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1// SPDX-License-Identifier: GPL-2.02/*3 * Extensible Firmware Interface4 *5 * Based on Extensible Firmware Interface Specification version 2.46 *7 * Copyright (C) 2013, 2014 Linaro Ltd.8 */9 10#include <linux/dmi.h>11#include <linux/efi.h>12#include <linux/io.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>21#include <linux/pgtable.h>22 23#include <asm/cacheflush.h>24#include <asm/efi.h>25#include <asm/mmu.h>26#include <asm/pgalloc.h>27 28#if defined(CONFIG_PTDUMP_DEBUGFS) || defined(CONFIG_ARM_PTDUMP_DEBUGFS)29#include <asm/ptdump.h>30 31static struct ptdump_info efi_ptdump_info = {32 .mm = &efi_mm,33 .markers = (struct addr_marker[]){34 { 0, "UEFI runtime start" },35 { EFI_RUNTIME_MAP_END, "UEFI runtime end" },36 { -1, NULL }37 },38 .base_addr = 0,39};40 41static int __init ptdump_init(void)42{43 if (efi_enabled(EFI_RUNTIME_SERVICES))44 ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");45 46 return 0;47}48device_initcall(ptdump_init);49 50#endif51 52static bool __init efi_virtmap_init(void)53{54 efi_memory_desc_t *md;55 56 efi_mm.pgd = pgd_alloc(&efi_mm);57 mm_init_cpumask(&efi_mm);58 init_new_context(NULL, &efi_mm);59 60 for_each_efi_memory_desc(md) {61 phys_addr_t phys = md->phys_addr;62 int ret;63 64 if (!(md->attribute & EFI_MEMORY_RUNTIME))65 continue;66 if (md->virt_addr == U64_MAX)67 return false;68 69 ret = efi_create_mapping(&efi_mm, md);70 if (ret) {71 pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",72 &phys, ret);73 return false;74 }75 }76 77 if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))78 return false;79 80 return true;81}82 83/*84 * Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,85 * non-early mapping of the UEFI system table and virtual mappings for all86 * EFI_MEMORY_RUNTIME regions.87 */88static int __init arm_enable_runtime_services(void)89{90 u64 mapsize;91 92 if (!efi_enabled(EFI_BOOT)) {93 pr_info("EFI services will not be available.\n");94 return 0;95 }96 97 efi_memmap_unmap();98 99 mapsize = efi.memmap.desc_size * efi.memmap.nr_map;100 101 if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {102 pr_err("Failed to remap EFI memory map\n");103 return 0;104 }105 106 if (efi_soft_reserve_enabled()) {107 efi_memory_desc_t *md;108 109 for_each_efi_memory_desc(md) {110 u64 md_size = md->num_pages << EFI_PAGE_SHIFT;111 struct resource *res;112 113 if (!(md->attribute & EFI_MEMORY_SP))114 continue;115 116 res = kzalloc(sizeof(*res), GFP_KERNEL);117 if (WARN_ON(!res))118 break;119 120 res->start = md->phys_addr;121 res->end = md->phys_addr + md_size - 1;122 res->name = "Soft Reserved";123 res->flags = IORESOURCE_MEM;124 res->desc = IORES_DESC_SOFT_RESERVED;125 126 insert_resource(&iomem_resource, res);127 }128 }129 130 if (efi_runtime_disabled()) {131 pr_info("EFI runtime services will be disabled.\n");132 return 0;133 }134 135 if (efi_enabled(EFI_RUNTIME_SERVICES)) {136 pr_info("EFI runtime services access via paravirt.\n");137 return 0;138 }139 140 pr_info("Remapping and enabling EFI services.\n");141 142 if (!efi_virtmap_init()) {143 pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");144 return -ENOMEM;145 }146 147 /* Set up runtime services function pointers */148 efi_native_runtime_setup();149 set_bit(EFI_RUNTIME_SERVICES, &efi.flags);150 151 return 0;152}153early_initcall(arm_enable_runtime_services);154 155void efi_virtmap_load(void)156{157 preempt_disable();158 efi_set_pgd(&efi_mm);159}160 161void efi_virtmap_unload(void)162{163 efi_set_pgd(current->active_mm);164 preempt_enable();165}166 167 168static int __init arm_dmi_init(void)169{170 /*171 * On arm64/ARM, DMI depends on UEFI, and dmi_setup() needs to172 * be called early because dmi_id_init(), which is an arch_initcall173 * itself, depends on dmi_scan_machine() having been called already.174 */175 dmi_setup();176 return 0;177}178core_initcall(arm_dmi_init);179