drivers/firmware/memmap.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/drivers/firmware/memmap.c
  *  Copyright (C) 2008 SUSE LINUX Products GmbH
  *  by Bernhard Walle <bernhard.walle@gmx.de>
  */

 #include <linux/string.h>
 #include <linux/firmware-map.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/memblock.h>
 #include <linux/slab.h>
 #include <linux/mm.h>

 /*
  * Data types ------------------------------------------------------------------
  */

 /*
  * Firmware map entry. Because firmware memory maps are flat and not
  * hierarchical, it's ok to organise them in a linked list. No parent
  * information is necessary as for the resource tree.
  */
 struct firmware_map_entry {
 	/*
 	 * start and end must be u64 rather than resource_size_t, because e820
 	 * resources can lie at addresses above 4G.
 	 */
 	u64			start;	/* start of the memory range */
 	u64			end;	/* end of the memory range (incl.) */
 	const char		*type;	/* type of the memory range */
 	struct list_head	list;	/* entry for the linked list */
 	struct kobject		kobj;   /* kobject for each entry */
 };

 /*
  * Forward declarations --------------------------------------------------------
  */
 static ssize_t memmap_attr_show(struct kobject *kobj,
 				struct attribute *attr, char *buf);
 static ssize_t start_show(struct firmware_map_entry *entry, char *buf);
 static ssize_t end_show(struct firmware_map_entry *entry, char *buf);
 static ssize_t type_show(struct firmware_map_entry *entry, char *buf);

 static struct firmware_map_entry * __meminit
 firmware_map_find_entry(u64 start, u64 end, const char *type);

 /*
  * Static data -----------------------------------------------------------------
  */

 struct memmap_attribute {
 	struct attribute attr;
 	ssize_t (*show)(struct firmware_map_entry *entry, char *buf);
 };

 static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
 static struct memmap_attribute memmap_end_attr   = __ATTR_RO(end);
 static struct memmap_attribute memmap_type_attr  = __ATTR_RO(type);

 /*
  * These are default attributes that are added for every memmap entry.
  */
 static struct attribute *def_attrs[] = {
 	&memmap_start_attr.attr,
 	&memmap_end_attr.attr,
 	&memmap_type_attr.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(def);

 static const struct sysfs_ops memmap_attr_ops = {
 	.show = memmap_attr_show,
 };

 /* Firmware memory map entries. */
 static LIST_HEAD(map_entries);
 static DEFINE_SPINLOCK(map_entries_lock);

 /*
  * For memory hotplug, there is no way to free memory map entries allocated
  * by boot mem after the system is up. So when we hot-remove memory whose
  * map entry is allocated by bootmem, we need to remember the storage and
  * reuse it when the memory is hot-added again.
  */
 static LIST_HEAD(map_entries_bootmem);
 static DEFINE_SPINLOCK(map_entries_bootmem_lock);


 static inline struct firmware_map_entry *
 to_memmap_entry(struct kobject *kobj)
 {
 	return container_of(kobj, struct firmware_map_entry, kobj);
 }

 static void __meminit release_firmware_map_entry(struct kobject *kobj)
 {
 	struct firmware_map_entry *entry = to_memmap_entry(kobj);

 	if (PageReserved(virt_to_page(entry))) {
 		/*
 		 * Remember the storage allocated by bootmem, and reuse it when
 		 * the memory is hot-added again. The entry will be added to
 		 * map_entries_bootmem here, and deleted from &map_entries in
 		 * firmware_map_remove_entry().
 		 */
 		spin_lock(&map_entries_bootmem_lock);
 		list_add(&entry->list, &map_entries_bootmem);
 		spin_unlock(&map_entries_bootmem_lock);

 		return;
 	}

 	kfree(entry);
 }

 static struct kobj_type __refdata memmap_ktype = {
 	.release	= release_firmware_map_entry,
 	.sysfs_ops	= &memmap_attr_ops,
 	.default_groups	= def_groups,
 };

 /*
  * Registration functions ------------------------------------------------------
  */

 /**
  * firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive).
  * @type:  Type of the memory range.
  * @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
  *         entry.
  *
  * Common implementation of firmware_map_add() and firmware_map_add_early()
  * which expects a pre-allocated struct firmware_map_entry.
  *
  * Return: 0 always
  */
 static int firmware_map_add_entry(u64 start, u64 end,
 				  const char *type,
 				  struct firmware_map_entry *entry)
 {
 	BUG_ON(start > end);

 	entry->start = start;
 	entry->end = end - 1;
 	entry->type = type;
 	INIT_LIST_HEAD(&entry->list);
 	kobject_init(&entry->kobj, &memmap_ktype);

 	spin_lock(&map_entries_lock);
 	list_add_tail(&entry->list, &map_entries);
 	spin_unlock(&map_entries_lock);

 	return 0;
 }

 /**
  * firmware_map_remove_entry() - Does the real work to remove a firmware
  * memmap entry.
  * @entry: removed entry.
  *
  * The caller must hold map_entries_lock, and release it properly.
  */
 static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
 {
 	list_del(&entry->list);
 }

 /*
  * Add memmap entry on sysfs
  */
 static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
 {
 	static int map_entries_nr;
 	static struct kset *mmap_kset;

 	if (entry->kobj.state_in_sysfs)
 		return -EEXIST;

 	if (!mmap_kset) {
 		mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
 		if (!mmap_kset)
 			return -ENOMEM;
 	}

 	entry->kobj.kset = mmap_kset;
 	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
 		kobject_put(&entry->kobj);

 	return 0;
 }

 /*
  * Remove memmap entry on sysfs
  */
 static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
 {
 	kobject_put(&entry->kobj);
 }

 /**
  * firmware_map_find_entry_in_list() - Search memmap entry in a given list.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive).
  * @type:  Type of the memory range.
  * @list:  In which to find the entry.
  *
  * This function is to find the memmap entey of a given memory range in a
  * given list. The caller must hold map_entries_lock, and must not release
  * the lock until the processing of the returned entry has completed.
  *
  * Return: Pointer to the entry to be found on success, or NULL on failure.
  */
 static struct firmware_map_entry * __meminit
 firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
 				struct list_head *list)
 {
 	struct firmware_map_entry *entry;

 	list_for_each_entry(entry, list, list)
 		if ((entry->start == start) && (entry->end == end) &&
 		    (!strcmp(entry->type, type))) {
 			return entry;
 		}

 	return NULL;
 }

 /**
  * firmware_map_find_entry() - Search memmap entry in map_entries.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive).
  * @type:  Type of the memory range.
  *
  * This function is to find the memmap entey of a given memory range.
  * The caller must hold map_entries_lock, and must not release the lock
  * until the processing of the returned entry has completed.
  *
  * Return: Pointer to the entry to be found on success, or NULL on failure.
  */
 static struct firmware_map_entry * __meminit
 firmware_map_find_entry(u64 start, u64 end, const char *type)
 {
 	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
 }

 /**
  * firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive).
  * @type:  Type of the memory range.
  *
  * This function is similar to firmware_map_find_entry except that it find the
  * given entry in map_entries_bootmem.
  *
  * Return: Pointer to the entry to be found on success, or NULL on failure.
  */
 static struct firmware_map_entry * __meminit
 firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
 {
 	return firmware_map_find_entry_in_list(start, end, type,
 					       &map_entries_bootmem);
 }

 /**
  * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
  * memory hotplug.
  * @start: Start of the memory range.
  * @end:   End of the memory range (exclusive)
  * @type:  Type of the memory range.
  *
  * Adds a firmware mapping entry. This function is for memory hotplug, it is
  * similar to function firmware_map_add_early(). The only difference is that
  * it will create the syfs entry dynamically.
  *
  * Return: 0 on success, or -ENOMEM if no memory could be allocated.
  */
 int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
 {
 	struct firmware_map_entry *entry;

 	entry = firmware_map_find_entry(start, end - 1, type);
 	if (entry)
 		return 0;

 	entry = firmware_map_find_entry_bootmem(start, end - 1, type);
 	if (!entry) {
 		entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
 		if (!entry)
 			return -ENOMEM;
 	} else {
 		/* Reuse storage allocated by bootmem. */
 		spin_lock(&map_entries_bootmem_lock);
 		list_del(&entry->list);
 		spin_unlock(&map_entries_bootmem_lock);

 		memset(entry, 0, sizeof(*entry));
 	}

 	firmware_map_add_entry(start, end, type, entry);
 	/* create the memmap entry */
 	add_sysfs_fw_map_entry(entry);

 	return 0;
 }

 /**
  * firmware_map_add_early() - Adds a firmware mapping entry.
  * @start: Start of the memory range.
  * @end:   End of the memory range.
  * @type:  Type of the memory range.
  *
  * Adds a firmware mapping entry. This function uses the bootmem allocator
  * for memory allocation.
  *
  * That function must be called before late_initcall.
  *
  * Return: 0 on success, or -ENOMEM if no memory could be allocated.
  */
 int __init firmware_map_add_early(u64 start, u64 end, const char *type)
 {
 	struct firmware_map_entry *entry;

 	entry = memblock_alloc(sizeof(struct firmware_map_entry),
 			       SMP_CACHE_BYTES);
 	if (WARN_ON(!entry))
 		return -ENOMEM;

 	return firmware_map_add_entry(start, end, type, entry);
 }

 /**
  * firmware_map_remove() - remove a firmware mapping entry
  * @start: Start of the memory range.
  * @end:   End of the memory range.
  * @type:  Type of the memory range.
  *
  * removes a firmware mapping entry.
  *
  * Return: 0 on success, or -EINVAL if no entry.
  */
 int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
 {
 	struct firmware_map_entry *entry;

 	spin_lock(&map_entries_lock);
 	entry = firmware_map_find_entry(start, end - 1, type);
 	if (!entry) {
 		spin_unlock(&map_entries_lock);
 		return -EINVAL;
 	}

 	firmware_map_remove_entry(entry);
 	spin_unlock(&map_entries_lock);

 	/* remove the memmap entry */
 	remove_sysfs_fw_map_entry(entry);

 	return 0;
 }

 /*
  * Sysfs functions -------------------------------------------------------------
  */

 static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
 {
 	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
 		(unsigned long long)entry->start);
 }

 static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
 {
 	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
 		(unsigned long long)entry->end);
 }

 static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
 {
 	return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
 }

 static inline struct memmap_attribute *to_memmap_attr(struct attribute *attr)
 {
 	return container_of(attr, struct memmap_attribute, attr);
 }

 static ssize_t memmap_attr_show(struct kobject *kobj,
 				struct attribute *attr, char *buf)
 {
 	struct firmware_map_entry *entry = to_memmap_entry(kobj);
 	struct memmap_attribute *memmap_attr = to_memmap_attr(attr);

 	return memmap_attr->show(entry, buf);
 }

 /*
  * Initialises stuff and adds the entries in the map_entries list to
  * sysfs. Important is that firmware_map_add() and firmware_map_add_early()
  * must be called before late_initcall. That's just because that function
  * is called as late_initcall() function, which means that if you call
  * firmware_map_add() or firmware_map_add_early() afterwards, the entries
  * are not added to sysfs.
  */
 static int __init firmware_memmap_init(void)
 {
 	struct firmware_map_entry *entry;

 	list_for_each_entry(entry, &map_entries, list)
 		add_sysfs_fw_map_entry(entry);

 	return 0;
 }
 late_initcall(firmware_memmap_init);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* linux/drivers/firmware/memmap.c
	* Copyright (C) 2008 SUSE LINUX Products GmbH
	* by Bernhard Walle <bernhard.walle@gmx.de>
	*/

	#include <linux/string.h>
	#include <linux/firmware-map.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/memblock.h>
	#include <linux/slab.h>
	#include <linux/mm.h>

	/*
	* Data types ------------------------------------------------------------------
	*/

	/*
	* Firmware map entry. Because firmware memory maps are flat and not
	* hierarchical, it's ok to organise them in a linked list. No parent
	* information is necessary as for the resource tree.
	*/
	struct firmware_map_entry {
	/*
	* start and end must be u64 rather than resource_size_t, because e820
	* resources can lie at addresses above 4G.
	*/
	u64 start; /* start of the memory range */
	u64 end; /* end of the memory range (incl.) */
	const char type; / type of the memory range */
	struct list_head list; /* entry for the linked list */
	struct kobject kobj; /* kobject for each entry */
	};

	/*
	* Forward declarations --------------------------------------------------------
	*/
	static ssize_t memmap_attr_show(struct kobject *kobj,
	struct attribute attr, char buf);
	static ssize_t start_show(struct firmware_map_entry entry, char buf);
	static ssize_t end_show(struct firmware_map_entry entry, char buf);
	static ssize_t type_show(struct firmware_map_entry entry, char buf);

	static struct firmware_map_entry * __meminit
	firmware_map_find_entry(u64 start, u64 end, const char *type);

	/*
	* Static data -----------------------------------------------------------------
	*/

	struct memmap_attribute {
	struct attribute attr;
	ssize_t (show)(struct firmware_map_entry entry, char *buf);
	};

	static struct memmap_attribute memmap_start_attr = __ATTR_RO(start);
	static struct memmap_attribute memmap_end_attr = __ATTR_RO(end);
	static struct memmap_attribute memmap_type_attr = __ATTR_RO(type);

	/*
	* These are default attributes that are added for every memmap entry.
	*/
	static struct attribute *def_attrs[] = {
	&memmap_start_attr.attr,
	&memmap_end_attr.attr,
	&memmap_type_attr.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(def);

	static const struct sysfs_ops memmap_attr_ops = {
	.show = memmap_attr_show,
	};

	/* Firmware memory map entries. */
	static LIST_HEAD(map_entries);
	static DEFINE_SPINLOCK(map_entries_lock);

	/*
	* For memory hotplug, there is no way to free memory map entries allocated
	* by boot mem after the system is up. So when we hot-remove memory whose
	* map entry is allocated by bootmem, we need to remember the storage and
	* reuse it when the memory is hot-added again.
	*/
	static LIST_HEAD(map_entries_bootmem);
	static DEFINE_SPINLOCK(map_entries_bootmem_lock);


	static inline struct firmware_map_entry *
	to_memmap_entry(struct kobject *kobj)
	{
	return container_of(kobj, struct firmware_map_entry, kobj);
	}

	static void __meminit release_firmware_map_entry(struct kobject *kobj)
	{
	struct firmware_map_entry *entry = to_memmap_entry(kobj);

	if (PageReserved(virt_to_page(entry))) {
	/*
	* Remember the storage allocated by bootmem, and reuse it when
	* the memory is hot-added again. The entry will be added to
	* map_entries_bootmem here, and deleted from &map_entries in
	* firmware_map_remove_entry().
	*/
	spin_lock(&map_entries_bootmem_lock);
	list_add(&entry->list, &map_entries_bootmem);
	spin_unlock(&map_entries_bootmem_lock);

	return;
	}

	kfree(entry);
	}

	static struct kobj_type __refdata memmap_ktype = {
	.release = release_firmware_map_entry,
	.sysfs_ops = &memmap_attr_ops,
	.default_groups = def_groups,
	};

	/*
	* Registration functions ------------------------------------------------------
	*/

	/**
	* firmware_map_add_entry() - Does the real work to add a firmware memmap entry.
	* @start: Start of the memory range.
	* @end: End of the memory range (exclusive).
	* @type: Type of the memory range.
	* @entry: Pre-allocated (either kmalloc() or bootmem allocator), uninitialised
	* entry.
	*
	* Common implementation of firmware_map_add() and firmware_map_add_early()
	* which expects a pre-allocated struct firmware_map_entry.
	*
	* Return: 0 always
	*/
	static int firmware_map_add_entry(u64 start, u64 end,
	const char *type,
	struct firmware_map_entry *entry)
	{
	BUG_ON(start > end);

	entry->start = start;
	entry->end = end - 1;
	entry->type = type;
	INIT_LIST_HEAD(&entry->list);
	kobject_init(&entry->kobj, &memmap_ktype);

	spin_lock(&map_entries_lock);
	list_add_tail(&entry->list, &map_entries);
	spin_unlock(&map_entries_lock);

	return 0;
	}

	/**
	* firmware_map_remove_entry() - Does the real work to remove a firmware
	* memmap entry.
	* @entry: removed entry.
	*
	* The caller must hold map_entries_lock, and release it properly.
	*/
	static inline void firmware_map_remove_entry(struct firmware_map_entry *entry)
	{
	list_del(&entry->list);
	}

	/*
	* Add memmap entry on sysfs
	*/
	static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
	{
	static int map_entries_nr;
	static struct kset *mmap_kset;

	if (entry->kobj.state_in_sysfs)
	return -EEXIST;

	if (!mmap_kset) {
	mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
	if (!mmap_kset)
	return -ENOMEM;
	}

	entry->kobj.kset = mmap_kset;
	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
	kobject_put(&entry->kobj);

	return 0;
	}

	/*
	* Remove memmap entry on sysfs
	*/
	static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry)
	{
	kobject_put(&entry->kobj);
	}

	/**
	* firmware_map_find_entry_in_list() - Search memmap entry in a given list.
	* @start: Start of the memory range.
	* @end: End of the memory range (exclusive).
	* @type: Type of the memory range.
	* @list: In which to find the entry.
	*
	* This function is to find the memmap entey of a given memory range in a
	* given list. The caller must hold map_entries_lock, and must not release
	* the lock until the processing of the returned entry has completed.
	*
	* Return: Pointer to the entry to be found on success, or NULL on failure.
	*/
	static struct firmware_map_entry * __meminit
	firmware_map_find_entry_in_list(u64 start, u64 end, const char *type,
	struct list_head *list)
	{
	struct firmware_map_entry *entry;

	list_for_each_entry(entry, list, list)
	if ((entry->start == start) && (entry->end == end) &&
	(!strcmp(entry->type, type))) {
	return entry;
	}

	return NULL;
	}

	/**
	* firmware_map_find_entry() - Search memmap entry in map_entries.
	* @start: Start of the memory range.
	* @end: End of the memory range (exclusive).
	* @type: Type of the memory range.
	*
	* This function is to find the memmap entey of a given memory range.
	* The caller must hold map_entries_lock, and must not release the lock
	* until the processing of the returned entry has completed.
	*
	* Return: Pointer to the entry to be found on success, or NULL on failure.
	*/
	static struct firmware_map_entry * __meminit
	firmware_map_find_entry(u64 start, u64 end, const char *type)
	{
	return firmware_map_find_entry_in_list(start, end, type, &map_entries);
	}

	/**
	* firmware_map_find_entry_bootmem() - Search memmap entry in map_entries_bootmem.
	* @start: Start of the memory range.
	* @end: End of the memory range (exclusive).
	* @type: Type of the memory range.
	*
	* This function is similar to firmware_map_find_entry except that it find the
	* given entry in map_entries_bootmem.
	*
	* Return: Pointer to the entry to be found on success, or NULL on failure.
	*/
	static struct firmware_map_entry * __meminit
	firmware_map_find_entry_bootmem(u64 start, u64 end, const char *type)
	{
	return firmware_map_find_entry_in_list(start, end, type,
	&map_entries_bootmem);
	}

	/**
	* firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
	* memory hotplug.
	* @start: Start of the memory range.
	* @end: End of the memory range (exclusive)
	* @type: Type of the memory range.
	*
	* Adds a firmware mapping entry. This function is for memory hotplug, it is
	* similar to function firmware_map_add_early(). The only difference is that
	* it will create the syfs entry dynamically.
	*
	* Return: 0 on success, or -ENOMEM if no memory could be allocated.
	*/
	int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
	{
	struct firmware_map_entry *entry;

	entry = firmware_map_find_entry(start, end - 1, type);
	if (entry)
	return 0;

	entry = firmware_map_find_entry_bootmem(start, end - 1, type);
	if (!entry) {
	entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
	if (!entry)
	return -ENOMEM;
	} else {
	/* Reuse storage allocated by bootmem. */
	spin_lock(&map_entries_bootmem_lock);
	list_del(&entry->list);
	spin_unlock(&map_entries_bootmem_lock);

	memset(entry, 0, sizeof(*entry));
	}

	firmware_map_add_entry(start, end, type, entry);
	/* create the memmap entry */
	add_sysfs_fw_map_entry(entry);

	return 0;
	}

	/**
	* firmware_map_add_early() - Adds a firmware mapping entry.
	* @start: Start of the memory range.
	* @end: End of the memory range.
	* @type: Type of the memory range.
	*
	* Adds a firmware mapping entry. This function uses the bootmem allocator
	* for memory allocation.
	*
	* That function must be called before late_initcall.
	*
	* Return: 0 on success, or -ENOMEM if no memory could be allocated.
	*/
	int __init firmware_map_add_early(u64 start, u64 end, const char *type)
	{
	struct firmware_map_entry *entry;

	entry = memblock_alloc(sizeof(struct firmware_map_entry),
	SMP_CACHE_BYTES);
	if (WARN_ON(!entry))
	return -ENOMEM;

	return firmware_map_add_entry(start, end, type, entry);
	}

	/**
	* firmware_map_remove() - remove a firmware mapping entry
	* @start: Start of the memory range.
	* @end: End of the memory range.
	* @type: Type of the memory range.
	*
	* removes a firmware mapping entry.
	*
	* Return: 0 on success, or -EINVAL if no entry.
	*/
	int __meminit firmware_map_remove(u64 start, u64 end, const char *type)
	{
	struct firmware_map_entry *entry;

	spin_lock(&map_entries_lock);
	entry = firmware_map_find_entry(start, end - 1, type);
	if (!entry) {
	spin_unlock(&map_entries_lock);
	return -EINVAL;
	}

	firmware_map_remove_entry(entry);
	spin_unlock(&map_entries_lock);

	/* remove the memmap entry */
	remove_sysfs_fw_map_entry(entry);

	return 0;
	}

	/*
	* Sysfs functions -------------------------------------------------------------
	*/

	static ssize_t start_show(struct firmware_map_entry entry, char buf)
	{
	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
	(unsigned long long)entry->start);
	}

	static ssize_t end_show(struct firmware_map_entry entry, char buf)
	{
	return snprintf(buf, PAGE_SIZE, "0x%llx\n",
	(unsigned long long)entry->end);
	}

	static ssize_t type_show(struct firmware_map_entry entry, char buf)
	{
	return snprintf(buf, PAGE_SIZE, "%s\n", entry->type);
	}

	static inline struct memmap_attribute to_memmap_attr(struct attribute attr)
	{
	return container_of(attr, struct memmap_attribute, attr);
	}

	static ssize_t memmap_attr_show(struct kobject *kobj,
	struct attribute attr, char buf)
	{
	struct firmware_map_entry *entry = to_memmap_entry(kobj);
	struct memmap_attribute *memmap_attr = to_memmap_attr(attr);

	return memmap_attr->show(entry, buf);
	}

	/*
	* Initialises stuff and adds the entries in the map_entries list to
	* sysfs. Important is that firmware_map_add() and firmware_map_add_early()
	* must be called before late_initcall. That's just because that function
	* is called as late_initcall() function, which means that if you call
	* firmware_map_add() or firmware_map_add_early() afterwards, the entries
	* are not added to sysfs.
	*/
	static int __init firmware_memmap_init(void)
	{
	struct firmware_map_entry *entry;

	list_for_each_entry(entry, &map_entries, list)
	add_sysfs_fw_map_entry(entry);

	return 0;
	}
	late_initcall(firmware_memmap_init);