openrisc: drop _PAGE_FILE and pte_file()-related helpers

We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/openrisc/include/asm/pgtable.h

@@ -125,7 +125,6 @@ extern void paging_init(void);
 #define _PAGE_CC       0x001 /* software: pte contains a translation */
 #define _PAGE_CI       0x002 /* cache inhibit          */
 #define _PAGE_WBC      0x004 /* write back cache       */
-#define _PAGE_FILE     0x004 /* set: pagecache, unset: swap (when !PRESENT) */
 #define _PAGE_WOM      0x008 /* weakly ordered memory  */
 
 #define _PAGE_A        0x010 /* accessed               */
@@ -240,7 +239,6 @@ static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
 static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC; }
 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 0; }
 static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
 
@@ -438,12 +436,6 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
 
-/* Encode and decode a nonlinear file mapping entry */
-
-#define PTE_FILE_MAX_BITS               26
-#define pte_to_pgoff(x)	                (pte_val(x) >> 6)
-#define pgoff_to_pte(x)	                __pte(((x) << 6) | _PAGE_FILE)
-
 #define kern_addr_valid(addr)           (1)
 
 #include <asm-generic/pgtable.h>

arch/openrisc/kernel/head.S

@@ -754,11 +754,6 @@ _dc_enable:
 
 /* ===============================================[ page table masks ]=== */
 
-/* bit 4 is used in hardware as write back cache bit. we never use this bit
- * explicitly, so we can reuse it as _PAGE_FILE bit and mask it out when
- * writing into hardware pte's
- */
-
 #define DTLB_UP_CONVERT_MASK  0x3fa
 #define ITLB_UP_CONVERT_MASK  0x3a