diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/rwsem-spinlock.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/rwsem-spinlock.h')
-rw-r--r-- | include/linux/rwsem-spinlock.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h new file mode 100644 index 000000000000..b52a2af25f1f --- /dev/null +++ b/include/linux/rwsem-spinlock.h | |||
@@ -0,0 +1,65 @@ | |||
1 | /* rwsem-spinlock.h: fallback C implementation | ||
2 | * | ||
3 | * Copyright (c) 2001 David Howells (dhowells@redhat.com). | ||
4 | * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de> | ||
5 | * - Derived also from comments by Linus | ||
6 | */ | ||
7 | |||
8 | #ifndef _LINUX_RWSEM_SPINLOCK_H | ||
9 | #define _LINUX_RWSEM_SPINLOCK_H | ||
10 | |||
11 | #ifndef _LINUX_RWSEM_H | ||
12 | #error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead" | ||
13 | #endif | ||
14 | |||
15 | #include <linux/spinlock.h> | ||
16 | #include <linux/list.h> | ||
17 | |||
18 | #ifdef __KERNEL__ | ||
19 | |||
20 | #include <linux/types.h> | ||
21 | |||
22 | struct rwsem_waiter; | ||
23 | |||
24 | /* | ||
25 | * the rw-semaphore definition | ||
26 | * - if activity is 0 then there are no active readers or writers | ||
27 | * - if activity is +ve then that is the number of active readers | ||
28 | * - if activity is -1 then there is one active writer | ||
29 | * - if wait_list is not empty, then there are processes waiting for the semaphore | ||
30 | */ | ||
31 | struct rw_semaphore { | ||
32 | __s32 activity; | ||
33 | spinlock_t wait_lock; | ||
34 | struct list_head wait_list; | ||
35 | #if RWSEM_DEBUG | ||
36 | int debug; | ||
37 | #endif | ||
38 | }; | ||
39 | |||
40 | /* | ||
41 | * initialisation | ||
42 | */ | ||
43 | #if RWSEM_DEBUG | ||
44 | #define __RWSEM_DEBUG_INIT , 0 | ||
45 | #else | ||
46 | #define __RWSEM_DEBUG_INIT /* */ | ||
47 | #endif | ||
48 | |||
49 | #define __RWSEM_INITIALIZER(name) \ | ||
50 | { 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT } | ||
51 | |||
52 | #define DECLARE_RWSEM(name) \ | ||
53 | struct rw_semaphore name = __RWSEM_INITIALIZER(name) | ||
54 | |||
55 | extern void FASTCALL(init_rwsem(struct rw_semaphore *sem)); | ||
56 | extern void FASTCALL(__down_read(struct rw_semaphore *sem)); | ||
57 | extern int FASTCALL(__down_read_trylock(struct rw_semaphore *sem)); | ||
58 | extern void FASTCALL(__down_write(struct rw_semaphore *sem)); | ||
59 | extern int FASTCALL(__down_write_trylock(struct rw_semaphore *sem)); | ||
60 | extern void FASTCALL(__up_read(struct rw_semaphore *sem)); | ||
61 | extern void FASTCALL(__up_write(struct rw_semaphore *sem)); | ||
62 | extern void FASTCALL(__downgrade_write(struct rw_semaphore *sem)); | ||
63 | |||
64 | #endif /* __KERNEL__ */ | ||
65 | #endif /* _LINUX_RWSEM_SPINLOCK_H */ | ||