[apple/xnu.git] / osfmk / i386 / cswitch.s

/*
 * Copyright (c) 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@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */

#include <cpus.h>
#include <platforms.h>

#include <i386/asm.h>
#include <i386/proc_reg.h>
#include <assym.s>

#if	NCPUS > 1

#ifdef	SYMMETRY
#include <sqt/asm_macros.h>
#endif

#if	AT386
#include <i386/mp.h>
#endif	/* AT386 */

#define	CX(addr, reg)	addr(,reg,4)

#else	/* NCPUS == 1 */

#define	CPU_NUMBER(reg)
#define	CX(addr,reg)	addr

#endif	/* NCPUS == 1 */

/*
 * Context switch routines for i386.
 */

Entry(Load_context)
	movl	S_ARG0,%ecx			/* get thread */
	movl	TH_KERNEL_STACK(%ecx),%ecx	/* get kernel stack */
	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
						/* point to stack top */
	CPU_NUMBER(%eax)
	movl	%ecx,CX(EXT(active_stacks),%eax) /* store stack address */
	movl	%edx,CX(EXT(kernel_stack),%eax)	/* store stack top */

	movl	KSS_ESP(%ecx),%esp		/* switch stacks */
	movl	KSS_ESI(%ecx),%esi		/* restore registers */
	movl	KSS_EDI(%ecx),%edi
	movl	KSS_EBP(%ecx),%ebp
	movl	KSS_EBX(%ecx),%ebx
	xorl	%eax,%eax			/* return zero (no old thread) */
	jmp	*KSS_EIP(%ecx)			/* resume thread */

/*
 *	This really only has to save registers
 *	when there is no explicit continuation.
 */

Entry(Switch_context)
	CPU_NUMBER(%edx)
	movl	CX(EXT(active_stacks),%edx),%ecx /* get old kernel stack */

	movl	%ebx,KSS_EBX(%ecx)		/* save registers */
	movl	%ebp,KSS_EBP(%ecx)
	movl	%edi,KSS_EDI(%ecx)
	movl	%esi,KSS_ESI(%ecx)
	popl	KSS_EIP(%ecx)			/* save return PC */
	movl	%esp,KSS_ESP(%ecx)		/* save SP */

	movl	0(%esp),%eax			/* return old thread */
	movl	8(%esp),%esi			/* get new thread */
	movl	TH_TOP_ACT(%esi),%ebx	/* get new_thread->top_act */
	movl    $ CPD_ACTIVE_THREAD,%ecx
	movl    %ebx,%gs:(%ecx)                /* new thread is active */
	movl	TH_KERNEL_STACK(%esi),%ecx	/* get its kernel stack */
	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
						/* point to stack top */

	movl	%ecx,CX(EXT(active_stacks),%edx) /* set current stack */
	movl	%ebx,CX(EXT(kernel_stack),%edx)	/* set stack top */


	movl	$0,CX(EXT(active_kloaded),%edx)

	movl	KSS_ESP(%ecx),%esp		/* switch stacks */
	movl	KSS_ESI(%ecx),%esi		/* restore registers */
	movl	KSS_EDI(%ecx),%edi
	movl	KSS_EBP(%ecx),%ebp
	movl	KSS_EBX(%ecx),%ebx
	jmp	*KSS_EIP(%ecx)			/* return old thread */

Entry(Thread_continue)
	pushl	%eax				/* push the thread argument */
	xorl	%ebp,%ebp			/* zero frame pointer */
	call	*%ebx				/* call real continuation */

#if	NCPUS > 1
/*
 * void switch_to_shutdown_context(thread_t thread,
 *				   void (*routine)(processor_t),
 *				   processor_t processor)
 *
 * saves the kernel context of the thread,
 * switches to the interrupt stack,
 * continues the thread (with thread_continue),
 * then runs routine on the interrupt stack.
 *
 * Assumes that the thread is a kernel thread (thus
 * has no FPU state)
 */
Entry(switch_to_shutdown_context)
	CPU_NUMBER(%edx)
	movl	EXT(active_stacks)(,%edx,4),%ecx /* get old kernel stack */
	movl	%ebx,KSS_EBX(%ecx)		/* save registers */
	movl	%ebp,KSS_EBP(%ecx)
	movl	%edi,KSS_EDI(%ecx)
	movl	%esi,KSS_ESI(%ecx)
	popl	KSS_EIP(%ecx)			/* save return PC */
	movl	%esp,KSS_ESP(%ecx)		/* save SP */

	movl	0(%esp),%eax			/* get old thread */
	movl	%ecx,TH_KERNEL_STACK(%eax)	/* save old stack */
	movl	4(%esp),%ebx			/* get routine to run next */
	movl	8(%esp),%esi			/* get its argument */

	movl	CX(EXT(interrupt_stack),%edx),%ecx /* point to its intr stack */
	lea	INTSTACK_SIZE(%ecx),%esp	/* switch to it (top) */
	
	pushl	%eax				/* push thread */
	call	EXT(thread_dispatch)		/* reschedule thread */
	addl	$4,%esp				/* clean stack */

	pushl	%esi				/* push argument */
	call	*%ebx				/* call routine to run */
	hlt					/* (should never return) */

#endif	/* NCPUS > 1 */

        .text

	.globl	EXT(locore_end)
LEXT(locore_end)
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 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	* @OSF_COPYRIGHT@
	27	*/
	28	/*
	29	* Mach Operating System
	30	* Copyright (c) 1991,1990 Carnegie Mellon University
	31	* All Rights Reserved.
	32	*
	33	* Permission to use, copy, modify and distribute this software and its
	34	* documentation is hereby granted, provided that both the copyright
	35	* notice and this permission notice appear in all copies of the
	36	* software, derivative works or modified versions, and any portions
	37	* thereof, and that both notices appear in supporting documentation.
	38	*
	39	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	40	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	41	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	42	*
	43	* Carnegie Mellon requests users of this software to return to
	44	*
	45	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	46	* School of Computer Science
	47	* Carnegie Mellon University
	48	* Pittsburgh PA 15213-3890
	49	*
	50	* any improvements or extensions that they make and grant Carnegie Mellon
	51	* the rights to redistribute these changes.
	52	*/
	53	/*
	54	*/
	55
	56	#include <cpus.h>
	57	#include <platforms.h>
	58
	59	#include <i386/asm.h>
	60	#include <i386/proc_reg.h>
	61	#include <assym.s>
	62
	63	#if NCPUS > 1
	64
	65	#ifdef SYMMETRY
	66	#include <sqt/asm_macros.h>
	67	#endif
	68
	69	#if AT386
55e303ae	70	#include <i386/mp.h>
1c79356b A	71	#endif /* AT386 */
	72
	73	#define CX(addr, reg) addr(,reg,4)
	74
	75	#else /* NCPUS == 1 */
	76
	77	#define CPU_NUMBER(reg)
	78	#define CX(addr,reg) addr
	79
	80	#endif /* NCPUS == 1 */
	81
	82	/*
	83	* Context switch routines for i386.
	84	*/
	85
	86	Entry(Load_context)
	87	movl S_ARG0,%ecx /* get thread */
	88	movl TH_KERNEL_STACK(%ecx),%ecx /* get kernel stack */
	89	lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
	90	/* point to stack top */
	91	CPU_NUMBER(%eax)
	92	movl %ecx,CX(EXT(active_stacks),%eax) /* store stack address */
	93	movl %edx,CX(EXT(kernel_stack),%eax) /* store stack top */
	94
	95	movl KSS_ESP(%ecx),%esp /* switch stacks */
	96	movl KSS_ESI(%ecx),%esi /* restore registers */
	97	movl KSS_EDI(%ecx),%edi
	98	movl KSS_EBP(%ecx),%ebp
	99	movl KSS_EBX(%ecx),%ebx
	100	xorl %eax,%eax /* return zero (no old thread) */
	101	jmp KSS_EIP(%ecx) / resume thread */
	102
	103	/*
	104	* This really only has to save registers
	105	* when there is no explicit continuation.
	106	*/
	107
	108	Entry(Switch_context)
	109	CPU_NUMBER(%edx)
	110	movl CX(EXT(active_stacks),%edx),%ecx /* get old kernel stack */
	111
	112	movl %ebx,KSS_EBX(%ecx) /* save registers */
	113	movl %ebp,KSS_EBP(%ecx)
	114	movl %edi,KSS_EDI(%ecx)
	115	movl %esi,KSS_ESI(%ecx)
	116	popl KSS_EIP(%ecx) /* save return PC */
	117	movl %esp,KSS_ESP(%ecx) /* save SP */
	118
55e303ae	119	movl 0(%esp),%eax /* return old thread */
1c79356b	120	movl 8(%esp),%esi /* get new thread */
55e303ae A	121	movl TH_TOP_ACT(%esi),%ebx /* get new_thread->top_act */
	122	movl $ CPD_ACTIVE_THREAD,%ecx
	123	movl %ebx,%gs:(%ecx) /* new thread is active */
1c79356b A	124	movl TH_KERNEL_STACK(%esi),%ecx /* get its kernel stack */
	125	lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
	126	/* point to stack top */
	127
	128	movl %ecx,CX(EXT(active_stacks),%edx) /* set current stack */
	129	movl %ebx,CX(EXT(kernel_stack),%edx) /* set stack top */
	130
55e303ae	131
1c79356b	132	movl $0,CX(EXT(active_kloaded),%edx)
55e303ae	133
1c79356b A	134	movl KSS_ESP(%ecx),%esp /* switch stacks */
	135	movl KSS_ESI(%ecx),%esi /* restore registers */
	136	movl KSS_EDI(%ecx),%edi
	137	movl KSS_EBP(%ecx),%ebp
	138	movl KSS_EBX(%ecx),%ebx
	139	jmp KSS_EIP(%ecx) / return old thread */
	140
	141	Entry(Thread_continue)
	142	pushl %eax /* push the thread argument */
	143	xorl %ebp,%ebp /* zero frame pointer */
	144	call %ebx / call real continuation */
	145
	146	#if NCPUS > 1
	147	/*
	148	* void switch_to_shutdown_context(thread_t thread,
	149	* void (*routine)(processor_t),
	150	* processor_t processor)
	151	*
	152	* saves the kernel context of the thread,
	153	* switches to the interrupt stack,
	154	* continues the thread (with thread_continue),
	155	* then runs routine on the interrupt stack.
	156	*
	157	* Assumes that the thread is a kernel thread (thus
	158	* has no FPU state)
	159	*/
	160	Entry(switch_to_shutdown_context)
	161	CPU_NUMBER(%edx)
	162	movl EXT(active_stacks)(,%edx,4),%ecx /* get old kernel stack */
	163	movl %ebx,KSS_EBX(%ecx) /* save registers */
	164	movl %ebp,KSS_EBP(%ecx)
	165	movl %edi,KSS_EDI(%ecx)
	166	movl %esi,KSS_ESI(%ecx)
	167	popl KSS_EIP(%ecx) /* save return PC */
	168	movl %esp,KSS_ESP(%ecx) /* save SP */
	169
	170	movl 0(%esp),%eax /* get old thread */
1c79356b A	171	movl %ecx,TH_KERNEL_STACK(%eax) /* save old stack */
	172	movl 4(%esp),%ebx /* get routine to run next */
	173	movl 8(%esp),%esi /* get its argument */
	174
	175	movl CX(EXT(interrupt_stack),%edx),%ecx /* point to its intr stack */
	176	lea INTSTACK_SIZE(%ecx),%esp /* switch to it (top) */
	177
	178	pushl %eax /* push thread */
	179	call EXT(thread_dispatch) /* reschedule thread */
	180	addl $4,%esp /* clean stack */
	181
	182	pushl %esi /* push argument */
	183	call %ebx / call routine to run */
	184	hlt /* (should never return) */
	185
	186	#endif /* NCPUS > 1 */
	187
	188	.text
	189
	190	.globl EXT(locore_end)
	191	LEXT(locore_end)
	192