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/* Nonexistent functions intended to cause link errors. */
24extern unsigned long __xchg_called_with_bad_pointer(void);
25extern unsigned long __cmpxchg_called_with_bad_pointer(void);
26
27#define xchg(ptr, x)							\
28	({								\
29		typeof(*(ptr)) __x;					\
30		switch (sizeof(*(ptr))) {				\
31		case 4:							\
32			__x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \
33				(atomic_t *)(ptr),			\
34				(u32)(typeof((x)-(x)))(x));		\
35			break;						\
36		case 8:							\
37			__x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \
38				(atomic64_t *)(ptr),			\
39				(u64)(typeof((x)-(x)))(x));		\
40			break;						\
41		default:						\
42			__xchg_called_with_bad_pointer();		\
43		}							\
44		__x;							\
45	})
46
47#define cmpxchg(ptr, o, n)						\
48	({								\
49		typeof(*(ptr)) __x;					\
50		switch (sizeof(*(ptr))) {				\
51		case 4:							\
52			__x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \
53				(atomic_t *)(ptr),			\
54				(u32)(typeof((o)-(o)))(o),		\
55				(u32)(typeof((n)-(n)))(n));		\
56			break;						\
57		case 8:							\
58			__x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \
59				(atomic64_t *)(ptr),			\
60				(u64)(typeof((o)-(o)))(o),		\
61				(u64)(typeof((n)-(n)))(n));		\
62			break;						\
63		default:						\
64			__cmpxchg_called_with_bad_pointer();		\
65		}							\
66		__x;							\
67	})
68
69#define tas(ptr) (xchg((ptr), 1))
70
71#endif /* __ASSEMBLY__ */
72
73#endif /* _ASM_TILE_CMPXCHG_H */