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 #ifdef CONFIG_UNACCEPTED_MEMORY 100 &efi.unaccepted, 101 #endif 102 }; 103 104 u64 efi_setup; /* efi setup_data physical address */ 105 106 static int add_efi_memmap __initdata; 107 static int __init setup_add_efi_memmap(char *arg) 108 { 109 add_efi_memmap = 1; 110 return 0; 111 } 112 early_param("add_efi_memmap", setup_add_efi_memmap); 113 114 /* 115 * Tell the kernel about the EFI memory map. This might include 116 * more than the max 128 entries that can fit in the passed in e820 117 * legacy (zeropage) memory map, but the kernel's e820 table can hold 118 * E820_MAX_ENTRIES. 119 */ 120 121 static void __init do_add_efi_memmap(void) 122 { 123 efi_memory_desc_t *md; 124 125 if (!efi_enabled(EFI_MEMMAP)) 126 return; 127 128 for_each_efi_memory_desc(md) { 129 unsigned long long start = md->phys_addr; 130 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 131 int e820_type; 132 133 switch (md->type) { 134 case EFI_LOADER_CODE: 135 case EFI_LOADER_DATA: 136 case EFI_BOOT_SERVICES_CODE: 137 case EFI_BOOT_SERVICES_DATA: 138 case EFI_CONVENTIONAL_MEMORY: 139 if (efi_soft_reserve_enabled() 140 && (md->attribute & EFI_MEMORY_SP)) 141 e820_type = E820_TYPE_SOFT_RESERVED; 142 else if (md->attribute & EFI_MEMORY_WB) 143 e820_type = E820_TYPE_RAM; 144 else 145 e820_type = E820_TYPE_RESERVED; 146 break; 147 case EFI_ACPI_RECLAIM_MEMORY: 148 e820_type = E820_TYPE_ACPI; 149 break; 150 case EFI_ACPI_MEMORY_NVS: 151 e820_type = E820_TYPE_NVS; 152 break; 153 case EFI_UNUSABLE_MEMORY: 154 e820_type = E820_TYPE_UNUSABLE; 155 break; 156 case EFI_PERSISTENT_MEMORY: 157 e820_type = E820_TYPE_PMEM; 158 break; 159 default: 160 /* 161 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 162 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 163 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 164 */ 165 e820_type = E820_TYPE_RESERVED; 166 break; 167 } 168 169 e820__range_add(start, size, e820_type); 170 } 171 e820__update_table(e820_table); 172 } 173 174 /* 175 * Given add_efi_memmap defaults to 0 and there is no alternative 176 * e820 mechanism for soft-reserved memory, import the full EFI memory 177 * map if soft reservations are present and enabled. Otherwise, the 178 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is 179 * the efi=nosoftreserve option. 180 */ 181 static bool do_efi_soft_reserve(void) 182 { 183 efi_memory_desc_t *md; 184 185 if (!efi_enabled(EFI_MEMMAP)) 186 return false; 187 188 if (!efi_soft_reserve_enabled()) 189 return false; 190 191 for_each_efi_memory_desc(md) 192 if (md->type == EFI_CONVENTIONAL_MEMORY && 193 (md->attribute & EFI_MEMORY_SP)) 194 return true; 195 return false; 196 } 197 198 int __init efi_memblock_x86_reserve_range(void) 199 { 200 struct efi_info *e = &boot_params.efi_info; 201 struct efi_memory_map_data data; 202 phys_addr_t pmap; 203 int rv; 204 205 if (efi_enabled(EFI_PARAVIRT)) 206 return 0; 207 208 /* Can't handle firmware tables above 4GB on i386 */ 209 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) { 210 pr_err("Memory map is above 4GB, disabling EFI.\n"); 211 return -EINVAL; 212 } 213 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32)); 214 215 data.phys_map = pmap; 216 data.size = e->efi_memmap_size; 217 data.desc_size = e->efi_memdesc_size; 218 data.desc_version = e->efi_memdesc_version; 219 220 if (!efi_enabled(EFI_PARAVIRT)) { 221 rv = efi_memmap_init_early(&data); 222 if (rv) 223 return rv; 224 } 225 226 if (add_efi_memmap || do_efi_soft_reserve()) 227 do_add_efi_memmap(); 228 229 WARN(efi.memmap.desc_version != 1, 230 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 231 efi.memmap.desc_version); 232 233 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); 234 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags); 235 236 return 0; 237 } 238 239 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 240 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 241 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 242 243 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 244 { 245 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 246 u64 end_hi = 0; 247 char buf[64]; 248 249 if (md->num_pages == 0) { 250 end = 0; 251 } else if (md->num_pages > EFI_PAGES_MAX || 252 EFI_PAGES_MAX - md->num_pages < 253 (md->phys_addr >> EFI_PAGE_SHIFT)) { 254 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 255 >> OVERFLOW_ADDR_SHIFT; 256 257 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 258 end_hi += 1; 259 } else { 260 return true; 261 } 262 263 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 264 265 if (end_hi) { 266 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 267 i, efi_md_typeattr_format(buf, sizeof(buf), md), 268 md->phys_addr, end_hi, end); 269 } else { 270 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 271 i, efi_md_typeattr_format(buf, sizeof(buf), md), 272 md->phys_addr, end); 273 } 274 return false; 275 } 276 277 static void __init efi_clean_memmap(void) 278 { 279 efi_memory_desc_t *out = efi.memmap.map; 280 const efi_memory_desc_t *in = out; 281 const efi_memory_desc_t *end = efi.memmap.map_end; 282 int i, n_removal; 283 284 for (i = n_removal = 0; in < end; i++) { 285 if (efi_memmap_entry_valid(in, i)) { 286 if (out != in) 287 memcpy(out, in, efi.memmap.desc_size); 288 out = (void *)out + efi.memmap.desc_size; 289 } else { 290 n_removal++; 291 } 292 in = (void *)in + efi.memmap.desc_size; 293 } 294 295 if (n_removal > 0) { 296 struct efi_memory_map_data data = { 297 .phys_map = efi.memmap.phys_map, 298 .desc_version = efi.memmap.desc_version, 299 .desc_size = efi.memmap.desc_size, 300 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal), 301 .flags = 0, 302 }; 303 304 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 305 efi_memmap_install(&data); 306 } 307 } 308 309 /* 310 * Firmware can use EfiMemoryMappedIO to request that MMIO regions be 311 * mapped by the OS so they can be accessed by EFI runtime services, but 312 * should have no other significance to the OS (UEFI r2.10, sec 7.2). 313 * However, most bootloaders and EFI stubs convert EfiMemoryMappedIO 314 * regions to E820_TYPE_RESERVED entries, which prevent Linux from 315 * allocating space from them (see remove_e820_regions()). 316 * 317 * Some platforms use EfiMemoryMappedIO entries for PCI MMCONFIG space and 318 * PCI host bridge windows, which means Linux can't allocate BAR space for 319 * hot-added devices. 320 * 321 * Remove large EfiMemoryMappedIO regions from the E820 map to avoid this 322 * problem. 323 * 324 * Retain small EfiMemoryMappedIO regions because on some platforms, these 325 * describe non-window space that's included in host bridge _CRS. If we 326 * assign that space to PCI devices, they don't work. 327 */ 328 static void __init efi_remove_e820_mmio(void) 329 { 330 efi_memory_desc_t *md; 331 u64 size, start, end; 332 int i = 0; 333 334 for_each_efi_memory_desc(md) { 335 if (md->type == EFI_MEMORY_MAPPED_IO) { 336 size = md->num_pages << EFI_PAGE_SHIFT; 337 start = md->phys_addr; 338 end = start + size - 1; 339 if (size >= 256*1024) { 340 pr_info("Remove mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluMB) from e820 map\n", 341 i, start, end, size >> 20); 342 e820__range_remove(start, size, 343 E820_TYPE_RESERVED, 1); 344 } else { 345 pr_info("Not removing mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluKB) from e820 map\n", 346 i, start, end, size >> 10); 347 } 348 } 349 i++; 350 } 351 } 352 353 void __init efi_print_memmap(void) 354 { 355 efi_memory_desc_t *md; 356 int i = 0; 357 358 for_each_efi_memory_desc(md) { 359 char buf[64]; 360 361 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 362 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 363 md->phys_addr, 364 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 365 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 366 } 367 } 368 369 static int __init efi_systab_init(unsigned long phys) 370 { 371 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t) 372 : sizeof(efi_system_table_32_t); 373 const efi_table_hdr_t *hdr; 374 bool over4g = false; 375 void *p; 376 int ret; 377 378 hdr = p = early_memremap_ro(phys, size); 379 if (p == NULL) { 380 pr_err("Couldn't map the system table!\n"); 381 return -ENOMEM; 382 } 383 384 ret = efi_systab_check_header(hdr); 385 if (ret) { 386 early_memunmap(p, size); 387 return ret; 388 } 389 390 if (efi_enabled(EFI_64BIT)) { 391 const efi_system_table_64_t *systab64 = p; 392 393 efi_runtime = systab64->runtime; 394 over4g = systab64->runtime > U32_MAX; 395 396 if (efi_setup) { 397 struct efi_setup_data *data; 398 399 data = early_memremap_ro(efi_setup, sizeof(*data)); 400 if (!data) { 401 early_memunmap(p, size); 402 return -ENOMEM; 403 } 404 405 efi_fw_vendor = (unsigned long)data->fw_vendor; 406 efi_config_table = (unsigned long)data->tables; 407 408 over4g |= data->fw_vendor > U32_MAX || 409 data->tables > U32_MAX; 410 411 early_memunmap(data, sizeof(*data)); 412 } else { 413 efi_fw_vendor = systab64->fw_vendor; 414 efi_config_table = systab64->tables; 415 416 over4g |= systab64->fw_vendor > U32_MAX || 417 systab64->tables > U32_MAX; 418 } 419 efi_nr_tables = systab64->nr_tables; 420 } else { 421 const efi_system_table_32_t *systab32 = p; 422 423 efi_fw_vendor = systab32->fw_vendor; 424 efi_runtime = systab32->runtime; 425 efi_config_table = systab32->tables; 426 efi_nr_tables = systab32->nr_tables; 427 } 428 429 efi.runtime_version = hdr->revision; 430 431 efi_systab_report_header(hdr, efi_fw_vendor); 432 early_memunmap(p, size); 433 434 if (IS_ENABLED(CONFIG_X86_32) && over4g) { 435 pr_err("EFI data located above 4GB, disabling EFI.\n"); 436 return -EINVAL; 437 } 438 439 return 0; 440 } 441 442 static int __init efi_config_init(const efi_config_table_type_t *arch_tables) 443 { 444 void *config_tables; 445 int sz, ret; 446 447 if (efi_nr_tables == 0) 448 return 0; 449 450 if (efi_enabled(EFI_64BIT)) 451 sz = sizeof(efi_config_table_64_t); 452 else 453 sz = sizeof(efi_config_table_32_t); 454 455 /* 456 * Let's see what config tables the firmware passed to us. 457 */ 458 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz); 459 if (config_tables == NULL) { 460 pr_err("Could not map Configuration table!\n"); 461 return -ENOMEM; 462 } 463 464 ret = efi_config_parse_tables(config_tables, efi_nr_tables, 465 arch_tables); 466 467 early_memunmap(config_tables, efi_nr_tables * sz); 468 return ret; 469 } 470 471 void __init efi_init(void) 472 { 473 if (IS_ENABLED(CONFIG_X86_32) && 474 (boot_params.efi_info.efi_systab_hi || 475 boot_params.efi_info.efi_memmap_hi)) { 476 pr_info("Table located above 4GB, disabling EFI.\n"); 477 return; 478 } 479 480 efi_systab_phys = boot_params.efi_info.efi_systab | 481 ((__u64)boot_params.efi_info.efi_systab_hi << 32); 482 483 if (efi_systab_init(efi_systab_phys)) 484 return; 485 486 if (efi_reuse_config(efi_config_table, efi_nr_tables)) 487 return; 488 489 if (efi_config_init(arch_tables)) 490 return; 491 492 /* 493 * Note: We currently don't support runtime services on an EFI 494 * that doesn't match the kernel 32/64-bit mode. 495 */ 496 497 if (!efi_runtime_supported()) 498 pr_err("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 499 500 if (!efi_runtime_supported() || efi_runtime_disabled()) { 501 efi_memmap_unmap(); 502 return; 503 } 504 505 /* Parse the EFI Properties table if it exists */ 506 if (prop_phys != EFI_INVALID_TABLE_ADDR) { 507 efi_properties_table_t *tbl; 508 509 tbl = early_memremap_ro(prop_phys, sizeof(*tbl)); 510 if (tbl == NULL) { 511 pr_err("Could not map Properties table!\n"); 512 } else { 513 if (tbl->memory_protection_attribute & 514 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA) 515 set_bit(EFI_NX_PE_DATA, &efi.flags); 516 517 early_memunmap(tbl, sizeof(*tbl)); 518 } 519 } 520 521 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 522 efi_clean_memmap(); 523 524 efi_remove_e820_mmio(); 525 526 if (efi_enabled(EFI_DBG)) 527 efi_print_memmap(); 528 } 529 530 /* Merge contiguous regions of the same type and attribute */ 531 static void __init efi_merge_regions(void) 532 { 533 efi_memory_desc_t *md, *prev_md = NULL; 534 535 for_each_efi_memory_desc(md) { 536 u64 prev_size; 537 538 if (!prev_md) { 539 prev_md = md; 540 continue; 541 } 542 543 if (prev_md->type != md->type || 544 prev_md->attribute != md->attribute) { 545 prev_md = md; 546 continue; 547 } 548 549 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 550 551 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 552 prev_md->num_pages += md->num_pages; 553 md->type = EFI_RESERVED_TYPE; 554 md->attribute = 0; 555 continue; 556 } 557 prev_md = md; 558 } 559 } 560 561 static void *realloc_pages(void *old_memmap, int old_shift) 562 { 563 void *ret; 564 565 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 566 if (!ret) 567 goto out; 568 569 /* 570 * A first-time allocation doesn't have anything to copy. 571 */ 572 if (!old_memmap) 573 return ret; 574 575 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 576 577 out: 578 free_pages((unsigned long)old_memmap, old_shift); 579 return ret; 580 } 581 582 /* 583 * Iterate the EFI memory map in reverse order because the regions 584 * will be mapped top-down. The end result is the same as if we had 585 * mapped things forward, but doesn't require us to change the 586 * existing implementation of efi_map_region(). 587 */ 588 static inline void *efi_map_next_entry_reverse(void *entry) 589 { 590 /* Initial call */ 591 if (!entry) 592 return efi.memmap.map_end - efi.memmap.desc_size; 593 594 entry -= efi.memmap.desc_size; 595 if (entry < efi.memmap.map) 596 return NULL; 597 598 return entry; 599 } 600 601 /* 602 * efi_map_next_entry - Return the next EFI memory map descriptor 603 * @entry: Previous EFI memory map descriptor 604 * 605 * This is a helper function to iterate over the EFI memory map, which 606 * we do in different orders depending on the current configuration. 607 * 608 * To begin traversing the memory map @entry must be %NULL. 609 * 610 * Returns %NULL when we reach the end of the memory map. 611 */ 612 static void *efi_map_next_entry(void *entry) 613 { 614 if (efi_enabled(EFI_64BIT)) { 615 /* 616 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 617 * config table feature requires us to map all entries 618 * in the same order as they appear in the EFI memory 619 * map. That is to say, entry N must have a lower 620 * virtual address than entry N+1. This is because the 621 * firmware toolchain leaves relative references in 622 * the code/data sections, which are split and become 623 * separate EFI memory regions. Mapping things 624 * out-of-order leads to the firmware accessing 625 * unmapped addresses. 626 * 627 * Since we need to map things this way whether or not 628 * the kernel actually makes use of 629 * EFI_PROPERTIES_TABLE, let's just switch to this 630 * scheme by default for 64-bit. 631 */ 632 return efi_map_next_entry_reverse(entry); 633 } 634 635 /* Initial call */ 636 if (!entry) 637 return efi.memmap.map; 638 639 entry += efi.memmap.desc_size; 640 if (entry >= efi.memmap.map_end) 641 return NULL; 642 643 return entry; 644 } 645 646 static bool should_map_region(efi_memory_desc_t *md) 647 { 648 /* 649 * Runtime regions always require runtime mappings (obviously). 650 */ 651 if (md->attribute & EFI_MEMORY_RUNTIME) 652 return true; 653 654 /* 655 * 32-bit EFI doesn't suffer from the bug that requires us to 656 * reserve boot services regions, and mixed mode support 657 * doesn't exist for 32-bit kernels. 658 */ 659 if (IS_ENABLED(CONFIG_X86_32)) 660 return false; 661 662 /* 663 * EFI specific purpose memory may be reserved by default 664 * depending on kernel config and boot options. 665 */ 666 if (md->type == EFI_CONVENTIONAL_MEMORY && 667 efi_soft_reserve_enabled() && 668 (md->attribute & EFI_MEMORY_SP)) 669 return false; 670 671 /* 672 * Map all of RAM so that we can access arguments in the 1:1 673 * mapping when making EFI runtime calls. 674 */ 675 if (efi_is_mixed()) { 676 if (md->type == EFI_CONVENTIONAL_MEMORY || 677 md->type == EFI_LOADER_DATA || 678 md->type == EFI_LOADER_CODE) 679 return true; 680 } 681 682 /* 683 * Map boot services regions as a workaround for buggy 684 * firmware that accesses them even when they shouldn't. 685 * 686 * See efi_{reserve,free}_boot_services(). 687 */ 688 if (md->type == EFI_BOOT_SERVICES_CODE || 689 md->type == EFI_BOOT_SERVICES_DATA) 690 return true; 691 692 return false; 693 } 694 695 /* 696 * Map the efi memory ranges of the runtime services and update new_mmap with 697 * virtual addresses. 698 */ 699 static void * __init efi_map_regions(int *count, int *pg_shift) 700 { 701 void *p, *new_memmap = NULL; 702 unsigned long left = 0; 703 unsigned long desc_size; 704 efi_memory_desc_t *md; 705 706 desc_size = efi.memmap.desc_size; 707 708 p = NULL; 709 while ((p = efi_map_next_entry(p))) { 710 md = p; 711 712 if (!should_map_region(md)) 713 continue; 714 715 efi_map_region(md); 716 717 if (left < desc_size) { 718 new_memmap = realloc_pages(new_memmap, *pg_shift); 719 if (!new_memmap) 720 return NULL; 721 722 left += PAGE_SIZE << *pg_shift; 723 (*pg_shift)++; 724 } 725 726 memcpy(new_memmap + (*count * desc_size), md, desc_size); 727 728 left -= desc_size; 729 (*count)++; 730 } 731 732 return new_memmap; 733 } 734 735 static void __init kexec_enter_virtual_mode(void) 736 { 737 #ifdef CONFIG_KEXEC_CORE 738 efi_memory_desc_t *md; 739 unsigned int num_pages; 740 741 /* 742 * We don't do virtual mode, since we don't do runtime services, on 743 * non-native EFI. 744 */ 745 if (efi_is_mixed()) { 746 efi_memmap_unmap(); 747 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 748 return; 749 } 750 751 if (efi_alloc_page_tables()) { 752 pr_err("Failed to allocate EFI page tables\n"); 753 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 754 return; 755 } 756 757 /* 758 * Map efi regions which were passed via setup_data. The virt_addr is a 759 * fixed addr which was used in first kernel of a kexec boot. 760 */ 761 for_each_efi_memory_desc(md) 762 efi_map_region_fixed(md); /* FIXME: add error handling */ 763 764 /* 765 * Unregister the early EFI memmap from efi_init() and install 766 * the new EFI memory map. 767 */ 768 efi_memmap_unmap(); 769 770 if (efi_memmap_init_late(efi.memmap.phys_map, 771 efi.memmap.desc_size * efi.memmap.nr_map)) { 772 pr_err("Failed to remap late EFI memory map\n"); 773 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 774 return; 775 } 776 777 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 778 num_pages >>= PAGE_SHIFT; 779 780 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 781 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 782 return; 783 } 784 785 efi_sync_low_kernel_mappings(); 786 efi_native_runtime_setup(); 787 #endif 788 } 789 790 /* 791 * This function will switch the EFI runtime services to virtual mode. 792 * Essentially, we look through the EFI memmap and map every region that 793 * has the runtime attribute bit set in its memory descriptor into the 794 * efi_pgd page table. 795 * 796 * The new method does a pagetable switch in a preemption-safe manner 797 * so that we're in a different address space when calling a runtime 798 * function. For function arguments passing we do copy the PUDs of the 799 * kernel page table into efi_pgd prior to each call. 800 * 801 * Specially for kexec boot, efi runtime maps in previous kernel should 802 * be passed in via setup_data. In that case runtime ranges will be mapped 803 * to the same virtual addresses as the first kernel, see 804 * kexec_enter_virtual_mode(). 805 */ 806 static void __init __efi_enter_virtual_mode(void) 807 { 808 int count = 0, pg_shift = 0; 809 void *new_memmap = NULL; 810 efi_status_t status; 811 unsigned long pa; 812 813 if (efi_alloc_page_tables()) { 814 pr_err("Failed to allocate EFI page tables\n"); 815 goto err; 816 } 817 818 efi_merge_regions(); 819 new_memmap = efi_map_regions(&count, &pg_shift); 820 if (!new_memmap) { 821 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 822 goto err; 823 } 824 825 pa = __pa(new_memmap); 826 827 /* 828 * Unregister the early EFI memmap from efi_init() and install 829 * the new EFI memory map that we are about to pass to the 830 * firmware via SetVirtualAddressMap(). 831 */ 832 efi_memmap_unmap(); 833 834 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 835 pr_err("Failed to remap late EFI memory map\n"); 836 goto err; 837 } 838 839 if (efi_enabled(EFI_DBG)) { 840 pr_info("EFI runtime memory map:\n"); 841 efi_print_memmap(); 842 } 843 844 if (efi_setup_page_tables(pa, 1 << pg_shift)) 845 goto err; 846 847 efi_sync_low_kernel_mappings(); 848 849 status = efi_set_virtual_address_map(efi.memmap.desc_size * count, 850 efi.memmap.desc_size, 851 efi.memmap.desc_version, 852 (efi_memory_desc_t *)pa, 853 efi_systab_phys); 854 if (status != EFI_SUCCESS) { 855 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n", 856 status); 857 goto err; 858 } 859 860 efi_check_for_embedded_firmwares(); 861 efi_free_boot_services(); 862 863 if (!efi_is_mixed()) 864 efi_native_runtime_setup(); 865 else 866 efi_thunk_runtime_setup(); 867 868 /* 869 * Apply more restrictive page table mapping attributes now that 870 * SVAM() has been called and the firmware has performed all 871 * necessary relocation fixups for the new virtual addresses. 872 */ 873 efi_runtime_update_mappings(); 874 875 /* clean DUMMY object */ 876 efi_delete_dummy_variable(); 877 return; 878 879 err: 880 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 881 } 882 883 void __init efi_enter_virtual_mode(void) 884 { 885 if (efi_enabled(EFI_PARAVIRT)) 886 return; 887 888 efi.runtime = (efi_runtime_services_t *)efi_runtime; 889 890 if (efi_setup) 891 kexec_enter_virtual_mode(); 892 else 893 __efi_enter_virtual_mode(); 894 895 efi_dump_pagetable(); 896 } 897 898 bool efi_is_table_address(unsigned long phys_addr) 899 { 900 unsigned int i; 901 902 if (phys_addr == EFI_INVALID_TABLE_ADDR) 903 return false; 904 905 for (i = 0; i < ARRAY_SIZE(efi_tables); i++) 906 if (*(efi_tables[i]) == phys_addr) 907 return true; 908 909 return false; 910 } 911 912 char *efi_systab_show_arch(char *str) 913 { 914 if (uga_phys != EFI_INVALID_TABLE_ADDR) 915 str += sprintf(str, "UGA=0x%lx\n", uga_phys); 916 return str; 917 } 918 919 #define EFI_FIELD(var) efi_ ## var 920 921 #define EFI_ATTR_SHOW(name) \ 922 static ssize_t name##_show(struct kobject *kobj, \ 923 struct kobj_attribute *attr, char *buf) \ 924 { \ 925 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \ 926 } 927 928 EFI_ATTR_SHOW(fw_vendor); 929 EFI_ATTR_SHOW(runtime); 930 EFI_ATTR_SHOW(config_table); 931 932 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); 933 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); 934 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); 935 936 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) 937 { 938 if (attr == &efi_attr_fw_vendor.attr) { 939 if (efi_enabled(EFI_PARAVIRT) || 940 efi_fw_vendor == EFI_INVALID_TABLE_ADDR) 941 return 0; 942 } else if (attr == &efi_attr_runtime.attr) { 943 if (efi_runtime == EFI_INVALID_TABLE_ADDR) 944 return 0; 945 } else if (attr == &efi_attr_config_table.attr) { 946 if (efi_config_table == EFI_INVALID_TABLE_ADDR) 947 return 0; 948 } 949 return attr->mode; 950 } 951 952 enum efi_secureboot_mode __x86_ima_efi_boot_mode(void) 953 { 954 return boot_params.secure_boot; 955 } 956