1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Common EFI (Extensible Firmware Interface) support functions 4 * Based on Extensible Firmware Interface Specification version 1.0 5 * 6 * Copyright (C) 1999 VA Linux Systems 7 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> 8 * Copyright (C) 1999-2002 Hewlett-Packard Co. 9 * David Mosberger-Tang <davidm@hpl.hp.com> 10 * Stephane Eranian <eranian@hpl.hp.com> 11 * Copyright (C) 2005-2008 Intel Co. 12 * Fenghua Yu <fenghua.yu@intel.com> 13 * Bibo Mao <bibo.mao@intel.com> 14 * Chandramouli Narayanan <mouli@linux.intel.com> 15 * Huang Ying <ying.huang@intel.com> 16 * Copyright (C) 2013 SuSE Labs 17 * Borislav Petkov <bp@suse.de> - runtime services VA mapping 18 * 19 * Copied from efi_32.c to eliminate the duplicated code between EFI 20 * 32/64 support code. --ying 2007-10-26 21 * 22 * All EFI Runtime Services are not implemented yet as EFI only 23 * supports physical mode addressing on SoftSDV. This is to be fixed 24 * in a future version. --drummond 1999-07-20 25 * 26 * Implemented EFI runtime services and virtual mode calls. --davidm 27 * 28 * Goutham Rao: <goutham.rao@intel.com> 29 * Skip non-WB memory and ignore empty memory ranges. 30 */ 31 32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 34 #include <linux/kernel.h> 35 #include <linux/init.h> 36 #include <linux/efi.h> 37 #include <linux/efi-bgrt.h> 38 #include <linux/export.h> 39 #include <linux/memblock.h> 40 #include <linux/slab.h> 41 #include <linux/spinlock.h> 42 #include <linux/uaccess.h> 43 #include <linux/time.h> 44 #include <linux/io.h> 45 #include <linux/reboot.h> 46 #include <linux/bcd.h> 47 48 #include <asm/setup.h> 49 #include <asm/efi.h> 50 #include <asm/e820/api.h> 51 #include <asm/time.h> 52 #include <asm/tlbflush.h> 53 #include <asm/x86_init.h> 54 #include <asm/uv/uv.h> 55 56 static unsigned long efi_systab_phys __initdata; 57 static unsigned long efi_runtime, efi_nr_tables; 58 59 unsigned long efi_fw_vendor, efi_config_table; 60 61 static const efi_config_table_type_t arch_tables[] __initconst = { 62 #ifdef CONFIG_X86_UV 63 {UV_SYSTEM_TABLE_GUID, &uv_systab_phys, "UVsystab" }, 64 #endif 65 {}, 66 }; 67 68 static const unsigned long * const efi_tables[] = { 69 &efi.acpi, 70 &efi.acpi20, 71 &efi.smbios, 72 &efi.smbios3, 73 #ifdef CONFIG_X86_UV 74 &uv_systab_phys, 75 #endif 76 &efi_fw_vendor, 77 &efi_runtime, 78 &efi_config_table, 79 &efi.esrt, 80 &efi_mem_attr_table, 81 #ifdef CONFIG_EFI_RCI2_TABLE 82 &rci2_table_phys, 83 #endif 84 &efi.tpm_log, 85 &efi.tpm_final_log, 86 &efi_rng_seed, 87 #ifdef CONFIG_LOAD_UEFI_KEYS 88 &efi.mokvar_table, 89 #endif 90 #ifdef CONFIG_EFI_COCO_SECRET 91 &efi.coco_secret, 92 #endif 93 #ifdef CONFIG_UNACCEPTED_MEMORY 94 &efi.unaccepted, 95 #endif 96 }; 97 98 u64 efi_setup; /* efi setup_data physical address */ 99 100 static int add_efi_memmap __initdata; 101 static int __init setup_add_efi_memmap(char *arg) 102 { 103 add_efi_memmap = 1; 104 return 0; 105 } 106 early_param("add_efi_memmap", setup_add_efi_memmap); 107 108 /* 109 * Tell the kernel about the EFI memory map. This might include 110 * more than the max 128 entries that can fit in the passed in e820 111 * legacy (zeropage) memory map, but the kernel's e820 table can hold 112 * E820_MAX_ENTRIES. 113 */ 114 115 static void __init do_add_efi_memmap(void) 116 { 117 efi_memory_desc_t *md; 118 119 if (!efi_enabled(EFI_MEMMAP)) 120 return; 121 122 for_each_efi_memory_desc(md) { 123 unsigned long long start = md->phys_addr; 124 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 125 int e820_type; 126 127 switch (md->type) { 128 case EFI_LOADER_CODE: 129 case EFI_LOADER_DATA: 130 case EFI_BOOT_SERVICES_CODE: 131 case EFI_BOOT_SERVICES_DATA: 132 case EFI_CONVENTIONAL_MEMORY: 133 if (efi_soft_reserve_enabled() 134 && (md->attribute & EFI_MEMORY_SP)) 135 e820_type = E820_TYPE_SOFT_RESERVED; 136 else if (md->attribute & EFI_MEMORY_WB) 137 e820_type = E820_TYPE_RAM; 138 else 139 e820_type = E820_TYPE_RESERVED; 140 break; 141 case EFI_ACPI_RECLAIM_MEMORY: 142 e820_type = E820_TYPE_ACPI; 143 break; 144 case EFI_ACPI_MEMORY_NVS: 145 e820_type = E820_TYPE_NVS; 146 break; 147 case EFI_UNUSABLE_MEMORY: 148 e820_type = E820_TYPE_UNUSABLE; 149 break; 150 case EFI_PERSISTENT_MEMORY: 151 e820_type = E820_TYPE_PMEM; 152 break; 153 default: 154 /* 155 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 156 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 157 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 158 */ 159 e820_type = E820_TYPE_RESERVED; 160 break; 161 } 162 163 e820__range_add(start, size, e820_type); 164 } 165 e820__update_table(e820_table); 166 } 167 168 /* 169 * Given add_efi_memmap defaults to 0 and there is no alternative 170 * e820 mechanism for soft-reserved memory, import the full EFI memory 171 * map if soft reservations are present and enabled. Otherwise, the 172 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is 173 * the efi=nosoftreserve option. 174 */ 175 static bool do_efi_soft_reserve(void) 176 { 177 efi_memory_desc_t *md; 178 179 if (!efi_enabled(EFI_MEMMAP)) 180 return false; 181 182 if (!efi_soft_reserve_enabled()) 183 return false; 184 185 for_each_efi_memory_desc(md) 186 if (md->type == EFI_CONVENTIONAL_MEMORY && 187 (md->attribute & EFI_MEMORY_SP)) 188 return true; 189 return false; 190 } 191 192 int __init efi_memblock_x86_reserve_range(void) 193 { 194 struct efi_info *e = &boot_params.efi_info; 195 struct efi_memory_map_data data; 196 phys_addr_t pmap; 197 int rv; 198 199 if (efi_enabled(EFI_PARAVIRT)) 200 return 0; 201 202 /* Can't handle firmware tables above 4GB on i386 */ 203 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) { 204 pr_err("Memory map is above 4GB, disabling EFI.\n"); 205 return -EINVAL; 206 } 207 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32)); 208 209 data.phys_map = pmap; 210 data.size = e->efi_memmap_size; 211 data.desc_size = e->efi_memdesc_size; 212 data.desc_version = e->efi_memdesc_version; 213 214 if (!efi_enabled(EFI_PARAVIRT)) { 215 rv = efi_memmap_init_early(&data); 216 if (rv) 217 return rv; 218 } 219 220 if (add_efi_memmap || do_efi_soft_reserve()) 221 do_add_efi_memmap(); 222 223 WARN(efi.memmap.desc_version != 1, 224 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 225 efi.memmap.desc_version); 226 227 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); 228 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags); 229 230 return 0; 231 } 232 233 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 234 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 235 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 236 237 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 238 { 239 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 240 u64 end_hi = 0; 241 char buf[64]; 242 243 if (md->num_pages == 0) { 244 end = 0; 245 } else if (md->num_pages > EFI_PAGES_MAX || 246 EFI_PAGES_MAX - md->num_pages < 247 (md->phys_addr >> EFI_PAGE_SHIFT)) { 248 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 249 >> OVERFLOW_ADDR_SHIFT; 250 251 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 252 end_hi += 1; 253 } else { 254 return true; 255 } 256 257 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 258 259 if (end_hi) { 260 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 261 i, efi_md_typeattr_format(buf, sizeof(buf), md), 262 md->phys_addr, end_hi, end); 263 } else { 264 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 265 i, efi_md_typeattr_format(buf, sizeof(buf), md), 266 md->phys_addr, end); 267 } 268 return false; 269 } 270 271 static void __init efi_clean_memmap(void) 272 { 273 efi_memory_desc_t *out = efi.memmap.map; 274 const efi_memory_desc_t *in = out; 275 const efi_memory_desc_t *end = efi.memmap.map_end; 276 int i, n_removal; 277 278 for (i = n_removal = 0; in < end; i++) { 279 if (efi_memmap_entry_valid(in, i)) { 280 if (out != in) 281 memcpy(out, in, efi.memmap.desc_size); 282 out = (void *)out + efi.memmap.desc_size; 283 } else { 284 n_removal++; 285 } 286 in = (void *)in + efi.memmap.desc_size; 287 } 288 289 if (n_removal > 0) { 290 struct efi_memory_map_data data = { 291 .phys_map = efi.memmap.phys_map, 292 .desc_version = efi.memmap.desc_version, 293 .desc_size = efi.memmap.desc_size, 294 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal), 295 .flags = 0, 296 }; 297 298 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 299 efi_memmap_install(&data); 300 } 301 } 302 303 /* 304 * Firmware can use EfiMemoryMappedIO to request that MMIO regions be 305 * mapped by the OS so they can be accessed by EFI runtime services, but 306 * should have no other significance to the OS (UEFI r2.10, sec 7.2). 307 * However, most bootloaders and EFI stubs convert EfiMemoryMappedIO 308 * regions to E820_TYPE_RESERVED entries, which prevent Linux from 309 * allocating space from them (see remove_e820_regions()). 310 * 311 * Some platforms use EfiMemoryMappedIO entries for PCI MMCONFIG space and 312 * PCI host bridge windows, which means Linux can't allocate BAR space for 313 * hot-added devices. 314 * 315 * Remove large EfiMemoryMappedIO regions from the E820 map to avoid this 316 * problem. 317 * 318 * Retain small EfiMemoryMappedIO regions because on some platforms, these 319 * describe non-window space that's included in host bridge _CRS. If we 320 * assign that space to PCI devices, they don't work. 321 */ 322 static void __init efi_remove_e820_mmio(void) 323 { 324 efi_memory_desc_t *md; 325 u64 size, start, end; 326 int i = 0; 327 328 for_each_efi_memory_desc(md) { 329 if (md->type == EFI_MEMORY_MAPPED_IO) { 330 size = md->num_pages << EFI_PAGE_SHIFT; 331 start = md->phys_addr; 332 end = start + size - 1; 333 if (size >= 256*1024) { 334 pr_info("Remove mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluMB) from e820 map\n", 335 i, start, end, size >> 20); 336 e820__range_remove(start, size, E820_TYPE_RESERVED); 337 } else { 338 pr_info("Not removing mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluKB) from e820 map\n", 339 i, start, end, size >> 10); 340 } 341 } 342 i++; 343 } 344 } 345 346 void __init efi_print_memmap(void) 347 { 348 efi_memory_desc_t *md; 349 int i = 0; 350 351 for_each_efi_memory_desc(md) { 352 char buf[64]; 353 354 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 355 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 356 md->phys_addr, 357 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 358 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 359 } 360 } 361 362 static int __init efi_systab_init(unsigned long phys) 363 { 364 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t) 365 : sizeof(efi_system_table_32_t); 366 const efi_table_hdr_t *hdr; 367 bool over4g = false; 368 void *p; 369 int ret; 370 371 hdr = p = early_memremap_ro(phys, size); 372 if (p == NULL) { 373 pr_err("Couldn't map the system table!\n"); 374 return -ENOMEM; 375 } 376 377 ret = efi_systab_check_header(hdr); 378 if (ret) { 379 early_memunmap(p, size); 380 return ret; 381 } 382 383 if (efi_enabled(EFI_64BIT)) { 384 const efi_system_table_64_t *systab64 = p; 385 386 efi_runtime = systab64->runtime; 387 over4g = systab64->runtime > U32_MAX; 388 389 if (efi_setup) { 390 struct efi_setup_data *data; 391 392 data = early_memremap_ro(efi_setup, sizeof(*data)); 393 if (!data) { 394 early_memunmap(p, size); 395 return -ENOMEM; 396 } 397 398 efi_fw_vendor = (unsigned long)data->fw_vendor; 399 efi_config_table = (unsigned long)data->tables; 400 401 over4g |= data->fw_vendor > U32_MAX || 402 data->tables > U32_MAX; 403 404 early_memunmap(data, sizeof(*data)); 405 } else { 406 efi_fw_vendor = systab64->fw_vendor; 407 efi_config_table = systab64->tables; 408 409 over4g |= systab64->fw_vendor > U32_MAX || 410 systab64->tables > U32_MAX; 411 } 412 efi_nr_tables = systab64->nr_tables; 413 } else { 414 const efi_system_table_32_t *systab32 = p; 415 416 efi_fw_vendor = systab32->fw_vendor; 417 efi_runtime = systab32->runtime; 418 efi_config_table = systab32->tables; 419 efi_nr_tables = systab32->nr_tables; 420 } 421 422 efi.runtime_version = hdr->revision; 423 424 efi_systab_report_header(hdr, efi_fw_vendor); 425 early_memunmap(p, size); 426 427 if (IS_ENABLED(CONFIG_X86_32) && over4g) { 428 pr_err("EFI data located above 4GB, disabling EFI.\n"); 429 return -EINVAL; 430 } 431 432 return 0; 433 } 434 435 static int __init efi_config_init(const efi_config_table_type_t *arch_tables) 436 { 437 void *config_tables; 438 int sz, ret; 439 440 if (efi_nr_tables == 0) 441 return 0; 442 443 if (efi_enabled(EFI_64BIT)) 444 sz = sizeof(efi_config_table_64_t); 445 else 446 sz = sizeof(efi_config_table_32_t); 447 448 /* 449 * Let's see what config tables the firmware passed to us. 450 */ 451 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz); 452 if (config_tables == NULL) { 453 pr_err("Could not map Configuration table!\n"); 454 return -ENOMEM; 455 } 456 457 ret = efi_config_parse_tables(config_tables, efi_nr_tables, 458 arch_tables); 459 460 early_memunmap(config_tables, efi_nr_tables * sz); 461 return ret; 462 } 463 464 void __init efi_init(void) 465 { 466 if (IS_ENABLED(CONFIG_X86_32) && 467 (boot_params.efi_info.efi_systab_hi || 468 boot_params.efi_info.efi_memmap_hi)) { 469 pr_info("Table located above 4GB, disabling EFI.\n"); 470 return; 471 } 472 473 efi_systab_phys = boot_params.efi_info.efi_systab | 474 ((__u64)boot_params.efi_info.efi_systab_hi << 32); 475 476 if (efi_systab_init(efi_systab_phys)) 477 return; 478 479 if (efi_reuse_config(efi_config_table, efi_nr_tables)) 480 return; 481 482 if (efi_config_init(arch_tables)) 483 return; 484 485 /* 486 * Note: We currently don't support runtime services on an EFI 487 * that doesn't match the kernel 32/64-bit mode. 488 */ 489 490 if (!efi_runtime_supported()) 491 pr_err("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 492 493 if (!efi_runtime_supported() || efi_runtime_disabled()) { 494 efi_memmap_unmap(); 495 return; 496 } 497 498 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 499 efi_clean_memmap(); 500 501 efi_remove_e820_mmio(); 502 503 if (efi_enabled(EFI_DBG)) 504 efi_print_memmap(); 505 } 506 507 /* Merge contiguous regions of the same type and attribute */ 508 static void __init efi_merge_regions(void) 509 { 510 efi_memory_desc_t *md, *prev_md = NULL; 511 512 for_each_efi_memory_desc(md) { 513 u64 prev_size; 514 515 if (!prev_md) { 516 prev_md = md; 517 continue; 518 } 519 520 if (prev_md->type != md->type || 521 prev_md->attribute != md->attribute) { 522 prev_md = md; 523 continue; 524 } 525 526 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 527 528 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 529 prev_md->num_pages += md->num_pages; 530 md->type = EFI_RESERVED_TYPE; 531 md->attribute = 0; 532 continue; 533 } 534 prev_md = md; 535 } 536 } 537 538 static void *realloc_pages(void *old_memmap, int old_shift) 539 { 540 void *ret; 541 542 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 543 if (!ret) 544 goto out; 545 546 /* 547 * A first-time allocation doesn't have anything to copy. 548 */ 549 if (!old_memmap) 550 return ret; 551 552 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 553 554 out: 555 free_pages((unsigned long)old_memmap, old_shift); 556 return ret; 557 } 558 559 /* 560 * Iterate the EFI memory map in reverse order because the regions 561 * will be mapped top-down. The end result is the same as if we had 562 * mapped things forward, but doesn't require us to change the 563 * existing implementation of efi_map_region(). 564 */ 565 static inline void *efi_map_next_entry_reverse(void *entry) 566 { 567 /* Initial call */ 568 if (!entry) 569 return efi.memmap.map_end - efi.memmap.desc_size; 570 571 entry -= efi.memmap.desc_size; 572 if (entry < efi.memmap.map) 573 return NULL; 574 575 return entry; 576 } 577 578 /* 579 * efi_map_next_entry - Return the next EFI memory map descriptor 580 * @entry: Previous EFI memory map descriptor 581 * 582 * This is a helper function to iterate over the EFI memory map, which 583 * we do in different orders depending on the current configuration. 584 * 585 * To begin traversing the memory map @entry must be %NULL. 586 * 587 * Returns %NULL when we reach the end of the memory map. 588 */ 589 static void *efi_map_next_entry(void *entry) 590 { 591 if (efi_enabled(EFI_64BIT)) { 592 /* 593 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 594 * config table feature requires us to map all entries 595 * in the same order as they appear in the EFI memory 596 * map. That is to say, entry N must have a lower 597 * virtual address than entry N+1. This is because the 598 * firmware toolchain leaves relative references in 599 * the code/data sections, which are split and become 600 * separate EFI memory regions. Mapping things 601 * out-of-order leads to the firmware accessing 602 * unmapped addresses. 603 * 604 * Since we need to map things this way whether or not 605 * the kernel actually makes use of 606 * EFI_PROPERTIES_TABLE, let's just switch to this 607 * scheme by default for 64-bit. 608 */ 609 return efi_map_next_entry_reverse(entry); 610 } 611 612 /* Initial call */ 613 if (!entry) 614 return efi.memmap.map; 615 616 entry += efi.memmap.desc_size; 617 if (entry >= efi.memmap.map_end) 618 return NULL; 619 620 return entry; 621 } 622 623 static bool should_map_region(efi_memory_desc_t *md) 624 { 625 /* 626 * Runtime regions always require runtime mappings (obviously). 627 */ 628 if (md->attribute & EFI_MEMORY_RUNTIME) 629 return true; 630 631 /* 632 * 32-bit EFI doesn't suffer from the bug that requires us to 633 * reserve boot services regions, and mixed mode support 634 * doesn't exist for 32-bit kernels. 635 */ 636 if (IS_ENABLED(CONFIG_X86_32)) 637 return false; 638 639 /* 640 * EFI specific purpose memory may be reserved by default 641 * depending on kernel config and boot options. 642 */ 643 if (md->type == EFI_CONVENTIONAL_MEMORY && 644 efi_soft_reserve_enabled() && 645 (md->attribute & EFI_MEMORY_SP)) 646 return false; 647 648 /* 649 * Map all of RAM so that we can access arguments in the 1:1 650 * mapping when making EFI runtime calls. 651 */ 652 if (efi_is_mixed()) { 653 if (md->type == EFI_CONVENTIONAL_MEMORY || 654 md->type == EFI_LOADER_DATA || 655 md->type == EFI_LOADER_CODE) 656 return true; 657 } 658 659 /* 660 * Map boot services regions as a workaround for buggy 661 * firmware that accesses them even when they shouldn't. 662 * 663 * See efi_{reserve,free}_boot_services(). 664 */ 665 if (md->type == EFI_BOOT_SERVICES_CODE || 666 md->type == EFI_BOOT_SERVICES_DATA) 667 return true; 668 669 return false; 670 } 671 672 /* 673 * Map the efi memory ranges of the runtime services and update new_mmap with 674 * virtual addresses. 675 */ 676 static void * __init efi_map_regions(int *count, int *pg_shift) 677 { 678 void *p, *new_memmap = NULL; 679 unsigned long left = 0; 680 unsigned long desc_size; 681 efi_memory_desc_t *md; 682 683 desc_size = efi.memmap.desc_size; 684 685 p = NULL; 686 while ((p = efi_map_next_entry(p))) { 687 md = p; 688 689 if (!should_map_region(md)) 690 continue; 691 692 efi_map_region(md); 693 694 if (left < desc_size) { 695 new_memmap = realloc_pages(new_memmap, *pg_shift); 696 if (!new_memmap) 697 return NULL; 698 699 left += PAGE_SIZE << *pg_shift; 700 (*pg_shift)++; 701 } 702 703 memcpy(new_memmap + (*count * desc_size), md, desc_size); 704 705 left -= desc_size; 706 (*count)++; 707 } 708 709 return new_memmap; 710 } 711 712 static void __init kexec_enter_virtual_mode(void) 713 { 714 #ifdef CONFIG_KEXEC_CORE 715 efi_memory_desc_t *md; 716 unsigned int num_pages; 717 718 /* 719 * We don't do virtual mode, since we don't do runtime services, on 720 * non-native EFI. 721 */ 722 if (efi_is_mixed()) { 723 efi_memmap_unmap(); 724 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 725 return; 726 } 727 728 if (efi_alloc_page_tables()) { 729 pr_err("Failed to allocate EFI page tables\n"); 730 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 731 return; 732 } 733 734 /* 735 * Map efi regions which were passed via setup_data. The virt_addr is a 736 * fixed addr which was used in first kernel of a kexec boot. 737 */ 738 for_each_efi_memory_desc(md) 739 efi_map_region_fixed(md); /* FIXME: add error handling */ 740 741 /* 742 * Unregister the early EFI memmap from efi_init() and install 743 * the new EFI memory map. 744 */ 745 efi_memmap_unmap(); 746 747 if (efi_memmap_init_late(efi.memmap.phys_map, 748 efi.memmap.desc_size * efi.memmap.nr_map)) { 749 pr_err("Failed to remap late EFI memory map\n"); 750 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 751 return; 752 } 753 754 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 755 num_pages >>= PAGE_SHIFT; 756 757 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 758 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 759 return; 760 } 761 762 efi_sync_low_kernel_mappings(); 763 efi_native_runtime_setup(); 764 efi_runtime_update_mappings(); 765 #endif 766 } 767 768 /* 769 * This function will switch the EFI runtime services to virtual mode. 770 * Essentially, we look through the EFI memmap and map every region that 771 * has the runtime attribute bit set in its memory descriptor into the 772 * efi_pgd page table. 773 * 774 * The new method does a pagetable switch in a preemption-safe manner 775 * so that we're in a different address space when calling a runtime 776 * function. For function arguments passing we do copy the PUDs of the 777 * kernel page table into efi_pgd prior to each call. 778 * 779 * Specially for kexec boot, efi runtime maps in previous kernel should 780 * be passed in via setup_data. In that case runtime ranges will be mapped 781 * to the same virtual addresses as the first kernel, see 782 * kexec_enter_virtual_mode(). 783 */ 784 static void __init __efi_enter_virtual_mode(void) 785 { 786 int count = 0, pg_shift = 0; 787 void *new_memmap = NULL; 788 efi_status_t status; 789 unsigned long pa; 790 791 if (efi_alloc_page_tables()) { 792 pr_err("Failed to allocate EFI page tables\n"); 793 goto err; 794 } 795 796 efi_merge_regions(); 797 new_memmap = efi_map_regions(&count, &pg_shift); 798 if (!new_memmap) { 799 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 800 goto err; 801 } 802 803 pa = __pa(new_memmap); 804 805 /* 806 * Unregister the early EFI memmap from efi_init() and install 807 * the new EFI memory map that we are about to pass to the 808 * firmware via SetVirtualAddressMap(). 809 */ 810 efi_memmap_unmap(); 811 812 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 813 pr_err("Failed to remap late EFI memory map\n"); 814 goto err; 815 } 816 817 if (efi_enabled(EFI_DBG)) { 818 pr_info("EFI runtime memory map:\n"); 819 efi_print_memmap(); 820 } 821 822 if (efi_setup_page_tables(pa, 1 << pg_shift)) 823 goto err; 824 825 efi_sync_low_kernel_mappings(); 826 827 status = efi_set_virtual_address_map(efi.memmap.desc_size * count, 828 efi.memmap.desc_size, 829 efi.memmap.desc_version, 830 (efi_memory_desc_t *)pa, 831 efi_systab_phys); 832 if (status != EFI_SUCCESS) { 833 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n", 834 status); 835 goto err; 836 } 837 838 efi_check_for_embedded_firmwares(); 839 efi_free_boot_services(); 840 841 if (!efi_is_mixed()) 842 efi_native_runtime_setup(); 843 else 844 efi_thunk_runtime_setup(); 845 846 /* 847 * Apply more restrictive page table mapping attributes now that 848 * SVAM() has been called and the firmware has performed all 849 * necessary relocation fixups for the new virtual addresses. 850 */ 851 efi_runtime_update_mappings(); 852 853 /* clean DUMMY object */ 854 efi_delete_dummy_variable(); 855 return; 856 857 err: 858 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 859 } 860 861 void __init efi_enter_virtual_mode(void) 862 { 863 if (efi_enabled(EFI_PARAVIRT)) 864 return; 865 866 efi.runtime = (efi_runtime_services_t *)efi_runtime; 867 868 if (efi_setup) 869 kexec_enter_virtual_mode(); 870 else 871 __efi_enter_virtual_mode(); 872 873 efi_dump_pagetable(); 874 } 875 876 bool efi_is_table_address(unsigned long phys_addr) 877 { 878 unsigned int i; 879 880 if (phys_addr == EFI_INVALID_TABLE_ADDR) 881 return false; 882 883 for (i = 0; i < ARRAY_SIZE(efi_tables); i++) 884 if (*(efi_tables[i]) == phys_addr) 885 return true; 886 887 return false; 888 } 889 890 #define EFI_FIELD(var) efi_ ## var 891 892 #define EFI_ATTR_SHOW(name) \ 893 static ssize_t name##_show(struct kobject *kobj, \ 894 struct kobj_attribute *attr, char *buf) \ 895 { \ 896 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \ 897 } 898 899 EFI_ATTR_SHOW(fw_vendor); 900 EFI_ATTR_SHOW(runtime); 901 EFI_ATTR_SHOW(config_table); 902 903 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); 904 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); 905 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); 906 907 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) 908 { 909 if (attr == &efi_attr_fw_vendor.attr) { 910 if (efi_enabled(EFI_PARAVIRT) || 911 efi_fw_vendor == EFI_INVALID_TABLE_ADDR) 912 return 0; 913 } else if (attr == &efi_attr_runtime.attr) { 914 if (efi_runtime == EFI_INVALID_TABLE_ADDR) 915 return 0; 916 } else if (attr == &efi_attr_config_table.attr) { 917 if (efi_config_table == EFI_INVALID_TABLE_ADDR) 918 return 0; 919 } 920 return attr->mode; 921 } 922 923 enum efi_secureboot_mode __x86_ima_efi_boot_mode(void) 924 { 925 return boot_params.secure_boot; 926 } 927