[apple/xnu.git] / iokit / IOKit / i386 / IOSharedLockImp.h

/*
 * 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
 * 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.
 *
 * This is basically a ripoff of the spin locks under the cthreads packages.
 */

#ifndef _IOKIT_IOSHAREDLOCKIMP_H
#define _IOKIT_IOSHAREDLOCKIMP_H

#include <architecture/i386/asm_help.h>

#ifndef KERNEL
#error this file for kernel only; comm page has user versions
#endif

	TEXT

/*
 * void
 * ev_unlock(p)
 *	int *p;
 *
 * Unlock the lock pointed to by p.
 */
LEAF(_ev_unlock, 0)
LEAF(_IOSpinUnlock, 0)
#if __x86_64__
	movl		$0, (%rdi)
#else
	movl		4(%esp), %ecx
	movl		$0, (%ecx)
#endif
END(_ev_unlock)


/*
 * int
 * ev_try_lock(p)
 *	int *p;
 *
 * Try to lock p.  Return zero if not successful.
 */

LEAF(_ev_try_lock, 0)
LEAF(_IOTrySpinLock, 0)
#if __x86_64__
	xorl		%eax, %eax
	orl		$-1, %edx
	lock
	cmpxchgl	%edx, (%rdi)
	setz		%dl
	movzbl		%dl, %eax
#else
        movl            4(%esp), %ecx 
	xorl		%eax, %eax
        lock
        cmpxchgl        %ecx, (%ecx)
	jne	1f
	movl	$1, %eax		/* yes */
	ret
1:
	xorl	%eax, %eax		/* no */
#endif
END(_ev_try_lock)


#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* Copyright (c) 1998 Apple Computer, Inc. All rights reserved.
	30	*
	31	* HISTORY
	32	*
	33	*/
	34
	35	/* Copyright (c) 1992 NeXT Computer, Inc. All rights reserved.
	36	*
	37	* EventShmemLock.h - Shared memory area locks for use between the
	38	* WindowServer and the Event Driver.
	39	*
	40	*
	41	* HISTORY
	42	* 29 April 1992 Mike Paquette at NeXT
	43	* Created.
	44	*
	45	* Multiprocessor locks used within the shared memory area between the
	46	* kernel and event system. These must work in both user and kernel mode.
	47	* The locks are defined in an include file so they get exported to the local
	48	* include file area.
	49	*
	50	* This is basically a ripoff of the spin locks under the cthreads packages.
	51	*/
	52
	53	#ifndef _IOKIT_IOSHAREDLOCKIMP_H
	54	#define _IOKIT_IOSHAREDLOCKIMP_H
	55
	56	#include <architecture/i386/asm_help.h>
	57
1c79356b	58	#ifndef KERNEL
b0d623f7	59	#error this file for kernel only; comm page has user versions
1c79356b A	60	#endif
1c79356b A	61
b0d623f7 A	62	TEXT
b0d623f7 A	63
1c79356b A	64	/*
	65	* void
	66	* ev_unlock(p)
	67	* int *p;
	68	*
	69	* Unlock the lock pointed to by p.
	70	*/
	71	LEAF(_ev_unlock, 0)
	72	LEAF(_IOSpinUnlock, 0)
b0d623f7 A	73	#if __x86_64__
	74	movl $0, (%rdi)
	75	#else
55e303ae A	76	movl 4(%esp), %ecx
55e303ae A	77	movl $0, (%ecx)
b0d623f7	78	#endif
1c79356b A	79	END(_ev_unlock)
	80
	81
1c79356b A	82	/*
	83	* int
	84	* ev_try_lock(p)
	85	* int *p;
	86	*
	87	* Try to lock p. Return zero if not successful.
	88	*/
	89
	90	LEAF(_ev_try_lock, 0)
	91	LEAF(_IOTrySpinLock, 0)
b0d623f7 A	92	#if __x86_64__
	93	xorl %eax, %eax
	94	orl $-1, %edx
	95	lock
	96	cmpxchgl %edx, (%rdi)
	97	setz %dl
	98	movzbl %dl, %eax
	99	#else
55e303ae A	100	movl 4(%esp), %ecx
	101	xorl %eax, %eax
	102	lock
	103	cmpxchgl %ecx, (%ecx)
	104	jne 1f
1c79356b A	105	movl $1, %eax /* yes */
	106	ret
	107	1:
1c79356b	108	xorl %eax, %eax /* no */
b0d623f7	109	#endif
1c79356b A	110	END(_ev_try_lock)
	111
	112
	113	#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */