1 /******************************************************************************* 2 * Filename: target_core_hba.c 3 * 4 * This file copntains the iSCSI 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 <net/sock.h> 36 #include <net/tcp.h> 37 38 #include <target/target_core_base.h> 39 #include <target/target_core_device.h> 40 #include <target/target_core_tpg.h> 41 #include <target/target_core_transport.h> 42 43 #include "target_core_hba.h" 44 45 static LIST_HEAD(subsystem_list); 46 static DEFINE_MUTEX(subsystem_mutex); 47 48 int transport_subsystem_register(struct se_subsystem_api *sub_api) 49 { 50 struct se_subsystem_api *s; 51 52 INIT_LIST_HEAD(&sub_api->sub_api_list); 53 54 mutex_lock(&subsystem_mutex); 55 list_for_each_entry(s, &subsystem_list, sub_api_list) { 56 if (!(strcmp(s->name, sub_api->name))) { 57 printk(KERN_ERR "%p is already registered with" 58 " duplicate name %s, unable to process" 59 " request\n", s, s->name); 60 mutex_unlock(&subsystem_mutex); 61 return -EEXIST; 62 } 63 } 64 list_add_tail(&sub_api->sub_api_list, &subsystem_list); 65 mutex_unlock(&subsystem_mutex); 66 67 printk(KERN_INFO "TCM: Registered subsystem plugin: %s struct module:" 68 " %p\n", sub_api->name, sub_api->owner); 69 return 0; 70 } 71 EXPORT_SYMBOL(transport_subsystem_register); 72 73 void transport_subsystem_release(struct se_subsystem_api *sub_api) 74 { 75 mutex_lock(&subsystem_mutex); 76 list_del(&sub_api->sub_api_list); 77 mutex_unlock(&subsystem_mutex); 78 } 79 EXPORT_SYMBOL(transport_subsystem_release); 80 81 static struct se_subsystem_api *core_get_backend(const char *sub_name) 82 { 83 struct se_subsystem_api *s; 84 85 mutex_lock(&subsystem_mutex); 86 list_for_each_entry(s, &subsystem_list, sub_api_list) { 87 if (!strcmp(s->name, sub_name)) 88 goto found; 89 } 90 mutex_unlock(&subsystem_mutex); 91 return NULL; 92 found: 93 if (s->owner && !try_module_get(s->owner)) 94 s = NULL; 95 mutex_unlock(&subsystem_mutex); 96 return s; 97 } 98 99 struct se_hba * 100 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags) 101 { 102 struct se_hba *hba; 103 int ret = 0; 104 105 hba = kzalloc(sizeof(*hba), GFP_KERNEL); 106 if (!hba) { 107 printk(KERN_ERR "Unable to allocate struct se_hba\n"); 108 return ERR_PTR(-ENOMEM); 109 } 110 111 INIT_LIST_HEAD(&hba->hba_dev_list); 112 spin_lock_init(&hba->device_lock); 113 spin_lock_init(&hba->hba_queue_lock); 114 mutex_init(&hba->hba_access_mutex); 115 116 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX); 117 hba->hba_flags |= hba_flags; 118 119 atomic_set(&hba->max_queue_depth, 0); 120 atomic_set(&hba->left_queue_depth, 0); 121 122 hba->transport = core_get_backend(plugin_name); 123 if (!hba->transport) { 124 ret = -EINVAL; 125 goto out_free_hba; 126 } 127 128 ret = hba->transport->attach_hba(hba, plugin_dep_id); 129 if (ret < 0) 130 goto out_module_put; 131 132 spin_lock(&se_global->hba_lock); 133 hba->hba_id = se_global->g_hba_id_counter++; 134 list_add_tail(&hba->hba_list, &se_global->g_hba_list); 135 spin_unlock(&se_global->hba_lock); 136 137 printk(KERN_INFO "CORE_HBA[%d] - Attached HBA to Generic Target" 138 " Core\n", hba->hba_id); 139 140 return hba; 141 142 out_module_put: 143 if (hba->transport->owner) 144 module_put(hba->transport->owner); 145 hba->transport = NULL; 146 out_free_hba: 147 kfree(hba); 148 return ERR_PTR(ret); 149 } 150 151 int 152 core_delete_hba(struct se_hba *hba) 153 { 154 if (!list_empty(&hba->hba_dev_list)) 155 dump_stack(); 156 157 hba->transport->detach_hba(hba); 158 159 spin_lock(&se_global->hba_lock); 160 list_del(&hba->hba_list); 161 spin_unlock(&se_global->hba_lock); 162 163 printk(KERN_INFO "CORE_HBA[%d] - Detached HBA from Generic Target" 164 " Core\n", hba->hba_id); 165 166 if (hba->transport->owner) 167 module_put(hba->transport->owner); 168 169 hba->transport = NULL; 170 kfree(hba); 171 return 0; 172 } 173