blob: 85938711542d89182369105c670ca785ad3f3fb9 [file] [log] [blame]
Ley Foon Tan97da0d62014-11-06 15:20:09 +08001/*
2 * Copyright (C) 2004 Microtronix Datacom Ltd.
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 */
8
9#ifndef _ASM_NIOS2_CMPXCHG_H
10#define _ASM_NIOS2_CMPXCHG_H
11
12#include <linux/irqflags.h>
13
14#define xchg(ptr, x) \
15 ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
16
17struct __xchg_dummy { unsigned long a[100]; };
18#define __xg(x) ((volatile struct __xchg_dummy *)(x))
19
20static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
21 int size)
22{
23 unsigned long tmp, flags;
24
25 local_irq_save(flags);
26
27 switch (size) {
28 case 1:
29 __asm__ __volatile__(
30 "ldb %0, %2\n"
31 "stb %1, %2\n"
32 : "=&r" (tmp)
33 : "r" (x), "m" (*__xg(ptr))
34 : "memory");
35 break;
36 case 2:
37 __asm__ __volatile__(
38 "ldh %0, %2\n"
39 "sth %1, %2\n"
40 : "=&r" (tmp)
41 : "r" (x), "m" (*__xg(ptr))
42 : "memory");
43 break;
44 case 4:
45 __asm__ __volatile__(
46 "ldw %0, %2\n"
47 "stw %1, %2\n"
48 : "=&r" (tmp)
49 : "r" (x), "m" (*__xg(ptr))
50 : "memory");
51 break;
52 }
53
54 local_irq_restore(flags);
55 return tmp;
56}
57
58#include <asm-generic/cmpxchg.h>
59#include <asm-generic/cmpxchg-local.h>
60
61#endif /* _ASM_NIOS2_CMPXCHG_H */