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 EXPORT_SYMBOL_GPL(rds_trans_register); 57 58 void rds_trans_unregister(struct rds_transport *trans) 59 { 60 down_write(&rds_trans_sem); 61 62 list_del_init(&trans->t_item); 63 printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name); 64 65 up_write(&rds_trans_sem); 66 } 67 EXPORT_SYMBOL_GPL(rds_trans_unregister); 68 69 struct rds_transport *rds_trans_get_preferred(__be32 addr) 70 { 71 struct rds_transport *trans; 72 struct rds_transport *ret = NULL; 73 74 if (IN_LOOPBACK(ntohl(addr))) 75 return &rds_loop_transport; 76 77 down_read(&rds_trans_sem); 78 list_for_each_entry(trans, &rds_transports, t_item) { 79 if (trans->laddr_check(addr) == 0) { 80 ret = trans; 81 break; 82 } 83 } 84 up_read(&rds_trans_sem); 85 86 return ret; 87 } 88 89 /* 90 * This returns the number of stats entries in the snapshot and only 91 * copies them using the iter if there is enough space for them. The 92 * caller passes in the global stats so that we can size and copy while 93 * holding the lock. 94 */ 95 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter, 96 unsigned int avail) 97 98 { 99 struct rds_transport *trans; 100 unsigned int total = 0; 101 unsigned int part; 102 103 rds_info_iter_unmap(iter); 104 down_read(&rds_trans_sem); 105 106 list_for_each_entry(trans, &rds_transports, t_item) { 107 if (trans->stats_info_copy == NULL) 108 continue; 109 110 part = trans->stats_info_copy(iter, avail); 111 avail -= min(avail, part); 112 total += part; 113 } 114 115 up_read(&rds_trans_sem); 116 117 return total; 118 } 119 120