radix-tree.h

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