1#ifndef _ASM_IA64_CMPXCHG_H
2#define _ASM_IA64_CMPXCHG_H
3
4/*
5 * Compare/Exchange, forked from asm/intrinsics.h
6 * which was:
7 *
8 *	Copyright (C) 2002-2003 Hewlett-Packard Co
9 *	David Mosberger-Tang <davidm@hpl.hp.com>
10 */
11
12#ifndef __ASSEMBLY__
13
14#include <linux/types.h>
15/* include compiler specific intrinsics */
16#include <asm/ia64regs.h>
17#ifdef __INTEL_COMPILER
18# include <asm/intel_intrin.h>
19#else
20# include <asm/gcc_intrin.h>
21#endif
22
23/*
24 * This function doesn't exist, so you'll get a linker error if
25 * something tries to do an invalid xchg().
26 */
27extern void ia64_xchg_called_with_bad_pointer(void);
28
29#define __xchg(x, ptr, size)						\
30({									\
31	unsigned long __xchg_result;					\
32									\
33	switch (size) {							\
34	case 1:								\
35		__xchg_result = ia64_xchg1((__u8 *)ptr, x);		\
36		break;							\
37									\
38	case 2:								\
39		__xchg_result = ia64_xchg2((__u16 *)ptr, x);		\
40		break;							\
41									\
42	case 4:								\
43		__xchg_result = ia64_xchg4((__u32 *)ptr, x);		\
44		break;							\
45									\
46	case 8:								\
47		__xchg_result = ia64_xchg8((__u64 *)ptr, x);		\
48		break;							\
49	default:							\
50		ia64_xchg_called_with_bad_pointer();			\
51	}								\
52	__xchg_result;							\
53})
54
55#define xchg(ptr, x)							\
56((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr))))
57
58/*
59 * Atomic compare and exchange.  Compare OLD with MEM, if identical,
60 * store NEW in MEM.  Return the initial value in MEM.  Success is
61 * indicated by comparing RETURN with OLD.
62 */
63
64#define __HAVE_ARCH_CMPXCHG 1
65
66/*
67 * This function doesn't exist, so you'll get a linker error
68 * if something tries to do an invalid cmpxchg().
69 */
70extern long ia64_cmpxchg_called_with_bad_pointer(void);
71
72#define ia64_cmpxchg(sem, ptr, old, new, size)				\
73({									\
74	__u64 _o_, _r_;							\
75									\
76	switch (size) {							\
77	case 1:								\
78		_o_ = (__u8) (long) (old);				\
79		break;							\
80	case 2:								\
81		_o_ = (__u16) (long) (old);				\
82		break;							\
83	case 4:								\
84		_o_ = (__u32) (long) (old);				\
85		break;							\
86	case 8:								\
87		_o_ = (__u64) (long) (old);				\
88		break;							\
89	default:							\
90		break;							\
91	}								\
92	switch (size) {							\
93	case 1:								\
94		_r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_);	\
95		break;							\
96									\
97	case 2:								\
98		_r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_);	\
99		break;							\
100									\
101	case 4:								\
102		_r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_);	\
103		break;							\
104									\
105	case 8:								\
106		_r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_);	\
107		break;							\
108									\
109	default:							\
110		_r_ = ia64_cmpxchg_called_with_bad_pointer();		\
111		break;							\
112	}								\
113	(__typeof__(old)) _r_;						\
114})
115
116#define cmpxchg_acq(ptr, o, n)	\
117	ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
118#define cmpxchg_rel(ptr, o, n)	\
119	ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
120
121/*
122 * Worse still - early processor implementations actually just ignored
123 * the acquire/release and did a full fence all the time.  Unfortunately
124 * this meant a lot of badly written code that used .acq when they really
125 * wanted .rel became legacy out in the wild - so when we made a cpu
126 * that strictly did the .acq or .rel ... all that code started breaking - so
127 * we had to back-pedal and keep the "legacy" behavior of a full fence :-(
128 */
129
130/* for compatibility with other platforms: */
131#define cmpxchg(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))
132#define cmpxchg64(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))
133
134#define cmpxchg_local		cmpxchg
135#define cmpxchg64_local		cmpxchg64
136
137#ifdef CONFIG_IA64_DEBUG_CMPXCHG
138# define CMPXCHG_BUGCHECK_DECL	int _cmpxchg_bugcheck_count = 128;
139# define CMPXCHG_BUGCHECK(v)						\
140do {									\
141	if (_cmpxchg_bugcheck_count-- <= 0) {				\
142		void *ip;						\
143		extern int printk(const char *fmt, ...);		\
144		ip = (void *) ia64_getreg(_IA64_REG_IP);		\
145		printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
146		break;							\
147	}								\
148} while (0)
149#else /* !CONFIG_IA64_DEBUG_CMPXCHG */
150# define CMPXCHG_BUGCHECK_DECL
151# define CMPXCHG_BUGCHECK(v)
152#endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
153
154#endif /* !__ASSEMBLY__ */
155
156#endif /* _ASM_IA64_CMPXCHG_H */
157