1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef __ASM_CSKY_CMPXCHG_H
4#define __ASM_CSKY_CMPXCHG_H
5
6#ifdef CONFIG_CPU_HAS_LDSTEX
7#include <asm/barrier.h>
8
9extern void __bad_xchg(void);
10
11#define __xchg(new, ptr, size)					\
12({								\
13	__typeof__(ptr) __ptr = (ptr);				\
14	__typeof__(new) __new = (new);				\
15	__typeof__(*(ptr)) __ret;				\
16	unsigned long tmp;					\
17	switch (size) {						\
18	case 4:							\
19		smp_mb();					\
20		asm volatile (					\
21		"1:	ldex.w		%0, (%3) \n"		\
22		"	mov		%1, %2   \n"		\
23		"	stex.w		%1, (%3) \n"		\
24		"	bez		%1, 1b   \n"		\
25			: "=&r" (__ret), "=&r" (tmp)		\
26			: "r" (__new), "r"(__ptr)		\
27			:);					\
28		smp_mb();					\
29		break;						\
30	default:						\
31		__bad_xchg();					\
32	}							\
33	__ret;							\
34})
35
36#define xchg(ptr, x)	(__xchg((x), (ptr), sizeof(*(ptr))))
37
38#define __cmpxchg(ptr, old, new, size)				\
39({								\
40	__typeof__(ptr) __ptr = (ptr);				\
41	__typeof__(new) __new = (new);				\
42	__typeof__(new) __tmp;					\
43	__typeof__(old) __old = (old);				\
44	__typeof__(*(ptr)) __ret;				\
45	switch (size) {						\
46	case 4:							\
47		smp_mb();					\
48		asm volatile (					\
49		"1:	ldex.w		%0, (%3) \n"		\
50		"	cmpne		%0, %4   \n"		\
51		"	bt		2f       \n"		\
52		"	mov		%1, %2   \n"		\
53		"	stex.w		%1, (%3) \n"		\
54		"	bez		%1, 1b   \n"		\
55		"2:				 \n"		\
56			: "=&r" (__ret), "=&r" (__tmp)		\
57			: "r" (__new), "r"(__ptr), "r"(__old)	\
58			:);					\
59		smp_mb();					\
60		break;						\
61	default:						\
62		__bad_xchg();					\
63	}							\
64	__ret;							\
65})
66
67#define cmpxchg(ptr, o, n) \
68	(__cmpxchg((ptr), (o), (n), sizeof(*(ptr))))
69#else
70#include <asm-generic/cmpxchg.h>
71#endif
72
73#endif /* __ASM_CSKY_CMPXCHG_H */
74