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/efi.h>
16 #include <linux/memblock.h>
17 #include <linux/mm_types.h>
18 #include <linux/preempt.h>
19 #include <linux/rbtree.h>
20 #include <linux/rwsem.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/spinlock.h>
25 #include <asm/cacheflush.h>
28 #include <asm/pgalloc.h>
29 #include <asm/pgtable.h>
31 extern u64 efi_system_table;
33 static struct mm_struct efi_mm = {
35 .mm_users = ATOMIC_INIT(2),
36 .mm_count = ATOMIC_INIT(1),
37 .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
38 .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
39 .mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
42 #ifdef CONFIG_ARM64_PTDUMP
43 #include <asm/ptdump.h>
45 static struct ptdump_info efi_ptdump_info = {
47 .markers = (struct addr_marker[]){
48 { 0, "UEFI runtime start" },
49 { TASK_SIZE_64, "UEFI runtime end" }
54 static int __init ptdump_init(void)
56 return ptdump_register(&efi_ptdump_info, "efi_page_tables");
58 device_initcall(ptdump_init);
62 static bool __init efi_virtmap_init(void)
64 efi_memory_desc_t *md;
67 efi_mm.pgd = pgd_alloc(&efi_mm);
68 mm_init_cpumask(&efi_mm);
69 init_new_context(NULL, &efi_mm);
72 for_each_efi_memory_desc(md) {
73 phys_addr_t phys = md->phys_addr;
76 if (!(md->attribute & EFI_MEMORY_RUNTIME))
78 if (md->virt_addr == 0)
81 ret = efi_create_mapping(&efi_mm, md);
83 pr_info(" EFI remap %pa => %p\n",
84 &phys, (void *)(unsigned long)md->virt_addr);
86 pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
91 * If this entry covers the address of the UEFI system table,
92 * calculate and record its virtual address.
94 if (efi_system_table >= phys &&
95 efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
96 efi.systab = (void *)(unsigned long)(efi_system_table -
97 phys + md->virt_addr);
102 pr_err("No virtual mapping found for the UEFI System Table\n");
106 if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
113 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
114 * non-early mapping of the UEFI system table and virtual mappings for all
115 * EFI_MEMORY_RUNTIME regions.
117 static int __init arm_enable_runtime_services(void)
121 if (!efi_enabled(EFI_BOOT)) {
122 pr_info("EFI services will not be available.\n");
128 if (efi_runtime_disabled()) {
129 pr_info("EFI runtime services will be disabled.\n");
133 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
134 pr_info("EFI runtime services access via paravirt.\n");
138 pr_info("Remapping and enabling EFI services.\n");
140 mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
142 if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
143 pr_err("Failed to remap EFI memory map\n");
147 if (!efi_virtmap_init()) {
148 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
152 /* Set up runtime services function pointers */
153 efi_native_runtime_setup();
154 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
158 early_initcall(arm_enable_runtime_services);
160 void efi_virtmap_load(void)
163 efi_set_pgd(&efi_mm);
166 void efi_virtmap_unload(void)
168 efi_set_pgd(current->active_mm);