1 /*******************************************************************************
2 * Filename: target_core_hba.c
3 *
4 * This file contains the TCM HBA Transport related functions.
5 *
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
10 *
11 * Nicholas A. Bellinger <nab@kernel.org>
12 *
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.
17 *
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.
22 *
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.
26 *
27 ******************************************************************************/
28
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>
34 #include <linux/in.h>
35 #include <linux/module.h>
36 #include <net/sock.h>
37 #include <net/tcp.h>
38
39 #include <target/target_core_base.h>
40 #include <target/target_core_backend.h>
41 #include <target/target_core_fabric.h>
42
43 #include "target_core_internal.h"
44
45 static LIST_HEAD(subsystem_list);
46 static DEFINE_MUTEX(subsystem_mutex);
47
48 static u32 hba_id_counter;
49
50 static DEFINE_SPINLOCK(hba_lock);
51 static LIST_HEAD(hba_list);
52
transport_subsystem_register(struct se_subsystem_api * sub_api)53 int transport_subsystem_register(struct se_subsystem_api *sub_api)
54 {
55 struct se_subsystem_api *s;
56
57 INIT_LIST_HEAD(&sub_api->sub_api_list);
58
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);
66 return -EEXIST;
67 }
68 }
69 list_add_tail(&sub_api->sub_api_list, &subsystem_list);
70 mutex_unlock(&subsystem_mutex);
71
72 pr_debug("TCM: Registered subsystem plugin: %s struct module:"
73 " %p\n", sub_api->name, sub_api->owner);
74 return 0;
75 }
76 EXPORT_SYMBOL(transport_subsystem_register);
77
transport_subsystem_release(struct se_subsystem_api * sub_api)78 void transport_subsystem_release(struct se_subsystem_api *sub_api)
79 {
80 mutex_lock(&subsystem_mutex);
81 list_del(&sub_api->sub_api_list);
82 mutex_unlock(&subsystem_mutex);
83 }
84 EXPORT_SYMBOL(transport_subsystem_release);
85
core_get_backend(const char * sub_name)86 static struct se_subsystem_api *core_get_backend(const char *sub_name)
87 {
88 struct se_subsystem_api *s;
89
90 mutex_lock(&subsystem_mutex);
91 list_for_each_entry(s, &subsystem_list, sub_api_list) {
92 if (!strcmp(s->name, sub_name))
93 goto found;
94 }
95 mutex_unlock(&subsystem_mutex);
96 return NULL;
97 found:
98 if (s->owner && !try_module_get(s->owner))
99 s = NULL;
100 mutex_unlock(&subsystem_mutex);
101 return s;
102 }
103
104 struct se_hba *
core_alloc_hba(const char * plugin_name,u32 plugin_dep_id,u32 hba_flags)105 core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
106 {
107 struct se_hba *hba;
108 int ret = 0;
109
110 hba = kzalloc(sizeof(*hba), GFP_KERNEL);
111 if (!hba) {
112 pr_err("Unable to allocate struct se_hba\n");
113 return ERR_PTR(-ENOMEM);
114 }
115
116 INIT_LIST_HEAD(&hba->hba_dev_list);
117 spin_lock_init(&hba->device_lock);
118 mutex_init(&hba->hba_access_mutex);
119
120 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
121 hba->hba_flags |= hba_flags;
122
123 hba->transport = core_get_backend(plugin_name);
124 if (!hba->transport) {
125 ret = -EINVAL;
126 goto out_free_hba;
127 }
128
129 ret = hba->transport->attach_hba(hba, plugin_dep_id);
130 if (ret < 0)
131 goto out_module_put;
132
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);
137
138 pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
139 " Core\n", hba->hba_id);
140
141 return hba;
142
143 out_module_put:
144 if (hba->transport->owner)
145 module_put(hba->transport->owner);
146 hba->transport = NULL;
147 out_free_hba:
148 kfree(hba);
149 return ERR_PTR(ret);
150 }
151
152 int
core_delete_hba(struct se_hba * hba)153 core_delete_hba(struct se_hba *hba)
154 {
155 if (!list_empty(&hba->hba_dev_list))
156 dump_stack();
157
158 hba->transport->detach_hba(hba);
159
160 spin_lock(&hba_lock);
161 list_del(&hba->hba_node);
162 spin_unlock(&hba_lock);
163
164 pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
165 " Core\n", hba->hba_id);
166
167 if (hba->transport->owner)
168 module_put(hba->transport->owner);
169
170 hba->transport = NULL;
171 kfree(hba);
172 return 0;
173 }
174