/*
* Copyright 2011 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* Do not include directly; use <linux/atomic.h>.
*/

#ifndef _ASM_TILE_ATOMIC_64_H
#define _ASM_TILE_ATOMIC_64_H

#ifndef __ASSEMBLY__

#include <asm/barrier.h>
#include <arch/spr_def.h>

/* First, the 32-bit atomic ops that are "real" on our 64-bit platform. */

#define atomic_set(v, i) ((v)->counter = (i))

/*
* The smp_mb() operations throughout are to support the fact that
* Linux requires memory barriers before and after the operation,
* on any routine which updates memory and returns a value.
*/

static inline void atomic_add(int i, atomic_t *v)
{
__insn_fetchadd4((void *)&v->counter, i);
}

static inline int atomic_add_return(int i, atomic_t *v)
{
int val;
smp_mb(); /* barrier for proper semantics */
val = __insn_fetchadd4((void *)&v->counter, i) + i;
barrier(); /* the "+ i" above will wait on memory */
return val;
}

static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int guess, oldval = v->counter;
do {
if (oldval == u)
break;
guess = oldval;
oldval = cmpxchg(&v->counter, guess, guess + a);
} while (guess != oldval);
return oldval;
}

/* Now the true 64-bit operations. */

#define ATOMIC64_INIT(i) { (i) }

#define atomic64_read(v) ((v)->counter)
#define atomic64_set(v, i) ((v)->counter = (i))

static inline void atomic64_add(long i, atomic64_t *v)
{
__insn_fetchadd((void *)&v->counter, i);
}

static inline long atomic64_add_return(long i, atomic64_t *v)
{
int val;
smp_mb(); /* barrier for proper semantics */
val = __insn_fetchadd((void *)&v->counter, i) + i;
barrier(); /* the "+ i" above will wait on memory */
return val;
}

static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
{
long guess, oldval = v->counter;
do {
if (oldval == u)
break;
guess = oldval;
oldval = cmpxchg(&v->counter, guess, guess + a);
} while (guess != oldval);
return oldval != u;
}

#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v))
#define atomic64_sub(i, v) atomic64_add(-(i), (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_inc(v) atomic64_add(1, (v))
#define atomic64_dec(v) atomic64_sub(1, (v))

#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)

#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)

/* Atomic dec and inc don't implement barrier, so provide them if needed. */
#define smp_mb__before_atomic_dec() smp_mb()
#define smp_mb__after_atomic_dec() smp_mb()
#define smp_mb__before_atomic_inc() smp_mb()
#define smp_mb__after_atomic_inc() smp_mb()

/* Define this to indicate that cmpxchg is an efficient operation. */
#define __HAVE_ARCH_CMPXCHG

#endif /* !__ASSEMBLY__ */

#endif /* _ASM_TILE_ATOMIC_64_H */