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 debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__, 134 start, pages, memory_type, overlap_only_ram ? "yes" : "no"); 135 136 if (!pages) 137 return start; 138 139 newlist = calloc(1, sizeof(*newlist)); 140 newlist->desc.type = memory_type; 141 newlist->desc.physical_start = start; 142 newlist->desc.virtual_start = start; 143 newlist->desc.num_pages = pages; 144 145 switch (memory_type) { 146 case EFI_RUNTIME_SERVICES_CODE: 147 case EFI_RUNTIME_SERVICES_DATA: 148 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) | 149 (1ULL << EFI_MEMORY_RUNTIME_SHIFT); 150 break; 151 case EFI_MMAP_IO: 152 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT; 153 break; 154 default: 155 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT; 156 break; 157 } 158 159 /* Add our new map */ 160 do { 161 carve_again = false; 162 list_for_each(lhandle, &efi_mem) { 163 struct efi_mem_list *lmem; 164 int r; 165 166 lmem = list_entry(lhandle, struct efi_mem_list, link); 167 r = efi_mem_carve_out(lmem, &newlist->desc, 168 overlap_only_ram); 169 switch (r) { 170 case EFI_CARVE_OVERLAPS_NONRAM: 171 /* 172 * The user requested to only have RAM overlaps, 173 * but we hit a non-RAM region. Error out. 174 */ 175 return 0; 176 case EFI_CARVE_NO_OVERLAP: 177 /* Just ignore this list entry */ 178 break; 179 case EFI_CARVE_LOOP_AGAIN: 180 /* 181 * We split an entry, but need to loop through 182 * the list again to actually carve it. 183 */ 184 carve_again = true; 185 break; 186 default: 187 /* We carved a number of pages */ 188 carved_pages += r; 189 carve_again = true; 190 break; 191 } 192 193 if (carve_again) { 194 /* The list changed, we need to start over */ 195 break; 196 } 197 } 198 } while (carve_again); 199 200 if (overlap_only_ram && (carved_pages != pages)) { 201 /* 202 * The payload wanted to have RAM overlaps, but we overlapped 203 * with an unallocated region. Error out. 204 */ 205 return 0; 206 } 207 208 /* Add our new map */ 209 list_add_tail(&newlist->link, &efi_mem); 210 211 /* And make sure memory is listed in descending order */ 212 efi_mem_sort(); 213 214 return start; 215 } 216 217 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr) 218 { 219 struct list_head *lhandle; 220 221 list_for_each(lhandle, &efi_mem) { 222 struct efi_mem_list *lmem = list_entry(lhandle, 223 struct efi_mem_list, link); 224 struct efi_mem_desc *desc = &lmem->desc; 225 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT; 226 uint64_t desc_end = desc->physical_start + desc_len; 227 uint64_t curmax = min(max_addr, desc_end); 228 uint64_t ret = curmax - len; 229 230 /* We only take memory from free RAM */ 231 if (desc->type != EFI_CONVENTIONAL_MEMORY) 232 continue; 233 234 /* Out of bounds for max_addr */ 235 if ((ret + len) > max_addr) 236 continue; 237 238 /* Out of bounds for upper map limit */ 239 if ((ret + len) > desc_end) 240 continue; 241 242 /* Out of bounds for lower map limit */ 243 if (ret < desc->physical_start) 244 continue; 245 246 /* Return the highest address in this map within bounds */ 247 return ret; 248 } 249 250 return 0; 251 } 252 253 efi_status_t efi_allocate_pages(int type, int memory_type, 254 unsigned long pages, uint64_t *memory) 255 { 256 u64 len = pages << EFI_PAGE_SHIFT; 257 efi_status_t r = EFI_SUCCESS; 258 uint64_t addr; 259 260 switch (type) { 261 case 0: 262 /* Any page */ 263 addr = efi_find_free_memory(len, gd->start_addr_sp); 264 if (!addr) { 265 r = EFI_NOT_FOUND; 266 break; 267 } 268 break; 269 case 1: 270 /* Max address */ 271 addr = efi_find_free_memory(len, *memory); 272 if (!addr) { 273 r = EFI_NOT_FOUND; 274 break; 275 } 276 break; 277 case 2: 278 /* Exact address, reserve it. The addr is already in *memory. */ 279 addr = *memory; 280 break; 281 default: 282 /* UEFI doesn't specify other allocation types */ 283 r = EFI_INVALID_PARAMETER; 284 break; 285 } 286 287 if (r == EFI_SUCCESS) { 288 uint64_t ret; 289 290 /* Reserve that map in our memory maps */ 291 ret = efi_add_memory_map(addr, pages, memory_type, true); 292 if (ret == addr) { 293 *memory = addr; 294 } else { 295 /* Map would overlap, bail out */ 296 r = EFI_OUT_OF_RESOURCES; 297 } 298 } 299 300 return r; 301 } 302 303 void *efi_alloc(uint64_t len, int memory_type) 304 { 305 uint64_t ret = 0; 306 uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT; 307 efi_status_t r; 308 309 r = efi_allocate_pages(0, memory_type, pages, &ret); 310 if (r == EFI_SUCCESS) 311 return (void*)(uintptr_t)ret; 312 313 return NULL; 314 } 315 316 efi_status_t efi_free_pages(uint64_t memory, unsigned long pages) 317 { 318 /* We don't free, let's cross our fingers we have plenty RAM */ 319 return EFI_SUCCESS; 320 } 321 322 efi_status_t efi_get_memory_map(unsigned long *memory_map_size, 323 struct efi_mem_desc *memory_map, 324 unsigned long *map_key, 325 unsigned long *descriptor_size, 326 uint32_t *descriptor_version) 327 { 328 ulong map_size = 0; 329 int map_entries = 0; 330 struct list_head *lhandle; 331 332 list_for_each(lhandle, &efi_mem) 333 map_entries++; 334 335 map_size = map_entries * sizeof(struct efi_mem_desc); 336 337 *memory_map_size = map_size; 338 339 if (descriptor_size) 340 *descriptor_size = sizeof(struct efi_mem_desc); 341 342 if (*memory_map_size < map_size) 343 return EFI_BUFFER_TOO_SMALL; 344 345 /* Copy list into array */ 346 if (memory_map) { 347 /* Return the list in ascending order */ 348 memory_map = &memory_map[map_entries - 1]; 349 list_for_each(lhandle, &efi_mem) { 350 struct efi_mem_list *lmem; 351 352 lmem = list_entry(lhandle, struct efi_mem_list, link); 353 *memory_map = lmem->desc; 354 memory_map--; 355 } 356 } 357 358 return EFI_SUCCESS; 359 } 360 361 int efi_memory_init(void) 362 { 363 unsigned long runtime_start, runtime_end, runtime_pages; 364 unsigned long uboot_start, uboot_pages; 365 unsigned long uboot_stack_size = 16 * 1024 * 1024; 366 int i; 367 368 /* Add RAM */ 369 for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) { 370 u64 ram_start = gd->bd->bi_dram[i].start; 371 u64 ram_size = gd->bd->bi_dram[i].size; 372 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK; 373 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT; 374 375 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY, 376 false); 377 } 378 379 /* Add U-Boot */ 380 uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK; 381 uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT; 382 efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false); 383 384 /* Add Runtime Services */ 385 runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK; 386 runtime_end = (ulong)&__efi_runtime_stop; 387 runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK; 388 runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT; 389 efi_add_memory_map(runtime_start, runtime_pages, 390 EFI_RUNTIME_SERVICES_CODE, false); 391 392 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER 393 /* Request a 32bit 64MB bounce buffer region */ 394 uint64_t efi_bounce_buffer_addr = 0xffffffff; 395 396 if (efi_allocate_pages(1, EFI_LOADER_DATA, 397 (64 * 1024 * 1024) >> EFI_PAGE_SHIFT, 398 &efi_bounce_buffer_addr) != EFI_SUCCESS) 399 return -1; 400 401 efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr; 402 #endif 403 404 return 0; 405 } 406