1/*
  2 * cmpxchg.h -- forked from asm/atomic.h with this copyright:
  3 *
  4 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  5 *
  6 *   This program is free software; you can redistribute it and/or
  7 *   modify it under the terms of the GNU General Public License
  8 *   as published by the Free Software Foundation, version 2.
  9 *
 10 *   This program is distributed in the hope that it will be useful, but
 11 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 12 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 13 *   NON INFRINGEMENT.  See the GNU General Public License for
 14 *   more details.
 15 *
 16 */
 17
 18#ifndef _ASM_TILE_CMPXCHG_H
 19#define _ASM_TILE_CMPXCHG_H
 20
 21#ifndef __ASSEMBLY__
 22
 23#include <asm/barrier.h>
 24
 25/* Nonexistent functions intended to cause compile errors. */
 26extern void __xchg_called_with_bad_pointer(void)
 27	__compiletime_error("Bad argument size for xchg");
 28extern void __cmpxchg_called_with_bad_pointer(void)
 29	__compiletime_error("Bad argument size for cmpxchg");
 30
 31#ifndef __tilegx__
 32
 33/* Note the _atomic_xxx() routines include a final mb(). */
 34int _atomic_xchg(int *ptr, int n);
 35int _atomic_xchg_add(int *v, int i);
 36int _atomic_xchg_add_unless(int *v, int a, int u);
 37int _atomic_cmpxchg(int *ptr, int o, int n);
 38long long _atomic64_xchg(long long *v, long long n);
 39long long _atomic64_xchg_add(long long *v, long long i);
 40long long _atomic64_xchg_add_unless(long long *v, long long a, long long u);
 41long long _atomic64_cmpxchg(long long *v, long long o, long long n);
 42
 43#define xchg(ptr, n)							\
 44	({								\
 45		if (sizeof(*(ptr)) != 4)				\
 46			__xchg_called_with_bad_pointer();		\
 47		smp_mb();						\
 48		(typeof(*(ptr)))_atomic_xchg((int *)(ptr), (int)(n));	\
 49	})
 50
 51#define cmpxchg(ptr, o, n)						\
 52	({								\
 53		if (sizeof(*(ptr)) != 4)				\
 54			__cmpxchg_called_with_bad_pointer();		\
 55		smp_mb();						\
 56		(typeof(*(ptr)))_atomic_cmpxchg((int *)ptr, (int)o,	\
 57						(int)n);		\
 58	})
 59
 60#define xchg64(ptr, n)							\
 61	({								\
 62		if (sizeof(*(ptr)) != 8)				\
 63			__xchg_called_with_bad_pointer();		\
 64		smp_mb();						\
 65		(typeof(*(ptr)))_atomic64_xchg((long long *)(ptr),	\
 66						(long long)(n));	\
 67	})
 68
 69#define cmpxchg64(ptr, o, n)						\
 70	({								\
 71		if (sizeof(*(ptr)) != 8)				\
 72			__cmpxchg_called_with_bad_pointer();		\
 73		smp_mb();						\
 74		(typeof(*(ptr)))_atomic64_cmpxchg((long long *)ptr,	\
 75					(long long)o, (long long)n);	\
 76	})
 77
 78#else
 79
 80#define xchg(ptr, n)							\
 81	({								\
 82		typeof(*(ptr)) __x;					\
 83		smp_mb();						\
 84		switch (sizeof(*(ptr))) {				\
 85		case 4:							\
 86			__x = (typeof(__x))(unsigned long)		\
 87				__insn_exch4((ptr),			\
 88					(u32)(unsigned long)(n));	\
 89			break;						\
 90		case 8:							\
 91			__x = (typeof(__x))				\
 92				__insn_exch((ptr), (unsigned long)(n));	\
 93			break;						\
 94		default:						\
 95			__xchg_called_with_bad_pointer();		\
 96			break;						\
 97		}							\
 98		smp_mb();						\
 99		__x;							\
100	})
101
102#define cmpxchg(ptr, o, n)						\
103	({								\
104		typeof(*(ptr)) __x;					\
105		__insn_mtspr(SPR_CMPEXCH_VALUE, (unsigned long)(o));	\
106		smp_mb();						\
107		switch (sizeof(*(ptr))) {				\
108		case 4:							\
109			__x = (typeof(__x))(unsigned long)		\
110				__insn_cmpexch4((ptr),			\
111					(u32)(unsigned long)(n));	\
112			break;						\
113		case 8:							\
114			__x = (typeof(__x))__insn_cmpexch((ptr),	\
115						(long long)(n));	\
116			break;						\
117		default:						\
118			__cmpxchg_called_with_bad_pointer();		\
119			break;						\
120		}							\
121		smp_mb();						\
122		__x;							\
123	})
124
125#define xchg64 xchg
126#define cmpxchg64 cmpxchg
127
128#endif
129
130#endif /* __ASSEMBLY__ */
131
132#endif /* _ASM_TILE_CMPXCHG_H */