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