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