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