diff options
Diffstat (limited to 'drivers/firmware/efi/efi.c')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c new file mode 100644 index 00000000000..dc79346689e --- /dev/null +++ b/drivers/firmware/efi/efi.c @@ -0,0 +1,407 @@ +/* + * 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 */ |