xref: /OK3568_Linux_fs/kernel/arch/m68k/include/asm/cmpxchg.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef __ARCH_M68K_CMPXCHG__
3*4882a593Smuzhiyun #define __ARCH_M68K_CMPXCHG__
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #include <linux/irqflags.h>
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun struct __xchg_dummy { unsigned long a[100]; };
8*4882a593Smuzhiyun #define __xg(x) ((volatile struct __xchg_dummy *)(x))
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
11*4882a593Smuzhiyun 
12*4882a593Smuzhiyun #ifndef CONFIG_RMW_INSNS
__xchg(unsigned long x,volatile void * ptr,int size)13*4882a593Smuzhiyun static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun 	unsigned long flags, tmp;
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun 	local_irq_save(flags);
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun 	switch (size) {
20*4882a593Smuzhiyun 	case 1:
21*4882a593Smuzhiyun 		tmp = *(u8 *)ptr;
22*4882a593Smuzhiyun 		*(u8 *)ptr = x;
23*4882a593Smuzhiyun 		x = tmp;
24*4882a593Smuzhiyun 		break;
25*4882a593Smuzhiyun 	case 2:
26*4882a593Smuzhiyun 		tmp = *(u16 *)ptr;
27*4882a593Smuzhiyun 		*(u16 *)ptr = x;
28*4882a593Smuzhiyun 		x = tmp;
29*4882a593Smuzhiyun 		break;
30*4882a593Smuzhiyun 	case 4:
31*4882a593Smuzhiyun 		tmp = *(u32 *)ptr;
32*4882a593Smuzhiyun 		*(u32 *)ptr = x;
33*4882a593Smuzhiyun 		x = tmp;
34*4882a593Smuzhiyun 		break;
35*4882a593Smuzhiyun 	default:
36*4882a593Smuzhiyun 		tmp = __invalid_xchg_size(x, ptr, size);
37*4882a593Smuzhiyun 		break;
38*4882a593Smuzhiyun 	}
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	local_irq_restore(flags);
41*4882a593Smuzhiyun 	return x;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun #else
__xchg(unsigned long x,volatile void * ptr,int size)44*4882a593Smuzhiyun static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun 	switch (size) {
47*4882a593Smuzhiyun 	case 1:
48*4882a593Smuzhiyun 		__asm__ __volatile__
49*4882a593Smuzhiyun 			("moveb %2,%0\n\t"
50*4882a593Smuzhiyun 			 "1:\n\t"
51*4882a593Smuzhiyun 			 "casb %0,%1,%2\n\t"
52*4882a593Smuzhiyun 			 "jne 1b"
53*4882a593Smuzhiyun 			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
54*4882a593Smuzhiyun 		break;
55*4882a593Smuzhiyun 	case 2:
56*4882a593Smuzhiyun 		__asm__ __volatile__
57*4882a593Smuzhiyun 			("movew %2,%0\n\t"
58*4882a593Smuzhiyun 			 "1:\n\t"
59*4882a593Smuzhiyun 			 "casw %0,%1,%2\n\t"
60*4882a593Smuzhiyun 			 "jne 1b"
61*4882a593Smuzhiyun 			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
62*4882a593Smuzhiyun 		break;
63*4882a593Smuzhiyun 	case 4:
64*4882a593Smuzhiyun 		__asm__ __volatile__
65*4882a593Smuzhiyun 			("movel %2,%0\n\t"
66*4882a593Smuzhiyun 			 "1:\n\t"
67*4882a593Smuzhiyun 			 "casl %0,%1,%2\n\t"
68*4882a593Smuzhiyun 			 "jne 1b"
69*4882a593Smuzhiyun 			 : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
70*4882a593Smuzhiyun 		break;
71*4882a593Smuzhiyun 	default:
72*4882a593Smuzhiyun 		x = __invalid_xchg_size(x, ptr, size);
73*4882a593Smuzhiyun 		break;
74*4882a593Smuzhiyun 	}
75*4882a593Smuzhiyun 	return x;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun #endif
78*4882a593Smuzhiyun 
79*4882a593Smuzhiyun #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun #include <asm-generic/cmpxchg-local.h>
82*4882a593Smuzhiyun 
83*4882a593Smuzhiyun #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
84*4882a593Smuzhiyun 
85*4882a593Smuzhiyun extern unsigned long __invalid_cmpxchg_size(volatile void *,
86*4882a593Smuzhiyun 					    unsigned long, unsigned long, int);
87*4882a593Smuzhiyun 
88*4882a593Smuzhiyun /*
89*4882a593Smuzhiyun  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
90*4882a593Smuzhiyun  * store NEW in MEM.  Return the initial value in MEM.  Success is
91*4882a593Smuzhiyun  * indicated by comparing RETURN with OLD.
92*4882a593Smuzhiyun  */
93*4882a593Smuzhiyun #ifdef CONFIG_RMW_INSNS
94*4882a593Smuzhiyun 
__cmpxchg(volatile void * p,unsigned long old,unsigned long new,int size)95*4882a593Smuzhiyun static inline unsigned long __cmpxchg(volatile void *p, unsigned long old,
96*4882a593Smuzhiyun 				      unsigned long new, int size)
97*4882a593Smuzhiyun {
98*4882a593Smuzhiyun 	switch (size) {
99*4882a593Smuzhiyun 	case 1:
100*4882a593Smuzhiyun 		__asm__ __volatile__ ("casb %0,%2,%1"
101*4882a593Smuzhiyun 				      : "=d" (old), "=m" (*(char *)p)
102*4882a593Smuzhiyun 				      : "d" (new), "0" (old), "m" (*(char *)p));
103*4882a593Smuzhiyun 		break;
104*4882a593Smuzhiyun 	case 2:
105*4882a593Smuzhiyun 		__asm__ __volatile__ ("casw %0,%2,%1"
106*4882a593Smuzhiyun 				      : "=d" (old), "=m" (*(short *)p)
107*4882a593Smuzhiyun 				      : "d" (new), "0" (old), "m" (*(short *)p));
108*4882a593Smuzhiyun 		break;
109*4882a593Smuzhiyun 	case 4:
110*4882a593Smuzhiyun 		__asm__ __volatile__ ("casl %0,%2,%1"
111*4882a593Smuzhiyun 				      : "=d" (old), "=m" (*(int *)p)
112*4882a593Smuzhiyun 				      : "d" (new), "0" (old), "m" (*(int *)p));
113*4882a593Smuzhiyun 		break;
114*4882a593Smuzhiyun 	default:
115*4882a593Smuzhiyun 		old = __invalid_cmpxchg_size(p, old, new, size);
116*4882a593Smuzhiyun 		break;
117*4882a593Smuzhiyun 	}
118*4882a593Smuzhiyun 	return old;
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun 
121*4882a593Smuzhiyun #define cmpxchg(ptr, o, n)						    \
122*4882a593Smuzhiyun 	((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),	    \
123*4882a593Smuzhiyun 			(unsigned long)(n), sizeof(*(ptr))))
124*4882a593Smuzhiyun #define cmpxchg_local(ptr, o, n)					    \
125*4882a593Smuzhiyun 	((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),	    \
126*4882a593Smuzhiyun 			(unsigned long)(n), sizeof(*(ptr))))
127*4882a593Smuzhiyun 
128*4882a593Smuzhiyun #define cmpxchg64(ptr, o, n)	cmpxchg64_local((ptr), (o), (n))
129*4882a593Smuzhiyun 
130*4882a593Smuzhiyun #else
131*4882a593Smuzhiyun 
132*4882a593Smuzhiyun #include <asm-generic/cmpxchg.h>
133*4882a593Smuzhiyun 
134*4882a593Smuzhiyun #endif
135*4882a593Smuzhiyun 
136*4882a593Smuzhiyun #endif /* __ARCH_M68K_CMPXCHG__ */
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