arch/mips/mm/hugetlbpage.c

   1 /*
   2  * MIPS Huge TLB Page Support for Kernel.
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
   9  * Copyright 2005, Embedded Alley Solutions, Inc.
  10  * Matt Porter <mporter@embeddedalley.com>
  11  * Copyright (C) 2008, 2009 Cavium Networks, Inc.
  12  */
  13
  14 #include <linux/fs.h>
  15 #include <linux/mm.h>
  16 #include <linux/hugetlb.h>
  17 #include <linux/pagemap.h>
  18 #include <linux/err.h>
  19 #include <linux/sysctl.h>
  20 #include <asm/mman.h>
  21 #include <asm/tlb.h>
  22 #include <asm/tlbflush.h>
  23
  24 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
  25                       unsigned long sz)
  26 {
  27         pgd_t *pgd;
  28         p4d_t *p4d;
  29         pud_t *pud;
  30         pte_t *pte = NULL;
  31
  32         pgd = pgd_offset(mm, addr);
  33         p4d = p4d_alloc(mm, pgd, addr);
  34         pud = pud_alloc(mm, p4d, addr);
  35         if (pud)
  36                 pte = (pte_t *)pmd_alloc(mm, pud, addr);
  37
  38         return pte;
  39 }
  40
  41 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
  42                        unsigned long sz)
  43 {
  44         pgd_t *pgd;
  45         p4d_t *p4d;
  46         pud_t *pud;
  47         pmd_t *pmd = NULL;
  48
  49         pgd = pgd_offset(mm, addr);
  50         if (pgd_present(*pgd)) {
  51                 p4d = p4d_offset(pgd, addr);
  52                 if (p4d_present(*p4d)) {
  53                         pud = pud_offset(p4d, addr);
  54                         if (pud_present(*pud))
  55                                 pmd = pmd_offset(pud, addr);
  56                 }
  57         }
  58         return (pte_t *) pmd;
  59 }
  60
  61 int pmd_huge(pmd_t pmd)
  62 {
  63         return (pmd_val(pmd) & _PAGE_HUGE) != 0;
  64 }
  65
  66 int pud_huge(pud_t pud)
  67 {
  68         return (pud_val(pud) & _PAGE_HUGE) != 0;
  69 }