Subject: [PATCH 03/13] powerpc/64s: masked interrupt returns to kernel so avoid r13 restore

From: Nicholas Piggin <[email-masked]>
Date: Sun, 6 Aug 2017 03:02:31 +1000

Places in the kernel where r13 is not the PACA pointer must have
maskable interrupts disabled, so r13 does not have to be restored
when returning from a soft-masked interrupt.

Signed-off-by: Nicholas Piggin <[email-masked]>
---
 arch/powerpc/kernel/exceptions-64s.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index c4f50a9e2ab5..67321be3122c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1379,7 +1379,7 @@ masked_##_H##interrupt:					\
 	ld	r9,PACA_EXGEN+EX_R9(r13);		\
 	ld	r10,PACA_EXGEN+EX_R10(r13);		\
 	ld	r11,PACA_EXGEN+EX_R11(r13);		\
-	GET_SCRATCH0(r13);				\
+	/* returns to kernel where r13 must be set up, so don't restore it */ \
 	##_H##rfid;					\
 	b	.;					\
 	MASKED_DEC_HANDLER(_H)
-- 
2.11.0