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 43 void 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 EXPORT_SYMBOL_GPL(rds_trans_register); 60 61 void rds_trans_unregister(struct rds_transport *trans) 62 { 63 down_write(&rds_trans_sem); 64 65 transports[trans->t_type] = NULL; 66 printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name); 67 68 up_write(&rds_trans_sem); 69 } 70 EXPORT_SYMBOL_GPL(rds_trans_unregister); 71 72 void rds_trans_put(struct rds_transport *trans) 73 { 74 if (trans) 75 module_put(trans->t_owner); 76 } 77 78 struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr) 79 { 80 struct rds_transport *ret = NULL; 81 struct rds_transport *trans; 82 unsigned int i; 83 84 if (IN_LOOPBACK(ntohl(addr))) 85 return &rds_loop_transport; 86 87 down_read(&rds_trans_sem); 88 for (i = 0; i < RDS_TRANS_COUNT; i++) { 89 trans = transports[i]; 90 91 if (trans && (trans->laddr_check(net, addr) == 0) && 92 (!trans->t_owner || try_module_get(trans->t_owner))) { 93 ret = trans; 94 break; 95 } 96 } 97 up_read(&rds_trans_sem); 98 99 return ret; 100 } 101 102 struct rds_transport *rds_trans_get(int t_type) 103 { 104 struct rds_transport *ret = NULL; 105 struct rds_transport *trans; 106 unsigned int i; 107 108 down_read(&rds_trans_sem); 109 for (i = 0; i < RDS_TRANS_COUNT; i++) { 110 trans = transports[i]; 111 112 if (trans && trans->t_type == t_type && 113 (!trans->t_owner || try_module_get(trans->t_owner))) { 114 ret = trans; 115 break; 116 } 117 } 118 up_read(&rds_trans_sem); 119 120 return ret; 121 } 122 123 /* 124 * This returns the number of stats entries in the snapshot and only 125 * copies them using the iter if there is enough space for them. The 126 * caller passes in the global stats so that we can size and copy while 127 * holding the lock. 128 */ 129 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter, 130 unsigned int avail) 131 132 { 133 struct rds_transport *trans; 134 unsigned int total = 0; 135 unsigned int part; 136 int i; 137 138 rds_info_iter_unmap(iter); 139 down_read(&rds_trans_sem); 140 141 for (i = 0; i < RDS_TRANS_COUNT; i++) { 142 trans = transports[i]; 143 if (!trans || !trans->stats_info_copy) 144 continue; 145 146 part = trans->stats_info_copy(iter, avail); 147 avail -= min(avail, part); 148 total += part; 149 } 150 151 up_read(&rds_trans_sem); 152 153 return total; 154 } 155 156