xref: /linux/include/asm-generic/atomic64.h (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Generic implementation of 64-bit atomics using spinlocks,
4  * useful on processors that don't have 64-bit atomic instructions.
5  *
6  * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
7  */
8 #ifndef _ASM_GENERIC_ATOMIC64_H
9 #define _ASM_GENERIC_ATOMIC64_H
10 #include <linux/types.h>
11 
12 typedef struct {
13 	s64 counter;
14 } atomic64_t;
15 
16 #define ATOMIC64_INIT(i)	{ (i) }
17 
18 extern s64 atomic64_read(const atomic64_t *v);
19 extern void atomic64_set(atomic64_t *v, s64 i);
20 
21 #define atomic64_set_release(v, i)	atomic64_set((v), (i))
22 
23 #define ATOMIC64_OP(op)							\
24 extern void	 atomic64_##op(s64 a, atomic64_t *v);
25 
26 #define ATOMIC64_OP_RETURN(op)						\
27 extern s64 atomic64_##op##_return(s64 a, atomic64_t *v);
28 
29 #define ATOMIC64_FETCH_OP(op)						\
30 extern s64 atomic64_fetch_##op(s64 a, atomic64_t *v);
31 
32 #define ATOMIC64_OPS(op)	ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op)
33 
34 ATOMIC64_OPS(add)
35 ATOMIC64_OPS(sub)
36 
37 #undef ATOMIC64_OPS
38 #define ATOMIC64_OPS(op)	ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op)
39 
40 ATOMIC64_OPS(and)
41 ATOMIC64_OPS(or)
42 ATOMIC64_OPS(xor)
43 
44 #undef ATOMIC64_OPS
45 #undef ATOMIC64_FETCH_OP
46 #undef ATOMIC64_OP_RETURN
47 #undef ATOMIC64_OP
48 
49 extern s64 atomic64_dec_if_positive(atomic64_t *v);
50 #define atomic64_dec_if_positive atomic64_dec_if_positive
51 extern s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n);
52 extern s64 atomic64_xchg(atomic64_t *v, s64 new);
53 extern s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u);
54 #define atomic64_fetch_add_unless atomic64_fetch_add_unless
55 
56 #endif  /*  _ASM_GENERIC_ATOMIC64_H  */
57