undef ATOMIC_OPS
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
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 */
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