1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Macros for manipulating and testing flags related to a
4 * pageblock_nr_pages number of pages.
6 * Copyright (C) IBM Corporation, 2006
8 * Original author, Mel Gorman
9 * Major cleanups and reduction of bit operations, Andy Whitcroft
11 #ifndef PAGEBLOCK_FLAGS_H
12 #define PAGEBLOCK_FLAGS_H
14 #include <linux/types.h>
16 #define PB_migratetype_bits 3
17 /* Bit indices that affect a whole block of pages */
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 */
25 * Assume the bits will always align on a word. If this assumption
26 * changes then get/set pageblock needs updating.
31 #ifdef CONFIG_HUGETLB_PAGE
33 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
35 /* Huge page sizes are variable */
36 extern unsigned int pageblock_order;
38 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
41 * Huge pages are a constant size, but don't exceed the maximum allocation
44 #define pageblock_order min_t(unsigned int, HUGETLB_PAGE_ORDER, MAX_ORDER - 1)
46 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
48 #else /* CONFIG_HUGETLB_PAGE */
50 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
51 #define pageblock_order (MAX_ORDER-1)
53 #endif /* CONFIG_HUGETLB_PAGE */
55 #define pageblock_nr_pages (1UL << pageblock_order)
57 /* Forward declaration */
60 unsigned long get_pfnblock_flags_mask(const struct page *page,
64 void set_pfnblock_flags_mask(struct page *page,
69 /* Declarations for getting and setting flags. See mm/page_alloc.c */
70 #ifdef CONFIG_COMPACTION
71 #define get_pageblock_skip(page) \
72 get_pfnblock_flags_mask(page, page_to_pfn(page), \
73 (1 << (PB_migrate_skip)))
74 #define clear_pageblock_skip(page) \
75 set_pfnblock_flags_mask(page, 0, page_to_pfn(page), \
76 (1 << PB_migrate_skip))
77 #define set_pageblock_skip(page) \
78 set_pfnblock_flags_mask(page, (1 << PB_migrate_skip), \
80 (1 << PB_migrate_skip))
82 static inline bool get_pageblock_skip(struct page *page)
86 static inline void clear_pageblock_skip(struct page *page)
89 static inline void set_pageblock_skip(struct page *page)
92 #endif /* CONFIG_COMPACTION */
94 #endif /* PAGEBLOCK_FLAGS_H */