diff options
Diffstat (limited to 'drivers/target/target_core_hba.c')
| -rw-r--r-- | drivers/target/target_core_hba.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c new file mode 100644 index 000000000..22390e0e0 --- /dev/null +++ b/drivers/target/target_core_hba.c @@ -0,0 +1,191 @@ +/******************************************************************************* + * Filename: target_core_hba.c + * + * This file contains the TCM HBA Transport related functions. + * + * (c) Copyright 2003-2013 Datera, Inc. + * + * 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(backend_list); +static DEFINE_MUTEX(backend_mutex); + +static u32 hba_id_counter; + +static DEFINE_SPINLOCK(hba_lock); +static LIST_HEAD(hba_list); + + +int transport_backend_register(const struct target_backend_ops *ops) +{ + struct target_backend *tb, *old; + + tb = kzalloc(sizeof(*tb), GFP_KERNEL); + if (!tb) + return -ENOMEM; + tb->ops = ops; + + mutex_lock(&backend_mutex); + list_for_each_entry(old, &backend_list, list) { + if (!strcmp(old->ops->name, ops->name)) { + pr_err("backend %s already registered.\n", ops->name); + mutex_unlock(&backend_mutex); + kfree(tb); + return -EEXIST; + } + } + target_setup_backend_cits(tb); + list_add_tail(&tb->list, &backend_list); + mutex_unlock(&backend_mutex); + + pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n", + ops->name, ops->owner); + return 0; +} +EXPORT_SYMBOL(transport_backend_register); + +void target_backend_unregister(const struct target_backend_ops *ops) +{ + struct target_backend *tb; + + mutex_lock(&backend_mutex); + list_for_each_entry(tb, &backend_list, list) { + if (tb->ops == ops) { + list_del(&tb->list); + mutex_unlock(&backend_mutex); + /* + * Wait for any outstanding backend driver ->rcu_head + * callbacks to complete post TBO->free_device() -> + * call_rcu(), before allowing backend driver module + * unload of target_backend_ops->owner to proceed. + */ + rcu_barrier(); + kfree(tb); + return; + } + } + mutex_unlock(&backend_mutex); +} +EXPORT_SYMBOL(target_backend_unregister); + +static struct target_backend *core_get_backend(const char *name) +{ + struct target_backend *tb; + + mutex_lock(&backend_mutex); + list_for_each_entry(tb, &backend_list, list) { + if (!strcmp(tb->ops->name, name)) + goto found; + } + mutex_unlock(&backend_mutex); + return NULL; +found: + if (tb->ops->owner && !try_module_get(tb->ops->owner)) + tb = NULL; + mutex_unlock(&backend_mutex); + return tb; +} + +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->backend = core_get_backend(plugin_name); + if (!hba->backend) { + ret = -EINVAL; + goto out_free_hba; + } + + ret = hba->backend->ops->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: + module_put(hba->backend->ops->owner); + hba->backend = NULL; +out_free_hba: + kfree(hba); + return ERR_PTR(ret); +} + +int +core_delete_hba(struct se_hba *hba) +{ + WARN_ON(hba->dev_count); + + hba->backend->ops->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); + + module_put(hba->backend->ops->owner); + + hba->backend = NULL; + kfree(hba); + return 0; +} + +bool target_sense_desc_format(struct se_device *dev) +{ + return (dev) ? dev->transport->get_blocks(dev) > U32_MAX : false; +} |