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