arch/sparc/mm/hugetlbpage.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SPARC64 Huge TLB page support.
   4  *
   5  * Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/mm.h>
  10 #include <linux/sched/mm.h>
  11 #include <linux/hugetlb.h>
  12 #include <linux/pagemap.h>
  13 #include <linux/sysctl.h>
  14
  15 #include <asm/mman.h>
  16 #include <asm/pgalloc.h>
  17 #include <asm/pgtable.h>
  18 #include <asm/tlb.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/cacheflush.h>
  21 #include <asm/mmu_context.h>
  22
  23 /* Slightly simplified from the non-hugepage variant because by
  24  * definition we don't have to worry about any page coloring stuff
  25  */
  26
  27 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
  28                                                         unsigned long addr,
  29                                                         unsigned long len,
  30                                                         unsigned long pgoff,
  31                                                         unsigned long flags)
  32 {
  33         struct hstate *h = hstate_file(filp);
  34         unsigned long task_size = TASK_SIZE;
  35         struct vm_unmapped_area_info info;
  36
  37         if (test_thread_flag(TIF_32BIT))
  38                 task_size = STACK_TOP32;
  39
  40         info.flags = 0;
  41         info.length = len;
  42         info.low_limit = TASK_UNMAPPED_BASE;
  43         info.high_limit = min(task_size, VA_EXCLUDE_START);
  44         info.align_mask = PAGE_MASK & ~huge_page_mask(h);
  45         info.align_offset = 0;
  46         addr = vm_unmapped_area(&info);
  47
  48         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
  49                 VM_BUG_ON(addr != -ENOMEM);
  50                 info.low_limit = VA_EXCLUDE_END;
  51                 info.high_limit = task_size;
  52                 addr = vm_unmapped_area(&info);
  53         }
  54
  55         return addr;
  56 }
  57
  58 static unsigned long
  59 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
  60                                   const unsigned long len,
  61                                   const unsigned long pgoff,
  62                                   const unsigned long flags)
  63 {
  64         struct hstate *h = hstate_file(filp);
  65         struct mm_struct *mm = current->mm;
  66         unsigned long addr = addr0;
  67         struct vm_unmapped_area_info info;
  68
  69         /* This should only ever run for 32-bit processes.  */
  70         BUG_ON(!test_thread_flag(TIF_32BIT));
  71
  72         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
  73         info.length = len;
  74         info.low_limit = PAGE_SIZE;
  75         info.high_limit = mm->mmap_base;
  76         info.align_mask = PAGE_MASK & ~huge_page_mask(h);
  77         info.align_offset = 0;
  78         addr = vm_unmapped_area(&info);
  79
  80         /*
  81          * A failed mmap() very likely causes application failure,
  82          * so fall back to the bottom-up function here. This scenario
  83          * can happen with large stack limits and large mmap()
  84          * allocations.
  85          */
  86         if (addr & ~PAGE_MASK) {
  87                 VM_BUG_ON(addr != -ENOMEM);
  88                 info.flags = 0;
  89                 info.low_limit = TASK_UNMAPPED_BASE;
  90                 info.high_limit = STACK_TOP32;
  91                 addr = vm_unmapped_area(&info);
  92         }
  93
  94         return addr;
  95 }
  96
  97 unsigned long
  98 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
  99                 unsigned long len, unsigned long pgoff, unsigned long flags)
 100 {
 101         struct hstate *h = hstate_file(file);
 102         struct mm_struct *mm = current->mm;
 103         struct vm_area_struct *vma;
 104         unsigned long task_size = TASK_SIZE;
 105
 106         if (test_thread_flag(TIF_32BIT))
 107                 task_size = STACK_TOP32;
 108
 109         if (len & ~huge_page_mask(h))
 110                 return -EINVAL;
 111         if (len > task_size)
 112                 return -ENOMEM;
 113
 114         if (flags & MAP_FIXED) {
 115                 if (prepare_hugepage_range(file, addr, len))
 116                         return -EINVAL;
 117                 return addr;
 118         }
 119
 120         if (addr) {
 121                 addr = ALIGN(addr, huge_page_size(h));
 122                 vma = find_vma(mm, addr);
 123                 if (task_size - len >= addr &&
 124                     (!vma || addr + len <= vm_start_gap(vma)))
 125                         return addr;
 126         }
 127         if (mm->get_unmapped_area == arch_get_unmapped_area)
 128                 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
 129                                 pgoff, flags);
 130         else
 131                 return hugetlb_get_unmapped_area_topdown(file, addr, len,
 132                                 pgoff, flags);
 133 }
 134
 135 static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 136 {
 137         return entry;
 138 }
 139
 140 static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 141 {
 142         unsigned long hugepage_size = _PAGE_SZ4MB_4V;
 143
 144         pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;
 145
 146         switch (shift) {
 147         case HPAGE_16GB_SHIFT:
 148                 hugepage_size = _PAGE_SZ16GB_4V;
 149                 pte_val(entry) |= _PAGE_PUD_HUGE;
 150                 break;
 151         case HPAGE_2GB_SHIFT:
 152                 hugepage_size = _PAGE_SZ2GB_4V;
 153                 pte_val(entry) |= _PAGE_PMD_HUGE;
 154                 break;
 155         case HPAGE_256MB_SHIFT:
 156                 hugepage_size = _PAGE_SZ256MB_4V;
 157                 pte_val(entry) |= _PAGE_PMD_HUGE;
 158                 break;
 159         case HPAGE_SHIFT:
 160                 pte_val(entry) |= _PAGE_PMD_HUGE;
 161                 break;
 162         case HPAGE_64K_SHIFT:
 163                 hugepage_size = _PAGE_SZ64K_4V;
 164                 break;
 165         default:
 166                 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift);
 167         }
 168
 169         pte_val(entry) = pte_val(entry) | hugepage_size;
 170         return entry;
 171 }
 172
 173 static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 174 {
 175         if (tlb_type == hypervisor)
 176                 return sun4v_hugepage_shift_to_tte(entry, shift);
 177         else
 178                 return sun4u_hugepage_shift_to_tte(entry, shift);
 179 }
 180
 181 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
 182                          struct page *page, int writeable)
 183 {
 184         unsigned int shift = huge_page_shift(hstate_vma(vma));
 185
 186         return hugepage_shift_to_tte(entry, shift);
 187 }
 188
 189 static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
 190 {
 191         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
 192         unsigned int shift;
 193
 194         switch (tte_szbits) {
 195         case _PAGE_SZ16GB_4V:
 196                 shift = HPAGE_16GB_SHIFT;
 197                 break;
 198         case _PAGE_SZ2GB_4V:
 199                 shift = HPAGE_2GB_SHIFT;
 200                 break;
 201         case _PAGE_SZ256MB_4V:
 202                 shift = HPAGE_256MB_SHIFT;
 203                 break;
 204         case _PAGE_SZ4MB_4V:
 205                 shift = REAL_HPAGE_SHIFT;
 206                 break;
 207         case _PAGE_SZ64K_4V:
 208                 shift = HPAGE_64K_SHIFT;
 209                 break;
 210         default:
 211                 shift = PAGE_SHIFT;
 212                 break;
 213         }
 214         return shift;
 215 }
 216
 217 static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
 218 {
 219         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
 220         unsigned int shift;
 221
 222         switch (tte_szbits) {
 223         case _PAGE_SZ256MB_4U:
 224                 shift = HPAGE_256MB_SHIFT;
 225                 break;
 226         case _PAGE_SZ4MB_4U:
 227                 shift = REAL_HPAGE_SHIFT;
 228                 break;
 229         case _PAGE_SZ64K_4U:
 230                 shift = HPAGE_64K_SHIFT;
 231                 break;
 232         default:
 233                 shift = PAGE_SHIFT;
 234                 break;
 235         }
 236         return shift;
 237 }
 238
 239 static unsigned int huge_tte_to_shift(pte_t entry)
 240 {
 241         unsigned long shift;
 242
 243         if (tlb_type == hypervisor)
 244                 shift = sun4v_huge_tte_to_shift(entry);
 245         else
 246                 shift = sun4u_huge_tte_to_shift(entry);
 247
 248         if (shift == PAGE_SHIFT)
 249                 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
 250                           pte_val(entry));
 251
 252         return shift;
 253 }
 254
 255 static unsigned long huge_tte_to_size(pte_t pte)
 256 {
 257         unsigned long size = 1UL << huge_tte_to_shift(pte);
 258
 259         if (size == REAL_HPAGE_SIZE)
 260                 size = HPAGE_SIZE;
 261         return size;
 262 }
 263
 264 pte_t *huge_pte_alloc(struct mm_struct *mm,
 265                         unsigned long addr, unsigned long sz)
 266 {
 267         pgd_t *pgd;
 268         pud_t *pud;
 269         pmd_t *pmd;
 270
 271         pgd = pgd_offset(mm, addr);
 272         pud = pud_alloc(mm, pgd, addr);
 273         if (!pud)
 274                 return NULL;
 275         if (sz >= PUD_SIZE)
 276                 return (pte_t *)pud;
 277         pmd = pmd_alloc(mm, pud, addr);
 278         if (!pmd)
 279                 return NULL;
 280         if (sz >= PMD_SIZE)
 281                 return (pte_t *)pmd;
 282         return pte_alloc_map(mm, pmd, addr);
 283 }
 284
 285 pte_t *huge_pte_offset(struct mm_struct *mm,
 286                        unsigned long addr, unsigned long sz)
 287 {
 288         pgd_t *pgd;
 289         pud_t *pud;
 290         pmd_t *pmd;
 291
 292         pgd = pgd_offset(mm, addr);
 293         if (pgd_none(*pgd))
 294                 return NULL;
 295         pud = pud_offset(pgd, addr);
 296         if (pud_none(*pud))
 297                 return NULL;
 298         if (is_hugetlb_pud(*pud))
 299                 return (pte_t *)pud;
 300         pmd = pmd_offset(pud, addr);
 301         if (pmd_none(*pmd))
 302                 return NULL;
 303         if (is_hugetlb_pmd(*pmd))
 304                 return (pte_t *)pmd;
 305         return pte_offset_map(pmd, addr);
 306 }
 307
 308 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 309                      pte_t *ptep, pte_t entry)
 310 {
 311         unsigned int nptes, orig_shift, shift;
 312         unsigned long i, size;
 313         pte_t orig;
 314
 315         size = huge_tte_to_size(entry);
 316
 317         shift = PAGE_SHIFT;
 318         if (size >= PUD_SIZE)
 319                 shift = PUD_SHIFT;
 320         else if (size >= PMD_SIZE)
 321                 shift = PMD_SHIFT;
 322         else
 323                 shift = PAGE_SHIFT;
 324
 325         nptes = size >> shift;
 326
 327         if (!pte_present(*ptep) && pte_present(entry))
 328                 mm->context.hugetlb_pte_count += nptes;
 329
 330         addr &= ~(size - 1);
 331         orig = *ptep;
 332         orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
 333
 334         for (i = 0; i < nptes; i++)
 335                 ptep[i] = __pte(pte_val(entry) + (i << shift));
 336
 337         maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
 338         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 339         if (size == HPAGE_SIZE)
 340                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
 341                                     orig_shift);
 342 }
 343
 344 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 345                               pte_t *ptep)
 346 {
 347         unsigned int i, nptes, orig_shift, shift;
 348         unsigned long size;
 349         pte_t entry;
 350
 351         entry = *ptep;
 352         size = huge_tte_to_size(entry);
 353
 354         shift = PAGE_SHIFT;
 355         if (size >= PUD_SIZE)
 356                 shift = PUD_SHIFT;
 357         else if (size >= PMD_SIZE)
 358                 shift = PMD_SHIFT;
 359         else
 360                 shift = PAGE_SHIFT;
 361
 362         nptes = size >> shift;
 363         orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
 364
 365         if (pte_present(entry))
 366                 mm->context.hugetlb_pte_count -= nptes;
 367
 368         addr &= ~(size - 1);
 369         for (i = 0; i < nptes; i++)
 370                 ptep[i] = __pte(0UL);
 371
 372         maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
 373         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 374         if (size == HPAGE_SIZE)
 375                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
 376                                     orig_shift);
 377
 378         return entry;
 379 }
 380
 381 int pmd_huge(pmd_t pmd)
 382 {
 383         return !pmd_none(pmd) &&
 384                 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
 385 }
 386
 387 int pud_huge(pud_t pud)
 388 {
 389         return !pud_none(pud) &&
 390                 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
 391 }
 392
 393 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 394                            unsigned long addr)
 395 {
 396         pgtable_t token = pmd_pgtable(*pmd);
 397
 398         pmd_clear(pmd);
 399         pte_free_tlb(tlb, token, addr);
 400         atomic_long_dec(&tlb->mm->nr_ptes);
 401 }
 402
 403 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 404                                    unsigned long addr, unsigned long end,
 405                                    unsigned long floor, unsigned long ceiling)
 406 {
 407         pmd_t *pmd;
 408         unsigned long next;
 409         unsigned long start;
 410
 411         start = addr;
 412         pmd = pmd_offset(pud, addr);
 413         do {
 414                 next = pmd_addr_end(addr, end);
 415                 if (pmd_none(*pmd))
 416                         continue;
 417                 if (is_hugetlb_pmd(*pmd))
 418                         pmd_clear(pmd);
 419                 else
 420                         hugetlb_free_pte_range(tlb, pmd, addr);
 421         } while (pmd++, addr = next, addr != end);
 422
 423         start &= PUD_MASK;
 424         if (start < floor)
 425                 return;
 426         if (ceiling) {
 427                 ceiling &= PUD_MASK;
 428                 if (!ceiling)
 429                         return;
 430         }
 431         if (end - 1 > ceiling - 1)
 432                 return;
 433
 434         pmd = pmd_offset(pud, start);
 435         pud_clear(pud);
 436         pmd_free_tlb(tlb, pmd, start);
 437         mm_dec_nr_pmds(tlb->mm);
 438 }
 439
 440 static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
 441                                    unsigned long addr, unsigned long end,
 442                                    unsigned long floor, unsigned long ceiling)
 443 {
 444         pud_t *pud;
 445         unsigned long next;
 446         unsigned long start;
 447
 448         start = addr;
 449         pud = pud_offset(pgd, addr);
 450         do {
 451                 next = pud_addr_end(addr, end);
 452                 if (pud_none_or_clear_bad(pud))
 453                         continue;
 454                 if (is_hugetlb_pud(*pud))
 455                         pud_clear(pud);
 456                 else
 457                         hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
 458                                                ceiling);
 459         } while (pud++, addr = next, addr != end);
 460
 461         start &= PGDIR_MASK;
 462         if (start < floor)
 463                 return;
 464         if (ceiling) {
 465                 ceiling &= PGDIR_MASK;
 466                 if (!ceiling)
 467                         return;
 468         }
 469         if (end - 1 > ceiling - 1)
 470                 return;
 471
 472         pud = pud_offset(pgd, start);
 473         pgd_clear(pgd);
 474         pud_free_tlb(tlb, pud, start);
 475 }
 476
 477 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 478                             unsigned long addr, unsigned long end,
 479                             unsigned long floor, unsigned long ceiling)
 480 {
 481         pgd_t *pgd;
 482         unsigned long next;
 483
 484         addr &= PMD_MASK;
 485         if (addr < floor) {
 486                 addr += PMD_SIZE;
 487                 if (!addr)
 488                         return;
 489         }
 490         if (ceiling) {
 491                 ceiling &= PMD_MASK;
 492                 if (!ceiling)
 493                         return;
 494         }
 495         if (end - 1 > ceiling - 1)
 496                 end -= PMD_SIZE;
 497         if (addr > end - 1)
 498                 return;
 499
 500         pgd = pgd_offset(tlb->mm, addr);
 501         do {
 502                 next = pgd_addr_end(addr, end);
 503                 if (pgd_none_or_clear_bad(pgd))
 504                         continue;
 505                 hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
 506         } while (pgd++, addr = next, addr != end);
 507 }