xref: /openbmc/linux/arch/s390/include/asm/cmpxchg.h (revision a2818ee4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright IBM Corp. 1999, 2011
4  *
5  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
6  */
7 
8 #ifndef __ASM_CMPXCHG_H
9 #define __ASM_CMPXCHG_H
10 
11 #include <linux/mmdebug.h>
12 #include <linux/types.h>
13 #include <linux/bug.h>
14 
15 #define cmpxchg(ptr, o, n)						\
16 ({									\
17 	__typeof__(*(ptr)) __o = (o);					\
18 	__typeof__(*(ptr)) __n = (n);					\
19 	(__typeof__(*(ptr))) __sync_val_compare_and_swap((ptr),__o,__n);\
20 })
21 
22 #define cmpxchg64	cmpxchg
23 #define cmpxchg_local	cmpxchg
24 #define cmpxchg64_local	cmpxchg
25 
26 #define xchg(ptr, x)							\
27 ({									\
28 	__typeof__(ptr) __ptr = (ptr);					\
29 	__typeof__(*(ptr)) __old;					\
30 	do {								\
31 		__old = *__ptr;						\
32 	} while (!__sync_bool_compare_and_swap(__ptr, __old, x));	\
33 	__old;								\
34 })
35 
36 #define __cmpxchg_double(p1, p2, o1, o2, n1, n2)			\
37 ({									\
38 	register __typeof__(*(p1)) __old1 asm("2") = (o1);		\
39 	register __typeof__(*(p2)) __old2 asm("3") = (o2);		\
40 	register __typeof__(*(p1)) __new1 asm("4") = (n1);		\
41 	register __typeof__(*(p2)) __new2 asm("5") = (n2);		\
42 	int cc;								\
43 	asm volatile(							\
44 		"	cdsg	%[old],%[new],%[ptr]\n"			\
45 		"	ipm	%[cc]\n"				\
46 		"	srl	%[cc],28"				\
47 		: [cc] "=d" (cc), [old] "+d" (__old1), "+d" (__old2)	\
48 		: [new] "d" (__new1), "d" (__new2),			\
49 		  [ptr] "Q" (*(p1)), "Q" (*(p2))			\
50 		: "memory", "cc");					\
51 	!cc;								\
52 })
53 
54 #define cmpxchg_double(p1, p2, o1, o2, n1, n2)				\
55 ({									\
56 	__typeof__(p1) __p1 = (p1);					\
57 	__typeof__(p2) __p2 = (p2);					\
58 	BUILD_BUG_ON(sizeof(*(p1)) != sizeof(long));			\
59 	BUILD_BUG_ON(sizeof(*(p2)) != sizeof(long));			\
60 	VM_BUG_ON((unsigned long)((__p1) + 1) != (unsigned long)(__p2));\
61 	__cmpxchg_double(__p1, __p2, o1, o2, n1, n2);			\
62 })
63 
64 #define system_has_cmpxchg_double()	1
65 
66 #endif /* __ASM_CMPXCHG_H */
67