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Mel Gorman835c1342007-10-16 01:25:47 -07001/*
2 * Macros for manipulating and testing flags related to a
Mel Gormand9c23402007-10-16 01:26:01 -07003 * pageblock_nr_pages number of pages.
Mel Gorman835c1342007-10-16 01:25:47 -07004 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation version 2 of the License
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright (C) IBM Corporation, 2006
19 *
20 * Original author, Mel Gorman
21 * Major cleanups and reduction of bit operations, Andy Whitcroft
22 */
23#ifndef PAGEBLOCK_FLAGS_H
24#define PAGEBLOCK_FLAGS_H
25
26#include <linux/types.h>
27
Mel Gorman835c1342007-10-16 01:25:47 -070028/* Bit indices that affect a whole block of pages */
29enum pageblock_bits {
Paul Jacksonc801ed32008-05-14 08:15:23 -070030 PB_migrate,
31 PB_migrate_end = PB_migrate + 3 - 1,
32 /* 3 bits required for migrate types */
Mel Gorman835c1342007-10-16 01:25:47 -070033 NR_PAGEBLOCK_BITS
34};
35
Mel Gormand9c23402007-10-16 01:26:01 -070036#ifdef CONFIG_HUGETLB_PAGE
37
38#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
39
40/* Huge page sizes are variable */
41extern int pageblock_order;
42
43#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
44
45/* Huge pages are a constant size */
46#define pageblock_order HUGETLB_PAGE_ORDER
47
48#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
49
50#else /* CONFIG_HUGETLB_PAGE */
51
52/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
53#define pageblock_order (MAX_ORDER-1)
54
55#endif /* CONFIG_HUGETLB_PAGE */
56
57#define pageblock_nr_pages (1UL << pageblock_order)
58
Mel Gorman835c1342007-10-16 01:25:47 -070059/* Forward declaration */
60struct page;
61
62/* Declarations for getting and setting flags. See mm/page_alloc.c */
63unsigned long get_pageblock_flags_group(struct page *page,
64 int start_bitidx, int end_bitidx);
65void set_pageblock_flags_group(struct page *page, unsigned long flags,
66 int start_bitidx, int end_bitidx);
67
68#define get_pageblock_flags(page) \
69 get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
70#define set_pageblock_flags(page) \
71 set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
72
73#endif /* PAGEBLOCK_FLAGS_H */