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 PB_migrate_skip,/* If set the block is skipped by compaction */ 34 35 /* 36 * Assume the bits will always align on a word. If this assumption 37 * changes then get/set pageblock needs updating. 38 */ 39 NR_PAGEBLOCK_BITS 40 }; 41 42 #ifdef CONFIG_HUGETLB_PAGE 43 44 #ifdef CONFIG_HUGETLB_PAGE_SIZE_VARIABLE 45 46 /* Huge page sizes are variable */ 47 extern unsigned 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 65 /* Forward declaration */ 66 struct page; 67 68 unsigned long get_pfnblock_flags_mask(struct page *page, 69 unsigned long pfn, 70 unsigned long end_bitidx, 71 unsigned long mask); 72 73 void set_pfnblock_flags_mask(struct page *page, 74 unsigned long flags, 75 unsigned long pfn, 76 unsigned long end_bitidx, 77 unsigned long mask); 78 79 /* Declarations for getting and setting flags. See mm/page_alloc.c */ 80 #define get_pageblock_flags_group(page, start_bitidx, end_bitidx) \ 81 get_pfnblock_flags_mask(page, page_to_pfn(page), \ 82 end_bitidx, \ 83 (1 << (end_bitidx - start_bitidx + 1)) - 1) 84 #define set_pageblock_flags_group(page, flags, start_bitidx, end_bitidx) \ 85 set_pfnblock_flags_mask(page, flags, page_to_pfn(page), \ 86 end_bitidx, \ 87 (1 << (end_bitidx - start_bitidx + 1)) - 1) 88 89 #ifdef CONFIG_COMPACTION 90 #define get_pageblock_skip(page) \ 91 get_pageblock_flags_group(page, PB_migrate_skip, \ 92 PB_migrate_skip) 93 #define clear_pageblock_skip(page) \ 94 set_pageblock_flags_group(page, 0, PB_migrate_skip, \ 95 PB_migrate_skip) 96 #define set_pageblock_skip(page) \ 97 set_pageblock_flags_group(page, 1, PB_migrate_skip, \ 98 PB_migrate_skip) 99 #endif /* CONFIG_COMPACTION */ 100 101 #endif /* PAGEBLOCK_FLAGS_H */ 102