[PATCH v2 03/14] powerpc/64s: masked interrupt returns to kernel so avoid r13 restore

Nicholas Piggin npiggin at gmail.com
Sat Aug 12 02:39:01 AEST 2017


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 <npiggin at gmail.com>
---
 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)
-- 
2.13.3



More information about the Linuxppc-dev mailing list