1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Extensible Firmware Interface 4 * 5 * Based on Extensible Firmware Interface Specification version 2.4 6 * 7 * Copyright (C) 2013 - 2015 Linaro Ltd. 8 */ 9 10 #define pr_fmt(fmt) "efi: " fmt 11 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 25 unsigned long __initdata screen_info_table = EFI_INVALID_TABLE_ADDR; 26 27 static 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 after 37 * SetVirtualAddressMap() has been called. 38 */ 39 static 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 56 extern __weak const efi_config_table_type_t efi_arch_tables[]; 57 58 static void __init init_screen_info(void) 59 { 60 struct screen_info *si; 61 62 if (screen_info_table != EFI_INVALID_TABLE_ADDR) { 63 si = early_memremap(screen_info_table, sizeof(*si)); 64 if (!si) { 65 pr_err("Could not map screen_info config table\n"); 66 return; 67 } 68 screen_info = *si; 69 memset(si, 0, sizeof(*si)); 70 early_memunmap(si, sizeof(*si)); 71 72 if (memblock_is_map_memory(screen_info.lfb_base)) 73 memblock_mark_nomap(screen_info.lfb_base, 74 screen_info.lfb_size); 75 } 76 } 77 78 static int __init uefi_init(u64 efi_system_table) 79 { 80 efi_config_table_t *config_tables; 81 efi_system_table_t *systab; 82 size_t table_size; 83 int retval; 84 85 systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t)); 86 if (systab == NULL) { 87 pr_warn("Unable to map EFI system table.\n"); 88 return -ENOMEM; 89 } 90 91 set_bit(EFI_BOOT, &efi.flags); 92 if (IS_ENABLED(CONFIG_64BIT)) 93 set_bit(EFI_64BIT, &efi.flags); 94 95 retval = efi_systab_check_header(&systab->hdr, 2); 96 if (retval) 97 goto out; 98 99 efi.runtime = systab->runtime; 100 efi.runtime_version = systab->hdr.revision; 101 102 efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor)); 103 104 table_size = sizeof(efi_config_table_t) * systab->nr_tables; 105 config_tables = early_memremap_ro(efi_to_phys(systab->tables), 106 table_size); 107 if (config_tables == NULL) { 108 pr_warn("Unable to map EFI config table array.\n"); 109 retval = -ENOMEM; 110 goto out; 111 } 112 retval = efi_config_parse_tables(config_tables, systab->nr_tables, 113 efi_arch_tables); 114 115 early_memunmap(config_tables, table_size); 116 out: 117 early_memunmap(systab, sizeof(efi_system_table_t)); 118 return retval; 119 } 120 121 /* 122 * Return true for regions that can be used as System RAM. 123 */ 124 static __init int is_usable_memory(efi_memory_desc_t *md) 125 { 126 switch (md->type) { 127 case EFI_LOADER_CODE: 128 case EFI_LOADER_DATA: 129 case EFI_ACPI_RECLAIM_MEMORY: 130 case EFI_BOOT_SERVICES_CODE: 131 case EFI_BOOT_SERVICES_DATA: 132 case EFI_CONVENTIONAL_MEMORY: 133 case EFI_PERSISTENT_MEMORY: 134 /* 135 * Special purpose memory is 'soft reserved', which means it 136 * is set aside initially, but can be hotplugged back in or 137 * be assigned to the dax driver after boot. 138 */ 139 if (efi_soft_reserve_enabled() && 140 (md->attribute & EFI_MEMORY_SP)) 141 return false; 142 143 /* 144 * According to the spec, these regions are no longer reserved 145 * after calling ExitBootServices(). However, we can only use 146 * them as System RAM if they can be mapped writeback cacheable. 147 */ 148 return (md->attribute & EFI_MEMORY_WB); 149 default: 150 break; 151 } 152 return false; 153 } 154 155 static __init void reserve_regions(void) 156 { 157 efi_memory_desc_t *md; 158 u64 paddr, npages, size; 159 160 if (efi_enabled(EFI_DBG)) 161 pr_info("Processing EFI memory map:\n"); 162 163 /* 164 * Discard memblocks discovered so far: if there are any at this 165 * point, they originate from memory nodes in the DT, and UEFI 166 * uses its own memory map instead. 167 */ 168 memblock_dump_all(); 169 memblock_remove(0, PHYS_ADDR_MAX); 170 171 for_each_efi_memory_desc(md) { 172 paddr = md->phys_addr; 173 npages = md->num_pages; 174 175 if (efi_enabled(EFI_DBG)) { 176 char buf[64]; 177 178 pr_info(" 0x%012llx-0x%012llx %s\n", 179 paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1, 180 efi_md_typeattr_format(buf, sizeof(buf), md)); 181 } 182 183 memrange_efi_to_native(&paddr, &npages); 184 size = npages << PAGE_SHIFT; 185 186 if (is_memory(md)) { 187 early_init_dt_add_memory_arch(paddr, size); 188 189 if (!is_usable_memory(md)) 190 memblock_mark_nomap(paddr, size); 191 192 /* keep ACPI reclaim memory intact for kexec etc. */ 193 if (md->type == EFI_ACPI_RECLAIM_MEMORY) 194 memblock_reserve(paddr, size); 195 } 196 } 197 } 198 199 void __init efi_init(void) 200 { 201 struct efi_memory_map_data data; 202 u64 efi_system_table; 203 204 /* Grab UEFI information placed in FDT by stub */ 205 efi_system_table = efi_get_fdt_params(&data); 206 if (!efi_system_table) 207 return; 208 209 if (efi_memmap_init_early(&data) < 0) { 210 /* 211 * If we are booting via UEFI, the UEFI memory map is the only 212 * description of memory we have, so there is little point in 213 * proceeding if we cannot access it. 214 */ 215 panic("Unable to map EFI memory map.\n"); 216 } 217 218 WARN(efi.memmap.desc_version != 1, 219 "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", 220 efi.memmap.desc_version); 221 222 if (uefi_init(efi_system_table) < 0) { 223 efi_memmap_unmap(); 224 return; 225 } 226 227 reserve_regions(); 228 /* 229 * For memblock manipulation, the cap should come after the memblock_add(). 230 * And now, memblock is fully populated, it is time to do capping. 231 */ 232 early_init_dt_check_for_usable_mem_range(); 233 efi_find_mirror(); 234 efi_esrt_init(); 235 efi_mokvar_table_init(); 236 237 memblock_reserve(data.phys_map & PAGE_MASK, 238 PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK))); 239 240 init_screen_info(); 241 } 242