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 } 417