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_allocate_pages_aligned() - Allocate memory pages 10 * @size: minimum number of bytes to allocate 11 * @addr: On return the address of the first allocated page. The first 12 * allocated page has alignment EFI_ALLOC_ALIGN which is an 13 * architecture dependent multiple of the page size. 14 * @max: the address that the last allocated memory page shall not 15 * exceed 16 * @align: minimum alignment of the base of the allocation 17 * 18 * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according 19 * to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will 20 * not exceed the address given by @max. 21 * 22 * Return: status code 23 */ 24 efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, 25 unsigned long max, unsigned long align, 26 int memory_type) 27 { 28 efi_physical_addr_t alloc_addr; 29 efi_status_t status; 30 int slack; 31 32 if (align < EFI_ALLOC_ALIGN) 33 align = EFI_ALLOC_ALIGN; 34 35 alloc_addr = ALIGN_DOWN(max + 1, align) - 1; 36 size = round_up(size, EFI_ALLOC_ALIGN); 37 slack = align / EFI_PAGE_SIZE - 1; 38 39 status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, 40 memory_type, size / EFI_PAGE_SIZE + slack, 41 &alloc_addr); 42 if (status != EFI_SUCCESS) 43 return status; 44 45 *addr = ALIGN((unsigned long)alloc_addr, align); 46 47 if (slack > 0) { 48 int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE; 49 50 if (l) { 51 efi_bs_call(free_pages, alloc_addr, slack - l + 1); 52 slack = l - 1; 53 } 54 if (slack) 55 efi_bs_call(free_pages, *addr + size, slack); 56 } 57 return EFI_SUCCESS; 58 } 59