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 LIST_HEAD(rds_transports); 41 static DECLARE_RWSEM(rds_trans_sem); 42 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 list_add_tail(&trans->t_item, &rds_transports); 50 printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name); 51 52 up_write(&rds_trans_sem); 53 54 return 0; 55 } 56 57 void rds_trans_unregister(struct rds_transport *trans) 58 { 59 down_write(&rds_trans_sem); 60 61 list_del_init(&trans->t_item); 62 printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name); 63 64 up_write(&rds_trans_sem); 65 } 66 67 struct rds_transport *rds_trans_get_preferred(__be32 addr) 68 { 69 struct rds_transport *trans; 70 struct rds_transport *ret = NULL; 71 72 if (IN_LOOPBACK(ntohl(addr))) 73 return &rds_loop_transport; 74 75 down_read(&rds_trans_sem); 76 list_for_each_entry(trans, &rds_transports, t_item) { 77 if (trans->laddr_check(addr) == 0) { 78 ret = trans; 79 break; 80 } 81 } 82 up_read(&rds_trans_sem); 83 84 return ret; 85 } 86 87 /* 88 * This returns the number of stats entries in the snapshot and only 89 * copies them using the iter if there is enough space for them. The 90 * caller passes in the global stats so that we can size and copy while 91 * holding the lock. 92 */ 93 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter, 94 unsigned int avail) 95 96 { 97 struct rds_transport *trans; 98 unsigned int total = 0; 99 unsigned int part; 100 101 rds_info_iter_unmap(iter); 102 down_read(&rds_trans_sem); 103 104 list_for_each_entry(trans, &rds_transports, t_item) { 105 if (trans->stats_info_copy == NULL) 106 continue; 107 108 part = trans->stats_info_copy(iter, avail); 109 avail -= min(avail, part); 110 total += part; 111 } 112 113 up_read(&rds_trans_sem); 114 115 return total; 116 } 117 118