LXR linux/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/init.h>
  15#include <linux/fs.h>
  16#include <linux/mm.h>
  17#include <linux/hugetlb.h>
  18#include <linux/pagemap.h>
  19#include <linux/err.h>
  20#include <linux/sysctl.h>
  21#include <asm/mman.h>
  22#include <asm/tlb.h>
  23#include <asm/tlbflush.h>
  24
  25pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
  26                      unsigned long sz)
  27{
  28        pgd_t *pgd;
  29        pud_t *pud;
  30        pte_t *pte = NULL;
  31
  32        pgd = pgd_offset(mm, addr);
  33        pud = pud_alloc(mm, pgd, addr);
  34        if (pud)
  35                pte = (pte_t *)pmd_alloc(mm, pud, addr);
  36
  37        return pte;
  38}
  39
  40pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
  41{
  42        pgd_t *pgd;
  43        pud_t *pud;
  44        pmd_t *pmd = NULL;
  45
  46        pgd = pgd_offset(mm, addr);
  47        if (pgd_present(*pgd)) {
  48                pud = pud_offset(pgd, addr);
  49                if (pud_present(*pud))
  50                        pmd = pmd_offset(pud, addr);
  51        }
  52        return (pte_t *) pmd;
  53}
  54
  55int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
  56{
  57        return 0;
  58}
  59
  60/*
  61 * This function checks for proper alignment of input addr and len parameters.
  62 */
  63int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
  64{
  65        if (len & ~HPAGE_MASK)
  66                return -EINVAL;
  67        if (addr & ~HPAGE_MASK)
  68                return -EINVAL;
  69        return 0;
  70}
  71
  72struct page *
  73follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
  74{
  75        return ERR_PTR(-EINVAL);
  76}
  77
  78int pmd_huge(pmd_t pmd)
  79{
  80        return (pmd_val(pmd) & _PAGE_HUGE) != 0;
  81}
  82
  83int pud_huge(pud_t pud)
  84{
  85        return (pud_val(pud) & _PAGE_HUGE) != 0;
  86}
  87
  88struct page *
  89follow_huge_pmd(struct mm_struct *mm, unsigned long address,
  90                pmd_t *pmd, int write)
  91{
  92        struct page *page;
  93
  94        page = pte_page(*(pte_t *)pmd);
  95        if (page)
  96                page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
  97        return page;
  98}
  99