1 /*******************************************************************************
2 * Filename: target_core_hba.c
4 * This file contains the TCM HBA Transport related functions.
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
11 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
27 ******************************************************************************/
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>
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>
43 #include "target_core_hba.h"
45 static LIST_HEAD(subsystem_list);
46 static DEFINE_MUTEX(subsystem_mutex);
48 static u32 hba_id_counter;
50 static DEFINE_SPINLOCK(hba_lock);
51 static LIST_HEAD(hba_list);
53 int transport_subsystem_register(struct se_subsystem_api *sub_api)
55 struct se_subsystem_api *s;
57 INIT_LIST_HEAD(&sub_api->sub_api_list);
59 mutex_lock(&subsystem_mutex);
60 list_for_each_entry(s, &subsystem_list, sub_api_list) {
61 if (!strcmp(s->name, sub_api->name)) {
62 pr_err("%p is already registered with"
63 " duplicate name %s, unable to process"
64 " request\n", s, s->name);
65 mutex_unlock(&subsystem_mutex);
69 list_add_tail(&sub_api->sub_api_list, &subsystem_list);
70 mutex_unlock(&subsystem_mutex);
72 pr_debug("TCM: Registered subsystem plugin: %s struct module:"
73 " %p\n", sub_api->name, sub_api->owner);
76 EXPORT_SYMBOL(transport_subsystem_register);
78 void transport_subsystem_release(struct se_subsystem_api *sub_api)
80 mutex_lock(&subsystem_mutex);
81 list_del(&sub_api->sub_api_list);
82 mutex_unlock(&subsystem_mutex);
84 EXPORT_SYMBOL(transport_subsystem_release);
86 static struct se_subsystem_api *core_get_backend(const char *sub_name)
88 struct se_subsystem_api *s;
90 mutex_lock(&subsystem_mutex);
91 list_for_each_entry(s, &subsystem_list, sub_api_list) {
92 if (!strcmp(s->name, sub_name))
95 mutex_unlock(&subsystem_mutex);
98 if (s->owner && !try_module_get(s->owner))
100 mutex_unlock(&subsystem_mutex);
105 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
110 hba = kzalloc(sizeof(*hba), GFP_KERNEL);
112 pr_err("Unable to allocate struct se_hba\n");
113 return ERR_PTR(-ENOMEM);
116 INIT_LIST_HEAD(&hba->hba_dev_list);
117 spin_lock_init(&hba->device_lock);
118 mutex_init(&hba->hba_access_mutex);
120 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
121 hba->hba_flags |= hba_flags;
123 hba->transport = core_get_backend(plugin_name);
124 if (!hba->transport) {
129 ret = hba->transport->attach_hba(hba, plugin_dep_id);
133 spin_lock(&hba_lock);
134 hba->hba_id = hba_id_counter++;
135 list_add_tail(&hba->hba_node, &hba_list);
136 spin_unlock(&hba_lock);
138 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
139 " Core\n", hba->hba_id);
144 if (hba->transport->owner)
145 module_put(hba->transport->owner);
146 hba->transport = NULL;
153 core_delete_hba(struct se_hba *hba)
155 if (!list_empty(&hba->hba_dev_list))
158 hba->transport->detach_hba(hba);
160 spin_lock(&hba_lock);
161 list_del(&hba->hba_node);
162 spin_unlock(&hba_lock);
164 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
165 " Core\n", hba->hba_id);
167 if (hba->transport->owner)
168 module_put(hba->transport->owner);
170 hba->transport = NULL;