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 int huge_tte_to_shift(pte_t entry)
 251 {
 252         unsigned long shift;
 253
 254         if (tlb_type == hypervisor)
 255                 shift = sun4v_huge_tte_to_shift(entry);
 256         else
 257                 shift = sun4u_huge_tte_to_shift(entry);
 258
 259         if (shift == PAGE_SHIFT)
 260                 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
 261                           pte_val(entry));
 262
 263         return shift;
 264 }
 265
 266 static unsigned long huge_tte_to_size(pte_t pte)
 267 {
 268         unsigned long size = 1UL << huge_tte_to_shift(pte);
 269
 270         if (size == REAL_HPAGE_SIZE)
 271                 size = HPAGE_SIZE;
 272         return size;
 273 }
 274
 275 pte_t *huge_pte_alloc(struct mm_struct *mm,
 276                         unsigned long addr, unsigned long sz)
 277 {
 278         pgd_t *pgd;
 279         p4d_t *p4d;
 280         pud_t *pud;
 281         pmd_t *pmd;
 282
 283         pgd = pgd_offset(mm, addr);
 284         p4d = p4d_offset(pgd, addr);
 285         pud = pud_alloc(mm, p4d, addr);
 286         if (!pud)
 287                 return NULL;
 288         if (sz >= PUD_SIZE)
 289                 return (pte_t *)pud;
 290         pmd = pmd_alloc(mm, pud, addr);
 291         if (!pmd)
 292                 return NULL;
 293         if (sz >= PMD_SIZE)
 294                 return (pte_t *)pmd;
 295         return pte_alloc_map(mm, pmd, addr);
 296 }
 297
 298 pte_t *huge_pte_offset(struct mm_struct *mm,
 299                        unsigned long addr, unsigned long sz)
 300 {
 301         pgd_t *pgd;
 302         p4d_t *p4d;
 303         pud_t *pud;
 304         pmd_t *pmd;
 305
 306         pgd = pgd_offset(mm, addr);
 307         if (pgd_none(*pgd))
 308                 return NULL;
 309         p4d = p4d_offset(pgd, addr);
 310         if (p4d_none(*p4d))
 311                 return NULL;
 312         pud = pud_offset(p4d, addr);
 313         if (pud_none(*pud))
 314                 return NULL;
 315         if (is_hugetlb_pud(*pud))
 316                 return (pte_t *)pud;
 317         pmd = pmd_offset(pud, addr);
 318         if (pmd_none(*pmd))
 319                 return NULL;
 320         if (is_hugetlb_pmd(*pmd))
 321                 return (pte_t *)pmd;
 322         return pte_offset_map(pmd, addr);
 323 }
 324
 325 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 326                      pte_t *ptep, pte_t entry)
 327 {
 328         unsigned int nptes, orig_shift, shift;
 329         unsigned long i, size;
 330         pte_t orig;
 331
 332         size = huge_tte_to_size(entry);
 333
 334         shift = PAGE_SHIFT;
 335         if (size >= PUD_SIZE)
 336                 shift = PUD_SHIFT;
 337         else if (size >= PMD_SIZE)
 338                 shift = PMD_SHIFT;
 339         else
 340                 shift = PAGE_SHIFT;
 341
 342         nptes = size >> shift;
 343
 344         if (!pte_present(*ptep) && pte_present(entry))
 345                 mm->context.hugetlb_pte_count += nptes;
 346
 347         addr &= ~(size - 1);
 348         orig = *ptep;
 349         orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
 350
 351         for (i = 0; i < nptes; i++)
 352                 ptep[i] = __pte(pte_val(entry) + (i << shift));
 353
 354         maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
 355         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 356         if (size == HPAGE_SIZE)
 357                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
 358                                     orig_shift);
 359 }
 360
 361 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 362                               pte_t *ptep)
 363 {
 364         unsigned int i, nptes, orig_shift, shift;
 365         unsigned long size;
 366         pte_t entry;
 367
 368         entry = *ptep;
 369         size = huge_tte_to_size(entry);
 370
 371         shift = PAGE_SHIFT;
 372         if (size >= PUD_SIZE)
 373                 shift = PUD_SHIFT;
 374         else if (size >= PMD_SIZE)
 375                 shift = PMD_SHIFT;
 376         else
 377                 shift = PAGE_SHIFT;
 378
 379         nptes = size >> shift;
 380         orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
 381
 382         if (pte_present(entry))
 383                 mm->context.hugetlb_pte_count -= nptes;
 384
 385         addr &= ~(size - 1);
 386         for (i = 0; i < nptes; i++)
 387                 ptep[i] = __pte(0UL);
 388
 389         maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
 390         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 391         if (size == HPAGE_SIZE)
 392                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
 393                                     orig_shift);
 394
 395         return entry;
 396 }
 397
 398 int pmd_huge(pmd_t pmd)
 399 {
 400         return !pmd_none(pmd) &&
 401                 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
 402 }
 403
 404 int pud_huge(pud_t pud)
 405 {
 406         return !pud_none(pud) &&
 407                 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
 408 }
 409
 410 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 411                            unsigned long addr)
 412 {
 413         pgtable_t token = pmd_pgtable(*pmd);
 414
 415         pmd_clear(pmd);
 416         pte_free_tlb(tlb, token, addr);
 417         mm_dec_nr_ptes(tlb->mm);
 418 }
 419
 420 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 421                                    unsigned long addr, unsigned long end,
 422                                    unsigned long floor, unsigned long ceiling)
 423 {
 424         pmd_t *pmd;
 425         unsigned long next;
 426         unsigned long start;
 427
 428         start = addr;
 429         pmd = pmd_offset(pud, addr);
 430         do {
 431                 next = pmd_addr_end(addr, end);
 432                 if (pmd_none(*pmd))
 433                         continue;
 434                 if (is_hugetlb_pmd(*pmd))
 435                         pmd_clear(pmd);
 436                 else
 437                         hugetlb_free_pte_range(tlb, pmd, addr);
 438         } while (pmd++, addr = next, addr != end);
 439
 440         start &= PUD_MASK;
 441         if (start < floor)
 442                 return;
 443         if (ceiling) {
 444                 ceiling &= PUD_MASK;
 445                 if (!ceiling)
 446                         return;
 447         }
 448         if (end - 1 > ceiling - 1)
 449                 return;
 450
 451         pmd = pmd_offset(pud, start);
 452         pud_clear(pud);
 453         pmd_free_tlb(tlb, pmd, start);
 454         mm_dec_nr_pmds(tlb->mm);
 455 }
 456
 457 static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
 458                                    unsigned long addr, unsigned long end,
 459                                    unsigned long floor, unsigned long ceiling)
 460 {
 461         pud_t *pud;
 462         unsigned long next;
 463         unsigned long start;
 464
 465         start = addr;
 466         pud = pud_offset(p4d, addr);
 467         do {
 468                 next = pud_addr_end(addr, end);
 469                 if (pud_none_or_clear_bad(pud))
 470                         continue;
 471                 if (is_hugetlb_pud(*pud))
 472                         pud_clear(pud);
 473                 else
 474                         hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
 475                                                ceiling);
 476         } while (pud++, addr = next, addr != end);
 477
 478         start &= PGDIR_MASK;
 479         if (start < floor)
 480                 return;
 481         if (ceiling) {
 482                 ceiling &= PGDIR_MASK;
 483                 if (!ceiling)
 484                         return;
 485         }
 486         if (end - 1 > ceiling - 1)
 487                 return;
 488
 489         pud = pud_offset(p4d, start);
 490         p4d_clear(p4d);
 491         pud_free_tlb(tlb, pud, start);
 492         mm_dec_nr_puds(tlb->mm);
 493 }
 494
 495 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 496                             unsigned long addr, unsigned long end,
 497                             unsigned long floor, unsigned long ceiling)
 498 {
 499         pgd_t *pgd;
 500         p4d_t *p4d;
 501         unsigned long next;
 502
 503         addr &= PMD_MASK;
 504         if (addr < floor) {
 505                 addr += PMD_SIZE;
 506                 if (!addr)
 507                         return;
 508         }
 509         if (ceiling) {
 510                 ceiling &= PMD_MASK;
 511                 if (!ceiling)
 512                         return;
 513         }
 514         if (end - 1 > ceiling - 1)
 515                 end -= PMD_SIZE;
 516         if (addr > end - 1)
 517                 return;
 518
 519         pgd = pgd_offset(tlb->mm, addr);
 520         p4d = p4d_offset(pgd, addr);
 521         do {
 522                 next = p4d_addr_end(addr, end);
 523                 if (p4d_none_or_clear_bad(p4d))
 524                         continue;
 525                 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
 526         } while (p4d++, addr = next, addr != end);
 527 }