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