swtch64.S revision 174599
1/* $FreeBSD: head/sys/powerpc/aim/swtch.S 172887 2007-10-23 00:52:25Z grehan $ */
2/* $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $ */
3
4/*-
5 * Copyright (C) 2001 Benno Rice
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27*/
28/*-
29 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
30 * Copyright (C) 1995, 1996 TooLs GmbH.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 *    must display the following acknowledgement:
43 *	This product includes software developed by TooLs GmbH.
44 * 4. The name of TooLs GmbH may not be used to endorse or promote products
45 *    derived from this software without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
50 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
51 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
52 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
53 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
54 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
55 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
56 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
57 */
58
59#include "assym.s"
60
61#include <sys/syscall.h>
62
63#include <machine/trap.h>
64#include <machine/param.h>
65#include <machine/sr.h>
66#include <machine/psl.h>
67#include <machine/asm.h>
68
69/*
70 * void cpu_switch(struct thread *old,
71 *		   struct thread *new,
72 *		   struct mutex *mtx);
73 *
74 * Switch to a new thread saving the current state in the old thread.
75 */
76ENTRY(cpu_switch)
77	stw	%r5,TD_LOCK(%r3)	/* ULE:	update old thread's lock */
78					/* XXX needs to change for MP */
79
80	lwz	%r5,TD_PCB(%r3)		/* Get the old thread's PCB ptr */
81	mr	%r12,%r2
82	stmw	%r12,PCB_CONTEXT(%r5)	/* Save the non-volatile GP regs.
83					   These can now be used for scratch */
84
85	mfcr	%r16			/* Save the condition register */
86	stw	%r16,PCB_CR(%r5)
87	mflr	%r16			/* Save the link register */
88	stw	%r16,PCB_LR(%r5)
89	mfsr	%r16,USER_SR		/* Save USER_SR for copyin/out */
90	isync
91	stw	%r16,PCB_USR(%r5)
92	stw	%r1,PCB_SP(%r5)		/* Save the stack pointer */
93
94	mr	%r14,%r3		/* Copy the old thread ptr... */
95	mr	%r15,%r4		/* and the new thread ptr in scratch */
96
97	lwz	%r6,PCB_FLAGS(%r5)	/* Save FPU context if needed */
98	andi.	%r6, %r6, PCB_FPU
99	beq	.L1
100	bl	save_fpu
101	mr	%r3,%r14		/* restore old thread ptr */
102.L1:
103	bl	pmap_deactivate		/* Deactivate the current pmap */
104
105	mr	%r3,%r15		/* Get new thread ptr */
106	bl	pmap_activate		/* Activate the new address space */
107
108	mfsprg	%r7,0			/* Get the pcpu pointer */
109	stw	%r15,PC_CURTHREAD(%r7)	/* Store new current thread */
110	lwz	%r17,TD_PCB(%r15)	/* Store new current PCB */
111	stw	%r17,PC_CURPCB(%r7)
112
113	lwz	%r6, PCB_FLAGS(%r17)	/* Restore FPU context if needed */
114	andi.	%r6, %r6, PCB_FPU
115	beq	.L2
116	mr	%r3,%r15		/* Pass curthread to enable_fpu */
117	bl	enable_fpu
118
119	/* thread to restore is in r3 */
120.L2:
121	mr	%r3,%r17		/* Recover PCB ptr */
122	lmw	%r12,PCB_CONTEXT(%r3)	/* Load the non-volatile GP regs */
123	mr	%r2,%r12
124	lwz	%r5,PCB_CR(%r3)		/* Load the condition register */
125	mtcr	%r5
126	lwz	%r5,PCB_LR(%r3)		/* Load the link register */
127	mtlr	%r5
128	lwz	%r5,PCB_USR(%r3)	/* Load the USER_SR segment reg */
129	mtsr	USER_SR,%r5
130	isync
131	lwz	%r1,PCB_SP(%r3)		/* Load the stack pointer */
132	blr
133
134/*
135 * savectx(pcb)
136 * Update pcb, saving current processor state
137 */
138ENTRY(savectx)
139	mr	%r12,%r2
140	stmw	%r12,PCB_CONTEXT(%r3)	/* Save the non-volatile GP regs */
141	mfcr	%r4			/* Save the condition register */
142	stw	%r4,PCB_CONTEXT(%r3)
143	blr
144
145/*
146 * fork_trampoline()
147 * Set up the return from cpu_fork()
148 */
149ENTRY(fork_trampoline)
150	lwz	%r3,CF_FUNC(%r1)
151	lwz	%r4,CF_ARG0(%r1)
152	lwz	%r5,CF_ARG1(%r1)
153	bl	fork_exit
154	addi	%r1,%r1,CF_SIZE-FSP	/* Allow 8 bytes in front of
155					   trapframe to simulate FRAME_SETUP
156					   does when allocating space for
157					   a frame pointer/saved LR */
158	b	trapexit
159