blob: 62ea4e8e70a8935398f2a0e86fc44627dfa3368e [file] [log] [blame]
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -08001/*******************************************************************************
2 * Filename: target_core_hba.c
3 *
Andy Grovere3d6f902011-07-19 08:55:10 +00004 * This file contains the TCM HBA Transport related functions.
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -08005 *
Nicholas Bellinger4c762512013-09-05 15:29:12 -07006 * (c) Copyright 2003-2013 Datera, Inc.
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -08007 *
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>
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080031#include <linux/in.h>
Paul Gortmaker827509e2011-08-30 14:20:44 -040032#include <linux/module.h>
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080033#include <net/sock.h>
34#include <net/tcp.h>
35
36#include <target/target_core_base.h>
Christoph Hellwigc4795fb2011-11-16 09:46:48 -050037#include <target/target_core_backend.h>
38#include <target/target_core_fabric.h>
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080039
Christoph Hellwige26d99a2011-11-14 12:30:30 -050040#include "target_core_internal.h"
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080041
Christoph Hellwig0a06d432015-05-10 18:14:56 +020042static LIST_HEAD(backend_list);
43static DEFINE_MUTEX(backend_mutex);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080044
Andy Grovere3d6f902011-07-19 08:55:10 +000045static u32 hba_id_counter;
46
47static DEFINE_SPINLOCK(hba_lock);
48static LIST_HEAD(hba_list);
49
Christoph Hellwig0a06d432015-05-10 18:14:56 +020050
51int transport_backend_register(const struct target_backend_ops *ops)
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080052{
Christoph Hellwig0a06d432015-05-10 18:14:56 +020053 struct target_backend *tb, *old;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080054
Christoph Hellwig0a06d432015-05-10 18:14:56 +020055 tb = kzalloc(sizeof(*tb), GFP_KERNEL);
56 if (!tb)
57 return -ENOMEM;
58 tb->ops = ops;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080059
Christoph Hellwig0a06d432015-05-10 18:14:56 +020060 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);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080066 return -EEXIST;
67 }
68 }
Christoph Hellwig0a06d432015-05-10 18:14:56 +020069 target_setup_backend_cits(tb);
70 list_add_tail(&tb->list, &backend_list);
71 mutex_unlock(&backend_mutex);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080072
Christoph Hellwig0a06d432015-05-10 18:14:56 +020073 pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
74 ops->name, ops->owner);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080075 return 0;
76}
Christoph Hellwig0a06d432015-05-10 18:14:56 +020077EXPORT_SYMBOL(transport_backend_register);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080078
Christoph Hellwig0a06d432015-05-10 18:14:56 +020079void target_backend_unregister(const struct target_backend_ops *ops)
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080080{
Christoph Hellwig0a06d432015-05-10 18:14:56 +020081 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);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080092}
Christoph Hellwig0a06d432015-05-10 18:14:56 +020093EXPORT_SYMBOL(target_backend_unregister);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080094
Christoph Hellwig0a06d432015-05-10 18:14:56 +020095static struct target_backend *core_get_backend(const char *name)
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080096{
Christoph Hellwig0a06d432015-05-10 18:14:56 +020097 struct target_backend *tb;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -080098
Christoph Hellwig0a06d432015-05-10 18:14:56 +020099 mutex_lock(&backend_mutex);
100 list_for_each_entry(tb, &backend_list, list) {
101 if (!strcmp(tb->ops->name, name))
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800102 goto found;
103 }
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200104 mutex_unlock(&backend_mutex);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800105 return NULL;
106found:
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200107 if (tb->ops->owner && !try_module_get(tb->ops->owner))
108 tb = NULL;
109 mutex_unlock(&backend_mutex);
110 return tb;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800111}
112
113struct se_hba *
114core_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) {
Andy Grover6708bb22011-06-08 10:36:43 -0700121 pr_err("Unable to allocate struct se_hba\n");
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800122 return ERR_PTR(-ENOMEM);
123 }
124
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800125 spin_lock_init(&hba->device_lock);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800126 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
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200131 hba->backend = core_get_backend(plugin_name);
132 if (!hba->backend) {
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800133 ret = -EINVAL;
134 goto out_free_hba;
135 }
136
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200137 ret = hba->backend->ops->attach_hba(hba, plugin_dep_id);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800138 if (ret < 0)
139 goto out_module_put;
140
Andy Grovere3d6f902011-07-19 08:55:10 +0000141 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);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800145
Andy Grover6708bb22011-06-08 10:36:43 -0700146 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800147 " Core\n", hba->hba_id);
148
149 return hba;
150
151out_module_put:
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200152 module_put(hba->backend->ops->owner);
153 hba->backend = NULL;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800154out_free_hba:
155 kfree(hba);
156 return ERR_PTR(ret);
157}
158
159int
160core_delete_hba(struct se_hba *hba)
161{
Christoph Hellwig0fd97cc2012-10-08 00:03:19 -0400162 WARN_ON(hba->dev_count);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800163
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200164 hba->backend->ops->detach_hba(hba);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800165
Andy Grovere3d6f902011-07-19 08:55:10 +0000166 spin_lock(&hba_lock);
167 list_del(&hba->hba_node);
168 spin_unlock(&hba_lock);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800169
Andy Grover6708bb22011-06-08 10:36:43 -0700170 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800171 " Core\n", hba->hba_id);
172
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200173 module_put(hba->backend->ops->owner);
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800174
Christoph Hellwig0a06d432015-05-10 18:14:56 +0200175 hba->backend = NULL;
Nicholas Bellingerc66ac9d2010-12-17 11:11:26 -0800176 kfree(hba);
177 return 0;
178}