parisc/pgtable: Do not drop upper 5 address bits of physical address

When calculating the pfn for the iitlbt/idtlbt instruction, do not
drop the upper 5 address bits. This doesn't seem to have an effect
on physical hardware which uses less physical address bits, but in
qemu the missing bits are visible.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc:  <stable@vger.kernel.org>

arch/parisc/kernel/entry.S

@@ -475,13 +475,13 @@
 	 * to a CPU TLB 4k PFN (4k => 12 bits to shift) */
 	#define PAGE_ADD_SHIFT		(PAGE_SHIFT-12)
 	#define PAGE_ADD_HUGE_SHIFT	(REAL_HPAGE_SHIFT-12)
+	#define PFN_START_BIT	(63-ASM_PFN_PTE_SHIFT+(63-58)-PAGE_ADD_SHIFT)
 
 	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
 	.macro		convert_for_tlb_insert20 pte,tmp
 #ifdef CONFIG_HUGETLB_PAGE
 	copy		\pte,\tmp
-	extrd,u		\tmp,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
-				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
+	extrd,u		\tmp,PFN_START_BIT,PFN_START_BIT+1,\pte
 
 	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
 				(63-58)+PAGE_ADD_SHIFT,\pte
@@ -489,8 +489,7 @@
 	depdi		_HUGE_PAGE_SIZE_ENCODING_DEFAULT,63,\
 				(63-58)+PAGE_ADD_HUGE_SHIFT,\pte
 #else /* Huge pages disabled */
-	extrd,u		\pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
-				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
+	extrd,u		\pte,PFN_START_BIT,PFN_START_BIT+1,\pte
 	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
 				(63-58)+PAGE_ADD_SHIFT,\pte
 #endif