1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Macros for manipulating and testing flags related to a
4 * pageblock_nr_pages number of pages.
5 *
6 * Copyright (C) IBM Corporation, 2006
7 *
8 * Original author, Mel Gorman
9 * Major cleanups and reduction of bit operations, Andy Whitcroft
10 */
11 #ifndef PAGEBLOCK_FLAGS_H
12 #define PAGEBLOCK_FLAGS_H
13
14 #include <linux/types.h>
15
16 #define PB_migratetype_bits 3
17 /* Bit indices that affect a whole block of pages */
18 enum pageblock_bits {
19 PB_migrate,
20 PB_migrate_end = PB_migrate + PB_migratetype_bits - 1,
21 /* 3 bits required for migrate types */
22 PB_migrate_skip,/* If set the block is skipped by compaction */
23
24 /*
25 * Assume the bits will always align on a word. If this assumption
26 * changes then get/set pageblock needs updating.
27 */
28 NR_PAGEBLOCK_BITS
29 };
30
31 #ifdef CONFIG_HUGETLB_PAGE
32
33 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
34
35 /* Huge page sizes are variable */
36 extern unsigned int pageblock_order;
37
38 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
39
40 /* Huge pages are a constant size */
41 #define pageblock_order HUGETLB_PAGE_ORDER
42
43 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
44
45 #else /* CONFIG_HUGETLB_PAGE */
46
47 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
48 #define pageblock_order (MAX_ORDER-1)
49
50 #endif /* CONFIG_HUGETLB_PAGE */
51
52 #define pageblock_nr_pages (1UL << pageblock_order)
53
54 /* Forward declaration */
55 struct page;
56
57 unsigned long get_pfnblock_flags_mask(const struct page *page,
58 unsigned long pfn,
59 unsigned long mask);
60
61 void set_pfnblock_flags_mask(struct page *page,
62 unsigned long flags,
63 unsigned long pfn,
64 unsigned long mask);
65
66 /* Declarations for getting and setting flags. See mm/page_alloc.c */
67 #ifdef CONFIG_COMPACTION
68 #define get_pageblock_skip(page) \
69 get_pfnblock_flags_mask(page, page_to_pfn(page), \
70 (1 << (PB_migrate_skip)))
71 #define clear_pageblock_skip(page) \
72 set_pfnblock_flags_mask(page, 0, page_to_pfn(page), \
73 (1 << PB_migrate_skip))
74 #define set_pageblock_skip(page) \
75 set_pfnblock_flags_mask(page, (1 << PB_migrate_skip), \
76 page_to_pfn(page), \
77 (1 << PB_migrate_skip))
78 #else
get_pageblock_skip(struct page * page)79 static inline bool get_pageblock_skip(struct page *page)
80 {
81 return false;
82 }
clear_pageblock_skip(struct page * page)83 static inline void clear_pageblock_skip(struct page *page)
84 {
85 }
set_pageblock_skip(struct page * page)86 static inline void set_pageblock_skip(struct page *page)
87 {
88 }
89 #endif /* CONFIG_COMPACTION */
90
91 #endif /* PAGEBLOCK_FLAGS_H */
92