arch/arm64/mm/hugetlbpage.c

   1 /*
   2  * arch/arm64/mm/hugetlbpage.c
   3  *
   4  * Copyright (C) 2013 Linaro Ltd.
   5  *
   6  * Based on arch/x86/mm/hugetlbpage.c.
   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 #ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
  35 int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
  36 {
  37         return 0;
  38 }
  39 #endif
  40
  41 struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
  42                               int write)
  43 {
  44         return ERR_PTR(-EINVAL);
  45 }
  46
  47 int pmd_huge(pmd_t pmd)
  48 {
  49         return !(pmd_val(pmd) & PMD_TABLE_BIT);
  50 }
  51
  52 int pud_huge(pud_t pud)
  53 {
  54 #ifndef __PAGETABLE_PMD_FOLDED
  55         return !(pud_val(pud) & PUD_TABLE_BIT);
  56 #else
  57         return 0;
  58 #endif
  59 }
  60
  61 static __init int setup_hugepagesz(char *opt)
  62 {
  63         unsigned long ps = memparse(opt, &opt);
  64         if (ps == PMD_SIZE) {
  65                 hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
  66         } else if (ps == PUD_SIZE) {
  67                 hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
  68         } else {
  69                 pr_err("hugepagesz: Unsupported page size %lu M\n", ps >> 20);
  70                 return 0;
  71         }
  72         return 1;
  73 }
  74 __setup("hugepagesz=", setup_hugepagesz);