powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception

In order to be able to switch MMU on in exception prolog, save
SRR0 and SRR1 earlier.

Also save r10 and r11 into stack earlier to better match with the
normal exception prolog.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/79a93f253d72dc97ac968c9c62b5066960b688ed.1615552866.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-03-12 12:50:13 +00:00 committed by Michael Ellerman
parent 9d3c18a11a
commit fcd4b43c36
2 changed files with 8 additions and 9 deletions

View File

@ -107,15 +107,6 @@ _ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
#ifdef CONFIG_40x
.globl crit_transfer_to_handler
crit_transfer_to_handler:
lwz r0,crit_r10@l(0)
stw r0,GPR10(r11)
lwz r0,crit_r11@l(0)
stw r0,GPR11(r11)
mfspr r0,SPRN_SRR0
stw r0,crit_srr0@l(0)
mfspr r0,SPRN_SRR1
stw r0,crit_srr1@l(0)
/* set the stack limit to the current stack */
mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)

View File

@ -103,6 +103,10 @@ _ENTRY(saved_ksp_limit)
.macro CRITICAL_EXCEPTION_PROLOG
stw r10,crit_r10@l(0) /* save two registers to work with */
stw r11,crit_r11@l(0)
mfspr r10,SPRN_SRR0
mfspr r11,SPRN_SRR1
stw r10,crit_srr0@l(0)
stw r11,crit_srr1@l(0)
mfcr r10 /* save CR in r10 for now */
mfspr r11,SPRN_SRR3 /* check whether user or kernel */
andi. r11,r11,MSR_PR
@ -120,6 +124,10 @@ _ENTRY(saved_ksp_limit)
stw r9,GPR9(r11)
mflr r10
stw r10,_LINK(r11)
lwz r10,crit_r10@l(0)
lwz r12,crit_r11@l(0)
stw r10,GPR10(r11)
stw r12,GPR11(r11)
mfspr r12,SPRN_DEAR /* save DEAR and ESR in the frame */
stw r12,_DEAR(r11) /* since they may have had stuff */
mfspr r9,SPRN_ESR /* in them at the point where the */