1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_CMPXCHG_H
3 #define __ASM_SH_CMPXCHG_H
4
5 /*
6 * Atomic operations that C can't guarantee us. Useful for
7 * resource counting etc..
8 */
9
10 #include <linux/compiler.h>
11 #include <linux/types.h>
12
13 #if defined(CONFIG_GUSA_RB)
14 #include <asm/cmpxchg-grb.h>
15 #elif defined(CONFIG_CPU_SH4A)
16 #include <asm/cmpxchg-llsc.h>
17 #elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
18 #include <asm/cmpxchg-cas.h>
19 #else
20 #include <asm/cmpxchg-irq.h>
21 #endif
22
23 extern void __xchg_called_with_bad_pointer(void);
24
25 #define __xchg(ptr, x, size) \
26 ({ \
27 unsigned long __xchg__res; \
28 volatile void *__xchg_ptr = (ptr); \
29 switch (size) { \
30 case 4: \
31 __xchg__res = xchg_u32(__xchg_ptr, x); \
32 break; \
33 case 2: \
34 __xchg__res = xchg_u16(__xchg_ptr, x); \
35 break; \
36 case 1: \
37 __xchg__res = xchg_u8(__xchg_ptr, x); \
38 break; \
39 default: \
40 __xchg_called_with_bad_pointer(); \
41 __xchg__res = x; \
42 break; \
43 } \
44 \
45 __xchg__res; \
46 })
47
48 #define arch_xchg(ptr,x) \
49 ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
50
51 /* This function doesn't exist, so you'll get a linker error
52 * if something tries to do an invalid cmpxchg(). */
53 extern void __cmpxchg_called_with_bad_pointer(void);
54
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new,int size)55 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
56 unsigned long new, int size)
57 {
58 switch (size) {
59 case 4:
60 return __cmpxchg_u32(ptr, old, new);
61 }
62 __cmpxchg_called_with_bad_pointer();
63 return old;
64 }
65
66 #define arch_cmpxchg(ptr,o,n) \
67 ({ \
68 __typeof__(*(ptr)) _o_ = (o); \
69 __typeof__(*(ptr)) _n_ = (n); \
70 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
71 (unsigned long)_n_, sizeof(*(ptr))); \
72 })
73
74 #endif /* __ASM_SH_CMPXCHG_H */
75