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 EFI_CARVE_NO_OVERLAP if the regions don't overlap.
  66  * Returns EFI_CARVE_OVERLAPS_NONRAM if the carve and map overlap,
  67  *    and the map contains anything but free ram.
  68  *    (only when overlap_only_ram is true)
  69  * Returns EFI_CARVE_LOOP_AGAIN if the mapping list should be traversed
  70  *    again, as it has been altered
  71  * Returns the number of overlapping pages. The pages are removed from
  72  *     the mapping list.
  73  *
  74  * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
  75  * to readd the already carved out pages to the mapping.
  76  */
  77 static int efi_mem_carve_out(struct efi_mem_list *map,
  78                              struct efi_mem_desc *carve_desc,
  79                              bool overlap_only_ram)
  80 {
  81         struct efi_mem_list *newmap;
  82         struct efi_mem_desc *map_desc = &map->desc;
  83         uint64_t map_start = map_desc->physical_start;
  84         uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
  85         uint64_t carve_start = carve_desc->physical_start;
  86         uint64_t carve_end = carve_start +
  87                              (carve_desc->num_pages << EFI_PAGE_SHIFT);
  88
  89         /* check whether we're overlapping */
  90         if ((carve_end <= map_start) || (carve_start >= map_end))
  91                 return EFI_CARVE_NO_OVERLAP;
  92
  93         /* We're overlapping with non-RAM, warn the caller if desired */
  94         if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
  95                 return EFI_CARVE_OVERLAPS_NONRAM;
  96
  97         /* Sanitize carve_start and carve_end to lie within our bounds */
  98         carve_start = max(carve_start, map_start);
  99         carve_end = min(carve_end, map_end);
 100
 101         /* Carving at the beginning of our map? Just move it! */
 102         if (carve_start == map_start) {
 103                 if (map_end == carve_end) {
 104                         /* Full overlap, just remove map */
 105                         list_del(&map->link);
 106                 }
 107
 108                 map_desc->physical_start = carve_end;
 109                 map_desc->num_pages = (map_end - carve_end) >> EFI_PAGE_SHIFT;
 110                 return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
 111         }
 112
 113         /*
 114          * Overlapping maps, just split the list map at carve_start,
 115          * it will get moved or removed in the next iteration.
 116          *
 117          * [ map_desc |__carve_start__| newmap ]
 118          */
 119
 120         /* Create a new map from [ carve_start ... map_end ] */
 121         newmap = calloc(1, sizeof(*newmap));
 122         newmap->desc = map->desc;
 123         newmap->desc.physical_start = carve_start;
 124         newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
 125         list_add_tail(&newmap->link, &efi_mem);
 126
 127         /* Shrink the map to [ map_start ... carve_start ] */
 128         map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
 129
 130         return EFI_CARVE_LOOP_AGAIN;
 131 }
 132
 133 uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 134                             bool overlap_only_ram)
 135 {
 136         struct list_head *lhandle;
 137         struct efi_mem_list *newlist;
 138         bool carve_again;
 139         uint64_t carved_pages = 0;
 140
 141         debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
 142               start, pages, memory_type, overlap_only_ram ? "yes" : "no");
 143
 144         if (!pages)
 145                 return start;
 146
 147         newlist = calloc(1, sizeof(*newlist));
 148         newlist->desc.type = memory_type;
 149         newlist->desc.physical_start = start;
 150         newlist->desc.virtual_start = start;
 151         newlist->desc.num_pages = pages;
 152
 153         switch (memory_type) {
 154         case EFI_RUNTIME_SERVICES_CODE:
 155         case EFI_RUNTIME_SERVICES_DATA:
 156                 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
 157                                           (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
 158                 break;
 159         case EFI_MMAP_IO:
 160                 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
 161                 break;
 162         default:
 163                 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
 164                 break;
 165         }
 166
 167         /* Add our new map */
 168         do {
 169                 carve_again = false;
 170                 list_for_each(lhandle, &efi_mem) {
 171                         struct efi_mem_list *lmem;
 172                         int r;
 173
 174                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 175                         r = efi_mem_carve_out(lmem, &newlist->desc,
 176                                               overlap_only_ram);
 177                         switch (r) {
 178                         case EFI_CARVE_OVERLAPS_NONRAM:
 179                                 /*
 180                                  * The user requested to only have RAM overlaps,
 181                                  * but we hit a non-RAM region. Error out.
 182                                  */
 183                                 return 0;
 184                         case EFI_CARVE_NO_OVERLAP:
 185                                 /* Just ignore this list entry */
 186                                 break;
 187                         case EFI_CARVE_LOOP_AGAIN:
 188                                 /*
 189                                  * We split an entry, but need to loop through
 190                                  * the list again to actually carve it.
 191                                  */
 192                                 carve_again = true;
 193                                 break;
 194                         default:
 195                                 /* We carved a number of pages */
 196                                 carved_pages += r;
 197                                 carve_again = true;
 198                                 break;
 199                         }
 200
 201                         if (carve_again) {
 202                                 /* The list changed, we need to start over */
 203                                 break;
 204                         }
 205                 }
 206         } while (carve_again);
 207
 208         if (overlap_only_ram && (carved_pages != pages)) {
 209                 /*
 210                  * The payload wanted to have RAM overlaps, but we overlapped
 211                  * with an unallocated region. Error out.
 212                  */
 213                 return 0;
 214         }
 215
 216         /* Add our new map */
 217         list_add_tail(&newlist->link, &efi_mem);
 218
 219         /* And make sure memory is listed in descending order */
 220         efi_mem_sort();
 221
 222         return start;
 223 }
 224
 225 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
 226 {
 227         struct list_head *lhandle;
 228
 229         list_for_each(lhandle, &efi_mem) {
 230                 struct efi_mem_list *lmem = list_entry(lhandle,
 231                         struct efi_mem_list, link);
 232                 struct efi_mem_desc *desc = &lmem->desc;
 233                 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
 234                 uint64_t desc_end = desc->physical_start + desc_len;
 235                 uint64_t curmax = min(max_addr, desc_end);
 236                 uint64_t ret = curmax - len;
 237
 238                 /* We only take memory from free RAM */
 239                 if (desc->type != EFI_CONVENTIONAL_MEMORY)
 240                         continue;
 241
 242                 /* Out of bounds for max_addr */
 243                 if ((ret + len) > max_addr)
 244                         continue;
 245
 246                 /* Out of bounds for upper map limit */
 247                 if ((ret + len) > desc_end)
 248                         continue;
 249
 250                 /* Out of bounds for lower map limit */
 251                 if (ret < desc->physical_start)
 252                         continue;
 253
 254                 /* Return the highest address in this map within bounds */
 255                 return ret;
 256         }
 257
 258         return 0;
 259 }
 260
 261 efi_status_t efi_allocate_pages(int type, int memory_type,
 262                                 unsigned long pages, uint64_t *memory)
 263 {
 264         u64 len = pages << EFI_PAGE_SHIFT;
 265         efi_status_t r = EFI_SUCCESS;
 266         uint64_t addr;
 267
 268         switch (type) {
 269         case 0:
 270                 /* Any page */
 271                 addr = efi_find_free_memory(len, gd->start_addr_sp);
 272                 if (!addr) {
 273                         r = EFI_NOT_FOUND;
 274                         break;
 275                 }
 276                 break;
 277         case 1:
 278                 /* Max address */
 279                 addr = efi_find_free_memory(len, *memory);
 280                 if (!addr) {
 281                         r = EFI_NOT_FOUND;
 282                         break;
 283                 }
 284                 break;
 285         case 2:
 286                 /* Exact address, reserve it. The addr is already in *memory. */
 287                 addr = *memory;
 288                 break;
 289         default:
 290                 /* UEFI doesn't specify other allocation types */
 291                 r = EFI_INVALID_PARAMETER;
 292                 break;
 293         }
 294
 295         if (r == EFI_SUCCESS) {
 296                 uint64_t ret;
 297
 298                 /* Reserve that map in our memory maps */
 299                 ret = efi_add_memory_map(addr, pages, memory_type, true);
 300                 if (ret == addr) {
 301                         *memory = addr;
 302                 } else {
 303                         /* Map would overlap, bail out */
 304                         r = EFI_OUT_OF_RESOURCES;
 305                 }
 306         }
 307
 308         return r;
 309 }
 310
 311 void *efi_alloc(uint64_t len, int memory_type)
 312 {
 313         uint64_t ret = 0;
 314         uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 315         efi_status_t r;
 316
 317         r = efi_allocate_pages(0, memory_type, pages, &ret);
 318         if (r == EFI_SUCCESS)
 319                 return (void*)(uintptr_t)ret;
 320
 321         return NULL;
 322 }
 323
 324 efi_status_t efi_free_pages(uint64_t memory, unsigned long pages)
 325 {
 326         /* We don't free, let's cross our fingers we have plenty RAM */
 327         return EFI_SUCCESS;
 328 }
 329
 330 efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
 331                                struct efi_mem_desc *memory_map,
 332                                unsigned long *map_key,
 333                                unsigned long *descriptor_size,
 334                                uint32_t *descriptor_version)
 335 {
 336         ulong map_size = 0;
 337         int map_entries = 0;
 338         struct list_head *lhandle;
 339
 340         list_for_each(lhandle, &efi_mem)
 341                 map_entries++;
 342
 343         map_size = map_entries * sizeof(struct efi_mem_desc);
 344
 345         *memory_map_size = map_size;
 346
 347         if (descriptor_size)
 348                 *descriptor_size = sizeof(struct efi_mem_desc);
 349
 350         if (descriptor_version)
 351                 *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
 352
 353         if (*memory_map_size < map_size)
 354                 return EFI_BUFFER_TOO_SMALL;
 355
 356         /* Copy list into array */
 357         if (memory_map) {
 358                 /* Return the list in ascending order */
 359                 memory_map = &memory_map[map_entries - 1];
 360                 list_for_each(lhandle, &efi_mem) {
 361                         struct efi_mem_list *lmem;
 362
 363                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 364                         *memory_map = lmem->desc;
 365                         memory_map--;
 366                 }
 367         }
 368
 369         return EFI_SUCCESS;
 370 }
 371
 372 int efi_memory_init(void)
 373 {
 374         unsigned long runtime_start, runtime_end, runtime_pages;
 375         unsigned long uboot_start, uboot_pages;
 376         unsigned long uboot_stack_size = 16 * 1024 * 1024;
 377         int i;
 378
 379         /* Add RAM */
 380         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
 381                 u64 ram_start = gd->bd->bi_dram[i].start;
 382                 u64 ram_size = gd->bd->bi_dram[i].size;
 383                 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 384                 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 385
 386                 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
 387                                    false);
 388         }
 389
 390         /* Add U-Boot */
 391         uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
 392         uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
 393         efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
 394
 395         /* Add Runtime Services */
 396         runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
 397         runtime_end = (ulong)&__efi_runtime_stop;
 398         runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 399         runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
 400         efi_add_memory_map(runtime_start, runtime_pages,
 401                            EFI_RUNTIME_SERVICES_CODE, false);
 402
 403 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 404         /* Request a 32bit 64MB bounce buffer region */
 405         uint64_t efi_bounce_buffer_addr = 0xffffffff;
 406
 407         if (efi_allocate_pages(1, EFI_LOADER_DATA,
 408                                (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
 409                                &efi_bounce_buffer_addr) != EFI_SUCCESS)
 410                 return -1;
 411
 412         efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
 413 #endif
 414
 415         return 0;
 416 }