summaryrefslogtreecommitdiff
path: root/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
blob: 42b4b4c4e452eae8b712fb0ef295f304a7ab7492 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/*
 * 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, struct list_head *a, 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 *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 *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 *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 *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)