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