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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 - 2015 Linaro Ltd.8 */9 10#define pr_fmt(fmt) "efi: " fmt11 12#include <linux/efi.h>13#include <linux/fwnode.h>14#include <linux/init.h>15#include <linux/memblock.h>16#include <linux/mm_types.h>17#include <linux/of.h>18#include <linux/of_address.h>19#include <linux/of_fdt.h>20#include <linux/platform_device.h>21#include <linux/screen_info.h>22 23#include <asm/efi.h>24 25unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR;26 27static int __init is_memory(efi_memory_desc_t *md)28{29 if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))30 return 1;31 return 0;32}33 34/*35 * Translate a EFI virtual address into a physical address: this is necessary,36 * as some data members of the EFI system table are virtually remapped after37 * SetVirtualAddressMap() has been called.38 */39static phys_addr_t __init efi_to_phys(unsigned long addr)40{41 efi_memory_desc_t *md;42 43 for_each_efi_memory_desc(md) {44 if (!(md->attribute & EFI_MEMORY_RUNTIME))45 continue;46 if (md->virt_addr == 0)47 /* no virtual mapping has been installed by the stub */48 break;49 if (md->virt_addr <= addr &&50 (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))51 return md->phys_addr + addr - md->virt_addr;52 }53 return addr;54}55 56extern __weak const efi_config_table_type_t efi_arch_tables[];57 58/*59 * x86 defines its own screen_info and uses it even without EFI,60 * everything else can get it from here.61 */62#if !defined(CONFIG_X86) && (defined(CONFIG_SYSFB) || defined(CONFIG_EFI_EARLYCON))63struct screen_info screen_info __section(".data");64EXPORT_SYMBOL_GPL(screen_info);65#endif66 67static void __init init_screen_info(void)68{69 struct screen_info *si;70 71 if (screen_info_table != EFI_INVALID_TABLE_ADDR) {72 si = early_memremap(screen_info_table, sizeof(*si));73 if (!si) {74 pr_err("Could not map screen_info config table\n");75 return;76 }77 screen_info = *si;78 memset(si, 0, sizeof(*si));79 early_memunmap(si, sizeof(*si));80 81 if (memblock_is_map_memory(screen_info.lfb_base))82 memblock_mark_nomap(screen_info.lfb_base,83 screen_info.lfb_size);84 85 if (IS_ENABLED(CONFIG_EFI_EARLYCON))86 efi_earlycon_reprobe();87 }88}89 90static int __init uefi_init(u64 efi_system_table)91{92 efi_config_table_t *config_tables;93 efi_system_table_t *systab;94 size_t table_size;95 int retval;96 97 systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t));98 if (systab == NULL) {99 pr_warn("Unable to map EFI system table.\n");100 return -ENOMEM;101 }102 103 set_bit(EFI_BOOT, &efi.flags);104 if (IS_ENABLED(CONFIG_64BIT))105 set_bit(EFI_64BIT, &efi.flags);106 107 retval = efi_systab_check_header(&systab->hdr);108 if (retval)109 goto out;110 111 efi.runtime = systab->runtime;112 efi.runtime_version = systab->hdr.revision;113 114 efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor));115 116 table_size = sizeof(efi_config_table_t) * systab->nr_tables;117 config_tables = early_memremap_ro(efi_to_phys(systab->tables),118 table_size);119 if (config_tables == NULL) {120 pr_warn("Unable to map EFI config table array.\n");121 retval = -ENOMEM;122 goto out;123 }124 retval = efi_config_parse_tables(config_tables, systab->nr_tables,125 efi_arch_tables);126 127 early_memunmap(config_tables, table_size);128out:129 early_memunmap(systab, sizeof(efi_system_table_t));130 return retval;131}132 133/*134 * Return true for regions that can be used as System RAM.135 */136static __init int is_usable_memory(efi_memory_desc_t *md)137{138 switch (md->type) {139 case EFI_LOADER_CODE:140 case EFI_LOADER_DATA:141 case EFI_ACPI_RECLAIM_MEMORY:142 case EFI_BOOT_SERVICES_CODE:143 case EFI_BOOT_SERVICES_DATA:144 case EFI_CONVENTIONAL_MEMORY:145 case EFI_PERSISTENT_MEMORY:146 /*147 * According to the spec, these regions are no longer reserved148 * after calling ExitBootServices(). However, we can only use149 * them as System RAM if they can be mapped writeback cacheable.150 */151 return (md->attribute & EFI_MEMORY_WB);152 default:153 break;154 }155 return false;156}157 158static __init void reserve_regions(void)159{160 efi_memory_desc_t *md;161 u64 paddr, npages, size;162 163 if (efi_enabled(EFI_DBG))164 pr_info("Processing EFI memory map:\n");165 166 /*167 * Discard memblocks discovered so far: if there are any at this168 * point, they originate from memory nodes in the DT, and UEFI169 * uses its own memory map instead.170 */171 memblock_dump_all();172 memblock_remove(0, PHYS_ADDR_MAX);173 174 for_each_efi_memory_desc(md) {175 paddr = md->phys_addr;176 npages = md->num_pages;177 178 if (efi_enabled(EFI_DBG)) {179 char buf[64];180 181 pr_info(" 0x%012llx-0x%012llx %s\n",182 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,183 efi_md_typeattr_format(buf, sizeof(buf), md));184 }185 186 memrange_efi_to_native(&paddr, &npages);187 size = npages << PAGE_SHIFT;188 189 if (is_memory(md)) {190 /*191 * Special purpose memory is 'soft reserved', which192 * means it is set aside initially. Don't add a memblock193 * for it now so that it can be hotplugged back in or194 * be assigned to the dax driver after boot.195 */196 if (efi_soft_reserve_enabled() &&197 (md->attribute & EFI_MEMORY_SP))198 continue;199 200 early_init_dt_add_memory_arch(paddr, size);201 202 if (!is_usable_memory(md))203 memblock_mark_nomap(paddr, size);204 205 /* keep ACPI reclaim memory intact for kexec etc. */206 if (md->type == EFI_ACPI_RECLAIM_MEMORY)207 memblock_reserve(paddr, size);208 }209 }210}211 212void __init efi_init(void)213{214 struct efi_memory_map_data data;215 u64 efi_system_table;216 217 /* Grab UEFI information placed in FDT by stub */218 efi_system_table = efi_get_fdt_params(&data);219 if (!efi_system_table)220 return;221 222 if (efi_memmap_init_early(&data) < 0) {223 /*224 * If we are booting via UEFI, the UEFI memory map is the only225 * description of memory we have, so there is little point in226 * proceeding if we cannot access it.227 */228 panic("Unable to map EFI memory map.\n");229 }230 231 WARN(efi.memmap.desc_version != 1,232 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",233 efi.memmap.desc_version);234 235 if (uefi_init(efi_system_table) < 0) {236 efi_memmap_unmap();237 return;238 }239 240 reserve_regions();241 /*242 * For memblock manipulation, the cap should come after the memblock_add().243 * And now, memblock is fully populated, it is time to do capping.244 */245 early_init_dt_check_for_usable_mem_range();246 efi_find_mirror();247 efi_esrt_init();248 efi_mokvar_table_init();249 250 memblock_reserve(data.phys_map & PAGE_MASK,251 PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));252 253 if (IS_ENABLED(CONFIG_X86) ||254 IS_ENABLED(CONFIG_SYSFB) ||255 IS_ENABLED(CONFIG_EFI_EARLYCON))256 init_screen_info();257}258