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/set_memory.h> 53 #include <asm/tlbflush.h> 54 #include <asm/x86_init.h> 55 #include <asm/uv/uv.h> 56 57 static unsigned long efi_systab_phys __initdata; 58 static unsigned long prop_phys = EFI_INVALID_TABLE_ADDR; 59 static unsigned long uga_phys = EFI_INVALID_TABLE_ADDR; 60 static unsigned long efi_runtime, efi_nr_tables; 61 62 unsigned long efi_fw_vendor, efi_config_table; 63 64 static const efi_config_table_type_t arch_tables[] __initconst = { 65 {EFI_PROPERTIES_TABLE_GUID, &prop_phys, "PROP" }, 66 {UGA_IO_PROTOCOL_GUID, &uga_phys, "UGA" }, 67 #ifdef CONFIG_X86_UV 68 {UV_SYSTEM_TABLE_GUID, &uv_systab_phys, "UVsystab" }, 69 #endif 70 {}, 71 }; 72 73 static const unsigned long * const efi_tables[] = { 74 &efi.acpi, 75 &efi.acpi20, 76 &efi.smbios, 77 &efi.smbios3, 78 &uga_phys, 79 #ifdef CONFIG_X86_UV 80 &uv_systab_phys, 81 #endif 82 &efi_fw_vendor, 83 &efi_runtime, 84 &efi_config_table, 85 &efi.esrt, 86 &prop_phys, 87 &efi_mem_attr_table, 88 #ifdef CONFIG_EFI_RCI2_TABLE 89 &rci2_table_phys, 90 #endif 91 &efi.tpm_log, 92 &efi.tpm_final_log, 93 &efi_rng_seed, 94 }; 95 96 u64 efi_setup; /* efi setup_data physical address */ 97 98 static int add_efi_memmap __initdata; 99 static int __init setup_add_efi_memmap(char *arg) 100 { 101 add_efi_memmap = 1; 102 return 0; 103 } 104 early_param("add_efi_memmap", setup_add_efi_memmap); 105 106 void __init efi_find_mirror(void) 107 { 108 efi_memory_desc_t *md; 109 u64 mirror_size = 0, total_size = 0; 110 111 if (!efi_enabled(EFI_MEMMAP)) 112 return; 113 114 for_each_efi_memory_desc(md) { 115 unsigned long long start = md->phys_addr; 116 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 117 118 total_size += size; 119 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { 120 memblock_mark_mirror(start, size); 121 mirror_size += size; 122 } 123 } 124 if (mirror_size) 125 pr_info("Memory: %lldM/%lldM mirrored memory\n", 126 mirror_size>>20, total_size>>20); 127 } 128 129 /* 130 * Tell the kernel about the EFI memory map. This might include 131 * more than the max 128 entries that can fit in the passed in e820 132 * legacy (zeropage) memory map, but the kernel's e820 table can hold 133 * E820_MAX_ENTRIES. 134 */ 135 136 static void __init do_add_efi_memmap(void) 137 { 138 efi_memory_desc_t *md; 139 140 if (!efi_enabled(EFI_MEMMAP)) 141 return; 142 143 for_each_efi_memory_desc(md) { 144 unsigned long long start = md->phys_addr; 145 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 146 int e820_type; 147 148 switch (md->type) { 149 case EFI_LOADER_CODE: 150 case EFI_LOADER_DATA: 151 case EFI_BOOT_SERVICES_CODE: 152 case EFI_BOOT_SERVICES_DATA: 153 case EFI_CONVENTIONAL_MEMORY: 154 if (efi_soft_reserve_enabled() 155 && (md->attribute & EFI_MEMORY_SP)) 156 e820_type = E820_TYPE_SOFT_RESERVED; 157 else if (md->attribute & EFI_MEMORY_WB) 158 e820_type = E820_TYPE_RAM; 159 else 160 e820_type = E820_TYPE_RESERVED; 161 break; 162 case EFI_ACPI_RECLAIM_MEMORY: 163 e820_type = E820_TYPE_ACPI; 164 break; 165 case EFI_ACPI_MEMORY_NVS: 166 e820_type = E820_TYPE_NVS; 167 break; 168 case EFI_UNUSABLE_MEMORY: 169 e820_type = E820_TYPE_UNUSABLE; 170 break; 171 case EFI_PERSISTENT_MEMORY: 172 e820_type = E820_TYPE_PMEM; 173 break; 174 default: 175 /* 176 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 177 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 178 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 179 */ 180 e820_type = E820_TYPE_RESERVED; 181 break; 182 } 183 184 e820__range_add(start, size, e820_type); 185 } 186 e820__update_table(e820_table); 187 } 188 189 /* 190 * Given add_efi_memmap defaults to 0 and there there is no alternative 191 * e820 mechanism for soft-reserved memory, import the full EFI memory 192 * map if soft reservations are present and enabled. Otherwise, the 193 * mechanism to disable the kernel's consideration of EFI_MEMORY_SP is 194 * the efi=nosoftreserve option. 195 */ 196 static bool do_efi_soft_reserve(void) 197 { 198 efi_memory_desc_t *md; 199 200 if (!efi_enabled(EFI_MEMMAP)) 201 return false; 202 203 if (!efi_soft_reserve_enabled()) 204 return false; 205 206 for_each_efi_memory_desc(md) 207 if (md->type == EFI_CONVENTIONAL_MEMORY && 208 (md->attribute & EFI_MEMORY_SP)) 209 return true; 210 return false; 211 } 212 213 int __init efi_memblock_x86_reserve_range(void) 214 { 215 struct efi_info *e = &boot_params.efi_info; 216 struct efi_memory_map_data data; 217 phys_addr_t pmap; 218 int rv; 219 220 if (efi_enabled(EFI_PARAVIRT)) 221 return 0; 222 223 /* Can't handle firmware tables above 4GB on i386 */ 224 if (IS_ENABLED(CONFIG_X86_32) && e->efi_memmap_hi > 0) { 225 pr_err("Memory map is above 4GB, disabling EFI.\n"); 226 return -EINVAL; 227 } 228 pmap = (phys_addr_t)(e->efi_memmap | ((u64)e->efi_memmap_hi << 32)); 229 230 data.phys_map = pmap; 231 data.size = e->efi_memmap_size; 232 data.desc_size = e->efi_memdesc_size; 233 data.desc_version = e->efi_memdesc_version; 234 235 rv = efi_memmap_init_early(&data); 236 if (rv) 237 return rv; 238 239 if (add_efi_memmap || do_efi_soft_reserve()) 240 do_add_efi_memmap(); 241 242 efi_fake_memmap_early(); 243 244 WARN(efi.memmap.desc_version != 1, 245 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 246 efi.memmap.desc_version); 247 248 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); 249 set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags); 250 251 return 0; 252 } 253 254 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 255 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 256 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 257 258 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 259 { 260 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 261 u64 end_hi = 0; 262 char buf[64]; 263 264 if (md->num_pages == 0) { 265 end = 0; 266 } else if (md->num_pages > EFI_PAGES_MAX || 267 EFI_PAGES_MAX - md->num_pages < 268 (md->phys_addr >> EFI_PAGE_SHIFT)) { 269 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 270 >> OVERFLOW_ADDR_SHIFT; 271 272 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 273 end_hi += 1; 274 } else { 275 return true; 276 } 277 278 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 279 280 if (end_hi) { 281 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 282 i, efi_md_typeattr_format(buf, sizeof(buf), md), 283 md->phys_addr, end_hi, end); 284 } else { 285 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 286 i, efi_md_typeattr_format(buf, sizeof(buf), md), 287 md->phys_addr, end); 288 } 289 return false; 290 } 291 292 static void __init efi_clean_memmap(void) 293 { 294 efi_memory_desc_t *out = efi.memmap.map; 295 const efi_memory_desc_t *in = out; 296 const efi_memory_desc_t *end = efi.memmap.map_end; 297 int i, n_removal; 298 299 for (i = n_removal = 0; in < end; i++) { 300 if (efi_memmap_entry_valid(in, i)) { 301 if (out != in) 302 memcpy(out, in, efi.memmap.desc_size); 303 out = (void *)out + efi.memmap.desc_size; 304 } else { 305 n_removal++; 306 } 307 in = (void *)in + efi.memmap.desc_size; 308 } 309 310 if (n_removal > 0) { 311 struct efi_memory_map_data data = { 312 .phys_map = efi.memmap.phys_map, 313 .desc_version = efi.memmap.desc_version, 314 .desc_size = efi.memmap.desc_size, 315 .size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal), 316 .flags = 0, 317 }; 318 319 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 320 efi_memmap_install(&data); 321 } 322 } 323 324 void __init efi_print_memmap(void) 325 { 326 efi_memory_desc_t *md; 327 int i = 0; 328 329 for_each_efi_memory_desc(md) { 330 char buf[64]; 331 332 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 333 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 334 md->phys_addr, 335 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 336 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 337 } 338 } 339 340 static int __init efi_systab_init(unsigned long phys) 341 { 342 int size = efi_enabled(EFI_64BIT) ? sizeof(efi_system_table_64_t) 343 : sizeof(efi_system_table_32_t); 344 const efi_table_hdr_t *hdr; 345 bool over4g = false; 346 void *p; 347 int ret; 348 349 hdr = p = early_memremap_ro(phys, size); 350 if (p == NULL) { 351 pr_err("Couldn't map the system table!\n"); 352 return -ENOMEM; 353 } 354 355 ret = efi_systab_check_header(hdr, 1); 356 if (ret) { 357 early_memunmap(p, size); 358 return ret; 359 } 360 361 if (efi_enabled(EFI_64BIT)) { 362 const efi_system_table_64_t *systab64 = p; 363 364 efi_runtime = systab64->runtime; 365 over4g = systab64->runtime > U32_MAX; 366 367 if (efi_setup) { 368 struct efi_setup_data *data; 369 370 data = early_memremap_ro(efi_setup, sizeof(*data)); 371 if (!data) { 372 early_memunmap(p, size); 373 return -ENOMEM; 374 } 375 376 efi_fw_vendor = (unsigned long)data->fw_vendor; 377 efi_config_table = (unsigned long)data->tables; 378 379 over4g |= data->fw_vendor > U32_MAX || 380 data->tables > U32_MAX; 381 382 early_memunmap(data, sizeof(*data)); 383 } else { 384 efi_fw_vendor = systab64->fw_vendor; 385 efi_config_table = systab64->tables; 386 387 over4g |= systab64->fw_vendor > U32_MAX || 388 systab64->tables > U32_MAX; 389 } 390 efi_nr_tables = systab64->nr_tables; 391 } else { 392 const efi_system_table_32_t *systab32 = p; 393 394 efi_fw_vendor = systab32->fw_vendor; 395 efi_runtime = systab32->runtime; 396 efi_config_table = systab32->tables; 397 efi_nr_tables = systab32->nr_tables; 398 } 399 400 efi.runtime_version = hdr->revision; 401 402 efi_systab_report_header(hdr, efi_fw_vendor); 403 early_memunmap(p, size); 404 405 if (IS_ENABLED(CONFIG_X86_32) && over4g) { 406 pr_err("EFI data located above 4GB, disabling EFI.\n"); 407 return -EINVAL; 408 } 409 410 return 0; 411 } 412 413 static int __init efi_config_init(const efi_config_table_type_t *arch_tables) 414 { 415 void *config_tables; 416 int sz, ret; 417 418 if (efi_nr_tables == 0) 419 return 0; 420 421 if (efi_enabled(EFI_64BIT)) 422 sz = sizeof(efi_config_table_64_t); 423 else 424 sz = sizeof(efi_config_table_32_t); 425 426 /* 427 * Let's see what config tables the firmware passed to us. 428 */ 429 config_tables = early_memremap(efi_config_table, efi_nr_tables * sz); 430 if (config_tables == NULL) { 431 pr_err("Could not map Configuration table!\n"); 432 return -ENOMEM; 433 } 434 435 ret = efi_config_parse_tables(config_tables, efi_nr_tables, 436 arch_tables); 437 438 early_memunmap(config_tables, efi_nr_tables * sz); 439 return ret; 440 } 441 442 void __init efi_init(void) 443 { 444 if (IS_ENABLED(CONFIG_X86_32) && 445 (boot_params.efi_info.efi_systab_hi || 446 boot_params.efi_info.efi_memmap_hi)) { 447 pr_info("Table located above 4GB, disabling EFI.\n"); 448 return; 449 } 450 451 efi_systab_phys = boot_params.efi_info.efi_systab | 452 ((__u64)boot_params.efi_info.efi_systab_hi << 32); 453 454 if (efi_systab_init(efi_systab_phys)) 455 return; 456 457 if (efi_reuse_config(efi_config_table, efi_nr_tables)) 458 return; 459 460 if (efi_config_init(arch_tables)) 461 return; 462 463 /* 464 * Note: We currently don't support runtime services on an EFI 465 * that doesn't match the kernel 32/64-bit mode. 466 */ 467 468 if (!efi_runtime_supported()) 469 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 470 471 if (!efi_runtime_supported() || efi_runtime_disabled()) { 472 efi_memmap_unmap(); 473 return; 474 } 475 476 /* Parse the EFI Properties table if it exists */ 477 if (prop_phys != EFI_INVALID_TABLE_ADDR) { 478 efi_properties_table_t *tbl; 479 480 tbl = early_memremap_ro(prop_phys, sizeof(*tbl)); 481 if (tbl == NULL) { 482 pr_err("Could not map Properties table!\n"); 483 } else { 484 if (tbl->memory_protection_attribute & 485 EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA) 486 set_bit(EFI_NX_PE_DATA, &efi.flags); 487 488 early_memunmap(tbl, sizeof(*tbl)); 489 } 490 } 491 492 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 493 efi_clean_memmap(); 494 495 if (efi_enabled(EFI_DBG)) 496 efi_print_memmap(); 497 } 498 499 #if defined(CONFIG_X86_32) 500 501 void __init efi_set_executable(efi_memory_desc_t *md, bool executable) 502 { 503 u64 addr, npages; 504 505 addr = md->virt_addr; 506 npages = md->num_pages; 507 508 memrange_efi_to_native(&addr, &npages); 509 510 if (executable) 511 set_memory_x(addr, npages); 512 else 513 set_memory_nx(addr, npages); 514 } 515 516 void __init runtime_code_page_mkexec(void) 517 { 518 efi_memory_desc_t *md; 519 520 /* Make EFI runtime service code area executable */ 521 for_each_efi_memory_desc(md) { 522 if (md->type != EFI_RUNTIME_SERVICES_CODE) 523 continue; 524 525 efi_set_executable(md, true); 526 } 527 } 528 529 void __init efi_memory_uc(u64 addr, unsigned long size) 530 { 531 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; 532 u64 npages; 533 534 npages = round_up(size, page_shift) / page_shift; 535 memrange_efi_to_native(&addr, &npages); 536 set_memory_uc(addr, npages); 537 } 538 539 void __init old_map_region(efi_memory_desc_t *md) 540 { 541 u64 start_pfn, end_pfn, end; 542 unsigned long size; 543 void *va; 544 545 start_pfn = PFN_DOWN(md->phys_addr); 546 size = md->num_pages << PAGE_SHIFT; 547 end = md->phys_addr + size; 548 end_pfn = PFN_UP(end); 549 550 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 551 va = __va(md->phys_addr); 552 553 if (!(md->attribute & EFI_MEMORY_WB)) 554 efi_memory_uc((u64)(unsigned long)va, size); 555 } else 556 va = efi_ioremap(md->phys_addr, size, 557 md->type, md->attribute); 558 559 md->virt_addr = (u64) (unsigned long) va; 560 if (!va) 561 pr_err("ioremap of 0x%llX failed!\n", 562 (unsigned long long)md->phys_addr); 563 } 564 565 #endif 566 567 /* Merge contiguous regions of the same type and attribute */ 568 static void __init efi_merge_regions(void) 569 { 570 efi_memory_desc_t *md, *prev_md = NULL; 571 572 for_each_efi_memory_desc(md) { 573 u64 prev_size; 574 575 if (!prev_md) { 576 prev_md = md; 577 continue; 578 } 579 580 if (prev_md->type != md->type || 581 prev_md->attribute != md->attribute) { 582 prev_md = md; 583 continue; 584 } 585 586 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 587 588 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 589 prev_md->num_pages += md->num_pages; 590 md->type = EFI_RESERVED_TYPE; 591 md->attribute = 0; 592 continue; 593 } 594 prev_md = md; 595 } 596 } 597 598 static void *realloc_pages(void *old_memmap, int old_shift) 599 { 600 void *ret; 601 602 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 603 if (!ret) 604 goto out; 605 606 /* 607 * A first-time allocation doesn't have anything to copy. 608 */ 609 if (!old_memmap) 610 return ret; 611 612 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 613 614 out: 615 free_pages((unsigned long)old_memmap, old_shift); 616 return ret; 617 } 618 619 /* 620 * Iterate the EFI memory map in reverse order because the regions 621 * will be mapped top-down. The end result is the same as if we had 622 * mapped things forward, but doesn't require us to change the 623 * existing implementation of efi_map_region(). 624 */ 625 static inline void *efi_map_next_entry_reverse(void *entry) 626 { 627 /* Initial call */ 628 if (!entry) 629 return efi.memmap.map_end - efi.memmap.desc_size; 630 631 entry -= efi.memmap.desc_size; 632 if (entry < efi.memmap.map) 633 return NULL; 634 635 return entry; 636 } 637 638 /* 639 * efi_map_next_entry - Return the next EFI memory map descriptor 640 * @entry: Previous EFI memory map descriptor 641 * 642 * This is a helper function to iterate over the EFI memory map, which 643 * we do in different orders depending on the current configuration. 644 * 645 * To begin traversing the memory map @entry must be %NULL. 646 * 647 * Returns %NULL when we reach the end of the memory map. 648 */ 649 static void *efi_map_next_entry(void *entry) 650 { 651 if (efi_enabled(EFI_64BIT)) { 652 /* 653 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 654 * config table feature requires us to map all entries 655 * in the same order as they appear in the EFI memory 656 * map. That is to say, entry N must have a lower 657 * virtual address than entry N+1. This is because the 658 * firmware toolchain leaves relative references in 659 * the code/data sections, which are split and become 660 * separate EFI memory regions. Mapping things 661 * out-of-order leads to the firmware accessing 662 * unmapped addresses. 663 * 664 * Since we need to map things this way whether or not 665 * the kernel actually makes use of 666 * EFI_PROPERTIES_TABLE, let's just switch to this 667 * scheme by default for 64-bit. 668 */ 669 return efi_map_next_entry_reverse(entry); 670 } 671 672 /* Initial call */ 673 if (!entry) 674 return efi.memmap.map; 675 676 entry += efi.memmap.desc_size; 677 if (entry >= efi.memmap.map_end) 678 return NULL; 679 680 return entry; 681 } 682 683 static bool should_map_region(efi_memory_desc_t *md) 684 { 685 /* 686 * Runtime regions always require runtime mappings (obviously). 687 */ 688 if (md->attribute & EFI_MEMORY_RUNTIME) 689 return true; 690 691 /* 692 * 32-bit EFI doesn't suffer from the bug that requires us to 693 * reserve boot services regions, and mixed mode support 694 * doesn't exist for 32-bit kernels. 695 */ 696 if (IS_ENABLED(CONFIG_X86_32)) 697 return false; 698 699 /* 700 * EFI specific purpose memory may be reserved by default 701 * depending on kernel config and boot options. 702 */ 703 if (md->type == EFI_CONVENTIONAL_MEMORY && 704 efi_soft_reserve_enabled() && 705 (md->attribute & EFI_MEMORY_SP)) 706 return false; 707 708 /* 709 * Map all of RAM so that we can access arguments in the 1:1 710 * mapping when making EFI runtime calls. 711 */ 712 if (efi_is_mixed()) { 713 if (md->type == EFI_CONVENTIONAL_MEMORY || 714 md->type == EFI_LOADER_DATA || 715 md->type == EFI_LOADER_CODE) 716 return true; 717 } 718 719 /* 720 * Map boot services regions as a workaround for buggy 721 * firmware that accesses them even when they shouldn't. 722 * 723 * See efi_{reserve,free}_boot_services(). 724 */ 725 if (md->type == EFI_BOOT_SERVICES_CODE || 726 md->type == EFI_BOOT_SERVICES_DATA) 727 return true; 728 729 return false; 730 } 731 732 /* 733 * Map the efi memory ranges of the runtime services and update new_mmap with 734 * virtual addresses. 735 */ 736 static void * __init efi_map_regions(int *count, int *pg_shift) 737 { 738 void *p, *new_memmap = NULL; 739 unsigned long left = 0; 740 unsigned long desc_size; 741 efi_memory_desc_t *md; 742 743 desc_size = efi.memmap.desc_size; 744 745 p = NULL; 746 while ((p = efi_map_next_entry(p))) { 747 md = p; 748 749 if (!should_map_region(md)) 750 continue; 751 752 efi_map_region(md); 753 754 if (left < desc_size) { 755 new_memmap = realloc_pages(new_memmap, *pg_shift); 756 if (!new_memmap) 757 return NULL; 758 759 left += PAGE_SIZE << *pg_shift; 760 (*pg_shift)++; 761 } 762 763 memcpy(new_memmap + (*count * desc_size), md, desc_size); 764 765 left -= desc_size; 766 (*count)++; 767 } 768 769 return new_memmap; 770 } 771 772 static void __init kexec_enter_virtual_mode(void) 773 { 774 #ifdef CONFIG_KEXEC_CORE 775 efi_memory_desc_t *md; 776 unsigned int num_pages; 777 778 /* 779 * We don't do virtual mode, since we don't do runtime services, on 780 * non-native EFI. 781 */ 782 if (efi_is_mixed()) { 783 efi_memmap_unmap(); 784 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 785 return; 786 } 787 788 if (efi_alloc_page_tables()) { 789 pr_err("Failed to allocate EFI page tables\n"); 790 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 791 return; 792 } 793 794 /* 795 * Map efi regions which were passed via setup_data. The virt_addr is a 796 * fixed addr which was used in first kernel of a kexec boot. 797 */ 798 for_each_efi_memory_desc(md) 799 efi_map_region_fixed(md); /* FIXME: add error handling */ 800 801 /* 802 * Unregister the early EFI memmap from efi_init() and install 803 * the new EFI memory map. 804 */ 805 efi_memmap_unmap(); 806 807 if (efi_memmap_init_late(efi.memmap.phys_map, 808 efi.memmap.desc_size * efi.memmap.nr_map)) { 809 pr_err("Failed to remap late EFI memory map\n"); 810 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 811 return; 812 } 813 814 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 815 num_pages >>= PAGE_SHIFT; 816 817 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 818 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 819 return; 820 } 821 822 efi_sync_low_kernel_mappings(); 823 efi_native_runtime_setup(); 824 #endif 825 } 826 827 /* 828 * This function will switch the EFI runtime services to virtual mode. 829 * Essentially, we look through the EFI memmap and map every region that 830 * has the runtime attribute bit set in its memory descriptor into the 831 * efi_pgd page table. 832 * 833 * The new method does a pagetable switch in a preemption-safe manner 834 * so that we're in a different address space when calling a runtime 835 * function. For function arguments passing we do copy the PUDs of the 836 * kernel page table into efi_pgd prior to each call. 837 * 838 * Specially for kexec boot, efi runtime maps in previous kernel should 839 * be passed in via setup_data. In that case runtime ranges will be mapped 840 * to the same virtual addresses as the first kernel, see 841 * kexec_enter_virtual_mode(). 842 */ 843 static void __init __efi_enter_virtual_mode(void) 844 { 845 int count = 0, pg_shift = 0; 846 void *new_memmap = NULL; 847 efi_status_t status; 848 unsigned long pa; 849 850 if (efi_alloc_page_tables()) { 851 pr_err("Failed to allocate EFI page tables\n"); 852 goto err; 853 } 854 855 efi_merge_regions(); 856 new_memmap = efi_map_regions(&count, &pg_shift); 857 if (!new_memmap) { 858 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 859 goto err; 860 } 861 862 pa = __pa(new_memmap); 863 864 /* 865 * Unregister the early EFI memmap from efi_init() and install 866 * the new EFI memory map that we are about to pass to the 867 * firmware via SetVirtualAddressMap(). 868 */ 869 efi_memmap_unmap(); 870 871 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 872 pr_err("Failed to remap late EFI memory map\n"); 873 goto err; 874 } 875 876 if (efi_enabled(EFI_DBG)) { 877 pr_info("EFI runtime memory map:\n"); 878 efi_print_memmap(); 879 } 880 881 if (efi_setup_page_tables(pa, 1 << pg_shift)) 882 goto err; 883 884 efi_sync_low_kernel_mappings(); 885 886 status = efi_set_virtual_address_map(efi.memmap.desc_size * count, 887 efi.memmap.desc_size, 888 efi.memmap.desc_version, 889 (efi_memory_desc_t *)pa, 890 efi_systab_phys); 891 if (status != EFI_SUCCESS) { 892 pr_err("Unable to switch EFI into virtual mode (status=%lx)!\n", 893 status); 894 goto err; 895 } 896 897 efi_check_for_embedded_firmwares(); 898 efi_free_boot_services(); 899 900 if (!efi_is_mixed()) 901 efi_native_runtime_setup(); 902 else 903 efi_thunk_runtime_setup(); 904 905 /* 906 * Apply more restrictive page table mapping attributes now that 907 * SVAM() has been called and the firmware has performed all 908 * necessary relocation fixups for the new virtual addresses. 909 */ 910 efi_runtime_update_mappings(); 911 912 /* clean DUMMY object */ 913 efi_delete_dummy_variable(); 914 return; 915 916 err: 917 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 918 } 919 920 void __init efi_enter_virtual_mode(void) 921 { 922 if (efi_enabled(EFI_PARAVIRT)) 923 return; 924 925 efi.runtime = (efi_runtime_services_t *)efi_runtime; 926 927 if (efi_setup) 928 kexec_enter_virtual_mode(); 929 else 930 __efi_enter_virtual_mode(); 931 932 efi_dump_pagetable(); 933 } 934 935 bool efi_is_table_address(unsigned long phys_addr) 936 { 937 unsigned int i; 938 939 if (phys_addr == EFI_INVALID_TABLE_ADDR) 940 return false; 941 942 for (i = 0; i < ARRAY_SIZE(efi_tables); i++) 943 if (*(efi_tables[i]) == phys_addr) 944 return true; 945 946 return false; 947 } 948 949 char *efi_systab_show_arch(char *str) 950 { 951 if (uga_phys != EFI_INVALID_TABLE_ADDR) 952 str += sprintf(str, "UGA=0x%lx\n", uga_phys); 953 return str; 954 } 955 956 #define EFI_FIELD(var) efi_ ## var 957 958 #define EFI_ATTR_SHOW(name) \ 959 static ssize_t name##_show(struct kobject *kobj, \ 960 struct kobj_attribute *attr, char *buf) \ 961 { \ 962 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \ 963 } 964 965 EFI_ATTR_SHOW(fw_vendor); 966 EFI_ATTR_SHOW(runtime); 967 EFI_ATTR_SHOW(config_table); 968 969 struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); 970 struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); 971 struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); 972 973 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) 974 { 975 if (attr == &efi_attr_fw_vendor.attr) { 976 if (efi_enabled(EFI_PARAVIRT) || 977 efi_fw_vendor == EFI_INVALID_TABLE_ADDR) 978 return 0; 979 } else if (attr == &efi_attr_runtime.attr) { 980 if (efi_runtime == EFI_INVALID_TABLE_ADDR) 981 return 0; 982 } else if (attr == &efi_attr_config_table.attr) { 983 if (efi_config_table == EFI_INVALID_TABLE_ADDR) 984 return 0; 985 } 986 return attr->mode; 987 } 988