+++ /dev/null
-/*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the License
- * may not be used to create, or enable the creation or redistribution of,
- * unlawful or unlicensed copies of an Apple operating system, or to
- * circumvent, violate, or enable the circumvention or violation of, any
- * terms of an Apple operating system software license agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
- */
-/*
- * Copyright (c) 1998 Apple Computer, Inc. All rights reserved.
- *
- * HISTORY
- *
- */
-
-/* Copyright (c) 1992 NeXT Computer, Inc. All rights reserved.
- *
- * EventShmemLock.h - Shared memory area locks for use between the
- * WindowServer and the Event Driver.
- *
- * HISTORY
- * 30 Nov 1992 Ben Fathi (benf@next.com)
- * Ported to m98k.
- *
- * 29 April 1992 Mike Paquette at NeXT
- * Created.
- *
- * Multiprocessor locks used within the shared memory area between the
- * kernel and event system. These must work in both user and kernel mode.
- * The locks are defined in an include file so they get exported to the local
- * include file area.
- */
-
-
-#ifndef _IOKIT_IOSHAREDLOCKIMP_H
-#define _IOKIT_IOSHAREDLOCKIMP_H
-
-#include <architecture/ppc/asm_help.h>
-#ifdef KERNEL
-#undef END
-#include <mach/ppc/asm.h>
-#endif
-
-/*
- * void
- * ev_lock(p)
- * register int *p;
- *
- * Lock the lock pointed to by p. Spin (possibly forever) until
- * the lock is available. Test and test and set logic used.
- */
- TEXT
-
-#ifndef KERNEL
-LEAF(_ev_lock)
-
- li a6,1 // lock value
-
-8: lwz a7,0(a0) // Get lock word
- mr. a7,a7 // Is it held?
- bne-- 8b // Yup...
-
-9: lwarx a7,0,a0 // read the lock
- mr. a7,a7 // Is it held?
- bne-- 7f // yes, kill reservation
- stwcx. a6,0,a0 // try to get the lock
- bne-- 9b // failed, try again
- isync
- blr // got it, return
-
-7: li a7,-4 // Point to a spot in the red zone
- stwcx. a7,a7,r1 // Kill reservation
- b 8b // Go wait some more...
-
-
-END(_ev_lock)
-
-LEAF(_IOSpinLock)
-
- li a6,1 // lock value
-
-8: lwz a7,0(a0) // Get lock word
- mr. a7,a7 // Is it held?
- bne-- 8b // Yup...
-
-9: lwarx a7,0,a0 // read the lock
- mr. a7,a7 // Is it held?
- bne-- 7f // yes, kill reservation
- stwcx. a6,0,a0 // try to get the lock
- bne-- 9b // failed, try again
- isync
- blr // got it, return
-
-7: li a7,-4 // Point to a spot in the red zone
- stwcx. a7,a7,r1 // Kill reservation
- b 8b // Go wait some more...
-END(_IOSpinLock)
-#endif
-
-/*
- * void
- * spin_unlock(p)
- * int *p;
- *
- * Unlock the lock pointed to by p.
- */
-
-LEAF(_ev_unlock)
- sync
- li a7,0
- stw a7,0(a0)
- blr
-END(_ev_unlock)
-
-LEAF(_IOSpinUnlock)
- sync
- li a7,0
- stw a7,0(a0)
- blr
-END(_IOSpinUnlock)
-
-
-/*
- * ev_try_lock(p)
- * int *p;
- *
- * Try to lock p. Return TRUE if successful in obtaining lock.
- */
-
-LEAF(_ev_try_lock)
- li a6,1 // lock value
-
- lwz a7,0(a0) // Get lock word
- mr. a7,a7 // Is it held?
- bne-- 6f // Yup...
-
-9: lwarx a7,0,a0 // read the lock
- mr. a7,a7 // Is it held?
- bne-- 7f // yes, kill reservation
- stwcx. a6,0,a0 // try to get the lock
- bne-- 9b // failed, try again
- li a0,1 // return TRUE
- isync
- blr // got it, return
-
-7: li a7,-4 // Point to a spot in the red zone
- stwcx. a7,a7,r1 // Kill reservation
-
-6:
- li a0,0 // return FALSE
- blr
-
-END(_ev_try_lock)
-
-LEAF(_IOTrySpinLock)
- li a6,1 // lock value
-
- lwz a7,0(a0) // Get lock word
- mr. a7,a7 // Is it held?
- bne-- 6f // Yup...
-
-9: lwarx a7,0,a0 // read the lock
- mr. a7,a7 // Is it held?
- bne-- 7f // yes, kill reservation
- stwcx. a6,0,a0 // try to get the lock
- bne-- 9b // failed, try again
- li a0,1 // return TRUE
- isync
- blr // got it, return
-
-7: li a7,-4 // Point to a spot in the red zone
- stwcx. a7,a7,r1 // Kill reservation
-
-6:
- li a0,0 // return FALSE
- blr
-
-END(_IOTrySpinLock)
-
-#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */
projects / apple / xnu.git / blobdiff