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 */