nios2: switch to generic version of pte allocation

nios2 allocates kernel PTE pages with

        __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTE_ORDER);

and user page tables with

        pte = alloc_pages(GFP_KERNEL, PTE_ORDER);
        if (pte)
                clear_highpage();

The PTE_ORDER is hardwired to zero, which makes nios2 implementation almost
identical to the generic one.

Switch nios2 to the generic version that does exactly the same thing for
the kernel page tables and adds __GFP_ACCOUNT for the user PTEs.

The pte_free_kernel() and pte_free() versions on nios2 are identical to the
generic ones and can be simply dropped.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Anton Ivanov <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Greentime Hu <[email protected]>
Cc: Guan Xuetao <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ley Foon Tan <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Burton <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Richard Kuo <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sam Creasey <[email protected]>
Cc: Vincent Chen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

arch/nios2/include/asm/pgalloc.h

@@ -12,6 +12,8 @@
 
 #include <linux/mm.h>
 
+#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
 	pte_t *pte)
 {
@@ -37,41 +39,6 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 	free_pages((unsigned long)pgd, PGD_ORDER);
 }
 
-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
-	pte_t *pte;
-
-	pte = (pte_t *) __get_free_pages(GFP_KERNEL|__GFP_ZERO, PTE_ORDER);
-
-	return pte;
-}
-
-static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
-{
-	struct page *pte;
-
-	pte = alloc_pages(GFP_KERNEL, PTE_ORDER);
-	if (pte) {
-		if (!pgtable_page_ctor(pte)) {
-			__free_page(pte);
-			return NULL;
-		}
-		clear_highpage(pte);
-	}
-	return pte;
-}
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
-	free_pages((unsigned long)pte, PTE_ORDER);
-}
-
-static inline void pte_free(struct mm_struct *mm, struct page *pte)
-{
-	pgtable_page_dtor(pte);
-	__free_pages(pte, PTE_ORDER);
-}
-
 #define __pte_free_tlb(tlb, pte, addr)				\
 	do {							\
 		pgtable_page_dtor(pte);				\