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

/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 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	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Copyright (c) 1998 Apple Computer, Inc. All rights reserved.
	24	*
	25	* HISTORY
	26	*
	27	*/
	28
	29	/* Copyright (c) 1992 NeXT Computer, Inc. All rights reserved.
	30	*
	31	* EventShmemLock.h - Shared memory area locks for use between the
	32	* WindowServer and the Event Driver.
	33	*
	34	* HISTORY
	35	* 30 Nov 1992 Ben Fathi (benf@next.com)
	36	* Ported to m98k.
	37	*
	38	* 29 April 1992 Mike Paquette at NeXT
	39	* Created.
	40	*
	41	* Multiprocessor locks used within the shared memory area between the
	42	* kernel and event system. These must work in both user and kernel mode.
	43	* The locks are defined in an include file so they get exported to the local
	44	* include file area.
	45	*/
	46
	47
	48	#ifndef _IOKIT_IOSHAREDLOCKIMP_H
	49	#define _IOKIT_IOSHAREDLOCKIMP_H
	50
	51	#include <architecture/ppc/asm_help.h>
7b1edb79 A	52	#ifdef KERNEL
	53	#undef END
	54	#include <mach/ppc/asm.h>
	55	#endif
1c79356b	56
1c79356b A	57	.macro DISABLE_PREEMPTION
1c79356b A	58	#ifdef KERNEL
7b1edb79 A	59	stwu r1,-(FM_SIZE)(r1)
	60	mflr r0
	61	stw r3,FM_ARG0(r1)
	62	stw r0,(FM_SIZE+FM_LR_SAVE)(r1)
	63	bl EXT(_disable_preemption)
	64	lwz r3,FM_ARG0(r1)
	65	lwz r1,0(r1)
	66	lwz r0,FM_LR_SAVE(r1)
	67	mtlr r0
1c79356b A	68	#endif
	69	.endmacro
	70	.macro ENABLE_PREEMPTION
	71	#ifdef KERNEL
7b1edb79 A	72	stwu r1,-(FM_SIZE)(r1)
	73	mflr r0
	74	stw r3,FM_ARG0(r1)
	75	stw r0,(FM_SIZE+FM_LR_SAVE)(r1)
	76	bl EXT(_enable_preemption)
	77	lwz r3,FM_ARG0(r1)
	78	lwz r1,0(r1)
	79	lwz r0,FM_LR_SAVE(r1)
	80	mtlr r0
1c79356b A	81	#endif
	82	.endmacro
	83
	84	/*
	85	* void
	86	* ev_lock(p)
	87	* register int *p;
	88	*
	89	* Lock the lock pointed to by p. Spin (possibly forever) until
	90	* the lock is available. Test and test and set logic used.
	91	*/
	92	TEXT
	93
	94	#ifndef KERNEL
	95	LEAF(_ev_lock)
0b4e3aa0 A	96	li a6,1 // lock value
0b4e3aa0 A	97	lwarx a7,0,a0 // CEMV10
1c79356b A	98	9:
1c79356b A	99	sync
0b4e3aa0 A	100	lwarx a7,0,a0 // read the lock
	101	cmpwi cr0,a7,0 // is it busy?
	102	bne- 9b // yes, spin
1c79356b	103	sync
0b4e3aa0 A	104	stwcx. a6,0,a0 // try to get the lock
0b4e3aa0 A	105	bne- 9b // failed, try again
1c79356b	106	isync
0b4e3aa0	107	blr // got it, return
1c79356b	108	END(_ev_lock)
0b4e3aa0 A	109
	110	LEAF(_IOSpinLock)
	111	li a6,1 // lock value
	112	lwarx a7,0,a0 // CEMV10
	113	9:
	114	sync
	115	lwarx a7,0,a0 // read the lock
	116	cmpwi cr0,a7,0 // is it busy?
	117	bne- 9b // yes, spin
	118	sync
	119	stwcx. a6,0,a0 // try to get the lock
	120	bne- 9b // failed, try again
	121	isync
	122	blr // got it, return
	123	END(_IOSpinLock)
1c79356b A	124	#endif
	125
	126	/*
	127	* void
	128	* spin_unlock(p)
	129	* int *p;
	130	*
	131	* Unlock the lock pointed to by p.
	132	*/
	133
	134	LEAF(_ev_unlock)
1c79356b A	135	sync
	136	li a7,0
	137	stw a7,0(a0)
	138	ENABLE_PREEMPTION()
	139	blr
	140	END(_ev_unlock)
	141
0b4e3aa0 A	142	LEAF(_IOSpinUnlock)
	143	sync
	144	li a7,0
	145	stw a7,0(a0)
	146	ENABLE_PREEMPTION()
	147	blr
	148	END(_IOSpinUnlock)
	149
1c79356b A	150
	151	/*
	152	* ev_try_lock(p)
	153	* int *p;
	154	*
	155	* Try to lock p. Return TRUE if successful in obtaining lock.
	156	*/
	157
	158	LEAF(_ev_try_lock)
0b4e3aa0	159	li a6,1 // lock value
1c79356b	160	DISABLE_PREEMPTION()
0b4e3aa0	161	lwarx a7,0,a0 // CEMV10
1c79356b A	162	8:
1c79356b A	163	sync
0b4e3aa0 A	164	lwarx a7,0,a0 // read the lock
	165	cmpwi cr0,a7,0 // is it busy?
	166	bne- 9f // yes, give up
1c79356b	167	sync
0b4e3aa0 A	168	stwcx. a6,0,a0 // try to get the lock
	169	bne- 8b // failed, try again
	170	li a0,1 // return TRUE
1c79356b A	171	isync
	172	blr
	173	9:
	174	ENABLE_PREEMPTION()
0b4e3aa0	175	li a0,0 // return FALSE
1c79356b A	176	blr
	177	END(_ev_try_lock)
	178
0b4e3aa0 A	179	LEAF(_IOTrySpinLock)
	180	li a6,1 // lock value
	181	DISABLE_PREEMPTION()
	182	lwarx a7,0,a0 // CEMV10
	183	8:
	184	sync
	185	lwarx a7,0,a0 // read the lock
	186	cmpwi cr0,a7,0 // is it busy?
	187	bne- 9f // yes, give up
	188	sync
	189	stwcx. a6,0,a0 // try to get the lock
	190	bne- 8b // failed, try again
	191	li a0,1 // return TRUE
	192	isync
	193	blr
	194	9:
	195	ENABLE_PREEMPTION()
	196	li a0,0 // return FALSE
	197	blr
	198	END(_IOTrySpinLock)
	199
1c79356b	200	#endif /* ! _IOKIT_IOSHAREDLOCKIMP_H */