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path: root/drivers/firmware/efi/efi.c
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Diffstat (limited to 'drivers/firmware/efi/efi.c')
-rw-r--r--drivers/firmware/efi/efi.c517
1 files changed, 517 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
new file mode 100644
index 000000000..e14363d12
--- /dev/null
+++ b/drivers/firmware/efi/efi.c
@@ -0,0 +1,517 @@
+/*
+ * 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>
+#include <linux/platform_device.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,
+ .smbios3 = 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 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;
+}
+
+static int __init parse_efi_cmdline(char *str)
+{
+ if (parse_option_str(str, "noruntime"))
+ disable_runtime = true;
+
+ return 0;
+}
+early_param("efi", parse_efi_cmdline);
+
+static struct kobject *efi_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.smbios3 != EFI_INVALID_TABLE_ADDR)
+ str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
+ 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 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);
+}
+
+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 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_vendor.attr,
+ &efi_attr_runtime.attr,
+ &efi_attr_config_table.attr,
+ &efi_attr_fw_platform_size.attr,
+ NULL,
+};
+
+static umode_t efi_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int n)
+{
+ if (attr == &efi_attr_fw_vendor.attr) {
+ if (efi_enabled(EFI_PARAVIRT) ||
+ efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
+ return 0;
+ } else if (attr == &efi_attr_runtime.attr) {
+ if (efi.runtime == EFI_INVALID_TABLE_ADDR)
+ return 0;
+ } else if (attr == &efi_attr_config_table.attr) {
+ if (efi.config_table == EFI_INVALID_TABLE_ADDR)
+ return 0;
+ }
+
+ return attr->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 */
+ error = sysfs_create_mount_point(efi_kobj, "efivars");
+ if (error) {
+ pr_err("efivars: Subsystem registration failed.\n");
+ 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},
+ {SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
+ {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)
+{
+ int i;
+
+ if (table_types) {
+ 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;
+ pr_cont(" %s=0x%lx ",
+ table_types[i].name, table);
+ return 1;
+ }
+ }
+ }
+
+ return 0;
+}
+
+int __init efi_config_parse_tables(void *config_tables, int count, int sz,
+ efi_config_table_type_t *arch_tables)
+{
+ void *tablep;
+ int i;
+
+ tablep = config_tables;
+ pr_info("");
+ for (i = 0; i < count; 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");
+ 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");
+ set_bit(EFI_CONFIG_TABLES, &efi.flags);
+ return 0;
+}
+
+int __init efi_config_init(efi_config_table_type_t *arch_tables)
+{
+ void *config_tables;
+ int sz, ret;
+
+ 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;
+ }
+
+ ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
+ arch_tables);
+
+ early_memunmap(config_tables, efi.systab->nr_tables * sz);
+ return ret;
+}
+
+#ifdef CONFIG_EFI_VARS_MODULE
+static int __init efi_load_efivars(void)
+{
+ struct platform_device *pdev;
+
+ if (!efi_enabled(EFI_RUNTIME_SERVICES))
+ return 0;
+
+ pdev = platform_device_register_simple("efivars", 0, NULL, 0);
+ return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
+}
+device_initcall(efi_load_efivars);
+#endif
+
+#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)
+ 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 */
+
+static __initdata char memory_type_name[][20] = {
+ "Reserved",
+ "Loader Code",
+ "Loader Data",
+ "Boot Code",
+ "Boot Data",
+ "Runtime Code",
+ "Runtime Data",
+ "Conventional Memory",
+ "Unusable Memory",
+ "ACPI Reclaim Memory",
+ "ACPI Memory NVS",
+ "Memory Mapped I/O",
+ "MMIO Port Space",
+ "PAL Code"
+};
+
+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_WP |
+ EFI_MEMORY_RP | EFI_MEMORY_XP | EFI_MEMORY_RUNTIME))
+ snprintf(pos, size, "|attr=0x%016llx]",
+ (unsigned long long)attr);
+ else
+ snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
+ attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
+ attr & EFI_MEMORY_XP ? "XP" : "",
+ attr & EFI_MEMORY_RP ? "RP" : "",
+ attr & EFI_MEMORY_WP ? "WP" : "",
+ 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;
+}