1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun #include <linux/efi.h>
4*4882a593Smuzhiyun #include <asm/efi.h>
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include "efistub.h"
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun /**
9*4882a593Smuzhiyun * efi_allocate_pages_aligned() - Allocate memory pages
10*4882a593Smuzhiyun * @size: minimum number of bytes to allocate
11*4882a593Smuzhiyun * @addr: On return the address of the first allocated page. The first
12*4882a593Smuzhiyun * allocated page has alignment EFI_ALLOC_ALIGN which is an
13*4882a593Smuzhiyun * architecture dependent multiple of the page size.
14*4882a593Smuzhiyun * @max: the address that the last allocated memory page shall not
15*4882a593Smuzhiyun * exceed
16*4882a593Smuzhiyun * @align: minimum alignment of the base of the allocation
17*4882a593Smuzhiyun *
18*4882a593Smuzhiyun * Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according
19*4882a593Smuzhiyun * to @align, which should be >= EFI_ALLOC_ALIGN. The last allocated page will
20*4882a593Smuzhiyun * not exceed the address given by @max.
21*4882a593Smuzhiyun *
22*4882a593Smuzhiyun * Return: status code
23*4882a593Smuzhiyun */
efi_allocate_pages_aligned(unsigned long size,unsigned long * addr,unsigned long max,unsigned long align)24*4882a593Smuzhiyun efi_status_t efi_allocate_pages_aligned(unsigned long size, unsigned long *addr,
25*4882a593Smuzhiyun unsigned long max, unsigned long align)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun efi_physical_addr_t alloc_addr;
28*4882a593Smuzhiyun efi_status_t status;
29*4882a593Smuzhiyun int slack;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun if (align < EFI_ALLOC_ALIGN)
32*4882a593Smuzhiyun align = EFI_ALLOC_ALIGN;
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun alloc_addr = ALIGN_DOWN(max + 1, align) - 1;
35*4882a593Smuzhiyun size = round_up(size, EFI_ALLOC_ALIGN);
36*4882a593Smuzhiyun slack = align / EFI_PAGE_SIZE - 1;
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
39*4882a593Smuzhiyun EFI_LOADER_DATA, size / EFI_PAGE_SIZE + slack,
40*4882a593Smuzhiyun &alloc_addr);
41*4882a593Smuzhiyun if (status != EFI_SUCCESS)
42*4882a593Smuzhiyun return status;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun *addr = ALIGN((unsigned long)alloc_addr, align);
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun if (slack > 0) {
47*4882a593Smuzhiyun int l = (alloc_addr & (align - 1)) / EFI_PAGE_SIZE;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun if (l) {
50*4882a593Smuzhiyun efi_bs_call(free_pages, alloc_addr, slack - l + 1);
51*4882a593Smuzhiyun slack = l - 1;
52*4882a593Smuzhiyun }
53*4882a593Smuzhiyun if (slack)
54*4882a593Smuzhiyun efi_bs_call(free_pages, *addr + size, slack);
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun return EFI_SUCCESS;
57*4882a593Smuzhiyun }
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