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