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1// SPDX-License-Identifier: GPL-2.02 3#include <linux/efi.h>4#include <asm/efi.h>5 6#include "efistub.h"7 8/**9 * efi_get_memory_map() - get memory map10 * @map: pointer to memory map pointer to which to assign the11 * newly allocated memory map12 * @install_cfg_tbl: whether or not to install the boot memory map as a13 * configuration table14 *15 * Retrieve the UEFI memory map. The allocated memory leaves room for16 * up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries.17 *18 * Return: status code19 */20efi_status_t efi_get_memory_map(struct efi_boot_memmap **map,21 bool install_cfg_tbl)22{23 int memtype = install_cfg_tbl ? EFI_ACPI_RECLAIM_MEMORY24 : EFI_LOADER_DATA;25 efi_guid_t tbl_guid = LINUX_EFI_BOOT_MEMMAP_GUID;26 struct efi_boot_memmap *m, tmp;27 efi_status_t status;28 unsigned long size;29 30 tmp.map_size = 0;31 status = efi_bs_call(get_memory_map, &tmp.map_size, NULL, &tmp.map_key,32 &tmp.desc_size, &tmp.desc_ver);33 if (status != EFI_BUFFER_TOO_SMALL)34 return EFI_LOAD_ERROR;35 36 size = tmp.map_size + tmp.desc_size * EFI_MMAP_NR_SLACK_SLOTS;37 status = efi_bs_call(allocate_pool, memtype, sizeof(*m) + size,38 (void **)&m);39 if (status != EFI_SUCCESS)40 return status;41 42 if (install_cfg_tbl) {43 /*44 * Installing a configuration table might allocate memory, and45 * this may modify the memory map. This means we should install46 * the configuration table first, and re-install or delete it47 * as needed.48 */49 status = efi_bs_call(install_configuration_table, &tbl_guid, m);50 if (status != EFI_SUCCESS)51 goto free_map;52 }53 54 m->buff_size = m->map_size = size;55 status = efi_bs_call(get_memory_map, &m->map_size, m->map, &m->map_key,56 &m->desc_size, &m->desc_ver);57 if (status != EFI_SUCCESS)58 goto uninstall_table;59 60 *map = m;61 return EFI_SUCCESS;62 63uninstall_table:64 if (install_cfg_tbl)65 efi_bs_call(install_configuration_table, &tbl_guid, NULL);66free_map:67 efi_bs_call(free_pool, m);68 return status;69}70 71/**72 * efi_allocate_pages() - Allocate memory pages73 * @size: minimum number of bytes to allocate74 * @addr: On return the address of the first allocated page. The first75 * allocated page has alignment EFI_ALLOC_ALIGN which is an76 * architecture dependent multiple of the page size.77 * @max: the address that the last allocated memory page shall not78 * exceed79 *80 * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according81 * to EFI_ALLOC_ALIGN. The last allocated page will not exceed the address82 * given by @max.83 *84 * Return: status code85 */86efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,87 unsigned long max)88{89 efi_physical_addr_t alloc_addr;90 efi_status_t status;91 92 max = min(max, EFI_ALLOC_LIMIT);93 94 if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE)95 return efi_allocate_pages_aligned(size, addr, max,96 EFI_ALLOC_ALIGN,97 EFI_LOADER_DATA);98 99 alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1;100 status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,101 EFI_LOADER_DATA, DIV_ROUND_UP(size, EFI_PAGE_SIZE),102 &alloc_addr);103 if (status != EFI_SUCCESS)104 return status;105 106 *addr = alloc_addr;107 return EFI_SUCCESS;108}109 110/**111 * efi_free() - free memory pages112 * @size: size of the memory area to free in bytes113 * @addr: start of the memory area to free (must be EFI_PAGE_SIZE114 * aligned)115 *116 * @size is rounded up to a multiple of EFI_ALLOC_ALIGN which is an117 * architecture specific multiple of EFI_PAGE_SIZE. So this function should118 * only be used to return pages allocated with efi_allocate_pages() or119 * efi_low_alloc_above().120 */121void efi_free(unsigned long size, unsigned long addr)122{123 unsigned long nr_pages;124 125 if (!size)126 return;127 128 nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;129 efi_bs_call(free_pages, addr, nr_pages);130}131