1 // SPDX-License-Identifier: GPL-2.0+
3 * EFI application memory management
5 * Copyright (c) 2016 Alexander Graf
9 #include <efi_loader.h>
14 #include <linux/list_sort.h>
16 DECLARE_GLOBAL_DATA_PTR;
18 efi_uintn_t efi_memory_map_key;
21 struct list_head link;
22 struct efi_mem_desc desc;
25 #define EFI_CARVE_NO_OVERLAP -1
26 #define EFI_CARVE_LOOP_AGAIN -2
27 #define EFI_CARVE_OVERLAPS_NONRAM -3
29 /* This list contains all memory map items */
32 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
33 void *efi_bounce_buffer;
37 * U-Boot services each EFI AllocatePool request as a separate
38 * (multiple) page allocation. We have to track the number of pages
39 * to be able to free the correct amount later.
40 * EFI requires 8 byte alignment for pool allocations, so we can
41 * prepend each allocation with an 64 bit header tracking the
42 * allocation size, and hand out the remainder to the caller.
44 struct efi_pool_allocation {
46 char data[] __aligned(ARCH_DMA_MINALIGN);
50 * Sorts the memory list from highest address to lowest address
52 * When allocating memory we should always start from the highest
53 * address chunk, so sort the memory list such that the first list
54 * iterator gets the highest address and goes lower from there.
56 static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
58 struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
59 struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);
61 if (mema->desc.physical_start == memb->desc.physical_start)
63 else if (mema->desc.physical_start < memb->desc.physical_start)
69 static void efi_mem_sort(void)
71 list_sort(NULL, &efi_mem, efi_mem_cmp);
74 /** efi_mem_carve_out - unmap memory region
77 * @carve_desc: memory region to unmap
78 * @overlap_only_ram: the carved out region may only overlap RAM
79 * Return Value: the number of overlapping pages which have been
80 * removed from the map,
81 * EFI_CARVE_NO_OVERLAP, if the regions don't overlap,
82 * EFI_CARVE_OVERLAPS_NONRAM, if the carve and map overlap,
83 * and the map contains anything but free ram
84 * (only when overlap_only_ram is true),
85 * EFI_CARVE_LOOP_AGAIN, if the mapping list should be
86 * traversed again, as it has been altered.
88 * Unmaps all memory occupied by the carve_desc region from the list entry
91 * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
92 * to re-add the already carved out pages to the mapping.
94 static s64 efi_mem_carve_out(struct efi_mem_list *map,
95 struct efi_mem_desc *carve_desc,
96 bool overlap_only_ram)
98 struct efi_mem_list *newmap;
99 struct efi_mem_desc *map_desc = &map->desc;
100 uint64_t map_start = map_desc->physical_start;
101 uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
102 uint64_t carve_start = carve_desc->physical_start;
103 uint64_t carve_end = carve_start +
104 (carve_desc->num_pages << EFI_PAGE_SHIFT);
106 /* check whether we're overlapping */
107 if ((carve_end <= map_start) || (carve_start >= map_end))
108 return EFI_CARVE_NO_OVERLAP;
110 /* We're overlapping with non-RAM, warn the caller if desired */
111 if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
112 return EFI_CARVE_OVERLAPS_NONRAM;
114 /* Sanitize carve_start and carve_end to lie within our bounds */
115 carve_start = max(carve_start, map_start);
116 carve_end = min(carve_end, map_end);
118 /* Carving at the beginning of our map? Just move it! */
119 if (carve_start == map_start) {
120 if (map_end == carve_end) {
121 /* Full overlap, just remove map */
122 list_del(&map->link);
125 map->desc.physical_start = carve_end;
126 map->desc.num_pages = (map_end - carve_end)
130 return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
134 * Overlapping maps, just split the list map at carve_start,
135 * it will get moved or removed in the next iteration.
137 * [ map_desc |__carve_start__| newmap ]
140 /* Create a new map from [ carve_start ... map_end ] */
141 newmap = calloc(1, sizeof(*newmap));
142 newmap->desc = map->desc;
143 newmap->desc.physical_start = carve_start;
144 newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
145 /* Insert before current entry (descending address order) */
146 list_add_tail(&newmap->link, &map->link);
148 /* Shrink the map to [ map_start ... carve_start ] */
149 map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
151 return EFI_CARVE_LOOP_AGAIN;
154 uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
155 bool overlap_only_ram)
157 struct list_head *lhandle;
158 struct efi_mem_list *newlist;
160 uint64_t carved_pages = 0;
162 debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
163 start, pages, memory_type, overlap_only_ram ? "yes" : "no");
165 if (memory_type >= EFI_MAX_MEMORY_TYPE)
166 return EFI_INVALID_PARAMETER;
171 ++efi_memory_map_key;
172 newlist = calloc(1, sizeof(*newlist));
173 newlist->desc.type = memory_type;
174 newlist->desc.physical_start = start;
175 newlist->desc.virtual_start = start;
176 newlist->desc.num_pages = pages;
178 switch (memory_type) {
179 case EFI_RUNTIME_SERVICES_CODE:
180 case EFI_RUNTIME_SERVICES_DATA:
181 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
182 (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
185 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
188 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
192 /* Add our new map */
195 list_for_each(lhandle, &efi_mem) {
196 struct efi_mem_list *lmem;
199 lmem = list_entry(lhandle, struct efi_mem_list, link);
200 r = efi_mem_carve_out(lmem, &newlist->desc,
203 case EFI_CARVE_OVERLAPS_NONRAM:
205 * The user requested to only have RAM overlaps,
206 * but we hit a non-RAM region. Error out.
209 case EFI_CARVE_NO_OVERLAP:
210 /* Just ignore this list entry */
212 case EFI_CARVE_LOOP_AGAIN:
214 * We split an entry, but need to loop through
215 * the list again to actually carve it.
220 /* We carved a number of pages */
227 /* The list changed, we need to start over */
231 } while (carve_again);
233 if (overlap_only_ram && (carved_pages != pages)) {
235 * The payload wanted to have RAM overlaps, but we overlapped
236 * with an unallocated region. Error out.
241 /* Add our new map */
242 list_add_tail(&newlist->link, &efi_mem);
244 /* And make sure memory is listed in descending order */
250 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
252 struct list_head *lhandle;
254 list_for_each(lhandle, &efi_mem) {
255 struct efi_mem_list *lmem = list_entry(lhandle,
256 struct efi_mem_list, link);
257 struct efi_mem_desc *desc = &lmem->desc;
258 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
259 uint64_t desc_end = desc->physical_start + desc_len;
260 uint64_t curmax = min(max_addr, desc_end);
261 uint64_t ret = curmax - len;
263 /* We only take memory from free RAM */
264 if (desc->type != EFI_CONVENTIONAL_MEMORY)
267 /* Out of bounds for max_addr */
268 if ((ret + len) > max_addr)
271 /* Out of bounds for upper map limit */
272 if ((ret + len) > desc_end)
275 /* Out of bounds for lower map limit */
276 if (ret < desc->physical_start)
279 /* Return the highest address in this map within bounds */
287 * Allocate memory pages.
289 * @type type of allocation to be performed
290 * @memory_type usage type of the allocated memory
291 * @pages number of pages to be allocated
292 * @memory allocated memory
293 * @return status code
295 efi_status_t efi_allocate_pages(int type, int memory_type,
296 efi_uintn_t pages, uint64_t *memory)
298 u64 len = pages << EFI_PAGE_SHIFT;
299 efi_status_t r = EFI_SUCCESS;
303 return EFI_INVALID_PARAMETER;
306 case EFI_ALLOCATE_ANY_PAGES:
308 addr = efi_find_free_memory(len, gd->start_addr_sp);
314 case EFI_ALLOCATE_MAX_ADDRESS:
316 addr = efi_find_free_memory(len, *memory);
322 case EFI_ALLOCATE_ADDRESS:
323 /* Exact address, reserve it. The addr is already in *memory. */
327 /* UEFI doesn't specify other allocation types */
328 r = EFI_INVALID_PARAMETER;
332 if (r == EFI_SUCCESS) {
335 /* Reserve that map in our memory maps */
336 ret = efi_add_memory_map(addr, pages, memory_type, true);
338 *memory = (uintptr_t)map_sysmem(addr, len);
340 /* Map would overlap, bail out */
341 r = EFI_OUT_OF_RESOURCES;
348 void *efi_alloc(uint64_t len, int memory_type)
351 uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
354 r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages,
356 if (r == EFI_SUCCESS)
357 return (void*)(uintptr_t)ret;
365 * @memory start of the memory area to be freed
366 * @pages number of pages to be freed
367 * @return status code
369 efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
372 uint64_t addr = map_to_sysmem((void *)(uintptr_t)memory);
374 r = efi_add_memory_map(addr, pages, EFI_CONVENTIONAL_MEMORY, false);
375 /* Merging of adjacent free regions is missing */
380 return EFI_NOT_FOUND;
384 * Allocate memory from pool.
386 * @pool_type type of the pool from which memory is to be allocated
387 * @size number of bytes to be allocated
388 * @buffer allocated memory
389 * @return status code
391 efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
394 struct efi_pool_allocation *alloc;
395 u64 num_pages = (size + sizeof(struct efi_pool_allocation) +
396 EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
399 return EFI_INVALID_PARAMETER;
406 r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, pool_type, num_pages,
409 if (r == EFI_SUCCESS) {
410 alloc->num_pages = num_pages;
411 *buffer = alloc->data;
418 * Free memory from pool.
420 * @buffer start of memory to be freed
421 * @return status code
423 efi_status_t efi_free_pool(void *buffer)
426 struct efi_pool_allocation *alloc;
429 return EFI_INVALID_PARAMETER;
431 alloc = container_of(buffer, struct efi_pool_allocation, data);
432 /* Sanity check, was the supplied address returned by allocate_pool */
433 assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);
435 r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);
441 * Get map describing memory usage.
443 * @memory_map_size on entry the size, in bytes, of the memory map buffer,
444 * on exit the size of the copied memory map
445 * @memory_map buffer to which the memory map is written
446 * @map_key key for the memory map
447 * @descriptor_size size of an individual memory descriptor
448 * @descriptor_version version number of the memory descriptor structure
449 * @return status code
451 efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
452 struct efi_mem_desc *memory_map,
453 efi_uintn_t *map_key,
454 efi_uintn_t *descriptor_size,
455 uint32_t *descriptor_version)
457 efi_uintn_t map_size = 0;
459 struct list_head *lhandle;
460 efi_uintn_t provided_map_size;
462 if (!memory_map_size)
463 return EFI_INVALID_PARAMETER;
465 provided_map_size = *memory_map_size;
467 list_for_each(lhandle, &efi_mem)
470 map_size = map_entries * sizeof(struct efi_mem_desc);
472 *memory_map_size = map_size;
474 if (provided_map_size < map_size)
475 return EFI_BUFFER_TOO_SMALL;
478 return EFI_INVALID_PARAMETER;
481 *descriptor_size = sizeof(struct efi_mem_desc);
483 if (descriptor_version)
484 *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
486 /* Copy list into array */
487 /* Return the list in ascending order */
488 memory_map = &memory_map[map_entries - 1];
489 list_for_each(lhandle, &efi_mem) {
490 struct efi_mem_list *lmem;
492 lmem = list_entry(lhandle, struct efi_mem_list, link);
493 *memory_map = lmem->desc;
498 *map_key = efi_memory_map_key;
503 __weak void efi_add_known_memory(void)
508 for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
509 u64 ram_start = gd->bd->bi_dram[i].start;
510 u64 ram_size = gd->bd->bi_dram[i].size;
511 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
512 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
514 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
519 /* Add memory regions for U-Boot's memory and for the runtime services code */
520 static void add_u_boot_and_runtime(void)
522 unsigned long runtime_start, runtime_end, runtime_pages;
523 unsigned long uboot_start, uboot_pages;
524 unsigned long uboot_stack_size = 16 * 1024 * 1024;
527 uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
528 uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
529 efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
531 /* Add Runtime Services */
532 runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
533 runtime_end = (ulong)&__efi_runtime_stop;
534 runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
535 runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
536 efi_add_memory_map(runtime_start, runtime_pages,
537 EFI_RUNTIME_SERVICES_CODE, false);
540 int efi_memory_init(void)
542 efi_add_known_memory();
544 if (!IS_ENABLED(CONFIG_SANDBOX))
545 add_u_boot_and_runtime();
547 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
548 /* Request a 32bit 64MB bounce buffer region */
549 uint64_t efi_bounce_buffer_addr = 0xffffffff;
551 if (efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, EFI_LOADER_DATA,
552 (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
553 &efi_bounce_buffer_addr) != EFI_SUCCESS)
556 efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;