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/* Bit indices that affect a whole block of pages */
 17enum pageblock_bits {
 18	PB_migrate_0,
 19	PB_migrate_1,
 20	PB_migrate_2,
 21	PB_compact_skip,/* If set the block is skipped by compaction */
 22
 23#ifdef CONFIG_MEMORY_ISOLATION
 24	/*
 25	 * Pageblock isolation is represented with a separate bit, so that
 26	 * the migratetype of a block is not overwritten by isolation.
 27	 */
 28	PB_migrate_isolate, /* If set the block is isolated */
 29#endif
 30	/*
 31	 * Assume the bits will always align on a word. If this assumption
 32	 * changes then get/set pageblock needs updating.
 33	 */
 34	__NR_PAGEBLOCK_BITS
 35};
 36
 37#define NR_PAGEBLOCK_BITS (roundup_pow_of_two(__NR_PAGEBLOCK_BITS))
 38
 39#define MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
 40
 41#ifdef CONFIG_MEMORY_ISOLATION
 42#define MIGRATETYPE_AND_ISO_MASK (MIGRATETYPE_MASK | BIT(PB_migrate_isolate))
 43#else
 44#define MIGRATETYPE_AND_ISO_MASK MIGRATETYPE_MASK
 45#endif
 46
 47#if defined(CONFIG_HUGETLB_PAGE)
 48
 49#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
 50
 51/* Huge page sizes are variable */
 52extern unsigned int pageblock_order;
 53
 54#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
 55
 56/*
 57 * Huge pages are a constant size, but don't exceed the maximum allocation
 58 * granularity.
 59 */
 60#define pageblock_order		MIN_T(unsigned int, HUGETLB_PAGE_ORDER, PAGE_BLOCK_MAX_ORDER)
 61
 62#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
 63
 64#elif defined(CONFIG_TRANSPARENT_HUGEPAGE)
 65
 66#define pageblock_order		MIN_T(unsigned int, HPAGE_PMD_ORDER, PAGE_BLOCK_MAX_ORDER)
 67
 68#else /* CONFIG_TRANSPARENT_HUGEPAGE */
 69
 70/* If huge pages are not used, group by PAGE_BLOCK_MAX_ORDER */
 71#define pageblock_order		PAGE_BLOCK_MAX_ORDER
 72
 73#endif /* CONFIG_HUGETLB_PAGE */
 74
 75#define pageblock_nr_pages	(1UL << pageblock_order)
 76#define pageblock_align(pfn)	ALIGN((pfn), pageblock_nr_pages)
 77#define pageblock_aligned(pfn)	IS_ALIGNED((pfn), pageblock_nr_pages)
 78#define pageblock_start_pfn(pfn)	ALIGN_DOWN((pfn), pageblock_nr_pages)
 79#define pageblock_end_pfn(pfn)		ALIGN((pfn) + 1, pageblock_nr_pages)
 80
 81/* Forward declaration */
 82struct page;
 83
 84enum migratetype get_pfnblock_migratetype(const struct page *page,
 85					  unsigned long pfn);
 86bool get_pfnblock_bit(const struct page *page, unsigned long pfn,
 87		      enum pageblock_bits pb_bit);
 88void set_pfnblock_bit(const struct page *page, unsigned long pfn,
 89		      enum pageblock_bits pb_bit);
 90void clear_pfnblock_bit(const struct page *page, unsigned long pfn,
 91			enum pageblock_bits pb_bit);
 92
 93/* Declarations for getting and setting flags. See mm/page_alloc.c */
 94#ifdef CONFIG_COMPACTION
 95#define get_pageblock_skip(page) \
 96	get_pfnblock_bit(page, page_to_pfn(page), PB_compact_skip)
 97#define clear_pageblock_skip(page) \
 98	clear_pfnblock_bit(page, page_to_pfn(page), PB_compact_skip)
 99#define set_pageblock_skip(page) \
100	set_pfnblock_bit(page, page_to_pfn(page), PB_compact_skip)
101#else
102static inline bool get_pageblock_skip(struct page *page)
103{
104	return false;
105}
106static inline void clear_pageblock_skip(struct page *page)
107{
108}
109static inline void set_pageblock_skip(struct page *page)
110{
111}
112#endif /* CONFIG_COMPACTION */
113
114#endif	/* PAGEBLOCK_FLAGS_H */