nds32: switch to generic version of pte allocation

The nds32 implementation of pte_alloc_one_kernel() differs from the
generic in the use of __GFP_RETRY_MAYFAIL flag, which is removed after the
conversion.

The nds32 version of pte_alloc_one() missed the call to
pgtable_page_ctor() and also used __GFP_RETRY_MAYFAIL.  Switching it to
use generic __pte_alloc_one() for the PTE page allocation ensures that
page table constructor is run and the user page tables are allocated with
__GFP_ACCOUNT.

The conversion to the generic version of pte_free_kernel() removes the
NULL check for pte.

The pte_free() version on nds32 is identical to the generic one and can be
simply dropped.

Link: http://lkml.kernel.org/r/1557296232-15361-10-git-send-email-rppt@linux.ibm.comSigned-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Creasey <sammy@sammy.net>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/nds32/include/asm/pgalloc.h

@@ -9,6 +9,9 @@
 #include <asm/tlbflush.h>
 #include <asm/proc-fns.h>
 
+#define __HAVE_ARCH_PTE_ALLOC_ONE
+#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+
 /*
  * Since we have only two-level page tables, these are trivial
  */
@@ -22,43 +25,17 @@ extern void pgd_free(struct mm_struct *mm, pgd_t * pgd);
 
 #define check_pgt_cache()		do { } while (0)
 
-static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
-{
-	pte_t *pte;
-
-	pte =
-	    (pte_t *) __get_free_page(GFP_KERNEL | __GFP_RETRY_MAYFAIL |
-				      __GFP_ZERO);
-
-	return pte;
-}
-
 static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
 {
 	pgtable_t pte;
 
-	pte = alloc_pages(GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO, 0);
+	pte = __pte_alloc_one(mm, GFP_PGTABLE_USER);
 	if (pte)
 		cpu_dcache_wb_page((unsigned long)page_address(pte));
 
 	return pte;
 }
 
-/*
- * Free one PTE table.
- */
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t * pte)
-{
-	if (pte) {
-		free_page((unsigned long)pte);
-	}
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
-	__free_page(pte);
-}
-
 /*
  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
  * of the mm address space.