| // SPDX-License-Identifier: GPL-2.0 |
| |
| #include <linux/efi.h> |
| #include <asm/efi.h> |
| |
| #include "efistub.h" |
| |
| /** |
| * efi_allocate_pages_aligned() - Allocate memory pages |
| * @size: minimum number of bytes to allocate |
| * @addr: On return the address of the first allocated page. The first |
| * allocated page has alignment EFI_ALLOC_ALIGN which is an |
| * architecture dependent multiple of the page size. |
| * @max: the address that the last allocated memory page shall not |
| * exceed |
| * @align: minimum alignment of the base of the allocation |
| * |
| * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according |
| * to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will |
| * not exceed the address given by @max. |
| * |
| * Return: status code |
| */ |
| efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr, |
| unsigned long max, unsigned long align) |
| { |
| efi_physical_addr_t alloc_addr; |
| efi_status_t status; |
| int slack; |
| |
| if (align < EFI_ALLOC_ALIGN) |
| align = EFI_ALLOC_ALIGN; |
| |
| alloc_addr = ALIGN_DOWN(max + 1, align) - 1; |
| size = round_up(size, EFI_ALLOC_ALIGN); |
| slack = align / EFI_PAGE_SIZE - 1; |
| |
| status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS, |
| EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack, |
| &alloc_addr); |
| if (status != EFI_SUCCESS) |
| return status; |
| |
| *addr = ALIGN((unsigned long)alloc_addr, align); |
| |
| if (slack > 0) { |
| int l = (alloc_addr % align) / EFI_PAGE_SIZE; |
| |
| if (l) { |
| efi_bs_call(free_pages, alloc_addr, slack - l + 1); |
| slack = l - 1; |
| } |
| if (slack) |
| efi_bs_call(free_pages, *addr + size, slack); |
| } |
| return EFI_SUCCESS; |
| } |
