Nicholas Bellinger | c66ac9d | 2010-12-17 11:11:26 -0800 | [diff] [blame] | 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 | |
| 47 | static LIST_HEAD(subsystem_list); |
| 48 | static DEFINE_MUTEX(subsystem_mutex); |
| 49 | |
| 50 | int 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 | } |
| 73 | EXPORT_SYMBOL(transport_subsystem_register); |
| 74 | |
| 75 | void 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 | } |
| 81 | EXPORT_SYMBOL(transport_subsystem_release); |
| 82 | |
| 83 | static 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; |
| 94 | found: |
| 95 | if (s->owner && !try_module_get(s->owner)) |
| 96 | s = NULL; |
| 97 | mutex_unlock(&subsystem_mutex); |
| 98 | return s; |
| 99 | } |
| 100 | |
| 101 | struct se_hba * |
| 102 | core_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 | |
| 144 | out_module_put: |
| 145 | if (hba->transport->owner) |
| 146 | module_put(hba->transport->owner); |
| 147 | hba->transport = NULL; |
| 148 | out_free_hba: |
| 149 | kfree(hba); |
| 150 | return ERR_PTR(ret); |
| 151 | } |
| 152 | |
| 153 | int |
| 154 | core_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 | } |