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/tlb.h>
  18 #include <asm/tlbflush.h>
  19 #include <asm/cacheflush.h>
  20 #include <asm/mmu_context.h>
  21
  22 /* Slightly simplified from the non-hugepage variant because by
  23  * definition we don't have to worry about any page coloring stuff
  24  */
  25
  26 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
  27                                                         unsigned long addr,
  28                                                         unsigned long len,
  29                                                         unsigned long pgoff,
  30                                                         unsigned long flags)
  31 {
  32         struct hstate *h = hstate_file(filp);
  33         unsigned long task_size = TASK_SIZE;
  34         struct vm_unmapped_area_info info;
  35
  36         if (test_thread_flag(TIF_32BIT))
  37                 task_size = STACK_TOP32;
  38
  39         info.flags = 0;
  40         info.length = len;
  41         info.low_limit = TASK_UNMAPPED_BASE;
  42         info.high_limit = min(task_size, VA_EXCLUDE_START);
  43         info.align_mask = PAGE_MASK & ~huge_page_mask(h);
  44         info.align_offset = 0;
  45         addr = vm_unmapped_area(&info);
  46
  47         if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
  48                 VM_BUG_ON(addr != -ENOMEM);
  49                 info.low_limit = VA_EXCLUDE_END;
  50                 info.high_limit = task_size;
  51                 addr = vm_unmapped_area(&info);
  52         }
  53
  54         return addr;
  55 }
  56
  57 static unsigned long
  58 hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
  59                                   const unsigned long len,
  60                                   const unsigned long pgoff,
  61                                   const unsigned long flags)
  62 {
  63         struct hstate *h = hstate_file(filp);
  64         struct mm_struct *mm = current->mm;
  65         unsigned long addr = addr0;
  66         struct vm_unmapped_area_info info;
  67
  68         /* This should only ever run for 32-bit processes.  */
  69         BUG_ON(!test_thread_flag(TIF_32BIT));
  70
  71         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
  72         info.length = len;
  73         info.low_limit = PAGE_SIZE;
  74         info.high_limit = mm->mmap_base;
  75         info.align_mask = PAGE_MASK & ~huge_page_mask(h);
  76         info.align_offset = 0;
  77         addr = vm_unmapped_area(&info);
  78
  79         /*
  80          * A failed mmap() very likely causes application failure,
  81          * so fall back to the bottom-up function here. This scenario
  82          * can happen with large stack limits and large mmap()
  83          * allocations.
  84          */
  85         if (addr & ~PAGE_MASK) {
  86                 VM_BUG_ON(addr != -ENOMEM);
  87                 info.flags = 0;
  88                 info.low_limit = TASK_UNMAPPED_BASE;
  89                 info.high_limit = STACK_TOP32;
  90                 addr = vm_unmapped_area(&info);
  91         }
  92
  93         return addr;
  94 }
  95
  96 unsigned long
  97 hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
  98                 unsigned long len, unsigned long pgoff, unsigned long flags)
  99 {
 100         struct hstate *h = hstate_file(file);
 101         struct mm_struct *mm = current->mm;
 102         struct vm_area_struct *vma;
 103         unsigned long task_size = TASK_SIZE;
 104
 105         if (test_thread_flag(TIF_32BIT))
 106                 task_size = STACK_TOP32;
 107
 108         if (len & ~huge_page_mask(h))
 109                 return -EINVAL;
 110         if (len > task_size)
 111                 return -ENOMEM;
 112
 113         if (flags & MAP_FIXED) {
 114                 if (prepare_hugepage_range(file, addr, len))
 115                         return -EINVAL;
 116                 return addr;
 117         }
 118
 119         if (addr) {
 120                 addr = ALIGN(addr, huge_page_size(h));
 121                 vma = find_vma(mm, addr);
 122                 if (task_size - len >= addr &&
 123                     (!vma || addr + len <= vm_start_gap(vma)))
 124                         return addr;
 125         }
 126         if (mm->get_unmapped_area == arch_get_unmapped_area)
 127                 return hugetlb_get_unmapped_area_bottomup(file, addr, len,
 128                                 pgoff, flags);
 129         else
 130                 return hugetlb_get_unmapped_area_topdown(file, addr, len,
 131                                 pgoff, flags);
 132 }
 133
 134 static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 135 {
 136         return entry;
 137 }
 138
 139 static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 140 {
 141         unsigned long hugepage_size = _PAGE_SZ4MB_4V;
 142
 143         pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;
 144
 145         switch (shift) {
 146         case HPAGE_16GB_SHIFT:
 147                 hugepage_size = _PAGE_SZ16GB_4V;
 148                 pte_val(entry) |= _PAGE_PUD_HUGE;
 149                 break;
 150         case HPAGE_2GB_SHIFT:
 151                 hugepage_size = _PAGE_SZ2GB_4V;
 152                 pte_val(entry) |= _PAGE_PMD_HUGE;
 153                 break;
 154         case HPAGE_256MB_SHIFT:
 155                 hugepage_size = _PAGE_SZ256MB_4V;
 156                 pte_val(entry) |= _PAGE_PMD_HUGE;
 157                 break;
 158         case HPAGE_SHIFT:
 159                 pte_val(entry) |= _PAGE_PMD_HUGE;
 160                 break;
 161         case HPAGE_64K_SHIFT:
 162                 hugepage_size = _PAGE_SZ64K_4V;
 163                 break;
 164         default:
 165                 WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift);
 166         }
 167
 168         pte_val(entry) = pte_val(entry) | hugepage_size;
 169         return entry;
 170 }
 171
 172 static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift)
 173 {
 174         if (tlb_type == hypervisor)
 175                 return sun4v_hugepage_shift_to_tte(entry, shift);
 176         else
 177                 return sun4u_hugepage_shift_to_tte(entry, shift);
 178 }
 179
 180 pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
 181                          struct page *page, int writeable)
 182 {
 183         unsigned int shift = huge_page_shift(hstate_vma(vma));
 184         pte_t pte;
 185
 186         pte = hugepage_shift_to_tte(entry, shift);
 187
 188 #ifdef CONFIG_SPARC64
 189         /* If this vma has ADI enabled on it, turn on TTE.mcd
 190          */
 191         if (vma->vm_flags & VM_SPARC_ADI)
 192                 return pte_mkmcd(pte);
 193         else
 194                 return pte_mknotmcd(pte);
 195 #else
 196         return pte;
 197 #endif
 198 }
 199
 200 static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
 201 {
 202         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
 203         unsigned int shift;
 204
 205         switch (tte_szbits) {
 206         case _PAGE_SZ16GB_4V:
 207                 shift = HPAGE_16GB_SHIFT;
 208                 break;
 209         case _PAGE_SZ2GB_4V:
 210                 shift = HPAGE_2GB_SHIFT;
 211                 break;
 212         case _PAGE_SZ256MB_4V:
 213                 shift = HPAGE_256MB_SHIFT;
 214                 break;
 215         case _PAGE_SZ4MB_4V:
 216                 shift = REAL_HPAGE_SHIFT;
 217                 break;
 218         case _PAGE_SZ64K_4V:
 219                 shift = HPAGE_64K_SHIFT;
 220                 break;
 221         default:
 222                 shift = PAGE_SHIFT;
 223                 break;
 224         }
 225         return shift;
 226 }
 227
 228 static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
 229 {
 230         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
 231         unsigned int shift;
 232
 233         switch (tte_szbits) {
 234         case _PAGE_SZ256MB_4U:
 235                 shift = HPAGE_256MB_SHIFT;
 236                 break;
 237         case _PAGE_SZ4MB_4U:
 238                 shift = REAL_HPAGE_SHIFT;
 239                 break;
 240         case _PAGE_SZ64K_4U:
 241                 shift = HPAGE_64K_SHIFT;
 242                 break;
 243         default:
 244                 shift = PAGE_SHIFT;
 245                 break;
 246         }
 247         return shift;
 248 }
 249
 250 static unsigned long tte_to_shift(pte_t entry)
 251 {
 252         if (tlb_type == hypervisor)
 253                 return sun4v_huge_tte_to_shift(entry);
 254
 255         return sun4u_huge_tte_to_shift(entry);
 256 }
 257
 258 static unsigned int huge_tte_to_shift(pte_t entry)
 259 {
 260         unsigned long shift = tte_to_shift(entry);
 261
 262         if (shift == PAGE_SHIFT)
 263                 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
 264                           pte_val(entry));
 265
 266         return shift;
 267 }
 268
 269 static unsigned long huge_tte_to_size(pte_t pte)
 270 {
 271         unsigned long size = 1UL << huge_tte_to_shift(pte);
 272
 273         if (size == REAL_HPAGE_SIZE)
 274                 size = HPAGE_SIZE;
 275         return size;
 276 }
 277
 278 unsigned long pud_leaf_size(pud_t pud) { return 1UL << tte_to_shift(*(pte_t *)&pud); }
 279 unsigned long pmd_leaf_size(pmd_t pmd) { return 1UL << tte_to_shift(*(pte_t *)&pmd); }
 280 unsigned long pte_leaf_size(pte_t pte) { return 1UL << tte_to_shift(pte); }
 281
 282 pte_t *huge_pte_alloc(struct mm_struct *mm,
 283                         unsigned long addr, unsigned long sz)
 284 {
 285         pgd_t *pgd;
 286         p4d_t *p4d;
 287         pud_t *pud;
 288         pmd_t *pmd;
 289
 290         pgd = pgd_offset(mm, addr);
 291         p4d = p4d_offset(pgd, addr);
 292         pud = pud_alloc(mm, p4d, addr);
 293         if (!pud)
 294                 return NULL;
 295         if (sz >= PUD_SIZE)
 296                 return (pte_t *)pud;
 297         pmd = pmd_alloc(mm, pud, addr);
 298         if (!pmd)
 299                 return NULL;
 300         if (sz >= PMD_SIZE)
 301                 return (pte_t *)pmd;
 302         return pte_alloc_map(mm, pmd, addr);
 303 }
 304
 305 pte_t *huge_pte_offset(struct mm_struct *mm,
 306                        unsigned long addr, unsigned long sz)
 307 {
 308         pgd_t *pgd;
 309         p4d_t *p4d;
 310         pud_t *pud;
 311         pmd_t *pmd;
 312
 313         pgd = pgd_offset(mm, addr);
 314         if (pgd_none(*pgd))
 315                 return NULL;
 316         p4d = p4d_offset(pgd, addr);
 317         if (p4d_none(*p4d))
 318                 return NULL;
 319         pud = pud_offset(p4d, addr);
 320         if (pud_none(*pud))
 321                 return NULL;
 322         if (is_hugetlb_pud(*pud))
 323                 return (pte_t *)pud;
 324         pmd = pmd_offset(pud, addr);
 325         if (pmd_none(*pmd))
 326                 return NULL;
 327         if (is_hugetlb_pmd(*pmd))
 328                 return (pte_t *)pmd;
 329         return pte_offset_map(pmd, addr);
 330 }
 331
 332 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 333                      pte_t *ptep, pte_t entry)
 334 {
 335         unsigned int nptes, orig_shift, shift;
 336         unsigned long i, size;
 337         pte_t orig;
 338
 339         size = huge_tte_to_size(entry);
 340
 341         shift = PAGE_SHIFT;
 342         if (size >= PUD_SIZE)
 343                 shift = PUD_SHIFT;
 344         else if (size >= PMD_SIZE)
 345                 shift = PMD_SHIFT;
 346         else
 347                 shift = PAGE_SHIFT;
 348
 349         nptes = size >> shift;
 350
 351         if (!pte_present(*ptep) && pte_present(entry))
 352                 mm->context.hugetlb_pte_count += nptes;
 353
 354         addr &= ~(size - 1);
 355         orig = *ptep;
 356         orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
 357
 358         for (i = 0; i < nptes; i++)
 359                 ptep[i] = __pte(pte_val(entry) + (i << shift));
 360
 361         maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
 362         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 363         if (size == HPAGE_SIZE)
 364                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
 365                                     orig_shift);
 366 }
 367
 368 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 369                               pte_t *ptep)
 370 {
 371         unsigned int i, nptes, orig_shift, shift;
 372         unsigned long size;
 373         pte_t entry;
 374
 375         entry = *ptep;
 376         size = huge_tte_to_size(entry);
 377
 378         shift = PAGE_SHIFT;
 379         if (size >= PUD_SIZE)
 380                 shift = PUD_SHIFT;
 381         else if (size >= PMD_SIZE)
 382                 shift = PMD_SHIFT;
 383         else
 384                 shift = PAGE_SHIFT;
 385
 386         nptes = size >> shift;
 387         orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
 388
 389         if (pte_present(entry))
 390                 mm->context.hugetlb_pte_count -= nptes;
 391
 392         addr &= ~(size - 1);
 393         for (i = 0; i < nptes; i++)
 394                 ptep[i] = __pte(0UL);
 395
 396         maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
 397         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 398         if (size == HPAGE_SIZE)
 399                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
 400                                     orig_shift);
 401
 402         return entry;
 403 }
 404
 405 int pmd_huge(pmd_t pmd)
 406 {
 407         return !pmd_none(pmd) &&
 408                 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
 409 }
 410
 411 int pud_huge(pud_t pud)
 412 {
 413         return !pud_none(pud) &&
 414                 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
 415 }
 416
 417 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 418                            unsigned long addr)
 419 {
 420         pgtable_t token = pmd_pgtable(*pmd);
 421
 422         pmd_clear(pmd);
 423         pte_free_tlb(tlb, token, addr);
 424         mm_dec_nr_ptes(tlb->mm);
 425 }
 426
 427 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 428                                    unsigned long addr, unsigned long end,
 429                                    unsigned long floor, unsigned long ceiling)
 430 {
 431         pmd_t *pmd;
 432         unsigned long next;
 433         unsigned long start;
 434
 435         start = addr;
 436         pmd = pmd_offset(pud, addr);
 437         do {
 438                 next = pmd_addr_end(addr, end);
 439                 if (pmd_none(*pmd))
 440                         continue;
 441                 if (is_hugetlb_pmd(*pmd))
 442                         pmd_clear(pmd);
 443                 else
 444                         hugetlb_free_pte_range(tlb, pmd, addr);
 445         } while (pmd++, addr = next, addr != end);
 446
 447         start &= PUD_MASK;
 448         if (start < floor)
 449                 return;
 450         if (ceiling) {
 451                 ceiling &= PUD_MASK;
 452                 if (!ceiling)
 453                         return;
 454         }
 455         if (end - 1 > ceiling - 1)
 456                 return;
 457
 458         pmd = pmd_offset(pud, start);
 459         pud_clear(pud);
 460         pmd_free_tlb(tlb, pmd, start);
 461         mm_dec_nr_pmds(tlb->mm);
 462 }
 463
 464 static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
 465                                    unsigned long addr, unsigned long end,
 466                                    unsigned long floor, unsigned long ceiling)
 467 {
 468         pud_t *pud;
 469         unsigned long next;
 470         unsigned long start;
 471
 472         start = addr;
 473         pud = pud_offset(p4d, addr);
 474         do {
 475                 next = pud_addr_end(addr, end);
 476                 if (pud_none_or_clear_bad(pud))
 477                         continue;
 478                 if (is_hugetlb_pud(*pud))
 479                         pud_clear(pud);
 480                 else
 481                         hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
 482                                                ceiling);
 483         } while (pud++, addr = next, addr != end);
 484
 485         start &= PGDIR_MASK;
 486         if (start < floor)
 487                 return;
 488         if (ceiling) {
 489                 ceiling &= PGDIR_MASK;
 490                 if (!ceiling)
 491                         return;
 492         }
 493         if (end - 1 > ceiling - 1)
 494                 return;
 495
 496         pud = pud_offset(p4d, start);
 497         p4d_clear(p4d);
 498         pud_free_tlb(tlb, pud, start);
 499         mm_dec_nr_puds(tlb->mm);
 500 }
 501
 502 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 503                             unsigned long addr, unsigned long end,
 504                             unsigned long floor, unsigned long ceiling)
 505 {
 506         pgd_t *pgd;
 507         p4d_t *p4d;
 508         unsigned long next;
 509
 510         addr &= PMD_MASK;
 511         if (addr < floor) {
 512                 addr += PMD_SIZE;
 513                 if (!addr)
 514                         return;
 515         }
 516         if (ceiling) {
 517                 ceiling &= PMD_MASK;
 518                 if (!ceiling)
 519                         return;
 520         }
 521         if (end - 1 > ceiling - 1)
 522                 end -= PMD_SIZE;
 523         if (addr > end - 1)
 524                 return;
 525
 526         pgd = pgd_offset(tlb->mm, addr);
 527         p4d = p4d_offset(pgd, addr);
 528         do {
 529                 next = p4d_addr_end(addr, end);
 530                 if (p4d_none_or_clear_bad(p4d))
 531                         continue;
 532                 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
 533         } while (p4d++, addr = next, addr != end);
 534 }