lib/efi_loader/efi_memory.c

   1 /*
   2  *  EFI application memory management
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <efi_loader.h>
  11 #include <malloc.h>
  12 #include <asm/global_data.h>
  13 #include <libfdt_env.h>
  14 #include <linux/list_sort.h>
  15 #include <inttypes.h>
  16 #include <watchdog.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 struct efi_mem_list {
  21         struct list_head link;
  22         struct efi_mem_desc desc;
  23 };
  24
  25 #define EFI_CARVE_NO_OVERLAP            -1
  26 #define EFI_CARVE_LOOP_AGAIN            -2
  27 #define EFI_CARVE_OVERLAPS_NONRAM       -3
  28
  29 /* This list contains all memory map items */
  30 LIST_HEAD(efi_mem);
  31
  32 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
  33 void *efi_bounce_buffer;
  34 #endif
  35
  36 /*
  37  * Sorts the memory list from highest address to lowest address
  38  *
  39  * When allocating memory we should always start from the highest
  40  * address chunk, so sort the memory list such that the first list
  41  * iterator gets the highest address and goes lower from there.
  42  */
  43 static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
  44 {
  45         struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
  46         struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);
  47
  48         if (mema->desc.physical_start == memb->desc.physical_start)
  49                 return 0;
  50         else if (mema->desc.physical_start < memb->desc.physical_start)
  51                 return 1;
  52         else
  53                 return -1;
  54 }
  55
  56 static void efi_mem_sort(void)
  57 {
  58         list_sort(NULL, &efi_mem, efi_mem_cmp);
  59 }
  60
  61 /*
  62  * Unmaps all memory occupied by the carve_desc region from the
  63  * list entry pointed to by map.
  64  *
  65  * Returns 1 if carving was performed or 0 if the regions don't overlap.
  66  * Returns -1 if it would affect non-RAM regions but overlap_only_ram is set.
  67  * Carving is only guaranteed to complete when all regions return 0.
  68  */
  69 static int efi_mem_carve_out(struct efi_mem_list *map,
  70                              struct efi_mem_desc *carve_desc,
  71                              bool overlap_only_ram)
  72 {
  73         struct efi_mem_list *newmap;
  74         struct efi_mem_desc *map_desc = &map->desc;
  75         uint64_t map_start = map_desc->physical_start;
  76         uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
  77         uint64_t carve_start = carve_desc->physical_start;
  78         uint64_t carve_end = carve_start +
  79                              (carve_desc->num_pages << EFI_PAGE_SHIFT);
  80
  81         /* check whether we're overlapping */
  82         if ((carve_end <= map_start) || (carve_start >= map_end))
  83                 return EFI_CARVE_NO_OVERLAP;
  84
  85         /* We're overlapping with non-RAM, warn the caller if desired */
  86         if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
  87                 return EFI_CARVE_OVERLAPS_NONRAM;
  88
  89         /* Sanitize carve_start and carve_end to lie within our bounds */
  90         carve_start = max(carve_start, map_start);
  91         carve_end = min(carve_end, map_end);
  92
  93         /* Carving at the beginning of our map? Just move it! */
  94         if (carve_start == map_start) {
  95                 if (map_end == carve_end) {
  96                         /* Full overlap, just remove map */
  97                         list_del(&map->link);
  98                 }
  99
 100                 map_desc->physical_start = carve_end;
 101                 map_desc->num_pages = (map_end - carve_end) >> EFI_PAGE_SHIFT;
 102                 return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
 103         }
 104
 105         /*
 106          * Overlapping maps, just split the list map at carve_start,
 107          * it will get moved or removed in the next iteration.
 108          *
 109          * [ map_desc |__carve_start__| newmap ]
 110          */
 111
 112         /* Create a new map from [ carve_start ... map_end ] */
 113         newmap = calloc(1, sizeof(*newmap));
 114         newmap->desc = map->desc;
 115         newmap->desc.physical_start = carve_start;
 116         newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
 117         list_add_tail(&newmap->link, &efi_mem);
 118
 119         /* Shrink the map to [ map_start ... carve_start ] */
 120         map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
 121
 122         return EFI_CARVE_LOOP_AGAIN;
 123 }
 124
 125 uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 126                             bool overlap_only_ram)
 127 {
 128         struct list_head *lhandle;
 129         struct efi_mem_list *newlist;
 130         bool carve_again;
 131         uint64_t carved_pages = 0;
 132
 133         debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
 134               start, pages, memory_type, overlap_only_ram ? "yes" : "no");
 135
 136         if (!pages)
 137                 return start;
 138
 139         newlist = calloc(1, sizeof(*newlist));
 140         newlist->desc.type = memory_type;
 141         newlist->desc.physical_start = start;
 142         newlist->desc.virtual_start = start;
 143         newlist->desc.num_pages = pages;
 144
 145         switch (memory_type) {
 146         case EFI_RUNTIME_SERVICES_CODE:
 147         case EFI_RUNTIME_SERVICES_DATA:
 148                 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
 149                                           (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
 150                 break;
 151         case EFI_MMAP_IO:
 152                 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
 153                 break;
 154         default:
 155                 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
 156                 break;
 157         }
 158
 159         /* Add our new map */
 160         do {
 161                 carve_again = false;
 162                 list_for_each(lhandle, &efi_mem) {
 163                         struct efi_mem_list *lmem;
 164                         int r;
 165
 166                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 167                         r = efi_mem_carve_out(lmem, &newlist->desc,
 168                                               overlap_only_ram);
 169                         switch (r) {
 170                         case EFI_CARVE_OVERLAPS_NONRAM:
 171                                 /*
 172                                  * The user requested to only have RAM overlaps,
 173                                  * but we hit a non-RAM region. Error out.
 174                                  */
 175                                 return 0;
 176                         case EFI_CARVE_NO_OVERLAP:
 177                                 /* Just ignore this list entry */
 178                                 break;
 179                         case EFI_CARVE_LOOP_AGAIN:
 180                                 /*
 181                                  * We split an entry, but need to loop through
 182                                  * the list again to actually carve it.
 183                                  */
 184                                 carve_again = true;
 185                                 break;
 186                         default:
 187                                 /* We carved a number of pages */
 188                                 carved_pages += r;
 189                                 carve_again = true;
 190                                 break;
 191                         }
 192
 193                         if (carve_again) {
 194                                 /* The list changed, we need to start over */
 195                                 break;
 196                         }
 197                 }
 198         } while (carve_again);
 199
 200         if (overlap_only_ram && (carved_pages != pages)) {
 201                 /*
 202                  * The payload wanted to have RAM overlaps, but we overlapped
 203                  * with an unallocated region. Error out.
 204                  */
 205                 return 0;
 206         }
 207
 208         /* Add our new map */
 209         list_add_tail(&newlist->link, &efi_mem);
 210
 211         /* And make sure memory is listed in descending order */
 212         efi_mem_sort();
 213
 214         return start;
 215 }
 216
 217 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
 218 {
 219         struct list_head *lhandle;
 220
 221         list_for_each(lhandle, &efi_mem) {
 222                 struct efi_mem_list *lmem = list_entry(lhandle,
 223                         struct efi_mem_list, link);
 224                 struct efi_mem_desc *desc = &lmem->desc;
 225                 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
 226                 uint64_t desc_end = desc->physical_start + desc_len;
 227                 uint64_t curmax = min(max_addr, desc_end);
 228                 uint64_t ret = curmax - len;
 229
 230                 /* We only take memory from free RAM */
 231                 if (desc->type != EFI_CONVENTIONAL_MEMORY)
 232                         continue;
 233
 234                 /* Out of bounds for max_addr */
 235                 if ((ret + len) > max_addr)
 236                         continue;
 237
 238                 /* Out of bounds for upper map limit */
 239                 if ((ret + len) > desc_end)
 240                         continue;
 241
 242                 /* Out of bounds for lower map limit */
 243                 if (ret < desc->physical_start)
 244                         continue;
 245
 246                 /* Return the highest address in this map within bounds */
 247                 return ret;
 248         }
 249
 250         return 0;
 251 }
 252
 253 efi_status_t efi_allocate_pages(int type, int memory_type,
 254                                 unsigned long pages, uint64_t *memory)
 255 {
 256         u64 len = pages << EFI_PAGE_SHIFT;
 257         efi_status_t r = EFI_SUCCESS;
 258         uint64_t addr;
 259
 260         switch (type) {
 261         case 0:
 262                 /* Any page */
 263                 addr = efi_find_free_memory(len, gd->start_addr_sp);
 264                 if (!addr) {
 265                         r = EFI_NOT_FOUND;
 266                         break;
 267                 }
 268                 break;
 269         case 1:
 270                 /* Max address */
 271                 addr = efi_find_free_memory(len, *memory);
 272                 if (!addr) {
 273                         r = EFI_NOT_FOUND;
 274                         break;
 275                 }
 276                 break;
 277         case 2:
 278                 /* Exact address, reserve it. The addr is already in *memory. */
 279                 addr = *memory;
 280                 break;
 281         default:
 282                 /* UEFI doesn't specify other allocation types */
 283                 r = EFI_INVALID_PARAMETER;
 284                 break;
 285         }
 286
 287         if (r == EFI_SUCCESS) {
 288                 uint64_t ret;
 289
 290                 /* Reserve that map in our memory maps */
 291                 ret = efi_add_memory_map(addr, pages, memory_type, true);
 292                 if (ret == addr) {
 293                         *memory = addr;
 294                 } else {
 295                         /* Map would overlap, bail out */
 296                         r = EFI_OUT_OF_RESOURCES;
 297                 }
 298         }
 299
 300         return r;
 301 }
 302
 303 void *efi_alloc(uint64_t len, int memory_type)
 304 {
 305         uint64_t ret = 0;
 306         uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 307         efi_status_t r;
 308
 309         r = efi_allocate_pages(0, memory_type, pages, &ret);
 310         if (r == EFI_SUCCESS)
 311                 return (void*)(uintptr_t)ret;
 312
 313         return NULL;
 314 }
 315
 316 efi_status_t efi_free_pages(uint64_t memory, unsigned long pages)
 317 {
 318         /* We don't free, let's cross our fingers we have plenty RAM */
 319         return EFI_SUCCESS;
 320 }
 321
 322 efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
 323                                struct efi_mem_desc *memory_map,
 324                                unsigned long *map_key,
 325                                unsigned long *descriptor_size,
 326                                uint32_t *descriptor_version)
 327 {
 328         ulong map_size = 0;
 329         int map_entries = 0;
 330         struct list_head *lhandle;
 331
 332         list_for_each(lhandle, &efi_mem)
 333                 map_entries++;
 334
 335         map_size = map_entries * sizeof(struct efi_mem_desc);
 336
 337         *memory_map_size = map_size;
 338
 339         if (descriptor_size)
 340                 *descriptor_size = sizeof(struct efi_mem_desc);
 341
 342         if (*memory_map_size < map_size)
 343                 return EFI_BUFFER_TOO_SMALL;
 344
 345         /* Copy list into array */
 346         if (memory_map) {
 347                 /* Return the list in ascending order */
 348                 memory_map = &memory_map[map_entries - 1];
 349                 list_for_each(lhandle, &efi_mem) {
 350                         struct efi_mem_list *lmem;
 351
 352                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 353                         *memory_map = lmem->desc;
 354                         memory_map--;
 355                 }
 356         }
 357
 358         return EFI_SUCCESS;
 359 }
 360
 361 int efi_memory_init(void)
 362 {
 363         unsigned long runtime_start, runtime_end, runtime_pages;
 364         unsigned long uboot_start, uboot_pages;
 365         unsigned long uboot_stack_size = 16 * 1024 * 1024;
 366         int i;
 367
 368         /* Add RAM */
 369         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
 370                 u64 ram_start = gd->bd->bi_dram[i].start;
 371                 u64 ram_size = gd->bd->bi_dram[i].size;
 372                 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 373                 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 374
 375                 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
 376                                    false);
 377         }
 378
 379         /* Add U-Boot */
 380         uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
 381         uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
 382         efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
 383
 384         /* Add Runtime Services */
 385         runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
 386         runtime_end = (ulong)&__efi_runtime_stop;
 387         runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 388         runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
 389         efi_add_memory_map(runtime_start, runtime_pages,
 390                            EFI_RUNTIME_SERVICES_CODE, false);
 391
 392 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 393         /* Request a 32bit 64MB bounce buffer region */
 394         uint64_t efi_bounce_buffer_addr = 0xffffffff;
 395
 396         if (efi_allocate_pages(1, EFI_LOADER_DATA,
 397                                (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
 398                                &efi_bounce_buffer_addr) != EFI_SUCCESS)
 399                 return -1;
 400
 401         efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
 402 #endif
 403
 404         return 0;
 405 }