diff options
author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-05-21 08:05:13 -0400 |
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committer | Ingo Molnar <mingo@elte.hu> | 2010-06-09 05:12:36 -0400 |
commit | 1996bda2a42480c275656233e631ee0966574be4 (patch) | |
tree | c4c61b6bde252d3d6f1dc0b62d48cf3a3e486ec1 /include/asm-generic/local64.h | |
parent | d57e34fdd60be7ffd0b1d86bfa1a553df86b7172 (diff) |
arch: Implement local64_t
On 64bit, local_t is of size long, and thus we make local64_t an alias.
On 32bit, we fall back to atomic64_t. (architecture can provide optimized
32-bit version)
(This new facility is to be used by perf events optimizations.)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-arch@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-generic/local64.h')
-rw-r--r-- | include/asm-generic/local64.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/include/asm-generic/local64.h b/include/asm-generic/local64.h new file mode 100644 index 000000000000..02ac760c1a8b --- /dev/null +++ b/include/asm-generic/local64.h | |||
@@ -0,0 +1,96 @@ | |||
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 */ | ||