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835c134e MG |
1 | /* |
2 | * Macros for manipulating and testing flags related to a | |
d9c23400 | 3 | * pageblock_nr_pages number of pages. |
835c134e MG |
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 */ | |
33 | enum pageblock_bits { | |
a5d76b54 | 34 | PB_range(PB_migrate, 3), /* 3 bits required for migrate types */ |
835c134e MG |
35 | NR_PAGEBLOCK_BITS |
36 | }; | |
37 | ||
d9c23400 MG |
38 | #ifdef CONFIG_HUGETLB_PAGE |
39 | ||
40 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE | |
41 | ||
42 | /* Huge page sizes are variable */ | |
43 | extern 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 | ||
835c134e MG |
61 | /* Forward declaration */ |
62 | struct page; | |
63 | ||
64 | /* Declarations for getting and setting flags. See mm/page_alloc.c */ | |
65 | unsigned long get_pageblock_flags_group(struct page *page, | |
66 | int start_bitidx, int end_bitidx); | |
67 | void 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 */ |