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

/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * 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. 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_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

.macro DISABLE_PREEMPTION
#ifdef KERNEL
	stwu	r1,-(FM_SIZE)(r1)
	mflr	r0
	stw		r3,FM_ARG0(r1)
	stw		r0,(FM_SIZE+FM_LR_SAVE)(r1)
	bl		EXT(_disable_preemption)
	lwz		r3,FM_ARG0(r1)
	lwz		r1,0(r1)
	lwz		r0,FM_LR_SAVE(r1)
	mtlr	r0
#endif
.endmacro
.macro ENABLE_PREEMPTION
#ifdef KERNEL
	stwu	r1,-(FM_SIZE)(r1)
	mflr	r0
	stw		r3,FM_ARG0(r1)
	stw		r0,(FM_SIZE+FM_LR_SAVE)(r1)
	bl		EXT(_enable_preemption)
	lwz		r3,FM_ARG0(r1)
	lwz		r1,0(r1)
	lwz		r0,FM_LR_SAVE(r1)
	mtlr	r0
#endif
.endmacro

/*
 *	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
	lwarx	a7,0,a0			// CEMV10
9:
	sync
	lwarx	a7,0,a0			// read the lock
	cmpwi	cr0,a7,0		// is it busy?
	bne-	9b 			// yes, spin
	sync
	stwcx.	a6,0,a0			// try to get the lock
	bne-	9b 			// failed, try again
	isync
	blr				// got it, return
END(_ev_lock)

LEAF(_IOSpinLock)
	li	a6,1			// lock value
	lwarx	a7,0,a0			// CEMV10
9:
	sync
	lwarx	a7,0,a0			// read the lock
	cmpwi	cr0,a7,0		// is it busy?
	bne-	9b			// yes, spin
	sync
	stwcx.	a6,0,a0			// try to get the lock
	bne-	9b			// failed, try again
	isync
	blr				// got it, return
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)
	ENABLE_PREEMPTION()
	blr
END(_ev_unlock)

LEAF(_IOSpinUnlock)
	sync
	li	a7,0
	stw	a7,0(a0)
	ENABLE_PREEMPTION()
	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
        DISABLE_PREEMPTION()
	lwarx	a7,0,a0			// CEMV10
8:
	sync
	lwarx	a7,0,a0			// read the lock
	cmpwi	cr0,a7,0		// is it busy?
	bne-	9f			// yes, give up
	sync
	stwcx.	a6,0,a0			// try to get the lock
	bne-	8b			// failed, try again
	li	a0,1			// return TRUE
	isync
	blr
9:
	ENABLE_PREEMPTION()
	li	a0,0			// return FALSE
	blr
END(_ev_try_lock)

LEAF(_IOTrySpinLock)
	li	a6,1			// lock value
        DISABLE_PREEMPTION()
	lwarx	a7,0,a0			// CEMV10
8:
	sync
	lwarx	a7,0,a0			// read the lock
	cmpwi	cr0,a7,0		// is it busy?
	bne-	9f			// yes, give up
	sync
	stwcx.	a6,0,a0			// try to get the lock
	bne-	8b			// failed, try again
	li	a0,1			// return TRUE
	isync
	blr
9:
	ENABLE_PREEMPTION()
	li	a0,0			// return FALSE
	blr
END(_IOTrySpinLock)

#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
43866e37	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
43866e37 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
43866e37 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1998 Apple Computer, Inc. All rights reserved.
	27	*
	28	* HISTORY
	29	*
	30	*/
	31
	32	/* Copyright (c) 1992 NeXT Computer, Inc. All rights reserved.
	33	*
	34	* EventShmemLock.h - Shared memory area locks for use between the
	35	* WindowServer and the Event Driver.
	36	*
	37	* HISTORY
	38	* 30 Nov 1992 Ben Fathi (benf@next.com)
	39	* Ported to m98k.
	40	*
	41	* 29 April 1992 Mike Paquette at NeXT
	42	* Created.
	43	*
	44	* Multiprocessor locks used within the shared memory area between the
	45	* kernel and event system. These must work in both user and kernel mode.
	46	* The locks are defined in an include file so they get exported to the local
	47	* include file area.
	48	*/
	49
	50
	51	#ifndef _IOKIT_IOSHAREDLOCKIMP_H
	52	#define _IOKIT_IOSHAREDLOCKIMP_H
	53
	54	#include <architecture/ppc/asm_help.h>
7b1edb79 A	55	#ifdef KERNEL
	56	#undef END
	57	#include <mach/ppc/asm.h>
	58	#endif
1c79356b	59
1c79356b A	60	.macro DISABLE_PREEMPTION
1c79356b A	61	#ifdef KERNEL
7b1edb79 A	62	stwu r1,-(FM_SIZE)(r1)
	63	mflr r0
	64	stw r3,FM_ARG0(r1)
	65	stw r0,(FM_SIZE+FM_LR_SAVE)(r1)
	66	bl EXT(_disable_preemption)
	67	lwz r3,FM_ARG0(r1)
	68	lwz r1,0(r1)
	69	lwz r0,FM_LR_SAVE(r1)
	70	mtlr r0
1c79356b A	71	#endif
	72	.endmacro
	73	.macro ENABLE_PREEMPTION
	74	#ifdef KERNEL
7b1edb79 A	75	stwu r1,-(FM_SIZE)(r1)
	76	mflr r0
	77	stw r3,FM_ARG0(r1)
	78	stw r0,(FM_SIZE+FM_LR_SAVE)(r1)
	79	bl EXT(_enable_preemption)
	80	lwz r3,FM_ARG0(r1)
	81	lwz r1,0(r1)
	82	lwz r0,FM_LR_SAVE(r1)
	83	mtlr r0
1c79356b A	84	#endif
	85	.endmacro
	86
	87	/*
	88	* void
	89	* ev_lock(p)
	90	* register int *p;
	91	*
	92	* Lock the lock pointed to by p. Spin (possibly forever) until
	93	* the lock is available. Test and test and set logic used.
	94	*/
	95	TEXT
	96
	97	#ifndef KERNEL
	98	LEAF(_ev_lock)
de355530 A	99	li a6,1 // lock value
	100	lwarx a7,0,a0 // CEMV10
	101	9:
	102	sync
	103	lwarx a7,0,a0 // read the lock
	104	cmpwi cr0,a7,0 // is it busy?
	105	bne- 9b // yes, spin
	106	sync
	107	stwcx. a6,0,a0 // try to get the lock
	108	bne- 9b // failed, try again
	109	isync
	110	blr // got it, return
1c79356b	111	END(_ev_lock)
0b4e3aa0 A	112
0b4e3aa0 A	113	LEAF(_IOSpinLock)
de355530 A	114	li a6,1 // lock value
	115	lwarx a7,0,a0 // CEMV10
	116	9:
	117	sync
	118	lwarx a7,0,a0 // read the lock
	119	cmpwi cr0,a7,0 // is it busy?
	120	bne- 9b // yes, spin
	121	sync
	122	stwcx. a6,0,a0 // try to get the lock
	123	bne- 9b // failed, try again
	124	isync
	125	blr // got it, return
0b4e3aa0	126	END(_IOSpinLock)
1c79356b A	127	#endif
	128
	129	/*
	130	* void
	131	* spin_unlock(p)
	132	* int *p;
	133	*
	134	* Unlock the lock pointed to by p.
	135	*/
	136
	137	LEAF(_ev_unlock)
1c79356b A	138	sync
	139	li a7,0
	140	stw a7,0(a0)
	141	ENABLE_PREEMPTION()
	142	blr
	143	END(_ev_unlock)
	144
0b4e3aa0 A	145	LEAF(_IOSpinUnlock)
	146	sync
	147	li a7,0
	148	stw a7,0(a0)
	149	ENABLE_PREEMPTION()
	150	blr
	151	END(_IOSpinUnlock)
	152
1c79356b A	153
	154	/*
	155	* ev_try_lock(p)
	156	* int *p;
	157	*
	158	* Try to lock p. Return TRUE if successful in obtaining lock.
	159	*/
	160
	161	LEAF(_ev_try_lock)
de355530 A	162	li a6,1 // lock value
	163	DISABLE_PREEMPTION()
	164	lwarx a7,0,a0 // CEMV10
	165	8:
	166	sync
	167	lwarx a7,0,a0 // read the lock
	168	cmpwi cr0,a7,0 // is it busy?
	169	bne- 9f // yes, give up
	170	sync
	171	stwcx. a6,0,a0 // try to get the lock
	172	bne- 8b // failed, try again
	173	li a0,1 // return TRUE
	174	isync
	175	blr
	176	9:
	177	ENABLE_PREEMPTION()
	178	li a0,0 // return FALSE
	179	blr
1c79356b A	180	END(_ev_try_lock)
1c79356b A	181
0b4e3aa0	182	LEAF(_IOTrySpinLock)
de355530 A	183	li a6,1 // lock value
	184	DISABLE_PREEMPTION()
	185	lwarx a7,0,a0 // CEMV10
	186	8:
	187	sync
	188	lwarx a7,0,a0 // read the lock
	189	cmpwi cr0,a7,0 // is it busy?
	190	bne- 9f // yes, give up
	191	sync
	192	stwcx. a6,0,a0 // try to get the lock
	193	bne- 8b // failed, try again
	194	li a0,1 // return TRUE
	195	isync
	196	blr
	197	9:
	198	ENABLE_PREEMPTION()
	199	li a0,0 // return FALSE
	200	blr
0b4e3aa0 A	201	END(_IOTrySpinLock)
0b4e3aa0 A	202
1c79356b	203	#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */