xref: /linux/arch/sh/include/asm/cmpxchg.h (revision 5ce42b5de461c3154f61a023b191dd6b77ee66c0)
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 #include <linux/cmpxchg-emu.h>
13 
14 #if defined(CONFIG_GUSA_RB)
15 #include <asm/cmpxchg-grb.h>
16 #elif defined(CONFIG_CPU_SH4A)
17 #include <asm/cmpxchg-llsc.h>
18 #elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
19 #include <asm/cmpxchg-cas.h>
20 #else
21 #include <asm/cmpxchg-irq.h>
22 #endif
23 
24 extern void __xchg_called_with_bad_pointer(void);
25 
26 #define __arch_xchg(ptr, x, size)				\
27 ({							\
28 	unsigned long __xchg__res;			\
29 	volatile void *__xchg_ptr = (ptr);		\
30 	switch (size) {					\
31 	case 4:						\
32 		__xchg__res = xchg_u32(__xchg_ptr, x);	\
33 		break;					\
34 	case 2:						\
35 		__xchg__res = xchg_u16(__xchg_ptr, x);	\
36 		break;					\
37 	case 1:						\
38 		__xchg__res = xchg_u8(__xchg_ptr, x);	\
39 		break;					\
40 	default:					\
41 		__xchg_called_with_bad_pointer();	\
42 		__xchg__res = x;			\
43 		break;					\
44 	}						\
45 							\
46 	__xchg__res;					\
47 })
48 
49 #define arch_xchg(ptr,x)	\
50 	((__typeof__(*(ptr)))__arch_xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
51 
52 /* This function doesn't exist, so you'll get a linker error
53  * if something tries to do an invalid cmpxchg(). */
54 extern void __cmpxchg_called_with_bad_pointer(void);
55 
56 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
57 		unsigned long new, int size)
58 {
59 	switch (size) {
60 	case 1:
61 		return cmpxchg_emu_u8(ptr, old, new);
62 	case 4:
63 		return __cmpxchg_u32(ptr, old, new);
64 	}
65 	__cmpxchg_called_with_bad_pointer();
66 	return old;
67 }
68 
69 #define arch_cmpxchg(ptr,o,n)						 \
70   ({									 \
71      __typeof__(*(ptr)) _o_ = (o);					 \
72      __typeof__(*(ptr)) _n_ = (n);					 \
73      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
74 				    (unsigned long)_n_, sizeof(*(ptr))); \
75   })
76 
77 #include <asm-generic/cmpxchg-local.h>
78 
79 #define arch_cmpxchg_local(ptr, o, n) ({				\
80 	(__typeof__(*ptr))__generic_cmpxchg_local((ptr),		\
81 						  (unsigned long)(o),	\
82 						  (unsigned long)(n),	\
83 						  sizeof(*(ptr)));	\
84 })
85 
86 #endif /* __ASM_SH_CMPXCHG_H */
87