[PATCH v4 13/13] powerpc/40x: Don't save CR in SPRN_SPRG_SCRATCH6

From: Christophe Leroy
Date: Sat Apr 25 2020 - 04:43:53 EST


We have r12 available, use it to keep CR around and don't
save it in SPRN_SPRG_SCRATCH6.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/kernel/head_40x.S | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 804cbd0899ac..f9b880235aee 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -253,9 +253,8 @@ _ENTRY(saved_ksp_limit)
mtspr SPRN_SPRG_SCRATCH1, r11
mtspr SPRN_SPRG_SCRATCH3, r12
mtspr SPRN_SPRG_SCRATCH4, r9
- mfcr r11
+ mfcr r12
mfspr r9, SPRN_PID
- mtspr SPRN_SPRG_SCRATCH6, r11
mtspr SPRN_SPRG_SCRATCH5, r9
mfspr r10, SPRN_DEAR /* Get faulting address */

@@ -322,9 +321,8 @@ _ENTRY(saved_ksp_limit)
* and call the heavyweights to help us out.
*/
mfspr r9, SPRN_SPRG_SCRATCH5
- mfspr r11, SPRN_SPRG_SCRATCH6
mtspr SPRN_PID, r9
- mtcr r11
+ mtcr r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
mfspr r11, SPRN_SPRG_SCRATCH1
@@ -340,9 +338,8 @@ _ENTRY(saved_ksp_limit)
mtspr SPRN_SPRG_SCRATCH1, r11
mtspr SPRN_SPRG_SCRATCH3, r12
mtspr SPRN_SPRG_SCRATCH4, r9
- mfcr r11
+ mfcr r12
mfspr r9, SPRN_PID
- mtspr SPRN_SPRG_SCRATCH6, r11
mtspr SPRN_SPRG_SCRATCH5, r9
mfspr r10, SPRN_SRR0 /* Get faulting address */

@@ -409,9 +406,8 @@ _ENTRY(saved_ksp_limit)
* and call the heavyweights to help us out.
*/
mfspr r9, SPRN_SPRG_SCRATCH5
- mfspr r11, SPRN_SPRG_SCRATCH6
mtspr SPRN_PID, r9
- mtcr r11
+ mtcr r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
mfspr r11, SPRN_SPRG_SCRATCH1
@@ -555,9 +551,8 @@ finish_tlb_load:
/* Done...restore registers and get out of here.
*/
mfspr r9, SPRN_SPRG_SCRATCH5
- mfspr r11, SPRN_SPRG_SCRATCH6
mtspr SPRN_PID, r9
- mtcr r11
+ mtcr r12
mfspr r9, SPRN_SPRG_SCRATCH4
mfspr r12, SPRN_SPRG_SCRATCH3
mfspr r11, SPRN_SPRG_SCRATCH1
--
2.25.0