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 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 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 74 struct rds_transport *rds_trans_get_preferred(__be32 addr) 75 { 76 struct rds_transport *ret = NULL; 77 int i; 78 79 if (IN_LOOPBACK(ntohl(addr))) 80 return &rds_loop_transport; 81 82 down_read(&rds_trans_sem); 83 for (i = 0; i < RDS_TRANS_COUNT; i++) 84 { 85 if (transports[i] && (transports[i]->laddr_check(addr) == 0)) { 86 ret = transports[i]; 87 break; 88 } 89 } 90 up_read(&rds_trans_sem); 91 92 return ret; 93 } 94 95 /* 96 * This returns the number of stats entries in the snapshot and only 97 * copies them using the iter if there is enough space for them. The 98 * caller passes in the global stats so that we can size and copy while 99 * holding the lock. 100 */ 101 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter, 102 unsigned int avail) 103 104 { 105 struct rds_transport *trans; 106 unsigned int total = 0; 107 unsigned int part; 108 int i; 109 110 rds_info_iter_unmap(iter); 111 down_read(&rds_trans_sem); 112 113 for (i = 0; i < RDS_TRANS_COUNT; i++) 114 { 115 trans = transports[i]; 116 if (!trans || !trans->stats_info_copy) 117 continue; 118 119 part = trans->stats_info_copy(iter, avail); 120 avail -= min(avail, part); 121 total += part; 122 } 123 124 up_read(&rds_trans_sem); 125 126 return total; 127 } 128 129