arch/sh64/mm/hugetlbpage.c

   1 /*
   2  * arch/sh64/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         if (write_access)
  68                 entry = pte_mkwrite(pte_mkdirty(mk_pte(page,
  69                                                        vma->vm_page_prot)));
  70         else
  71                 entry = pte_wrprotect(mk_pte(page, vma->vm_page_prot));
  72         entry = pte_mkyoung(entry);
  73         mk_pte_huge(entry);
  74
  75         for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
  76                 set_pte(page_table, entry);
  77                 page_table++;
  78
  79                 pte_val(entry) += PAGE_SIZE;
  80         }
  81 }
  82
  83 /*
  84  * This function checks for proper alignment of input addr and len parameters.
  85  */
  86 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
  87 {
  88         if (len & ~HPAGE_MASK)
  89                 return -EINVAL;
  90         if (addr & ~HPAGE_MASK)
  91                 return -EINVAL;
  92         return 0;
  93 }
  94
  95 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
  96                             struct vm_area_struct *vma)
  97 {
  98         pte_t *src_pte, *dst_pte, entry;
  99         struct page *ptepage;
 100         unsigned long addr = vma->vm_start;
 101         unsigned long end = vma->vm_end;
 102         int i;
 103
 104         while (addr < end) {
 105                 dst_pte = huge_pte_alloc(dst, addr);
 106                 if (!dst_pte)
 107                         goto nomem;
 108                 src_pte = huge_pte_offset(src, addr);
 109                 BUG_ON(!src_pte || pte_none(*src_pte));
 110                 entry = *src_pte;
 111                 ptepage = pte_page(entry);
 112                 get_page(ptepage);
 113                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 114                         set_pte(dst_pte, entry);
 115                         pte_val(entry) += PAGE_SIZE;
 116                         dst_pte++;
 117                 }
 118                 // dst->rss += (HPAGE_SIZE / PAGE_SIZE);
 119                 vx_rsspages_add(dst, HPAGE_SIZE / PAGE_SIZE);
 120                 addr += HPAGE_SIZE;
 121         }
 122         return 0;
 123
 124 nomem:
 125         return -ENOMEM;
 126 }
 127
 128 int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 129                         struct page **pages, struct vm_area_struct **vmas,
 130                         unsigned long *position, int *length, int i)
 131 {
 132         unsigned long vaddr = *position;
 133         int remainder = *length;
 134
 135         WARN_ON(!is_vm_hugetlb_page(vma));
 136
 137         while (vaddr < vma->vm_end && remainder) {
 138                 if (pages) {
 139                         pte_t *pte;
 140                         struct page *page;
 141
 142                         pte = huge_pte_offset(mm, vaddr);
 143
 144                         /* hugetlb should be locked, and hence, prefaulted */
 145                         BUG_ON(!pte || pte_none(*pte));
 146
 147                         page = pte_page(*pte);
 148
 149                         WARN_ON(!PageCompound(page));
 150
 151                         get_page(page);
 152                         pages[i] = page;
 153                 }
 154
 155                 if (vmas)
 156                         vmas[i] = vma;
 157
 158                 vaddr += PAGE_SIZE;
 159                 --remainder;
 160                 ++i;
 161         }
 162
 163         *length = remainder;
 164         *position = vaddr;
 165
 166         return i;
 167 }
 168
 169 struct page *follow_huge_addr(struct mm_struct *mm,
 170                               unsigned long address, int write)
 171 {
 172         return ERR_PTR(-EINVAL);
 173 }
 174
 175 int pmd_huge(pmd_t pmd)
 176 {
 177         return 0;
 178 }
 179
 180 struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
 181                              pmd_t *pmd, int write)
 182 {
 183         return NULL;
 184 }
 185
 186 void unmap_hugepage_range(struct vm_area_struct *vma,
 187                           unsigned long start, unsigned long end)
 188 {
 189         struct mm_struct *mm = vma->vm_mm;
 190         unsigned long address;
 191         pte_t *pte;
 192         struct page *page;
 193         int i;
 194
 195         BUG_ON(start & (HPAGE_SIZE - 1));
 196         BUG_ON(end & (HPAGE_SIZE - 1));
 197
 198         for (address = start; address < end; address += HPAGE_SIZE) {
 199                 pte = huge_pte_offset(mm, address);
 200                 BUG_ON(!pte);
 201                 if (pte_none(*pte))
 202                         continue;
 203                 page = pte_page(*pte);
 204                 put_page(page);
 205                 for (i = 0; i < (1 << HUGETLB_PAGE_ORDER); i++) {
 206                         pte_clear(pte);
 207                         pte++;
 208                 }
 209         }
 210         // mm->rss -= (end - start) >> PAGE_SHIFT;
 211         vx_rsspages_sub(mm, (end - start) >> PAGE_SHIFT);
 212         flush_tlb_range(vma, start, end);
 213 }
 214
 215 int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
 216 {
 217         struct mm_struct *mm = current->mm;
 218         unsigned long addr;
 219         int ret = 0;
 220
 221         BUG_ON(vma->vm_start & ~HPAGE_MASK);
 222         BUG_ON(vma->vm_end & ~HPAGE_MASK);
 223
 224         spin_lock(&mm->page_table_lock);
 225         for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
 226                 unsigned long idx;
 227                 pte_t *pte = huge_pte_alloc(mm, addr);
 228                 struct page *page;
 229
 230                 if (!pte) {
 231                         ret = -ENOMEM;
 232                         goto out;
 233                 }
 234                 if (!pte_none(*pte))
 235                         continue;
 236
 237                 idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
 238                         + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
 239                 page = find_get_page(mapping, idx);
 240                 if (!page) {
 241                         /* charge the fs quota first */
 242                         if (hugetlb_get_quota(mapping)) {
 243                                 ret = -ENOMEM;
 244                                 goto out;
 245                         }
 246                         page = alloc_huge_page();
 247                         if (!page) {
 248                                 hugetlb_put_quota(mapping);
 249                                 ret = -ENOMEM;
 250                                 goto out;
 251                         }
 252                         ret = add_to_page_cache(page, mapping, idx, GFP_ATOMIC);
 253                         if (! ret) {
 254                                 unlock_page(page);
 255                         } else {
 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 }