/*
* Copyright IBM Corporation, 2012
* Author Aneesh Kumar K.V <[email protected]>
*
* 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/res_counter.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(!PageHuge(page));

if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
return NULL;
return (struct hugetlb_cgroup *)page[2].lru.next;
}

static inline
int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
{
VM_BUG_ON(!PageHuge(page));

if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
return -1;
page[2].lru.next = (void *)h_cg;
return 0;
}

static inline bool hugetlb_cgroup_disabled(void)
{
if (hugetlb_subsys.disabled)
return true;
return false;
}

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)
{
return;
}

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

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

static inline void hugetlb_cgroup_file_init(void)
{
}

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

#endif /* CONFIG_MEM_RES_CTLR_HUGETLB */
#endif