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

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_OSREFERENCE_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_LICENSE_OSREFERENCE_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 <platforms.h>

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

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

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

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

/*
 * 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 */
	movl	%ecx,%gs:CPU_ACTIVE_STACK	/* store stack address */
	movl	%edx,%gs:CPU_KERNEL_STACK	/* store stack top */

	movl	%edx,%esp
	movl	%edx,%ebp

	xorl	%eax,%eax			/* return zero (no old thread) */
	pushl	%eax
	call	EXT(thread_continue)

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

Entry(Switch_context)
	movl	%gs:CPU_ACTIVE_STACK,%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),%ebx			/* get new thread */
	movl    %ebx,%gs:CPU_ACTIVE_THREAD                /* new thread is active */
	movl	TH_KERNEL_STACK(%ebx),%ecx	/* get its kernel stack */
	lea	KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
						/* point to stack top */

	movl	%ecx,%gs:CPU_ACTIVE_STACK	/* set current stack */
	movl	%ebx,%gs:CPU_KERNEL_STACK	/* set stack top */


	movl	$0,%gs:CPU_ACTIVE_KLOADED

	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 */

/*
 * void machine_processor_shutdown(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(machine_processor_shutdown)
	movl	%gs:CPU_ACTIVE_STACK,%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	%gs:CPU_INT_STACK_TOP,%esp 	/* switch to interrupt stack */

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


        .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	*
8ad349bb	4	* @APPLE_LICENSE_OSREFERENCE_HEADER_START@
1c79356b	5	*
8ad349bb 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
	10	* License may not be used to create, or enable the creation or
	11	* redistribution of, unlawful or unlicensed copies of an Apple operating
	12	* system, or to circumvent, violate, or enable the circumvention or
	13	* violation of, any terms of an Apple operating system software license
	14	* agreement.
	15	*
	16	* Please obtain a copy of the License at
	17	* http://www.opensource.apple.com/apsl/ and read it before using this
	18	* file.
	19	*
	20	* The Original Code and all software distributed under the License are
	21	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	22	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	23	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	24	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	25	* Please see the License for the specific language governing rights and
	26	* limitations under the License.
	27	*
	28	* @APPLE_LICENSE_OSREFERENCE_HEADER_END@
1c79356b A	29	*/
	30	/*
	31	* @OSF_COPYRIGHT@
	32	*/
	33	/*
	34	* Mach Operating System
	35	* Copyright (c) 1991,1990 Carnegie Mellon University
	36	* All Rights Reserved.
	37	*
	38	* Permission to use, copy, modify and distribute this software and its
	39	* documentation is hereby granted, provided that both the copyright
	40	* notice and this permission notice appear in all copies of the
	41	* software, derivative works or modified versions, and any portions
	42	* thereof, and that both notices appear in supporting documentation.
	43	*
	44	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	45	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	46	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	47	*
	48	* Carnegie Mellon requests users of this software to return to
	49	*
	50	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	51	* School of Computer Science
	52	* Carnegie Mellon University
	53	* Pittsburgh PA 15213-3890
	54	*
	55	* any improvements or extensions that they make and grant Carnegie Mellon
	56	* the rights to redistribute these changes.
	57	*/
	58	/*
	59	*/
	60
1c79356b A	61	#include <platforms.h>
	62
	63	#include <i386/asm.h>
	64	#include <i386/proc_reg.h>
	65	#include <assym.s>
	66
1c79356b A	67	#ifdef SYMMETRY
	68	#include <sqt/asm_macros.h>
	69	#endif
	70
	71	#if AT386
55e303ae	72	#include <i386/mp.h>
1c79356b A	73	#endif /* AT386 */
	74
	75	#define CX(addr, reg) addr(,reg,4)
	76
1c79356b A	77	/*
	78	* Context switch routines for i386.
	79	*/
	80
	81	Entry(Load_context)
	82	movl S_ARG0,%ecx /* get thread */
	83	movl TH_KERNEL_STACK(%ecx),%ecx /* get kernel stack */
	84	lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
	85	/* point to stack top */
91447636 A	86	movl %ecx,%gs:CPU_ACTIVE_STACK /* store stack address */
	87	movl %edx,%gs:CPU_KERNEL_STACK /* store stack top */
	88
	89	movl %edx,%esp
	90	movl %edx,%ebp
1c79356b	91
1c79356b	92	xorl %eax,%eax /* return zero (no old thread) */
91447636 A	93	pushl %eax
91447636 A	94	call EXT(thread_continue)
1c79356b A	95
1c79356b A	96	/*
8ad349bb	97	* This really only has to save registers
1c79356b A	98	* when there is no explicit continuation.
	99	*/
	100
	101	Entry(Switch_context)
8ad349bb	102	movl %gs:CPU_ACTIVE_STACK,%ecx /* get old kernel stack */
1c79356b A	103
	104	movl %ebx,KSS_EBX(%ecx) /* save registers */
	105	movl %ebp,KSS_EBP(%ecx)
	106	movl %edi,KSS_EDI(%ecx)
	107	movl %esi,KSS_ESI(%ecx)
8ad349bb	108	popl KSS_EIP(%ecx) /* save return PC */
1c79356b	109	movl %esp,KSS_ESP(%ecx) /* save SP */
8ad349bb	110
55e303ae	111	movl 0(%esp),%eax /* return old thread */
91447636	112	movl 8(%esp),%ebx /* get new thread */
8ad349bb	113	movl %ebx,%gs:CPU_ACTIVE_THREAD /* new thread is active */
91447636	114	movl TH_KERNEL_STACK(%ebx),%ecx /* get its kernel stack */
1c79356b A	115	lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%ebx
	116	/* point to stack top */
	117
91447636 A	118	movl %ecx,%gs:CPU_ACTIVE_STACK /* set current stack */
91447636 A	119	movl %ebx,%gs:CPU_KERNEL_STACK /* set stack top */
1c79356b	120
8ad349bb A	121
	122	movl $0,%gs:CPU_ACTIVE_KLOADED
	123
1c79356b A	124	movl KSS_ESP(%ecx),%esp /* switch stacks */
	125	movl KSS_ESI(%ecx),%esi /* restore registers */
	126	movl KSS_EDI(%ecx),%edi
	127	movl KSS_EBP(%ecx),%ebp
	128	movl KSS_EBX(%ecx),%ebx
	129	jmp KSS_EIP(%ecx) / return old thread */
	130
	131	Entry(Thread_continue)
	132	pushl %eax /* push the thread argument */
	133	xorl %ebp,%ebp /* zero frame pointer */
	134	call %ebx / call real continuation */
	135
1c79356b	136	/*
8ad349bb A	137	* void machine_processor_shutdown(thread_t thread,
	138	* void (*routine)(processor_t),
	139	* processor_t processor)
1c79356b A	140	*
	141	* saves the kernel context of the thread,
	142	* switches to the interrupt stack,
	143	* continues the thread (with thread_continue),
	144	* then runs routine on the interrupt stack.
	145	*
8ad349bb A	146	* Assumes that the thread is a kernel thread (thus
8ad349bb A	147	* has no FPU state)
1c79356b	148	*/
8ad349bb	149	Entry(machine_processor_shutdown)
91447636	150	movl %gs:CPU_ACTIVE_STACK,%ecx /* get old kernel stack */
1c79356b A	151	movl %ebx,KSS_EBX(%ecx) /* save registers */
	152	movl %ebp,KSS_EBP(%ecx)
	153	movl %edi,KSS_EDI(%ecx)
	154	movl %esi,KSS_ESI(%ecx)
	155	popl KSS_EIP(%ecx) /* save return PC */
	156	movl %esp,KSS_ESP(%ecx) /* save SP */
	157
	158	movl 0(%esp),%eax /* get old thread */
1c79356b A	159	movl %ecx,TH_KERNEL_STACK(%eax) /* save old stack */
	160	movl 4(%esp),%ebx /* get routine to run next */
	161	movl 8(%esp),%esi /* get its argument */
	162
91447636	163	movl %gs:CPU_INT_STACK_TOP,%esp /* switch to interrupt stack */
1c79356b A	164
	165	pushl %esi /* push argument */
	166	call %ebx / call routine to run */
	167	hlt /* (should never return) */
8ad349bb A	168
	169
	170	.text
	171
	172	.globl EXT(locore_end)
	173	LEXT(locore_end)
	174