1 /*
2 * Copyright (c) 2006 Oracle. 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 * OpenIB.org 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 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/in.h>
36
37 #include "rds.h"
38 #include "loop.h"
39
40 static struct rds_transport *transports[RDS_TRANS_COUNT];
41 static DECLARE_RWSEM(rds_trans_sem);
42
rds_trans_register(struct rds_transport * trans)43 int rds_trans_register(struct rds_transport *trans)
44 {
45 BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ);
46
47 down_write(&rds_trans_sem);
48
49 if (transports[trans->t_type])
50 printk(KERN_ERR "RDS Transport type %d already registered\n",
51 trans->t_type);
52 else {
53 transports[trans->t_type] = trans;
54 printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
55 }
56
57 up_write(&rds_trans_sem);
58
59 return 0;
60 }
61 EXPORT_SYMBOL_GPL(rds_trans_register);
62
rds_trans_unregister(struct rds_transport * trans)63 void rds_trans_unregister(struct rds_transport *trans)
64 {
65 down_write(&rds_trans_sem);
66
67 transports[trans->t_type] = NULL;
68 printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
69
70 up_write(&rds_trans_sem);
71 }
72 EXPORT_SYMBOL_GPL(rds_trans_unregister);
73
rds_trans_put(struct rds_transport * trans)74 void rds_trans_put(struct rds_transport *trans)
75 {
76 if (trans && trans->t_owner)
77 module_put(trans->t_owner);
78 }
79
rds_trans_get_preferred(__be32 addr)80 struct rds_transport *rds_trans_get_preferred(__be32 addr)
81 {
82 struct rds_transport *ret = NULL;
83 struct rds_transport *trans;
84 unsigned int i;
85
86 if (IN_LOOPBACK(ntohl(addr)))
87 return &rds_loop_transport;
88
89 down_read(&rds_trans_sem);
90 for (i = 0; i < RDS_TRANS_COUNT; i++) {
91 trans = transports[i];
92
93 if (trans && (trans->laddr_check(addr) == 0) &&
94 (!trans->t_owner || try_module_get(trans->t_owner))) {
95 ret = trans;
96 break;
97 }
98 }
99 up_read(&rds_trans_sem);
100
101 return ret;
102 }
103
104 /*
105 * This returns the number of stats entries in the snapshot and only
106 * copies them using the iter if there is enough space for them. The
107 * caller passes in the global stats so that we can size and copy while
108 * holding the lock.
109 */
rds_trans_stats_info_copy(struct rds_info_iterator * iter,unsigned int avail)110 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
111 unsigned int avail)
112
113 {
114 struct rds_transport *trans;
115 unsigned int total = 0;
116 unsigned int part;
117 int i;
118
119 rds_info_iter_unmap(iter);
120 down_read(&rds_trans_sem);
121
122 for (i = 0; i < RDS_TRANS_COUNT; i++)
123 {
124 trans = transports[i];
125 if (!trans || !trans->stats_info_copy)
126 continue;
127
128 part = trans->stats_info_copy(iter, avail);
129 avail -= min(avail, part);
130 total += part;
131 }
132
133 up_read(&rds_trans_sem);
134
135 return total;
136 }
137
138