xref: /openbmc/linux/arch/openrisc/include/asm/atomic.h (revision cabce92d)
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 arch_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 arch_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 arch_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(add)
79 ATOMIC_OP(sub)
80 ATOMIC_OP(and)
81 ATOMIC_OP(or)
82 ATOMIC_OP(xor)
83 
84 #undef ATOMIC_FETCH_OP
85 #undef ATOMIC_OP_RETURN
86 #undef ATOMIC_OP
87 
88 #define arch_atomic_add_return	arch_atomic_add_return
89 #define arch_atomic_sub_return	arch_atomic_sub_return
90 #define arch_atomic_fetch_add	arch_atomic_fetch_add
91 #define arch_atomic_fetch_sub	arch_atomic_fetch_sub
92 #define arch_atomic_fetch_and	arch_atomic_fetch_and
93 #define arch_atomic_fetch_or	arch_atomic_fetch_or
94 #define arch_atomic_fetch_xor	arch_atomic_fetch_xor
95 #define arch_atomic_add		arch_atomic_add
96 #define arch_atomic_sub		arch_atomic_sub
97 #define arch_atomic_and		arch_atomic_and
98 #define arch_atomic_or		arch_atomic_or
99 #define arch_atomic_xor		arch_atomic_xor
100 
101 /*
102  * Atomically add a to v->counter as long as v is not already u.
103  * Returns the original value at v->counter.
104  *
105  * This is often used through atomic_inc_not_zero()
106  */
107 static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
108 {
109 	int old, tmp;
110 
111 	__asm__ __volatile__(
112 		"1:	l.lwa %0, 0(%2)		\n"
113 		"	l.sfeq %0, %4		\n"
114 		"	l.bf 2f			\n"
115 		"	 l.add %1, %0, %3	\n"
116 		"	l.swa 0(%2), %1		\n"
117 		"	l.bnf 1b		\n"
118 		"	 l.nop			\n"
119 		"2:				\n"
120 		: "=&r"(old), "=&r" (tmp)
121 		: "r"(&v->counter), "r"(a), "r"(u)
122 		: "cc", "memory");
123 
124 	return old;
125 }
126 #define arch_atomic_fetch_add_unless	arch_atomic_fetch_add_unless
127 
128 #define arch_atomic_read(v)		READ_ONCE((v)->counter)
129 #define arch_atomic_set(v,i)		WRITE_ONCE((v)->counter, (i))
130 
131 #include <asm/cmpxchg.h>
132 
133 #endif /* __ASM_OPENRISC_ATOMIC_H */
134