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/* sparc64 assembly.
* Don't include directly, use asm.h instead.
*
* Most of this code comes straight out of the Linux kernel.
*
* The terms of the GPL v2 apply.
*
*/
#define membar_safe(type) \
do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \
" membar " type "\n" \
"1:\n" \
: : : "memory"); \
} while (0)
#define mb() \
membar_safe("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
static inline void barrier(void)
{
mb();
}
#define cpu_relax() barrier()
static inline int
cmpxchg(volatile int *m, int old, int new)
{
__asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
"cas [%2], %3, %0\n\t"
"membar #StoreLoad | #StoreStore"
: "=&r" (new)
: "0" (new), "r" (m), "r" (old)
: "memory");
return new;
}
typedef struct { int counter; } atomic_t;
#define ATOMIC_INIT(i) { (i) }
/**
* atomic_read - read atomic variable
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v.
*/
#define atomic_read(v) ((v)->counter)
/**
* atomic_set - set atomic variable
* @v: pointer of type atomic_t
* @i: required value
*
* Atomically sets the value of @v to @i.
*/
#define atomic_set(v,i) (((v)->counter) = (i))
/**
* atomic_add_return - add and return
* @v: pointer of type atomic_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns @i + @v
*/
static __inline__ int atomic_add_return(int i, atomic_t *v)
{
int old;
int ret;
goto first;
do {
cpu_relax();
first:
old = atomic_read(v);
ret = cmpxchg(&v->counter, old, old + i);
} while (ret != old);
return old + i;
}
static __inline__ void atomic_add(int i, atomic_t *v)
{
atomic_add_return(i, v);
}
#define atomic_inc_return(v) (atomic_add_return(1,v))
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