// SPDX-License-Identifier: GPL-2.0-only /* * efi.c - EFI subsystem * * Copyright (C) 2001,2003,2004 Dell * Copyright (C) 2004 Intel Corporation * Copyright (C) 2013 Tom Gundersen * * This code registers /sys/firmware/efi{,/efivars} when EFI is supported, * allowing the efivarfs to be mounted or the efivars module to be loaded. * The existance of /sys/firmware/efi may also be used by userspace to * determine that the system supports EFI. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct efi __read_mostly efi = { .runtime_supported_mask = EFI_RT_SUPPORTED_ALL, .acpi = EFI_INVALID_TABLE_ADDR, .acpi20 = EFI_INVALID_TABLE_ADDR, .smbios = EFI_INVALID_TABLE_ADDR, .smbios3 = EFI_INVALID_TABLE_ADDR, .esrt = EFI_INVALID_TABLE_ADDR, .tpm_log = EFI_INVALID_TABLE_ADDR, .tpm_final_log = EFI_INVALID_TABLE_ADDR, #ifdef CONFIG_LOAD_UEFI_KEYS .mokvar_table = EFI_INVALID_TABLE_ADDR, #endif }; EXPORT_SYMBOL(efi); unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR; static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR; static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR; struct mm_struct efi_mm = { .mm_rb = RB_ROOT, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), .write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq), MMAP_LOCK_INITIALIZER(efi_mm) .page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(efi_mm.mmlist), .cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0}, }; struct workqueue_struct *efi_rts_wq; static bool disable_runtime; static int __init setup_noefi(char *arg) { disable_runtime = true; return 0; } early_param("noefi", setup_noefi); bool efi_runtime_disabled(void) { return disable_runtime; } bool __pure __efi_soft_reserve_enabled(void) { return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE); } static int __init parse_efi_cmdline(char *str) { if (!str) { pr_warn("need at least one option\n"); return -EINVAL; } if (parse_option_str(str, "debug")) set_bit(EFI_DBG, &efi.flags); if (parse_option_str(str, "noruntime")) disable_runtime = true; if (parse_option_str(str, "nosoftreserve")) set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags); return 0; } early_param("efi", parse_efi_cmdline); struct kobject *efi_kobj; /* * Let's not leave out systab information that snuck into * the efivars driver * Note, do not add more fields in systab sysfs file as it breaks sysfs * one value per file rule! */ static ssize_t systab_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { char *str = buf; if (!kobj || !buf) return -EINVAL; if (efi.acpi20 != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20); if (efi.acpi != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "ACPI=0x%lx\n", efi.acpi); /* * If both SMBIOS and SMBIOS3 entry points are implemented, the * SMBIOS3 entry point shall be preferred, so we list it first to * let applications stop parsing after the first match. */ if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3); if (efi.smbios != EFI_INVALID_TABLE_ADDR) str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86)) str = efi_systab_show_arch(str); return str - buf; } static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400); static ssize_t fw_platform_size_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32); } extern __weak struct kobj_attribute efi_attr_fw_vendor; extern __weak struct kobj_attribute efi_attr_runtime; extern __weak struct kobj_attribute efi_attr_config_table; static struct kobj_attribute efi_attr_fw_platform_size = __ATTR_RO(fw_platform_size); static struct attribute *efi_subsys_attrs[] = { &efi_attr_systab.attr, &efi_attr_fw_platform_size.attr, &efi_attr_fw_vendor.attr, &efi_attr_runtime.attr, &efi_attr_config_table.attr, NULL, }; umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) { return attr->mode; } static const struct attribute_group efi_subsys_attr_group = { .attrs = efi_subsys_attrs, .is_visible = efi_attr_is_visible, }; static struct efivars generic_efivars; static struct efivar_operations generic_ops; static int generic_ops_register(void) { generic_ops.get_variable = efi.get_variable; generic_ops.get_next_variable = efi.get_next_variable; generic_ops.query_variable_store = efi_query_variable_store; if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) { generic_ops.set_variable = efi.set_variable; generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking; } return efivars_register(&generic_efivars, &generic_ops, efi_kobj); } static void generic_ops_unregister(void) { efivars_unregister(&generic_efivars); } #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str) { int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); if (ret) return ret; if (strlen(str) < sizeof(efivar_ssdt)) memcpy(efivar_ssdt, str, strlen(str)); else pr_warn("efivar_ssdt: name too long: %s\n", str); return 0; } __setup("efivar_ssdt=", efivar_ssdt_setup); static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor, unsigned long name_size, void *data) { struct efivar_entry *entry; struct list_head *list = data; char utf8_name[EFIVAR_SSDT_NAME_MAX]; int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size); ucs2_as_utf8(utf8_name, name, limit - 1); if (strncmp(utf8_name, efivar_ssdt, limit) != 0) return 0; entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return 0; memcpy(entry->var.VariableName, name, name_size); memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t)); efivar_entry_add(entry, list); return 0; } static __init int efivar_ssdt_load(void) { LIST_HEAD(entries); struct efivar_entry *entry, *aux; unsigned long size; void *data; int ret; if (!efivar_ssdt[0]) return 0; ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries); list_for_each_entry_safe(entry, aux, &entries, list) { pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &entry->var.VendorGuid); list_del(&entry->list); ret = efivar_entry_size(entry, &size); if (ret) { pr_err("failed to get var size\n"); goto free_entry; } data = kmalloc(size, GFP_KERNEL); if (!data) { ret = -ENOMEM; goto free_entry; } ret = efivar_entry_get(entry, NULL, &size, data); if (ret) { pr_err("failed to get var data\n"); goto free_data; } ret = acpi_load_table(data, NULL); if (ret) { pr_err("failed to load table: %d\n", ret); goto free_data; } goto free_entry; free_data: kfree(data); free_entry: kfree(entry); } return ret; } #else static inline int efivar_ssdt_load(void) { return 0; } #endif #ifdef CONFIG_DEBUG_FS #define EFI_DEBUGFS_MAX_BLOBS 32 static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS]; static void __init efi_debugfs_init(void) { struct dentry *efi_debugfs; efi_memory_desc_t *md; char name[32]; int type_count[EFI_BOOT_SERVICES_DATA + 1] = {}; int i = 0; efi_debugfs = debugfs_create_dir("efi", NULL); if (IS_ERR_OR_NULL(efi_debugfs)) return; for_each_efi_memory_desc(md) { switch (md->type) { case EFI_BOOT_SERVICES_CODE: snprintf(name, sizeof(name), "boot_services_code%d", type_count[md->type]++); break; case EFI_BOOT_SERVICES_DATA: snprintf(name, sizeof(name), "boot_services_data%d", type_count[md->type]++); break; default: continue; } if (i >= EFI_DEBUGFS_MAX_BLOBS) { pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n", EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS); break; } debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT; debugfs_blob[i].data = memremap(md->phys_addr, debugfs_blob[i].size, MEMREMAP_WB); if (!debugfs_blob[i].data) continue; debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]); i++; } } #else static inline void efi_debugfs_init(void) {} #endif /* * We register the efi subsystem with the firmware subsystem and the * efivars subsystem with the efi subsystem, if the system was booted with * EFI. */ static int __init efisubsys_init(void) { int error; if (!efi_enabled(EFI_RUNTIME_SERVICES)) efi.runtime_supported_mask = 0; if (!efi_enabled(EFI_BOOT)) return 0; if (efi.runtime_supported_mask) { /* * Since we process only one efi_runtime_service() at a time, an * ordered workqueue (which creates only one execution context) * should suffice for all our needs. */ efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0); if (!efi_rts_wq) { pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n"); clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); efi.runtime_supported_mask = 0; return 0; } } if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES)) platform_device_register_simple("rtc-efi", 0, NULL, 0); /* We register the efi directory at /sys/firmware/efi */ efi_kobj = kobject_create_and_add("efi", firmware_kobj); if (!efi_kobj) { pr_err("efi: Firmware registration failed.\n"); destroy_workqueue(efi_rts_wq); return -ENOMEM; } if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) { error = generic_ops_register(); if (error) goto err_put; efivar_ssdt_load(); platform_device_register_simple("efivars", 0, NULL, 0); } error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group); if (error) { pr_err("efi: Sysfs attribute export failed with error %d.\n", error); goto err_unregister; } error = efi_runtime_map_init(efi_kobj); if (error) goto err_remove_group; /* and the standard mountpoint for efivarfs */ error = sysfs_create_mount_point(efi_kobj, "efivars"); if (error) { pr_err("efivars: Subsystem registration failed.\n"); goto err_remove_group; } if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS)) efi_debugfs_init(); return 0; err_remove_group: sysfs_remove_group(efi_kobj, &efi_subsys_attr_group); err_unregister: if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE | EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) generic_ops_unregister(); err_put: kobject_put(efi_kobj); destroy_workqueue(efi_rts_wq); return error; } subsys_initcall(efisubsys_init); /* * Find the efi memory descriptor for a given physical address. Given a * physical address, determine if it exists within an EFI Memory Map entry, * and if so, populate the supplied memory descriptor with the appropriate * data. */ int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) { efi_memory_desc_t *md; if (!efi_enabled(EFI_MEMMAP)) { pr_err_once("EFI_MEMMAP is not enabled.\n"); return -EINVAL; } if (!out_md) { pr_err_once("out_md is null.\n"); return -EINVAL; } for_each_efi_memory_desc(md) { u64 size; u64 end; size = md->num_pages << EFI_PAGE_SHIFT; end = md->phys_addr + size; if (phys_addr >= md->phys_addr && phys_addr < end) { memcpy(out_md, md, sizeof(*out_md)); return 0; } } return -ENOENT; } /* * Calculate the highest address of an efi memory descriptor. */ u64 __init efi_mem_desc_end(efi_memory_desc_t *md) { u64 size = md->num_pages << EFI_PAGE_SHIFT; u64 end = md->phys_addr + size; return end; } void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} /** * efi_mem_reserve - Reserve an EFI memory region * @addr: Physical address to reserve * @size: Size of reservation * * Mark a region as reserved from general kernel allocation and * prevent it being released by efi_free_boot_services(). * * This function should be called drivers once they've parsed EFI * configuration tables to figure out where their data lives, e.g. * efi_esrt_init(). */ void __init efi_mem_reserve(phys_addr_t addr, u64 size) { if (!memblock_is_region_reserved(addr, size)) memblock_reserve(addr, size); /* * Some architectures (x86) reserve all boot services ranges * until efi_free_boot_services() because of buggy firmware * implementations. This means the above memblock_reserve() is * superfluous on x86 and instead what it needs to do is * ensure the @start, @size is not freed. */ efi_arch_mem_reserve(addr, size); } static const efi_config_table_type_t common_tables[] __initconst = { {ACPI_20_TABLE_GUID, &efi.acpi20, "ACPI 2.0" }, {ACPI_TABLE_GUID, &efi.acpi, "ACPI" }, {SMBIOS_TABLE_GUID, &efi.smbios, "SMBIOS" }, {SMBIOS3_TABLE_GUID, &efi.smbios3, "SMBIOS 3.0" }, {EFI_SYSTEM_RESOURCE_TABLE_GUID, &efi.esrt, "ESRT" }, {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, &efi_mem_attr_table, "MEMATTR" }, {LINUX_EFI_RANDOM_SEED_TABLE_GUID, &efi_rng_seed, "RNG" }, {LINUX_EFI_TPM_EVENT_LOG_GUID, &efi.tpm_log, "TPMEventLog" }, {LINUX_EFI_TPM_FINAL_LOG_GUID, &efi.tpm_final_log, "TPMFinalLog" }, {LINUX_EFI_MEMRESERVE_TABLE_GUID, &mem_reserve, "MEMRESERVE" }, {EFI_RT_PROPERTIES_TABLE_GUID, &rt_prop, "RTPROP" }, #ifdef CONFIG_EFI_RCI2_TABLE {DELLEMC_EFI_RCI2_TABLE_GUID, &rci2_table_phys }, #endif #ifdef CONFIG_LOAD_UEFI_KEYS {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" }, #endif {}, }; static __init int match_config_table(const efi_guid_t *guid, unsigned long table, const efi_config_table_type_t *table_types) { int i; for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) { if (!efi_guidcmp(*guid, table_types[i].guid)) { *(table_types[i].ptr) = table; if (table_types[i].name[0]) pr_cont("%s=0x%lx ", table_types[i].name, table); return 1; } } return 0; } int __init efi_config_parse_tables(const efi_config_table_t *config_tables, int count, const efi_config_table_type_t *arch_tables) { const efi_config_table_64_t *tbl64 = (void *)config_tables; const efi_config_table_32_t *tbl32 = (void *)config_tables; const efi_guid_t *guid; unsigned long table; int i; pr_info(""); for (i = 0; i < count; i++) { if (!IS_ENABLED(CONFIG_X86)) { guid = &config_tables[i].guid; table = (unsigned long)config_tables[i].table; } else if (efi_enabled(EFI_64BIT)) { guid = &tbl64[i].guid; table = tbl64[i].table; if (IS_ENABLED(CONFIG_X86_32) && tbl64[i].table > U32_MAX) { pr_cont("\n"); pr_err("Table located above 4GB, disabling EFI.\n"); return -EINVAL; } } else { guid = &tbl32[i].guid; table = tbl32[i].table; } if (!match_config_table(guid, table, common_tables) && arch_tables) match_config_table(guid, table, arch_tables); } pr_cont("\n"); set_bit(EFI_CONFIG_TABLES, &efi.flags); if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) { struct linux_efi_random_seed *seed; u32 size = 0; seed = early_memremap(efi_rng_seed, sizeof(*seed)); if (seed != NULL) { size = READ_ONCE(seed->size); early_memunmap(seed, sizeof(*seed)); } else { pr_err("Could not map UEFI random seed!\n"); } if (size > 0) { seed = early_memremap(efi_rng_seed, sizeof(*seed) + size); if (seed != NULL) { pr_notice("seeding entropy pool\n"); add_bootloader_randomness(seed->bits, size); early_memunmap(seed, sizeof(*seed) + size); } else { pr_err("Could not map UEFI random seed!\n"); } } } if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP)) efi_memattr_init(); efi_tpm_eventlog_init(); if (mem_reserve != EFI_INVALID_TABLE_ADDR) { unsigned long prsv = mem_reserve; while (prsv) { struct linux_efi_memreserve *rsv; u8 *p; /* * Just map a full page: that is what we will get * anyway, and it permits us to map the entire entry * before knowing its size. */ p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE), PAGE_SIZE); if (p == NULL) { pr_err("Could not map UEFI memreserve entry!\n"); return -ENOMEM; } rsv = (void *)(p + prsv % PAGE_SIZE); /* reserve the entry itself */ memblock_reserve(prsv, struct_size(rsv, entry, rsv->size)); for (i = 0; i < atomic_read(&rsv->count); i++) { memblock_reserve(rsv->entry[i].base, rsv->entry[i].size); } prsv = rsv->next; early_memunmap(p, PAGE_SIZE); } } if (rt_prop != EFI_INVALID_TABLE_ADDR) { efi_rt_properties_table_t *tbl; tbl = early_memremap(rt_prop, sizeof(*tbl)); if (tbl) { efi.runtime_supported_mask &= tbl->runtime_services_supported; early_memunmap(tbl, sizeof(*tbl)); } } return 0; } int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr, int min_major_version) { if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) { pr_err("System table signature incorrect!\n"); return -EINVAL; } if ((systab_hdr->revision >> 16) < min_major_version) pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n", systab_hdr->revision >> 16, systab_hdr->revision & 0xffff, min_major_version); return 0; } #ifndef CONFIG_IA64 static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor, size_t size) { const efi_char16_t *ret; ret = early_memremap_ro(fw_vendor, size); if (!ret) pr_err("Could not map the firmware vendor!\n"); return ret; } static void __init unmap_fw_vendor(const void *fw_vendor, size_t size) { early_memunmap((void *)fw_vendor, size); } #else #define map_fw_vendor(p, s) __va(p) #define unmap_fw_vendor(v, s) #endif void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr, unsigned long fw_vendor) { char vendor[100] = "unknown"; const efi_char16_t *c16; size_t i; c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t)); if (c16) { for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i) vendor[i] = c16[i]; vendor[i] = '\0'; unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t)); } pr_info("EFI v%u.%.02u by %s\n", systab_hdr->revision >> 16, systab_hdr->revision & 0xffff, vendor); if (IS_ENABLED(CONFIG_X86_64) && systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION && !strcmp(vendor, "Apple")) { pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n"); efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION; } } static __initdata char memory_type_name[][13] = { "Reserved", "Loader Code", "Loader Data", "Boot Code", "Boot Data", "Runtime Code", "Runtime Data", "Conventional", "Unusable", "ACPI Reclaim", "ACPI Mem NVS", "MMIO", "MMIO Port", "PAL Code", "Persistent", }; char * __init efi_md_typeattr_format(char *buf, size_t size, const efi_memory_desc_t *md) { char *pos; int type_len; u64 attr; pos = buf; if (md->type >= ARRAY_SIZE(memory_type_name)) type_len = snprintf(pos, size, "[type=%u", md->type); else type_len = snprintf(pos, size, "[%-*s", (int)(sizeof(memory_type_name[0]) - 1), memory_type_name[md->type]); if (type_len >= size) return buf; pos += type_len; size -= type_len; attr = md->attribute; if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT | EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO | EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO | EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE)) snprintf(pos, size, "|attr=0x%016llx]", (unsigned long long)attr); else snprintf(pos, size, "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]", attr & EFI_MEMORY_RUNTIME ? "RUN" : "", attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "", attr & EFI_MEMORY_CPU_CRYPTO ? "CC" : "", attr & EFI_MEMORY_SP ? "SP" : "", attr & EFI_MEMORY_NV ? "NV" : "", attr & EFI_MEMORY_XP ? "XP" : "", attr & EFI_MEMORY_RP ? "RP" : "", attr & EFI_MEMORY_WP ? "WP" : "", attr & EFI_MEMORY_RO ? "RO" : "", attr & EFI_MEMORY_UCE ? "UCE" : "", attr & EFI_MEMORY_WB ? "WB" : "", attr & EFI_MEMORY_WT ? "WT" : "", attr & EFI_MEMORY_WC ? "WC" : "", attr & EFI_MEMORY_UC ? "UC" : ""); return buf; } /* * IA64 has a funky EFI memory map that doesn't work the same way as * other architectures. */ #ifndef CONFIG_IA64 /* * efi_mem_attributes - lookup memmap attributes for physical address * @phys_addr: the physical address to lookup * * Search in the EFI memory map for the region covering * @phys_addr. Returns the EFI memory attributes if the region * was found in the memory map, 0 otherwise. */ u64 efi_mem_attributes(unsigned long phys_addr) { efi_memory_desc_t *md; if (!efi_enabled(EFI_MEMMAP)) return 0; for_each_efi_memory_desc(md) { if ((md->phys_addr <= phys_addr) && (phys_addr < (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT)))) return md->attribute; } return 0; } /* * efi_mem_type - lookup memmap type for physical address * @phys_addr: the physical address to lookup * * Search in the EFI memory map for the region covering @phys_addr. * Returns the EFI memory type if the region was found in the memory * map, -EINVAL otherwise. */ int efi_mem_type(unsigned long phys_addr) { const efi_memory_desc_t *md; if (!efi_enabled(EFI_MEMMAP)) return -ENOTSUPP; for_each_efi_memory_desc(md) { if ((md->phys_addr <= phys_addr) && (phys_addr < (md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT)))) return md->type; } return -EINVAL; } #endif int efi_status_to_err(efi_status_t status) { int err; switch (status) { case EFI_SUCCESS: err = 0; break; case EFI_INVALID_PARAMETER: err = -EINVAL; break; case EFI_OUT_OF_RESOURCES: err = -ENOSPC; break; case EFI_DEVICE_ERROR: err = -EIO; break; case EFI_WRITE_PROTECTED: err = -EROFS; break; case EFI_SECURITY_VIOLATION: err = -EACCES; break; case EFI_NOT_FOUND: err = -ENOENT; break; case EFI_ABORTED: err = -EINTR; break; default: err = -EINVAL; } return err; } static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock); static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init; static int __init efi_memreserve_map_root(void) { if (mem_reserve == EFI_INVALID_TABLE_ADDR) return -ENODEV; efi_memreserve_root = memremap(mem_reserve, sizeof(*efi_memreserve_root), MEMREMAP_WB); if (WARN_ON_ONCE(!efi_memreserve_root)) return -ENOMEM; return 0; } static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) { struct resource *res, *parent; int ret; res = kzalloc(sizeof(struct resource), GFP_ATOMIC); if (!res) return -ENOMEM; res->name = "reserved"; res->flags = IORESOURCE_MEM; res->start = addr; res->end = addr + size - 1; /* we expect a conflict with a 'System RAM' region */ parent = request_resource_conflict(&iomem_resource, res); ret = parent ? request_resource(parent, res) : 0; /* * Given that efi_mem_reserve_iomem() can be called at any * time, only call memblock_reserve() if the architecture * keeps the infrastructure around. */ if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret) memblock_reserve(addr, size); return ret; } int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) { struct linux_efi_memreserve *rsv; unsigned long prsv; int rc, index; if (efi_memreserve_root == (void *)ULONG_MAX) return -ENODEV; if (!efi_memreserve_root) { rc = efi_memreserve_map_root(); if (rc) return rc; } /* first try to find a slot in an existing linked list entry */ for (prsv = efi_memreserve_root->next; prsv; ) { rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB); index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size); if (index < rsv->size) { rsv->entry[index].base = addr; rsv->entry[index].size = size; memunmap(rsv); return efi_mem_reserve_iomem(addr, size); } prsv = rsv->next; memunmap(rsv); } /* no slot found - allocate a new linked list entry */ rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC); if (!rsv) return -ENOMEM; rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K); if (rc) { free_page((unsigned long)rsv); return rc; } /* * The memremap() call above assumes that a linux_efi_memreserve entry * never crosses a page boundary, so let's ensure that this remains true * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by * using SZ_4K explicitly in the size calculation below. */ rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K); atomic_set(&rsv->count, 1); rsv->entry[0].base = addr; rsv->entry[0].size = size; spin_lock(&efi_mem_reserve_persistent_lock); rsv->next = efi_memreserve_root->next; efi_memreserve_root->next = __pa(rsv); spin_unlock(&efi_mem_reserve_persistent_lock); return efi_mem_reserve_iomem(addr, size); } static int __init efi_memreserve_root_init(void) { if (efi_memreserve_root) return 0; if (efi_memreserve_map_root()) efi_memreserve_root = (void *)ULONG_MAX; return 0; } early_initcall(efi_memreserve_root_init); #ifdef CONFIG_KEXEC static int update_efi_random_seed(struct notifier_block *nb, unsigned long code, void *unused) { struct linux_efi_random_seed *seed; u32 size = 0; if (!kexec_in_progress) return NOTIFY_DONE; seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB); if (seed != NULL) { size = min(seed->size, EFI_RANDOM_SEED_SIZE); memunmap(seed); } else { pr_err("Could not map UEFI random seed!\n"); } if (size > 0) { seed = memremap(efi_rng_seed, sizeof(*seed) + size, MEMREMAP_WB); if (seed != NULL) { seed->size = size; get_random_bytes(seed->bits, seed->size); memunmap(seed); } else { pr_err("Could not map UEFI random seed!\n"); } } return NOTIFY_DONE; } static struct notifier_block efi_random_seed_nb = { .notifier_call = update_efi_random_seed, }; static int __init register_update_efi_random_seed(void) { if (efi_rng_seed == EFI_INVALID_TABLE_ADDR) return 0; return register_reboot_notifier(&efi_random_seed_nb); } late_initcall(register_update_efi_random_seed); #endif