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freebsd-skq/sys/powerpc/aim/trap_subr64.S
nwhitehorn ecfb41d217 Restructure the way the copyin/copyout segment is stored to prevent a 
concurrency bug. Since all SLB/SR entries were invalidated during an
exception, a decrementer exception could cause the user segment to be
invalidated during a copyin()/copyout() without a thread switch that
would cause it to be restored from the PCB, potentially causing the
operation to continue on invalid memory. This is now handled by explicit
restoration of segment 12 from the PCB on 32-bit systems and a check in
the Data Segment Exception handler on 64-bit.

While here, cause copyin()/copyout() to check whether the requested
user segment is already installed, saving some pipeline flushes, and
fix the synchronization primitives around the mtsr and slbmte
instructions to prevent accessing stale segments.

MFC after:	2 weeks
2010-10-30 23:07:30 +00:00

649 lines
19 KiB
ArmAsm
Raw Blame History

/* $FreeBSD$ */
/* $NetBSD: trap_subr.S,v 1.20 2002/04/22 23:20:08 kleink Exp $ */
/*-
* 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.
*/
/*
* NOTICE: This is not a standalone file. to use it, #include it in
* your port's locore.S, like so:
*
* #include <powerpc/aim/trap_subr.S>
*/
/*
* Save/restore segment registers
*/
/*
* Restore SRs for a pmap
*
* Requires that r28-r31 be scratch, with r28 initialized to the SLB cache
*/
/*
* User SRs are loaded through a pointer to the current pmap.
*/
restore_usersrs:
GET_CPUINFO(%r28);
ld %r28,PC_USERSLB(%r28);
li %r29, 0 /* Set the counter to zero */
slbia
slbmfee %r31,%r29
clrrdi %r31,%r31,28
slbie %r31
instuserslb:
ld %r31, 0(%r28); /* Load SLB entry pointer */
cmpli 0, %r31, 0; /* If NULL, stop */
beqlr;
ld %r30, 0(%r31) /* Load SLBV */
ld %r31, 8(%r31) /* Load SLBE */
or %r31, %r31, %r29 /* Set SLBE slot */
slbmte %r30, %r31; /* Install SLB entry */
addi %r28, %r28, 8; /* Advance pointer */
addi %r29, %r29, 1;
cmpli 0, %r29, 64; /* Repeat if we are not at the end */
blt instuserslb;
blr;
/*
* Kernel SRs are loaded directly from the PCPU fields
*/
restore_kernsrs:
GET_CPUINFO(%r28);
addi %r28,%r28,PC_KERNSLB;
li %r29, 0 /* Set the counter to zero */
slbia
slbmfee %r31,%r29
clrrdi %r31,%r31,28
slbie %r31
instkernslb:
ld %r31, 8(%r28); /* Load SLBE */
cmpli 0, %r31, 0; /* If SLBE is not valid, stop */
beqlr;
ld %r30, 0(%r28) /* Load SLBV */
slbmte %r30, %r31; /* Install SLB entry */
addi %r28, %r28, 16; /* Advance pointer */
addi %r29, %r29, 1;
cmpli 0, %r29, USER_SLB_SLOT; /* Repeat if we are not at the end */
blt instkernslb;
blr;
/*
* FRAME_SETUP assumes:
* SPRG1 SP (1)
* SPRG3 trap type
* savearea r27-r31,DAR,DSISR (DAR & DSISR only for DSI traps)
* r28 LR
* r29 CR
* r30 scratch
* r31 scratch
* r1 kernel stack
* SRR0/1 as at start of trap
*/
#define FRAME_SETUP(savearea) \
/* Have to enable translation to allow access of kernel stack: */ \
GET_CPUINFO(%r31); \
mfsrr0 %r30; \
std %r30,(savearea+CPUSAVE_SRR0)(%r31); /* save SRR0 */ \
mfsrr1 %r30; \
std %r30,(savearea+CPUSAVE_SRR1)(%r31); /* save SRR1 */ \
mfmsr %r30; \
ori %r30,%r30,(PSL_DR|PSL_IR|PSL_RI)@l; /* relocation on */ \
mtmsr %r30; /* stack can now be accessed */ \
isync; \
mfsprg1 %r31; /* get saved SP */ \
stdu %r31,-(FRAMELEN+288)(%r1); /* save it in the callframe */ \
std %r0, FRAME_0+48(%r1); /* save r0 in the trapframe */ \
std %r31,FRAME_1+48(%r1); /* save SP " " */ \
std %r2, FRAME_2+48(%r1); /* save r2 " " */ \
std %r28,FRAME_LR+48(%r1); /* save LR " " */ \
std %r29,FRAME_CR+48(%r1); /* save CR " " */ \
GET_CPUINFO(%r2); \
ld %r27,(savearea+CPUSAVE_R27)(%r2); /* get saved r27 */ \
ld %r28,(savearea+CPUSAVE_R28)(%r2); /* get saved r28 */ \
ld %r29,(savearea+CPUSAVE_R29)(%r2); /* get saved r29 */ \
ld %r30,(savearea+CPUSAVE_R30)(%r2); /* get saved r30 */ \
ld %r31,(savearea+CPUSAVE_R31)(%r2); /* get saved r31 */ \
std %r3, FRAME_3+48(%r1); /* save r3-r31 */ \
std %r4, FRAME_4+48(%r1); \
std %r5, FRAME_5+48(%r1); \
std %r6, FRAME_6+48(%r1); \
std %r7, FRAME_7+48(%r1); \
std %r8, FRAME_8+48(%r1); \
std %r9, FRAME_9+48(%r1); \
std %r10, FRAME_10+48(%r1); \
std %r11, FRAME_11+48(%r1); \
std %r12, FRAME_12+48(%r1); \
std %r13, FRAME_13+48(%r1); \
std %r14, FRAME_14+48(%r1); \
std %r15, FRAME_15+48(%r1); \
std %r16, FRAME_16+48(%r1); \
std %r17, FRAME_17+48(%r1); \
std %r18, FRAME_18+48(%r1); \
std %r19, FRAME_19+48(%r1); \
std %r20, FRAME_20+48(%r1); \
std %r21, FRAME_21+48(%r1); \
std %r22, FRAME_22+48(%r1); \
std %r23, FRAME_23+48(%r1); \
std %r24, FRAME_24+48(%r1); \
std %r25, FRAME_25+48(%r1); \
std %r26, FRAME_26+48(%r1); \
std %r27, FRAME_27+48(%r1); \
std %r28, FRAME_28+48(%r1); \
std %r29, FRAME_29+48(%r1); \
std %r30, FRAME_30+48(%r1); \
std %r31, FRAME_31+48(%r1); \
ld %r28,(savearea+CPUSAVE_AIM_DAR)(%r2); /* saved DAR */ \
ld %r29,(savearea+CPUSAVE_AIM_DSISR)(%r2);/* saved DSISR */\
ld %r30,(savearea+CPUSAVE_SRR0)(%r2); /* saved SRR0 */ \
ld %r31,(savearea+CPUSAVE_SRR1)(%r2); /* saved SRR1 */ \
mfxer %r3; \
mfctr %r4; \
mfsprg3 %r5; \
std %r3, FRAME_XER+48(1); /* save xer/ctr/exc */ \
std %r4, FRAME_CTR+48(1); \
std %r5, FRAME_EXC+48(1); \
std %r28,FRAME_AIM_DAR+48(1); \
std %r29,FRAME_AIM_DSISR+48(1); /* save dsisr/srr0/srr1 */ \
std %r30,FRAME_SRR0+48(1); \
std %r31,FRAME_SRR1+48(1)
#define FRAME_LEAVE(savearea) \
/* Now restore regs: */ \
ld %r2,FRAME_SRR0+48(%r1); \
ld %r3,FRAME_SRR1+48(%r1); \
ld %r4,FRAME_CTR+48(%r1); \
ld %r5,FRAME_XER+48(%r1); \
ld %r6,FRAME_LR+48(%r1); \
GET_CPUINFO(%r7); \
std %r2,(savearea+CPUSAVE_SRR0)(%r7); /* save SRR0 */ \
std %r3,(savearea+CPUSAVE_SRR1)(%r7); /* save SRR1 */ \
ld %r7,FRAME_CR+48(%r1); \
mtctr %r4; \
mtxer %r5; \
mtlr %r6; \
mtsprg1 %r7; /* save cr */ \
ld %r31,FRAME_31+48(%r1); /* restore r0-31 */ \
ld %r30,FRAME_30+48(%r1); \
ld %r29,FRAME_29+48(%r1); \
ld %r28,FRAME_28+48(%r1); \
ld %r27,FRAME_27+48(%r1); \
ld %r26,FRAME_26+48(%r1); \
ld %r25,FRAME_25+48(%r1); \
ld %r24,FRAME_24+48(%r1); \
ld %r23,FRAME_23+48(%r1); \
ld %r22,FRAME_22+48(%r1); \
ld %r21,FRAME_21+48(%r1); \
ld %r20,FRAME_20+48(%r1); \
ld %r19,FRAME_19+48(%r1); \
ld %r18,FRAME_18+48(%r1); \
ld %r17,FRAME_17+48(%r1); \
ld %r16,FRAME_16+48(%r1); \
ld %r15,FRAME_15+48(%r1); \
ld %r14,FRAME_14+48(%r1); \
ld %r13,FRAME_13+48(%r1); \
ld %r12,FRAME_12+48(%r1); \
ld %r11,FRAME_11+48(%r1); \
ld %r10,FRAME_10+48(%r1); \
ld %r9, FRAME_9+48(%r1); \
ld %r8, FRAME_8+48(%r1); \
ld %r7, FRAME_7+48(%r1); \
ld %r6, FRAME_6+48(%r1); \
ld %r5, FRAME_5+48(%r1); \
ld %r4, FRAME_4+48(%r1); \
ld %r3, FRAME_3+48(%r1); \
ld %r2, FRAME_2+48(%r1); \
ld %r0, FRAME_0+48(%r1); \
ld %r1, FRAME_1+48(%r1); \
/* Can't touch %r1 from here on */ \
mtsprg2 %r2; /* save r2 & r3 */ \
mtsprg3 %r3; \
/* Disable translation, machine check and recoverability: */ \
mfmsr %r2; \
andi. %r2,%r2,~(PSL_DR|PSL_IR|PSL_EE|PSL_ME|PSL_RI)@l; \
mtmsr %r2; \
isync; \
/* Decide whether we return to user mode: */ \
GET_CPUINFO(%r2); \
ld %r3,(savearea+CPUSAVE_SRR1)(%r2); \
mtcr %r3; \
bf 17,1f; /* branch if PSL_PR is false */ \
/* Restore user SRs */ \
GET_CPUINFO(%r3); \
std %r27,(savearea+CPUSAVE_R27)(%r3); \
std %r28,(savearea+CPUSAVE_R28)(%r3); \
std %r29,(savearea+CPUSAVE_R29)(%r3); \
std %r30,(savearea+CPUSAVE_R30)(%r3); \
std %r31,(savearea+CPUSAVE_R31)(%r3); \
mflr %r27; /* preserve LR */ \
bl restore_usersrs; /* uses r28-r31 */ \
mtlr %r27; \
ld %r31,(savearea+CPUSAVE_R31)(%r3); \
ld %r30,(savearea+CPUSAVE_R30)(%r3); \
ld %r29,(savearea+CPUSAVE_R29)(%r3); \
ld %r28,(savearea+CPUSAVE_R28)(%r3); \
ld %r27,(savearea+CPUSAVE_R27)(%r3); \
1: mfsprg1 %r2; /* restore cr */ \
mtcr %r2; \
GET_CPUINFO(%r2); \
ld %r3,(savearea+CPUSAVE_SRR0)(%r2); /* restore srr0 */ \
mtsrr0 %r3; \
ld %r3,(savearea+CPUSAVE_SRR1)(%r2); /* restore srr1 */ \
mtsrr1 %r3; \
mfsprg2 %r2; /* restore r2 & r3 */ \
mfsprg3 %r3
#ifdef SMP
/*
* Processor reset exception handler. These are typically
* the first instructions the processor executes after a
* software reset. We do this in two bits so that we are
* not still hanging around in the trap handling region
* once the MMU is turned on.
*/
.globl CNAME(rstcode), CNAME(rstsize)
CNAME(rstcode):
/* Explicitly set MSR[SF] */
mfmsr %r9
li %r8,1
insrdi %r9,%r8,1,0
mtmsrd %r9
isync
ba cpu_reset
CNAME(rstsize) = . - CNAME(rstcode)
cpu_reset:
lis %r1,(tmpstk+TMPSTKSZ-48)@ha /* get new SP */
addi %r1,%r1,(tmpstk+TMPSTKSZ-48)@l
lis %r3,tocbase@ha
ld %r2,tocbase@l(%r3)
lis %r3,1@l
bl CNAME(.cpudep_ap_early_bootstrap) /* Set PCPU */
nop
bl CNAME(.pmap_cpu_bootstrap) /* Turn on virtual memory */
nop
bl CNAME(.cpudep_ap_bootstrap) /* Set up PCPU and stack */
nop
mr %r1,%r3 /* Use new stack */
bl CNAME(.machdep_ap_bootstrap) /* And away! */
nop
/* Should not be reached */
9:
b 9b
#endif
/*
* This code gets copied to all the trap vectors
* (except ISI/DSI, ALI, and the interrupts)
*/
.globl CNAME(trapcode),CNAME(trapsize)
CNAME(trapcode):
mtsprg1 %r1 /* save SP */
mflr %r1 /* Save the old LR in r1 */
mtsprg2 %r1 /* And then in SPRG2 */
li %r1, 0xA0 /* How to get the vector from LR */
bla generictrap /* LR & SPRG3 is exception # */
CNAME(trapsize) = .-CNAME(trapcode)
/*
* For ALI: has to save DSISR and DAR
*/
.globl CNAME(alitrap),CNAME(alisize)
CNAME(alitrap):
mtsprg1 %r1 /* save SP */
GET_CPUINFO(%r1)
std %r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1) /* free r27-r31 */
std %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
std %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
std %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mfdar %r30
mfdsisr %r31
std %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
mfsprg1 %r1 /* restore SP, in case of branch */
mflr %r28 /* save LR */
mfcr %r29 /* save CR */
/* Put our exception vector in SPRG3 */
li %r31, EXC_ALI
mtsprg3 %r31
/* Test whether we already had PR set */
mfsrr1 %r31
mtcr %r31
bla s_trap
CNAME(alisize) = .-CNAME(alitrap)
/*
* Similar to the above for DSI
* Has to handle BAT spills
* and standard pagetable spills
*/
.globl CNAME(dsitrap),CNAME(dsisize)
CNAME(dsitrap):
mtsprg1 %r1 /* save SP */
GET_CPUINFO(%r1)
std %r27,(PC_DISISAVE+CPUSAVE_R27)(%r1) /* free r27-r31 */
std %r28,(PC_DISISAVE+CPUSAVE_R28)(%r1)
std %r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
std %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
std %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
mfsprg1 %r1 /* restore SP */
mfcr %r29 /* save CR */
mfxer %r30 /* save XER */
mtsprg2 %r30 /* in SPRG2 */
mfsrr1 %r31 /* test kernel mode */
mtcr %r31
mflr %r28 /* save LR (SP already saved) */
bla disitrap
CNAME(dsisize) = .-CNAME(dsitrap)
/*
* Preamble code for DSI/ISI traps
*/
disitrap:
/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
mflr %r1
andi. %r1,%r1,0xff00
mtsprg3 %r1
GET_CPUINFO(%r1)
ld %r31,(PC_DISISAVE+CPUSAVE_R27)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
ld %r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
std %r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
ld %r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
ld %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
std %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
ld %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mfdar %r30
mfdsisr %r31
std %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
#ifdef KDB
/* Try and detect a kernel stack overflow */
mfsrr1 %r31
mtcr %r31
bt 17,realtrap /* branch is user mode */
mfsprg1 %r31 /* get old SP */
sub. %r30,%r31,%r30 /* SP - DAR */
bge 1f
neg %r30,%r30 /* modulo value */
1: cmpldi %cr0,%r30,4096 /* is DAR within a page of SP? */
bge %cr0,realtrap /* no, too far away. */
/* Now convert this DSI into a DDB trap. */
GET_CPUINFO(%r1)
ld %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
std %r30,(PC_DBSAVE +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
ld %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
std %r30,(PC_DBSAVE +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
ld %r31,(PC_DISISAVE+CPUSAVE_R27)(%r1) /* get r27 */
std %r31,(PC_DBSAVE +CPUSAVE_R27)(%r1) /* save r27 */
ld %r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get r28 */
std %r30,(PC_DBSAVE +CPUSAVE_R28)(%r1) /* save r28 */
ld %r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get r29 */
std %r31,(PC_DBSAVE +CPUSAVE_R29)(%r1) /* save r29 */
ld %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get r30 */
std %r30,(PC_DBSAVE +CPUSAVE_R30)(%r1) /* save r30 */
ld %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get r31 */
std %r31,(PC_DBSAVE +CPUSAVE_R31)(%r1) /* save r31 */
b dbtrap
#endif
/* XXX need stack probe here */
realtrap:
/* Test whether we already had PR set */
mfsrr1 %r1
mtcr %r1
mfsprg1 %r1 /* restore SP (might have been
overwritten) */
bf 17,k_trap /* branch if PSL_PR is false */
GET_CPUINFO(%r1)
ld %r1,PC_CURPCB(%r1)
mr %r27,%r28 /* Save LR, r29 */
mtsprg2 %r29
bl restore_kernsrs /* enable kernel mapping */
mfsprg2 %r29
mr %r28,%r27
ba s_trap
/*
* generictrap does some standard setup for trap handling to minimize
* the code that need be installed in the actual vectors. It expects
* the following conditions.
*
* R1 - Trap vector = LR & (0xff00 | R1)
* SPRG1 - Original R1 contents
* SPRG2 - Original LR
*/
generictrap:
/* Save R1 for computing the exception vector */
mtsprg3 %r1
/* Save interesting registers */
GET_CPUINFO(%r1)
std %r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1) /* free r27-r31 */
std %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
std %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
std %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mfdar %r30
std %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
mfsprg1 %r1 /* restore SP, in case of branch */
mfsprg2 %r28 /* save LR */
mfcr %r29 /* save CR */
/* Compute the exception vector from the link register */
mfsprg3 %r31
ori %r31,%r31,0xff00
mflr %r30
and %r30,%r30,%r31
mtsprg3 %r30
/* Test whether we already had PR set */
mfsrr1 %r31
mtcr %r31
s_trap:
bf 17,k_trap /* branch if PSL_PR is false */
GET_CPUINFO(%r1)
u_trap:
ld %r1,PC_CURPCB(%r1)
mr %r27,%r28 /* Save LR, r29 */
mtsprg2 %r29
bl restore_kernsrs /* enable kernel mapping */
mfsprg2 %r29
mr %r28,%r27
/*
* Now the common trap catching code.
*/
k_trap:
FRAME_SETUP(PC_TEMPSAVE)
/* Call C interrupt dispatcher: */
trapagain:
lis %r3,tocbase@ha
ld %r2,tocbase@l(%r3)
addi %r3,%r1,48
bl CNAME(.powerpc_interrupt)
nop
.globl CNAME(trapexit) /* backtrace code sentinel */
CNAME(trapexit):
/* Disable interrupts: */
mfmsr %r3
andi. %r3,%r3,~PSL_EE@l
mtmsr %r3
/* Test AST pending: */
ld %r5,FRAME_SRR1+48(%r1)
mtcr %r5
bf 17,1f /* branch if PSL_PR is false */
GET_CPUINFO(%r3) /* get per-CPU pointer */
ld %r4, PC_CURTHREAD(%r3) /* deref to get curthread */
lwz %r4, TD_FLAGS(%r4) /* get thread flags value */
lis %r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@h
ori %r5,%r5, (TDF_ASTPENDING|TDF_NEEDRESCHED)@l
and. %r4,%r4,%r5
beq 1f
mfmsr %r3 /* re-enable interrupts */
ori %r3,%r3,PSL_EE@l
mtmsr %r3
isync
lis %r3,tocbase@ha
ld %r2,tocbase@l(%r3)
addi %r3,%r1,48
bl CNAME(.ast)
nop
.globl CNAME(asttrapexit) /* backtrace code sentinel #2 */
CNAME(asttrapexit):
b trapexit /* test ast ret value ? */
1:
FRAME_LEAVE(PC_TEMPSAVE)
rfid
#if defined(KDB)
/*
* Deliberate entry to dbtrap
*/
ASENTRY(breakpoint)
mtsprg1 %r1
mfmsr %r3
mtsrr1 %r3
andi. %r3,%r3,~(PSL_EE|PSL_ME)@l
mtmsr %r3 /* disable interrupts */
isync
GET_CPUINFO(%r3)
std %r27,(PC_DBSAVE+CPUSAVE_R27)(%r3)
std %r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
std %r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
std %r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
std %r31,(PC_DBSAVE+CPUSAVE_R31)(%r3)
mflr %r28
li %r29,EXC_BPT
mtlr %r29
mfcr %r29
mtsrr0 %r28
/*
* Now the kdb trap catching code.
*/
dbtrap:
/* Write the trap vector to SPRG3 by computing LR & 0xff00 */
mflr %r1
andi. %r1,%r1,0xff00
mtsprg3 %r1
lis %r1,(tmpstk+TMPSTKSZ-48)@ha /* get new SP */
addi %r1,%r1,(tmpstk+TMPSTKSZ-48)@l
FRAME_SETUP(PC_DBSAVE)
/* Call C trap code: */
lis %r3,tocbase@ha
ld %r2,tocbase@l(%r3)
addi %r3,%r1,48
bl CNAME(.db_trap_glue)
nop
or. %r3,%r3,%r3
bne dbleave
/* This wasn't for KDB, so switch to real trap: */
ld %r3,FRAME_EXC+48(%r1) /* save exception */
GET_CPUINFO(%r4)
std %r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
FRAME_LEAVE(PC_DBSAVE)
mtsprg1 %r1 /* prepare for entrance to realtrap */
GET_CPUINFO(%r1)
std %r27,(PC_TEMPSAVE+CPUSAVE_R27)(%r1)
std %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
std %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
std %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
std %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mflr %r28
mfcr %r29
ld %r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
mtsprg3 %r31 /* SPRG3 was clobbered by FRAME_LEAVE */
mfsprg1 %r1
b realtrap
dbleave:
FRAME_LEAVE(PC_DBSAVE)
rfid
/*
* In case of KDB we want a separate trap catcher for it
*/
.globl CNAME(dblow),CNAME(dbsize)
CNAME(dblow):
mtsprg1 %r1 /* save SP */
mtsprg2 %r29 /* save r29 */
mfcr %r29 /* save CR in r29 */
mfsrr1 %r1
mtcr %r1
bf 17,1f /* branch if privileged */
/* Unprivileged case */
mtcr %r29 /* put the condition register back */
mfsprg2 %r29 /* ... and r29 */
mflr %r1 /* save LR */
mtsprg2 %r1 /* And then in SPRG2 */
li %r1, 0 /* How to get the vector from LR */
bla generictrap /* and we look like a generic trap */
1:
/* Privileged, so drop to KDB */
GET_CPUINFO(%r1)
std %r27,(PC_DBSAVE+CPUSAVE_R27)(%r1) /* free r27 */
std %r28,(PC_DBSAVE+CPUSAVE_R28)(%r1) /* free r28 */
mfsprg2 %r28 /* r29 holds cr... */
std %r28,(PC_DBSAVE+CPUSAVE_R29)(%r1) /* free r29 */
std %r30,(PC_DBSAVE+CPUSAVE_R30)(%r1) /* free r30 */
std %r31,(PC_DBSAVE+CPUSAVE_R31)(%r1) /* free r31 */
mflr %r28 /* save LR */
bla dbtrap
CNAME(dbsize) = .-CNAME(dblow)
#endif /* KDB */
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