include/scsi/scsi_transport_iscsi.h

   1 /*
   2  * iSCSI transport class definitions
   3  *
   4  * Copyright (C) IBM Corporation, 2004
   5  * Copyright (C) Mike Christie, 2004 - 2006
   6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
   7  * Copyright (C) Alex Aizman, 2004 - 2005
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23 #ifndef SCSI_TRANSPORT_ISCSI_H
  24 #define SCSI_TRANSPORT_ISCSI_H
  25
  26 #include <linux/device.h>
  27 #include <linux/list.h>
  28 #include <linux/mutex.h>
  29 #include <scsi/iscsi_if.h>
  30
  31 struct scsi_transport_template;
  32 struct iscsi_transport;
  33 struct Scsi_Host;
  34 struct iscsi_cls_conn;
  35 struct iscsi_conn;
  36 struct iscsi_cmd_task;
  37 struct iscsi_mgmt_task;
  38 struct sockaddr;
  39
  40 /**
  41  * struct iscsi_transport - iSCSI Transport template
  42  *
  43  * @name:               transport name
  44  * @caps:               iSCSI Data-Path capabilities
  45  * @create_session:     create new iSCSI session object
  46  * @destroy_session:    destroy existing iSCSI session object
  47  * @create_conn:        create new iSCSI connection
  48  * @bind_conn:          associate this connection with existing iSCSI session
  49  *                      and specified transport descriptor
  50  * @destroy_conn:       destroy inactive iSCSI connection
  51  * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  52  *                      when param is not supported, and a -Exx value on other
  53  *                      error.
  54  * @get_param           get iSCSI parameter. Must return number of bytes
  55  *                      copied to buffer on success, -ENODATA when param
  56  *                      is not supported, and a -Exx value on other error
  57  * @start_conn:         set connection to be operational
  58  * @stop_conn:          suspend/recover/terminate connection
  59  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  60  * @session_recovery_timedout: notify LLD a block during recovery timed out
  61  * @init_cmd_task:      Initialize a iscsi_cmd_task and any internal structs.
  62  *                      Called from queuecommand with session lock held.
  63  * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.
  64  *                      Called from iscsi_conn_send_generic with xmitmutex.
  65  * @xmit_cmd_task:      Requests LLD to transfer cmd task. Returns 0 or the
  66  *                      the number of bytes transferred on success, and -Exyz
  67  *                      value on error.
  68  * @xmit_mgmt_task:     Requests LLD to transfer mgmt task. Returns 0 or the
  69  *                      the number of bytes transferred on success, and -Exyz
  70  *                      value on error.
  71  * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex
  72  *                      and session->lock after the connection has been
  73  *                      suspended and terminated during recovery. If called
  74  *                      from abort task then connection is not suspended
  75  *                      or terminated but sk_callback_lock is held
  76  *
  77  * Template API provided by iSCSI Transport
  78  */
  79 struct iscsi_transport {
  80         struct module *owner;
  81         char *name;
  82         unsigned int caps;
  83         /* LLD sets this to indicate what values it can export to sysfs */
  84         uint64_t param_mask;
  85         uint64_t host_param_mask;
  86         /* LLD connection data size */
  87         int conndata_size;
  88         /* LLD session data size */
  89         int sessiondata_size;
  90         struct iscsi_cls_session *(*create_session) (struct Scsi_Host *shost,
  91                                         uint16_t cmds_max, uint16_t qdepth,
  92                                         uint32_t sn, uint32_t *hn);
  93         void (*destroy_session) (struct iscsi_cls_session *session);
  94         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  95                                 uint32_t cid);
  96         int (*bind_conn) (struct iscsi_cls_session *session,
  97                           struct iscsi_cls_conn *cls_conn,
  98                           uint64_t transport_eph, int is_leading);
  99         int (*start_conn) (struct iscsi_cls_conn *conn);
 100         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 101         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 102         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 103                           char *buf, int buflen);
 104         int (*get_conn_param) (struct iscsi_cls_conn *conn,
 105                                enum iscsi_param param, char *buf);
 106         int (*get_session_param) (struct iscsi_cls_session *session,
 107                                   enum iscsi_param param, char *buf);
 108         int (*get_host_param) (struct Scsi_Host *shost,
 109                                 enum iscsi_host_param param, char *buf);
 110         int (*set_host_param) (struct Scsi_Host *shost,
 111                                enum iscsi_host_param param, char *buf,
 112                                int buflen);
 113         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 114                          char *data, uint32_t data_size);
 115         void (*get_stats) (struct iscsi_cls_conn *conn,
 116                            struct iscsi_stats *stats);
 117         int (*init_cmd_task) (struct iscsi_cmd_task *ctask);
 118         void (*init_mgmt_task) (struct iscsi_conn *conn,
 119                                 struct iscsi_mgmt_task *mtask);
 120         int (*xmit_cmd_task) (struct iscsi_conn *conn,
 121                               struct iscsi_cmd_task *ctask);
 122         void (*cleanup_cmd_task) (struct iscsi_conn *conn,
 123                                   struct iscsi_cmd_task *ctask);
 124         int (*xmit_mgmt_task) (struct iscsi_conn *conn,
 125                                struct iscsi_mgmt_task *mtask);
 126         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 127         int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
 128                            uint64_t *ep_handle);
 129         int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
 130         void (*ep_disconnect) (uint64_t ep_handle);
 131         int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 132                           uint32_t enable, struct sockaddr *dst_addr);
 133 };
 134
 135 /*
 136  * transport registration upcalls
 137  */
 138 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 139 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 140
 141 /*
 142  * control plane upcalls
 143  */
 144 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
 145 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 146                           char *data, uint32_t data_size);
 147
 148 struct iscsi_cls_conn {
 149         struct list_head conn_list;     /* item in connlist */
 150         void *dd_data;                  /* LLD private data */
 151         struct iscsi_transport *transport;
 152         uint32_t cid;                   /* connection id */
 153
 154         int active;                     /* must be accessed with the connlock */
 155         struct device dev;              /* sysfs transport/container device */
 156 };
 157
 158 #define iscsi_dev_to_conn(_dev) \
 159         container_of(_dev, struct iscsi_cls_conn, dev)
 160
 161 #define iscsi_conn_to_session(_conn) \
 162         iscsi_dev_to_session(_conn->dev.parent)
 163
 164 /* iscsi class session state */
 165 enum {
 166         ISCSI_SESSION_LOGGED_IN,
 167         ISCSI_SESSION_FAILED,
 168         ISCSI_SESSION_FREE,
 169 };
 170
 171 struct iscsi_cls_session {
 172         struct list_head sess_list;             /* item in session_list */
 173         struct list_head host_list;
 174         struct iscsi_transport *transport;
 175         spinlock_t lock;
 176         struct work_struct block_work;
 177         struct work_struct unblock_work;
 178         struct work_struct scan_work;
 179         struct work_struct unbind_work;
 180
 181         /* recovery fields */
 182         int recovery_tmo;
 183         struct delayed_work recovery_work;
 184
 185         int target_id;
 186
 187         int state;
 188         int sid;                                /* session id */
 189         void *dd_data;                          /* LLD private data */
 190         struct device dev;      /* sysfs transport/container device */
 191 };
 192
 193 #define iscsi_dev_to_session(_dev) \
 194         container_of(_dev, struct iscsi_cls_session, dev)
 195
 196 #define iscsi_session_to_shost(_session) \
 197         dev_to_shost(_session->dev.parent)
 198
 199 #define starget_to_session(_stgt) \
 200         iscsi_dev_to_session(_stgt->dev.parent)
 201
 202 struct iscsi_cls_host {
 203         struct list_head sessions;
 204         atomic_t nr_scans;
 205         struct mutex mutex;
 206         struct workqueue_struct *scan_workq;
 207         char scan_workq_name[KOBJ_NAME_LEN];
 208 };
 209
 210 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 211                                 void (*fn)(struct iscsi_cls_session *));
 212
 213
 214 /*
 215  * session and connection functions that can be used by HW iSCSI LLDs
 216  */
 217 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 218         dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 219
 220 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 221         dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 222
 223 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 224 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 225                                         struct iscsi_transport *transport);
 226 extern int iscsi_add_session(struct iscsi_cls_session *session,
 227                              unsigned int target_id);
 228 extern int iscsi_session_event(struct iscsi_cls_session *session,
 229                                enum iscsi_uevent_e event);
 230 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 231                                                 struct iscsi_transport *t,
 232                                                 unsigned int target_id);
 233 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 234 extern void iscsi_free_session(struct iscsi_cls_session *session);
 235 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 236 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 237                                             uint32_t cid);
 238 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 239 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 240 extern void iscsi_block_session(struct iscsi_cls_session *session);
 241 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 242
 243 #endif