kernel-lib/radix-tree.h

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 /*
  20  * Copyright (C) 2001 Momchil Velikov
  21  * Portions Copyright (C) 2001 Christoph Hellwig
  22  *
  23  * This program is free software; you can redistribute it and/or
  24  * modify it under the terms of the GNU General Public License as
  25  * published by the Free Software Foundation; either version 2, or (at
  26  * your option) any later version.
  27  *
  28  * This program is distributed in the hope that it will be useful, but
  29  * WITHOUT ANY WARRANTY; without even the implied warranty of
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  31  * General Public License for more details.
  32  *
  33  * You should have received a copy of the GNU General Public License
  34  * along with this program; if not, write to the Free Software
  35  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  36  */
  37 #ifndef _LINUX_RADIX_TREE_H
  38 #define _LINUX_RADIX_TREE_H
  39
  40 #if BTRFS_FLAT_INCLUDES
  41 #include "kerncompat.h"
  42 #else
  43 #include <btrfs/kerncompat.h>
  44 #endif /* BTRFS_FLAT_INCLUDES */
  45
  46 #define RADIX_TREE_MAX_TAGS 2
  47
  48 /* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */
  49 struct radix_tree_root {
  50         unsigned int            height;
  51         gfp_t                   gfp_mask;
  52         struct radix_tree_node  *rnode;
  53 };
  54
  55 #define RADIX_TREE_INIT(mask)   {                                       \
  56         .height = 0,                                                    \
  57         .gfp_mask = (mask),                                             \
  58         .rnode = NULL,                                                  \
  59 }
  60
  61 #define RADIX_TREE(name, mask) \
  62         struct radix_tree_root name = RADIX_TREE_INIT(mask)
  63
  64 #define INIT_RADIX_TREE(root, mask)                                     \
  65 do {                                                                    \
  66         (root)->height = 0;                                             \
  67         (root)->gfp_mask = (mask);                                      \
  68         (root)->rnode = NULL;                                           \
  69 } while (0)
  70
  71 int radix_tree_insert(struct radix_tree_root *, unsigned long, void *);
  72 void *radix_tree_lookup(struct radix_tree_root *, unsigned long);
  73 void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);
  74 void *radix_tree_delete(struct radix_tree_root *, unsigned long);
  75 unsigned int
  76 radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
  77                         unsigned long first_index, unsigned int max_items);
  78 int radix_tree_preload(gfp_t gfp_mask);
  79 void radix_tree_init(void);
  80 void *radix_tree_tag_set(struct radix_tree_root *root,
  81                         unsigned long index, unsigned int tag);
  82 void *radix_tree_tag_clear(struct radix_tree_root *root,
  83                         unsigned long index, unsigned int tag);
  84 int radix_tree_tag_get(struct radix_tree_root *root,
  85                         unsigned long index, unsigned int tag);
  86 unsigned int
  87 radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
  88                 unsigned long first_index, unsigned int max_items,
  89                 unsigned int tag);
  90 int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);
  91
  92 static inline void radix_tree_preload_end(void)
  93 {
  94         preempt_enable();
  95 }
  96
  97 #endif /* _LINUX_RADIX_TREE_H */