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", &efi.uv_systab}, 63 #endif 64 {NULL_GUID, NULL, NULL}, 65 }; 66 67 u64 efi_setup; /* efi setup_data physical address */ 68 69 static int add_efi_memmap __initdata; 70 static int __init setup_add_efi_memmap(char *arg) 71 { 72 add_efi_memmap = 1; 73 return 0; 74 } 75 early_param("add_efi_memmap", setup_add_efi_memmap); 76 77 static efi_status_t __init phys_efi_set_virtual_address_map( 78 unsigned long memory_map_size, 79 unsigned long descriptor_size, 80 u32 descriptor_version, 81 efi_memory_desc_t *virtual_map) 82 { 83 efi_status_t status; 84 unsigned long flags; 85 pgd_t *save_pgd; 86 87 save_pgd = efi_call_phys_prolog(); 88 89 /* Disable interrupts around EFI calls: */ 90 local_irq_save(flags); 91 status = efi_call_phys(efi_phys.set_virtual_address_map, 92 memory_map_size, descriptor_size, 93 descriptor_version, virtual_map); 94 local_irq_restore(flags); 95 96 efi_call_phys_epilog(save_pgd); 97 98 return status; 99 } 100 101 void __init efi_find_mirror(void) 102 { 103 efi_memory_desc_t *md; 104 u64 mirror_size = 0, total_size = 0; 105 106 for_each_efi_memory_desc(md) { 107 unsigned long long start = md->phys_addr; 108 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 109 110 total_size += size; 111 if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { 112 memblock_mark_mirror(start, size); 113 mirror_size += size; 114 } 115 } 116 if (mirror_size) 117 pr_info("Memory: %lldM/%lldM mirrored memory\n", 118 mirror_size>>20, total_size>>20); 119 } 120 121 /* 122 * Tell the kernel about the EFI memory map. This might include 123 * more than the max 128 entries that can fit in the e820 legacy 124 * (zeropage) memory map. 125 */ 126 127 static void __init do_add_efi_memmap(void) 128 { 129 efi_memory_desc_t *md; 130 131 for_each_efi_memory_desc(md) { 132 unsigned long long start = md->phys_addr; 133 unsigned long long size = md->num_pages << EFI_PAGE_SHIFT; 134 int e820_type; 135 136 switch (md->type) { 137 case EFI_LOADER_CODE: 138 case EFI_LOADER_DATA: 139 case EFI_BOOT_SERVICES_CODE: 140 case EFI_BOOT_SERVICES_DATA: 141 case EFI_CONVENTIONAL_MEMORY: 142 if (md->attribute & EFI_MEMORY_WB) 143 e820_type = E820_TYPE_RAM; 144 else 145 e820_type = E820_TYPE_RESERVED; 146 break; 147 case EFI_ACPI_RECLAIM_MEMORY: 148 e820_type = E820_TYPE_ACPI; 149 break; 150 case EFI_ACPI_MEMORY_NVS: 151 e820_type = E820_TYPE_NVS; 152 break; 153 case EFI_UNUSABLE_MEMORY: 154 e820_type = E820_TYPE_UNUSABLE; 155 break; 156 case EFI_PERSISTENT_MEMORY: 157 e820_type = E820_TYPE_PMEM; 158 break; 159 default: 160 /* 161 * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE 162 * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO 163 * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE 164 */ 165 e820_type = E820_TYPE_RESERVED; 166 break; 167 } 168 e820__range_add(start, size, e820_type); 169 } 170 e820__update_table(e820_table); 171 } 172 173 int __init efi_memblock_x86_reserve_range(void) 174 { 175 struct efi_info *e = &boot_params.efi_info; 176 struct efi_memory_map_data data; 177 phys_addr_t pmap; 178 int rv; 179 180 if (efi_enabled(EFI_PARAVIRT)) 181 return 0; 182 183 #ifdef CONFIG_X86_32 184 /* Can't handle data above 4GB at this time */ 185 if (e->efi_memmap_hi) { 186 pr_err("Memory map is above 4GB, disabling EFI.\n"); 187 return -EINVAL; 188 } 189 pmap = e->efi_memmap; 190 #else 191 pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); 192 #endif 193 data.phys_map = pmap; 194 data.size = e->efi_memmap_size; 195 data.desc_size = e->efi_memdesc_size; 196 data.desc_version = e->efi_memdesc_version; 197 198 rv = efi_memmap_init_early(&data); 199 if (rv) 200 return rv; 201 202 if (add_efi_memmap) 203 do_add_efi_memmap(); 204 205 WARN(efi.memmap.desc_version != 1, 206 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 207 efi.memmap.desc_version); 208 209 memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size); 210 211 return 0; 212 } 213 214 #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT) 215 #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT) 216 #define U64_HIGH_BIT (~(U64_MAX >> 1)) 217 218 static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i) 219 { 220 u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1; 221 u64 end_hi = 0; 222 char buf[64]; 223 224 if (md->num_pages == 0) { 225 end = 0; 226 } else if (md->num_pages > EFI_PAGES_MAX || 227 EFI_PAGES_MAX - md->num_pages < 228 (md->phys_addr >> EFI_PAGE_SHIFT)) { 229 end_hi = (md->num_pages & OVERFLOW_ADDR_MASK) 230 >> OVERFLOW_ADDR_SHIFT; 231 232 if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT)) 233 end_hi += 1; 234 } else { 235 return true; 236 } 237 238 pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n"); 239 240 if (end_hi) { 241 pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n", 242 i, efi_md_typeattr_format(buf, sizeof(buf), md), 243 md->phys_addr, end_hi, end); 244 } else { 245 pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n", 246 i, efi_md_typeattr_format(buf, sizeof(buf), md), 247 md->phys_addr, end); 248 } 249 return false; 250 } 251 252 static void __init efi_clean_memmap(void) 253 { 254 efi_memory_desc_t *out = efi.memmap.map; 255 const efi_memory_desc_t *in = out; 256 const efi_memory_desc_t *end = efi.memmap.map_end; 257 int i, n_removal; 258 259 for (i = n_removal = 0; in < end; i++) { 260 if (efi_memmap_entry_valid(in, i)) { 261 if (out != in) 262 memcpy(out, in, efi.memmap.desc_size); 263 out = (void *)out + efi.memmap.desc_size; 264 } else { 265 n_removal++; 266 } 267 in = (void *)in + efi.memmap.desc_size; 268 } 269 270 if (n_removal > 0) { 271 u64 size = efi.memmap.nr_map - n_removal; 272 273 pr_warn("Removing %d invalid memory map entries.\n", n_removal); 274 efi_memmap_install(efi.memmap.phys_map, size); 275 } 276 } 277 278 void __init efi_print_memmap(void) 279 { 280 efi_memory_desc_t *md; 281 int i = 0; 282 283 for_each_efi_memory_desc(md) { 284 char buf[64]; 285 286 pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n", 287 i++, efi_md_typeattr_format(buf, sizeof(buf), md), 288 md->phys_addr, 289 md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1, 290 (md->num_pages >> (20 - EFI_PAGE_SHIFT))); 291 } 292 } 293 294 static int __init efi_systab_init(void *phys) 295 { 296 if (efi_enabled(EFI_64BIT)) { 297 efi_system_table_64_t *systab64; 298 struct efi_setup_data *data = NULL; 299 u64 tmp = 0; 300 301 if (efi_setup) { 302 data = early_memremap(efi_setup, sizeof(*data)); 303 if (!data) 304 return -ENOMEM; 305 } 306 systab64 = early_memremap((unsigned long)phys, 307 sizeof(*systab64)); 308 if (systab64 == NULL) { 309 pr_err("Couldn't map the system table!\n"); 310 if (data) 311 early_memunmap(data, sizeof(*data)); 312 return -ENOMEM; 313 } 314 315 efi_systab.hdr = systab64->hdr; 316 efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor : 317 systab64->fw_vendor; 318 tmp |= data ? data->fw_vendor : systab64->fw_vendor; 319 efi_systab.fw_revision = systab64->fw_revision; 320 efi_systab.con_in_handle = systab64->con_in_handle; 321 tmp |= systab64->con_in_handle; 322 efi_systab.con_in = systab64->con_in; 323 tmp |= systab64->con_in; 324 efi_systab.con_out_handle = systab64->con_out_handle; 325 tmp |= systab64->con_out_handle; 326 efi_systab.con_out = systab64->con_out; 327 tmp |= systab64->con_out; 328 efi_systab.stderr_handle = systab64->stderr_handle; 329 tmp |= systab64->stderr_handle; 330 efi_systab.stderr = systab64->stderr; 331 tmp |= systab64->stderr; 332 efi_systab.runtime = data ? 333 (void *)(unsigned long)data->runtime : 334 (void *)(unsigned long)systab64->runtime; 335 tmp |= data ? data->runtime : systab64->runtime; 336 efi_systab.boottime = (void *)(unsigned long)systab64->boottime; 337 tmp |= systab64->boottime; 338 efi_systab.nr_tables = systab64->nr_tables; 339 efi_systab.tables = data ? (unsigned long)data->tables : 340 systab64->tables; 341 tmp |= data ? data->tables : systab64->tables; 342 343 early_memunmap(systab64, sizeof(*systab64)); 344 if (data) 345 early_memunmap(data, sizeof(*data)); 346 #ifdef CONFIG_X86_32 347 if (tmp >> 32) { 348 pr_err("EFI data located above 4GB, disabling EFI.\n"); 349 return -EINVAL; 350 } 351 #endif 352 } else { 353 efi_system_table_32_t *systab32; 354 355 systab32 = early_memremap((unsigned long)phys, 356 sizeof(*systab32)); 357 if (systab32 == NULL) { 358 pr_err("Couldn't map the system table!\n"); 359 return -ENOMEM; 360 } 361 362 efi_systab.hdr = systab32->hdr; 363 efi_systab.fw_vendor = systab32->fw_vendor; 364 efi_systab.fw_revision = systab32->fw_revision; 365 efi_systab.con_in_handle = systab32->con_in_handle; 366 efi_systab.con_in = systab32->con_in; 367 efi_systab.con_out_handle = systab32->con_out_handle; 368 efi_systab.con_out = systab32->con_out; 369 efi_systab.stderr_handle = systab32->stderr_handle; 370 efi_systab.stderr = systab32->stderr; 371 efi_systab.runtime = (void *)(unsigned long)systab32->runtime; 372 efi_systab.boottime = (void *)(unsigned long)systab32->boottime; 373 efi_systab.nr_tables = systab32->nr_tables; 374 efi_systab.tables = systab32->tables; 375 376 early_memunmap(systab32, sizeof(*systab32)); 377 } 378 379 efi.systab = &efi_systab; 380 381 /* 382 * Verify the EFI Table 383 */ 384 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) { 385 pr_err("System table signature incorrect!\n"); 386 return -EINVAL; 387 } 388 if ((efi.systab->hdr.revision >> 16) == 0) 389 pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n", 390 efi.systab->hdr.revision >> 16, 391 efi.systab->hdr.revision & 0xffff); 392 393 return 0; 394 } 395 396 static int __init efi_runtime_init32(void) 397 { 398 efi_runtime_services_32_t *runtime; 399 400 runtime = early_memremap((unsigned long)efi.systab->runtime, 401 sizeof(efi_runtime_services_32_t)); 402 if (!runtime) { 403 pr_err("Could not map the runtime service table!\n"); 404 return -ENOMEM; 405 } 406 407 /* 408 * We will only need *early* access to the SetVirtualAddressMap 409 * EFI runtime service. All other runtime services will be called 410 * via the virtual mapping. 411 */ 412 efi_phys.set_virtual_address_map = 413 (efi_set_virtual_address_map_t *) 414 (unsigned long)runtime->set_virtual_address_map; 415 early_memunmap(runtime, sizeof(efi_runtime_services_32_t)); 416 417 return 0; 418 } 419 420 static int __init efi_runtime_init64(void) 421 { 422 efi_runtime_services_64_t *runtime; 423 424 runtime = early_memremap((unsigned long)efi.systab->runtime, 425 sizeof(efi_runtime_services_64_t)); 426 if (!runtime) { 427 pr_err("Could not map the runtime service table!\n"); 428 return -ENOMEM; 429 } 430 431 /* 432 * We will only need *early* access to the SetVirtualAddressMap 433 * EFI runtime service. All other runtime services will be called 434 * via the virtual mapping. 435 */ 436 efi_phys.set_virtual_address_map = 437 (efi_set_virtual_address_map_t *) 438 (unsigned long)runtime->set_virtual_address_map; 439 early_memunmap(runtime, sizeof(efi_runtime_services_64_t)); 440 441 return 0; 442 } 443 444 static int __init efi_runtime_init(void) 445 { 446 int rv; 447 448 /* 449 * Check out the runtime services table. We need to map 450 * the runtime services table so that we can grab the physical 451 * address of several of the EFI runtime functions, needed to 452 * set the firmware into virtual mode. 453 * 454 * When EFI_PARAVIRT is in force then we could not map runtime 455 * service memory region because we do not have direct access to it. 456 * However, runtime services are available through proxy functions 457 * (e.g. in case of Xen dom0 EFI implementation they call special 458 * hypercall which executes relevant EFI functions) and that is why 459 * they are always enabled. 460 */ 461 462 if (!efi_enabled(EFI_PARAVIRT)) { 463 if (efi_enabled(EFI_64BIT)) 464 rv = efi_runtime_init64(); 465 else 466 rv = efi_runtime_init32(); 467 468 if (rv) 469 return rv; 470 } 471 472 set_bit(EFI_RUNTIME_SERVICES, &efi.flags); 473 474 return 0; 475 } 476 477 void __init efi_init(void) 478 { 479 efi_char16_t *c16; 480 char vendor[100] = "unknown"; 481 int i = 0; 482 void *tmp; 483 484 #ifdef CONFIG_X86_32 485 if (boot_params.efi_info.efi_systab_hi || 486 boot_params.efi_info.efi_memmap_hi) { 487 pr_info("Table located above 4GB, disabling EFI.\n"); 488 return; 489 } 490 efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab; 491 #else 492 efi_phys.systab = (efi_system_table_t *) 493 (boot_params.efi_info.efi_systab | 494 ((__u64)boot_params.efi_info.efi_systab_hi<<32)); 495 #endif 496 497 if (efi_systab_init(efi_phys.systab)) 498 return; 499 500 efi.config_table = (unsigned long)efi.systab->tables; 501 efi.fw_vendor = (unsigned long)efi.systab->fw_vendor; 502 efi.runtime = (unsigned long)efi.systab->runtime; 503 504 /* 505 * Show what we know for posterity 506 */ 507 c16 = tmp = early_memremap(efi.systab->fw_vendor, 2); 508 if (c16) { 509 for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i) 510 vendor[i] = *c16++; 511 vendor[i] = '\0'; 512 } else 513 pr_err("Could not map the firmware vendor!\n"); 514 early_memunmap(tmp, 2); 515 516 pr_info("EFI v%u.%.02u by %s\n", 517 efi.systab->hdr.revision >> 16, 518 efi.systab->hdr.revision & 0xffff, vendor); 519 520 if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables)) 521 return; 522 523 if (efi_config_init(arch_tables)) 524 return; 525 526 /* 527 * Note: We currently don't support runtime services on an EFI 528 * that doesn't match the kernel 32/64-bit mode. 529 */ 530 531 if (!efi_runtime_supported()) 532 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n"); 533 else { 534 if (efi_runtime_disabled() || efi_runtime_init()) { 535 efi_memmap_unmap(); 536 return; 537 } 538 } 539 540 efi_clean_memmap(); 541 542 if (efi_enabled(EFI_DBG)) 543 efi_print_memmap(); 544 } 545 546 void __init efi_set_executable(efi_memory_desc_t *md, bool executable) 547 { 548 u64 addr, npages; 549 550 addr = md->virt_addr; 551 npages = md->num_pages; 552 553 memrange_efi_to_native(&addr, &npages); 554 555 if (executable) 556 set_memory_x(addr, npages); 557 else 558 set_memory_nx(addr, npages); 559 } 560 561 void __init runtime_code_page_mkexec(void) 562 { 563 efi_memory_desc_t *md; 564 565 /* Make EFI runtime service code area executable */ 566 for_each_efi_memory_desc(md) { 567 if (md->type != EFI_RUNTIME_SERVICES_CODE) 568 continue; 569 570 efi_set_executable(md, true); 571 } 572 } 573 574 void __init efi_memory_uc(u64 addr, unsigned long size) 575 { 576 unsigned long page_shift = 1UL << EFI_PAGE_SHIFT; 577 u64 npages; 578 579 npages = round_up(size, page_shift) / page_shift; 580 memrange_efi_to_native(&addr, &npages); 581 set_memory_uc(addr, npages); 582 } 583 584 void __init old_map_region(efi_memory_desc_t *md) 585 { 586 u64 start_pfn, end_pfn, end; 587 unsigned long size; 588 void *va; 589 590 start_pfn = PFN_DOWN(md->phys_addr); 591 size = md->num_pages << PAGE_SHIFT; 592 end = md->phys_addr + size; 593 end_pfn = PFN_UP(end); 594 595 if (pfn_range_is_mapped(start_pfn, end_pfn)) { 596 va = __va(md->phys_addr); 597 598 if (!(md->attribute & EFI_MEMORY_WB)) 599 efi_memory_uc((u64)(unsigned long)va, size); 600 } else 601 va = efi_ioremap(md->phys_addr, size, 602 md->type, md->attribute); 603 604 md->virt_addr = (u64) (unsigned long) va; 605 if (!va) 606 pr_err("ioremap of 0x%llX failed!\n", 607 (unsigned long long)md->phys_addr); 608 } 609 610 /* Merge contiguous regions of the same type and attribute */ 611 static void __init efi_merge_regions(void) 612 { 613 efi_memory_desc_t *md, *prev_md = NULL; 614 615 for_each_efi_memory_desc(md) { 616 u64 prev_size; 617 618 if (!prev_md) { 619 prev_md = md; 620 continue; 621 } 622 623 if (prev_md->type != md->type || 624 prev_md->attribute != md->attribute) { 625 prev_md = md; 626 continue; 627 } 628 629 prev_size = prev_md->num_pages << EFI_PAGE_SHIFT; 630 631 if (md->phys_addr == (prev_md->phys_addr + prev_size)) { 632 prev_md->num_pages += md->num_pages; 633 md->type = EFI_RESERVED_TYPE; 634 md->attribute = 0; 635 continue; 636 } 637 prev_md = md; 638 } 639 } 640 641 static void __init get_systab_virt_addr(efi_memory_desc_t *md) 642 { 643 unsigned long size; 644 u64 end, systab; 645 646 size = md->num_pages << EFI_PAGE_SHIFT; 647 end = md->phys_addr + size; 648 systab = (u64)(unsigned long)efi_phys.systab; 649 if (md->phys_addr <= systab && systab < end) { 650 systab += md->virt_addr - md->phys_addr; 651 efi.systab = (efi_system_table_t *)(unsigned long)systab; 652 } 653 } 654 655 static void *realloc_pages(void *old_memmap, int old_shift) 656 { 657 void *ret; 658 659 ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1); 660 if (!ret) 661 goto out; 662 663 /* 664 * A first-time allocation doesn't have anything to copy. 665 */ 666 if (!old_memmap) 667 return ret; 668 669 memcpy(ret, old_memmap, PAGE_SIZE << old_shift); 670 671 out: 672 free_pages((unsigned long)old_memmap, old_shift); 673 return ret; 674 } 675 676 /* 677 * Iterate the EFI memory map in reverse order because the regions 678 * will be mapped top-down. The end result is the same as if we had 679 * mapped things forward, but doesn't require us to change the 680 * existing implementation of efi_map_region(). 681 */ 682 static inline void *efi_map_next_entry_reverse(void *entry) 683 { 684 /* Initial call */ 685 if (!entry) 686 return efi.memmap.map_end - efi.memmap.desc_size; 687 688 entry -= efi.memmap.desc_size; 689 if (entry < efi.memmap.map) 690 return NULL; 691 692 return entry; 693 } 694 695 /* 696 * efi_map_next_entry - Return the next EFI memory map descriptor 697 * @entry: Previous EFI memory map descriptor 698 * 699 * This is a helper function to iterate over the EFI memory map, which 700 * we do in different orders depending on the current configuration. 701 * 702 * To begin traversing the memory map @entry must be %NULL. 703 * 704 * Returns %NULL when we reach the end of the memory map. 705 */ 706 static void *efi_map_next_entry(void *entry) 707 { 708 if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) { 709 /* 710 * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE 711 * config table feature requires us to map all entries 712 * in the same order as they appear in the EFI memory 713 * map. That is to say, entry N must have a lower 714 * virtual address than entry N+1. This is because the 715 * firmware toolchain leaves relative references in 716 * the code/data sections, which are split and become 717 * separate EFI memory regions. Mapping things 718 * out-of-order leads to the firmware accessing 719 * unmapped addresses. 720 * 721 * Since we need to map things this way whether or not 722 * the kernel actually makes use of 723 * EFI_PROPERTIES_TABLE, let's just switch to this 724 * scheme by default for 64-bit. 725 */ 726 return efi_map_next_entry_reverse(entry); 727 } 728 729 /* Initial call */ 730 if (!entry) 731 return efi.memmap.map; 732 733 entry += efi.memmap.desc_size; 734 if (entry >= efi.memmap.map_end) 735 return NULL; 736 737 return entry; 738 } 739 740 static bool should_map_region(efi_memory_desc_t *md) 741 { 742 /* 743 * Runtime regions always require runtime mappings (obviously). 744 */ 745 if (md->attribute & EFI_MEMORY_RUNTIME) 746 return true; 747 748 /* 749 * 32-bit EFI doesn't suffer from the bug that requires us to 750 * reserve boot services regions, and mixed mode support 751 * doesn't exist for 32-bit kernels. 752 */ 753 if (IS_ENABLED(CONFIG_X86_32)) 754 return false; 755 756 /* 757 * Map all of RAM so that we can access arguments in the 1:1 758 * mapping when making EFI runtime calls. 759 */ 760 if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) { 761 if (md->type == EFI_CONVENTIONAL_MEMORY || 762 md->type == EFI_LOADER_DATA || 763 md->type == EFI_LOADER_CODE) 764 return true; 765 } 766 767 /* 768 * Map boot services regions as a workaround for buggy 769 * firmware that accesses them even when they shouldn't. 770 * 771 * See efi_{reserve,free}_boot_services(). 772 */ 773 if (md->type == EFI_BOOT_SERVICES_CODE || 774 md->type == EFI_BOOT_SERVICES_DATA) 775 return true; 776 777 return false; 778 } 779 780 /* 781 * Map the efi memory ranges of the runtime services and update new_mmap with 782 * virtual addresses. 783 */ 784 static void * __init efi_map_regions(int *count, int *pg_shift) 785 { 786 void *p, *new_memmap = NULL; 787 unsigned long left = 0; 788 unsigned long desc_size; 789 efi_memory_desc_t *md; 790 791 desc_size = efi.memmap.desc_size; 792 793 p = NULL; 794 while ((p = efi_map_next_entry(p))) { 795 md = p; 796 797 if (!should_map_region(md)) 798 continue; 799 800 efi_map_region(md); 801 get_systab_virt_addr(md); 802 803 if (left < desc_size) { 804 new_memmap = realloc_pages(new_memmap, *pg_shift); 805 if (!new_memmap) 806 return NULL; 807 808 left += PAGE_SIZE << *pg_shift; 809 (*pg_shift)++; 810 } 811 812 memcpy(new_memmap + (*count * desc_size), md, desc_size); 813 814 left -= desc_size; 815 (*count)++; 816 } 817 818 return new_memmap; 819 } 820 821 static void __init kexec_enter_virtual_mode(void) 822 { 823 #ifdef CONFIG_KEXEC_CORE 824 efi_memory_desc_t *md; 825 unsigned int num_pages; 826 827 efi.systab = NULL; 828 829 /* 830 * We don't do virtual mode, since we don't do runtime services, on 831 * non-native EFI. With efi=old_map, we don't do runtime services in 832 * kexec kernel because in the initial boot something else might 833 * have been mapped at these virtual addresses. 834 */ 835 if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) { 836 efi_memmap_unmap(); 837 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 838 return; 839 } 840 841 if (efi_alloc_page_tables()) { 842 pr_err("Failed to allocate EFI page tables\n"); 843 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 844 return; 845 } 846 847 /* 848 * Map efi regions which were passed via setup_data. The virt_addr is a 849 * fixed addr which was used in first kernel of a kexec boot. 850 */ 851 for_each_efi_memory_desc(md) { 852 efi_map_region_fixed(md); /* FIXME: add error handling */ 853 get_systab_virt_addr(md); 854 } 855 856 /* 857 * Unregister the early EFI memmap from efi_init() and install 858 * the new EFI memory map. 859 */ 860 efi_memmap_unmap(); 861 862 if (efi_memmap_init_late(efi.memmap.phys_map, 863 efi.memmap.desc_size * efi.memmap.nr_map)) { 864 pr_err("Failed to remap late EFI memory map\n"); 865 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 866 return; 867 } 868 869 BUG_ON(!efi.systab); 870 871 num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE); 872 num_pages >>= PAGE_SHIFT; 873 874 if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) { 875 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 876 return; 877 } 878 879 efi_sync_low_kernel_mappings(); 880 881 /* 882 * Now that EFI is in virtual mode, update the function 883 * pointers in the runtime service table to the new virtual addresses. 884 * 885 * Call EFI services through wrapper functions. 886 */ 887 efi.runtime_version = efi_systab.hdr.revision; 888 889 efi_native_runtime_setup(); 890 891 efi.set_virtual_address_map = NULL; 892 893 if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX)) 894 runtime_code_page_mkexec(); 895 896 /* clean DUMMY object */ 897 efi_delete_dummy_variable(); 898 #endif 899 } 900 901 /* 902 * This function will switch the EFI runtime services to virtual mode. 903 * Essentially, we look through the EFI memmap and map every region that 904 * has the runtime attribute bit set in its memory descriptor into the 905 * efi_pgd page table. 906 * 907 * The old method which used to update that memory descriptor with the 908 * virtual address obtained from ioremap() is still supported when the 909 * kernel is booted with efi=old_map on its command line. Same old 910 * method enabled the runtime services to be called without having to 911 * thunk back into physical mode for every invocation. 912 * 913 * The new method does a pagetable switch in a preemption-safe manner 914 * so that we're in a different address space when calling a runtime 915 * function. For function arguments passing we do copy the PUDs of the 916 * kernel page table into efi_pgd prior to each call. 917 * 918 * Specially for kexec boot, efi runtime maps in previous kernel should 919 * be passed in via setup_data. In that case runtime ranges will be mapped 920 * to the same virtual addresses as the first kernel, see 921 * kexec_enter_virtual_mode(). 922 */ 923 static void __init __efi_enter_virtual_mode(void) 924 { 925 int count = 0, pg_shift = 0; 926 void *new_memmap = NULL; 927 efi_status_t status; 928 unsigned long pa; 929 930 efi.systab = NULL; 931 932 if (efi_alloc_page_tables()) { 933 pr_err("Failed to allocate EFI page tables\n"); 934 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 935 return; 936 } 937 938 efi_merge_regions(); 939 new_memmap = efi_map_regions(&count, &pg_shift); 940 if (!new_memmap) { 941 pr_err("Error reallocating memory, EFI runtime non-functional!\n"); 942 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 943 return; 944 } 945 946 pa = __pa(new_memmap); 947 948 /* 949 * Unregister the early EFI memmap from efi_init() and install 950 * the new EFI memory map that we are about to pass to the 951 * firmware via SetVirtualAddressMap(). 952 */ 953 efi_memmap_unmap(); 954 955 if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) { 956 pr_err("Failed to remap late EFI memory map\n"); 957 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 958 return; 959 } 960 961 if (efi_enabled(EFI_DBG)) { 962 pr_info("EFI runtime memory map:\n"); 963 efi_print_memmap(); 964 } 965 966 BUG_ON(!efi.systab); 967 968 if (efi_setup_page_tables(pa, 1 << pg_shift)) { 969 clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); 970 return; 971 } 972 973 efi_sync_low_kernel_mappings(); 974 975 if (efi_is_native()) { 976 status = phys_efi_set_virtual_address_map( 977 efi.memmap.desc_size * count, 978 efi.memmap.desc_size, 979 efi.memmap.desc_version, 980 (efi_memory_desc_t *)pa); 981 } else { 982 status = efi_thunk_set_virtual_address_map( 983 efi_phys.set_virtual_address_map, 984 efi.memmap.desc_size * count, 985 efi.memmap.desc_size, 986 efi.memmap.desc_version, 987 (efi_memory_desc_t *)pa); 988 } 989 990 if (status != EFI_SUCCESS) { 991 pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n", 992 status); 993 panic("EFI call to SetVirtualAddressMap() failed!"); 994 } 995 996 efi_free_boot_services(); 997 998 /* 999 * Now that EFI is in virtual mode, update the function 1000 * pointers in the runtime service table to the new virtual addresses. 1001 * 1002 * Call EFI services through wrapper functions. 1003 */ 1004 efi.runtime_version = efi_systab.hdr.revision; 1005 1006 if (efi_is_native()) 1007 efi_native_runtime_setup(); 1008 else 1009 efi_thunk_runtime_setup(); 1010 1011 efi.set_virtual_address_map = NULL; 1012 1013 /* 1014 * Apply more restrictive page table mapping attributes now that 1015 * SVAM() has been called and the firmware has performed all 1016 * necessary relocation fixups for the new virtual addresses. 1017 */ 1018 efi_runtime_update_mappings(); 1019 1020 /* clean DUMMY object */ 1021 efi_delete_dummy_variable(); 1022 } 1023 1024 void __init efi_enter_virtual_mode(void) 1025 { 1026 if (efi_enabled(EFI_PARAVIRT)) 1027 return; 1028 1029 if (efi_setup) 1030 kexec_enter_virtual_mode(); 1031 else 1032 __efi_enter_virtual_mode(); 1033 1034 efi_dump_pagetable(); 1035 } 1036 1037 static int __init arch_parse_efi_cmdline(char *str) 1038 { 1039 if (!str) { 1040 pr_warn("need at least one option\n"); 1041 return -EINVAL; 1042 } 1043 1044 if (parse_option_str(str, "old_map")) 1045 set_bit(EFI_OLD_MEMMAP, &efi.flags); 1046 1047 return 0; 1048 } 1049 early_param("efi", arch_parse_efi_cmdline); 1050