lib: Uplevel the pmem "region" ida to a global allocator
[linux-2.6-microblaze.git] / net / rds / transport.c
1 /*
2  * Copyright (c) 2006, 2017 Oracle and/or its affiliates. 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 #include <linux/ipv6.h>
37
38 #include "rds.h"
39 #include "loop.h"
40
41 static struct rds_transport *transports[RDS_TRANS_COUNT];
42 static DECLARE_RWSEM(rds_trans_sem);
43
44 void rds_trans_register(struct rds_transport *trans)
45 {
46         BUG_ON(strlen(trans->t_name) + 1 > TRANSNAMSIZ);
47
48         down_write(&rds_trans_sem);
49
50         if (transports[trans->t_type])
51                 printk(KERN_ERR "RDS Transport type %d already registered\n",
52                         trans->t_type);
53         else {
54                 transports[trans->t_type] = trans;
55                 printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
56         }
57
58         up_write(&rds_trans_sem);
59 }
60 EXPORT_SYMBOL_GPL(rds_trans_register);
61
62 void rds_trans_unregister(struct rds_transport *trans)
63 {
64         down_write(&rds_trans_sem);
65
66         transports[trans->t_type] = NULL;
67         printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
68
69         up_write(&rds_trans_sem);
70 }
71 EXPORT_SYMBOL_GPL(rds_trans_unregister);
72
73 void rds_trans_put(struct rds_transport *trans)
74 {
75         if (trans)
76                 module_put(trans->t_owner);
77 }
78
79 struct rds_transport *rds_trans_get_preferred(struct net *net,
80                                               const struct in6_addr *addr,
81                                               __u32 scope_id)
82 {
83         struct rds_transport *ret = NULL;
84         struct rds_transport *trans;
85         unsigned int i;
86
87         if (ipv6_addr_v4mapped(addr)) {
88                 if (*(u_int8_t *)&addr->s6_addr32[3] == IN_LOOPBACKNET)
89                         return &rds_loop_transport;
90         } else if (ipv6_addr_loopback(addr)) {
91                 return &rds_loop_transport;
92         }
93
94         down_read(&rds_trans_sem);
95         for (i = 0; i < RDS_TRANS_COUNT; i++) {
96                 trans = transports[i];
97
98                 if (trans && (trans->laddr_check(net, addr, scope_id) == 0) &&
99                     (!trans->t_owner || try_module_get(trans->t_owner))) {
100                         ret = trans;
101                         break;
102                 }
103         }
104         up_read(&rds_trans_sem);
105
106         return ret;
107 }
108
109 struct rds_transport *rds_trans_get(int t_type)
110 {
111         struct rds_transport *ret = NULL;
112         struct rds_transport *trans;
113         unsigned int i;
114
115         down_read(&rds_trans_sem);
116         for (i = 0; i < RDS_TRANS_COUNT; i++) {
117                 trans = transports[i];
118
119                 if (trans && trans->t_type == t_type &&
120                     (!trans->t_owner || try_module_get(trans->t_owner))) {
121                         ret = trans;
122                         break;
123                 }
124         }
125         up_read(&rds_trans_sem);
126
127         return ret;
128 }
129
130 /*
131  * This returns the number of stats entries in the snapshot and only
132  * copies them using the iter if there is enough space for them.  The
133  * caller passes in the global stats so that we can size and copy while
134  * holding the lock.
135  */
136 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
137                                        unsigned int avail)
138
139 {
140         struct rds_transport *trans;
141         unsigned int total = 0;
142         unsigned int part;
143         int i;
144
145         rds_info_iter_unmap(iter);
146         down_read(&rds_trans_sem);
147
148         for (i = 0; i < RDS_TRANS_COUNT; i++) {
149                 trans = transports[i];
150                 if (!trans || !trans->stats_info_copy)
151                         continue;
152
153                 part = trans->stats_info_copy(iter, avail);
154                 avail -= min(avail, part);
155                 total += part;
156         }
157
158         up_read(&rds_trans_sem);
159
160         return total;
161 }