Merge tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

Pull EFI updates from Ard Biesheuvel:

 - Enable mirrored memory for arm64

 - Fix up several abuses of the efivar API

 - Refactor the efivar API in preparation for moving the 'business
   logic' part of it into efivarfs

 - Enable ACPI PRM on arm64

* tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits)
  ACPI: Move PRM config option under the main ACPI config
  ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64
  ACPI: PRM: Change handler_addr type to void pointer
  efi: Simplify arch_efi_call_virt() macro
  drivers: fix typo in firmware/efi/memmap.c
  efi: vars: Drop __efivar_entry_iter() helper which is no longer used
  efi: vars: Use locking version to iterate over efivars linked lists
  efi: pstore: Omit efivars caching EFI varstore access layer
  efi: vars: Add thin wrapper around EFI get/set variable interface
  efi: vars: Don't drop lock in the middle of efivar_init()
  pstore: Add priv field to pstore_record for backend specific use
  Input: applespi - avoid efivars API and invoke EFI services directly
  selftests/kexec: remove broken EFI_VARS secure boot fallback check
  brcmfmac: Switch to appropriate helper to load EFI variable contents
  iwlwifi: Switch to proper EFI variable store interface
  media: atomisp_gmin_platform: stop abusing efivar API
  efi: efibc: avoid efivar API for setting variables
  efi: avoid efivars layer when loading SSDTs from variables
  efi: Correct comment on efi_memmap_alloc
  memblock: Disable mirror feature if kernelcore is not specified
  ...

8 files changed, 354 insertions, 516 deletions

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 7aa4717cdcac..7fe8b5c686d2 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -22,6 +22,7 @@ config EFI_ESRT
 config EFI_VARS_PSTORE
 	tristate "Register efivars backend for pstore"
 	depends on PSTORE
+	select UCS2_STRING
 	default y
 	help
 	  Say Y here to enable use efivars as a backend to pstore. This
@@ -145,6 +146,7 @@ config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER
 
 config EFI_BOOTLOADER_CONTROL
 	tristate "EFI Bootloader Control"
+	select UCS2_STRING
 	default n
 	help
 	  This module installs a reboot hook, such that if reboot() is
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c
index b2c829e95bd1..3928dbff76d0 100644
--- a/drivers/firmware/efi/efi-init.c
+++ b/drivers/firmware/efi/efi-init.c
@@ -240,6 +240,7 @@ void __init efi_init(void)
 	 * And now, memblock is fully populated, it is time to do capping.
 	 */
 	early_init_dt_check_for_usable_mem_range();
+	efi_find_mirror();
 	efi_esrt_init();
 	efi_mokvar_table_init();
 
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 7e771c56c13c..3bddc152fcd4 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -6,6 +6,8 @@
 #include <linux/slab.h>
 #include <linux/ucs2_string.h>
 
+MODULE_IMPORT_NS(EFIVAR);
+
 #define DUMP_NAME_LEN 66
 
 #define EFIVARS_DATA_SIZE_MAX 1024
@@ -20,18 +22,25 @@ module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
 	 EFI_VARIABLE_BOOTSERVICE_ACCESS | \
 	 EFI_VARIABLE_RUNTIME_ACCESS)
 
-static LIST_HEAD(efi_pstore_list);
-static DECLARE_WORK(efivar_work, NULL);
-
 static int efi_pstore_open(struct pstore_info *psi)
 {
-	psi->data = NULL;
+	int err;
+
+	err = efivar_lock();
+	if (err)
+		return err;
+
+	psi->data = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
+	if (!psi->data)
+		return -ENOMEM;
+
 	return 0;
 }
 
 static int efi_pstore_close(struct pstore_info *psi)
 {
-	psi->data = NULL;
+	efivar_unlock();
+	kfree(psi->data);
 	return 0;
 }
 
@@ -40,22 +49,17 @@ static inline u64 generic_id(u64 timestamp, unsigned int part, int count)
 	return (timestamp * 100 + part) * 1000 + count;
 }
 
-static int efi_pstore_read_func(struct efivar_entry *entry,
-				struct pstore_record *record)
+static int efi_pstore_read_func(struct pstore_record *record,
+				efi_char16_t *varname)
 {
-	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
+	unsigned long wlen, size = EFIVARS_DATA_SIZE_MAX;
 	char name[DUMP_NAME_LEN], data_type;
-	int i;
+	efi_status_t status;
 	int cnt;
 	unsigned int part;
-	unsigned long size;
 	u64 time;
 
-	if (efi_guidcmp(entry->var.VendorGuid, vendor))
-		return 0;
-
-	for (i = 0; i < DUMP_NAME_LEN; i++)
-		name[i] = entry->var.VariableName[i];
+	ucs2_as_utf8(name, varname, DUMP_NAME_LEN);
 
 	if (sscanf(name, "dump-type%u-%u-%d-%llu-%c",
 		   &record->type, &part, &cnt, &time, &data_type) == 5) {
@@ -95,161 +99,75 @@ static int efi_pstore_read_func(struct efivar_entry *entry,
 	} else
 		return 0;
 
-	entry->var.DataSize = 1024;
-	__efivar_entry_get(entry, &entry->var.Attributes,
-			   &entry->var.DataSize, entry->var.Data);
-	size = entry->var.DataSize;
-	memcpy(record->buf, entry->var.Data,
-	       (size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
-
-	return size;
-}
-
-/**
- * efi_pstore_scan_sysfs_enter
- * @pos: scanning entry
- * @next: next entry
- * @head: list head
- */
-static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
-					struct efivar_entry *next,
-					struct list_head *head)
-{
-	pos->scanning = true;
-	if (&next->list != head)
-		next->scanning = true;
-}
-
-/**
- * __efi_pstore_scan_sysfs_exit
- * @entry: deleting entry
- * @turn_off_scanning: Check if a scanning flag should be turned off
- */
-static inline int __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
-						bool turn_off_scanning)
-{
-	if (entry->deleting) {
-		list_del(&entry->list);
-		efivar_entry_iter_end();
-		kfree(entry);
-		if (efivar_entry_iter_begin())
-			return -EINTR;
-	} else if (turn_off_scanning)
-		entry->scanning = false;
-
-	return 0;
-}
-
-/**
- * efi_pstore_scan_sysfs_exit
- * @pos: scanning entry
- * @next: next entry
- * @head: list head
- * @stop: a flag checking if scanning will stop
- */
-static int efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
-				       struct efivar_entry *next,
-				       struct list_head *head, bool stop)
-{
-	int ret = __efi_pstore_scan_sysfs_exit(pos, true);
-
-	if (ret)
-		return ret;
-
-	if (stop)
-		ret = __efi_pstore_scan_sysfs_exit(next, &next->list != head);
-	return ret;
-}
+	record->buf = kmalloc(size, GFP_KERNEL);
+	if (!record->buf)
+		return -ENOMEM;
 
-/**
- * efi_pstore_sysfs_entry_iter
- *
- * @record: pstore record to pass to callback
- *
- * You MUST call efivar_entry_iter_begin() before this function, and
- * efivar_entry_iter_end() afterwards.
- *
- */
-static int efi_pstore_sysfs_entry_iter(struct pstore_record *record)
-{
-	struct efivar_entry **pos = (struct efivar_entry **)&record->psi->data;
-	struct efivar_entry *entry, *n;
-	struct list_head *head = &efi_pstore_list;
-	int size = 0;
-	int ret;
-
-	if (!*pos) {
-		list_for_each_entry_safe(entry, n, head, list) {
-			efi_pstore_scan_sysfs_enter(entry, n, head);
-
-			size = efi_pstore_read_func(entry, record);
-			ret = efi_pstore_scan_sysfs_exit(entry, n, head,
-							 size < 0);
-			if (ret)
-				return ret;
-			if (size)
-				break;
-		}
-		*pos = n;
-		return size;
+	status = efivar_get_variable(varname, &LINUX_EFI_CRASH_GUID, NULL,
+				     &size, record->buf);
+	if (status != EFI_SUCCESS) {
+		kfree(record->buf);
+		return -EIO;
 	}
 
-	list_for_each_entry_safe_from((*pos), n, head, list) {
-		efi_pstore_scan_sysfs_enter((*pos), n, head);
-
-		size = efi_pstore_read_func((*pos), record);
-		ret = efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
-		if (ret)
-			return ret;
-		if (size)
-			break;
+	/*
+	 * Store the name of the variable in the pstore_record priv field, so
+	 * we can reuse it later if we need to delete the EFI variable from the
+	 * variable store.
+	 */
+	wlen = (ucs2_strnlen(varname, DUMP_NAME_LEN) + 1) * sizeof(efi_char16_t);
+	record->priv = kmemdup(varname, wlen, GFP_KERNEL);
+	if (!record->priv) {
+		kfree(record->buf);
+		return -ENOMEM;
 	}
-	*pos = n;
+
 	return size;
 }
 
-/**
- * efi_pstore_read
- *
- * This function returns a size of NVRAM entry logged via efi_pstore_write().
- * The meaning and behavior of efi_pstore/pstore are as below.
- *
- * size > 0: Got data of an entry logged via efi_pstore_write() successfully,
- *           and pstore filesystem will continue reading subsequent entries.
- * size == 0: Entry was not logged via efi_pstore_write(),
- *            and efi_pstore driver will continue reading subsequent entries.
- * size < 0: Failed to get data of entry logging via efi_pstore_write(),
- *           and pstore will stop reading entry.
- */
 static ssize_t efi_pstore_read(struct pstore_record *record)
 {
-	ssize_t size;
+	efi_char16_t *varname = record->psi->data;
+	efi_guid_t guid = LINUX_EFI_CRASH_GUID;
+	unsigned long varname_size;
+	efi_status_t status;
 
-	record->buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
-	if (!record->buf)
-		return -ENOMEM;
+	for (;;) {
+		varname_size = EFIVARS_DATA_SIZE_MAX;
 
-	if (efivar_entry_iter_begin()) {
-		size = -EINTR;
-		goto out;
-	}
-	size = efi_pstore_sysfs_entry_iter(record);
-	efivar_entry_iter_end();
+		/*
+		 * If this is the first read() call in the pstore enumeration,
+		 * varname will be the empty string, and the GetNextVariable()
+		 * runtime service call will return the first EFI variable in
+		 * its own enumeration order, ignoring the guid argument.
+		 *
+		 * Subsequent calls to GetNextVariable() must pass the name and
+		 * guid values returned by the previous call, which is why we
+		 * store varname in record->psi->data. Given that we only
+		 * enumerate variables with the efi-pstore GUID, there is no
+		 * need to record the guid return value.
+		 */
+		status = efivar_get_next_variable(&varname_size, varname, &guid);
+		if (status == EFI_NOT_FOUND)
+			return 0;
 
-out:
-	if (size <= 0) {
-		kfree(record->buf);
-		record->buf = NULL;
+		if (status != EFI_SUCCESS)
+			return -EIO;
+
+		/* skip variables that don't concern us */
+		if (efi_guidcmp(guid, LINUX_EFI_CRASH_GUID))
+			continue;
+
+		return efi_pstore_read_func(record, varname);
 	}
-	return size;
 }
 
 static int efi_pstore_write(struct pstore_record *record)
 {
 	char name[DUMP_NAME_LEN];
 	efi_char16_t efi_name[DUMP_NAME_LEN];
-	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
-	int i, ret = 0;
+	efi_status_t status;
+	int i;
 
 	record->id = generic_id(record->time.tv_sec, record->part,
 				record->count);
@@ -265,88 +183,26 @@ static int efi_pstore_write(struct pstore_record *record)
 	for (i = 0; i < DUMP_NAME_LEN; i++)
 		efi_name[i] = name[i];
 
-	ret = efivar_entry_set_safe(efi_name, vendor, PSTORE_EFI_ATTRIBUTES,
-			      false, record->size, record->psi->buf);
-
-	if (record->reason == KMSG_DUMP_OOPS && try_module_get(THIS_MODULE))
-		if (!schedule_work(&efivar_work))
-			module_put(THIS_MODULE);
-
-	return ret;
+	if (efivar_trylock())
+		return -EBUSY;
+	status = efivar_set_variable_locked(efi_name, &LINUX_EFI_CRASH_GUID,
+					    PSTORE_EFI_ATTRIBUTES,
+					    record->size, record->psi->buf,
+					    true);
+	efivar_unlock();
+	return status == EFI_SUCCESS ? 0 : -EIO;
 };
 
-/*
- * Clean up an entry with the same name
- */
-static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
-{
-	efi_char16_t *efi_name = data;
-	efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
-	unsigned long ucs2_len = ucs2_strlen(efi_name);
-
-	if (efi_guidcmp(entry->var.VendorGuid, vendor))
-		return 0;
-
-	if (ucs2_strncmp(entry->var.VariableName, efi_name, (size_t)ucs2_len))
-		return 0;
-
-	if (entry->scanning) {
-		/*
-		 * Skip deletion because this entry will be deleted
-		 * after scanning is completed.
-		 */
-		entry->deleting = true;
-	} else
-		list_del(&entry->list);
-
-	/* found */
-	__efivar_entry_delete(entry);
-
-	return 1;
-}
-
-static int efi_pstore_erase_name(const char *name)
-{
-	struct efivar_entry *entry = NULL;
-	efi_char16_t efi_name[DUMP_NAME_LEN];
-	int found, i;
-
-	for (i = 0; i < DUMP_NAME_LEN; i++) {
-		efi_name[i] = name[i];
-		if (name[i] == '\0')
-			break;
-	}
-
-	if (efivar_entry_iter_begin())
-		return -EINTR;
-
-	found = __efivar_entry_iter(efi_pstore_erase_func, &efi_pstore_list,
-				    efi_name, &entry);
-	efivar_entry_iter_end();
-
-	if (found && !entry->scanning)
-		kfree(entry);
-
-	return found ? 0 : -ENOENT;
-}
-
 static int efi_pstore_erase(struct pstore_record *record)
 {
-	char name[DUMP_NAME_LEN];
-	int ret;
-
-	snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lld",
-		 record->type, record->part, record->count,
-		 (long long)record->time.tv_sec);
-	ret = efi_pstore_erase_name(name);
-	if (ret != -ENOENT)
-		return ret;
+	efi_status_t status;
 
-	snprintf(name, sizeof(name), "dump-type%u-%u-%lld",
-		record->type, record->part, (long long)record->time.tv_sec);
-	ret = efi_pstore_erase_name(name);
+	status = efivar_set_variable(record->priv, &LINUX_EFI_CRASH_GUID,
+				     PSTORE_EFI_ATTRIBUTES, 0, NULL);
 
-	return ret;
+	if (status != EFI_SUCCESS && status != EFI_NOT_FOUND)
+		return -EIO;
+	return 0;
 }
 
 static struct pstore_info efi_pstore_info = {
@@ -360,77 +216,14 @@ static struct pstore_info efi_pstore_info = {
 	.erase		= efi_pstore_erase,
 };
 
-static int efi_pstore_callback(efi_char16_t *name, efi_guid_t vendor,
-			       unsigned long name_size, void *data)
-{
-	struct efivar_entry *entry;
-	int ret;
-
-	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
-	if (!entry)
-		return -ENOMEM;
-
-	memcpy(entry->var.VariableName, name, name_size);
-	entry->var.VendorGuid = vendor;
-
-	ret = efivar_entry_add(entry, &efi_pstore_list);
-	if (ret)
-		kfree(entry);
-
-	return ret;
-}
-
-static int efi_pstore_update_entry(efi_char16_t *name, efi_guid_t vendor,
-				   unsigned long name_size, void *data)
-{
-	struct efivar_entry *entry = data;
-
-	if (efivar_entry_find(name, vendor, &efi_pstore_list, false))
-		return 0;
-
-	memcpy(entry->var.VariableName, name, name_size);
-	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
-
-	return 1;
-}
-
-static void efi_pstore_update_entries(struct work_struct *work)
-{
-	struct efivar_entry *entry;
-	int err;
-
-	/* Add new sysfs entries */
-	while (1) {
-		entry = kzalloc(sizeof(*entry), GFP_KERNEL);
-		if (!entry)
-			return;
-
-		err = efivar_init(efi_pstore_update_entry, entry,
-				  false, &efi_pstore_list);
-		if (!err)
-			break;
-
-		efivar_entry_add(entry, &efi_pstore_list);
-	}
-
-	kfree(entry);
-	module_put(THIS_MODULE);
-}
-
 static __init int efivars_pstore_init(void)
 {
-	int ret;
-
-	if (!efivars_kobject() || !efivar_supports_writes())
+	if (!efivar_supports_writes())
 		return 0;
 
 	if (efivars_pstore_disable)
 		return 0;
 
-	ret = efivar_init(efi_pstore_callback, NULL, true, &efi_pstore_list);
-	if (ret)
-		return ret;
-
 	efi_pstore_info.buf = kmalloc(4096, GFP_KERNEL);
 	if (!efi_pstore_info.buf)
 		return -ENOMEM;
@@ -443,8 +236,6 @@ static __init int efivars_pstore_init(void)
 		efi_pstore_info.bufsize = 0;
 	}
 
-	INIT_WORK(&efivar_work, efi_pstore_update_entries);
-
 	return 0;
 }
 
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 860534bcfdac..7f06065d3eb0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -202,7 +202,7 @@ static void generic_ops_unregister(void)
 }
 
 #ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS
-#define EFIVAR_SSDT_NAME_MAX	16
+#define EFIVAR_SSDT_NAME_MAX	16UL
 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
 static int __init efivar_ssdt_setup(char *str)
 {
@@ -219,83 +219,62 @@ static int __init efivar_ssdt_setup(char *str)
 }
 __setup("efivar_ssdt=", efivar_ssdt_setup);
 
-static __init int efivar_ssdt_iter(efi_char16_t *name, efi_guid_t vendor,
-				   unsigned long name_size, void *data)
-{
-	struct efivar_entry *entry;
-	struct list_head *list = data;
-	char utf8_name[EFIVAR_SSDT_NAME_MAX];
-	int limit = min_t(unsigned long, EFIVAR_SSDT_NAME_MAX, name_size);
-
-	ucs2_as_utf8(utf8_name, name, limit - 1);
-	if (strncmp(utf8_name, efivar_ssdt, limit) != 0)
-		return 0;
-
-	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
-	if (!entry)
-		return 0;
-
-	memcpy(entry->var.VariableName, name, name_size);
-	memcpy(&entry->var.VendorGuid, &vendor, sizeof(efi_guid_t));
-
-	efivar_entry_add(entry, list);
-
-	return 0;
-}
-
 static __init int efivar_ssdt_load(void)
 {
-	LIST_HEAD(entries);
-	struct efivar_entry *entry, *aux;
-	unsigned long size;
-	void *data;
-	int ret;
+	unsigned long name_size = 256;
+	efi_char16_t *name = NULL;
+	efi_status_t status;
+	efi_guid_t guid;
 
 	if (!efivar_ssdt[0])
 		return 0;
 
-	ret = efivar_init(efivar_ssdt_iter, &entries, true, &entries);
-
-	list_for_each_entry_safe(entry, aux, &entries, list) {
-		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt,
-			&entry->var.VendorGuid);
+	name = kzalloc(name_size, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
 
-		list_del(&entry->list);
+	for (;;) {
+		char utf8_name[EFIVAR_SSDT_NAME_MAX];
+		unsigned long data_size = 0;
+		void *data;
+		int limit;
 
-		ret = efivar_entry_size(entry, &size);
-		if (ret) {
-			pr_err("failed to get var size\n");
-			goto free_entry;
+		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;
 		}
 
-		data = kmalloc(size, GFP_KERNEL);
-		if (!data) {
-			ret = -ENOMEM;
-			goto free_entry;
-		}
+		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;
 
-		ret = efivar_entry_get(entry, NULL, &size, data);
-		if (ret) {
-			pr_err("failed to get var data\n");
-			goto free_data;
-		}
+		pr_info("loading SSDT from variable %s-%pUl\n", efivar_ssdt, &guid);
 
-		ret = acpi_load_table(data, NULL);
-		if (ret) {
-			pr_err("failed to load table: %d\n", ret);
-			goto free_data;
-		}
+		status = efi.get_variable(name, &guid, NULL, &data_size, NULL);
+		if (status != EFI_BUFFER_TOO_SMALL || !data_size)
+			return -EIO;
 
-		goto free_entry;
+		data = kmalloc(data_size, GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
 
-free_data:
+		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);
+		}
 		kfree(data);
-
-free_entry:
-		kfree(entry);
 	}
-
-	return ret;
+	return 0;
 }
 #else
 static inline int efivar_ssdt_load(void) { return 0; }
@@ -446,6 +425,29 @@ err_put:
 
 subsys_initcall(efisubsys_init);
 
+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);
+}
+
 /*
  * Find the efi memory descriptor for a given physical address.  Given a
  * physical address, determine if it exists within an EFI Memory Map entry,
diff --git a/drivers/firmware/efi/efibc.c b/drivers/firmware/efi/efibc.c
index 15a47539dc56..8ced7af8e56d 100644
--- a/drivers/firmware/efi/efibc.c
+++ b/drivers/firmware/efi/efibc.c
@@ -10,69 +10,51 @@
 #include <linux/module.h>
 #include <linux/reboot.h>
 #include <linux/slab.h>
+#include <linux/ucs2_string.h>
 
-static void efibc_str_to_str16(const char *str, efi_char16_t *str16)
-{
-	size_t i;
-
-	for (i = 0; i < strlen(str); i++)
-		str16[i] = str[i];
-
-	str16[i] = '\0';
-}
+#define MAX_DATA_LEN	512
 
-static int efibc_set_variable(const char *name, const char *value)
+static int efibc_set_variable(efi_char16_t *name, efi_char16_t *value,
+			      unsigned long len)
 {
-	int ret;
-	efi_guid_t guid = LINUX_EFI_LOADER_ENTRY_GUID;
-	struct efivar_entry *entry;
-	size_t size = (strlen(value) + 1) * sizeof(efi_char16_t);
+	efi_status_t status;
 
-	if (size > sizeof(entry->var.Data)) {
-		pr_err("value is too large (%zu bytes) for '%s' EFI variable\n", size, name);
-		return -EINVAL;
-	}
+	status = efi.set_variable(name, &LINUX_EFI_LOADER_ENTRY_GUID,
+				  EFI_VARIABLE_NON_VOLATILE
+				  | EFI_VARIABLE_BOOTSERVICE_ACCESS
+				  | EFI_VARIABLE_RUNTIME_ACCESS,
+				  len * sizeof(efi_char16_t), value);
 
-	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
-	if (!entry) {
-		pr_err("failed to allocate efivar entry for '%s' EFI variable\n", name);
-		return -ENOMEM;
+	if (status != EFI_SUCCESS) {
+		pr_err("failed to set EFI variable: 0x%lx\n", status);
+		return -EIO;
 	}
-
-	efibc_str_to_str16(name, entry->var.VariableName);
-	efibc_str_to_str16(value, (efi_char16_t *)entry->var.Data);
-	memcpy(&entry->var.VendorGuid, &guid, sizeof(guid));
-
-	ret = efivar_entry_set_safe(entry->var.VariableName,
-				    entry->var.VendorGuid,
-				    EFI_VARIABLE_NON_VOLATILE
-				    | EFI_VARIABLE_BOOTSERVICE_ACCESS
-				    | EFI_VARIABLE_RUNTIME_ACCESS,
-				    false, size, entry->var.Data);
-
-	if (ret)
-		pr_err("failed to set %s EFI variable: 0x%x\n",
-		       name, ret);
-
-	kfree(entry);
-	return ret;
+	return 0;
 }
 
 static int efibc_reboot_notifier_call(struct notifier_block *notifier,
 				      unsigned long event, void *data)
 {
-	const char *reason = "shutdown";
+	efi_char16_t *reason = event == SYS_RESTART ? L"reboot"
+						    : L"shutdown";
+	const u8 *str = data;
+	efi_char16_t *wdata;
+	unsigned long l;
 	int ret;
 
-	if (event == SYS_RESTART)
-		reason = "reboot";
-
-	ret = efibc_set_variable("LoaderEntryRebootReason", reason);
+	ret = efibc_set_variable(L"LoaderEntryRebootReason", reason,
+				 ucs2_strlen(reason));
 	if (ret || !data)
 		return NOTIFY_DONE;
 
-	efibc_set_variable("LoaderEntryOneShot", (char *)data);
+	wdata = kmalloc(MAX_DATA_LEN * sizeof(efi_char16_t), GFP_KERNEL);
+	for (l = 0; l < MAX_DATA_LEN - 1 && str[l] != '\0'; l++)
+		wdata[l] = str[l];
+	wdata[l] = L'\0';
+
+	efibc_set_variable(L"LoaderEntryOneShot", wdata, l);
 
+	kfree(wdata);
 	return NOTIFY_DONE;
 }
 
@@ -84,7 +66,7 @@ static int __init efibc_init(void)
 {
 	int ret;
 
-	if (!efivars_kobject() || !efivar_supports_writes())
+	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE))
 		return -ENODEV;
 
 	ret = register_reboot_notifier(&efibc_reboot_notifier);
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index ea0bc39dc965..801a65582172 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -467,16 +467,12 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
 	else if (__efivar_entry_delete(entry))
 		err = -EIO;
 
-	if (err) {
-		efivar_entry_iter_end();
+	efivar_entry_iter_end();
+
+	if (err)
 		return err;
-	}
 
-	if (!entry->scanning) {
-		efivar_entry_iter_end();
-		efivar_unregister(entry);
-	} else
-		efivar_entry_iter_end();
+	efivar_unregister(entry);
 
 	/* It's dead Jim.... */
 	return count;
@@ -527,10 +523,7 @@ efivar_create_sysfs_entry(struct efivar_entry *new_var)
 	}
 
 	kobject_uevent(&new_var->kobj, KOBJ_ADD);
-	if (efivar_entry_add(new_var, &efivar_sysfs_list)) {
-		efivar_unregister(new_var);
-		return -EINTR;
-	}
+	__efivar_entry_add(new_var, &efivar_sysfs_list);
 
 	return 0;
 }
@@ -609,10 +602,7 @@ static int efivars_sysfs_callback(efi_char16_t *name, efi_guid_t vendor,
 
 static int efivar_sysfs_destroy(struct efivar_entry *entry, void *data)
 {
-	int err = efivar_entry_remove(entry);
-
-	if (err)
-		return err;
+	efivar_entry_remove(entry);
 	efivar_unregister(entry);
 	return 0;
 }
@@ -622,8 +612,7 @@ static void efivars_sysfs_exit(void)
 	/* Remove all entries and destroy */
 	int err;
 
-	err = __efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list,
-				  NULL, NULL);
+	err = efivar_entry_iter(efivar_sysfs_destroy, &efivar_sysfs_list, NULL);
 	if (err) {
 		pr_err("efivars: Failed to destroy sysfs entries\n");
 		return;
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index 4df55a55da84..6ec7970dbd40 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -59,8 +59,7 @@ static void __init efi_memmap_free(void)
  * Depending on whether mm_init() has already been invoked or not,
  * either memblock or "normal" page allocation is used.
  *
- * Returns the physical address of the allocated memory map on
- * success, zero on failure.
+ * Returns zero on success, a negative error code on failure.
  */
 int __init efi_memmap_alloc(unsigned int num_entries,
 		struct efi_memory_map_data *data)
@@ -245,7 +244,7 @@ int __init efi_memmap_install(struct efi_memory_map_data *data)
  * @range: Address range (start, end) to split around
  *
  * Returns the number of additional EFI memmap entries required to
- * accomodate @range.
+ * accommodate @range.
  */
 int __init efi_memmap_split_count(efi_memory_desc_t *md, struct range *range)
 {
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index cae590bd08f2..932435945c85 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -298,14 +298,10 @@ efivar_variable_is_removable(efi_guid_t vendor, const char *var_name,
 }
 EXPORT_SYMBOL_GPL(efivar_variable_is_removable);
 
-static efi_status_t
-check_var_size(u32 attributes, unsigned long size)
+efi_status_t check_var_size(u32 attributes, unsigned long size)
 {
 	const struct efivar_operations *fops;
 
-	if (!__efivars)
-		return EFI_UNSUPPORTED;
-
 	fops = __efivars->ops;
 
 	if (!fops->query_variable_store)
@@ -313,15 +309,12 @@ check_var_size(u32 attributes, unsigned long size)
 
 	return fops->query_variable_store(attributes, size, false);
 }
+EXPORT_SYMBOL_NS_GPL(check_var_size, EFIVAR);
 
-static efi_status_t
-check_var_size_nonblocking(u32 attributes, unsigned long size)
+efi_status_t check_var_size_nonblocking(u32 attributes, unsigned long size)
 {
 	const struct efivar_operations *fops;
 
-	if (!__efivars)
-		return EFI_UNSUPPORTED;
-
 	fops = __efivars->ops;
 
 	if (!fops->query_variable_store)
@@ -329,6 +322,7 @@ check_var_size_nonblocking(u32 attributes, unsigned long size)
 
 	return fops->query_variable_store(attributes, size, true);
 }
+EXPORT_SYMBOL_NS_GPL(check_var_size_nonblocking, EFIVAR);
 
 static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
 				struct list_head *head)
@@ -450,9 +444,6 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
 						&vendor_guid);
 		switch (status) {
 		case EFI_SUCCESS:
-			if (duplicates)
-				up(&efivars_lock);
-
 			variable_name_size = var_name_strnsize(variable_name,
 							       variable_name_size);
 
@@ -476,14 +467,6 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
 				if (err)
 					status = EFI_NOT_FOUND;
 			}
-
-			if (duplicates) {
-				if (down_interruptible(&efivars_lock)) {
-					err = -EINTR;
-					goto free;
-				}
-			}
-
 			break;
 		case EFI_UNSUPPORTED:
 			err = -EOPNOTSUPP;
@@ -527,19 +510,23 @@ int efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
 EXPORT_SYMBOL_GPL(efivar_entry_add);
 
 /**
+ * __efivar_entry_add - add entry to variable list
+ * @entry: entry to add to list
+ * @head: list head
+ */
+void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
+{
+	list_add(&entry->list, head);
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_add);
+
+/**
  * efivar_entry_remove - remove entry from variable list
  * @entry: entry to remove from list
- *
- * Returns 0 on success, or a kernel error code on failure.
  */
-int efivar_entry_remove(struct efivar_entry *entry)
+void efivar_entry_remove(struct efivar_entry *entry)
 {
-	if (down_interruptible(&efivars_lock))
-		return -EINTR;
 	list_del(&entry->list);
-	up(&efivars_lock);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(efivar_entry_remove);
 
@@ -827,16 +814,8 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
 	if (!found)
 		return NULL;
 
-	if (remove) {
-		if (entry->scanning) {
-			/*
-			 * The entry will be deleted
-			 * after scanning is completed.
-			 */
-			entry->deleting = true;
-		} else
-			list_del(&entry->list);
-	}
+	if (remove)
+		list_del(&entry->list);
 
 	return entry;
 }
@@ -1056,59 +1035,6 @@ void efivar_entry_iter_end(void)
 EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
 
 /**
- * __efivar_entry_iter - iterate over variable list
- * @func: callback function
- * @head: head of the variable list
- * @data: function-specific data to pass to callback
- * @prev: entry to begin iterating from
- *
- * Iterate over the list of EFI variables and call @func with every
- * entry on the list. It is safe for @func to remove entries in the
- * list via efivar_entry_delete().
- *
- * You MUST call efivar_entry_iter_begin() before this function, and
- * efivar_entry_iter_end() afterwards.
- *
- * It is possible to begin iteration from an arbitrary entry within
- * the list by passing @prev. @prev is updated on return to point to
- * the last entry passed to @func. To begin iterating from the
- * beginning of the list @prev must be %NULL.
- *
- * The restrictions for @func are the same as documented for
- * efivar_entry_iter().
- */
-int __efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
-			struct list_head *head, void *data,
-			struct efivar_entry **prev)
-{
-	struct efivar_entry *entry, *n;
-	int err = 0;
-
-	if (!prev || !*prev) {
-		list_for_each_entry_safe(entry, n, head, list) {
-			err = func(entry, data);
-			if (err)
-				break;
-		}
-
-		if (prev)
-			*prev = entry;
-
-		return err;
-	}
-
-
-	list_for_each_entry_safe_continue((*prev), n, head, list) {
-		err = func(*prev, data);
-		if (err)
-			break;
-	}
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(__efivar_entry_iter);
-
-/**
  * efivar_entry_iter - iterate over variable list
  * @func: callback function
  * @head: head of variable list
@@ -1125,12 +1051,18 @@ EXPORT_SYMBOL_GPL(__efivar_entry_iter);
 int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
 		      struct list_head *head, void *data)
 {
+	struct efivar_entry *entry, *n;
 	int err = 0;
 
 	err = efivar_entry_iter_begin();
 	if (err)
 		return err;
-	err = __efivar_entry_iter(func, head, data, NULL);
+
+	list_for_each_entry_safe(entry, n, head, list) {
+		err = func(entry, data);
+		if (err)
+			break;
+	}
 	efivar_entry_iter_end();
 
 	return err;
@@ -1220,3 +1152,143 @@ int efivar_supports_writes(void)
 	return __efivars && __efivars->ops->set_variable;
 }
 EXPORT_SYMBOL_GPL(efivar_supports_writes);
+
+/*
+ * efivar_lock() - obtain the efivar lock, wait for it if needed
+ * @return 0 on success, error code on failure
+ */
+int efivar_lock(void)
+{
+	if (down_interruptible(&efivars_lock))
+		return -EINTR;
+	if (!__efivars->ops) {
+		up(&efivars_lock);
+		return -ENODEV;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_lock, EFIVAR);
+
+/*
+ * efivar_lock() - obtain the efivar lock if it is free
+ * @return 0 on success, error code on failure
+ */
+int efivar_trylock(void)
+{
+	if (down_trylock(&efivars_lock))
+		 return -EBUSY;
+	if (!__efivars->ops) {
+		up(&efivars_lock);
+		return -ENODEV;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_trylock, EFIVAR);
+
+/*
+ * efivar_unlock() - release the efivar lock
+ */
+void efivar_unlock(void)
+{
+	up(&efivars_lock);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_unlock, EFIVAR);
+
+/*
+ * efivar_get_variable() - retrieve a variable identified by name/vendor
+ *
+ * Must be called with efivars_lock held.
+ */
+efi_status_t efivar_get_variable(efi_char16_t *name, efi_guid_t *vendor,
+				 u32 *attr, unsigned long *size, void *data)
+{
+	return __efivars->ops->get_variable(name, vendor, attr, size, data);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_get_variable, EFIVAR);
+
+/*
+ * efivar_get_next_variable() - enumerate the next name/vendor pair
+ *
+ * Must be called with efivars_lock held.
+ */
+efi_status_t efivar_get_next_variable(unsigned long *name_size,
+				      efi_char16_t *name, efi_guid_t *vendor)
+{
+	return __efivars->ops->get_next_variable(name_size, name, vendor);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_get_next_variable, EFIVAR);
+
+/*
+ * efivar_set_variable_blocking() - local helper function for set_variable
+ *
+ * Must be called with efivars_lock held.
+ */
+static efi_status_t
+efivar_set_variable_blocking(efi_char16_t *name, efi_guid_t *vendor,
+			     u32 attr, unsigned long data_size, void *data)
+{
+	efi_status_t status;
+
+	if (data_size > 0) {
+		status = check_var_size(attr, data_size +
+					      ucs2_strsize(name, 1024));
+		if (status != EFI_SUCCESS)
+			return status;
+	}
+	return __efivars->ops->set_variable(name, vendor, attr, data_size, data);
+}
+
+/*
+ * efivar_set_variable_locked() - set a variable identified by name/vendor
+ *
+ * Must be called with efivars_lock held. If @nonblocking is set, it will use
+ * non-blocking primitives so it is guaranteed not to sleep.
+ */
+efi_status_t efivar_set_variable_locked(efi_char16_t *name, efi_guid_t *vendor,
+					u32 attr, unsigned long data_size,
+					void *data, bool nonblocking)
+{
+	efi_set_variable_t *setvar;
+	efi_status_t status;
+
+	if (!nonblocking)
+		return efivar_set_variable_blocking(name, vendor, attr,
+						    data_size, data);
+
+	/*
+	 * If no _nonblocking variant exists, the ordinary one
+	 * is assumed to be non-blocking.
+	 */
+	setvar = __efivars->ops->set_variable_nonblocking ?:
+		 __efivars->ops->set_variable;
+
+	if (data_size > 0) {
+		status = check_var_size_nonblocking(attr, data_size +
+							  ucs2_strsize(name, 1024));
+		if (status != EFI_SUCCESS)
+			return status;
+	}
+	return setvar(name, vendor, attr, data_size, data);
+}
+EXPORT_SYMBOL_NS_GPL(efivar_set_variable_locked, EFIVAR);
+
+/*
+ * efivar_set_variable() - set a variable identified by name/vendor
+ *
+ * Can be called without holding the efivars_lock. Will sleep on obtaining the
+ * lock, or on obtaining other locks that are needed in order to complete the
+ * call.
+ */
+efi_status_t efivar_set_variable(efi_char16_t *name, efi_guid_t *vendor,
+				 u32 attr, unsigned long data_size, void *data)
+{
+	efi_status_t status;
+
+	if (efivar_lock())
+		return EFI_ABORTED;
+
+	status = efivar_set_variable_blocking(name, vendor, attr, data_size, data);
+	efivar_unlock();
+	return status;
+}
+EXPORT_SYMBOL_NS_GPL(efivar_set_variable, EFIVAR);