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

/*
 * Copyright (c) 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@
 */
/*
 * @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/AT386/mp/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			/* get old thread */
	movl	4(%esp),%ebx			/* get continuation */
	movl	%ebx,TH_CONTINUATION(%eax)	/* save continuation */
	movl	%ecx,TH_KERNEL_STACK(%eax)	/* save kernel stack */

	movl	8(%esp),%esi			/* get new thread */
        movl    $ CPD_ACTIVE_THREAD,%ecx
        movl    %esi,%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	TH_TOP_ACT(%esi),%esi		/* get new_thread->top_act */
	cmpl	$0,ACT_KLOADED(%esi)		/* check kernel-loaded flag */
	je	0f
	movl	%esi,CX(EXT(active_kloaded),%edx)
	jmp	1f
0:
	movl	$0,CX(EXT(active_kloaded),%edx)
1:
	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	$0,TH_CONTINUATION(%eax)	/* clear continuation */
	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	*
de355530 A	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.
1c79356b	11	*
de355530 A	12	* This Original Code and all software distributed under the License are
de355530 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
de355530 A	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.
1c79356b A	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* Mach Operating System
	27	* Copyright (c) 1991,1990 Carnegie Mellon University
	28	* All Rights Reserved.
	29	*
	30	* Permission to use, copy, modify and distribute this software and its
	31	* documentation is hereby granted, provided that both the copyright
	32	* notice and this permission notice appear in all copies of the
	33	* software, derivative works or modified versions, and any portions
	34	* thereof, and that both notices appear in supporting documentation.
	35	*
	36	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	37	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	38	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	39	*
	40	* Carnegie Mellon requests users of this software to return to
	41	*
	42	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	43	* School of Computer Science
	44	* Carnegie Mellon University
	45	* Pittsburgh PA 15213-3890
	46	*
	47	* any improvements or extensions that they make and grant Carnegie Mellon
	48	* the rights to redistribute these changes.
	49	*/
	50	/*
	51	*/
	52
	53	#include <cpus.h>
	54	#include <platforms.h>
	55
	56	#include <i386/asm.h>
	57	#include <i386/proc_reg.h>
	58	#include <assym.s>
	59
	60	#if NCPUS > 1
	61
	62	#ifdef SYMMETRY
	63	#include <sqt/asm_macros.h>
	64	#endif
	65
	66	#if AT386
	67	#include <i386/AT386/mp/mp.h>
	68	#endif /* AT386 */
	69
	70	#define CX(addr, reg) addr(,reg,4)
	71
	72	#else /* NCPUS == 1 */
	73
	74	#define CPU_NUMBER(reg)
	75	#define CX(addr,reg) addr
	76
	77	#endif /* NCPUS == 1 */
	78
	79	/*
	80	* Context switch routines for i386.
	81	*/
	82
83	Entry(Load_context)
84	movl S_ARG0,%ecx /* get thread */
85	movl TH_KERNEL_STACK(%ecx),%ecx /* get kernel stack */
86	lea KERNEL_STACK_SIZE-IKS_SIZE-IEL_SIZE(%ecx),%edx
87	/* point to stack top */
88	CPU_NUMBER(%eax)
89	movl %ecx,CX(EXT(active_stacks),%eax) /* store stack address */
90	movl %edx,CX(EXT(kernel_stack),%eax) /* store stack top */
91
92	movl KSS_ESP(%ecx),%esp /* switch stacks */
93	movl KSS_ESI(%ecx),%esi /* restore registers */
94	movl KSS_EDI(%ecx),%edi
95	movl KSS_EBP(%ecx),%ebp
96	movl KSS_EBX(%ecx),%ebx
97	xorl %eax,%eax /* return zero (no old thread) */
98	jmp KSS_EIP(%ecx) / resume thread */
99
100	/*
101	* This really only has to save registers
102	* when there is no explicit continuation.
103	*/
104
105	Entry(Switch_context)
106	CPU_NUMBER(%edx)
107	movl CX(EXT(active_stacks),%edx),%ecx /* get old kernel stack */
108
109	movl %ebx,KSS_EBX(%ecx) /* save registers */
110	movl %ebp,KSS_EBP(%ecx)
111	movl %edi,KSS_EDI(%ecx)
112	movl %esi,KSS_ESI(%ecx)
113	popl KSS_EIP(%ecx) /* save return PC */
114	movl %esp,KSS_ESP(%ecx) /* save SP */
115
116	movl 0(%esp),%eax /* get old thread */
117	movl 4(%esp),%ebx /* get continuation */
118	movl %ebx,TH_CONTINUATION(%eax) /* save continuation */
119	movl %ecx,TH_KERNEL_STACK(%eax) /* save kernel stack */
120
121	movl 8(%esp),%esi /* get new thread */
9bccf70c	122	movl $ CPD_ACTIVE_THREAD,%ecx
1c79356b A	123	movl %esi,%gs:(%ecx) /* new thread is active */
	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
	131	movl TH_TOP_ACT(%esi),%esi /* get new_thread->top_act */
	132	cmpl $0,ACT_KLOADED(%esi) /* check kernel-loaded flag */
	133	je 0f
	134	movl %esi,CX(EXT(active_kloaded),%edx)
	135	jmp 1f
	136	0:
	137	movl $0,CX(EXT(active_kloaded),%edx)
	138	1:
	139	movl KSS_ESP(%ecx),%esp /* switch stacks */
	140	movl KSS_ESI(%ecx),%esi /* restore registers */
	141	movl KSS_EDI(%ecx),%edi
	142	movl KSS_EBP(%ecx),%ebp
	143	movl KSS_EBX(%ecx),%ebx
	144	jmp KSS_EIP(%ecx) / return old thread */
	145
	146	Entry(Thread_continue)
	147	pushl %eax /* push the thread argument */
	148	xorl %ebp,%ebp /* zero frame pointer */
	149	call %ebx / call real continuation */
	150
	151	#if NCPUS > 1
	152	/*
	153	* void switch_to_shutdown_context(thread_t thread,
	154	* void (*routine)(processor_t),
	155	* processor_t processor)
	156	*
	157	* saves the kernel context of the thread,
	158	* switches to the interrupt stack,
	159	* continues the thread (with thread_continue),
	160	* then runs routine on the interrupt stack.
	161	*
	162	* Assumes that the thread is a kernel thread (thus
	163	* has no FPU state)
	164	*/
	165	Entry(switch_to_shutdown_context)
	166	CPU_NUMBER(%edx)
	167	movl EXT(active_stacks)(,%edx,4),%ecx /* get old kernel stack */
	168	movl %ebx,KSS_EBX(%ecx) /* save registers */
	169	movl %ebp,KSS_EBP(%ecx)
	170	movl %edi,KSS_EDI(%ecx)
	171	movl %esi,KSS_ESI(%ecx)
	172	popl KSS_EIP(%ecx) /* save return PC */
	173	movl %esp,KSS_ESP(%ecx) /* save SP */
	174
	175	movl 0(%esp),%eax /* get old thread */
	176	movl $0,TH_CONTINUATION(%eax) /* clear continuation */
	177	movl %ecx,TH_KERNEL_STACK(%eax) /* save old stack */
	178	movl 4(%esp),%ebx /* get routine to run next */
	179	movl 8(%esp),%esi /* get its argument */
	180
	181	movl CX(EXT(interrupt_stack),%edx),%ecx /* point to its intr stack */
	182	lea INTSTACK_SIZE(%ecx),%esp /* switch to it (top) */
	183
	184	pushl %eax /* push thread */
	185	call EXT(thread_dispatch) /* reschedule thread */
	186	addl $4,%esp /* clean stack */
187
188	pushl %esi /* push argument */
189	call %ebx / call routine to run */
190	hlt /* (should never return) */
191
192	#endif /* NCPUS > 1 */
193
194	.text
195
196	.globl EXT(locore_end)
197	LEXT(locore_end)
198