tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
27u64 efi_system_table;
28
29static int __init is_normal_ram(efi_memory_desc_t *md)
30{
31 if (md->attribute & EFI_MEMORY_WB)
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 */
41static 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
58static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
59
60static __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
65static 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
88static 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);
149out:
150 early_memunmap(efi.systab, sizeof(efi_system_table_t));
151 return retval;
152}
153
154/*
155 * Return true for RAM regions we want to permanently reserve.
156 */
157static __init int is_reserve_region(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 return 0;
167 default:
168 break;
169 }
170 return is_normal_ram(md);
171}
172
173static __init void reserve_regions(void)
174{
175 efi_memory_desc_t *md;
176 u64 paddr, npages, size;
177 int resv;
178
179 if (efi_enabled(EFI_DBG))
180 pr_info("Processing EFI memory map:\n");
181
182 /*
183 * Discard memblocks discovered so far: if there are any at this
184 * point, they originate from memory nodes in the DT, and UEFI
185 * uses its own memory map instead.
186 */
187 memblock_dump_all();
188 memblock_remove(0, (phys_addr_t)ULLONG_MAX);
189
190 for_each_efi_memory_desc(md) {
191 paddr = md->phys_addr;
192 npages = md->num_pages;
193
194 resv = is_reserve_region(md);
195 if (efi_enabled(EFI_DBG)) {
196 char buf[64];
197
198 pr_info(" 0x%012llx-0x%012llx %s%s\n",
199 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
200 efi_md_typeattr_format(buf, sizeof(buf), md),
201 resv ? "*" : "");
202 }
203
204 memrange_efi_to_native(&paddr, &npages);
205 size = npages << PAGE_SHIFT;
206
207 if (is_normal_ram(md))
208 early_init_dt_add_memory_arch(paddr, size);
209
210 if (resv)
211 memblock_mark_nomap(paddr, size);
212
213 }
214
215 set_bit(EFI_MEMMAP, &efi.flags);
216}
217
218void __init efi_init(void)
219{
220 struct efi_fdt_params params;
221
222 /* Grab UEFI information placed in FDT by stub */
223 if (!efi_get_fdt_params(¶ms))
224 return;
225
226 efi_system_table = params.system_table;
227
228 efi.memmap.phys_map = params.mmap;
229 efi.memmap.map = early_memremap_ro(params.mmap, params.mmap_size);
230 if (efi.memmap.map == NULL) {
231 /*
232 * If we are booting via UEFI, the UEFI memory map is the only
233 * description of memory we have, so there is little point in
234 * proceeding if we cannot access it.
235 */
236 panic("Unable to map EFI memory map.\n");
237 }
238 efi.memmap.map_end = efi.memmap.map + params.mmap_size;
239 efi.memmap.desc_size = params.desc_size;
240 efi.memmap.desc_version = params.desc_ver;
241
242 WARN(efi.memmap.desc_version != 1,
243 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
244 efi.memmap.desc_version);
245
246 if (uefi_init() < 0)
247 return;
248
249 reserve_regions();
250 efi_memattr_init();
251 early_memunmap(efi.memmap.map, params.mmap_size);
252
253 memblock_reserve(params.mmap & PAGE_MASK,
254 PAGE_ALIGN(params.mmap_size +
255 (params.mmap & ~PAGE_MASK)));
256
257 init_screen_info();
258}
259
260static int __init register_gop_device(void)
261{
262 void *pd;
263
264 if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
265 return 0;
266
267 pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
268 &screen_info, sizeof(screen_info));
269 return PTR_ERR_OR_ZERO(pd);
270}
271subsys_initcall(register_gop_device);