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 iscsi_endpoint;
  34 struct Scsi_Host;
  35 struct iscsi_cls_conn;
  36 struct iscsi_conn;
  37 struct iscsi_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_task:          Initialize a iscsi_task and any internal structs.
  62  *                      When offloading the data path, this is called from
  63  *                      queuecommand with the session lock, or from the
  64  *                      iscsi_conn_send_pdu context with the session lock.
  65  *                      When not offloading the data path, this is called
  66  *                      from the scsi work queue without the session lock.
  67  * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  68  *                      the number of bytes transferred on success, and -Exyz
  69  *                      value on error. When offloading the data path, this
  70  *                      is called from queuecommand with the session lock, or
  71  *                      from the iscsi_conn_send_pdu context with the session
  72  *                      lock. When not offloading the data path, this is called
  73  *                      from the scsi work queue without the session lock.
  74  * @cleanup_task:       requests LLD to fail task. Called with session lock
  75  *                      and after the connection has been suspended and
  76  *                      terminated during recovery. If called
  77  *                      from abort task then connection is not suspended
  78  *                      or terminated but sk_callback_lock is held
  79  *
  80  * Template API provided by iSCSI Transport
  81  */
  82 struct iscsi_transport {
  83         struct module *owner;
  84         char *name;
  85         unsigned int caps;
  86         /* LLD sets this to indicate what values it can export to sysfs */
  87         uint64_t param_mask;
  88         uint64_t host_param_mask;
  89         struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
  90                                         uint16_t cmds_max, uint16_t qdepth,
  91                                         uint32_t sn);
  92         void (*destroy_session) (struct iscsi_cls_session *session);
  93         struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
  94                                 uint32_t cid);
  95         int (*bind_conn) (struct iscsi_cls_session *session,
  96                           struct iscsi_cls_conn *cls_conn,
  97                           uint64_t transport_eph, int is_leading);
  98         int (*start_conn) (struct iscsi_cls_conn *conn);
  99         void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
 100         void (*destroy_conn) (struct iscsi_cls_conn *conn);
 101         int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 102                           char *buf, int buflen);
 103         int (*get_conn_param) (struct iscsi_cls_conn *conn,
 104                                enum iscsi_param param, char *buf);
 105         int (*get_session_param) (struct iscsi_cls_session *session,
 106                                   enum iscsi_param param, char *buf);
 107         int (*get_host_param) (struct Scsi_Host *shost,
 108                                 enum iscsi_host_param param, char *buf);
 109         int (*set_host_param) (struct Scsi_Host *shost,
 110                                enum iscsi_host_param param, char *buf,
 111                                int buflen);
 112         int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 113                          char *data, uint32_t data_size);
 114         void (*get_stats) (struct iscsi_cls_conn *conn,
 115                            struct iscsi_stats *stats);
 116
 117         int (*init_task) (struct iscsi_task *task);
 118         int (*xmit_task) (struct iscsi_task *task);
 119         void (*cleanup_task) (struct iscsi_task *task);
 120
 121         int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
 122         int (*xmit_pdu) (struct iscsi_task *task);
 123         int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
 124                          unsigned int count);
 125         void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
 126                                int *index, int *age);
 127
 128         void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 129         struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
 130                                               struct sockaddr *dst_addr,
 131                                               int non_blocking);
 132         int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
 133         void (*ep_disconnect) (struct iscsi_endpoint *ep);
 134         int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 135                           uint32_t enable, struct sockaddr *dst_addr);
 136         int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
 137 };
 138
 139 /*
 140  * transport registration upcalls
 141  */
 142 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 143 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 144
 145 /*
 146  * control plane upcalls
 147  */
 148 extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
 149                                    enum iscsi_err error);
 150 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 151                           char *data, uint32_t data_size);
 152
 153 extern int iscsi_offload_mesg(struct Scsi_Host *shost,
 154                               struct iscsi_transport *transport, uint32_t type,
 155                               char *data, uint16_t data_size);
 156
 157 struct iscsi_cls_conn {
 158         struct list_head conn_list;     /* item in connlist */
 159         void *dd_data;                  /* LLD private data */
 160         struct iscsi_transport *transport;
 161         uint32_t cid;                   /* connection id */
 162
 163         int active;                     /* must be accessed with the connlock */
 164         struct device dev;              /* sysfs transport/container device */
 165 };
 166
 167 #define iscsi_dev_to_conn(_dev) \
 168         container_of(_dev, struct iscsi_cls_conn, dev)
 169
 170 #define iscsi_conn_to_session(_conn) \
 171         iscsi_dev_to_session(_conn->dev.parent)
 172
 173 /* iscsi class session state */
 174 enum {
 175         ISCSI_SESSION_LOGGED_IN,
 176         ISCSI_SESSION_FAILED,
 177         ISCSI_SESSION_FREE,
 178 };
 179
 180 #define ISCSI_MAX_TARGET -1
 181
 182 struct iscsi_cls_session {
 183         struct list_head sess_list;             /* item in session_list */
 184         struct iscsi_transport *transport;
 185         spinlock_t lock;
 186         struct work_struct block_work;
 187         struct work_struct unblock_work;
 188         struct work_struct scan_work;
 189         struct work_struct unbind_work;
 190
 191         /* recovery fields */
 192         int recovery_tmo;
 193         struct delayed_work recovery_work;
 194
 195         unsigned int target_id;
 196
 197         int state;
 198         int sid;                                /* session id */
 199         void *dd_data;                          /* LLD private data */
 200         struct device dev;      /* sysfs transport/container device */
 201 };
 202
 203 #define iscsi_dev_to_session(_dev) \
 204         container_of(_dev, struct iscsi_cls_session, dev)
 205
 206 #define iscsi_session_to_shost(_session) \
 207         dev_to_shost(_session->dev.parent)
 208
 209 #define starget_to_session(_stgt) \
 210         iscsi_dev_to_session(_stgt->dev.parent)
 211
 212 struct iscsi_cls_host {
 213         atomic_t nr_scans;
 214         struct mutex mutex;
 215 };
 216
 217 extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 218                                 void (*fn)(struct iscsi_cls_session *));
 219
 220 struct iscsi_endpoint {
 221         void *dd_data;                  /* LLD private data */
 222         struct device dev;
 223         uint64_t id;
 224 };
 225
 226 /*
 227  * session and connection functions that can be used by HW iSCSI LLDs
 228  */
 229 #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 230         dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 231
 232 #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 233         dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 234
 235 extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 236 extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 237                                 struct iscsi_transport *transport, int dd_size);
 238 extern int iscsi_add_session(struct iscsi_cls_session *session,
 239                              unsigned int target_id);
 240 extern int iscsi_session_event(struct iscsi_cls_session *session,
 241                                enum iscsi_uevent_e event);
 242 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 243                                                 struct iscsi_transport *t,
 244                                                 int dd_size,
 245                                                 unsigned int target_id);
 246 extern void iscsi_remove_session(struct iscsi_cls_session *session);
 247 extern void iscsi_free_session(struct iscsi_cls_session *session);
 248 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 249 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 250                                                 int dd_size, uint32_t cid);
 251 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 252 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 253 extern void iscsi_block_session(struct iscsi_cls_session *session);
 254 extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 255 extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
 256 extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
 257 extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
 258
 259 #endif