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