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Subject[RFC PATCH v1 05/41] powerpc/40x: Reorder a few instructions in critical exception prolog
Date
In order to ease preparation for CONFIG_VMAP_STACK, reorder
a few instruction, especially save r1 into stack frame earlier.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/head_40x.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 067ae1302c1c..5b337bf49bcb 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -119,6 +119,9 @@ _ENTRY(saved_ksp_limit)
lwz r11,TASK_STACK-THREAD(r11) /* this thread's kernel stack */
1: addi r11,r11,THREAD_SIZE-INT_FRAME_SIZE /* Alloc an excpt frm */
tophys(r11,r11)
+ stw r1,GPR1(r11)
+ stw r1,0(r11)
+ tovirt(r1,r11)
stw r10,_CCR(r11) /* save various registers */
stw r12,GPR12(r11)
stw r9,GPR9(r11)
@@ -129,14 +132,11 @@ _ENTRY(saved_ksp_limit)
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 */
+ stw r12,_DEAR(r11) /* since they may have had stuff */
stw r9,_ESR(r11) /* exception was taken */
mfspr r12,SPRN_SRR2
- stw r1,GPR1(r11)
mfspr r9,SPRN_SRR3
- stw r1,0(r11)
- tovirt(r1,r11)
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
stw r0,GPR0(r11)
lis r10, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
--
2.25.0
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