1 // SPDX-License-Identifier: GPL-2.0+
3 * EFI application memory management
5 * Copyright (c) 2016 Alexander Graf
9 #include <efi_loader.h>
13 #include <linux/list_sort.h>
14 #include <linux/sizes.h>
16 DECLARE_GLOBAL_DATA_PTR;
18 /* Magic number identifying memory allocated from pool */
19 #define EFI_ALLOC_POOL_MAGIC 0x1fe67ddf6491caa2
21 efi_uintn_t efi_memory_map_key;
24 struct list_head link;
25 struct efi_mem_desc desc;
28 #define EFI_CARVE_NO_OVERLAP -1
29 #define EFI_CARVE_LOOP_AGAIN -2
30 #define EFI_CARVE_OVERLAPS_NONRAM -3
32 /* This list contains all memory map items */
35 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
36 void *efi_bounce_buffer;
40 * efi_pool_allocation - memory block allocated from pool
42 * @num_pages: number of pages allocated
45 * U-Boot services each EFI AllocatePool request as a separate
46 * (multiple) page allocation. We have to track the number of pages
47 * to be able to free the correct amount later.
48 * EFI requires 8 byte alignment for pool allocations, so we can
49 * prepend each allocation with an 64 bit header tracking the
50 * allocation size, and hand out the remainder to the caller.
52 struct efi_pool_allocation {
55 char data[] __aligned(ARCH_DMA_MINALIGN);
59 * checksum() - calculate checksum for memory allocated from pool
61 * @alloc: allocation header
62 * Return: checksum, always non-zero
64 static u64 checksum(struct efi_pool_allocation *alloc)
66 u64 addr = (uintptr_t)alloc;
67 u64 ret = (addr >> 32) ^ (addr << 32) ^ alloc->num_pages ^
75 * Sorts the memory list from highest address to lowest address
77 * When allocating memory we should always start from the highest
78 * address chunk, so sort the memory list such that the first list
79 * iterator gets the highest address and goes lower from there.
81 static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
83 struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
84 struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);
86 if (mema->desc.physical_start == memb->desc.physical_start)
88 else if (mema->desc.physical_start < memb->desc.physical_start)
94 static uint64_t desc_get_end(struct efi_mem_desc *desc)
96 return desc->physical_start + (desc->num_pages << EFI_PAGE_SHIFT);
99 static void efi_mem_sort(void)
101 struct list_head *lhandle;
102 struct efi_mem_list *prevmem = NULL;
103 bool merge_again = true;
105 list_sort(NULL, &efi_mem, efi_mem_cmp);
107 /* Now merge entries that can be merged */
108 while (merge_again) {
110 list_for_each(lhandle, &efi_mem) {
111 struct efi_mem_list *lmem;
112 struct efi_mem_desc *prev = &prevmem->desc;
113 struct efi_mem_desc *cur;
116 lmem = list_entry(lhandle, struct efi_mem_list, link);
124 if ((desc_get_end(cur) == prev->physical_start) &&
125 (prev->type == cur->type) &&
126 (prev->attribute == cur->attribute)) {
127 /* There is an existing map before, reuse it */
128 pages = cur->num_pages;
129 prev->num_pages += pages;
130 prev->physical_start -= pages << EFI_PAGE_SHIFT;
131 prev->virtual_start -= pages << EFI_PAGE_SHIFT;
132 list_del(&lmem->link);
144 /** efi_mem_carve_out - unmap memory region
147 * @carve_desc: memory region to unmap
148 * @overlap_only_ram: the carved out region may only overlap RAM
149 * Return Value: the number of overlapping pages which have been
150 * removed from the map,
151 * EFI_CARVE_NO_OVERLAP, if the regions don't overlap,
152 * EFI_CARVE_OVERLAPS_NONRAM, if the carve and map overlap,
153 * and the map contains anything but free ram
154 * (only when overlap_only_ram is true),
155 * EFI_CARVE_LOOP_AGAIN, if the mapping list should be
156 * traversed again, as it has been altered.
158 * Unmaps all memory occupied by the carve_desc region from the list entry
161 * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
162 * to re-add the already carved out pages to the mapping.
164 static s64 efi_mem_carve_out(struct efi_mem_list *map,
165 struct efi_mem_desc *carve_desc,
166 bool overlap_only_ram)
168 struct efi_mem_list *newmap;
169 struct efi_mem_desc *map_desc = &map->desc;
170 uint64_t map_start = map_desc->physical_start;
171 uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
172 uint64_t carve_start = carve_desc->physical_start;
173 uint64_t carve_end = carve_start +
174 (carve_desc->num_pages << EFI_PAGE_SHIFT);
176 /* check whether we're overlapping */
177 if ((carve_end <= map_start) || (carve_start >= map_end))
178 return EFI_CARVE_NO_OVERLAP;
180 /* We're overlapping with non-RAM, warn the caller if desired */
181 if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
182 return EFI_CARVE_OVERLAPS_NONRAM;
184 /* Sanitize carve_start and carve_end to lie within our bounds */
185 carve_start = max(carve_start, map_start);
186 carve_end = min(carve_end, map_end);
188 /* Carving at the beginning of our map? Just move it! */
189 if (carve_start == map_start) {
190 if (map_end == carve_end) {
191 /* Full overlap, just remove map */
192 list_del(&map->link);
195 map->desc.physical_start = carve_end;
196 map->desc.virtual_start = carve_end;
197 map->desc.num_pages = (map_end - carve_end)
201 return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
205 * Overlapping maps, just split the list map at carve_start,
206 * it will get moved or removed in the next iteration.
208 * [ map_desc |__carve_start__| newmap ]
211 /* Create a new map from [ carve_start ... map_end ] */
212 newmap = calloc(1, sizeof(*newmap));
213 newmap->desc = map->desc;
214 newmap->desc.physical_start = carve_start;
215 newmap->desc.virtual_start = carve_start;
216 newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
217 /* Insert before current entry (descending address order) */
218 list_add_tail(&newmap->link, &map->link);
220 /* Shrink the map to [ map_start ... carve_start ] */
221 map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
223 return EFI_CARVE_LOOP_AGAIN;
226 uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
227 bool overlap_only_ram)
229 struct list_head *lhandle;
230 struct efi_mem_list *newlist;
232 uint64_t carved_pages = 0;
233 struct efi_event *evt;
235 EFI_PRINT("%s: 0x%llx 0x%llx %d %s\n", __func__,
236 start, pages, memory_type, overlap_only_ram ? "yes" : "no");
238 if (memory_type >= EFI_MAX_MEMORY_TYPE)
239 return EFI_INVALID_PARAMETER;
244 ++efi_memory_map_key;
245 newlist = calloc(1, sizeof(*newlist));
246 newlist->desc.type = memory_type;
247 newlist->desc.physical_start = start;
248 newlist->desc.virtual_start = start;
249 newlist->desc.num_pages = pages;
251 switch (memory_type) {
252 case EFI_RUNTIME_SERVICES_CODE:
253 case EFI_RUNTIME_SERVICES_DATA:
254 newlist->desc.attribute = EFI_MEMORY_WB | EFI_MEMORY_RUNTIME;
257 newlist->desc.attribute = EFI_MEMORY_RUNTIME;
260 newlist->desc.attribute = EFI_MEMORY_WB;
264 /* Add our new map */
267 list_for_each(lhandle, &efi_mem) {
268 struct efi_mem_list *lmem;
271 lmem = list_entry(lhandle, struct efi_mem_list, link);
272 r = efi_mem_carve_out(lmem, &newlist->desc,
275 case EFI_CARVE_OVERLAPS_NONRAM:
277 * The user requested to only have RAM overlaps,
278 * but we hit a non-RAM region. Error out.
281 case EFI_CARVE_NO_OVERLAP:
282 /* Just ignore this list entry */
284 case EFI_CARVE_LOOP_AGAIN:
286 * We split an entry, but need to loop through
287 * the list again to actually carve it.
292 /* We carved a number of pages */
299 /* The list changed, we need to start over */
303 } while (carve_again);
305 if (overlap_only_ram && (carved_pages != pages)) {
307 * The payload wanted to have RAM overlaps, but we overlapped
308 * with an unallocated region. Error out.
313 /* Add our new map */
314 list_add_tail(&newlist->link, &efi_mem);
316 /* And make sure memory is listed in descending order */
319 /* Notify that the memory map was changed */
320 list_for_each_entry(evt, &efi_events, link) {
323 &efi_guid_event_group_memory_map_change)) {
324 efi_signal_event(evt, false);
333 * efi_check_allocated() - validate address to be freed
335 * Check that the address is within allocated memory:
337 * * The address cannot be NULL.
338 * * The address must be in a range of the memory map.
339 * * The address may not point to EFI_CONVENTIONAL_MEMORY.
341 * Page alignment is not checked as this is not a requirement of
344 * @addr: address of page to be freed
345 * @must_be_allocated: return success if the page is allocated
346 * Return: status code
348 static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated)
350 struct efi_mem_list *item;
353 return EFI_INVALID_PARAMETER;
354 list_for_each_entry(item, &efi_mem, link) {
355 u64 start = item->desc.physical_start;
356 u64 end = start + (item->desc.num_pages << EFI_PAGE_SHIFT);
358 if (addr >= start && addr < end) {
359 if (must_be_allocated ^
360 (item->desc.type == EFI_CONVENTIONAL_MEMORY))
363 return EFI_NOT_FOUND;
367 return EFI_NOT_FOUND;
370 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
372 struct list_head *lhandle;
375 * Prealign input max address, so we simplify our matching
376 * logic below and can just reuse it as return pointer.
378 max_addr &= ~EFI_PAGE_MASK;
380 list_for_each(lhandle, &efi_mem) {
381 struct efi_mem_list *lmem = list_entry(lhandle,
382 struct efi_mem_list, link);
383 struct efi_mem_desc *desc = &lmem->desc;
384 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
385 uint64_t desc_end = desc->physical_start + desc_len;
386 uint64_t curmax = min(max_addr, desc_end);
387 uint64_t ret = curmax - len;
389 /* We only take memory from free RAM */
390 if (desc->type != EFI_CONVENTIONAL_MEMORY)
393 /* Out of bounds for max_addr */
394 if ((ret + len) > max_addr)
397 /* Out of bounds for upper map limit */
398 if ((ret + len) > desc_end)
401 /* Out of bounds for lower map limit */
402 if (ret < desc->physical_start)
405 /* Return the highest address in this map within bounds */
413 * Allocate memory pages.
415 * @type type of allocation to be performed
416 * @memory_type usage type of the allocated memory
417 * @pages number of pages to be allocated
418 * @memory allocated memory
419 * @return status code
421 efi_status_t efi_allocate_pages(int type, int memory_type,
422 efi_uintn_t pages, uint64_t *memory)
424 u64 len = pages << EFI_PAGE_SHIFT;
428 /* Check import parameters */
429 if (memory_type >= EFI_PERSISTENT_MEMORY_TYPE &&
430 memory_type <= 0x6FFFFFFF)
431 return EFI_INVALID_PARAMETER;
433 return EFI_INVALID_PARAMETER;
436 case EFI_ALLOCATE_ANY_PAGES:
438 addr = efi_find_free_memory(len, -1ULL);
440 return EFI_OUT_OF_RESOURCES;
442 case EFI_ALLOCATE_MAX_ADDRESS:
444 addr = efi_find_free_memory(len, *memory);
446 return EFI_OUT_OF_RESOURCES;
448 case EFI_ALLOCATE_ADDRESS:
449 /* Exact address, reserve it. The addr is already in *memory. */
450 ret = efi_check_allocated(*memory, false);
451 if (ret != EFI_SUCCESS)
452 return EFI_NOT_FOUND;
456 /* UEFI doesn't specify other allocation types */
457 return EFI_INVALID_PARAMETER;
460 /* Reserve that map in our memory maps */
461 if (efi_add_memory_map(addr, pages, memory_type, true) != addr)
462 /* Map would overlap, bail out */
463 return EFI_OUT_OF_RESOURCES;
470 void *efi_alloc(uint64_t len, int memory_type)
473 uint64_t pages = efi_size_in_pages(len);
476 r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages,
478 if (r == EFI_SUCCESS)
479 return (void*)(uintptr_t)ret;
485 * efi_free_pages() - free memory pages
487 * @memory: start of the memory area to be freed
488 * @pages: number of pages to be freed
489 * Return: status code
491 efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
496 ret = efi_check_allocated(memory, true);
497 if (ret != EFI_SUCCESS)
501 if (!memory || (memory & EFI_PAGE_MASK) || !pages) {
502 printf("%s: illegal free 0x%llx, 0x%zx\n", __func__,
504 return EFI_INVALID_PARAMETER;
507 r = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
508 /* Merging of adjacent free regions is missing */
513 return EFI_NOT_FOUND;
517 * efi_allocate_pool - allocate memory from pool
519 * @pool_type: type of the pool from which memory is to be allocated
520 * @size: number of bytes to be allocated
521 * @buffer: allocated memory
522 * Return: status code
524 efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
528 struct efi_pool_allocation *alloc;
529 u64 num_pages = efi_size_in_pages(size +
530 sizeof(struct efi_pool_allocation));
533 return EFI_INVALID_PARAMETER;
540 r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, pool_type, num_pages,
542 if (r == EFI_SUCCESS) {
543 alloc = (struct efi_pool_allocation *)(uintptr_t)addr;
544 alloc->num_pages = num_pages;
545 alloc->checksum = checksum(alloc);
546 *buffer = alloc->data;
553 * efi_free_pool() - free memory from pool
555 * @buffer: start of memory to be freed
556 * Return: status code
558 efi_status_t efi_free_pool(void *buffer)
561 struct efi_pool_allocation *alloc;
563 ret = efi_check_allocated((uintptr_t)buffer, true);
564 if (ret != EFI_SUCCESS)
567 alloc = container_of(buffer, struct efi_pool_allocation, data);
569 /* Check that this memory was allocated by efi_allocate_pool() */
570 if (((uintptr_t)alloc & EFI_PAGE_MASK) ||
571 alloc->checksum != checksum(alloc)) {
572 printf("%s: illegal free 0x%p\n", __func__, buffer);
573 return EFI_INVALID_PARAMETER;
575 /* Avoid double free */
578 ret = efi_free_pages((uintptr_t)alloc, alloc->num_pages);
584 * Get map describing memory usage.
586 * @memory_map_size on entry the size, in bytes, of the memory map buffer,
587 * on exit the size of the copied memory map
588 * @memory_map buffer to which the memory map is written
589 * @map_key key for the memory map
590 * @descriptor_size size of an individual memory descriptor
591 * @descriptor_version version number of the memory descriptor structure
592 * @return status code
594 efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
595 struct efi_mem_desc *memory_map,
596 efi_uintn_t *map_key,
597 efi_uintn_t *descriptor_size,
598 uint32_t *descriptor_version)
600 efi_uintn_t map_size = 0;
602 struct list_head *lhandle;
603 efi_uintn_t provided_map_size;
605 if (!memory_map_size)
606 return EFI_INVALID_PARAMETER;
608 provided_map_size = *memory_map_size;
610 list_for_each(lhandle, &efi_mem)
613 map_size = map_entries * sizeof(struct efi_mem_desc);
615 *memory_map_size = map_size;
617 if (provided_map_size < map_size)
618 return EFI_BUFFER_TOO_SMALL;
621 return EFI_INVALID_PARAMETER;
624 *descriptor_size = sizeof(struct efi_mem_desc);
626 if (descriptor_version)
627 *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
629 /* Copy list into array */
630 /* Return the list in ascending order */
631 memory_map = &memory_map[map_entries - 1];
632 list_for_each(lhandle, &efi_mem) {
633 struct efi_mem_list *lmem;
635 lmem = list_entry(lhandle, struct efi_mem_list, link);
636 *memory_map = lmem->desc;
641 *map_key = efi_memory_map_key;
646 __weak void efi_add_known_memory(void)
648 u64 ram_top = board_get_usable_ram_top(0) & ~EFI_PAGE_MASK;
652 * ram_top is just outside mapped memory. So use an offset of one for
653 * mapping the sandbox address.
655 ram_top = (uintptr_t)map_sysmem(ram_top - 1, 0) + 1;
657 /* Fix for 32bit targets with ram_top at 4G */
659 ram_top = 0x100000000ULL;
662 for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
663 u64 ram_end, ram_start, pages;
665 ram_start = (uintptr_t)map_sysmem(gd->bd->bi_dram[i].start, 0);
666 ram_end = ram_start + gd->bd->bi_dram[i].size;
668 /* Remove partial pages */
669 ram_end &= ~EFI_PAGE_MASK;
670 ram_start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
672 if (ram_end <= ram_start) {
673 /* Invalid mapping, keep going. */
677 pages = (ram_end - ram_start) >> EFI_PAGE_SHIFT;
679 efi_add_memory_map(ram_start, pages,
680 EFI_CONVENTIONAL_MEMORY, false);
683 * Boards may indicate to the U-Boot memory core that they
684 * can not support memory above ram_top. Let's honor this
685 * in the efi_loader subsystem too by declaring any memory
686 * above ram_top as "already occupied by firmware".
688 if (ram_top < ram_start) {
689 /* ram_top is before this region, reserve all */
690 efi_add_memory_map(ram_start, pages,
691 EFI_BOOT_SERVICES_DATA, true);
692 } else if ((ram_top >= ram_start) && (ram_top < ram_end)) {
693 /* ram_top is inside this region, reserve parts */
694 pages = (ram_end - ram_top) >> EFI_PAGE_SHIFT;
696 efi_add_memory_map(ram_top, pages,
697 EFI_BOOT_SERVICES_DATA, true);
702 /* Add memory regions for U-Boot's memory and for the runtime services code */
703 static void add_u_boot_and_runtime(void)
705 unsigned long runtime_start, runtime_end, runtime_pages;
706 unsigned long runtime_mask = EFI_PAGE_MASK;
707 unsigned long uboot_start, uboot_pages;
708 unsigned long uboot_stack_size = 16 * 1024 * 1024;
711 uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
712 uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
713 efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
715 #if defined(__aarch64__)
717 * Runtime Services must be 64KiB aligned according to the
718 * "AArch64 Platforms" section in the UEFI spec (2.7+).
721 runtime_mask = SZ_64K - 1;
725 * Add Runtime Services. We mark surrounding boottime code as runtime as
726 * well to fulfill the runtime alignment constraints but avoid padding.
728 runtime_start = (ulong)&__efi_runtime_start & ~runtime_mask;
729 runtime_end = (ulong)&__efi_runtime_stop;
730 runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
731 runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
732 efi_add_memory_map(runtime_start, runtime_pages,
733 EFI_RUNTIME_SERVICES_CODE, false);
736 int efi_memory_init(void)
738 efi_add_known_memory();
740 if (!IS_ENABLED(CONFIG_SANDBOX))
741 add_u_boot_and_runtime();
743 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
744 /* Request a 32bit 64MB bounce buffer region */
745 uint64_t efi_bounce_buffer_addr = 0xffffffff;
747 if (efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, EFI_LOADER_DATA,
748 (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
749 &efi_bounce_buffer_addr) != EFI_SUCCESS)
752 efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;