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>
35 #include <linux/module.h>
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>
44 #include "target_core_hba.h"
46 static LIST_HEAD(subsystem_list
);
47 static DEFINE_MUTEX(subsystem_mutex
);
49 static u32 hba_id_counter
;
51 static DEFINE_SPINLOCK(hba_lock
);
52 static LIST_HEAD(hba_list
);
54 int transport_subsystem_register(struct se_subsystem_api
*sub_api
)
56 struct se_subsystem_api
*s
;
58 INIT_LIST_HEAD(&sub_api
->sub_api_list
);
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
);
70 list_add_tail(&sub_api
->sub_api_list
, &subsystem_list
);
71 mutex_unlock(&subsystem_mutex
);
73 pr_debug("TCM: Registered subsystem plugin: %s struct module:"
74 " %p\n", sub_api
->name
, sub_api
->owner
);
77 EXPORT_SYMBOL(transport_subsystem_register
);
79 void transport_subsystem_release(struct se_subsystem_api
*sub_api
)
81 mutex_lock(&subsystem_mutex
);
82 list_del(&sub_api
->sub_api_list
);
83 mutex_unlock(&subsystem_mutex
);
85 EXPORT_SYMBOL(transport_subsystem_release
);
87 static struct se_subsystem_api
*core_get_backend(const char *sub_name
)
89 struct se_subsystem_api
*s
;
91 mutex_lock(&subsystem_mutex
);
92 list_for_each_entry(s
, &subsystem_list
, sub_api_list
) {
93 if (!strcmp(s
->name
, sub_name
))
96 mutex_unlock(&subsystem_mutex
);
99 if (s
->owner
&& !try_module_get(s
->owner
))
101 mutex_unlock(&subsystem_mutex
);
106 core_alloc_hba(const char *plugin_name
, u32 plugin_dep_id
, u32 hba_flags
)
111 hba
= kzalloc(sizeof(*hba
), GFP_KERNEL
);
113 pr_err("Unable to allocate struct se_hba\n");
114 return ERR_PTR(-ENOMEM
);
117 INIT_LIST_HEAD(&hba
->hba_dev_list
);
118 spin_lock_init(&hba
->device_lock
);
119 mutex_init(&hba
->hba_access_mutex
);
121 hba
->hba_index
= scsi_get_new_index(SCSI_INST_INDEX
);
122 hba
->hba_flags
|= hba_flags
;
124 hba
->transport
= core_get_backend(plugin_name
);
125 if (!hba
->transport
) {
130 ret
= hba
->transport
->attach_hba(hba
, plugin_dep_id
);
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
);
139 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
140 " Core\n", hba
->hba_id
);
145 if (hba
->transport
->owner
)
146 module_put(hba
->transport
->owner
);
147 hba
->transport
= NULL
;
154 core_delete_hba(struct se_hba
*hba
)
156 if (!list_empty(&hba
->hba_dev_list
))
159 hba
->transport
->detach_hba(hba
);
161 spin_lock(&hba_lock
);
162 list_del(&hba
->hba_node
);
163 spin_unlock(&hba_lock
);
165 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
166 " Core\n", hba
->hba_id
);
168 if (hba
->transport
->owner
)
169 module_put(hba
->transport
->owner
);
171 hba
->transport
= NULL
;