1 // SPDX-License-Identifier: GPL-2.0
3 * Extensible Firmware Interface
5 * Based on Extensible Firmware Interface Specification version 2.4
7 * Copyright (C) 2013, 2014 Linaro Ltd.
10 #include <linux/dmi.h>
11 #include <linux/efi.h>
13 #include <linux/memblock.h>
14 #include <linux/mm_types.h>
15 #include <linux/preempt.h>
16 #include <linux/rbtree.h>
17 #include <linux/rwsem.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
22 #include <asm/cacheflush.h>
25 #include <asm/pgalloc.h>
26 #include <asm/pgtable.h>
28 extern u64 efi_system_table;
30 #ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
31 #include <asm/ptdump.h>
33 static struct ptdump_info efi_ptdump_info = {
35 .markers = (struct addr_marker[]){
36 { 0, "UEFI runtime start" },
37 { DEFAULT_MAP_WINDOW_64, "UEFI runtime end" },
43 static int __init ptdump_init(void)
45 if (efi_enabled(EFI_RUNTIME_SERVICES))
46 ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
50 device_initcall(ptdump_init);
54 static bool __init efi_virtmap_init(void)
56 efi_memory_desc_t *md;
59 efi_mm.pgd = pgd_alloc(&efi_mm);
60 mm_init_cpumask(&efi_mm);
61 init_new_context(NULL, &efi_mm);
64 for_each_efi_memory_desc(md) {
65 phys_addr_t phys = md->phys_addr;
68 if (!(md->attribute & EFI_MEMORY_RUNTIME))
70 if (md->virt_addr == 0)
73 ret = efi_create_mapping(&efi_mm, md);
75 pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
80 * If this entry covers the address of the UEFI system table,
81 * calculate and record its virtual address.
83 if (efi_system_table >= phys &&
84 efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
85 efi.systab = (void *)(unsigned long)(efi_system_table -
86 phys + md->virt_addr);
91 pr_err("No virtual mapping found for the UEFI System Table\n");
95 if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
102 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
103 * non-early mapping of the UEFI system table and virtual mappings for all
104 * EFI_MEMORY_RUNTIME regions.
106 static int __init arm_enable_runtime_services(void)
110 if (!efi_enabled(EFI_BOOT)) {
111 pr_info("EFI services will not be available.\n");
117 mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
119 if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
120 pr_err("Failed to remap EFI memory map\n");
124 if (efi_runtime_disabled()) {
125 pr_info("EFI runtime services will be disabled.\n");
129 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
130 pr_info("EFI runtime services access via paravirt.\n");
134 pr_info("Remapping and enabling EFI services.\n");
136 if (!efi_virtmap_init()) {
137 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
141 /* Set up runtime services function pointers */
142 efi_native_runtime_setup();
143 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
147 early_initcall(arm_enable_runtime_services);
149 void efi_virtmap_load(void)
152 efi_set_pgd(&efi_mm);
155 void efi_virtmap_unload(void)
157 efi_set_pgd(current->active_mm);
162 static int __init arm_dmi_init(void)
165 * On arm64/ARM, DMI depends on UEFI, and dmi_setup() needs to
166 * be called early because dmi_id_init(), which is an arch_initcall
167 * itself, depends on dmi_scan_machine() having been called already.
172 core_initcall(arm_dmi_init);