/*
* cmpxchg.h -- forked from asm/atomic.h with this copyright:
*
* Copyright 2010 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.
*
*/

#ifndef _ASM_TILE_CMPXCHG_H
#define _ASM_TILE_CMPXCHG_H

#ifndef __ASSEMBLY__

#include <asm/barrier.h>

/* Nonexistent functions intended to cause compile errors. */
extern void __xchg_called_with_bad_pointer(void)
__compiletime_error("Bad argument size for xchg");
extern void __cmpxchg_called_with_bad_pointer(void)
__compiletime_error("Bad argument size for cmpxchg");

#ifndef __tilegx__

/* Note the _atomic_xxx() routines include a final mb(). */
int _atomic_xchg(int *ptr, int n);
int _atomic_xchg_add(int *v, int i);
int _atomic_xchg_add_unless(int *v, int a, int u);
int _atomic_cmpxchg(int *ptr, int o, int n);
long long _atomic64_xchg(long long *v, long long n);
long long _atomic64_xchg_add(long long *v, long long i);
long long _atomic64_xchg_add_unless(long long *v, long long a, long long u);
long long _atomic64_cmpxchg(long long *v, long long o, long long n);

#define xchg(ptr, n) \
({ \
if (sizeof(*(ptr)) != 4) \
__xchg_called_with_bad_pointer(); \
smp_mb(); \
(typeof(*(ptr)))_atomic_xchg((int *)(ptr), (int)(n)); \
})

#define cmpxchg(ptr, o, n) \
({ \
if (sizeof(*(ptr)) != 4) \
__cmpxchg_called_with_bad_pointer(); \
smp_mb(); \
(typeof(*(ptr)))_atomic_cmpxchg((int *)ptr, (int)o, \
(int)n); \
})

#define xchg64(ptr, n) \
({ \
if (sizeof(*(ptr)) != 8) \
__xchg_called_with_bad_pointer(); \
smp_mb(); \
(typeof(*(ptr)))_atomic64_xchg((long long *)(ptr), \
(long long)(n)); \
})

#define cmpxchg64(ptr, o, n) \
({ \
if (sizeof(*(ptr)) != 8) \
__cmpxchg_called_with_bad_pointer(); \
smp_mb(); \
(typeof(*(ptr)))_atomic64_cmpxchg((long long *)ptr, \
(long long)o, (long long)n); \
})

#else

#define xchg(ptr, n) \
({ \
typeof(*(ptr)) __x; \
smp_mb(); \
switch (sizeof(*(ptr))) { \
case 4: \
__x = (typeof(__x))(unsigned long) \
__insn_exch4((ptr), \
(u32)(unsigned long)(n)); \
break; \
case 8: \
__x = (typeof(__x)) \
__insn_exch((ptr), (unsigned long)(n)); \
break; \
default: \
__xchg_called_with_bad_pointer(); \
break; \
} \
smp_mb(); \
__x; \
})

#define cmpxchg(ptr, o, n) \
({ \
typeof(*(ptr)) __x; \
__insn_mtspr(SPR_CMPEXCH_VALUE, (unsigned long)(o)); \
smp_mb(); \
switch (sizeof(*(ptr))) { \
case 4: \
__x = (typeof(__x))(unsigned long) \
__insn_cmpexch4((ptr), \
(u32)(unsigned long)(n)); \
break; \
case 8: \
__x = (typeof(__x))__insn_cmpexch((ptr), \
(long long)(n)); \
break; \
default: \
__cmpxchg_called_with_bad_pointer(); \
break; \
} \
smp_mb(); \
__x; \
})

#define xchg64 xchg
#define cmpxchg64 cmpxchg

#endif

#define tas(ptr) xchg((ptr), 1)

#endif /* __ASSEMBLY__ */

#endif /* _ASM_TILE_CMPXCHG_H */