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_task;
  37 struct sockaddr;
  38
  39 /**
  40  * struct iscsi_transport - iSCSI Transport template
  41  *
  42  * @name:               transport name
  43  * @caps:               iSCSI Data-Path capabilities
  44  * @create_session:     create new iSCSI session object
  45  * @destroy_session:    destroy existing iSCSI session object
  46  * @create_conn:        create new iSCSI connection
  47  * @bind_conn:          associate this connection with existing iSCSI session
  48  *                      and specified transport descriptor
  49  * @destroy_conn:       destroy inactive iSCSI connection
  50  * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  51  *                      when param is not supported, and a -Exx value on other
  52  *                      error.
  53  * @get_param           get iSCSI parameter. Must return number of bytes
  54  *                      copied to buffer on success, -ENODATA when param
  55  *                      is not supported, and a -Exx value on other error
  56  * @start_conn:         set connection to be operational
  57  * @stop_conn:          suspend/recover/terminate connection
  58  * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  59  * @session_recovery_timedout: notify LLD a block during recovery timed out
  60  * @init_task:          Initialize a iscsi_task and any internal structs.
  61  *                      When offloading the data path, this is called from
  62  *                      queuecommand with the session lock, or from the
  63  *                      iscsi_conn_send_pdu context with the session lock.
  64  *                      When not offloading the data path, this is called
  65  *                      from the scsi work queue without the session lock.
  66  * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  67  *                      the number of bytes transferred on success, and -Exyz
  68  *                      value on error. When offloading the data path, this
  69  *                      is called from queuecommand with the session lock, or
  70  *                      from the iscsi_conn_send_pdu context with the session
  71  *                      lock. When not offloading the data path, this is called
  72  *                      from the scsi work queue without the session lock.
  73  * @cleanup_task:       requests LLD to fail task. Called with session lock
  74  *                      and after the connection has been suspended and
  75  *                      terminated during recovery. If called
  76  *                      from abort task then connection is not suspended
  77  *                      or terminated but sk_callback_lock is held
  78  *
  79  * Template API provided by iSCSI Transport
  80  */
  81 struct iscsi_transport {
  82         struct module *owner;
  83         char *name;
  84         unsigned int caps;
  85         /* LLD sets this to indicate what values it can export to sysfs */
  86         uint64_t param_mask;
  87         uint64_t host_param_mask;
  88         struct iscsi_cls_session *(*create_session) (struct Scsi_Host *shost,
  89                                         uint16_t cmds_max, uint16_t qdepth,
  90                                         uint32_t sn, uint32_t *hn);
  91         void (*destroy_session) (struct iscsi_cls_session *session);
  92         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  93                                 uint32_t cid);
  94         int (*bind_conn) (struct iscsi_cls_session *session,
  95                           struct iscsi_cls_conn *cls_conn,
  96                           uint64_t transport_eph, int is_leading);
  97         int (*start_conn) (struct iscsi_cls_conn *conn);
  98         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
  99         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 100         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 101                           char *buf, int buflen);
 102         int (*get_conn_param) (struct iscsi_cls_conn *conn,
 103                                enum iscsi_param param, char *buf);
 104         int (*get_session_param) (struct iscsi_cls_session *session,
 105                                   enum iscsi_param param, char *buf);
 106         int (*get_host_param) (struct Scsi_Host *shost,
 107                                 enum iscsi_host_param param, char *buf);
 108         int (*set_host_param) (struct Scsi_Host *shost,
 109                                enum iscsi_host_param param, char *buf,
 110                                int buflen);
 111         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 112                          char *data, uint32_t data_size);
 113         void (*get_stats) (struct iscsi_cls_conn *conn,
 114                            struct iscsi_stats *stats);
 115         int (*init_task) (struct iscsi_task *task);
 116         int (*xmit_task) (struct iscsi_task *task);
 117         void (*cleanup_task) (struct iscsi_conn *conn,
 118                                   struct iscsi_task *task);
 119         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 120         int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
 121                            uint64_t *ep_handle);
 122         int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
 123         void (*ep_disconnect) (uint64_t ep_handle);
 124         int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 125                           uint32_t enable, struct sockaddr *dst_addr);
 126 };
 127
 128 /*
 129  * transport registration upcalls
 130  */
 131 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 132 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 133
 134 /*
 135  * control plane upcalls
 136  */
 137 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
 138 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 139                           char *data, uint32_t data_size);
 140
 141 struct iscsi_cls_conn {
 142         struct list_head conn_list;     /* item in connlist */
 143         void *dd_data;                  /* LLD private data */
 144         struct iscsi_transport *transport;
 145         uint32_t cid;                   /* connection id */
 146
 147         int active;                     /* must be accessed with the connlock */
 148         struct device dev;              /* sysfs transport/container device */
 149 };
 150
 151 #define iscsi_dev_to_conn(_dev) \
 152         container_of(_dev, struct iscsi_cls_conn, dev)
 153
 154 #define iscsi_conn_to_session(_conn) \
 155         iscsi_dev_to_session(_conn->dev.parent)
 156
 157 /* iscsi class session state */
 158 enum {
 159         ISCSI_SESSION_LOGGED_IN,
 160         ISCSI_SESSION_FAILED,
 161         ISCSI_SESSION_FREE,
 162 };
 163
 164 #define ISCSI_MAX_TARGET -1
 165
 166 struct iscsi_cls_session {
 167         struct list_head sess_list;             /* item in session_list */
 168         struct iscsi_transport *transport;
 169         spinlock_t lock;
 170         struct work_struct block_work;
 171         struct work_struct unblock_work;
 172         struct work_struct scan_work;
 173         struct work_struct unbind_work;
 174
 175         /* recovery fields */
 176         int recovery_tmo;
 177         struct delayed_work recovery_work;
 178
 179         unsigned int target_id;
 180
 181         int state;
 182         int sid;                                /* session id */
 183         void *dd_data;                          /* LLD private data */
 184         struct device dev;      /* sysfs transport/container device */
 185 };
 186
 187 #define iscsi_dev_to_session(_dev) \
 188         container_of(_dev, struct iscsi_cls_session, dev)
 189
 190 #define iscsi_session_to_shost(_session) \
 191         dev_to_shost(_session->dev.parent)
 192
 193 #define starget_to_session(_stgt) \
 194         iscsi_dev_to_session(_stgt->dev.parent)
 195
 196 struct iscsi_cls_host {
 197         atomic_t nr_scans;
 198         struct mutex mutex;
 199         struct workqueue_struct *scan_workq;
 200         char scan_workq_name[KOBJ_NAME_LEN];
 201 };
 202
 203 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 204                                 void (*fn)(struct iscsi_cls_session *));
 205
 206
 207 /*
 208  * session and connection functions that can be used by HW iSCSI LLDs
 209  */
 210 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 211         dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 212
 213 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 214         dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 215
 216 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 217 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 218                                 struct iscsi_transport *transport, int dd_size);
 219 extern int iscsi_add_session(struct iscsi_cls_session *session,
 220                              unsigned int target_id);
 221 extern int iscsi_session_event(struct iscsi_cls_session *session,
 222                                enum iscsi_uevent_e event);
 223 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 224                                                 struct iscsi_transport *t,
 225                                                 int dd_size,
 226                                                 unsigned int target_id);
 227 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 228 extern void iscsi_free_session(struct iscsi_cls_session *session);
 229 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 230 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 231                                                 int dd_size, uint32_t cid);
 232 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 233 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 234 extern void iscsi_block_session(struct iscsi_cls_session *session);
 235 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 236
 237 #endif