xref: /openbmc/linux/arch/loongarch/kernel/efi.c (revision 83146efc)
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/screen_info.h>
22 #include <linux/uaccess.h>
23 
24 #include <asm/early_ioremap.h>
25 #include <asm/efi.h>
26 #include <asm/loongson.h>
27 
28 static unsigned long efi_nr_tables;
29 static unsigned long efi_config_table;
30 
31 static unsigned long __initdata boot_memmap = EFI_INVALID_TABLE_ADDR;
32 static unsigned long __initdata fdt_pointer = EFI_INVALID_TABLE_ADDR;
33 
34 static efi_system_table_t *efi_systab;
35 static efi_config_table_type_t arch_tables[] __initdata = {
36 	{LINUX_EFI_BOOT_MEMMAP_GUID,	&boot_memmap,	"MEMMAP" },
37 	{DEVICE_TREE_GUID,		&fdt_pointer,	"FDTPTR" },
38 	{},
39 };
40 
41 void __init *efi_fdt_pointer(void)
42 {
43 	if (!efi_systab)
44 		return NULL;
45 
46 	if (fdt_pointer == EFI_INVALID_TABLE_ADDR)
47 		return NULL;
48 
49 	return early_memremap_ro(fdt_pointer, SZ_64K);
50 }
51 
52 void __init efi_runtime_init(void)
53 {
54 	if (!efi_enabled(EFI_BOOT) || !efi_systab->runtime)
55 		return;
56 
57 	if (efi_runtime_disabled()) {
58 		pr_info("EFI runtime services will be disabled.\n");
59 		return;
60 	}
61 
62 	efi.runtime = (efi_runtime_services_t *)efi_systab->runtime;
63 	efi.runtime_version = (unsigned int)efi.runtime->hdr.revision;
64 
65 	efi_native_runtime_setup();
66 	set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
67 }
68 
69 unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;
70 
71 static void __init init_screen_info(void)
72 {
73 	struct screen_info *si;
74 
75 	if (screen_info_table == EFI_INVALID_TABLE_ADDR)
76 		return;
77 
78 	si = early_memremap(screen_info_table, sizeof(*si));
79 	if (!si) {
80 		pr_err("Could not map screen_info config table\n");
81 		return;
82 	}
83 	screen_info = *si;
84 	memset(si, 0, sizeof(*si));
85 	early_memunmap(si, sizeof(*si));
86 
87 	memblock_reserve(screen_info.lfb_base, screen_info.lfb_size);
88 }
89 
90 void __init efi_init(void)
91 {
92 	int size;
93 	void *config_tables;
94 	struct efi_boot_memmap *tbl;
95 
96 	if (!efi_system_table)
97 		return;
98 
99 	efi_systab = (efi_system_table_t *)early_memremap_ro(efi_system_table, sizeof(*efi_systab));
100 	if (!efi_systab) {
101 		pr_err("Can't find EFI system table.\n");
102 		return;
103 	}
104 
105 	efi_systab_report_header(&efi_systab->hdr, efi_systab->fw_vendor);
106 
107 	set_bit(EFI_64BIT, &efi.flags);
108 	efi_nr_tables	 = efi_systab->nr_tables;
109 	efi_config_table = (unsigned long)efi_systab->tables;
110 
111 	size = sizeof(efi_config_table_t);
112 	config_tables = early_memremap(efi_config_table, efi_nr_tables * size);
113 	efi_config_parse_tables(config_tables, efi_systab->nr_tables, arch_tables);
114 	early_memunmap(config_tables, efi_nr_tables * size);
115 
116 	set_bit(EFI_CONFIG_TABLES, &efi.flags);
117 
118 	init_screen_info();
119 
120 	if (boot_memmap == EFI_INVALID_TABLE_ADDR)
121 		return;
122 
123 	tbl = early_memremap_ro(boot_memmap, sizeof(*tbl));
124 	if (tbl) {
125 		struct efi_memory_map_data data;
126 
127 		data.phys_map		= boot_memmap + sizeof(*tbl);
128 		data.size		= tbl->map_size;
129 		data.desc_size		= tbl->desc_size;
130 		data.desc_version	= tbl->desc_ver;
131 
132 		if (efi_memmap_init_early(&data) < 0)
133 			panic("Unable to map EFI memory map.\n");
134 
135 		early_memunmap(tbl, sizeof(*tbl));
136 	}
137 }
138