xref: /openbmc/linux/arch/sh/include/asm/atomic-llsc.h (revision 4f6cce39)
1 #ifndef __ASM_SH_ATOMIC_LLSC_H
2 #define __ASM_SH_ATOMIC_LLSC_H
3 
4 /*
5  * SH-4A note:
6  *
7  * We basically get atomic_xxx_return() for free compared with
8  * atomic_xxx(). movli.l/movco.l require r0 due to the instruction
9  * encoding, so the retval is automatically set without having to
10  * do any special work.
11  */
12 /*
13  * To get proper branch prediction for the main line, we must branch
14  * forward to code at the end of this object's .text section, then
15  * branch back to restart the operation.
16  */
17 
18 #define ATOMIC_OP(op)							\
19 static inline void atomic_##op(int i, atomic_t *v)			\
20 {									\
21 	unsigned long tmp;						\
22 									\
23 	__asm__ __volatile__ (						\
24 "1:	movli.l @%2, %0		! atomic_" #op "\n"			\
25 "	" #op "	%1, %0				\n"			\
26 "	movco.l	%0, @%2				\n"			\
27 "	bf	1b				\n"			\
28 	: "=&z" (tmp)							\
29 	: "r" (i), "r" (&v->counter)					\
30 	: "t");								\
31 }
32 
33 #define ATOMIC_OP_RETURN(op)						\
34 static inline int atomic_##op##_return(int i, atomic_t *v)		\
35 {									\
36 	unsigned long temp;						\
37 									\
38 	__asm__ __volatile__ (						\
39 "1:	movli.l @%2, %0		! atomic_" #op "_return	\n"		\
40 "	" #op "	%1, %0					\n"		\
41 "	movco.l	%0, @%2					\n"		\
42 "	bf	1b					\n"		\
43 "	synco						\n"		\
44 	: "=&z" (temp)							\
45 	: "r" (i), "r" (&v->counter)					\
46 	: "t");								\
47 									\
48 	return temp;							\
49 }
50 
51 #define ATOMIC_FETCH_OP(op)						\
52 static inline int atomic_fetch_##op(int i, atomic_t *v)			\
53 {									\
54 	unsigned long res, temp;					\
55 									\
56 	__asm__ __volatile__ (						\
57 "1:	movli.l @%3, %0		! atomic_fetch_" #op "	\n"		\
58 "	mov %0, %1					\n"		\
59 "	" #op "	%2, %0					\n"		\
60 "	movco.l	%0, @%3					\n"		\
61 "	bf	1b					\n"		\
62 "	synco						\n"		\
63 	: "=&z" (temp), "=&r" (res)					\
64 	: "r" (i), "r" (&v->counter)					\
65 	: "t");								\
66 									\
67 	return res;							\
68 }
69 
70 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
71 
72 ATOMIC_OPS(add)
73 ATOMIC_OPS(sub)
74 
75 #undef ATOMIC_OPS
76 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
77 
78 ATOMIC_OPS(and)
79 ATOMIC_OPS(or)
80 ATOMIC_OPS(xor)
81 
82 #undef ATOMIC_OPS
83 #undef ATOMIC_FETCH_OP
84 #undef ATOMIC_OP_RETURN
85 #undef ATOMIC_OP
86 
87 #endif /* __ASM_SH_ATOMIC_LLSC_H */
88