Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 1096 insertions, 0 deletions

diff --git a/kernel/drivers/firmware/efi/vars.c b/kernel/drivers/firmware/efi/vars.c
new file mode 100644
index 000000000..70a0fb105
--- /dev/null
+++ b/kernel/drivers/firmware/efi/vars.c
@@ -0,0 +1,1096 @@
+/*
+ * Originally from efivars.c
+ *
+ * Copyright (C) 2001,2003,2004 Dell <Matt_Domsch@dell.com>
+ * Copyright (C) 2004 Intel Corporation <matthew.e.tolentino@intel.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/capability.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/smp.h>
+#include <linux/efi.h>
+#include <linux/sysfs.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/ucs2_string.h>
+
+/* Private pointer to registered efivars */
+static struct efivars *__efivars;
+
+static bool efivar_wq_enabled = true;
+DECLARE_WORK(efivar_work, NULL);
+EXPORT_SYMBOL_GPL(efivar_work);
+
+static bool
+validate_device_path(efi_char16_t *var_name, int match, u8 *buffer,
+		     unsigned long len)
+{
+	struct efi_generic_dev_path *node;
+	int offset = 0;
+
+	node = (struct efi_generic_dev_path *)buffer;
+
+	if (len < sizeof(*node))
+		return false;
+
+	while (offset <= len - sizeof(*node) &&
+	       node->length >= sizeof(*node) &&
+		node->length <= len - offset) {
+		offset += node->length;
+
+		if ((node->type == EFI_DEV_END_PATH ||
+		     node->type == EFI_DEV_END_PATH2) &&
+		    node->sub_type == EFI_DEV_END_ENTIRE)
+			return true;
+
+		node = (struct efi_generic_dev_path *)(buffer + offset);
+	}
+
+	/*
+	 * If we're here then either node->length pointed past the end
+	 * of the buffer or we reached the end of the buffer without
+	 * finding a device path end node.
+	 */
+	return false;
+}
+
+static bool
+validate_boot_order(efi_char16_t *var_name, int match, u8 *buffer,
+		    unsigned long len)
+{
+	/* An array of 16-bit integers */
+	if ((len % 2) != 0)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_load_option(efi_char16_t *var_name, int match, u8 *buffer,
+		     unsigned long len)
+{
+	u16 filepathlength;
+	int i, desclength = 0, namelen;
+
+	namelen = ucs2_strnlen(var_name, EFI_VAR_NAME_LEN);
+
+	/* Either "Boot" or "Driver" followed by four digits of hex */
+	for (i = match; i < match+4; i++) {
+		if (var_name[i] > 127 ||
+		    hex_to_bin(var_name[i] & 0xff) < 0)
+			return true;
+	}
+
+	/* Reject it if there's 4 digits of hex and then further content */
+	if (namelen > match + 4)
+		return false;
+
+	/* A valid entry must be at least 8 bytes */
+	if (len < 8)
+		return false;
+
+	filepathlength = buffer[4] | buffer[5] << 8;
+
+	/*
+	 * There's no stored length for the description, so it has to be
+	 * found by hand
+	 */
+	desclength = ucs2_strsize((efi_char16_t *)(buffer + 6), len - 6) + 2;
+
+	/* Each boot entry must have a descriptor */
+	if (!desclength)
+		return false;
+
+	/*
+	 * If the sum of the length of the description, the claimed filepath
+	 * length and the original header are greater than the length of the
+	 * variable, it's malformed
+	 */
+	if ((desclength + filepathlength + 6) > len)
+		return false;
+
+	/*
+	 * And, finally, check the filepath
+	 */
+	return validate_device_path(var_name, match, buffer + desclength + 6,
+				    filepathlength);
+}
+
+static bool
+validate_uint16(efi_char16_t *var_name, int match, u8 *buffer,
+		unsigned long len)
+{
+	/* A single 16-bit integer */
+	if (len != 2)
+		return false;
+
+	return true;
+}
+
+static bool
+validate_ascii_string(efi_char16_t *var_name, int match, u8 *buffer,
+		      unsigned long len)
+{
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if (buffer[i] > 127)
+			return false;
+
+		if (buffer[i] == 0)
+			return true;
+	}
+
+	return false;
+}
+
+struct variable_validate {
+	char *name;
+	bool (*validate)(efi_char16_t *var_name, int match, u8 *data,
+			 unsigned long len);
+};
+
+static const struct variable_validate variable_validate[] = {
+	{ "BootNext", validate_uint16 },
+	{ "BootOrder", validate_boot_order },
+	{ "DriverOrder", validate_boot_order },
+	{ "Boot*", validate_load_option },
+	{ "Driver*", validate_load_option },
+	{ "ConIn", validate_device_path },
+	{ "ConInDev", validate_device_path },
+	{ "ConOut", validate_device_path },
+	{ "ConOutDev", validate_device_path },
+	{ "ErrOut", validate_device_path },
+	{ "ErrOutDev", validate_device_path },
+	{ "Timeout", validate_uint16 },
+	{ "Lang", validate_ascii_string },
+	{ "PlatformLang", validate_ascii_string },
+	{ "", NULL },
+};
+
+bool
+efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len)
+{
+	int i;
+	u16 *unicode_name = var_name;
+
+	for (i = 0; variable_validate[i].validate != NULL; i++) {
+		const char *name = variable_validate[i].name;
+		int match;
+
+		for (match = 0; ; match++) {
+			char c = name[match];
+			u16 u = unicode_name[match];
+
+			/* All special variables are plain ascii */
+			if (u > 127)
+				return true;
+
+			/* Wildcard in the matching name means we've matched */
+			if (c == '*')
+				return variable_validate[i].validate(var_name,
+							     match, data, len);
+
+			/* Case sensitive match */
+			if (c != u)
+				break;
+
+			/* Reached the end of the string while matching */
+			if (!c)
+				return variable_validate[i].validate(var_name,
+							     match, data, len);
+		}
+	}
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(efivar_validate);
+
+static efi_status_t
+check_var_size(u32 attributes, unsigned long size)
+{
+	const struct efivar_operations *fops = __efivars->ops;
+
+	if (!fops->query_variable_store)
+		return EFI_UNSUPPORTED;
+
+	return fops->query_variable_store(attributes, size);
+}
+
+static 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;
+	default:
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
+static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
+				struct list_head *head)
+{
+	struct efivar_entry *entry, *n;
+	unsigned long strsize1, strsize2;
+	bool found = false;
+
+	strsize1 = ucs2_strsize(variable_name, 1024);
+	list_for_each_entry_safe(entry, n, head, list) {
+		strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
+		if (strsize1 == strsize2 &&
+			!memcmp(variable_name, &(entry->var.VariableName),
+				strsize2) &&
+			!efi_guidcmp(entry->var.VendorGuid,
+				*vendor)) {
+			found = true;
+			break;
+		}
+	}
+	return found;
+}
+
+/*
+ * Returns the size of variable_name, in bytes, including the
+ * terminating NULL character, or variable_name_size if no NULL
+ * character is found among the first variable_name_size bytes.
+ */
+static unsigned long var_name_strnsize(efi_char16_t *variable_name,
+				       unsigned long variable_name_size)
+{
+	unsigned long len;
+	efi_char16_t c;
+
+	/*
+	 * The variable name is, by definition, a NULL-terminated
+	 * string, so make absolutely sure that variable_name_size is
+	 * the value we expect it to be. If not, return the real size.
+	 */
+	for (len = 2; len <= variable_name_size; len += sizeof(c)) {
+		c = variable_name[(len / sizeof(c)) - 1];
+		if (!c)
+			break;
+	}
+
+	return min(len, variable_name_size);
+}
+
+/*
+ * Print a warning when duplicate EFI variables are encountered and
+ * disable the sysfs workqueue since the firmware is buggy.
+ */
+static void dup_variable_bug(efi_char16_t *str16, efi_guid_t *vendor_guid,
+			     unsigned long len16)
+{
+	size_t i, len8 = len16 / sizeof(efi_char16_t);
+	char *str8;
+
+	/*
+	 * Disable the workqueue since the algorithm it uses for
+	 * detecting new variables won't work with this buggy
+	 * implementation of GetNextVariableName().
+	 */
+	efivar_wq_enabled = false;
+
+	str8 = kzalloc(len8, GFP_KERNEL);
+	if (!str8)
+		return;
+
+	for (i = 0; i < len8; i++)
+		str8[i] = str16[i];
+
+	printk(KERN_WARNING "efivars: duplicate variable: %s-%pUl\n",
+	       str8, vendor_guid);
+	kfree(str8);
+}
+
+/**
+ * efivar_init - build the initial list of EFI variables
+ * @func: callback function to invoke for every variable
+ * @data: function-specific data to pass to @func
+ * @atomic: do we need to execute the @func-loop atomically?
+ * @duplicates: error if we encounter duplicates on @head?
+ * @head: initialised head of variable list
+ *
+ * Get every EFI variable from the firmware and invoke @func. @func
+ * should call efivar_entry_add() to build the list of variables.
+ *
+ * Returns 0 on success, or a kernel error code on failure.
+ */
+int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
+		void *data, bool atomic, bool duplicates,
+		struct list_head *head)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	unsigned long variable_name_size = 1024;
+	efi_char16_t *variable_name;
+	efi_status_t status;
+	efi_guid_t vendor_guid;
+	int err = 0;
+
+	variable_name = kzalloc(variable_name_size, GFP_KERNEL);
+	if (!variable_name) {
+		printk(KERN_ERR "efivars: Memory allocation failed.\n");
+		return -ENOMEM;
+	}
+
+	spin_lock_irq(&__efivars->lock);
+
+	/*
+	 * Per EFI spec, the maximum storage allocated for both
+	 * the variable name and variable data is 1024 bytes.
+	 */
+
+	do {
+		variable_name_size = 1024;
+
+		status = ops->get_next_variable(&variable_name_size,
+						variable_name,
+						&vendor_guid);
+		switch (status) {
+		case EFI_SUCCESS:
+			if (!atomic)
+				spin_unlock_irq(&__efivars->lock);
+
+			variable_name_size = var_name_strnsize(variable_name,
+							       variable_name_size);
+
+			/*
+			 * Some firmware implementations return the
+			 * same variable name on multiple calls to
+			 * get_next_variable(). Terminate the loop
+			 * immediately as there is no guarantee that
+			 * we'll ever see a different variable name,
+			 * and may end up looping here forever.
+			 */
+			if (duplicates &&
+			    variable_is_present(variable_name, &vendor_guid, head)) {
+				dup_variable_bug(variable_name, &vendor_guid,
+						 variable_name_size);
+				if (!atomic)
+					spin_lock_irq(&__efivars->lock);
+
+				status = EFI_NOT_FOUND;
+				break;
+			}
+
+			err = func(variable_name, vendor_guid, variable_name_size, data);
+			if (err)
+				status = EFI_NOT_FOUND;
+
+			if (!atomic)
+				spin_lock_irq(&__efivars->lock);
+
+			break;
+		case EFI_NOT_FOUND:
+			break;
+		default:
+			printk(KERN_WARNING "efivars: get_next_variable: status=%lx\n",
+				status);
+			status = EFI_NOT_FOUND;
+			break;
+		}
+
+	} while (status != EFI_NOT_FOUND);
+
+	spin_unlock_irq(&__efivars->lock);
+
+	kfree(variable_name);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(efivar_init);
+
+/**
+ * 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)
+{
+	spin_lock_irq(&__efivars->lock);
+	list_add(&entry->list, head);
+	spin_unlock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_add);
+
+/**
+ * efivar_entry_remove - remove entry from variable list
+ * @entry: entry to remove from list
+ */
+void efivar_entry_remove(struct efivar_entry *entry)
+{
+	spin_lock_irq(&__efivars->lock);
+	list_del(&entry->list);
+	spin_unlock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_remove);
+
+/*
+ * efivar_entry_list_del_unlock - remove entry from variable list
+ * @entry: entry to remove
+ *
+ * Remove @entry from the variable list and release the list lock.
+ *
+ * NOTE: slightly weird locking semantics here - we expect to be
+ * called with the efivars lock already held, and we release it before
+ * returning. This is because this function is usually called after
+ * set_variable() while the lock is still held.
+ */
+static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
+{
+	lockdep_assert_held(&__efivars->lock);
+
+	list_del(&entry->list);
+	spin_unlock_irq(&__efivars->lock);
+}
+
+/**
+ * __efivar_entry_delete - delete an EFI variable
+ * @entry: entry containing EFI variable to delete
+ *
+ * Delete the variable from the firmware but leave @entry on the
+ * variable list.
+ *
+ * This function differs from efivar_entry_delete() because it does
+ * not remove @entry from the variable list. Also, it is safe to be
+ * called from within a efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() region, unlike efivar_entry_delete().
+ *
+ * Returns 0 on success, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int __efivar_entry_delete(struct efivar_entry *entry)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+
+	lockdep_assert_held(&__efivars->lock);
+
+	status = ops->set_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid,
+				   0, 0, NULL);
+
+	return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_delete);
+
+/**
+ * efivar_entry_delete - delete variable and remove entry from list
+ * @entry: entry containing variable to delete
+ *
+ * Delete the variable from the firmware and remove @entry from the
+ * variable list. It is the caller's responsibility to free @entry
+ * once we return.
+ *
+ * Returns 0 on success, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int efivar_entry_delete(struct efivar_entry *entry)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+
+	spin_lock_irq(&__efivars->lock);
+	status = ops->set_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid,
+				   0, 0, NULL);
+	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
+		spin_unlock_irq(&__efivars->lock);
+		return efi_status_to_err(status);
+	}
+
+	efivar_entry_list_del_unlock(entry);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_delete);
+
+/**
+ * efivar_entry_set - call set_variable()
+ * @entry: entry containing the EFI variable to write
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer containing variable data
+ * @head: head of variable list
+ *
+ * Calls set_variable() for an EFI variable. If creating a new EFI
+ * variable, this function is usually followed by efivar_entry_add().
+ *
+ * Before writing the variable, the remaining EFI variable storage
+ * space is checked to ensure there is enough room available.
+ *
+ * If @head is not NULL a lookup is performed to determine whether
+ * the entry is already on the list.
+ *
+ * Returns 0 on success, -EEXIST if a lookup is performed and the entry
+ * already exists on the list, or a converted EFI status code if
+ * set_variable() fails.
+ */
+int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
+		     unsigned long size, void *data, struct list_head *head)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+	efi_char16_t *name = entry->var.VariableName;
+	efi_guid_t vendor = entry->var.VendorGuid;
+
+	spin_lock_irq(&__efivars->lock);
+
+	if (head && efivar_entry_find(name, vendor, head, false)) {
+		spin_unlock_irq(&__efivars->lock);
+		return -EEXIST;
+	}
+
+	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
+	if (status == EFI_SUCCESS || status == EFI_UNSUPPORTED)
+		status = ops->set_variable(name, &vendor,
+					   attributes, size, data);
+
+	spin_unlock_irq(&__efivars->lock);
+
+	return efi_status_to_err(status);
+
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set);
+
+/*
+ * efivar_entry_set_nonblocking - call set_variable_nonblocking()
+ *
+ * This function is guaranteed to not block and is suitable for calling
+ * from crash/panic handlers.
+ *
+ * Crucially, this function will not block if it cannot acquire
+ * __efivars->lock. Instead, it returns -EBUSY.
+ */
+static int
+efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
+			     u32 attributes, unsigned long size, void *data)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	unsigned long flags;
+	efi_status_t status;
+
+	if (!spin_trylock_irqsave(&__efivars->lock, flags))
+		return -EBUSY;
+
+	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
+	if (status != EFI_SUCCESS) {
+		spin_unlock_irqrestore(&__efivars->lock, flags);
+		return -ENOSPC;
+	}
+
+	status = ops->set_variable_nonblocking(name, &vendor, attributes,
+					       size, data);
+
+	spin_unlock_irqrestore(&__efivars->lock, flags);
+	return efi_status_to_err(status);
+}
+
+/**
+ * efivar_entry_set_safe - call set_variable() if enough space in firmware
+ * @name: buffer containing the variable name
+ * @vendor: variable vendor guid
+ * @attributes: variable attributes
+ * @block: can we block in this context?
+ * @size: size of @data buffer
+ * @data: buffer containing variable data
+ *
+ * Ensures there is enough free storage in the firmware for this variable, and
+ * if so, calls set_variable(). If creating a new EFI variable, this function
+ * is usually followed by efivar_entry_add().
+ *
+ * Returns 0 on success, -ENOSPC if the firmware does not have enough
+ * space for set_variable() to succeed, or a converted EFI status code
+ * if set_variable() fails.
+ */
+int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
+			  bool block, unsigned long size, void *data)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	unsigned long flags;
+	efi_status_t status;
+
+	if (!ops->query_variable_store)
+		return -ENOSYS;
+
+	/*
+	 * If the EFI variable backend provides a non-blocking
+	 * ->set_variable() operation and we're in a context where we
+	 * cannot block, then we need to use it to avoid live-locks,
+	 * since the implication is that the regular ->set_variable()
+	 * will block.
+	 *
+	 * If no ->set_variable_nonblocking() is provided then
+	 * ->set_variable() is assumed to be non-blocking.
+	 */
+	if (!block && ops->set_variable_nonblocking)
+		return efivar_entry_set_nonblocking(name, vendor, attributes,
+						    size, data);
+
+	if (!block) {
+		if (!spin_trylock_irqsave(&__efivars->lock, flags))
+			return -EBUSY;
+	} else {
+		spin_lock_irqsave(&__efivars->lock, flags);
+	}
+
+	status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
+	if (status != EFI_SUCCESS) {
+		spin_unlock_irqrestore(&__efivars->lock, flags);
+		return -ENOSPC;
+	}
+
+	status = ops->set_variable(name, &vendor, attributes, size, data);
+
+	spin_unlock_irqrestore(&__efivars->lock, flags);
+
+	return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set_safe);
+
+/**
+ * efivar_entry_find - search for an entry
+ * @name: the EFI variable name
+ * @guid: the EFI variable vendor's guid
+ * @head: head of the variable list
+ * @remove: should we remove the entry from the list?
+ *
+ * Search for an entry on the variable list that has the EFI variable
+ * name @name and vendor guid @guid. If an entry is found on the list
+ * and @remove is true, the entry is removed from the list.
+ *
+ * The caller MUST call efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() before and after the invocation of this
+ * function, respectively.
+ *
+ * Returns the entry if found on the list, %NULL otherwise.
+ */
+struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
+				       struct list_head *head, bool remove)
+{
+	struct efivar_entry *entry, *n;
+	int strsize1, strsize2;
+	bool found = false;
+
+	lockdep_assert_held(&__efivars->lock);
+
+	list_for_each_entry_safe(entry, n, head, list) {
+		strsize1 = ucs2_strsize(name, 1024);
+		strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
+		if (strsize1 == strsize2 &&
+		    !memcmp(name, &(entry->var.VariableName), strsize1) &&
+		    !efi_guidcmp(guid, entry->var.VendorGuid)) {
+			found = true;
+			break;
+		}
+	}
+
+	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);
+	}
+
+	return entry;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_find);
+
+/**
+ * efivar_entry_size - obtain the size of a variable
+ * @entry: entry for this variable
+ * @size: location to store the variable's size
+ */
+int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+
+	*size = 0;
+
+	spin_lock_irq(&__efivars->lock);
+	status = ops->get_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid, NULL, size, NULL);
+	spin_unlock_irq(&__efivars->lock);
+
+	if (status != EFI_BUFFER_TOO_SMALL)
+		return efi_status_to_err(status);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_size);
+
+/**
+ * __efivar_entry_get - call get_variable()
+ * @entry: read data for this variable
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer to store variable data
+ *
+ * The caller MUST call efivar_entry_iter_begin() and
+ * efivar_entry_iter_end() before and after the invocation of this
+ * function, respectively.
+ */
+int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		       unsigned long *size, void *data)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+
+	lockdep_assert_held(&__efivars->lock);
+
+	status = ops->get_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid,
+				   attributes, size, data);
+
+	return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(__efivar_entry_get);
+
+/**
+ * efivar_entry_get - call get_variable()
+ * @entry: read data for this variable
+ * @attributes: variable attributes
+ * @size: size of @data buffer
+ * @data: buffer to store variable data
+ */
+int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
+		     unsigned long *size, void *data)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_status_t status;
+
+	spin_lock_irq(&__efivars->lock);
+	status = ops->get_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid,
+				   attributes, size, data);
+	spin_unlock_irq(&__efivars->lock);
+
+	return efi_status_to_err(status);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_get);
+
+/**
+ * efivar_entry_set_get_size - call set_variable() and get new size (atomic)
+ * @entry: entry containing variable to set and get
+ * @attributes: attributes of variable to be written
+ * @size: size of data buffer
+ * @data: buffer containing data to write
+ * @set: did the set_variable() call succeed?
+ *
+ * This is a pretty special (complex) function. See efivarfs_file_write().
+ *
+ * Atomically call set_variable() for @entry and if the call is
+ * successful, return the new size of the variable from get_variable()
+ * in @size. The success of set_variable() is indicated by @set.
+ *
+ * Returns 0 on success, -EINVAL if the variable data is invalid,
+ * -ENOSPC if the firmware does not have enough available space, or a
+ * converted EFI status code if either of set_variable() or
+ * get_variable() fail.
+ *
+ * If the EFI variable does not exist when calling set_variable()
+ * (EFI_NOT_FOUND), @entry is removed from the variable list.
+ */
+int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
+			      unsigned long *size, void *data, bool *set)
+{
+	const struct efivar_operations *ops = __efivars->ops;
+	efi_char16_t *name = entry->var.VariableName;
+	efi_guid_t *vendor = &entry->var.VendorGuid;
+	efi_status_t status;
+	int err;
+
+	*set = false;
+
+	if (efivar_validate(name, data, *size) == false)
+		return -EINVAL;
+
+	/*
+	 * The lock here protects the get_variable call, the conditional
+	 * set_variable call, and removal of the variable from the efivars
+	 * list (in the case of an authenticated delete).
+	 */
+	spin_lock_irq(&__efivars->lock);
+
+	/*
+	 * Ensure that the available space hasn't shrunk below the safe level
+	 */
+	status = check_var_size(attributes, *size + ucs2_strsize(name, 1024));
+	if (status != EFI_SUCCESS) {
+		if (status != EFI_UNSUPPORTED) {
+			err = efi_status_to_err(status);
+			goto out;
+		}
+
+		if (*size > 65536) {
+			err = -ENOSPC;
+			goto out;
+		}
+	}
+
+	status = ops->set_variable(name, vendor, attributes, *size, data);
+	if (status != EFI_SUCCESS) {
+		err = efi_status_to_err(status);
+		goto out;
+	}
+
+	*set = true;
+
+	/*
+	 * Writing to the variable may have caused a change in size (which
+	 * could either be an append or an overwrite), or the variable to be
+	 * deleted. Perform a GetVariable() so we can tell what actually
+	 * happened.
+	 */
+	*size = 0;
+	status = ops->get_variable(entry->var.VariableName,
+				   &entry->var.VendorGuid,
+				   NULL, size, NULL);
+
+	if (status == EFI_NOT_FOUND)
+		efivar_entry_list_del_unlock(entry);
+	else
+		spin_unlock_irq(&__efivars->lock);
+
+	if (status && status != EFI_BUFFER_TOO_SMALL)
+		return efi_status_to_err(status);
+
+	return 0;
+
+out:
+	spin_unlock_irq(&__efivars->lock);
+	return err;
+
+}
+EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
+
+/**
+ * efivar_entry_iter_begin - begin iterating the variable list
+ *
+ * Lock the variable list to prevent entry insertion and removal until
+ * efivar_entry_iter_end() is called. This function is usually used in
+ * conjunction with __efivar_entry_iter() or efivar_entry_iter().
+ */
+void efivar_entry_iter_begin(void)
+{
+	spin_lock_irq(&__efivars->lock);
+}
+EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
+
+/**
+ * efivar_entry_iter_end - finish iterating the variable list
+ *
+ * Unlock the variable list and allow modifications to the list again.
+ */
+void efivar_entry_iter_end(void)
+{
+	spin_unlock_irq(&__efivars->lock);
+}
+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_enter_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
+ * @data: function-specific data to pass to callback
+ *
+ * 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() while iterating.
+ *
+ * Some notes for the callback function:
+ *  - a non-zero return value indicates an error and terminates the loop
+ *  - @func is called from atomic context
+ */
+int efivar_entry_iter(int (*func)(struct efivar_entry *, void *),
+		      struct list_head *head, void *data)
+{
+	int err = 0;
+
+	efivar_entry_iter_begin();
+	err = __efivar_entry_iter(func, head, data, NULL);
+	efivar_entry_iter_end();
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(efivar_entry_iter);
+
+/**
+ * efivars_kobject - get the kobject for the registered efivars
+ *
+ * If efivars_register() has not been called we return NULL,
+ * otherwise return the kobject used at registration time.
+ */
+struct kobject *efivars_kobject(void)
+{
+	if (!__efivars)
+		return NULL;
+
+	return __efivars->kobject;
+}
+EXPORT_SYMBOL_GPL(efivars_kobject);
+
+/**
+ * efivar_run_worker - schedule the efivar worker thread
+ */
+void efivar_run_worker(void)
+{
+	if (efivar_wq_enabled)
+		schedule_work(&efivar_work);
+}
+EXPORT_SYMBOL_GPL(efivar_run_worker);
+
+/**
+ * efivars_register - register an efivars
+ * @efivars: efivars to register
+ * @ops: efivars operations
+ * @kobject: @efivars-specific kobject
+ *
+ * Only a single efivars can be registered at any time.
+ */
+int efivars_register(struct efivars *efivars,
+		     const struct efivar_operations *ops,
+		     struct kobject *kobject)
+{
+	spin_lock_init(&efivars->lock);
+	efivars->ops = ops;
+	efivars->kobject = kobject;
+
+	__efivars = efivars;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(efivars_register);
+
+/**
+ * efivars_unregister - unregister an efivars
+ * @efivars: efivars to unregister
+ *
+ * The caller must have already removed every entry from the list,
+ * failure to do so is an error.
+ */
+int efivars_unregister(struct efivars *efivars)
+{
+	int rv;
+
+	if (!__efivars) {
+		printk(KERN_ERR "efivars not registered\n");
+		rv = -EINVAL;
+		goto out;
+	}
+
+	if (__efivars != efivars) {
+		rv = -EINVAL;
+		goto out;
+	}
+
+	__efivars = NULL;
+
+	rv = 0;
+out:
+	return rv;
+}
+EXPORT_SYMBOL_GPL(efivars_unregister);