[PATCH 7/9] powerpc/64s: paca EX_LR can be merged with EX_DAR

Nicholas Piggin npiggin at gmail.com
Sun May 21 23:15:48 AEST 2017


EX_LR is used only for a small section of the SLB miss handler.
Merge it with EX_DAR.

Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
---
 arch/powerpc/include/asm/exception-64s.h | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index e1103dc9d8e8..ba03db14e1e8 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -35,12 +35,19 @@
 #define EX_DSISR	48
 #define EX_CCR		52
 #define EX_R3		56
-#define EX_LR		64
-#define EX_CFAR		72
-#define EX_PPR		80	/* SMT thread status register (priority) */
-#define EX_CTR		88
+#define EX_CFAR		64
+#define EX_PPR		72
+#define EX_CTR		80
 
-#define EX_SIZE		12	/* size in u64 units */
+#define EX_SIZE		11	/* size in u64 units */
+
+/*
+ * EX_LR is only used in EXSLB and where it does not overlap with EX_DAR
+ * EX_CCR similarly with DSISR, but being 4 byte registers there is a hole
+ * in the save area so it's not necessary to overlap them. Could be used
+ * for future savings though if another 4 byte register was to be saved.
+ */
+#define EX_LR		EX_DAR
 
 #ifdef __ASSEMBLY__
 
-- 
2.11.0



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