LXR linux/include/linux/pageblock-flags.h

   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 */
  18enum 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 */
  36extern 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 */
  55struct page;
  56
  57unsigned long get_pfnblock_flags_mask(struct page *page,
  58                                unsigned long pfn,
  59                                unsigned long end_bitidx,
  60                                unsigned long mask);
  61
  62void set_pfnblock_flags_mask(struct page *page,
  63                                unsigned long flags,
  64                                unsigned long pfn,
  65                                unsigned long end_bitidx,
  66                                unsigned long mask);
  67
  68/* Declarations for getting and setting flags. See mm/page_alloc.c */
  69#define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \
  70        get_pfnblock_flags_mask(page, page_to_pfn(page),                \
  71                        end_bitidx,                                     \
  72                        (1 << (end_bitidx - start_bitidx + 1)) - 1)
  73#define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \
  74        set_pfnblock_flags_mask(page, flags, page_to_pfn(page),         \
  75                        end_bitidx,                                     \
  76                        (1 << (end_bitidx - start_bitidx + 1)) - 1)
  77
  78#ifdef CONFIG_COMPACTION
  79#define get_pageblock_skip(page) \
  80                        get_pageblock_flags_group(page, PB_migrate_skip,     \
  81                                                        PB_migrate_skip)
  82#define clear_pageblock_skip(page) \
  83                        set_pageblock_flags_group(page, 0, PB_migrate_skip,  \
  84                                                        PB_migrate_skip)
  85#define set_pageblock_skip(page) \
  86                        set_pageblock_flags_group(page, 1, PB_migrate_skip,  \
  87                                                        PB_migrate_skip)
  88#else
  89static inline bool get_pageblock_skip(struct page *page)
  90{
  91        return false;
  92}
  93static inline void clear_pageblock_skip(struct page *page)
  94{
  95}
  96static inline void set_pageblock_skip(struct page *page)
  97{
  98}
  99#endif /* CONFIG_COMPACTION */
 100
 101#endif  /* PAGEBLOCK_FLAGS_H */
 102