/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Macros for manipulating and testing flags related to a
* pageblock_nr_pages number of pages.
*
* Copyright (C) IBM Corporation, 2006
*
* Original author, Mel Gorman
* Major cleanups and reduction of bit operations, Andy Whitcroft
*/
#ifndef PAGEBLOCK_FLAGS_H
#define PAGEBLOCK_FLAGS_H
#include <linux/types.h>
#define PB_migratetype_bits 3
/* Bit indices that affect a whole block of pages */
enum pageblock_bits {
PB_migrate,
PB_migrate_end = PB_migrate + PB_migratetype_bits - 1,
/* 3 bits required for migrate types */
PB_migrate_skip,/* If set the block is skipped by compaction */
/*
* Assume the bits will always align on a word. If this assumption
* changes then get/set pageblock needs updating.
*/
NR_PAGEBLOCK_BITS
};
#ifdef CONFIG_HUGETLB_PAGE
#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
/* Huge page sizes are variable */
extern unsigned int pageblock_order;
#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
/* Huge pages are a constant size */
#define pageblock_order HUGETLB_PAGE_ORDER
#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
#else /* CONFIG_HUGETLB_PAGE */
/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
#define pageblock_order (MAX_ORDER-1)
#endif /* CONFIG_HUGETLB_PAGE */
#define pageblock_nr_pages (1UL << pageblock_order)
/* Forward declaration */
struct page;
unsigned long get_pfnblock_flags_mask(struct page *page,
unsigned long pfn,
unsigned long mask);
void set_pfnblock_flags_mask(struct page *page,
unsigned long flags,
unsigned long pfn,
unsigned long mask);
/* Declarations for getting and setting flags. See mm/page_alloc.c */
#ifdef CONFIG_COMPACTION
#define get_pageblock_skip(page) \
get_pfnblock_flags_mask(page, page_to_pfn(page), \
(1 << (PB_migrate_skip)))
#define clear_pageblock_skip(page) \
set_pfnblock_flags_mask(page, 0, page_to_pfn(page), \
(1 << PB_migrate_skip))
#define set_pageblock_skip(page) \
set_pfnblock_flags_mask(page, (1 << PB_migrate_skip), \
page_to_pfn(page), \
(1 << PB_migrate_skip))
#else
static inline bool get_pageblock_skip(struct page *page)
{
return false;
}
static inline void clear_pageblock_skip(struct page *page)
{
}
static inline void set_pageblock_skip(struct page *page)
{
}
#endif /* CONFIG_COMPACTION */
#endif /* PAGEBLOCK_FLAGS_H */
