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 <vgupta@synopsys.com>

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