1 /* 2 * Common EFI (Extensible Firmware Interface) support functions 3 * Based on Extensible Firmware Interface Specification version 1.0 4 * 5 * Copyright (C) 1999 VA Linux Systems 6 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> 7 * Copyright (C) 1999-2002 Hewlett-Packard Co. 8 * David Mosberger-Tang <davidm@hpl.hp.com> 9 * Stephane Eranian <eranian@hpl.hp.com> 10 * Copyright (C) 2005-2008 Intel Co. 11 * Fenghua Yu <fenghua.yu@intel.com> 12 * Bibo Mao <bibo.mao@intel.com> 13 * Chandramouli Narayanan <mouli@linux.intel.com> 14 * Huang Ying <ying.huang@intel.com> 15 * Copyright (C) 2013 SuSE Labs 16 * Borislav Petkov <bp@suse.de> - runtime services VA mapping 17 * 18 * Copied from efi_32.c to eliminate the duplicated code between EFI 19 * 32/64 support code. --ying 2007-10-26 20 * 21 * All EFI Runtime Services are not implemented yet as EFI only 22 * supports physical mode addressing on SoftSDV. This is to be fixed 23 * in a future version. --drummond 1999-07-20 24 * 25 * Implemented EFI runtime services and virtual mode calls. --davidm 26 * 27 * Goutham Rao: <goutham.rao@intel.com> 28 * Skip non-WB memory and ignore empty memory ranges. 29 */ 30 31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 32 33 #include <linux/kernel.h> 34 #include <linux/init.h> 35 #include <linux/efi.h> 36 #include <linux/efi-bgrt.h> 37 #include <linux/export.h> 38 #include <linux/bootmem.h> 39 #include <linux/slab.h> 40 #include <linux/memblock.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/time.h> 51 #include <asm/cacheflush.h> 52 #include <asm/tlbflush.h> 53 #include <asm/x86_init.h> 54 #include <asm/rtc.h> 55 #include <asm/uv/uv.h> 56 57 #define EFI_DEBUG 58 59 struct efi_memory_map memmap; 60 61 static struct efi efi_phys __initdata; 62 static efi_system_table_t efi_systab __initdata; 63 64 static efi_config_table_type_t arch_tables[] __initdata = { 65 #ifdef CONFIG_X86_UV 66 {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab}, 67 #endif 68 {NULL_GUID, NULL, NULL}, 69 }; 70 71 u64 efi_setup; /* efi setup_data physical address */ 72 73 static int add_efi_memmap __initdata; 74 static int __init setup_add_efi_memmap(char *arg) 75 { 76 add_efi_memmap = 1; 77 return 0; 78 } 79 early_param("add_efi_memmap", setup_add_efi_memmap); 80 81 static efi_status_t __init phys_efi_set_virtual_address_map( 82 unsigned long memory_map_size, 83 unsigned long descriptor_size, 84 u32 descriptor_version, 85 efi_memory_desc_t *virtual_map) 86 { 87 efi_status_t status; 88 unsigned long flags; 89 pgd_t *save_pgd; 90 91 save_pgd = efi_call_phys_prolog(); 92 93 /* Disable interrupts around EFI calls: */ 94 local_irq_save(flags); 95 status = efi_call_phys(efi_phys.set_virtual_address_map, 96 memory_map_size, descriptor_size, 97 descriptor_version, virtual_map); 98 local_irq_restore(flags); 99 100 efi_call_phys_epilog(save_pgd); 101 102 return status; 103 } 104 105 void efi_get_time(struct timespec *now) 106 { 107 efi_status_t status; 108 efi_time_t eft; 109 efi_time_cap_t cap; 110 111 status = efi.get_time(&eft, &cap); 112 if (status != EFI_SUCCESS) 113 pr_err("Oops: efitime: can't read time!\n"); 114 115 now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour, 116 eft.minute, eft.second); 117 now->tv_nsec = 0; 118 } 119 120 void __init efi_find_mirror(void) 121 { 122 void *p; 123 u64 mirror_size = 0, total_size = 0; 124 125 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 126 efi_memory_desc_t *md = p; 127 unsigned long long start = md->phys_addr; 128 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 129 130 total_size += size; 131 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { 132 memblock_mark_mirror(start, size); 133 mirror_size += size; 134 } 135 } 136 if (mirror_size) 137 pr_info("Memory: %lldM/%lldM mirrored memory\n", 138 mirror_size>>20, total_size>>20); 139 } 140 141 /* 142 * Tell the kernel about the EFI memory map. This might include 143 * more than the max 128 entries that can fit in the e820 legacy 144 * (zeropage) memory map. 145 */ 146 147 static void __init do_add_efi_memmap(void) 148 { 149 void *p; 150 151 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 152 efi_memory_desc_t *md = p; 153 unsigned long long start = md->phys_addr; 154 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 155 int e820_type; 156 157 switch (md->type) { 158 case EFI_LOADER_CODE: 159 case EFI_LOADER_DATA: 160 case EFI_BOOT_SERVICES_CODE: 161 case EFI_BOOT_SERVICES_DATA: 162 case EFI_CONVENTIONAL_MEMORY: 163 if (md->attribute & EFI_MEMORY_WB) 164 e820_type = E820_RAM; 165 else 166 e820_type = E820_RESERVED; 167 break; 168 case EFI_ACPI_RECLAIM_MEMORY: 169 e820_type = E820_ACPI; 170 break; 171 case EFI_ACPI_MEMORY_NVS: 172 e820_type = E820_NVS; 173 break; 174 case EFI_UNUSABLE_MEMORY: 175 e820_type = E820_UNUSABLE; 176 break; 177 case EFI_PERSISTENT_MEMORY: 178 e820_type = E820_PMEM; 179 break; 180 default: 181 /* 182 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 183 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 184 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 185 */ 186 e820_type = E820_RESERVED; 187 break; 188 } 189 e820_add_region(start, size, e820_type); 190 } 191 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); 192 } 193 194 int __init efi_memblock_x86_reserve_range(void) 195 { 196 struct efi_info *e = &boot_params.efi_info; 197 unsigned long pmap; 198 199 if (efi_enabled(EFI_PARAVIRT)) 200 return 0; 201 202 #ifdef CONFIG_X86_32 203 /* Can't handle data above 4GB at this time */ 204 if (e->efi_memmap_hi) { 205 pr_err("Memory map is above 4GB, disabling EFI.\n"); 206 return -EINVAL; 207 } 208 pmap = e->efi_memmap; 209 #else 210 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); 211 #endif 212 memmap.phys_map = (void *)pmap; 213 memmap.nr_map = e->efi_memmap_size / 214 e->efi_memdesc_size; 215 memmap.desc_size = e->efi_memdesc_size; 216 memmap.desc_version = e->efi_memdesc_version; 217 218 memblock_reserve(pmap, memmap.nr_map * memmap.desc_size); 219 220 efi.memmap = &memmap; 221 222 return 0; 223 } 224 225 static void __init print_efi_memmap(void) 226 { 227 #ifdef EFI_DEBUG 228 efi_memory_desc_t *md; 229 void *p; 230 int i; 231 232 for (p = memmap.map, i = 0; 233 p < memmap.map_end; 234 p += memmap.desc_size, i++) { 235 char buf[64]; 236 237 md = p; 238 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx) (%lluMB)\n", 239 i, efi_md_typeattr_format(buf, sizeof(buf), md), 240 md->phys_addr, 241 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT), 242 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 243 } 244 #endif /* EFI_DEBUG */ 245 } 246 247 void __init efi_unmap_memmap(void) 248 { 249 clear_bit(EFI_MEMMAP, &efi.flags); 250 if (memmap.map) { 251 early_memunmap(memmap.map, memmap.nr_map * memmap.desc_size); 252 memmap.map = NULL; 253 } 254 } 255 256 static int __init efi_systab_init(void *phys) 257 { 258 if (efi_enabled(EFI_64BIT)) { 259 efi_system_table_64_t *systab64; 260 struct efi_setup_data *data = NULL; 261 u64 tmp = 0; 262 263 if (efi_setup) { 264 data = early_memremap(efi_setup, sizeof(*data)); 265 if (!data) 266 return -ENOMEM; 267 } 268 systab64 = early_memremap((unsigned long)phys, 269 sizeof(*systab64)); 270 if (systab64 == NULL) { 271 pr_err("Couldn't map the system table!\n"); 272 if (data) 273 early_memunmap(data, sizeof(*data)); 274 return -ENOMEM; 275 } 276 277 efi_systab.hdr = systab64->hdr; 278 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor : 279 systab64->fw_vendor; 280 tmp |= data ? data->fw_vendor : systab64->fw_vendor; 281 efi_systab.fw_revision = systab64->fw_revision; 282 efi_systab.con_in_handle = systab64->con_in_handle; 283 tmp |= systab64->con_in_handle; 284 efi_systab.con_in = systab64->con_in; 285 tmp |= systab64->con_in; 286 efi_systab.con_out_handle = systab64->con_out_handle; 287 tmp |= systab64->con_out_handle; 288 efi_systab.con_out = systab64->con_out; 289 tmp |= systab64->con_out; 290 efi_systab.stderr_handle = systab64->stderr_handle; 291 tmp |= systab64->stderr_handle; 292 efi_systab.stderr = systab64->stderr; 293 tmp |= systab64->stderr; 294 efi_systab.runtime = data ? 295 (void *)(unsigned long)data->runtime : 296 (void *)(unsigned long)systab64->runtime; 297 tmp |= data ? data->runtime : systab64->runtime; 298 efi_systab.boottime = (void *)(unsigned long)systab64->boottime; 299 tmp |= systab64->boottime; 300 efi_systab.nr_tables = systab64->nr_tables; 301 efi_systab.tables = data ? (unsigned long)data->tables : 302 systab64->tables; 303 tmp |= data ? data->tables : systab64->tables; 304 305 early_memunmap(systab64, sizeof(*systab64)); 306 if (data) 307 early_memunmap(data, sizeof(*data)); 308 #ifdef CONFIG_X86_32 309 if (tmp >> 32) { 310 pr_err("EFI data located above 4GB, disabling EFI.\n"); 311 return -EINVAL; 312 } 313 #endif 314 } else { 315 efi_system_table_32_t *systab32; 316 317 systab32 = early_memremap((unsigned long)phys, 318 sizeof(*systab32)); 319 if (systab32 == NULL) { 320 pr_err("Couldn't map the system table!\n"); 321 return -ENOMEM; 322 } 323 324 efi_systab.hdr = systab32->hdr; 325 efi_systab.fw_vendor = systab32->fw_vendor; 326 efi_systab.fw_revision = systab32->fw_revision; 327 efi_systab.con_in_handle = systab32->con_in_handle; 328 efi_systab.con_in = systab32->con_in; 329 efi_systab.con_out_handle = systab32->con_out_handle; 330 efi_systab.con_out = systab32->con_out; 331 efi_systab.stderr_handle = systab32->stderr_handle; 332 efi_systab.stderr = systab32->stderr; 333 efi_systab.runtime = (void *)(unsigned long)systab32->runtime; 334 efi_systab.boottime = (void *)(unsigned long)systab32->boottime; 335 efi_systab.nr_tables = systab32->nr_tables; 336 efi_systab.tables = systab32->tables; 337 338 early_memunmap(systab32, sizeof(*systab32)); 339 } 340 341 efi.systab = &efi_systab; 342 343 /* 344 * Verify the EFI Table 345 */ 346 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { 347 pr_err("System table signature incorrect!\n"); 348 return -EINVAL; 349 } 350 if ((efi.systab->hdr.revision >> 16) == 0) 351 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n", 352 efi.systab->hdr.revision >> 16, 353 efi.systab->hdr.revision & 0xffff); 354 355 set_bit(EFI_SYSTEM_TABLES, &efi.flags); 356 357 return 0; 358 } 359 360 static int __init efi_runtime_init32(void) 361 { 362 efi_runtime_services_32_t *runtime; 363 364 runtime = early_memremap((unsigned long)efi.systab->runtime, 365 sizeof(efi_runtime_services_32_t)); 366 if (!runtime) { 367 pr_err("Could not map the runtime service table!\n"); 368 return -ENOMEM; 369 } 370 371 /* 372 * We will only need *early* access to the SetVirtualAddressMap 373 * EFI runtime service. All other runtime services will be called 374 * via the virtual mapping. 375 */ 376 efi_phys.set_virtual_address_map = 377 (efi_set_virtual_address_map_t *) 378 (unsigned long)runtime->set_virtual_address_map; 379 early_memunmap(runtime, sizeof(efi_runtime_services_32_t)); 380 381 return 0; 382 } 383 384 static int __init efi_runtime_init64(void) 385 { 386 efi_runtime_services_64_t *runtime; 387 388 runtime = early_memremap((unsigned long)efi.systab->runtime, 389 sizeof(efi_runtime_services_64_t)); 390 if (!runtime) { 391 pr_err("Could not map the runtime service table!\n"); 392 return -ENOMEM; 393 } 394 395 /* 396 * We will only need *early* access to the SetVirtualAddressMap 397 * EFI runtime service. All other runtime services will be called 398 * via the virtual mapping. 399 */ 400 efi_phys.set_virtual_address_map = 401 (efi_set_virtual_address_map_t *) 402 (unsigned long)runtime->set_virtual_address_map; 403 early_memunmap(runtime, sizeof(efi_runtime_services_64_t)); 404 405 return 0; 406 } 407 408 static int __init efi_runtime_init(void) 409 { 410 int rv; 411 412 /* 413 * Check out the runtime services table. We need to map 414 * the runtime services table so that we can grab the physical 415 * address of several of the EFI runtime functions, needed to 416 * set the firmware into virtual mode. 417 * 418 * When EFI_PARAVIRT is in force then we could not map runtime 419 * service memory region because we do not have direct access to it. 420 * However, runtime services are available through proxy functions 421 * (e.g. in case of Xen dom0 EFI implementation they call special 422 * hypercall which executes relevant EFI functions) and that is why 423 * they are always enabled. 424 */ 425 426 if (!efi_enabled(EFI_PARAVIRT)) { 427 if (efi_enabled(EFI_64BIT)) 428 rv = efi_runtime_init64(); 429 else 430 rv = efi_runtime_init32(); 431 432 if (rv) 433 return rv; 434 } 435 436 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 437 438 return 0; 439 } 440 441 static int __init efi_memmap_init(void) 442 { 443 if (efi_enabled(EFI_PARAVIRT)) 444 return 0; 445 446 /* Map the EFI memory map */ 447 memmap.map = early_memremap((unsigned long)memmap.phys_map, 448 memmap.nr_map * memmap.desc_size); 449 if (memmap.map == NULL) { 450 pr_err("Could not map the memory map!\n"); 451 return -ENOMEM; 452 } 453 memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size); 454 455 if (add_efi_memmap) 456 do_add_efi_memmap(); 457 458 set_bit(EFI_MEMMAP, &efi.flags); 459 460 return 0; 461 } 462 463 void __init efi_init(void) 464 { 465 efi_char16_t *c16; 466 char vendor[100] = "unknown"; 467 int i = 0; 468 void *tmp; 469 470 #ifdef CONFIG_X86_32 471 if (boot_params.efi_info.efi_systab_hi || 472 boot_params.efi_info.efi_memmap_hi) { 473 pr_info("Table located above 4GB, disabling EFI.\n"); 474 return; 475 } 476 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; 477 #else 478 efi_phys.systab = (efi_system_table_t *) 479 (boot_params.efi_info.efi_systab | 480 ((__u64)boot_params.efi_info.efi_systab_hi<<32)); 481 #endif 482 483 if (efi_systab_init(efi_phys.systab)) 484 return; 485 486 efi.config_table = (unsigned long)efi.systab->tables; 487 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; 488 efi.runtime = (unsigned long)efi.systab->runtime; 489 490 /* 491 * Show what we know for posterity 492 */ 493 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2); 494 if (c16) { 495 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i) 496 vendor[i] = *c16++; 497 vendor[i] = '\0'; 498 } else 499 pr_err("Could not map the firmware vendor!\n"); 500 early_memunmap(tmp, 2); 501 502 pr_info("EFI v%u.%.02u by %s\n", 503 efi.systab->hdr.revision >> 16, 504 efi.systab->hdr.revision & 0xffff, vendor); 505 506 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables)) 507 return; 508 509 if (efi_config_init(arch_tables)) 510 return; 511 512 /* 513 * Note: We currently don't support runtime services on an EFI 514 * that doesn't match the kernel 32/64-bit mode. 515 */ 516 517 if (!efi_runtime_supported()) 518 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 519 else { 520 if (efi_runtime_disabled() || efi_runtime_init()) 521 return; 522 } 523 if (efi_memmap_init()) 524 return; 525 526 if (efi_enabled(EFI_DBG)) 527 print_efi_memmap(); 528 529 efi_esrt_init(); 530 } 531 532 void __init efi_late_init(void) 533 { 534 efi_bgrt_init(); 535 } 536 537 void __init efi_set_executable(efi_memory_desc_t *md, bool executable) 538 { 539 u64 addr, npages; 540 541 addr = md->virt_addr; 542 npages = md->num_pages; 543 544 memrange_efi_to_native(&addr, &npages); 545 546 if (executable) 547 set_memory_x(addr, npages); 548 else 549 set_memory_nx(addr, npages); 550 } 551 552 void __init runtime_code_page_mkexec(void) 553 { 554 efi_memory_desc_t *md; 555 void *p; 556 557 /* Make EFI runtime service code area executable */ 558 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 559 md = p; 560 561 if (md->type != EFI_RUNTIME_SERVICES_CODE) 562 continue; 563 564 efi_set_executable(md, true); 565 } 566 } 567 568 void __init efi_memory_uc(u64 addr, unsigned long size) 569 { 570 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; 571 u64 npages; 572 573 npages = round_up(size, page_shift) / page_shift; 574 memrange_efi_to_native(&addr, &npages); 575 set_memory_uc(addr, npages); 576 } 577 578 void __init old_map_region(efi_memory_desc_t *md) 579 { 580 u64 start_pfn, end_pfn, end; 581 unsigned long size; 582 void *va; 583 584 start_pfn = PFN_DOWN(md->phys_addr); 585 size = md->num_pages << PAGE_SHIFT; 586 end = md->phys_addr + size; 587 end_pfn = PFN_UP(end); 588 589 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 590 va = __va(md->phys_addr); 591 592 if (!(md->attribute & EFI_MEMORY_WB)) 593 efi_memory_uc((u64)(unsigned long)va, size); 594 } else 595 va = efi_ioremap(md->phys_addr, size, 596 md->type, md->attribute); 597 598 md->virt_addr = (u64) (unsigned long) va; 599 if (!va) 600 pr_err("ioremap of 0x%llX failed!\n", 601 (unsigned long long)md->phys_addr); 602 } 603 604 /* Merge contiguous regions of the same type and attribute */ 605 static void __init efi_merge_regions(void) 606 { 607 void *p; 608 efi_memory_desc_t *md, *prev_md = NULL; 609 610 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 611 u64 prev_size; 612 md = p; 613 614 if (!prev_md) { 615 prev_md = md; 616 continue; 617 } 618 619 if (prev_md->type != md->type || 620 prev_md->attribute != md->attribute) { 621 prev_md = md; 622 continue; 623 } 624 625 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 626 627 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 628 prev_md->num_pages += md->num_pages; 629 md->type = EFI_RESERVED_TYPE; 630 md->attribute = 0; 631 continue; 632 } 633 prev_md = md; 634 } 635 } 636 637 static void __init get_systab_virt_addr(efi_memory_desc_t *md) 638 { 639 unsigned long size; 640 u64 end, systab; 641 642 size = md->num_pages << EFI_PAGE_SHIFT; 643 end = md->phys_addr + size; 644 systab = (u64)(unsigned long)efi_phys.systab; 645 if (md->phys_addr <= systab && systab < end) { 646 systab += md->virt_addr - md->phys_addr; 647 efi.systab = (efi_system_table_t *)(unsigned long)systab; 648 } 649 } 650 651 static void __init save_runtime_map(void) 652 { 653 #ifdef CONFIG_KEXEC_CORE 654 efi_memory_desc_t *md; 655 void *tmp, *p, *q = NULL; 656 int count = 0; 657 658 if (efi_enabled(EFI_OLD_MEMMAP)) 659 return; 660 661 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 662 md = p; 663 664 if (!(md->attribute & EFI_MEMORY_RUNTIME) || 665 (md->type == EFI_BOOT_SERVICES_CODE) || 666 (md->type == EFI_BOOT_SERVICES_DATA)) 667 continue; 668 tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL); 669 if (!tmp) 670 goto out; 671 q = tmp; 672 673 memcpy(q + count * memmap.desc_size, md, memmap.desc_size); 674 count++; 675 } 676 677 efi_runtime_map_setup(q, count, memmap.desc_size); 678 return; 679 680 out: 681 kfree(q); 682 pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n"); 683 #endif 684 } 685 686 static void *realloc_pages(void *old_memmap, int old_shift) 687 { 688 void *ret; 689 690 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 691 if (!ret) 692 goto out; 693 694 /* 695 * A first-time allocation doesn't have anything to copy. 696 */ 697 if (!old_memmap) 698 return ret; 699 700 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 701 702 out: 703 free_pages((unsigned long)old_memmap, old_shift); 704 return ret; 705 } 706 707 /* 708 * Iterate the EFI memory map in reverse order because the regions 709 * will be mapped top-down. The end result is the same as if we had 710 * mapped things forward, but doesn't require us to change the 711 * existing implementation of efi_map_region(). 712 */ 713 static inline void *efi_map_next_entry_reverse(void *entry) 714 { 715 /* Initial call */ 716 if (!entry) 717 return memmap.map_end - memmap.desc_size; 718 719 entry -= memmap.desc_size; 720 if (entry < memmap.map) 721 return NULL; 722 723 return entry; 724 } 725 726 /* 727 * efi_map_next_entry - Return the next EFI memory map descriptor 728 * @entry: Previous EFI memory map descriptor 729 * 730 * This is a helper function to iterate over the EFI memory map, which 731 * we do in different orders depending on the current configuration. 732 * 733 * To begin traversing the memory map @entry must be %NULL. 734 * 735 * Returns %NULL when we reach the end of the memory map. 736 */ 737 static void *efi_map_next_entry(void *entry) 738 { 739 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) { 740 /* 741 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 742 * config table feature requires us to map all entries 743 * in the same order as they appear in the EFI memory 744 * map. That is to say, entry N must have a lower 745 * virtual address than entry N+1. This is because the 746 * firmware toolchain leaves relative references in 747 * the code/data sections, which are split and become 748 * separate EFI memory regions. Mapping things 749 * out-of-order leads to the firmware accessing 750 * unmapped addresses. 751 * 752 * Since we need to map things this way whether or not 753 * the kernel actually makes use of 754 * EFI_PROPERTIES_TABLE, let's just switch to this 755 * scheme by default for 64-bit. 756 */ 757 return efi_map_next_entry_reverse(entry); 758 } 759 760 /* Initial call */ 761 if (!entry) 762 return memmap.map; 763 764 entry += memmap.desc_size; 765 if (entry >= memmap.map_end) 766 return NULL; 767 768 return entry; 769 } 770 771 /* 772 * Map the efi memory ranges of the runtime services and update new_mmap with 773 * virtual addresses. 774 */ 775 static void * __init efi_map_regions(int *count, int *pg_shift) 776 { 777 void *p, *new_memmap = NULL; 778 unsigned long left = 0; 779 efi_memory_desc_t *md; 780 781 p = NULL; 782 while ((p = efi_map_next_entry(p))) { 783 md = p; 784 if (!(md->attribute & EFI_MEMORY_RUNTIME)) { 785 #ifdef CONFIG_X86_64 786 if (md->type != EFI_BOOT_SERVICES_CODE && 787 md->type != EFI_BOOT_SERVICES_DATA) 788 #endif 789 continue; 790 } 791 792 efi_map_region(md); 793 get_systab_virt_addr(md); 794 795 if (left < memmap.desc_size) { 796 new_memmap = realloc_pages(new_memmap, *pg_shift); 797 if (!new_memmap) 798 return NULL; 799 800 left += PAGE_SIZE << *pg_shift; 801 (*pg_shift)++; 802 } 803 804 memcpy(new_memmap + (*count * memmap.desc_size), md, 805 memmap.desc_size); 806 807 left -= memmap.desc_size; 808 (*count)++; 809 } 810 811 return new_memmap; 812 } 813 814 static void __init kexec_enter_virtual_mode(void) 815 { 816 #ifdef CONFIG_KEXEC_CORE 817 efi_memory_desc_t *md; 818 void *p; 819 820 efi.systab = NULL; 821 822 /* 823 * We don't do virtual mode, since we don't do runtime services, on 824 * non-native EFI 825 */ 826 if (!efi_is_native()) { 827 efi_unmap_memmap(); 828 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 829 return; 830 } 831 832 /* 833 * Map efi regions which were passed via setup_data. The virt_addr is a 834 * fixed addr which was used in first kernel of a kexec boot. 835 */ 836 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 837 md = p; 838 efi_map_region_fixed(md); /* FIXME: add error handling */ 839 get_systab_virt_addr(md); 840 } 841 842 save_runtime_map(); 843 844 BUG_ON(!efi.systab); 845 846 efi_sync_low_kernel_mappings(); 847 848 /* 849 * Now that EFI is in virtual mode, update the function 850 * pointers in the runtime service table to the new virtual addresses. 851 * 852 * Call EFI services through wrapper functions. 853 */ 854 efi.runtime_version = efi_systab.hdr.revision; 855 856 efi_native_runtime_setup(); 857 858 efi.set_virtual_address_map = NULL; 859 860 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) 861 runtime_code_page_mkexec(); 862 863 /* clean DUMMY object */ 864 efi_delete_dummy_variable(); 865 #endif 866 } 867 868 /* 869 * This function will switch the EFI runtime services to virtual mode. 870 * Essentially, we look through the EFI memmap and map every region that 871 * has the runtime attribute bit set in its memory descriptor into the 872 * ->trampoline_pgd page table using a top-down VA allocation scheme. 873 * 874 * The old method which used to update that memory descriptor with the 875 * virtual address obtained from ioremap() is still supported when the 876 * kernel is booted with efi=old_map on its command line. Same old 877 * method enabled the runtime services to be called without having to 878 * thunk back into physical mode for every invocation. 879 * 880 * The new method does a pagetable switch in a preemption-safe manner 881 * so that we're in a different address space when calling a runtime 882 * function. For function arguments passing we do copy the PGDs of the 883 * kernel page table into ->trampoline_pgd prior to each call. 884 * 885 * Specially for kexec boot, efi runtime maps in previous kernel should 886 * be passed in via setup_data. In that case runtime ranges will be mapped 887 * to the same virtual addresses as the first kernel, see 888 * kexec_enter_virtual_mode(). 889 */ 890 static void __init __efi_enter_virtual_mode(void) 891 { 892 int count = 0, pg_shift = 0; 893 void *new_memmap = NULL; 894 efi_status_t status; 895 896 efi.systab = NULL; 897 898 efi_merge_regions(); 899 new_memmap = efi_map_regions(&count, &pg_shift); 900 if (!new_memmap) { 901 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 902 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 903 return; 904 } 905 906 save_runtime_map(); 907 908 BUG_ON(!efi.systab); 909 910 if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift)) { 911 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 912 return; 913 } 914 915 efi_sync_low_kernel_mappings(); 916 efi_dump_pagetable(); 917 918 if (efi_is_native()) { 919 status = phys_efi_set_virtual_address_map( 920 memmap.desc_size * count, 921 memmap.desc_size, 922 memmap.desc_version, 923 (efi_memory_desc_t *)__pa(new_memmap)); 924 } else { 925 status = efi_thunk_set_virtual_address_map( 926 efi_phys.set_virtual_address_map, 927 memmap.desc_size * count, 928 memmap.desc_size, 929 memmap.desc_version, 930 (efi_memory_desc_t *)__pa(new_memmap)); 931 } 932 933 if (status != EFI_SUCCESS) { 934 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", 935 status); 936 panic("EFI call to SetVirtualAddressMap() failed!"); 937 } 938 939 /* 940 * Now that EFI is in virtual mode, update the function 941 * pointers in the runtime service table to the new virtual addresses. 942 * 943 * Call EFI services through wrapper functions. 944 */ 945 efi.runtime_version = efi_systab.hdr.revision; 946 947 if (efi_is_native()) 948 efi_native_runtime_setup(); 949 else 950 efi_thunk_runtime_setup(); 951 952 efi.set_virtual_address_map = NULL; 953 954 efi_runtime_mkexec(); 955 956 /* 957 * We mapped the descriptor array into the EFI pagetable above but we're 958 * not unmapping it here. Here's why: 959 * 960 * We're copying select PGDs from the kernel page table to the EFI page 961 * table and when we do so and make changes to those PGDs like unmapping 962 * stuff from them, those changes appear in the kernel page table and we 963 * go boom. 964 * 965 * From setup_real_mode(): 966 * 967 * ... 968 * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd; 969 * 970 * In this particular case, our allocation is in PGD 0 of the EFI page 971 * table but we've copied that PGD from PGD[272] of the EFI page table: 972 * 973 * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272 974 * 975 * where the direct memory mapping in kernel space is. 976 * 977 * new_memmap's VA comes from that direct mapping and thus clearing it, 978 * it would get cleared in the kernel page table too. 979 * 980 * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift); 981 */ 982 free_pages((unsigned long)new_memmap, pg_shift); 983 984 /* clean DUMMY object */ 985 efi_delete_dummy_variable(); 986 } 987 988 void __init efi_enter_virtual_mode(void) 989 { 990 if (efi_enabled(EFI_PARAVIRT)) 991 return; 992 993 if (efi_setup) 994 kexec_enter_virtual_mode(); 995 else 996 __efi_enter_virtual_mode(); 997 } 998 999 /* 1000 * Convenience functions to obtain memory types and attributes 1001 */ 1002 u32 efi_mem_type(unsigned long phys_addr) 1003 { 1004 efi_memory_desc_t *md; 1005 void *p; 1006 1007 if (!efi_enabled(EFI_MEMMAP)) 1008 return 0; 1009 1010 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 1011 md = p; 1012 if ((md->phys_addr <= phys_addr) && 1013 (phys_addr < (md->phys_addr + 1014 (md->num_pages << EFI_PAGE_SHIFT)))) 1015 return md->type; 1016 } 1017 return 0; 1018 } 1019 1020 u64 efi_mem_attributes(unsigned long phys_addr) 1021 { 1022 efi_memory_desc_t *md; 1023 void *p; 1024 1025 if (!efi_enabled(EFI_MEMMAP)) 1026 return 0; 1027 1028 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) { 1029 md = p; 1030 if ((md->phys_addr <= phys_addr) && 1031 (phys_addr < (md->phys_addr + 1032 (md->num_pages << EFI_PAGE_SHIFT)))) 1033 return md->attribute; 1034 } 1035 return 0; 1036 } 1037 1038 static int __init arch_parse_efi_cmdline(char *str) 1039 { 1040 if (!str) { 1041 pr_warn("need at least one option\n"); 1042 return -EINVAL; 1043 } 1044 1045 if (parse_option_str(str, "old_map")) 1046 set_bit(EFI_OLD_MEMMAP, &efi.flags); 1047 if (parse_option_str(str, "debug")) 1048 set_bit(EFI_DBG, &efi.flags); 1049 1050 return 0; 1051 } 1052 early_param("efi", arch_parse_efi_cmdline); 1053