xref: /openbmc/linux/drivers/firmware/efi/efi.c (revision bc5aa3a0)
1 /*
2  * efi.c - EFI subsystem
3  *
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>
7  *
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.
12  *
13  * This file is released under the GPLv2.
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
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>
23 #include <linux/of.h>
24 #include <linux/of_fdt.h>
25 #include <linux/io.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/acpi.h>
29 #include <linux/ucs2_string.h>
30 
31 #include <asm/early_ioremap.h>
32 
33 struct efi __read_mostly efi = {
34 	.mps			= EFI_INVALID_TABLE_ADDR,
35 	.acpi			= EFI_INVALID_TABLE_ADDR,
36 	.acpi20			= EFI_INVALID_TABLE_ADDR,
37 	.smbios			= EFI_INVALID_TABLE_ADDR,
38 	.smbios3		= EFI_INVALID_TABLE_ADDR,
39 	.sal_systab		= EFI_INVALID_TABLE_ADDR,
40 	.boot_info		= EFI_INVALID_TABLE_ADDR,
41 	.hcdp			= EFI_INVALID_TABLE_ADDR,
42 	.uga			= EFI_INVALID_TABLE_ADDR,
43 	.uv_systab		= EFI_INVALID_TABLE_ADDR,
44 	.fw_vendor		= EFI_INVALID_TABLE_ADDR,
45 	.runtime		= EFI_INVALID_TABLE_ADDR,
46 	.config_table		= EFI_INVALID_TABLE_ADDR,
47 	.esrt			= EFI_INVALID_TABLE_ADDR,
48 	.properties_table	= EFI_INVALID_TABLE_ADDR,
49 	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
50 };
51 EXPORT_SYMBOL(efi);
52 
53 static bool disable_runtime;
54 static int __init setup_noefi(char *arg)
55 {
56 	disable_runtime = true;
57 	return 0;
58 }
59 early_param("noefi", setup_noefi);
60 
61 bool efi_runtime_disabled(void)
62 {
63 	return disable_runtime;
64 }
65 
66 static int __init parse_efi_cmdline(char *str)
67 {
68 	if (!str) {
69 		pr_warn("need at least one option\n");
70 		return -EINVAL;
71 	}
72 
73 	if (parse_option_str(str, "debug"))
74 		set_bit(EFI_DBG, &efi.flags);
75 
76 	if (parse_option_str(str, "noruntime"))
77 		disable_runtime = true;
78 
79 	return 0;
80 }
81 early_param("efi", parse_efi_cmdline);
82 
83 struct kobject *efi_kobj;
84 
85 /*
86  * Let's not leave out systab information that snuck into
87  * the efivars driver
88  */
89 static ssize_t systab_show(struct kobject *kobj,
90 			   struct kobj_attribute *attr, char *buf)
91 {
92 	char *str = buf;
93 
94 	if (!kobj || !buf)
95 		return -EINVAL;
96 
97 	if (efi.mps != EFI_INVALID_TABLE_ADDR)
98 		str += sprintf(str, "MPS=0x%lx\n", efi.mps);
99 	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
100 		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
101 	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
102 		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
103 	/*
104 	 * If both SMBIOS and SMBIOS3 entry points are implemented, the
105 	 * SMBIOS3 entry point shall be preferred, so we list it first to
106 	 * let applications stop parsing after the first match.
107 	 */
108 	if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
109 		str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
110 	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
111 		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
112 	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
113 		str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
114 	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
115 		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
116 	if (efi.uga != EFI_INVALID_TABLE_ADDR)
117 		str += sprintf(str, "UGA=0x%lx\n", efi.uga);
118 
119 	return str - buf;
120 }
121 
122 static struct kobj_attribute efi_attr_systab =
123 			__ATTR(systab, 0400, systab_show, NULL);
124 
125 #define EFI_FIELD(var) efi.var
126 
127 #define EFI_ATTR_SHOW(name) \
128 static ssize_t name##_show(struct kobject *kobj, \
129 				struct kobj_attribute *attr, char *buf) \
130 { \
131 	return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
132 }
133 
134 EFI_ATTR_SHOW(fw_vendor);
135 EFI_ATTR_SHOW(runtime);
136 EFI_ATTR_SHOW(config_table);
137 
138 static ssize_t fw_platform_size_show(struct kobject *kobj,
139 				     struct kobj_attribute *attr, char *buf)
140 {
141 	return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
142 }
143 
144 static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
145 static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
146 static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
147 static struct kobj_attribute efi_attr_fw_platform_size =
148 	__ATTR_RO(fw_platform_size);
149 
150 static struct attribute *efi_subsys_attrs[] = {
151 	&efi_attr_systab.attr,
152 	&efi_attr_fw_vendor.attr,
153 	&efi_attr_runtime.attr,
154 	&efi_attr_config_table.attr,
155 	&efi_attr_fw_platform_size.attr,
156 	NULL,
157 };
158 
159 static umode_t efi_attr_is_visible(struct kobject *kobj,
160 				   struct attribute *attr, int n)
161 {
162 	if (attr == &efi_attr_fw_vendor.attr) {
163 		if (efi_enabled(EFI_PARAVIRT) ||
164 				efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
165 			return 0;
166 	} else if (attr == &efi_attr_runtime.attr) {
167 		if (efi.runtime == EFI_INVALID_TABLE_ADDR)
168 			return 0;
169 	} else if (attr == &efi_attr_config_table.attr) {
170 		if (efi.config_table == EFI_INVALID_TABLE_ADDR)
171 			return 0;
172 	}
173 
174 	return attr->mode;
175 }
176 
177 static struct attribute_group efi_subsys_attr_group = {
178 	.attrs = efi_subsys_attrs,
179 	.is_visible = efi_attr_is_visible,
180 };
181 
182 static struct efivars generic_efivars;
183 static struct efivar_operations generic_ops;
184 
185 static int generic_ops_register(void)
186 {
187 	generic_ops.get_variable = efi.get_variable;
188 	generic_ops.set_variable = efi.set_variable;
189 	generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
190 	generic_ops.get_next_variable = efi.get_next_variable;
191 	generic_ops.query_variable_store = efi_query_variable_store;
192 
193 	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
194 }
195 
196 static void generic_ops_unregister(void)
197 {
198 	efivars_unregister(&generic_efivars);
199 }
200 
201 #if IS_ENABLED(CONFIG_ACPI)
202 #define EFIVAR_SSDT_NAME_MAX	16
203 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
204 static int __init efivar_ssdt_setup(char *str)
205 {
206 	if (strlen(str) < sizeof(efivar_ssdt))
207 		memcpy(efivar_ssdt, str, strlen(str));
208 	else
209 		pr_warn("efivar_ssdt: name too long: %s\n", str);
210 	return 0;
211 }
212 __setup("efivar_ssdt=", efivar_ssdt_setup);
213 
214 static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
215 				   unsigned long name_size, void *data)
216 {
217 	struct efivar_entry *entry;
218 	struct list_head *list = data;
219 	char utf8_name[EFIVAR_SSDT_NAME_MAX];
220 	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
221 
222 	ucs2_as_utf8(utf8_name, name, limit - 1);
223 	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
224 		return 0;
225 
226 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
227 	if (!entry)
228 		return 0;
229 
230 	memcpy(entry->var.VariableName, name, name_size);
231 	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
232 
233 	efivar_entry_add(entry, list);
234 
235 	return 0;
236 }
237 
238 static __init int efivar_ssdt_load(void)
239 {
240 	LIST_HEAD(entries);
241 	struct efivar_entry *entry, *aux;
242 	unsigned long size;
243 	void *data;
244 	int ret;
245 
246 	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
247 
248 	list_for_each_entry_safe(entry, aux, &entries, list) {
249 		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
250 			&entry->var.VendorGuid);
251 
252 		list_del(&entry->list);
253 
254 		ret = efivar_entry_size(entry, &size);
255 		if (ret) {
256 			pr_err("failed to get var size\n");
257 			goto free_entry;
258 		}
259 
260 		data = kmalloc(size, GFP_KERNEL);
261 		if (!data)
262 			goto free_entry;
263 
264 		ret = efivar_entry_get(entry, NULL, &size, data);
265 		if (ret) {
266 			pr_err("failed to get var data\n");
267 			goto free_data;
268 		}
269 
270 		ret = acpi_load_table(data);
271 		if (ret) {
272 			pr_err("failed to load table: %d\n", ret);
273 			goto free_data;
274 		}
275 
276 		goto free_entry;
277 
278 free_data:
279 		kfree(data);
280 
281 free_entry:
282 		kfree(entry);
283 	}
284 
285 	return ret;
286 }
287 #else
288 static inline int efivar_ssdt_load(void) { return 0; }
289 #endif
290 
291 /*
292  * We register the efi subsystem with the firmware subsystem and the
293  * efivars subsystem with the efi subsystem, if the system was booted with
294  * EFI.
295  */
296 static int __init efisubsys_init(void)
297 {
298 	int error;
299 
300 	if (!efi_enabled(EFI_BOOT))
301 		return 0;
302 
303 	/* We register the efi directory at /sys/firmware/efi */
304 	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
305 	if (!efi_kobj) {
306 		pr_err("efi: Firmware registration failed.\n");
307 		return -ENOMEM;
308 	}
309 
310 	error = generic_ops_register();
311 	if (error)
312 		goto err_put;
313 
314 	if (efi_enabled(EFI_RUNTIME_SERVICES))
315 		efivar_ssdt_load();
316 
317 	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
318 	if (error) {
319 		pr_err("efi: Sysfs attribute export failed with error %d.\n",
320 		       error);
321 		goto err_unregister;
322 	}
323 
324 	error = efi_runtime_map_init(efi_kobj);
325 	if (error)
326 		goto err_remove_group;
327 
328 	/* and the standard mountpoint for efivarfs */
329 	error = sysfs_create_mount_point(efi_kobj, "efivars");
330 	if (error) {
331 		pr_err("efivars: Subsystem registration failed.\n");
332 		goto err_remove_group;
333 	}
334 
335 	return 0;
336 
337 err_remove_group:
338 	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
339 err_unregister:
340 	generic_ops_unregister();
341 err_put:
342 	kobject_put(efi_kobj);
343 	return error;
344 }
345 
346 subsys_initcall(efisubsys_init);
347 
348 /*
349  * Find the efi memory descriptor for a given physical address.  Given a
350  * physicall address, determine if it exists within an EFI Memory Map entry,
351  * and if so, populate the supplied memory descriptor with the appropriate
352  * data.
353  */
354 int __init efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
355 {
356 	struct efi_memory_map *map = &efi.memmap;
357 	phys_addr_t p, e;
358 
359 	if (!efi_enabled(EFI_MEMMAP)) {
360 		pr_err_once("EFI_MEMMAP is not enabled.\n");
361 		return -EINVAL;
362 	}
363 
364 	if (!map) {
365 		pr_err_once("efi.memmap is not set.\n");
366 		return -EINVAL;
367 	}
368 	if (!out_md) {
369 		pr_err_once("out_md is null.\n");
370 		return -EINVAL;
371         }
372 	if (WARN_ON_ONCE(!map->phys_map))
373 		return -EINVAL;
374 	if (WARN_ON_ONCE(map->nr_map == 0) || WARN_ON_ONCE(map->desc_size == 0))
375 		return -EINVAL;
376 
377 	e = map->phys_map + map->nr_map * map->desc_size;
378 	for (p = map->phys_map; p < e; p += map->desc_size) {
379 		efi_memory_desc_t *md;
380 		u64 size;
381 		u64 end;
382 
383 		/*
384 		 * If a driver calls this after efi_free_boot_services,
385 		 * ->map will be NULL, and the target may also not be mapped.
386 		 * So just always get our own virtual map on the CPU.
387 		 *
388 		 */
389 		md = early_memremap(p, sizeof (*md));
390 		if (!md) {
391 			pr_err_once("early_memremap(%pa, %zu) failed.\n",
392 				    &p, sizeof (*md));
393 			return -ENOMEM;
394 		}
395 
396 		if (!(md->attribute & EFI_MEMORY_RUNTIME) &&
397 		    md->type != EFI_BOOT_SERVICES_DATA &&
398 		    md->type != EFI_RUNTIME_SERVICES_DATA) {
399 			early_memunmap(md, sizeof (*md));
400 			continue;
401 		}
402 
403 		size = md->num_pages << EFI_PAGE_SHIFT;
404 		end = md->phys_addr + size;
405 		if (phys_addr >= md->phys_addr && phys_addr < end) {
406 			memcpy(out_md, md, sizeof(*out_md));
407 			early_memunmap(md, sizeof (*md));
408 			return 0;
409 		}
410 
411 		early_memunmap(md, sizeof (*md));
412 	}
413 	pr_err_once("requested map not found.\n");
414 	return -ENOENT;
415 }
416 
417 /*
418  * Calculate the highest address of an efi memory descriptor.
419  */
420 u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
421 {
422 	u64 size = md->num_pages << EFI_PAGE_SHIFT;
423 	u64 end = md->phys_addr + size;
424 	return end;
425 }
426 
427 static __initdata efi_config_table_type_t common_tables[] = {
428 	{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
429 	{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
430 	{HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
431 	{MPS_TABLE_GUID, "MPS", &efi.mps},
432 	{SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
433 	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
434 	{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
435 	{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
436 	{EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
437 	{EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
438 	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
439 	{NULL_GUID, NULL, NULL},
440 };
441 
442 static __init int match_config_table(efi_guid_t *guid,
443 				     unsigned long table,
444 				     efi_config_table_type_t *table_types)
445 {
446 	int i;
447 
448 	if (table_types) {
449 		for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
450 			if (!efi_guidcmp(*guid, table_types[i].guid)) {
451 				*(table_types[i].ptr) = table;
452 				if (table_types[i].name)
453 					pr_cont(" %s=0x%lx ",
454 						table_types[i].name, table);
455 				return 1;
456 			}
457 		}
458 	}
459 
460 	return 0;
461 }
462 
463 int __init efi_config_parse_tables(void *config_tables, int count, int sz,
464 				   efi_config_table_type_t *arch_tables)
465 {
466 	void *tablep;
467 	int i;
468 
469 	tablep = config_tables;
470 	pr_info("");
471 	for (i = 0; i < count; i++) {
472 		efi_guid_t guid;
473 		unsigned long table;
474 
475 		if (efi_enabled(EFI_64BIT)) {
476 			u64 table64;
477 			guid = ((efi_config_table_64_t *)tablep)->guid;
478 			table64 = ((efi_config_table_64_t *)tablep)->table;
479 			table = table64;
480 #ifndef CONFIG_64BIT
481 			if (table64 >> 32) {
482 				pr_cont("\n");
483 				pr_err("Table located above 4GB, disabling EFI.\n");
484 				return -EINVAL;
485 			}
486 #endif
487 		} else {
488 			guid = ((efi_config_table_32_t *)tablep)->guid;
489 			table = ((efi_config_table_32_t *)tablep)->table;
490 		}
491 
492 		if (!match_config_table(&guid, table, common_tables))
493 			match_config_table(&guid, table, arch_tables);
494 
495 		tablep += sz;
496 	}
497 	pr_cont("\n");
498 	set_bit(EFI_CONFIG_TABLES, &efi.flags);
499 
500 	/* Parse the EFI Properties table if it exists */
501 	if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
502 		efi_properties_table_t *tbl;
503 
504 		tbl = early_memremap(efi.properties_table, sizeof(*tbl));
505 		if (tbl == NULL) {
506 			pr_err("Could not map Properties table!\n");
507 			return -ENOMEM;
508 		}
509 
510 		if (tbl->memory_protection_attribute &
511 		    EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
512 			set_bit(EFI_NX_PE_DATA, &efi.flags);
513 
514 		early_memunmap(tbl, sizeof(*tbl));
515 	}
516 
517 	return 0;
518 }
519 
520 int __init efi_config_init(efi_config_table_type_t *arch_tables)
521 {
522 	void *config_tables;
523 	int sz, ret;
524 
525 	if (efi_enabled(EFI_64BIT))
526 		sz = sizeof(efi_config_table_64_t);
527 	else
528 		sz = sizeof(efi_config_table_32_t);
529 
530 	/*
531 	 * Let's see what config tables the firmware passed to us.
532 	 */
533 	config_tables = early_memremap(efi.systab->tables,
534 				       efi.systab->nr_tables * sz);
535 	if (config_tables == NULL) {
536 		pr_err("Could not map Configuration table!\n");
537 		return -ENOMEM;
538 	}
539 
540 	ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
541 				      arch_tables);
542 
543 	early_memunmap(config_tables, efi.systab->nr_tables * sz);
544 	return ret;
545 }
546 
547 #ifdef CONFIG_EFI_VARS_MODULE
548 static int __init efi_load_efivars(void)
549 {
550 	struct platform_device *pdev;
551 
552 	if (!efi_enabled(EFI_RUNTIME_SERVICES))
553 		return 0;
554 
555 	pdev = platform_device_register_simple("efivars", 0, NULL, 0);
556 	return IS_ERR(pdev) ? PTR_ERR(pdev) : 0;
557 }
558 device_initcall(efi_load_efivars);
559 #endif
560 
561 #ifdef CONFIG_EFI_PARAMS_FROM_FDT
562 
563 #define UEFI_PARAM(name, prop, field)			   \
564 	{						   \
565 		{ name },				   \
566 		{ prop },				   \
567 		offsetof(struct efi_fdt_params, field),    \
568 		FIELD_SIZEOF(struct efi_fdt_params, field) \
569 	}
570 
571 struct params {
572 	const char name[32];
573 	const char propname[32];
574 	int offset;
575 	int size;
576 };
577 
578 static __initdata struct params fdt_params[] = {
579 	UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
580 	UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
581 	UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
582 	UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
583 	UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
584 };
585 
586 static __initdata struct params xen_fdt_params[] = {
587 	UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
588 	UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
589 	UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
590 	UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
591 	UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
592 };
593 
594 #define EFI_FDT_PARAMS_SIZE	ARRAY_SIZE(fdt_params)
595 
596 static __initdata struct {
597 	const char *uname;
598 	const char *subnode;
599 	struct params *params;
600 } dt_params[] = {
601 	{ "hypervisor", "uefi", xen_fdt_params },
602 	{ "chosen", NULL, fdt_params },
603 };
604 
605 struct param_info {
606 	int found;
607 	void *params;
608 	const char *missing;
609 };
610 
611 static int __init __find_uefi_params(unsigned long node,
612 				     struct param_info *info,
613 				     struct params *params)
614 {
615 	const void *prop;
616 	void *dest;
617 	u64 val;
618 	int i, len;
619 
620 	for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
621 		prop = of_get_flat_dt_prop(node, params[i].propname, &len);
622 		if (!prop) {
623 			info->missing = params[i].name;
624 			return 0;
625 		}
626 
627 		dest = info->params + params[i].offset;
628 		info->found++;
629 
630 		val = of_read_number(prop, len / sizeof(u32));
631 
632 		if (params[i].size == sizeof(u32))
633 			*(u32 *)dest = val;
634 		else
635 			*(u64 *)dest = val;
636 
637 		if (efi_enabled(EFI_DBG))
638 			pr_info("  %s: 0x%0*llx\n", params[i].name,
639 				params[i].size * 2, val);
640 	}
641 
642 	return 1;
643 }
644 
645 static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
646 				       int depth, void *data)
647 {
648 	struct param_info *info = data;
649 	int i;
650 
651 	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
652 		const char *subnode = dt_params[i].subnode;
653 
654 		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
655 			info->missing = dt_params[i].params[0].name;
656 			continue;
657 		}
658 
659 		if (subnode) {
660 			node = of_get_flat_dt_subnode_by_name(node, subnode);
661 			if (node < 0)
662 				return 0;
663 		}
664 
665 		return __find_uefi_params(node, info, dt_params[i].params);
666 	}
667 
668 	return 0;
669 }
670 
671 int __init efi_get_fdt_params(struct efi_fdt_params *params)
672 {
673 	struct param_info info;
674 	int ret;
675 
676 	pr_info("Getting EFI parameters from FDT:\n");
677 
678 	info.found = 0;
679 	info.params = params;
680 
681 	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
682 	if (!info.found)
683 		pr_info("UEFI not found.\n");
684 	else if (!ret)
685 		pr_err("Can't find '%s' in device tree!\n",
686 		       info.missing);
687 
688 	return ret;
689 }
690 #endif /* CONFIG_EFI_PARAMS_FROM_FDT */
691 
692 static __initdata char memory_type_name[][20] = {
693 	"Reserved",
694 	"Loader Code",
695 	"Loader Data",
696 	"Boot Code",
697 	"Boot Data",
698 	"Runtime Code",
699 	"Runtime Data",
700 	"Conventional Memory",
701 	"Unusable Memory",
702 	"ACPI Reclaim Memory",
703 	"ACPI Memory NVS",
704 	"Memory Mapped I/O",
705 	"MMIO Port Space",
706 	"PAL Code",
707 	"Persistent Memory",
708 };
709 
710 char * __init efi_md_typeattr_format(char *buf, size_t size,
711 				     const efi_memory_desc_t *md)
712 {
713 	char *pos;
714 	int type_len;
715 	u64 attr;
716 
717 	pos = buf;
718 	if (md->type >= ARRAY_SIZE(memory_type_name))
719 		type_len = snprintf(pos, size, "[type=%u", md->type);
720 	else
721 		type_len = snprintf(pos, size, "[%-*s",
722 				    (int)(sizeof(memory_type_name[0]) - 1),
723 				    memory_type_name[md->type]);
724 	if (type_len >= size)
725 		return buf;
726 
727 	pos += type_len;
728 	size -= type_len;
729 
730 	attr = md->attribute;
731 	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
732 		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
733 		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
734 		     EFI_MEMORY_NV |
735 		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
736 		snprintf(pos, size, "|attr=0x%016llx]",
737 			 (unsigned long long)attr);
738 	else
739 		snprintf(pos, size,
740 			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
741 			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
742 			 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
743 			 attr & EFI_MEMORY_NV      ? "NV"  : "",
744 			 attr & EFI_MEMORY_XP      ? "XP"  : "",
745 			 attr & EFI_MEMORY_RP      ? "RP"  : "",
746 			 attr & EFI_MEMORY_WP      ? "WP"  : "",
747 			 attr & EFI_MEMORY_RO      ? "RO"  : "",
748 			 attr & EFI_MEMORY_UCE     ? "UCE" : "",
749 			 attr & EFI_MEMORY_WB      ? "WB"  : "",
750 			 attr & EFI_MEMORY_WT      ? "WT"  : "",
751 			 attr & EFI_MEMORY_WC      ? "WC"  : "",
752 			 attr & EFI_MEMORY_UC      ? "UC"  : "");
753 	return buf;
754 }
755 
756 /*
757  * efi_mem_attributes - lookup memmap attributes for physical address
758  * @phys_addr: the physical address to lookup
759  *
760  * Search in the EFI memory map for the region covering
761  * @phys_addr. Returns the EFI memory attributes if the region
762  * was found in the memory map, 0 otherwise.
763  *
764  * Despite being marked __weak, most architectures should *not*
765  * override this function. It is __weak solely for the benefit
766  * of ia64 which has a funky EFI memory map that doesn't work
767  * the same way as other architectures.
768  */
769 u64 __weak efi_mem_attributes(unsigned long phys_addr)
770 {
771 	efi_memory_desc_t *md;
772 
773 	if (!efi_enabled(EFI_MEMMAP))
774 		return 0;
775 
776 	for_each_efi_memory_desc(md) {
777 		if ((md->phys_addr <= phys_addr) &&
778 		    (phys_addr < (md->phys_addr +
779 		    (md->num_pages << EFI_PAGE_SHIFT))))
780 			return md->attribute;
781 	}
782 	return 0;
783 }
784 
785 int efi_status_to_err(efi_status_t status)
786 {
787 	int err;
788 
789 	switch (status) {
790 	case EFI_SUCCESS:
791 		err = 0;
792 		break;
793 	case EFI_INVALID_PARAMETER:
794 		err = -EINVAL;
795 		break;
796 	case EFI_OUT_OF_RESOURCES:
797 		err = -ENOSPC;
798 		break;
799 	case EFI_DEVICE_ERROR:
800 		err = -EIO;
801 		break;
802 	case EFI_WRITE_PROTECTED:
803 		err = -EROFS;
804 		break;
805 	case EFI_SECURITY_VIOLATION:
806 		err = -EACCES;
807 		break;
808 	case EFI_NOT_FOUND:
809 		err = -ENOENT;
810 		break;
811 	default:
812 		err = -EINVAL;
813 	}
814 
815 	return err;
816 }
817