efi.c 26.9 KB
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// SPDX-License-Identifier: GPL-2.0-only
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/*
 * efi.c - EFI subsystem
 *
 * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
 * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
 * Copyright (C) 2013 Tom Gundersen <teg@jklm.no>
 *
 * This code registers /sys/firmware/efi{,/efivars} when EFI is supported,
 * allowing the efivarfs to be mounted or the efivars module to be loaded.
 * The existance of /sys/firmware/efi may also be used by userspace to
 * determine that the system supports EFI.
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/init.h>
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#include <linux/debugfs.h>
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#include <linux/device.h>
#include <linux/efi.h>
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#include <linux/of.h>
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#include <linux/io.h>
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#include <linux/kexec.h>
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#include <linux/platform_device.h>
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#include <linux/random.h>
#include <linux/reboot.h>
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#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/ucs2_string.h>
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#include <linux/memblock.h>
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#include <linux/security.h>
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#include <asm/early_ioremap.h>
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struct efi __read_mostly efi = {
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	.runtime_supported_mask = EFI_RT_SUPPORTED_ALL,
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	.acpi			= EFI_INVALID_TABLE_ADDR,
	.acpi20			= EFI_INVALID_TABLE_ADDR,
	.smbios			= EFI_INVALID_TABLE_ADDR,
	.smbios3		= EFI_INVALID_TABLE_ADDR,
	.esrt			= EFI_INVALID_TABLE_ADDR,
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	.tpm_log		= EFI_INVALID_TABLE_ADDR,
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	.tpm_final_log		= EFI_INVALID_TABLE_ADDR,
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#ifdef CONFIG_LOAD_UEFI_KEYS
	.mokvar_table		= EFI_INVALID_TABLE_ADDR,
#endif
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#ifdef CONFIG_EFI_COCO_SECRET
	.coco_secret		= EFI_INVALID_TABLE_ADDR,
#endif
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};
EXPORT_SYMBOL(efi);
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unsigned long __ro_after_init efi_rng_seed = EFI_INVALID_TABLE_ADDR;
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static unsigned long __initdata mem_reserve = EFI_INVALID_TABLE_ADDR;
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static unsigned long __initdata rt_prop = EFI_INVALID_TABLE_ADDR;
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struct mm_struct efi_mm = {
	.mm_rb			= RB_ROOT,
	.mm_users		= ATOMIC_INIT(2),
	.mm_count		= ATOMIC_INIT(1),
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	.write_protect_seq      = SEQCNT_ZERO(efi_mm.write_protect_seq),
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	MMAP_LOCK_INITIALIZER(efi_mm)
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	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
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	.cpu_bitmap		= { [BITS_TO_LONGS(NR_CPUS)] = 0},
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};

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struct workqueue_struct *efi_rts_wq;

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static bool disable_runtime = IS_ENABLED(CONFIG_EFI_DISABLE_RUNTIME);
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static int __init setup_noefi(char *arg)
{
	disable_runtime = true;
	return 0;
}
early_param("noefi", setup_noefi);

bool efi_runtime_disabled(void)
{
	return disable_runtime;
}

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bool __pure __efi_soft_reserve_enabled(void)
{
	return !efi_enabled(EFI_MEM_NO_SOFT_RESERVE);
}

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static int __init parse_efi_cmdline(char *str)
{
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	if (!str) {
		pr_warn("need at least one option\n");
		return -EINVAL;
	}

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	if (parse_option_str(str, "debug"))
		set_bit(EFI_DBG, &efi.flags);

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	if (parse_option_str(str, "noruntime"))
		disable_runtime = true;

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	if (parse_option_str(str, "runtime"))
		disable_runtime = false;

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	if (parse_option_str(str, "nosoftreserve"))
		set_bit(EFI_MEM_NO_SOFT_RESERVE, &efi.flags);
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	return 0;
}
early_param("efi", parse_efi_cmdline);

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struct kobject *efi_kobj;
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/*
 * Let's not leave out systab information that snuck into
 * the efivars driver
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 * Note, do not add more fields in systab sysfs file as it breaks sysfs
 * one value per file rule!
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 */
static ssize_t systab_show(struct kobject *kobj,
			   struct kobj_attribute *attr, char *buf)
{
	char *str = buf;

	if (!kobj || !buf)
		return -EINVAL;

	if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
	if (efi.acpi != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
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	/*
	 * If both SMBIOS and SMBIOS3 entry points are implemented, the
	 * SMBIOS3 entry point shall be preferred, so we list it first to
	 * let applications stop parsing after the first match.
	 */
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	if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
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	if (efi.smbios != EFI_INVALID_TABLE_ADDR)
		str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
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	if (IS_ENABLED(CONFIG_IA64) || IS_ENABLED(CONFIG_X86))
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		str = efi_systab_show_arch(str);

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	return str - buf;
}

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static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
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static ssize_t fw_platform_size_show(struct kobject *kobj,
				     struct kobj_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32);
}

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extern __weak struct kobj_attribute efi_attr_fw_vendor;
extern __weak struct kobj_attribute efi_attr_runtime;
extern __weak struct kobj_attribute efi_attr_config_table;
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static struct kobj_attribute efi_attr_fw_platform_size =
	__ATTR_RO(fw_platform_size);
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static struct attribute *efi_subsys_attrs[] = {
	&efi_attr_systab.attr,
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	&efi_attr_fw_platform_size.attr,
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	&efi_attr_fw_vendor.attr,
	&efi_attr_runtime.attr,
	&efi_attr_config_table.attr,
	NULL,
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};

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umode_t __weak efi_attr_is_visible(struct kobject *kobj, struct attribute *attr,
				   int n)
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{
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	return attr->mode;
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}

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static const struct attribute_group efi_subsys_attr_group = {
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	.attrs = efi_subsys_attrs,
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	.is_visible = efi_attr_is_visible,
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};

static struct efivars generic_efivars;
static struct efivar_operations generic_ops;

static int generic_ops_register(void)
{
	generic_ops.get_variable = efi.get_variable;
	generic_ops.get_next_variable = efi.get_next_variable;
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	generic_ops.query_variable_store = efi_query_variable_store;
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	if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) {
		generic_ops.set_variable = efi.set_variable;
		generic_ops.set_variable_nonblocking = efi.set_variable_nonblocking;
	}
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	return efivars_register(&generic_efivars, &generic_ops, efi_kobj);
}

static void generic_ops_unregister(void)
{
	efivars_unregister(&generic_efivars);
}

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#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
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#define EFIVAR_SSDT_NAME_MAX	16UL
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static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
static int __init efivar_ssdt_setup(char *str)
{
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	int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);

	if (ret)
		return ret;

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	if (strlen(str) < sizeof(efivar_ssdt))
		memcpy(efivar_ssdt, str, strlen(str));
	else
		pr_warn("efivar_ssdt: name too long: %s\n", str);
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	return 1;
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}
__setup("efivar_ssdt=", efivar_ssdt_setup);

static __init int efivar_ssdt_load(void)
{
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	unsigned long name_size = 256;
	efi_char16_t *name = NULL;
	efi_status_t status;
	efi_guid_t guid;
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	if (!efivar_ssdt[0])
		return 0;

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	name = kzalloc(name_size, GFP_KERNEL);
	if (!name)
		return -ENOMEM;

	for (;;) {
		char utf8_name[EFIVAR_SSDT_NAME_MAX];
		unsigned long data_size = 0;
		void *data;
		int limit;

		status = efi.get_next_variable(&name_size, name, &guid);
		if (status == EFI_NOT_FOUND) {
			break;
		} else if (status == EFI_BUFFER_TOO_SMALL) {
			name = krealloc(name, name_size, GFP_KERNEL);
			if (!name)
				return -ENOMEM;
			continue;
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		}

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		limit = min(EFIVAR_SSDT_NAME_MAX, name_size);
		ucs2_as_utf8(utf8_name, name, limit - 1);
		if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
			continue;
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		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid);
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		status = efi.get_variable(name, &guid, NULL, &data_size, NULL);
		if (status != EFI_BUFFER_TOO_SMALL || !data_size)
			return -EIO;
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		data = kmalloc(data_size, GFP_KERNEL);
		if (!data)
			return -ENOMEM;
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		status = efi.get_variable(name, &guid, NULL, &data_size, data);
		if (status == EFI_SUCCESS) {
			acpi_status ret = acpi_load_table(data, NULL);
			if (ret)
				pr_err("failed to load table: %u\n", ret);
		} else {
			pr_err("failed to get var data: 0x%lx\n", status);
		}
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		kfree(data);
	}
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	return 0;
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}
#else
static inline int efivar_ssdt_load(void) { return 0; }
#endif

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#ifdef CONFIG_DEBUG_FS

#define EFI_DEBUGFS_MAX_BLOBS 32

static struct debugfs_blob_wrapper debugfs_blob[EFI_DEBUGFS_MAX_BLOBS];

static void __init efi_debugfs_init(void)
{
	struct dentry *efi_debugfs;
	efi_memory_desc_t *md;
	char name[32];
	int type_count[EFI_BOOT_SERVICES_DATA + 1] = {};
	int i = 0;

	efi_debugfs = debugfs_create_dir("efi", NULL);
	if (IS_ERR_OR_NULL(efi_debugfs))
		return;

	for_each_efi_memory_desc(md) {
		switch (md->type) {
		case EFI_BOOT_SERVICES_CODE:
			snprintf(name, sizeof(name), "boot_services_code%d",
				 type_count[md->type]++);
			break;
		case EFI_BOOT_SERVICES_DATA:
			snprintf(name, sizeof(name), "boot_services_data%d",
				 type_count[md->type]++);
			break;
		default:
			continue;
		}

		if (i >= EFI_DEBUGFS_MAX_BLOBS) {
			pr_warn("More then %d EFI boot service segments, only showing first %d in debugfs\n",
				EFI_DEBUGFS_MAX_BLOBS, EFI_DEBUGFS_MAX_BLOBS);
			break;
		}

		debugfs_blob[i].size = md->num_pages << EFI_PAGE_SHIFT;
		debugfs_blob[i].data = memremap(md->phys_addr,
						debugfs_blob[i].size,
						MEMREMAP_WB);
		if (!debugfs_blob[i].data)
			continue;

		debugfs_create_blob(name, 0400, efi_debugfs, &debugfs_blob[i]);
		i++;
	}
}
#else
static inline void efi_debugfs_init(void) {}
#endif

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/*
 * We register the efi subsystem with the firmware subsystem and the
 * efivars subsystem with the efi subsystem, if the system was booted with
 * EFI.
 */
static int __init efisubsys_init(void)
{
	int error;

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	if (!efi_enabled(EFI_RUNTIME_SERVICES))
		efi.runtime_supported_mask = 0;

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	if (!efi_enabled(EFI_BOOT))
		return 0;

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	if (efi.runtime_supported_mask) {
		/*
		 * Since we process only one efi_runtime_service() at a time, an
		 * ordered workqueue (which creates only one execution context)
		 * should suffice for all our needs.
		 */
		efi_rts_wq = alloc_ordered_workqueue("efi_rts_wq", 0);
		if (!efi_rts_wq) {
			pr_err("Creating efi_rts_wq failed, EFI runtime services disabled.\n");
			clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
			efi.runtime_supported_mask = 0;
			return 0;
		}
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	}

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	if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
		platform_device_register_simple("rtc-efi", 0, NULL, 0);

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	/* We register the efi directory at /sys/firmware/efi */
	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
	if (!efi_kobj) {
		pr_err("efi: Firmware registration failed.\n");
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		destroy_workqueue(efi_rts_wq);
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		return -ENOMEM;
	}

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	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME)) {
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		error = generic_ops_register();
		if (error)
			goto err_put;
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		efivar_ssdt_load();
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		platform_device_register_simple("efivars", 0, NULL, 0);
	}
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	error = sysfs_create_group(efi_kobj, &efi_subsys_attr_group);
	if (error) {
		pr_err("efi: Sysfs attribute export failed with error %d.\n",
		       error);
		goto err_unregister;
	}

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	error = efi_runtime_map_init(efi_kobj);
	if (error)
		goto err_remove_group;

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	/* and the standard mountpoint for efivarfs */
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	error = sysfs_create_mount_point(efi_kobj, "efivars");
	if (error) {
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		pr_err("efivars: Subsystem registration failed.\n");
		goto err_remove_group;
	}

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	if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
		efi_debugfs_init();

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#ifdef CONFIG_EFI_COCO_SECRET
	if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
		platform_device_register_simple("efi_secret", 0, NULL, 0);
#endif

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	return 0;

err_remove_group:
	sysfs_remove_group(efi_kobj, &efi_subsys_attr_group);
err_unregister:
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	if (efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE |
				      EFI_RT_SUPPORTED_GET_NEXT_VARIABLE_NAME))
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		generic_ops_unregister();
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err_put:
	kobject_put(efi_kobj);
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	destroy_workqueue(efi_rts_wq);
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	return error;
}

subsys_initcall(efisubsys_init);
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void __init efi_find_mirror(void)
{
	efi_memory_desc_t *md;
	u64 mirror_size = 0, total_size = 0;

	if (!efi_enabled(EFI_MEMMAP))
		return;

	for_each_efi_memory_desc(md) {
		unsigned long long start = md->phys_addr;
		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;

		total_size += size;
		if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
			memblock_mark_mirror(start, size);
			mirror_size += size;
		}
	}
	if (mirror_size)
		pr_info("Memory: %lldM/%lldM mirrored memory\n",
			mirror_size>>20, total_size>>20);
}

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/*
 * Find the efi memory descriptor for a given physical address.  Given a
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 * physical address, determine if it exists within an EFI Memory Map entry,
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 * and if so, populate the supplied memory descriptor with the appropriate
 * data.
 */
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int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
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{
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	efi_memory_desc_t *md;
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	if (!efi_enabled(EFI_MEMMAP)) {
		pr_err_once("EFI_MEMMAP is not enabled.\n");
		return -EINVAL;
	}

	if (!out_md) {
		pr_err_once("out_md is null.\n");
		return -EINVAL;
        }

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	for_each_efi_memory_desc(md) {
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		u64 size;
		u64 end;

		size = md->num_pages << EFI_PAGE_SHIFT;
		end = md->phys_addr + size;
		if (phys_addr >= md->phys_addr && phys_addr < end) {
			memcpy(out_md, md, sizeof(*out_md));
			return 0;
		}
	}
	return -ENOENT;
}

/*
 * Calculate the highest address of an efi memory descriptor.
 */
u64 __init efi_mem_desc_end(efi_memory_desc_t *md)
{
	u64 size = md->num_pages << EFI_PAGE_SHIFT;
	u64 end = md->phys_addr + size;
	return end;
}
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void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {}

/**
 * efi_mem_reserve - Reserve an EFI memory region
 * @addr: Physical address to reserve
 * @size: Size of reservation
 *
 * Mark a region as reserved from general kernel allocation and
 * prevent it being released by efi_free_boot_services().
 *
 * This function should be called drivers once they've parsed EFI
 * configuration tables to figure out where their data lives, e.g.
 * efi_esrt_init().
 */
void __init efi_mem_reserve(phys_addr_t addr, u64 size)
{
	if (!memblock_is_region_reserved(addr, size))
		memblock_reserve(addr, size);

	/*
	 * Some architectures (x86) reserve all boot services ranges
	 * until efi_free_boot_services() because of buggy firmware
	 * implementations. This means the above memblock_reserve() is
	 * superfluous on x86 and instead what it needs to do is
	 * ensure the @start, @size is not freed.
	 */
	efi_arch_mem_reserve(addr, size);
}

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static const efi_config_table_type_t common_tables[] __initconst = {
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	{ACPI_20_TABLE_GUID,			&efi.acpi20,		"ACPI 2.0"	},
	{ACPI_TABLE_GUID,			&efi.acpi,		"ACPI"		},
	{SMBIOS_TABLE_GUID,			&efi.smbios,		"SMBIOS"	},
	{SMBIOS3_TABLE_GUID,			&efi.smbios3,		"SMBIOS 3.0"	},
	{EFI_SYSTEM_RESOURCE_TABLE_GUID,	&efi.esrt,		"ESRT"		},
	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID,	&efi_mem_attr_table,	"MEMATTR"	},
	{LINUX_EFI_RANDOM_SEED_TABLE_GUID,	&efi_rng_seed,		"RNG"		},
	{LINUX_EFI_TPM_EVENT_LOG_GUID,		&efi.tpm_log,		"TPMEventLog"	},
	{LINUX_EFI_TPM_FINAL_LOG_GUID,		&efi.tpm_final_log,	"TPMFinalLog"	},
	{LINUX_EFI_MEMRESERVE_TABLE_GUID,	&mem_reserve,		"MEMRESERVE"	},
	{EFI_RT_PROPERTIES_TABLE_GUID,		&rt_prop,		"RTPROP"	},
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#ifdef CONFIG_EFI_RCI2_TABLE
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	{DELLEMC_EFI_RCI2_TABLE_GUID,		&rci2_table_phys			},
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#endif
#ifdef CONFIG_LOAD_UEFI_KEYS
	{LINUX_EFI_MOK_VARIABLE_TABLE_GUID,	&efi.mokvar_table,	"MOKvar"	},
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#endif
#ifdef CONFIG_EFI_COCO_SECRET
	{LINUX_EFI_COCO_SECRET_AREA_GUID,	&efi.coco_secret,	"CocoSecret"	},
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#endif
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	{},
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};

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static __init int match_config_table(const efi_guid_t *guid,
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				     unsigned long table,
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				     const efi_config_table_type_t *table_types)
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{
	int i;

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	for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
		if (!efi_guidcmp(*guid, table_types[i].guid)) {
			*(table_types[i].ptr) = table;
			if (table_types[i].name[0])
				pr_cont("%s=0x%lx ",
					table_types[i].name, table);
			return 1;
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		}
	}

	return 0;
}

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int __init efi_config_parse_tables(const efi_config_table_t *config_tables,
				   int count,
				   const efi_config_table_type_t *arch_tables)
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{
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	const efi_config_table_64_t *tbl64 = (void *)config_tables;
	const efi_config_table_32_t *tbl32 = (void *)config_tables;
	const efi_guid_t *guid;
	unsigned long table;
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	int i;
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	pr_info("");
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	for (i = 0; i < count; i++) {
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		if (!IS_ENABLED(CONFIG_X86)) {
			guid = &config_tables[i].guid;
			table = (unsigned long)config_tables[i].table;
		} else if (efi_enabled(EFI_64BIT)) {
			guid = &tbl64[i].guid;
			table = tbl64[i].table;

			if (IS_ENABLED(CONFIG_X86_32) &&
			    tbl64[i].table > U32_MAX) {
588 589 590 591 592
				pr_cont("\n");
				pr_err("Table located above 4GB, disabling EFI.\n");
				return -EINVAL;
			}
		} else {
593 594
			guid = &tbl32[i].guid;
			table = tbl32[i].table;
595 596
		}

597
		if (!match_config_table(guid, table, common_tables) && arch_tables)
598
			match_config_table(guid, table, arch_tables);
599 600
	}
	pr_cont("\n");
601
	set_bit(EFI_CONFIG_TABLES, &efi.flags);
602

603
	if (efi_rng_seed != EFI_INVALID_TABLE_ADDR) {
604 605 606
		struct linux_efi_random_seed *seed;
		u32 size = 0;

607
		seed = early_memremap(efi_rng_seed, sizeof(*seed));
608
		if (seed != NULL) {
609
			size = READ_ONCE(seed->size);
610 611 612 613 614
			early_memunmap(seed, sizeof(*seed));
		} else {
			pr_err("Could not map UEFI random seed!\n");
		}
		if (size > 0) {
615 616
			seed = early_memremap(efi_rng_seed,
					      sizeof(*seed) + size);
617
			if (seed != NULL) {
618
				pr_notice("seeding entropy pool\n");
619
				add_bootloader_randomness(seed->bits, size);
620 621 622 623 624 625 626
				early_memunmap(seed, sizeof(*seed) + size);
			} else {
				pr_err("Could not map UEFI random seed!\n");
			}
		}
	}

627
	if (!IS_ENABLED(CONFIG_X86_32) && efi_enabled(EFI_MEMMAP))
628
		efi_memattr_init();
629

630 631
	efi_tpm_eventlog_init();

632 633
	if (mem_reserve != EFI_INVALID_TABLE_ADDR) {
		unsigned long prsv = mem_reserve;
634 635 636

		while (prsv) {
			struct linux_efi_memreserve *rsv;
637 638 639 640 641 642 643 644 645 646
			u8 *p;

			/*
			 * Just map a full page: that is what we will get
			 * anyway, and it permits us to map the entire entry
			 * before knowing its size.
			 */
			p = early_memremap(ALIGN_DOWN(prsv, PAGE_SIZE),
					   PAGE_SIZE);
			if (p == NULL) {
647 648 649 650
				pr_err("Could not map UEFI memreserve entry!\n");
				return -ENOMEM;
			}

651 652 653
			rsv = (void *)(p + prsv % PAGE_SIZE);

			/* reserve the entry itself */
654 655
			memblock_reserve(prsv,
					 struct_size(rsv, entry, rsv->size));
656 657 658 659 660

			for (i = 0; i < atomic_read(&rsv->count); i++) {
				memblock_reserve(rsv->entry[i].base,
						 rsv->entry[i].size);
			}
661 662

			prsv = rsv->next;
663
			early_memunmap(p, PAGE_SIZE);
664 665 666
		}
	}

667 668 669 670 671 672 673 674 675 676
	if (rt_prop != EFI_INVALID_TABLE_ADDR) {
		efi_rt_properties_table_t *tbl;

		tbl = early_memremap(rt_prop, sizeof(*tbl));
		if (tbl) {
			efi.runtime_supported_mask &= tbl->runtime_services_supported;
			early_memunmap(tbl, sizeof(*tbl));
		}
	}

677 678
	return 0;
}
679

680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
int __init efi_systab_check_header(const efi_table_hdr_t *systab_hdr,
				   int min_major_version)
{
	if (systab_hdr->signature != EFI_SYSTEM_TABLE_SIGNATURE) {
		pr_err("System table signature incorrect!\n");
		return -EINVAL;
	}

	if ((systab_hdr->revision >> 16) < min_major_version)
		pr_err("Warning: System table version %d.%02d, expected %d.00 or greater!\n",
		       systab_hdr->revision >> 16,
		       systab_hdr->revision & 0xffff,
		       min_major_version);

	return 0;
}

#ifndef CONFIG_IA64
static const efi_char16_t *__init map_fw_vendor(unsigned long fw_vendor,
						size_t size)
{
	const efi_char16_t *ret;

	ret = early_memremap_ro(fw_vendor, size);
	if (!ret)
		pr_err("Could not map the firmware vendor!\n");
	return ret;
}

static void __init unmap_fw_vendor(const void *fw_vendor, size_t size)
{
	early_memunmap((void *)fw_vendor, size);
}
#else
#define map_fw_vendor(p, s)	__va(p)
#define unmap_fw_vendor(v, s)
#endif

void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr,
				     unsigned long fw_vendor)
{
	char vendor[100] = "unknown";
	const efi_char16_t *c16;
	size_t i;

	c16 = map_fw_vendor(fw_vendor, sizeof(vendor) * sizeof(efi_char16_t));
	if (c16) {
		for (i = 0; i < sizeof(vendor) - 1 && c16[i]; ++i)
			vendor[i] = c16[i];
		vendor[i] = '\0';

		unmap_fw_vendor(c16, sizeof(vendor) * sizeof(efi_char16_t));
	}

	pr_info("EFI v%u.%.02u by %s\n",
		systab_hdr->revision >> 16,
		systab_hdr->revision & 0xffff,
		vendor);
738 739 740 741 742 743 744

	if (IS_ENABLED(CONFIG_X86_64) &&
	    systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION &&
	    !strcmp(vendor, "Apple")) {
		pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n");
		efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION;
	}
745 746
}

747
static __initdata char memory_type_name[][13] = {
748 749 750 751 752 753 754
	"Reserved",
	"Loader Code",
	"Loader Data",
	"Boot Code",
	"Boot Data",
	"Runtime Code",
	"Runtime Data",
755 756 757 758 759 760
	"Conventional",
	"Unusable",
	"ACPI Reclaim",
	"ACPI Mem NVS",
	"MMIO",
	"MMIO Port",
761
	"PAL Code",
762
	"Persistent",
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786
};

char * __init efi_md_typeattr_format(char *buf, size_t size,
				     const efi_memory_desc_t *md)
{
	char *pos;
	int type_len;
	u64 attr;

	pos = buf;
	if (md->type >= ARRAY_SIZE(memory_type_name))
		type_len = snprintf(pos, size, "[type=%u", md->type);
	else
		type_len = snprintf(pos, size, "[%-*s",
				    (int)(sizeof(memory_type_name[0]) - 1),
				    memory_type_name[md->type]);
	if (type_len >= size)
		return buf;

	pos += type_len;
	size -= type_len;

	attr = md->attribute;
	if (attr & ~(EFI_MEMORY_UC | EFI_MEMORY_WC | EFI_MEMORY_WT |
787 788
		     EFI_MEMORY_WB | EFI_MEMORY_UCE | EFI_MEMORY_RO |
		     EFI_MEMORY_WP | EFI_MEMORY_RP | EFI_MEMORY_XP |
789
		     EFI_MEMORY_NV | EFI_MEMORY_SP | EFI_MEMORY_CPU_CRYPTO |
790
		     EFI_MEMORY_RUNTIME | EFI_MEMORY_MORE_RELIABLE))
791 792 793
		snprintf(pos, size, "|attr=0x%016llx]",
			 (unsigned long long)attr);
	else
R
Robert Elliott 已提交
794
		snprintf(pos, size,
795 796 797 798 799 800 801 802 803 804 805 806 807 808 809
			 "|%3s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
			 attr & EFI_MEMORY_RUNTIME		? "RUN" : "",
			 attr & EFI_MEMORY_MORE_RELIABLE	? "MR"  : "",
			 attr & EFI_MEMORY_CPU_CRYPTO   	? "CC"  : "",
			 attr & EFI_MEMORY_SP			? "SP"  : "",
			 attr & EFI_MEMORY_NV			? "NV"  : "",
			 attr & EFI_MEMORY_XP			? "XP"  : "",
			 attr & EFI_MEMORY_RP			? "RP"  : "",
			 attr & EFI_MEMORY_WP			? "WP"  : "",
			 attr & EFI_MEMORY_RO			? "RO"  : "",
			 attr & EFI_MEMORY_UCE			? "UCE" : "",
			 attr & EFI_MEMORY_WB			? "WB"  : "",
			 attr & EFI_MEMORY_WT			? "WT"  : "",
			 attr & EFI_MEMORY_WC			? "WC"  : "",
			 attr & EFI_MEMORY_UC			? "UC"  : "");
810 811
	return buf;
}
812

813 814 815 816 817
/*
 * IA64 has a funky EFI memory map that doesn't work the same way as
 * other architectures.
 */
#ifndef CONFIG_IA64
818 819 820 821 822 823 824 825
/*
 * efi_mem_attributes - lookup memmap attributes for physical address
 * @phys_addr: the physical address to lookup
 *
 * Search in the EFI memory map for the region covering
 * @phys_addr. Returns the EFI memory attributes if the region
 * was found in the memory map, 0 otherwise.
 */
826
u64 efi_mem_attributes(unsigned long phys_addr)
827 828 829 830 831 832
{
	efi_memory_desc_t *md;

	if (!efi_enabled(EFI_MEMMAP))
		return 0;

833
	for_each_efi_memory_desc(md) {
834 835 836 837 838 839 840
		if ((md->phys_addr <= phys_addr) &&
		    (phys_addr < (md->phys_addr +
		    (md->num_pages << EFI_PAGE_SHIFT))))
			return md->attribute;
	}
	return 0;
}
841

842 843 844 845 846 847
/*
 * efi_mem_type - lookup memmap type for physical address
 * @phys_addr: the physical address to lookup
 *
 * Search in the EFI memory map for the region covering @phys_addr.
 * Returns the EFI memory type if the region was found in the memory
848
 * map, -EINVAL otherwise.
849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866
 */
int efi_mem_type(unsigned long phys_addr)
{
	const efi_memory_desc_t *md;

	if (!efi_enabled(EFI_MEMMAP))
		return -ENOTSUPP;

	for_each_efi_memory_desc(md) {
		if ((md->phys_addr <= phys_addr) &&
		    (phys_addr < (md->phys_addr +
				  (md->num_pages << EFI_PAGE_SHIFT))))
			return md->type;
	}
	return -EINVAL;
}
#endif

867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892
int efi_status_to_err(efi_status_t status)
{
	int err;

	switch (status) {
	case EFI_SUCCESS:
		err = 0;
		break;
	case EFI_INVALID_PARAMETER:
		err = -EINVAL;
		break;
	case EFI_OUT_OF_RESOURCES:
		err = -ENOSPC;
		break;
	case EFI_DEVICE_ERROR:
		err = -EIO;
		break;
	case EFI_WRITE_PROTECTED:
		err = -EROFS;
		break;
	case EFI_SECURITY_VIOLATION:
		err = -EACCES;
		break;
	case EFI_NOT_FOUND:
		err = -ENOENT;
		break;
893 894 895
	case EFI_ABORTED:
		err = -EINTR;
		break;
896 897 898 899 900
	default:
		err = -EINVAL;
	}

	return err;
901 902
}

903
static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
904
static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
905

906 907
static int __init efi_memreserve_map_root(void)
{
908
	if (mem_reserve == EFI_INVALID_TABLE_ADDR)
909 910
		return -ENODEV;

911
	efi_memreserve_root = memremap(mem_reserve,
912 913 914 915 916 917 918
				       sizeof(*efi_memreserve_root),
				       MEMREMAP_WB);
	if (WARN_ON_ONCE(!efi_memreserve_root))
		return -ENOMEM;
	return 0;
}

919 920 921
static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
{
	struct resource *res, *parent;
922
	int ret;
923 924 925 926 927 928 929 930 931 932 933 934

	res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
	if (!res)
		return -ENOMEM;

	res->name	= "reserved";
	res->flags	= IORESOURCE_MEM;
	res->start	= addr;
	res->end	= addr + size - 1;

	/* we expect a conflict with a 'System RAM' region */
	parent = request_resource_conflict(&iomem_resource, res);
935 936 937 938 939 940 941 942 943 944 945
	ret = parent ? request_resource(parent, res) : 0;

	/*
	 * Given that efi_mem_reserve_iomem() can be called at any
	 * time, only call memblock_reserve() if the architecture
	 * keeps the infrastructure around.
	 */
	if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
		memblock_reserve(addr, size);

	return ret;
946 947
}

948
int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
949
{
950
	struct linux_efi_memreserve *rsv;
951 952
	unsigned long prsv;
	int rc, index;
953

954
	if (efi_memreserve_root == (void *)ULONG_MAX)
955 956
		return -ENODEV;

957 958 959 960 961 962
	if (!efi_memreserve_root) {
		rc = efi_memreserve_map_root();
		if (rc)
			return rc;
	}

963
	/* first try to find a slot in an existing linked list entry */
964
	for (prsv = efi_memreserve_root->next; prsv; ) {
965
		rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
966 967 968 969 970
		index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
		if (index < rsv->size) {
			rsv->entry[index].base = addr;
			rsv->entry[index].size = size;

971
			memunmap(rsv);
972
			return efi_mem_reserve_iomem(addr, size);
973
		}
974
		prsv = rsv->next;
975
		memunmap(rsv);
976 977 978 979
	}

	/* no slot found - allocate a new linked list entry */
	rsv = (struct linux_efi_memreserve *)__get_free_page(GFP_ATOMIC);
980 981 982
	if (!rsv)
		return -ENOMEM;

983 984 985 986 987 988
	rc = efi_mem_reserve_iomem(__pa(rsv), SZ_4K);
	if (rc) {
		free_page((unsigned long)rsv);
		return rc;
	}

989 990 991 992 993 994 995
	/*
	 * The memremap() call above assumes that a linux_efi_memreserve entry
	 * never crosses a page boundary, so let's ensure that this remains true
	 * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
	 * using SZ_4K explicitly in the size calculation below.
	 */
	rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
996 997 998
	atomic_set(&rsv->count, 1);
	rsv->entry[0].base = addr;
	rsv->entry[0].size = size;
999 1000

	spin_lock(&efi_mem_reserve_persistent_lock);
1001 1002
	rsv->next = efi_memreserve_root->next;
	efi_memreserve_root->next = __pa(rsv);
1003 1004
	spin_unlock(&efi_mem_reserve_persistent_lock);

1005
	return efi_mem_reserve_iomem(addr, size);
1006
}
1007

1008 1009
static int __init efi_memreserve_root_init(void)
{
1010 1011 1012 1013
	if (efi_memreserve_root)
		return 0;
	if (efi_memreserve_map_root())
		efi_memreserve_root = (void *)ULONG_MAX;
1014 1015
	return 0;
}
1016
early_initcall(efi_memreserve_root_init);
1017

1018 1019 1020 1021 1022 1023 1024 1025 1026 1027
#ifdef CONFIG_KEXEC
static int update_efi_random_seed(struct notifier_block *nb,
				  unsigned long code, void *unused)
{
	struct linux_efi_random_seed *seed;
	u32 size = 0;

	if (!kexec_in_progress)
		return NOTIFY_DONE;

1028
	seed = memremap(efi_rng_seed, sizeof(*seed), MEMREMAP_WB);
1029
	if (seed != NULL) {
1030
		size = min(seed->size, EFI_RANDOM_SEED_SIZE);
1031 1032 1033 1034 1035
		memunmap(seed);
	} else {
		pr_err("Could not map UEFI random seed!\n");
	}
	if (size > 0) {
1036 1037
		seed = memremap(efi_rng_seed, sizeof(*seed) + size,
				MEMREMAP_WB);
1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
		if (seed != NULL) {
			seed->size = size;
			get_random_bytes(seed->bits, seed->size);
			memunmap(seed);
		} else {
			pr_err("Could not map UEFI random seed!\n");
		}
	}
	return NOTIFY_DONE;
}

static struct notifier_block efi_random_seed_nb = {
	.notifier_call = update_efi_random_seed,
};

1053
static int __init register_update_efi_random_seed(void)
1054
{
1055
	if (efi_rng_seed == EFI_INVALID_TABLE_ADDR)
1056 1057 1058 1059 1060
		return 0;
	return register_reboot_notifier(&efi_random_seed_nb);
}
late_initcall(register_update_efi_random_seed);
#endif