arch/arm/mm/hugetlbpage.c

   1 /*
   2  * arch/arm/mm/hugetlbpage.c
   3  *
   4  * Copyright (C) 2012 ARM Ltd.
   5  *
   6  * Based on arch/x86/include/asm/hugetlb.h and Bill Carson's patches
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/fs.h>
  24 #include <linux/mm.h>
  25 #include <linux/hugetlb.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/err.h>
  28 #include <linux/sysctl.h>
  29 #include <asm/mman.h>
  30 #include <asm/tlb.h>
  31 #include <asm/tlbflush.h>
  32 #include <asm/pgalloc.h>
  33
  34 /*
  35  * On ARM, huge pages are backed by pmd's rather than pte's, so we do a lot
  36  * of type casting from pmd_t * to pte_t *.
  37  */
  38
  39 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
  40                               int write)
  41 {
  42         return ERR_PTR(-EINVAL);
  43 }
  44
  45 int pud_huge(pud_t pud)
  46 {
  47         return 0;
  48 }
  49
  50 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
  51 {
  52         return 0;
  53 }
  54
  55 int pmd_huge(pmd_t pmd)
  56 {
  57         return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
  58 }