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
9 extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
10
11 #ifndef CONFIG_RMW_INSNS
12 static 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 x = __invalid_xchg_size(x, ptr, size);
36 break;
37 }
38
39 local_irq_restore(flags);
40 return x;
41 }
42 #else
43 static 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
84 extern 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
94 static 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), "" (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), "" (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), "" (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
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