drivers/firmware/efi/efi-stub-helper.c

   1 /*
   2  * Helper functions used by the EFI stub on multiple
   3  * architectures. This should be #included by the EFI stub
   4  * implementation files.
   5  *
   6  * Copyright 2011 Intel Corporation; author Matt Fleming
   7  *
   8  * This file is part of the Linux kernel, and is made available
   9  * under the terms of the GNU General Public License version 2.
  10  *
  11  */
  12 #define EFI_READ_CHUNK_SIZE     (1024 * 1024)
  13
  14 struct file_info {
  15         efi_file_handle_t *handle;
  16         u64 size;
  17 };
  18
  19
  20
  21
  22 static void efi_char16_printk(efi_system_table_t *sys_table_arg,
  23                               efi_char16_t *str)
  24 {
  25         struct efi_simple_text_output_protocol *out;
  26
  27         out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
  28         efi_call_phys2(out->output_string, out, str);
  29 }
  30
  31 static void efi_printk(efi_system_table_t *sys_table_arg, char *str)
  32 {
  33         char *s8;
  34
  35         for (s8 = str; *s8; s8++) {
  36                 efi_char16_t ch[2] = { 0 };
  37
  38                 ch[0] = *s8;
  39                 if (*s8 == '\n') {
  40                         efi_char16_t nl[2] = { '\r', 0 };
  41                         efi_char16_printk(sys_table_arg, nl);
  42                 }
  43
  44                 efi_char16_printk(sys_table_arg, ch);
  45         }
  46 }
  47
  48
  49 static efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
  50                                        efi_memory_desc_t **map,
  51                                        unsigned long *map_size,
  52                                        unsigned long *desc_size,
  53                                        u32 *desc_ver,
  54                                        unsigned long *key_ptr)
  55 {
  56         efi_memory_desc_t *m = NULL;
  57         efi_status_t status;
  58         unsigned long key;
  59         u32 desc_version;
  60
  61         *map_size = sizeof(*m) * 32;
  62 again:
  63         /*
  64          * Add an additional efi_memory_desc_t because we're doing an
  65          * allocation which may be in a new descriptor region.
  66          */
  67         *map_size += sizeof(*m);
  68         status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
  69                                 EFI_LOADER_DATA, *map_size, (void **)&m);
  70         if (status != EFI_SUCCESS)
  71                 goto fail;
  72
  73         status = efi_call_phys5(sys_table_arg->boottime->get_memory_map,
  74                                 map_size, m, &key, desc_size, &desc_version);
  75         if (status == EFI_BUFFER_TOO_SMALL) {
  76                 efi_call_phys1(sys_table_arg->boottime->free_pool, m);
  77                 goto again;
  78         }
  79
  80         if (status != EFI_SUCCESS)
  81                 efi_call_phys1(sys_table_arg->boottime->free_pool, m);
  82         if (key_ptr && status == EFI_SUCCESS)
  83                 *key_ptr = key;
  84         if (desc_ver && status == EFI_SUCCESS)
  85                 *desc_ver = desc_version;
  86
  87 fail:
  88         *map = m;
  89         return status;
  90 }
  91
  92 /*
  93  * Allocate at the highest possible address that is not above 'max'.
  94  */
  95 static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
  96                                unsigned long size, unsigned long align,
  97                                unsigned long *addr, unsigned long max)
  98 {
  99         unsigned long map_size, desc_size;
 100         efi_memory_desc_t *map;
 101         efi_status_t status;
 102         unsigned long nr_pages;
 103         u64 max_addr = 0;
 104         int i;
 105
 106         status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
 107                                     NULL, NULL);
 108         if (status != EFI_SUCCESS)
 109                 goto fail;
 110
 111         /*
 112          * Enforce minimum alignment that EFI requires when requesting
 113          * a specific address.  We are doing page-based allocations,
 114          * so we must be aligned to a page.
 115          */
 116         if (align < EFI_PAGE_SIZE)
 117                 align = EFI_PAGE_SIZE;
 118
 119         nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
 120 again:
 121         for (i = 0; i < map_size / desc_size; i++) {
 122                 efi_memory_desc_t *desc;
 123                 unsigned long m = (unsigned long)map;
 124                 u64 start, end;
 125
 126                 desc = (efi_memory_desc_t *)(m + (i * desc_size));
 127                 if (desc->type != EFI_CONVENTIONAL_MEMORY)
 128                         continue;
 129
 130                 if (desc->num_pages < nr_pages)
 131                         continue;
 132
 133                 start = desc->phys_addr;
 134                 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
 135
 136                 if ((start + size) > end || (start + size) > max)
 137                         continue;
 138
 139                 if (end - size > max)
 140                         end = max;
 141
 142                 if (round_down(end - size, align) < start)
 143                         continue;
 144
 145                 start = round_down(end - size, align);
 146
 147                 /*
 148                  * Don't allocate at 0x0. It will confuse code that
 149                  * checks pointers against NULL.
 150                  */
 151                 if (start == 0x0)
 152                         continue;
 153
 154                 if (start > max_addr)
 155                         max_addr = start;
 156         }
 157
 158         if (!max_addr)
 159                 status = EFI_NOT_FOUND;
 160         else {
 161                 status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
 162                                         EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 163                                         nr_pages, &max_addr);
 164                 if (status != EFI_SUCCESS) {
 165                         max = max_addr;
 166                         max_addr = 0;
 167                         goto again;
 168                 }
 169
 170                 *addr = max_addr;
 171         }
 172
 173         efi_call_phys1(sys_table_arg->boottime->free_pool, map);
 174
 175 fail:
 176         return status;
 177 }
 178
 179 /*
 180  * Allocate at the lowest possible address.
 181  */
 182 static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
 183                               unsigned long size, unsigned long align,
 184                               unsigned long *addr)
 185 {
 186         unsigned long map_size, desc_size;
 187         efi_memory_desc_t *map;
 188         efi_status_t status;
 189         unsigned long nr_pages;
 190         int i;
 191
 192         status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
 193                                     NULL, NULL);
 194         if (status != EFI_SUCCESS)
 195                 goto fail;
 196
 197         /*
 198          * Enforce minimum alignment that EFI requires when requesting
 199          * a specific address.  We are doing page-based allocations,
 200          * so we must be aligned to a page.
 201          */
 202         if (align < EFI_PAGE_SIZE)
 203                 align = EFI_PAGE_SIZE;
 204
 205         nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
 206         for (i = 0; i < map_size / desc_size; i++) {
 207                 efi_memory_desc_t *desc;
 208                 unsigned long m = (unsigned long)map;
 209                 u64 start, end;
 210
 211                 desc = (efi_memory_desc_t *)(m + (i * desc_size));
 212
 213                 if (desc->type != EFI_CONVENTIONAL_MEMORY)
 214                         continue;
 215
 216                 if (desc->num_pages < nr_pages)
 217                         continue;
 218
 219                 start = desc->phys_addr;
 220                 end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT);
 221
 222                 /*
 223                  * Don't allocate at 0x0. It will confuse code that
 224                  * checks pointers against NULL. Skip the first 8
 225                  * bytes so we start at a nice even number.
 226                  */
 227                 if (start == 0x0)
 228                         start += 8;
 229
 230                 start = round_up(start, align);
 231                 if ((start + size) > end)
 232                         continue;
 233
 234                 status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
 235                                         EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 236                                         nr_pages, &start);
 237                 if (status == EFI_SUCCESS) {
 238                         *addr = start;
 239                         break;
 240                 }
 241         }
 242
 243         if (i == map_size / desc_size)
 244                 status = EFI_NOT_FOUND;
 245
 246         efi_call_phys1(sys_table_arg->boottime->free_pool, map);
 247 fail:
 248         return status;
 249 }
 250
 251 static void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
 252                      unsigned long addr)
 253 {
 254         unsigned long nr_pages;
 255
 256         if (!size)
 257                 return;
 258
 259         nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
 260         efi_call_phys2(sys_table_arg->boottime->free_pages, addr, nr_pages);
 261 }
 262
 263
 264 /*
 265  * Check the cmdline for a LILO-style file= arguments.
 266  *
 267  * We only support loading a file from the same filesystem as
 268  * the kernel image.
 269  */
 270 static efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 271                                          efi_loaded_image_t *image,
 272                                          char *cmd_line, char *option_string,
 273                                          unsigned long max_addr,
 274                                          unsigned long *load_addr,
 275                                          unsigned long *load_size)
 276 {
 277         struct file_info *files;
 278         unsigned long file_addr;
 279         efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
 280         u64 file_size_total;
 281         efi_file_io_interface_t *io;
 282         efi_file_handle_t *fh;
 283         efi_status_t status;
 284         int nr_files;
 285         char *str;
 286         int i, j, k;
 287
 288         file_addr = 0;
 289         file_size_total = 0;
 290
 291         str = cmd_line;
 292
 293         j = 0;                  /* See close_handles */
 294
 295         if (!load_addr || !load_size)
 296                 return EFI_INVALID_PARAMETER;
 297
 298         *load_addr = 0;
 299         *load_size = 0;
 300
 301         if (!str || !*str)
 302                 return EFI_SUCCESS;
 303
 304         for (nr_files = 0; *str; nr_files++) {
 305                 str = strstr(str, option_string);
 306                 if (!str)
 307                         break;
 308
 309                 str += strlen(option_string);
 310
 311                 /* Skip any leading slashes */
 312                 while (*str == '/' || *str == '\\')
 313                         str++;
 314
 315                 while (*str && *str != ' ' && *str != '\n')
 316                         str++;
 317         }
 318
 319         if (!nr_files)
 320                 return EFI_SUCCESS;
 321
 322         status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
 323                                 EFI_LOADER_DATA,
 324                                 nr_files * sizeof(*files),
 325                                 (void **)&files);
 326         if (status != EFI_SUCCESS) {
 327                 efi_printk(sys_table_arg, "Failed to alloc mem for file handle list\n");
 328                 goto fail;
 329         }
 330
 331         str = cmd_line;
 332         for (i = 0; i < nr_files; i++) {
 333                 struct file_info *file;
 334                 efi_file_handle_t *h;
 335                 efi_file_info_t *info;
 336                 efi_char16_t filename_16[256];
 337                 unsigned long info_sz;
 338                 efi_guid_t info_guid = EFI_FILE_INFO_ID;
 339                 efi_char16_t *p;
 340                 u64 file_sz;
 341
 342                 str = strstr(str, option_string);
 343                 if (!str)
 344                         break;
 345
 346                 str += strlen(option_string);
 347
 348                 file = &files[i];
 349                 p = filename_16;
 350
 351                 /* Skip any leading slashes */
 352                 while (*str == '/' || *str == '\\')
 353                         str++;
 354
 355                 while (*str && *str != ' ' && *str != '\n') {
 356                         if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16))
 357                                 break;
 358
 359                         if (*str == '/') {
 360                                 *p++ = '\\';
 361                                 str++;
 362                         } else {
 363                                 *p++ = *str++;
 364                         }
 365                 }
 366
 367                 *p = '\0';
 368
 369                 /* Only open the volume once. */
 370                 if (!i) {
 371                         efi_boot_services_t *boottime;
 372
 373                         boottime = sys_table_arg->boottime;
 374
 375                         status = efi_call_phys3(boottime->handle_protocol,
 376                                         image->device_handle, &fs_proto,
 377                                                 (void **)&io);
 378                         if (status != EFI_SUCCESS) {
 379                                 efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
 380                                 goto free_files;
 381                         }
 382
 383                         status = efi_call_phys2(io->open_volume, io, &fh);
 384                         if (status != EFI_SUCCESS) {
 385                                 efi_printk(sys_table_arg, "Failed to open volume\n");
 386                                 goto free_files;
 387                         }
 388                 }
 389
 390                 status = efi_call_phys5(fh->open, fh, &h, filename_16,
 391                                         EFI_FILE_MODE_READ, (u64)0);
 392                 if (status != EFI_SUCCESS) {
 393                         efi_printk(sys_table_arg, "Failed to open file: ");
 394                         efi_char16_printk(sys_table_arg, filename_16);
 395                         efi_printk(sys_table_arg, "\n");
 396                         goto close_handles;
 397                 }
 398
 399                 file->handle = h;
 400
 401                 info_sz = 0;
 402                 status = efi_call_phys4(h->get_info, h, &info_guid,
 403                                         &info_sz, NULL);
 404                 if (status != EFI_BUFFER_TOO_SMALL) {
 405                         efi_printk(sys_table_arg, "Failed to get file info size\n");
 406                         goto close_handles;
 407                 }
 408
 409 grow:
 410                 status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
 411                                         EFI_LOADER_DATA, info_sz,
 412                                         (void **)&info);
 413                 if (status != EFI_SUCCESS) {
 414                         efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
 415                         goto close_handles;
 416                 }
 417
 418                 status = efi_call_phys4(h->get_info, h, &info_guid,
 419                                         &info_sz, info);
 420                 if (status == EFI_BUFFER_TOO_SMALL) {
 421                         efi_call_phys1(sys_table_arg->boottime->free_pool,
 422                                        info);
 423                         goto grow;
 424                 }
 425
 426                 file_sz = info->file_size;
 427                 efi_call_phys1(sys_table_arg->boottime->free_pool, info);
 428
 429                 if (status != EFI_SUCCESS) {
 430                         efi_printk(sys_table_arg, "Failed to get file info\n");
 431                         goto close_handles;
 432                 }
 433
 434                 file->size = file_sz;
 435                 file_size_total += file_sz;
 436         }
 437
 438         if (file_size_total) {
 439                 unsigned long addr;
 440
 441                 /*
 442                  * Multiple files need to be at consecutive addresses in memory,
 443                  * so allocate enough memory for all the files.  This is used
 444                  * for loading multiple files.
 445                  */
 446                 status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000,
 447                                     &file_addr, max_addr);
 448                 if (status != EFI_SUCCESS) {
 449                         efi_printk(sys_table_arg, "Failed to alloc highmem for files\n");
 450                         goto close_handles;
 451                 }
 452
 453                 /* We've run out of free low memory. */
 454                 if (file_addr > max_addr) {
 455                         efi_printk(sys_table_arg, "We've run out of free low memory\n");
 456                         status = EFI_INVALID_PARAMETER;
 457                         goto free_file_total;
 458                 }
 459
 460                 addr = file_addr;
 461                 for (j = 0; j < nr_files; j++) {
 462                         unsigned long size;
 463
 464                         size = files[j].size;
 465                         while (size) {
 466                                 unsigned long chunksize;
 467                                 if (size > EFI_READ_CHUNK_SIZE)
 468                                         chunksize = EFI_READ_CHUNK_SIZE;
 469                                 else
 470                                         chunksize = size;
 471                                 status = efi_call_phys3(fh->read,
 472                                                         files[j].handle,
 473                                                         &chunksize,
 474                                                         (void *)addr);
 475                                 if (status != EFI_SUCCESS) {
 476                                         efi_printk(sys_table_arg, "Failed to read file\n");
 477                                         goto free_file_total;
 478                                 }
 479                                 addr += chunksize;
 480                                 size -= chunksize;
 481                         }
 482
 483                         efi_call_phys1(fh->close, files[j].handle);
 484                 }
 485
 486         }
 487
 488         efi_call_phys1(sys_table_arg->boottime->free_pool, files);
 489
 490         *load_addr = file_addr;
 491         *load_size = file_size_total;
 492
 493         return status;
 494
 495 free_file_total:
 496         efi_free(sys_table_arg, file_size_total, file_addr);
 497
 498 close_handles:
 499         for (k = j; k < i; k++)
 500                 efi_call_phys1(fh->close, files[k].handle);
 501 free_files:
 502         efi_call_phys1(sys_table_arg->boottime->free_pool, files);
 503 fail:
 504         *load_addr = 0;
 505         *load_size = 0;
 506
 507         return status;
 508 }
 509 /*
 510  * Relocate a kernel image, either compressed or uncompressed.
 511  * In the ARM64 case, all kernel images are currently
 512  * uncompressed, and as such when we relocate it we need to
 513  * allocate additional space for the BSS segment. Any low
 514  * memory that this function should avoid needs to be
 515  * unavailable in the EFI memory map, as if the preferred
 516  * address is not available the lowest available address will
 517  * be used.
 518  */
 519 static efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg,
 520                                         unsigned long *image_addr,
 521                                         unsigned long image_size,
 522                                         unsigned long alloc_size,
 523                                         unsigned long preferred_addr,
 524                                         unsigned long alignment)
 525 {
 526         unsigned long cur_image_addr;
 527         unsigned long new_addr = 0;
 528         efi_status_t status;
 529         unsigned long nr_pages;
 530         efi_physical_addr_t efi_addr = preferred_addr;
 531
 532         if (!image_addr || !image_size || !alloc_size)
 533                 return EFI_INVALID_PARAMETER;
 534         if (alloc_size < image_size)
 535                 return EFI_INVALID_PARAMETER;
 536
 537         cur_image_addr = *image_addr;
 538
 539         /*
 540          * The EFI firmware loader could have placed the kernel image
 541          * anywhere in memory, but the kernel has restrictions on the
 542          * max physical address it can run at.  Some architectures
 543          * also have a prefered address, so first try to relocate
 544          * to the preferred address.  If that fails, allocate as low
 545          * as possible while respecting the required alignment.
 546          */
 547         nr_pages = round_up(alloc_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
 548         status = efi_call_phys4(sys_table_arg->boottime->allocate_pages,
 549                                 EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA,
 550                                 nr_pages, &efi_addr);
 551         new_addr = efi_addr;
 552         /*
 553          * If preferred address allocation failed allocate as low as
 554          * possible.
 555          */
 556         if (status != EFI_SUCCESS) {
 557                 status = efi_low_alloc(sys_table_arg, alloc_size, alignment,
 558                                        &new_addr);
 559         }
 560         if (status != EFI_SUCCESS) {
 561                 efi_printk(sys_table_arg, "ERROR: Failed to allocate usable memory for kernel.\n");
 562                 return status;
 563         }
 564
 565         /*
 566          * We know source/dest won't overlap since both memory ranges
 567          * have been allocated by UEFI, so we can safely use memcpy.
 568          */
 569         memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
 570
 571         /* Return the new address of the relocated image. */
 572         *image_addr = new_addr;
 573
 574         return status;
 575 }
 576
 577 /*
 578  * Convert the unicode UEFI command line to ASCII to pass to kernel.
 579  * Size of memory allocated return in *cmd_line_len.
 580  * Returns NULL on error.
 581  */
 582 static char *efi_convert_cmdline_to_ascii(efi_system_table_t *sys_table_arg,
 583                                       efi_loaded_image_t *image,
 584                                       int *cmd_line_len)
 585 {
 586         u16 *s2;
 587         u8 *s1 = NULL;
 588         unsigned long cmdline_addr = 0;
 589         int load_options_size = image->load_options_size / 2; /* ASCII */
 590         void *options = image->load_options;
 591         int options_size = 0;
 592         efi_status_t status;
 593         int i;
 594         u16 zero = 0;
 595
 596         if (options) {
 597                 s2 = options;
 598                 while (*s2 && *s2 != '\n' && options_size < load_options_size) {
 599                         s2++;
 600                         options_size++;
 601                 }
 602         }
 603
 604         if (options_size == 0) {
 605                 /* No command line options, so return empty string*/
 606                 options_size = 1;
 607                 options = &zero;
 608         }
 609
 610         options_size++;  /* NUL termination */
 611 #ifdef CONFIG_ARM
 612         /*
 613          * For ARM, allocate at a high address to avoid reserved
 614          * regions at low addresses that we don't know the specfics of
 615          * at the time we are processing the command line.
 616          */
 617         status = efi_high_alloc(sys_table_arg, options_size, 0,
 618                             &cmdline_addr, 0xfffff000);
 619 #else
 620         status = efi_low_alloc(sys_table_arg, options_size, 0,
 621                             &cmdline_addr);
 622 #endif
 623         if (status != EFI_SUCCESS)
 624                 return NULL;
 625
 626         s1 = (u8 *)cmdline_addr;
 627         s2 = (u16 *)options;
 628
 629         for (i = 0; i < options_size - 1; i++)
 630                 *s1++ = *s2++;
 631
 632         *s1 = '\0';
 633
 634         *cmd_line_len = options_size;
 635         return (char *)cmdline_addr;
 636 }