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/ioport.h> 26 #include <linux/kexec.h> 27 #include <linux/libfdt.h> 28 #include <linux/mman.h> 29 #include <linux/nodemask.h> 30 #include <linux/memblock.h> 31 #include <linux/fs.h> 32 #include <linux/io.h> 33 #include <linux/mm.h> 34 #include <linux/vmalloc.h> 35 36 #include <asm/barrier.h> 37 #include <asm/cputype.h> 38 #include <asm/fixmap.h> 39 #include <asm/kasan.h> 40 #include <asm/kernel-pgtable.h> 41 #include <asm/sections.h> 42 #include <asm/setup.h> 43 #include <asm/sizes.h> 44 #include <asm/tlb.h> 45 #include <asm/memblock.h> 46 #include <asm/mmu_context.h> 47 #include <asm/ptdump.h> 48 49 #define NO_BLOCK_MAPPINGS BIT(0) 50 #define NO_CONT_MAPPINGS BIT(1) 51 52 u64 idmap_t0sz = TCR_T0SZ(VA_BITS); 53 54 u64 kimage_voffset __ro_after_init; 55 EXPORT_SYMBOL(kimage_voffset); 56 57 /* 58 * Empty_zero_page is a special page that is used for zero-initialized data 59 * and COW. 60 */ 61 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; 62 EXPORT_SYMBOL(empty_zero_page); 63 64 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; 65 static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused; 66 static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused; 67 68 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 69 unsigned long size, pgprot_t vma_prot) 70 { 71 if (!pfn_valid(pfn)) 72 return pgprot_noncached(vma_prot); 73 else if (file->f_flags & O_SYNC) 74 return pgprot_writecombine(vma_prot); 75 return vma_prot; 76 } 77 EXPORT_SYMBOL(phys_mem_access_prot); 78 79 static phys_addr_t __init early_pgtable_alloc(void) 80 { 81 phys_addr_t phys; 82 void *ptr; 83 84 phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 85 86 /* 87 * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE 88 * slot will be free, so we can (ab)use the FIX_PTE slot to initialise 89 * any level of table. 90 */ 91 ptr = pte_set_fixmap(phys); 92 93 memset(ptr, 0, PAGE_SIZE); 94 95 /* 96 * Implicit barriers also ensure the zeroed page is visible to the page 97 * table walker 98 */ 99 pte_clear_fixmap(); 100 101 return phys; 102 } 103 104 static bool pgattr_change_is_safe(u64 old, u64 new) 105 { 106 /* 107 * The following mapping attributes may be updated in live 108 * kernel mappings without the need for break-before-make. 109 */ 110 static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE; 111 112 /* creating or taking down mappings is always safe */ 113 if (old == 0 || new == 0) 114 return true; 115 116 /* live contiguous mappings may not be manipulated at all */ 117 if ((old | new) & PTE_CONT) 118 return false; 119 120 return ((old ^ new) & ~mask) == 0; 121 } 122 123 static void init_pte(pmd_t *pmd, unsigned long addr, unsigned long end, 124 phys_addr_t phys, pgprot_t prot) 125 { 126 pte_t *pte; 127 128 pte = pte_set_fixmap_offset(pmd, addr); 129 do { 130 pte_t old_pte = *pte; 131 132 set_pte(pte, pfn_pte(__phys_to_pfn(phys), prot)); 133 134 /* 135 * After the PTE entry has been populated once, we 136 * only allow updates to the permission attributes. 137 */ 138 BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), pte_val(*pte))); 139 140 phys += PAGE_SIZE; 141 } while (pte++, addr += PAGE_SIZE, addr != end); 142 143 pte_clear_fixmap(); 144 } 145 146 static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr, 147 unsigned long end, phys_addr_t phys, 148 pgprot_t prot, 149 phys_addr_t (*pgtable_alloc)(void), 150 int flags) 151 { 152 unsigned long next; 153 154 BUG_ON(pmd_sect(*pmd)); 155 if (pmd_none(*pmd)) { 156 phys_addr_t pte_phys; 157 BUG_ON(!pgtable_alloc); 158 pte_phys = pgtable_alloc(); 159 __pmd_populate(pmd, pte_phys, PMD_TYPE_TABLE); 160 } 161 BUG_ON(pmd_bad(*pmd)); 162 163 do { 164 pgprot_t __prot = prot; 165 166 next = pte_cont_addr_end(addr, end); 167 168 /* use a contiguous mapping if the range is suitably aligned */ 169 if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) && 170 (flags & NO_CONT_MAPPINGS) == 0) 171 __prot = __pgprot(pgprot_val(prot) | PTE_CONT); 172 173 init_pte(pmd, addr, next, phys, __prot); 174 175 phys += next - addr; 176 } while (addr = next, addr != end); 177 } 178 179 static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, 180 phys_addr_t phys, pgprot_t prot, 181 phys_addr_t (*pgtable_alloc)(void), int flags) 182 { 183 unsigned long next; 184 pmd_t *pmd; 185 186 pmd = pmd_set_fixmap_offset(pud, addr); 187 do { 188 pmd_t old_pmd = *pmd; 189 190 next = pmd_addr_end(addr, end); 191 192 /* try section mapping first */ 193 if (((addr | next | phys) & ~SECTION_MASK) == 0 && 194 (flags & NO_BLOCK_MAPPINGS) == 0) { 195 pmd_set_huge(pmd, phys, prot); 196 197 /* 198 * After the PMD entry has been populated once, we 199 * only allow updates to the permission attributes. 200 */ 201 BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd), 202 pmd_val(*pmd))); 203 } else { 204 alloc_init_cont_pte(pmd, addr, next, phys, prot, 205 pgtable_alloc, flags); 206 207 BUG_ON(pmd_val(old_pmd) != 0 && 208 pmd_val(old_pmd) != pmd_val(*pmd)); 209 } 210 phys += next - addr; 211 } while (pmd++, addr = next, addr != end); 212 213 pmd_clear_fixmap(); 214 } 215 216 static void alloc_init_cont_pmd(pud_t *pud, unsigned long addr, 217 unsigned long end, phys_addr_t phys, 218 pgprot_t prot, 219 phys_addr_t (*pgtable_alloc)(void), int flags) 220 { 221 unsigned long next; 222 223 /* 224 * Check for initial section mappings in the pgd/pud. 225 */ 226 BUG_ON(pud_sect(*pud)); 227 if (pud_none(*pud)) { 228 phys_addr_t pmd_phys; 229 BUG_ON(!pgtable_alloc); 230 pmd_phys = pgtable_alloc(); 231 __pud_populate(pud, pmd_phys, PUD_TYPE_TABLE); 232 } 233 BUG_ON(pud_bad(*pud)); 234 235 do { 236 pgprot_t __prot = prot; 237 238 next = pmd_cont_addr_end(addr, end); 239 240 /* use a contiguous mapping if the range is suitably aligned */ 241 if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) && 242 (flags & NO_CONT_MAPPINGS) == 0) 243 __prot = __pgprot(pgprot_val(prot) | PTE_CONT); 244 245 init_pmd(pud, addr, next, phys, __prot, pgtable_alloc, flags); 246 247 phys += next - addr; 248 } while (addr = next, addr != end); 249 } 250 251 static inline bool use_1G_block(unsigned long addr, unsigned long next, 252 unsigned long phys) 253 { 254 if (PAGE_SHIFT != 12) 255 return false; 256 257 if (((addr | next | phys) & ~PUD_MASK) != 0) 258 return false; 259 260 return true; 261 } 262 263 static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end, 264 phys_addr_t phys, pgprot_t prot, 265 phys_addr_t (*pgtable_alloc)(void), 266 int flags) 267 { 268 pud_t *pud; 269 unsigned long next; 270 271 if (pgd_none(*pgd)) { 272 phys_addr_t pud_phys; 273 BUG_ON(!pgtable_alloc); 274 pud_phys = pgtable_alloc(); 275 __pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE); 276 } 277 BUG_ON(pgd_bad(*pgd)); 278 279 pud = pud_set_fixmap_offset(pgd, addr); 280 do { 281 pud_t old_pud = *pud; 282 283 next = pud_addr_end(addr, end); 284 285 /* 286 * For 4K granule only, attempt to put down a 1GB block 287 */ 288 if (use_1G_block(addr, next, phys) && 289 (flags & NO_BLOCK_MAPPINGS) == 0) { 290 pud_set_huge(pud, phys, prot); 291 292 /* 293 * After the PUD entry has been populated once, we 294 * only allow updates to the permission attributes. 295 */ 296 BUG_ON(!pgattr_change_is_safe(pud_val(old_pud), 297 pud_val(*pud))); 298 } else { 299 alloc_init_cont_pmd(pud, addr, next, phys, prot, 300 pgtable_alloc, flags); 301 302 BUG_ON(pud_val(old_pud) != 0 && 303 pud_val(old_pud) != pud_val(*pud)); 304 } 305 phys += next - addr; 306 } while (pud++, addr = next, addr != end); 307 308 pud_clear_fixmap(); 309 } 310 311 static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, 312 unsigned long virt, phys_addr_t size, 313 pgprot_t prot, 314 phys_addr_t (*pgtable_alloc)(void), 315 int flags) 316 { 317 unsigned long addr, length, end, next; 318 pgd_t *pgd = pgd_offset_raw(pgdir, virt); 319 320 /* 321 * If the virtual and physical address don't have the same offset 322 * within a page, we cannot map the region as the caller expects. 323 */ 324 if (WARN_ON((phys ^ virt) & ~PAGE_MASK)) 325 return; 326 327 phys &= PAGE_MASK; 328 addr = virt & PAGE_MASK; 329 length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); 330 331 end = addr + length; 332 do { 333 next = pgd_addr_end(addr, end); 334 alloc_init_pud(pgd, addr, next, phys, prot, pgtable_alloc, 335 flags); 336 phys += next - addr; 337 } while (pgd++, addr = next, addr != end); 338 } 339 340 static phys_addr_t pgd_pgtable_alloc(void) 341 { 342 void *ptr = (void *)__get_free_page(PGALLOC_GFP); 343 if (!ptr || !pgtable_page_ctor(virt_to_page(ptr))) 344 BUG(); 345 346 /* Ensure the zeroed page is visible to the page table walker */ 347 dsb(ishst); 348 return __pa(ptr); 349 } 350 351 /* 352 * This function can only be used to modify existing table entries, 353 * without allocating new levels of table. Note that this permits the 354 * creation of new section or page entries. 355 */ 356 static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt, 357 phys_addr_t size, pgprot_t prot) 358 { 359 if (virt < VMALLOC_START) { 360 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", 361 &phys, virt); 362 return; 363 } 364 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, 365 NO_CONT_MAPPINGS); 366 } 367 368 void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, 369 unsigned long virt, phys_addr_t size, 370 pgprot_t prot, bool page_mappings_only) 371 { 372 int flags = 0; 373 374 BUG_ON(mm == &init_mm); 375 376 if (page_mappings_only) 377 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; 378 379 __create_pgd_mapping(mm->pgd, phys, virt, size, prot, 380 pgd_pgtable_alloc, flags); 381 } 382 383 static void update_mapping_prot(phys_addr_t phys, unsigned long virt, 384 phys_addr_t size, pgprot_t prot) 385 { 386 if (virt < VMALLOC_START) { 387 pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n", 388 &phys, virt); 389 return; 390 } 391 392 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, 393 NO_CONT_MAPPINGS); 394 395 /* flush the TLBs after updating live kernel mappings */ 396 flush_tlb_kernel_range(virt, virt + size); 397 } 398 399 static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, 400 phys_addr_t end, pgprot_t prot, int flags) 401 { 402 __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start, 403 prot, early_pgtable_alloc, flags); 404 } 405 406 void __init mark_linear_text_alias_ro(void) 407 { 408 /* 409 * Remove the write permissions from the linear alias of .text/.rodata 410 */ 411 update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text), 412 (unsigned long)__init_begin - (unsigned long)_text, 413 PAGE_KERNEL_RO); 414 } 415 416 static void __init map_mem(pgd_t *pgd) 417 { 418 phys_addr_t kernel_start = __pa_symbol(_text); 419 phys_addr_t kernel_end = __pa_symbol(__init_begin); 420 struct memblock_region *reg; 421 int flags = 0; 422 423 if (debug_pagealloc_enabled()) 424 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; 425 426 /* 427 * Take care not to create a writable alias for the 428 * read-only text and rodata sections of the kernel image. 429 * So temporarily mark them as NOMAP to skip mappings in 430 * the following for-loop 431 */ 432 memblock_mark_nomap(kernel_start, kernel_end - kernel_start); 433 #ifdef CONFIG_KEXEC_CORE 434 if (crashk_res.end) 435 memblock_mark_nomap(crashk_res.start, 436 resource_size(&crashk_res)); 437 #endif 438 439 /* map all the memory banks */ 440 for_each_memblock(memory, reg) { 441 phys_addr_t start = reg->base; 442 phys_addr_t end = start + reg->size; 443 444 if (start >= end) 445 break; 446 if (memblock_is_nomap(reg)) 447 continue; 448 449 __map_memblock(pgd, start, end, PAGE_KERNEL, flags); 450 } 451 452 /* 453 * Map the linear alias of the [_text, __init_begin) interval 454 * as non-executable now, and remove the write permission in 455 * mark_linear_text_alias_ro() below (which will be called after 456 * alternative patching has completed). This makes the contents 457 * of the region accessible to subsystems such as hibernate, 458 * but protects it from inadvertent modification or execution. 459 * Note that contiguous mappings cannot be remapped in this way, 460 * so we should avoid them here. 461 */ 462 __map_memblock(pgd, kernel_start, kernel_end, 463 PAGE_KERNEL, NO_CONT_MAPPINGS); 464 memblock_clear_nomap(kernel_start, kernel_end - kernel_start); 465 466 #ifdef CONFIG_KEXEC_CORE 467 /* 468 * Use page-level mappings here so that we can shrink the region 469 * in page granularity and put back unused memory to buddy system 470 * through /sys/kernel/kexec_crash_size interface. 471 */ 472 if (crashk_res.end) { 473 __map_memblock(pgd, crashk_res.start, crashk_res.end + 1, 474 PAGE_KERNEL, 475 NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); 476 memblock_clear_nomap(crashk_res.start, 477 resource_size(&crashk_res)); 478 } 479 #endif 480 } 481 482 void mark_rodata_ro(void) 483 { 484 unsigned long section_size; 485 486 /* 487 * mark .rodata as read only. Use __init_begin rather than __end_rodata 488 * to cover NOTES and EXCEPTION_TABLE. 489 */ 490 section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata; 491 update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, 492 section_size, PAGE_KERNEL_RO); 493 494 debug_checkwx(); 495 } 496 497 static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end, 498 pgprot_t prot, struct vm_struct *vma, 499 int flags, unsigned long vm_flags) 500 { 501 phys_addr_t pa_start = __pa_symbol(va_start); 502 unsigned long size = va_end - va_start; 503 504 BUG_ON(!PAGE_ALIGNED(pa_start)); 505 BUG_ON(!PAGE_ALIGNED(size)); 506 507 __create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot, 508 early_pgtable_alloc, flags); 509 510 if (!(vm_flags & VM_NO_GUARD)) 511 size += PAGE_SIZE; 512 513 vma->addr = va_start; 514 vma->phys_addr = pa_start; 515 vma->size = size; 516 vma->flags = VM_MAP | vm_flags; 517 vma->caller = __builtin_return_address(0); 518 519 vm_area_add_early(vma); 520 } 521 522 static int __init parse_rodata(char *arg) 523 { 524 return strtobool(arg, &rodata_enabled); 525 } 526 early_param("rodata", parse_rodata); 527 528 /* 529 * Create fine-grained mappings for the kernel. 530 */ 531 static void __init map_kernel(pgd_t *pgd) 532 { 533 static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, 534 vmlinux_initdata, vmlinux_data; 535 536 /* 537 * External debuggers may need to write directly to the text 538 * mapping to install SW breakpoints. Allow this (only) when 539 * explicitly requested with rodata=off. 540 */ 541 pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; 542 543 /* 544 * Only rodata will be remapped with different permissions later on, 545 * all other segments are allowed to use contiguous mappings. 546 */ 547 map_kernel_segment(pgd, _text, _etext, text_prot, &vmlinux_text, 0, 548 VM_NO_GUARD); 549 map_kernel_segment(pgd, __start_rodata, __inittext_begin, PAGE_KERNEL, 550 &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD); 551 map_kernel_segment(pgd, __inittext_begin, __inittext_end, text_prot, 552 &vmlinux_inittext, 0, VM_NO_GUARD); 553 map_kernel_segment(pgd, __initdata_begin, __initdata_end, PAGE_KERNEL, 554 &vmlinux_initdata, 0, VM_NO_GUARD); 555 map_kernel_segment(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0); 556 557 if (!pgd_val(*pgd_offset_raw(pgd, FIXADDR_START))) { 558 /* 559 * The fixmap falls in a separate pgd to the kernel, and doesn't 560 * live in the carveout for the swapper_pg_dir. We can simply 561 * re-use the existing dir for the fixmap. 562 */ 563 set_pgd(pgd_offset_raw(pgd, FIXADDR_START), 564 *pgd_offset_k(FIXADDR_START)); 565 } else if (CONFIG_PGTABLE_LEVELS > 3) { 566 /* 567 * The fixmap shares its top level pgd entry with the kernel 568 * mapping. This can really only occur when we are running 569 * with 16k/4 levels, so we can simply reuse the pud level 570 * entry instead. 571 */ 572 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); 573 set_pud(pud_set_fixmap_offset(pgd, FIXADDR_START), 574 __pud(__pa_symbol(bm_pmd) | PUD_TYPE_TABLE)); 575 pud_clear_fixmap(); 576 } else { 577 BUG(); 578 } 579 580 kasan_copy_shadow(pgd); 581 } 582 583 /* 584 * paging_init() sets up the page tables, initialises the zone memory 585 * maps and sets up the zero page. 586 */ 587 void __init paging_init(void) 588 { 589 phys_addr_t pgd_phys = early_pgtable_alloc(); 590 pgd_t *pgd = pgd_set_fixmap(pgd_phys); 591 592 map_kernel(pgd); 593 map_mem(pgd); 594 595 /* 596 * We want to reuse the original swapper_pg_dir so we don't have to 597 * communicate the new address to non-coherent secondaries in 598 * secondary_entry, and so cpu_switch_mm can generate the address with 599 * adrp+add rather than a load from some global variable. 600 * 601 * To do this we need to go via a temporary pgd. 602 */ 603 cpu_replace_ttbr1(__va(pgd_phys)); 604 memcpy(swapper_pg_dir, pgd, PGD_SIZE); 605 cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); 606 607 pgd_clear_fixmap(); 608 memblock_free(pgd_phys, PAGE_SIZE); 609 610 /* 611 * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd 612 * allocated with it. 613 */ 614 memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE, 615 SWAPPER_DIR_SIZE - PAGE_SIZE); 616 } 617 618 /* 619 * Check whether a kernel address is valid (derived from arch/x86/). 620 */ 621 int kern_addr_valid(unsigned long addr) 622 { 623 pgd_t *pgd; 624 pud_t *pud; 625 pmd_t *pmd; 626 pte_t *pte; 627 628 if ((((long)addr) >> VA_BITS) != -1UL) 629 return 0; 630 631 pgd = pgd_offset_k(addr); 632 if (pgd_none(*pgd)) 633 return 0; 634 635 pud = pud_offset(pgd, addr); 636 if (pud_none(*pud)) 637 return 0; 638 639 if (pud_sect(*pud)) 640 return pfn_valid(pud_pfn(*pud)); 641 642 pmd = pmd_offset(pud, addr); 643 if (pmd_none(*pmd)) 644 return 0; 645 646 if (pmd_sect(*pmd)) 647 return pfn_valid(pmd_pfn(*pmd)); 648 649 pte = pte_offset_kernel(pmd, addr); 650 if (pte_none(*pte)) 651 return 0; 652 653 return pfn_valid(pte_pfn(*pte)); 654 } 655 #ifdef CONFIG_SPARSEMEM_VMEMMAP 656 #if !ARM64_SWAPPER_USES_SECTION_MAPS 657 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 658 { 659 return vmemmap_populate_basepages(start, end, node); 660 } 661 #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ 662 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 663 { 664 unsigned long addr = start; 665 unsigned long next; 666 pgd_t *pgd; 667 pud_t *pud; 668 pmd_t *pmd; 669 670 do { 671 next = pmd_addr_end(addr, end); 672 673 pgd = vmemmap_pgd_populate(addr, node); 674 if (!pgd) 675 return -ENOMEM; 676 677 pud = vmemmap_pud_populate(pgd, addr, node); 678 if (!pud) 679 return -ENOMEM; 680 681 pmd = pmd_offset(pud, addr); 682 if (pmd_none(*pmd)) { 683 void *p = NULL; 684 685 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 686 if (!p) 687 return -ENOMEM; 688 689 set_pmd(pmd, __pmd(__pa(p) | PROT_SECT_NORMAL)); 690 } else 691 vmemmap_verify((pte_t *)pmd, node, addr, next); 692 } while (addr = next, addr != end); 693 694 return 0; 695 } 696 #endif /* CONFIG_ARM64_64K_PAGES */ 697 void vmemmap_free(unsigned long start, unsigned long end) 698 { 699 } 700 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 701 702 static inline pud_t * fixmap_pud(unsigned long addr) 703 { 704 pgd_t *pgd = pgd_offset_k(addr); 705 706 BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); 707 708 return pud_offset_kimg(pgd, addr); 709 } 710 711 static inline pmd_t * fixmap_pmd(unsigned long addr) 712 { 713 pud_t *pud = fixmap_pud(addr); 714 715 BUG_ON(pud_none(*pud) || pud_bad(*pud)); 716 717 return pmd_offset_kimg(pud, addr); 718 } 719 720 static inline pte_t * fixmap_pte(unsigned long addr) 721 { 722 return &bm_pte[pte_index(addr)]; 723 } 724 725 /* 726 * The p*d_populate functions call virt_to_phys implicitly so they can't be used 727 * directly on kernel symbols (bm_p*d). This function is called too early to use 728 * lm_alias so __p*d_populate functions must be used to populate with the 729 * physical address from __pa_symbol. 730 */ 731 void __init early_fixmap_init(void) 732 { 733 pgd_t *pgd; 734 pud_t *pud; 735 pmd_t *pmd; 736 unsigned long addr = FIXADDR_START; 737 738 pgd = pgd_offset_k(addr); 739 if (CONFIG_PGTABLE_LEVELS > 3 && 740 !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa_symbol(bm_pud))) { 741 /* 742 * We only end up here if the kernel mapping and the fixmap 743 * share the top level pgd entry, which should only happen on 744 * 16k/4 levels configurations. 745 */ 746 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); 747 pud = pud_offset_kimg(pgd, addr); 748 } else { 749 if (pgd_none(*pgd)) 750 __pgd_populate(pgd, __pa_symbol(bm_pud), PUD_TYPE_TABLE); 751 pud = fixmap_pud(addr); 752 } 753 if (pud_none(*pud)) 754 __pud_populate(pud, __pa_symbol(bm_pmd), PMD_TYPE_TABLE); 755 pmd = fixmap_pmd(addr); 756 __pmd_populate(pmd, __pa_symbol(bm_pte), PMD_TYPE_TABLE); 757 758 /* 759 * The boot-ioremap range spans multiple pmds, for which 760 * we are not prepared: 761 */ 762 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 763 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 764 765 if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN))) 766 || pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) { 767 WARN_ON(1); 768 pr_warn("pmd %p != %p, %p\n", 769 pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)), 770 fixmap_pmd(fix_to_virt(FIX_BTMAP_END))); 771 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 772 fix_to_virt(FIX_BTMAP_BEGIN)); 773 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 774 fix_to_virt(FIX_BTMAP_END)); 775 776 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 777 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); 778 } 779 } 780 781 /* 782 * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we 783 * ever need to use IPIs for TLB broadcasting, then we're in trouble here. 784 */ 785 void __set_fixmap(enum fixed_addresses idx, 786 phys_addr_t phys, pgprot_t flags) 787 { 788 unsigned long addr = __fix_to_virt(idx); 789 pte_t *pte; 790 791 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 792 793 pte = fixmap_pte(addr); 794 795 if (pgprot_val(flags)) { 796 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); 797 } else { 798 pte_clear(&init_mm, addr, pte); 799 flush_tlb_kernel_range(addr, addr+PAGE_SIZE); 800 } 801 } 802 803 void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) 804 { 805 const u64 dt_virt_base = __fix_to_virt(FIX_FDT); 806 int offset; 807 void *dt_virt; 808 809 /* 810 * Check whether the physical FDT address is set and meets the minimum 811 * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be 812 * at least 8 bytes so that we can always access the magic and size 813 * fields of the FDT header after mapping the first chunk, double check 814 * here if that is indeed the case. 815 */ 816 BUILD_BUG_ON(MIN_FDT_ALIGN < 8); 817 if (!dt_phys || dt_phys % MIN_FDT_ALIGN) 818 return NULL; 819 820 /* 821 * Make sure that the FDT region can be mapped without the need to 822 * allocate additional translation table pages, so that it is safe 823 * to call create_mapping_noalloc() this early. 824 * 825 * On 64k pages, the FDT will be mapped using PTEs, so we need to 826 * be in the same PMD as the rest of the fixmap. 827 * On 4k pages, we'll use section mappings for the FDT so we only 828 * have to be in the same PUD. 829 */ 830 BUILD_BUG_ON(dt_virt_base % SZ_2M); 831 832 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT != 833 __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT); 834 835 offset = dt_phys % SWAPPER_BLOCK_SIZE; 836 dt_virt = (void *)dt_virt_base + offset; 837 838 /* map the first chunk so we can read the size from the header */ 839 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), 840 dt_virt_base, SWAPPER_BLOCK_SIZE, prot); 841 842 if (fdt_magic(dt_virt) != FDT_MAGIC) 843 return NULL; 844 845 *size = fdt_totalsize(dt_virt); 846 if (*size > MAX_FDT_SIZE) 847 return NULL; 848 849 if (offset + *size > SWAPPER_BLOCK_SIZE) 850 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base, 851 round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot); 852 853 return dt_virt; 854 } 855 856 void *__init fixmap_remap_fdt(phys_addr_t dt_phys) 857 { 858 void *dt_virt; 859 int size; 860 861 dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); 862 if (!dt_virt) 863 return NULL; 864 865 memblock_reserve(dt_phys, size); 866 return dt_virt; 867 } 868 869 int __init arch_ioremap_pud_supported(void) 870 { 871 /* only 4k granule supports level 1 block mappings */ 872 return IS_ENABLED(CONFIG_ARM64_4K_PAGES); 873 } 874 875 int __init arch_ioremap_pmd_supported(void) 876 { 877 return 1; 878 } 879 880 int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot) 881 { 882 BUG_ON(phys & ~PUD_MASK); 883 set_pud(pud, __pud(phys | PUD_TYPE_SECT | pgprot_val(mk_sect_prot(prot)))); 884 return 1; 885 } 886 887 int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot) 888 { 889 BUG_ON(phys & ~PMD_MASK); 890 set_pmd(pmd, __pmd(phys | PMD_TYPE_SECT | pgprot_val(mk_sect_prot(prot)))); 891 return 1; 892 } 893 894 int pud_clear_huge(pud_t *pud) 895 { 896 if (!pud_sect(*pud)) 897 return 0; 898 pud_clear(pud); 899 return 1; 900 } 901 902 int pmd_clear_huge(pmd_t *pmd) 903 { 904 if (!pmd_sect(*pmd)) 905 return 0; 906 pmd_clear(pmd); 907 return 1; 908 } 909