github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-28 00:53:34 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

powerpc/40x: Prepare normal exception handler for enabling MMU early

Browse Source 
Ensure normal exception handler are able to manage stuff with
MMU enabled. For that we use CONFIG_VMAP_STACK related code
allthough there is no intention to really activate CONFIG_VMAP_STACK
on powerpc 40x for the moment.

40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of
SPRN_DSISR. Take it into account in common macros.

40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in
common macros that will be used also with 40x.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-03-12 12:50:16 +00:00 committed by Michael Ellerman
parent 0fc1e93481
commit 0512aadd75
3 changed files with 21 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/kernel/entry_32.S
View File

@ -162,7 +162,7 @@ transfer_to_handler:
li r12,-1 /* clear all pending debug events */
mtspr SPRN_DBSR,r12
lis r11,global_dbcr0@ha
tophys(r11,r11)
tophys_novmstack r11,r11
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)

15
arch/powerpc/kernel/head_32.h
View File

@ -22,9 +22,17 @@
#ifdef CONFIG_VMAP_STACK
mfspr r10, SPRN_SPRG_THREAD
.if \handle_dar_dsisr
#ifdef CONFIG_40x
mfspr r11, SPRN_DEAR
#else
mfspr r11, SPRN_DAR
#endif
stw r11, DAR(r10)
#ifdef CONFIG_40x
mfspr r11, SPRN_ESR
#else
mfspr r11, SPRN_DSISR
#endif
stw r11, DSISR(r10)
.endif
mfspr r11, SPRN_SRR0
@ -61,7 +69,7 @@
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
#ifdef CONFIG_VMAP_STACK
li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR | MSR_RI)) /* can take DTLB miss */
mtmsr r11
isync
mfspr r11, SPRN_SPRG_SCRATCH2
@ -158,8 +166,13 @@
.macro save_dar_dsisr_on_stack reg1, reg2, sp
#ifndef CONFIG_VMAP_STACK
#ifdef CONFIG_40x
mfspr \reg1, SPRN_DEAR
mfspr \reg2, SPRN_ESR
#else
mfspr \reg1, SPRN_DAR
mfspr \reg2, SPRN_DSISR
#endif
stw \reg1, _DAR(\sp)
stw \reg2, _DSISR(\sp)
#endif

17
arch/powerpc/kernel/head_40x.S
View File

@ -221,11 +221,8 @@ _ENTRY(saved_ksp_limit)
* if they can't resolve the lightweight TLB fault.
*/
START_EXCEPTION(0x0300, DataStorage)
EXCEPTION_PROLOG
mfspr r5, SPRN_ESR /* Grab the ESR, save it */
stw r5, _ESR(r11)
mfspr r4, SPRN_DEAR /* Grab the DEAR, save it */
stw r4, _DEAR(r11)
EXCEPTION_PROLOG handle_dar_dsisr=1
save_dar_dsisr_on_stack r4, r5, r11
EXC_XFER_LITE(0x300, handle_page_fault)
/*
@ -244,17 +241,15 @@ _ENTRY(saved_ksp_limit)
/* 0x0600 - Alignment Exception */
START_EXCEPTION(0x0600, Alignment)
EXCEPTION_PROLOG
mfspr r4,SPRN_DEAR /* Grab the DEAR and save it */
stw r4,_DEAR(r11)
EXCEPTION_PROLOG handle_dar_dsisr=1
save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x600, alignment_exception)
/* 0x0700 - Program Exception */
START_EXCEPTION(0x0700, ProgramCheck)
EXCEPTION_PROLOG
mfspr r4,SPRN_ESR /* Grab the ESR and save it */
stw r4,_ESR(r11)
EXCEPTION_PROLOG handle_dar_dsisr=1
save_dar_dsisr_on_stack r4, r5, r11
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_STD(0x700, program_check_exception)