drivers/firmware/efi/libstub/x86-stub.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 /* -----------------------------------------------------------------------
   4  *
   5  *   Copyright 2011 Intel Corporation; author Matt Fleming
   6  *
   7  * ----------------------------------------------------------------------- */
   8
   9 #include <linux/efi.h>
  10 #include <linux/pci.h>
  11 #include <linux/stddef.h>
  12
  13 #include <asm/efi.h>
  14 #include <asm/e820/types.h>
  15 #include <asm/setup.h>
  16 #include <asm/desc.h>
  17 #include <asm/boot.h>
  18 #include <asm/kaslr.h>
  19 #include <asm/sev.h>
  20
  21 #include "efistub.h"
  22 #include "x86-stub.h"
  23
  24 extern char _bss[], _ebss[];
  25
  26 const efi_system_table_t *efi_system_table;
  27 const efi_dxe_services_table_t *efi_dxe_table;
  28 static efi_loaded_image_t *image = NULL;
  29 static efi_memory_attribute_protocol_t *memattr;
  30
  31 typedef union sev_memory_acceptance_protocol sev_memory_acceptance_protocol_t;
  32 union sev_memory_acceptance_protocol {
  33         struct {
  34                 efi_status_t (__efiapi * allow_unaccepted_memory)(
  35                         sev_memory_acceptance_protocol_t *);
  36         };
  37         struct {
  38                 u32 allow_unaccepted_memory;
  39         } mixed_mode;
  40 };
  41
  42 static efi_status_t
  43 preserve_pci_rom_image(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
  44 {
  45         struct pci_setup_rom *rom = NULL;
  46         efi_status_t status;
  47         unsigned long size;
  48         uint64_t romsize;
  49         void *romimage;
  50
  51         /*
  52          * Some firmware images contain EFI function pointers at the place where
  53          * the romimage and romsize fields are supposed to be. Typically the EFI
  54          * code is mapped at high addresses, translating to an unrealistically
  55          * large romsize. The UEFI spec limits the size of option ROMs to 16
  56          * MiB so we reject any ROMs over 16 MiB in size to catch this.
  57          */
  58         romimage = efi_table_attr(pci, romimage);
  59         romsize = efi_table_attr(pci, romsize);
  60         if (!romimage || !romsize || romsize > SZ_16M)
  61                 return EFI_INVALID_PARAMETER;
  62
  63         size = romsize + sizeof(*rom);
  64
  65         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
  66                              (void **)&rom);
  67         if (status != EFI_SUCCESS) {
  68                 efi_err("Failed to allocate memory for 'rom'\n");
  69                 return status;
  70         }
  71
  72         memset(rom, 0, sizeof(*rom));
  73
  74         rom->data.type  = SETUP_PCI;
  75         rom->data.len   = size - sizeof(struct setup_data);
  76         rom->data.next  = 0;
  77         rom->pcilen     = romsize;
  78         *__rom = rom;
  79
  80         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  81                                 PCI_VENDOR_ID, 1, &rom->vendor);
  82
  83         if (status != EFI_SUCCESS) {
  84                 efi_err("Failed to read rom->vendor\n");
  85                 goto free_struct;
  86         }
  87
  88         status = efi_call_proto(pci, pci.read, EfiPciIoWidthUint16,
  89                                 PCI_DEVICE_ID, 1, &rom->devid);
  90
  91         if (status != EFI_SUCCESS) {
  92                 efi_err("Failed to read rom->devid\n");
  93                 goto free_struct;
  94         }
  95
  96         status = efi_call_proto(pci, get_location, &rom->segment, &rom->bus,
  97                                 &rom->device, &rom->function);
  98
  99         if (status != EFI_SUCCESS)
 100                 goto free_struct;
 101
 102         memcpy(rom->romdata, romimage, romsize);
 103         return status;
 104
 105 free_struct:
 106         efi_bs_call(free_pool, rom);
 107         return status;
 108 }
 109
 110 /*
 111  * There's no way to return an informative status from this function,
 112  * because any analysis (and printing of error messages) needs to be
 113  * done directly at the EFI function call-site.
 114  *
 115  * For example, EFI_INVALID_PARAMETER could indicate a bug or maybe we
 116  * just didn't find any PCI devices, but there's no way to tell outside
 117  * the context of the call.
 118  */
 119 static void setup_efi_pci(struct boot_params *params)
 120 {
 121         efi_status_t status;
 122         void **pci_handle = NULL;
 123         efi_guid_t pci_proto = EFI_PCI_IO_PROTOCOL_GUID;
 124         unsigned long size = 0;
 125         struct setup_data *data;
 126         efi_handle_t h;
 127         int i;
 128
 129         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 130                              &pci_proto, NULL, &size, pci_handle);
 131
 132         if (status == EFI_BUFFER_TOO_SMALL) {
 133                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 134                                      (void **)&pci_handle);
 135
 136                 if (status != EFI_SUCCESS) {
 137                         efi_err("Failed to allocate memory for 'pci_handle'\n");
 138                         return;
 139                 }
 140
 141                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 142                                      &pci_proto, NULL, &size, pci_handle);
 143         }
 144
 145         if (status != EFI_SUCCESS)
 146                 goto free_handle;
 147
 148         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 149
 150         while (data && data->next)
 151                 data = (struct setup_data *)(unsigned long)data->next;
 152
 153         for_each_efi_handle(h, pci_handle, size, i) {
 154                 efi_pci_io_protocol_t *pci = NULL;
 155                 struct pci_setup_rom *rom;
 156
 157                 status = efi_bs_call(handle_protocol, h, &pci_proto,
 158                                      (void **)&pci);
 159                 if (status != EFI_SUCCESS || !pci)
 160                         continue;
 161
 162                 status = preserve_pci_rom_image(pci, &rom);
 163                 if (status != EFI_SUCCESS)
 164                         continue;
 165
 166                 if (data)
 167                         data->next = (unsigned long)rom;
 168                 else
 169                         params->hdr.setup_data = (unsigned long)rom;
 170
 171                 data = (struct setup_data *)rom;
 172         }
 173
 174 free_handle:
 175         efi_bs_call(free_pool, pci_handle);
 176 }
 177
 178 static void retrieve_apple_device_properties(struct boot_params *boot_params)
 179 {
 180         efi_guid_t guid = APPLE_PROPERTIES_PROTOCOL_GUID;
 181         struct setup_data *data, *new;
 182         efi_status_t status;
 183         u32 size = 0;
 184         apple_properties_protocol_t *p;
 185
 186         status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&p);
 187         if (status != EFI_SUCCESS)
 188                 return;
 189
 190         if (efi_table_attr(p, version) != 0x10000) {
 191                 efi_err("Unsupported properties proto version\n");
 192                 return;
 193         }
 194
 195         efi_call_proto(p, get_all, NULL, &size);
 196         if (!size)
 197                 return;
 198
 199         do {
 200                 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
 201                                      size + sizeof(struct setup_data),
 202                                      (void **)&new);
 203                 if (status != EFI_SUCCESS) {
 204                         efi_err("Failed to allocate memory for 'properties'\n");
 205                         return;
 206                 }
 207
 208                 status = efi_call_proto(p, get_all, new->data, &size);
 209
 210                 if (status == EFI_BUFFER_TOO_SMALL)
 211                         efi_bs_call(free_pool, new);
 212         } while (status == EFI_BUFFER_TOO_SMALL);
 213
 214         new->type = SETUP_APPLE_PROPERTIES;
 215         new->len  = size;
 216         new->next = 0;
 217
 218         data = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
 219         if (!data) {
 220                 boot_params->hdr.setup_data = (unsigned long)new;
 221         } else {
 222                 while (data->next)
 223                         data = (struct setup_data *)(unsigned long)data->next;
 224                 data->next = (unsigned long)new;
 225         }
 226 }
 227
 228 static bool apple_match_product_name(void)
 229 {
 230         static const char type1_product_matches[][15] = {
 231                 "MacBookPro11,3",
 232                 "MacBookPro11,5",
 233                 "MacBookPro13,3",
 234                 "MacBookPro14,3",
 235                 "MacBookPro15,1",
 236                 "MacBookPro15,3",
 237                 "MacBookPro16,1",
 238                 "MacBookPro16,4",
 239         };
 240         const struct efi_smbios_type1_record *record;
 241         const u8 *product;
 242
 243         record = (struct efi_smbios_type1_record *)efi_get_smbios_record(1);
 244         if (!record)
 245                 return false;
 246
 247         product = efi_get_smbios_string(record, product_name);
 248         if (!product)
 249                 return false;
 250
 251         for (int i = 0; i < ARRAY_SIZE(type1_product_matches); i++) {
 252                 if (!strcmp(product, type1_product_matches[i]))
 253                         return true;
 254         }
 255
 256         return false;
 257 }
 258
 259 static void apple_set_os(void)
 260 {
 261         struct {
 262                 unsigned long version;
 263                 efi_status_t (__efiapi *set_os_version)(const char *);
 264                 efi_status_t (__efiapi *set_os_vendor)(const char *);
 265         } *set_os;
 266         efi_status_t status;
 267
 268         if (!efi_is_64bit() || !apple_match_product_name())
 269                 return;
 270
 271         status = efi_bs_call(locate_protocol, &APPLE_SET_OS_PROTOCOL_GUID, NULL,
 272                              (void **)&set_os);
 273         if (status != EFI_SUCCESS)
 274                 return;
 275
 276         if (set_os->version >= 2) {
 277                 status = set_os->set_os_vendor("Apple Inc.");
 278                 if (status != EFI_SUCCESS)
 279                         efi_err("Failed to set OS vendor via apple_set_os\n");
 280         }
 281
 282         if (set_os->version > 0) {
 283                 /* The version being set doesn't seem to matter */
 284                 status = set_os->set_os_version("Mac OS X 10.9");
 285                 if (status != EFI_SUCCESS)
 286                         efi_err("Failed to set OS version via apple_set_os\n");
 287         }
 288 }
 289
 290 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
 291                                                 unsigned long size)
 292 {
 293         efi_status_t status;
 294         efi_gcd_memory_space_desc_t desc;
 295         unsigned long end, next;
 296         unsigned long rounded_start, rounded_end;
 297         unsigned long unprotect_start, unprotect_size;
 298
 299         rounded_start = rounddown(start, EFI_PAGE_SIZE);
 300         rounded_end = roundup(start + size, EFI_PAGE_SIZE);
 301
 302         if (memattr != NULL) {
 303                 status = efi_call_proto(memattr, set_memory_attributes,
 304                                         rounded_start,
 305                                         rounded_end - rounded_start,
 306                                         EFI_MEMORY_RO);
 307                 if (status != EFI_SUCCESS) {
 308                         efi_warn("Failed to set EFI_MEMORY_RO attribute\n");
 309                         return status;
 310                 }
 311
 312                 status = efi_call_proto(memattr, clear_memory_attributes,
 313                                         rounded_start,
 314                                         rounded_end - rounded_start,
 315                                         EFI_MEMORY_XP);
 316                 if (status != EFI_SUCCESS)
 317                         efi_warn("Failed to clear EFI_MEMORY_XP attribute\n");
 318                 return status;
 319         }
 320
 321         if (efi_dxe_table == NULL)
 322                 return EFI_SUCCESS;
 323
 324         /*
 325          * Don't modify memory region attributes, they are
 326          * already suitable, to lower the possibility to
 327          * encounter firmware bugs.
 328          */
 329
 330         for (end = start + size; start < end; start = next) {
 331
 332                 status = efi_dxe_call(get_memory_space_descriptor, start, &desc);
 333
 334                 if (status != EFI_SUCCESS)
 335                         break;
 336
 337                 next = desc.base_address + desc.length;
 338
 339                 /*
 340                  * Only system memory is suitable for trampoline/kernel image placement,
 341                  * so only this type of memory needs its attributes to be modified.
 342                  */
 343
 344                 if (desc.gcd_memory_type != EfiGcdMemoryTypeSystemMemory ||
 345                     (desc.attributes & (EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0)
 346                         continue;
 347
 348                 unprotect_start = max(rounded_start, (unsigned long)desc.base_address);
 349                 unprotect_size = min(rounded_end, next) - unprotect_start;
 350
 351                 status = efi_dxe_call(set_memory_space_attributes,
 352                                       unprotect_start, unprotect_size,
 353                                       EFI_MEMORY_WB);
 354
 355                 if (status != EFI_SUCCESS) {
 356                         efi_warn("Unable to unprotect memory range [%08lx,%08lx]: %lx\n",
 357                                  unprotect_start,
 358                                  unprotect_start + unprotect_size,
 359                                  status);
 360                         break;
 361                 }
 362         }
 363         return EFI_SUCCESS;
 364 }
 365
 366 static void setup_unaccepted_memory(void)
 367 {
 368         efi_guid_t mem_acceptance_proto = OVMF_SEV_MEMORY_ACCEPTANCE_PROTOCOL_GUID;
 369         sev_memory_acceptance_protocol_t *proto;
 370         efi_status_t status;
 371
 372         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
 373                 return;
 374
 375         /*
 376          * Enable unaccepted memory before calling exit boot services in order
 377          * for the UEFI to not accept all memory on EBS.
 378          */
 379         status = efi_bs_call(locate_protocol, &mem_acceptance_proto, NULL,
 380                              (void **)&proto);
 381         if (status != EFI_SUCCESS)
 382                 return;
 383
 384         status = efi_call_proto(proto, allow_unaccepted_memory);
 385         if (status != EFI_SUCCESS)
 386                 efi_err("Memory acceptance protocol failed\n");
 387 }
 388
 389 static efi_char16_t *efistub_fw_vendor(void)
 390 {
 391         unsigned long vendor = efi_table_attr(efi_system_table, fw_vendor);
 392
 393         return (efi_char16_t *)vendor;
 394 }
 395
 396 static const efi_char16_t apple[] = L"Apple";
 397
 398 static void setup_quirks(struct boot_params *boot_params)
 399 {
 400         if (!memcmp(efistub_fw_vendor(), apple, sizeof(apple))) {
 401                 if (IS_ENABLED(CONFIG_APPLE_PROPERTIES))
 402                         retrieve_apple_device_properties(boot_params);
 403
 404                 apple_set_os();
 405         }
 406 }
 407
 408 /*
 409  * See if we have Universal Graphics Adapter (UGA) protocol
 410  */
 411 static efi_status_t
 412 setup_uga(struct screen_info *si, efi_guid_t *uga_proto, unsigned long size)
 413 {
 414         efi_status_t status;
 415         u32 width, height;
 416         void **uga_handle = NULL;
 417         efi_uga_draw_protocol_t *uga = NULL, *first_uga;
 418         efi_handle_t handle;
 419         int i;
 420
 421         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 422                              (void **)&uga_handle);
 423         if (status != EFI_SUCCESS)
 424                 return status;
 425
 426         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 427                              uga_proto, NULL, &size, uga_handle);
 428         if (status != EFI_SUCCESS)
 429                 goto free_handle;
 430
 431         height = 0;
 432         width = 0;
 433
 434         first_uga = NULL;
 435         for_each_efi_handle(handle, uga_handle, size, i) {
 436                 efi_guid_t pciio_proto = EFI_PCI_IO_PROTOCOL_GUID;
 437                 u32 w, h, depth, refresh;
 438                 void *pciio;
 439
 440                 status = efi_bs_call(handle_protocol, handle, uga_proto,
 441                                      (void **)&uga);
 442                 if (status != EFI_SUCCESS)
 443                         continue;
 444
 445                 pciio = NULL;
 446                 efi_bs_call(handle_protocol, handle, &pciio_proto, &pciio);
 447
 448                 status = efi_call_proto(uga, get_mode, &w, &h, &depth, &refresh);
 449                 if (status == EFI_SUCCESS && (!first_uga || pciio)) {
 450                         width = w;
 451                         height = h;
 452
 453                         /*
 454                          * Once we've found a UGA supporting PCIIO,
 455                          * don't bother looking any further.
 456                          */
 457                         if (pciio)
 458                                 break;
 459
 460                         first_uga = uga;
 461                 }
 462         }
 463
 464         if (!width && !height)
 465                 goto free_handle;
 466
 467         /* EFI framebuffer */
 468         si->orig_video_isVGA    = VIDEO_TYPE_EFI;
 469
 470         si->lfb_depth           = 32;
 471         si->lfb_width           = width;
 472         si->lfb_height          = height;
 473
 474         si->red_size            = 8;
 475         si->red_pos             = 16;
 476         si->green_size          = 8;
 477         si->green_pos           = 8;
 478         si->blue_size           = 8;
 479         si->blue_pos            = 0;
 480         si->rsvd_size           = 8;
 481         si->rsvd_pos            = 24;
 482
 483 free_handle:
 484         efi_bs_call(free_pool, uga_handle);
 485
 486         return status;
 487 }
 488
 489 static void setup_graphics(struct boot_params *boot_params)
 490 {
 491         efi_guid_t graphics_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
 492         struct screen_info *si;
 493         efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 494         efi_status_t status;
 495         unsigned long size;
 496         void **gop_handle = NULL;
 497         void **uga_handle = NULL;
 498
 499         si = &boot_params->screen_info;
 500         memset(si, 0, sizeof(*si));
 501
 502         size = 0;
 503         status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 504                              &graphics_proto, NULL, &size, gop_handle);
 505         if (status == EFI_BUFFER_TOO_SMALL)
 506                 status = efi_setup_gop(si, &graphics_proto, size);
 507
 508         if (status != EFI_SUCCESS) {
 509                 size = 0;
 510                 status = efi_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
 511                                      &uga_proto, NULL, &size, uga_handle);
 512                 if (status == EFI_BUFFER_TOO_SMALL)
 513                         setup_uga(si, &uga_proto, size);
 514         }
 515 }
 516
 517
 518 static void __noreturn efi_exit(efi_handle_t handle, efi_status_t status)
 519 {
 520         efi_bs_call(exit, handle, status, 0, NULL);
 521         for(;;)
 522                 asm("hlt");
 523 }
 524
 525 void __noreturn efi_stub_entry(efi_handle_t handle,
 526                                efi_system_table_t *sys_table_arg,
 527                                struct boot_params *boot_params);
 528
 529 /*
 530  * Because the x86 boot code expects to be passed a boot_params we
 531  * need to create one ourselves (usually the bootloader would create
 532  * one for us).
 533  */
 534 efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 535                                    efi_system_table_t *sys_table_arg)
 536 {
 537         efi_guid_t proto = LOADED_IMAGE_PROTOCOL_GUID;
 538         struct boot_params *boot_params;
 539         struct setup_header *hdr;
 540         efi_status_t status;
 541         unsigned long alloc;
 542         char *cmdline_ptr;
 543
 544         efi_system_table = sys_table_arg;
 545
 546         /* Check if we were booted by the EFI firmware */
 547         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 548                 efi_exit(handle, EFI_INVALID_PARAMETER);
 549
 550         status = efi_bs_call(handle_protocol, handle, &proto, (void **)&image);
 551         if (status != EFI_SUCCESS) {
 552                 efi_err("Failed to get handle for LOADED_IMAGE_PROTOCOL\n");
 553                 efi_exit(handle, status);
 554         }
 555
 556         status = efi_allocate_pages(PARAM_SIZE, &alloc, ULONG_MAX);
 557         if (status != EFI_SUCCESS)
 558                 efi_exit(handle, status);
 559
 560         boot_params = memset((void *)alloc, 0x0, PARAM_SIZE);
 561         hdr         = &boot_params->hdr;
 562
 563         /* Assign the setup_header fields that the kernel actually cares about */
 564         hdr->root_flags = 1;
 565         hdr->vid_mode   = 0xffff;
 566
 567         hdr->type_of_loader = 0x21;
 568         hdr->initrd_addr_max = INT_MAX;
 569
 570         /* Convert unicode cmdline to ascii */
 571         cmdline_ptr = efi_convert_cmdline(image);
 572         if (!cmdline_ptr) {
 573                 efi_free(PARAM_SIZE, alloc);
 574                 efi_exit(handle, EFI_OUT_OF_RESOURCES);
 575         }
 576
 577         efi_set_u64_split((unsigned long)cmdline_ptr, &hdr->cmd_line_ptr,
 578                           &boot_params->ext_cmd_line_ptr);
 579
 580         efi_stub_entry(handle, sys_table_arg, boot_params);
 581         /* not reached */
 582 }
 583
 584 static void add_e820ext(struct boot_params *params,
 585                         struct setup_data *e820ext, u32 nr_entries)
 586 {
 587         struct setup_data *data;
 588
 589         e820ext->type = SETUP_E820_EXT;
 590         e820ext->len  = nr_entries * sizeof(struct boot_e820_entry);
 591         e820ext->next = 0;
 592
 593         data = (struct setup_data *)(unsigned long)params->hdr.setup_data;
 594
 595         while (data && data->next)
 596                 data = (struct setup_data *)(unsigned long)data->next;
 597
 598         if (data)
 599                 data->next = (unsigned long)e820ext;
 600         else
 601                 params->hdr.setup_data = (unsigned long)e820ext;
 602 }
 603
 604 static efi_status_t
 605 setup_e820(struct boot_params *params, struct setup_data *e820ext, u32 e820ext_size)
 606 {
 607         struct boot_e820_entry *entry = params->e820_table;
 608         struct efi_info *efi = &params->efi_info;
 609         struct boot_e820_entry *prev = NULL;
 610         u32 nr_entries;
 611         u32 nr_desc;
 612         int i;
 613
 614         nr_entries = 0;
 615         nr_desc = efi->efi_memmap_size / efi->efi_memdesc_size;
 616
 617         for (i = 0; i < nr_desc; i++) {
 618                 efi_memory_desc_t *d;
 619                 unsigned int e820_type = 0;
 620                 unsigned long m = efi->efi_memmap;
 621
 622 #ifdef CONFIG_X86_64
 623                 m |= (u64)efi->efi_memmap_hi << 32;
 624 #endif
 625
 626                 d = efi_memdesc_ptr(m, efi->efi_memdesc_size, i);
 627                 switch (d->type) {
 628                 case EFI_RESERVED_TYPE:
 629                 case EFI_RUNTIME_SERVICES_CODE:
 630                 case EFI_RUNTIME_SERVICES_DATA:
 631                 case EFI_MEMORY_MAPPED_IO:
 632                 case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
 633                 case EFI_PAL_CODE:
 634                         e820_type = E820_TYPE_RESERVED;
 635                         break;
 636
 637                 case EFI_UNUSABLE_MEMORY:
 638                         e820_type = E820_TYPE_UNUSABLE;
 639                         break;
 640
 641                 case EFI_ACPI_RECLAIM_MEMORY:
 642                         e820_type = E820_TYPE_ACPI;
 643                         break;
 644
 645                 case EFI_LOADER_CODE:
 646                 case EFI_LOADER_DATA:
 647                 case EFI_BOOT_SERVICES_CODE:
 648                 case EFI_BOOT_SERVICES_DATA:
 649                 case EFI_CONVENTIONAL_MEMORY:
 650                         if (efi_soft_reserve_enabled() &&
 651                             (d->attribute & EFI_MEMORY_SP))
 652                                 e820_type = E820_TYPE_SOFT_RESERVED;
 653                         else
 654                                 e820_type = E820_TYPE_RAM;
 655                         break;
 656
 657                 case EFI_ACPI_MEMORY_NVS:
 658                         e820_type = E820_TYPE_NVS;
 659                         break;
 660
 661                 case EFI_PERSISTENT_MEMORY:
 662                         e820_type = E820_TYPE_PMEM;
 663                         break;
 664
 665                 case EFI_UNACCEPTED_MEMORY:
 666                         if (!IS_ENABLED(CONFIG_UNACCEPTED_MEMORY))
 667                                 continue;
 668                         e820_type = E820_TYPE_RAM;
 669                         process_unaccepted_memory(d->phys_addr,
 670                                                   d->phys_addr + PAGE_SIZE * d->num_pages);
 671                         break;
 672                 default:
 673                         continue;
 674                 }
 675
 676                 /* Merge adjacent mappings */
 677                 if (prev && prev->type == e820_type &&
 678                     (prev->addr + prev->size) == d->phys_addr) {
 679                         prev->size += d->num_pages << 12;
 680                         continue;
 681                 }
 682
 683                 if (nr_entries == ARRAY_SIZE(params->e820_table)) {
 684                         u32 need = (nr_desc - i) * sizeof(struct e820_entry) +
 685                                    sizeof(struct setup_data);
 686
 687                         if (!e820ext || e820ext_size < need)
 688                                 return EFI_BUFFER_TOO_SMALL;
 689
 690                         /* boot_params map full, switch to e820 extended */
 691                         entry = (struct boot_e820_entry *)e820ext->data;
 692                 }
 693
 694                 entry->addr = d->phys_addr;
 695                 entry->size = d->num_pages << PAGE_SHIFT;
 696                 entry->type = e820_type;
 697                 prev = entry++;
 698                 nr_entries++;
 699         }
 700
 701         if (nr_entries > ARRAY_SIZE(params->e820_table)) {
 702                 u32 nr_e820ext = nr_entries - ARRAY_SIZE(params->e820_table);
 703
 704                 add_e820ext(params, e820ext, nr_e820ext);
 705                 nr_entries -= nr_e820ext;
 706         }
 707
 708         params->e820_entries = (u8)nr_entries;
 709
 710         return EFI_SUCCESS;
 711 }
 712
 713 static efi_status_t alloc_e820ext(u32 nr_desc, struct setup_data **e820ext,
 714                                   u32 *e820ext_size)
 715 {
 716         efi_status_t status;
 717         unsigned long size;
 718
 719         size = sizeof(struct setup_data) +
 720                 sizeof(struct e820_entry) * nr_desc;
 721
 722         if (*e820ext) {
 723                 efi_bs_call(free_pool, *e820ext);
 724                 *e820ext = NULL;
 725                 *e820ext_size = 0;
 726         }
 727
 728         status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
 729                              (void **)e820ext);
 730         if (status == EFI_SUCCESS)
 731                 *e820ext_size = size;
 732
 733         return status;
 734 }
 735
 736 static efi_status_t allocate_e820(struct boot_params *params,
 737                                   struct setup_data **e820ext,
 738                                   u32 *e820ext_size)
 739 {
 740         struct efi_boot_memmap *map;
 741         efi_status_t status;
 742         __u32 nr_desc;
 743
 744         status = efi_get_memory_map(&map, false);
 745         if (status != EFI_SUCCESS)
 746                 return status;
 747
 748         nr_desc = map->map_size / map->desc_size;
 749         if (nr_desc > ARRAY_SIZE(params->e820_table) - EFI_MMAP_NR_SLACK_SLOTS) {
 750                 u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table) +
 751                                  EFI_MMAP_NR_SLACK_SLOTS;
 752
 753                 status = alloc_e820ext(nr_e820ext, e820ext, e820ext_size);
 754         }
 755
 756         if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && status == EFI_SUCCESS)
 757                 status = allocate_unaccepted_bitmap(nr_desc, map);
 758
 759         efi_bs_call(free_pool, map);
 760         return status;
 761 }
 762
 763 struct exit_boot_struct {
 764         struct boot_params      *boot_params;
 765         struct efi_info         *efi;
 766 };
 767
 768 static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 769                                    void *priv)
 770 {
 771         const char *signature;
 772         struct exit_boot_struct *p = priv;
 773
 774         signature = efi_is_64bit() ? EFI64_LOADER_SIGNATURE
 775                                    : EFI32_LOADER_SIGNATURE;
 776         memcpy(&p->efi->efi_loader_signature, signature, sizeof(__u32));
 777
 778         efi_set_u64_split((unsigned long)efi_system_table,
 779                           &p->efi->efi_systab, &p->efi->efi_systab_hi);
 780         p->efi->efi_memdesc_size        = map->desc_size;
 781         p->efi->efi_memdesc_version     = map->desc_ver;
 782         efi_set_u64_split((unsigned long)map->map,
 783                           &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
 784         p->efi->efi_memmap_size         = map->map_size;
 785
 786         return EFI_SUCCESS;
 787 }
 788
 789 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 790 {
 791         struct setup_data *e820ext = NULL;
 792         __u32 e820ext_size = 0;
 793         efi_status_t status;
 794         struct exit_boot_struct priv;
 795
 796         priv.boot_params        = boot_params;
 797         priv.efi                = &boot_params->efi_info;
 798
 799         status = allocate_e820(boot_params, &e820ext, &e820ext_size);
 800         if (status != EFI_SUCCESS)
 801                 return status;
 802
 803         /* Might as well exit boot services now */
 804         status = efi_exit_boot_services(handle, &priv, exit_boot_func);
 805         if (status != EFI_SUCCESS)
 806                 return status;
 807
 808         /* Historic? */
 809         boot_params->alt_mem_k  = 32 * 1024;
 810
 811         status = setup_e820(boot_params, e820ext, e820ext_size);
 812         if (status != EFI_SUCCESS)
 813                 return status;
 814
 815         return EFI_SUCCESS;
 816 }
 817
 818 static bool have_unsupported_snp_features(void)
 819 {
 820         u64 unsupported;
 821
 822         unsupported = snp_get_unsupported_features(sev_get_status());
 823         if (unsupported) {
 824                 efi_err("Unsupported SEV-SNP features detected: 0x%llx\n",
 825                         unsupported);
 826                 return true;
 827         }
 828         return false;
 829 }
 830
 831 static void efi_get_seed(void *seed, int size)
 832 {
 833         efi_get_random_bytes(size, seed);
 834
 835         /*
 836          * This only updates seed[0] when running on 32-bit, but in that case,
 837          * seed[1] is not used anyway, as there is no virtual KASLR on 32-bit.
 838          */
 839         *(unsigned long *)seed ^= kaslr_get_random_long("EFI");
 840 }
 841
 842 static void error(char *str)
 843 {
 844         efi_warn("Decompression failed: %s\n", str);
 845 }
 846
 847 static const char *cmdline_memmap_override;
 848
 849 static efi_status_t parse_options(const char *cmdline)
 850 {
 851         static const char opts[][14] = {
 852                 "mem=", "memmap=", "hugepages="
 853         };
 854
 855         for (int i = 0; i < ARRAY_SIZE(opts); i++) {
 856                 const char *p = strstr(cmdline, opts[i]);
 857
 858                 if (p == cmdline || (p > cmdline && isspace(p[-1]))) {
 859                         cmdline_memmap_override = opts[i];
 860                         break;
 861                 }
 862         }
 863
 864         return efi_parse_options(cmdline);
 865 }
 866
 867 static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
 868 {
 869         unsigned long virt_addr = LOAD_PHYSICAL_ADDR;
 870         unsigned long addr, alloc_size, entry;
 871         efi_status_t status;
 872         u32 seed[2] = {};
 873
 874         /* determine the required size of the allocation */
 875         alloc_size = ALIGN(max_t(unsigned long, output_len, kernel_total_size),
 876                            MIN_KERNEL_ALIGN);
 877
 878         if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
 879                 u64 range = KERNEL_IMAGE_SIZE - LOAD_PHYSICAL_ADDR - kernel_total_size;
 880                 static const efi_char16_t ami[] = L"American Megatrends";
 881
 882                 efi_get_seed(seed, sizeof(seed));
 883
 884                 virt_addr += (range * seed[1]) >> 32;
 885                 virt_addr &= ~(CONFIG_PHYSICAL_ALIGN - 1);
 886
 887                 /*
 888                  * Older Dell systems with AMI UEFI firmware v2.0 may hang
 889                  * while decompressing the kernel if physical address
 890                  * randomization is enabled.
 891                  *
 892                  * https://bugzilla.kernel.org/show_bug.cgi?id=218173
 893                  */
 894                 if (efi_system_table->hdr.revision <= EFI_2_00_SYSTEM_TABLE_REVISION &&
 895                     !memcmp(efistub_fw_vendor(), ami, sizeof(ami))) {
 896                         efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
 897                         seed[0] = 0;
 898                 } else if (cmdline_memmap_override) {
 899                         efi_info("%s detected on the kernel command line - disabling physical KASLR\n",
 900                                  cmdline_memmap_override);
 901                         seed[0] = 0;
 902                 }
 903
 904                 boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
 905         }
 906
 907         status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
 908                                   seed[0], EFI_LOADER_CODE,
 909                                   LOAD_PHYSICAL_ADDR,
 910                                   EFI_X86_KERNEL_ALLOC_LIMIT);
 911         if (status != EFI_SUCCESS)
 912                 return status;
 913
 914         entry = decompress_kernel((void *)addr, virt_addr, error);
 915         if (entry == ULONG_MAX) {
 916                 efi_free(alloc_size, addr);
 917                 return EFI_LOAD_ERROR;
 918         }
 919
 920         *kernel_entry = addr + entry;
 921
 922         return efi_adjust_memory_range_protection(addr, kernel_text_size);
 923 }
 924
 925 static void __noreturn enter_kernel(unsigned long kernel_addr,
 926                                     struct boot_params *boot_params)
 927 {
 928         /* enter decompressed kernel with boot_params pointer in RSI/ESI */
 929         asm("jmp *%0"::"r"(kernel_addr), "S"(boot_params));
 930
 931         unreachable();
 932 }
 933
 934 /*
 935  * On success, this routine will jump to the relocated image directly and never
 936  * return.  On failure, it will exit to the firmware via efi_exit() instead of
 937  * returning.
 938  */
 939 void __noreturn efi_stub_entry(efi_handle_t handle,
 940                                efi_system_table_t *sys_table_arg,
 941                                struct boot_params *boot_params)
 942 {
 943         efi_guid_t guid = EFI_MEMORY_ATTRIBUTE_PROTOCOL_GUID;
 944         struct setup_header *hdr = &boot_params->hdr;
 945         const struct linux_efi_initrd *initrd = NULL;
 946         unsigned long kernel_entry;
 947         efi_status_t status;
 948
 949         boot_params_ptr = boot_params;
 950
 951         efi_system_table = sys_table_arg;
 952         /* Check if we were booted by the EFI firmware */
 953         if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
 954                 efi_exit(handle, EFI_INVALID_PARAMETER);
 955
 956         if (have_unsupported_snp_features())
 957                 efi_exit(handle, EFI_UNSUPPORTED);
 958
 959         if (IS_ENABLED(CONFIG_EFI_DXE_MEM_ATTRIBUTES)) {
 960                 efi_dxe_table = get_efi_config_table(EFI_DXE_SERVICES_TABLE_GUID);
 961                 if (efi_dxe_table &&
 962                     efi_dxe_table->hdr.signature != EFI_DXE_SERVICES_TABLE_SIGNATURE) {
 963                         efi_warn("Ignoring DXE services table: invalid signature\n");
 964                         efi_dxe_table = NULL;
 965                 }
 966         }
 967
 968         /* grab the memory attributes protocol if it exists */
 969         efi_bs_call(locate_protocol, &guid, NULL, (void **)&memattr);
 970
 971         status = efi_setup_5level_paging();
 972         if (status != EFI_SUCCESS) {
 973                 efi_err("efi_setup_5level_paging() failed!\n");
 974                 goto fail;
 975         }
 976
 977 #ifdef CONFIG_CMDLINE_BOOL
 978         status = parse_options(CONFIG_CMDLINE);
 979         if (status != EFI_SUCCESS) {
 980                 efi_err("Failed to parse options\n");
 981                 goto fail;
 982         }
 983 #endif
 984         if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
 985                 unsigned long cmdline_paddr = ((u64)hdr->cmd_line_ptr |
 986                                                ((u64)boot_params->ext_cmd_line_ptr << 32));
 987                 status = parse_options((char *)cmdline_paddr);
 988                 if (status != EFI_SUCCESS) {
 989                         efi_err("Failed to parse options\n");
 990                         goto fail;
 991                 }
 992         }
 993
 994         if (efi_mem_encrypt > 0)
 995                 hdr->xloadflags |= XLF_MEM_ENCRYPTION;
 996
 997         status = efi_decompress_kernel(&kernel_entry);
 998         if (status != EFI_SUCCESS) {
 999                 efi_err("Failed to decompress kernel\n");
1000                 goto fail;
1001         }
1002
1003         /*
1004          * At this point, an initrd may already have been loaded by the
1005          * bootloader and passed via bootparams. We permit an initrd loaded
1006          * from the LINUX_EFI_INITRD_MEDIA_GUID device path to supersede it.
1007          *
1008          * If the device path is not present, any command-line initrd=
1009          * arguments will be processed only if image is not NULL, which will be
1010          * the case only if we were loaded via the PE entry point.
1011          */
1012         status = efi_load_initrd(image, hdr->initrd_addr_max, ULONG_MAX,
1013                                  &initrd);
1014         if (status != EFI_SUCCESS)
1015                 goto fail;
1016         if (initrd && initrd->size > 0) {
1017                 efi_set_u64_split(initrd->base, &hdr->ramdisk_image,
1018                                   &boot_params->ext_ramdisk_image);
1019                 efi_set_u64_split(initrd->size, &hdr->ramdisk_size,
1020                                   &boot_params->ext_ramdisk_size);
1021         }
1022
1023
1024         /*
1025          * If the boot loader gave us a value for secure_boot then we use that,
1026          * otherwise we ask the BIOS.
1027          */
1028         if (boot_params->secure_boot == efi_secureboot_mode_unset)
1029                 boot_params->secure_boot = efi_get_secureboot();
1030
1031         /* Ask the firmware to clear memory on unclean shutdown */
1032         efi_enable_reset_attack_mitigation();
1033
1034         efi_random_get_seed();
1035
1036         efi_retrieve_eventlog();
1037
1038         setup_graphics(boot_params);
1039
1040         setup_efi_pci(boot_params);
1041
1042         setup_quirks(boot_params);
1043
1044         setup_unaccepted_memory();
1045
1046         status = exit_boot(boot_params, handle);
1047         if (status != EFI_SUCCESS) {
1048                 efi_err("exit_boot() failed!\n");
1049                 goto fail;
1050         }
1051
1052         /*
1053          * Call the SEV init code while still running with the firmware's
1054          * GDT/IDT, so #VC exceptions will be handled by EFI.
1055          */
1056         sev_enable(boot_params);
1057
1058         efi_5level_switch();
1059
1060         enter_kernel(kernel_entry, boot_params);
1061 fail:
1062         efi_err("efi_stub_entry() failed!\n");
1063
1064         efi_exit(handle, status);
1065 }
1066
1067 #ifdef CONFIG_EFI_HANDOVER_PROTOCOL
1068 void efi_handover_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1069                         struct boot_params *boot_params)
1070 {
1071         memset(_bss, 0, _ebss - _bss);
1072         efi_stub_entry(handle, sys_table_arg, boot_params);
1073 }
1074
1075 #ifndef CONFIG_EFI_MIXED
1076 extern __alias(efi_handover_entry)
1077 void efi32_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1078                       struct boot_params *boot_params);
1079
1080 extern __alias(efi_handover_entry)
1081 void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
1082                       struct boot_params *boot_params);
1083 #endif
1084 #endif