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 | #define PB_migratetype_bits 3 |
29 | /* Bit indices that affect a whole block of pages */ |
30 | enum pageblock_bits { |
31 | PB_migrate, |
32 | PB_migrate_end = PB_migrate + PB_migratetype_bits - 1, |
33 | /* 3 bits required for migrate types */ |
34 | PB_migrate_skip,/* If set the block is skipped by compaction */ |
35 | |
36 | /* |
37 | * Assume the bits will always align on a word. If this assumption |
38 | * changes then get/set pageblock needs updating. |
39 | */ |
40 | NR_PAGEBLOCK_BITS |
41 | }; |
42 | |
43 | #ifdef CONFIG_HUGETLB_PAGE |
44 | |
45 | #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE |
46 | |
47 | /* Huge page sizes are variable */ |
48 | extern unsigned int pageblock_order; |
49 | |
50 | #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ |
51 | |
52 | /* Huge pages are a constant size */ |
53 | #define pageblock_order HUGETLB_PAGE_ORDER |
54 | |
55 | #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ |
56 | |
57 | #else /* CONFIG_HUGETLB_PAGE */ |
58 | |
59 | /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */ |
60 | #define pageblock_order (MAX_ORDER-1) |
61 | |
62 | #endif /* CONFIG_HUGETLB_PAGE */ |
63 | |
64 | #define pageblock_nr_pages (1UL << pageblock_order) |
65 | |
66 | /* Forward declaration */ |
67 | struct page; |
68 | |
69 | unsigned long get_pfnblock_flags_mask(struct page *page, |
70 | unsigned long pfn, |
71 | unsigned long end_bitidx, |
72 | unsigned long mask); |
73 | |
74 | void set_pfnblock_flags_mask(struct page *page, |
75 | unsigned long flags, |
76 | unsigned long pfn, |
77 | unsigned long end_bitidx, |
78 | unsigned long mask); |
79 | |
80 | /* Declarations for getting and setting flags. See mm/page_alloc.c */ |
81 | #define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \ |
82 | get_pfnblock_flags_mask(page, page_to_pfn(page), \ |
83 | end_bitidx, \ |
84 | (1 << (end_bitidx - start_bitidx + 1)) - 1) |
85 | #define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \ |
86 | set_pfnblock_flags_mask(page, flags, page_to_pfn(page), \ |
87 | end_bitidx, \ |
88 | (1 << (end_bitidx - start_bitidx + 1)) - 1) |
89 | |
90 | #ifdef CONFIG_COMPACTION |
91 | #define get_pageblock_skip(page) \ |
92 | get_pageblock_flags_group(page, PB_migrate_skip, \ |
93 | PB_migrate_skip) |
94 | #define clear_pageblock_skip(page) \ |
95 | set_pageblock_flags_group(page, 0, PB_migrate_skip, \ |
96 | PB_migrate_skip) |
97 | #define set_pageblock_skip(page) \ |
98 | set_pageblock_flags_group(page, 1, PB_migrate_skip, \ |
99 | PB_migrate_skip) |
100 | #else |
101 | static inline bool get_pageblock_skip(struct page *page) |
102 | { |
103 | return false; |
104 | } |
105 | static inline void clear_pageblock_skip(struct page *page) |
106 | { |
107 | } |
108 | static inline void set_pageblock_skip(struct page *page) |
109 | { |
110 | } |
111 | #endif /* CONFIG_COMPACTION */ |
112 | |
113 | #endif /* PAGEBLOCK_FLAGS_H */ |
114 | |