powerpc/mm: Merge various PTE bits and accessors definitions

Now that they are almost identical, we can merge some of the definitions
related to the PTE format into common files.

This creates a new pte-common.h which is included by both 32 and 64-bit
right after the CPU specific pte-*.h file, and which defines some
bits to "default" values if they haven't been defined already, and
then provides a generic definition of most of the bit combinations
based on these and exposed to the rest of the kernel.

I also moved to the common pgtable.h most of the "small" accessors to the
PTE bits and modification helpers (pte_mk*). The actual accessors remain
in their separate files.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index 5a575f2..768e0f0 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -80,82 +80,8 @@
  * Include the PTE bits definitions
  */
 #include <asm/pte-hash64.h>
+#include <asm/pte-common.h>
 
-/* Some other useful definitions */
-#define PTE_RPN_MAX	(1UL << (64 - PTE_RPN_SHIFT))
-#define PTE_RPN_MASK	(~((1UL<<PTE_RPN_SHIFT)-1))
-
-/* _PAGE_CHG_MASK masks of bits that are to be preserved accross
- * pgprot changes
- */
-#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
-                         _PAGE_ACCESSED | _PAGE_SPECIAL)
-
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
-#define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
-
-
-/* Permission masks used to generate the __P and __S table,
- *
- * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
- */
-#define PAGE_NONE	__pgprot(_PAGE_BASE)
-#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
-#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
-#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
-#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-
-/* 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)
-#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
-				 _PAGE_NO_CACHE | _PAGE_GUARDED)
-#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
-#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
-#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
-
-/* Protection bits for use by pte_pgprot() */
-#define PAGE_PROT_BITS	(_PAGE_GUARDED | _PAGE_COHERENT | \
-			 _PAGE_NO_CACHE | _PAGE_WRITETHRU |		\
-			 _PAGE_4K_PFN | _PAGE_USER | _PAGE_RW |		\
-			 _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_EXEC)
-
-
-/* We always have _PAGE_SPECIAL on 64 bit */
-#define __HAVE_ARCH_PTE_SPECIAL
-
-/* Make modules code happy. We don't set RO yet */
-#define PAGE_KERNEL_EXEC	PAGE_KERNEL_X
-
-/*
- * POWER4 and newer have per page execute protection, older chips can only
- * do this on a segment (256MB) basis.
- *
- * Also, write permissions imply read permissions.
- * This is the closest we can get..
- *
- * Note due to the way vm flags are laid out, the bits are XWR
- */
-#define __P000	PAGE_NONE
-#define __P001	PAGE_READONLY
-#define __P010	PAGE_COPY
-#define __P011	PAGE_COPY
-#define __P100	PAGE_READONLY_X
-#define __P101	PAGE_READONLY_X
-#define __P110	PAGE_COPY_X
-#define __P111	PAGE_COPY_X
-
-#define __S000	PAGE_NONE
-#define __S001	PAGE_READONLY
-#define __S010	PAGE_SHARED
-#define __S011	PAGE_SHARED
-#define __S100	PAGE_READONLY_X
-#define __S101	PAGE_READONLY_X
-#define __S110	PAGE_SHARED_X
-#define __S111	PAGE_SHARED_X
 
 #ifdef CONFIG_PPC_MM_SLICES
 #define HAVE_ARCH_UNMAPPED_AREA
@@ -196,34 +122,8 @@
 #endif /* __real_pte */
 
 
-/*
- * Conversion functions: convert a page and protection to a page entry,
- * and a page entry and page directory to the page they refer to.
- *
- * mk_pte takes a (struct page *) as input
- */
-#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
-
-static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
-{
-	pte_t pte;
-
-
-	pte_val(pte) = (pfn << PTE_RPN_SHIFT) | pgprot_val(pgprot);
-	return pte;
-}
-
-#define pte_modify(_pte, newprot) \
-  (__pte((pte_val(_pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)))
-
-#define pte_none(pte)		((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
-#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
-
 /* pte_clear moved to later in this file */
 
-#define pte_pfn(x)		((unsigned long)((pte_val(x)>>PTE_RPN_SHIFT)))
-#define pte_page(x)		pfn_to_page(pte_pfn(x))
-
 #define PMD_BAD_BITS		(PTE_TABLE_SIZE-1)
 #define PUD_BAD_BITS		(PMD_TABLE_SIZE-1)
 
@@ -271,36 +171,6 @@
 /* This now only contains the vmalloc pages */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-/*
- * The following only work if pte_present() is true.
- * Undefined behaviour if not..
- */
-static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
-static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
-static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
-static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
-static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-
-static inline pte_t pte_wrprotect(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_RW); return pte; }
-static inline pte_t pte_mkclean(pte_t pte) {
-	pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
-static inline pte_t pte_mkold(pte_t pte) {
-	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkwrite(pte_t pte) {
-	pte_val(pte) |= _PAGE_RW; return pte; }
-static inline pte_t pte_mkdirty(pte_t pte) {
-	pte_val(pte) |= _PAGE_DIRTY; return pte; }
-static inline pte_t pte_mkyoung(pte_t pte) {
-	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
-static inline pte_t pte_mkhuge(pte_t pte) {
-	return pte; }
-static inline pte_t pte_mkspecial(pte_t pte) {
-	pte_val(pte) |= _PAGE_SPECIAL; return pte; }
-static inline pgprot_t pte_pgprot(pte_t pte)
-{
-	return __pgprot(pte_val(pte) & PAGE_PROT_BITS);
-}
 
 /* Atomic PTE updates */
 static inline unsigned long pte_update(struct mm_struct *mm,