arch/arm64/mm/mmu.c

   1 /*
   2  * Based on arch/arm/mm/mmu.c
   3  *
   4  * Copyright (C) 1995-2005 Russell King
   5  * Copyright (C) 2012 ARM Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/cache.h>
  21 #include <linux/export.h>
  22 #include <linux/kernel.h>
  23 #include <linux/errno.h>
  24 #include <linux/init.h>
  25 #include <linux/libfdt.h>
  26 #include <linux/mman.h>
  27 #include <linux/nodemask.h>
  28 #include <linux/memblock.h>
  29 #include <linux/fs.h>
  30 #include <linux/io.h>
  31 #include <linux/slab.h>
  32 #include <linux/stop_machine.h>
  33
  34 #include <asm/barrier.h>
  35 #include <asm/cputype.h>
  36 #include <asm/fixmap.h>
  37 #include <asm/kasan.h>
  38 #include <asm/kernel-pgtable.h>
  39 #include <asm/sections.h>
  40 #include <asm/setup.h>
  41 #include <asm/sizes.h>
  42 #include <asm/tlb.h>
  43 #include <asm/memblock.h>
  44 #include <asm/mmu_context.h>
  45
  46 u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
  47
  48 u64 kimage_voffset __ro_after_init;
  49 EXPORT_SYMBOL(kimage_voffset);
  50
  51 /*
  52  * Empty_zero_page is a special page that is used for zero-initialized data
  53  * and COW.
  54  */
  55 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  56 EXPORT_SYMBOL(empty_zero_page);
  57
  58 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
  59 static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
  60 static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
  61
  62 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  63                               unsigned long size, pgprot_t vma_prot)
  64 {
  65         if (!pfn_valid(pfn))
  66                 return pgprot_noncached(vma_prot);
  67         else if (file->f_flags & O_SYNC)
  68                 return pgprot_writecombine(vma_prot);
  69         return vma_prot;
  70 }
  71 EXPORT_SYMBOL(phys_mem_access_prot);
  72
  73 static phys_addr_t __init early_pgtable_alloc(void)
  74 {
  75         phys_addr_t phys;
  76         void *ptr;
  77
  78         phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  79
  80         /*
  81          * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
  82          * slot will be free, so we can (ab)use the FIX_PTE slot to initialise
  83          * any level of table.
  84          */
  85         ptr = pte_set_fixmap(phys);
  86
  87         memset(ptr, 0, PAGE_SIZE);
  88
  89         /*
  90          * Implicit barriers also ensure the zeroed page is visible to the page
  91          * table walker
  92          */
  93         pte_clear_fixmap();
  94
  95         return phys;
  96 }
  97
  98 static void alloc_init_pte(pmd_t *pmd, unsigned long addr,
  99                                   unsigned long end, unsigned long pfn,
 100                                   pgprot_t prot,
 101                                   phys_addr_t (*pgtable_alloc)(void))
 102 {
 103         pte_t *pte;
 104
 105         BUG_ON(pmd_sect(*pmd));
 106         if (pmd_none(*pmd)) {
 107                 phys_addr_t pte_phys;
 108                 BUG_ON(!pgtable_alloc);
 109                 pte_phys = pgtable_alloc();
 110                 pte = pte_set_fixmap(pte_phys);
 111                 __pmd_populate(pmd, pte_phys, PMD_TYPE_TABLE);
 112                 pte_clear_fixmap();
 113         }
 114         BUG_ON(pmd_bad(*pmd));
 115
 116         pte = pte_set_fixmap_offset(pmd, addr);
 117         do {
 118                 set_pte(pte, pfn_pte(pfn, prot));
 119                 pfn++;
 120         } while (pte++, addr += PAGE_SIZE, addr != end);
 121
 122         pte_clear_fixmap();
 123 }
 124
 125 static void alloc_init_pmd(pud_t *pud, unsigned long addr, unsigned long end,
 126                                   phys_addr_t phys, pgprot_t prot,
 127                                   phys_addr_t (*pgtable_alloc)(void),
 128                                   bool allow_block_mappings)
 129 {
 130         pmd_t *pmd;
 131         unsigned long next;
 132
 133         /*
 134          * Check for initial section mappings in the pgd/pud and remove them.
 135          */
 136         BUG_ON(pud_sect(*pud));
 137         if (pud_none(*pud)) {
 138                 phys_addr_t pmd_phys;
 139                 BUG_ON(!pgtable_alloc);
 140                 pmd_phys = pgtable_alloc();
 141                 pmd = pmd_set_fixmap(pmd_phys);
 142                 __pud_populate(pud, pmd_phys, PUD_TYPE_TABLE);
 143                 pmd_clear_fixmap();
 144         }
 145         BUG_ON(pud_bad(*pud));
 146
 147         pmd = pmd_set_fixmap_offset(pud, addr);
 148         do {
 149                 next = pmd_addr_end(addr, end);
 150                 /* try section mapping first */
 151                 if (((addr | next | phys) & ~SECTION_MASK) == 0 &&
 152                       allow_block_mappings) {
 153                         pmd_t old_pmd =*pmd;
 154                         pmd_set_huge(pmd, phys, prot);
 155                         /*
 156                          * Check for previous table entries created during
 157                          * boot (__create_page_tables) and flush them.
 158                          */
 159                         if (!pmd_none(old_pmd)) {
 160                                 flush_tlb_all();
 161                                 if (pmd_table(old_pmd)) {
 162                                         phys_addr_t table = pmd_page_paddr(old_pmd);
 163                                         if (!WARN_ON_ONCE(slab_is_available()))
 164                                                 memblock_free(table, PAGE_SIZE);
 165                                 }
 166                         }
 167                 } else {
 168                         alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),
 169                                        prot, pgtable_alloc);
 170                 }
 171                 phys += next - addr;
 172         } while (pmd++, addr = next, addr != end);
 173
 174         pmd_clear_fixmap();
 175 }
 176
 177 static inline bool use_1G_block(unsigned long addr, unsigned long next,
 178                         unsigned long phys)
 179 {
 180         if (PAGE_SHIFT != 12)
 181                 return false;
 182
 183         if (((addr | next | phys) & ~PUD_MASK) != 0)
 184                 return false;
 185
 186         return true;
 187 }
 188
 189 static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
 190                                   phys_addr_t phys, pgprot_t prot,
 191                                   phys_addr_t (*pgtable_alloc)(void),
 192                                   bool allow_block_mappings)
 193 {
 194         pud_t *pud;
 195         unsigned long next;
 196
 197         if (pgd_none(*pgd)) {
 198                 phys_addr_t pud_phys;
 199                 BUG_ON(!pgtable_alloc);
 200                 pud_phys = pgtable_alloc();
 201                 __pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE);
 202         }
 203         BUG_ON(pgd_bad(*pgd));
 204
 205         pud = pud_set_fixmap_offset(pgd, addr);
 206         do {
 207                 next = pud_addr_end(addr, end);
 208
 209                 /*
 210                  * For 4K granule only, attempt to put down a 1GB block
 211                  */
 212                 if (use_1G_block(addr, next, phys) && allow_block_mappings) {
 213                         pud_t old_pud = *pud;
 214                         pud_set_huge(pud, phys, prot);
 215
 216                         /*
 217                          * If we have an old value for a pud, it will
 218                          * be pointing to a pmd table that we no longer
 219                          * need (from swapper_pg_dir).
 220                          *
 221                          * Look up the old pmd table and free it.
 222                          */
 223                         if (!pud_none(old_pud)) {
 224                                 flush_tlb_all();
 225                                 if (pud_table(old_pud)) {
 226                                         phys_addr_t table = pud_page_paddr(old_pud);
 227                                         if (!WARN_ON_ONCE(slab_is_available()))
 228                                                 memblock_free(table, PAGE_SIZE);
 229                                 }
 230                         }
 231                 } else {
 232                         alloc_init_pmd(pud, addr, next, phys, prot,
 233                                        pgtable_alloc, allow_block_mappings);
 234                 }
 235                 phys += next - addr;
 236         } while (pud++, addr = next, addr != end);
 237
 238         pud_clear_fixmap();
 239 }
 240
 241 static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
 242                                  unsigned long virt, phys_addr_t size,
 243                                  pgprot_t prot,
 244                                  phys_addr_t (*pgtable_alloc)(void),
 245                                  bool allow_block_mappings)
 246 {
 247         unsigned long addr, length, end, next;
 248         pgd_t *pgd = pgd_offset_raw(pgdir, virt);
 249
 250         /*
 251          * If the virtual and physical address don't have the same offset
 252          * within a page, we cannot map the region as the caller expects.
 253          */
 254         if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
 255                 return;
 256
 257         phys &= PAGE_MASK;
 258         addr = virt & PAGE_MASK;
 259         length = PAGE_ALIGN(size + (virt & ~PAGE_MASK));
 260
 261         end = addr + length;
 262         do {
 263                 next = pgd_addr_end(addr, end);
 264                 alloc_init_pud(pgd, addr, next, phys, prot, pgtable_alloc,
 265                                allow_block_mappings);
 266                 phys += next - addr;
 267         } while (pgd++, addr = next, addr != end);
 268 }
 269
 270 static phys_addr_t pgd_pgtable_alloc(void)
 271 {
 272         void *ptr = (void *)__get_free_page(PGALLOC_GFP);
 273         if (!ptr || !pgtable_page_ctor(virt_to_page(ptr)))
 274                 BUG();
 275
 276         /* Ensure the zeroed page is visible to the page table walker */
 277         dsb(ishst);
 278         return __pa(ptr);
 279 }
 280
 281 /*
 282  * This function can only be used to modify existing table entries,
 283  * without allocating new levels of table. Note that this permits the
 284  * creation of new section or page entries.
 285  */
 286 static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
 287                                   phys_addr_t size, pgprot_t prot)
 288 {
 289         if (virt < VMALLOC_START) {
 290                 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
 291                         &phys, virt);
 292                 return;
 293         }
 294         __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, true);
 295 }
 296
 297 void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
 298                                unsigned long virt, phys_addr_t size,
 299                                pgprot_t prot, bool allow_block_mappings)
 300 {
 301         BUG_ON(mm == &init_mm);
 302
 303         __create_pgd_mapping(mm->pgd, phys, virt, size, prot,
 304                              pgd_pgtable_alloc, allow_block_mappings);
 305 }
 306
 307 static void create_mapping_late(phys_addr_t phys, unsigned long virt,
 308                                   phys_addr_t size, pgprot_t prot)
 309 {
 310         if (virt < VMALLOC_START) {
 311                 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
 312                         &phys, virt);
 313                 return;
 314         }
 315
 316         __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot,
 317                              NULL, !debug_pagealloc_enabled());
 318 }
 319
 320 static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end)
 321 {
 322         unsigned long kernel_start = __pa(_text);
 323         unsigned long kernel_end = __pa(__init_begin);
 324
 325         /*
 326          * Take care not to create a writable alias for the
 327          * read-only text and rodata sections of the kernel image.
 328          */
 329
 330         /* No overlap with the kernel text/rodata */
 331         if (end < kernel_start || start >= kernel_end) {
 332                 __create_pgd_mapping(pgd, start, __phys_to_virt(start),
 333                                      end - start, PAGE_KERNEL,
 334                                      early_pgtable_alloc,
 335                                      !debug_pagealloc_enabled());
 336                 return;
 337         }
 338
 339         /*
 340          * This block overlaps the kernel text/rodata mappings.
 341          * Map the portion(s) which don't overlap.
 342          */
 343         if (start < kernel_start)
 344                 __create_pgd_mapping(pgd, start,
 345                                      __phys_to_virt(start),
 346                                      kernel_start - start, PAGE_KERNEL,
 347                                      early_pgtable_alloc,
 348                                      !debug_pagealloc_enabled());
 349         if (kernel_end < end)
 350                 __create_pgd_mapping(pgd, kernel_end,
 351                                      __phys_to_virt(kernel_end),
 352                                      end - kernel_end, PAGE_KERNEL,
 353                                      early_pgtable_alloc,
 354                                      !debug_pagealloc_enabled());
 355
 356         /*
 357          * Map the linear alias of the [_text, __init_begin) interval as
 358          * read-only/non-executable. This makes the contents of the
 359          * region accessible to subsystems such as hibernate, but
 360          * protects it from inadvertent modification or execution.
 361          */
 362         __create_pgd_mapping(pgd, kernel_start, __phys_to_virt(kernel_start),
 363                              kernel_end - kernel_start, PAGE_KERNEL_RO,
 364                              early_pgtable_alloc, !debug_pagealloc_enabled());
 365 }
 366
 367 static void __init map_mem(pgd_t *pgd)
 368 {
 369         struct memblock_region *reg;
 370
 371         /* map all the memory banks */
 372         for_each_memblock(memory, reg) {
 373                 phys_addr_t start = reg->base;
 374                 phys_addr_t end = start + reg->size;
 375
 376                 if (start >= end)
 377                         break;
 378                 if (memblock_is_nomap(reg))
 379                         continue;
 380
 381                 __map_memblock(pgd, start, end);
 382         }
 383 }
 384
 385 void mark_rodata_ro(void)
 386 {
 387         unsigned long section_size;
 388
 389         section_size = (unsigned long)_etext - (unsigned long)_text;
 390         create_mapping_late(__pa(_text), (unsigned long)_text,
 391                             section_size, PAGE_KERNEL_ROX);
 392         /*
 393          * mark .rodata as read only. Use __init_begin rather than __end_rodata
 394          * to cover NOTES and EXCEPTION_TABLE.
 395          */
 396         section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;
 397         create_mapping_late(__pa(__start_rodata), (unsigned long)__start_rodata,
 398                             section_size, PAGE_KERNEL_RO);
 399 }
 400
 401 static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end,
 402                                       pgprot_t prot, struct vm_struct *vma)
 403 {
 404         phys_addr_t pa_start = __pa(va_start);
 405         unsigned long size = va_end - va_start;
 406
 407         BUG_ON(!PAGE_ALIGNED(pa_start));
 408         BUG_ON(!PAGE_ALIGNED(size));
 409
 410         __create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot,
 411                              early_pgtable_alloc, !debug_pagealloc_enabled());
 412
 413         vma->addr       = va_start;
 414         vma->phys_addr  = pa_start;
 415         vma->size       = size;
 416         vma->flags      = VM_MAP;
 417         vma->caller     = __builtin_return_address(0);
 418
 419         vm_area_add_early(vma);
 420 }
 421
 422 /*
 423  * Create fine-grained mappings for the kernel.
 424  */
 425 static void __init map_kernel(pgd_t *pgd)
 426 {
 427         static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_init, vmlinux_data;
 428
 429         map_kernel_segment(pgd, _text, _etext, PAGE_KERNEL_EXEC, &vmlinux_text);
 430         map_kernel_segment(pgd, __start_rodata, __init_begin, PAGE_KERNEL, &vmlinux_rodata);
 431         map_kernel_segment(pgd, __init_begin, __init_end, PAGE_KERNEL_EXEC,
 432                            &vmlinux_init);
 433         map_kernel_segment(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data);
 434
 435         if (!pgd_val(*pgd_offset_raw(pgd, FIXADDR_START))) {
 436                 /*
 437                  * The fixmap falls in a separate pgd to the kernel, and doesn't
 438                  * live in the carveout for the swapper_pg_dir. We can simply
 439                  * re-use the existing dir for the fixmap.
 440                  */
 441                 set_pgd(pgd_offset_raw(pgd, FIXADDR_START),
 442                         *pgd_offset_k(FIXADDR_START));
 443         } else if (CONFIG_PGTABLE_LEVELS > 3) {
 444                 /*
 445                  * The fixmap shares its top level pgd entry with the kernel
 446                  * mapping. This can really only occur when we are running
 447                  * with 16k/4 levels, so we can simply reuse the pud level
 448                  * entry instead.
 449                  */
 450                 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
 451                 set_pud(pud_set_fixmap_offset(pgd, FIXADDR_START),
 452                         __pud(__pa(bm_pmd) | PUD_TYPE_TABLE));
 453                 pud_clear_fixmap();
 454         } else {
 455                 BUG();
 456         }
 457
 458         kasan_copy_shadow(pgd);
 459 }
 460
 461 /*
 462  * paging_init() sets up the page tables, initialises the zone memory
 463  * maps and sets up the zero page.
 464  */
 465 void __init paging_init(void)
 466 {
 467         phys_addr_t pgd_phys = early_pgtable_alloc();
 468         pgd_t *pgd = pgd_set_fixmap(pgd_phys);
 469
 470         map_kernel(pgd);
 471         map_mem(pgd);
 472
 473         /*
 474          * We want to reuse the original swapper_pg_dir so we don't have to
 475          * communicate the new address to non-coherent secondaries in
 476          * secondary_entry, and so cpu_switch_mm can generate the address with
 477          * adrp+add rather than a load from some global variable.
 478          *
 479          * To do this we need to go via a temporary pgd.
 480          */
 481         cpu_replace_ttbr1(__va(pgd_phys));
 482         memcpy(swapper_pg_dir, pgd, PAGE_SIZE);
 483         cpu_replace_ttbr1(swapper_pg_dir);
 484
 485         pgd_clear_fixmap();
 486         memblock_free(pgd_phys, PAGE_SIZE);
 487
 488         /*
 489          * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
 490          * allocated with it.
 491          */
 492         memblock_free(__pa(swapper_pg_dir) + PAGE_SIZE,
 493                       SWAPPER_DIR_SIZE - PAGE_SIZE);
 494 }
 495
 496 /*
 497  * Check whether a kernel address is valid (derived from arch/x86/).
 498  */
 499 int kern_addr_valid(unsigned long addr)
 500 {
 501         pgd_t *pgd;
 502         pud_t *pud;
 503         pmd_t *pmd;
 504         pte_t *pte;
 505
 506         if ((((long)addr) >> VA_BITS) != -1UL)
 507                 return 0;
 508
 509         pgd = pgd_offset_k(addr);
 510         if (pgd_none(*pgd))
 511                 return 0;
 512
 513         pud = pud_offset(pgd, addr);
 514         if (pud_none(*pud))
 515                 return 0;
 516
 517         if (pud_sect(*pud))
 518                 return pfn_valid(pud_pfn(*pud));
 519
 520         pmd = pmd_offset(pud, addr);
 521         if (pmd_none(*pmd))
 522                 return 0;
 523
 524         if (pmd_sect(*pmd))
 525                 return pfn_valid(pmd_pfn(*pmd));
 526
 527         pte = pte_offset_kernel(pmd, addr);
 528         if (pte_none(*pte))
 529                 return 0;
 530
 531         return pfn_valid(pte_pfn(*pte));
 532 }
 533 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 534 #if !ARM64_SWAPPER_USES_SECTION_MAPS
 535 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 536 {
 537         return vmemmap_populate_basepages(start, end, node);
 538 }
 539 #else   /* !ARM64_SWAPPER_USES_SECTION_MAPS */
 540 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 541 {
 542         unsigned long addr = start;
 543         unsigned long next;
 544         pgd_t *pgd;
 545         pud_t *pud;
 546         pmd_t *pmd;
 547
 548         do {
 549                 next = pmd_addr_end(addr, end);
 550
 551                 pgd = vmemmap_pgd_populate(addr, node);
 552                 if (!pgd)
 553                         return -ENOMEM;
 554
 555                 pud = vmemmap_pud_populate(pgd, addr, node);
 556                 if (!pud)
 557                         return -ENOMEM;
 558
 559                 pmd = pmd_offset(pud, addr);
 560                 if (pmd_none(*pmd)) {
 561                         void *p = NULL;
 562
 563                         p = vmemmap_alloc_block_buf(PMD_SIZE, node);
 564                         if (!p)
 565                                 return -ENOMEM;
 566
 567                         set_pmd(pmd, __pmd(__pa(p) | PROT_SECT_NORMAL));
 568                 } else
 569                         vmemmap_verify((pte_t *)pmd, node, addr, next);
 570         } while (addr = next, addr != end);
 571
 572         return 0;
 573 }
 574 #endif  /* CONFIG_ARM64_64K_PAGES */
 575 void vmemmap_free(unsigned long start, unsigned long end)
 576 {
 577 }
 578 #endif  /* CONFIG_SPARSEMEM_VMEMMAP */
 579
 580 static inline pud_t * fixmap_pud(unsigned long addr)
 581 {
 582         pgd_t *pgd = pgd_offset_k(addr);
 583
 584         BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));
 585
 586         return pud_offset_kimg(pgd, addr);
 587 }
 588
 589 static inline pmd_t * fixmap_pmd(unsigned long addr)
 590 {
 591         pud_t *pud = fixmap_pud(addr);
 592
 593         BUG_ON(pud_none(*pud) || pud_bad(*pud));
 594
 595         return pmd_offset_kimg(pud, addr);
 596 }
 597
 598 static inline pte_t * fixmap_pte(unsigned long addr)
 599 {
 600         return &bm_pte[pte_index(addr)];
 601 }
 602
 603 void __init early_fixmap_init(void)
 604 {
 605         pgd_t *pgd;
 606         pud_t *pud;
 607         pmd_t *pmd;
 608         unsigned long addr = FIXADDR_START;
 609
 610         pgd = pgd_offset_k(addr);
 611         if (CONFIG_PGTABLE_LEVELS > 3 &&
 612             !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa(bm_pud))) {
 613                 /*
 614                  * We only end up here if the kernel mapping and the fixmap
 615                  * share the top level pgd entry, which should only happen on
 616                  * 16k/4 levels configurations.
 617                  */
 618                 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
 619                 pud = pud_offset_kimg(pgd, addr);
 620         } else {
 621                 pgd_populate(&init_mm, pgd, bm_pud);
 622                 pud = fixmap_pud(addr);
 623         }
 624         pud_populate(&init_mm, pud, bm_pmd);
 625         pmd = fixmap_pmd(addr);
 626         pmd_populate_kernel(&init_mm, pmd, bm_pte);
 627
 628         /*
 629          * The boot-ioremap range spans multiple pmds, for which
 630          * we are not prepared:
 631          */
 632         BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
 633                      != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
 634
 635         if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)))
 636              || pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) {
 637                 WARN_ON(1);
 638                 pr_warn("pmd %p != %p, %p\n",
 639                         pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)),
 640                         fixmap_pmd(fix_to_virt(FIX_BTMAP_END)));
 641                 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
 642                         fix_to_virt(FIX_BTMAP_BEGIN));
 643                 pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
 644                         fix_to_virt(FIX_BTMAP_END));
 645
 646                 pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
 647                 pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
 648         }
 649 }
 650
 651 void __set_fixmap(enum fixed_addresses idx,
 652                                phys_addr_t phys, pgprot_t flags)
 653 {
 654         unsigned long addr = __fix_to_virt(idx);
 655         pte_t *pte;
 656
 657         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 658
 659         pte = fixmap_pte(addr);
 660
 661         if (pgprot_val(flags)) {
 662                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 663         } else {
 664                 pte_clear(&init_mm, addr, pte);
 665                 flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
 666         }
 667 }
 668
 669 void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
 670 {
 671         const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
 672         int offset;
 673         void *dt_virt;
 674
 675         /*
 676          * Check whether the physical FDT address is set and meets the minimum
 677          * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
 678          * at least 8 bytes so that we can always access the magic and size
 679          * fields of the FDT header after mapping the first chunk, double check
 680          * here if that is indeed the case.
 681          */
 682         BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
 683         if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
 684                 return NULL;
 685
 686         /*
 687          * Make sure that the FDT region can be mapped without the need to
 688          * allocate additional translation table pages, so that it is safe
 689          * to call create_mapping_noalloc() this early.
 690          *
 691          * On 64k pages, the FDT will be mapped using PTEs, so we need to
 692          * be in the same PMD as the rest of the fixmap.
 693          * On 4k pages, we'll use section mappings for the FDT so we only
 694          * have to be in the same PUD.
 695          */
 696         BUILD_BUG_ON(dt_virt_base % SZ_2M);
 697
 698         BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT !=
 699                      __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT);
 700
 701         offset = dt_phys % SWAPPER_BLOCK_SIZE;
 702         dt_virt = (void *)dt_virt_base + offset;
 703
 704         /* map the first chunk so we can read the size from the header */
 705         create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE),
 706                         dt_virt_base, SWAPPER_BLOCK_SIZE, prot);
 707
 708         if (fdt_magic(dt_virt) != FDT_MAGIC)
 709                 return NULL;
 710
 711         *size = fdt_totalsize(dt_virt);
 712         if (*size > MAX_FDT_SIZE)
 713                 return NULL;
 714
 715         if (offset + *size > SWAPPER_BLOCK_SIZE)
 716                 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base,
 717                                round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot);
 718
 719         return dt_virt;
 720 }
 721
 722 void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
 723 {
 724         void *dt_virt;
 725         int size;
 726
 727         dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
 728         if (!dt_virt)
 729                 return NULL;
 730
 731         memblock_reserve(dt_phys, size);
 732         return dt_virt;
 733 }
 734
 735 int __init arch_ioremap_pud_supported(void)
 736 {
 737         /* only 4k granule supports level 1 block mappings */
 738         return IS_ENABLED(CONFIG_ARM64_4K_PAGES);
 739 }
 740
 741 int __init arch_ioremap_pmd_supported(void)
 742 {
 743         return 1;
 744 }
 745
 746 int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)
 747 {
 748         BUG_ON(phys & ~PUD_MASK);
 749         set_pud(pud, __pud(phys | PUD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
 750         return 1;
 751 }
 752
 753 int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)
 754 {
 755         BUG_ON(phys & ~PMD_MASK);
 756         set_pmd(pmd, __pmd(phys | PMD_TYPE_SECT | pgprot_val(mk_sect_prot(prot))));
 757         return 1;
 758 }
 759
 760 int pud_clear_huge(pud_t *pud)
 761 {
 762         if (!pud_sect(*pud))
 763                 return 0;
 764         pud_clear(pud);
 765         return 1;
 766 }
 767
 768 int pmd_clear_huge(pmd_t *pmd)
 769 {
 770         if (!pmd_sect(*pmd))
 771                 return 0;
 772         pmd_clear(pmd);
 773         return 1;
 774 }