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0f96a99d TI |
1 | /* |
2 | * fake_mem.c | |
3 | * | |
4 | * Copyright (C) 2015 FUJITSU LIMITED | |
5 | * Author: Taku Izumi <izumi.taku@jp.fujitsu.com> | |
6 | * | |
7 | * This code introduces new boot option named "efi_fake_mem" | |
8 | * By specifying this parameter, you can add arbitrary attribute to | |
9 | * specific memory range by updating original (firmware provided) EFI | |
10 | * memmap. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify it | |
13 | * under the terms and conditions of the GNU General Public License, | |
14 | * version 2, as published by the Free Software Foundation. | |
15 | * | |
16 | * This program is distributed in the hope it will be useful, but WITHOUT | |
17 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
18 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
19 | * more details. | |
20 | * | |
21 | * You should have received a copy of the GNU General Public License along with | |
22 | * this program; if not, see <http://www.gnu.org/licenses/>. | |
23 | * | |
24 | * The full GNU General Public License is included in this distribution in | |
25 | * the file called "COPYING". | |
26 | */ | |
27 | ||
28 | #include <linux/kernel.h> | |
29 | #include <linux/efi.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/memblock.h> | |
32 | #include <linux/types.h> | |
33 | #include <linux/sort.h> | |
34 | #include <asm/efi.h> | |
35 | ||
36 | #define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM | |
37 | ||
38 | struct fake_mem { | |
39 | struct range range; | |
40 | u64 attribute; | |
41 | }; | |
42 | static struct fake_mem fake_mems[EFI_MAX_FAKEMEM]; | |
43 | static int nr_fake_mem; | |
44 | ||
45 | static int __init cmp_fake_mem(const void *x1, const void *x2) | |
46 | { | |
47 | const struct fake_mem *m1 = x1; | |
48 | const struct fake_mem *m2 = x2; | |
49 | ||
50 | if (m1->range.start < m2->range.start) | |
51 | return -1; | |
52 | if (m1->range.start > m2->range.start) | |
53 | return 1; | |
54 | return 0; | |
55 | } | |
56 | ||
57 | void __init efi_fake_memmap(void) | |
58 | { | |
59 | u64 start, end, m_start, m_end, m_attr; | |
884f4f66 | 60 | int new_nr_map = efi.memmap.nr_map; |
0f96a99d | 61 | efi_memory_desc_t *md; |
78b9bc94 | 62 | phys_addr_t new_memmap_phy; |
0f96a99d TI |
63 | void *new_memmap; |
64 | void *old, *new; | |
65 | int i; | |
66 | ||
4971531a | 67 | if (!nr_fake_mem) |
0f96a99d TI |
68 | return; |
69 | ||
70 | /* count up the number of EFI memory descriptor */ | |
78ce248f | 71 | for_each_efi_memory_desc(md) { |
0f96a99d TI |
72 | start = md->phys_addr; |
73 | end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; | |
74 | ||
75 | for (i = 0; i < nr_fake_mem; i++) { | |
76 | /* modifying range */ | |
77 | m_start = fake_mems[i].range.start; | |
78 | m_end = fake_mems[i].range.end; | |
79 | ||
80 | if (m_start <= start) { | |
81 | /* split into 2 parts */ | |
82 | if (start < m_end && m_end < end) | |
83 | new_nr_map++; | |
84 | } | |
85 | if (start < m_start && m_start < end) { | |
86 | /* split into 3 parts */ | |
87 | if (m_end < end) | |
88 | new_nr_map += 2; | |
89 | /* split into 2 parts */ | |
90 | if (end <= m_end) | |
91 | new_nr_map++; | |
92 | } | |
93 | } | |
94 | } | |
95 | ||
96 | /* allocate memory for new EFI memmap */ | |
884f4f66 | 97 | new_memmap_phy = memblock_alloc(efi.memmap.desc_size * new_nr_map, |
0f96a99d TI |
98 | PAGE_SIZE); |
99 | if (!new_memmap_phy) | |
100 | return; | |
101 | ||
102 | /* create new EFI memmap */ | |
103 | new_memmap = early_memremap(new_memmap_phy, | |
884f4f66 | 104 | efi.memmap.desc_size * new_nr_map); |
0f96a99d | 105 | if (!new_memmap) { |
884f4f66 | 106 | memblock_free(new_memmap_phy, efi.memmap.desc_size * new_nr_map); |
0f96a99d TI |
107 | return; |
108 | } | |
109 | ||
884f4f66 MF |
110 | for (old = efi.memmap.map, new = new_memmap; |
111 | old < efi.memmap.map_end; | |
112 | old += efi.memmap.desc_size, new += efi.memmap.desc_size) { | |
0f96a99d TI |
113 | |
114 | /* copy original EFI memory descriptor */ | |
884f4f66 | 115 | memcpy(new, old, efi.memmap.desc_size); |
0f96a99d TI |
116 | md = new; |
117 | start = md->phys_addr; | |
118 | end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; | |
119 | ||
120 | for (i = 0; i < nr_fake_mem; i++) { | |
121 | /* modifying range */ | |
122 | m_start = fake_mems[i].range.start; | |
123 | m_end = fake_mems[i].range.end; | |
124 | m_attr = fake_mems[i].attribute; | |
125 | ||
126 | if (m_start <= start && end <= m_end) | |
127 | md->attribute |= m_attr; | |
128 | ||
129 | if (m_start <= start && | |
130 | (start < m_end && m_end < end)) { | |
131 | /* first part */ | |
132 | md->attribute |= m_attr; | |
133 | md->num_pages = (m_end - md->phys_addr + 1) >> | |
134 | EFI_PAGE_SHIFT; | |
135 | /* latter part */ | |
884f4f66 MF |
136 | new += efi.memmap.desc_size; |
137 | memcpy(new, old, efi.memmap.desc_size); | |
0f96a99d TI |
138 | md = new; |
139 | md->phys_addr = m_end + 1; | |
140 | md->num_pages = (end - md->phys_addr + 1) >> | |
141 | EFI_PAGE_SHIFT; | |
142 | } | |
143 | ||
144 | if ((start < m_start && m_start < end) && m_end < end) { | |
145 | /* first part */ | |
146 | md->num_pages = (m_start - md->phys_addr) >> | |
147 | EFI_PAGE_SHIFT; | |
148 | /* middle part */ | |
884f4f66 MF |
149 | new += efi.memmap.desc_size; |
150 | memcpy(new, old, efi.memmap.desc_size); | |
0f96a99d TI |
151 | md = new; |
152 | md->attribute |= m_attr; | |
153 | md->phys_addr = m_start; | |
154 | md->num_pages = (m_end - m_start + 1) >> | |
155 | EFI_PAGE_SHIFT; | |
156 | /* last part */ | |
884f4f66 MF |
157 | new += efi.memmap.desc_size; |
158 | memcpy(new, old, efi.memmap.desc_size); | |
0f96a99d TI |
159 | md = new; |
160 | md->phys_addr = m_end + 1; | |
161 | md->num_pages = (end - m_end) >> | |
162 | EFI_PAGE_SHIFT; | |
163 | } | |
164 | ||
165 | if ((start < m_start && m_start < end) && | |
166 | (end <= m_end)) { | |
167 | /* first part */ | |
168 | md->num_pages = (m_start - md->phys_addr) >> | |
169 | EFI_PAGE_SHIFT; | |
170 | /* latter part */ | |
884f4f66 MF |
171 | new += efi.memmap.desc_size; |
172 | memcpy(new, old, efi.memmap.desc_size); | |
0f96a99d TI |
173 | md = new; |
174 | md->phys_addr = m_start; | |
175 | md->num_pages = (end - md->phys_addr + 1) >> | |
176 | EFI_PAGE_SHIFT; | |
177 | md->attribute |= m_attr; | |
178 | } | |
179 | } | |
180 | } | |
181 | ||
182 | /* swap into new EFI memmap */ | |
183 | efi_unmap_memmap(); | |
884f4f66 MF |
184 | efi.memmap.map = new_memmap; |
185 | efi.memmap.phys_map = new_memmap_phy; | |
186 | efi.memmap.nr_map = new_nr_map; | |
187 | efi.memmap.map_end = efi.memmap.map + efi.memmap.nr_map * efi.memmap.desc_size; | |
0f96a99d TI |
188 | set_bit(EFI_MEMMAP, &efi.flags); |
189 | ||
190 | /* print new EFI memmap */ | |
191 | efi_print_memmap(); | |
192 | } | |
193 | ||
194 | static int __init setup_fake_mem(char *p) | |
195 | { | |
196 | u64 start = 0, mem_size = 0, attribute = 0; | |
197 | int i; | |
198 | ||
199 | if (!p) | |
200 | return -EINVAL; | |
201 | ||
202 | while (*p != '\0') { | |
203 | mem_size = memparse(p, &p); | |
204 | if (*p == '@') | |
205 | start = memparse(p+1, &p); | |
206 | else | |
207 | break; | |
208 | ||
209 | if (*p == ':') | |
210 | attribute = simple_strtoull(p+1, &p, 0); | |
211 | else | |
212 | break; | |
213 | ||
214 | if (nr_fake_mem >= EFI_MAX_FAKEMEM) | |
215 | break; | |
216 | ||
217 | fake_mems[nr_fake_mem].range.start = start; | |
218 | fake_mems[nr_fake_mem].range.end = start + mem_size - 1; | |
219 | fake_mems[nr_fake_mem].attribute = attribute; | |
220 | nr_fake_mem++; | |
221 | ||
222 | if (*p == ',') | |
223 | p++; | |
224 | } | |
225 | ||
226 | sort(fake_mems, nr_fake_mem, sizeof(struct fake_mem), | |
227 | cmp_fake_mem, NULL); | |
228 | ||
229 | for (i = 0; i < nr_fake_mem; i++) | |
230 | pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]", | |
231 | fake_mems[i].attribute, fake_mems[i].range.start, | |
232 | fake_mems[i].range.end); | |
233 | ||
234 | return *p == '\0' ? 0 : -EINVAL; | |
235 | } | |
236 | ||
237 | early_param("efi_fake_mem", setup_fake_mem); |