[PATCH v3 08/11] powerpc/8xx: Handle CR out of exception PROLOG/EPILOG

Christophe Leroy christophe.leroy at c-s.fr
Tue Feb 3 22:38:18 AEDT 2015


In order to be able to reduce scope during which CR is saved, we take
CR saving/restoring out of exception PROLOG and EPILOG

Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>

---
v2: no change
v3: no change (but impacted by patch 07)

 arch/powerpc/kernel/head_8xx.S | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 59039a6..429428c 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -116,13 +116,13 @@ turn_on_mmu:
  */
 #define EXCEPTION_PROLOG	\
 	EXCEPTION_PROLOG_0;	\
+	mfcr	r10;		\
 	EXCEPTION_PROLOG_1;	\
 	EXCEPTION_PROLOG_2
 
 #define EXCEPTION_PROLOG_0	\
 	mtspr	SPRN_SPRG_SCRATCH0,r10;	\
-	mtspr	SPRN_SPRG_SCRATCH1,r11;	\
-	mfcr	r10
+	mtspr	SPRN_SPRG_SCRATCH1,r11
 
 #define EXCEPTION_PROLOG_1	\
 	mfspr	r11,SPRN_SRR1;		/* check whether user or kernel */ \
@@ -162,7 +162,6 @@ turn_on_mmu:
  * Exception exit code.
  */
 #define EXCEPTION_EPILOG_0	\
-	mtcr	r10;		\
 	mfspr	r10,SPRN_SPRG_SCRATCH0;	\
 	mfspr	r11,SPRN_SPRG_SCRATCH1
 
@@ -313,6 +312,7 @@ InstructionTLBMiss:
 	mtspr	SPRN_DAR, r3
 #endif
 	EXCEPTION_PROLOG_0
+	mfcr	r10
 	mtspr	SPRN_SPRG_SCRATCH2, r10
 	mfspr	r10, SPRN_SRR0	/* Get effective address of fault */
 	INVALIDATE_ADJACENT_PAGES_CPU15(r11, r10)
@@ -363,6 +363,7 @@ InstructionTLBMiss:
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
 #endif
 	mfspr	r10, SPRN_SPRG_SCRATCH2
+	mtcr	r10
 	EXCEPTION_EPILOG_0
 	rfi
 
@@ -372,6 +373,7 @@ DataStoreTLBMiss:
 	mtspr	SPRN_DAR, r3
 #endif
 	EXCEPTION_PROLOG_0
+	mfcr	r10
 	mtspr	SPRN_SPRG_SCRATCH2, r10
 	mfspr	r10, SPRN_MD_EPN
 
@@ -440,6 +442,7 @@ DataStoreTLBMiss:
 #endif
 	mtspr	SPRN_DAR, r11	/* Tag DAR */
 	mfspr	r10, SPRN_SPRG_SCRATCH2
+	mtcr	r10
 	EXCEPTION_EPILOG_0
 	rfi
 
@@ -465,6 +468,7 @@ InstructionTLBError:
 	. = 0x1400
 DataTLBError:
 	EXCEPTION_PROLOG_0
+	mfcr	r10
 
 	mfspr	r11, SPRN_DAR
 	cmpwi	cr0, r11, RPN_PATTERN
-- 
2.1.0



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