1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Common EFI memory map functions.
4 */
5
6#define pr_fmt(fmt) "efi: " fmt
7
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/efi.h>
11#include <linux/io.h>
12#include <asm/early_ioremap.h>
13#include <asm/efi.h>
14#include <linux/memblock.h>
15#include <linux/slab.h>
16
17static phys_addr_t __init __efi_memmap_alloc_early(unsigned long size)
18{
19 return memblock_phys_alloc(size, SMP_CACHE_BYTES);
20}
21
22static phys_addr_t __init __efi_memmap_alloc_late(unsigned long size)
23{
24 unsigned int order = get_order(size);
25 struct page *p = alloc_pages(GFP_KERNEL, order);
26
27 if (!p)
28 return 0;
29
30 return PFN_PHYS(page_to_pfn(p));
31}
32
33void __init __efi_memmap_free(u64 phys, unsigned long size, unsigned long flags)
34{
35 if (flags & EFI_MEMMAP_MEMBLOCK) {
36 if (slab_is_available())
37 memblock_free_late(base: phys, size);
38 else
39 memblock_phys_free(base: phys, size);
40 } else if (flags & EFI_MEMMAP_SLAB) {
41 struct page *p = pfn_to_page(PHYS_PFN(phys));
42 unsigned int order = get_order(size);
43
44 free_pages(addr: (unsigned long) page_address(p), order);
45 }
46}
47
48/**
49 * efi_memmap_alloc - Allocate memory for the EFI memory map
50 * @num_entries: Number of entries in the allocated map.
51 * @data: efi memmap installation parameters
52 *
53 * Depending on whether mm_init() has already been invoked or not,
54 * either memblock or "normal" page allocation is used.
55 *
56 * Returns zero on success, a negative error code on failure.
57 */
58int __init efi_memmap_alloc(unsigned int num_entries,
59 struct efi_memory_map_data *data)
60{
61 /* Expect allocation parameters are zero initialized */
62 WARN_ON(data->phys_map || data->size);
63
64 data->size = num_entries * efi.memmap.desc_size;
65 data->desc_version = efi.memmap.desc_version;
66 data->desc_size = efi.memmap.desc_size;
67 data->flags &= ~(EFI_MEMMAP_SLAB | EFI_MEMMAP_MEMBLOCK);
68 data->flags |= efi.memmap.flags & EFI_MEMMAP_LATE;
69
70 if (slab_is_available()) {
71 data->flags |= EFI_MEMMAP_SLAB;
72 data->phys_map = __efi_memmap_alloc_late(size: data->size);
73 } else {
74 data->flags |= EFI_MEMMAP_MEMBLOCK;
75 data->phys_map = __efi_memmap_alloc_early(size: data->size);
76 }
77
78 if (!data->phys_map)
79 return -ENOMEM;
80 return 0;
81}
82
83/**
84 * efi_memmap_install - Install a new EFI memory map in efi.memmap
85 * @data: efi memmap installation parameters
86 *
87 * Unlike efi_memmap_init_*(), this function does not allow the caller
88 * to switch from early to late mappings. It simply uses the existing
89 * mapping function and installs the new memmap.
90 *
91 * Returns zero on success, a negative error code on failure.
92 */
93int __init efi_memmap_install(struct efi_memory_map_data *data)
94{
95 efi_memmap_unmap();
96
97 if (efi_enabled(EFI_PARAVIRT))
98 return 0;
99
100 return __efi_memmap_init(data);
101}
102
103/**
104 * efi_memmap_split_count - Count number of additional EFI memmap entries
105 * @md: EFI memory descriptor to split
106 * @range: Address range (start, end) to split around
107 *
108 * Returns the number of additional EFI memmap entries required to
109 * accommodate @range.
110 */
111int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range)
112{
113 u64 m_start, m_end;
114 u64 start, end;
115 int count = 0;
116
117 start = md->phys_addr;
118 end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
119
120 /* modifying range */
121 m_start = range->start;
122 m_end = range->end;
123
124 if (m_start <= start) {
125 /* split into 2 parts */
126 if (start < m_end && m_end < end)
127 count++;
128 }
129
130 if (start < m_start && m_start < end) {
131 /* split into 3 parts */
132 if (m_end < end)
133 count += 2;
134 /* split into 2 parts */
135 if (end <= m_end)
136 count++;
137 }
138
139 return count;
140}
141
142/**
143 * efi_memmap_insert - Insert a memory region in an EFI memmap
144 * @old_memmap: The existing EFI memory map structure
145 * @buf: Address of buffer to store new map
146 * @mem: Memory map entry to insert
147 *
148 * It is suggested that you call efi_memmap_split_count() first
149 * to see how large @buf needs to be.
150 */
151void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
152 struct efi_mem_range *mem)
153{
154 u64 m_start, m_end, m_attr;
155 efi_memory_desc_t *md;
156 u64 start, end;
157 void *old, *new;
158
159 /* modifying range */
160 m_start = mem->range.start;
161 m_end = mem->range.end;
162 m_attr = mem->attribute;
163
164 /*
165 * The EFI memory map deals with regions in EFI_PAGE_SIZE
166 * units. Ensure that the region described by 'mem' is aligned
167 * correctly.
168 */
169 if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) ||
170 !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) {
171 WARN_ON(1);
172 return;
173 }
174
175 for (old = old_memmap->map, new = buf;
176 old < old_memmap->map_end;
177 old += old_memmap->desc_size, new += old_memmap->desc_size) {
178
179 /* copy original EFI memory descriptor */
180 memcpy(new, old, old_memmap->desc_size);
181 md = new;
182 start = md->phys_addr;
183 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
184
185 if (m_start <= start && end <= m_end)
186 md->attribute |= m_attr;
187
188 if (m_start <= start &&
189 (start < m_end && m_end < end)) {
190 /* first part */
191 md->attribute |= m_attr;
192 md->num_pages = (m_end - md->phys_addr + 1) >>
193 EFI_PAGE_SHIFT;
194 /* latter part */
195 new += old_memmap->desc_size;
196 memcpy(new, old, old_memmap->desc_size);
197 md = new;
198 md->phys_addr = m_end + 1;
199 md->num_pages = (end - md->phys_addr + 1) >>
200 EFI_PAGE_SHIFT;
201 }
202
203 if ((start < m_start && m_start < end) && m_end < end) {
204 /* first part */
205 md->num_pages = (m_start - md->phys_addr) >>
206 EFI_PAGE_SHIFT;
207 /* middle part */
208 new += old_memmap->desc_size;
209 memcpy(new, old, old_memmap->desc_size);
210 md = new;
211 md->attribute |= m_attr;
212 md->phys_addr = m_start;
213 md->num_pages = (m_end - m_start + 1) >>
214 EFI_PAGE_SHIFT;
215 /* last part */
216 new += old_memmap->desc_size;
217 memcpy(new, old, old_memmap->desc_size);
218 md = new;
219 md->phys_addr = m_end + 1;
220 md->num_pages = (end - m_end) >>
221 EFI_PAGE_SHIFT;
222 }
223
224 if ((start < m_start && m_start < end) &&
225 (end <= m_end)) {
226 /* first part */
227 md->num_pages = (m_start - md->phys_addr) >>
228 EFI_PAGE_SHIFT;
229 /* latter part */
230 new += old_memmap->desc_size;
231 memcpy(new, old, old_memmap->desc_size);
232 md = new;
233 md->phys_addr = m_start;
234 md->num_pages = (end - md->phys_addr + 1) >>
235 EFI_PAGE_SHIFT;
236 md->attribute |= m_attr;
237 }
238 }
239}
240

source code of linux/arch/x86/platform/efi/memmap.c