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 u64 idmap_ptrs_per_pgd = PTRS_PER_PGD; 54 55 u64 kimage_voffset __ro_after_init; 56 EXPORT_SYMBOL(kimage_voffset); 57 58 /* 59 * Empty_zero_page is a special page that is used for zero-initialized data 60 * and COW. 61 */ 62 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; 63 EXPORT_SYMBOL(empty_zero_page); 64 65 static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; 66 static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused; 67 static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused; 68 69 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 70 unsigned long size, pgprot_t vma_prot) 71 { 72 if (!pfn_valid(pfn)) 73 return pgprot_noncached(vma_prot); 74 else if (file->f_flags & O_SYNC) 75 return pgprot_writecombine(vma_prot); 76 return vma_prot; 77 } 78 EXPORT_SYMBOL(phys_mem_access_prot); 79 80 static phys_addr_t __init early_pgtable_alloc(void) 81 { 82 phys_addr_t phys; 83 void *ptr; 84 85 phys = memblock_alloc(PAGE_SIZE, PAGE_SIZE); 86 87 /* 88 * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE 89 * slot will be free, so we can (ab)use the FIX_PTE slot to initialise 90 * any level of table. 91 */ 92 ptr = pte_set_fixmap(phys); 93 94 memset(ptr, 0, PAGE_SIZE); 95 96 /* 97 * Implicit barriers also ensure the zeroed page is visible to the page 98 * table walker 99 */ 100 pte_clear_fixmap(); 101 102 return phys; 103 } 104 105 static bool pgattr_change_is_safe(u64 old, u64 new) 106 { 107 /* 108 * The following mapping attributes may be updated in live 109 * kernel mappings without the need for break-before-make. 110 */ 111 static const pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE; 112 113 /* creating or taking down mappings is always safe */ 114 if (old == 0 || new == 0) 115 return true; 116 117 /* live contiguous mappings may not be manipulated at all */ 118 if ((old | new) & PTE_CONT) 119 return false; 120 121 return ((old ^ new) & ~mask) == 0; 122 } 123 124 static void init_pte(pmd_t *pmd, unsigned long addr, unsigned long end, 125 phys_addr_t phys, pgprot_t prot) 126 { 127 pte_t *pte; 128 129 pte = pte_set_fixmap_offset(pmd, addr); 130 do { 131 pte_t old_pte = *pte; 132 133 set_pte(pte, pfn_pte(__phys_to_pfn(phys), prot)); 134 135 /* 136 * After the PTE entry has been populated once, we 137 * only allow updates to the permission attributes. 138 */ 139 BUG_ON(!pgattr_change_is_safe(pte_val(old_pte), pte_val(*pte))); 140 141 phys += PAGE_SIZE; 142 } while (pte++, addr += PAGE_SIZE, addr != end); 143 144 pte_clear_fixmap(); 145 } 146 147 static void alloc_init_cont_pte(pmd_t *pmd, unsigned long addr, 148 unsigned long end, phys_addr_t phys, 149 pgprot_t prot, 150 phys_addr_t (*pgtable_alloc)(void), 151 int flags) 152 { 153 unsigned long next; 154 155 BUG_ON(pmd_sect(*pmd)); 156 if (pmd_none(*pmd)) { 157 phys_addr_t pte_phys; 158 BUG_ON(!pgtable_alloc); 159 pte_phys = pgtable_alloc(); 160 __pmd_populate(pmd, pte_phys, PMD_TYPE_TABLE); 161 } 162 BUG_ON(pmd_bad(*pmd)); 163 164 do { 165 pgprot_t __prot = prot; 166 167 next = pte_cont_addr_end(addr, end); 168 169 /* use a contiguous mapping if the range is suitably aligned */ 170 if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) && 171 (flags & NO_CONT_MAPPINGS) == 0) 172 __prot = __pgprot(pgprot_val(prot) | PTE_CONT); 173 174 init_pte(pmd, addr, next, phys, __prot); 175 176 phys += next - addr; 177 } while (addr = next, addr != end); 178 } 179 180 static void init_pmd(pud_t *pud, unsigned long addr, unsigned long end, 181 phys_addr_t phys, pgprot_t prot, 182 phys_addr_t (*pgtable_alloc)(void), int flags) 183 { 184 unsigned long next; 185 pmd_t *pmd; 186 187 pmd = pmd_set_fixmap_offset(pud, addr); 188 do { 189 pmd_t old_pmd = *pmd; 190 191 next = pmd_addr_end(addr, end); 192 193 /* try section mapping first */ 194 if (((addr | next | phys) & ~SECTION_MASK) == 0 && 195 (flags & NO_BLOCK_MAPPINGS) == 0) { 196 pmd_set_huge(pmd, phys, prot); 197 198 /* 199 * After the PMD entry has been populated once, we 200 * only allow updates to the permission attributes. 201 */ 202 BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd), 203 pmd_val(*pmd))); 204 } else { 205 alloc_init_cont_pte(pmd, addr, next, phys, prot, 206 pgtable_alloc, flags); 207 208 BUG_ON(pmd_val(old_pmd) != 0 && 209 pmd_val(old_pmd) != pmd_val(*pmd)); 210 } 211 phys += next - addr; 212 } while (pmd++, addr = next, addr != end); 213 214 pmd_clear_fixmap(); 215 } 216 217 static void alloc_init_cont_pmd(pud_t *pud, unsigned long addr, 218 unsigned long end, phys_addr_t phys, 219 pgprot_t prot, 220 phys_addr_t (*pgtable_alloc)(void), int flags) 221 { 222 unsigned long next; 223 224 /* 225 * Check for initial section mappings in the pgd/pud. 226 */ 227 BUG_ON(pud_sect(*pud)); 228 if (pud_none(*pud)) { 229 phys_addr_t pmd_phys; 230 BUG_ON(!pgtable_alloc); 231 pmd_phys = pgtable_alloc(); 232 __pud_populate(pud, pmd_phys, PUD_TYPE_TABLE); 233 } 234 BUG_ON(pud_bad(*pud)); 235 236 do { 237 pgprot_t __prot = prot; 238 239 next = pmd_cont_addr_end(addr, end); 240 241 /* use a contiguous mapping if the range is suitably aligned */ 242 if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) && 243 (flags & NO_CONT_MAPPINGS) == 0) 244 __prot = __pgprot(pgprot_val(prot) | PTE_CONT); 245 246 init_pmd(pud, addr, next, phys, __prot, pgtable_alloc, flags); 247 248 phys += next - addr; 249 } while (addr = next, addr != end); 250 } 251 252 static inline bool use_1G_block(unsigned long addr, unsigned long next, 253 unsigned long phys) 254 { 255 if (PAGE_SHIFT != 12) 256 return false; 257 258 if (((addr | next | phys) & ~PUD_MASK) != 0) 259 return false; 260 261 return true; 262 } 263 264 static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end, 265 phys_addr_t phys, pgprot_t prot, 266 phys_addr_t (*pgtable_alloc)(void), 267 int flags) 268 { 269 pud_t *pud; 270 unsigned long next; 271 272 if (pgd_none(*pgd)) { 273 phys_addr_t pud_phys; 274 BUG_ON(!pgtable_alloc); 275 pud_phys = pgtable_alloc(); 276 __pgd_populate(pgd, pud_phys, PUD_TYPE_TABLE); 277 } 278 BUG_ON(pgd_bad(*pgd)); 279 280 pud = pud_set_fixmap_offset(pgd, addr); 281 do { 282 pud_t old_pud = *pud; 283 284 next = pud_addr_end(addr, end); 285 286 /* 287 * For 4K granule only, attempt to put down a 1GB block 288 */ 289 if (use_1G_block(addr, next, phys) && 290 (flags & NO_BLOCK_MAPPINGS) == 0) { 291 pud_set_huge(pud, phys, prot); 292 293 /* 294 * After the PUD entry has been populated once, we 295 * only allow updates to the permission attributes. 296 */ 297 BUG_ON(!pgattr_change_is_safe(pud_val(old_pud), 298 pud_val(*pud))); 299 } else { 300 alloc_init_cont_pmd(pud, addr, next, phys, prot, 301 pgtable_alloc, flags); 302 303 BUG_ON(pud_val(old_pud) != 0 && 304 pud_val(old_pud) != pud_val(*pud)); 305 } 306 phys += next - addr; 307 } while (pud++, addr = next, addr != end); 308 309 pud_clear_fixmap(); 310 } 311 312 static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys, 313 unsigned long virt, phys_addr_t size, 314 pgprot_t prot, 315 phys_addr_t (*pgtable_alloc)(void), 316 int flags) 317 { 318 unsigned long addr, length, end, next; 319 pgd_t *pgd = pgd_offset_raw(pgdir, virt); 320 321 /* 322 * If the virtual and physical address don't have the same offset 323 * within a page, we cannot map the region as the caller expects. 324 */ 325 if (WARN_ON((phys ^ virt) & ~PAGE_MASK)) 326 return; 327 328 phys &= PAGE_MASK; 329 addr = virt & PAGE_MASK; 330 length = PAGE_ALIGN(size + (virt & ~PAGE_MASK)); 331 332 end = addr + length; 333 do { 334 next = pgd_addr_end(addr, end); 335 alloc_init_pud(pgd, addr, next, phys, prot, pgtable_alloc, 336 flags); 337 phys += next - addr; 338 } while (pgd++, addr = next, addr != end); 339 } 340 341 static phys_addr_t pgd_pgtable_alloc(void) 342 { 343 void *ptr = (void *)__get_free_page(PGALLOC_GFP); 344 if (!ptr || !pgtable_page_ctor(virt_to_page(ptr))) 345 BUG(); 346 347 /* Ensure the zeroed page is visible to the page table walker */ 348 dsb(ishst); 349 return __pa(ptr); 350 } 351 352 /* 353 * This function can only be used to modify existing table entries, 354 * without allocating new levels of table. Note that this permits the 355 * creation of new section or page entries. 356 */ 357 static void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt, 358 phys_addr_t size, pgprot_t prot) 359 { 360 if (virt < VMALLOC_START) { 361 pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n", 362 &phys, virt); 363 return; 364 } 365 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, 366 NO_CONT_MAPPINGS); 367 } 368 369 void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, 370 unsigned long virt, phys_addr_t size, 371 pgprot_t prot, bool page_mappings_only) 372 { 373 int flags = 0; 374 375 BUG_ON(mm == &init_mm); 376 377 if (page_mappings_only) 378 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; 379 380 __create_pgd_mapping(mm->pgd, phys, virt, size, prot, 381 pgd_pgtable_alloc, flags); 382 } 383 384 static void update_mapping_prot(phys_addr_t phys, unsigned long virt, 385 phys_addr_t size, pgprot_t prot) 386 { 387 if (virt < VMALLOC_START) { 388 pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n", 389 &phys, virt); 390 return; 391 } 392 393 __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, 394 NO_CONT_MAPPINGS); 395 396 /* flush the TLBs after updating live kernel mappings */ 397 flush_tlb_kernel_range(virt, virt + size); 398 } 399 400 static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, 401 phys_addr_t end, pgprot_t prot, int flags) 402 { 403 __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start, 404 prot, early_pgtable_alloc, flags); 405 } 406 407 void __init mark_linear_text_alias_ro(void) 408 { 409 /* 410 * Remove the write permissions from the linear alias of .text/.rodata 411 */ 412 update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text), 413 (unsigned long)__init_begin - (unsigned long)_text, 414 PAGE_KERNEL_RO); 415 } 416 417 static void __init map_mem(pgd_t *pgd) 418 { 419 phys_addr_t kernel_start = __pa_symbol(_text); 420 phys_addr_t kernel_end = __pa_symbol(__init_begin); 421 struct memblock_region *reg; 422 int flags = 0; 423 424 if (debug_pagealloc_enabled()) 425 flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; 426 427 /* 428 * Take care not to create a writable alias for the 429 * read-only text and rodata sections of the kernel image. 430 * So temporarily mark them as NOMAP to skip mappings in 431 * the following for-loop 432 */ 433 memblock_mark_nomap(kernel_start, kernel_end - kernel_start); 434 #ifdef CONFIG_KEXEC_CORE 435 if (crashk_res.end) 436 memblock_mark_nomap(crashk_res.start, 437 resource_size(&crashk_res)); 438 #endif 439 440 /* map all the memory banks */ 441 for_each_memblock(memory, reg) { 442 phys_addr_t start = reg->base; 443 phys_addr_t end = start + reg->size; 444 445 if (start >= end) 446 break; 447 if (memblock_is_nomap(reg)) 448 continue; 449 450 __map_memblock(pgd, start, end, PAGE_KERNEL, flags); 451 } 452 453 /* 454 * Map the linear alias of the [_text, __init_begin) interval 455 * as non-executable now, and remove the write permission in 456 * mark_linear_text_alias_ro() below (which will be called after 457 * alternative patching has completed). This makes the contents 458 * of the region accessible to subsystems such as hibernate, 459 * but protects it from inadvertent modification or execution. 460 * Note that contiguous mappings cannot be remapped in this way, 461 * so we should avoid them here. 462 */ 463 __map_memblock(pgd, kernel_start, kernel_end, 464 PAGE_KERNEL, NO_CONT_MAPPINGS); 465 memblock_clear_nomap(kernel_start, kernel_end - kernel_start); 466 467 #ifdef CONFIG_KEXEC_CORE 468 /* 469 * Use page-level mappings here so that we can shrink the region 470 * in page granularity and put back unused memory to buddy system 471 * through /sys/kernel/kexec_crash_size interface. 472 */ 473 if (crashk_res.end) { 474 __map_memblock(pgd, crashk_res.start, crashk_res.end + 1, 475 PAGE_KERNEL, 476 NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); 477 memblock_clear_nomap(crashk_res.start, 478 resource_size(&crashk_res)); 479 } 480 #endif 481 } 482 483 void mark_rodata_ro(void) 484 { 485 unsigned long section_size; 486 487 /* 488 * mark .rodata as read only. Use __init_begin rather than __end_rodata 489 * to cover NOTES and EXCEPTION_TABLE. 490 */ 491 section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata; 492 update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, 493 section_size, PAGE_KERNEL_RO); 494 495 debug_checkwx(); 496 } 497 498 static void __init map_kernel_segment(pgd_t *pgd, void *va_start, void *va_end, 499 pgprot_t prot, struct vm_struct *vma, 500 int flags, unsigned long vm_flags) 501 { 502 phys_addr_t pa_start = __pa_symbol(va_start); 503 unsigned long size = va_end - va_start; 504 505 BUG_ON(!PAGE_ALIGNED(pa_start)); 506 BUG_ON(!PAGE_ALIGNED(size)); 507 508 __create_pgd_mapping(pgd, pa_start, (unsigned long)va_start, size, prot, 509 early_pgtable_alloc, flags); 510 511 if (!(vm_flags & VM_NO_GUARD)) 512 size += PAGE_SIZE; 513 514 vma->addr = va_start; 515 vma->phys_addr = pa_start; 516 vma->size = size; 517 vma->flags = VM_MAP | vm_flags; 518 vma->caller = __builtin_return_address(0); 519 520 vm_area_add_early(vma); 521 } 522 523 static int __init parse_rodata(char *arg) 524 { 525 return strtobool(arg, &rodata_enabled); 526 } 527 early_param("rodata", parse_rodata); 528 529 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 530 static int __init map_entry_trampoline(void) 531 { 532 pgprot_t prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; 533 phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start); 534 535 /* The trampoline is always mapped and can therefore be global */ 536 pgprot_val(prot) &= ~PTE_NG; 537 538 /* Map only the text into the trampoline page table */ 539 memset(tramp_pg_dir, 0, PGD_SIZE); 540 __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS, PAGE_SIZE, 541 prot, pgd_pgtable_alloc, 0); 542 543 /* Map both the text and data into the kernel page table */ 544 __set_fixmap(FIX_ENTRY_TRAMP_TEXT, pa_start, prot); 545 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 546 extern char __entry_tramp_data_start[]; 547 548 __set_fixmap(FIX_ENTRY_TRAMP_DATA, 549 __pa_symbol(__entry_tramp_data_start), 550 PAGE_KERNEL_RO); 551 } 552 553 return 0; 554 } 555 core_initcall(map_entry_trampoline); 556 #endif 557 558 /* 559 * Create fine-grained mappings for the kernel. 560 */ 561 static void __init map_kernel(pgd_t *pgd) 562 { 563 static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext, 564 vmlinux_initdata, vmlinux_data; 565 566 /* 567 * External debuggers may need to write directly to the text 568 * mapping to install SW breakpoints. Allow this (only) when 569 * explicitly requested with rodata=off. 570 */ 571 pgprot_t text_prot = rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC; 572 573 /* 574 * Only rodata will be remapped with different permissions later on, 575 * all other segments are allowed to use contiguous mappings. 576 */ 577 map_kernel_segment(pgd, _text, _etext, text_prot, &vmlinux_text, 0, 578 VM_NO_GUARD); 579 map_kernel_segment(pgd, __start_rodata, __inittext_begin, PAGE_KERNEL, 580 &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD); 581 map_kernel_segment(pgd, __inittext_begin, __inittext_end, text_prot, 582 &vmlinux_inittext, 0, VM_NO_GUARD); 583 map_kernel_segment(pgd, __initdata_begin, __initdata_end, PAGE_KERNEL, 584 &vmlinux_initdata, 0, VM_NO_GUARD); 585 map_kernel_segment(pgd, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0); 586 587 if (!pgd_val(*pgd_offset_raw(pgd, FIXADDR_START))) { 588 /* 589 * The fixmap falls in a separate pgd to the kernel, and doesn't 590 * live in the carveout for the swapper_pg_dir. We can simply 591 * re-use the existing dir for the fixmap. 592 */ 593 set_pgd(pgd_offset_raw(pgd, FIXADDR_START), 594 *pgd_offset_k(FIXADDR_START)); 595 } else if (CONFIG_PGTABLE_LEVELS > 3) { 596 /* 597 * The fixmap shares its top level pgd entry with the kernel 598 * mapping. This can really only occur when we are running 599 * with 16k/4 levels, so we can simply reuse the pud level 600 * entry instead. 601 */ 602 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); 603 pud_populate(&init_mm, pud_set_fixmap_offset(pgd, FIXADDR_START), 604 lm_alias(bm_pmd)); 605 pud_clear_fixmap(); 606 } else { 607 BUG(); 608 } 609 610 kasan_copy_shadow(pgd); 611 } 612 613 /* 614 * paging_init() sets up the page tables, initialises the zone memory 615 * maps and sets up the zero page. 616 */ 617 void __init paging_init(void) 618 { 619 phys_addr_t pgd_phys = early_pgtable_alloc(); 620 pgd_t *pgd = pgd_set_fixmap(pgd_phys); 621 622 map_kernel(pgd); 623 map_mem(pgd); 624 625 /* 626 * We want to reuse the original swapper_pg_dir so we don't have to 627 * communicate the new address to non-coherent secondaries in 628 * secondary_entry, and so cpu_switch_mm can generate the address with 629 * adrp+add rather than a load from some global variable. 630 * 631 * To do this we need to go via a temporary pgd. 632 */ 633 cpu_replace_ttbr1(__va(pgd_phys)); 634 memcpy(swapper_pg_dir, pgd, PGD_SIZE); 635 cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); 636 637 pgd_clear_fixmap(); 638 memblock_free(pgd_phys, PAGE_SIZE); 639 640 /* 641 * We only reuse the PGD from the swapper_pg_dir, not the pud + pmd 642 * allocated with it. 643 */ 644 memblock_free(__pa_symbol(swapper_pg_dir) + PAGE_SIZE, 645 __pa_symbol(swapper_pg_end) - __pa_symbol(swapper_pg_dir) 646 - PAGE_SIZE); 647 } 648 649 /* 650 * Check whether a kernel address is valid (derived from arch/x86/). 651 */ 652 int kern_addr_valid(unsigned long addr) 653 { 654 pgd_t *pgd; 655 pud_t *pud; 656 pmd_t *pmd; 657 pte_t *pte; 658 659 if ((((long)addr) >> VA_BITS) != -1UL) 660 return 0; 661 662 pgd = pgd_offset_k(addr); 663 if (pgd_none(*pgd)) 664 return 0; 665 666 pud = pud_offset(pgd, addr); 667 if (pud_none(*pud)) 668 return 0; 669 670 if (pud_sect(*pud)) 671 return pfn_valid(pud_pfn(*pud)); 672 673 pmd = pmd_offset(pud, addr); 674 if (pmd_none(*pmd)) 675 return 0; 676 677 if (pmd_sect(*pmd)) 678 return pfn_valid(pmd_pfn(*pmd)); 679 680 pte = pte_offset_kernel(pmd, addr); 681 if (pte_none(*pte)) 682 return 0; 683 684 return pfn_valid(pte_pfn(*pte)); 685 } 686 #ifdef CONFIG_SPARSEMEM_VMEMMAP 687 #if !ARM64_SWAPPER_USES_SECTION_MAPS 688 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 689 { 690 return vmemmap_populate_basepages(start, end, node); 691 } 692 #else /* !ARM64_SWAPPER_USES_SECTION_MAPS */ 693 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node) 694 { 695 unsigned long addr = start; 696 unsigned long next; 697 pgd_t *pgd; 698 pud_t *pud; 699 pmd_t *pmd; 700 701 do { 702 next = pmd_addr_end(addr, end); 703 704 pgd = vmemmap_pgd_populate(addr, node); 705 if (!pgd) 706 return -ENOMEM; 707 708 pud = vmemmap_pud_populate(pgd, addr, node); 709 if (!pud) 710 return -ENOMEM; 711 712 pmd = pmd_offset(pud, addr); 713 if (pmd_none(*pmd)) { 714 void *p = NULL; 715 716 p = vmemmap_alloc_block_buf(PMD_SIZE, node); 717 if (!p) 718 return -ENOMEM; 719 720 pmd_set_huge(pmd, __pa(p), __pgprot(PROT_SECT_NORMAL)); 721 } else 722 vmemmap_verify((pte_t *)pmd, node, addr, next); 723 } while (addr = next, addr != end); 724 725 return 0; 726 } 727 #endif /* CONFIG_ARM64_64K_PAGES */ 728 void vmemmap_free(unsigned long start, unsigned long end) 729 { 730 } 731 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 732 733 static inline pud_t * fixmap_pud(unsigned long addr) 734 { 735 pgd_t *pgd = pgd_offset_k(addr); 736 737 BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd)); 738 739 return pud_offset_kimg(pgd, addr); 740 } 741 742 static inline pmd_t * fixmap_pmd(unsigned long addr) 743 { 744 pud_t *pud = fixmap_pud(addr); 745 746 BUG_ON(pud_none(*pud) || pud_bad(*pud)); 747 748 return pmd_offset_kimg(pud, addr); 749 } 750 751 static inline pte_t * fixmap_pte(unsigned long addr) 752 { 753 return &bm_pte[pte_index(addr)]; 754 } 755 756 /* 757 * The p*d_populate functions call virt_to_phys implicitly so they can't be used 758 * directly on kernel symbols (bm_p*d). This function is called too early to use 759 * lm_alias so __p*d_populate functions must be used to populate with the 760 * physical address from __pa_symbol. 761 */ 762 void __init early_fixmap_init(void) 763 { 764 pgd_t *pgd; 765 pud_t *pud; 766 pmd_t *pmd; 767 unsigned long addr = FIXADDR_START; 768 769 pgd = pgd_offset_k(addr); 770 if (CONFIG_PGTABLE_LEVELS > 3 && 771 !(pgd_none(*pgd) || pgd_page_paddr(*pgd) == __pa_symbol(bm_pud))) { 772 /* 773 * We only end up here if the kernel mapping and the fixmap 774 * share the top level pgd entry, which should only happen on 775 * 16k/4 levels configurations. 776 */ 777 BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); 778 pud = pud_offset_kimg(pgd, addr); 779 } else { 780 if (pgd_none(*pgd)) 781 __pgd_populate(pgd, __pa_symbol(bm_pud), PUD_TYPE_TABLE); 782 pud = fixmap_pud(addr); 783 } 784 if (pud_none(*pud)) 785 __pud_populate(pud, __pa_symbol(bm_pmd), PMD_TYPE_TABLE); 786 pmd = fixmap_pmd(addr); 787 __pmd_populate(pmd, __pa_symbol(bm_pte), PMD_TYPE_TABLE); 788 789 /* 790 * The boot-ioremap range spans multiple pmds, for which 791 * we are not prepared: 792 */ 793 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 794 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 795 796 if ((pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN))) 797 || pmd != fixmap_pmd(fix_to_virt(FIX_BTMAP_END))) { 798 WARN_ON(1); 799 pr_warn("pmd %p != %p, %p\n", 800 pmd, fixmap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)), 801 fixmap_pmd(fix_to_virt(FIX_BTMAP_END))); 802 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 803 fix_to_virt(FIX_BTMAP_BEGIN)); 804 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 805 fix_to_virt(FIX_BTMAP_END)); 806 807 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 808 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); 809 } 810 } 811 812 /* 813 * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we 814 * ever need to use IPIs for TLB broadcasting, then we're in trouble here. 815 */ 816 void __set_fixmap(enum fixed_addresses idx, 817 phys_addr_t phys, pgprot_t flags) 818 { 819 unsigned long addr = __fix_to_virt(idx); 820 pte_t *pte; 821 822 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 823 824 pte = fixmap_pte(addr); 825 826 if (pgprot_val(flags)) { 827 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags)); 828 } else { 829 pte_clear(&init_mm, addr, pte); 830 flush_tlb_kernel_range(addr, addr+PAGE_SIZE); 831 } 832 } 833 834 void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) 835 { 836 const u64 dt_virt_base = __fix_to_virt(FIX_FDT); 837 int offset; 838 void *dt_virt; 839 840 /* 841 * Check whether the physical FDT address is set and meets the minimum 842 * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be 843 * at least 8 bytes so that we can always access the magic and size 844 * fields of the FDT header after mapping the first chunk, double check 845 * here if that is indeed the case. 846 */ 847 BUILD_BUG_ON(MIN_FDT_ALIGN < 8); 848 if (!dt_phys || dt_phys % MIN_FDT_ALIGN) 849 return NULL; 850 851 /* 852 * Make sure that the FDT region can be mapped without the need to 853 * allocate additional translation table pages, so that it is safe 854 * to call create_mapping_noalloc() this early. 855 * 856 * On 64k pages, the FDT will be mapped using PTEs, so we need to 857 * be in the same PMD as the rest of the fixmap. 858 * On 4k pages, we'll use section mappings for the FDT so we only 859 * have to be in the same PUD. 860 */ 861 BUILD_BUG_ON(dt_virt_base % SZ_2M); 862 863 BUILD_BUG_ON(__fix_to_virt(FIX_FDT_END) >> SWAPPER_TABLE_SHIFT != 864 __fix_to_virt(FIX_BTMAP_BEGIN) >> SWAPPER_TABLE_SHIFT); 865 866 offset = dt_phys % SWAPPER_BLOCK_SIZE; 867 dt_virt = (void *)dt_virt_base + offset; 868 869 /* map the first chunk so we can read the size from the header */ 870 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), 871 dt_virt_base, SWAPPER_BLOCK_SIZE, prot); 872 873 if (fdt_magic(dt_virt) != FDT_MAGIC) 874 return NULL; 875 876 *size = fdt_totalsize(dt_virt); 877 if (*size > MAX_FDT_SIZE) 878 return NULL; 879 880 if (offset + *size > SWAPPER_BLOCK_SIZE) 881 create_mapping_noalloc(round_down(dt_phys, SWAPPER_BLOCK_SIZE), dt_virt_base, 882 round_up(offset + *size, SWAPPER_BLOCK_SIZE), prot); 883 884 return dt_virt; 885 } 886 887 void *__init fixmap_remap_fdt(phys_addr_t dt_phys) 888 { 889 void *dt_virt; 890 int size; 891 892 dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); 893 if (!dt_virt) 894 return NULL; 895 896 memblock_reserve(dt_phys, size); 897 return dt_virt; 898 } 899 900 int __init arch_ioremap_pud_supported(void) 901 { 902 /* only 4k granule supports level 1 block mappings */ 903 return IS_ENABLED(CONFIG_ARM64_4K_PAGES); 904 } 905 906 int __init arch_ioremap_pmd_supported(void) 907 { 908 return 1; 909 } 910 911 int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot) 912 { 913 pgprot_t sect_prot = __pgprot(PUD_TYPE_SECT | 914 pgprot_val(mk_sect_prot(prot))); 915 BUG_ON(phys & ~PUD_MASK); 916 set_pud(pud, pfn_pud(__phys_to_pfn(phys), sect_prot)); 917 return 1; 918 } 919 920 int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot) 921 { 922 pgprot_t sect_prot = __pgprot(PMD_TYPE_SECT | 923 pgprot_val(mk_sect_prot(prot))); 924 BUG_ON(phys & ~PMD_MASK); 925 set_pmd(pmd, pfn_pmd(__phys_to_pfn(phys), sect_prot)); 926 return 1; 927 } 928 929 int pud_clear_huge(pud_t *pud) 930 { 931 if (!pud_sect(*pud)) 932 return 0; 933 pud_clear(pud); 934 return 1; 935 } 936 937 int pmd_clear_huge(pmd_t *pmd) 938 { 939 if (!pmd_sect(*pmd)) 940 return 0; 941 pmd_clear(pmd); 942 return 1; 943 } 944