1/*
2 * Copyright IBM Corporation, 2012
3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 */
14
15#ifndef _LINUX_HUGETLB_CGROUP_H
16#define _LINUX_HUGETLB_CGROUP_H
17
18#include <linux/mmdebug.h>
19
20struct hugetlb_cgroup;
21/*
22 * Minimum page order trackable by hugetlb cgroup.
23 * At least 3 pages are necessary for all the tracking information.
24 */
25#define HUGETLB_CGROUP_MIN_ORDER	2
26
27#ifdef CONFIG_CGROUP_HUGETLB
28
29static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
30{
31	VM_BUG_ON_PAGE(!PageHuge(page), page);
32
33	if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
34		return NULL;
35	return (struct hugetlb_cgroup *)page[2].private;
36}
37
38static inline
39int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
40{
41	VM_BUG_ON_PAGE(!PageHuge(page), page);
42
43	if (compound_order(page) < HUGETLB_CGROUP_MIN_ORDER)
44		return -1;
45	page[2].private	= (unsigned long)h_cg;
46	return 0;
47}
48
49static inline bool hugetlb_cgroup_disabled(void)
50{
51	return !cgroup_subsys_enabled(hugetlb_cgrp_subsys);
52}
53
54extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
55					struct hugetlb_cgroup **ptr);
56extern void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
57					 struct hugetlb_cgroup *h_cg,
58					 struct page *page);
59extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
60					 struct page *page);
61extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
62					   struct hugetlb_cgroup *h_cg);
63extern void hugetlb_cgroup_file_init(void) __init;
64extern void hugetlb_cgroup_migrate(struct page *oldhpage,
65				   struct page *newhpage);
66
67#else
68static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
69{
70	return NULL;
71}
72
73static inline
74int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
75{
76	return 0;
77}
78
79static inline bool hugetlb_cgroup_disabled(void)
80{
81	return true;
82}
83
84static inline int
85hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
86			     struct hugetlb_cgroup **ptr)
87{
88	return 0;
89}
90
91static inline void
92hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
93			     struct hugetlb_cgroup *h_cg,
94			     struct page *page)
95{
96	return;
97}
98
99static inline void
100hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page)
101{
102	return;
103}
104
105static inline void
106hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
107			       struct hugetlb_cgroup *h_cg)
108{
109	return;
110}
111
112static inline void hugetlb_cgroup_file_init(void)
113{
114}
115
116static inline void hugetlb_cgroup_migrate(struct page *oldhpage,
117					  struct page *newhpage)
118{
119	return;
120}
121
122#endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
123#endif
124