1 /******************************************************************************* 2 * Filename: target_core_hba.c 3 * 4 * This file contains the TCM HBA Transport related functions. 5 * 6 * (c) Copyright 2003-2013 Datera, Inc. 7 * 8 * Nicholas A. Bellinger <nab@kernel.org> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 23 * 24 ******************************************************************************/ 25 26 #include <linux/net.h> 27 #include <linux/string.h> 28 #include <linux/timer.h> 29 #include <linux/slab.h> 30 #include <linux/spinlock.h> 31 #include <linux/in.h> 32 #include <linux/module.h> 33 #include <net/sock.h> 34 #include <net/tcp.h> 35 36 #include <target/target_core_base.h> 37 #include <target/target_core_backend.h> 38 #include <target/target_core_fabric.h> 39 40 #include "target_core_internal.h" 41 42 static LIST_HEAD(backend_list); 43 static DEFINE_MUTEX(backend_mutex); 44 45 static u32 hba_id_counter; 46 47 static DEFINE_SPINLOCK(hba_lock); 48 static LIST_HEAD(hba_list); 49 50 51 int transport_backend_register(const struct target_backend_ops *ops) 52 { 53 struct target_backend *tb, *old; 54 55 tb = kzalloc(sizeof(*tb), GFP_KERNEL); 56 if (!tb) 57 return -ENOMEM; 58 tb->ops = ops; 59 60 mutex_lock(&backend_mutex); 61 list_for_each_entry(old, &backend_list, list) { 62 if (!strcmp(old->ops->name, ops->name)) { 63 pr_err("backend %s already registered.\n", ops->name); 64 mutex_unlock(&backend_mutex); 65 kfree(tb); 66 return -EEXIST; 67 } 68 } 69 target_setup_backend_cits(tb); 70 list_add_tail(&tb->list, &backend_list); 71 mutex_unlock(&backend_mutex); 72 73 pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n", 74 ops->name, ops->owner); 75 return 0; 76 } 77 EXPORT_SYMBOL(transport_backend_register); 78 79 void target_backend_unregister(const struct target_backend_ops *ops) 80 { 81 struct target_backend *tb; 82 83 mutex_lock(&backend_mutex); 84 list_for_each_entry(tb, &backend_list, list) { 85 if (tb->ops == ops) { 86 list_del(&tb->list); 87 kfree(tb); 88 break; 89 } 90 } 91 mutex_unlock(&backend_mutex); 92 } 93 EXPORT_SYMBOL(target_backend_unregister); 94 95 static struct target_backend *core_get_backend(const char *name) 96 { 97 struct target_backend *tb; 98 99 mutex_lock(&backend_mutex); 100 list_for_each_entry(tb, &backend_list, list) { 101 if (!strcmp(tb->ops->name, name)) 102 goto found; 103 } 104 mutex_unlock(&backend_mutex); 105 return NULL; 106 found: 107 if (tb->ops->owner && !try_module_get(tb->ops->owner)) 108 tb = NULL; 109 mutex_unlock(&backend_mutex); 110 return tb; 111 } 112 113 struct se_hba * 114 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags) 115 { 116 struct se_hba *hba; 117 int ret = 0; 118 119 hba = kzalloc(sizeof(*hba), GFP_KERNEL); 120 if (!hba) { 121 pr_err("Unable to allocate struct se_hba\n"); 122 return ERR_PTR(-ENOMEM); 123 } 124 125 spin_lock_init(&hba->device_lock); 126 mutex_init(&hba->hba_access_mutex); 127 128 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX); 129 hba->hba_flags |= hba_flags; 130 131 hba->backend = core_get_backend(plugin_name); 132 if (!hba->backend) { 133 ret = -EINVAL; 134 goto out_free_hba; 135 } 136 137 ret = hba->backend->ops->attach_hba(hba, plugin_dep_id); 138 if (ret < 0) 139 goto out_module_put; 140 141 spin_lock(&hba_lock); 142 hba->hba_id = hba_id_counter++; 143 list_add_tail(&hba->hba_node, &hba_list); 144 spin_unlock(&hba_lock); 145 146 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target" 147 " Core\n", hba->hba_id); 148 149 return hba; 150 151 out_module_put: 152 module_put(hba->backend->ops->owner); 153 hba->backend = NULL; 154 out_free_hba: 155 kfree(hba); 156 return ERR_PTR(ret); 157 } 158 159 int 160 core_delete_hba(struct se_hba *hba) 161 { 162 WARN_ON(hba->dev_count); 163 164 hba->backend->ops->detach_hba(hba); 165 166 spin_lock(&hba_lock); 167 list_del(&hba->hba_node); 168 spin_unlock(&hba_lock); 169 170 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target" 171 " Core\n", hba->hba_id); 172 173 module_put(hba->backend->ops->owner); 174 175 hba->backend = NULL; 176 kfree(hba); 177 return 0; 178 } 179 180 bool target_sense_desc_format(struct se_device *dev) 181 { 182 return dev->transport->get_blocks(dev) > U32_MAX; 183 } 184