Thread (29 messages) flat view 29 messages, 4 authors, 2017-08-10
STALE3327d

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

From: Nicholas Piggin <npiggin@gmail.com>
Date: 2017-08-05 17:03:08
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Linus Torvalds

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@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)
-- 
2.11.0
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