Linux kernel mirror (for testing)
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1/*
2 * Macros for manipulating and testing flags related to a
3 * pageblock_nr_pages number of pages.
4 *
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
28/* Macro to aid the definition of ranges of bits */
29#define PB_range(name, required_bits) \
30 name, name ## _end = (name + required_bits) - 1
31
32/* Bit indices that affect a whole block of pages */
33enum pageblock_bits {
34 PB_range(PB_migrate, 3), /* 3 bits required for migrate types */
35 NR_PAGEBLOCK_BITS
36};
37
38#ifdef CONFIG_HUGETLB_PAGE
39
40#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
41
42/* Huge page sizes are variable */
43extern int pageblock_order;
44
45#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
46
47/* Huge pages are a constant size */
48#define pageblock_order HUGETLB_PAGE_ORDER
49
50#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
51
52#else /* CONFIG_HUGETLB_PAGE */
53
54/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
55#define pageblock_order (MAX_ORDER-1)
56
57#endif /* CONFIG_HUGETLB_PAGE */
58
59#define pageblock_nr_pages (1UL << pageblock_order)
60
61/* Forward declaration */
62struct page;
63
64/* Declarations for getting and setting flags. See mm/page_alloc.c */
65unsigned long get_pageblock_flags_group(struct page *page,
66 int start_bitidx, int end_bitidx);
67void set_pageblock_flags_group(struct page *page, unsigned long flags,
68 int start_bitidx, int end_bitidx);
69
70#define get_pageblock_flags(page) \
71 get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
72#define set_pageblock_flags(page) \
73 set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
74
75#endif /* PAGEBLOCK_FLAGS_H */