/*
* 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>
/* Macro to aid the definition of ranges of bits */
#define PB_range(name, required_bits) \
name, name ## _end = (name + required_bits) - 1
/* Bit indices that affect a whole block of pages */
enum pageblock_bits {
PB_range(PB_migrate, 3), /* 3 bits required for migrate types */
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;
/* Declarations for getting and setting flags. See mm/page_alloc.c */
unsigned long get_pageblock_flags_group(struct page *page,
int start_bitidx, int end_bitidx);
void set_pageblock_flags_group(struct page *page, unsigned long flags,
int start_bitidx, int end_bitidx);
#define get_pageblock_flags(page) \
get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
#define set_pageblock_flags(page) \
set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
#endif /* PAGEBLOCK_FLAGS_H */
