/* atomic.h: atomic operation emulation for FR-V
*
* For an explanation of how atomic ops work in this arch, see:
* Documentation/frv/atomic-ops.txt
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells ([email protected])
*
* 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; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H

#include <linux/types.h>
#include <asm/spr-regs.h>
#include <asm/cmpxchg.h>

#ifdef CONFIG_SMP
#error not SMP safe
#endif

/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
*
* We do not have SMP systems, so we don't have to deal with that.
*/

/* Atomic operations are already serializing */
#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()

#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) (*(volatile int *)&(v)->counter)
#define atomic_set(v, i) (((v)->counter) = (i))

#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long val;

asm("0: \n"
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
" ckeq icc3,cc7 \n"
" ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
" add%I2 %1,%2,%1 \n"
" cst.p %1,%M0 ,cc3,#1 \n"
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
" beq icc3,#0,0b \n"
: "+U"(v->counter), "=&r"(val)
: "NPr"(i)
: "memory", "cc7", "cc3", "icc3"
);

return val;
}

static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long val;

asm("0: \n"
" orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */
" ckeq icc3,cc7 \n"
" ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */
" orcr cc7,cc7,cc3 \n" /* set CC3 to true */
" sub%I2 %1,%2,%1 \n"
" cst.p %1,%M0 ,cc3,#1 \n"
" corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */
" beq icc3,#0,0b \n"
: "+U"(v->counter), "=&r"(val)
: "NPr"(i)
: "memory", "cc7", "cc3", "icc3"
);

return val;
}

#else

extern int atomic_add_return(int i, atomic_t *v);
extern int atomic_sub_return(int i, atomic_t *v);

#endif

static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}

static inline void atomic_add(int i, atomic_t *v)
{
atomic_add_return(i, v);
}

static inline void atomic_sub(int i, atomic_t *v)
{
atomic_sub_return(i, v);
}

static inline void atomic_inc(atomic_t *v)
{
atomic_add_return(1, v);
}

static inline void atomic_dec(atomic_t *v)
{
atomic_sub_return(1, v);
}

#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))

#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_and_test(v) (atomic_add_return(1, (v)) == 0)

/*
* 64-bit atomic ops
*/
typedef struct {
volatile long long counter;
} atomic64_t;

#define ATOMIC64_INIT(i) { (i) }

static inline long long atomic64_read(atomic64_t *v)
{
long long counter;

asm("ldd%I1 %M1,%0"
: "=e"(counter)
: "m"(v->counter));
return counter;
}

static inline void atomic64_set(atomic64_t *v, long long i)
{
asm volatile("std%I0 %1,%M0"
: "=m"(v->counter)
: "e"(i));
}

extern long long atomic64_inc_return(atomic64_t *v);
extern long long atomic64_dec_return(atomic64_t *v);
extern long long atomic64_add_return(long long i, atomic64_t *v);
extern long long atomic64_sub_return(long long i, atomic64_t *v);

static inline long long atomic64_add_negative(long long i, atomic64_t *v)
{
return atomic64_add_return(i, v) < 0;
}

static inline void atomic64_add(long long i, atomic64_t *v)
{
atomic64_add_return(i, v);
}

static inline void atomic64_sub(long long i, atomic64_t *v)
{
atomic64_sub_return(i, v);
}

static inline void atomic64_inc(atomic64_t *v)
{
atomic64_inc_return(v);
}

static inline void atomic64_dec(atomic64_t *v)
{
atomic64_dec_return(v);
}

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

#define atomic_cmpxchg(v, old, new) (cmpxchg(&(v)->counter, old, new))
#define atomic_xchg(v, new) (xchg(&(v)->counter, new))
#define atomic64_cmpxchg(v, old, new) (__cmpxchg_64(old, new, &(v)->counter))
#define atomic64_xchg(v, new) (__xchg_64(new, &(v)->counter))

static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c;
}


#endif /* _ASM_ATOMIC_H */