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/*
  41 * Huge pages are a constant size, but don't exceed the maximum allocation
  42 * granularity.
  43 */
  44#define pageblock_order         min_t(unsigned int, HUGETLB_PAGE_ORDER, MAX_ORDER - 1)
  45
  46#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
  47
  48#else /* CONFIG_HUGETLB_PAGE */
  49
  50/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
  51#define pageblock_order         (MAX_ORDER-1)
  52
  53#endif /* CONFIG_HUGETLB_PAGE */
  54
  55#define pageblock_nr_pages      (1UL << pageblock_order)
  56
  57/* Forward declaration */
  58struct page;
  59
  60unsigned long get_pfnblock_flags_mask(const struct page *page,
  61                                unsigned long pfn,
  62                                unsigned long mask);
  63
  64void set_pfnblock_flags_mask(struct page *page,
  65                                unsigned long flags,
  66                                unsigned long pfn,
  67                                unsigned long mask);
  68
  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),   \
  79                        page_to_pfn(page),                      \
  80                        (1 << PB_migrate_skip))
  81#else
  82static inline bool get_pageblock_skip(struct page *page)
  83{
  84        return false;
  85}
  86static inline void clear_pageblock_skip(struct page *page)
  87{
  88}
  89static inline void set_pageblock_skip(struct page *page)
  90{
  91}
  92#endif /* CONFIG_COMPACTION */
  93
  94#endif  /* PAGEBLOCK_FLAGS_H */
  95