powerpc/nohash: Deduplicate _PAGE_CHG_MASK

_PAGE_CHG_MASK is identical between nohash/32 and nohash/64,
deduplicate it.

While at it, clean the #ifdef for PTE_RPN_MASK in nohash/32 as
it is already CONFIG_PPC32.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/c1a1893dbba4afb825bfa78b262f0b0e0fc3b490.1695659959.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/nohash/32/pgtable.h

@@ -143,7 +143,7 @@
  * The mask covered by the RPN must be a ULL on 32-bit platforms with
  * 64-bit PTEs.
  */
-#if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
+#ifdef CONFIG_PTE_64BIT
 #define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
 #define MAX_POSSIBLE_PHYSMEM_BITS 36
 #else
@@ -151,12 +151,6 @@
 #define MAX_POSSIBLE_PHYSMEM_BITS 32
 #endif
 
-/*
- * _PAGE_CHG_MASK masks of bits that are to be preserved across
- * pgprot changes.
- */
-#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
-
 #ifndef __ASSEMBLY__
 
 #define pte_clear(mm, addr, ptep) \

arch/powerpc/include/asm/nohash/64/pgtable.h

@@ -75,12 +75,6 @@
 
 #define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
 
-/*
- * _PAGE_CHG_MASK masks of bits that are to be preserved across
- * pgprot changes.
- */
-#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
-
 #define H_PAGE_4K_PFN 0
 
 #ifndef __ASSEMBLY__

arch/powerpc/include/asm/nohash/pgtable.h

@@ -13,6 +13,12 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 #include <asm/nohash/32/pgtable.h>
 #endif
 
+/*
+ * _PAGE_CHG_MASK masks of bits that are to be preserved across
+ * pgprot changes.
+ */
+#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
+
 /* Permission masks used for kernel mappings */
 #define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
 #define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)