1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/efi.h> 4 #include <asm/efi.h> 5 6 #include "efistub.h" 7 8 /** 9 * efi_get_memory_map() - get memory map 10 * @map: pointer to memory map pointer to which to assign the 11 * newly allocated memory map 12 * 13 * Retrieve the UEFI memory map. The allocated memory leaves room for 14 * up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries. 15 * 16 * Return: status code 17 */ 18 efi_status_t efi_get_memory_map(struct efi_boot_memmap **map) 19 { 20 struct efi_boot_memmap *m, tmp; 21 efi_status_t status; 22 unsigned long size; 23 24 tmp.map_size = 0; 25 status = efi_bs_call(get_memory_map, &tmp.map_size, NULL, &tmp.map_key, 26 &tmp.desc_size, &tmp.desc_ver); 27 if (status != EFI_BUFFER_TOO_SMALL) 28 return EFI_LOAD_ERROR; 29 30 size = tmp.map_size + tmp.desc_size * EFI_MMAP_NR_SLACK_SLOTS; 31 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*m) + size, 32 (void **)&m); 33 if (status != EFI_SUCCESS) 34 return status; 35 36 m->buff_size = m->map_size = size; 37 status = efi_bs_call(get_memory_map, &m->map_size, m->map, &m->map_key, 38 &m->desc_size, &m->desc_ver); 39 if (status != EFI_SUCCESS) 40 goto free_map; 41 42 *map = m; 43 return EFI_SUCCESS; 44 45 free_map: 46 efi_bs_call(free_pool, m); 47 return status; 48 } 49 50 /** 51 * efi_allocate_pages() - Allocate memory pages 52 * @size: minimum number of bytes to allocate 53 * @addr: On return the address of the first allocated page. The first 54 * allocated page has alignment EFI_ALLOC_ALIGN which is an 55 * architecture dependent multiple of the page size. 56 * @max: the address that the last allocated memory page shall not 57 * exceed 58 * 59 * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according 60 * to EFI_ALLOC_ALIGN. The last allocated page will not exceed the address 61 * given by @max. 62 * 63 * Return: status code 64 */ 65 efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr, 66 unsigned long max) 67 { 68 efi_physical_addr_t alloc_addr; 69 efi_status_t status; 70 71 if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE) 72 return efi_allocate_pages_aligned(size, addr, max, 73 EFI_ALLOC_ALIGN); 74 75 alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1; 76 status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, 77 EFI_LOADER_DATA, DIV_ROUND_UP(size, EFI_PAGE_SIZE), 78 &alloc_addr); 79 if (status != EFI_SUCCESS) 80 return status; 81 82 *addr = alloc_addr; 83 return EFI_SUCCESS; 84 } 85 86 /** 87 * efi_free() - free memory pages 88 * @size: size of the memory area to free in bytes 89 * @addr: start of the memory area to free (must be EFI_PAGE_SIZE 90 * aligned) 91 * 92 * @size is rounded up to a multiple of EFI_ALLOC_ALIGN which is an 93 * architecture specific multiple of EFI_PAGE_SIZE. So this function should 94 * only be used to return pages allocated with efi_allocate_pages() or 95 * efi_low_alloc_above(). 96 */ 97 void efi_free(unsigned long size, unsigned long addr) 98 { 99 unsigned long nr_pages; 100 101 if (!size) 102 return; 103 104 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; 105 efi_bs_call(free_pages, addr, nr_pages); 106 } 107