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