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 #ifdef CONFIG_COMPACTION 34 PB_migrate_skip,/* If set the block is skipped by compaction */ 35 #endif /* CONFIG_COMPACTION */ 36 NR_PAGEBLOCK_BITS 37 }; 38 39 #ifdef CONFIG_HUGETLB_PAGE 40 41 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 42 43 /* Huge page sizes are variable */ 44 extern int pageblock_order; 45 46 #else /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 47 48 /* Huge pages are a constant size */ 49 #define pageblock_order HUGETLB_PAGE_ORDER 50 51 #endif /* CONFIG_HUGETLB_PAGE_SIZE_VARIABLE */ 52 53 #else /* CONFIG_HUGETLB_PAGE */ 54 55 /* If huge pages are not used, group by MAX_ORDER_NR_PAGES */ 56 #define pageblock_order (MAX_ORDER-1) 57 58 #endif /* CONFIG_HUGETLB_PAGE */ 59 60 #define pageblock_nr_pages (1UL << pageblock_order) 61 62 /* Forward declaration */ 63 struct page; 64 65 /* Declarations for getting and setting flags. See mm/page_alloc.c */ 66 unsigned long get_pageblock_flags_group(struct page *page, 67 int start_bitidx, int end_bitidx); 68 void set_pageblock_flags_group(struct page *page, unsigned long flags, 69 int start_bitidx, int end_bitidx); 70 71 #ifdef CONFIG_COMPACTION 72 #define get_pageblock_skip(page) \ 73 get_pageblock_flags_group(page, PB_migrate_skip, \ 74 PB_migrate_skip) 75 #define clear_pageblock_skip(page) \ 76 set_pageblock_flags_group(page, 0, PB_migrate_skip, \ 77 PB_migrate_skip) 78 #define set_pageblock_skip(page) \ 79 set_pageblock_flags_group(page, 1, PB_migrate_skip, \ 80 PB_migrate_skip) 81 #endif /* CONFIG_COMPACTION */ 82 83 #define get_pageblock_flags(page) \ 84 get_pageblock_flags_group(page, 0, PB_migrate_end) 85 #define set_pageblock_flags(page, flags) \ 86 set_pageblock_flags_group(page, flags, \ 87 0, PB_migrate_end) 88 89 #endif /* PAGEBLOCK_FLAGS_H */ 90