Use SPRN_SPRG_SCRATCH2 as a third scratch register in
exception prologs in order to simplify them and avoid
data going back and forth from/to CR.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
arch/powerpc/kernel/head_32.h | 22 +++++++---------------
1 file changed, 7 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h
index 5e3393122d29..a1ee1e12241e 100644
--- a/arch/powerpc/kernel/head_32.h
+++ b/arch/powerpc/kernel/head_32.h
@@ -40,7 +40,7 @@
.macro EXCEPTION_PROLOG_1 for_rtas=0
#ifdef CONFIG_VMAP_STACK
- mr r11, r1
+ mtspr SPRN_SPRG_SCRATCH2,r1
subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
beq 1f
mfspr r1,SPRN_SPRG_THREAD
@@ -61,15 +61,10 @@
.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
#ifdef CONFIG_VMAP_STACK
- mtcr r10
- li r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
- mtmsr r10
+ li r11, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
+ mtmsr r11
isync
-#else
- stw r10,_CCR(r11) /* save registers */
-#endif
- mfspr r10, SPRN_SPRG_SCRATCH0
-#ifdef CONFIG_VMAP_STACK
+ mfspr r11, SPRN_SPRG_SCRATCH2
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
@@ -78,14 +73,12 @@
stw r1,0(r11)
tovirt(r1, r11) /* set new kernel sp */
#endif
+ stw r10,_CCR(r11) /* save registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
- stw r10,GPR10(r11)
-#ifdef CONFIG_VMAP_STACK
- mfcr r10
- stw r10, _CCR(r11)
-#endif
+ mfspr r10,SPRN_SPRG_SCRATCH0
mfspr r12,SPRN_SPRG_SCRATCH1
+ stw r10,GPR10(r11)
stw r12,GPR11(r11)
mflr r10
stw r10,_LINK(r11)
@@ -99,7 +92,6 @@
stw r10, _DSISR(r11)
.endif
lwz r9, SRR1(r12)
- andi. r10, r9, MSR_PR
lwz r12, SRR0(r12)
#else
mfspr r12,SPRN_SRR0
--
2.25.0
