1 /*
2 * Extensible Firmware Interface
3 *
4 * Based on Extensible Firmware Interface Specification version 2.4
5 *
6 * Copyright (C) 2013 - 2015 Linaro Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14 #define pr_fmt(fmt) "efi: " fmt
15
16 #include <linux/efi.h>
17 #include <linux/init.h>
18 #include <linux/memblock.h>
19 #include <linux/mm_types.h>
20 #include <linux/of.h>
21 #include <linux/of_fdt.h>
22 #include <linux/platform_device.h>
23 #include <linux/screen_info.h>
24
25 #include <asm/efi.h>
26
27 u64 efi_system_table;
28
is_memory(efi_memory_desc_t * md)29 static int __init is_memory(efi_memory_desc_t *md)
30 {
31 if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
32 return 1;
33 return 0;
34 }
35
36 /*
37 * Translate a EFI virtual address into a physical address: this is necessary,
38 * as some data members of the EFI system table are virtually remapped after
39 * SetVirtualAddressMap() has been called.
40 */
efi_to_phys(unsigned long addr)41 static phys_addr_t efi_to_phys(unsigned long addr)
42 {
43 efi_memory_desc_t *md;
44
45 for_each_efi_memory_desc(md) {
46 if (!(md->attribute & EFI_MEMORY_RUNTIME))
47 continue;
48 if (md->virt_addr == 0)
49 /* no virtual mapping has been installed by the stub */
50 break;
51 if (md->virt_addr <= addr &&
52 (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
53 return md->phys_addr + addr - md->virt_addr;
54 }
55 return addr;
56 }
57
58 static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
59
60 static __initdata efi_config_table_type_t arch_tables[] = {
61 {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
62 {NULL_GUID, NULL, NULL}
63 };
64
init_screen_info(void)65 static void __init init_screen_info(void)
66 {
67 struct screen_info *si;
68
69 if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
70 si = early_memremap_ro(screen_info_table, sizeof(*si));
71 if (!si) {
72 pr_err("Could not map screen_info config table\n");
73 return;
74 }
75 screen_info = *si;
76 early_memunmap(si, sizeof(*si));
77
78 /* dummycon on ARM needs non-zero values for columns/lines */
79 screen_info.orig_video_cols = 80;
80 screen_info.orig_video_lines = 25;
81 }
82
83 if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
84 memblock_is_map_memory(screen_info.lfb_base))
85 memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
86 }
87
uefi_init(void)88 static int __init uefi_init(void)
89 {
90 efi_char16_t *c16;
91 void *config_tables;
92 size_t table_size;
93 char vendor[100] = "unknown";
94 int i, retval;
95
96 efi.systab = early_memremap_ro(efi_system_table,
97 sizeof(efi_system_table_t));
98 if (efi.systab == NULL) {
99 pr_warn("Unable to map EFI system table.\n");
100 return -ENOMEM;
101 }
102
103 set_bit(EFI_BOOT, &efi.flags);
104 if (IS_ENABLED(CONFIG_64BIT))
105 set_bit(EFI_64BIT, &efi.flags);
106
107 /*
108 * Verify the EFI Table
109 */
110 if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
111 pr_err("System table signature incorrect\n");
112 retval = -EINVAL;
113 goto out;
114 }
115 if ((efi.systab->hdr.revision >> 16) < 2)
116 pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
117 efi.systab->hdr.revision >> 16,
118 efi.systab->hdr.revision & 0xffff);
119
120 efi.runtime_version = efi.systab->hdr.revision;
121
122 /* Show what we know for posterity */
123 c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
124 sizeof(vendor) * sizeof(efi_char16_t));
125 if (c16) {
126 for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
127 vendor[i] = c16[i];
128 vendor[i] = '\0';
129 early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
130 }
131
132 pr_info("EFI v%u.%.02u by %s\n",
133 efi.systab->hdr.revision >> 16,
134 efi.systab->hdr.revision & 0xffff, vendor);
135
136 table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
137 config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
138 table_size);
139 if (config_tables == NULL) {
140 pr_warn("Unable to map EFI config table array.\n");
141 retval = -ENOMEM;
142 goto out;
143 }
144 retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
145 sizeof(efi_config_table_t),
146 arch_tables);
147
148 early_memunmap(config_tables, table_size);
149 out:
150 early_memunmap(efi.systab, sizeof(efi_system_table_t));
151 return retval;
152 }
153
154 /*
155 * Return true for regions that can be used as System RAM.
156 */
is_usable_memory(efi_memory_desc_t * md)157 static __init int is_usable_memory(efi_memory_desc_t *md)
158 {
159 switch (md->type) {
160 case EFI_LOADER_CODE:
161 case EFI_LOADER_DATA:
162 case EFI_BOOT_SERVICES_CODE:
163 case EFI_BOOT_SERVICES_DATA:
164 case EFI_CONVENTIONAL_MEMORY:
165 case EFI_PERSISTENT_MEMORY:
166 /*
167 * According to the spec, these regions are no longer reserved
168 * after calling ExitBootServices(). However, we can only use
169 * them as System RAM if they can be mapped writeback cacheable.
170 */
171 return (md->attribute & EFI_MEMORY_WB);
172 default:
173 break;
174 }
175 return false;
176 }
177
reserve_regions(void)178 static __init void reserve_regions(void)
179 {
180 efi_memory_desc_t *md;
181 u64 paddr, npages, size;
182
183 if (efi_enabled(EFI_DBG))
184 pr_info("Processing EFI memory map:\n");
185
186 /*
187 * Discard memblocks discovered so far: if there are any at this
188 * point, they originate from memory nodes in the DT, and UEFI
189 * uses its own memory map instead.
190 */
191 memblock_dump_all();
192 memblock_remove(0, (phys_addr_t)ULLONG_MAX);
193
194 for_each_efi_memory_desc(md) {
195 paddr = md->phys_addr;
196 npages = md->num_pages;
197
198 if (efi_enabled(EFI_DBG)) {
199 char buf[64];
200
201 pr_info(" 0x%012llx-0x%012llx %s\n",
202 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
203 efi_md_typeattr_format(buf, sizeof(buf), md));
204 }
205
206 memrange_efi_to_native(&paddr, &npages);
207 size = npages << PAGE_SHIFT;
208
209 if (is_memory(md)) {
210 early_init_dt_add_memory_arch(paddr, size);
211
212 if (!is_usable_memory(md))
213 memblock_mark_nomap(paddr, size);
214 }
215 }
216 }
217
efi_init(void)218 void __init efi_init(void)
219 {
220 struct efi_memory_map_data data;
221 struct efi_fdt_params params;
222
223 /* Grab UEFI information placed in FDT by stub */
224 if (!efi_get_fdt_params(¶ms))
225 return;
226
227 efi_system_table = params.system_table;
228
229 data.desc_version = params.desc_ver;
230 data.desc_size = params.desc_size;
231 data.size = params.mmap_size;
232 data.phys_map = params.mmap;
233
234 if (efi_memmap_init_early(&data) < 0) {
235 /*
236 * If we are booting via UEFI, the UEFI memory map is the only
237 * description of memory we have, so there is little point in
238 * proceeding if we cannot access it.
239 */
240 panic("Unable to map EFI memory map.\n");
241 }
242
243 WARN(efi.memmap.desc_version != 1,
244 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
245 efi.memmap.desc_version);
246
247 if (uefi_init() < 0)
248 return;
249
250 reserve_regions();
251 efi_memattr_init();
252 efi_esrt_init();
253 efi_memmap_unmap();
254
255 memblock_reserve(params.mmap & PAGE_MASK,
256 PAGE_ALIGN(params.mmap_size +
257 (params.mmap & ~PAGE_MASK)));
258
259 init_screen_info();
260 }
261
register_gop_device(void)262 static int __init register_gop_device(void)
263 {
264 void *pd;
265
266 if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
267 return 0;
268
269 pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
270 &screen_info, sizeof(screen_info));
271 return PTR_ERR_OR_ZERO(pd);
272 }
273 subsys_initcall(register_gop_device);
274