1 /* 2 * Macros for manipulating and testing flags related to a 3 * pageblock_nr_pages number of pages. 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 28 /* Macro to aid the definition of ranges of bits */ 29 #define PB_range(name, required_bits) \ 30 name, name ## _end = (name + required_bits) - 1 31 32 /* Bit indices that affect a whole block of pages */ 33 enum pageblock_bits { 34 PB_range(PB_migrate, 3), /* 3 bits required for migrate types */ 35 NR_PAGEBLOCK_BITS 36 }; 37 38 #ifdef CONFIG_HUGETLB_PAGE 39 40 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 41 42 /* Huge page sizes are variable */ 43 extern int pageblock_order; 44 45 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 46 47 /* Huge pages are a constant size */ 48 #define pageblock_order HUGETLB_PAGE_ORDER 49 50 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 51 52 #else /* CONFIG_HUGETLB_PAGE */ 53 54 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */ 55 #define pageblock_order (MAX_ORDER-1) 56 57 #endif /* CONFIG_HUGETLB_PAGE */ 58 59 #define pageblock_nr_pages (1UL << pageblock_order) 60 61 /* Forward declaration */ 62 struct page; 63 64 /* Declarations for getting and setting flags. See mm/page_alloc.c */ 65 unsigned long get_pageblock_flags_group(struct page *page, 66 int start_bitidx, int end_bitidx); 67 void set_pageblock_flags_group(struct page *page, unsigned long flags, 68 int start_bitidx, int end_bitidx); 69 70 #define get_pageblock_flags(page) \ 71 get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1) 72 #define set_pageblock_flags(page) \ 73 set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1) 74 75 #endif /* PAGEBLOCK_FLAGS_H */ 76