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 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 214 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 215 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 216 217 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 218 { 219 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 220 u64 end_hi = 0; 221 char buf[64]; 222 223 if (md->num_pages == 0) { 224 end = 0; 225 } else if (md->num_pages > EFI_PAGES_MAX || 226 EFI_PAGES_MAX - md->num_pages < 227 (md->phys_addr >> EFI_PAGE_SHIFT)) { 228 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 229 >> OVERFLOW_ADDR_SHIFT; 230 231 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 232 end_hi += 1; 233 } else { 234 return true; 235 } 236 237 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 238 239 if (end_hi) { 240 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 241 i, efi_md_typeattr_format(buf, sizeof(buf), md), 242 md->phys_addr, end_hi, end); 243 } else { 244 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 245 i, efi_md_typeattr_format(buf, sizeof(buf), md), 246 md->phys_addr, end); 247 } 248 return false; 249 } 250 251 static void __init efi_clean_memmap(void) 252 { 253 efi_memory_desc_t *out = efi.memmap.map; 254 const efi_memory_desc_t *in = out; 255 const efi_memory_desc_t *end = efi.memmap.map_end; 256 int i, n_removal; 257 258 for (i = n_removal = 0; in < end; i++) { 259 if (efi_memmap_entry_valid(in, i)) { 260 if (out != in) 261 memcpy(out, in, efi.memmap.desc_size); 262 out = (void *)out + efi.memmap.desc_size; 263 } else { 264 n_removal++; 265 } 266 in = (void *)in + efi.memmap.desc_size; 267 } 268 269 if (n_removal > 0) { 270 u64 size = efi.memmap.nr_map - n_removal; 271 272 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 273 efi_memmap_install(efi.memmap.phys_map, size); 274 } 275 } 276 277 void __init efi_print_memmap(void) 278 { 279 efi_memory_desc_t *md; 280 int i = 0; 281 282 for_each_efi_memory_desc(md) { 283 char buf[64]; 284 285 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 286 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 287 md->phys_addr, 288 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 289 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 290 } 291 } 292 293 static int __init efi_systab_init(void *phys) 294 { 295 if (efi_enabled(EFI_64BIT)) { 296 efi_system_table_64_t *systab64; 297 struct efi_setup_data *data = NULL; 298 u64 tmp = 0; 299 300 if (efi_setup) { 301 data = early_memremap(efi_setup, sizeof(*data)); 302 if (!data) 303 return -ENOMEM; 304 } 305 systab64 = early_memremap((unsigned long)phys, 306 sizeof(*systab64)); 307 if (systab64 == NULL) { 308 pr_err("Couldn't map the system table!\n"); 309 if (data) 310 early_memunmap(data, sizeof(*data)); 311 return -ENOMEM; 312 } 313 314 efi_systab.hdr = systab64->hdr; 315 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor : 316 systab64->fw_vendor; 317 tmp |= data ? data->fw_vendor : systab64->fw_vendor; 318 efi_systab.fw_revision = systab64->fw_revision; 319 efi_systab.con_in_handle = systab64->con_in_handle; 320 tmp |= systab64->con_in_handle; 321 efi_systab.con_in = systab64->con_in; 322 tmp |= systab64->con_in; 323 efi_systab.con_out_handle = systab64->con_out_handle; 324 tmp |= systab64->con_out_handle; 325 efi_systab.con_out = systab64->con_out; 326 tmp |= systab64->con_out; 327 efi_systab.stderr_handle = systab64->stderr_handle; 328 tmp |= systab64->stderr_handle; 329 efi_systab.stderr = systab64->stderr; 330 tmp |= systab64->stderr; 331 efi_systab.runtime = data ? 332 (void *)(unsigned long)data->runtime : 333 (void *)(unsigned long)systab64->runtime; 334 tmp |= data ? data->runtime : systab64->runtime; 335 efi_systab.boottime = (void *)(unsigned long)systab64->boottime; 336 tmp |= systab64->boottime; 337 efi_systab.nr_tables = systab64->nr_tables; 338 efi_systab.tables = data ? (unsigned long)data->tables : 339 systab64->tables; 340 tmp |= data ? data->tables : systab64->tables; 341 342 early_memunmap(systab64, sizeof(*systab64)); 343 if (data) 344 early_memunmap(data, sizeof(*data)); 345 #ifdef CONFIG_X86_32 346 if (tmp >> 32) { 347 pr_err("EFI data located above 4GB, disabling EFI.\n"); 348 return -EINVAL; 349 } 350 #endif 351 } else { 352 efi_system_table_32_t *systab32; 353 354 systab32 = early_memremap((unsigned long)phys, 355 sizeof(*systab32)); 356 if (systab32 == NULL) { 357 pr_err("Couldn't map the system table!\n"); 358 return -ENOMEM; 359 } 360 361 efi_systab.hdr = systab32->hdr; 362 efi_systab.fw_vendor = systab32->fw_vendor; 363 efi_systab.fw_revision = systab32->fw_revision; 364 efi_systab.con_in_handle = systab32->con_in_handle; 365 efi_systab.con_in = systab32->con_in; 366 efi_systab.con_out_handle = systab32->con_out_handle; 367 efi_systab.con_out = systab32->con_out; 368 efi_systab.stderr_handle = systab32->stderr_handle; 369 efi_systab.stderr = systab32->stderr; 370 efi_systab.runtime = (void *)(unsigned long)systab32->runtime; 371 efi_systab.boottime = (void *)(unsigned long)systab32->boottime; 372 efi_systab.nr_tables = systab32->nr_tables; 373 efi_systab.tables = systab32->tables; 374 375 early_memunmap(systab32, sizeof(*systab32)); 376 } 377 378 efi.systab = &efi_systab; 379 380 /* 381 * Verify the EFI Table 382 */ 383 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { 384 pr_err("System table signature incorrect!\n"); 385 return -EINVAL; 386 } 387 if ((efi.systab->hdr.revision >> 16) == 0) 388 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n", 389 efi.systab->hdr.revision >> 16, 390 efi.systab->hdr.revision & 0xffff); 391 392 return 0; 393 } 394 395 static int __init efi_runtime_init32(void) 396 { 397 efi_runtime_services_32_t *runtime; 398 399 runtime = early_memremap((unsigned long)efi.systab->runtime, 400 sizeof(efi_runtime_services_32_t)); 401 if (!runtime) { 402 pr_err("Could not map the runtime service table!\n"); 403 return -ENOMEM; 404 } 405 406 /* 407 * We will only need *early* access to the SetVirtualAddressMap 408 * EFI runtime service. All other runtime services will be called 409 * via the virtual mapping. 410 */ 411 efi_phys.set_virtual_address_map = 412 (efi_set_virtual_address_map_t *) 413 (unsigned long)runtime->set_virtual_address_map; 414 early_memunmap(runtime, sizeof(efi_runtime_services_32_t)); 415 416 return 0; 417 } 418 419 static int __init efi_runtime_init64(void) 420 { 421 efi_runtime_services_64_t *runtime; 422 423 runtime = early_memremap((unsigned long)efi.systab->runtime, 424 sizeof(efi_runtime_services_64_t)); 425 if (!runtime) { 426 pr_err("Could not map the runtime service table!\n"); 427 return -ENOMEM; 428 } 429 430 /* 431 * We will only need *early* access to the SetVirtualAddressMap 432 * EFI runtime service. All other runtime services will be called 433 * via the virtual mapping. 434 */ 435 efi_phys.set_virtual_address_map = 436 (efi_set_virtual_address_map_t *) 437 (unsigned long)runtime->set_virtual_address_map; 438 early_memunmap(runtime, sizeof(efi_runtime_services_64_t)); 439 440 return 0; 441 } 442 443 static int __init efi_runtime_init(void) 444 { 445 int rv; 446 447 /* 448 * Check out the runtime services table. We need to map 449 * the runtime services table so that we can grab the physical 450 * address of several of the EFI runtime functions, needed to 451 * set the firmware into virtual mode. 452 * 453 * When EFI_PARAVIRT is in force then we could not map runtime 454 * service memory region because we do not have direct access to it. 455 * However, runtime services are available through proxy functions 456 * (e.g. in case of Xen dom0 EFI implementation they call special 457 * hypercall which executes relevant EFI functions) and that is why 458 * they are always enabled. 459 */ 460 461 if (!efi_enabled(EFI_PARAVIRT)) { 462 if (efi_enabled(EFI_64BIT)) 463 rv = efi_runtime_init64(); 464 else 465 rv = efi_runtime_init32(); 466 467 if (rv) 468 return rv; 469 } 470 471 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 472 473 return 0; 474 } 475 476 void __init efi_init(void) 477 { 478 efi_char16_t *c16; 479 char vendor[100] = "unknown"; 480 int i = 0; 481 void *tmp; 482 483 #ifdef CONFIG_X86_32 484 if (boot_params.efi_info.efi_systab_hi || 485 boot_params.efi_info.efi_memmap_hi) { 486 pr_info("Table located above 4GB, disabling EFI.\n"); 487 return; 488 } 489 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; 490 #else 491 efi_phys.systab = (efi_system_table_t *) 492 (boot_params.efi_info.efi_systab | 493 ((__u64)boot_params.efi_info.efi_systab_hi<<32)); 494 #endif 495 496 if (efi_systab_init(efi_phys.systab)) 497 return; 498 499 efi.config_table = (unsigned long)efi.systab->tables; 500 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; 501 efi.runtime = (unsigned long)efi.systab->runtime; 502 503 /* 504 * Show what we know for posterity 505 */ 506 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2); 507 if (c16) { 508 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i) 509 vendor[i] = *c16++; 510 vendor[i] = '\0'; 511 } else 512 pr_err("Could not map the firmware vendor!\n"); 513 early_memunmap(tmp, 2); 514 515 pr_info("EFI v%u.%.02u by %s\n", 516 efi.systab->hdr.revision >> 16, 517 efi.systab->hdr.revision & 0xffff, vendor); 518 519 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables)) 520 return; 521 522 if (efi_config_init(arch_tables)) 523 return; 524 525 /* 526 * Note: We currently don't support runtime services on an EFI 527 * that doesn't match the kernel 32/64-bit mode. 528 */ 529 530 if (!efi_runtime_supported()) 531 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 532 else { 533 if (efi_runtime_disabled() || efi_runtime_init()) { 534 efi_memmap_unmap(); 535 return; 536 } 537 } 538 539 efi_clean_memmap(); 540 541 if (efi_enabled(EFI_DBG)) 542 efi_print_memmap(); 543 } 544 545 void __init efi_set_executable(efi_memory_desc_t *md, bool executable) 546 { 547 u64 addr, npages; 548 549 addr = md->virt_addr; 550 npages = md->num_pages; 551 552 memrange_efi_to_native(&addr, &npages); 553 554 if (executable) 555 set_memory_x(addr, npages); 556 else 557 set_memory_nx(addr, npages); 558 } 559 560 void __init runtime_code_page_mkexec(void) 561 { 562 efi_memory_desc_t *md; 563 564 /* Make EFI runtime service code area executable */ 565 for_each_efi_memory_desc(md) { 566 if (md->type != EFI_RUNTIME_SERVICES_CODE) 567 continue; 568 569 efi_set_executable(md, true); 570 } 571 } 572 573 void __init efi_memory_uc(u64 addr, unsigned long size) 574 { 575 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; 576 u64 npages; 577 578 npages = round_up(size, page_shift) / page_shift; 579 memrange_efi_to_native(&addr, &npages); 580 set_memory_uc(addr, npages); 581 } 582 583 void __init old_map_region(efi_memory_desc_t *md) 584 { 585 u64 start_pfn, end_pfn, end; 586 unsigned long size; 587 void *va; 588 589 start_pfn = PFN_DOWN(md->phys_addr); 590 size = md->num_pages << PAGE_SHIFT; 591 end = md->phys_addr + size; 592 end_pfn = PFN_UP(end); 593 594 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 595 va = __va(md->phys_addr); 596 597 if (!(md->attribute & EFI_MEMORY_WB)) 598 efi_memory_uc((u64)(unsigned long)va, size); 599 } else 600 va = efi_ioremap(md->phys_addr, size, 601 md->type, md->attribute); 602 603 md->virt_addr = (u64) (unsigned long) va; 604 if (!va) 605 pr_err("ioremap of 0x%llX failed!\n", 606 (unsigned long long)md->phys_addr); 607 } 608 609 /* Merge contiguous regions of the same type and attribute */ 610 static void __init efi_merge_regions(void) 611 { 612 efi_memory_desc_t *md, *prev_md = NULL; 613 614 for_each_efi_memory_desc(md) { 615 u64 prev_size; 616 617 if (!prev_md) { 618 prev_md = md; 619 continue; 620 } 621 622 if (prev_md->type != md->type || 623 prev_md->attribute != md->attribute) { 624 prev_md = md; 625 continue; 626 } 627 628 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 629 630 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 631 prev_md->num_pages += md->num_pages; 632 md->type = EFI_RESERVED_TYPE; 633 md->attribute = 0; 634 continue; 635 } 636 prev_md = md; 637 } 638 } 639 640 static void __init get_systab_virt_addr(efi_memory_desc_t *md) 641 { 642 unsigned long size; 643 u64 end, systab; 644 645 size = md->num_pages << EFI_PAGE_SHIFT; 646 end = md->phys_addr + size; 647 systab = (u64)(unsigned long)efi_phys.systab; 648 if (md->phys_addr <= systab && systab < end) { 649 systab += md->virt_addr - md->phys_addr; 650 efi.systab = (efi_system_table_t *)(unsigned long)systab; 651 } 652 } 653 654 static void *realloc_pages(void *old_memmap, int old_shift) 655 { 656 void *ret; 657 658 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 659 if (!ret) 660 goto out; 661 662 /* 663 * A first-time allocation doesn't have anything to copy. 664 */ 665 if (!old_memmap) 666 return ret; 667 668 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 669 670 out: 671 free_pages((unsigned long)old_memmap, old_shift); 672 return ret; 673 } 674 675 /* 676 * Iterate the EFI memory map in reverse order because the regions 677 * will be mapped top-down. The end result is the same as if we had 678 * mapped things forward, but doesn't require us to change the 679 * existing implementation of efi_map_region(). 680 */ 681 static inline void *efi_map_next_entry_reverse(void *entry) 682 { 683 /* Initial call */ 684 if (!entry) 685 return efi.memmap.map_end - efi.memmap.desc_size; 686 687 entry -= efi.memmap.desc_size; 688 if (entry < efi.memmap.map) 689 return NULL; 690 691 return entry; 692 } 693 694 /* 695 * efi_map_next_entry - Return the next EFI memory map descriptor 696 * @entry: Previous EFI memory map descriptor 697 * 698 * This is a helper function to iterate over the EFI memory map, which 699 * we do in different orders depending on the current configuration. 700 * 701 * To begin traversing the memory map @entry must be %NULL. 702 * 703 * Returns %NULL when we reach the end of the memory map. 704 */ 705 static void *efi_map_next_entry(void *entry) 706 { 707 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) { 708 /* 709 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 710 * config table feature requires us to map all entries 711 * in the same order as they appear in the EFI memory 712 * map. That is to say, entry N must have a lower 713 * virtual address than entry N+1. This is because the 714 * firmware toolchain leaves relative references in 715 * the code/data sections, which are split and become 716 * separate EFI memory regions. Mapping things 717 * out-of-order leads to the firmware accessing 718 * unmapped addresses. 719 * 720 * Since we need to map things this way whether or not 721 * the kernel actually makes use of 722 * EFI_PROPERTIES_TABLE, let's just switch to this 723 * scheme by default for 64-bit. 724 */ 725 return efi_map_next_entry_reverse(entry); 726 } 727 728 /* Initial call */ 729 if (!entry) 730 return efi.memmap.map; 731 732 entry += efi.memmap.desc_size; 733 if (entry >= efi.memmap.map_end) 734 return NULL; 735 736 return entry; 737 } 738 739 static bool should_map_region(efi_memory_desc_t *md) 740 { 741 /* 742 * Runtime regions always require runtime mappings (obviously). 743 */ 744 if (md->attribute & EFI_MEMORY_RUNTIME) 745 return true; 746 747 /* 748 * 32-bit EFI doesn't suffer from the bug that requires us to 749 * reserve boot services regions, and mixed mode support 750 * doesn't exist for 32-bit kernels. 751 */ 752 if (IS_ENABLED(CONFIG_X86_32)) 753 return false; 754 755 /* 756 * Map all of RAM so that we can access arguments in the 1:1 757 * mapping when making EFI runtime calls. 758 */ 759 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) { 760 if (md->type == EFI_CONVENTIONAL_MEMORY || 761 md->type == EFI_LOADER_DATA || 762 md->type == EFI_LOADER_CODE) 763 return true; 764 } 765 766 /* 767 * Map boot services regions as a workaround for buggy 768 * firmware that accesses them even when they shouldn't. 769 * 770 * See efi_{reserve,free}_boot_services(). 771 */ 772 if (md->type == EFI_BOOT_SERVICES_CODE || 773 md->type == EFI_BOOT_SERVICES_DATA) 774 return true; 775 776 return false; 777 } 778 779 /* 780 * Map the efi memory ranges of the runtime services and update new_mmap with 781 * virtual addresses. 782 */ 783 static void * __init efi_map_regions(int *count, int *pg_shift) 784 { 785 void *p, *new_memmap = NULL; 786 unsigned long left = 0; 787 unsigned long desc_size; 788 efi_memory_desc_t *md; 789 790 desc_size = efi.memmap.desc_size; 791 792 p = NULL; 793 while ((p = efi_map_next_entry(p))) { 794 md = p; 795 796 if (!should_map_region(md)) 797 continue; 798 799 efi_map_region(md); 800 get_systab_virt_addr(md); 801 802 if (left < desc_size) { 803 new_memmap = realloc_pages(new_memmap, *pg_shift); 804 if (!new_memmap) 805 return NULL; 806 807 left += PAGE_SIZE << *pg_shift; 808 (*pg_shift)++; 809 } 810 811 memcpy(new_memmap + (*count * desc_size), md, desc_size); 812 813 left -= desc_size; 814 (*count)++; 815 } 816 817 return new_memmap; 818 } 819 820 static void __init kexec_enter_virtual_mode(void) 821 { 822 #ifdef CONFIG_KEXEC_CORE 823 efi_memory_desc_t *md; 824 unsigned int num_pages; 825 826 efi.systab = NULL; 827 828 /* 829 * We don't do virtual mode, since we don't do runtime services, on 830 * non-native EFI 831 */ 832 if (!efi_is_native()) { 833 efi_memmap_unmap(); 834 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 835 return; 836 } 837 838 if (efi_alloc_page_tables()) { 839 pr_err("Failed to allocate EFI page tables\n"); 840 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 841 return; 842 } 843 844 /* 845 * Map efi regions which were passed via setup_data. The virt_addr is a 846 * fixed addr which was used in first kernel of a kexec boot. 847 */ 848 for_each_efi_memory_desc(md) { 849 efi_map_region_fixed(md); /* FIXME: add error handling */ 850 get_systab_virt_addr(md); 851 } 852 853 /* 854 * Unregister the early EFI memmap from efi_init() and install 855 * the new EFI memory map. 856 */ 857 efi_memmap_unmap(); 858 859 if (efi_memmap_init_late(efi.memmap.phys_map, 860 efi.memmap.desc_size * efi.memmap.nr_map)) { 861 pr_err("Failed to remap late EFI memory map\n"); 862 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 863 return; 864 } 865 866 BUG_ON(!efi.systab); 867 868 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 869 num_pages >>= PAGE_SHIFT; 870 871 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 872 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 873 return; 874 } 875 876 efi_sync_low_kernel_mappings(); 877 878 /* 879 * Now that EFI is in virtual mode, update the function 880 * pointers in the runtime service table to the new virtual addresses. 881 * 882 * Call EFI services through wrapper functions. 883 */ 884 efi.runtime_version = efi_systab.hdr.revision; 885 886 efi_native_runtime_setup(); 887 888 efi.set_virtual_address_map = NULL; 889 890 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) 891 runtime_code_page_mkexec(); 892 893 /* clean DUMMY object */ 894 efi_delete_dummy_variable(); 895 #endif 896 } 897 898 /* 899 * This function will switch the EFI runtime services to virtual mode. 900 * Essentially, we look through the EFI memmap and map every region that 901 * has the runtime attribute bit set in its memory descriptor into the 902 * efi_pgd page table. 903 * 904 * The old method which used to update that memory descriptor with the 905 * virtual address obtained from ioremap() is still supported when the 906 * kernel is booted with efi=old_map on its command line. Same old 907 * method enabled the runtime services to be called without having to 908 * thunk back into physical mode for every invocation. 909 * 910 * The new method does a pagetable switch in a preemption-safe manner 911 * so that we're in a different address space when calling a runtime 912 * function. For function arguments passing we do copy the PUDs of the 913 * kernel page table into efi_pgd prior to each call. 914 * 915 * Specially for kexec boot, efi runtime maps in previous kernel should 916 * be passed in via setup_data. In that case runtime ranges will be mapped 917 * to the same virtual addresses as the first kernel, see 918 * kexec_enter_virtual_mode(). 919 */ 920 static void __init __efi_enter_virtual_mode(void) 921 { 922 int count = 0, pg_shift = 0; 923 void *new_memmap = NULL; 924 efi_status_t status; 925 unsigned long pa; 926 927 efi.systab = NULL; 928 929 if (efi_alloc_page_tables()) { 930 pr_err("Failed to allocate EFI page tables\n"); 931 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 932 return; 933 } 934 935 efi_merge_regions(); 936 new_memmap = efi_map_regions(&count, &pg_shift); 937 if (!new_memmap) { 938 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 939 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 940 return; 941 } 942 943 pa = __pa(new_memmap); 944 945 /* 946 * Unregister the early EFI memmap from efi_init() and install 947 * the new EFI memory map that we are about to pass to the 948 * firmware via SetVirtualAddressMap(). 949 */ 950 efi_memmap_unmap(); 951 952 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 953 pr_err("Failed to remap late EFI memory map\n"); 954 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 955 return; 956 } 957 958 if (efi_enabled(EFI_DBG)) { 959 pr_info("EFI runtime memory map:\n"); 960 efi_print_memmap(); 961 } 962 963 BUG_ON(!efi.systab); 964 965 if (efi_setup_page_tables(pa, 1 << pg_shift)) { 966 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 967 return; 968 } 969 970 efi_sync_low_kernel_mappings(); 971 972 if (efi_is_native()) { 973 status = phys_efi_set_virtual_address_map( 974 efi.memmap.desc_size * count, 975 efi.memmap.desc_size, 976 efi.memmap.desc_version, 977 (efi_memory_desc_t *)pa); 978 } else { 979 status = efi_thunk_set_virtual_address_map( 980 efi_phys.set_virtual_address_map, 981 efi.memmap.desc_size * count, 982 efi.memmap.desc_size, 983 efi.memmap.desc_version, 984 (efi_memory_desc_t *)pa); 985 } 986 987 if (status != EFI_SUCCESS) { 988 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", 989 status); 990 panic("EFI call to SetVirtualAddressMap() failed!"); 991 } 992 993 /* 994 * Now that EFI is in virtual mode, update the function 995 * pointers in the runtime service table to the new virtual addresses. 996 * 997 * Call EFI services through wrapper functions. 998 */ 999 efi.runtime_version = efi_systab.hdr.revision; 1000 1001 if (efi_is_native()) 1002 efi_native_runtime_setup(); 1003 else 1004 efi_thunk_runtime_setup(); 1005 1006 efi.set_virtual_address_map = NULL; 1007 1008 /* 1009 * Apply more restrictive page table mapping attributes now that 1010 * SVAM() has been called and the firmware has performed all 1011 * necessary relocation fixups for the new virtual addresses. 1012 */ 1013 efi_runtime_update_mappings(); 1014 efi_dump_pagetable(); 1015 1016 /* clean DUMMY object */ 1017 efi_delete_dummy_variable(); 1018 } 1019 1020 void __init efi_enter_virtual_mode(void) 1021 { 1022 if (efi_enabled(EFI_PARAVIRT)) 1023 return; 1024 1025 if (efi_setup) 1026 kexec_enter_virtual_mode(); 1027 else 1028 __efi_enter_virtual_mode(); 1029 } 1030 1031 /* 1032 * Convenience functions to obtain memory types and attributes 1033 */ 1034 u32 efi_mem_type(unsigned long phys_addr) 1035 { 1036 efi_memory_desc_t *md; 1037 1038 if (!efi_enabled(EFI_MEMMAP)) 1039 return 0; 1040 1041 for_each_efi_memory_desc(md) { 1042 if ((md->phys_addr <= phys_addr) && 1043 (phys_addr < (md->phys_addr + 1044 (md->num_pages << EFI_PAGE_SHIFT)))) 1045 return md->type; 1046 } 1047 return 0; 1048 } 1049 1050 static int __init arch_parse_efi_cmdline(char *str) 1051 { 1052 if (!str) { 1053 pr_warn("need at least one option\n"); 1054 return -EINVAL; 1055 } 1056 1057 if (parse_option_str(str, "old_map")) 1058 set_bit(EFI_OLD_MEMMAP, &efi.flags); 1059 1060 return 0; 1061 } 1062 early_param("efi", arch_parse_efi_cmdline); 1063