xref: /freebsd/sys/powerpc/powerpc/swtch32.S (revision d6b92ffa)
1/* $FreeBSD$ */
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#include "opt_sched.h"
61
62#include <sys/syscall.h>
63
64#include <machine/trap.h>
65#include <machine/param.h>
66#include <machine/asm.h>
67#include <machine/spr.h>
68
69/*
70 * void cpu_throw(struct thread *old, struct thread *new)
71 */
72ENTRY(cpu_throw)
73	mr	%r2, %r4
74	li	%r14,0	/* Tell cpu_switchin not to release a thread */
75
76	b	cpu_switchin
77
78/*
79 * void cpu_switch(struct thread *old,
80 *		   struct thread *new,
81 *		   struct mutex *mtx);
82 *
83 * Switch to a new thread saving the current state in the old thread.
84 */
85ENTRY(cpu_switch)
86	lwz	%r6,TD_PCB(%r3)		/* Get the old thread's PCB ptr */
87	stmw	%r12,PCB_CONTEXT(%r6)	/* Save the non-volatile GP regs.
88					   These can now be used for scratch */
89
90	mfcr	%r16			/* Save the condition register */
91	stw	%r16,PCB_CR(%r6)
92	mflr	%r16			/* Save the link register */
93	stw	%r16,PCB_LR(%r6)
94	stw	%r1,PCB_SP(%r6)		/* Save the stack pointer */
95
96	mr	%r14,%r3		/* Copy the old thread ptr... */
97	mr	%r2,%r4			/* and the new thread ptr in curthread */
98	mr	%r16,%r5		/* and the new lock */
99	mr	%r17,%r6		/* and the PCB */
100
101	lwz	%r7,PCB_FLAGS(%r17)
102	/* Save FPU context if needed */
103	andi.	%r7, %r7, PCB_FPU
104	beq	.L1
105	bl	save_fpu
106
107.L1:
108	mr	%r3,%r14		/* restore old thread ptr */
109	lwz	%r7,PCB_FLAGS(%r17)
110	/* Save Altivec context if needed */
111	andi.	%r7, %r7, PCB_VEC
112	beq	.L2
113	bl	save_vec
114
115.L2:
116	mr	%r3,%r14		/* restore old thread ptr */
117	bl	pmap_deactivate		/* Deactivate the current pmap */
118
119	sync				/* Make sure all of that finished */
120
121cpu_switchin:
122#if defined(SMP) && defined(SCHED_ULE)
123	/* Wait for the new thread to become unblocked */
124	bl	_GLOBAL_OFFSET_TABLE_@local-4
125	mflr	%r6
126	lwz	%r6,blocked_lock@got(%r6)
127blocked_loop:
128	lwz	%r7,TD_LOCK(%r2)
129	cmpw	%r6,%r7
130	beq-	blocked_loop
131	isync
132#endif
133
134	lwz	%r17,TD_PCB(%r2)	/* Get new current PCB */
135	lwz	%r1,PCB_SP(%r17)	/* Load new stack pointer */
136
137	/* Release old thread now that we have a stack pointer set up */
138	cmpwi	%r14,0
139	beq-	1f
140	stw	%r16,TD_LOCK(%r14)	/* ULE:	update old thread's lock */
141
1421:	mfsprg	%r7,0			/* Get the pcpu pointer */
143	stw	%r2,PC_CURTHREAD(%r7)	/* Store new current thread */
144	lwz	%r17,TD_PCB(%r2)	/* Store new current PCB */
145	stw	%r17,PC_CURPCB(%r7)
146
147	mr	%r3,%r2			/* Get new thread ptr */
148	bl	pmap_activate		/* Activate the new address space */
149
150	lwz	%r6, PCB_FLAGS(%r17)
151	/* Restore FPU context if needed */
152	andi.	%r6, %r6, PCB_FPU
153	beq	.L3
154	mr	%r3,%r2			/* Pass curthread to enable_fpu */
155	bl	enable_fpu
156
157.L3:
158	lwz	%r6, PCB_FLAGS(%r17)
159	/* Restore Altivec context if needed */
160	andi.	%r6, %r6, PCB_VEC
161	beq	.L4
162	mr	%r3,%r2			/* Pass curthread to enable_vec */
163	bl	enable_vec
164
165.L4:
166	/* thread to restore is in r3 */
167	mr	%r3,%r17		/* Recover PCB ptr */
168	lmw	%r12,PCB_CONTEXT(%r3)	/* Load the non-volatile GP regs */
169	lwz	%r5,PCB_CR(%r3)		/* Load the condition register */
170	mtcr	%r5
171	lwz	%r5,PCB_LR(%r3)		/* Load the link register */
172	mtlr	%r5
173	lwz	%r1,PCB_SP(%r3)		/* Load the stack pointer */
174	/*
175	 * Perform a dummy stwcx. to clear any reservations we may have
176	 * inherited from the previous thread. It doesn't matter if the
177	 * stwcx succeeds or not. pcb_context[0] can be clobbered.
178	 */
179	stwcx.	%r1, 0, %r3
180	blr
181
182/*
183 * savectx(pcb)
184 * Update pcb, saving current processor state
185 */
186ENTRY(savectx)
187	stmw	%r12,PCB_CONTEXT(%r3)	/* Save the non-volatile GP regs */
188	mfcr	%r4			/* Save the condition register */
189	stw	%r4,PCB_CR(%r3)
190	mflr	%r4			/* Save the link register */
191	stw	%r4,PCB_LR(%r3)
192	blr
193
194/*
195 * fork_trampoline()
196 * Set up the return from cpu_fork()
197 */
198ENTRY(fork_trampoline)
199	lwz	%r3,CF_FUNC(%r1)
200	lwz	%r4,CF_ARG0(%r1)
201	lwz	%r5,CF_ARG1(%r1)
202	bl	fork_exit
203	addi	%r1,%r1,CF_SIZE-FSP	/* Allow 8 bytes in front of
204					   trapframe to simulate FRAME_SETUP
205					   does when allocating space for
206					   a frame pointer/saved LR */
207	b	trapexit
208