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  */
27 extern 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  */
70 extern 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 /* for compatibility with other platforms: */
122 #define cmpxchg(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))
123 #define cmpxchg64(ptr, o, n)	cmpxchg_acq((ptr), (o), (n))
124 
125 #define cmpxchg_local		cmpxchg
126 #define cmpxchg64_local		cmpxchg64
127 
128 #ifdef CONFIG_IA64_DEBUG_CMPXCHG
129 # define CMPXCHG_BUGCHECK_DECL	int _cmpxchg_bugcheck_count = 128;
130 # define CMPXCHG_BUGCHECK(v)						\
131 do {									\
132 	if (_cmpxchg_bugcheck_count-- <= 0) {				\
133 		void *ip;						\
134 		extern int printk(const char *fmt, ...);		\
135 		ip = (void *) ia64_getreg(_IA64_REG_IP);		\
136 		printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
137 		break;							\
138 	}								\
139 } while (0)
140 #else /* !CONFIG_IA64_DEBUG_CMPXCHG */
141 # define CMPXCHG_BUGCHECK_DECL
142 # define CMPXCHG_BUGCHECK(v)
143 #endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
144 
145 #endif /* !__ASSEMBLY__ */
146 
147 #endif /* _ASM_IA64_CMPXCHG_H */
148