powerpc/book3s32: Reorder _PAGE_XXX flags to simplify TLB handling

For pages without _PAGE_USER, PP field is 00
For pages with _PAGE_USER, PP field is 10 for RW and 11 for RO.

This patch sets _PAGE_USER to 0x002 and _PAGE_RW to 0x001
is order to simplify TLB handling by reducing amount of shifts.

The location of _PAGE_PRESENT and _PAGE_HASHPTE doesn't matter
as they are only SW related flags.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/head_32.S

@@ -522,7 +522,6 @@ InstructionTLBMiss:
 	andc.	r1,r1,r0		/* check access & ~permission */
 	bne-	InstructionAddressInvalid /* return if access not permitted */
 	/* Convert linux-style PTE to low word of PPC-style PTE */
-	rlwimi	r0,r0,32-1,30,30	/* _PAGE_USER -> PP msb */
 	ori	r1, r1, 0xe05		/* clear out reserved bits */
 	andc	r1, r0, r1		/* PP = user? 2 : 0 */
 BEGIN_FTR_SECTION
@@ -590,8 +589,7 @@ DataLoadTLBMiss:
 	 * we would need to update the pte atomically with lwarx/stwcx.
 	 */
 	/* Convert linux-style PTE to low word of PPC-style PTE */
-	rlwinm	r1,r0,32-10,31,31	/* _PAGE_RW -> PP lsb */
-	rlwimi	r0,r0,32-1,30,30	/* _PAGE_USER -> PP msb */
+	rlwinm	r1, r0, 0, 31, 31	/* _PAGE_RW -> PP lsb */
 	rlwimi	r0,r0,32-1,31,31	/* _PAGE_USER -> PP lsb */
 	ori	r1,r1,0xe04		/* clear out reserved bits */
 	andc	r1,r0,r1		/* PP = user? rw? 2: 3: 0 */
@@ -670,7 +668,6 @@ DataStoreTLBMiss:
 	 * we would need to update the pte atomically with lwarx/stwcx.
 	 */
 	/* Convert linux-style PTE to low word of PPC-style PTE */
-	rlwimi	r0,r0,32-1,30,30	/* _PAGE_USER -> PP msb */
 	li	r1,0xe05		/* clear out reserved bits & PP lsb */
 	andc	r1,r0,r1		/* PP = user? 2: 0 */
 BEGIN_FTR_SECTION