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         if (!pages)
 134                 return start;
 135
 136         newlist = calloc(1, sizeof(*newlist));
 137         newlist->desc.type = memory_type;
 138         newlist->desc.physical_start = start;
 139         newlist->desc.virtual_start = start;
 140         newlist->desc.num_pages = pages;
 141
 142         switch (memory_type) {
 143         case EFI_RUNTIME_SERVICES_CODE:
 144         case EFI_RUNTIME_SERVICES_DATA:
 145                 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
 146                                           (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
 147                 break;
 148         case EFI_MMAP_IO:
 149                 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
 150                 break;
 151         default:
 152                 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
 153                 break;
 154         }
 155
 156         /* Add our new map */
 157         do {
 158                 carve_again = false;
 159                 list_for_each(lhandle, &efi_mem) {
 160                         struct efi_mem_list *lmem;
 161                         int r;
 162
 163                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 164                         r = efi_mem_carve_out(lmem, &newlist->desc,
 165                                               overlap_only_ram);
 166                         switch (r) {
 167                         case EFI_CARVE_OVERLAPS_NONRAM:
 168                                 /*
 169                                  * The user requested to only have RAM overlaps,
 170                                  * but we hit a non-RAM region. Error out.
 171                                  */
 172                                 return 0;
 173                         case EFI_CARVE_NO_OVERLAP:
 174                                 /* Just ignore this list entry */
 175                                 break;
 176                         case EFI_CARVE_LOOP_AGAIN:
 177                                 /*
 178                                  * We split an entry, but need to loop through
 179                                  * the list again to actually carve it.
 180                                  */
 181                                 carve_again = true;
 182                                 break;
 183                         default:
 184                                 /* We carved a number of pages */
 185                                 carved_pages += r;
 186                                 carve_again = true;
 187                                 break;
 188                         }
 189
 190                         if (carve_again) {
 191                                 /* The list changed, we need to start over */
 192                                 break;
 193                         }
 194                 }
 195         } while (carve_again);
 196
 197         if (overlap_only_ram && (carved_pages != pages)) {
 198                 /*
 199                  * The payload wanted to have RAM overlaps, but we overlapped
 200                  * with an unallocated region. Error out.
 201                  */
 202                 return 0;
 203         }
 204
 205         /* Add our new map */
 206         list_add_tail(&newlist->link, &efi_mem);
 207
 208         /* And make sure memory is listed in descending order */
 209         efi_mem_sort();
 210
 211         return start;
 212 }
 213
 214 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
 215 {
 216         struct list_head *lhandle;
 217
 218         list_for_each(lhandle, &efi_mem) {
 219                 struct efi_mem_list *lmem = list_entry(lhandle,
 220                         struct efi_mem_list, link);
 221                 struct efi_mem_desc *desc = &lmem->desc;
 222                 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
 223                 uint64_t desc_end = desc->physical_start + desc_len;
 224                 uint64_t curmax = min(max_addr, desc_end);
 225                 uint64_t ret = curmax - len;
 226
 227                 /* We only take memory from free RAM */
 228                 if (desc->type != EFI_CONVENTIONAL_MEMORY)
 229                         continue;
 230
 231                 /* Out of bounds for max_addr */
 232                 if ((ret + len) > max_addr)
 233                         continue;
 234
 235                 /* Out of bounds for upper map limit */
 236                 if ((ret + len) > desc_end)
 237                         continue;
 238
 239                 /* Out of bounds for lower map limit */
 240                 if (ret < desc->physical_start)
 241                         continue;
 242
 243                 /* Return the highest address in this map within bounds */
 244                 return ret;
 245         }
 246
 247         return 0;
 248 }
 249
 250 efi_status_t efi_allocate_pages(int type, int memory_type,
 251                                 unsigned long pages, uint64_t *memory)
 252 {
 253         u64 len = pages << EFI_PAGE_SHIFT;
 254         efi_status_t r = EFI_SUCCESS;
 255         uint64_t addr;
 256
 257         switch (type) {
 258         case 0:
 259                 /* Any page */
 260                 addr = efi_find_free_memory(len, gd->start_addr_sp);
 261                 if (!addr) {
 262                         r = EFI_NOT_FOUND;
 263                         break;
 264                 }
 265                 break;
 266         case 1:
 267                 /* Max address */
 268                 addr = efi_find_free_memory(len, *memory);
 269                 if (!addr) {
 270                         r = EFI_NOT_FOUND;
 271                         break;
 272                 }
 273                 break;
 274         case 2:
 275                 /* Exact address, reserve it. The addr is already in *memory. */
 276                 addr = *memory;
 277                 break;
 278         default:
 279                 /* UEFI doesn't specify other allocation types */
 280                 r = EFI_INVALID_PARAMETER;
 281                 break;
 282         }
 283
 284         if (r == EFI_SUCCESS) {
 285                 uint64_t ret;
 286
 287                 /* Reserve that map in our memory maps */
 288                 ret = efi_add_memory_map(addr, pages, memory_type, true);
 289                 if (ret == addr) {
 290                         *memory = addr;
 291                 } else {
 292                         /* Map would overlap, bail out */
 293                         r = EFI_OUT_OF_RESOURCES;
 294                 }
 295         }
 296
 297         return r;
 298 }
 299
 300 void *efi_alloc(uint64_t len, int memory_type)
 301 {
 302         uint64_t ret = 0;
 303         uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 304         efi_status_t r;
 305
 306         r = efi_allocate_pages(0, memory_type, pages, &ret);
 307         if (r == EFI_SUCCESS)
 308                 return (void*)(uintptr_t)ret;
 309
 310         return NULL;
 311 }
 312
 313 efi_status_t efi_free_pages(uint64_t memory, unsigned long pages)
 314 {
 315         /* We don't free, let's cross our fingers we have plenty RAM */
 316         return EFI_SUCCESS;
 317 }
 318
 319 efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
 320                                struct efi_mem_desc *memory_map,
 321                                unsigned long *map_key,
 322                                unsigned long *descriptor_size,
 323                                uint32_t *descriptor_version)
 324 {
 325         ulong map_size = 0;
 326         int map_entries = 0;
 327         struct list_head *lhandle;
 328
 329         list_for_each(lhandle, &efi_mem)
 330                 map_entries++;
 331
 332         map_size = map_entries * sizeof(struct efi_mem_desc);
 333
 334         *memory_map_size = map_size;
 335
 336         if (descriptor_size)
 337                 *descriptor_size = sizeof(struct efi_mem_desc);
 338
 339         if (*memory_map_size < map_size)
 340                 return EFI_BUFFER_TOO_SMALL;
 341
 342         /* Copy list into array */
 343         if (memory_map) {
 344                 /* Return the list in ascending order */
 345                 memory_map = &memory_map[map_entries - 1];
 346                 list_for_each(lhandle, &efi_mem) {
 347                         struct efi_mem_list *lmem;
 348
 349                         lmem = list_entry(lhandle, struct efi_mem_list, link);
 350                         *memory_map = lmem->desc;
 351                         memory_map--;
 352                 }
 353         }
 354
 355         return EFI_SUCCESS;
 356 }
 357
 358 int efi_memory_init(void)
 359 {
 360         unsigned long runtime_start, runtime_end, runtime_pages;
 361         unsigned long uboot_start, uboot_pages;
 362         unsigned long uboot_stack_size = 16 * 1024 * 1024;
 363         int i;
 364
 365         /* Add RAM */
 366         for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
 367                 u64 ram_start = gd->bd->bi_dram[i].start;
 368                 u64 ram_size = gd->bd->bi_dram[i].size;
 369                 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 370                 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
 371
 372                 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
 373                                    false);
 374         }
 375
 376         /* Add U-Boot */
 377         uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
 378         uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
 379         efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
 380
 381         /* Add Runtime Services */
 382         runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
 383         runtime_end = (ulong)&__efi_runtime_stop;
 384         runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
 385         runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
 386         efi_add_memory_map(runtime_start, runtime_pages,
 387                            EFI_RUNTIME_SERVICES_CODE, false);
 388
 389 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 390         /* Request a 32bit 64MB bounce buffer region */
 391         uint64_t efi_bounce_buffer_addr = 0xffffffff;
 392
 393         if (efi_allocate_pages(1, EFI_LOADER_DATA,
 394                                (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
 395                                &efi_bounce_buffer_addr) != EFI_SUCCESS)
 396                 return -1;
 397
 398         efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
 399 #endif
 400
 401         return 0;
 402 }