path: root/drivers/scsi/libfc/fc_rport.c

/*
 * Copyright(c) 2007 - 2008 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained at www.Open-FCoE.org
 */

/*
 * RPORT GENERAL INFO
 *
 * This file contains all processing regarding fc_rports. It contains the
 * rport state machine and does all rport interaction with the transport class.
 * There should be no other places in libfc that interact directly with the
 * transport class in regards to adding and deleting rports.
 *
 * fc_rport's represent N_Port's within the fabric.
 */

/*
 * RPORT LOCKING
 *
 * The rport should never hold the rport mutex and then attempt to acquire
 * either the lport or disc mutexes. The rport's mutex is considered lesser
 * than both the lport's mutex and the disc mutex. Refer to fc_lport.c for
 * more comments on the heirarchy.
 *
 * The locking strategy is similar to the lport's strategy. The lock protects
 * the rport's states and is held and released by the entry points to the rport
 * block. All _enter_* functions correspond to rport states and expect the rport
 * mutex to be locked before calling them. This means that rports only handle
 * one request or response at a time, since they're not critical for the I/O
 * path this potential over-use of the mutex is acceptable.
 */

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/rcupdate.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/unaligned.h>

#include <scsi/libfc.h>
#include <scsi/fc_encode.h>

static int fc_rport_debug;

#define FC_DEBUG_RPORT(fmt...)			\
	do {					\
		if (fc_rport_debug)		\
			FC_DBG(fmt);		\
	} while (0)

struct workqueue_struct *rport_event_queue;

static void fc_rport_enter_plogi(struct fc_rport *);
static void fc_rport_enter_prli(struct fc_rport *);
static void fc_rport_enter_rtv(struct fc_rport *);
static void fc_rport_enter_ready(struct fc_rport *);
static void fc_rport_enter_logo(struct fc_rport *);

static void fc_rport_recv_plogi_req(struct fc_rport *,
				    struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_prli_req(struct fc_rport *,
				   struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_prlo_req(struct fc_rport *,
				   struct fc_seq *, struct fc_frame *);
static void fc_rport_recv_logo_req(struct fc_rport *,
				   struct fc_seq *, struct fc_frame *);
static void fc_rport_timeout(struct work_struct *);
static void fc_rport_error(struct fc_rport *, struct fc_frame *);
static void fc_rport_e