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