| /* |
| * efi.c - EFI subsystem |
| * |
| * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com> |
| * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com> |
| * Copyright (C) 2013 Tom Gundersen <teg@jklm.no> |
| * |
| * 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. |
| * |
| * This file is released under the GPLv2. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/kobject.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/device.h> |
| #include <linux/efi.h> |
| #include <linux/of.h> |
| #include <linux/of_fdt.h> |
| #include <linux/io.h> |
| |
| struct efi __read_mostly efi = { |
| .mps = EFI_INVALID_TABLE_ADDR, |
| .acpi = EFI_INVALID_TABLE_ADDR, |
| .acpi20 = EFI_INVALID_TABLE_ADDR, |
| .smbios = EFI_INVALID_TABLE_ADDR, |
| .sal_systab = EFI_INVALID_TABLE_ADDR, |
| .boot_info = EFI_INVALID_TABLE_ADDR, |
| .hcdp = EFI_INVALID_TABLE_ADDR, |
| .uga = EFI_INVALID_TABLE_ADDR, |
| .uv_systab = EFI_INVALID_TABLE_ADDR, |
| .fw_vendor = EFI_INVALID_TABLE_ADDR, |
| .runtime = EFI_INVALID_TABLE_ADDR, |
| .config_table = EFI_INVALID_TABLE_ADDR, |
| }; |
| EXPORT_SYMBOL(efi); |
| |
| static struct kobject *efi_kobj; |
| static struct kobject *efivars_kobj; |
| |
| /* |
| * Let's not leave out systab information that snuck into |
| * the efivars driver |
| */ |
| static ssize_t systab_show(struct kobject *kobj, |
| struct kobj_attribute *attr, char *buf) |
| { |
| char *str = buf; |
| |
| if (!kobj || !buf) |
| return -EINVAL; |
| |
| if (efi.mps != EFI_INVALID_TABLE_ADDR) |
| str += sprintf(str, "MPS=0x%lx\n", efi.mps); |
| 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 (efi.smbios != EFI_INVALID_TABLE_ADDR) |
| str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios); |
| if (efi.hcdp != EFI_INVALID_TABLE_ADDR) |
| str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp); |
| if (efi.boot_info != EFI_INVALID_TABLE_ADDR) |
| str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info); |
| if (efi.uga != EFI_INVALID_TABLE_ADDR) |
| str += sprintf(str, "UGA=0x%lx\n", efi.uga); |
| |
| return str - buf; |
| } |
| |
| static struct kobj_attribute efi_attr_systab = |
| __ATTR(systab, 0400, systab_show, NULL); |
| |
| #define EFI_FIELD(var) efi.var |
| |
| #define EFI_ATTR_SHOW(name) \ |
| static ssize_t name##_show(struct kobject *kobj, \ |
| struct kobj_attribute *attr, char *buf) \ |
| { \ |
| return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \ |
| } |
| |
| EFI_ATTR_SHOW(fw_vendor); |
| EFI_ATTR_SHOW(runtime); |
| EFI_ATTR_SHOW(config_table); |
| |
| static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); |
| static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); |
| static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); |
| |
| static struct attribute *efi_subsys_attrs[] = { |
| &efi_attr_systab.attr, |
| &efi_attr_fw_vendor.attr, |
| &efi_attr_runtime.attr, |
| &efi_attr_config_table.attr, |
| NULL, |
| }; |
| |
| static umode_t efi_attr_is_visible(struct kobject *kobj, |
| struct attribute *attr, int n) |
| { |
| umode_t mode = attr->mode; |
| |
| if (attr == &efi_attr_fw_vendor.attr) |
| return (efi.fw_vendor == EFI_INVALID_TABLE_ADDR) ? 0 : mode; |
| else if (attr == &efi_attr_runtime.attr) |
| return (efi.runtime == EFI_INVALID_TABLE_ADDR) ? 0 : mode; |
| else if (attr == &efi_attr_config_table.attr) |
| return (efi.config_table == EFI_INVALID_TABLE_ADDR) ? 0 : mode; |
| |
| return mode; |
| } |
| |
| static 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.set_variable = efi.set_variable; |
| generic_ops.get_next_variable = efi.get_next_variable; |
| generic_ops.query_variable_store = efi_query_variable_store; |
| |
| return efivars_register(&generic_efivars, &generic_ops, efi_kobj); |
| } |
| |
| static void generic_ops_unregister(void) |
| { |
| efivars_unregister(&generic_efivars); |
| } |
| |
| /* |
| * 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_BOOT)) |
| return 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"); |
| return -ENOMEM; |
| } |
| |
| error = generic_ops_register(); |
| if (error) |
| goto err_put; |
| |
| 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 */ |
| efivars_kobj = kobject_create_and_add("efivars", efi_kobj); |
| if (!efivars_kobj) { |
| pr_err("efivars: Subsystem registration failed.\n"); |
| error = -ENOMEM; |
| goto err_remove_group; |
| } |
| |
| return 0; |
| |
| err_remove_group: |
| sysfs_remove_group(efi_kobj, &efi_subsys_attr_group); |
| err_unregister: |
| generic_ops_unregister(); |
| err_put: |
| kobject_put(efi_kobj); |
| return error; |
| } |
| |
| subsys_initcall(efisubsys_init); |
| |
| |
| /* |
| * We can't ioremap data in EFI boot services RAM, because we've already mapped |
| * it as RAM. So, look it up in the existing EFI memory map instead. Only |
| * callable after efi_enter_virtual_mode and before efi_free_boot_services. |
| */ |
| void __iomem *efi_lookup_mapped_addr(u64 phys_addr) |
| { |
| struct efi_memory_map *map; |
| void *p; |
| map = efi.memmap; |
| if (!map) |
| return NULL; |
| if (WARN_ON(!map->map)) |
| return NULL; |
| for (p = map->map; p < map->map_end; p += map->desc_size) { |
| efi_memory_desc_t *md = p; |
| u64 size = md->num_pages << EFI_PAGE_SHIFT; |
| u64 end = md->phys_addr + size; |
| if (!(md->attribute & EFI_MEMORY_RUNTIME) && |
| md->type != EFI_BOOT_SERVICES_CODE && |
| md->type != EFI_BOOT_SERVICES_DATA) |
| continue; |
| if (!md->virt_addr) |
| continue; |
| if (phys_addr >= md->phys_addr && phys_addr < end) { |
| phys_addr += md->virt_addr - md->phys_addr; |
| return (__force void __iomem *)(unsigned long)phys_addr; |
| } |
| } |
| return NULL; |
| } |
| |
| static __initdata efi_config_table_type_t common_tables[] = { |
| {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20}, |
| {ACPI_TABLE_GUID, "ACPI", &efi.acpi}, |
| {HCDP_TABLE_GUID, "HCDP", &efi.hcdp}, |
| {MPS_TABLE_GUID, "MPS", &efi.mps}, |
| {SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab}, |
| {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios}, |
| {UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga}, |
| {NULL_GUID, NULL, NULL}, |
| }; |
| |
| static __init int match_config_table(efi_guid_t *guid, |
| unsigned long table, |
| efi_config_table_type_t *table_types) |
| { |
| u8 str[EFI_VARIABLE_GUID_LEN + 1]; |
| int i; |
| |
| if (table_types) { |
| efi_guid_unparse(guid, str); |
| |
| for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) { |
| efi_guid_unparse(&table_types[i].guid, str); |
| |
| if (!efi_guidcmp(*guid, table_types[i].guid)) { |
| *(table_types[i].ptr) = table; |
| pr_cont(" %s=0x%lx ", |
| table_types[i].name, table); |
| return 1; |
| } |
| } |
| } |
| |
| return 0; |
| } |
| |
| int __init efi_config_init(efi_config_table_type_t *arch_tables) |
| { |
| void *config_tables, *tablep; |
| int i, sz; |
| |
| if (efi_enabled(EFI_64BIT)) |
| sz = sizeof(efi_config_table_64_t); |
| else |
| sz = sizeof(efi_config_table_32_t); |
| |
| /* |
| * Let's see what config tables the firmware passed to us. |
| */ |
| config_tables = early_memremap(efi.systab->tables, |
| efi.systab->nr_tables * sz); |
| if (config_tables == NULL) { |
| pr_err("Could not map Configuration table!\n"); |
| return -ENOMEM; |
| } |
| |
| tablep = config_tables; |
| pr_info(""); |
| for (i = 0; i < efi.systab->nr_tables; i++) { |
| efi_guid_t guid; |
| unsigned long table; |
| |
| if (efi_enabled(EFI_64BIT)) { |
| u64 table64; |
| guid = ((efi_config_table_64_t *)tablep)->guid; |
| table64 = ((efi_config_table_64_t *)tablep)->table; |
| table = table64; |
| #ifndef CONFIG_64BIT |
| if (table64 >> 32) { |
| pr_cont("\n"); |
| pr_err("Table located above 4GB, disabling EFI.\n"); |
| early_iounmap(config_tables, |
| efi.systab->nr_tables * sz); |
| return -EINVAL; |
| } |
| #endif |
| } else { |
| guid = ((efi_config_table_32_t *)tablep)->guid; |
| table = ((efi_config_table_32_t *)tablep)->table; |
| } |
| |
| if (!match_config_table(&guid, table, common_tables)) |
| match_config_table(&guid, table, arch_tables); |
| |
| tablep += sz; |
| } |
| pr_cont("\n"); |
| early_iounmap(config_tables, efi.systab->nr_tables * sz); |
| |
| set_bit(EFI_CONFIG_TABLES, &efi.flags); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_EFI_PARAMS_FROM_FDT |
| |
| #define UEFI_PARAM(name, prop, field) \ |
| { \ |
| { name }, \ |
| { prop }, \ |
| offsetof(struct efi_fdt_params, field), \ |
| FIELD_SIZEOF(struct efi_fdt_params, field) \ |
| } |
| |
| static __initdata struct { |
| const char name[32]; |
| const char propname[32]; |
| int offset; |
| int size; |
| } dt_params[] = { |
| UEFI_PARAM("System Table", "linux,uefi-system-table", system_table), |
| UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap), |
| UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size), |
| UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size), |
| UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver) |
| }; |
| |
| struct param_info { |
| int verbose; |
| int found; |
| void *params; |
| }; |
| |
| static int __init fdt_find_uefi_params(unsigned long node, const char *uname, |
| int depth, void *data) |
| { |
| struct param_info *info = data; |
| const void *prop; |
| void *dest; |
| u64 val; |
| int i, len; |
| |
| if (depth != 1 || |
| (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) |
| return 0; |
| |
| for (i = 0; i < ARRAY_SIZE(dt_params); i++) { |
| prop = of_get_flat_dt_prop(node, dt_params[i].propname, &len); |
| if (!prop) |
| return 0; |
| dest = info->params + dt_params[i].offset; |
| info->found++; |
| |
| val = of_read_number(prop, len / sizeof(u32)); |
| |
| if (dt_params[i].size == sizeof(u32)) |
| *(u32 *)dest = val; |
| else |
| *(u64 *)dest = val; |
| |
| if (info->verbose) |
| pr_info(" %s: 0x%0*llx\n", dt_params[i].name, |
| dt_params[i].size * 2, val); |
| } |
| return 1; |
| } |
| |
| int __init efi_get_fdt_params(struct efi_fdt_params *params, int verbose) |
| { |
| struct param_info info; |
| int ret; |
| |
| pr_info("Getting EFI parameters from FDT:\n"); |
| |
| info.verbose = verbose; |
| info.found = 0; |
| info.params = params; |
| |
| ret = of_scan_flat_dt(fdt_find_uefi_params, &info); |
| if (!info.found) |
| pr_info("UEFI not found.\n"); |
| else if (!ret) |
| pr_err("Can't find '%s' in device tree!\n", |
| dt_params[info.found].name); |
| |
| return ret; |
| } |
| #endif /* CONFIG_EFI_PARAMS_FROM_FDT */ |