1 /*******************************************************************************
2 * Filename: target_core_hba.c
4 * This file contains the TCM HBA Transport related functions.
6 * (c) Copyright 2003-2013 Datera, Inc.
8 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
24 ******************************************************************************/
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>
32 #include <linux/module.h>
36 #include <target/target_core_base.h>
37 #include <target/target_core_backend.h>
38 #include <target/target_core_fabric.h>
40 #include "target_core_internal.h"
42 static LIST_HEAD(backend_list);
43 static DEFINE_MUTEX(backend_mutex);
45 static u32 hba_id_counter;
47 static DEFINE_SPINLOCK(hba_lock);
48 static LIST_HEAD(hba_list);
51 int transport_backend_register(const struct target_backend_ops *ops)
53 struct target_backend *tb, *old;
55 tb = kzalloc(sizeof(*tb), GFP_KERNEL);
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);
69 target_setup_backend_cits(tb);
70 list_add_tail(&tb->list, &backend_list);
71 mutex_unlock(&backend_mutex);
73 pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
74 ops->name, ops->owner);
77 EXPORT_SYMBOL(transport_backend_register);
79 void target_backend_unregister(const struct target_backend_ops *ops)
81 struct target_backend *tb;
83 mutex_lock(&backend_mutex);
84 list_for_each_entry(tb, &backend_list, list) {
91 mutex_unlock(&backend_mutex);
93 EXPORT_SYMBOL(target_backend_unregister);
95 static struct target_backend *core_get_backend(const char *name)
97 struct target_backend *tb;
99 mutex_lock(&backend_mutex);
100 list_for_each_entry(tb, &backend_list, list) {
101 if (!strcmp(tb->ops->name, name))
104 mutex_unlock(&backend_mutex);
107 if (tb->ops->owner && !try_module_get(tb->ops->owner))
109 mutex_unlock(&backend_mutex);
114 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
119 hba = kzalloc(sizeof(*hba), GFP_KERNEL);
121 pr_err("Unable to allocate struct se_hba\n");
122 return ERR_PTR(-ENOMEM);
125 spin_lock_init(&hba->device_lock);
126 mutex_init(&hba->hba_access_mutex);
128 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
129 hba->hba_flags |= hba_flags;
131 hba->backend = core_get_backend(plugin_name);
137 ret = hba->backend->ops->attach_hba(hba, plugin_dep_id);
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);
146 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
147 " Core\n", hba->hba_id);
152 module_put(hba->backend->ops->owner);
160 core_delete_hba(struct se_hba *hba)
162 WARN_ON(hba->dev_count);
164 hba->backend->ops->detach_hba(hba);
166 spin_lock(&hba_lock);
167 list_del(&hba->hba_node);
168 spin_unlock(&hba_lock);
170 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
171 " Core\n", hba->hba_id);
173 module_put(hba->backend->ops->owner);