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 static 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 static 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 static void set_huge_pte(struct mm_struct *mm, struct vm_area_struct *vma,
  60                          struct page *page, pte_t * page_table, int write_access)
  61 {
  62         unsigned long i;
  63         pte_t entry;
  64
  65         // mm->rss += (HPAGE_SIZE / PAGE_SIZE);
  66         vx_rsspages_add(mm, HPAGE_SIZE / PAGE_SIZE);
  67
  68         if (write_access)
  69                 entry = pte_mkwrite(pte_mkdirty(mk_pte(page,
  70                                                        vma->vm_page_prot)));
  71         else
  72                 entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
  73         entry = pte_mkyoung(entry);
  74         mk_pte_huge(entry);
  75
  76         for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
  77                 set_pte(page_table, entry);
  78                 page_table++;
  79
  80                 pte_val(entry) += PAGE_SIZE;
  81         }
  82 }
  83
  84 /*
  85  * This function checks for proper alignment of input addr and len parameters.
  86  */
  87 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
  88 {
  89         if (len & ~HPAGE_MASK)
  90                 return -EINVAL;
  91         if (addr & ~HPAGE_MASK)
  92                 return -EINVAL;
  93         return 0;
  94 }
  95
  96 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
  97                             struct vm_area_struct *vma)
  98 {
  99         pte_t *src_pte, *dst_pte, entry;
 100         struct page *ptepage;
 101         unsigned long addr = vma->vm_start;
 102         unsigned long end = vma->vm_end;
 103         int i;
 104
 105         while (addr < end) {
 106                 dst_pte = huge_pte_alloc(dst, addr);
 107                 if (!dst_pte)
 108                         goto nomem;
 109                 src_pte = huge_pte_offset(src, addr);
 110                 BUG_ON(!src_pte || pte_none(*src_pte));
 111                 entry = *src_pte;
 112                 ptepage = pte_page(entry);
 113                 get_page(ptepage);
 114                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 115                         set_pte(dst_pte, entry);
 116                         pte_val(entry) += PAGE_SIZE;
 117                         dst_pte++;
 118                 }
 119                 // dst->rss += (HPAGE_SIZE / PAGE_SIZE);
 120                 vx_rsspages_add(dst, HPAGE_SIZE / PAGE_SIZE);
 121                 addr += HPAGE_SIZE;
 122         }
 123         return 0;
 124
 125 nomem:
 126         return -ENOMEM;
 127 }
 128
 129 int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 130                         struct page **pages, struct vm_area_struct **vmas,
 131                         unsigned long *position, int *length, int i)
 132 {
 133         unsigned long vaddr = *position;
 134         int remainder = *length;
 135
 136         WARN_ON(!is_vm_hugetlb_page(vma));
 137
 138         while (vaddr < vma->vm_end && remainder) {
 139                 if (pages) {
 140                         pte_t *pte;
 141                         struct page *page;
 142
 143                         pte = huge_pte_offset(mm, vaddr);
 144
 145                         /* hugetlb should be locked, and hence, prefaulted */
 146                         BUG_ON(!pte || pte_none(*pte));
 147
 148                         page = pte_page(*pte);
 149
 150                         WARN_ON(!PageCompound(page));
 151
 152                         get_page(page);
 153                         pages[i] = page;
 154                 }
 155
 156                 if (vmas)
 157                         vmas[i] = vma;
 158
 159                 vaddr += PAGE_SIZE;
 160                 --remainder;
 161                 ++i;
 162         }
 163
 164         *length = remainder;
 165         *position = vaddr;
 166
 167         return i;
 168 }
 169
 170 struct page *follow_huge_addr(struct mm_struct *mm,
 171                               unsigned long address, int write)
 172 {
 173         return ERR_PTR(-EINVAL);
 174 }
 175
 176 int pmd_huge(pmd_t pmd)
 177 {
 178         return 0;
 179 }
 180
 181 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 182                              pmd_t *pmd, int write)
 183 {
 184         return NULL;
 185 }
 186
 187 void unmap_hugepage_range(struct vm_area_struct *vma,
 188                           unsigned long start, unsigned long end)
 189 {
 190         struct mm_struct *mm = vma->vm_mm;
 191         unsigned long address;
 192         pte_t *pte;
 193         struct page *page;
 194         int i;
 195
 196         BUG_ON(start & (HPAGE_SIZE - 1));
 197         BUG_ON(end & (HPAGE_SIZE - 1));
 198
 199         for (address = start; address < end; address += HPAGE_SIZE) {
 200                 pte = huge_pte_offset(mm, address);
 201                 BUG_ON(!pte);
 202                 if (pte_none(*pte))
 203                         continue;
 204                 page = pte_page(*pte);
 205                 put_page(page);
 206                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 207                         pte_clear(pte);
 208                         pte++;
 209                 }
 210         }
 211         // mm->rss -= (end - start) >> PAGE_SHIFT;
 212         vx_rsspages_sub(mm, (end - start) >> PAGE_SHIFT);
 213         flush_tlb_range(vma, start, end);
 214 }
 215
 216 int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
 217 {
 218         struct mm_struct *mm = current->mm;
 219         unsigned long addr;
 220         int ret = 0;
 221
 222         BUG_ON(vma->vm_start & ~HPAGE_MASK);
 223         BUG_ON(vma->vm_end & ~HPAGE_MASK);
 224
 225         spin_lock(&mm->page_table_lock);
 226         for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
 227                 unsigned long idx;
 228                 pte_t *pte = huge_pte_alloc(mm, addr);
 229                 struct page *page;
 230
 231                 if (!pte) {
 232                         ret = -ENOMEM;
 233                         goto out;
 234                 }
 235                 if (!pte_none(*pte))
 236                         continue;
 237
 238                 idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
 239                         + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
 240                 page = find_get_page(mapping, idx);
 241                 if (!page) {
 242                         /* charge the fs quota first */
 243                         if (hugetlb_get_quota(mapping)) {
 244                                 ret = -ENOMEM;
 245                                 goto out;
 246                         }
 247                         page = alloc_huge_page();
 248                         if (!page) {
 249                                 hugetlb_put_quota(mapping);
 250                                 ret = -ENOMEM;
 251                                 goto out;
 252                         }
 253                         ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
 254                         unlock_page(page);
 255                         if (ret) {
 256                                 hugetlb_put_quota(mapping);
 257                                 free_huge_page(page);
 258                                 goto out;
 259                         }
 260                 }
 261                 set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
 262         }
 263 out:
 264         spin_unlock(&mm->page_table_lock);
 265         return ret;
 266 }