1685d8164SArd Biesheuvel // SPDX-License-Identifier: GPL-2.0
2685d8164SArd Biesheuvel
3685d8164SArd Biesheuvel #include <linux/efi.h>
4685d8164SArd Biesheuvel #include <asm/efi.h>
5685d8164SArd Biesheuvel
6685d8164SArd Biesheuvel #include "efistub.h"
7685d8164SArd Biesheuvel
8685d8164SArd Biesheuvel /**
9685d8164SArd Biesheuvel * efi_low_alloc_above() - allocate pages at or above given address
10685d8164SArd Biesheuvel * @size: size of the memory area to allocate
11685d8164SArd Biesheuvel * @align: minimum alignment of the allocated memory area. It should
12685d8164SArd Biesheuvel * a power of two.
13685d8164SArd Biesheuvel * @addr: on exit the address of the allocated memory
14685d8164SArd Biesheuvel * @min: minimum address to used for the memory allocation
15685d8164SArd Biesheuvel *
16685d8164SArd Biesheuvel * Allocate at the lowest possible address that is not below @min as
17685d8164SArd Biesheuvel * EFI_LOADER_DATA. The allocated pages are aligned according to @align but at
18685d8164SArd Biesheuvel * least EFI_ALLOC_ALIGN. The first allocated page will not below the address
19685d8164SArd Biesheuvel * given by @min.
20685d8164SArd Biesheuvel *
21685d8164SArd Biesheuvel * Return: status code
22685d8164SArd Biesheuvel */
efi_low_alloc_above(unsigned long size,unsigned long align,unsigned long * addr,unsigned long min)231a895dbfSArd Biesheuvel efi_status_t efi_low_alloc_above(unsigned long size, unsigned long align,
24685d8164SArd Biesheuvel unsigned long *addr, unsigned long min)
25685d8164SArd Biesheuvel {
26eab31265SArd Biesheuvel struct efi_boot_memmap *map;
27685d8164SArd Biesheuvel efi_status_t status;
28685d8164SArd Biesheuvel unsigned long nr_pages;
29685d8164SArd Biesheuvel int i;
30685d8164SArd Biesheuvel
31171539f5SArd Biesheuvel status = efi_get_memory_map(&map, false);
32685d8164SArd Biesheuvel if (status != EFI_SUCCESS)
33685d8164SArd Biesheuvel goto fail;
34685d8164SArd Biesheuvel
35685d8164SArd Biesheuvel /*
36685d8164SArd Biesheuvel * Enforce minimum alignment that EFI or Linux requires when
37685d8164SArd Biesheuvel * requesting a specific address. We are doing page-based (or
38685d8164SArd Biesheuvel * larger) allocations, and both the address and size must meet
39685d8164SArd Biesheuvel * alignment constraints.
40685d8164SArd Biesheuvel */
41685d8164SArd Biesheuvel if (align < EFI_ALLOC_ALIGN)
42685d8164SArd Biesheuvel align = EFI_ALLOC_ALIGN;
43685d8164SArd Biesheuvel
44685d8164SArd Biesheuvel size = round_up(size, EFI_ALLOC_ALIGN);
45685d8164SArd Biesheuvel nr_pages = size / EFI_PAGE_SIZE;
46eab31265SArd Biesheuvel for (i = 0; i < map->map_size / map->desc_size; i++) {
47685d8164SArd Biesheuvel efi_memory_desc_t *desc;
48eab31265SArd Biesheuvel unsigned long m = (unsigned long)map->map;
49685d8164SArd Biesheuvel u64 start, end;
50685d8164SArd Biesheuvel
51*887c4cf5SKees Cook desc = efi_memdesc_ptr(m, map->desc_size, i);
52685d8164SArd Biesheuvel
53685d8164SArd Biesheuvel if (desc->type != EFI_CONVENTIONAL_MEMORY)
54685d8164SArd Biesheuvel continue;
55685d8164SArd Biesheuvel
56685d8164SArd Biesheuvel if (efi_soft_reserve_enabled() &&
57685d8164SArd Biesheuvel (desc->attribute & EFI_MEMORY_SP))
58685d8164SArd Biesheuvel continue;
59685d8164SArd Biesheuvel
60685d8164SArd Biesheuvel if (desc->num_pages < nr_pages)
61685d8164SArd Biesheuvel continue;
62685d8164SArd Biesheuvel
63685d8164SArd Biesheuvel start = desc->phys_addr;
64685d8164SArd Biesheuvel end = start + desc->num_pages * EFI_PAGE_SIZE;
65685d8164SArd Biesheuvel
66685d8164SArd Biesheuvel if (start < min)
67685d8164SArd Biesheuvel start = min;
68685d8164SArd Biesheuvel
69685d8164SArd Biesheuvel start = round_up(start, align);
70685d8164SArd Biesheuvel if ((start + size) > end)
71685d8164SArd Biesheuvel continue;
72685d8164SArd Biesheuvel
73685d8164SArd Biesheuvel status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
74685d8164SArd Biesheuvel EFI_LOADER_DATA, nr_pages, &start);
75685d8164SArd Biesheuvel if (status == EFI_SUCCESS) {
76685d8164SArd Biesheuvel *addr = start;
77685d8164SArd Biesheuvel break;
78685d8164SArd Biesheuvel }
79685d8164SArd Biesheuvel }
80685d8164SArd Biesheuvel
81eab31265SArd Biesheuvel if (i == map->map_size / map->desc_size)
82685d8164SArd Biesheuvel status = EFI_NOT_FOUND;
83685d8164SArd Biesheuvel
84685d8164SArd Biesheuvel efi_bs_call(free_pool, map);
85685d8164SArd Biesheuvel fail:
86685d8164SArd Biesheuvel return status;
87685d8164SArd Biesheuvel }
88685d8164SArd Biesheuvel
89685d8164SArd Biesheuvel /**
90685d8164SArd Biesheuvel * efi_relocate_kernel() - copy memory area
91685d8164SArd Biesheuvel * @image_addr: pointer to address of memory area to copy
92685d8164SArd Biesheuvel * @image_size: size of memory area to copy
93685d8164SArd Biesheuvel * @alloc_size: minimum size of memory to allocate, must be greater or
94685d8164SArd Biesheuvel * equal to image_size
95685d8164SArd Biesheuvel * @preferred_addr: preferred target address
96685d8164SArd Biesheuvel * @alignment: minimum alignment of the allocated memory area. It
97685d8164SArd Biesheuvel * should be a power of two.
98685d8164SArd Biesheuvel * @min_addr: minimum target address
99685d8164SArd Biesheuvel *
100685d8164SArd Biesheuvel * Copy a memory area to a newly allocated memory area aligned according
101685d8164SArd Biesheuvel * to @alignment but at least EFI_ALLOC_ALIGN. If the preferred address
102685d8164SArd Biesheuvel * is not available, the allocated address will not be below @min_addr.
103685d8164SArd Biesheuvel * On exit, @image_addr is updated to the target copy address that was used.
104685d8164SArd Biesheuvel *
105685d8164SArd Biesheuvel * This function is used to copy the Linux kernel verbatim. It does not apply
106685d8164SArd Biesheuvel * any relocation changes.
107685d8164SArd Biesheuvel *
108685d8164SArd Biesheuvel * Return: status code
109685d8164SArd Biesheuvel */
efi_relocate_kernel(unsigned long * image_addr,unsigned long image_size,unsigned long alloc_size,unsigned long preferred_addr,unsigned long alignment,unsigned long min_addr)110685d8164SArd Biesheuvel efi_status_t efi_relocate_kernel(unsigned long *image_addr,
111685d8164SArd Biesheuvel unsigned long image_size,
112685d8164SArd Biesheuvel unsigned long alloc_size,
113685d8164SArd Biesheuvel unsigned long preferred_addr,
114685d8164SArd Biesheuvel unsigned long alignment,
115685d8164SArd Biesheuvel unsigned long min_addr)
116685d8164SArd Biesheuvel {
117685d8164SArd Biesheuvel unsigned long cur_image_addr;
118685d8164SArd Biesheuvel unsigned long new_addr = 0;
119685d8164SArd Biesheuvel efi_status_t status;
120685d8164SArd Biesheuvel unsigned long nr_pages;
121685d8164SArd Biesheuvel efi_physical_addr_t efi_addr = preferred_addr;
122685d8164SArd Biesheuvel
123685d8164SArd Biesheuvel if (!image_addr || !image_size || !alloc_size)
124685d8164SArd Biesheuvel return EFI_INVALID_PARAMETER;
125685d8164SArd Biesheuvel if (alloc_size < image_size)
126685d8164SArd Biesheuvel return EFI_INVALID_PARAMETER;
127685d8164SArd Biesheuvel
128685d8164SArd Biesheuvel cur_image_addr = *image_addr;
129685d8164SArd Biesheuvel
130685d8164SArd Biesheuvel /*
131685d8164SArd Biesheuvel * The EFI firmware loader could have placed the kernel image
132685d8164SArd Biesheuvel * anywhere in memory, but the kernel has restrictions on the
133685d8164SArd Biesheuvel * max physical address it can run at. Some architectures
13440262299SJoe Perches * also have a preferred address, so first try to relocate
135685d8164SArd Biesheuvel * to the preferred address. If that fails, allocate as low
136685d8164SArd Biesheuvel * as possible while respecting the required alignment.
137685d8164SArd Biesheuvel */
138685d8164SArd Biesheuvel nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
139685d8164SArd Biesheuvel status = efi_bs_call(allocate_pages, EFI_ALLOCATE_ADDRESS,
140685d8164SArd Biesheuvel EFI_LOADER_DATA, nr_pages, &efi_addr);
141685d8164SArd Biesheuvel new_addr = efi_addr;
142685d8164SArd Biesheuvel /*
143685d8164SArd Biesheuvel * If preferred address allocation failed allocate as low as
144685d8164SArd Biesheuvel * possible.
145685d8164SArd Biesheuvel */
146685d8164SArd Biesheuvel if (status != EFI_SUCCESS) {
147685d8164SArd Biesheuvel status = efi_low_alloc_above(alloc_size, alignment, &new_addr,
148685d8164SArd Biesheuvel min_addr);
149685d8164SArd Biesheuvel }
150685d8164SArd Biesheuvel if (status != EFI_SUCCESS) {
151793473c2SArvind Sankar efi_err("Failed to allocate usable memory for kernel.\n");
152685d8164SArd Biesheuvel return status;
153685d8164SArd Biesheuvel }
154685d8164SArd Biesheuvel
155685d8164SArd Biesheuvel /*
156685d8164SArd Biesheuvel * We know source/dest won't overlap since both memory ranges
157685d8164SArd Biesheuvel * have been allocated by UEFI, so we can safely use memcpy.
158685d8164SArd Biesheuvel */
159685d8164SArd Biesheuvel memcpy((void *)new_addr, (void *)cur_image_addr, image_size);
160685d8164SArd Biesheuvel
161685d8164SArd Biesheuvel /* Return the new address of the relocated image. */
162685d8164SArd Biesheuvel *image_addr = new_addr;
163685d8164SArd Biesheuvel
164685d8164SArd Biesheuvel return status;
165685d8164SArd Biesheuvel }
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