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 struct efi efi_phys __initdata; 58 static efi_system_table_t efi_systab __initdata; 59 60 static efi_config_table_type_t arch_tables[] __initdata = { 61 #ifdef CONFIG_X86_UV 62 {UV_SYSTEM_TABLE_GUID, "UVsystab", &uv_systab_phys}, 63 #endif 64 {NULL_GUID, NULL, NULL}, 65 }; 66 67 static const unsigned long * const efi_tables[] = { 68 &efi.mps, 69 &efi.acpi, 70 &efi.acpi20, 71 &efi.smbios, 72 &efi.smbios3, 73 &efi.boot_info, 74 &efi.hcdp, 75 &efi.uga, 76 #ifdef CONFIG_X86_UV 77 &uv_systab_phys, 78 #endif 79 &efi.fw_vendor, 80 &efi.runtime, 81 &efi.config_table, 82 &efi.esrt, 83 &efi.properties_table, 84 &efi.mem_attr_table, 85 }; 86 87 u64 efi_setup; /* efi setup_data physical address */ 88 89 static int add_efi_memmap __initdata; 90 static int __init setup_add_efi_memmap(char *arg) 91 { 92 add_efi_memmap = 1; 93 return 0; 94 } 95 early_param("add_efi_memmap", setup_add_efi_memmap); 96 97 static efi_status_t __init phys_efi_set_virtual_address_map( 98 unsigned long memory_map_size, 99 unsigned long descriptor_size, 100 u32 descriptor_version, 101 efi_memory_desc_t *virtual_map) 102 { 103 efi_status_t status; 104 unsigned long flags; 105 pgd_t *save_pgd; 106 107 save_pgd = efi_call_phys_prolog(); 108 if (!save_pgd) 109 return EFI_ABORTED; 110 111 /* Disable interrupts around EFI calls: */ 112 local_irq_save(flags); 113 status = efi_call_phys(efi_phys.set_virtual_address_map, 114 memory_map_size, descriptor_size, 115 descriptor_version, virtual_map); 116 local_irq_restore(flags); 117 118 efi_call_phys_epilog(save_pgd); 119 120 return status; 121 } 122 123 void __init efi_find_mirror(void) 124 { 125 efi_memory_desc_t *md; 126 u64 mirror_size = 0, total_size = 0; 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; 131 132 total_size += size; 133 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { 134 memblock_mark_mirror(start, size); 135 mirror_size += size; 136 } 137 } 138 if (mirror_size) 139 pr_info("Memory: %lldM/%lldM mirrored memory\n", 140 mirror_size>>20, total_size>>20); 141 } 142 143 /* 144 * Tell the kernel about the EFI memory map. This might include 145 * more than the max 128 entries that can fit in the e820 legacy 146 * (zeropage) memory map. 147 */ 148 149 static void __init do_add_efi_memmap(void) 150 { 151 efi_memory_desc_t *md; 152 153 for_each_efi_memory_desc(md) { 154 unsigned long long start = md->phys_addr; 155 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 156 int e820_type; 157 158 switch (md->type) { 159 case EFI_LOADER_CODE: 160 case EFI_LOADER_DATA: 161 case EFI_BOOT_SERVICES_CODE: 162 case EFI_BOOT_SERVICES_DATA: 163 case EFI_CONVENTIONAL_MEMORY: 164 if (md->attribute & EFI_MEMORY_WB) 165 e820_type = E820_TYPE_RAM; 166 else 167 e820_type = E820_TYPE_RESERVED; 168 break; 169 case EFI_ACPI_RECLAIM_MEMORY: 170 e820_type = E820_TYPE_ACPI; 171 break; 172 case EFI_ACPI_MEMORY_NVS: 173 e820_type = E820_TYPE_NVS; 174 break; 175 case EFI_UNUSABLE_MEMORY: 176 e820_type = E820_TYPE_UNUSABLE; 177 break; 178 case EFI_PERSISTENT_MEMORY: 179 e820_type = E820_TYPE_PMEM; 180 break; 181 default: 182 /* 183 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 184 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 185 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 186 */ 187 e820_type = E820_TYPE_RESERVED; 188 break; 189 } 190 e820__range_add(start, size, e820_type); 191 } 192 e820__update_table(e820_table); 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 #ifdef CONFIG_X86_32 206 /* Can't handle data above 4GB at this time */ 207 if (e->efi_memmap_hi) { 208 pr_err("Memory map is above 4GB, disabling EFI.\n"); 209 return -EINVAL; 210 } 211 pmap = e->efi_memmap; 212 #else 213 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); 214 #endif 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 rv = efi_memmap_init_early(&data); 221 if (rv) 222 return rv; 223 224 if (add_efi_memmap) 225 do_add_efi_memmap(); 226 227 WARN(efi.memmap.desc_version != 1, 228 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 229 efi.memmap.desc_version); 230 231 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); 232 233 return 0; 234 } 235 236 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 237 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 238 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 239 240 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 241 { 242 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 243 u64 end_hi = 0; 244 char buf[64]; 245 246 if (md->num_pages == 0) { 247 end = 0; 248 } else if (md->num_pages > EFI_PAGES_MAX || 249 EFI_PAGES_MAX - md->num_pages < 250 (md->phys_addr >> EFI_PAGE_SHIFT)) { 251 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 252 >> OVERFLOW_ADDR_SHIFT; 253 254 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 255 end_hi += 1; 256 } else { 257 return true; 258 } 259 260 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 261 262 if (end_hi) { 263 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 264 i, efi_md_typeattr_format(buf, sizeof(buf), md), 265 md->phys_addr, end_hi, end); 266 } else { 267 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 268 i, efi_md_typeattr_format(buf, sizeof(buf), md), 269 md->phys_addr, end); 270 } 271 return false; 272 } 273 274 static void __init efi_clean_memmap(void) 275 { 276 efi_memory_desc_t *out = efi.memmap.map; 277 const efi_memory_desc_t *in = out; 278 const efi_memory_desc_t *end = efi.memmap.map_end; 279 int i, n_removal; 280 281 for (i = n_removal = 0; in < end; i++) { 282 if (efi_memmap_entry_valid(in, i)) { 283 if (out != in) 284 memcpy(out, in, efi.memmap.desc_size); 285 out = (void *)out + efi.memmap.desc_size; 286 } else { 287 n_removal++; 288 } 289 in = (void *)in + efi.memmap.desc_size; 290 } 291 292 if (n_removal > 0) { 293 u64 size = efi.memmap.nr_map - n_removal; 294 295 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 296 efi_memmap_install(efi.memmap.phys_map, size); 297 } 298 } 299 300 void __init efi_print_memmap(void) 301 { 302 efi_memory_desc_t *md; 303 int i = 0; 304 305 for_each_efi_memory_desc(md) { 306 char buf[64]; 307 308 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 309 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 310 md->phys_addr, 311 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 312 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 313 } 314 } 315 316 static int __init efi_systab_init(void *phys) 317 { 318 if (efi_enabled(EFI_64BIT)) { 319 efi_system_table_64_t *systab64; 320 struct efi_setup_data *data = NULL; 321 u64 tmp = 0; 322 323 if (efi_setup) { 324 data = early_memremap(efi_setup, sizeof(*data)); 325 if (!data) 326 return -ENOMEM; 327 } 328 systab64 = early_memremap((unsigned long)phys, 329 sizeof(*systab64)); 330 if (systab64 == NULL) { 331 pr_err("Couldn't map the system table!\n"); 332 if (data) 333 early_memunmap(data, sizeof(*data)); 334 return -ENOMEM; 335 } 336 337 efi_systab.hdr = systab64->hdr; 338 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor : 339 systab64->fw_vendor; 340 tmp |= data ? data->fw_vendor : systab64->fw_vendor; 341 efi_systab.fw_revision = systab64->fw_revision; 342 efi_systab.con_in_handle = systab64->con_in_handle; 343 tmp |= systab64->con_in_handle; 344 efi_systab.con_in = systab64->con_in; 345 tmp |= systab64->con_in; 346 efi_systab.con_out_handle = systab64->con_out_handle; 347 tmp |= systab64->con_out_handle; 348 efi_systab.con_out = systab64->con_out; 349 tmp |= systab64->con_out; 350 efi_systab.stderr_handle = systab64->stderr_handle; 351 tmp |= systab64->stderr_handle; 352 efi_systab.stderr = systab64->stderr; 353 tmp |= systab64->stderr; 354 efi_systab.runtime = data ? 355 (void *)(unsigned long)data->runtime : 356 (void *)(unsigned long)systab64->runtime; 357 tmp |= data ? data->runtime : systab64->runtime; 358 efi_systab.boottime = (void *)(unsigned long)systab64->boottime; 359 tmp |= systab64->boottime; 360 efi_systab.nr_tables = systab64->nr_tables; 361 efi_systab.tables = data ? (unsigned long)data->tables : 362 systab64->tables; 363 tmp |= data ? data->tables : systab64->tables; 364 365 early_memunmap(systab64, sizeof(*systab64)); 366 if (data) 367 early_memunmap(data, sizeof(*data)); 368 #ifdef CONFIG_X86_32 369 if (tmp >> 32) { 370 pr_err("EFI data located above 4GB, disabling EFI.\n"); 371 return -EINVAL; 372 } 373 #endif 374 } else { 375 efi_system_table_32_t *systab32; 376 377 systab32 = early_memremap((unsigned long)phys, 378 sizeof(*systab32)); 379 if (systab32 == NULL) { 380 pr_err("Couldn't map the system table!\n"); 381 return -ENOMEM; 382 } 383 384 efi_systab.hdr = systab32->hdr; 385 efi_systab.fw_vendor = systab32->fw_vendor; 386 efi_systab.fw_revision = systab32->fw_revision; 387 efi_systab.con_in_handle = systab32->con_in_handle; 388 efi_systab.con_in = systab32->con_in; 389 efi_systab.con_out_handle = systab32->con_out_handle; 390 efi_systab.con_out = systab32->con_out; 391 efi_systab.stderr_handle = systab32->stderr_handle; 392 efi_systab.stderr = systab32->stderr; 393 efi_systab.runtime = (void *)(unsigned long)systab32->runtime; 394 efi_systab.boottime = (void *)(unsigned long)systab32->boottime; 395 efi_systab.nr_tables = systab32->nr_tables; 396 efi_systab.tables = systab32->tables; 397 398 early_memunmap(systab32, sizeof(*systab32)); 399 } 400 401 efi.systab = &efi_systab; 402 403 /* 404 * Verify the EFI Table 405 */ 406 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { 407 pr_err("System table signature incorrect!\n"); 408 return -EINVAL; 409 } 410 if ((efi.systab->hdr.revision >> 16) == 0) 411 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n", 412 efi.systab->hdr.revision >> 16, 413 efi.systab->hdr.revision & 0xffff); 414 415 return 0; 416 } 417 418 static int __init efi_runtime_init32(void) 419 { 420 efi_runtime_services_32_t *runtime; 421 422 runtime = early_memremap((unsigned long)efi.systab->runtime, 423 sizeof(efi_runtime_services_32_t)); 424 if (!runtime) { 425 pr_err("Could not map the runtime service table!\n"); 426 return -ENOMEM; 427 } 428 429 /* 430 * We will only need *early* access to the SetVirtualAddressMap 431 * EFI runtime service. All other runtime services will be called 432 * via the virtual mapping. 433 */ 434 efi_phys.set_virtual_address_map = 435 (efi_set_virtual_address_map_t *) 436 (unsigned long)runtime->set_virtual_address_map; 437 early_memunmap(runtime, sizeof(efi_runtime_services_32_t)); 438 439 return 0; 440 } 441 442 static int __init efi_runtime_init64(void) 443 { 444 efi_runtime_services_64_t *runtime; 445 446 runtime = early_memremap((unsigned long)efi.systab->runtime, 447 sizeof(efi_runtime_services_64_t)); 448 if (!runtime) { 449 pr_err("Could not map the runtime service table!\n"); 450 return -ENOMEM; 451 } 452 453 /* 454 * We will only need *early* access to the SetVirtualAddressMap 455 * EFI runtime service. All other runtime services will be called 456 * via the virtual mapping. 457 */ 458 efi_phys.set_virtual_address_map = 459 (efi_set_virtual_address_map_t *) 460 (unsigned long)runtime->set_virtual_address_map; 461 early_memunmap(runtime, sizeof(efi_runtime_services_64_t)); 462 463 return 0; 464 } 465 466 static int __init efi_runtime_init(void) 467 { 468 int rv; 469 470 /* 471 * Check out the runtime services table. We need to map 472 * the runtime services table so that we can grab the physical 473 * address of several of the EFI runtime functions, needed to 474 * set the firmware into virtual mode. 475 * 476 * When EFI_PARAVIRT is in force then we could not map runtime 477 * service memory region because we do not have direct access to it. 478 * However, runtime services are available through proxy functions 479 * (e.g. in case of Xen dom0 EFI implementation they call special 480 * hypercall which executes relevant EFI functions) and that is why 481 * they are always enabled. 482 */ 483 484 if (!efi_enabled(EFI_PARAVIRT)) { 485 if (efi_enabled(EFI_64BIT)) 486 rv = efi_runtime_init64(); 487 else 488 rv = efi_runtime_init32(); 489 490 if (rv) 491 return rv; 492 } 493 494 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 495 496 return 0; 497 } 498 499 void __init efi_init(void) 500 { 501 efi_char16_t *c16; 502 char vendor[100] = "unknown"; 503 int i = 0; 504 void *tmp; 505 506 #ifdef CONFIG_X86_32 507 if (boot_params.efi_info.efi_systab_hi || 508 boot_params.efi_info.efi_memmap_hi) { 509 pr_info("Table located above 4GB, disabling EFI.\n"); 510 return; 511 } 512 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; 513 #else 514 efi_phys.systab = (efi_system_table_t *) 515 (boot_params.efi_info.efi_systab | 516 ((__u64)boot_params.efi_info.efi_systab_hi<<32)); 517 #endif 518 519 if (efi_systab_init(efi_phys.systab)) 520 return; 521 522 efi.config_table = (unsigned long)efi.systab->tables; 523 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; 524 efi.runtime = (unsigned long)efi.systab->runtime; 525 526 /* 527 * Show what we know for posterity 528 */ 529 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2); 530 if (c16) { 531 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i) 532 vendor[i] = *c16++; 533 vendor[i] = '\0'; 534 } else 535 pr_err("Could not map the firmware vendor!\n"); 536 early_memunmap(tmp, 2); 537 538 pr_info("EFI v%u.%.02u by %s\n", 539 efi.systab->hdr.revision >> 16, 540 efi.systab->hdr.revision & 0xffff, vendor); 541 542 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables)) 543 return; 544 545 if (efi_config_init(arch_tables)) 546 return; 547 548 /* 549 * Note: We currently don't support runtime services on an EFI 550 * that doesn't match the kernel 32/64-bit mode. 551 */ 552 553 if (!efi_runtime_supported()) 554 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 555 else { 556 if (efi_runtime_disabled() || efi_runtime_init()) { 557 efi_memmap_unmap(); 558 return; 559 } 560 } 561 562 efi_clean_memmap(); 563 564 if (efi_enabled(EFI_DBG)) 565 efi_print_memmap(); 566 } 567 568 void __init efi_set_executable(efi_memory_desc_t *md, bool executable) 569 { 570 u64 addr, npages; 571 572 addr = md->virt_addr; 573 npages = md->num_pages; 574 575 memrange_efi_to_native(&addr, &npages); 576 577 if (executable) 578 set_memory_x(addr, npages); 579 else 580 set_memory_nx(addr, npages); 581 } 582 583 void __init runtime_code_page_mkexec(void) 584 { 585 efi_memory_desc_t *md; 586 587 /* Make EFI runtime service code area executable */ 588 for_each_efi_memory_desc(md) { 589 if (md->type != EFI_RUNTIME_SERVICES_CODE) 590 continue; 591 592 efi_set_executable(md, true); 593 } 594 } 595 596 void __init efi_memory_uc(u64 addr, unsigned long size) 597 { 598 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; 599 u64 npages; 600 601 npages = round_up(size, page_shift) / page_shift; 602 memrange_efi_to_native(&addr, &npages); 603 set_memory_uc(addr, npages); 604 } 605 606 void __init old_map_region(efi_memory_desc_t *md) 607 { 608 u64 start_pfn, end_pfn, end; 609 unsigned long size; 610 void *va; 611 612 start_pfn = PFN_DOWN(md->phys_addr); 613 size = md->num_pages << PAGE_SHIFT; 614 end = md->phys_addr + size; 615 end_pfn = PFN_UP(end); 616 617 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 618 va = __va(md->phys_addr); 619 620 if (!(md->attribute & EFI_MEMORY_WB)) 621 efi_memory_uc((u64)(unsigned long)va, size); 622 } else 623 va = efi_ioremap(md->phys_addr, size, 624 md->type, md->attribute); 625 626 md->virt_addr = (u64) (unsigned long) va; 627 if (!va) 628 pr_err("ioremap of 0x%llX failed!\n", 629 (unsigned long long)md->phys_addr); 630 } 631 632 /* Merge contiguous regions of the same type and attribute */ 633 static void __init efi_merge_regions(void) 634 { 635 efi_memory_desc_t *md, *prev_md = NULL; 636 637 for_each_efi_memory_desc(md) { 638 u64 prev_size; 639 640 if (!prev_md) { 641 prev_md = md; 642 continue; 643 } 644 645 if (prev_md->type != md->type || 646 prev_md->attribute != md->attribute) { 647 prev_md = md; 648 continue; 649 } 650 651 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 652 653 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 654 prev_md->num_pages += md->num_pages; 655 md->type = EFI_RESERVED_TYPE; 656 md->attribute = 0; 657 continue; 658 } 659 prev_md = md; 660 } 661 } 662 663 static void __init get_systab_virt_addr(efi_memory_desc_t *md) 664 { 665 unsigned long size; 666 u64 end, systab; 667 668 size = md->num_pages << EFI_PAGE_SHIFT; 669 end = md->phys_addr + size; 670 systab = (u64)(unsigned long)efi_phys.systab; 671 if (md->phys_addr <= systab && systab < end) { 672 systab += md->virt_addr - md->phys_addr; 673 efi.systab = (efi_system_table_t *)(unsigned long)systab; 674 } 675 } 676 677 static void *realloc_pages(void *old_memmap, int old_shift) 678 { 679 void *ret; 680 681 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 682 if (!ret) 683 goto out; 684 685 /* 686 * A first-time allocation doesn't have anything to copy. 687 */ 688 if (!old_memmap) 689 return ret; 690 691 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 692 693 out: 694 free_pages((unsigned long)old_memmap, old_shift); 695 return ret; 696 } 697 698 /* 699 * Iterate the EFI memory map in reverse order because the regions 700 * will be mapped top-down. The end result is the same as if we had 701 * mapped things forward, but doesn't require us to change the 702 * existing implementation of efi_map_region(). 703 */ 704 static inline void *efi_map_next_entry_reverse(void *entry) 705 { 706 /* Initial call */ 707 if (!entry) 708 return efi.memmap.map_end - efi.memmap.desc_size; 709 710 entry -= efi.memmap.desc_size; 711 if (entry < efi.memmap.map) 712 return NULL; 713 714 return entry; 715 } 716 717 /* 718 * efi_map_next_entry - Return the next EFI memory map descriptor 719 * @entry: Previous EFI memory map descriptor 720 * 721 * This is a helper function to iterate over the EFI memory map, which 722 * we do in different orders depending on the current configuration. 723 * 724 * To begin traversing the memory map @entry must be %NULL. 725 * 726 * Returns %NULL when we reach the end of the memory map. 727 */ 728 static void *efi_map_next_entry(void *entry) 729 { 730 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) { 731 /* 732 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 733 * config table feature requires us to map all entries 734 * in the same order as they appear in the EFI memory 735 * map. That is to say, entry N must have a lower 736 * virtual address than entry N+1. This is because the 737 * firmware toolchain leaves relative references in 738 * the code/data sections, which are split and become 739 * separate EFI memory regions. Mapping things 740 * out-of-order leads to the firmware accessing 741 * unmapped addresses. 742 * 743 * Since we need to map things this way whether or not 744 * the kernel actually makes use of 745 * EFI_PROPERTIES_TABLE, let's just switch to this 746 * scheme by default for 64-bit. 747 */ 748 return efi_map_next_entry_reverse(entry); 749 } 750 751 /* Initial call */ 752 if (!entry) 753 return efi.memmap.map; 754 755 entry += efi.memmap.desc_size; 756 if (entry >= efi.memmap.map_end) 757 return NULL; 758 759 return entry; 760 } 761 762 static bool should_map_region(efi_memory_desc_t *md) 763 { 764 /* 765 * Runtime regions always require runtime mappings (obviously). 766 */ 767 if (md->attribute & EFI_MEMORY_RUNTIME) 768 return true; 769 770 /* 771 * 32-bit EFI doesn't suffer from the bug that requires us to 772 * reserve boot services regions, and mixed mode support 773 * doesn't exist for 32-bit kernels. 774 */ 775 if (IS_ENABLED(CONFIG_X86_32)) 776 return false; 777 778 /* 779 * Map all of RAM so that we can access arguments in the 1:1 780 * mapping when making EFI runtime calls. 781 */ 782 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) { 783 if (md->type == EFI_CONVENTIONAL_MEMORY || 784 md->type == EFI_LOADER_DATA || 785 md->type == EFI_LOADER_CODE) 786 return true; 787 } 788 789 /* 790 * Map boot services regions as a workaround for buggy 791 * firmware that accesses them even when they shouldn't. 792 * 793 * See efi_{reserve,free}_boot_services(). 794 */ 795 if (md->type == EFI_BOOT_SERVICES_CODE || 796 md->type == EFI_BOOT_SERVICES_DATA) 797 return true; 798 799 return false; 800 } 801 802 /* 803 * Map the efi memory ranges of the runtime services and update new_mmap with 804 * virtual addresses. 805 */ 806 static void * __init efi_map_regions(int *count, int *pg_shift) 807 { 808 void *p, *new_memmap = NULL; 809 unsigned long left = 0; 810 unsigned long desc_size; 811 efi_memory_desc_t *md; 812 813 desc_size = efi.memmap.desc_size; 814 815 p = NULL; 816 while ((p = efi_map_next_entry(p))) { 817 md = p; 818 819 if (!should_map_region(md)) 820 continue; 821 822 efi_map_region(md); 823 get_systab_virt_addr(md); 824 825 if (left < desc_size) { 826 new_memmap = realloc_pages(new_memmap, *pg_shift); 827 if (!new_memmap) 828 return NULL; 829 830 left += PAGE_SIZE << *pg_shift; 831 (*pg_shift)++; 832 } 833 834 memcpy(new_memmap + (*count * desc_size), md, desc_size); 835 836 left -= desc_size; 837 (*count)++; 838 } 839 840 return new_memmap; 841 } 842 843 static void __init kexec_enter_virtual_mode(void) 844 { 845 #ifdef CONFIG_KEXEC_CORE 846 efi_memory_desc_t *md; 847 unsigned int num_pages; 848 849 efi.systab = NULL; 850 851 /* 852 * We don't do virtual mode, since we don't do runtime services, on 853 * non-native EFI. With efi=old_map, we don't do runtime services in 854 * kexec kernel because in the initial boot something else might 855 * have been mapped at these virtual addresses. 856 */ 857 if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) { 858 efi_memmap_unmap(); 859 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 860 return; 861 } 862 863 if (efi_alloc_page_tables()) { 864 pr_err("Failed to allocate EFI page tables\n"); 865 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 866 return; 867 } 868 869 /* 870 * Map efi regions which were passed via setup_data. The virt_addr is a 871 * fixed addr which was used in first kernel of a kexec boot. 872 */ 873 for_each_efi_memory_desc(md) { 874 efi_map_region_fixed(md); /* FIXME: add error handling */ 875 get_systab_virt_addr(md); 876 } 877 878 /* 879 * Unregister the early EFI memmap from efi_init() and install 880 * the new EFI memory map. 881 */ 882 efi_memmap_unmap(); 883 884 if (efi_memmap_init_late(efi.memmap.phys_map, 885 efi.memmap.desc_size * efi.memmap.nr_map)) { 886 pr_err("Failed to remap late EFI memory map\n"); 887 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 888 return; 889 } 890 891 BUG_ON(!efi.systab); 892 893 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 894 num_pages >>= PAGE_SHIFT; 895 896 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 897 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 898 return; 899 } 900 901 efi_sync_low_kernel_mappings(); 902 903 /* 904 * Now that EFI is in virtual mode, update the function 905 * pointers in the runtime service table to the new virtual addresses. 906 * 907 * Call EFI services through wrapper functions. 908 */ 909 efi.runtime_version = efi_systab.hdr.revision; 910 911 efi_native_runtime_setup(); 912 913 efi.set_virtual_address_map = NULL; 914 915 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) 916 runtime_code_page_mkexec(); 917 918 /* clean DUMMY object */ 919 efi_delete_dummy_variable(); 920 #endif 921 } 922 923 /* 924 * This function will switch the EFI runtime services to virtual mode. 925 * Essentially, we look through the EFI memmap and map every region that 926 * has the runtime attribute bit set in its memory descriptor into the 927 * efi_pgd page table. 928 * 929 * The old method which used to update that memory descriptor with the 930 * virtual address obtained from ioremap() is still supported when the 931 * kernel is booted with efi=old_map on its command line. Same old 932 * method enabled the runtime services to be called without having to 933 * thunk back into physical mode for every invocation. 934 * 935 * The new method does a pagetable switch in a preemption-safe manner 936 * so that we're in a different address space when calling a runtime 937 * function. For function arguments passing we do copy the PUDs of the 938 * kernel page table into efi_pgd prior to each call. 939 * 940 * Specially for kexec boot, efi runtime maps in previous kernel should 941 * be passed in via setup_data. In that case runtime ranges will be mapped 942 * to the same virtual addresses as the first kernel, see 943 * kexec_enter_virtual_mode(). 944 */ 945 static void __init __efi_enter_virtual_mode(void) 946 { 947 int count = 0, pg_shift = 0; 948 void *new_memmap = NULL; 949 efi_status_t status; 950 unsigned long pa; 951 952 efi.systab = NULL; 953 954 if (efi_alloc_page_tables()) { 955 pr_err("Failed to allocate EFI page tables\n"); 956 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 957 return; 958 } 959 960 efi_merge_regions(); 961 new_memmap = efi_map_regions(&count, &pg_shift); 962 if (!new_memmap) { 963 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 964 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 965 return; 966 } 967 968 pa = __pa(new_memmap); 969 970 /* 971 * Unregister the early EFI memmap from efi_init() and install 972 * the new EFI memory map that we are about to pass to the 973 * firmware via SetVirtualAddressMap(). 974 */ 975 efi_memmap_unmap(); 976 977 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 978 pr_err("Failed to remap late EFI memory map\n"); 979 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 980 return; 981 } 982 983 if (efi_enabled(EFI_DBG)) { 984 pr_info("EFI runtime memory map:\n"); 985 efi_print_memmap(); 986 } 987 988 BUG_ON(!efi.systab); 989 990 if (efi_setup_page_tables(pa, 1 << pg_shift)) { 991 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 992 return; 993 } 994 995 efi_sync_low_kernel_mappings(); 996 997 if (efi_is_native()) { 998 status = phys_efi_set_virtual_address_map( 999 efi.memmap.desc_size * count, 1000 efi.memmap.desc_size, 1001 efi.memmap.desc_version, 1002 (efi_memory_desc_t *)pa); 1003 } else { 1004 status = efi_thunk_set_virtual_address_map( 1005 efi_phys.set_virtual_address_map, 1006 efi.memmap.desc_size * count, 1007 efi.memmap.desc_size, 1008 efi.memmap.desc_version, 1009 (efi_memory_desc_t *)pa); 1010 } 1011 1012 if (status != EFI_SUCCESS) { 1013 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", 1014 status); 1015 panic("EFI call to SetVirtualAddressMap() failed!"); 1016 } 1017 1018 efi_free_boot_services(); 1019 1020 /* 1021 * Now that EFI is in virtual mode, update the function 1022 * pointers in the runtime service table to the new virtual addresses. 1023 * 1024 * Call EFI services through wrapper functions. 1025 */ 1026 efi.runtime_version = efi_systab.hdr.revision; 1027 1028 if (efi_is_native()) 1029 efi_native_runtime_setup(); 1030 else 1031 efi_thunk_runtime_setup(); 1032 1033 efi.set_virtual_address_map = NULL; 1034 1035 /* 1036 * Apply more restrictive page table mapping attributes now that 1037 * SVAM() has been called and the firmware has performed all 1038 * necessary relocation fixups for the new virtual addresses. 1039 */ 1040 efi_runtime_update_mappings(); 1041 1042 /* clean DUMMY object */ 1043 efi_delete_dummy_variable(); 1044 } 1045 1046 void __init efi_enter_virtual_mode(void) 1047 { 1048 if (efi_enabled(EFI_PARAVIRT)) 1049 return; 1050 1051 if (efi_setup) 1052 kexec_enter_virtual_mode(); 1053 else 1054 __efi_enter_virtual_mode(); 1055 1056 efi_dump_pagetable(); 1057 } 1058 1059 static int __init arch_parse_efi_cmdline(char *str) 1060 { 1061 if (!str) { 1062 pr_warn("need at least one option\n"); 1063 return -EINVAL; 1064 } 1065 1066 if (parse_option_str(str, "old_map")) 1067 set_bit(EFI_OLD_MEMMAP, &efi.flags); 1068 1069 return 0; 1070 } 1071 early_param("efi", arch_parse_efi_cmdline); 1072 1073 bool efi_is_table_address(unsigned long phys_addr) 1074 { 1075 unsigned int i; 1076 1077 if (phys_addr == EFI_INVALID_TABLE_ADDR) 1078 return false; 1079 1080 for (i = 0; i < ARRAY_SIZE(efi_tables); i++) 1081 if (*(efi_tables[i]) == phys_addr) 1082 return true; 1083 1084 return false; 1085 } 1086