From c3e757a77cab461d11cd3e365d700e8c8fb3fae0 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 17 Jun 2013 11:35:15 +0530 Subject: ARC: [tlb-miss] Extraneous PTE bit testing/setting * No need to check for READ access in I-TLB Miss handler * Redundant PAGE_PRESENT update in PTE Post TLB entry installation, in updating PTE for software accessed/dity bits, no need to update PAGE_PRESENT since it will already be set. Infact the entry won't have installed if !PAGE_PRESENT. Signed-off-by: Vineet Gupta --- arch/arc/mm/tlbex.S | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/arc/mm') diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S index 8d61fdf7a43b..fcdc19ff6da7 100644 --- a/arch/arc/mm/tlbex.S +++ b/arch/arc/mm/tlbex.S @@ -277,16 +277,16 @@ ARC_ENTRY EV_TLBMissI ;---------------------------------------------------------------- ; VERIFY_PTE: Check if PTE permissions approp for executing code cmp_s r2, VMALLOC_START - mov.lo r2, (_PAGE_PRESENT | _PAGE_U_READ | _PAGE_U_EXECUTE) - mov.hs r2, (_PAGE_PRESENT | _PAGE_K_READ | _PAGE_K_EXECUTE) + mov.lo r2, (_PAGE_PRESENT | _PAGE_U_EXECUTE) + mov.hs r2, (_PAGE_PRESENT | _PAGE_K_EXECUTE) and r3, r0, r2 ; Mask out NON Flag bits from PTE xor.f r3, r3, r2 ; check ( ( pte & flags_test ) == flags_test ) bnz do_slow_path_pf ; Let Linux VM know that the page was accessed - or r0, r0, (_PAGE_PRESENT | _PAGE_ACCESSED) ; set Accessed Bit - st_s r0, [r1] ; Write back PTE + or r0, r0, _PAGE_ACCESSED ; set Accessed Bit + st_s r0, [r1] ; Write back PTE CONV_PTE_TO_TLB COMMIT_ENTRY_TO_MMU @@ -345,7 +345,7 @@ ARC_ENTRY EV_TLBMissD ;---------------------------------------------------------------- ; UPDATE_PTE: Let Linux VM know that page was accessed/dirty lr r3, [ecr] - or r0, r0, (_PAGE_PRESENT | _PAGE_ACCESSED) ; Accessed bit always + or r0, r0, _PAGE_ACCESSED ; Accessed bit always btst_s r3, ECR_C_BIT_DTLB_ST_MISS ; See if it was a Write Access ? or.nz r0, r0, _PAGE_MODIFIED ; if Write, set Dirty bit as well st_s r0, [r1] ; Write back PTE -- cgit v1.2.3