/*******************************************************************************
* Filename: target_core_hba.c
*
* This file contains the TCM HBA Transport related functions.
*
* (c) Copyright 2003-2012 RisingTide Systems LLC.
*
* 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_backend.h>
#include <target/target_core_fabric.h>
#include "target_core_internal.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);
}
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)
{
WARN_ON(hba->dev_count);
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;
}
