/*
* Copyright (c) 2014, Cisco Systems, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/list_sort.h>
#include <linux/interval_tree_generic.h>
#include "usnic_uiom_interval_tree.h"
#define START(node) ((node)->start)
#define LAST(node) ((node)->last)
#define MAKE_NODE(node, start, end, ref_cnt, flags, err, err_out) \
do { \
node = usnic_uiom_interval_node_alloc(start, \
end, ref_cnt, flags); \
if (!node) { \
err = -ENOMEM; \
goto err_out; \
} \
} while (0)
#define MARK_FOR_ADD(node, list) (list_add_tail(&node->link, list))
#define MAKE_NODE_AND_APPEND(node, start, end, ref_cnt, flags, err, \
err_out, list) \
do { \
MAKE_NODE(node, start, end, \
ref_cnt, flags, err, \
err_out); \
MARK_FOR_ADD(node, list); \
} while (0)
#define FLAGS_EQUAL(flags1, flags2, mask) \
(((flags1) & (mask)) == ((flags2) & (mask)))
static struct usnic_uiom_interval_node*
usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt,
int flags)
{
struct usnic_uiom_interval_node *interval = kzalloc(sizeof(*interval),
GFP_ATOMIC);
if (!interval)
return NULL;
interval->start = start;
interval->last = last;
interval->flags = flags;
interval->ref_cnt = ref_cnt;
return interval;
}
static int interval_cmp(void *priv, const struct list_head *a,
const struct list_head *b)
{
struct usnic_uiom_interval_node *node_a, *node_b;
node_a = list_entry(a, struct usnic_uiom_interval_node, link);
node_b = list_entry(b, struct usnic_uiom_interval_node, link);
/* long to int */
if (node_a->start < node_b->start)
return -1;
else if (node_a->start > node_b->start)
return 1;
return 0;
}
static void
find_intervals_intersection_sorted(struct rb_root_cached *root,
unsigned long start, unsigned long last,
struct list_head *list)
{
struct usnic_uiom_interval_node *node;
INIT_LIST_HEAD(list);
for (node = usnic_uiom_interval_tree_iter_first(root, start, last);
node;
node = usnic_uiom_interval_tree_iter_next(node, start, last))
list_add_tail(&node->link, list);
list_sort(NULL, list, interval_cmp);
}
int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
int flags, int flag_mask,
struct rb_root_cached *root,
struct list_head *diff_set)
{
struct usnic_uiom_interval_node *interval, *tmp;
int err = 0;
long int pivot = start;
LIST_HEAD(intersection_set);
INIT_LIST_HEAD(diff_set);
find_intervals_intersection_sorted(root, start, last,
&intersection_set);
list_for_each_entry(interval, &intersection_set, link) {
if (pivot < interval->start) {
MAKE_NODE_AND_APPEND(tmp, pivot, interval->start - 1,
1, flags, err, err_out,
diff_set);
pivot = interval->start;
}
/*
* Invariant: Set [start, pivot] is either in diff_set or root,
* but not in both.
*/
if (pivot > interval->last) {
continue;
} else if (pivot <= interval->last &&
FLAGS_EQUAL(interval->flags, flags,
flag_mask)) {
pivot = interval->last + 1;
}
}
if (pivot <= last)
MAKE_NODE_AND_APPEND(tmp, pivot, last, 1, flags, err, err_out,
diff_set);
return 0;
err_out:
list_for_each_entry_safe(interval, tmp, diff_set, link) {
list_del(&interval->link);
kfree(interval);
}
return err;
}
void usnic_uiom_put_interval_set(struct list_head *intervals)
{
struct usnic_uiom_interval_node *interval, *tmp;
list_for_each_entry_safe(interval, tmp, intervals, link)
kfree(interval);
}
int usnic_uiom_insert_interval(struct rb_root_cached *root, unsigned long start,
unsigned long last, int flags)
{
struct usnic_uiom_interval_node *interval, *tmp;
unsigned long istart, ilast;
int iref_cnt, iflags;
unsigned long lpivot = start;
int err = 0;
LIST_HEAD(to_add);
LIST_HEAD(intersection_set);
find_intervals_intersection_sorted(root, start, last,
&intersection_set);
list_for_each_entry(interval, &intersection_set, link) {
/*
* Invariant - lpivot is the left edge of next interval to be
* inserted
*/
istart = interval->start;
ilast = interval->last;
iref_cnt = interval->ref_cnt;
iflags = interval->flags;
if (istart < lpivot) {
MAKE_NODE_AND_APPEND(tmp, istart, lpivot - 1, iref_cnt,
iflags, err, err_out, &to_add);
} else if (istart > lpivot) {
MAKE_NODE_AND_APPEND(tmp, lpivot, istart - 1, 1, flags,
err, err_out, &to_add);
lpivot = istart;
} else {
lpivot = istart;
}
if (ilast > last) {
MAKE_NODE_AND_APPEND(tmp, lpivot, last, iref_cnt + 1,
iflags | flags, err, err_out,
&to_add);
MAKE_NODE_AND_APPEND(tmp, last + 1, ilast, iref_cnt,
iflags, err, err_out, &to_add);
} else {
MAKE_NODE_AND_APPEND(tmp, lpivot, ilast, iref_cnt + 1,
iflags | flags, err, err_out,
&to_add);
}
lpivot = ilast + 1;
}
if (lpivot <= last)
MAKE_NODE_AND_APPEND(tmp, lpivot, last, 1, flags, err, err_out,
&to_add);
list_for_each_entry_safe(interval, tmp, &intersection_set, link) {
usnic_uiom_interval_tree_remove(interval, root);
kfree(interval);
}
list_for_each_entry(interval, &to_add, link)
usnic_uiom_interval_tree_insert(interval, root);
return 0;
err_out:
list_for_each_entry_safe(interval, tmp, &to_add, link)
kfree(interval);
return err;
}
void usnic_uiom_remove_interval(struct rb_root_cached *root,
unsigned long start, unsigned long last,
struct list_head *removed)
{
struct usnic_uiom_interval_node *interval;
for (interval = usnic_uiom_interval_tree_iter_first(root, start, last);
interval;
interval = usnic_uiom_interval_tree_iter_next(interval,
start,
last)) {
if (--interval->ref_cnt == 0)
list_add_tail(&interval->link, removed);
}
list_for_each_entry(interval, removed, link)
usnic_uiom_interval_tree_remove(interval, root);
}
INTERVAL_TREE_DEFINE(struct usnic_uiom_interval_node, rb,
unsigned long, __subtree_last,
START, LAST, , usnic_uiom_interval_tree)
Codebase Browser
linux