Subject: [PATCH v4 03/21] powerpc/8xx: exception InstructionAccess does not exist on MPC8xx

From: Christophe Leroy <[email-masked]>
Date: Fri, 19 Sep 2014 10:36:06 +0200 (CEST)

Exception InstructionAccess does not exist on MPC8xx. No need to branch there from somewhere else. 
Handling can be done directly in InstructionTLBError Exception.

Signed-off-by: Christophe Leroy <[email-masked]>

---
Changes in v2:
- None

Changes in v3:
- arch/powerpc/mm/fault.c uses the vector number, so make sure it understand
the new ones.

Changes in v4:
- Removing the change to mm/fault.c, faking the exception id to make mm/fault
think it comes from InstructionAccess.

 arch/powerpc/kernel/head_8xx.S | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 3af6db1..ec1958f 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -234,15 +234,10 @@ DataAccess:
 	EXC_XFER_LITE(0x300, handle_page_fault)
 
 /* Instruction access exception.
- * This is "never generated" by the MPC8xx.  We jump to it for other
- * translation errors.
+ * This is "never generated" by the MPC8xx.
  */
 	. = 0x400
 InstructionAccess:
-	EXCEPTION_PROLOG
-	mr	r4,r12
-	mr	r5,r9
-	EXC_XFER_LITE(0x400, handle_page_fault)
 
 /* External interrupt */
 	EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
@@ -382,7 +377,7 @@ InstructionTLBMiss:
 #endif
 	mfspr	r10, SPRN_SPRG_SCRATCH2
 	EXCEPTION_EPILOG_0
-	b	InstructionAccess
+	b	InstructionTLBError
 
 	. = 0x1200
 DataStoreTLBMiss:
@@ -477,7 +472,11 @@ DataStoreTLBMiss:
  */
 	. = 0x1300
 InstructionTLBError:
-	b	InstructionAccess
+	EXCEPTION_PROLOG
+	mr	r4,r12
+	mr	r5,r9
+	/* 0x400 is InstructionAccess exception, needed by bad_page_fault() */
+	EXC_XFER_LITE(0x400, handle_page_fault)
 
 /* This is the data TLB error on the MPC8xx.  This could be due to
  * many reasons, including a dirty update to a pte.  We can catch that
-- 
2.1.0