freebsd-dev/sys/powerpc/booke/swtch.S
Rafal Jaworowski 0a35b40f8d Make Book-E debug register state part of the PCB context.
Previously, DBCR0 flags were set "globally", but this leads to problems
because Book-E fine grained debug settings work only in conjuction with the
debug master enable bit in MSR: in scenarios when the DBCR0 was set with
intention to debug one process, but another one with MSR[DE] set got
scheduled, the latter would immediately cause debug exceptions to occur upon
execution of its own code instructions (and not the one intended for
debugging).

To avoid such problems and properly handle debugging context, DBCR0 state
should be managed individually per process.

Submitted by:	Grzegorz Bernacki gjb ! semihalf dot com
Reviewed by:	marcel
2009-02-27 12:08:24 +00:00

151 lines
5.3 KiB
ArmAsm

/*-
* 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.
*
* from: $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $
* from: $FreeBSD$
*
* $FreeBSD$
*/
/*-
* 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/psl.h>
#include <machine/asm.h>
#include <machine/spr.h>
/*
* void cpu_switch(struct thread *old, struct thread *new)
*
* Switch to a new thread saving the current state in the old thread.
*/
ENTRY(cpu_switch)
lwz %r5, TD_PCB(%r3) /* Get the old thread's PCB ptr */
mr %r12, %r2
stmw %r12, PCB_CONTEXT(%r5) /* Save the non-volatile GP regs.
These can now be used for scratch */
mfcr %r16 /* Save the condition register */
stw %r16, PCB_CR(%r5)
mflr %r16 /* Save the link register */
stw %r16, PCB_LR(%r5)
mfctr %r16
stw %r16, PCB_BOOKE_CTR(%r5)
mfxer %r16
stw %r16, PCB_BOOKE_XER(%r5)
mfspr %r16, SPR_DBCR0
stw %r16, PCB_BOOKE_DBCR0(%r5)
stw %r1, PCB_SP(%r5) /* Save the stack pointer */
mr %r14, %r3 /* Copy the old thread ptr... */
mr %r15, %r4 /* and the new thread ptr in scratch */
bl pmap_deactivate /* Deactivate the current pmap */
mr %r3, %r15 /* Get new thread ptr */
bl pmap_activate /* Activate the new address space */
mfsprg %r7, 0 /* Get the pcpu pointer */
stw %r15, PC_CURTHREAD(%r7) /* Store new current thread */
lwz %r17, TD_PCB(%r15) /* Store new current PCB */
stw %r17, PC_CURPCB(%r7)
mr %r3, %r17 /* Recover PCB ptr */
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_BOOKE_CTR(%r3)
mtctr %r5
lwz %r5, PCB_BOOKE_XER(%r3)
mtxer %r5
lwz %r5, PCB_BOOKE_DBCR0(%r3)
mtspr SPR_DBCR0, %r5
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,CF_SIZE-FSP /* Allow 8 bytes in front of
trapframe to simulate FRAME_SETUP
does when allocating space for
a frame pointer/saved LR */
b trapexit