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/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013-2018 Mellanox Technologies, Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* $FreeBSD: head/sys/compat/linuxkpi/common/src/linux_radix.c 334483 2018-06-01 11:42:09Z hselasky $ */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <linux/radix-tree.h>
#define M_RADIX M_DRM
static inline unsigned long
radix_max(struct radix_tree_root *root)
{
return ((1UL << (root->height * RADIX_TREE_MAP_SHIFT)) - 1UL);
}
static inline int
radix_pos(long id, int height)
{
return (id >> (RADIX_TREE_MAP_SHIFT * height)) & RADIX_TREE_MAP_MASK;
}
void *
radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
{
struct radix_tree_node *node;
void *item;
int height;
item = NULL;
node = root->rnode;
height = root->height - 1;
if (index > radix_max(root))
goto out;
while (height && node)
node = node->slots[radix_pos(index, height--)];
if (node)
item = node->slots[radix_pos(index, 0)];
out:
return (item);
}
bool
radix_tree_iter_find(struct radix_tree_root *root, struct radix_tree_iter *iter,
void ***pppslot)
{
struct radix_tree_node *node;
unsigned long index = iter->index;
int height;
restart:
node = root->rnode;
if (node == NULL)
return (false);
height = root->height - 1;
if (height == -1 || index > radix_max(root))
return (false);
do {
unsigned long mask = RADIX_TREE_MAP_MASK << (RADIX_TREE_MAP_SHIFT * height);
unsigned long step = 1UL << (RADIX_TREE_MAP_SHIFT * height);
int pos = radix_pos(index, height);
struct radix_tree_node *next;
/* track last slot */
*pppslot = node->slots + pos;
next = node->slots[pos];
if (next == NULL) {
index += step;
index &= -step;
if ((index & mask) == 0)
goto restart;
} else {
node = next;
height--;
}
} while (height != -1);
iter->index = index;
return (true);
}
void *
radix_tree_delete(struct radix_tree_root *root, unsigned long index)
{
struct radix_tree_node *stack[RADIX_TREE_MAX_HEIGHT];
struct radix_tree_node *node;
void *item;
int height;
int idx;
item = NULL;
node = root->rnode;
height = root->height - 1;
if (index > radix_max(root))
goto out;
/*
* Find the node and record the path in stack.
*/
while (height && node) {
stack[height] = node;
node = node->slots[radix_pos(index, height--)];
}
idx = radix_pos(index, 0);
if (node)
item = node->slots[idx];
/*
* If we removed something reduce the height of the tree.
*/
if (item)
for (;;) {
node->slots[idx] = NULL;
node->count--;
if (node->count > 0)
break;
free(node, M_RADIX, sizeof(*node));
if (node == root->rnode) {
root->rnode = NULL;
root->height = 0;
break;
}
height++;
node = stack[height];
idx = radix_pos(index, height);
}
out:
return (item);
}
void
radix_tree_iter_delete(struct radix_tree_root *root,
struct radix_tree_iter *iter, void **slot)
{
radix_tree_delete(root, iter->index);
}
int
radix_tree_insert(struct radix_tree_root *root, unsigned long index, void *item)
{
struct radix_tree_node *node;
struct radix_tree_node *temp[RADIX_TREE_MAX_HEIGHT - 1];
int height;
int idx;
/* bail out upon insertion of a NULL item */
if (item == NULL)
return (-EINVAL);
/* get root node, if any */
node = root->rnode;
/* allocate root node, if any */
if (node == NULL) {
node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO);
if (node == NULL)
return (-ENOMEM);
root->rnode = node;
root->height++;
}
/* expand radix tree as needed */
while (radix_max(root) < index) {
/* check if the radix tree is getting too big */
if (root->height == RADIX_TREE_MAX_HEIGHT)
return (-E2BIG);
/*
* If the root radix level is not empty, we need to
* allocate a new radix level:
*/
if (node->count != 0) {
node = malloc(sizeof(*node), M_RADIX, root->gfp_mask | M_ZERO);
if (node == NULL)
return (-ENOMEM);
node->slots[0] = root->rnode;
node->count++;
root->rnode = node;
}
root->height++;
}
/* get radix tree height index */
height = root->height - 1;
/* walk down the tree until the first missing node, if any */
for ( ; height != 0; height--) {
idx = radix_pos(index, height);
if (node->slots[idx] == NULL)
break;
node = node->slots[idx];
}
/* allocate the missing radix levels, if any */
for (idx = 0; idx != height; idx++) {
temp[idx] = malloc(sizeof(*node), M_RADIX,
root->gfp_mask | M_ZERO);
if (temp[idx] == NULL) {
while(idx--)
free(temp[idx], M_RADIX, sizeof(*node));
/* Check if we should free the root node as well. */
if (root->rnode->count == 0) {
free(root->rnode, M_RADIX, sizeof(*root->rnode));
root->rnode = NULL;
root->height = 0;
}
return (-ENOMEM);
}
}
/* setup new radix levels, if any */
for ( ; height != 0; height--) {
idx = radix_pos(index, height);
node->slots[idx] = temp[height - 1];
node->count++;
node = node->slots[idx];
}
/*
* Insert and adjust count if the item does not already exist.
*/
idx = radix_pos(index, 0);
if (node->slots[idx])
return (-EEXIST);
node->slots[idx] = item;
node->count++;
return (0);
}
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