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].lru.next;
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].lru.next = (void *)h_cg;
46	return 0;
47}
48
49static inline bool hugetlb_cgroup_disabled(void)
50{
51	if (hugetlb_cgrp_subsys.disabled)
52		return true;
53	return false;
54}
55
56extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
57					struct hugetlb_cgroup **ptr);
58extern void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
59					 struct hugetlb_cgroup *h_cg,
60					 struct page *page);
61extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
62					 struct page *page);
63extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
64					   struct hugetlb_cgroup *h_cg);
65extern void hugetlb_cgroup_file_init(void) __init;
66extern void hugetlb_cgroup_migrate(struct page *oldhpage,
67				   struct page *newhpage);
68
69#else
70static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page)
71{
72	return NULL;
73}
74
75static inline
76int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg)
77{
78	return 0;
79}
80
81static inline bool hugetlb_cgroup_disabled(void)
82{
83	return true;
84}
85
86static inline int
87hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
88			     struct hugetlb_cgroup **ptr)
89{
90	return 0;
91}
92
93static inline void
94hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
95			     struct hugetlb_cgroup *h_cg,
96			     struct page *page)
97{
98	return;
99}
100
101static inline void
102hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, struct page *page)
103{
104	return;
105}
106
107static inline void
108hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
109			       struct hugetlb_cgroup *h_cg)
110{
111	return;
112}
113
114static inline void hugetlb_cgroup_file_init(void)
115{
116}
117
118static inline void hugetlb_cgroup_migrate(struct page *oldhpage,
119					  struct page *newhpage)
120{
121	return;
122}
123
124#endif  /* CONFIG_MEM_RES_CTLR_HUGETLB */
125#endif
126