xref: /linux/include/asm-generic/local64.h (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_LOCAL64_H
3 #define _ASM_GENERIC_LOCAL64_H
4 
5 #include <linux/percpu.h>
6 #include <asm/types.h>
7 
8 /*
9  * A signed long type for operations which are atomic for a single CPU.
10  * Usually used in combination with per-cpu variables.
11  *
12  * This is the default implementation, which uses atomic64_t.  Which is
13  * rather pointless.  The whole point behind local64_t is that some processors
14  * can perform atomic adds and subtracts in a manner which is atomic wrt IRQs
15  * running on this CPU.  local64_t allows exploitation of such capabilities.
16  */
17 
18 /* Implement in terms of atomics. */
19 
20 #if BITS_PER_LONG == 64
21 
22 #include <asm/local.h>
23 
24 typedef struct {
25 	local_t a;
26 } local64_t;
27 
28 #define LOCAL64_INIT(i)	{ LOCAL_INIT(i) }
29 
30 #define local64_read(l)		local_read(&(l)->a)
31 #define local64_set(l,i)	local_set((&(l)->a),(i))
32 #define local64_inc(l)		local_inc(&(l)->a)
33 #define local64_dec(l)		local_dec(&(l)->a)
34 #define local64_add(i,l)	local_add((i),(&(l)->a))
35 #define local64_sub(i,l)	local_sub((i),(&(l)->a))
36 
37 #define local64_sub_and_test(i, l) local_sub_and_test((i), (&(l)->a))
38 #define local64_dec_and_test(l) local_dec_and_test(&(l)->a)
39 #define local64_inc_and_test(l) local_inc_and_test(&(l)->a)
40 #define local64_add_negative(i, l) local_add_negative((i), (&(l)->a))
41 #define local64_add_return(i, l) local_add_return((i), (&(l)->a))
42 #define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
43 #define local64_inc_return(l)	local_inc_return(&(l)->a)
44 
45 #define local64_cmpxchg(l, o, n) local_cmpxchg((&(l)->a), (o), (n))
46 #define local64_xchg(l, n)	local_xchg((&(l)->a), (n))
47 #define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
48 #define local64_inc_not_zero(l)	local_inc_not_zero(&(l)->a)
49 
50 /* Non-atomic variants, ie. preemption disabled and won't be touched
51  * in interrupt, etc.  Some archs can optimize this case well. */
52 #define __local64_inc(l)	local64_set((l), local64_read(l) + 1)
53 #define __local64_dec(l)	local64_set((l), local64_read(l) - 1)
54 #define __local64_add(i,l)	local64_set((l), local64_read(l) + (i))
55 #define __local64_sub(i,l)	local64_set((l), local64_read(l) - (i))
56 
57 #else /* BITS_PER_LONG != 64 */
58 
59 #include <linux/atomic.h>
60 
61 /* Don't use typedef: don't want them to be mixed with atomic_t's. */
62 typedef struct {
63 	atomic64_t a;
64 } local64_t;
65 
66 #define LOCAL64_INIT(i)	{ ATOMIC_LONG_INIT(i) }
67 
68 #define local64_read(l)		atomic64_read(&(l)->a)
69 #define local64_set(l,i)	atomic64_set((&(l)->a),(i))
70 #define local64_inc(l)		atomic64_inc(&(l)->a)
71 #define local64_dec(l)		atomic64_dec(&(l)->a)
72 #define local64_add(i,l)	atomic64_add((i),(&(l)->a))
73 #define local64_sub(i,l)	atomic64_sub((i),(&(l)->a))
74 
75 #define local64_sub_and_test(i, l) atomic64_sub_and_test((i), (&(l)->a))
76 #define local64_dec_and_test(l) atomic64_dec_and_test(&(l)->a)
77 #define local64_inc_and_test(l) atomic64_inc_and_test(&(l)->a)
78 #define local64_add_negative(i, l) atomic64_add_negative((i), (&(l)->a))
79 #define local64_add_return(i, l) atomic64_add_return((i), (&(l)->a))
80 #define local64_sub_return(i, l) atomic64_sub_return((i), (&(l)->a))
81 #define local64_inc_return(l)	atomic64_inc_return(&(l)->a)
82 
83 #define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
84 #define local64_xchg(l, n)	atomic64_xchg((&(l)->a), (n))
85 #define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
86 #define local64_inc_not_zero(l)	atomic64_inc_not_zero(&(l)->a)
87 
88 /* Non-atomic variants, ie. preemption disabled and won't be touched
89  * in interrupt, etc.  Some archs can optimize this case well. */
90 #define __local64_inc(l)	local64_set((l), local64_read(l) + 1)
91 #define __local64_dec(l)	local64_set((l), local64_read(l) - 1)
92 #define __local64_add(i,l)	local64_set((l), local64_read(l) + (i))
93 #define __local64_sub(i,l)	local64_set((l), local64_read(l) - (i))
94 
95 #endif /* BITS_PER_LONG != 64 */
96 
97 #endif /* _ASM_GENERIC_LOCAL64_H */
98