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, unsigned int shift, vm_flags_t flags)
 181 {
 182         pte_t pte;
 183
 184         entry = pte_mkhuge(entry);
 185         pte = hugepage_shift_to_tte(entry, shift);
 186
 187 #ifdef CONFIG_SPARC64
 188         /* If this vma has ADI enabled on it, turn on TTE.mcd
 189          */
 190         if (flags & VM_SPARC_ADI)
 191                 return pte_mkmcd(pte);
 192         else
 193                 return pte_mknotmcd(pte);
 194 #else
 195         return pte;
 196 #endif
 197 }
 198
 199 static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
 200 {
 201         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
 202         unsigned int shift;
 203
 204         switch (tte_szbits) {
 205         case _PAGE_SZ16GB_4V:
 206                 shift = HPAGE_16GB_SHIFT;
 207                 break;
 208         case _PAGE_SZ2GB_4V:
 209                 shift = HPAGE_2GB_SHIFT;
 210                 break;
 211         case _PAGE_SZ256MB_4V:
 212                 shift = HPAGE_256MB_SHIFT;
 213                 break;
 214         case _PAGE_SZ4MB_4V:
 215                 shift = REAL_HPAGE_SHIFT;
 216                 break;
 217         case _PAGE_SZ64K_4V:
 218                 shift = HPAGE_64K_SHIFT;
 219                 break;
 220         default:
 221                 shift = PAGE_SHIFT;
 222                 break;
 223         }
 224         return shift;
 225 }
 226
 227 static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
 228 {
 229         unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
 230         unsigned int shift;
 231
 232         switch (tte_szbits) {
 233         case _PAGE_SZ256MB_4U:
 234                 shift = HPAGE_256MB_SHIFT;
 235                 break;
 236         case _PAGE_SZ4MB_4U:
 237                 shift = REAL_HPAGE_SHIFT;
 238                 break;
 239         case _PAGE_SZ64K_4U:
 240                 shift = HPAGE_64K_SHIFT;
 241                 break;
 242         default:
 243                 shift = PAGE_SHIFT;
 244                 break;
 245         }
 246         return shift;
 247 }
 248
 249 static unsigned long tte_to_shift(pte_t entry)
 250 {
 251         if (tlb_type == hypervisor)
 252                 return sun4v_huge_tte_to_shift(entry);
 253
 254         return sun4u_huge_tte_to_shift(entry);
 255 }
 256
 257 static unsigned int huge_tte_to_shift(pte_t entry)
 258 {
 259         unsigned long shift = tte_to_shift(entry);
 260
 261         if (shift == PAGE_SHIFT)
 262                 WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
 263                           pte_val(entry));
 264
 265         return shift;
 266 }
 267
 268 static unsigned long huge_tte_to_size(pte_t pte)
 269 {
 270         unsigned long size = 1UL << huge_tte_to_shift(pte);
 271
 272         if (size == REAL_HPAGE_SIZE)
 273                 size = HPAGE_SIZE;
 274         return size;
 275 }
 276
 277 unsigned long pud_leaf_size(pud_t pud) { return 1UL << tte_to_shift(*(pte_t *)&pud); }
 278 unsigned long pmd_leaf_size(pmd_t pmd) { return 1UL << tte_to_shift(*(pte_t *)&pmd); }
 279 unsigned long pte_leaf_size(pte_t pte) { return 1UL << tte_to_shift(pte); }
 280
 281 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 282                         unsigned long addr, unsigned long sz)
 283 {
 284         pgd_t *pgd;
 285         p4d_t *p4d;
 286         pud_t *pud;
 287         pmd_t *pmd;
 288
 289         pgd = pgd_offset(mm, addr);
 290         p4d = p4d_offset(pgd, addr);
 291         pud = pud_alloc(mm, p4d, addr);
 292         if (!pud)
 293                 return NULL;
 294         if (sz >= PUD_SIZE)
 295                 return (pte_t *)pud;
 296         pmd = pmd_alloc(mm, pud, addr);
 297         if (!pmd)
 298                 return NULL;
 299         if (sz >= PMD_SIZE)
 300                 return (pte_t *)pmd;
 301         return pte_alloc_huge(mm, pmd, addr);
 302 }
 303
 304 pte_t *huge_pte_offset(struct mm_struct *mm,
 305                        unsigned long addr, unsigned long sz)
 306 {
 307         pgd_t *pgd;
 308         p4d_t *p4d;
 309         pud_t *pud;
 310         pmd_t *pmd;
 311
 312         pgd = pgd_offset(mm, addr);
 313         if (pgd_none(*pgd))
 314                 return NULL;
 315         p4d = p4d_offset(pgd, addr);
 316         if (p4d_none(*p4d))
 317                 return NULL;
 318         pud = pud_offset(p4d, addr);
 319         if (pud_none(*pud))
 320                 return NULL;
 321         if (is_hugetlb_pud(*pud))
 322                 return (pte_t *)pud;
 323         pmd = pmd_offset(pud, addr);
 324         if (pmd_none(*pmd))
 325                 return NULL;
 326         if (is_hugetlb_pmd(*pmd))
 327                 return (pte_t *)pmd;
 328         return pte_offset_huge(pmd, addr);
 329 }
 330
 331 void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 332                      pte_t *ptep, pte_t entry)
 333 {
 334         unsigned int nptes, orig_shift, shift;
 335         unsigned long i, size;
 336         pte_t orig;
 337
 338         size = huge_tte_to_size(entry);
 339
 340         shift = PAGE_SHIFT;
 341         if (size >= PUD_SIZE)
 342                 shift = PUD_SHIFT;
 343         else if (size >= PMD_SIZE)
 344                 shift = PMD_SHIFT;
 345         else
 346                 shift = PAGE_SHIFT;
 347
 348         nptes = size >> shift;
 349
 350         if (!pte_present(*ptep) && pte_present(entry))
 351                 mm->context.hugetlb_pte_count += nptes;
 352
 353         addr &= ~(size - 1);
 354         orig = *ptep;
 355         orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
 356
 357         for (i = 0; i < nptes; i++)
 358                 ptep[i] = __pte(pte_val(entry) + (i << shift));
 359
 360         maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
 361         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 362         if (size == HPAGE_SIZE)
 363                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
 364                                     orig_shift);
 365 }
 366
 367 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 368                      pte_t *ptep, pte_t entry, unsigned long sz)
 369 {
 370         __set_huge_pte_at(mm, addr, ptep, entry);
 371 }
 372
 373 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 374                               pte_t *ptep)
 375 {
 376         unsigned int i, nptes, orig_shift, shift;
 377         unsigned long size;
 378         pte_t entry;
 379
 380         entry = *ptep;
 381         size = huge_tte_to_size(entry);
 382
 383         shift = PAGE_SHIFT;
 384         if (size >= PUD_SIZE)
 385                 shift = PUD_SHIFT;
 386         else if (size >= PMD_SIZE)
 387                 shift = PMD_SHIFT;
 388         else
 389                 shift = PAGE_SHIFT;
 390
 391         nptes = size >> shift;
 392         orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
 393
 394         if (pte_present(entry))
 395                 mm->context.hugetlb_pte_count -= nptes;
 396
 397         addr &= ~(size - 1);
 398         for (i = 0; i < nptes; i++)
 399                 ptep[i] = __pte(0UL);
 400
 401         maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
 402         /* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
 403         if (size == HPAGE_SIZE)
 404                 maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
 405                                     orig_shift);
 406
 407         return entry;
 408 }
 409
 410 int pmd_huge(pmd_t pmd)
 411 {
 412         return !pmd_none(pmd) &&
 413                 (pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
 414 }
 415
 416 int pud_huge(pud_t pud)
 417 {
 418         return !pud_none(pud) &&
 419                 (pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
 420 }
 421
 422 static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
 423                            unsigned long addr)
 424 {
 425         pgtable_t token = pmd_pgtable(*pmd);
 426
 427         pmd_clear(pmd);
 428         pte_free_tlb(tlb, token, addr);
 429         mm_dec_nr_ptes(tlb->mm);
 430 }
 431
 432 static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 433                                    unsigned long addr, unsigned long end,
 434                                    unsigned long floor, unsigned long ceiling)
 435 {
 436         pmd_t *pmd;
 437         unsigned long next;
 438         unsigned long start;
 439
 440         start = addr;
 441         pmd = pmd_offset(pud, addr);
 442         do {
 443                 next = pmd_addr_end(addr, end);
 444                 if (pmd_none(*pmd))
 445                         continue;
 446                 if (is_hugetlb_pmd(*pmd))
 447                         pmd_clear(pmd);
 448                 else
 449                         hugetlb_free_pte_range(tlb, pmd, addr);
 450         } while (pmd++, addr = next, addr != end);
 451
 452         start &= PUD_MASK;
 453         if (start < floor)
 454                 return;
 455         if (ceiling) {
 456                 ceiling &= PUD_MASK;
 457                 if (!ceiling)
 458                         return;
 459         }
 460         if (end - 1 > ceiling - 1)
 461                 return;
 462
 463         pmd = pmd_offset(pud, start);
 464         pud_clear(pud);
 465         pmd_free_tlb(tlb, pmd, start);
 466         mm_dec_nr_pmds(tlb->mm);
 467 }
 468
 469 static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
 470                                    unsigned long addr, unsigned long end,
 471                                    unsigned long floor, unsigned long ceiling)
 472 {
 473         pud_t *pud;
 474         unsigned long next;
 475         unsigned long start;
 476
 477         start = addr;
 478         pud = pud_offset(p4d, addr);
 479         do {
 480                 next = pud_addr_end(addr, end);
 481                 if (pud_none_or_clear_bad(pud))
 482                         continue;
 483                 if (is_hugetlb_pud(*pud))
 484                         pud_clear(pud);
 485                 else
 486                         hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
 487                                                ceiling);
 488         } while (pud++, addr = next, addr != end);
 489
 490         start &= PGDIR_MASK;
 491         if (start < floor)
 492                 return;
 493         if (ceiling) {
 494                 ceiling &= PGDIR_MASK;
 495                 if (!ceiling)
 496                         return;
 497         }
 498         if (end - 1 > ceiling - 1)
 499                 return;
 500
 501         pud = pud_offset(p4d, start);
 502         p4d_clear(p4d);
 503         pud_free_tlb(tlb, pud, start);
 504         mm_dec_nr_puds(tlb->mm);
 505 }
 506
 507 void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 508                             unsigned long addr, unsigned long end,
 509                             unsigned long floor, unsigned long ceiling)
 510 {
 511         pgd_t *pgd;
 512         p4d_t *p4d;
 513         unsigned long next;
 514
 515         addr &= PMD_MASK;
 516         if (addr < floor) {
 517                 addr += PMD_SIZE;
 518                 if (!addr)
 519                         return;
 520         }
 521         if (ceiling) {
 522                 ceiling &= PMD_MASK;
 523                 if (!ceiling)
 524                         return;
 525         }
 526         if (end - 1 > ceiling - 1)
 527                 end -= PMD_SIZE;
 528         if (addr > end - 1)
 529                 return;
 530
 531         pgd = pgd_offset(tlb->mm, addr);
 532         p4d = p4d_offset(pgd, addr);
 533         do {
 534                 next = p4d_addr_end(addr, end);
 535                 if (p4d_none_or_clear_bad(p4d))
 536                         continue;
 537                 hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
 538         } while (p4d++, addr = next, addr != end);
 539 }