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freebsd/sys/powerpc/aim/swtch.S
Peter Grehan f86c114f3d Add the USER_SR segment register to pcb state. Initialize correctly,
and save/restore during a context switch.

The USER_SR could be overwritten when the current thread was switched
out with a faulting copyin/copyout.

Approved by: Benno
2002-10-21 05:27:41 +00:00

162 lines
5.5 KiB
ArmAsm

/* $FreeBSD$ */
/* $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $ */
/*
* Copyright (C) 2001 Benno Rice
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "assym.s"
#include <sys/syscall.h>
#include <machine/trap.h>
#include <machine/param.h>
#include <machine/sr.h>
#include <machine/psl.h>
#include <machine/asm.h>
/*
* void cpu_switch()
* Find a runnable thread and switch to it.
*/
ENTRY(cpu_switch)
mfsprg %r3,0 /* Get the pcpu pointer */
lwz %r4,PC_CURTHREAD(%r3) /* Get the current thread */
lwz %r3,TD_PCB(%r4) /* Get a pointer to the PCB */
mr %r12,%r2
stmw %r12,PCB_CONTEXT(%r3) /* Save the non-volatile GP regs */
mr %r14,%r3 /* Copy the current pcb pointer */
mr %r15,%r4 /* ... and the curthread pointer */
mfcr %r16 /* Save the condition register */
stw %r16,PCB_CR(%r3)
mflr %r16 /* Save the link register */
stw %r16,PCB_LR(%r3)
mfsr %r16,USER_SR /* Save USER_SR for copyin/out */
isync
stw %r16,PCB_USR(%r3)
stw %r1,PCB_SP(%r3) /* Save the stack pointer */
#if 0
lwz %r29,PCB_FLAGS(%r3)
andi. %r9, %r29, 1 /* XXX - don't hard code */
beq .L1
bl save_fpu
#endif
.L1:
bl choosethread /* Find a new thread to run */
cmplw 0,%r3,%r15 /* Compare to curthread */
beq .L2 /* If it's the same, we're done */
mr %r16,%r3 /* Save off the (struct thread *) */
mr %r3,%r15
bl pmap_deactivate /* Deactivate the current pmap */
mr %r3,%r16
bl pmap_activate /* Activate the new address space */
mfsprg %r4,0 /* Get the pcpu pointer */
stw %r16,PC_CURTHREAD(%r4) /* Store new current thread */
mr %r3,%r16 /* and save in r3 */
lwz %r16,TD_PCB(%r16) /* Store new current PCB */
stw %r16,PC_CURPCB(%r4)
#if 0
lwz %r29, PCB_FLAGS(%r4) /* Restore FPU regs if needed */
andi. %r9, %r29, 1
beq .L2
mr %r3, %r4
bl enable_fpu
#endif
/* thread to restore is in r3 */
.L2:
lwz %r3, TD_PCB(%r3)
lmw %r12,PCB_CONTEXT(%r3) /* Load the non-volatile GP regs */
mr %r2,%r12
lwz %r5,PCB_CR(%r3) /* Load the condition register */
mtcr %r5
lwz %r5,PCB_LR(%r3) /* Load the link register */
mtlr %r5
lwz %r5,PCB_USR(%r3) /* Load the USER_SR segment reg */
mtsr USER_SR,%r5
isync
lwz %r1,PCB_SP(%r3) /* Load the stack pointer */
blr
/*
* savectx(pcb)
* Update pcb, saving current processor state
*/
ENTRY(savectx)
mr %r12,%r2
stmw %r12,PCB_CONTEXT(%r3) /* Save the non-volatile GP regs */
mfcr %r4 /* Save the condition register */
stw %r4,PCB_CONTEXT(%r3)
blr
/*
* fork_trampoline()
* Set up the return from cpu_fork()
*/
ENTRY(fork_trampoline)
lwz %r3,CF_FUNC(%r1)
lwz %r4,CF_ARG0(%r1)
lwz %r5,CF_ARG1(%r1)
bl fork_exit
addi %r1,%r1,4
b trapexit