/*

   * iSCSI transport class definitions
   *
   * Copyright (C) IBM Corporation, 2004

   * Copyright (C) Mike Christie, 2004 - 2006

   * Copyright (C) Dmitry Yusupov, 2004 - 2005
   * Copyright (C) Alex Aizman, 2004 - 2005

   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   */
  #ifndef SCSI_TRANSPORT_ISCSI_H
  #define SCSI_TRANSPORT_ISCSI_H

  #include <linux/device.h>

  #include <linux/list.h>
  #include <linux/mutex.h>

  #include <scsi/iscsi_if.h>

  struct scsi_transport_template;

  struct iscsi_transport;

  struct iscsi_endpoint;

  struct Scsi_Host;

  struct scsi_cmnd;

  struct iscsi_cls_conn;

  struct iscsi_conn;

  struct iscsi_task;

  struct sockaddr;

  struct iscsi_iface;

  struct bsg_job;

  /**
   * struct iscsi_transport - iSCSI Transport template
   *
   * @name:		transport name
   * @caps:		iSCSI Data-Path capabilities
   * @create_session:	create new iSCSI session object
   * @destroy_session:	destroy existing iSCSI session object
   * @create_conn:	create new iSCSI connection
   * @bind_conn:		associate this connection with existing iSCSI session
   *			and specified transport descriptor
   * @destroy_conn:	destroy inactive iSCSI connection

   * @set_param:		set iSCSI parameter. Return 0 on success, -ENODATA
   *			when param is not supported, and a -Exx value on other
   *			error.
   * @get_param		get iSCSI parameter. Must return number of bytes
   *			copied to buffer on success, -ENODATA when param
   *			is not supported, and a -Exx value on other error

   * @start_conn:		set connection to be operational
   * @stop_conn:		suspend/recover/terminate connection
   * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.

   * @session_recovery_timedout: notify LLD a block during recovery timed out

   * @init_task:		Initialize a iscsi_task and any internal structs.
   *			When offloading the data path, this is called from
   *			queuecommand with the session lock, or from the
   *			iscsi_conn_send_pdu context with the session lock.
   *			When not offloading the data path, this is called
   *			from the scsi work queue without the session lock.
   * @xmit_task		Requests LLD to transfer cmd task. Returns 0 or the

   *			the number of bytes transferred on success, and -Exyz

   *			value on error. When offloading the data path, this
   *			is called from queuecommand with the session lock, or
   *			from the iscsi_conn_send_pdu context with the session
   *			lock. When not offloading the data path, this is called
   *			from the scsi work queue without the session lock.
   * @cleanup_task:	requests LLD to fail task. Called with session lock
   *			and after the connection has been suspended and
   *			terminated during recovery. If called

   *			from abort task then connection is not suspended
   *			or terminated but sk_callback_lock is held

   *
   * Template API provided by iSCSI Transport
   */
  struct iscsi_transport {
  	struct module *owner;
  	char *name;
  	unsigned int caps;

  	struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,

  					uint16_t cmds_max, uint16_t qdepth,

  					uint32_t sn);

  	void (*destroy_session) (struct iscsi_cls_session *session);
  	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,

  				uint32_t cid);

  	int (*bind_conn) (struct iscsi_cls_session *session,
  			  struct iscsi_cls_conn *cls_conn,

  			  uint64_t transport_eph, int is_leading);

  	int (*start_conn) (struct iscsi_cls_conn *conn);
  	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);

  	void (*destroy_conn) (struct iscsi_cls_conn *conn);

  	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,

  			  char *buf, int buflen);

  	int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
  			     char *buf);

  	int (*get_conn_param) (struct iscsi_cls_conn *conn,

  			       enum iscsi_param param, char *buf);

  	int (*get_session_param) (struct iscsi_cls_session *session,

  				  enum iscsi_param param, char *buf);

  	int (*get_host_param) (struct Scsi_Host *shost,
  				enum iscsi_host_param param, char *buf);

  	int (*set_host_param) (struct Scsi_Host *shost,
  			       enum iscsi_host_param param, char *buf,
  			       int buflen);

  	int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,

  			 char *data, uint32_t data_size);

  	void (*get_stats) (struct iscsi_cls_conn *conn,
  			   struct iscsi_stats *stats);

  	int (*init_task) (struct iscsi_task *task);
  	int (*xmit_task) (struct iscsi_task *task);

  	void (*cleanup_task) (struct iscsi_task *task);

  	int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);

  	int (*xmit_pdu) (struct iscsi_task *task);
  	int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
  			 unsigned int count);

  	void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
  			       int *index, int *age);

  	void (*session_recovery_timedout) (struct iscsi_cls_session *session);

  	struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
  					      struct sockaddr *dst_addr,

  					      int non_blocking);
  	int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
  	void (*ep_disconnect) (struct iscsi_endpoint *ep);

  	int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,

  			  uint32_t enable, struct sockaddr *dst_addr);

  	int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);

  	int (*set_iface_param) (struct Scsi_Host *shost, void *data,
  				uint32_t len);

  	int (*get_iface_param) (struct iscsi_iface *iface,
  				enum iscsi_param_type param_type,
  				int param, char *buf);

  	umode_t (*attr_is_visible)(int param_type, int param);

  	int (*bsg_request)(struct bsg_job *job);

  };
  
  /*

   * transport registration upcalls

   */

  extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);

  extern int iscsi_unregister_transport(struct iscsi_transport *tt);

  
  /*

   * control plane upcalls

   */

  extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
  				   enum iscsi_err error);

  extern void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
  				   enum iscsi_conn_state state);

  extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,

  			  char *data, uint32_t data_size);

  extern int iscsi_offload_mesg(struct Scsi_Host *shost,
  			      struct iscsi_transport *transport, uint32_t type,
  			      char *data, uint16_t data_size);

  struct iscsi_cls_conn {
  	struct list_head conn_list;	/* item in connlist */
  	void *dd_data;			/* LLD private data */
  	struct iscsi_transport *transport;

  	uint32_t cid;			/* connection id */

  	struct mutex ep_mutex;
  	struct iscsi_endpoint *ep;

  	struct device dev;		/* sysfs transport/container device */

  };
  
  #define iscsi_dev_to_conn(_dev) \
  	container_of(_dev, struct iscsi_cls_conn, dev)

  #define transport_class_to_conn(_cdev) \
  	iscsi_dev_to_conn(_cdev->parent)

  #define iscsi_conn_to_session(_conn) \
  	iscsi_dev_to_session(_conn->dev.parent)
  
  /* iscsi class session state */
  enum {
  	ISCSI_SESSION_LOGGED_IN,
  	ISCSI_SESSION_FAILED,
  	ISCSI_SESSION_FREE,
  };

  #define ISCSI_MAX_TARGET -1

  struct iscsi_cls_session {

  	struct list_head sess_list;		/* item in session_list */

  	struct iscsi_transport *transport;

  	spinlock_t lock;

  	struct work_struct block_work;
  	struct work_struct unblock_work;

  	struct work_struct scan_work;
  	struct work_struct unbind_work;

  	/* recovery fields */
  	int recovery_tmo;

  	struct delayed_work recovery_work;

  	unsigned int target_id;

  	bool ida_used;

  	/*
  	 * pid of userspace process that created session or -1 if
  	 * created by the kernel.
  	 */
  	pid_t creator;

  	int state;

  	int sid;				/* session id */
  	void *dd_data;				/* LLD private data */

  	struct device dev;	/* sysfs transport/container device */
  };
  
  #define iscsi_dev_to_session(_dev) \
  	container_of(_dev, struct iscsi_cls_session, dev)

  #define transport_class_to_session(_cdev) \
  	iscsi_dev_to_session(_cdev->parent)

  #define iscsi_session_to_shost(_session) \
  	dev_to_shost(_session->dev.parent)

  #define starget_to_session(_stgt) \
  	iscsi_dev_to_session(_stgt->dev.parent)

  struct iscsi_cls_host {

  	atomic_t nr_scans;

  	struct mutex mutex;

  	struct request_queue *bsg_q;

  };

  #define iscsi_job_to_shost(_job) \
          dev_to_shost(_job->dev)

  extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
  				void (*fn)(struct iscsi_cls_session *));

  struct iscsi_endpoint {
  	void *dd_data;			/* LLD private data */
  	struct device dev;

  	uint64_t id;

  	struct iscsi_cls_conn *conn;

  };

  struct iscsi_iface {
  	struct device dev;
  	struct iscsi_transport *transport;
  	uint32_t iface_type;	/* IPv4 or IPv6 */
  	uint32_t iface_num;	/* iface number, 0 - n */
  	void *dd_data;		/* LLD private data */
  };
  
  #define iscsi_dev_to_iface(_dev) \
  	container_of(_dev, struct iscsi_iface, dev)
  
  #define iscsi_iface_to_shost(_iface) \
  	dev_to_shost(_iface->dev.parent)

  /*
   * session and connection functions that can be used by HW iSCSI LLDs
   */

  #define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
  	dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)
  
  #define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
  	dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)

  extern int iscsi_session_chkready(struct iscsi_cls_session *session);

  extern int iscsi_is_session_online(struct iscsi_cls_session *session);

  extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,

  				struct iscsi_transport *transport, int dd_size);

  extern int iscsi_add_session(struct iscsi_cls_session *session,
  			     unsigned int target_id);

  extern int iscsi_session_event(struct iscsi_cls_session *session,
  			       enum iscsi_uevent_e event);

  extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,

  						struct iscsi_transport *t,

  						int dd_size,

  						unsigned int target_id);

  extern void iscsi_remove_session(struct iscsi_cls_session *session);
  extern void iscsi_free_session(struct iscsi_cls_session *session);

  extern int iscsi_destroy_session(struct iscsi_cls_session *session);
  extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,

  						int dd_size, uint32_t cid);

  extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);

  extern void iscsi_unblock_session(struct iscsi_cls_session *session);
  extern void iscsi_block_session(struct iscsi_cls_session *session);

  extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);

  extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
  extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
  extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);

  extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);

  extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
  					      struct iscsi_transport *t,
  					      uint32_t iface_type,
  					      uint32_t iface_num, int dd_size);
  extern void iscsi_destroy_iface(struct iscsi_iface *iface);
  extern struct iscsi_iface *iscsi_lookup_iface(int handle);

  #endif