2 * EFI application memory management
4 * Copyright (c) 2016 Alexander Graf
6 * SPDX-License-Identifier: GPL-2.0+
10 #include <efi_loader.h>
14 #include <asm/global_data.h>
15 #include <linux/list_sort.h>
17 DECLARE_GLOBAL_DATA_PTR;
20 struct list_head link;
21 struct efi_mem_desc desc;
24 #define EFI_CARVE_NO_OVERLAP -1
25 #define EFI_CARVE_LOOP_AGAIN -2
26 #define EFI_CARVE_OVERLAPS_NONRAM -3
28 /* This list contains all memory map items */
31 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
32 void *efi_bounce_buffer;
36 * U-Boot services each EFI AllocatePool request as a separate
37 * (multiple) page allocation. We have to track the number of pages
38 * to be able to free the correct amount later.
39 * EFI requires 8 byte alignment for pool allocations, so we can
40 * prepend each allocation with an 64 bit header tracking the
41 * allocation size, and hand out the remainder to the caller.
43 struct efi_pool_allocation {
45 char data[] __aligned(ARCH_DMA_MINALIGN);
49 * Sorts the memory list from highest address to lowest address
51 * When allocating memory we should always start from the highest
52 * address chunk, so sort the memory list such that the first list
53 * iterator gets the highest address and goes lower from there.
55 static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
57 struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
58 struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);
60 if (mema->desc.physical_start == memb->desc.physical_start)
62 else if (mema->desc.physical_start < memb->desc.physical_start)
68 static void efi_mem_sort(void)
70 list_sort(NULL, &efi_mem, efi_mem_cmp);
74 * Unmaps all memory occupied by the carve_desc region from the
75 * list entry pointed to by map.
77 * Returns EFI_CARVE_NO_OVERLAP if the regions don't overlap.
78 * Returns EFI_CARVE_OVERLAPS_NONRAM if the carve and map overlap,
79 * and the map contains anything but free ram.
80 * (only when overlap_only_ram is true)
81 * Returns EFI_CARVE_LOOP_AGAIN if the mapping list should be traversed
82 * again, as it has been altered
83 * Returns the number of overlapping pages. The pages are removed from
86 * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
87 * to readd the already carved out pages to the mapping.
89 static int efi_mem_carve_out(struct efi_mem_list *map,
90 struct efi_mem_desc *carve_desc,
91 bool overlap_only_ram)
93 struct efi_mem_list *newmap;
94 struct efi_mem_desc *map_desc = &map->desc;
95 uint64_t map_start = map_desc->physical_start;
96 uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
97 uint64_t carve_start = carve_desc->physical_start;
98 uint64_t carve_end = carve_start +
99 (carve_desc->num_pages << EFI_PAGE_SHIFT);
101 /* check whether we're overlapping */
102 if ((carve_end <= map_start) || (carve_start >= map_end))
103 return EFI_CARVE_NO_OVERLAP;
105 /* We're overlapping with non-RAM, warn the caller if desired */
106 if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
107 return EFI_CARVE_OVERLAPS_NONRAM;
109 /* Sanitize carve_start and carve_end to lie within our bounds */
110 carve_start = max(carve_start, map_start);
111 carve_end = min(carve_end, map_end);
113 /* Carving at the beginning of our map? Just move it! */
114 if (carve_start == map_start) {
115 if (map_end == carve_end) {
116 /* Full overlap, just remove map */
117 list_del(&map->link);
120 map->desc.physical_start = carve_end;
121 map->desc.num_pages = (map_end - carve_end)
125 return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
129 * Overlapping maps, just split the list map at carve_start,
130 * it will get moved or removed in the next iteration.
132 * [ map_desc |__carve_start__| newmap ]
135 /* Create a new map from [ carve_start ... map_end ] */
136 newmap = calloc(1, sizeof(*newmap));
137 newmap->desc = map->desc;
138 newmap->desc.physical_start = carve_start;
139 newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
140 /* Insert before current entry (descending address order) */
141 list_add_tail(&newmap->link, &map->link);
143 /* Shrink the map to [ map_start ... carve_start ] */
144 map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;
146 return EFI_CARVE_LOOP_AGAIN;
149 uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
150 bool overlap_only_ram)
152 struct list_head *lhandle;
153 struct efi_mem_list *newlist;
155 uint64_t carved_pages = 0;
157 debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
158 start, pages, memory_type, overlap_only_ram ? "yes" : "no");
163 newlist = calloc(1, sizeof(*newlist));
164 newlist->desc.type = memory_type;
165 newlist->desc.physical_start = start;
166 newlist->desc.virtual_start = start;
167 newlist->desc.num_pages = pages;
169 switch (memory_type) {
170 case EFI_RUNTIME_SERVICES_CODE:
171 case EFI_RUNTIME_SERVICES_DATA:
172 newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
173 (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
176 newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
179 newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
183 /* Add our new map */
186 list_for_each(lhandle, &efi_mem) {
187 struct efi_mem_list *lmem;
190 lmem = list_entry(lhandle, struct efi_mem_list, link);
191 r = efi_mem_carve_out(lmem, &newlist->desc,
194 case EFI_CARVE_OVERLAPS_NONRAM:
196 * The user requested to only have RAM overlaps,
197 * but we hit a non-RAM region. Error out.
200 case EFI_CARVE_NO_OVERLAP:
201 /* Just ignore this list entry */
203 case EFI_CARVE_LOOP_AGAIN:
205 * We split an entry, but need to loop through
206 * the list again to actually carve it.
211 /* We carved a number of pages */
218 /* The list changed, we need to start over */
222 } while (carve_again);
224 if (overlap_only_ram && (carved_pages != pages)) {
226 * The payload wanted to have RAM overlaps, but we overlapped
227 * with an unallocated region. Error out.
232 /* Add our new map */
233 list_add_tail(&newlist->link, &efi_mem);
235 /* And make sure memory is listed in descending order */
241 static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
243 struct list_head *lhandle;
245 list_for_each(lhandle, &efi_mem) {
246 struct efi_mem_list *lmem = list_entry(lhandle,
247 struct efi_mem_list, link);
248 struct efi_mem_desc *desc = &lmem->desc;
249 uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
250 uint64_t desc_end = desc->physical_start + desc_len;
251 uint64_t curmax = min(max_addr, desc_end);
252 uint64_t ret = curmax - len;
254 /* We only take memory from free RAM */
255 if (desc->type != EFI_CONVENTIONAL_MEMORY)
258 /* Out of bounds for max_addr */
259 if ((ret + len) > max_addr)
262 /* Out of bounds for upper map limit */
263 if ((ret + len) > desc_end)
266 /* Out of bounds for lower map limit */
267 if (ret < desc->physical_start)
270 /* Return the highest address in this map within bounds */
278 * Allocate memory pages.
280 * @type type of allocation to be performed
281 * @memory_type usage type of the allocated memory
282 * @pages number of pages to be allocated
283 * @memory allocated memory
284 * @return status code
286 efi_status_t efi_allocate_pages(int type, int memory_type,
287 efi_uintn_t pages, uint64_t *memory)
289 u64 len = pages << EFI_PAGE_SHIFT;
290 efi_status_t r = EFI_SUCCESS;
294 case EFI_ALLOCATE_ANY_PAGES:
296 addr = efi_find_free_memory(len, gd->start_addr_sp);
302 case EFI_ALLOCATE_MAX_ADDRESS:
304 addr = efi_find_free_memory(len, *memory);
310 case EFI_ALLOCATE_ADDRESS:
311 /* Exact address, reserve it. The addr is already in *memory. */
315 /* UEFI doesn't specify other allocation types */
316 r = EFI_INVALID_PARAMETER;
320 if (r == EFI_SUCCESS) {
323 /* Reserve that map in our memory maps */
324 ret = efi_add_memory_map(addr, pages, memory_type, true);
328 /* Map would overlap, bail out */
329 r = EFI_OUT_OF_RESOURCES;
336 void *efi_alloc(uint64_t len, int memory_type)
339 uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
342 r = efi_allocate_pages(0, memory_type, pages, &ret);
343 if (r == EFI_SUCCESS)
344 return (void*)(uintptr_t)ret;
352 * @memory start of the memory area to be freed
353 * @pages number of pages to be freed
354 * @return status code
356 efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
360 r = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
361 /* Merging of adjacent free regions is missing */
366 return EFI_NOT_FOUND;
370 * Allocate memory from pool.
372 * @pool_type type of the pool from which memory is to be allocated
373 * @size number of bytes to be allocated
374 * @buffer allocated memory
375 * @return status code
377 efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
380 efi_physical_addr_t t;
381 u64 num_pages = (size + sizeof(struct efi_pool_allocation) +
382 EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
389 r = efi_allocate_pages(0, pool_type, num_pages, &t);
391 if (r == EFI_SUCCESS) {
392 struct efi_pool_allocation *alloc = (void *)(uintptr_t)t;
393 alloc->num_pages = num_pages;
394 *buffer = alloc->data;
401 * Free memory from pool.
403 * @buffer start of memory to be freed
404 * @return status code
406 efi_status_t efi_free_pool(void *buffer)
409 struct efi_pool_allocation *alloc;
412 return EFI_INVALID_PARAMETER;
414 alloc = container_of(buffer, struct efi_pool_allocation, data);
415 /* Sanity check, was the supplied address returned by allocate_pool */
416 assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);
418 r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);
424 * Get map describing memory usage.
426 * @memory_map_size on entry the size, in bytes, of the memory map buffer,
427 * on exit the size of the copied memory map
428 * @memory_map buffer to which the memory map is written
429 * @map_key key for the memory map
430 * @descriptor_size size of an individual memory descriptor
431 * @descriptor_version version number of the memory descriptor structure
432 * @return status code
434 efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
435 struct efi_mem_desc *memory_map,
436 efi_uintn_t *map_key,
437 efi_uintn_t *descriptor_size,
438 uint32_t *descriptor_version)
440 efi_uintn_t map_size = 0;
442 struct list_head *lhandle;
443 efi_uintn_t provided_map_size = *memory_map_size;
445 list_for_each(lhandle, &efi_mem)
448 map_size = map_entries * sizeof(struct efi_mem_desc);
450 *memory_map_size = map_size;
452 if (provided_map_size < map_size)
453 return EFI_BUFFER_TOO_SMALL;
456 *descriptor_size = sizeof(struct efi_mem_desc);
458 if (descriptor_version)
459 *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;
461 /* Copy list into array */
463 /* Return the list in ascending order */
464 memory_map = &memory_map[map_entries - 1];
465 list_for_each(lhandle, &efi_mem) {
466 struct efi_mem_list *lmem;
468 lmem = list_entry(lhandle, struct efi_mem_list, link);
469 *memory_map = lmem->desc;
479 __weak void efi_add_known_memory(void)
484 for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
485 u64 ram_start = gd->bd->bi_dram[i].start;
486 u64 ram_size = gd->bd->bi_dram[i].size;
487 u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
488 u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
490 efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
495 int efi_memory_init(void)
497 unsigned long runtime_start, runtime_end, runtime_pages;
498 unsigned long uboot_start, uboot_pages;
499 unsigned long uboot_stack_size = 16 * 1024 * 1024;
501 efi_add_known_memory();
504 uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
505 uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
506 efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);
508 /* Add Runtime Services */
509 runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
510 runtime_end = (ulong)&__efi_runtime_stop;
511 runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
512 runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
513 efi_add_memory_map(runtime_start, runtime_pages,
514 EFI_RUNTIME_SERVICES_CODE, false);
516 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
517 /* Request a 32bit 64MB bounce buffer region */
518 uint64_t efi_bounce_buffer_addr = 0xffffffff;
520 if (efi_allocate_pages(1, EFI_LOADER_DATA,
521 (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
522 &efi_bounce_buffer_addr) != EFI_SUCCESS)
525 efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;