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// 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 - 1)) / 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;
}
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