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v5.9
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * efi.c - EFI subsystem
   4 *
   5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
   6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
   7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
   8 *
   9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
  10 * allowing the efivarfs to be mounted or the efivars module to be loaded.
  11 * The existance of /sys/firmware/efi may also be used by userspace to
  12 * determine that the system supports EFI.
  13 */
  14
  15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17#include <linux/kobject.h>
  18#include <linux/module.h>
  19#include <linux/init.h>
  20#include <linux/debugfs.h>
  21#include <linux/device.h>
  22#include <linux/efi.h>
  23#include <linux/of.h>
 
  24#include <linux/io.h>
  25#include <linux/kexec.h>
  26#include <linux/platform_device.h>
  27#include <linux/random.h>
  28#include <linux/reboot.h>
  29#include <linux/slab.h>
  30#include <linux/acpi.h>
  31#include <linux/ucs2_string.h>
  32#include <linux/memblock.h>
  33#include <linux/security.h>
  34
  35#include <asm/early_ioremap.h>
  36
  37struct efi __read_mostly efi = {
  38	.runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
  39	.acpi			= EFI_INVALID_TABLE_ADDR,
  40	.acpi20			= EFI_INVALID_TABLE_ADDR,
  41	.smbios			= EFI_INVALID_TABLE_ADDR,
  42	.smbios3		= EFI_INVALID_TABLE_ADDR,
 
 
 
 
 
 
  43	.esrt			= EFI_INVALID_TABLE_ADDR,
 
 
 
  44	.tpm_log		= EFI_INVALID_TABLE_ADDR,
  45	.tpm_final_log		= EFI_INVALID_TABLE_ADDR,
 
  46};
  47EXPORT_SYMBOL(efi);
  48
  49unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
  50static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
  51static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
  52
  53struct mm_struct efi_mm = {
  54	.mm_rb			= RB_ROOT,
  55	.mm_users		= ATOMIC_INIT(2),
  56	.mm_count		= ATOMIC_INIT(1),
  57	MMAP_LOCK_INITIALIZER(efi_mm)
  58	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
  59	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
  60	.cpu_bitmap		= { [BITS_TO_LONGS(NR_CPUS)] = 0},
  61};
  62
  63struct workqueue_struct *efi_rts_wq;
  64
  65static bool disable_runtime;
  66static int __init setup_noefi(char *arg)
  67{
  68	disable_runtime = true;
  69	return 0;
  70}
  71early_param("noefi", setup_noefi);
  72
  73bool efi_runtime_disabled(void)
  74{
  75	return disable_runtime;
  76}
  77
  78bool __pure __efi_soft_reserve_enabled(void)
  79{
  80	return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
  81}
  82
  83static int __init parse_efi_cmdline(char *str)
  84{
  85	if (!str) {
  86		pr_warn("need at least one option\n");
  87		return -EINVAL;
  88	}
  89
  90	if (parse_option_str(str, "debug"))
  91		set_bit(EFI_DBG, &efi.flags);
  92
  93	if (parse_option_str(str, "noruntime"))
  94		disable_runtime = true;
  95
  96	if (parse_option_str(str, "nosoftreserve"))
  97		set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
  98
  99	return 0;
 100}
 101early_param("efi", parse_efi_cmdline);
 102
 103struct kobject *efi_kobj;
 104
 105/*
 106 * Let's not leave out systab information that snuck into
 107 * the efivars driver
 108 * Note, do not add more fields in systab sysfs file as it breaks sysfs
 109 * one value per file rule!
 110 */
 111static ssize_t systab_show(struct kobject *kobj,
 112			   struct kobj_attribute *attr, char *buf)
 113{
 114	char *str = buf;
 115
 116	if (!kobj || !buf)
 117		return -EINVAL;
 118
 
 
 119	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
 120		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
 121	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
 122		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
 123	/*
 124	 * If both SMBIOS and SMBIOS3 entry points are implemented, the
 125	 * SMBIOS3 entry point shall be preferred, so we list it first to
 126	 * let applications stop parsing after the first match.
 127	 */
 128	if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
 129		str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
 130	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
 131		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
 132
 133	if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
 134		str = efi_systab_show_arch(str);
 
 
 
 135
 136	return str - buf;
 137}
 138
 139static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
 140
 
 
 
 
 
 
 
 
 
 
 
 
 
 141static ssize_t fw_platform_size_show(struct kobject *kobj,
 142				     struct kobj_attribute *attr, char *buf)
 143{
 144	return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
 145}
 146
 147extern __weak struct kobj_attribute efi_attr_fw_vendor;
 148extern __weak struct kobj_attribute efi_attr_runtime;
 149extern __weak struct kobj_attribute efi_attr_config_table;
 150static struct kobj_attribute efi_attr_fw_platform_size =
 151	__ATTR_RO(fw_platform_size);
 152
 153static struct attribute *efi_subsys_attrs[] = {
 154	&efi_attr_systab.attr,
 155	&efi_attr_fw_platform_size.attr,
 156	&efi_attr_fw_vendor.attr,
 157	&efi_attr_runtime.attr,
 158	&efi_attr_config_table.attr,
 
 159	NULL,
 160};
 161
 162umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
 163				   int n)
 164{
 
 
 
 
 
 
 
 
 
 
 
 
 165	return attr->mode;
 166}
 167
 168static const struct attribute_group efi_subsys_attr_group = {
 169	.attrs = efi_subsys_attrs,
 170	.is_visible = efi_attr_is_visible,
 171};
 172
 173static struct efivars generic_efivars;
 174static struct efivar_operations generic_ops;
 175
 176static int generic_ops_register(void)
 177{
 178	generic_ops.get_variable = efi.get_variable;
 
 
 179	generic_ops.get_next_variable = efi.get_next_variable;
 180	generic_ops.query_variable_store = efi_query_variable_store;
 181
 182	if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
 183		generic_ops.set_variable = efi.set_variable;
 184		generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
 185	}
 186	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
 187}
 188
 189static void generic_ops_unregister(void)
 190{
 191	efivars_unregister(&generic_efivars);
 192}
 193
 194#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
 195#define EFIVAR_SSDT_NAME_MAX	16
 196static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
 197static int __init efivar_ssdt_setup(char *str)
 198{
 199	int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
 200
 201	if (ret)
 202		return ret;
 203
 204	if (strlen(str) < sizeof(efivar_ssdt))
 205		memcpy(efivar_ssdt, str, strlen(str));
 206	else
 207		pr_warn("efivar_ssdt: name too long: %s\n", str);
 208	return 0;
 209}
 210__setup("efivar_ssdt=", efivar_ssdt_setup);
 211
 212static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
 213				   unsigned long name_size, void *data)
 214{
 215	struct efivar_entry *entry;
 216	struct list_head *list = data;
 217	char utf8_name[EFIVAR_SSDT_NAME_MAX];
 218	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
 219
 220	ucs2_as_utf8(utf8_name, name, limit - 1);
 221	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
 222		return 0;
 223
 224	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 225	if (!entry)
 226		return 0;
 227
 228	memcpy(entry->var.VariableName, name, name_size);
 229	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
 230
 231	efivar_entry_add(entry, list);
 232
 233	return 0;
 234}
 235
 236static __init int efivar_ssdt_load(void)
 237{
 238	LIST_HEAD(entries);
 239	struct efivar_entry *entry, *aux;
 240	unsigned long size;
 241	void *data;
 242	int ret;
 243
 244	if (!efivar_ssdt[0])
 245		return 0;
 246
 247	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
 248
 249	list_for_each_entry_safe(entry, aux, &entries, list) {
 250		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
 251			&entry->var.VendorGuid);
 252
 253		list_del(&entry->list);
 254
 255		ret = efivar_entry_size(entry, &size);
 256		if (ret) {
 257			pr_err("failed to get var size\n");
 258			goto free_entry;
 259		}
 260
 261		data = kmalloc(size, GFP_KERNEL);
 262		if (!data) {
 263			ret = -ENOMEM;
 264			goto free_entry;
 265		}
 266
 267		ret = efivar_entry_get(entry, NULL, &size, data);
 268		if (ret) {
 269			pr_err("failed to get var data\n");
 270			goto free_data;
 271		}
 272
 273		ret = acpi_load_table(data, NULL);
 274		if (ret) {
 275			pr_err("failed to load table: %d\n", ret);
 276			goto free_data;
 277		}
 278
 279		goto free_entry;
 280
 281free_data:
 282		kfree(data);
 283
 284free_entry:
 285		kfree(entry);
 286	}
 287
 288	return ret;
 289}
 290#else
 291static inline int efivar_ssdt_load(void) { return 0; }
 292#endif
 293
 294#ifdef CONFIG_DEBUG_FS
 295
 296#define EFI_DEBUGFS_MAX_BLOBS 32
 297
 298static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];
 299
 300static void __init efi_debugfs_init(void)
 301{
 302	struct dentry *efi_debugfs;
 303	efi_memory_desc_t *md;
 304	char name[32];
 305	int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
 306	int i = 0;
 307
 308	efi_debugfs = debugfs_create_dir("efi", NULL);
 309	if (IS_ERR_OR_NULL(efi_debugfs))
 310		return;
 311
 312	for_each_efi_memory_desc(md) {
 313		switch (md->type) {
 314		case EFI_BOOT_SERVICES_CODE:
 315			snprintf(name, sizeof(name), "boot_services_code%d",
 316				 type_count[md->type]++);
 317			break;
 318		case EFI_BOOT_SERVICES_DATA:
 319			snprintf(name, sizeof(name), "boot_services_data%d",
 320				 type_count[md->type]++);
 321			break;
 322		default:
 323			continue;
 324		}
 325
 326		if (i >= EFI_DEBUGFS_MAX_BLOBS) {
 327			pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
 328				EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
 329			break;
 330		}
 331
 332		debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
 333		debugfs_blob[i].data = memremap(md->phys_addr,
 334						debugfs_blob[i].size,
 335						MEMREMAP_WB);
 336		if (!debugfs_blob[i].data)
 337			continue;
 338
 339		debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
 340		i++;
 341	}
 342}
 343#else
 344static inline void efi_debugfs_init(void) {}
 345#endif
 346
 347/*
 348 * We register the efi subsystem with the firmware subsystem and the
 349 * efivars subsystem with the efi subsystem, if the system was booted with
 350 * EFI.
 351 */
 352static int __init efisubsys_init(void)
 353{
 354	int error;
 355
 356	if (!efi_enabled(EFI_RUNTIME_SERVICES))
 357		efi.runtime_supported_mask = 0;
 358
 359	if (!efi_enabled(EFI_BOOT))
 360		return 0;
 361
 362	if (efi.runtime_supported_mask) {
 363		/*
 364		 * Since we process only one efi_runtime_service() at a time, an
 365		 * ordered workqueue (which creates only one execution context)
 366		 * should suffice for all our needs.
 367		 */
 368		efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
 369		if (!efi_rts_wq) {
 370			pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
 371			clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 372			efi.runtime_supported_mask = 0;
 373			return 0;
 374		}
 375	}
 376
 377	if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
 378		platform_device_register_simple("rtc-efi", 0, NULL, 0);
 379
 380	/* We register the efi directory at /sys/firmware/efi */
 381	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
 382	if (!efi_kobj) {
 383		pr_err("efi: Firmware registration failed.\n");
 384		destroy_workqueue(efi_rts_wq);
 385		return -ENOMEM;
 386	}
 387
 388	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
 389				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
 
 
 
 390		efivar_ssdt_load();
 391		error = generic_ops_register();
 392		if (error)
 393			goto err_put;
 394		platform_device_register_simple("efivars", 0, NULL, 0);
 395	}
 396
 397	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
 398	if (error) {
 399		pr_err("efi: Sysfs attribute export failed with error %d.\n",
 400		       error);
 401		goto err_unregister;
 402	}
 403
 404	error = efi_runtime_map_init(efi_kobj);
 405	if (error)
 406		goto err_remove_group;
 407
 408	/* and the standard mountpoint for efivarfs */
 409	error = sysfs_create_mount_point(efi_kobj, "efivars");
 410	if (error) {
 411		pr_err("efivars: Subsystem registration failed.\n");
 412		goto err_remove_group;
 413	}
 414
 415	if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
 416		efi_debugfs_init();
 417
 418	return 0;
 419
 420err_remove_group:
 421	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
 422err_unregister:
 423	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
 424				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
 425		generic_ops_unregister();
 426err_put:
 427	kobject_put(efi_kobj);
 428	destroy_workqueue(efi_rts_wq);
 429	return error;
 430}
 431
 432subsys_initcall(efisubsys_init);
 433
 434/*
 435 * Find the efi memory descriptor for a given physical address.  Given a
 436 * physical address, determine if it exists within an EFI Memory Map entry,
 437 * and if so, populate the supplied memory descriptor with the appropriate
 438 * data.
 439 */
 440int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 441{
 442	efi_memory_desc_t *md;
 443
 444	if (!efi_enabled(EFI_MEMMAP)) {
 445		pr_err_once("EFI_MEMMAP is not enabled.\n");
 446		return -EINVAL;
 447	}
 448
 449	if (!out_md) {
 450		pr_err_once("out_md is null.\n");
 451		return -EINVAL;
 452        }
 453
 454	for_each_efi_memory_desc(md) {
 455		u64 size;
 456		u64 end;
 457
 458		size = md->num_pages << EFI_PAGE_SHIFT;
 459		end = md->phys_addr + size;
 460		if (phys_addr >= md->phys_addr && phys_addr < end) {
 461			memcpy(out_md, md, sizeof(*out_md));
 462			return 0;
 463		}
 464	}
 465	return -ENOENT;
 466}
 467
 468/*
 469 * Calculate the highest address of an efi memory descriptor.
 470 */
 471u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
 472{
 473	u64 size = md->num_pages << EFI_PAGE_SHIFT;
 474	u64 end = md->phys_addr + size;
 475	return end;
 476}
 477
 478void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
 479
 480/**
 481 * efi_mem_reserve - Reserve an EFI memory region
 482 * @addr: Physical address to reserve
 483 * @size: Size of reservation
 484 *
 485 * Mark a region as reserved from general kernel allocation and
 486 * prevent it being released by efi_free_boot_services().
 487 *
 488 * This function should be called drivers once they've parsed EFI
 489 * configuration tables to figure out where their data lives, e.g.
 490 * efi_esrt_init().
 491 */
 492void __init efi_mem_reserve(phys_addr_t addr, u64 size)
 493{
 494	if (!memblock_is_region_reserved(addr, size))
 495		memblock_reserve(addr, size);
 496
 497	/*
 498	 * Some architectures (x86) reserve all boot services ranges
 499	 * until efi_free_boot_services() because of buggy firmware
 500	 * implementations. This means the above memblock_reserve() is
 501	 * superfluous on x86 and instead what it needs to do is
 502	 * ensure the @start, @size is not freed.
 503	 */
 504	efi_arch_mem_reserve(addr, size);
 505}
 506
 507static const efi_config_table_type_t common_tables[] __initconst = {
 508	{ACPI_20_TABLE_GUID,			&efi.acpi20,		"ACPI 2.0"	},
 509	{ACPI_TABLE_GUID,			&efi.acpi,		"ACPI"		},
 510	{SMBIOS_TABLE_GUID,			&efi.smbios,		"SMBIOS"	},
 511	{SMBIOS3_TABLE_GUID,			&efi.smbios3,		"SMBIOS 3.0"	},
 512	{EFI_SYSTEM_RESOURCE_TABLE_GUID,	&efi.esrt,		"ESRT"		},
 513	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID,	&efi_mem_attr_table,	"MEMATTR"	},
 514	{LINUX_EFI_RANDOM_SEED_TABLE_GUID,	&efi_rng_seed,		"RNG"		},
 515	{LINUX_EFI_TPM_EVENT_LOG_GUID,		&efi.tpm_log,		"TPMEventLog"	},
 516	{LINUX_EFI_TPM_FINAL_LOG_GUID,		&efi.tpm_final_log,	"TPMFinalLog"	},
 517	{LINUX_EFI_MEMRESERVE_TABLE_GUID,	&mem_reserve,		"MEMRESERVE"	},
 518	{EFI_RT_PROPERTIES_TABLE_GUID,		&rt_prop,		"RTPROP"	},
 
 
 
 519#ifdef CONFIG_EFI_RCI2_TABLE
 520	{DELLEMC_EFI_RCI2_TABLE_GUID,		&rci2_table_phys			},
 521#endif
 522	{},
 523};
 524
 525static __init int match_config_table(const efi_guid_t *guid,
 526				     unsigned long table,
 527				     const efi_config_table_type_t *table_types)
 528{
 529	int i;
 530
 531	for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
 532		if (!efi_guidcmp(*guid, table_types[i].guid)) {
 533			*(table_types[i].ptr) = table;
 534			if (table_types[i].name[0])
 535				pr_cont("%s=0x%lx ",
 536					table_types[i].name, table);
 537			return 1;
 
 
 538		}
 539	}
 540
 541	return 0;
 542}
 543
 544int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
 545				   int count,
 546				   const efi_config_table_type_t *arch_tables)
 547{
 548	const efi_config_table_64_t *tbl64 = (void *)config_tables;
 549	const efi_config_table_32_t *tbl32 = (void *)config_tables;
 550	const efi_guid_t *guid;
 551	unsigned long table;
 552	int i;
 553
 
 554	pr_info("");
 555	for (i = 0; i < count; i++) {
 556		if (!IS_ENABLED(CONFIG_X86)) {
 557			guid = &config_tables[i].guid;
 558			table = (unsigned long)config_tables[i].table;
 559		} else if (efi_enabled(EFI_64BIT)) {
 560			guid = &tbl64[i].guid;
 561			table = tbl64[i].table;
 562
 563			if (IS_ENABLED(CONFIG_X86_32) &&
 564			    tbl64[i].table > U32_MAX) {
 
 
 
 
 
 565				pr_cont("\n");
 566				pr_err("Table located above 4GB, disabling EFI.\n");
 567				return -EINVAL;
 568			}
 
 569		} else {
 570			guid = &tbl32[i].guid;
 571			table = tbl32[i].table;
 572		}
 573
 574		if (!match_config_table(guid, table, common_tables) && arch_tables)
 575			match_config_table(guid, table, arch_tables);
 
 
 576	}
 577	pr_cont("\n");
 578	set_bit(EFI_CONFIG_TABLES, &efi.flags);
 579
 580	if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
 581		struct linux_efi_random_seed *seed;
 582		u32 size = 0;
 583
 584		seed = early_memremap(efi_rng_seed, sizeof(*seed));
 585		if (seed != NULL) {
 586			size = READ_ONCE(seed->size);
 587			early_memunmap(seed, sizeof(*seed));
 588		} else {
 589			pr_err("Could not map UEFI random seed!\n");
 590		}
 591		if (size > 0) {
 592			seed = early_memremap(efi_rng_seed,
 593					      sizeof(*seed) + size);
 594			if (seed != NULL) {
 595				pr_notice("seeding entropy pool\n");
 596				add_bootloader_randomness(seed->bits, size);
 597				early_memunmap(seed, sizeof(*seed) + size);
 598			} else {
 599				pr_err("Could not map UEFI random seed!\n");
 600			}
 601		}
 602	}
 603
 604	if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
 605		efi_memattr_init();
 606
 607	efi_tpm_eventlog_init();
 608
 609	if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
 610		unsigned long prsv = mem_reserve;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 611
 612		while (prsv) {
 613			struct linux_efi_memreserve *rsv;
 614			u8 *p;
 
 615
 616			/*
 617			 * Just map a full page: that is what we will get
 618			 * anyway, and it permits us to map the entire entry
 619			 * before knowing its size.
 620			 */
 621			p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
 622					   PAGE_SIZE);
 623			if (p == NULL) {
 624				pr_err("Could not map UEFI memreserve entry!\n");
 625				return -ENOMEM;
 626			}
 627
 628			rsv = (void *)(p + prsv % PAGE_SIZE);
 629
 630			/* reserve the entry itself */
 631			memblock_reserve(prsv,
 632					 struct_size(rsv, entry, rsv->size));
 633
 634			for (i = 0; i < atomic_read(&rsv->count); i++) {
 635				memblock_reserve(rsv->entry[i].base,
 636						 rsv->entry[i].size);
 637			}
 638
 639			prsv = rsv->next;
 640			early_memunmap(p, PAGE_SIZE);
 641		}
 642	}
 643
 644	if (rt_prop != EFI_INVALID_TABLE_ADDR) {
 645		efi_rt_properties_table_t *tbl;
 646
 647		tbl = early_memremap(rt_prop, sizeof(*tbl));
 648		if (tbl) {
 649			efi.runtime_supported_mask &= tbl->runtime_services_supported;
 650			early_memunmap(tbl, sizeof(*tbl));
 651		}
 652	}
 653
 654	return 0;
 655}
 656
 657int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
 658				   int min_major_version)
 659{
 660	if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
 661		pr_err("System table signature incorrect!\n");
 662		return -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 663	}
 664
 665	if ((systab_hdr->revision >> 16) < min_major_version)
 666		pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
 667		       systab_hdr->revision >> 16,
 668		       systab_hdr->revision & 0xffff,
 669		       min_major_version);
 670
 671	return 0;
 
 672}
 673
 674#ifndef CONFIG_IA64
 675static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
 676						size_t size)
 677{
 678	const efi_char16_t *ret;
 679
 680	ret = early_memremap_ro(fw_vendor, size);
 681	if (!ret)
 682		pr_err("Could not map the firmware vendor!\n");
 683	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 684}
 685
 686static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
 
 687{
 688	early_memunmap((void *)fw_vendor, size);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 689}
 690#else
 691#define map_fw_vendor(p, s)	__va(p)
 692#define unmap_fw_vendor(v, s)
 693#endif
 694
 695void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
 696				     unsigned long fw_vendor)
 697{
 698	char vendor[100] = "unknown";
 699	const efi_char16_t *c16;
 700	size_t i;
 701
 702	c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
 703	if (c16) {
 704		for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
 705			vendor[i] = c16[i];
 706		vendor[i] = '\0';
 707
 708		unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
 709	}
 710
 711	pr_info("EFI v%u.%.02u by %s\n",
 712		systab_hdr->revision >> 16,
 713		systab_hdr->revision & 0xffff,
 714		vendor);
 715}
 
 716
 717static __initdata char memory_type_name[][20] = {
 718	"Reserved",
 719	"Loader Code",
 720	"Loader Data",
 721	"Boot Code",
 722	"Boot Data",
 723	"Runtime Code",
 724	"Runtime Data",
 725	"Conventional Memory",
 726	"Unusable Memory",
 727	"ACPI Reclaim Memory",
 728	"ACPI Memory NVS",
 729	"Memory Mapped I/O",
 730	"MMIO Port Space",
 731	"PAL Code",
 732	"Persistent Memory",
 733};
 734
 735char * __init efi_md_typeattr_format(char *buf, size_t size,
 736				     const efi_memory_desc_t *md)
 737{
 738	char *pos;
 739	int type_len;
 740	u64 attr;
 741
 742	pos = buf;
 743	if (md->type >= ARRAY_SIZE(memory_type_name))
 744		type_len = snprintf(pos, size, "[type=%u", md->type);
 745	else
 746		type_len = snprintf(pos, size, "[%-*s",
 747				    (int)(sizeof(memory_type_name[0]) - 1),
 748				    memory_type_name[md->type]);
 749	if (type_len >= size)
 750		return buf;
 751
 752	pos += type_len;
 753	size -= type_len;
 754
 755	attr = md->attribute;
 756	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
 757		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
 758		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
 759		     EFI_MEMORY_NV | EFI_MEMORY_SP |
 760		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
 761		snprintf(pos, size, "|attr=0x%016llx]",
 762			 (unsigned long long)attr);
 763	else
 764		snprintf(pos, size,
 765			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
 766			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
 767			 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
 768			 attr & EFI_MEMORY_SP      ? "SP"  : "",
 769			 attr & EFI_MEMORY_NV      ? "NV"  : "",
 770			 attr & EFI_MEMORY_XP      ? "XP"  : "",
 771			 attr & EFI_MEMORY_RP      ? "RP"  : "",
 772			 attr & EFI_MEMORY_WP      ? "WP"  : "",
 773			 attr & EFI_MEMORY_RO      ? "RO"  : "",
 774			 attr & EFI_MEMORY_UCE     ? "UCE" : "",
 775			 attr & EFI_MEMORY_WB      ? "WB"  : "",
 776			 attr & EFI_MEMORY_WT      ? "WT"  : "",
 777			 attr & EFI_MEMORY_WC      ? "WC"  : "",
 778			 attr & EFI_MEMORY_UC      ? "UC"  : "");
 779	return buf;
 780}
 781
 782/*
 783 * IA64 has a funky EFI memory map that doesn't work the same way as
 784 * other architectures.
 785 */
 786#ifndef CONFIG_IA64
 787/*
 788 * efi_mem_attributes - lookup memmap attributes for physical address
 789 * @phys_addr: the physical address to lookup
 790 *
 791 * Search in the EFI memory map for the region covering
 792 * @phys_addr. Returns the EFI memory attributes if the region
 793 * was found in the memory map, 0 otherwise.
 794 */
 795u64 efi_mem_attributes(unsigned long phys_addr)
 796{
 797	efi_memory_desc_t *md;
 798
 799	if (!efi_enabled(EFI_MEMMAP))
 800		return 0;
 801
 802	for_each_efi_memory_desc(md) {
 803		if ((md->phys_addr <= phys_addr) &&
 804		    (phys_addr < (md->phys_addr +
 805		    (md->num_pages << EFI_PAGE_SHIFT))))
 806			return md->attribute;
 807	}
 808	return 0;
 809}
 810
 811/*
 812 * efi_mem_type - lookup memmap type for physical address
 813 * @phys_addr: the physical address to lookup
 814 *
 815 * Search in the EFI memory map for the region covering @phys_addr.
 816 * Returns the EFI memory type if the region was found in the memory
 817 * map, -EINVAL otherwise.
 818 */
 819int efi_mem_type(unsigned long phys_addr)
 820{
 821	const efi_memory_desc_t *md;
 822
 823	if (!efi_enabled(EFI_MEMMAP))
 824		return -ENOTSUPP;
 825
 826	for_each_efi_memory_desc(md) {
 827		if ((md->phys_addr <= phys_addr) &&
 828		    (phys_addr < (md->phys_addr +
 829				  (md->num_pages << EFI_PAGE_SHIFT))))
 830			return md->type;
 831	}
 832	return -EINVAL;
 833}
 834#endif
 835
 836int efi_status_to_err(efi_status_t status)
 837{
 838	int err;
 839
 840	switch (status) {
 841	case EFI_SUCCESS:
 842		err = 0;
 843		break;
 844	case EFI_INVALID_PARAMETER:
 845		err = -EINVAL;
 846		break;
 847	case EFI_OUT_OF_RESOURCES:
 848		err = -ENOSPC;
 849		break;
 850	case EFI_DEVICE_ERROR:
 851		err = -EIO;
 852		break;
 853	case EFI_WRITE_PROTECTED:
 854		err = -EROFS;
 855		break;
 856	case EFI_SECURITY_VIOLATION:
 857		err = -EACCES;
 858		break;
 859	case EFI_NOT_FOUND:
 860		err = -ENOENT;
 861		break;
 862	case EFI_ABORTED:
 863		err = -EINTR;
 864		break;
 865	default:
 866		err = -EINVAL;
 867	}
 868
 869	return err;
 870}
 871
 872static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
 873static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
 874
 875static int __init efi_memreserve_map_root(void)
 876{
 877	if (mem_reserve == EFI_INVALID_TABLE_ADDR)
 878		return -ENODEV;
 879
 880	efi_memreserve_root = memremap(mem_reserve,
 881				       sizeof(*efi_memreserve_root),
 882				       MEMREMAP_WB);
 883	if (WARN_ON_ONCE(!efi_memreserve_root))
 884		return -ENOMEM;
 885	return 0;
 886}
 887
 888static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
 889{
 890	struct resource *res, *parent;
 891
 892	res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
 893	if (!res)
 894		return -ENOMEM;
 895
 896	res->name	= "reserved";
 897	res->flags	= IORESOURCE_MEM;
 898	res->start	= addr;
 899	res->end	= addr + size - 1;
 900
 901	/* we expect a conflict with a 'System RAM' region */
 902	parent = request_resource_conflict(&iomem_resource, res);
 903	return parent ? request_resource(parent, res) : 0;
 904}
 905
 906int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 907{
 908	struct linux_efi_memreserve *rsv;
 909	unsigned long prsv;
 910	int rc, index;
 911
 912	if (efi_memreserve_root == (void *)ULONG_MAX)
 913		return -ENODEV;
 914
 915	if (!efi_memreserve_root) {
 916		rc = efi_memreserve_map_root();
 917		if (rc)
 918			return rc;
 919	}
 920
 921	/* first try to find a slot in an existing linked list entry */
 922	for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
 923		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 924		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 925		if (index < rsv->size) {
 926			rsv->entry[index].base = addr;
 927			rsv->entry[index].size = size;
 928
 929			memunmap(rsv);
 930			return efi_mem_reserve_iomem(addr, size);
 931		}
 932		memunmap(rsv);
 933	}
 934
 935	/* no slot found - allocate a new linked list entry */
 936	rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
 937	if (!rsv)
 938		return -ENOMEM;
 939
 940	rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
 941	if (rc) {
 942		free_page((unsigned long)rsv);
 943		return rc;
 944	}
 945
 946	/*
 947	 * The memremap() call above assumes that a linux_efi_memreserve entry
 948	 * never crosses a page boundary, so let's ensure that this remains true
 949	 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
 950	 * using SZ_4K explicitly in the size calculation below.
 951	 */
 952	rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
 953	atomic_set(&rsv->count, 1);
 954	rsv->entry[0].base = addr;
 955	rsv->entry[0].size = size;
 956
 957	spin_lock(&efi_mem_reserve_persistent_lock);
 958	rsv->next = efi_memreserve_root->next;
 959	efi_memreserve_root->next = __pa(rsv);
 960	spin_unlock(&efi_mem_reserve_persistent_lock);
 961
 962	return efi_mem_reserve_iomem(addr, size);
 963}
 964
 965static int __init efi_memreserve_root_init(void)
 966{
 967	if (efi_memreserve_root)
 968		return 0;
 969	if (efi_memreserve_map_root())
 970		efi_memreserve_root = (void *)ULONG_MAX;
 971	return 0;
 972}
 973early_initcall(efi_memreserve_root_init);
 974
 975#ifdef CONFIG_KEXEC
 976static int update_efi_random_seed(struct notifier_block *nb,
 977				  unsigned long code, void *unused)
 978{
 979	struct linux_efi_random_seed *seed;
 980	u32 size = 0;
 981
 982	if (!kexec_in_progress)
 983		return NOTIFY_DONE;
 984
 985	seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
 986	if (seed != NULL) {
 987		size = min(seed->size, EFI_RANDOM_SEED_SIZE);
 988		memunmap(seed);
 989	} else {
 990		pr_err("Could not map UEFI random seed!\n");
 991	}
 992	if (size > 0) {
 993		seed = memremap(efi_rng_seed, sizeof(*seed) + size,
 994				MEMREMAP_WB);
 995		if (seed != NULL) {
 996			seed->size = size;
 997			get_random_bytes(seed->bits, seed->size);
 998			memunmap(seed);
 999		} else {
1000			pr_err("Could not map UEFI random seed!\n");
1001		}
1002	}
1003	return NOTIFY_DONE;
1004}
1005
1006static struct notifier_block efi_random_seed_nb = {
1007	.notifier_call = update_efi_random_seed,
1008};
1009
1010static int __init register_update_efi_random_seed(void)
1011{
1012	if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1013		return 0;
1014	return register_reboot_notifier(&efi_random_seed_nb);
1015}
1016late_initcall(register_update_efi_random_seed);
1017#endif
v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * efi.c - EFI subsystem
   4 *
   5 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
   6 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
   7 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
   8 *
   9 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
  10 * allowing the efivarfs to be mounted or the efivars module to be loaded.
  11 * The existance of /sys/firmware/efi may also be used by userspace to
  12 * determine that the system supports EFI.
  13 */
  14
  15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17#include <linux/kobject.h>
  18#include <linux/module.h>
  19#include <linux/init.h>
 
  20#include <linux/device.h>
  21#include <linux/efi.h>
  22#include <linux/of.h>
  23#include <linux/of_fdt.h>
  24#include <linux/io.h>
  25#include <linux/kexec.h>
  26#include <linux/platform_device.h>
  27#include <linux/random.h>
  28#include <linux/reboot.h>
  29#include <linux/slab.h>
  30#include <linux/acpi.h>
  31#include <linux/ucs2_string.h>
  32#include <linux/memblock.h>
  33#include <linux/security.h>
  34
  35#include <asm/early_ioremap.h>
  36
  37struct efi __read_mostly efi = {
  38	.mps			= EFI_INVALID_TABLE_ADDR,
  39	.acpi			= EFI_INVALID_TABLE_ADDR,
  40	.acpi20			= EFI_INVALID_TABLE_ADDR,
  41	.smbios			= EFI_INVALID_TABLE_ADDR,
  42	.smbios3		= EFI_INVALID_TABLE_ADDR,
  43	.boot_info		= EFI_INVALID_TABLE_ADDR,
  44	.hcdp			= EFI_INVALID_TABLE_ADDR,
  45	.uga			= EFI_INVALID_TABLE_ADDR,
  46	.fw_vendor		= EFI_INVALID_TABLE_ADDR,
  47	.runtime		= EFI_INVALID_TABLE_ADDR,
  48	.config_table		= EFI_INVALID_TABLE_ADDR,
  49	.esrt			= EFI_INVALID_TABLE_ADDR,
  50	.properties_table	= EFI_INVALID_TABLE_ADDR,
  51	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
  52	.rng_seed		= EFI_INVALID_TABLE_ADDR,
  53	.tpm_log		= EFI_INVALID_TABLE_ADDR,
  54	.tpm_final_log		= EFI_INVALID_TABLE_ADDR,
  55	.mem_reserve		= EFI_INVALID_TABLE_ADDR,
  56};
  57EXPORT_SYMBOL(efi);
  58
 
 
 
 
  59struct mm_struct efi_mm = {
  60	.mm_rb			= RB_ROOT,
  61	.mm_users		= ATOMIC_INIT(2),
  62	.mm_count		= ATOMIC_INIT(1),
  63	.mmap_sem		= __RWSEM_INITIALIZER(efi_mm.mmap_sem),
  64	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
  65	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
  66	.cpu_bitmap		= { [BITS_TO_LONGS(NR_CPUS)] = 0},
  67};
  68
  69struct workqueue_struct *efi_rts_wq;
  70
  71static bool disable_runtime;
  72static int __init setup_noefi(char *arg)
  73{
  74	disable_runtime = true;
  75	return 0;
  76}
  77early_param("noefi", setup_noefi);
  78
  79bool efi_runtime_disabled(void)
  80{
  81	return disable_runtime;
  82}
  83
 
 
 
 
 
  84static int __init parse_efi_cmdline(char *str)
  85{
  86	if (!str) {
  87		pr_warn("need at least one option\n");
  88		return -EINVAL;
  89	}
  90
  91	if (parse_option_str(str, "debug"))
  92		set_bit(EFI_DBG, &efi.flags);
  93
  94	if (parse_option_str(str, "noruntime"))
  95		disable_runtime = true;
  96
 
 
 
  97	return 0;
  98}
  99early_param("efi", parse_efi_cmdline);
 100
 101struct kobject *efi_kobj;
 102
 103/*
 104 * Let's not leave out systab information that snuck into
 105 * the efivars driver
 106 * Note, do not add more fields in systab sysfs file as it breaks sysfs
 107 * one value per file rule!
 108 */
 109static ssize_t systab_show(struct kobject *kobj,
 110			   struct kobj_attribute *attr, char *buf)
 111{
 112	char *str = buf;
 113
 114	if (!kobj || !buf)
 115		return -EINVAL;
 116
 117	if (efi.mps != EFI_INVALID_TABLE_ADDR)
 118		str += sprintf(str, "MPS=0x%lx\n", efi.mps);
 119	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
 120		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
 121	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
 122		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
 123	/*
 124	 * If both SMBIOS and SMBIOS3 entry points are implemented, the
 125	 * SMBIOS3 entry point shall be preferred, so we list it first to
 126	 * let applications stop parsing after the first match.
 127	 */
 128	if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
 129		str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
 130	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
 131		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
 132	if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
 133		str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
 134	if (efi.boot_info != EFI_INVALID_TABLE_ADDR)
 135		str += sprintf(str, "BOOTINFO=0x%lx\n", efi.boot_info);
 136	if (efi.uga != EFI_INVALID_TABLE_ADDR)
 137		str += sprintf(str, "UGA=0x%lx\n", efi.uga);
 138
 139	return str - buf;
 140}
 141
 142static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
 143
 144#define EFI_FIELD(var) efi.var
 145
 146#define EFI_ATTR_SHOW(name) \
 147static ssize_t name##_show(struct kobject *kobj, \
 148				struct kobj_attribute *attr, char *buf) \
 149{ \
 150	return sprintf(buf, "0x%lx\n", EFI_FIELD(name)); \
 151}
 152
 153EFI_ATTR_SHOW(fw_vendor);
 154EFI_ATTR_SHOW(runtime);
 155EFI_ATTR_SHOW(config_table);
 156
 157static ssize_t fw_platform_size_show(struct kobject *kobj,
 158				     struct kobj_attribute *attr, char *buf)
 159{
 160	return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
 161}
 162
 163static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
 164static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
 165static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
 166static struct kobj_attribute efi_attr_fw_platform_size =
 167	__ATTR_RO(fw_platform_size);
 168
 169static struct attribute *efi_subsys_attrs[] = {
 170	&efi_attr_systab.attr,
 
 171	&efi_attr_fw_vendor.attr,
 172	&efi_attr_runtime.attr,
 173	&efi_attr_config_table.attr,
 174	&efi_attr_fw_platform_size.attr,
 175	NULL,
 176};
 177
 178static umode_t efi_attr_is_visible(struct kobject *kobj,
 179				   struct attribute *attr, int n)
 180{
 181	if (attr == &efi_attr_fw_vendor.attr) {
 182		if (efi_enabled(EFI_PARAVIRT) ||
 183				efi.fw_vendor == EFI_INVALID_TABLE_ADDR)
 184			return 0;
 185	} else if (attr == &efi_attr_runtime.attr) {
 186		if (efi.runtime == EFI_INVALID_TABLE_ADDR)
 187			return 0;
 188	} else if (attr == &efi_attr_config_table.attr) {
 189		if (efi.config_table == EFI_INVALID_TABLE_ADDR)
 190			return 0;
 191	}
 192
 193	return attr->mode;
 194}
 195
 196static const struct attribute_group efi_subsys_attr_group = {
 197	.attrs = efi_subsys_attrs,
 198	.is_visible = efi_attr_is_visible,
 199};
 200
 201static struct efivars generic_efivars;
 202static struct efivar_operations generic_ops;
 203
 204static int generic_ops_register(void)
 205{
 206	generic_ops.get_variable = efi.get_variable;
 207	generic_ops.set_variable = efi.set_variable;
 208	generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
 209	generic_ops.get_next_variable = efi.get_next_variable;
 210	generic_ops.query_variable_store = efi_query_variable_store;
 211
 
 
 
 
 212	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
 213}
 214
 215static void generic_ops_unregister(void)
 216{
 217	efivars_unregister(&generic_efivars);
 218}
 219
 220#if IS_ENABLED(CONFIG_ACPI)
 221#define EFIVAR_SSDT_NAME_MAX	16
 222static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
 223static int __init efivar_ssdt_setup(char *str)
 224{
 225	int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
 226
 227	if (ret)
 228		return ret;
 229
 230	if (strlen(str) < sizeof(efivar_ssdt))
 231		memcpy(efivar_ssdt, str, strlen(str));
 232	else
 233		pr_warn("efivar_ssdt: name too long: %s\n", str);
 234	return 0;
 235}
 236__setup("efivar_ssdt=", efivar_ssdt_setup);
 237
 238static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
 239				   unsigned long name_size, void *data)
 240{
 241	struct efivar_entry *entry;
 242	struct list_head *list = data;
 243	char utf8_name[EFIVAR_SSDT_NAME_MAX];
 244	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
 245
 246	ucs2_as_utf8(utf8_name, name, limit - 1);
 247	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
 248		return 0;
 249
 250	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 251	if (!entry)
 252		return 0;
 253
 254	memcpy(entry->var.VariableName, name, name_size);
 255	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
 256
 257	efivar_entry_add(entry, list);
 258
 259	return 0;
 260}
 261
 262static __init int efivar_ssdt_load(void)
 263{
 264	LIST_HEAD(entries);
 265	struct efivar_entry *entry, *aux;
 266	unsigned long size;
 267	void *data;
 268	int ret;
 269
 270	if (!efivar_ssdt[0])
 271		return 0;
 272
 273	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
 274
 275	list_for_each_entry_safe(entry, aux, &entries, list) {
 276		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
 277			&entry->var.VendorGuid);
 278
 279		list_del(&entry->list);
 280
 281		ret = efivar_entry_size(entry, &size);
 282		if (ret) {
 283			pr_err("failed to get var size\n");
 284			goto free_entry;
 285		}
 286
 287		data = kmalloc(size, GFP_KERNEL);
 288		if (!data) {
 289			ret = -ENOMEM;
 290			goto free_entry;
 291		}
 292
 293		ret = efivar_entry_get(entry, NULL, &size, data);
 294		if (ret) {
 295			pr_err("failed to get var data\n");
 296			goto free_data;
 297		}
 298
 299		ret = acpi_load_table(data);
 300		if (ret) {
 301			pr_err("failed to load table: %d\n", ret);
 302			goto free_data;
 303		}
 304
 305		goto free_entry;
 306
 307free_data:
 308		kfree(data);
 309
 310free_entry:
 311		kfree(entry);
 312	}
 313
 314	return ret;
 315}
 316#else
 317static inline int efivar_ssdt_load(void) { return 0; }
 318#endif
 319
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 320/*
 321 * We register the efi subsystem with the firmware subsystem and the
 322 * efivars subsystem with the efi subsystem, if the system was booted with
 323 * EFI.
 324 */
 325static int __init efisubsys_init(void)
 326{
 327	int error;
 328
 
 
 
 329	if (!efi_enabled(EFI_BOOT))
 330		return 0;
 331
 332	/*
 333	 * Since we process only one efi_runtime_service() at a time, an
 334	 * ordered workqueue (which creates only one execution context)
 335	 * should suffice all our needs.
 336	 */
 337	efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
 338	if (!efi_rts_wq) {
 339		pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
 340		clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
 341		return 0;
 
 
 
 342	}
 343
 
 
 
 344	/* We register the efi directory at /sys/firmware/efi */
 345	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
 346	if (!efi_kobj) {
 347		pr_err("efi: Firmware registration failed.\n");
 
 348		return -ENOMEM;
 349	}
 350
 351	error = generic_ops_register();
 352	if (error)
 353		goto err_put;
 354
 355	if (efi_enabled(EFI_RUNTIME_SERVICES))
 356		efivar_ssdt_load();
 
 
 
 
 
 357
 358	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
 359	if (error) {
 360		pr_err("efi: Sysfs attribute export failed with error %d.\n",
 361		       error);
 362		goto err_unregister;
 363	}
 364
 365	error = efi_runtime_map_init(efi_kobj);
 366	if (error)
 367		goto err_remove_group;
 368
 369	/* and the standard mountpoint for efivarfs */
 370	error = sysfs_create_mount_point(efi_kobj, "efivars");
 371	if (error) {
 372		pr_err("efivars: Subsystem registration failed.\n");
 373		goto err_remove_group;
 374	}
 375
 
 
 
 376	return 0;
 377
 378err_remove_group:
 379	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
 380err_unregister:
 381	generic_ops_unregister();
 
 
 382err_put:
 383	kobject_put(efi_kobj);
 
 384	return error;
 385}
 386
 387subsys_initcall(efisubsys_init);
 388
 389/*
 390 * Find the efi memory descriptor for a given physical address.  Given a
 391 * physical address, determine if it exists within an EFI Memory Map entry,
 392 * and if so, populate the supplied memory descriptor with the appropriate
 393 * data.
 394 */
 395int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
 396{
 397	efi_memory_desc_t *md;
 398
 399	if (!efi_enabled(EFI_MEMMAP)) {
 400		pr_err_once("EFI_MEMMAP is not enabled.\n");
 401		return -EINVAL;
 402	}
 403
 404	if (!out_md) {
 405		pr_err_once("out_md is null.\n");
 406		return -EINVAL;
 407        }
 408
 409	for_each_efi_memory_desc(md) {
 410		u64 size;
 411		u64 end;
 412
 413		size = md->num_pages << EFI_PAGE_SHIFT;
 414		end = md->phys_addr + size;
 415		if (phys_addr >= md->phys_addr && phys_addr < end) {
 416			memcpy(out_md, md, sizeof(*out_md));
 417			return 0;
 418		}
 419	}
 420	return -ENOENT;
 421}
 422
 423/*
 424 * Calculate the highest address of an efi memory descriptor.
 425 */
 426u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
 427{
 428	u64 size = md->num_pages << EFI_PAGE_SHIFT;
 429	u64 end = md->phys_addr + size;
 430	return end;
 431}
 432
 433void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}
 434
 435/**
 436 * efi_mem_reserve - Reserve an EFI memory region
 437 * @addr: Physical address to reserve
 438 * @size: Size of reservation
 439 *
 440 * Mark a region as reserved from general kernel allocation and
 441 * prevent it being released by efi_free_boot_services().
 442 *
 443 * This function should be called drivers once they've parsed EFI
 444 * configuration tables to figure out where their data lives, e.g.
 445 * efi_esrt_init().
 446 */
 447void __init efi_mem_reserve(phys_addr_t addr, u64 size)
 448{
 449	if (!memblock_is_region_reserved(addr, size))
 450		memblock_reserve(addr, size);
 451
 452	/*
 453	 * Some architectures (x86) reserve all boot services ranges
 454	 * until efi_free_boot_services() because of buggy firmware
 455	 * implementations. This means the above memblock_reserve() is
 456	 * superfluous on x86 and instead what it needs to do is
 457	 * ensure the @start, @size is not freed.
 458	 */
 459	efi_arch_mem_reserve(addr, size);
 460}
 461
 462static __initdata efi_config_table_type_t common_tables[] = {
 463	{ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20},
 464	{ACPI_TABLE_GUID, "ACPI", &efi.acpi},
 465	{HCDP_TABLE_GUID, "HCDP", &efi.hcdp},
 466	{MPS_TABLE_GUID, "MPS", &efi.mps},
 467	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
 468	{SMBIOS3_TABLE_GUID, "SMBIOS 3.0", &efi.smbios3},
 469	{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
 470	{EFI_SYSTEM_RESOURCE_TABLE_GUID, "ESRT", &efi.esrt},
 471	{EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table},
 472	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
 473	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
 474	{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
 475	{LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log},
 476	{LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
 477#ifdef CONFIG_EFI_RCI2_TABLE
 478	{DELLEMC_EFI_RCI2_TABLE_GUID, NULL, &rci2_table_phys},
 479#endif
 480	{NULL_GUID, NULL, NULL},
 481};
 482
 483static __init int match_config_table(efi_guid_t *guid,
 484				     unsigned long table,
 485				     efi_config_table_type_t *table_types)
 486{
 487	int i;
 488
 489	if (table_types) {
 490		for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
 491			if (!efi_guidcmp(*guid, table_types[i].guid)) {
 492				*(table_types[i].ptr) = table;
 493				if (table_types[i].name)
 494					pr_cont(" %s=0x%lx ",
 495						table_types[i].name, table);
 496				return 1;
 497			}
 498		}
 499	}
 500
 501	return 0;
 502}
 503
 504int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 505				   efi_config_table_type_t *arch_tables)
 
 506{
 507	void *tablep;
 
 
 
 508	int i;
 509
 510	tablep = config_tables;
 511	pr_info("");
 512	for (i = 0; i < count; i++) {
 513		efi_guid_t guid;
 514		unsigned long table;
 
 
 
 
 515
 516		if (efi_enabled(EFI_64BIT)) {
 517			u64 table64;
 518			guid = ((efi_config_table_64_t *)tablep)->guid;
 519			table64 = ((efi_config_table_64_t *)tablep)->table;
 520			table = table64;
 521#ifndef CONFIG_64BIT
 522			if (table64 >> 32) {
 523				pr_cont("\n");
 524				pr_err("Table located above 4GB, disabling EFI.\n");
 525				return -EINVAL;
 526			}
 527#endif
 528		} else {
 529			guid = ((efi_config_table_32_t *)tablep)->guid;
 530			table = ((efi_config_table_32_t *)tablep)->table;
 531		}
 532
 533		if (!match_config_table(&guid, table, common_tables))
 534			match_config_table(&guid, table, arch_tables);
 535
 536		tablep += sz;
 537	}
 538	pr_cont("\n");
 539	set_bit(EFI_CONFIG_TABLES, &efi.flags);
 540
 541	if (efi.rng_seed != EFI_INVALID_TABLE_ADDR) {
 542		struct linux_efi_random_seed *seed;
 543		u32 size = 0;
 544
 545		seed = early_memremap(efi.rng_seed, sizeof(*seed));
 546		if (seed != NULL) {
 547			size = seed->size;
 548			early_memunmap(seed, sizeof(*seed));
 549		} else {
 550			pr_err("Could not map UEFI random seed!\n");
 551		}
 552		if (size > 0) {
 553			seed = early_memremap(efi.rng_seed,
 554					      sizeof(*seed) + size);
 555			if (seed != NULL) {
 556				pr_notice("seeding entropy pool\n");
 557				add_bootloader_randomness(seed->bits, seed->size);
 558				early_memunmap(seed, sizeof(*seed) + size);
 559			} else {
 560				pr_err("Could not map UEFI random seed!\n");
 561			}
 562		}
 563	}
 564
 565	if (efi_enabled(EFI_MEMMAP))
 566		efi_memattr_init();
 567
 568	efi_tpm_eventlog_init();
 569
 570	/* Parse the EFI Properties table if it exists */
 571	if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
 572		efi_properties_table_t *tbl;
 573
 574		tbl = early_memremap(efi.properties_table, sizeof(*tbl));
 575		if (tbl == NULL) {
 576			pr_err("Could not map Properties table!\n");
 577			return -ENOMEM;
 578		}
 579
 580		if (tbl->memory_protection_attribute &
 581		    EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA)
 582			set_bit(EFI_NX_PE_DATA, &efi.flags);
 583
 584		early_memunmap(tbl, sizeof(*tbl));
 585	}
 586
 587	if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
 588		unsigned long prsv = efi.mem_reserve;
 589
 590		while (prsv) {
 591			struct linux_efi_memreserve *rsv;
 592			u8 *p;
 593			int i;
 594
 595			/*
 596			 * Just map a full page: that is what we will get
 597			 * anyway, and it permits us to map the entire entry
 598			 * before knowing its size.
 599			 */
 600			p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
 601					   PAGE_SIZE);
 602			if (p == NULL) {
 603				pr_err("Could not map UEFI memreserve entry!\n");
 604				return -ENOMEM;
 605			}
 606
 607			rsv = (void *)(p + prsv % PAGE_SIZE);
 608
 609			/* reserve the entry itself */
 610			memblock_reserve(prsv, EFI_MEMRESERVE_SIZE(rsv->size));
 
 611
 612			for (i = 0; i < atomic_read(&rsv->count); i++) {
 613				memblock_reserve(rsv->entry[i].base,
 614						 rsv->entry[i].size);
 615			}
 616
 617			prsv = rsv->next;
 618			early_memunmap(p, PAGE_SIZE);
 619		}
 620	}
 621
 
 
 
 
 
 
 
 
 
 
 622	return 0;
 623}
 624
 625int __init efi_config_init(efi_config_table_type_t *arch_tables)
 
 626{
 627	void *config_tables;
 628	int sz, ret;
 629
 630	if (efi.systab->nr_tables == 0)
 631		return 0;
 632
 633	if (efi_enabled(EFI_64BIT))
 634		sz = sizeof(efi_config_table_64_t);
 635	else
 636		sz = sizeof(efi_config_table_32_t);
 637
 638	/*
 639	 * Let's see what config tables the firmware passed to us.
 640	 */
 641	config_tables = early_memremap(efi.systab->tables,
 642				       efi.systab->nr_tables * sz);
 643	if (config_tables == NULL) {
 644		pr_err("Could not map Configuration table!\n");
 645		return -ENOMEM;
 646	}
 647
 648	ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz,
 649				      arch_tables);
 
 
 
 650
 651	early_memunmap(config_tables, efi.systab->nr_tables * sz);
 652	return ret;
 653}
 654
 655#ifdef CONFIG_EFI_VARS_MODULE
 656static int __init efi_load_efivars(void)
 
 657{
 658	struct platform_device *pdev;
 659
 660	if (!efi_enabled(EFI_RUNTIME_SERVICES))
 661		return 0;
 662
 663	pdev = platform_device_register_simple("efivars", 0, NULL, 0);
 664	return PTR_ERR_OR_ZERO(pdev);
 665}
 666device_initcall(efi_load_efivars);
 667#endif
 668
 669#ifdef CONFIG_EFI_PARAMS_FROM_FDT
 670
 671#define UEFI_PARAM(name, prop, field)			   \
 672	{						   \
 673		{ name },				   \
 674		{ prop },				   \
 675		offsetof(struct efi_fdt_params, field),    \
 676		FIELD_SIZEOF(struct efi_fdt_params, field) \
 677	}
 678
 679struct params {
 680	const char name[32];
 681	const char propname[32];
 682	int offset;
 683	int size;
 684};
 685
 686static __initdata struct params fdt_params[] = {
 687	UEFI_PARAM("System Table", "linux,uefi-system-table", system_table),
 688	UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap),
 689	UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size),
 690	UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size),
 691	UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver)
 692};
 693
 694static __initdata struct params xen_fdt_params[] = {
 695	UEFI_PARAM("System Table", "xen,uefi-system-table", system_table),
 696	UEFI_PARAM("MemMap Address", "xen,uefi-mmap-start", mmap),
 697	UEFI_PARAM("MemMap Size", "xen,uefi-mmap-size", mmap_size),
 698	UEFI_PARAM("MemMap Desc. Size", "xen,uefi-mmap-desc-size", desc_size),
 699	UEFI_PARAM("MemMap Desc. Version", "xen,uefi-mmap-desc-ver", desc_ver)
 700};
 701
 702#define EFI_FDT_PARAMS_SIZE	ARRAY_SIZE(fdt_params)
 703
 704static __initdata struct {
 705	const char *uname;
 706	const char *subnode;
 707	struct params *params;
 708} dt_params[] = {
 709	{ "hypervisor", "uefi", xen_fdt_params },
 710	{ "chosen", NULL, fdt_params },
 711};
 712
 713struct param_info {
 714	int found;
 715	void *params;
 716	const char *missing;
 717};
 718
 719static int __init __find_uefi_params(unsigned long node,
 720				     struct param_info *info,
 721				     struct params *params)
 722{
 723	const void *prop;
 724	void *dest;
 725	u64 val;
 726	int i, len;
 727
 728	for (i = 0; i < EFI_FDT_PARAMS_SIZE; i++) {
 729		prop = of_get_flat_dt_prop(node, params[i].propname, &len);
 730		if (!prop) {
 731			info->missing = params[i].name;
 732			return 0;
 733		}
 734
 735		dest = info->params + params[i].offset;
 736		info->found++;
 737
 738		val = of_read_number(prop, len / sizeof(u32));
 739
 740		if (params[i].size == sizeof(u32))
 741			*(u32 *)dest = val;
 742		else
 743			*(u64 *)dest = val;
 744
 745		if (efi_enabled(EFI_DBG))
 746			pr_info("  %s: 0x%0*llx\n", params[i].name,
 747				params[i].size * 2, val);
 748	}
 749
 750	return 1;
 751}
 752
 753static int __init fdt_find_uefi_params(unsigned long node, const char *uname,
 754				       int depth, void *data)
 755{
 756	struct param_info *info = data;
 757	int i;
 758
 759	for (i = 0; i < ARRAY_SIZE(dt_params); i++) {
 760		const char *subnode = dt_params[i].subnode;
 761
 762		if (depth != 1 || strcmp(uname, dt_params[i].uname) != 0) {
 763			info->missing = dt_params[i].params[0].name;
 764			continue;
 765		}
 766
 767		if (subnode) {
 768			int err = of_get_flat_dt_subnode_by_name(node, subnode);
 769
 770			if (err < 0)
 771				return 0;
 772
 773			node = err;
 774		}
 775
 776		return __find_uefi_params(node, info, dt_params[i].params);
 777	}
 778
 779	return 0;
 780}
 
 
 
 
 781
 782int __init efi_get_fdt_params(struct efi_fdt_params *params)
 
 783{
 784	struct param_info info;
 785	int ret;
 786
 787	pr_info("Getting EFI parameters from FDT:\n");
 788
 789	info.found = 0;
 790	info.params = params;
 791
 792	ret = of_scan_flat_dt(fdt_find_uefi_params, &info);
 793	if (!info.found)
 794		pr_info("UEFI not found.\n");
 795	else if (!ret)
 796		pr_err("Can't find '%s' in device tree!\n",
 797		       info.missing);
 798
 799	return ret;
 
 800}
 801#endif /* CONFIG_EFI_PARAMS_FROM_FDT */
 802
 803static __initdata char memory_type_name[][20] = {
 804	"Reserved",
 805	"Loader Code",
 806	"Loader Data",
 807	"Boot Code",
 808	"Boot Data",
 809	"Runtime Code",
 810	"Runtime Data",
 811	"Conventional Memory",
 812	"Unusable Memory",
 813	"ACPI Reclaim Memory",
 814	"ACPI Memory NVS",
 815	"Memory Mapped I/O",
 816	"MMIO Port Space",
 817	"PAL Code",
 818	"Persistent Memory",
 819};
 820
 821char * __init efi_md_typeattr_format(char *buf, size_t size,
 822				     const efi_memory_desc_t *md)
 823{
 824	char *pos;
 825	int type_len;
 826	u64 attr;
 827
 828	pos = buf;
 829	if (md->type >= ARRAY_SIZE(memory_type_name))
 830		type_len = snprintf(pos, size, "[type=%u", md->type);
 831	else
 832		type_len = snprintf(pos, size, "[%-*s",
 833				    (int)(sizeof(memory_type_name[0]) - 1),
 834				    memory_type_name[md->type]);
 835	if (type_len >= size)
 836		return buf;
 837
 838	pos += type_len;
 839	size -= type_len;
 840
 841	attr = md->attribute;
 842	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
 843		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
 844		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
 845		     EFI_MEMORY_NV |
 846		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
 847		snprintf(pos, size, "|attr=0x%016llx]",
 848			 (unsigned long long)attr);
 849	else
 850		snprintf(pos, size,
 851			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
 852			 attr & EFI_MEMORY_RUNTIME ? "RUN" : "",
 853			 attr & EFI_MEMORY_MORE_RELIABLE ? "MR" : "",
 
 854			 attr & EFI_MEMORY_NV      ? "NV"  : "",
 855			 attr & EFI_MEMORY_XP      ? "XP"  : "",
 856			 attr & EFI_MEMORY_RP      ? "RP"  : "",
 857			 attr & EFI_MEMORY_WP      ? "WP"  : "",
 858			 attr & EFI_MEMORY_RO      ? "RO"  : "",
 859			 attr & EFI_MEMORY_UCE     ? "UCE" : "",
 860			 attr & EFI_MEMORY_WB      ? "WB"  : "",
 861			 attr & EFI_MEMORY_WT      ? "WT"  : "",
 862			 attr & EFI_MEMORY_WC      ? "WC"  : "",
 863			 attr & EFI_MEMORY_UC      ? "UC"  : "");
 864	return buf;
 865}
 866
 867/*
 868 * IA64 has a funky EFI memory map that doesn't work the same way as
 869 * other architectures.
 870 */
 871#ifndef CONFIG_IA64
 872/*
 873 * efi_mem_attributes - lookup memmap attributes for physical address
 874 * @phys_addr: the physical address to lookup
 875 *
 876 * Search in the EFI memory map for the region covering
 877 * @phys_addr. Returns the EFI memory attributes if the region
 878 * was found in the memory map, 0 otherwise.
 879 */
 880u64 efi_mem_attributes(unsigned long phys_addr)
 881{
 882	efi_memory_desc_t *md;
 883
 884	if (!efi_enabled(EFI_MEMMAP))
 885		return 0;
 886
 887	for_each_efi_memory_desc(md) {
 888		if ((md->phys_addr <= phys_addr) &&
 889		    (phys_addr < (md->phys_addr +
 890		    (md->num_pages << EFI_PAGE_SHIFT))))
 891			return md->attribute;
 892	}
 893	return 0;
 894}
 895
 896/*
 897 * efi_mem_type - lookup memmap type for physical address
 898 * @phys_addr: the physical address to lookup
 899 *
 900 * Search in the EFI memory map for the region covering @phys_addr.
 901 * Returns the EFI memory type if the region was found in the memory
 902 * map, EFI_RESERVED_TYPE (zero) otherwise.
 903 */
 904int efi_mem_type(unsigned long phys_addr)
 905{
 906	const efi_memory_desc_t *md;
 907
 908	if (!efi_enabled(EFI_MEMMAP))
 909		return -ENOTSUPP;
 910
 911	for_each_efi_memory_desc(md) {
 912		if ((md->phys_addr <= phys_addr) &&
 913		    (phys_addr < (md->phys_addr +
 914				  (md->num_pages << EFI_PAGE_SHIFT))))
 915			return md->type;
 916	}
 917	return -EINVAL;
 918}
 919#endif
 920
 921int efi_status_to_err(efi_status_t status)
 922{
 923	int err;
 924
 925	switch (status) {
 926	case EFI_SUCCESS:
 927		err = 0;
 928		break;
 929	case EFI_INVALID_PARAMETER:
 930		err = -EINVAL;
 931		break;
 932	case EFI_OUT_OF_RESOURCES:
 933		err = -ENOSPC;
 934		break;
 935	case EFI_DEVICE_ERROR:
 936		err = -EIO;
 937		break;
 938	case EFI_WRITE_PROTECTED:
 939		err = -EROFS;
 940		break;
 941	case EFI_SECURITY_VIOLATION:
 942		err = -EACCES;
 943		break;
 944	case EFI_NOT_FOUND:
 945		err = -ENOENT;
 946		break;
 947	case EFI_ABORTED:
 948		err = -EINTR;
 949		break;
 950	default:
 951		err = -EINVAL;
 952	}
 953
 954	return err;
 955}
 956
 957static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
 958static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
 959
 960static int __init efi_memreserve_map_root(void)
 961{
 962	if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
 963		return -ENODEV;
 964
 965	efi_memreserve_root = memremap(efi.mem_reserve,
 966				       sizeof(*efi_memreserve_root),
 967				       MEMREMAP_WB);
 968	if (WARN_ON_ONCE(!efi_memreserve_root))
 969		return -ENOMEM;
 970	return 0;
 971}
 972
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 973int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
 974{
 975	struct linux_efi_memreserve *rsv;
 976	unsigned long prsv;
 977	int rc, index;
 978
 979	if (efi_memreserve_root == (void *)ULONG_MAX)
 980		return -ENODEV;
 981
 982	if (!efi_memreserve_root) {
 983		rc = efi_memreserve_map_root();
 984		if (rc)
 985			return rc;
 986	}
 987
 988	/* first try to find a slot in an existing linked list entry */
 989	for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
 990		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
 991		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
 992		if (index < rsv->size) {
 993			rsv->entry[index].base = addr;
 994			rsv->entry[index].size = size;
 995
 996			memunmap(rsv);
 997			return 0;
 998		}
 999		memunmap(rsv);
1000	}
1001
1002	/* no slot found - allocate a new linked list entry */
1003	rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
1004	if (!rsv)
1005		return -ENOMEM;
1006
 
 
 
 
 
 
1007	/*
1008	 * The memremap() call above assumes that a linux_efi_memreserve entry
1009	 * never crosses a page boundary, so let's ensure that this remains true
1010	 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
1011	 * using SZ_4K explicitly in the size calculation below.
1012	 */
1013	rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
1014	atomic_set(&rsv->count, 1);
1015	rsv->entry[0].base = addr;
1016	rsv->entry[0].size = size;
1017
1018	spin_lock(&efi_mem_reserve_persistent_lock);
1019	rsv->next = efi_memreserve_root->next;
1020	efi_memreserve_root->next = __pa(rsv);
1021	spin_unlock(&efi_mem_reserve_persistent_lock);
1022
1023	return 0;
1024}
1025
1026static int __init efi_memreserve_root_init(void)
1027{
1028	if (efi_memreserve_root)
1029		return 0;
1030	if (efi_memreserve_map_root())
1031		efi_memreserve_root = (void *)ULONG_MAX;
1032	return 0;
1033}
1034early_initcall(efi_memreserve_root_init);
1035
1036#ifdef CONFIG_KEXEC
1037static int update_efi_random_seed(struct notifier_block *nb,
1038				  unsigned long code, void *unused)
1039{
1040	struct linux_efi_random_seed *seed;
1041	u32 size = 0;
1042
1043	if (!kexec_in_progress)
1044		return NOTIFY_DONE;
1045
1046	seed = memremap(efi.rng_seed, sizeof(*seed), MEMREMAP_WB);
1047	if (seed != NULL) {
1048		size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1049		memunmap(seed);
1050	} else {
1051		pr_err("Could not map UEFI random seed!\n");
1052	}
1053	if (size > 0) {
1054		seed = memremap(efi.rng_seed, sizeof(*seed) + size,
1055				MEMREMAP_WB);
1056		if (seed != NULL) {
1057			seed->size = size;
1058			get_random_bytes(seed->bits, seed->size);
1059			memunmap(seed);
1060		} else {
1061			pr_err("Could not map UEFI random seed!\n");
1062		}
1063	}
1064	return NOTIFY_DONE;
1065}
1066
1067static struct notifier_block efi_random_seed_nb = {
1068	.notifier_call = update_efi_random_seed,
1069};
1070
1071static int register_update_efi_random_seed(void)
1072{
1073	if (efi.rng_seed == EFI_INVALID_TABLE_ADDR)
1074		return 0;
1075	return register_reboot_notifier(&efi_random_seed_nb);
1076}
1077late_initcall(register_update_efi_random_seed);
1078#endif