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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-18 08:25:29 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-18 08:25:29 -0700 |
commit | d7bb545d86825e635cab33a1dd81ca0ad7b92887 (patch) | |
tree | 34da4139ef06ceab6549aea3906639c7413978c8 /arch/s390/kernel/semaphore.c | |
parent | 75e98b34155264d943aa53edce465e87f3ccbadf (diff) | |
parent | 2342e51ba2b52a7f5b78227e6faa4603ed3632a0 (diff) |
Merge branch 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'semaphore' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc:
Remove DEBUG_SEMAPHORE from Kconfig
Improve semaphore documentation
Simplify semaphore implementation
Add down_timeout and change ACPI to use it
Introduce down_killable()
Generic semaphore implementation
Add semaphore.h to kernel_lock.c
Fix quota.h includes
Diffstat (limited to 'arch/s390/kernel/semaphore.c')
-rw-r--r-- | arch/s390/kernel/semaphore.c | 108 |
1 files changed, 0 insertions, 108 deletions
diff --git a/arch/s390/kernel/semaphore.c b/arch/s390/kernel/semaphore.c deleted file mode 100644 index 191303f6c1d..00000000000 --- a/arch/s390/kernel/semaphore.c +++ /dev/null @@ -1,108 +0,0 @@ -/* - * linux/arch/s390/kernel/semaphore.c - * - * S390 version - * Copyright (C) 1998-2000 IBM Corporation - * Author(s): Martin Schwidefsky - * - * Derived from "linux/arch/i386/kernel/semaphore.c - * Copyright (C) 1999, Linus Torvalds - * - */ -#include <linux/sched.h> -#include <linux/errno.h> -#include <linux/init.h> - -#include <asm/semaphore.h> - -/* - * Atomically update sem->count. Equivalent to: - * old_val = sem->count.counter; - * new_val = ((old_val >= 0) ? old_val : 0) + incr; - * sem->count.counter = new_val; - * return old_val; - */ -static inline int __sem_update_count(struct semaphore *sem, int incr) -{ - int old_val, new_val; - - asm volatile( - " l %0,0(%3)\n" - "0: ltr %1,%0\n" - " jhe 1f\n" - " lhi %1,0\n" - "1: ar %1,%4\n" - " cs %0,%1,0(%3)\n" - " jl 0b\n" - : "=&d" (old_val), "=&d" (new_val), "=m" (sem->count) - : "a" (&sem->count), "d" (incr), "m" (sem->count) - : "cc"); - return old_val; -} - -/* - * The inline function up() incremented count but the result - * was <= 0. This indicates that some process is waiting on - * the semaphore. The semaphore is free and we'll wake the - * first sleeping process, so we set count to 1 unless some - * other cpu has called up in the meantime in which case - * we just increment count by 1. - */ -void __up(struct semaphore *sem) -{ - __sem_update_count(sem, 1); - wake_up(&sem->wait); -} - -/* - * The inline function down() decremented count and the result - * was < 0. The wait loop will atomically test and update the - * semaphore counter following the rules: - * count > 0: decrement count, wake up queue and exit. - * count <= 0: set count to -1, go to sleep. - */ -void __sched __down(struct semaphore * sem) -{ - struct task_struct *tsk = current; - DECLARE_WAITQUEUE(wait, tsk); - - __set_task_state(tsk, TASK_UNINTERRUPTIBLE); - add_wait_queue_exclusive(&sem->wait, &wait); - while (__sem_update_count(sem, -1) <= 0) { - schedule(); - set_task_state(tsk, TASK_UNINTERRUPTIBLE); - } - remove_wait_queue(&sem->wait, &wait); - __set_task_state(tsk, TASK_RUNNING); - wake_up(&sem->wait); -} - -/* - * Same as __down() with an additional test for signals. - * If a signal is pending the count is updated as follows: - * count > 0: wake up queue and exit. - * count <= 0: set count to 0, wake up queue and exit. - */ -int __sched __down_interruptible(struct semaphore * sem) -{ - int retval = 0; - struct task_struct *tsk = current; - DECLARE_WAITQUEUE(wait, tsk); - - __set_task_state(tsk, TASK_INTERRUPTIBLE); - add_wait_queue_exclusive(&sem->wait, &wait); - while (__sem_update_count(sem, -1) <= 0) { - if (signal_pending(current)) { - __sem_update_count(sem, 0); - retval = -EINTR; - break; - } - schedule(); - set_task_state(tsk, TASK_INTERRUPTIBLE); - } - remove_wait_queue(&sem->wait, &wait); - __set_task_state(tsk, TASK_RUNNING); - wake_up(&sem->wait); - return retval; -} - |