--- /dev/null
+/*
+ * Copyright (C) 2001 Momchil Velikov
+ * Portions Copyright (C) 2001 Christoph Hellwig
+ * Copyright (C) 2005 SGI, Christoph Lameter <clameter@sgi.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <libxfs.h>
+#include "radix-tree.h"
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+#define RADIX_TREE_MAP_SHIFT 6
+#define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT)
+#define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1)
+
+#ifdef RADIX_TREE_TAGS
+#define RADIX_TREE_TAG_LONGS \
+ ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG)
+#endif
+
+struct radix_tree_node {
+ unsigned int count;
+ void *slots[RADIX_TREE_MAP_SIZE];
+#ifdef RADIX_TREE_TAGS
+ unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS];
+#endif
+};
+
+struct radix_tree_path {
+ struct radix_tree_node *node;
+ int offset;
+};
+
+#define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long))
+#define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2)
+
+static unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH];
+
+/*
+ * Radix tree node cache.
+ */
+
+#define radix_tree_node_alloc(r) ((struct radix_tree_node *) \
+ calloc(1, sizeof(struct radix_tree_node)))
+#define radix_tree_node_free(n) free(n)
+
+#ifdef RADIX_TREE_TAGS
+
+static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
+ int offset)
+{
+ *((__uint32_t *)node->tags[tag] + (offset >> 5)) |= (1 << (offset & 31));
+}
+
+static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
+ int offset)
+{
+ __uint32_t *p = (__uint32_t*)node->tags[tag] + (offset >> 5);
+ __uint32_t m = 1 << (offset & 31);
+ *p &= ~m;
+}
+
+static inline int tag_get(struct radix_tree_node *node, unsigned int tag,
+ int offset)
+{
+ return 1 & (((const __uint32_t *)node->tags[tag])[offset >> 5] >> (offset & 31));
+}
+
+/*
+ * Returns 1 if any slot in the node has this tag set.
+ * Otherwise returns 0.
+ */
+static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)
+{
+ int idx;
+ for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
+ if (node->tags[tag][idx])
+ return 1;
+ }
+ return 0;
+}
+
+#endif
+
+/*
+ * Return the maximum key which can be store into a
+ * radix tree with height HEIGHT.
+ */
+static inline unsigned long radix_tree_maxindex(unsigned int height)
+{
+ return height_to_maxindex[height];
+}
+
+/*
+ * Extend a radix tree so it can store key @index.
+ */
+static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
+{
+ struct radix_tree_node *node;
+ unsigned int height;
+#ifdef RADIX_TREE_TAGS
+ char tags[RADIX_TREE_MAX_TAGS];
+ int tag;
+#endif
+
+ /* Figure out what the height should be. */
+ height = root->height + 1;
+ while (index > radix_tree_maxindex(height))
+ height++;
+
+ if (root->rnode == NULL) {
+ root->height = height;
+ goto out;
+ }
+
+#ifdef RADIX_TREE_TAGS
+ /*
+ * Prepare the tag status of the top-level node for propagation
+ * into the newly-pushed top-level node(s)
+ */
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
+ tags[tag] = 0;
+ if (any_tag_set(root->rnode, tag))
+ tags[tag] = 1;
+ }
+#endif
+ do {
+ if (!(node = radix_tree_node_alloc(root)))
+ return -ENOMEM;
+
+ /* Increase the height. */
+ node->slots[0] = root->rnode;
+
+#ifdef RADIX_TREE_TAGS
+ /* Propagate the aggregated tag info into the new root */
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
+ if (tags[tag])
+ tag_set(node, tag, 0);
+ }
+#endif
+ node->count = 1;
+ root->rnode = node;
+ root->height++;
+ } while (height > root->height);
+out:
+ return 0;
+}
+
+/**
+ * radix_tree_insert - insert into a radix tree
+ * @root: radix tree root
+ * @index: index key
+ * @item: item to insert
+ *
+ * Insert an item into the radix tree at position @index.
+ */
+int radix_tree_insert(struct radix_tree_root *root,
+ unsigned long index, void *item)
+{
+ struct radix_tree_node *node = NULL, *slot;
+ unsigned int height, shift;
+ int offset;
+ int error;
+
+ /* Make sure the tree is high enough. */
+ if ((!index && !root->rnode) ||
+ index > radix_tree_maxindex(root->height)) {
+ error = radix_tree_extend(root, index);
+ if (error)
+ return error;
+ }
+
+ slot = root->rnode;
+ height = root->height;
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+
+ offset = 0; /* uninitialised var warning */
+ do {
+ if (slot == NULL) {
+ /* Have to add a child node. */
+ if (!(slot = radix_tree_node_alloc(root)))
+ return -ENOMEM;
+ if (node) {
+ node->slots[offset] = slot;
+ node->count++;
+ } else
+ root->rnode = slot;
+ }
+
+ /* Go a level down */
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ node = slot;
+ slot = node->slots[offset];
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ } while (height > 0);
+
+ if (slot != NULL)
+ return -EEXIST;
+
+ ASSERT(node);
+ node->count++;
+ node->slots[offset] = item;
+#ifdef RADIX_TREE_TAGS
+ ASSERT(!tag_get(node, 0, offset));
+ ASSERT(!tag_get(node, 1, offset));
+#endif
+ return 0;
+}
+
+static inline void **__lookup_slot(struct radix_tree_root *root,
+ unsigned long index)
+{
+ unsigned int height, shift;
+ struct radix_tree_node **slot;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ return NULL;
+
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ slot = &root->rnode;
+
+ while (height > 0) {
+ if (*slot == NULL)
+ return NULL;
+
+ slot = (struct radix_tree_node **)
+ ((*slot)->slots +
+ ((index >> shift) & RADIX_TREE_MAP_MASK));
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ return (void **)slot;
+}
+
+/**
+ * radix_tree_lookup_slot - lookup a slot in a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Lookup the slot corresponding to the position @index in the radix tree
+ * @root. This is useful for update-if-exists operations.
+ */
+void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index)
+{
+ return __lookup_slot(root, index);
+}
+
+/**
+ * radix_tree_lookup - perform lookup operation on a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Lookup the item at the position @index in the radix tree @root.
+ */
+void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
+{
+ void **slot;
+
+ slot = __lookup_slot(root, index);
+ return slot != NULL ? *slot : NULL;
+}
+
+/**
+ * raid_tree_first_key - find the first index key in the radix tree
+ * @root: radix tree root
+ * @index: where the first index will be placed
+ *
+ * Returns the first entry and index key in the radix tree @root.
+ */
+void *radix_tree_lookup_first(struct radix_tree_root *root, unsigned long *index)
+{
+ unsigned int height, shift;
+ struct radix_tree_node *slot;
+ unsigned long i;
+
+ height = root->height;
+ *index = 0;
+ if (height == 0)
+ return NULL;
+
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ slot = root->rnode;
+
+ for (; height > 1; height--) {
+ for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
+ if (slot->slots[i] != NULL)
+ break;
+ }
+ ASSERT(i < RADIX_TREE_MAP_SIZE);
+
+ *index |= (i << shift);
+ shift -= RADIX_TREE_MAP_SHIFT;
+ slot = slot->slots[i];
+ }
+ for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
+ if (slot->slots[i] != NULL) {
+ *index |= i;
+ return slot->slots[i];
+ }
+ }
+ return NULL;
+}
+
+#ifdef RADIX_TREE_TAGS
+
+/**
+ * radix_tree_tag_set - set a tag on a radix tree node
+ * @root: radix tree root
+ * @index: index key
+ * @tag: tag index
+ *
+ * Set the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ * corresponding to @index in the radix tree. From
+ * the root all the way down to the leaf node.
+ *
+ * Returns the address of the tagged item. Setting a tag on a not-present
+ * item is a bug.
+ */
+void *radix_tree_tag_set(struct radix_tree_root *root,
+ unsigned long index, unsigned int tag)
+{
+ unsigned int height, shift;
+ struct radix_tree_node *slot;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ return NULL;
+
+ shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ slot = root->rnode;
+
+ while (height > 0) {
+ int offset;
+
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ if (!tag_get(slot, tag, offset))
+ tag_set(slot, tag, offset);
+ slot = slot->slots[offset];
+ ASSERT(slot != NULL);
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ return slot;
+}
+
+/**
+ * radix_tree_tag_clear - clear a tag on a radix tree node
+ * @root: radix tree root
+ * @index: index key
+ * @tag: tag index
+ *
+ * Clear the search tag (which must be < RADIX_TREE_MAX_TAGS)
+ * corresponding to @index in the radix tree. If
+ * this causes the leaf node to have no tags set then clear the tag in the
+ * next-to-leaf node, etc.
+ *
+ * Returns the address of the tagged item on success, else NULL. ie:
+ * has the same return value and semantics as radix_tree_lookup().
+ */
+void *radix_tree_tag_clear(struct radix_tree_root *root,
+ unsigned long index, unsigned int tag)
+{
+ struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path;
+ struct radix_tree_node *slot;
+ unsigned int height, shift;
+ void *ret = NULL;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ goto out;
+
+ shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ pathp->node = NULL;
+ slot = root->rnode;
+
+ while (height > 0) {
+ int offset;
+
+ if (slot == NULL)
+ goto out;
+
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ pathp[1].offset = offset;
+ pathp[1].node = slot;
+ slot = slot->slots[offset];
+ pathp++;
+ shift -= RADIX_TREE_MAP_SHIFT;
+ height--;
+ }
+
+ ret = slot;
+ if (ret == NULL)
+ goto out;
+
+ do {
+ if (!tag_get(pathp->node, tag, pathp->offset))
+ goto out;
+ tag_clear(pathp->node, tag, pathp->offset);
+ if (any_tag_set(pathp->node, tag))
+ goto out;
+ pathp--;
+ } while (pathp->node);
+out:
+ return ret;
+}
+
+#endif
+
+static unsigned int
+__lookup(struct radix_tree_root *root, void **results, unsigned long index,
+ unsigned int max_items, unsigned long *next_index)
+{
+ unsigned int nr_found = 0;
+ unsigned int shift, height;
+ struct radix_tree_node *slot;
+ unsigned long i;
+
+ height = root->height;
+ if (height == 0)
+ goto out;
+
+ shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ slot = root->rnode;
+
+ for ( ; height > 1; height--) {
+
+ for (i = (index >> shift) & RADIX_TREE_MAP_MASK ;
+ i < RADIX_TREE_MAP_SIZE; i++) {
+ if (slot->slots[i] != NULL)
+ break;
+ index &= ~((1UL << shift) - 1);
+ index += 1UL << shift;
+ if (index == 0)
+ goto out; /* 32-bit wraparound */
+ }
+ if (i == RADIX_TREE_MAP_SIZE)
+ goto out;
+
+ shift -= RADIX_TREE_MAP_SHIFT;
+ slot = slot->slots[i];
+ }
+
+ /* Bottom level: grab some items */
+ for (i = index & RADIX_TREE_MAP_MASK; i < RADIX_TREE_MAP_SIZE; i++) {
+ index++;
+ if (slot->slots[i]) {
+ results[nr_found++] = slot->slots[i];
+ if (nr_found == max_items)
+ goto out;
+ }
+ }
+out:
+ *next_index = index;
+ return nr_found;
+}
+
+/**
+ * radix_tree_gang_lookup - perform multiple lookup on a radix tree
+ * @root: radix tree root
+ * @results: where the results of the lookup are placed
+ * @first_index: start the lookup from this key
+ * @max_items: place up to this many items at *results
+ *
+ * Performs an index-ascending scan of the tree for present items. Places
+ * them at *@results and returns the number of items which were placed at
+ * *@results.
+ *
+ * The implementation is naive.
+ */
+unsigned int
+radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
+ unsigned long first_index, unsigned int max_items)
+{
+ const unsigned long max_index = radix_tree_maxindex(root->height);
+ unsigned long cur_index = first_index;
+ unsigned int ret = 0;
+
+ while (ret < max_items) {
+ unsigned int nr_found;
+ unsigned long next_index; /* Index of next search */
+
+ if (cur_index > max_index)
+ break;
+ nr_found = __lookup(root, results + ret, cur_index,
+ max_items - ret, &next_index);
+ ret += nr_found;
+ if (next_index == 0)
+ break;
+ cur_index = next_index;
+ }
+ return ret;
+}
+
+/**
+ * radix_tree_gang_lookup_ex - perform multiple lookup on a radix tree
+ * @root: radix tree root
+ * @results: where the results of the lookup are placed
+ * @first_index: start the lookup from this key
+ * @last_index: don't lookup past this key
+ * @max_items: place up to this many items at *results
+ *
+ * Performs an index-ascending scan of the tree for present items starting
+ * @first_index until @last_index up to as many as @max_items. Places
+ * them at *@results and returns the number of items which were placed
+ * at *@results.
+ *
+ * The implementation is naive.
+ */
+unsigned int
+radix_tree_gang_lookup_ex(struct radix_tree_root *root, void **results,
+ unsigned long first_index, unsigned long last_index,
+ unsigned int max_items)
+{
+ const unsigned long max_index = radix_tree_maxindex(root->height);
+ unsigned long cur_index = first_index;
+ unsigned int ret = 0;
+
+ while (ret < max_items && cur_index < last_index) {
+ unsigned int nr_found;
+ unsigned long next_index; /* Index of next search */
+
+ if (cur_index > max_index)
+ break;
+ nr_found = __lookup(root, results + ret, cur_index,
+ max_items - ret, &next_index);
+ ret += nr_found;
+ if (next_index == 0)
+ break;
+ cur_index = next_index;
+ }
+ return ret;
+}
+
+#ifdef RADIX_TREE_TAGS
+
+static unsigned int
+__lookup_tag(struct radix_tree_root *root, void **results, unsigned long index,
+ unsigned int max_items, unsigned long *next_index, unsigned int tag)
+{
+ unsigned int nr_found = 0;
+ unsigned int shift;
+ unsigned int height = root->height;
+ struct radix_tree_node *slot;
+
+ shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ slot = root->rnode;
+
+ while (height > 0) {
+ unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK;
+
+ for ( ; i < RADIX_TREE_MAP_SIZE; i++) {
+ if (tag_get(slot, tag, i)) {
+ ASSERT(slot->slots[i] != NULL);
+ break;
+ }
+ index &= ~((1UL << shift) - 1);
+ index += 1UL << shift;
+ if (index == 0)
+ goto out; /* 32-bit wraparound */
+ }
+ if (i == RADIX_TREE_MAP_SIZE)
+ goto out;
+ height--;
+ if (height == 0) { /* Bottom level: grab some items */
+ unsigned long j = index & RADIX_TREE_MAP_MASK;
+
+ for ( ; j < RADIX_TREE_MAP_SIZE; j++) {
+ index++;
+ if (tag_get(slot, tag, j)) {
+ ASSERT(slot->slots[j] != NULL);
+ results[nr_found++] = slot->slots[j];
+ if (nr_found == max_items)
+ goto out;
+ }
+ }
+ }
+ shift -= RADIX_TREE_MAP_SHIFT;
+ slot = slot->slots[i];
+ }
+out:
+ *next_index = index;
+ return nr_found;
+}
+
+/**
+ * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree
+ * based on a tag
+ * @root: radix tree root
+ * @results: where the results of the lookup are placed
+ * @first_index: start the lookup from this key
+ * @max_items: place up to this many items at *results
+ * @tag: the tag index (< RADIX_TREE_MAX_TAGS)
+ *
+ * Performs an index-ascending scan of the tree for present items which
+ * have the tag indexed by @tag set. Places the items at *@results and
+ * returns the number of items which were placed at *@results.
+ */
+unsigned int
+radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
+ unsigned long first_index, unsigned int max_items,
+ unsigned int tag)
+{
+ const unsigned long max_index = radix_tree_maxindex(root->height);
+ unsigned long cur_index = first_index;
+ unsigned int ret = 0;
+
+ while (ret < max_items) {
+ unsigned int nr_found;
+ unsigned long next_index; /* Index of next search */
+
+ if (cur_index > max_index)
+ break;
+ nr_found = __lookup_tag(root, results + ret, cur_index,
+ max_items - ret, &next_index, tag);
+ ret += nr_found;
+ if (next_index == 0)
+ break;
+ cur_index = next_index;
+ }
+ return ret;
+}
+
+#endif
+
+/**
+ * radix_tree_shrink - shrink height of a radix tree to minimal
+ * @root radix tree root
+ */
+static inline void radix_tree_shrink(struct radix_tree_root *root)
+{
+ /* try to shrink tree height */
+ while (root->height > 1 &&
+ root->rnode->count == 1 &&
+ root->rnode->slots[0]) {
+ struct radix_tree_node *to_free = root->rnode;
+
+ root->rnode = to_free->slots[0];
+ root->height--;
+ /* must only free zeroed nodes into the slab */
+#ifdef RADIX_TREE_TAGS
+ tag_clear(to_free, 0, 0);
+ tag_clear(to_free, 1, 0);
+#endif
+ to_free->slots[0] = NULL;
+ to_free->count = 0;
+ radix_tree_node_free(to_free);
+ }
+}
+
+/**
+ * radix_tree_delete - delete an item from a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Remove the item at @index from the radix tree rooted at @root.
+ *
+ * Returns the address of the deleted item, or NULL if it was not present.
+ */
+void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+{
+ struct radix_tree_path path[RADIX_TREE_MAX_PATH + 1], *pathp = path;
+ struct radix_tree_path *orig_pathp;
+ struct radix_tree_node *slot;
+ unsigned int height, shift;
+ void *ret = NULL;
+#ifdef RADIX_TREE_TAGS
+ char tags[RADIX_TREE_MAX_TAGS];
+ int nr_cleared_tags;
+ int tag;
+#endif
+ int offset;
+
+ height = root->height;
+ if (index > radix_tree_maxindex(height))
+ goto out;
+
+ shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ pathp->node = NULL;
+ slot = root->rnode;
+
+ for ( ; height > 0; height--) {
+ if (slot == NULL)
+ goto out;
+
+ pathp++;
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ pathp->offset = offset;
+ pathp->node = slot;
+ slot = slot->slots[offset];
+ shift -= RADIX_TREE_MAP_SHIFT;
+ }
+
+ ret = slot;
+ if (ret == NULL)
+ goto out;
+
+ orig_pathp = pathp;
+
+#ifdef RADIX_TREE_TAGS
+ /*
+ * Clear all tags associated with the just-deleted item
+ */
+ nr_cleared_tags = 0;
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
+ tags[tag] = 1;
+ if (tag_get(pathp->node, tag, pathp->offset)) {
+ tag_clear(pathp->node, tag, pathp->offset);
+ if (!any_tag_set(pathp->node, tag)) {
+ tags[tag] = 0;
+ nr_cleared_tags++;
+ }
+ }
+ }
+
+ for (pathp--; nr_cleared_tags && pathp->node; pathp--) {
+ for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
+ if (tags[tag])
+ continue;
+
+ tag_clear(pathp->node, tag, pathp->offset);
+ if (any_tag_set(pathp->node, tag)) {
+ tags[tag] = 1;
+ nr_cleared_tags--;
+ }
+ }
+ }
+#endif
+ /* Now free the nodes we do not need anymore */
+ for (pathp = orig_pathp; pathp->node; pathp--) {
+ pathp->node->slots[pathp->offset] = NULL;
+ pathp->node->count--;
+
+ if (pathp->node->count) {
+ if (pathp->node == root->rnode)
+ radix_tree_shrink(root);
+ goto out;
+ }
+
+ /* Node with zero slots in use so free it */
+ radix_tree_node_free(pathp->node);
+ }
+ root->rnode = NULL;
+ root->height = 0;
+out:
+ return ret;
+}
+
+#ifdef RADIX_TREE_TAGS
+/**
+ * radix_tree_tagged - test whether any items in the tree are tagged
+ * @root: radix tree root
+ * @tag: tag to test
+ */
+int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag)
+{
+ struct radix_tree_node *rnode;
+ rnode = root->rnode;
+ if (!rnode)
+ return 0;
+ return any_tag_set(rnode, tag);
+}
+#endif
+
+static unsigned long __maxindex(unsigned int height)
+{
+ unsigned int tmp = height * RADIX_TREE_MAP_SHIFT;
+ unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1;
+
+ if (tmp >= RADIX_TREE_INDEX_BITS)
+ index = ~0UL;
+ return index;
+}
+
+static void radix_tree_init_maxindex(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++)
+ height_to_maxindex[i] = __maxindex(i);
+}
+
+void radix_tree_init(void)
+{
+ radix_tree_init_maxindex();
+}