tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*******************************************************************************
2 * Filename: target_core_hba.c
3 *
4 * This file copntains the iSCSI 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/smp_lock.h>
35#include <linux/in.h>
36#include <net/sock.h>
37#include <net/tcp.h>
38
39#include <target/target_core_base.h>
40#include <target/target_core_device.h>
41#include <target/target_core_device.h>
42#include <target/target_core_tpg.h>
43#include <target/target_core_transport.h>
44
45#include "target_core_hba.h"
46
47static LIST_HEAD(subsystem_list);
48static DEFINE_MUTEX(subsystem_mutex);
49
50int transport_subsystem_register(struct se_subsystem_api *sub_api)
51{
52 struct se_subsystem_api *s;
53
54 INIT_LIST_HEAD(&sub_api->sub_api_list);
55
56 mutex_lock(&subsystem_mutex);
57 list_for_each_entry(s, &subsystem_list, sub_api_list) {
58 if (!(strcmp(s->name, sub_api->name))) {
59 printk(KERN_ERR "%p is already registered with"
60 " duplicate name %s, unable to process"
61 " request\n", s, s->name);
62 mutex_unlock(&subsystem_mutex);
63 return -EEXIST;
64 }
65 }
66 list_add_tail(&sub_api->sub_api_list, &subsystem_list);
67 mutex_unlock(&subsystem_mutex);
68
69 printk(KERN_INFO "TCM: Registered subsystem plugin: %s struct module:"
70 " %p\n", sub_api->name, sub_api->owner);
71 return 0;
72}
73EXPORT_SYMBOL(transport_subsystem_register);
74
75void transport_subsystem_release(struct se_subsystem_api *sub_api)
76{
77 mutex_lock(&subsystem_mutex);
78 list_del(&sub_api->sub_api_list);
79 mutex_unlock(&subsystem_mutex);
80}
81EXPORT_SYMBOL(transport_subsystem_release);
82
83static struct se_subsystem_api *core_get_backend(const char *sub_name)
84{
85 struct se_subsystem_api *s;
86
87 mutex_lock(&subsystem_mutex);
88 list_for_each_entry(s, &subsystem_list, sub_api_list) {
89 if (!strcmp(s->name, sub_name))
90 goto found;
91 }
92 mutex_unlock(&subsystem_mutex);
93 return NULL;
94found:
95 if (s->owner && !try_module_get(s->owner))
96 s = NULL;
97 mutex_unlock(&subsystem_mutex);
98 return s;
99}
100
101struct se_hba *
102core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
103{
104 struct se_hba *hba;
105 int ret = 0;
106
107 hba = kzalloc(sizeof(*hba), GFP_KERNEL);
108 if (!hba) {
109 printk(KERN_ERR "Unable to allocate struct se_hba\n");
110 return ERR_PTR(-ENOMEM);
111 }
112
113 INIT_LIST_HEAD(&hba->hba_dev_list);
114 spin_lock_init(&hba->device_lock);
115 spin_lock_init(&hba->hba_queue_lock);
116 mutex_init(&hba->hba_access_mutex);
117
118 hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
119 hba->hba_flags |= hba_flags;
120
121 atomic_set(&hba->max_queue_depth, 0);
122 atomic_set(&hba->left_queue_depth, 0);
123
124 hba->transport = core_get_backend(plugin_name);
125 if (!hba->transport) {
126 ret = -EINVAL;
127 goto out_free_hba;
128 }
129
130 ret = hba->transport->attach_hba(hba, plugin_dep_id);
131 if (ret < 0)
132 goto out_module_put;
133
134 spin_lock(&se_global->hba_lock);
135 hba->hba_id = se_global->g_hba_id_counter++;
136 list_add_tail(&hba->hba_list, &se_global->g_hba_list);
137 spin_unlock(&se_global->hba_lock);
138
139 printk(KERN_INFO "CORE_HBA[%d] - Attached HBA to Generic Target"
140 " Core\n", hba->hba_id);
141
142 return hba;
143
144out_module_put:
145 if (hba->transport->owner)
146 module_put(hba->transport->owner);
147 hba->transport = NULL;
148out_free_hba:
149 kfree(hba);
150 return ERR_PTR(ret);
151}
152
153int
154core_delete_hba(struct se_hba *hba)
155{
156 struct se_device *dev, *dev_tmp;
157
158 spin_lock(&hba->device_lock);
159 list_for_each_entry_safe(dev, dev_tmp, &hba->hba_dev_list, dev_list) {
160
161 se_clear_dev_ports(dev);
162 spin_unlock(&hba->device_lock);
163
164 se_release_device_for_hba(dev);
165
166 spin_lock(&hba->device_lock);
167 }
168 spin_unlock(&hba->device_lock);
169
170 hba->transport->detach_hba(hba);
171
172 spin_lock(&se_global->hba_lock);
173 list_del(&hba->hba_list);
174 spin_unlock(&se_global->hba_lock);
175
176 printk(KERN_INFO "CORE_HBA[%d] - Detached HBA from Generic Target"
177 " Core\n", hba->hba_id);
178
179 if (hba->transport->owner)
180 module_put(hba->transport->owner);
181
182 hba->transport = NULL;
183 kfree(hba);
184 return 0;
185}