/*
   * linux/drivers/firmware/memmap.c
   *  Copyright (C) 2008 SUSE LINUX Products GmbH

   *  by Bernhard Walle <bernhard.walle@gmx.de>

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License v2.0 as published by
   * the Free Software Foundation
   *
   * 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.
   *
   */
  
  #include <linux/string.h>
  #include <linux/firmware-map.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/bootmem.h>

  #include <linux/slab.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 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
  };

  static const struct sysfs_ops memmap_attr_ops = {

  	.show = memmap_attr_show,
  };
  
  static struct kobj_type memmap_ktype = {
  	.sysfs_ops	= &memmap_attr_ops,
  	.default_attrs	= def_attrs,
  };
  
  /*
   * Registration functions ------------------------------------------------------
   */
  
  /*

   * Firmware memory map entries. No locking is needed because the
   * firmware_map_add() and firmware_map_add_early() functions are called
   * in firmware initialisation code in one single thread of execution.

   */
  static LIST_HEAD(map_entries);
  
  /**

   * 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 (inclusive).
   * @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.
   **/

  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;
  	entry->type = type;
  	INIT_LIST_HEAD(&entry->list);
  	kobject_init(&entry->kobj, &memmap_ktype);
  
  	list_add_tail(&entry->list, &map_entries);
  
  	return 0;
  }

  /*
   * 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 (!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;
  }

  /**

   * 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 (inclusive).
   * @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.

   *
   * Returns 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 = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);

  	if (!entry)
  		return -ENOMEM;

  	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 (inclusive).
   * @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.
   *
   * Returns 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 = alloc_bootmem(sizeof(struct firmware_map_entry));

  	if (WARN_ON(!entry))

  		return -ENOMEM;
  
  	return firmware_map_add_entry(start, end, type, entry);
  }
  
  /*
   * Sysfs functions -------------------------------------------------------------
   */
  
  static ssize_t start_show(struct firmware_map_entry *entry, char *buf)
  {

  	return snprintf(buf, PAGE_SIZE, "0x%llx
  ",
  		(unsigned long long)entry->start);

  }
  
  static ssize_t end_show(struct firmware_map_entry *entry, char *buf)
  {

  	return snprintf(buf, PAGE_SIZE, "0x%llx
  ",
  		(unsigned long long)entry->end);

  }
  
  static ssize_t type_show(struct firmware_map_entry *entry, char *buf)
  {
  	return snprintf(buf, PAGE_SIZE, "%s
  ", entry->type);
  }
  
  #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr)
  #define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj)
  
  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 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(memmap_init);