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Diffstat (limited to 'include/asm-i386/semaphore.h')
| -rw-r--r-- | include/asm-i386/semaphore.h | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/include/asm-i386/semaphore.h b/include/asm-i386/semaphore.h deleted file mode 100644 index 4e34a468c383..000000000000 --- a/include/asm-i386/semaphore.h +++ /dev/null @@ -1,176 +0,0 @@ -#ifndef _I386_SEMAPHORE_H -#define _I386_SEMAPHORE_H - -#include <linux/linkage.h> - -#ifdef __KERNEL__ - -/* - * SMP- and interrupt-safe semaphores.. - * - * (C) Copyright 1996 Linus Torvalds - * - * Modified 1996-12-23 by Dave Grothe <dave@gcom.com> to fix bugs in - * the original code and to make semaphore waits - * interruptible so that processes waiting on - * semaphores can be killed. - * Modified 1999-02-14 by Andrea Arcangeli, split the sched.c helper - * functions in asm/sempahore-helper.h while fixing a - * potential and subtle race discovered by Ulrich Schmid - * in down_interruptible(). Since I started to play here I - * also implemented the `trylock' semaphore operation. - * 1999-07-02 Artur Skawina <skawina@geocities.com> - * Optimized "0(ecx)" -> "(ecx)" (the assembler does not - * do this). Changed calling sequences from push/jmp to - * traditional call/ret. - * Modified 2001-01-01 Andreas Franck <afranck@gmx.de> - * Some hacks to ensure compatibility with recent - * GCC snapshots, to avoid stack corruption when compiling - * with -fomit-frame-pointer. It's not sure if this will - * be fixed in GCC, as our previous implementation was a - * bit dubious. - * - * If you would like to see an analysis of this implementation, please - * ftp to gcom.com and download the file - * /pub/linux/src/semaphore/semaphore-2.0.24.tar.gz. - * - */ - -#include <asm/system.h> -#include <asm/atomic.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -struct semaphore { - atomic_t count; - int sleepers; - wait_queue_head_t wait; -}; - - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(n), \ - .sleepers = 0, \ - .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ -} - -#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ - struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) - -#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) -#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) - -static inline void sema_init (struct semaphore *sem, int val) -{ -/* - * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); - * - * i'd rather use the more flexible initialization above, but sadly - * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well. - */ - atomic_set(&sem->count, val); - sem->sleepers = 0; - init_waitqueue_head(&sem->wait); -} - -static inline void init_MUTEX (struct semaphore *sem) -{ - sema_init(sem, 1); -} - -static inline void init_MUTEX_LOCKED (struct semaphore *sem) -{ - sema_init(sem, 0); -} - -fastcall void __down_failed(void /* special register calling convention */); -fastcall int __down_failed_interruptible(void /* params in registers */); -fastcall int __down_failed_trylock(void /* params in registers */); -fastcall void __up_wakeup(void /* special register calling convention */); - -/* - * This is ugly, but we want the default case to fall through. - * "__down_failed" is a special asm handler that calls the C - * routine that actually waits. See arch/i386/kernel/semaphore.c - */ -static inline void down(struct semaphore * sem) -{ - might_sleep(); - __asm__ __volatile__( - "# atomic down operation\n\t" - LOCK_PREFIX "decl %0\n\t" /* --sem->count */ - "jns 2f\n" - "\tlea %0,%%eax\n\t" - "call __down_failed\n" - "2:" - :"+m" (sem->count) - : - :"memory","ax"); -} - -/* - * Interruptible try to acquire a semaphore. If we obtained - * it, return zero. If we were interrupted, returns -EINTR - */ -static inline int down_interruptible(struct semaphore * sem) -{ - int result; - - might_sleep(); - __asm__ __volatile__( - "# atomic interruptible down operation\n\t" - "xorl %0,%0\n\t" - LOCK_PREFIX "decl %1\n\t" /* --sem->count */ - "jns 2f\n\t" - "lea %1,%%eax\n\t" - "call __down_failed_interruptible\n" - "2:" - :"=&a" (result), "+m" (sem->count) - : - :"memory"); - return result; -} - -/* - * Non-blockingly attempt to down() a semaphore. - * Returns zero if we acquired it - */ -static inline int down_trylock(struct semaphore * sem) -{ - int result; - - __asm__ __volatile__( - "# atomic interruptible down operation\n\t" - "xorl %0,%0\n\t" - LOCK_PREFIX "decl %1\n\t" /* --sem->count */ - "jns 2f\n\t" - "lea %1,%%eax\n\t" - "call __down_failed_trylock\n\t" - "2:\n" - :"=&a" (result), "+m" (sem->count) - : - :"memory"); - return result; -} - -/* - * Note! This is subtle. We jump to wake people up only if - * the semaphore was negative (== somebody was waiting on it). - */ -static inline void up(struct semaphore * sem) -{ - __asm__ __volatile__( - "# atomic up operation\n\t" - LOCK_PREFIX "incl %0\n\t" /* ++sem->count */ - "jg 1f\n\t" - "lea %0,%%eax\n\t" - "call __up_wakeup\n" - "1:" - :"+m" (sem->count) - : - :"memory","ax"); -} - -#endif -#endif |
