1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ARCH_M68K_CMPXCHG__
3#define __ARCH_M68K_CMPXCHG__
4
5#include <linux/irqflags.h>
6
7#define __xg(type, x) ((volatile type *)(x))
8
9extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
10
11#ifndef CONFIG_RMW_INSNS
12static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
13{
14	unsigned long flags, tmp;
15
16	local_irq_save(flags);
17
18	switch (size) {
19	case 1:
20		tmp = *(u8 *)ptr;
21		*(u8 *)ptr = x;
22		x = tmp;
23		break;
24	case 2:
25		tmp = *(u16 *)ptr;
26		*(u16 *)ptr = x;
27		x = tmp;
28		break;
29	case 4:
30		tmp = *(u32 *)ptr;
31		*(u32 *)ptr = x;
32		x = tmp;
33		break;
34	default:
35		tmp = __invalid_xchg_size(x, ptr, size);
36		break;
37	}
38
39	local_irq_restore(flags);
40	return x;
41}
42#else
43static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
44{
45	switch (size) {
46	case 1:
47		__asm__ __volatile__
48			("moveb %2,%0\n\t"
49			 "1:\n\t"
50			 "casb %0,%1,%2\n\t"
51			 "jne 1b"
52			 : "=&d" (x) : "d" (x), "m" (*__xg(u8, ptr)) : "memory");
53		break;
54	case 2:
55		__asm__ __volatile__
56			("movew %2,%0\n\t"
57			 "1:\n\t"
58			 "casw %0,%1,%2\n\t"
59			 "jne 1b"
60			 : "=&d" (x) : "d" (x), "m" (*__xg(u16, ptr)) : "memory");
61		break;
62	case 4:
63		__asm__ __volatile__
64			("movel %2,%0\n\t"
65			 "1:\n\t"
66			 "casl %0,%1,%2\n\t"
67			 "jne 1b"
68			 : "=&d" (x) : "d" (x), "m" (*__xg(u32, ptr)) : "memory");
69		break;
70	default:
71		x = __invalid_xchg_size(x, ptr, size);
72		break;
73	}
74	return x;
75}
76#endif
77
78#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
79
80#include <asm-generic/cmpxchg-local.h>
81
82#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
83
84extern unsigned long __invalid_cmpxchg_size(volatile void *,
85					    unsigned long, unsigned long, int);
86
87/*
88 * Atomic compare and exchange.  Compare OLD with MEM, if identical,
89 * store NEW in MEM.  Return the initial value in MEM.  Success is
90 * indicated by comparing RETURN with OLD.
91 */
92#ifdef CONFIG_RMW_INSNS
93
94static inline unsigned long __cmpxchg(volatile void *p, unsigned long old,
95				      unsigned long new, int size)
96{
97	switch (size) {
98	case 1:
99		__asm__ __volatile__ ("casb %0,%2,%1"
100				      : "=d" (old), "=m" (*(char *)p)
101				      : "d" (new), "0" (old), "m" (*(char *)p));
102		break;
103	case 2:
104		__asm__ __volatile__ ("casw %0,%2,%1"
105				      : "=d" (old), "=m" (*(short *)p)
106				      : "d" (new), "0" (old), "m" (*(short *)p));
107		break;
108	case 4:
109		__asm__ __volatile__ ("casl %0,%2,%1"
110				      : "=d" (old), "=m" (*(int *)p)
111				      : "d" (new), "0" (old), "m" (*(int *)p));
112		break;
113	default:
114		old = __invalid_cmpxchg_size(p, old, new, size);
115		break;
116	}
117	return old;
118}
119
120#define arch_cmpxchg(ptr, o, n)						    \
121	({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),	    \
122			(unsigned long)(n), sizeof(*(ptr)));})
123#define arch_cmpxchg_local(ptr, o, n)					    \
124	({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),	    \
125			(unsigned long)(n), sizeof(*(ptr)));})
126
127#define arch_cmpxchg64(ptr, o, n)	arch_cmpxchg64_local((ptr), (o), (n))
128
129#else
130
131#include <asm-generic/cmpxchg.h>
132
133#endif
134
135#endif /* __ARCH_M68K_CMPXCHG__ */
136