1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
// SPDX-License-Identifier: GPL-2.0
#include <linux/efi.h>
#include <asm/efi.h>
#include "efistub.h"
static inline bool mmap_has_headroom(unsigned long buff_size,
unsigned long map_size,
unsigned long desc_size)
{
unsigned long slack = buff_size - map_size;
return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
}
/**
* efi_get_memory_map() - get memory map
* @map: on return pointer to memory map
*
* Retrieve the UEFI memory map. The allocated memory leaves room for
* up to EFI_MMAP_NR_SLACK_SLOTS additional memory map entries.
*
* Return: status code
*/
efi_status_t efi_get_memory_map(struct efi_boot_memmap *map)
{
efi_memory_desc_t *m = NULL;
efi_status_t status;
unsigned long key;
u32 desc_version;
*map->desc_size = sizeof(*m);
*map->map_size = *map->desc_size * 32;
*map->buff_size = *map->map_size;
again:
status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
*map->map_size, (void **)&m);
if (status != EFI_SUCCESS)
goto fail;
*map->desc_size = 0;
key = 0;
status = efi_bs_call(get_memory_map, map->map_size, m,
&key, map->desc_size, &desc_version);
if (status == EFI_BUFFER_TOO_SMALL ||
!mmap_has_headroom(*map->buff_size, *map->map_size,
*map->desc_size)) {
efi_bs_call(free_pool, m);
/*
* Make sure there is some entries of headroom so that the
* buffer can be reused for a new map after allocations are
* no longer permitted. Its unlikely that the map will grow to
* exceed this headroom once we are ready to trigger
* ExitBootServices()
*/
*map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;
*map->buff_size = *map->map_size;
goto again;
}
if (status == EFI_SUCCESS) {
if (map->key_ptr)
*map->key_ptr = key;
if (map->desc_ver)
*map->desc_ver = desc_version;
} else {
efi_bs_call(free_pool, m);
}
fail:
*map->map = m;
return status;
}
/**
* efi_allocate_pages() - 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
*
* Allocate pages as EFI_LOADER_DATA. The allocated pages are aligned according
* to EFI_ALLOC_ALIGN. The last allocated page will not exceed the address
* given by @max.
*
* Return: status code
*/
efi_status_t efi_allocate_pages(unsigned long size, unsigned long *addr,
unsigned long max)
{
efi_physical_addr_t alloc_addr;
efi_status_t status;
if (EFI_ALLOC_ALIGN > EFI_PAGE_SIZE)
return efi_allocate_pages_aligned(size, addr, max,
EFI_ALLOC_ALIGN);
alloc_addr = ALIGN_DOWN(max + 1, EFI_ALLOC_ALIGN) - 1;
status = efi_bs_call(allocate_pages, EFI_ALLOCATE_MAX_ADDRESS,
EFI_LOADER_DATA, DIV_ROUND_UP(size, EFI_PAGE_SIZE),
&alloc_addr);
if (status != EFI_SUCCESS)
return status;
*addr = alloc_addr;
return EFI_SUCCESS;
}
/**
* efi_free() - free memory pages
* @size: size of the memory area to free in bytes
* @addr: start of the memory area to free (must be EFI_PAGE_SIZE
* aligned)
*
* @size is rounded up to a multiple of EFI_ALLOC_ALIGN which is an
* architecture specific multiple of EFI_PAGE_SIZE. So this function should
* only be used to return pages allocated with efi_allocate_pages() or
* efi_low_alloc_above().
*/
void efi_free(unsigned long size, unsigned long addr)
{
unsigned long nr_pages;
if (!size)
return;
nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE;
efi_bs_call(free_pages, addr, nr_pages);
}
|
