Linux 4.19.133
[linux/fpc-iii.git] / drivers / firmware / efi / arm-runtime.c
bloba00934d263c519a9d476a57a5bb2388c6041b810
1 /*
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>
16 #include <linux/io.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>
27 #include <asm/efi.h>
28 #include <asm/mmu.h>
29 #include <asm/pgalloc.h>
30 #include <asm/pgtable.h>
32 extern u64 efi_system_table;
34 #ifdef CONFIG_ARM64_PTDUMP_DEBUGFS
35 #include <asm/ptdump.h>
37 static struct ptdump_info efi_ptdump_info = {
38 .mm = &efi_mm,
39 .markers = (struct addr_marker[]){
40 { 0, "UEFI runtime start" },
41 { TASK_SIZE_64, "UEFI runtime end" }
43 .base_addr = 0,
46 static int __init ptdump_init(void)
48 if (!efi_enabled(EFI_RUNTIME_SERVICES))
49 return 0;
51 return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
53 device_initcall(ptdump_init);
55 #endif
57 static bool __init efi_virtmap_init(void)
59 efi_memory_desc_t *md;
60 bool systab_found;
62 efi_mm.pgd = pgd_alloc(&efi_mm);
63 mm_init_cpumask(&efi_mm);
64 init_new_context(NULL, &efi_mm);
66 systab_found = false;
67 for_each_efi_memory_desc(md) {
68 phys_addr_t phys = md->phys_addr;
69 int ret;
71 if (!(md->attribute & EFI_MEMORY_RUNTIME))
72 continue;
73 if (md->virt_addr == 0)
74 return false;
76 ret = efi_create_mapping(&efi_mm, md);
77 if (ret) {
78 pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
79 &phys, ret);
80 return false;
83 * If this entry covers the address of the UEFI system table,
84 * calculate and record its virtual address.
86 if (efi_system_table >= phys &&
87 efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
88 efi.systab = (void *)(unsigned long)(efi_system_table -
89 phys + md->virt_addr);
90 systab_found = true;
93 if (!systab_found) {
94 pr_err("No virtual mapping found for the UEFI System Table\n");
95 return false;
98 if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
99 return false;
101 return true;
105 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
106 * non-early mapping of the UEFI system table and virtual mappings for all
107 * EFI_MEMORY_RUNTIME regions.
109 static int __init arm_enable_runtime_services(void)
111 u64 mapsize;
113 if (!efi_enabled(EFI_BOOT)) {
114 pr_info("EFI services will not be available.\n");
115 return 0;
118 efi_memmap_unmap();
120 mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
122 if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
123 pr_err("Failed to remap EFI memory map\n");
124 return 0;
127 if (efi_runtime_disabled()) {
128 pr_info("EFI runtime services will be disabled.\n");
129 return 0;
132 if (efi_enabled(EFI_RUNTIME_SERVICES)) {
133 pr_info("EFI runtime services access via paravirt.\n");
134 return 0;
137 pr_info("Remapping and enabling EFI services.\n");
139 if (!efi_virtmap_init()) {
140 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
141 return -ENOMEM;
144 /* Set up runtime services function pointers */
145 efi_native_runtime_setup();
146 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
148 return 0;
150 early_initcall(arm_enable_runtime_services);
152 void efi_virtmap_load(void)
154 preempt_disable();
155 efi_set_pgd(&efi_mm);
158 void efi_virtmap_unload(void)
160 efi_set_pgd(current->active_mm);
161 preempt_enable();
165 static int __init arm_dmi_init(void)
168 * On arm64/ARM, DMI depends on UEFI, and dmi_scan_machine() needs to
169 * be called early because dmi_id_init(), which is an arch_initcall
170 * itself, depends on dmi_scan_machine() having been called already.
172 dmi_scan_machine();
173 if (dmi_available)
174 dmi_set_dump_stack_arch_desc();
175 return 0;
177 core_initcall(arm_dmi_init);