arch/sparc/mm/hugetlbpage.c

   1 /*
   2  * SPARC64 Huge TLB page support.
   3  *
   4  * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
   5  */
   6
   7 #include <linux/fs.h>
   8 #include <linux/mm.h>
   9 #include <linux/hugetlb.h>
  10 #include <linux/pagemap.h>
  11 #include <linux/sysctl.h>
  12
  13 #include <asm/mman.h>
  14 #include <asm/pgalloc.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/tlb.h>
  17 #include <asm/tlbflush.h>
  18 #include <asm/cacheflush.h>
  19 #include <asm/mmu_context.h>
  20
  21 /* Slightly simplified from the non-hugepage variant because by
  22  * definition we don't have to worry about any page coloring stuff
  23  */
  24
  25 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
  26                                                         unsigned long addr,
  27                                                         unsigned long len,
  28                                                         unsigned long pgoff,
  29                                                         unsigned long flags)
  30 {
  31         unsigned long task_size = TASK_SIZE;
  32         struct vm_unmapped_area_info info;
  33
  34         if (test_thread_flag(TIF_32BIT))
  35                 task_size = STACK_TOP32;
  36
  37         info.flags = 0;
  38         info.length = len;
  39         info.low_limit = TASK_UNMAPPED_BASE;
  40         info.high_limit = min(task_size, VA_EXCLUDE_START);
  41         info.align_mask = PAGE_MASK & ~HPAGE_MASK;
  42         info.align_offset = 0;
  43         addr = vm_unmapped_area(&info);
  44
  45         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
  46                 VM_BUG_ON(addr != -ENOMEM);
  47                 info.low_limit = VA_EXCLUDE_END;
  48                 info.high_limit = task_size;
  49                 addr = vm_unmapped_area(&info);
  50         }
  51
  52         return addr;
  53 }
  54
  55 static unsigned long
  56 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
  57                                   const unsigned long len,
  58                                   const unsigned long pgoff,
  59                                   const unsigned long flags)
  60 {
  61         struct mm_struct *mm = current->mm;
  62         unsigned long addr = addr0;
  63         struct vm_unmapped_area_info info;
  64
  65         /* This should only ever run for 32-bit processes.  */
  66         BUG_ON(!test_thread_flag(TIF_32BIT));
  67
  68         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
  69         info.length = len;
  70         info.low_limit = PAGE_SIZE;
  71         info.high_limit = mm->mmap_base;
  72         info.align_mask = PAGE_MASK & ~HPAGE_MASK;
  73         info.align_offset = 0;
  74         addr = vm_unmapped_area(&info);
  75
  76         /*
  77          * A failed mmap() very likely causes application failure,
  78          * so fall back to the bottom-up function here. This scenario
  79          * can happen with large stack limits and large mmap()
  80          * allocations.
  81          */
  82         if (addr & ~PAGE_MASK) {
  83                 VM_BUG_ON(addr != -ENOMEM);
  84                 info.flags = 0;
  85                 info.low_limit = TASK_UNMAPPED_BASE;
  86                 info.high_limit = STACK_TOP32;
  87                 addr = vm_unmapped_area(&info);
  88         }
  89
  90         return addr;
  91 }
  92
  93 unsigned long
  94 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
  95                 unsigned long len, unsigned long pgoff, unsigned long flags)
  96 {
  97         struct mm_struct *mm = current->mm;
  98         struct vm_area_struct *vma;
  99         unsigned long task_size = TASK_SIZE;
 100
 101         if (test_thread_flag(TIF_32BIT))
 102                 task_size = STACK_TOP32;
 103
 104         if (len & ~HPAGE_MASK)
 105                 return -EINVAL;
 106         if (len > task_size)
 107                 return -ENOMEM;
 108
 109         if (flags & MAP_FIXED) {
 110                 if (prepare_hugepage_range(file, addr, len))
 111                         return -EINVAL;
 112                 return addr;
 113         }
 114
 115         if (addr) {
 116                 addr = ALIGN(addr, HPAGE_SIZE);
 117                 vma = find_vma(mm, addr);
 118                 if (task_size - len >= addr &&
 119                     (!vma || addr + len <= vm_start_gap(vma)))
 120                         return addr;
 121         }
 122         if (mm->get_unmapped_area == arch_get_unmapped_area)
 123                 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
 124                                 pgoff, flags);
 125         else
 126                 return hugetlb_get_unmapped_area_topdown(file, addr, len,
 127                                 pgoff, flags);
 128 }
 129
 130 pte_t *huge_pte_alloc(struct mm_struct *mm,
 131                         unsigned long addr, unsigned long sz)
 132 {
 133         pgd_t *pgd;
 134         pud_t *pud;
 135         pte_t *pte = NULL;
 136
 137         pgd = pgd_offset(mm, addr);
 138         pud = pud_alloc(mm, pgd, addr);
 139         if (pud)
 140                 pte = (pte_t *)pmd_alloc(mm, pud, addr);
 141
 142         return pte;
 143 }
 144
 145 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 146 {
 147         pgd_t *pgd;
 148         pud_t *pud;
 149         pte_t *pte = NULL;
 150
 151         pgd = pgd_offset(mm, addr);
 152         if (!pgd_none(*pgd)) {
 153                 pud = pud_offset(pgd, addr);
 154                 if (!pud_none(*pud))
 155                         pte = (pte_t *)pmd_offset(pud, addr);
 156         }
 157         return pte;
 158 }
 159
 160 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 161                      pte_t *ptep, pte_t entry)
 162 {
 163         pte_t orig;
 164
 165         if (!pte_present(*ptep) && pte_present(entry))
 166                 mm->context.hugetlb_pte_count++;
 167
 168         addr &= HPAGE_MASK;
 169         orig = *ptep;
 170         *ptep = entry;
 171
 172         /* Issue TLB flush at REAL_HPAGE_SIZE boundaries */
 173         maybe_tlb_batch_add(mm, addr, ptep, orig, 0);
 174         maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0);
 175 }
 176
 177 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 178                               pte_t *ptep)
 179 {
 180         pte_t entry;
 181
 182         entry = *ptep;
 183         if (pte_present(entry))
 184                 mm->context.hugetlb_pte_count--;
 185
 186         addr &= HPAGE_MASK;
 187         *ptep = __pte(0UL);
 188
 189         /* Issue TLB flush at REAL_HPAGE_SIZE boundaries */
 190         maybe_tlb_batch_add(mm, addr, ptep, entry, 0);
 191         maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0);
 192
 193         return entry;
 194 }
 195
 196 int pmd_huge(pmd_t pmd)
 197 {
 198         return !pmd_none(pmd) &&
 199                 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
 200 }
 201
 202 int pud_huge(pud_t pud)
 203 {
 204         return 0;
 205 }
 206
 207 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 208                            unsigned long addr)
 209 {
 210         pgtable_t token = pmd_pgtable(*pmd);
 211
 212         pmd_clear(pmd);
 213         pte_free_tlb(tlb, token, addr);
 214         atomic_long_dec(&tlb->mm->nr_ptes);
 215 }
 216
 217 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 218                                    unsigned long addr, unsigned long end,
 219                                    unsigned long floor, unsigned long ceiling)
 220 {
 221         pmd_t *pmd;
 222         unsigned long next;
 223         unsigned long start;
 224
 225         start = addr;
 226         pmd = pmd_offset(pud, addr);
 227         do {
 228                 next = pmd_addr_end(addr, end);
 229                 if (pmd_none(*pmd))
 230                         continue;
 231                 if (is_hugetlb_pmd(*pmd))
 232                         pmd_clear(pmd);
 233                 else
 234                         hugetlb_free_pte_range(tlb, pmd, addr);
 235         } while (pmd++, addr = next, addr != end);
 236
 237         start &= PUD_MASK;
 238         if (start < floor)
 239                 return;
 240         if (ceiling) {
 241                 ceiling &= PUD_MASK;
 242                 if (!ceiling)
 243                         return;
 244         }
 245         if (end - 1 > ceiling - 1)
 246                 return;
 247
 248         pmd = pmd_offset(pud, start);
 249         pud_clear(pud);
 250         pmd_free_tlb(tlb, pmd, start);
 251         mm_dec_nr_pmds(tlb->mm);
 252 }
 253
 254 static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
 255                                    unsigned long addr, unsigned long end,
 256                                    unsigned long floor, unsigned long ceiling)
 257 {
 258         pud_t *pud;
 259         unsigned long next;
 260         unsigned long start;
 261
 262         start = addr;
 263         pud = pud_offset(pgd, addr);
 264         do {
 265                 next = pud_addr_end(addr, end);
 266                 if (pud_none_or_clear_bad(pud))
 267                         continue;
 268                 hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
 269                                        ceiling);
 270         } while (pud++, addr = next, addr != end);
 271
 272         start &= PGDIR_MASK;
 273         if (start < floor)
 274                 return;
 275         if (ceiling) {
 276                 ceiling &= PGDIR_MASK;
 277                 if (!ceiling)
 278                         return;
 279         }
 280         if (end - 1 > ceiling - 1)
 281                 return;
 282
 283         pud = pud_offset(pgd, start);
 284         pgd_clear(pgd);
 285         pud_free_tlb(tlb, pud, start);
 286 }
 287
 288 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 289                             unsigned long addr, unsigned long end,
 290                             unsigned long floor, unsigned long ceiling)
 291 {
 292         pgd_t *pgd;
 293         unsigned long next;
 294
 295         pgd = pgd_offset(tlb->mm, addr);
 296         do {
 297                 next = pgd_addr_end(addr, end);
 298                 if (pgd_none_or_clear_bad(pgd))
 299                         continue;
 300                 hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
 301         } while (pgd++, addr = next, addr != end);
 302 }