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