include/linux/pageblock-flags.h

   1 /*
   2  * Macros for manipulating and testing flags related to a
   3  * MAX_ORDER_NR_PAGES block 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, 1), /* 1 bit required for migrate types */
  35         NR_PAGEBLOCK_BITS
  36 };
  37
  38 /* Forward declaration */
  39 struct page;
  40
  41 /* Declarations for getting and setting flags. See mm/page_alloc.c */
  42 unsigned long get_pageblock_flags_group(struct page *page,
  43                                         int start_bitidx, int end_bitidx);
  44 void set_pageblock_flags_group(struct page *page, unsigned long flags,
  45                                         int start_bitidx, int end_bitidx);
  46
  47 #define get_pageblock_flags(page) \
  48                         get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
  49 #define set_pageblock_flags(page) \
  50                         set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1)
  51
  52 #endif  /* PAGEBLOCK_FLAGS_H */