1 /*
2 * Copyright (c) 2014, Cisco Systems, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33
34 #include <linux/init.h>
35 #include <linux/list.h>
36 #include <linux/slab.h>
37 #include <linux/list_sort.h>
38
39 #include <linux/interval_tree_generic.h>
40 #include "usnic_uiom_interval_tree.h"
41
42 #define START(node) ((node)->start)
43 #define LAST(node) ((node)->last)
44
45 #define MAKE_NODE(node, start, end, ref_cnt, flags, err, err_out) \
46 do { \
47 node = usnic_uiom_interval_node_alloc(start, \
48 end, ref_cnt, flags); \
49 if (!node) { \
50 err = -ENOMEM; \
51 goto err_out; \
52 } \
53 } while (0)
54
55 #define MARK_FOR_ADD(node, list) (list_add_tail(&node->link, list))
56
57 #define MAKE_NODE_AND_APPEND(node, start, end, ref_cnt, flags, err, \
58 err_out, list) \
59 do { \
60 MAKE_NODE(node, start, end, \
61 ref_cnt, flags, err, \
62 err_out); \
63 MARK_FOR_ADD(node, list); \
64 } while (0)
65
66 #define FLAGS_EQUAL(flags1, flags2, mask) \
67 (((flags1) & (mask)) == ((flags2) & (mask)))
68
69 static struct usnic_uiom_interval_node*
usnic_uiom_interval_node_alloc(long int start,long int last,int ref_cnt,int flags)70 usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt,
71 int flags)
72 {
73 struct usnic_uiom_interval_node *interval = kzalloc(sizeof(*interval),
74 GFP_ATOMIC);
75 if (!interval)
76 return NULL;
77
78 interval->start = start;
79 interval->last = last;
80 interval->flags = flags;
81 interval->ref_cnt = ref_cnt;
82
83 return interval;
84 }
85
interval_cmp(void * priv,const struct list_head * a,const struct list_head * b)86 static int interval_cmp(void *priv, const struct list_head *a,
87 const struct list_head *b)
88 {
89 struct usnic_uiom_interval_node *node_a, *node_b;
90
91 node_a = list_entry(a, struct usnic_uiom_interval_node, link);
92 node_b = list_entry(b, struct usnic_uiom_interval_node, link);
93
94 /* long to int */
95 if (node_a->start < node_b->start)
96 return -1;
97 else if (node_a->start > node_b->start)
98 return 1;
99
100 return 0;
101 }
102
103 static void
find_intervals_intersection_sorted(struct rb_root_cached * root,unsigned long start,unsigned long last,struct list_head * list)104 find_intervals_intersection_sorted(struct rb_root_cached *root,
105 unsigned long start, unsigned long last,
106 struct list_head *list)
107 {
108 struct usnic_uiom_interval_node *node;
109
110 INIT_LIST_HEAD(list);
111
112 for (node = usnic_uiom_interval_tree_iter_first(root, start, last);
113 node;
114 node = usnic_uiom_interval_tree_iter_next(node, start, last))
115 list_add_tail(&node->link, list);
116
117 list_sort(NULL, list, interval_cmp);
118 }
119
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)120 int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
121 int flags, int flag_mask,
122 struct rb_root_cached *root,
123 struct list_head *diff_set)
124 {
125 struct usnic_uiom_interval_node *interval, *tmp;
126 int err = 0;
127 long int pivot = start;
128 LIST_HEAD(intersection_set);
129
130 INIT_LIST_HEAD(diff_set);
131
132 find_intervals_intersection_sorted(root, start, last,
133 &intersection_set);
134
135 list_for_each_entry(interval, &intersection_set, link) {
136 if (pivot < interval->start) {
137 MAKE_NODE_AND_APPEND(tmp, pivot, interval->start - 1,
138 1, flags, err, err_out,
139 diff_set);
140 pivot = interval->start;
141 }
142
143 /*
144 * Invariant: Set [start, pivot] is either in diff_set or root,
145 * but not in both.
146 */
147
148 if (pivot > interval->last) {
149 continue;
150 } else if (pivot <= interval->last &&
151 FLAGS_EQUAL(interval->flags, flags,
152 flag_mask)) {
153 pivot = interval->last + 1;
154 }
155 }
156
157 if (pivot <= last)
158 MAKE_NODE_AND_APPEND(tmp, pivot, last, 1, flags, err, err_out,
159 diff_set);
160
161 return 0;
162
163 err_out:
164 list_for_each_entry_safe(interval, tmp, diff_set, link) {
165 list_del(&interval->link);
166 kfree(interval);
167 }
168
169 return err;
170 }
171
usnic_uiom_put_interval_set(struct list_head * intervals)172 void usnic_uiom_put_interval_set(struct list_head *intervals)
173 {
174 struct usnic_uiom_interval_node *interval, *tmp;
175 list_for_each_entry_safe(interval, tmp, intervals, link)
176 kfree(interval);
177 }
178
usnic_uiom_insert_interval(struct rb_root_cached * root,unsigned long start,unsigned long last,int flags)179 int usnic_uiom_insert_interval(struct rb_root_cached *root, unsigned long start,
180 unsigned long last, int flags)
181 {
182 struct usnic_uiom_interval_node *interval, *tmp;
183 unsigned long istart, ilast;
184 int iref_cnt, iflags;
185 unsigned long lpivot = start;
186 int err = 0;
187 LIST_HEAD(to_add);
188 LIST_HEAD(intersection_set);
189
190 find_intervals_intersection_sorted(root, start, last,
191 &intersection_set);
192
193 list_for_each_entry(interval, &intersection_set, link) {
194 /*
195 * Invariant - lpivot is the left edge of next interval to be
196 * inserted
197 */
198 istart = interval->start;
199 ilast = interval->last;
200 iref_cnt = interval->ref_cnt;
201 iflags = interval->flags;
202
203 if (istart < lpivot) {
204 MAKE_NODE_AND_APPEND(tmp, istart, lpivot - 1, iref_cnt,
205 iflags, err, err_out, &to_add);
206 } else if (istart > lpivot) {
207 MAKE_NODE_AND_APPEND(tmp, lpivot, istart - 1, 1, flags,
208 err, err_out, &to_add);
209 lpivot = istart;
210 } else {
211 lpivot = istart;
212 }
213
214 if (ilast > last) {
215 MAKE_NODE_AND_APPEND(tmp, lpivot, last, iref_cnt + 1,
216 iflags | flags, err, err_out,
217 &to_add);
218 MAKE_NODE_AND_APPEND(tmp, last + 1, ilast, iref_cnt,
219 iflags, err, err_out, &to_add);
220 } else {
221 MAKE_NODE_AND_APPEND(tmp, lpivot, ilast, iref_cnt + 1,
222 iflags | flags, err, err_out,
223 &to_add);
224 }
225
226 lpivot = ilast + 1;
227 }
228
229 if (lpivot <= last)
230 MAKE_NODE_AND_APPEND(tmp, lpivot, last, 1, flags, err, err_out,
231 &to_add);
232
233 list_for_each_entry_safe(interval, tmp, &intersection_set, link) {
234 usnic_uiom_interval_tree_remove(interval, root);
235 kfree(interval);
236 }
237
238 list_for_each_entry(interval, &to_add, link)
239 usnic_uiom_interval_tree_insert(interval, root);
240
241 return 0;
242
243 err_out:
244 list_for_each_entry_safe(interval, tmp, &to_add, link)
245 kfree(interval);
246
247 return err;
248 }
249
usnic_uiom_remove_interval(struct rb_root_cached * root,unsigned long start,unsigned long last,struct list_head * removed)250 void usnic_uiom_remove_interval(struct rb_root_cached *root,
251 unsigned long start, unsigned long last,
252 struct list_head *removed)
253 {
254 struct usnic_uiom_interval_node *interval;
255
256 for (interval = usnic_uiom_interval_tree_iter_first(root, start, last);
257 interval;
258 interval = usnic_uiom_interval_tree_iter_next(interval,
259 start,
260 last)) {
261 if (--interval->ref_cnt == 0)
262 list_add_tail(&interval->link, removed);
263 }
264
265 list_for_each_entry(interval, removed, link)
266 usnic_uiom_interval_tree_remove(interval, root);
267 }
268
269 INTERVAL_TREE_DEFINE(struct usnic_uiom_interval_node, rb,
270 unsigned long, __subtree_last,
271 START, LAST, , usnic_uiom_interval_tree)
272