1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * EFI initialization
4  *
5  * Author: Jianmin Lv <lvjianmin@loongson.cn>
6  *         Huacai Chen <chenhuacai@loongson.cn>
7  *
8  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
9  */
10 
11 #include <linux/acpi.h>
12 #include <linux/efi.h>
13 #include <linux/efi-bgrt.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/export.h>
17 #include <linux/io.h>
18 #include <linux/kobject.h>
19 #include <linux/memblock.h>
20 #include <linux/reboot.h>
21 #include <linux/uaccess.h>
22 
23 #include <asm/early_ioremap.h>
24 #include <asm/efi.h>
25 #include <asm/loongson.h>
26 
27 static unsigned long efi_nr_tables;
28 static unsigned long efi_config_table;
29 
30 static unsigned long __initdata boot_memmap = EFI_INVALID_TABLE_ADDR;
31 static unsigned long __initdata fdt_pointer = EFI_INVALID_TABLE_ADDR;
32 
33 static efi_system_table_t *efi_systab;
34 static efi_config_table_type_t arch_tables[] __initdata = {
35 	{LINUX_EFI_BOOT_MEMMAP_GUID,	&boot_memmap,	"MEMMAP" },
36 	{DEVICE_TREE_GUID,		&fdt_pointer,	"FDTPTR" },
37 	{},
38 };
39 
efi_fdt_pointer(void)40 void __init *efi_fdt_pointer(void)
41 {
42 	if (!efi_systab)
43 		return NULL;
44 
45 	if (fdt_pointer == EFI_INVALID_TABLE_ADDR)
46 		return NULL;
47 
48 	return early_memremap_ro(fdt_pointer, SZ_64K);
49 }
50 
efi_runtime_init(void)51 void __init efi_runtime_init(void)
52 {
53 	if (!efi_enabled(EFI_BOOT) || !efi_systab->runtime)
54 		return;
55 
56 	if (efi_runtime_disabled()) {
57 		pr_info("EFI runtime services will be disabled.\n");
58 		return;
59 	}
60 
61 	efi.runtime = (efi_runtime_services_t *)efi_systab->runtime;
62 	efi.runtime_version = (unsigned int)efi.runtime->hdr.revision;
63 
64 	efi_native_runtime_setup();
65 	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
66 }
67 
68 unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
69 
init_screen_info(void)70 static void __init init_screen_info(void)
71 {
72 	struct screen_info *si;
73 
74 	if (screen_info_table == EFI_INVALID_TABLE_ADDR)
75 		return;
76 
77 	si = early_memremap(screen_info_table, sizeof(*si));
78 	if (!si) {
79 		pr_err("Could not map screen_info config table\n");
80 		return;
81 	}
82 	screen_info = *si;
83 	memset(si, 0, sizeof(*si));
84 	early_memunmap(si, sizeof(*si));
85 
86 	memblock_reserve(screen_info.lfb_base, screen_info.lfb_size);
87 }
88 
efi_init(void)89 void __init efi_init(void)
90 {
91 	int size;
92 	void *config_tables;
93 	struct efi_boot_memmap *tbl;
94 
95 	if (!efi_system_table)
96 		return;
97 
98 	efi_systab = (efi_system_table_t *)early_memremap_ro(efi_system_table, sizeof(*efi_systab));
99 	if (!efi_systab) {
100 		pr_err("Can't find EFI system table.\n");
101 		return;
102 	}
103 
104 	efi_systab_report_header(&efi_systab->hdr, efi_systab->fw_vendor);
105 
106 	set_bit(EFI_64BIT, &efi.flags);
107 	efi_nr_tables	 = efi_systab->nr_tables;
108 	efi_config_table = (unsigned long)efi_systab->tables;
109 
110 	size = sizeof(efi_config_table_t);
111 	config_tables = early_memremap(efi_config_table, efi_nr_tables * size);
112 	efi_config_parse_tables(config_tables, efi_systab->nr_tables, arch_tables);
113 	early_memunmap(config_tables, efi_nr_tables * size);
114 
115 	set_bit(EFI_CONFIG_TABLES, &efi.flags);
116 
117 	init_screen_info();
118 
119 	if (boot_memmap == EFI_INVALID_TABLE_ADDR)
120 		return;
121 
122 	tbl = early_memremap_ro(boot_memmap, sizeof(*tbl));
123 	if (tbl) {
124 		struct efi_memory_map_data data;
125 
126 		data.phys_map		= boot_memmap + sizeof(*tbl);
127 		data.size		= tbl->map_size;
128 		data.desc_size		= tbl->desc_size;
129 		data.desc_version	= tbl->desc_ver;
130 
131 		if (efi_memmap_init_early(&data) < 0)
132 			panic("Unable to map EFI memory map.\n");
133 
134 		early_memunmap(tbl, sizeof(*tbl));
135 	}
136 }
137