/*
   * Copyright IBM Corporation, 2012
   * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of version 2.1 of the GNU Lesser General Public License
   * as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it would be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   *
   */
  
  #ifndef _LINUX_HUGETLB_CGROUP_H
  #define _LINUX_HUGETLB_CGROUP_H

  #include <linux/mmdebug.h>

  
  struct hugetlb_cgroup;

  /*
   * Minimum page order trackable by hugetlb cgroup.
   * At least 3 pages are necessary for all the tracking information.
   */
  #define HUGETLB_CGROUP_MIN_ORDER	2

  
  #ifdef CONFIG_CGROUP_HUGETLB

  
  static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
  {

  	VM_BUG_ON_PAGE(!PageHuge(page), page);

  
  	if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
  		return NULL;

  	return (struct hugetlb_cgroup *)page[2].private;

  }
  
  static inline
  int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
  {

  	VM_BUG_ON_PAGE(!PageHuge(page), page);

  
  	if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
  		return -1;

  	page[2].private	= (unsigned long)h_cg;

  	return 0;
  }

  static inline bool hugetlb_cgroup_disabled(void)
  {

  	return !cgroup_subsys_enabled(hugetlb_cgrp_subsys);

  }

  extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
  					struct hugetlb_cgroup **ptr);
  extern void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
  					 struct hugetlb_cgroup *h_cg,
  					 struct page *page);
  extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
  					 struct page *page);
  extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
  					   struct hugetlb_cgroup *h_cg);

  extern void hugetlb_cgroup_file_init(void) __init;

  extern void hugetlb_cgroup_migrate(struct page *oldhpage,
  				   struct page *newhpage);

  #else

  static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
  {
  	return NULL;
  }
  
  static inline
  int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
  {
  	return 0;
  }

  static inline bool hugetlb_cgroup_disabled(void)
  {
  	return true;
  }

  static inline int
  hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
  			     struct hugetlb_cgroup **ptr)
  {
  	return 0;
  }
  
  static inline void
  hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
  			     struct hugetlb_cgroup *h_cg,
  			     struct page *page)
  {

  }
  
  static inline void
  hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page)
  {

  }
  
  static inline void
  hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
  			       struct hugetlb_cgroup *h_cg)
  {

  }

  static inline void hugetlb_cgroup_file_init(void)

  {

  }

  static inline void hugetlb_cgroup_migrate(struct page *oldhpage,
  					  struct page *newhpage)
  {

  }

  #endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
  #endif