2 * efi.c - EFI subsystem
4 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
5 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
6 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
8 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
9 * allowing the efivarfs to be mounted or the efivars module to be loaded.
10 * The existance of /sys/firmware/efi may also be used by userspace to
11 * determine that the system supports EFI.
13 * This file is released under the GPLv2.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kobject.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/device.h>
22 #include <linux/efi.h>
24 #include <linux/of_fdt.h>
26 #include <linux/platform_device.h>
28 struct efi __read_mostly efi
= {
29 .mps
= EFI_INVALID_TABLE_ADDR
,
30 .acpi
= EFI_INVALID_TABLE_ADDR
,
31 .acpi20
= EFI_INVALID_TABLE_ADDR
,
32 .smbios
= EFI_INVALID_TABLE_ADDR
,
33 .sal_systab
= EFI_INVALID_TABLE_ADDR
,
34 .boot_info
= EFI_INVALID_TABLE_ADDR
,
35 .hcdp
= EFI_INVALID_TABLE_ADDR
,
36 .uga
= EFI_INVALID_TABLE_ADDR
,
37 .uv_systab
= EFI_INVALID_TABLE_ADDR
,
38 .fw_vendor
= EFI_INVALID_TABLE_ADDR
,
39 .runtime
= EFI_INVALID_TABLE_ADDR
,
40 .config_table
= EFI_INVALID_TABLE_ADDR
,
44 static struct kobject
*efi_kobj
;
45 static struct kobject
*efivars_kobj
;
48 * Let's not leave out systab information that snuck into
51 static ssize_t
systab_show(struct kobject
*kobj
,
52 struct kobj_attribute
*attr
, char *buf
)
59 if (efi
.mps
!= EFI_INVALID_TABLE_ADDR
)
60 str
+= sprintf(str
, "MPS=0x%lx\n", efi
.mps
);
61 if (efi
.acpi20
!= EFI_INVALID_TABLE_ADDR
)
62 str
+= sprintf(str
, "ACPI20=0x%lx\n", efi
.acpi20
);
63 if (efi
.acpi
!= EFI_INVALID_TABLE_ADDR
)
64 str
+= sprintf(str
, "ACPI=0x%lx\n", efi
.acpi
);
65 if (efi
.smbios
!= EFI_INVALID_TABLE_ADDR
)
66 str
+= sprintf(str
, "SMBIOS=0x%lx\n", efi
.smbios
);
67 if (efi
.hcdp
!= EFI_INVALID_TABLE_ADDR
)
68 str
+= sprintf(str
, "HCDP=0x%lx\n", efi
.hcdp
);
69 if (efi
.boot_info
!= EFI_INVALID_TABLE_ADDR
)
70 str
+= sprintf(str
, "BOOTINFO=0x%lx\n", efi
.boot_info
);
71 if (efi
.uga
!= EFI_INVALID_TABLE_ADDR
)
72 str
+= sprintf(str
, "UGA=0x%lx\n", efi
.uga
);
77 static struct kobj_attribute efi_attr_systab
=
78 __ATTR(systab
, 0400, systab_show
, NULL
);
80 #define EFI_FIELD(var) efi.var
82 #define EFI_ATTR_SHOW(name) \
83 static ssize_t name##_show(struct kobject *kobj, \
84 struct kobj_attribute *attr, char *buf) \
86 return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
89 EFI_ATTR_SHOW(fw_vendor
);
90 EFI_ATTR_SHOW(runtime
);
91 EFI_ATTR_SHOW(config_table
);
93 static struct kobj_attribute efi_attr_fw_vendor
= __ATTR_RO(fw_vendor
);
94 static struct kobj_attribute efi_attr_runtime
= __ATTR_RO(runtime
);
95 static struct kobj_attribute efi_attr_config_table
= __ATTR_RO(config_table
);
97 static struct attribute
*efi_subsys_attrs
[] = {
98 &efi_attr_systab
.attr
,
99 &efi_attr_fw_vendor
.attr
,
100 &efi_attr_runtime
.attr
,
101 &efi_attr_config_table
.attr
,
105 static umode_t
efi_attr_is_visible(struct kobject
*kobj
,
106 struct attribute
*attr
, int n
)
108 if (attr
== &efi_attr_fw_vendor
.attr
) {
109 if (efi_enabled(EFI_PARAVIRT
) ||
110 efi
.fw_vendor
== EFI_INVALID_TABLE_ADDR
)
112 } else if (attr
== &efi_attr_runtime
.attr
) {
113 if (efi
.runtime
== EFI_INVALID_TABLE_ADDR
)
115 } else if (attr
== &efi_attr_config_table
.attr
) {
116 if (efi
.config_table
== EFI_INVALID_TABLE_ADDR
)
123 static struct attribute_group efi_subsys_attr_group
= {
124 .attrs
= efi_subsys_attrs
,
125 .is_visible
= efi_attr_is_visible
,
128 static struct efivars generic_efivars
;
129 static struct efivar_operations generic_ops
;
131 static int generic_ops_register(void)
133 generic_ops
.get_variable
= efi
.get_variable
;
134 generic_ops
.set_variable
= efi
.set_variable
;
135 generic_ops
.get_next_variable
= efi
.get_next_variable
;
136 generic_ops
.query_variable_store
= efi_query_variable_store
;
138 return efivars_register(&generic_efivars
, &generic_ops
, efi_kobj
);
141 static void generic_ops_unregister(void)
143 efivars_unregister(&generic_efivars
);
147 * We register the efi subsystem with the firmware subsystem and the
148 * efivars subsystem with the efi subsystem, if the system was booted with
151 static int __init
efisubsys_init(void)
155 if (!efi_enabled(EFI_BOOT
))
158 /* We register the efi directory at /sys/firmware/efi */
159 efi_kobj
= kobject_create_and_add("efi", firmware_kobj
);
161 pr_err("efi: Firmware registration failed.\n");
165 error
= generic_ops_register();
169 error
= sysfs_create_group(efi_kobj
, &efi_subsys_attr_group
);
171 pr_err("efi: Sysfs attribute export failed with error %d.\n",
176 error
= efi_runtime_map_init(efi_kobj
);
178 goto err_remove_group
;
180 /* and the standard mountpoint for efivarfs */
181 efivars_kobj
= kobject_create_and_add("efivars", efi_kobj
);
183 pr_err("efivars: Subsystem registration failed.\n");
185 goto err_remove_group
;
191 sysfs_remove_group(efi_kobj
, &efi_subsys_attr_group
);
193 generic_ops_unregister();
195 kobject_put(efi_kobj
);
199 subsys_initcall(efisubsys_init
);
203 * We can't ioremap data in EFI boot services RAM, because we've already mapped
204 * it as RAM. So, look it up in the existing EFI memory map instead. Only
205 * callable after efi_enter_virtual_mode and before efi_free_boot_services.
207 void __iomem
*efi_lookup_mapped_addr(u64 phys_addr
)
209 struct efi_memory_map
*map
;
214 if (WARN_ON(!map
->map
))
216 for (p
= map
->map
; p
< map
->map_end
; p
+= map
->desc_size
) {
217 efi_memory_desc_t
*md
= p
;
218 u64 size
= md
->num_pages
<< EFI_PAGE_SHIFT
;
219 u64 end
= md
->phys_addr
+ size
;
220 if (!(md
->attribute
& EFI_MEMORY_RUNTIME
) &&
221 md
->type
!= EFI_BOOT_SERVICES_CODE
&&
222 md
->type
!= EFI_BOOT_SERVICES_DATA
)
226 if (phys_addr
>= md
->phys_addr
&& phys_addr
< end
) {
227 phys_addr
+= md
->virt_addr
- md
->phys_addr
;
228 return (__force
void __iomem
*)(unsigned long)phys_addr
;
234 static __initdata efi_config_table_type_t common_tables
[] = {
235 {ACPI_20_TABLE_GUID
, "ACPI 2.0", &efi
.acpi20
},
236 {ACPI_TABLE_GUID
, "ACPI", &efi
.acpi
},
237 {HCDP_TABLE_GUID
, "HCDP", &efi
.hcdp
},
238 {MPS_TABLE_GUID
, "MPS", &efi
.mps
},
239 {SAL_SYSTEM_TABLE_GUID
, "SALsystab", &efi
.sal_systab
},
240 {SMBIOS_TABLE_GUID
, "SMBIOS", &efi
.smbios
},
241 {UGA_IO_PROTOCOL_GUID
, "UGA", &efi
.uga
},
242 {NULL_GUID
, NULL
, NULL
},
245 static __init
int match_config_table(efi_guid_t
*guid
,
247 efi_config_table_type_t
*table_types
)
249 u8 str
[EFI_VARIABLE_GUID_LEN
+ 1];
253 efi_guid_unparse(guid
, str
);
255 for (i
= 0; efi_guidcmp(table_types
[i
].guid
, NULL_GUID
); i
++) {
256 efi_guid_unparse(&table_types
[i
].guid
, str
);
258 if (!efi_guidcmp(*guid
, table_types
[i
].guid
)) {
259 *(table_types
[i
].ptr
) = table
;
260 pr_cont(" %s=0x%lx ",
261 table_types
[i
].name
, table
);
270 int __init
efi_config_init(efi_config_table_type_t
*arch_tables
)
272 void *config_tables
, *tablep
;
275 if (efi_enabled(EFI_64BIT
))
276 sz
= sizeof(efi_config_table_64_t
);
278 sz
= sizeof(efi_config_table_32_t
);
281 * Let's see what config tables the firmware passed to us.
283 config_tables
= early_memremap(efi
.systab
->tables
,
284 efi
.systab
->nr_tables
* sz
);
285 if (config_tables
== NULL
) {
286 pr_err("Could not map Configuration table!\n");
290 tablep
= config_tables
;
292 for (i
= 0; i
< efi
.systab
->nr_tables
; i
++) {
296 if (efi_enabled(EFI_64BIT
)) {
298 guid
= ((efi_config_table_64_t
*)tablep
)->guid
;
299 table64
= ((efi_config_table_64_t
*)tablep
)->table
;
304 pr_err("Table located above 4GB, disabling EFI.\n");
305 early_memunmap(config_tables
,
306 efi
.systab
->nr_tables
* sz
);
311 guid
= ((efi_config_table_32_t
*)tablep
)->guid
;
312 table
= ((efi_config_table_32_t
*)tablep
)->table
;
315 if (!match_config_table(&guid
, table
, common_tables
))
316 match_config_table(&guid
, table
, arch_tables
);
321 early_memunmap(config_tables
, efi
.systab
->nr_tables
* sz
);
323 set_bit(EFI_CONFIG_TABLES
, &efi
.flags
);
328 #ifdef CONFIG_EFI_VARS_MODULE
329 static int __init
efi_load_efivars(void)
331 struct platform_device
*pdev
;
333 if (!efi_enabled(EFI_RUNTIME_SERVICES
))
336 pdev
= platform_device_register_simple("efivars", 0, NULL
, 0);
337 return IS_ERR(pdev
) ? PTR_ERR(pdev
) : 0;
339 device_initcall(efi_load_efivars
);
342 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
344 #define UEFI_PARAM(name, prop, field) \
348 offsetof(struct efi_fdt_params, field), \
349 FIELD_SIZEOF(struct efi_fdt_params, field) \
352 static __initdata
struct {
354 const char propname
[32];
358 UEFI_PARAM("System Table", "linux,uefi-system-table", system_table
),
359 UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap
),
360 UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size
),
361 UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size
),
362 UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver
)
371 static int __init
fdt_find_uefi_params(unsigned long node
, const char *uname
,
372 int depth
, void *data
)
374 struct param_info
*info
= data
;
381 (strcmp(uname
, "chosen") != 0 && strcmp(uname
, "chosen@0") != 0))
384 for (i
= 0; i
< ARRAY_SIZE(dt_params
); i
++) {
385 prop
= of_get_flat_dt_prop(node
, dt_params
[i
].propname
, &len
);
388 dest
= info
->params
+ dt_params
[i
].offset
;
391 val
= of_read_number(prop
, len
/ sizeof(u32
));
393 if (dt_params
[i
].size
== sizeof(u32
))
399 pr_info(" %s: 0x%0*llx\n", dt_params
[i
].name
,
400 dt_params
[i
].size
* 2, val
);
405 int __init
efi_get_fdt_params(struct efi_fdt_params
*params
, int verbose
)
407 struct param_info info
;
410 pr_info("Getting EFI parameters from FDT:\n");
412 info
.verbose
= verbose
;
414 info
.params
= params
;
416 ret
= of_scan_flat_dt(fdt_find_uefi_params
, &info
);
418 pr_info("UEFI not found.\n");
420 pr_err("Can't find '%s' in device tree!\n",
421 dt_params
[info
.found
].name
);
425 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */