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freebsd-dev/sys/powerpc/aim/trap_subr32.S
Leandro Lupori 6174048251 powerpc64: Add a trap stack area 
Currently, the trap code switches to the the temporary stack in the dbtrap
section. It works in most cases, but in the beginning of the execution, the
temp stack is being used, as starting in the powerpc_init() code.

In this current scenario, the stack is being overwritten, which causes the
return of breakpoint() to take abnormal execution.

This current patchset create a small stack to use by the dbtrap: codepath
avoiding the corruption of the temporary stack.

PR:		224872
Submitted by:	breno.leitao_gmail.com
Reviewed by:	jhibbits
Differential Revision:	https://reviews.freebsd.org/D14484
2019-02-04 16:02:03 +00:00

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/* $FreeBSD$ */
/* $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
*/
#define RESTORE_SRS(pmap,sr) mtsr 0,sr; \
lwz sr,1*4(pmap); mtsr 1,sr; \
lwz sr,2*4(pmap); mtsr 2,sr; \
lwz sr,3*4(pmap); mtsr 3,sr; \
lwz sr,4*4(pmap); mtsr 4,sr; \
lwz sr,5*4(pmap); mtsr 5,sr; \
lwz sr,6*4(pmap); mtsr 6,sr; \
lwz sr,7*4(pmap); mtsr 7,sr; \
lwz sr,8*4(pmap); mtsr 8,sr; \
lwz sr,9*4(pmap); mtsr 9,sr; \
lwz sr,10*4(pmap); mtsr 10,sr; \
lwz sr,11*4(pmap); mtsr 11,sr; \
/* Skip segment 12 (USER_SR), which is restored differently */ \
lwz sr,13*4(pmap); mtsr 13,sr; \
lwz sr,14*4(pmap); mtsr 14,sr; \
lwz sr,15*4(pmap); mtsr 15,sr; isync;
/*
* User SRs are loaded through a pointer to the current pmap.
*/
#define RESTORE_USER_SRS(pmap,sr) \
GET_CPUINFO(pmap); \
lwz pmap,PC_CURPMAP(pmap); \
lwzu sr,PM_SR(pmap); \
RESTORE_SRS(pmap,sr) \
/* Restore SR 12 */ \
lwz sr,12*4(pmap); mtsr 12,sr
/*
* Kernel SRs are loaded directly from kernel_pmap_
*/
#define RESTORE_KERN_SRS(pmap,sr) \
lwz pmap,TRAP_TOCBASE(0); \
lwz pmap,CNAME(kernel_pmap_store)@got(pmap); \
lwzu sr,PM_SR(pmap); \
RESTORE_SRS(pmap,sr)
/*
* FRAME_SETUP assumes:
* SPRG1 SP (1)
* SPRG3 trap type
* savearea r28-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; \
stw %r30,(savearea+CPUSAVE_SRR0)(%r31); /* save SRR0 */ \
mfsrr1 %r30; \
stw %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 */ \
stwu %r31,-FRAMELEN(%r1); /* save it in the callframe */ \
stw %r0, FRAME_0+8(%r1); /* save r0 in the trapframe */ \
stw %r31,FRAME_1+8(%r1); /* save SP " " */ \
stw %r2, FRAME_2+8(%r1); /* save r2 " " */ \
stw %r28,FRAME_LR+8(%r1); /* save LR " " */ \
stw %r29,FRAME_CR+8(%r1); /* save CR " " */ \
GET_CPUINFO(%r2); \
lwz %r28,(savearea+CPUSAVE_R28)(%r2); /* get saved r28 */ \
lwz %r29,(savearea+CPUSAVE_R29)(%r2); /* get saved r29 */ \
lwz %r30,(savearea+CPUSAVE_R30)(%r2); /* get saved r30 */ \
lwz %r31,(savearea+CPUSAVE_R31)(%r2); /* get saved r31 */ \
stw %r3, FRAME_3+8(%r1); /* save r3-r31 */ \
stw %r4, FRAME_4+8(%r1); \
stw %r5, FRAME_5+8(%r1); \
stw %r6, FRAME_6+8(%r1); \
stw %r7, FRAME_7+8(%r1); \
stw %r8, FRAME_8+8(%r1); \
stw %r9, FRAME_9+8(%r1); \
stw %r10, FRAME_10+8(%r1); \
stw %r11, FRAME_11+8(%r1); \
stw %r12, FRAME_12+8(%r1); \
stw %r13, FRAME_13+8(%r1); \
stw %r14, FRAME_14+8(%r1); \
stw %r15, FRAME_15+8(%r1); \
stw %r16, FRAME_16+8(%r1); \
stw %r17, FRAME_17+8(%r1); \
stw %r18, FRAME_18+8(%r1); \
stw %r19, FRAME_19+8(%r1); \
stw %r20, FRAME_20+8(%r1); \
stw %r21, FRAME_21+8(%r1); \
stw %r22, FRAME_22+8(%r1); \
stw %r23, FRAME_23+8(%r1); \
stw %r24, FRAME_24+8(%r1); \
stw %r25, FRAME_25+8(%r1); \
stw %r26, FRAME_26+8(%r1); \
stw %r27, FRAME_27+8(%r1); \
stw %r28, FRAME_28+8(%r1); \
stw %r29, FRAME_29+8(%r1); \
stw %r30, FRAME_30+8(%r1); \
stw %r31, FRAME_31+8(%r1); \
lwz %r28,(savearea+CPUSAVE_AIM_DAR)(%r2); /* saved DAR */ \
lwz %r29,(savearea+CPUSAVE_AIM_DSISR)(%r2);/* saved DSISR */\
lwz %r30,(savearea+CPUSAVE_SRR0)(%r2); /* saved SRR0 */ \
lwz %r31,(savearea+CPUSAVE_SRR1)(%r2); /* saved SRR1 */ \
mfxer %r3; \
mfctr %r4; \
mfsprg3 %r5; \
stw %r3, FRAME_XER+8(1); /* save xer/ctr/exc */ \
stw %r4, FRAME_CTR+8(1); \
stw %r5, FRAME_EXC+8(1); \
stw %r28,FRAME_AIM_DAR+8(1); \
stw %r29,FRAME_AIM_DSISR+8(1); /* save dsisr/srr0/srr1 */ \
stw %r30,FRAME_SRR0+8(1); \
stw %r31,FRAME_SRR1+8(1); \
lwz %r2,PC_CURTHREAD(%r2) /* set curthread pointer */
#define FRAME_LEAVE(savearea) \
/* Disable exceptions: */ \
mfmsr %r2; \
andi. %r2,%r2,~PSL_EE@l; \
mtmsr %r2; \
isync; \
/* Now restore regs: */ \
lwz %r2,FRAME_SRR0+8(%r1); \
lwz %r3,FRAME_SRR1+8(%r1); \
lwz %r4,FRAME_CTR+8(%r1); \
lwz %r5,FRAME_XER+8(%r1); \
lwz %r6,FRAME_LR+8(%r1); \
GET_CPUINFO(%r7); \
stw %r2,(savearea+CPUSAVE_SRR0)(%r7); /* save SRR0 */ \
stw %r3,(savearea+CPUSAVE_SRR1)(%r7); /* save SRR1 */ \
lwz %r7,FRAME_CR+8(%r1); \
mtctr %r4; \
mtxer %r5; \
mtlr %r6; \
mtsprg1 %r7; /* save cr */ \
lwz %r31,FRAME_31+8(%r1); /* restore r0-31 */ \
lwz %r30,FRAME_30+8(%r1); \
lwz %r29,FRAME_29+8(%r1); \
lwz %r28,FRAME_28+8(%r1); \
lwz %r27,FRAME_27+8(%r1); \
lwz %r26,FRAME_26+8(%r1); \
lwz %r25,FRAME_25+8(%r1); \
lwz %r24,FRAME_24+8(%r1); \
lwz %r23,FRAME_23+8(%r1); \
lwz %r22,FRAME_22+8(%r1); \
lwz %r21,FRAME_21+8(%r1); \
lwz %r20,FRAME_20+8(%r1); \
lwz %r19,FRAME_19+8(%r1); \
lwz %r18,FRAME_18+8(%r1); \
lwz %r17,FRAME_17+8(%r1); \
lwz %r16,FRAME_16+8(%r1); \
lwz %r15,FRAME_15+8(%r1); \
lwz %r14,FRAME_14+8(%r1); \
lwz %r13,FRAME_13+8(%r1); \
lwz %r12,FRAME_12+8(%r1); \
lwz %r11,FRAME_11+8(%r1); \
lwz %r10,FRAME_10+8(%r1); \
lwz %r9, FRAME_9+8(%r1); \
lwz %r8, FRAME_8+8(%r1); \
lwz %r7, FRAME_7+8(%r1); \
lwz %r6, FRAME_6+8(%r1); \
lwz %r5, FRAME_5+8(%r1); \
lwz %r4, FRAME_4+8(%r1); \
lwz %r3, FRAME_3+8(%r1); \
lwz %r2, FRAME_2+8(%r1); \
lwz %r0, FRAME_0+8(%r1); \
lwz %r1, FRAME_1+8(%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_ME|PSL_RI)@l; \
mtmsr %r2; \
isync; \
/* Decide whether we return to user mode: */ \
GET_CPUINFO(%r2); \
lwz %r3,(savearea+CPUSAVE_SRR1)(%r2); \
mtcr %r3; \
bf 17,1f; /* branch if PSL_PR is false */ \
/* Restore user SRs */ \
RESTORE_USER_SRS(%r2,%r3); \
1: mfsprg1 %r2; /* restore cr */ \
mtcr %r2; \
GET_CPUINFO(%r2); \
lwz %r3,(savearea+CPUSAVE_SRR0)(%r2); /* restore srr0 */ \
mtsrr0 %r3; \
lwz %r3,(savearea+CPUSAVE_SRR1)(%r2); /* restore srr1 */ \
\
/* Make sure HV bit of MSR propagated to SRR1 */ \
mfmsr %r2; \
or %r3,%r2,%r3; \
\
mtsrr1 %r3; \
mfsprg2 %r2; /* restore r2 & r3 */ \
mfsprg3 %r3
#ifdef KDTRACE_HOOKS
.data
.globl dtrace_invop_calltrap_addr
.align 4
.type dtrace_invop_calltrap_addr, @object
.size dtrace_invop_calltrap_addr, 4
dtrace_invop_calltrap_addr:
.word 0
.word 0
.text
#endif
/*
* The next two routines are 64-bit glue code. The first is used to test if
* we are on a 64-bit system. By copying it to the illegal instruction
* handler, we can test for 64-bit mode by trying to execute a 64-bit
* instruction and seeing what happens. The second gets copied in front
* of all the other handlers to restore 32-bit bridge mode when traps
* are taken.
*/
/* 64-bit test code. Sets SPRG2 to 0 if an illegal instruction is executed */
.globl CNAME(testppc64),CNAME(testppc64size)
CNAME(testppc64):
mtsprg1 %r31
mfsrr0 %r31
addi %r31, %r31, 4
mtsrr0 %r31
li %r31, 0
mtsprg2 %r31
mfsprg1 %r31
rfi
CNAME(testppc64size) = .-CNAME(testppc64)
/* 64-bit bridge mode restore snippet. Gets copied in front of everything else
* on 64-bit systems. */
.globl CNAME(restorebridge),CNAME(restorebridgesize)
CNAME(restorebridge):
mtsprg1 %r31
mfmsr %r31
clrldi %r31,%r31,1
mtmsrd %r31
mfsprg1 %r31
isync
CNAME(restorebridgesize) = .-CNAME(restorebridge)
/*
* 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(rstcodeend)
CNAME(rstcode):
bl 1f
.long cpu_reset
1: mflr %r31
lwz %r31,0(%r31)
mtlr %r31
blrl
CNAME(rstcodeend):
cpu_reset:
bl 1f
.space 124
1:
mflr %r1
addi %r1,%r1,(124-16)@l
bl CNAME(cpudep_ap_early_bootstrap)
lis %r3,1@l
bl CNAME(pmap_cpu_bootstrap)
bl CNAME(cpudep_ap_bootstrap)
mr %r1,%r3
bl CNAME(cpudep_ap_setup)
GET_CPUINFO(%r5)
lwz %r3,(PC_RESTORE)(%r5)
cmplwi %cr0,%r3,0
beq %cr0,2f
li %r4, 1
b CNAME(longjmp)
2:
#ifdef SMP
bl CNAME(machdep_ap_bootstrap)
#endif
/* Should not be reached */
9:
b 9b
/*
* This code gets copied to all the trap vectors
* (except ISI/DSI, ALI, and the interrupts)
*/
.globl CNAME(trapcode),CNAME(trapcodeend)
CNAME(trapcode):
mtsprg1 %r1 /* save SP */
mflr %r1 /* Save the old LR in r1 */
mtsprg2 %r1 /* And then in SPRG2 */
lwz %r1, TRAP_GENTRAP(0) /* Get branch address */
mtlr %r1
li %r1, 0xe0 /* How to get the vector from LR */
blrl /* LR & (0xff00 | r1) is exception # */
CNAME(trapcodeend):
/*
* For ALI: has to save DSISR and DAR
*/
.globl CNAME(alitrap),CNAME(aliend)
CNAME(alitrap):
mtsprg1 %r1 /* save SP */
GET_CPUINFO(%r1)
stw %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1) /* free r28-r31 */
stw %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
stw %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mfdar %r30
mfdsisr %r31
stw %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
stw %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
/* Jump to s_trap */
bl 1f
.long s_trap
1: mflr %r31
lwz %r31,0(%r31)
mtlr %r31
blrl
CNAME(aliend):
/*
* G2 specific: instuction TLB miss.
*/
.globl CNAME(imisstrap),CNAME(imisssize)
CNAME(imisstrap):
mfspr %r2, SPR_HASH1 /* get first pointer */
addi %r1, 0, 8 /* load 8 for counter */
mfctr %r0 /* save counter */
mfspr %r3, SPR_ICMP /* get first compare value */
addi %r2, %r2, -8 /* pre dec the pointer */
im0:
mtctr %r1 /* load counter */
im1:
lwzu %r1, 8(%r2) /* get next pte */
cmp 0, 0, %r1, %r3 /* see if found pte */
bdnzf 2, im1 /* dec count br if cmp ne and if
* count not zero */
bne instr_sec_hash /* if not found set up second hash
* or exit */
lwz %r1, +4(%r2) /* load tlb entry lower-word */
andi. %r3, %r1, 8 /* check G bit */
bne do_isi_prot /* if guarded, take an ISI */
mtctr %r0 /* restore counter */
mfspr %r0, SPR_IMISS /* get the miss address for the tlbli */
mfspr %r3, SPR_SRR1 /* get the saved cr0 bits */
mtcrf 0x80, %r3 /* restore CR0 */
mtspr SPR_RPA, %r1 /* set the pte */
ori %r1, %r1, 0x100 /* set reference bit */
srwi %r1, %r1, 8 /* get byte 7 of pte */
tlbli %r0 /* load the itlb */
stb %r1, +6(%r2) /* update page table */
rfi /* return to executing program */
instr_sec_hash:
andi. %r1, %r3, 0x0040 /* see if we have done second hash */
bne do_isi /* if so, go to ISI interrupt */
mfspr %r2, SPR_HASH2 /* get the second pointer */
ori %r3, %r3, 0x0040 /* change the compare value */
addi %r1, %r0, 8 /* load 8 for counter */
addi %r2, %r2, -8 /* pre dec for update on load */
b im0 /* try second hash */
/* Create a faked ISI interrupt as the address was not found */
do_isi_prot:
mfspr %r3, SPR_SRR1 /* get srr1 */
andi. %r2, %r3, 0xffff /* clean upper srr1 */
addis %r2, %r2, 0x0800 /* or in srr<4> = 1 to flag prot
* violation */
b isi1
do_isi:
mfspr %r3, SPR_SRR1 /* get srr1 */
andi. %r2, %r3, 0xffff /* clean srr1 */
addis %r2, %r2, 0x4000 /* or in srr1<1> = 1 to flag pte
* not found */
isi1:
mtctr %r0 /* restore counter */
mtspr SPR_SRR1, %r2 /* set srr1 */
mfmsr %r0 /* get msr */
xoris %r0, %r0, 0x2 /* flip the msr<tgpr> bit */
mtcrf 0x80, %r3 /* restore CR0 */
mtmsr %r0 /* flip back to the native gprs */
ba EXC_ISI /* go to instr. access interrupt */
CNAME(imisssize) = .-CNAME(imisstrap)
/*
* G2 specific: data load TLB miss.
*/
.globl CNAME(dlmisstrap),CNAME(dlmisssize)
CNAME(dlmisstrap):
mfspr %r2, SPR_HASH1 /* get first pointer */
addi %r1, 0, 8 /* load 8 for counter */
mfctr %r0 /* save counter */
mfspr %r3, SPR_DCMP /* get first compare value */
addi %r2, %r2, -8 /* pre dec the pointer */
dm0:
mtctr %r1 /* load counter */
dm1:
lwzu %r1, 8(%r2) /* get next pte */
cmp 0, 0, %r1, %r3 /* see if found pte */
bdnzf 2, dm1 /* dec count br if cmp ne and if
* count not zero */
bne data_sec_hash /* if not found set up second hash
* or exit */
lwz %r1, +4(%r2) /* load tlb entry lower-word */
mtctr %r0 /* restore counter */
mfspr %r0, SPR_DMISS /* get the miss address for the tlbld */
mfspr %r3, SPR_SRR1 /* get the saved cr0 bits */
mtcrf 0x80, %r3 /* restore CR0 */
mtspr SPR_RPA, %r1 /* set the pte */
ori %r1, %r1, 0x100 /* set reference bit */
srwi %r1, %r1, 8 /* get byte 7 of pte */
tlbld %r0 /* load the dtlb */
stb %r1, +6(%r2) /* update page table */
rfi /* return to executing program */
data_sec_hash:
andi. %r1, %r3, 0x0040 /* see if we have done second hash */
bne do_dsi /* if so, go to DSI interrupt */
mfspr %r2, SPR_HASH2 /* get the second pointer */
ori %r3, %r3, 0x0040 /* change the compare value */
addi %r1, 0, 8 /* load 8 for counter */
addi %r2, %r2, -8 /* pre dec for update on load */
b dm0 /* try second hash */
CNAME(dlmisssize) = .-CNAME(dlmisstrap)
/*
* G2 specific: data store TLB miss.
*/
.globl CNAME(dsmisstrap),CNAME(dsmisssize)
CNAME(dsmisstrap):
mfspr %r2, SPR_HASH1 /* get first pointer */
addi %r1, 0, 8 /* load 8 for counter */
mfctr %r0 /* save counter */
mfspr %r3, SPR_DCMP /* get first compare value */
addi %r2, %r2, -8 /* pre dec the pointer */
ds0:
mtctr %r1 /* load counter */
ds1:
lwzu %r1, 8(%r2) /* get next pte */
cmp 0, 0, %r1, %r3 /* see if found pte */
bdnzf 2, ds1 /* dec count br if cmp ne and if
* count not zero */
bne data_store_sec_hash /* if not found set up second hash
* or exit */
lwz %r1, +4(%r2) /* load tlb entry lower-word */
andi. %r3, %r1, 0x80 /* check the C-bit */
beq data_store_chk_prot /* if (C==0)
* go check protection modes */
ds2:
mtctr %r0 /* restore counter */
mfspr %r0, SPR_DMISS /* get the miss address for the tlbld */
mfspr %r3, SPR_SRR1 /* get the saved cr0 bits */
mtcrf 0x80, %r3 /* restore CR0 */
mtspr SPR_RPA, %r1 /* set the pte */
tlbld %r0 /* load the dtlb */
rfi /* return to executing program */
data_store_sec_hash:
andi. %r1, %r3, 0x0040 /* see if we have done second hash */
bne do_dsi /* if so, go to DSI interrupt */
mfspr %r2, SPR_HASH2 /* get the second pointer */
ori %r3, %r3, 0x0040 /* change the compare value */
addi %r1, 0, 8 /* load 8 for counter */
addi %r2, %r2, -8 /* pre dec for update on load */
b ds0 /* try second hash */
/* Check the protection before setting PTE(c-bit) */
data_store_chk_prot:
rlwinm. %r3,%r1,30,0,1 /* test PP */
bge- chk0 /* if (PP == 00 or PP == 01)
* goto chk0: */
andi. %r3, %r1, 1 /* test PP[0] */
beq+ chk2 /* return if PP[0] == 0 */
b do_dsi_prot /* else DSIp */
chk0:
mfspr %r3,SPR_SRR1 /* get old msr */
andis. %r3,%r3,0x0008 /* test the KEY bit (SRR1-bit 12) */
beq chk2 /* if (KEY==0) goto chk2: */
b do_dsi_prot /* else do_dsi_prot */
chk2:
ori %r1, %r1, 0x180 /* set reference and change bit */
sth %r1, 6(%r2) /* update page table */
b ds2 /* and back we go */
/* Create a faked DSI interrupt as the address was not found */
do_dsi:
mfspr %r3, SPR_SRR1 /* get srr1 */
rlwinm %r1,%r3,9,6,6 /* get srr1<flag> to bit 6 for
* load/store, zero rest */
addis %r1, %r1, 0x4000 /* or in dsisr<1> = 1 to flag pte
* not found */
b dsi1
do_dsi_prot:
mfspr %r3, SPR_SRR1 /* get srr1 */
rlwinm %r1,%r3,9,6,6 /* get srr1<flag> to bit 6 for
*load/store, zero rest */
addis %r1, %r1, 0x0800 /* or in dsisr<4> = 1 to flag prot
* violation */
dsi1:
mtctr %r0 /* restore counter */
andi. %r2, %r3, 0xffff /* clear upper bits of srr1 */
mtspr SPR_SRR1, %r2 /* set srr1 */
mtspr SPR_DSISR, %r1 /* load the dsisr */
mfspr %r1, SPR_DMISS /* get miss address */
rlwinm. %r2,%r2,0,31,31 /* test LE bit */
beq dsi2 /* if little endian then: */
xor %r1, %r1, 0x07 /* de-mung the data address */
dsi2:
mtspr SPR_DAR, %r1 /* put in dar */
mfmsr %r0 /* get msr */
xoris %r0, %r0, 0x2 /* flip the msr<tgpr> bit */
mtcrf 0x80, %r3 /* restore CR0 */
mtmsr %r0 /* flip back to the native gprs */
ba EXC_DSI /* branch to DSI interrupt */
CNAME(dsmisssize) = .-CNAME(dsmisstrap)
/*
* Similar to the above for DSI
* Has to handle BAT spills
* and standard pagetable spills
*/
.globl CNAME(dsitrap),CNAME(dsiend)
CNAME(dsitrap):
mtsprg1 %r1 /* save SP */
GET_CPUINFO(%r1)
stw %r28,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* free r28-r31 */
stw %r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
stw %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
stw %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
bt 17,1f /* branch if PSL_PR is set */
mfdar %r31 /* get fault address */
rlwinm %r31,%r31,7,25,28 /* get segment * 8 */
/* get batu */
lwz %r30,TRAP_TOCBASE(0)
lwz %r30,CNAME(battable)@got(%r30)
add %r31,%r30,%r31
lwz %r30,0(%r31)
mtcr %r30
bf 30,1f /* branch if supervisor valid is
false */
/* get batl */
lwz %r31,4(%r31)
/* We randomly use the highest two bat registers here */
mftb %r28
andi. %r28,%r28,1
bne 2f
mtdbatu 2,%r30
mtdbatl 2,%r31
b 3f
2:
mtdbatu 3,%r30
mtdbatl 3,%r31
3:
mfsprg2 %r30 /* restore XER */
mtxer %r30
mtcr %r29 /* restore CR */
mtsprg1 %r1
GET_CPUINFO(%r1)
lwz %r28,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* restore r28-r31 */
lwz %r29,(PC_DISISAVE+CPUSAVE_R29)(%r1)
lwz %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
lwz %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
mfsprg1 %r1
rfi /* return to trapped code */
1:
mflr %r28 /* save LR (SP already saved) */
/* Jump to disitrap */
bl 4f
.long disitrap
4: mflr %r1
lwz %r1,0(%r1)
mtlr %r1
blrl
CNAME(dsiend):
/*
* 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)
lwz %r30,(PC_DISISAVE+CPUSAVE_R28)(%r1)
stw %r30,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
lwz %r31,(PC_DISISAVE+CPUSAVE_R29)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
lwz %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1)
stw %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
lwz %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mfdar %r30
mfdsisr %r31
stw %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1)
#ifdef KDB
/* Try to detect a kernel stack overflow */
mfsrr1 %r31
mtcr %r31
bt 17,realtrap /* branch is user mode */
mfsprg1 %r31 /* get old SP */
clrrwi %r31,%r31,12 /* Round SP down to nearest page */
sub. %r30,%r31,%r30 /* SP - DAR */
bge 1f
neg %r30,%r30 /* modulo value */
1: cmplwi %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)
lwz %r30,(PC_TEMPSAVE+CPUSAVE_AIM_DAR)(%r1) /* get DAR */
stw %r30,(PC_DBSAVE +CPUSAVE_AIM_DAR)(%r1) /* save DAR */
lwz %r31,(PC_TEMPSAVE+CPUSAVE_AIM_DSISR)(%r1) /* get DSISR */
stw %r31,(PC_DBSAVE +CPUSAVE_AIM_DSISR)(%r1) /* save DSISR */
lwz %r30,(PC_DISISAVE+CPUSAVE_R28)(%r1) /* get r28 */
stw %r30,(PC_DBSAVE +CPUSAVE_R28)(%r1) /* save r28 */
lwz %r31,(PC_DISISAVE+CPUSAVE_R29)(%r1) /* get r29 */
stw %r31,(PC_DBSAVE +CPUSAVE_R29)(%r1) /* save r29 */
lwz %r30,(PC_DISISAVE+CPUSAVE_R30)(%r1) /* get r30 */
stw %r30,(PC_DBSAVE +CPUSAVE_R30)(%r1) /* save r30 */
lwz %r31,(PC_DISISAVE+CPUSAVE_R31)(%r1) /* get r31 */
stw %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)
lwz %r1,PC_CURPCB(%r1)
RESTORE_KERN_SRS(%r30,%r31) /* enable kernel mapping */
b 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
*/
.globl CNAME(generictrap64)
generictrap64:
mtsprg3 %r31
mfmsr %r31
clrldi %r31,%r31,1
mtmsrd %r31
mfsprg3 %r31
isync
.globl CNAME(generictrap)
generictrap:
/* Save R1 for computing the exception vector */
mtsprg3 %r1
/* Save interesting registers */
GET_CPUINFO(%r1)
stw %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1) /* free r28-r31 */
stw %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
stw %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%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:
lwz %r1,PC_CURPCB(%r1)
RESTORE_KERN_SRS(%r30,%r31) /* enable kernel mapping */
/*
* Now the common trap catching code.
*/
k_trap:
FRAME_SETUP(PC_TEMPSAVE)
/* Restore USER_SR */
GET_CPUINFO(%r30)
lwz %r30,PC_CURPCB(%r30)
lwz %r30,PCB_AIM_USR_VSID(%r30)
mtsr USER_SR,%r30; sync; isync
/* Call C interrupt dispatcher: */
trapagain:
addi %r3,%r1,8
bl CNAME(powerpc_interrupt)
.globl CNAME(trapexit) /* backtrace code sentinel */
CNAME(trapexit):
/* Disable interrupts: */
mfmsr %r3
andi. %r3,%r3,~PSL_EE@l
mtmsr %r3
/* Test AST pending: */
lwz %r5,FRAME_SRR1+8(%r1)
mtcr %r5
bf 17,1f /* branch if PSL_PR is false */
GET_CPUINFO(%r3) /* get per-CPU pointer */
lwz %r4, TD_FLAGS(%r2) /* get thread flags value
* (r2 is curthread) */
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
addi %r3,%r1,8
bl CNAME(ast)
.globl CNAME(asttrapexit) /* backtrace code sentinel #2 */
CNAME(asttrapexit):
b trapexit /* test ast ret value ? */
1:
FRAME_LEAVE(PC_TEMPSAVE)
.globl CNAME(rfi_patch1) /* replace rfi with rfid on ppc64 */
CNAME(rfi_patch1):
rfi
.globl CNAME(rfid_patch)
CNAME(rfid_patch):
rfid
#if defined(KDB)
/*
* Deliberate entry to dbtrap
*/
.globl CNAME(breakpoint)
CNAME(breakpoint):
mtsprg1 %r1
mfmsr %r3
mtsrr1 %r3
andi. %r3,%r3,~(PSL_EE|PSL_ME)@l
mtmsr %r3 /* disable interrupts */
isync
GET_CPUINFO(%r3)
stw %r28,(PC_DBSAVE+CPUSAVE_R28)(%r3)
stw %r29,(PC_DBSAVE+CPUSAVE_R29)(%r3)
stw %r30,(PC_DBSAVE+CPUSAVE_R30)(%r3)
stw %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
lwz %r1,TRAP_TOCBASE(0) /* get new SP */
lwz %r1,trapstk@got(%r1)
addi %r1,%r1,TRAPSTKSZ-16
FRAME_SETUP(PC_DBSAVE)
/* Call C trap code: */
addi %r3,%r1,8
bl CNAME(db_trap_glue)
or. %r3,%r3,%r3
bne dbleave
/* This wasn't for KDB, so switch to real trap: */
lwz %r3,FRAME_EXC+8(%r1) /* save exception */
GET_CPUINFO(%r4)
stw %r3,(PC_DBSAVE+CPUSAVE_R31)(%r4)
FRAME_LEAVE(PC_DBSAVE)
mtsprg1 %r1 /* prepare for entrance to realtrap */
GET_CPUINFO(%r1)
stw %r28,(PC_TEMPSAVE+CPUSAVE_R28)(%r1)
stw %r29,(PC_TEMPSAVE+CPUSAVE_R29)(%r1)
stw %r30,(PC_TEMPSAVE+CPUSAVE_R30)(%r1)
stw %r31,(PC_TEMPSAVE+CPUSAVE_R31)(%r1)
mflr %r28
mfcr %r29
lwz %r31,(PC_DBSAVE+CPUSAVE_R31)(%r1)
mtsprg3 %r31 /* SPRG3 was clobbered by FRAME_LEAVE */
mfsprg1 %r1
b realtrap
dbleave:
FRAME_LEAVE(PC_DBSAVE)
.globl CNAME(rfi_patch2) /* replace rfi with rfid on ppc64 */
CNAME(rfi_patch2):
rfi
/*
* In case of KDB we want a separate trap catcher for it
*/
.globl CNAME(dblow),CNAME(dbend)
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 */
lwz %r1, TRAP_GENTRAP(0) /* Get branch address */
mtlr %r1
li %r1, 0 /* How to get the vector from LR */
blrl /* LR & (0xff00 | r1) is exception # */
1:
/* Privileged, so drop to KDB */
GET_CPUINFO(%r1)
stw %r28,(PC_DBSAVE+CPUSAVE_R28)(%r1) /* free r28 */
mfsprg2 %r28 /* r29 holds cr... */
stw %r28,(PC_DBSAVE+CPUSAVE_R29)(%r1) /* free r29 */
stw %r30,(PC_DBSAVE+CPUSAVE_R30)(%r1) /* free r30 */
stw %r31,(PC_DBSAVE+CPUSAVE_R31)(%r1) /* free r31 */
mflr %r28 /* save LR */
/* Jump to dbtrap */
bl 2f
.long dbtrap
2: mflr %r1
lwz %r1,0(%r1)
mtlr %r1
blrl
CNAME(dbend):
#endif /* KDB */
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