NetBSD/sys/arch/powerpc/ibm4xx/4xx_trap_subr.S
2002-07-11 01:38:48 +00:00

159 lines
4.5 KiB
ArmAsm

/* $NetBSD: 4xx_trap_subr.S,v 1.2 2002/07/11 01:38:48 simonb Exp $ */
/*
* Copyright 2001 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
*
* 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 for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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.
*/
/* This file provides necessary handlers for 405GP CPU
* It should be included in locore.S after powerpc/powerpc/trap_subr.S
*/
.text
.globl _C_LABEL(pitfitwdog),_C_LABEL(pitfitwdogsize)
.align 4
_C_LABEL(pitfitwdog):
sync
ba pitint
.align 4
sync
ba fitint
.align 4
sync
ba wdoghandler
_C_LABEL(pitfitwdogsize) = .-_C_LABEL(pitfitwdog)
pithandler:
rfi
ba . /* Protect against prefetch */
wdoghandler:
rfi
ba . /* Protect against prefetch */
#define tlbstacksize 0x1000
#define tlbsave 0x3000
#define tlbstack tlbsave+tlbstacksize
/* If an unaligned excception (0x600) and DTLB miss exception (0x1100)
occur at the same time, the interrupt vector offsets of the two
exceptions are logically OR'ed together to produce 0x1700.
See PPC405GP Rev D/E Errata item 51 */
.globl _C_LABEL(errata51handler),_C_LABEL(errata51size)
_C_LABEL(errata51handler):
ba 0x1100
_C_LABEL(errata51size) = .-_C_LABEL(errata51handler)
.globl _C_LABEL(tlbdmiss4xx),_C_LABEL(tlbdm4size)
_C_LABEL(tlbdmiss4xx):
STANDARD_PROLOG(tlbsave)
mfdear r30 /* Get fault address */
mfesr r31
stmw r30,16+tlbsave(0)
bla s4xx_miss
_C_LABEL(tlbdm4size) = .-_C_LABEL(tlbdmiss4xx)
.globl _C_LABEL(tlbimiss4xx),_C_LABEL(tlbim4size)
_C_LABEL(tlbimiss4xx):
STANDARD_PROLOG(tlbsave)
mfsrr0 r30 /* XXX Get fault address */
mfesr r31
stmw r30,16+tlbsave(0)
bla s4xx_miss
_C_LABEL(tlbim4size) = .-_C_LABEL(tlbdmiss4xx)
s4xx_miss:
.globl _C_LABEL(pmap_tlbmiss)
/* If the kernel stack would fault, don't use it. */
mfpid r30
li r31,KERNEL_PID
mtpid r31
li r31,-FRAMELEN
tlbsx. r31,r31,r1
mtpid r30
beq 1f
/*
* The kernel we want to switch to is not in the TLB.
* To solve this problem, we will simulate a kernel
* fault on the kernel stack and let the miss handler
* bring it in, and return from the trap handler. The
* processor will immediately take the original fault,
* which we should be able to handle with the now-valid
* kernel stack.
*/
/* Switch to tlbstack */
addi r30,r1,-FRAMELEN
lis r1,tlbstack@ha
addi r1,r1,tlbstack@l
stw r30,4(1)
FRAME_SETUP(tlbsave)
/* Take an explicit fault at (kernelstack,pid) */
lwz r3, tlbstack+4(0)
li r4,KERNEL_PID
bl _C_LABEL(pmap_tlbmiss)
/*
* We can retry the old fault or switch stacks and
* take it now. It's easier to retry.
*/
mr. r3,r3
beq 2f
/* kernel stack not in the pmap? we should panic */
trap
ba trapagain
1:
FRAME_SETUP(tlbsave)
lwz r3,FRAME_DEAR+8(1)
lwz r4,FRAME_PID+8(1)
bl _C_LABEL(pmap_tlbmiss)
mr. r3,r3
beq 2f
/* XXX DEBUG -- make sure we're not on tlbstack */
addi r7,r1,-tlbsave
twllei r7,(tlbstacksize)
/* PTE not found, time to cause a fault */
ba trapagain
2:
FRAME_LEAVE(tlbsave)
rfi
ba . /* Protect against prefetch */