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