LXR linux/include/scsi/scsi_transport

   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
  31struct scsi_transport_template;
  32struct iscsi_transport;
  33struct iscsi_endpoint;
  34struct Scsi_Host;
  35struct scsi_cmnd;
  36struct iscsi_cls_conn;
  37struct iscsi_conn;
  38struct iscsi_task;
  39struct sockaddr;
  40struct iscsi_iface;
  41struct bsg_job;
  42
  43/**
  44 * struct iscsi_transport - iSCSI Transport template
  45 *
  46 * @name:               transport name
  47 * @caps:               iSCSI Data-Path capabilities
  48 * @create_session:     create new iSCSI session object
  49 * @destroy_session:    destroy existing iSCSI session object
  50 * @create_conn:        create new iSCSI connection
  51 * @bind_conn:          associate this connection with existing iSCSI session
  52 *                      and specified transport descriptor
  53 * @destroy_conn:       destroy inactive iSCSI connection
  54 * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
  55 *                      when param is not supported, and a -Exx value on other
  56 *                      error.
  57 * @get_param           get iSCSI parameter. Must return number of bytes
  58 *                      copied to buffer on success, -ENODATA when param
  59 *                      is not supported, and a -Exx value on other error
  60 * @start_conn:         set connection to be operational
  61 * @stop_conn:          suspend/recover/terminate connection
  62 * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
  63 * @session_recovery_timedout: notify LLD a block during recovery timed out
  64 * @init_task:          Initialize a iscsi_task and any internal structs.
  65 *                      When offloading the data path, this is called from
  66 *                      queuecommand with the session lock, or from the
  67 *                      iscsi_conn_send_pdu context with the session lock.
  68 *                      When not offloading the data path, this is called
  69 *                      from the scsi work queue without the session lock.
  70 * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
  71 *                      the number of bytes transferred on success, and -Exyz
  72 *                      value on error. When offloading the data path, this
  73 *                      is called from queuecommand with the session lock, or
  74 *                      from the iscsi_conn_send_pdu context with the session
  75 *                      lock. When not offloading the data path, this is called
  76 *                      from the scsi work queue without the session lock.
  77 * @cleanup_task:       requests LLD to fail task. Called with session lock
  78 *                      and after the connection has been suspended and
  79 *                      terminated during recovery. If called
  80 *                      from abort task then connection is not suspended
  81 *                      or terminated but sk_callback_lock is held
  82 *
  83 * Template API provided by iSCSI Transport
  84 */
  85struct iscsi_transport {
  86        struct module *owner;
  87        char *name;
  88        unsigned int caps;
  89
  90        struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
  91                                        uint16_t cmds_max, uint16_t qdepth,
  92                                        uint32_t sn);
  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_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
 105                             char *buf);
 106        int (*get_conn_param) (struct iscsi_cls_conn *conn,
 107                               enum iscsi_param param, char *buf);
 108        int (*get_session_param) (struct iscsi_cls_session *session,
 109                                  enum iscsi_param param, char *buf);
 110        int (*get_host_param) (struct Scsi_Host *shost,
 111                                enum iscsi_host_param param, char *buf);
 112        int (*set_host_param) (struct Scsi_Host *shost,
 113                               enum iscsi_host_param param, char *buf,
 114                               int buflen);
 115        int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 116                         char *data, uint32_t data_size);
 117        void (*get_stats) (struct iscsi_cls_conn *conn,
 118                           struct iscsi_stats *stats);
 119
 120        int (*init_task) (struct iscsi_task *task);
 121        int (*xmit_task) (struct iscsi_task *task);
 122        void (*cleanup_task) (struct iscsi_task *task);
 123
 124        int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
 125        int (*xmit_pdu) (struct iscsi_task *task);
 126        int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
 127                         unsigned int count);
 128        void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
 129                               int *index, int *age);
 130
 131        void (*session_recovery_timedout) (struct iscsi_cls_session *session);
 132        struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
 133                                              struct sockaddr *dst_addr,
 134                                              int non_blocking);
 135        int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
 136        void (*ep_disconnect) (struct iscsi_endpoint *ep);
 137        int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 138                          uint32_t enable, struct sockaddr *dst_addr);
 139        int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
 140        int (*set_iface_param) (struct Scsi_Host *shost, void *data,
 141                                uint32_t len);
 142        int (*get_iface_param) (struct iscsi_iface *iface,
 143                                enum iscsi_param_type param_type,
 144                                int param, char *buf);
 145        umode_t (*attr_is_visible)(int param_type, int param);
 146        int (*bsg_request)(struct bsg_job *job);
 147};
 148
 149/*
 150 * transport registration upcalls
 151 */
 152extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
 153extern int iscsi_unregister_transport(struct iscsi_transport *tt);
 154
 155/*
 156 * control plane upcalls
 157 */
 158extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
 159                                   enum iscsi_err error);
 160extern void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
 161                                   enum iscsi_conn_state state);
 162extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 163                          char *data, uint32_t data_size);
 164
 165extern int iscsi_offload_mesg(struct Scsi_Host *shost,
 166                              struct iscsi_transport *transport, uint32_t type,
 167                              char *data, uint16_t data_size);
 168
 169struct iscsi_cls_conn {
 170        struct list_head conn_list;     /* item in connlist */
 171        void *dd_data;                  /* LLD private data */
 172        struct iscsi_transport *transport;
 173        uint32_t cid;                   /* connection id */
 174        struct mutex ep_mutex;
 175        struct iscsi_endpoint *ep;
 176
 177        struct device dev;              /* sysfs transport/container device */
 178};
 179
 180#define iscsi_dev_to_conn(_dev) \
 181        container_of(_dev, struct iscsi_cls_conn, dev)
 182
 183#define transport_class_to_conn(_cdev) \
 184        iscsi_dev_to_conn(_cdev->parent)
 185
 186#define iscsi_conn_to_session(_conn) \
 187        iscsi_dev_to_session(_conn->dev.parent)
 188
 189/* iscsi class session state */
 190enum {
 191        ISCSI_SESSION_LOGGED_IN,
 192        ISCSI_SESSION_FAILED,
 193        ISCSI_SESSION_FREE,
 194};
 195
 196#define ISCSI_MAX_TARGET -1
 197
 198struct iscsi_cls_session {
 199        struct list_head sess_list;             /* item in session_list */
 200        struct iscsi_transport *transport;
 201        spinlock_t lock;
 202        struct work_struct block_work;
 203        struct work_struct unblock_work;
 204        struct work_struct scan_work;
 205        struct work_struct unbind_work;
 206
 207        /* recovery fields */
 208        int recovery_tmo;
 209        struct delayed_work recovery_work;
 210
 211        unsigned int target_id;
 212        bool ida_used;
 213
 214        /*
 215         * pid of userspace process that created session or -1 if
 216         * created by the kernel.
 217         */
 218        pid_t creator;
 219        int state;
 220        int sid;                                /* session id */
 221        void *dd_data;                          /* LLD private data */
 222        struct device dev;      /* sysfs transport/container device */
 223};
 224
 225#define iscsi_dev_to_session(_dev) \
 226        container_of(_dev, struct iscsi_cls_session, dev)
 227
 228#define transport_class_to_session(_cdev) \
 229        iscsi_dev_to_session(_cdev->parent)
 230
 231#define iscsi_session_to_shost(_session) \
 232        dev_to_shost(_session->dev.parent)
 233
 234#define starget_to_session(_stgt) \
 235        iscsi_dev_to_session(_stgt->dev.parent)
 236
 237struct iscsi_cls_host {
 238        atomic_t nr_scans;
 239        struct mutex mutex;
 240        struct request_queue *bsg_q;
 241};
 242
 243#define iscsi_job_to_shost(_job) \
 244        dev_to_shost(_job->dev)
 245
 246extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
 247                                void (*fn)(struct iscsi_cls_session *));
 248
 249struct iscsi_endpoint {
 250        void *dd_data;                  /* LLD private data */
 251        struct device dev;
 252        uint64_t id;
 253        struct iscsi_cls_conn *conn;
 254};
 255
 256struct iscsi_iface {
 257        struct device dev;
 258        struct iscsi_transport *transport;
 259        uint32_t iface_type;    /* IPv4 or IPv6 */
 260        uint32_t iface_num;     /* iface number, 0 - n */
 261        void *dd_data;          /* LLD private data */
 262};
 263
 264#define iscsi_dev_to_iface(_dev) \
 265        container_of(_dev, struct iscsi_iface, dev)
 266
 267#define iscsi_iface_to_shost(_iface) \
 268        dev_to_shost(_iface->dev.parent)
 269
 270/*
 271 * session and connection functions that can be used by HW iSCSI LLDs
 272 */
 273#define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
 274        dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
 275
 276#define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
 277        dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)
 278
 279extern int iscsi_session_chkready(struct iscsi_cls_session *session);
 280extern int iscsi_is_session_online(struct iscsi_cls_session *session);
 281extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
 282                                struct iscsi_transport *transport, int dd_size);
 283extern int iscsi_add_session(struct iscsi_cls_session *session,
 284                             unsigned int target_id);
 285extern int iscsi_session_event(struct iscsi_cls_session *session,
 286                               enum iscsi_uevent_e event);
 287extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
 288                                                struct iscsi_transport *t,
 289                                                int dd_size,
 290                                                unsigned int target_id);
 291extern void iscsi_remove_session(struct iscsi_cls_session *session);
 292extern void iscsi_free_session(struct iscsi_cls_session *session);
 293extern int iscsi_destroy_session(struct iscsi_cls_session *session);
 294extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
 295                                                int dd_size, uint32_t cid);
 296extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
 297extern void iscsi_unblock_session(struct iscsi_cls_session *session);
 298extern void iscsi_block_session(struct iscsi_cls_session *session);
 299extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
 300extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
 301extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
 302extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
 303extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
 304extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
 305                                              struct iscsi_transport *t,
 306                                              uint32_t iface_type,
 307                                              uint32_t iface_num, int dd_size);
 308extern void iscsi_destroy_iface(struct iscsi_iface *iface);
 309extern struct iscsi_iface *iscsi_lookup_iface(int handle);
 310
 311#endif
 312