diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/smp_lock.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/smp_lock.h')
-rw-r--r-- | include/linux/smp_lock.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/include/linux/smp_lock.h b/include/linux/smp_lock.h new file mode 100644 index 000000000000..b63ce7014093 --- /dev/null +++ b/include/linux/smp_lock.h | |||
@@ -0,0 +1,54 @@ | |||
1 | #ifndef __LINUX_SMPLOCK_H | ||
2 | #define __LINUX_SMPLOCK_H | ||
3 | |||
4 | #include <linux/config.h> | ||
5 | #include <linux/sched.h> | ||
6 | #include <linux/spinlock.h> | ||
7 | |||
8 | #ifdef CONFIG_LOCK_KERNEL | ||
9 | |||
10 | #define kernel_locked() (current->lock_depth >= 0) | ||
11 | |||
12 | extern int __lockfunc __reacquire_kernel_lock(void); | ||
13 | extern void __lockfunc __release_kernel_lock(void); | ||
14 | |||
15 | /* | ||
16 | * Release/re-acquire global kernel lock for the scheduler | ||
17 | */ | ||
18 | #define release_kernel_lock(tsk) do { \ | ||
19 | if (unlikely((tsk)->lock_depth >= 0)) \ | ||
20 | __release_kernel_lock(); \ | ||
21 | } while (0) | ||
22 | |||
23 | /* | ||
24 | * Non-SMP kernels will never block on the kernel lock, | ||
25 | * so we are better off returning a constant zero from | ||
26 | * reacquire_kernel_lock() so that the compiler can see | ||
27 | * it at compile-time. | ||
28 | */ | ||
29 | #if defined(CONFIG_SMP) && !defined(CONFIG_PREEMPT_BKL) | ||
30 | # define return_value_on_smp return | ||
31 | #else | ||
32 | # define return_value_on_smp | ||
33 | #endif | ||
34 | |||
35 | static inline int reacquire_kernel_lock(struct task_struct *task) | ||
36 | { | ||
37 | if (unlikely(task->lock_depth >= 0)) | ||
38 | return_value_on_smp __reacquire_kernel_lock(); | ||
39 | return 0; | ||
40 | } | ||
41 | |||
42 | extern void __lockfunc lock_kernel(void) __acquires(kernel_lock); | ||
43 | extern void __lockfunc unlock_kernel(void) __releases(kernel_lock); | ||
44 | |||
45 | #else | ||
46 | |||
47 | #define lock_kernel() do { } while(0) | ||
48 | #define unlock_kernel() do { } while(0) | ||
49 | #define release_kernel_lock(task) do { } while(0) | ||
50 | #define reacquire_kernel_lock(task) 0 | ||
51 | #define kernel_locked() 1 | ||
52 | |||
53 | #endif /* CONFIG_LOCK_KERNEL */ | ||
54 | #endif /* __LINUX_SMPLOCK_H */ | ||