1 /******************************************************************************* 2 * Filename: target_core_hba.c 3 * 4 * This file contains the TCM HBA Transport related functions. 5 * 6 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc. 7 * Copyright (c) 2005, 2006, 2007 SBE, Inc. 8 * Copyright (c) 2007-2010 Rising Tide Systems 9 * Copyright (c) 2008-2010 Linux-iSCSI.org 10 * 11 * Nicholas A. Bellinger <nab@kernel.org> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License as published by 15 * the Free Software Foundation; either version 2 of the License, or 16 * (at your option) any later version. 17 * 18 * This program is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 * GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with this program; if not, write to the Free Software 25 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 26 * 27 ******************************************************************************/ 28 29 #include <linux/net.h> 30 #include <linux/string.h> 31 #include <linux/timer.h> 32 #include <linux/slab.h> 33 #include <linux/spinlock.h> 34 #include <linux/in.h> 35 #include <linux/module.h> 36 #include <net/sock.h> 37 #include <net/tcp.h> 38 39 #include <target/target_core_base.h> 40 #include <target/target_core_device.h> 41 #include <target/target_core_tpg.h> 42 #include <target/target_core_transport.h> 43 44 #include "target_core_internal.h" 45 46 static LIST_HEAD(subsystem_list); 47 static DEFINE_MUTEX(subsystem_mutex); 48 49 static u32 hba_id_counter; 50 51 static DEFINE_SPINLOCK(hba_lock); 52 static LIST_HEAD(hba_list); 53 54 int transport_subsystem_register(struct se_subsystem_api *sub_api) 55 { 56 struct se_subsystem_api *s; 57 58 INIT_LIST_HEAD(&sub_api->sub_api_list); 59 60 mutex_lock(&subsystem_mutex); 61 list_for_each_entry(s, &subsystem_list, sub_api_list) { 62 if (!strcmp(s->name, sub_api->name)) { 63 pr_err("%p is already registered with" 64 " duplicate name %s, unable to process" 65 " request\n", s, s->name); 66 mutex_unlock(&subsystem_mutex); 67 return -EEXIST; 68 } 69 } 70 list_add_tail(&sub_api->sub_api_list, &subsystem_list); 71 mutex_unlock(&subsystem_mutex); 72 73 pr_debug("TCM: Registered subsystem plugin: %s struct module:" 74 " %p\n", sub_api->name, sub_api->owner); 75 return 0; 76 } 77 EXPORT_SYMBOL(transport_subsystem_register); 78 79 void transport_subsystem_release(struct se_subsystem_api *sub_api) 80 { 81 mutex_lock(&subsystem_mutex); 82 list_del(&sub_api->sub_api_list); 83 mutex_unlock(&subsystem_mutex); 84 } 85 EXPORT_SYMBOL(transport_subsystem_release); 86 87 static struct se_subsystem_api *core_get_backend(const char *sub_name) 88 { 89 struct se_subsystem_api *s; 90 91 mutex_lock(&subsystem_mutex); 92 list_for_each_entry(s, &subsystem_list, sub_api_list) { 93 if (!strcmp(s->name, sub_name)) 94 goto found; 95 } 96 mutex_unlock(&subsystem_mutex); 97 return NULL; 98 found: 99 if (s->owner && !try_module_get(s->owner)) 100 s = NULL; 101 mutex_unlock(&subsystem_mutex); 102 return s; 103 } 104 105 struct se_hba * 106 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags) 107 { 108 struct se_hba *hba; 109 int ret = 0; 110 111 hba = kzalloc(sizeof(*hba), GFP_KERNEL); 112 if (!hba) { 113 pr_err("Unable to allocate struct se_hba\n"); 114 return ERR_PTR(-ENOMEM); 115 } 116 117 INIT_LIST_HEAD(&hba->hba_dev_list); 118 spin_lock_init(&hba->device_lock); 119 mutex_init(&hba->hba_access_mutex); 120 121 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX); 122 hba->hba_flags |= hba_flags; 123 124 hba->transport = core_get_backend(plugin_name); 125 if (!hba->transport) { 126 ret = -EINVAL; 127 goto out_free_hba; 128 } 129 130 ret = hba->transport->attach_hba(hba, plugin_dep_id); 131 if (ret < 0) 132 goto out_module_put; 133 134 spin_lock(&hba_lock); 135 hba->hba_id = hba_id_counter++; 136 list_add_tail(&hba->hba_node, &hba_list); 137 spin_unlock(&hba_lock); 138 139 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target" 140 " Core\n", hba->hba_id); 141 142 return hba; 143 144 out_module_put: 145 if (hba->transport->owner) 146 module_put(hba->transport->owner); 147 hba->transport = NULL; 148 out_free_hba: 149 kfree(hba); 150 return ERR_PTR(ret); 151 } 152 153 int 154 core_delete_hba(struct se_hba *hba) 155 { 156 if (!list_empty(&hba->hba_dev_list)) 157 dump_stack(); 158 159 hba->transport->detach_hba(hba); 160 161 spin_lock(&hba_lock); 162 list_del(&hba->hba_node); 163 spin_unlock(&hba_lock); 164 165 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target" 166 " Core\n", hba->hba_id); 167 168 if (hba->transport->owner) 169 module_put(hba->transport->owner); 170 171 hba->transport = NULL; 172 kfree(hba); 173 return 0; 174 } 175