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