aboutsummaryrefslogtreecommitdiff
path: root/drivers/target/target_core_hba.c
blob: c68019d6c406292335522d536760fb8bb5904629 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*******************************************************************************
 * Filename:  target_core_hba.c
 *
 * This file contains the TCM HBA Transport related functions.
 *
 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/net.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/in.h>
#include <linux/module.h>
#include <net/sock.h>
#include <net/tcp.h>

#include <target/target_core_base.h>
#include <target/target_core_device.h>
#include <target/target_core_tpg.h>
#include <target/target_core_transport.h>

#include "target_core_hba.h"

static LIST_HEAD(subsystem_list);
static DEFINE_MUTEX(subsystem_mutex);

static u32 hba_id_counter;

static DEFINE_SPINLOCK(hba_lock);
static LIST_HEAD(hba_list);

int transport_subsystem_register(struct se_subsystem_api *sub_api)
{
	struct se_subsystem_api *s;

	INIT_LIST_HEAD(&sub_api->sub_api_list);

	mutex_lock(&subsystem_mutex);
	list_for_each_entry(s, &subsystem_list, sub_api_list) {
		if (!strcmp(s->name, sub_api->name)) {
			pr_err("%p is already registered with"
				" duplicate name %s, unable to process"
				" request\n", s, s->name);
			mutex_unlock(&subsystem_mutex);
			return -EEXIST;
		}
	}
	list_add_tail(&sub_api->sub_api_list, &subsystem_list);
	mutex_unlock(&subsystem_mutex);

	pr_debug("TCM: Registered subsystem plugin: %s struct module:"
			" %p\n", sub_api->name, sub_api->owner);
	return 0;
}
EXPORT_SYMBOL(transport_subsystem_register);

void transport_subsystem_release(struct se_subsystem_api *sub_api)
{
	mutex_lock(&subsystem_mutex);
	list_del(&sub_api->sub_api_list);
	mutex_unlock(&subsystem_mutex);
}
EXPORT_SYMBOL(transport_subsystem_release);

static struct se_subsystem_api *core_get_backend(const char *sub_name)
{
	struct se_subsystem_api *s;

	mutex_lock(&subsystem_mutex);
	list_for_each_entry(s, &subsystem_list, sub_api_list) {
		if (!strcmp(s->name, sub_name))
			goto found;
	}
	mutex_unlock(&subsystem_mutex);
	return NULL;
found:
	if (s->owner && !try_module_get(s->owner))
		s = NULL;
	mutex_unlock(&subsystem_mutex);
	return s;
}

struct se_hba *
core_alloc_hba(const char *plugin_name, u32 plugin_dep_id, u32 hba_flags)
{
	struct se_hba *hba;
	int ret = 0;

	hba = kzalloc(sizeof(*hba), GFP_KERNEL);
	if (!hba) {
		pr_err("Unable to allocate struct se_hba\n");
		return ERR_PTR(-ENOMEM);
	}

	INIT_LIST_HEAD(&hba->hba_dev_list);
	spin_lock_init(&hba->device_lock);
	mutex_init(&hba->hba_access_mutex);

	hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
	hba->hba_flags |= hba_flags;

	hba->transport = core_get_backend(plugin_name);
	if (!hba->transport) {
		ret = -EINVAL;
		goto out_free_hba;
	}

	ret = hba->transport->attach_hba(hba, plugin_dep_id);
	if (ret < 0)
		goto out_module_put;

	spin_lock(&hba_lock);
	hba->hba_id = hba_id_counter++;
	list_add_tail(&hba->hba_node, &hba_list);
	spin_unlock(&hba_lock);

	pr_debug("CORE_HBA[%d] - Attached HBA to Generic Target"
			" Core\n", hba->hba_id);

	return hba;

out_module_put:
	if (hba->transport->owner)
		module_put(hba->transport->owner);
	hba->transport = NULL;
out_free_hba:
	kfree(hba);
	return ERR_PTR(ret);
}

int
core_delete_hba(struct se_hba *hba)
{
	if (!list_empty(&hba->hba_dev_list))
		dump_stack();

	hba->transport->detach_hba(hba);

	spin_lock(&hba_lock);
	list_del(&hba->hba_node);
	spin_unlock(&hba_lock);

	pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
			" Core\n", hba->hba_id);

	if (hba->transport->owner)
		module_put(hba->transport->owner);

	hba->transport = NULL;
	kfree(hba);
	return 0;
}