1/*
2 * Copyright IBM Corp. 1999, 2011
3 *
4 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
5 */
6
7#ifndef __ASM_CMPXCHG_H
8#define __ASM_CMPXCHG_H
9
10#include <linux/mmdebug.h>
11#include <linux/types.h>
12#include <linux/bug.h>
13
14#define cmpxchg(ptr, o, n)						\
15({									\
16	__typeof__(*(ptr)) __o = (o);					\
17	__typeof__(*(ptr)) __n = (n);					\
18	(__typeof__(*(ptr))) __sync_val_compare_and_swap((ptr),__o,__n);\
19})
20
21#define cmpxchg64	cmpxchg
22#define cmpxchg_local	cmpxchg
23#define cmpxchg64_local	cmpxchg
24
25#define xchg(ptr, x)							\
26({									\
27	__typeof__(ptr) __ptr = (ptr);					\
28	__typeof__(*(ptr)) __old;					\
29	do {								\
30		__old = *__ptr;						\
31	} while (!__sync_bool_compare_and_swap(__ptr, __old, x));	\
32	__old;								\
33})
34
35#define __HAVE_ARCH_CMPXCHG
36
37#define __cmpxchg_double_op(p1, p2, o1, o2, n1, n2, insn)		\
38({									\
39	register __typeof__(*(p1)) __old1 asm("2") = (o1);		\
40	register __typeof__(*(p2)) __old2 asm("3") = (o2);		\
41	register __typeof__(*(p1)) __new1 asm("4") = (n1);		\
42	register __typeof__(*(p2)) __new2 asm("5") = (n2);		\
43	int cc;								\
44	asm volatile(							\
45			insn   " %[old],%[new],%[ptr]\n"		\
46		"	ipm	%[cc]\n"				\
47		"	srl	%[cc],28"				\
48		: [cc] "=d" (cc), [old] "+d" (__old1), "+d" (__old2)	\
49		: [new] "d" (__new1), "d" (__new2),			\
50		  [ptr] "Q" (*(p1)), "Q" (*(p2))			\
51		: "memory", "cc");					\
52	!cc;								\
53})
54
55#define __cmpxchg_double_4(p1, p2, o1, o2, n1, n2) \
56	__cmpxchg_double_op(p1, p2, o1, o2, n1, n2, "cds")
57
58#define __cmpxchg_double_8(p1, p2, o1, o2, n1, n2) \
59	__cmpxchg_double_op(p1, p2, o1, o2, n1, n2, "cdsg")
60
61extern void __cmpxchg_double_called_with_bad_pointer(void);
62
63#define __cmpxchg_double(p1, p2, o1, o2, n1, n2)			\
64({									\
65	int __ret;							\
66	switch (sizeof(*(p1))) {					\
67	case 4:								\
68		__ret = __cmpxchg_double_4(p1, p2, o1, o2, n1, n2);	\
69		break;							\
70	case 8:								\
71		__ret = __cmpxchg_double_8(p1, p2, o1, o2, n1, n2);	\
72		break;							\
73	default:							\
74		__cmpxchg_double_called_with_bad_pointer();		\
75	}								\
76	__ret;								\
77})
78
79#define cmpxchg_double(p1, p2, o1, o2, n1, n2)				\
80({									\
81	__typeof__(p1) __p1 = (p1);					\
82	__typeof__(p2) __p2 = (p2);					\
83	BUILD_BUG_ON(sizeof(*(p1)) != sizeof(long));			\
84	BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long));			\
85	VM_BUG_ON((unsigned long)((__p1) + 1) != (unsigned long)(__p2));\
86	__cmpxchg_double_8(__p1, __p2, o1, o2, n1, n2);			\
87})
88
89#define system_has_cmpxchg_double()	1
90
91#endif /* __ASM_CMPXCHG_H */
92