xref: /openbmc/linux/arch/openrisc/include/asm/atomic.h (revision 09c434b8)
1 /*
2  * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
3  *
4  * This file is licensed under the terms of the GNU General Public License
5  * version 2.  This program is licensed "as is" without any warranty of any
6  * kind, whether express or implied.
7  */
8 
9 #ifndef __ASM_OPENRISC_ATOMIC_H
10 #define __ASM_OPENRISC_ATOMIC_H
11 
12 #include <linux/types.h>
13 
14 /* Atomically perform op with v->counter and i */
15 #define ATOMIC_OP(op)							\
16 static inline void atomic_##op(int i, atomic_t *v)			\
17 {									\
18 	int tmp;							\
19 									\
20 	__asm__ __volatile__(						\
21 		"1:	l.lwa	%0,0(%1)	\n"			\
22 		"	l." #op " %0,%0,%2	\n"			\
23 		"	l.swa	0(%1),%0	\n"			\
24 		"	l.bnf	1b		\n"			\
25 		"	 l.nop			\n"			\
26 		: "=&r"(tmp)						\
27 		: "r"(&v->counter), "r"(i)				\
28 		: "cc", "memory");					\
29 }
30 
31 /* Atomically perform op with v->counter and i, return the result */
32 #define ATOMIC_OP_RETURN(op)						\
33 static inline int atomic_##op##_return(int i, atomic_t *v)		\
34 {									\
35 	int tmp;							\
36 									\
37 	__asm__ __volatile__(						\
38 		"1:	l.lwa	%0,0(%1)	\n"			\
39 		"	l." #op " %0,%0,%2	\n"			\
40 		"	l.swa	0(%1),%0	\n"			\
41 		"	l.bnf	1b		\n"			\
42 		"	 l.nop			\n"			\
43 		: "=&r"(tmp)						\
44 		: "r"(&v->counter), "r"(i)				\
45 		: "cc", "memory");					\
46 									\
47 	return tmp;							\
48 }
49 
50 /* Atomically perform op with v->counter and i, return orig v->counter */
51 #define ATOMIC_FETCH_OP(op)						\
52 static inline int atomic_fetch_##op(int i, atomic_t *v)			\
53 {									\
54 	int tmp, old;							\
55 									\
56 	__asm__ __volatile__(						\
57 		"1:	l.lwa	%0,0(%2)	\n"			\
58 		"	l." #op " %1,%0,%3	\n"			\
59 		"	l.swa	0(%2),%1	\n"			\
60 		"	l.bnf	1b		\n"			\
61 		"	 l.nop			\n"			\
62 		: "=&r"(old), "=&r"(tmp)				\
63 		: "r"(&v->counter), "r"(i)				\
64 		: "cc", "memory");					\
65 									\
66 	return old;							\
67 }
68 
69 ATOMIC_OP_RETURN(add)
70 ATOMIC_OP_RETURN(sub)
71 
72 ATOMIC_FETCH_OP(add)
73 ATOMIC_FETCH_OP(sub)
74 ATOMIC_FETCH_OP(and)
75 ATOMIC_FETCH_OP(or)
76 ATOMIC_FETCH_OP(xor)
77 
78 ATOMIC_OP(and)
79 ATOMIC_OP(or)
80 ATOMIC_OP(xor)
81 
82 #undef ATOMIC_FETCH_OP
83 #undef ATOMIC_OP_RETURN
84 #undef ATOMIC_OP
85 
86 #define atomic_add_return	atomic_add_return
87 #define atomic_sub_return	atomic_sub_return
88 #define atomic_fetch_add	atomic_fetch_add
89 #define atomic_fetch_sub	atomic_fetch_sub
90 #define atomic_fetch_and	atomic_fetch_and
91 #define atomic_fetch_or		atomic_fetch_or
92 #define atomic_fetch_xor	atomic_fetch_xor
93 #define atomic_and	atomic_and
94 #define atomic_or	atomic_or
95 #define atomic_xor	atomic_xor
96 
97 /*
98  * Atomically add a to v->counter as long as v is not already u.
99  * Returns the original value at v->counter.
100  *
101  * This is often used through atomic_inc_not_zero()
102  */
103 static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
104 {
105 	int old, tmp;
106 
107 	__asm__ __volatile__(
108 		"1:	l.lwa %0, 0(%2)		\n"
109 		"	l.sfeq %0, %4		\n"
110 		"	l.bf 2f			\n"
111 		"	 l.add %1, %0, %3	\n"
112 		"	l.swa 0(%2), %1		\n"
113 		"	l.bnf 1b		\n"
114 		"	 l.nop			\n"
115 		"2:				\n"
116 		: "=&r"(old), "=&r" (tmp)
117 		: "r"(&v->counter), "r"(a), "r"(u)
118 		: "cc", "memory");
119 
120 	return old;
121 }
122 #define atomic_fetch_add_unless	atomic_fetch_add_unless
123 
124 #include <asm-generic/atomic.h>
125 
126 #endif /* __ASM_OPENRISC_ATOMIC_H */
127