// SPDX-License-Identifier: GPL-2.0+ /* * EFI application memory management * * Copyright (c) 2016 Alexander Graf */ #include #include #include #include #include #include #include DECLARE_GLOBAL_DATA_PTR; /* Magic number identifying memory allocated from pool */ #define EFI_ALLOC_POOL_MAGIC 0x1fe67ddf6491caa2 efi_uintn_t efi_memory_map_key; struct efi_mem_list { struct list_head link; struct efi_mem_desc desc; }; #define EFI_CARVE_NO_OVERLAP -1 #define EFI_CARVE_LOOP_AGAIN -2 #define EFI_CARVE_OVERLAPS_NONRAM -3 /* This list contains all memory map items */ LIST_HEAD(efi_mem); #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER void *efi_bounce_buffer; #endif /** * efi_pool_allocation - memory block allocated from pool * * @num_pages: number of pages allocated * @checksum: checksum * * U-Boot services each EFI AllocatePool request as a separate * (multiple) page allocation. We have to track the number of pages * to be able to free the correct amount later. * EFI requires 8 byte alignment for pool allocations, so we can * prepend each allocation with an 64 bit header tracking the * allocation size, and hand out the remainder to the caller. */ struct efi_pool_allocation { u64 num_pages; u64 checksum; char data[] __aligned(ARCH_DMA_MINALIGN); }; /** * checksum() - calculate checksum for memory allocated from pool * * @alloc: allocation header * Return: checksum, always non-zero */ static u64 checksum(struct efi_pool_allocation *alloc) { u64 addr = (uintptr_t)alloc; u64 ret = (addr >> 32) ^ (addr << 32) ^ alloc->num_pages ^ EFI_ALLOC_POOL_MAGIC; if (!ret) ++ret; return ret; } /* * Sorts the memory list from highest address to lowest address * * When allocating memory we should always start from the highest * address chunk, so sort the memory list such that the first list * iterator gets the highest address and goes lower from there. */ static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b) { struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link); struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link); if (mema->desc.physical_start == memb->desc.physical_start) return 0; else if (mema->desc.physical_start < memb->desc.physical_start) return 1; else return -1; } static uint64_t desc_get_end(struct efi_mem_desc *desc) { return desc->physical_start + (desc->num_pages << EFI_PAGE_SHIFT); } static void efi_mem_sort(void) { struct list_head *lhandle; struct efi_mem_list *prevmem = NULL; bool merge_again = true; list_sort(NULL, &efi_mem, efi_mem_cmp); /* Now merge entries that can be merged */ while (merge_again) { merge_again = false; list_for_each(lhandle, &efi_mem) { struct efi_mem_list *lmem; struct efi_mem_desc *prev = &prevmem->desc; struct efi_mem_desc *cur; uint64_t pages; lmem = list_entry(lhandle, struct efi_mem_list, link); if (!prevmem) { prevmem = lmem; continue; } cur = &lmem->desc; if ((desc_get_end(cur) == prev->physical_start) && (prev->type == cur->type) && (prev->attribute == cur->attribute)) { /* There is an existing map before, reuse it */ pages = cur->num_pages; prev->num_pages += pages; prev->physical_start -= pages << EFI_PAGE_SHIFT; prev->virtual_start -= pages << EFI_PAGE_SHIFT; list_del(&lmem->link); free(lmem); merge_again = true; break; } prevmem = lmem; } } } /** efi_mem_carve_out - unmap memory region * * @map: memory map * @carve_desc: memory region to unmap * @overlap_only_ram: the carved out region may only overlap RAM * Return Value: the number of overlapping pages which have been * removed from the map, * EFI_CARVE_NO_OVERLAP, if the regions don't overlap, * EFI_CARVE_OVERLAPS_NONRAM, if the carve and map overlap, * and the map contains anything but free ram * (only when overlap_only_ram is true), * EFI_CARVE_LOOP_AGAIN, if the mapping list should be * traversed again, as it has been altered. * * Unmaps all memory occupied by the carve_desc region from the list entry * pointed to by map. * * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility * to re-add the already carved out pages to the mapping. */ static s64 efi_mem_carve_out(struct efi_mem_list *map, struct efi_mem_desc *carve_desc, bool overlap_only_ram) { struct efi_mem_list *newmap; struct efi_mem_desc *map_desc = &map->desc; uint64_t map_start = map_desc->physical_start; uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT); uint64_t carve_start = carve_desc->physical_start; uint64_t carve_end = carve_start + (carve_desc->num_pages << EFI_PAGE_SHIFT); /* check whether we're overlapping */ if ((carve_end <= map_start) || (carve_start >= map_end)) return EFI_CARVE_NO_OVERLAP; /* We're overlapping with non-RAM, warn the caller if desired */ if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY)) return EFI_CARVE_OVERLAPS_NONRAM; /* Sanitize carve_start and carve_end to lie within our bounds */ carve_start = max(carve_start, map_start); carve_end = min(carve_end, map_end); /* Carving at the beginning of our map? Just move it! */ if (carve_start == map_start) { if (map_end == carve_end) { /* Full overlap, just remove map */ list_del(&map->link); free(map); } else { map->desc.physical_start = carve_end; map->desc.virtual_start = carve_end; map->desc.num_pages = (map_end - carve_end) >> EFI_PAGE_SHIFT; } return (carve_end - carve_start) >> EFI_PAGE_SHIFT; } /* * Overlapping maps, just split the list map at carve_start, * it will get moved or removed in the next iteration. * * [ map_desc |__carve_start__| newmap ] */ /* Create a new map from [ carve_start ... map_end ] */ newmap = calloc(1, sizeof(*newmap)); newmap->desc = map->desc; newmap->desc.physical_start = carve_start; newmap->desc.virtual_start = carve_start; newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT; /* Insert before current entry (descending address order) */ list_add_tail(&newmap->link, &map->link); /* Shrink the map to [ map_start ... carve_start ] */ map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT; return EFI_CARVE_LOOP_AGAIN; } /** * efi_add_memory_map() - add memory area to the memory map * * @start: start address, must be a multiple of EFI_PAGE_SIZE * @pages: number of pages to add * @memory_type: type of memory added * @overlap_only_ram: the memory area must overlap existing * Return: status code */ efi_status_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type, bool overlap_only_ram) { struct list_head *lhandle; struct efi_mem_list *newlist; bool carve_again; uint64_t carved_pages = 0; struct efi_event *evt; EFI_PRINT("%s: 0x%llx 0x%llx %d %s\n", __func__, start, pages, memory_type, overlap_only_ram ? "yes" : "no"); if (memory_type >= EFI_MAX_MEMORY_TYPE) return EFI_INVALID_PARAMETER; if (!pages) return EFI_SUCCESS; ++efi_memory_map_key; newlist = calloc(1, sizeof(*newlist)); newlist->desc.type = memory_type; newlist->desc.physical_start = start; newlist->desc.virtual_start = start; newlist->desc.num_pages = pages; switch (memory_type) { case EFI_RUNTIME_SERVICES_CODE: case EFI_RUNTIME_SERVICES_DATA: newlist->desc.attribute = EFI_MEMORY_WB | EFI_MEMORY_RUNTIME; break; case EFI_MMAP_IO: newlist->desc.attribute = EFI_MEMORY_RUNTIME; break; default: newlist->desc.attribute = EFI_MEMORY_WB; break; } /* Add our new map */ do { carve_again = false; list_for_each(lhandle, &efi_mem) { struct efi_mem_list *lmem; s64 r; lmem = list_entry(lhandle, struct efi_mem_list, link); r = efi_mem_carve_out(lmem, &newlist->desc, overlap_only_ram); switch (r) { case EFI_CARVE_OVERLAPS_NONRAM: /* * The user requested to only have RAM overlaps, * but we hit a non-RAM region. Error out. */ return EFI_NO_MAPPING; case EFI_CARVE_NO_OVERLAP: /* Just ignore this list entry */ break; case EFI_CARVE_LOOP_AGAIN: /* * We split an entry, but need to loop through * the list again to actually carve it. */ carve_again = true; break; default: /* We carved a number of pages */ carved_pages += r; carve_again = true; break; } if (carve_again) { /* The list changed, we need to start over */ break; } } } while (carve_again); if (overlap_only_ram && (carved_pages != pages)) { /* * The payload wanted to have RAM overlaps, but we overlapped * with an unallocated region. Error out. */ return EFI_NO_MAPPING; } /* Add our new map */ list_add_tail(&newlist->link, &efi_mem); /* And make sure memory is listed in descending order */ efi_mem_sort(); /* Notify that the memory map was changed */ list_for_each_entry(evt, &efi_events, link) { if (evt->group && !guidcmp(evt->group, &efi_guid_event_group_memory_map_change)) { efi_signal_event(evt); break; } } return EFI_SUCCESS; } /** * efi_check_allocated() - validate address to be freed * * Check that the address is within allocated memory: * * * The address must be in a range of the memory map. * * The address may not point to EFI_CONVENTIONAL_MEMORY. * * Page alignment is not checked as this is not a requirement of * efi_free_pool(). * * @addr: address of page to be freed * @must_be_allocated: return success if the page is allocated * Return: status code */ static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated) { struct efi_mem_list *item; list_for_each_entry(item, &efi_mem, link) { u64 start = item->desc.physical_start; u64 end = start + (item->desc.num_pages << EFI_PAGE_SHIFT); if (addr >= start && addr < end) { if (must_be_allocated ^ (item->desc.type == EFI_CONVENTIONAL_MEMORY)) return EFI_SUCCESS; else return EFI_NOT_FOUND; } } return EFI_NOT_FOUND; } static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr) { struct list_head *lhandle; /* * Prealign input max address, so we simplify our matching * logic below and can just reuse it as return pointer. */ max_addr &= ~EFI_PAGE_MASK; list_for_each(lhandle, &efi_mem) { struct efi_mem_list *lmem = list_entry(lhandle, struct efi_mem_list, link); struct efi_mem_desc *desc = &lmem->desc; uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT; uint64_t desc_end = desc->physical_start + desc_len; uint64_t curmax = min(max_addr, desc_end); uint64_t ret = curmax - len; /* We only take memory from free RAM */ if (desc->type != EFI_CONVENTIONAL_MEMORY) continue; /* Out of bounds for max_addr */ if ((ret + len) > max_addr) continue; /* Out of bounds for upper map limit */ if ((ret + len) > desc_end) continue; /* Out of bounds for lower map limit */ if (ret < desc->physical_start) continue; /* Return the highest address in this map within bounds */ return ret; } return 0; } /* * Allocate memory pages. * * @type type of allocation to be performed * @memory_type usage type of the allocated memory * @pages number of pages to be allocated * @memory allocated memory * @return status code */ efi_status_t efi_allocate_pages(int type, int memory_type, efi_uintn_t pages, uint64_t *memory) { u64 len = pages << EFI_PAGE_SHIFT; efi_status_t ret; uint64_t addr; /* Check import parameters */ if (memory_type >= EFI_PERSISTENT_MEMORY_TYPE && memory_type <= 0x6FFFFFFF) return EFI_INVALID_PARAMETER; if (!memory) return EFI_INVALID_PARAMETER; switch (type) { case EFI_ALLOCATE_ANY_PAGES: /* Any page */ addr = efi_find_free_memory(len, -1ULL); if (!addr) return EFI_OUT_OF_RESOURCES; break; case EFI_ALLOCATE_MAX_ADDRESS: /* Max address */ addr = efi_find_free_memory(len, *memory); if (!addr) return EFI_OUT_OF_RESOURCES; break; case EFI_ALLOCATE_ADDRESS: /* Exact address, reserve it. The addr is already in *memory. */ ret = efi_check_allocated(*memory, false); if (ret != EFI_SUCCESS) return EFI_NOT_FOUND; addr = *memory; break; default: /* UEFI doesn't specify other allocation types */ return EFI_INVALID_PARAMETER; } /* Reserve that map in our memory maps */ if (efi_add_memory_map(addr, pages, memory_type, true) != EFI_SUCCESS) /* Map would overlap, bail out */ return EFI_OUT_OF_RESOURCES; *memory = addr; return EFI_SUCCESS; } void *efi_alloc(uint64_t len, int memory_type) { uint64_t ret = 0; uint64_t pages = efi_size_in_pages(len); efi_status_t r; r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages, &ret); if (r == EFI_SUCCESS) return (void*)(uintptr_t)ret; return NULL; } /** * efi_free_pages() - free memory pages * * @memory: start of the memory area to be freed * @pages: number of pages to be freed * Return: status code */ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages) { efi_status_t ret; ret = efi_check_allocated(memory, true); if (ret != EFI_SUCCESS) return ret; /* Sanity check */ if (!memory || (memory & EFI_PAGE_MASK) || !pages) { printf("%s: illegal free 0x%llx, 0x%zx\n", __func__, memory, pages); return EFI_INVALID_PARAMETER; } ret = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false); /* Merging of adjacent free regions is missing */ if (ret != EFI_SUCCESS) return EFI_NOT_FOUND; return ret; } /** * efi_allocate_pool - allocate memory from pool * * @pool_type: type of the pool from which memory is to be allocated * @size: number of bytes to be allocated * @buffer: allocated memory * Return: status code */ efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer) { efi_status_t r; u64 addr; struct efi_pool_allocation *alloc; u64 num_pages = efi_size_in_pages(size + sizeof(struct efi_pool_allocation)); if (!buffer) return EFI_INVALID_PARAMETER; if (size == 0) { *buffer = NULL; return EFI_SUCCESS; } r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, pool_type, num_pages, &addr); if (r == EFI_SUCCESS) { alloc = (struct efi_pool_allocation *)(uintptr_t)addr; alloc->num_pages = num_pages; alloc->checksum = checksum(alloc); *buffer = alloc->data; } return r; } /** * efi_free_pool() - free memory from pool * * @buffer: start of memory to be freed * Return: status code */ efi_status_t efi_free_pool(void *buffer) { efi_status_t ret; struct efi_pool_allocation *alloc; if (!buffer) return EFI_INVALID_PARAMETER; ret = efi_check_allocated((uintptr_t)buffer, true); if (ret != EFI_SUCCESS) return ret; alloc = container_of(buffer, struct efi_pool_allocation, data); /* Check that this memory was allocated by efi_allocate_pool() */ if (((uintptr_t)alloc & EFI_PAGE_MASK) || alloc->checksum != checksum(alloc)) { printf("%s: illegal free 0x%p\n", __func__, buffer); return EFI_INVALID_PARAMETER; } /* Avoid double free */ alloc->checksum = 0; ret = efi_free_pages((uintptr_t)alloc, alloc->num_pages); return ret; } /* * Get map describing memory usage. * * @memory_map_size on entry the size, in bytes, of the memory map buffer, * on exit the size of the copied memory map * @memory_map buffer to which the memory map is written * @map_key key for the memory map * @descriptor_size size of an individual memory descriptor * @descriptor_version version number of the memory descriptor structure * @return status code */ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size, struct efi_mem_desc *memory_map, efi_uintn_t *map_key, efi_uintn_t *descriptor_size, uint32_t *descriptor_version) { efi_uintn_t map_size = 0; int map_entries = 0; struct list_head *lhandle; efi_uintn_t provided_map_size; if (!memory_map_size) return EFI_INVALID_PARAMETER; provided_map_size = *memory_map_size; list_for_each(lhandle, &efi_mem) map_entries++; map_size = map_entries * sizeof(struct efi_mem_desc); *memory_map_size = map_size; if (provided_map_size < map_size) return EFI_BUFFER_TOO_SMALL; if (!memory_map) return EFI_INVALID_PARAMETER; if (descriptor_size) *descriptor_size = sizeof(struct efi_mem_desc); if (descriptor_version) *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION; /* Copy list into array */ /* Return the list in ascending order */ memory_map = &memory_map[map_entries - 1]; list_for_each(lhandle, &efi_mem) { struct efi_mem_list *lmem; lmem = list_entry(lhandle, struct efi_mem_list, link); *memory_map = lmem->desc; memory_map--; } if (map_key) *map_key = efi_memory_map_key; return EFI_SUCCESS; } __weak void efi_add_known_memory(void) { u64 ram_top = board_get_usable_ram_top(0) & ~EFI_PAGE_MASK; int i; /* * ram_top is just outside mapped memory. So use an offset of one for * mapping the sandbox address. */ ram_top = (uintptr_t)map_sysmem(ram_top - 1, 0) + 1; /* Fix for 32bit targets with ram_top at 4G */ if (!ram_top) ram_top = 0x100000000ULL; /* Add RAM */ for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) { u64 ram_end, ram_start, pages; ram_start = (uintptr_t)map_sysmem(gd->bd->bi_dram[i].start, 0); ram_end = ram_start + gd->bd->bi_dram[i].size; /* Remove partial pages */ ram_end &= ~EFI_PAGE_MASK; ram_start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK; if (ram_end <= ram_start) { /* Invalid mapping, keep going. */ continue; } pages = (ram_end - ram_start) >> EFI_PAGE_SHIFT; efi_add_memory_map(ram_start, pages, EFI_CONVENTIONAL_MEMORY, false); /* * Boards may indicate to the U-Boot memory core that they * can not support memory above ram_top. Let's honor this * in the efi_loader subsystem too by declaring any memory * above ram_top as "already occupied by firmware". */ if (ram_top < ram_start) { /* ram_top is before this region, reserve all */ efi_add_memory_map(ram_start, pages, EFI_BOOT_SERVICES_DATA, true); } else if ((ram_top >= ram_start) && (ram_top < ram_end)) { /* ram_top is inside this region, reserve parts */ pages = (ram_end - ram_top) >> EFI_PAGE_SHIFT; efi_add_memory_map(ram_top, pages, EFI_BOOT_SERVICES_DATA, true); } } } /* Add memory regions for U-Boot's memory and for the runtime services code */ static void add_u_boot_and_runtime(void) { unsigned long runtime_start, runtime_end, runtime_pages; unsigned long runtime_mask = EFI_PAGE_MASK; unsigned long uboot_start, uboot_pages; unsigned long uboot_stack_size = 16 * 1024 * 1024; /* Add U-Boot */ uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK; uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT; efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false); #if defined(__aarch64__) /* * Runtime Services must be 64KiB aligned according to the * "AArch64 Platforms" section in the UEFI spec (2.7+). */ runtime_mask = SZ_64K - 1; #endif /* * Add Runtime Services. We mark surrounding boottime code as runtime as * well to fulfill the runtime alignment constraints but avoid padding. */ runtime_start = (ulong)&__efi_runtime_start & ~runtime_mask; runtime_end = (ulong)&__efi_runtime_stop; runtime_end = (runtime_end + runtime_mask) & ~runtime_mask; runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT; efi_add_memory_map(runtime_start, runtime_pages, EFI_RUNTIME_SERVICES_CODE, false); } int efi_memory_init(void) { efi_add_known_memory(); if (!IS_ENABLED(CONFIG_SANDBOX)) add_u_boot_and_runtime(); #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER /* Request a 32bit 64MB bounce buffer region */ uint64_t efi_bounce_buffer_addr = 0xffffffff; if (efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, EFI_LOADER_DATA, (64 * 1024 * 1024) >> EFI_PAGE_SHIFT, &efi_bounce_buffer_addr) != EFI_SUCCESS) return -1; efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr; #endif return 0; }