[deliverable/linux.git] / include / linux / pageblock-flags.h

/*
 * Macros for manipulating and testing flags related to a
 * pageblock_nr_pages number of pages.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 2 of the License
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * 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>

/* Bit indices that affect a whole block of pages */
enum pageblock_bits {
	PB_migrate,
	PB_migrate_end = PB_migrate + 3 - 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 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_pageblock_flags_mask(struct page *page,
				unsigned long end_bitidx,
				unsigned long mask);
void set_pageblock_flags_mask(struct page *page,
				unsigned long flags,
				unsigned long end_bitidx,
				unsigned long mask);

/* Declarations for getting and setting flags. See mm/page_alloc.c */
static inline unsigned long get_pageblock_flags_group(struct page *page,
					int start_bitidx, int end_bitidx)
{
	unsigned long nr_flag_bits = end_bitidx - start_bitidx + 1;
	unsigned long mask = (1 << nr_flag_bits) - 1;

	return get_pageblock_flags_mask(page, end_bitidx, mask);
}

static inline void set_pageblock_flags_group(struct page *page,
					unsigned long flags,
					int start_bitidx, int end_bitidx)
{
	unsigned long nr_flag_bits = end_bitidx - start_bitidx + 1;
	unsigned long mask = (1 << nr_flag_bits) - 1;

	set_pageblock_flags_mask(page, flags, end_bitidx, mask);
}

#ifdef CONFIG_COMPACTION
#define get_pageblock_skip(page) \
			get_pageblock_flags_group(page, PB_migrate_skip,     \
							PB_migrate_skip)
#define clear_pageblock_skip(page) \
			set_pageblock_flags_group(page, 0, PB_migrate_skip,  \
							PB_migrate_skip)
#define set_pageblock_skip(page) \
			set_pageblock_flags_group(page, 1, PB_migrate_skip,  \
							PB_migrate_skip)
#endif /* CONFIG_COMPACTION */

#endif	/* PAGEBLOCK_FLAGS_H */
Commit	Line	Data
835c134e MG	1	/*
835c134e MG	2	* Macros for manipulating and testing flags related to a
d9c23400	3	* pageblock_nr_pages number of pages.
835c134e MG	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation version 2 of the License
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* Copyright (C) IBM Corporation, 2006
	19	*
	20	* Original author, Mel Gorman
	21	* Major cleanups and reduction of bit operations, Andy Whitcroft
	22	*/
	23	#ifndef PAGEBLOCK_FLAGS_H
	24	#define PAGEBLOCK_FLAGS_H
	25
	26	#include <linux/types.h>
	27
835c134e MG	28	/* Bit indices that affect a whole block of pages */
835c134e MG	29	enum pageblock_bits {
c801ed38 PJ	30	PB_migrate,
	31	PB_migrate_end = PB_migrate + 3 - 1,
	32	/* 3 bits required for migrate types */
bb13ffeb	33	PB_migrate_skip,/* If set the block is skipped by compaction */
e58469ba MG	34
	35	/*
	36	* Assume the bits will always align on a word. If this assumption
	37	* changes then get/set pageblock needs updating.
	38	*/
835c134e MG	39	NR_PAGEBLOCK_BITS
	40	};
	41
d9c23400 MG	42	#ifdef CONFIG_HUGETLB_PAGE
	43
	44	#ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE
	45
	46	/* Huge page sizes are variable */
	47	extern int pageblock_order;
	48
	49	#else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
	50
	51	/* Huge pages are a constant size */
	52	#define pageblock_order HUGETLB_PAGE_ORDER
	53
	54	#endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */
	55
	56	#else /* CONFIG_HUGETLB_PAGE */
	57
	58	/* If huge pages are not used, group by MAX_ORDER_NR_PAGES */
	59	#define pageblock_order (MAX_ORDER-1)
	60
	61	#endif /* CONFIG_HUGETLB_PAGE */
	62
	63	#define pageblock_nr_pages (1UL << pageblock_order)
	64
835c134e MG	65	/* Forward declaration */
	66	struct page;
	67
e58469ba MG	68	unsigned long get_pageblock_flags_mask(struct page *page,
	69	unsigned long end_bitidx,
	70	unsigned long mask);
	71	void set_pageblock_flags_mask(struct page *page,
	72	unsigned long flags,
	73	unsigned long end_bitidx,
	74	unsigned long mask);
	75
835c134e	76	/* Declarations for getting and setting flags. See mm/page_alloc.c */
e58469ba MG	77	static inline unsigned long get_pageblock_flags_group(struct page *page,
	78	int start_bitidx, int end_bitidx)
	79	{
	80	unsigned long nr_flag_bits = end_bitidx - start_bitidx + 1;
	81	unsigned long mask = (1 << nr_flag_bits) - 1;
	82
	83	return get_pageblock_flags_mask(page, end_bitidx, mask);
	84	}
	85
	86	static inline void set_pageblock_flags_group(struct page *page,
	87	unsigned long flags,
	88	int start_bitidx, int end_bitidx)
	89	{
	90	unsigned long nr_flag_bits = end_bitidx - start_bitidx + 1;
	91	unsigned long mask = (1 << nr_flag_bits) - 1;
	92
	93	set_pageblock_flags_mask(page, flags, end_bitidx, mask);
	94	}
835c134e	95
bb13ffeb MG	96	#ifdef CONFIG_COMPACTION
	97	#define get_pageblock_skip(page) \
	98	get_pageblock_flags_group(page, PB_migrate_skip, \
62726059	99	PB_migrate_skip)
bb13ffeb MG	100	#define clear_pageblock_skip(page) \
bb13ffeb MG	101	set_pageblock_flags_group(page, 0, PB_migrate_skip, \
62726059	102	PB_migrate_skip)
bb13ffeb MG	103	#define set_pageblock_skip(page) \
bb13ffeb MG	104	set_pageblock_flags_group(page, 1, PB_migrate_skip, \
62726059	105	PB_migrate_skip)
bb13ffeb MG	106	#endif /* CONFIG_COMPACTION */
bb13ffeb MG	107
835c134e	108	#endif /* PAGEBLOCK_FLAGS_H */