arch/sh/mm/hugetlbpage.c

   1 /*
   2  * arch/sh/mm/hugetlbpage.c
   3  *
   4  * SuperH HugeTLB page support.
   5  *
   6  * Cloned from sparc64 by Paul Mundt.
   7  *
   8  * Copyright (C) 2002, 2003 David S. Miller (davem@redhat.com)
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/init.h>
  13 #include <linux/fs.h>
  14 #include <linux/mm.h>
  15 #include <linux/hugetlb.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/slab.h>
  19 #include <linux/sysctl.h>
  20
  21 #include <asm/mman.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/tlb.h>
  24 #include <asm/tlbflush.h>
  25 #include <asm/cacheflush.h>
  26
  27 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
  28 {
  29         pgd_t *pgd;
  30         pmd_t *pmd;
  31         pte_t *pte = NULL;
  32
  33         pgd = pgd_offset(mm, addr);
  34         if (pgd) {
  35                 pmd = pmd_alloc(mm, pgd, addr);
  36                 if (pmd)
  37                         pte = pte_alloc_map(mm, pmd, addr);
  38         }
  39         return pte;
  40 }
  41
  42 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
  43 {
  44         pgd_t *pgd;
  45         pmd_t *pmd;
  46         pte_t *pte = NULL;
  47
  48         pgd = pgd_offset(mm, addr);
  49         if (pgd) {
  50                 pmd = pmd_offset(pgd, addr);
  51                 if (pmd)
  52                         pte = pte_offset_map(pmd, addr);
  53         }
  54         return pte;
  55 }
  56
  57 #define mk_pte_huge(entry) do { pte_val(entry) |= _PAGE_SZHUGE; } while (0)
  58
  59 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
  60                      pte_t *ptep, pte_t entry)
  61 {
  62         int i;
  63
  64         for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
  65                 set_pte_at(mm, addr, ptep, entry);
  66                 ptep++;
  67                 addr += PAGE_SIZE;
  68                 pte_val(entry) += PAGE_SIZE;
  69         }
  70 }
  71
  72 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
  73                               pte_t *ptep)
  74 {
  75         pte_t entry;
  76         int i;
  77
  78         entry = *ptep;
  79
  80         for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
  81                 pte_clear(mm, addr, ptep);
  82                 addr += PAGE_SIZE;
  83                 ptep++;
  84         }
  85
  86         return entry;
  87 }
  88
  89 /*
  90  * This function checks for proper alignment of input addr and len parameters.
  91  */
  92 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
  93 {
  94         if (len & ~HPAGE_MASK)
  95                 return -EINVAL;
  96         if (addr & ~HPAGE_MASK)
  97                 return -EINVAL;
  98         return 0;
  99 }
 100
 101 struct page *follow_huge_addr(struct mm_struct *mm,
 102                               unsigned long address, int write)
 103 {
 104         return ERR_PTR(-EINVAL);
 105 }
 106
 107 int pmd_huge(pmd_t pmd)
 108 {
 109         return 0;
 110 }
 111
 112 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 113                              pmd_t *pmd, int write)
 114 {
 115         return NULL;
 116 }