1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
3  *
4  * Copyright (c) 2014 Mellanox Technologies. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  */
34 
35 #include <sys/cdefs.h>
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/sched.h>
39 #include <linux/gfp.h>
40 #include <rdma/ib_umem_odp.h>
41 
42 /*
43  * The ib_umem list keeps track of memory regions for which the HW
44  * device request to receive notification when the related memory
45  * mapping is changed.
46  *
47  * ib_umem_lock protects the list.
48  */
49 
50 static inline u64 node_start(struct umem_odp_node *n)
51 {
52 	struct ib_umem_odp *umem_odp =
53 			container_of(n, struct ib_umem_odp, interval_tree);
54 
55 	return ib_umem_start(umem_odp->umem);
56 }
57 
58 /* Note that the representation of the intervals in the interval tree
59  * considers the ending point as contained in the interval, while the
60  * function ib_umem_end returns the first address which is not contained
61  * in the umem.
62  */
63 static inline u64 node_last(struct umem_odp_node *n)
64 {
65 	struct ib_umem_odp *umem_odp =
66 			container_of(n, struct ib_umem_odp, interval_tree);
67 
68 	return ib_umem_end(umem_odp->umem) - 1;
69 }
70 
71 INTERVAL_TREE_DEFINE(struct umem_odp_node, rb, u64, __subtree_last,
72 		     node_start, node_last, , rbt_ib_umem)
73 
74 /* @last is not a part of the interval. See comment for function
75  * node_last.
76  */
77 int rbt_ib_umem_for_each_in_range(struct rb_root *root,
78 				  u64 start, u64 last,
79 				  umem_call_back cb,
80 				  void *cookie)
81 {
82 	int ret_val = 0;
83 	struct umem_odp_node *node;
84 	struct ib_umem_odp *umem;
85 
86 	if (unlikely(start == last))
87 		return ret_val;
88 
89 	for (node = rbt_ib_umem_iter_first(root, start, last - 1); node;
90 			node = rbt_ib_umem_iter_next(node, start, last - 1)) {
91 		umem = container_of(node, struct ib_umem_odp, interval_tree);
92 		ret_val = cb(umem->umem, start, last, cookie) || ret_val;
93 	}
94 
95 	return ret_val;
96 }
97