arch/common/boot/grub2/kern/efi/mm.c

   1 /* mm.c - generic EFI memory management */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2006,2007  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/misc.h>
  21 #include <grub/mm.h>
  22 #include <grub/efi/api.h>
  23 #include <grub/efi/efi.h>
  24
  25 #define NEXT_MEMORY_DESCRIPTOR(desc, size)      \
  26   ((grub_efi_memory_descriptor_t *) ((char *) (desc) + (size)))
  27
  28 #define BYTES_TO_PAGES(bytes)   ((bytes) >> 12)
  29 #define PAGES_TO_BYTES(pages)   ((pages) << 12)
  30
  31 /* The size of a memory map obtained from the firmware. This must be
  32    a multiplier of 4KB.  */
  33 #define MEMORY_MAP_SIZE 0x3000
  34
  35 /* Maintain the list of allocated pages.  */
  36 struct allocated_page
  37 {
  38   grub_efi_physical_address_t addr;
  39   grub_efi_uint64_t num_pages;
  40 };
  41
  42 #define ALLOCATED_PAGES_SIZE    0x1000
  43 #define MAX_ALLOCATED_PAGES     \
  44   (ALLOCATED_PAGES_SIZE / sizeof (struct allocated_page))
  45
  46 static struct allocated_page *allocated_pages = 0;
  47
  48 /* The minimum and maximum heap size for GRUB itself.  */
  49 #define MIN_HEAP_SIZE   0x100000
  50 #define MAX_HEAP_SIZE   (16 * 0x100000)
  51
  52
  53 /* Allocate pages. Return the pointer to the first of allocated pages.  */
  54 void *
  55 grub_efi_allocate_pages (grub_efi_physical_address_t address,
  56                          grub_efi_uintn_t pages)
  57 {
  58   grub_efi_allocate_type_t type;
  59   grub_efi_status_t status;
  60   grub_efi_boot_services_t *b;
  61
  62 #if GRUB_TARGET_SIZEOF_VOID_P < 8
  63   /* Limit the memory access to less than 4GB for 32-bit platforms.  */
  64   if (address > 0xffffffff)
  65     return 0;
  66
  67   if (address == 0)
  68     {
  69       type = GRUB_EFI_ALLOCATE_MAX_ADDRESS;
  70       address = 0xffffffff;
  71     }
  72   else
  73     type = GRUB_EFI_ALLOCATE_ADDRESS;
  74 #else
  75   if (address == 0)
  76     type = GRUB_EFI_ALLOCATE_ANY_PAGES;
  77   else
  78     type = GRUB_EFI_ALLOCATE_ADDRESS;
  79 #endif
  80
  81   b = grub_efi_system_table->boot_services;
  82   status = efi_call_4 (b->allocate_pages, type, GRUB_EFI_LOADER_DATA, pages, &address);
  83   if (status != GRUB_EFI_SUCCESS)
  84     return 0;
  85
  86   if (address == 0)
  87     {
  88       /* Uggh, the address 0 was allocated... This is too annoying,
  89          so reallocate another one.  */
  90       address = 0xffffffff;
  91       status = efi_call_4 (b->allocate_pages, type, GRUB_EFI_LOADER_DATA, pages, &address);
  92       grub_efi_free_pages (0, pages);
  93       if (status != GRUB_EFI_SUCCESS)
  94         return 0;
  95     }
  96
  97   if (allocated_pages)
  98     {
  99       unsigned i;
 100
 101       for (i = 0; i < MAX_ALLOCATED_PAGES; i++)
 102         if (allocated_pages[i].addr == 0)
 103           {
 104             allocated_pages[i].addr = address;
 105             allocated_pages[i].num_pages = pages;
 106             break;
 107           }
 108
 109       if (i == MAX_ALLOCATED_PAGES)
 110         grub_fatal ("too many page allocations");
 111     }
 112
 113   return (void *) ((grub_addr_t) address);
 114 }
 115
 116 /* Free pages starting from ADDRESS.  */
 117 void
 118 grub_efi_free_pages (grub_efi_physical_address_t address,
 119                      grub_efi_uintn_t pages)
 120 {
 121   grub_efi_boot_services_t *b;
 122
 123   if (allocated_pages
 124       && ((grub_efi_physical_address_t) ((grub_addr_t) allocated_pages)
 125           != address))
 126     {
 127       unsigned i;
 128
 129       for (i = 0; i < MAX_ALLOCATED_PAGES; i++)
 130         if (allocated_pages[i].addr == address)
 131           {
 132             allocated_pages[i].addr = 0;
 133             break;
 134           }
 135     }
 136
 137   b = grub_efi_system_table->boot_services;
 138   efi_call_2 (b->free_pages, address, pages);
 139 }
 140
 141 /* Get the memory map as defined in the EFI spec. Return 1 if successful,
 142    return 0 if partial, or return -1 if an error occurs.  */
 143 int
 144 grub_efi_get_memory_map (grub_efi_uintn_t *memory_map_size,
 145                          grub_efi_memory_descriptor_t *memory_map,
 146                          grub_efi_uintn_t *map_key,
 147                          grub_efi_uintn_t *descriptor_size,
 148                          grub_efi_uint32_t *descriptor_version)
 149 {
 150   grub_efi_status_t status;
 151   grub_efi_boot_services_t *b;
 152   grub_efi_uintn_t key;
 153   grub_efi_uint32_t version;
 154
 155   /* Allow some parameters to be missing.  */
 156   if (! map_key)
 157     map_key = &key;
 158   if (! descriptor_version)
 159     descriptor_version = &version;
 160
 161   b = grub_efi_system_table->boot_services;
 162   status = efi_call_5 (b->get_memory_map, memory_map_size, memory_map, map_key,
 163                               descriptor_size, descriptor_version);
 164   if (status == GRUB_EFI_SUCCESS)
 165     return 1;
 166   else if (status == GRUB_EFI_BUFFER_TOO_SMALL)
 167     return 0;
 168   else
 169     return -1;
 170 }
 171
 172 /* Sort the memory map in place.  */
 173 static void
 174 sort_memory_map (grub_efi_memory_descriptor_t *memory_map,
 175                  grub_efi_uintn_t desc_size,
 176                  grub_efi_memory_descriptor_t *memory_map_end)
 177 {
 178   grub_efi_memory_descriptor_t *d1;
 179   grub_efi_memory_descriptor_t *d2;
 180
 181   for (d1 = memory_map;
 182        d1 < memory_map_end;
 183        d1 = NEXT_MEMORY_DESCRIPTOR (d1, desc_size))
 184     {
 185       grub_efi_memory_descriptor_t *max_desc = d1;
 186
 187       for (d2 = NEXT_MEMORY_DESCRIPTOR (d1, desc_size);
 188            d2 < memory_map_end;
 189            d2 = NEXT_MEMORY_DESCRIPTOR (d2, desc_size))
 190         {
 191           if (max_desc->num_pages < d2->num_pages)
 192             max_desc = d2;
 193         }
 194
 195       if (max_desc != d1)
 196         {
 197           grub_efi_memory_descriptor_t tmp;
 198
 199           tmp = *d1;
 200           *d1 = *max_desc;
 201           *max_desc = tmp;
 202         }
 203     }
 204 }
 205
 206 /* Filter the descriptors. GRUB needs only available memory.  */
 207 static grub_efi_memory_descriptor_t *
 208 filter_memory_map (grub_efi_memory_descriptor_t *memory_map,
 209                    grub_efi_memory_descriptor_t *filtered_memory_map,
 210                    grub_efi_uintn_t desc_size,
 211                    grub_efi_memory_descriptor_t *memory_map_end)
 212 {
 213   grub_efi_memory_descriptor_t *desc;
 214   grub_efi_memory_descriptor_t *filtered_desc;
 215
 216   for (desc = memory_map, filtered_desc = filtered_memory_map;
 217        desc < memory_map_end;
 218        desc = NEXT_MEMORY_DESCRIPTOR (desc, desc_size))
 219     {
 220       if (desc->type == GRUB_EFI_CONVENTIONAL_MEMORY
 221 #if GRUB_TARGET_SIZEOF_VOID_P < 8
 222           && desc->physical_start <= 0xffffffff
 223 #endif
 224           && desc->physical_start + PAGES_TO_BYTES (desc->num_pages) > 0x100000
 225           && desc->num_pages != 0)
 226         {
 227           grub_memcpy (filtered_desc, desc, desc_size);
 228
 229           /* Avoid less than 1MB, because some loaders seem to be confused.  */
 230           if (desc->physical_start < 0x100000)
 231             {
 232               desc->num_pages -= BYTES_TO_PAGES (0x100000
 233                                                  - desc->physical_start);
 234               desc->physical_start = 0x100000;
 235             }
 236
 237 #if GRUB_TARGET_SIZEOF_VOID_P < 8
 238           if (BYTES_TO_PAGES (filtered_desc->physical_start)
 239               + filtered_desc->num_pages
 240               > BYTES_TO_PAGES (0x100000000LL))
 241             filtered_desc->num_pages
 242               = (BYTES_TO_PAGES (0x100000000LL)
 243                  - BYTES_TO_PAGES (filtered_desc->physical_start));
 244 #endif
 245
 246           if (filtered_desc->num_pages == 0)
 247             continue;
 248
 249           filtered_desc = NEXT_MEMORY_DESCRIPTOR (filtered_desc, desc_size);
 250         }
 251     }
 252
 253   return filtered_desc;
 254 }
 255
 256 /* Return the total number of pages.  */
 257 static grub_efi_uint64_t
 258 get_total_pages (grub_efi_memory_descriptor_t *memory_map,
 259                  grub_efi_uintn_t desc_size,
 260                  grub_efi_memory_descriptor_t *memory_map_end)
 261 {
 262   grub_efi_memory_descriptor_t *desc;
 263   grub_efi_uint64_t total = 0;
 264
 265   for (desc = memory_map;
 266        desc < memory_map_end;
 267        desc = NEXT_MEMORY_DESCRIPTOR (desc, desc_size))
 268     total += desc->num_pages;
 269
 270   return total;
 271 }
 272
 273 /* Add memory regions.  */
 274 static void
 275 add_memory_regions (grub_efi_memory_descriptor_t *memory_map,
 276                     grub_efi_uintn_t desc_size,
 277                     grub_efi_memory_descriptor_t *memory_map_end,
 278                     grub_efi_uint64_t required_pages)
 279 {
 280   grub_efi_memory_descriptor_t *desc;
 281
 282   for (desc = memory_map;
 283        desc < memory_map_end;
 284        desc = NEXT_MEMORY_DESCRIPTOR (desc, desc_size))
 285     {
 286       grub_efi_uint64_t pages;
 287       grub_efi_physical_address_t start;
 288       void *addr;
 289
 290       start = desc->physical_start;
 291       pages = desc->num_pages;
 292       if (pages > required_pages)
 293         {
 294           start += PAGES_TO_BYTES (pages - required_pages);
 295           pages = required_pages;
 296         }
 297
 298       addr = grub_efi_allocate_pages (start, pages);
 299       if (! addr)
 300         grub_fatal ("cannot allocate conventional memory %p with %u pages",
 301                     (void *) ((grub_addr_t) start),
 302                     (unsigned) pages);
 303
 304       grub_mm_init_region (addr, PAGES_TO_BYTES (pages));
 305
 306       required_pages -= pages;
 307       if (required_pages == 0)
 308         break;
 309     }
 310
 311   if (required_pages > 0)
 312     grub_fatal ("too little memory");
 313 }
 314
 315 #if 0
 316 /* Print the memory map.  */
 317 static void
 318 print_memory_map (grub_efi_memory_descriptor_t *memory_map,
 319                   grub_efi_uintn_t desc_size,
 320                   grub_efi_memory_descriptor_t *memory_map_end)
 321 {
 322   grub_efi_memory_descriptor_t *desc;
 323   int i;
 324
 325   for (desc = memory_map, i = 0;
 326        desc < memory_map_end;
 327        desc = NEXT_MEMORY_DESCRIPTOR (desc, desc_size), i++)
 328     {
 329       grub_printf ("MD: t=%x, p=%llx, v=%llx, n=%llx, a=%llx\n",
 330                    desc->type, desc->physical_start, desc->virtual_start,
 331                    desc->num_pages, desc->attribute);
 332     }
 333 }
 334 #endif
 335
 336 void
 337 grub_efi_mm_init (void)
 338 {
 339   grub_efi_memory_descriptor_t *memory_map;
 340   grub_efi_memory_descriptor_t *memory_map_end;
 341   grub_efi_memory_descriptor_t *filtered_memory_map;
 342   grub_efi_memory_descriptor_t *filtered_memory_map_end;
 343   grub_efi_uintn_t map_size;
 344   grub_efi_uintn_t desc_size;
 345   grub_efi_uint64_t total_pages;
 346   grub_efi_uint64_t required_pages;
 347
 348   /* First of all, allocate pages to maintain allocations.  */
 349   allocated_pages
 350     = grub_efi_allocate_pages (0, BYTES_TO_PAGES (ALLOCATED_PAGES_SIZE));
 351   if (! allocated_pages)
 352     grub_fatal ("cannot allocate memory");
 353
 354   grub_memset (allocated_pages, 0, ALLOCATED_PAGES_SIZE);
 355
 356   /* Prepare a memory region to store two memory maps.  */
 357   memory_map = grub_efi_allocate_pages (0,
 358                                         2 * BYTES_TO_PAGES (MEMORY_MAP_SIZE));
 359   if (! memory_map)
 360     grub_fatal ("cannot allocate memory");
 361
 362   filtered_memory_map = NEXT_MEMORY_DESCRIPTOR (memory_map, MEMORY_MAP_SIZE);
 363
 364   /* Obtain descriptors for available memory.  */
 365   map_size = MEMORY_MAP_SIZE;
 366
 367   if (grub_efi_get_memory_map (&map_size, memory_map, 0, &desc_size, 0) < 0)
 368     grub_fatal ("cannot get memory map");
 369
 370   memory_map_end = NEXT_MEMORY_DESCRIPTOR (memory_map, map_size);
 371
 372   filtered_memory_map_end = filter_memory_map (memory_map, filtered_memory_map,
 373                                                desc_size, memory_map_end);
 374
 375   /* By default, request a quarter of the available memory.  */
 376   total_pages = get_total_pages (filtered_memory_map, desc_size,
 377                                  filtered_memory_map_end);
 378   required_pages = (total_pages >> 2);
 379   if (required_pages < BYTES_TO_PAGES (MIN_HEAP_SIZE))
 380     required_pages = BYTES_TO_PAGES (MIN_HEAP_SIZE);
 381   else if (required_pages > BYTES_TO_PAGES (MAX_HEAP_SIZE))
 382     required_pages = BYTES_TO_PAGES (MAX_HEAP_SIZE);
 383
 384   /* Sort the filtered descriptors, so that GRUB can allocate pages
 385      from smaller regions.  */
 386   sort_memory_map (filtered_memory_map, desc_size, filtered_memory_map_end);
 387
 388   /* Allocate memory regions for GRUB's memory management.  */
 389   add_memory_regions (filtered_memory_map, desc_size,
 390                       filtered_memory_map_end, required_pages);
 391
 392 #if 0
 393   /* For debug.  */
 394   map_size = MEMORY_MAP_SIZE;
 395
 396   if (grub_efi_get_memory_map (&map_size, memory_map, 0, &desc_size, 0) < 0)
 397     grub_fatal ("cannot get memory map");
 398
 399   grub_printf ("printing memory map\n");
 400   print_memory_map (memory_map, desc_size,
 401                     NEXT_MEMORY_DESCRIPTOR (memory_map, map_size));
 402   grub_abort ();
 403 #endif
 404
 405   /* Release the memory maps.  */
 406   grub_efi_free_pages ((grub_addr_t) memory_map,
 407                        2 * BYTES_TO_PAGES (MEMORY_MAP_SIZE));
 408 }
 409
 410 void
 411 grub_efi_mm_fini (void)
 412 {
 413   if (allocated_pages)
 414     {
 415       unsigned i;
 416
 417       for (i = 0; i < MAX_ALLOCATED_PAGES; i++)
 418         {
 419           struct allocated_page *p;
 420
 421           p = allocated_pages + i;
 422           if (p->addr != 0)
 423             grub_efi_free_pages ((grub_addr_t) p->addr, p->num_pages);
 424         }
 425
 426       grub_efi_free_pages ((grub_addr_t) allocated_pages,
 427                            BYTES_TO_PAGES (ALLOCATED_PAGES_SIZE));
 428     }
 429 }