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 * @memory_type: the type of memory to allocate
18 *
19 * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according
20 * to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will
21 * not exceed the address given by @max.
22 *
23 * Return:	status code
24 */
25efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr,
26					unsigned long max, unsigned long align,
27					int memory_type)
28{
29	efi_physical_addr_t alloc_addr;
30	efi_status_t status;
31	int slack;
32
33	max = min(max, EFI_ALLOC_LIMIT);
34
35	if (align < EFI_ALLOC_ALIGN)
36		align = EFI_ALLOC_ALIGN;
37
38	alloc_addr = ALIGN_DOWN(max + 1, align) - 1;
39	size = round_up(size, EFI_ALLOC_ALIGN);
40	slack = align / EFI_PAGE_SIZE - 1;
41
42	status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
43			     memory_type, size / EFI_PAGE_SIZE + slack,
44			     &alloc_addr);
45	if (status != EFI_SUCCESS)
46		return status;
47
48	*addr = ALIGN((unsigned long)alloc_addr, align);
49
50	if (slack > 0) {
51		int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;
52
53		if (l) {
54			efi_bs_call(free_pages, alloc_addr, slack - l + 1);
55			slack = l - 1;
56		}
57		if (slack)
58			efi_bs_call(free_pages, *addr + size, slack);
59	}
60	return EFI_SUCCESS;
61}

 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 */
24efi_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	max = min(max, EFI_ALLOC_LIMIT);
33
34	if (align < EFI_ALLOC_ALIGN)
35		align = EFI_ALLOC_ALIGN;
36
37	alloc_addr = ALIGN_DOWN(max + 1, align) - 1;
38	size = round_up(size, EFI_ALLOC_ALIGN);
39	slack = align / EFI_PAGE_SIZE - 1;
40
41	status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
42			     memory_type, size / EFI_PAGE_SIZE + slack,
43			     &alloc_addr);
44	if (status != EFI_SUCCESS)
45		return status;
46
47	*addr = ALIGN((unsigned long)alloc_addr, align);
48
49	if (slack > 0) {
50		int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;
51
52		if (l) {
53			efi_bs_call(free_pages, alloc_addr, slack - l + 1);
54			slack = l - 1;
55		}
56		if (slack)
57			efi_bs_call(free_pages, *addr + size, slack);
58	}
59	return EFI_SUCCESS;
60}