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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 | // SPDX-License-Identifier: GPL-2.0 /* * x86_64 specific EFI support functions * Based on Extensible Firmware Interface Specification version 1.0 * * Copyright (C) 2005-2008 Intel Co. * Fenghua Yu <fenghua.yu@intel.com> * Bibo Mao <bibo.mao@intel.com> * Chandramouli Narayanan <mouli@linux.intel.com> * Huang Ying <ying.huang@intel.com> * * Code to convert EFI to E820 map has been implemented in elilo bootloader * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table * is setup appropriately for EFI runtime code. * - mouli 06/14/2007. * */ #define pr_fmt(fmt) "efi: " fmt #include <linux/kernel.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/types.h> #include <linux/spinlock.h> #include <linux/memblock.h> #include <linux/ioport.h> #include <linux/mc146818rtc.h> #include <linux/efi.h> #include <linux/export.h> #include <linux/uaccess.h> #include <linux/io.h> #include <linux/reboot.h> #include <linux/slab.h> #include <linux/ucs2_string.h> #include <linux/mem_encrypt.h> #include <linux/sched/task.h> #include <asm/setup.h> #include <asm/page.h> #include <asm/e820/api.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> #include <asm/proto.h> #include <asm/efi.h> #include <asm/cacheflush.h> #include <asm/fixmap.h> #include <asm/realmode.h> #include <asm/time.h> #include <asm/pgalloc.h> /* * We allocate runtime services regions top-down, starting from -4G, i.e. * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G. */ static u64 efi_va = EFI_VA_START; struct efi_scratch efi_scratch; static void __init early_code_mapping_set_exec(int executable) { efi_memory_desc_t *md; if (!(__supported_pte_mask & _PAGE_NX)) return; /* Make EFI service code area executable */ for_each_efi_memory_desc(md) { if (md->type == EFI_RUNTIME_SERVICES_CODE || md->type == EFI_BOOT_SERVICES_CODE) efi_set_executable(md, executable); } } pgd_t * __init efi_call_phys_prolog(void) { unsigned long vaddr, addr_pgd, addr_p4d, addr_pud; pgd_t *save_pgd, *pgd_k, *pgd_efi; p4d_t *p4d, *p4d_k, *p4d_efi; pud_t *pud; int pgd; int n_pgds, i, j; if (!efi_enabled(EFI_OLD_MEMMAP)) { efi_switch_mm(&efi_mm); return efi_mm.pgd; } early_code_mapping_set_exec(1); n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE); save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL); if (!save_pgd) return NULL; /* * Build 1:1 identity mapping for efi=old_map usage. Note that * PAGE_OFFSET is PGDIR_SIZE aligned when KASLR is disabled, while * it is PUD_SIZE ALIGNED with KASLR enabled. So for a given physical * address X, the pud_index(X) != pud_index(__va(X)), we can only copy * PUD entry of __va(X) to fill in pud entry of X to build 1:1 mapping. * This means here we can only reuse the PMD tables of the direct mapping. */ for (pgd = 0; pgd < n_pgds; pgd++) { addr_pgd = (unsigned long)(pgd * PGDIR_SIZE); vaddr = (unsigned long)__va(pgd * PGDIR_SIZE); pgd_efi = pgd_offset_k(addr_pgd); save_pgd[pgd] = *pgd_efi; p4d = p4d_alloc(&init_mm, pgd_efi, addr_pgd); if (!p4d) { pr_err("Failed to allocate p4d table!\n"); goto out; } for (i = 0; i < PTRS_PER_P4D; i++) { addr_p4d = addr_pgd + i * P4D_SIZE; p4d_efi = p4d + p4d_index(addr_p4d); pud = pud_alloc(&init_mm, p4d_efi, addr_p4d); if (!pud) { pr_err("Failed to allocate pud table!\n"); goto out; } for (j = 0; j < PTRS_PER_PUD; j++) { addr_pud = addr_p4d + j * PUD_SIZE; if (addr_pud > (max_pfn << PAGE_SHIFT)) break; vaddr = (unsigned long)__va(addr_pud); pgd_k = pgd_offset_k(vaddr); p4d_k = p4d_offset(pgd_k, vaddr); pud[j] = *pud_offset(p4d_k, vaddr); } } pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX; } __flush_tlb_all(); return save_pgd; out: efi_call_phys_epilog(save_pgd); return NULL; } void __init efi_call_phys_epilog(pgd_t *save_pgd) { /* * After the lock is released, the original page table is restored. */ int pgd_idx, i; int nr_pgds; pgd_t *pgd; p4d_t *p4d; pud_t *pud; if (!efi_enabled(EFI_OLD_MEMMAP)) { efi_switch_mm(efi_scratch.prev_mm); return; } nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE); for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) { pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE); set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]); if (!pgd_present(*pgd)) continue; for (i = 0; i < PTRS_PER_P4D; i++) { p4d = p4d_offset(pgd, pgd_idx * PGDIR_SIZE + i * P4D_SIZE); if (!p4d_present(*p4d)) continue; pud = (pud_t *)p4d_page_vaddr(*p4d); pud_free(&init_mm, pud); } p4d = (p4d_t *)pgd_page_vaddr(*pgd); p4d_free(&init_mm, p4d); } kfree(save_pgd); __flush_tlb_all(); early_code_mapping_set_exec(0); } EXPORT_SYMBOL_GPL(efi_mm); /* * We need our own copy of the higher levels of the page tables * because we want to avoid inserting EFI region mappings (EFI_VA_END * to EFI_VA_START) into the standard kernel page tables. Everything * else can be shared, see efi_sync_low_kernel_mappings(). * * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the * allocation. */ int __init efi_alloc_page_tables(void) { pgd_t *pgd, *efi_pgd; p4d_t *p4d; pud_t *pud; gfp_t gfp_mask; if (efi_enabled(EFI_OLD_MEMMAP)) return 0; gfp_mask = GFP_KERNEL | __GFP_ZERO; efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER); if (!efi_pgd) return -ENOMEM; pgd = efi_pgd + pgd_index(EFI_VA_END); p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END); if (!p4d) { free_page((unsigned long)efi_pgd); return -ENOMEM; } pud = pud_alloc(&init_mm, p4d, EFI_VA_END); if (!pud) { if (pgtable_l5_enabled()) free_page((unsigned long) pgd_page_vaddr(*pgd)); free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER); return -ENOMEM; } efi_mm.pgd = efi_pgd; mm_init_cpumask(&efi_mm); init_new_context(NULL, &efi_mm); return 0; } /* * Add low kernel mappings for passing arguments to EFI functions. */ void efi_sync_low_kernel_mappings(void) { unsigned num_entries; pgd_t *pgd_k, *pgd_efi; p4d_t *p4d_k, *p4d_efi; pud_t *pud_k, *pud_efi; pgd_t *efi_pgd = efi_mm.pgd; if (efi_enabled(EFI_OLD_MEMMAP)) return; /* * We can share all PGD entries apart from the one entry that * covers the EFI runtime mapping space. * * Make sure the EFI runtime region mappings are guaranteed to * only span a single PGD entry and that the entry also maps * other important kernel regions. */ MAYBE_BUILD_BUG_ON(pgd_index(EFI_VA_END) != pgd_index(MODULES_END)); MAYBE_BUILD_BUG_ON((EFI_VA_START & PGDIR_MASK) != (EFI_VA_END & PGDIR_MASK)); pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET); pgd_k = pgd_offset_k(PAGE_OFFSET); num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET); memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries); /* * As with PGDs, we share all P4D entries apart from the one entry * that covers the EFI runtime mapping space. */ BUILD_BUG_ON(p4d_index(EFI_VA_END) != p4d_index(MODULES_END)); BUILD_BUG_ON((EFI_VA_START & P4D_MASK) != (EFI_VA_END & P4D_MASK)); pgd_efi = efi_pgd + pgd_index(EFI_VA_END); pgd_k = pgd_offset_k(EFI_VA_END); p4d_efi = p4d_offset(pgd_efi, 0); p4d_k = p4d_offset(pgd_k, 0); num_entries = p4d_index(EFI_VA_END); memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries); /* * We share all the PUD entries apart from those that map the * EFI regions. Copy around them. */ BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0); BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0); p4d_efi = p4d_offset(pgd_efi, EFI_VA_END); p4d_k = p4d_offset(pgd_k, EFI_VA_END); pud_efi = pud_offset(p4d_efi, 0); pud_k = pud_offset(p4d_k, 0); num_entries = pud_index(EFI_VA_END); memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries); pud_efi = pud_offset(p4d_efi, EFI_VA_START); pud_k = pud_offset(p4d_k, EFI_VA_START); num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START); memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries); } /* * Wrapper for slow_virt_to_phys() that handles NULL addresses. */ static inline phys_addr_t virt_to_phys_or_null_size(void *va, unsigned long size) { phys_addr_t pa; if (!va) return 0; if (virt_addr_valid(va)) return virt_to_phys(va); pa = slow_virt_to_phys(va); /* check if the object crosses a page boundary */ if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK)) return 0; return pa; } #define virt_to_phys_or_null(addr) \ virt_to_phys_or_null_size((addr), sizeof(*(addr))) int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { unsigned long pfn, text, pf; struct page *page; unsigned npages; pgd_t *pgd = efi_mm.pgd; if (efi_enabled(EFI_OLD_MEMMAP)) return 0; /* * It can happen that the physical address of new_memmap lands in memory * which is not mapped in the EFI page table. Therefore we need to go * and ident-map those pages containing the map before calling * phys_efi_set_virtual_address_map(). */ pfn = pa_memmap >> PAGE_SHIFT; pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC; if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) { pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap); return 1; } /* * Certain firmware versions are way too sentimential and still believe * they are exclusive and unquestionable owners of the first physical page, * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY * (but then write-access it later during SetVirtualAddressMap()). * * Create a 1:1 mapping for this page, to avoid triple faults during early * boot with such firmware. We are free to hand this page to the BIOS, * as trim_bios_range() will reserve the first page and isolate it away * from memory allocators anyway. */ pf = _PAGE_RW; if (sev_active()) pf |= _PAGE_ENC; if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) { pr_err("Failed to create 1:1 mapping for the first page!\n"); return 1; } /* * When making calls to the firmware everything needs to be 1:1 * mapped and addressable with 32-bit pointers. Map the kernel * text and allocate a new stack because we can't rely on the * stack pointer being < 4GB. */ if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native()) return 0; page = alloc_page(GFP_KERNEL|__GFP_DMA32); if (!page) { pr_err("Unable to allocate EFI runtime stack < 4GB\n"); return 1; } efi_scratch.phys_stack = page_to_phys(page + 1); /* stack grows down */ npages = (_etext - _text) >> PAGE_SHIFT; text = __pa(_text); pfn = text >> PAGE_SHIFT; pf = _PAGE_RW | _PAGE_ENC; if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) { pr_err("Failed to map kernel text 1:1\n"); return 1; } return 0; } static void __init __map_region(efi_memory_desc_t *md, u64 va) { unsigned long flags = _PAGE_RW; unsigned long pfn; pgd_t *pgd = efi_mm.pgd; if (!(md->attribute & EFI_MEMORY_WB)) flags |= _PAGE_PCD; if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO) flags |= _PAGE_ENC; pfn = md->phys_addr >> PAGE_SHIFT; if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags)) pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n", md->phys_addr, va); } void __init efi_map_region(efi_memory_desc_t *md) { unsigned long size = md->num_pages << PAGE_SHIFT; u64 pa = md->phys_addr; if (efi_enabled(EFI_OLD_MEMMAP)) return old_map_region(md); /* * Make sure the 1:1 mappings are present as a catch-all for b0rked * firmware which doesn't update all internal pointers after switching * to virtual mode and would otherwise crap on us. */ __map_region(md, md->phys_addr); /* * Enforce the 1:1 mapping as the default virtual address when * booting in EFI mixed mode, because even though we may be * running a 64-bit kernel, the firmware may only be 32-bit. */ if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) { md->virt_addr = md->phys_addr; return; } efi_va -= size; /* Is PA 2M-aligned? */ if (!(pa & (PMD_SIZE - 1))) { efi_va &= PMD_MASK; } else { u64 pa_offset = pa & (PMD_SIZE - 1); u64 prev_va = efi_va; /* get us the same offset within this 2M page */ efi_va = (efi_va & PMD_MASK) + pa_offset; if (efi_va > prev_va) efi_va -= PMD_SIZE; } if (efi_va < EFI_VA_END) { pr_warn(FW_WARN "VA address range overflow!\n"); return; } /* Do the VA map */ __map_region(md, efi_va); md->virt_addr = efi_va; } /* * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges. * md->virt_addr is the original virtual address which had been mapped in kexec * 1st kernel. */ void __init efi_map_region_fixed(efi_memory_desc_t *md) { __map_region(md, md->phys_addr); __map_region(md, md->virt_addr); } void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size, u32 type, u64 attribute) { unsigned long last_map_pfn; if (type == EFI_MEMORY_MAPPED_IO) return ioremap(phys_addr, size); last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size); if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) { unsigned long top = last_map_pfn << PAGE_SHIFT; efi_ioremap(top, size - (top - phys_addr), type, attribute); } if (!(attribute & EFI_MEMORY_WB)) efi_memory_uc((u64)(unsigned long)__va(phys_addr), size); return (void __iomem *)__va(phys_addr); } void __init parse_efi_setup(u64 phys_addr, u32 data_len) { efi_setup = phys_addr + sizeof(struct setup_data); } static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf) { unsigned long pfn; pgd_t *pgd = efi_mm.pgd; int err1, err2; /* Update the 1:1 mapping */ pfn = md->phys_addr >> PAGE_SHIFT; err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf); if (err1) { pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n", md->phys_addr, md->virt_addr); } err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf); if (err2) { pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n", md->phys_addr, md->virt_addr); } return err1 || err2; } static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md) { unsigned long pf = 0; if (md->attribute & EFI_MEMORY_XP) pf |= _PAGE_NX; if (!(md->attribute & EFI_MEMORY_RO)) pf |= _PAGE_RW; if (sev_active()) pf |= _PAGE_ENC; return efi_update_mappings(md, pf); } void __init efi_runtime_update_mappings(void) { efi_memory_desc_t *md; if (efi_enabled(EFI_OLD_MEMMAP)) { if (__supported_pte_mask & _PAGE_NX) runtime_code_page_mkexec(); return; } /* * Use the EFI Memory Attribute Table for mapping permissions if it * exists, since it is intended to supersede EFI_PROPERTIES_TABLE. */ if (efi_enabled(EFI_MEM_ATTR)) { efi_memattr_apply_permissions(NULL, efi_update_mem_attr); return; } /* * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not * published by the firmware. Even if we find a buggy implementation of * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to * EFI_PROPERTIES_TABLE, because of the same reason. */ if (!efi_enabled(EFI_NX_PE_DATA)) return; for_each_efi_memory_desc(md) { unsigned long pf = 0; if (!(md->attribute & EFI_MEMORY_RUNTIME)) continue; if (!(md->attribute & EFI_MEMORY_WB)) pf |= _PAGE_PCD; if ((md->attribute & EFI_MEMORY_XP) || (md->type == EFI_RUNTIME_SERVICES_DATA)) pf |= _PAGE_NX; if (!(md->attribute & EFI_MEMORY_RO) && (md->type != EFI_RUNTIME_SERVICES_CODE)) pf |= _PAGE_RW; if (sev_active()) pf |= _PAGE_ENC; efi_update_mappings(md, pf); } } void __init efi_dump_pagetable(void) { #ifdef CONFIG_EFI_PGT_DUMP if (efi_enabled(EFI_OLD_MEMMAP)) ptdump_walk_pgd_level(NULL, swapper_pg_dir); else ptdump_walk_pgd_level(NULL, efi_mm.pgd); #endif } /* * Makes the calling thread switch to/from efi_mm context. Can be used * in a kernel thread and user context. Preemption needs to remain disabled * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm * can not change under us. * It should be ensured that there are no concurent calls to this function. */ void efi_switch_mm(struct mm_struct *mm) { efi_scratch.prev_mm = current->active_mm; current->active_mm = mm; switch_mm(efi_scratch.prev_mm, mm, NULL); } #ifdef CONFIG_EFI_MIXED extern efi_status_t efi64_thunk(u32, ...); static DEFINE_SPINLOCK(efi_runtime_lock); #define runtime_service32(func) \ ({ \ u32 table = (u32)(unsigned long)efi.systab; \ u32 *rt, *___f; \ \ rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime)); \ ___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \ *___f; \ }) /* * Switch to the EFI page tables early so that we can access the 1:1 * runtime services mappings which are not mapped in any other page * tables. This function must be called before runtime_service32(). * * Also, disable interrupts because the IDT points to 64-bit handlers, * which aren't going to function correctly when we switch to 32-bit. */ #define efi_thunk(f, ...) \ ({ \ efi_status_t __s; \ u32 __func; \ \ arch_efi_call_virt_setup(); \ \ __func = runtime_service32(f); \ __s = efi64_thunk(__func, __VA_ARGS__); \ \ arch_efi_call_virt_teardown(); \ \ __s; \ }) efi_status_t efi_thunk_set_virtual_address_map( void *phys_set_virtual_address_map, unsigned long memory_map_size, unsigned long descriptor_size, u32 descriptor_version, efi_memory_desc_t *virtual_map) { efi_status_t status; unsigned long flags; u32 func; efi_sync_low_kernel_mappings(); local_irq_save(flags); efi_switch_mm(&efi_mm); func = (u32)(unsigned long)phys_set_virtual_address_map; status = efi64_thunk(func, memory_map_size, descriptor_size, descriptor_version, virtual_map); efi_switch_mm(efi_scratch.prev_mm); local_irq_restore(flags); return status; } static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc) { efi_status_t status; u32 phys_tm, phys_tc; unsigned long flags; spin_lock(&rtc_lock); spin_lock_irqsave(&efi_runtime_lock, flags); phys_tm = virt_to_phys_or_null(tm); phys_tc = virt_to_phys_or_null(tc); status = efi_thunk(get_time, phys_tm, phys_tc); spin_unlock_irqrestore(&efi_runtime_lock, flags); spin_unlock(&rtc_lock); return status; } static efi_status_t efi_thunk_set_time(efi_time_t *tm) { efi_status_t status; u32 phys_tm; unsigned long flags; spin_lock(&rtc_lock); spin_lock_irqsave(&efi_runtime_lock, flags); phys_tm = virt_to_phys_or_null(tm); status = efi_thunk(set_time, phys_tm); spin_unlock_irqrestore(&efi_runtime_lock, flags); spin_unlock(&rtc_lock); return status; } static efi_status_t efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending, efi_time_t *tm) { efi_status_t status; u32 phys_enabled, phys_pending, phys_tm; unsigned long flags; spin_lock(&rtc_lock); spin_lock_irqsave(&efi_runtime_lock, flags); phys_enabled = virt_to_phys_or_null(enabled); phys_pending = virt_to_phys_or_null(pending); phys_tm = virt_to_phys_or_null(tm); status = efi_thunk(get_wakeup_time, phys_enabled, phys_pending, phys_tm); spin_unlock_irqrestore(&efi_runtime_lock, flags); spin_unlock(&rtc_lock); return status; } static efi_status_t efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) { efi_status_t status; u32 phys_tm; unsigned long flags; spin_lock(&rtc_lock); spin_lock_irqsave(&efi_runtime_lock, flags); phys_tm = virt_to_phys_or_null(tm); status = efi_thunk(set_wakeup_time, enabled, phys_tm); spin_unlock_irqrestore(&efi_runtime_lock, flags); spin_unlock(&rtc_lock); return status; } static unsigned long efi_name_size(efi_char16_t *name) { return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1; } static efi_status_t efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, unsigned long *data_size, void *data) { u8 buf[24] __aligned(8); efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd)); efi_status_t status; u32 phys_name, phys_vendor, phys_attr; u32 phys_data_size, phys_data; unsigned long flags; spin_lock_irqsave(&efi_runtime_lock, flags); *vnd = *vendor; phys_data_size = virt_to_phys_or_null(data_size); phys_vendor = virt_to_phys_or_null(vnd); phys_name = virt_to_phys_or_null_size(name, efi_name_size(name)); phys_attr = virt_to_phys_or_null(attr); phys_data = virt_to_phys_or_null_size(data, *data_size); if (!phys_name || (data && !phys_data)) status = EFI_INVALID_PARAMETER; else status = efi_thunk(get_variable, phys_name, phys_vendor, phys_attr, phys_data_size, phys_data); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static efi_status_t efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { u8 buf[24] __aligned(8); efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd)); u32 phys_name, phys_vendor, phys_data; efi_status_t status; unsigned long flags; spin_lock_irqsave(&efi_runtime_lock, flags); *vnd = *vendor; phys_name = virt_to_phys_or_null_size(name, efi_name_size(name)); phys_vendor = virt_to_phys_or_null(vnd); phys_data = virt_to_phys_or_null_size(data, data_size); if (!phys_name || (data && !phys_data)) status = EFI_INVALID_PARAMETER; else status = efi_thunk(set_variable, phys_name, phys_vendor, attr, data_size, phys_data); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static efi_status_t efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { u8 buf[24] __aligned(8); efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd)); u32 phys_name, phys_vendor, phys_data; efi_status_t status; unsigned long flags; if (!spin_trylock_irqsave(&efi_runtime_lock, flags)) return EFI_NOT_READY; *vnd = *vendor; phys_name = virt_to_phys_or_null_size(name, efi_name_size(name)); phys_vendor = virt_to_phys_or_null(vnd); phys_data = virt_to_phys_or_null_size(data, data_size); if (!phys_name || (data && !phys_data)) status = EFI_INVALID_PARAMETER; else status = efi_thunk(set_variable, phys_name, phys_vendor, attr, data_size, phys_data); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static efi_status_t efi_thunk_get_next_variable(unsigned long *name_size, efi_char16_t *name, efi_guid_t *vendor) { u8 buf[24] __aligned(8); efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd)); efi_status_t status; u32 phys_name_size, phys_name, phys_vendor; unsigned long flags; spin_lock_irqsave(&efi_runtime_lock, flags); *vnd = *vendor; phys_name_size = virt_to_phys_or_null(name_size); phys_vendor = virt_to_phys_or_null(vnd); phys_name = virt_to_phys_or_null_size(name, *name_size); if (!phys_name) status = EFI_INVALID_PARAMETER; else status = efi_thunk(get_next_variable, phys_name_size, phys_name, phys_vendor); spin_unlock_irqrestore(&efi_runtime_lock, flags); *vendor = *vnd; return status; } static efi_status_t efi_thunk_get_next_high_mono_count(u32 *count) { efi_status_t status; u32 phys_count; unsigned long flags; spin_lock_irqsave(&efi_runtime_lock, flags); phys_count = virt_to_phys_or_null(count); status = efi_thunk(get_next_high_mono_count, phys_count); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static void efi_thunk_reset_system(int reset_type, efi_status_t status, unsigned long data_size, efi_char16_t *data) { u32 phys_data; unsigned long flags; spin_lock_irqsave(&efi_runtime_lock, flags); phys_data = virt_to_phys_or_null_size(data, data_size); efi_thunk(reset_system, reset_type, status, data_size, phys_data); spin_unlock_irqrestore(&efi_runtime_lock, flags); } static efi_status_t efi_thunk_update_capsule(efi_capsule_header_t **capsules, unsigned long count, unsigned long sg_list) { /* * To properly support this function we would need to repackage * 'capsules' because the firmware doesn't understand 64-bit * pointers. */ return EFI_UNSUPPORTED; } static efi_status_t efi_thunk_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { efi_status_t status; u32 phys_storage, phys_remaining, phys_max; unsigned long flags; if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; spin_lock_irqsave(&efi_runtime_lock, flags); phys_storage = virt_to_phys_or_null(storage_space); phys_remaining = virt_to_phys_or_null(remaining_space); phys_max = virt_to_phys_or_null(max_variable_size); status = efi_thunk(query_variable_info, attr, phys_storage, phys_remaining, phys_max); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static efi_status_t efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { efi_status_t status; u32 phys_storage, phys_remaining, phys_max; unsigned long flags; if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; if (!spin_trylock_irqsave(&efi_runtime_lock, flags)) return EFI_NOT_READY; phys_storage = virt_to_phys_or_null(storage_space); phys_remaining = virt_to_phys_or_null(remaining_space); phys_max = virt_to_phys_or_null(max_variable_size); status = efi_thunk(query_variable_info, attr, phys_storage, phys_remaining, phys_max); spin_unlock_irqrestore(&efi_runtime_lock, flags); return status; } static efi_status_t efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules, unsigned long count, u64 *max_size, int *reset_type) { /* * To properly support this function we would need to repackage * 'capsules' because the firmware doesn't understand 64-bit * pointers. */ return EFI_UNSUPPORTED; } void efi_thunk_runtime_setup(void) { efi.get_time = efi_thunk_get_time; efi.set_time = efi_thunk_set_time; efi.get_wakeup_time = efi_thunk_get_wakeup_time; efi.set_wakeup_time = efi_thunk_set_wakeup_time; efi.get_variable = efi_thunk_get_variable; efi.get_next_variable = efi_thunk_get_next_variable; efi.set_variable = efi_thunk_set_variable; efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking; efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count; efi.reset_system = efi_thunk_reset_system; efi.query_variable_info = efi_thunk_query_variable_info; efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking; efi.update_capsule = efi_thunk_update_capsule; efi.query_capsule_caps = efi_thunk_query_capsule_caps; } #endif /* CONFIG_EFI_MIXED */ |