[RFC v2 10/12] powerpc: Read AMR only if pkey-violation caused the exception.

[Ram Pai]

Signed-off-by: Ram Pai <linux...@us.ibm.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S 
b/arch/powerpc/kernel/exceptions-64s.S
index 8db9ef8..a4de1b4 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -493,13 +493,15 @@ EXC_COMMON_BEGIN(data_access_common)
        ld      r12,_MSR(r1)
        ld      r3,PACA_EXGEN+EX_DAR(r13)
        lwz     r4,PACA_EXGEN+EX_DSISR(r13)
+       std     r3,_DAR(r1)
+       std     r4,_DSISR(r1)
 #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+       andis.  r0,r4,DSISR_KEYFAULT@h /* save AMR only if its a key fault */
+       beq+    1f
        mfspr   r5,SPRN_AMR
        std     r5,PACA_AMR(r13)
 #endif /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
-       li      r5,0x300
-       std     r3,_DAR(r1)
-       std     r4,_DSISR(r1)
+1:     li      r5,0x300
 BEGIN_MMU_FTR_SECTION
        b       do_hash_page            /* Try to handle as hpte fault */
 MMU_FTR_SECTION_ELSE
@@ -565,13 +567,15 @@ EXC_COMMON_BEGIN(instruction_access_common)
        ld      r12,_MSR(r1)
        ld      r3,_NIP(r1)
        andis.  r4,r12,0x5820
+       std     r3,_DAR(r1)
+       std     r4,_DSISR(r1)
 #ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+       andis.  r0,r4,DSISR_KEYFAULT@h /* save AMR only if its a key fault */
+       beq+    1f
        mfspr   r5,SPRN_AMR
        std     r5,PACA_AMR(r13)
 #endif /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
-       li      r5,0x400
-       std     r3,_DAR(r1)
-       std     r4,_DSISR(r1)
+1:     li      r5,0x400
 BEGIN_MMU_FTR_SECTION
        b       do_hash_page            /* Try to handle as hpte fault */
 MMU_FTR_SECTION_ELSE
-- 
1.8.3.1