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