2 * Extensible Firmware Interface
4 * Based on Extensible Firmware Interface Specification version 2.4
6 * Copyright (C) 2013, 2014 Linaro Ltd.
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.
14 #include <linux/dmi.h>
15 #include <linux/efi.h>
17 #include <linux/memblock.h>
18 #include <linux/mm_types.h>
19 #include <linux/preempt.h>
20 #include <linux/rbtree.h>
21 #include <linux/rwsem.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/spinlock.h>
26 #include <asm/cacheflush.h>
29 #include <asm/pgalloc.h>
30 #include <asm/pgtable.h>
32 extern u64 efi_system_table;
34 static struct mm_struct efi_mm = {
36 .mm_users = ATOMIC_INIT(2),
37 .mm_count = ATOMIC_INIT(1),
38 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
39 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
40 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
43 #ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
44 #include <asm/ptdump.h>
46 static struct ptdump_info efi_ptdump_info = {
48 .markers = (struct addr_marker[]){
49 { 0, "UEFI runtime start" },
50 { TASK_SIZE_64, "UEFI runtime end" }
55 static int __init ptdump_init(void)
57 if (!efi_enabled(EFI_RUNTIME_SERVICES))
60 return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
62 device_initcall(ptdump_init);
66 static bool __init efi_virtmap_init(void)
68 efi_memory_desc_t *md;
71 efi_mm.pgd = pgd_alloc(&efi_mm);
72 mm_init_cpumask(&efi_mm);
73 init_new_context(NULL, &efi_mm);
76 for_each_efi_memory_desc(md) {
77 phys_addr_t phys = md->phys_addr;
80 if (!(md->attribute & EFI_MEMORY_RUNTIME))
82 if (md->virt_addr == 0)
85 ret = efi_create_mapping(&efi_mm, md);
87 pr_info(" EFI remap %pa => %p\n",
88 &phys, (void *)(unsigned long)md->virt_addr);
90 pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
95 * If this entry covers the address of the UEFI system table,
96 * calculate and record its virtual address.
98 if (efi_system_table >= phys &&
99 efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
100 efi.systab = (void *)(unsigned long)(efi_system_table -
101 phys + md->virt_addr);
106 pr_err("No virtual mapping found for the UEFI System Table\n");
110 if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
117 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
118 * non-early mapping of the UEFI system table and virtual mappings for all
119 * EFI_MEMORY_RUNTIME regions.
121 static int __init arm_enable_runtime_services(void)
125 if (!efi_enabled(EFI_BOOT)) {
126 pr_info("EFI services will not be available.\n");
132 if (efi_runtime_disabled()) {
133 pr_info("EFI runtime services will be disabled.\n");
137 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
138 pr_info("EFI runtime services access via paravirt.\n");
142 pr_info("Remapping and enabling EFI services.\n");
144 mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
146 if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
147 pr_err("Failed to remap EFI memory map\n");
151 if (!efi_virtmap_init()) {
152 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
156 /* Set up runtime services function pointers */
157 efi_native_runtime_setup();
158 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
162 early_initcall(arm_enable_runtime_services);
164 void efi_virtmap_load(void)
167 efi_set_pgd(&efi_mm);
170 void efi_virtmap_unload(void)
172 efi_set_pgd(current->active_mm);
177 static int __init arm_dmi_init(void)
180 * On arm64/ARM, DMI depends on UEFI, and dmi_scan_machine() needs to
181 * be called early because dmi_id_init(), which is an arch_initcall
182 * itself, depends on dmi_scan_machine() having been called already.
186 dmi_set_dump_stack_arch_desc();
189 core_initcall(arm_dmi_init);