Initial import

1 files changed, 2245 insertions, 0 deletions

diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
new file mode 100644
index 000000000..c6795941b
--- /dev/null
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -0,0 +1,2245 @@
+/*
+ * Copyright(c) 2007 Intel Corporation. All rights reserved.
+ * Copyright(c) 2008 Red Hat, Inc.  All rights reserved.
+ * Copyright(c) 2008 Mike Christie
+ *
+ * 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
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/scatterlist.h>
+#include <linux/err.h>
+#include <linux/crc32.h>
+#include <linux/slab.h>
+
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_cmnd.h>
+
+#include <scsi/fc/fc_fc2.h>
+
+#include <scsi/libfc.h>
+#include <scsi/fc_encode.h>
+
+#include "fc_libfc.h"
+
+static struct kmem_cache *scsi_pkt_cachep;
+
+/* SRB state definitions */
+#define FC_SRB_FREE		0		/* cmd is free */
+#define FC_SRB_CMD_SENT		(1 << 0)	/* cmd has been sent */
+#define FC_SRB_RCV_STATUS	(1 << 1)	/* response has arrived */
+#define FC_SRB_ABORT_PENDING	(1 << 2)	/* cmd abort sent to device */
+#define FC_SRB_ABORTED		(1 << 3)	/* abort acknowledged */
+#define FC_SRB_DISCONTIG	(1 << 4)	/* non-sequential data recvd */
+#define FC_SRB_COMPL		(1 << 5)	/* fc_io_compl has been run */
+#define FC_SRB_FCP_PROCESSING_TMO (1 << 6)	/* timer function processing */
+
+#define FC_SRB_READ		(1 << 1)
+#define FC_SRB_WRITE		(1 << 0)
+
+/*
+ * The SCp.ptr should be tested and set under the scsi_pkt_queue lock
+ */
+#define CMD_SP(Cmnd)		    ((struct fc_fcp_pkt *)(Cmnd)->SCp.ptr)
+#define CMD_ENTRY_STATUS(Cmnd)	    ((Cmnd)->SCp.have_data_in)
+#define CMD_COMPL_STATUS(Cmnd)	    ((Cmnd)->SCp.this_residual)
+#define CMD_SCSI_STATUS(Cmnd)	    ((Cmnd)->SCp.Status)
+#define CMD_RESID_LEN(Cmnd)	    ((Cmnd)->SCp.buffers_residual)
+
+/**
+ * struct fc_fcp_internal - FCP layer internal data
+ * @scsi_pkt_pool: Memory pool to draw FCP packets from
+ * @scsi_queue_lock: Protects the scsi_pkt_queue
+ * @scsi_pkt_queue: Current FCP packets
+ * @last_can_queue_ramp_down_time: ramp down time
+ * @last_can_queue_ramp_up_time: ramp up time
+ * @max_can_queue: max can_queue size
+ */
+struct fc_fcp_internal {
+	mempool_t		*scsi_pkt_pool;
+	spinlock_t		scsi_queue_lock;
+	struct list_head	scsi_pkt_queue;
+	unsigned long		last_can_queue_ramp_down_time;
+	unsigned long		last_can_queue_ramp_up_time;
+	int			max_can_queue;
+};
+
+#define fc_get_scsi_internal(x)	((struct fc_fcp_internal *)(x)->scsi_priv)
+
+/*
+ * function prototypes
+ * FC scsi I/O related functions
+ */
+static void fc_fcp_recv_data(struct fc_fcp_pkt *, struct fc_frame *);
+static void fc_fcp_recv(struct fc_seq *, struct fc_frame *, void *);
+static void fc_fcp_resp(struct fc_fcp_pkt *, struct fc_frame *);
+static void fc_fcp_complete_locked(struct fc_fcp_pkt *);
+static void fc_tm_done(struct fc_seq *, struct fc_frame *, void *);
+static void fc_fcp_error(struct fc_fcp_pkt *, struct fc_frame *);
+static void fc_fcp_recovery(struct fc_fcp_pkt *, u8 code);
+static void fc_fcp_timeout(unsigned long);
+static void fc_fcp_rec(struct fc_fcp_pkt *);
+static void fc_fcp_rec_error(struct fc_fcp_pkt *, struct fc_frame *);
+static void fc_fcp_rec_resp(struct fc_seq *, struct fc_frame *, void *);
+static void fc_io_compl(struct fc_fcp_pkt *);
+
+static void fc_fcp_srr(struct fc_fcp_pkt *, enum fc_rctl, u32);
+static void fc_fcp_srr_resp(struct fc_seq *, struct fc_frame *, void *);
+static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
+
+/*
+ * command status codes
+ */
+#define FC_COMPLETE		0
+#define FC_CMD_ABORTED		1
+#define FC_CMD_RESET		2
+#define FC_CMD_PLOGO		3
+#define FC_SNS_RCV		4
+#define FC_TRANS_ERR		5
+#define FC_DATA_OVRRUN		6
+#define FC_DATA_UNDRUN		7
+#define FC_ERROR		8
+#define FC_HRD_ERROR		9
+#define FC_CRC_ERROR		10
+#define FC_TIMED_OUT		11
+
+/*
+ * Error recovery timeout values.
+ */
+#define FC_SCSI_TM_TOV		(10 * HZ)
+#define FC_HOST_RESET_TIMEOUT	(30 * HZ)
+#define FC_CAN_QUEUE_PERIOD	(60 * HZ)
+
+#define FC_MAX_ERROR_CNT	5
+#define FC_MAX_RECOV_RETRY	3
+
+#define FC_FCP_DFLT_QUEUE_DEPTH 32
+
+/**
+ * fc_fcp_pkt_alloc() - Allocate a fcp_pkt
+ * @lport: The local port that the FCP packet is for
+ * @gfp:   GFP flags for allocation
+ *
+ * Return value: fcp_pkt structure or null on allocation failure.
+ * Context:	 Can be called from process context, no lock is required.
+ */
+static struct fc_fcp_pkt *fc_fcp_pkt_alloc(struct fc_lport *lport, gfp_t gfp)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+	struct fc_fcp_pkt *fsp;
+
+	fsp = mempool_alloc(si->scsi_pkt_pool, gfp);
+	if (fsp) {
+		memset(fsp, 0, sizeof(*fsp));
+		fsp->lp = lport;
+		fsp->xfer_ddp = FC_XID_UNKNOWN;
+		atomic_set(&fsp->ref_cnt, 1);
+		init_timer(&fsp->timer);
+		fsp->timer.data = (unsigned long)fsp;
+		INIT_LIST_HEAD(&fsp->list);
+		spin_lock_init(&fsp->scsi_pkt_lock);
+	} else {
+		per_cpu_ptr(lport->stats, get_cpu())->FcpPktAllocFails++;
+		put_cpu();
+	}
+	return fsp;
+}
+
+/**
+ * fc_fcp_pkt_release() - Release hold on a fcp_pkt
+ * @fsp: The FCP packet to be released
+ *
+ * Context: Can be called from process or interrupt context,
+ *	    no lock is required.
+ */
+static void fc_fcp_pkt_release(struct fc_fcp_pkt *fsp)
+{
+	if (atomic_dec_and_test(&fsp->ref_cnt)) {
+		struct fc_fcp_internal *si = fc_get_scsi_internal(fsp->lp);
+
+		mempool_free(fsp, si->scsi_pkt_pool);
+	}
+}
+
+/**
+ * fc_fcp_pkt_hold() - Hold a fcp_pkt
+ * @fsp: The FCP packet to be held
+ */
+static void fc_fcp_pkt_hold(struct fc_fcp_pkt *fsp)
+{
+	atomic_inc(&fsp->ref_cnt);
+}
+
+/**
+ * fc_fcp_pkt_destory() - Release hold on a fcp_pkt
+ * @seq: The sequence that the FCP packet is on (required by destructor API)
+ * @fsp: The FCP packet to be released
+ *
+ * This routine is called by a destructor callback in the exch_seq_send()
+ * routine of the libfc Transport Template. The 'struct fc_seq' is a required
+ * argument even though it is not used by this routine.
+ *
+ * Context: No locking required.
+ */
+static void fc_fcp_pkt_destroy(struct fc_seq *seq, void *fsp)
+{
+	fc_fcp_pkt_release(fsp);
+}
+
+/**
+ * fc_fcp_lock_pkt() - Lock a fcp_pkt and increase its reference count
+ * @fsp: The FCP packet to be locked and incremented
+ *
+ * We should only return error if we return a command to SCSI-ml before
+ * getting a response. This can happen in cases where we send a abort, but
+ * do not wait for the response and the abort and command can be passing
+ * each other on the wire/network-layer.
+ *
+ * Note: this function locks the packet and gets a reference to allow
+ * callers to call the completion function while the lock is held and
+ * not have to worry about the packets refcount.
+ *
+ * TODO: Maybe we should just have callers grab/release the lock and
+ * have a function that they call to verify the fsp and grab a ref if
+ * needed.
+ */
+static inline int fc_fcp_lock_pkt(struct fc_fcp_pkt *fsp)
+{
+	spin_lock_bh(&fsp->scsi_pkt_lock);
+	if (fsp->state & FC_SRB_COMPL) {
+		spin_unlock_bh(&fsp->scsi_pkt_lock);
+		return -EPERM;
+	}
+
+	fc_fcp_pkt_hold(fsp);
+	return 0;
+}
+
+/**
+ * fc_fcp_unlock_pkt() - Release a fcp_pkt's lock and decrement its
+ *			 reference count
+ * @fsp: The FCP packet to be unlocked and decremented
+ */
+static inline void fc_fcp_unlock_pkt(struct fc_fcp_pkt *fsp)
+{
+	spin_unlock_bh(&fsp->scsi_pkt_lock);
+	fc_fcp_pkt_release(fsp);
+}
+
+/**
+ * fc_fcp_timer_set() - Start a timer for a fcp_pkt
+ * @fsp:   The FCP packet to start a timer for
+ * @delay: The timeout period in jiffies
+ */
+static void fc_fcp_timer_set(struct fc_fcp_pkt *fsp, unsigned long delay)
+{
+	if (!(fsp->state & FC_SRB_COMPL))
+		mod_timer(&fsp->timer, jiffies + delay);
+}
+
+/**
+ * fc_fcp_send_abort() - Send an abort for exchanges associated with a
+ *			 fcp_pkt
+ * @fsp: The FCP packet to abort exchanges on
+ */
+static int fc_fcp_send_abort(struct fc_fcp_pkt *fsp)
+{
+	if (!fsp->seq_ptr)
+		return -EINVAL;
+
+	per_cpu_ptr(fsp->lp->stats, get_cpu())->FcpPktAborts++;
+	put_cpu();
+
+	fsp->state |= FC_SRB_ABORT_PENDING;
+	return fsp->lp->tt.seq_exch_abort(fsp->seq_ptr, 0);
+}
+
+/**
+ * fc_fcp_retry_cmd() - Retry a fcp_pkt
+ * @fsp: The FCP packet to be retried
+ *
+ * Sets the status code to be FC_ERROR and then calls
+ * fc_fcp_complete_locked() which in turn calls fc_io_compl().
+ * fc_io_compl() will notify the SCSI-ml that the I/O is done.
+ * The SCSI-ml will retry the command.
+ */
+static void fc_fcp_retry_cmd(struct fc_fcp_pkt *fsp)
+{
+	if (fsp->seq_ptr) {
+		fsp->lp->tt.exch_done(fsp->seq_ptr);
+		fsp->seq_ptr = NULL;
+	}
+
+	fsp->state &= ~FC_SRB_ABORT_PENDING;
+	fsp->io_status = 0;
+	fsp->status_code = FC_ERROR;
+	fc_fcp_complete_locked(fsp);
+}
+
+/**
+ * fc_fcp_ddp_setup() - Calls a LLD's ddp_setup routine to set up DDP context
+ * @fsp: The FCP packet that will manage the DDP frames
+ * @xid: The XID that will be used for the DDP exchange
+ */
+void fc_fcp_ddp_setup(struct fc_fcp_pkt *fsp, u16 xid)
+{
+	struct fc_lport *lport;
+
+	lport = fsp->lp;
+	if ((fsp->req_flags & FC_SRB_READ) &&
+	    (lport->lro_enabled) && (lport->tt.ddp_setup)) {
+		if (lport->tt.ddp_setup(lport, xid, scsi_sglist(fsp->cmd),
+					scsi_sg_count(fsp->cmd)))
+			fsp->xfer_ddp = xid;
+	}
+}
+
+/**
+ * fc_fcp_ddp_done() - Calls a LLD's ddp_done routine to release any
+ *		       DDP related resources for a fcp_pkt
+ * @fsp: The FCP packet that DDP had been used on
+ */
+void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp)
+{
+	struct fc_lport *lport;
+
+	if (!fsp)
+		return;
+
+	if (fsp->xfer_ddp == FC_XID_UNKNOWN)
+		return;
+
+	lport = fsp->lp;
+	if (lport->tt.ddp_done) {
+		fsp->xfer_len = lport->tt.ddp_done(lport, fsp->xfer_ddp);
+		fsp->xfer_ddp = FC_XID_UNKNOWN;
+	}
+}
+
+/**
+ * fc_fcp_can_queue_ramp_up() - increases can_queue
+ * @lport: lport to ramp up can_queue
+ */
+static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+	unsigned long flags;
+	int can_queue;
+
+	spin_lock_irqsave(lport->host->host_lock, flags);
+
+	if (si->last_can_queue_ramp_up_time &&
+	    (time_before(jiffies, si->last_can_queue_ramp_up_time +
+			 FC_CAN_QUEUE_PERIOD)))
+		goto unlock;
+
+	if (time_before(jiffies, si->last_can_queue_ramp_down_time +
+			FC_CAN_QUEUE_PERIOD))
+		goto unlock;
+
+	si->last_can_queue_ramp_up_time = jiffies;
+
+	can_queue = lport->host->can_queue << 1;
+	if (can_queue >= si->max_can_queue) {
+		can_queue = si->max_can_queue;
+		si->last_can_queue_ramp_down_time = 0;
+	}
+	lport->host->can_queue = can_queue;
+	shost_printk(KERN_ERR, lport->host, "libfc: increased "
+		     "can_queue to %d.\n", can_queue);
+
+unlock:
+	spin_unlock_irqrestore(lport->host->host_lock, flags);
+}
+
+/**
+ * fc_fcp_can_queue_ramp_down() - reduces can_queue
+ * @lport: lport to reduce can_queue
+ *
+ * If we are getting memory allocation failures, then we may
+ * be trying to execute too many commands. We let the running
+ * commands complete or timeout, then try again with a reduced
+ * can_queue. Eventually we will hit the point where we run
+ * on all reserved structs.
+ */
+static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+	unsigned long flags;
+	int can_queue;
+
+	spin_lock_irqsave(lport->host->host_lock, flags);
+
+	if (si->last_can_queue_ramp_down_time &&
+	    (time_before(jiffies, si->last_can_queue_ramp_down_time +
+			 FC_CAN_QUEUE_PERIOD)))
+		goto unlock;
+
+	si->last_can_queue_ramp_down_time = jiffies;
+
+	can_queue = lport->host->can_queue;
+	can_queue >>= 1;
+	if (!can_queue)
+		can_queue = 1;
+	lport->host->can_queue = can_queue;
+	shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n"
+		     "Reducing can_queue to %d.\n", can_queue);
+
+unlock:
+	spin_unlock_irqrestore(lport->host->host_lock, flags);
+}
+
+/*
+ * fc_fcp_frame_alloc() -  Allocates fc_frame structure and buffer.
+ * @lport:	fc lport struct
+ * @len:	payload length
+ *
+ * Allocates fc_frame structure and buffer but if fails to allocate
+ * then reduce can_queue.
+ */
+static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport,
+						  size_t len)
+{
+	struct fc_frame *fp;
+
+	fp = fc_frame_alloc(lport, len);
+	if (likely(fp))
+		return fp;
+
+	per_cpu_ptr(lport->stats, get_cpu())->FcpFrameAllocFails++;
+	put_cpu();
+	/* error case */
+	fc_fcp_can_queue_ramp_down(lport);
+	return NULL;
+}
+
+/**
+ * fc_fcp_recv_data() - Handler for receiving SCSI-FCP data from a target
+ * @fsp: The FCP packet the data is on
+ * @fp:	 The data frame
+ */
+static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	struct scsi_cmnd *sc = fsp->cmd;
+	struct fc_lport *lport = fsp->lp;
+	struct fc_stats *stats;
+	struct fc_frame_header *fh;
+	size_t start_offset;
+	size_t offset;
+	u32 crc;
+	u32 copy_len = 0;
+	size_t len;
+	void *buf;
+	struct scatterlist *sg;
+	u32 nents;
+	u8 host_bcode = FC_COMPLETE;
+
+	fh = fc_frame_header_get(fp);
+	offset = ntohl(fh->fh_parm_offset);
+	start_offset = offset;
+	len = fr_len(fp) - sizeof(*fh);
+	buf = fc_frame_payload_get(fp, 0);
+
+	/*
+	 * if this I/O is ddped then clear it and initiate recovery since data
+	 * frames are expected to be placed directly in that case.
+	 *
+	 * Indicate error to scsi-ml because something went wrong with the
+	 * ddp handling to get us here.
+	 */
+	if (fsp->xfer_ddp != FC_XID_UNKNOWN) {
+		fc_fcp_ddp_done(fsp);
+		FC_FCP_DBG(fsp, "DDP I/O in fc_fcp_recv_data set ERROR\n");
+		host_bcode = FC_ERROR;
+		goto err;
+	}
+	if (offset + len > fsp->data_len) {
+		/* this should never happen */
+		if ((fr_flags(fp) & FCPHF_CRC_UNCHECKED) &&
+		    fc_frame_crc_check(fp))
+			goto crc_err;
+		FC_FCP_DBG(fsp, "data received past end. len %zx offset %zx "
+			   "data_len %x\n", len, offset, fsp->data_len);
+
+		/* Data is corrupted indicate scsi-ml should retry */
+		host_bcode = FC_DATA_OVRRUN;
+		goto err;
+	}
+	if (offset != fsp->xfer_len)
+		fsp->state |= FC_SRB_DISCONTIG;
+
+	sg = scsi_sglist(sc);
+	nents = scsi_sg_count(sc);
+
+	if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
+		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
+						    &offset, NULL);
+	} else {
+		crc = crc32(~0, (u8 *) fh, sizeof(*fh));
+		copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
+						    &offset, &crc);
+		buf = fc_frame_payload_get(fp, 0);
+		if (len % 4)
+			crc = crc32(crc, buf + len, 4 - (len % 4));
+
+		if (~crc != le32_to_cpu(fr_crc(fp))) {
+crc_err:
+			stats = per_cpu_ptr(lport->stats, get_cpu());
+			stats->ErrorFrames++;
+			/* per cpu count, not total count, but OK for limit */
+			if (stats->InvalidCRCCount++ < FC_MAX_ERROR_CNT)
+				printk(KERN_WARNING "libfc: CRC error on data "
+				       "frame for port (%6.6x)\n",
+				       lport->port_id);
+			put_cpu();
+			/*
+			 * Assume the frame is total garbage.
+			 * We may have copied it over the good part
+			 * of the buffer.
+			 * If so, we need to retry the entire operation.
+			 * Otherwise, ignore it.
+			 */
+			if (fsp->state & FC_SRB_DISCONTIG) {
+				host_bcode = FC_CRC_ERROR;
+				goto err;
+			}
+			return;
+		}
+	}
+
+	if (fsp->xfer_contig_end == start_offset)
+		fsp->xfer_contig_end += copy_len;
+	fsp->xfer_len += copy_len;
+
+	/*
+	 * In the very rare event that this data arrived after the response
+	 * and completes the transfer, call the completion handler.
+	 */
+	if (unlikely(fsp->state & FC_SRB_RCV_STATUS) &&
+	    fsp->xfer_len == fsp->data_len - fsp->scsi_resid)
+		fc_fcp_complete_locked(fsp);
+	return;
+err:
+	fc_fcp_recovery(fsp, host_bcode);
+}
+
+/**
+ * fc_fcp_send_data() - Send SCSI data to a target
+ * @fsp:      The FCP packet the data is on
+ * @sp:	      The sequence the data is to be sent on
+ * @offset:   The starting offset for this data request
+ * @seq_blen: The burst length for this data request
+ *
+ * Called after receiving a Transfer Ready data descriptor.
+ * If the LLD is capable of sequence offload then send down the
+ * seq_blen amount of data in single frame, otherwise send
+ * multiple frames of the maximum frame payload supported by
+ * the target port.
+ */
+static int fc_fcp_send_data(struct fc_fcp_pkt *fsp, struct fc_seq *seq,
+			    size_t offset, size_t seq_blen)
+{
+	struct fc_exch *ep;
+	struct scsi_cmnd *sc;
+	struct scatterlist *sg;
+	struct fc_frame *fp = NULL;
+	struct fc_lport *lport = fsp->lp;
+	struct page *page;
+	size_t remaining;
+	size_t t_blen;
+	size_t tlen;
+	size_t sg_bytes;
+	size_t frame_offset, fh_parm_offset;
+	size_t off;
+	int error;
+	void *data = NULL;
+	void *page_addr;
+	int using_sg = lport->sg_supp;
+	u32 f_ctl;
+
+	WARN_ON(seq_blen <= 0);
+	if (unlikely(offset + seq_blen > fsp->data_len)) {
+		/* this should never happen */
+		FC_FCP_DBG(fsp, "xfer-ready past end. seq_blen %zx "
+			   "offset %zx\n", seq_blen, offset);
+		fc_fcp_send_abort(fsp);
+		return 0;
+	} else if (offset != fsp->xfer_len) {
+		/* Out of Order Data Request - no problem, but unexpected. */
+		FC_FCP_DBG(fsp, "xfer-ready non-contiguous. "
+			   "seq_blen %zx offset %zx\n", seq_blen, offset);
+	}
+
+	/*
+	 * if LLD is capable of seq_offload then set transport
+	 * burst length (t_blen) to seq_blen, otherwise set t_blen
+	 * to max FC frame payload previously set in fsp->max_payload.
+	 */
+	t_blen = fsp->max_payload;
+	if (lport->seq_offload) {
+		t_blen = min(seq_blen, (size_t)lport->lso_max);
+		FC_FCP_DBG(fsp, "fsp=%p:lso:blen=%zx lso_max=0x%x t_blen=%zx\n",
+			   fsp, seq_blen, lport->lso_max, t_blen);
+	}
+
+	if (t_blen > 512)
+		t_blen &= ~(512 - 1);	/* round down to block size */
+	sc = fsp->cmd;
+
+	remaining = seq_blen;
+	fh_parm_offset = frame_offset = offset;
+	tlen = 0;
+	seq = lport->tt.seq_start_next(seq);
+	f_ctl = FC_FC_REL_OFF;
+	WARN_ON(!seq);
+
+	sg = scsi_sglist(sc);
+
+	while (remaining > 0 && sg) {
+		if (offset >= sg->length) {
+			offset -= sg->length;
+			sg = sg_next(sg);
+			continue;
+		}
+		if (!fp) {
+			tlen = min(t_blen, remaining);
+
+			/*
+			 * TODO.  Temporary workaround.	 fc_seq_send() can't
+			 * handle odd lengths in non-linear skbs.
+			 * This will be the final fragment only.
+			 */
+			if (tlen % 4)
+				using_sg = 0;
+			fp = fc_frame_alloc(lport, using_sg ? 0 : tlen);
+			if (!fp)
+				return -ENOMEM;
+
+			data = fc_frame_header_get(fp) + 1;
+			fh_parm_offset = frame_offset;
+			fr_max_payload(fp) = fsp->max_payload;
+		}
+
+		off = offset + sg->offset;
+		sg_bytes = min(tlen, sg->length - offset);
+		sg_bytes = min(sg_bytes,
+			       (size_t) (PAGE_SIZE - (off & ~PAGE_MASK)));
+		page = sg_page(sg) + (off >> PAGE_SHIFT);
+		if (using_sg) {
+			get_page(page);
+			skb_fill_page_desc(fp_skb(fp),
+					   skb_shinfo(fp_skb(fp))->nr_frags,
+					   page, off & ~PAGE_MASK, sg_bytes);
+			fp_skb(fp)->data_len += sg_bytes;
+			fr_len(fp) += sg_bytes;
+			fp_skb(fp)->truesize += PAGE_SIZE;
+		} else {
+			/*
+			 * The scatterlist item may be bigger than PAGE_SIZE,
+			 * but we must not cross pages inside the kmap.
+			 */
+			page_addr = kmap_atomic(page);
+			memcpy(data, (char *)page_addr + (off & ~PAGE_MASK),
+			       sg_bytes);
+			kunmap_atomic(page_addr);
+			data += sg_bytes;
+		}
+		offset += sg_bytes;
+		frame_offset += sg_bytes;
+		tlen -= sg_bytes;
+		remaining -= sg_bytes;
+
+		if ((skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN) &&
+		    (tlen))
+			continue;
+
+		/*
+		 * Send sequence with transfer sequence initiative in case
+		 * this is last FCP frame of the sequence.
+		 */
+		if (remaining == 0)
+			f_ctl |= FC_FC_SEQ_INIT | FC_FC_END_SEQ;
+
+		ep = fc_seq_exch(seq);
+		fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
+			       FC_TYPE_FCP, f_ctl, fh_parm_offset);
+
+		/*
+		 * send fragment using for a sequence.
+		 */
+		error = lport->tt.seq_send(lport, seq, fp);
+		if (error) {
+			WARN_ON(1);		/* send error should be rare */
+			return error;
+		}
+		fp = NULL;
+	}
+	fsp->xfer_len += seq_blen;	/* premature count? */
+	return 0;
+}
+
+/**
+ * fc_fcp_abts_resp() - Receive an ABTS response
+ * @fsp: The FCP packet that is being aborted
+ * @fp:	 The response frame
+ */
+static void fc_fcp_abts_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	int ba_done = 1;
+	struct fc_ba_rjt *brp;
+	struct fc_frame_header *fh;
+
+	fh = fc_frame_header_get(fp);
+	switch (fh->fh_r_ctl) {
+	case FC_RCTL_BA_ACC:
+		break;
+	case FC_RCTL_BA_RJT:
+		brp = fc_frame_payload_get(fp, sizeof(*brp));
+		if (brp && brp->br_reason == FC_BA_RJT_LOG_ERR)
+			break;
+		/* fall thru */
+	default:
+		/*
+		 * we will let the command timeout
+		 * and scsi-ml recover in this case,
+		 * therefore cleared the ba_done flag.
+		 */
+		ba_done = 0;
+	}
+
+	if (ba_done) {
+		fsp->state |= FC_SRB_ABORTED;
+		fsp->state &= ~FC_SRB_ABORT_PENDING;
+
+		if (fsp->wait_for_comp)
+			complete(&fsp->tm_done);
+		else
+			fc_fcp_complete_locked(fsp);
+	}
+}
+
+/**
+ * fc_fcp_recv() - Receive an FCP frame
+ * @seq: The sequence the frame is on
+ * @fp:	 The received frame
+ * @arg: The related FCP packet
+ *
+ * Context: Called from Soft IRQ context. Can not be called
+ *	    holding the FCP packet list lock.
+ */
+static void fc_fcp_recv(struct fc_seq *seq, struct fc_frame *fp, void *arg)
+{
+	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
+	struct fc_lport *lport = fsp->lp;
+	struct fc_frame_header *fh;
+	struct fcp_txrdy *dd;
+	u8 r_ctl;
+	int rc = 0;
+
+	if (IS_ERR(fp)) {
+		fc_fcp_error(fsp, fp);
+		return;
+	}
+
+	fh = fc_frame_header_get(fp);
+	r_ctl = fh->fh_r_ctl;
+
+	if (lport->state != LPORT_ST_READY)
+		goto out;
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+
+	if (fh->fh_type == FC_TYPE_BLS) {
+		fc_fcp_abts_resp(fsp, fp);
+		goto unlock;
+	}
+
+	if (fsp->state & (FC_SRB_ABORTED | FC_SRB_ABORT_PENDING))
+		goto unlock;
+
+	if (r_ctl == FC_RCTL_DD_DATA_DESC) {
+		/*
+		 * received XFER RDY from the target
+		 * need to send data to the target
+		 */
+		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
+		dd = fc_frame_payload_get(fp, sizeof(*dd));
+		WARN_ON(!dd);
+
+		rc = fc_fcp_send_data(fsp, seq,
+				      (size_t) ntohl(dd->ft_data_ro),
+				      (size_t) ntohl(dd->ft_burst_len));
+		if (!rc)
+			seq->rec_data = fsp->xfer_len;
+	} else if (r_ctl == FC_RCTL_DD_SOL_DATA) {
+		/*
+		 * received a DATA frame
+		 * next we will copy the data to the system buffer
+		 */
+		WARN_ON(fr_len(fp) < sizeof(*fh));	/* len may be 0 */
+		fc_fcp_recv_data(fsp, fp);
+		seq->rec_data = fsp->xfer_contig_end;
+	} else if (r_ctl == FC_RCTL_DD_CMD_STATUS) {
+		WARN_ON(fr_flags(fp) & FCPHF_CRC_UNCHECKED);
+
+		fc_fcp_resp(fsp, fp);
+	} else {
+		FC_FCP_DBG(fsp, "unexpected frame.  r_ctl %x\n", r_ctl);
+	}
+unlock:
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fc_frame_free(fp);
+}
+
+/**
+ * fc_fcp_resp() - Handler for FCP responses
+ * @fsp: The FCP packet the response is for
+ * @fp:	 The response frame
+ */
+static void fc_fcp_resp(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	struct fc_frame_header *fh;
+	struct fcp_resp *fc_rp;
+	struct fcp_resp_ext *rp_ex;
+	struct fcp_resp_rsp_info *fc_rp_info;
+	u32 plen;
+	u32 expected_len;
+	u32 respl = 0;
+	u32 snsl = 0;
+	u8 flags = 0;
+
+	plen = fr_len(fp);
+	fh = (struct fc_frame_header *)fr_hdr(fp);
+	if (unlikely(plen < sizeof(*fh) + sizeof(*fc_rp)))
+		goto len_err;
+	plen -= sizeof(*fh);
+	fc_rp = (struct fcp_resp *)(fh + 1);
+	fsp->cdb_status = fc_rp->fr_status;
+	flags = fc_rp->fr_flags;
+	fsp->scsi_comp_flags = flags;
+	expected_len = fsp->data_len;
+
+	/* if ddp, update xfer len */
+	fc_fcp_ddp_done(fsp);
+
+	if (unlikely((flags & ~FCP_CONF_REQ) || fc_rp->fr_status)) {
+		rp_ex = (void *)(fc_rp + 1);
+		if (flags & (FCP_RSP_LEN_VAL | FCP_SNS_LEN_VAL)) {
+			if (plen < sizeof(*fc_rp) + sizeof(*rp_ex))
+				goto len_err;
+			fc_rp_info = (struct fcp_resp_rsp_info *)(rp_ex + 1);
+			if (flags & FCP_RSP_LEN_VAL) {
+				respl = ntohl(rp_ex->fr_rsp_len);
+				if ((respl != FCP_RESP_RSP_INFO_LEN4) &&
+				    (respl != FCP_RESP_RSP_INFO_LEN8))
+					goto len_err;
+				if (fsp->wait_for_comp) {
+					/* Abuse cdb_status for rsp code */
+					fsp->cdb_status = fc_rp_info->rsp_code;
+					complete(&fsp->tm_done);
+					/*
+					 * tmfs will not have any scsi cmd so
+					 * exit here
+					 */
+					return;
+				}
+			}
+			if (flags & FCP_SNS_LEN_VAL) {
+				snsl = ntohl(rp_ex->fr_sns_len);
+				if (snsl > SCSI_SENSE_BUFFERSIZE)
+					snsl = SCSI_SENSE_BUFFERSIZE;
+				memcpy(fsp->cmd->sense_buffer,
+				       (char *)fc_rp_info + respl, snsl);
+			}
+		}
+		if (flags & (FCP_RESID_UNDER | FCP_RESID_OVER)) {
+			if (plen < sizeof(*fc_rp) + sizeof(rp_ex->fr_resid))
+				goto len_err;
+			if (flags & FCP_RESID_UNDER) {
+				fsp->scsi_resid = ntohl(rp_ex->fr_resid);
+				/*
+				 * The cmnd->underflow is the minimum number of
+				 * bytes that must be transferred for this
+				 * command.  Provided a sense condition is not
+				 * present, make sure the actual amount
+				 * transferred is at least the underflow value
+				 * or fail.
+				 */
+				if (!(flags & FCP_SNS_LEN_VAL) &&
+				    (fc_rp->fr_status == 0) &&
+				    (scsi_bufflen(fsp->cmd) -
+				     fsp->scsi_resid) < fsp->cmd->underflow)
+					goto err;
+				expected_len -= fsp->scsi_resid;
+			} else {
+				fsp->status_code = FC_ERROR;
+			}
+		}
+	}
+	fsp->state |= FC_SRB_RCV_STATUS;
+
+	/*
+	 * Check for missing or extra data frames.
+	 */
+	if (unlikely(fsp->cdb_status == SAM_STAT_GOOD &&
+		     fsp->xfer_len != expected_len)) {
+		if (fsp->xfer_len < expected_len) {
+			/*
+			 * Some data may be queued locally,
+			 * Wait a at least one jiffy to see if it is delivered.
+			 * If this expires without data, we may do SRR.
+			 */
+			fc_fcp_timer_set(fsp, 2);
+			return;
+		}
+		fsp->status_code = FC_DATA_OVRRUN;
+		FC_FCP_DBG(fsp, "tgt %6.6x xfer len %zx greater than expected, "
+			   "len %x, data len %x\n",
+			   fsp->rport->port_id,
+			   fsp->xfer_len, expected_len, fsp->data_len);
+	}
+	fc_fcp_complete_locked(fsp);
+	return;
+
+len_err:
+	FC_FCP_DBG(fsp, "short FCP response. flags 0x%x len %u respl %u "
+		   "snsl %u\n", flags, fr_len(fp), respl, snsl);
+err:
+	fsp->status_code = FC_ERROR;
+	fc_fcp_complete_locked(fsp);
+}
+
+/**
+ * fc_fcp_complete_locked() - Complete processing of a fcp_pkt with the
+ *			      fcp_pkt lock held
+ * @fsp: The FCP packet to be completed
+ *
+ * This function may sleep if a timer is pending. The packet lock must be
+ * held, and the host lock must not be held.
+ */
+static void fc_fcp_complete_locked(struct fc_fcp_pkt *fsp)
+{
+	struct fc_lport *lport = fsp->lp;
+	struct fc_seq *seq;
+	struct fc_exch *ep;
+	u32 f_ctl;
+
+	if (fsp->state & FC_SRB_ABORT_PENDING)
+		return;
+
+	if (fsp->state & FC_SRB_ABORTED) {
+		if (!fsp->status_code)
+			fsp->status_code = FC_CMD_ABORTED;
+	} else {
+		/*
+		 * Test for transport underrun, independent of response
+		 * underrun status.
+		 */
+		if (fsp->cdb_status == SAM_STAT_GOOD &&
+		    fsp->xfer_len < fsp->data_len && !fsp->io_status &&
+		    (!(fsp->scsi_comp_flags & FCP_RESID_UNDER) ||
+		     fsp->xfer_len < fsp->data_len - fsp->scsi_resid))
+			fsp->status_code = FC_DATA_UNDRUN;
+	}
+
+	seq = fsp->seq_ptr;
+	if (seq) {
+		fsp->seq_ptr = NULL;
+		if (unlikely(fsp->scsi_comp_flags & FCP_CONF_REQ)) {
+			struct fc_frame *conf_frame;
+			struct fc_seq *csp;
+
+			csp = lport->tt.seq_start_next(seq);
+			conf_frame = fc_fcp_frame_alloc(fsp->lp, 0);
+			if (conf_frame) {
+				f_ctl = FC_FC_SEQ_INIT;
+				f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
+				ep = fc_seq_exch(seq);
+				fc_fill_fc_hdr(conf_frame, FC_RCTL_DD_SOL_CTL,
+					       ep->did, ep->sid,
+					       FC_TYPE_FCP, f_ctl, 0);
+				lport->tt.seq_send(lport, csp, conf_frame);
+			}
+		}
+		lport->tt.exch_done(seq);
+	}
+	/*
+	 * Some resets driven by SCSI are not I/Os and do not have
+	 * SCSI commands associated with the requests. We should not
+	 * call I/O completion if we do not have a SCSI command.
+	 */
+	if (fsp->cmd)
+		fc_io_compl(fsp);
+}
+
+/**
+ * fc_fcp_cleanup_cmd() - Cancel the active exchange on a fcp_pkt
+ * @fsp:   The FCP packet whose exchanges should be canceled
+ * @error: The reason for the cancellation
+ */
+static void fc_fcp_cleanup_cmd(struct fc_fcp_pkt *fsp, int error)
+{
+	struct fc_lport *lport = fsp->lp;
+
+	if (fsp->seq_ptr) {
+		lport->tt.exch_done(fsp->seq_ptr);
+		fsp->seq_ptr = NULL;
+	}
+	fsp->status_code = error;
+}
+
+/**
+ * fc_fcp_cleanup_each_cmd() - Cancel all exchanges on a local port
+ * @lport: The local port whose exchanges should be canceled
+ * @id:	   The target's ID
+ * @lun:   The LUN
+ * @error: The reason for cancellation
+ *
+ * If lun or id is -1, they are ignored.
+ */
+static void fc_fcp_cleanup_each_cmd(struct fc_lport *lport, unsigned int id,
+				    unsigned int lun, int error)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+	struct fc_fcp_pkt *fsp;
+	struct scsi_cmnd *sc_cmd;
+	unsigned long flags;
+
+	spin_lock_irqsave(&si->scsi_queue_lock, flags);
+restart:
+	list_for_each_entry(fsp, &si->scsi_pkt_queue, list) {
+		sc_cmd = fsp->cmd;
+		if (id != -1 && scmd_id(sc_cmd) != id)
+			continue;
+
+		if (lun != -1 && sc_cmd->device->lun != lun)
+			continue;
+
+		fc_fcp_pkt_hold(fsp);
+		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+
+		if (!fc_fcp_lock_pkt(fsp)) {
+			fc_fcp_cleanup_cmd(fsp, error);
+			fc_io_compl(fsp);
+			fc_fcp_unlock_pkt(fsp);
+		}
+
+		fc_fcp_pkt_release(fsp);
+		spin_lock_irqsave(&si->scsi_queue_lock, flags);
+		/*
+		 * while we dropped the lock multiple pkts could
+		 * have been released, so we have to start over.
+		 */
+		goto restart;
+	}
+	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+}
+
+/**
+ * fc_fcp_abort_io() - Abort all FCP-SCSI exchanges on a local port
+ * @lport: The local port whose exchanges are to be aborted
+ */
+static void fc_fcp_abort_io(struct fc_lport *lport)
+{
+	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_HRD_ERROR);
+}
+
+/**
+ * fc_fcp_pkt_send() - Send a fcp_pkt
+ * @lport: The local port to send the FCP packet on
+ * @fsp:   The FCP packet to send
+ *
+ * Return:  Zero for success and -1 for failure
+ * Locks:   Called without locks held
+ */
+static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+	unsigned long flags;
+	int rc;
+
+	fsp->cmd->SCp.ptr = (char *)fsp;
+	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
+	fsp->cdb_cmd.fc_flags = fsp->req_flags & ~FCP_CFL_LEN_MASK;
+
+	int_to_scsilun(fsp->cmd->device->lun, &fsp->cdb_cmd.fc_lun);
+	memcpy(fsp->cdb_cmd.fc_cdb, fsp->cmd->cmnd, fsp->cmd->cmd_len);
+
+	spin_lock_irqsave(&si->scsi_queue_lock, flags);
+	list_add_tail(&fsp->list, &si->scsi_pkt_queue);
+	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+	rc = lport->tt.fcp_cmd_send(lport, fsp, fc_fcp_recv);
+	if (unlikely(rc)) {
+		spin_lock_irqsave(&si->scsi_queue_lock, flags);
+		fsp->cmd->SCp.ptr = NULL;
+		list_del(&fsp->list);
+		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+	}
+
+	return rc;
+}
+
+/**
+ * get_fsp_rec_tov() - Helper function to get REC_TOV
+ * @fsp: the FCP packet
+ *
+ * Returns rec tov in jiffies as rpriv->e_d_tov + 1 second
+ */
+static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
+{
+	struct fc_rport_libfc_priv *rpriv = fsp->rport->dd_data;
+
+	return msecs_to_jiffies(rpriv->e_d_tov) + HZ;
+}
+
+/**
+ * fc_fcp_cmd_send() - Send a FCP command
+ * @lport: The local port to send the command on
+ * @fsp:   The FCP packet the command is on
+ * @resp:  The handler for the response
+ */
+static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
+			   void (*resp)(struct fc_seq *,
+					struct fc_frame *fp,
+					void *arg))
+{
+	struct fc_frame *fp;
+	struct fc_seq *seq;
+	struct fc_rport *rport;
+	struct fc_rport_libfc_priv *rpriv;
+	const size_t len = sizeof(fsp->cdb_cmd);
+	int rc = 0;
+
+	if (fc_fcp_lock_pkt(fsp))
+		return 0;
+
+	fp = fc_fcp_frame_alloc(lport, sizeof(fsp->cdb_cmd));
+	if (!fp) {
+		rc = -1;
+		goto unlock;
+	}
+
+	memcpy(fc_frame_payload_get(fp, len), &fsp->cdb_cmd, len);
+	fr_fsp(fp) = fsp;
+	rport = fsp->rport;
+	fsp->max_payload = rport->maxframe_size;
+	rpriv = rport->dd_data;
+
+	fc_fill_fc_hdr(fp, FC_RCTL_DD_UNSOL_CMD, rport->port_id,
+		       rpriv->local_port->port_id, FC_TYPE_FCP,
+		       FC_FCTL_REQ, 0);
+
+	seq = lport->tt.exch_seq_send(lport, fp, resp, fc_fcp_pkt_destroy,
+				      fsp, 0);
+	if (!seq) {
+		rc = -1;
+		goto unlock;
+	}
+	fsp->seq_ptr = seq;
+	fc_fcp_pkt_hold(fsp);	/* hold for fc_fcp_pkt_destroy */
+
+	setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
+	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
+		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
+
+unlock:
+	fc_fcp_unlock_pkt(fsp);
+	return rc;
+}
+
+/**
+ * fc_fcp_error() - Handler for FCP layer errors
+ * @fsp: The FCP packet the error is on
+ * @fp:	 The frame that has errored
+ */
+static void fc_fcp_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	int error = PTR_ERR(fp);
+
+	if (fc_fcp_lock_pkt(fsp))
+		return;
+
+	if (error == -FC_EX_CLOSED) {
+		fc_fcp_retry_cmd(fsp);
+		goto unlock;
+	}
+
+	/*
+	 * clear abort pending, because the lower layer
+	 * decided to force completion.
+	 */
+	fsp->state &= ~FC_SRB_ABORT_PENDING;
+	fsp->status_code = FC_CMD_PLOGO;
+	fc_fcp_complete_locked(fsp);
+unlock:
+	fc_fcp_unlock_pkt(fsp);
+}
+
+/**
+ * fc_fcp_pkt_abort() - Abort a fcp_pkt
+ * @fsp:   The FCP packet to abort on
+ *
+ * Called to send an abort and then wait for abort completion
+ */
+static int fc_fcp_pkt_abort(struct fc_fcp_pkt *fsp)
+{
+	int rc = FAILED;
+	unsigned long ticks_left;
+
+	if (fc_fcp_send_abort(fsp))
+		return FAILED;
+
+	init_completion(&fsp->tm_done);
+	fsp->wait_for_comp = 1;
+
+	spin_unlock_bh(&fsp->scsi_pkt_lock);
+	ticks_left = wait_for_completion_timeout(&fsp->tm_done,
+							FC_SCSI_TM_TOV);
+	spin_lock_bh(&fsp->scsi_pkt_lock);
+	fsp->wait_for_comp = 0;
+
+	if (!ticks_left) {
+		FC_FCP_DBG(fsp, "target abort cmd  failed\n");
+	} else if (fsp->state & FC_SRB_ABORTED) {
+		FC_FCP_DBG(fsp, "target abort cmd  passed\n");
+		rc = SUCCESS;
+		fc_fcp_complete_locked(fsp);
+	}
+
+	return rc;
+}
+
+/**
+ * fc_lun_reset_send() - Send LUN reset command
+ * @data: The FCP packet that identifies the LUN to be reset
+ */
+static void fc_lun_reset_send(unsigned long data)
+{
+	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
+	struct fc_lport *lport = fsp->lp;
+
+	if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
+		if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
+			return;
+		if (fc_fcp_lock_pkt(fsp))
+			return;
+		setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
+		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
+		fc_fcp_unlock_pkt(fsp);
+	}
+}
+
+/**
+ * fc_lun_reset() - Send a LUN RESET command to a device
+ *		    and wait for the reply
+ * @lport: The local port to sent the command on
+ * @fsp:   The FCP packet that identifies the LUN to be reset
+ * @id:	   The SCSI command ID
+ * @lun:   The LUN ID to be reset
+ */
+static int fc_lun_reset(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
+			unsigned int id, unsigned int lun)
+{
+	int rc;
+
+	fsp->cdb_cmd.fc_dl = htonl(fsp->data_len);
+	fsp->cdb_cmd.fc_tm_flags = FCP_TMF_LUN_RESET;
+	int_to_scsilun(lun, &fsp->cdb_cmd.fc_lun);
+
+	fsp->wait_for_comp = 1;
+	init_completion(&fsp->tm_done);
+
+	fc_lun_reset_send((unsigned long)fsp);
+
+	/*
+	 * wait for completion of reset
+	 * after that make sure all commands are terminated
+	 */
+	rc = wait_for_completion_timeout(&fsp->tm_done, FC_SCSI_TM_TOV);
+
+	spin_lock_bh(&fsp->scsi_pkt_lock);
+	fsp->state |= FC_SRB_COMPL;
+	spin_unlock_bh(&fsp->scsi_pkt_lock);
+
+	del_timer_sync(&fsp->timer);
+
+	spin_lock_bh(&fsp->scsi_pkt_lock);
+	if (fsp->seq_ptr) {
+		lport->tt.exch_done(fsp->seq_ptr);
+		fsp->seq_ptr = NULL;
+	}
+	fsp->wait_for_comp = 0;
+	spin_unlock_bh(&fsp->scsi_pkt_lock);
+
+	if (!rc) {
+		FC_SCSI_DBG(lport, "lun reset failed\n");
+		return FAILED;
+	}
+
+	/* cdb_status holds the tmf's rsp code */
+	if (fsp->cdb_status != FCP_TMF_CMPL)
+		return FAILED;
+
+	FC_SCSI_DBG(lport, "lun reset to lun %u completed\n", lun);
+	fc_fcp_cleanup_each_cmd(lport, id, lun, FC_CMD_ABORTED);
+	return SUCCESS;
+}
+
+/**
+ * fc_tm_done() - Task Management response handler
+ * @seq: The sequence that the response is on
+ * @fp:	 The response frame
+ * @arg: The FCP packet the response is for
+ */
+static void fc_tm_done(struct fc_seq *seq, struct fc_frame *fp, void *arg)
+{
+	struct fc_fcp_pkt *fsp = arg;
+	struct fc_frame_header *fh;
+
+	if (IS_ERR(fp)) {
+		/*
+		 * If there is an error just let it timeout or wait
+		 * for TMF to be aborted if it timedout.
+		 *
+		 * scsi-eh will escalate for when either happens.
+		 */
+		return;
+	}
+
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+
+	/*
+	 * raced with eh timeout handler.
+	 */
+	if (!fsp->seq_ptr || !fsp->wait_for_comp)
+		goto out_unlock;
+
+	fh = fc_frame_header_get(fp);
+	if (fh->fh_type != FC_TYPE_BLS)
+		fc_fcp_resp(fsp, fp);
+	fsp->seq_ptr = NULL;
+	fsp->lp->tt.exch_done(seq);
+out_unlock:
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fc_frame_free(fp);
+}
+
+/**
+ * fc_fcp_cleanup() - Cleanup all FCP exchanges on a local port
+ * @lport: The local port to be cleaned up
+ */
+static void fc_fcp_cleanup(struct fc_lport *lport)
+{
+	fc_fcp_cleanup_each_cmd(lport, -1, -1, FC_ERROR);
+}
+
+/**
+ * fc_fcp_timeout() - Handler for fcp_pkt timeouts
+ * @data: The FCP packet that has timed out
+ *
+ * If REC is supported then just issue it and return. The REC exchange will
+ * complete or time out and recovery can continue at that point. Otherwise,
+ * if the response has been received without all the data it has been
+ * ER_TIMEOUT since the response was received. If the response has not been
+ * received we see if data was received recently. If it has been then we
+ * continue waiting, otherwise, we abort the command.
+ */
+static void fc_fcp_timeout(unsigned long data)
+{
+	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
+	struct fc_rport *rport = fsp->rport;
+	struct fc_rport_libfc_priv *rpriv = rport->dd_data;
+
+	if (fc_fcp_lock_pkt(fsp))
+		return;
+
+	if (fsp->cdb_cmd.fc_tm_flags)
+		goto unlock;
+
+	fsp->state |= FC_SRB_FCP_PROCESSING_TMO;
+
+	if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
+		fc_fcp_rec(fsp);
+	else if (fsp->state & FC_SRB_RCV_STATUS)
+		fc_fcp_complete_locked(fsp);
+	else
+		fc_fcp_recovery(fsp, FC_TIMED_OUT);
+	fsp->state &= ~FC_SRB_FCP_PROCESSING_TMO;
+unlock:
+	fc_fcp_unlock_pkt(fsp);
+}
+
+/**
+ * fc_fcp_rec() - Send a REC ELS request
+ * @fsp: The FCP packet to send the REC request on
+ */
+static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
+{
+	struct fc_lport *lport;
+	struct fc_frame *fp;
+	struct fc_rport *rport;
+	struct fc_rport_libfc_priv *rpriv;
+
+	lport = fsp->lp;
+	rport = fsp->rport;
+	rpriv = rport->dd_data;
+	if (!fsp->seq_ptr || rpriv->rp_state != RPORT_ST_READY) {
+		fsp->status_code = FC_HRD_ERROR;
+		fsp->io_status = 0;
+		fc_fcp_complete_locked(fsp);
+		return;
+	}
+
+	fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
+	if (!fp)
+		goto retry;
+
+	fr_seq(fp) = fsp->seq_ptr;
+	fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, rport->port_id,
+		       rpriv->local_port->port_id, FC_TYPE_ELS,
+		       FC_FCTL_REQ, 0);
+	if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
+				 fc_fcp_rec_resp, fsp,
+				 2 * lport->r_a_tov)) {
+		fc_fcp_pkt_hold(fsp);		/* hold while REC outstanding */
+		return;
+	}
+retry:
+	if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
+		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
+	else
+		fc_fcp_recovery(fsp, FC_TIMED_OUT);
+}
+
+/**
+ * fc_fcp_rec_resp() - Handler for REC ELS responses
+ * @seq: The sequence the response is on
+ * @fp:	 The response frame
+ * @arg: The FCP packet the response is on
+ *
+ * If the response is a reject then the scsi layer will handle
+ * the timeout. If the response is a LS_ACC then if the I/O was not completed
+ * set the timeout and return. If the I/O was completed then complete the
+ * exchange and tell the SCSI layer.
+ */
+static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
+{
+	struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)arg;
+	struct fc_els_rec_acc *recp;
+	struct fc_els_ls_rjt *rjt;
+	u32 e_stat;
+	u8 opcode;
+	u32 offset;
+	enum dma_data_direction data_dir;
+	enum fc_rctl r_ctl;
+	struct fc_rport_libfc_priv *rpriv;
+
+	if (IS_ERR(fp)) {
+		fc_fcp_rec_error(fsp, fp);
+		return;
+	}
+
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+
+	fsp->recov_retry = 0;
+	opcode = fc_frame_payload_op(fp);
+	if (opcode == ELS_LS_RJT) {
+		rjt = fc_frame_payload_get(fp, sizeof(*rjt));
+		switch (rjt->er_reason) {
+		default:
+			FC_FCP_DBG(fsp, "device %x unexpected REC reject "
+				   "reason %d expl %d\n",
+				   fsp->rport->port_id, rjt->er_reason,
+				   rjt->er_explan);
+			/* fall through */
+		case ELS_RJT_UNSUP:
+			FC_FCP_DBG(fsp, "device does not support REC\n");
+			rpriv = fsp->rport->dd_data;
+			/*
+			 * if we do not spport RECs or got some bogus
+			 * reason then resetup timer so we check for
+			 * making progress.
+			 */
+			rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
+			break;
+		case ELS_RJT_LOGIC:
+		case ELS_RJT_UNAB:
+			/*
+			 * If no data transfer, the command frame got dropped
+			 * so we just retry.  If data was transferred, we
+			 * lost the response but the target has no record,
+			 * so we abort and retry.
+			 */
+			if (rjt->er_explan == ELS_EXPL_OXID_RXID &&
+			    fsp->xfer_len == 0) {
+				fc_fcp_retry_cmd(fsp);
+				break;
+			}
+			fc_fcp_recovery(fsp, FC_ERROR);
+			break;
+		}
+	} else if (opcode == ELS_LS_ACC) {
+		if (fsp->state & FC_SRB_ABORTED)
+			goto unlock_out;
+
+		data_dir = fsp->cmd->sc_data_direction;
+		recp = fc_frame_payload_get(fp, sizeof(*recp));
+		offset = ntohl(recp->reca_fc4value);
+		e_stat = ntohl(recp->reca_e_stat);
+
+		if (e_stat & ESB_ST_COMPLETE) {
+
+			/*
+			 * The exchange is complete.
+			 *
+			 * For output, we must've lost the response.
+			 * For input, all data must've been sent.
+			 * We lost may have lost the response
+			 * (and a confirmation was requested) and maybe
+			 * some data.
+			 *
+			 * If all data received, send SRR
+			 * asking for response.	 If partial data received,
+			 * or gaps, SRR requests data at start of gap.
+			 * Recovery via SRR relies on in-order-delivery.
+			 */
+			if (data_dir == DMA_TO_DEVICE) {
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+			} else if (fsp->xfer_contig_end == offset) {
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+			} else {
+				offset = fsp->xfer_contig_end;
+				r_ctl = FC_RCTL_DD_SOL_DATA;
+			}
+			fc_fcp_srr(fsp, r_ctl, offset);
+		} else if (e_stat & ESB_ST_SEQ_INIT) {
+			/*
+			 * The remote port has the initiative, so just
+			 * keep waiting for it to complete.
+			 */
+			fc_fcp_timer_set(fsp,  get_fsp_rec_tov(fsp));
+		} else {
+
+			/*
+			 * The exchange is incomplete, we have seq. initiative.
+			 * Lost response with requested confirmation,
+			 * lost confirmation, lost transfer ready or
+			 * lost write data.
+			 *
+			 * For output, if not all data was received, ask
+			 * for transfer ready to be repeated.
+			 *
+			 * If we received or sent all the data, send SRR to
+			 * request response.
+			 *
+			 * If we lost a response, we may have lost some read
+			 * data as well.
+			 */
+			r_ctl = FC_RCTL_DD_SOL_DATA;
+			if (data_dir == DMA_TO_DEVICE) {
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+				if (offset < fsp->data_len)
+					r_ctl = FC_RCTL_DD_DATA_DESC;
+			} else if (offset == fsp->xfer_contig_end) {
+				r_ctl = FC_RCTL_DD_CMD_STATUS;
+			} else if (fsp->xfer_contig_end < offset) {
+				offset = fsp->xfer_contig_end;
+			}
+			fc_fcp_srr(fsp, r_ctl, offset);
+		}
+	}
+unlock_out:
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
+	fc_frame_free(fp);
+}
+
+/**
+ * fc_fcp_rec_error() - Handler for REC errors
+ * @fsp: The FCP packet the error is on
+ * @fp:	 The REC frame
+ */
+static void fc_fcp_rec_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	int error = PTR_ERR(fp);
+
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+
+	switch (error) {
+	case -FC_EX_CLOSED:
+		fc_fcp_retry_cmd(fsp);
+		break;
+
+	default:
+		FC_FCP_DBG(fsp, "REC %p fid %6.6x error unexpected error %d\n",
+			   fsp, fsp->rport->port_id, error);
+		fsp->status_code = FC_CMD_PLOGO;
+		/* fall through */
+
+	case -FC_EX_TIMEOUT:
+		/*
+		 * Assume REC or LS_ACC was lost.
+		 * The exchange manager will have aborted REC, so retry.
+		 */
+		FC_FCP_DBG(fsp, "REC fid %6.6x error error %d retry %d/%d\n",
+			   fsp->rport->port_id, error, fsp->recov_retry,
+			   FC_MAX_RECOV_RETRY);
+		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
+			fc_fcp_rec(fsp);
+		else
+			fc_fcp_recovery(fsp, FC_ERROR);
+		break;
+	}
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fc_fcp_pkt_release(fsp);	/* drop hold for outstanding REC */
+}
+
+/**
+ * fc_fcp_recovery() - Handler for fcp_pkt recovery
+ * @fsp: The FCP pkt that needs to be aborted
+ */
+static void fc_fcp_recovery(struct fc_fcp_pkt *fsp, u8 code)
+{
+	fsp->status_code = code;
+	fsp->cdb_status = 0;
+	fsp->io_status = 0;
+	/*
+	 * if this fails then we let the scsi command timer fire and
+	 * scsi-ml escalate.
+	 */
+	fc_fcp_send_abort(fsp);
+}
+
+/**
+ * fc_fcp_srr() - Send a SRR request (Sequence Retransmission Request)
+ * @fsp:   The FCP packet the SRR is to be sent on
+ * @r_ctl: The R_CTL field for the SRR request
+ * This is called after receiving status but insufficient data, or
+ * when expecting status but the request has timed out.
+ */
+static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
+{
+	struct fc_lport *lport = fsp->lp;
+	struct fc_rport *rport;
+	struct fc_rport_libfc_priv *rpriv;
+	struct fc_exch *ep = fc_seq_exch(fsp->seq_ptr);
+	struct fc_seq *seq;
+	struct fcp_srr *srr;
+	struct fc_frame *fp;
+	unsigned int rec_tov;
+
+	rport = fsp->rport;
+	rpriv = rport->dd_data;
+
+	if (!(rpriv->flags & FC_RP_FLAGS_RETRY) ||
+	    rpriv->rp_state != RPORT_ST_READY)
+		goto retry;			/* shouldn't happen */
+	fp = fc_fcp_frame_alloc(lport, sizeof(*srr));
+	if (!fp)
+		goto retry;
+
+	srr = fc_frame_payload_get(fp, sizeof(*srr));
+	memset(srr, 0, sizeof(*srr));
+	srr->srr_op = ELS_SRR;
+	srr->srr_ox_id = htons(ep->oxid);
+	srr->srr_rx_id = htons(ep->rxid);
+	srr->srr_r_ctl = r_ctl;
+	srr->srr_rel_off = htonl(offset);
+
+	fc_fill_fc_hdr(fp, FC_RCTL_ELS4_REQ, rport->port_id,
+		       rpriv->local_port->port_id, FC_TYPE_FCP,
+		       FC_FCTL_REQ, 0);
+
+	rec_tov = get_fsp_rec_tov(fsp);
+	seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp,
+				      fc_fcp_pkt_destroy,
+				      fsp, jiffies_to_msecs(rec_tov));
+	if (!seq)
+		goto retry;
+
+	fsp->recov_seq = seq;
+	fsp->xfer_len = offset;
+	fsp->xfer_contig_end = offset;
+	fsp->state &= ~FC_SRB_RCV_STATUS;
+	fc_fcp_pkt_hold(fsp);		/* hold for outstanding SRR */
+	return;
+retry:
+	fc_fcp_retry_cmd(fsp);
+}
+
+/**
+ * fc_fcp_srr_resp() - Handler for SRR response
+ * @seq: The sequence the SRR is on
+ * @fp:	 The SRR frame
+ * @arg: The FCP packet the SRR is on
+ */
+static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
+{
+	struct fc_fcp_pkt *fsp = arg;
+	struct fc_frame_header *fh;
+
+	if (IS_ERR(fp)) {
+		fc_fcp_srr_error(fsp, fp);
+		return;
+	}
+
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+
+	fh = fc_frame_header_get(fp);
+	/*
+	 * BUG? fc_fcp_srr_error calls exch_done which would release
+	 * the ep. But if fc_fcp_srr_error had got -FC_EX_TIMEOUT,
+	 * then fc_exch_timeout would be sending an abort. The exch_done
+	 * call by fc_fcp_srr_error would prevent fc_exch.c from seeing
+	 * an abort response though.
+	 */
+	if (fh->fh_type == FC_TYPE_BLS) {
+		fc_fcp_unlock_pkt(fsp);
+		return;
+	}
+
+	switch (fc_frame_payload_op(fp)) {
+	case ELS_LS_ACC:
+		fsp->recov_retry = 0;
+		fc_fcp_timer_set(fsp, get_fsp_rec_tov(fsp));
+		break;
+	case ELS_LS_RJT:
+	default:
+		fc_fcp_recovery(fsp, FC_ERROR);
+		break;
+	}
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fsp->lp->tt.exch_done(seq);
+	fc_frame_free(fp);
+}
+
+/**
+ * fc_fcp_srr_error() - Handler for SRR errors
+ * @fsp: The FCP packet that the SRR error is on
+ * @fp:	 The SRR frame
+ */
+static void fc_fcp_srr_error(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
+{
+	if (fc_fcp_lock_pkt(fsp))
+		goto out;
+	switch (PTR_ERR(fp)) {
+	case -FC_EX_TIMEOUT:
+		if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
+			fc_fcp_rec(fsp);
+		else
+			fc_fcp_recovery(fsp, FC_TIMED_OUT);
+		break;
+	case -FC_EX_CLOSED:			/* e.g., link failure */
+		/* fall through */
+	default:
+		fc_fcp_retry_cmd(fsp);
+		break;
+	}
+	fc_fcp_unlock_pkt(fsp);
+out:
+	fsp->lp->tt.exch_done(fsp->recov_seq);
+}
+
+/**
+ * fc_fcp_lport_queue_ready() - Determine if the lport and it's queue is ready
+ * @lport: The local port to be checked
+ */
+static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport)
+{
+	/* lock ? */
+	return (lport->state == LPORT_ST_READY) &&
+		lport->link_up && !lport->qfull;
+}
+
+/**
+ * fc_queuecommand() - The queuecommand function of the SCSI template
+ * @shost: The Scsi_Host that the command was issued to
+ * @cmd:   The scsi_cmnd to be executed
+ *
+ * This is the i/o strategy routine, called by the SCSI layer.
+ */
+int fc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc_cmd)
+{
+	struct fc_lport *lport = shost_priv(shost);
+	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
+	struct fc_fcp_pkt *fsp;
+	struct fc_rport_libfc_priv *rpriv;
+	int rval;
+	int rc = 0;
+	struct fc_stats *stats;
+
+	rval = fc_remote_port_chkready(rport);
+	if (rval) {
+		sc_cmd->result = rval;
+		sc_cmd->scsi_done(sc_cmd);
+		return 0;
+	}
+
+	if (!*(struct fc_remote_port **)rport->dd_data) {
+		/*
+		 * rport is transitioning from blocked/deleted to
+		 * online
+		 */
+		sc_cmd->result = DID_IMM_RETRY << 16;
+		sc_cmd->scsi_done(sc_cmd);
+		goto out;
+	}
+
+	rpriv = rport->dd_data;
+
+	if (!fc_fcp_lport_queue_ready(lport)) {
+		if (lport->qfull)
+			fc_fcp_can_queue_ramp_down(lport);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	fsp = fc_fcp_pkt_alloc(lport, GFP_ATOMIC);
+	if (fsp == NULL) {
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+		goto out;
+	}
+
+	/*
+	 * build the libfc request pkt
+	 */
+	fsp->cmd = sc_cmd;	/* save the cmd */
+	fsp->rport = rport;	/* set the remote port ptr */
+
+	/*
+	 * set up the transfer length
+	 */
+	fsp->data_len = scsi_bufflen(sc_cmd);
+	fsp->xfer_len = 0;
+
+	/*
+	 * setup the data direction
+	 */
+	stats = per_cpu_ptr(lport->stats, get_cpu());
+	if (sc_cmd->sc_data_direction == DMA_FROM_DEVICE) {
+		fsp->req_flags = FC_SRB_READ;
+		stats->InputRequests++;
+		stats->InputBytes += fsp->data_len;
+	} else if (sc_cmd->sc_data_direction == DMA_TO_DEVICE) {
+		fsp->req_flags = FC_SRB_WRITE;
+		stats->OutputRequests++;
+		stats->OutputBytes += fsp->data_len;
+	} else {
+		fsp->req_flags = 0;
+		stats->ControlRequests++;
+	}
+	put_cpu();
+
+	/*
+	 * send it to the lower layer
+	 * if we get -1 return then put the request in the pending
+	 * queue.
+	 */
+	rval = fc_fcp_pkt_send(lport, fsp);
+	if (rval != 0) {
+		fsp->state = FC_SRB_FREE;
+		fc_fcp_pkt_release(fsp);
+		rc = SCSI_MLQUEUE_HOST_BUSY;
+	}
+out:
+	return rc;
+}
+EXPORT_SYMBOL(fc_queuecommand);
+
+/**
+ * fc_io_compl() - Handle responses for completed commands
+ * @fsp: The FCP packet that is complete
+ *
+ * Translates fcp_pkt errors to a Linux SCSI errors.
+ * The fcp packet lock must be held when calling.
+ */
+static void fc_io_compl(struct fc_fcp_pkt *fsp)
+{
+	struct fc_fcp_internal *si;
+	struct scsi_cmnd *sc_cmd;
+	struct fc_lport *lport;
+	unsigned long flags;
+
+	/* release outstanding ddp context */
+	fc_fcp_ddp_done(fsp);
+
+	fsp->state |= FC_SRB_COMPL;
+	if (!(fsp->state & FC_SRB_FCP_PROCESSING_TMO)) {
+		spin_unlock_bh(&fsp->scsi_pkt_lock);
+		del_timer_sync(&fsp->timer);
+		spin_lock_bh(&fsp->scsi_pkt_lock);
+	}
+
+	lport = fsp->lp;
+	si = fc_get_scsi_internal(lport);
+
+	/*
+	 * if can_queue ramp down is done then try can_queue ramp up
+	 * since commands are completing now.
+	 */
+	if (si->last_can_queue_ramp_down_time)
+		fc_fcp_can_queue_ramp_up(lport);
+
+	sc_cmd = fsp->cmd;
+	CMD_SCSI_STATUS(sc_cmd) = fsp->cdb_status;
+	switch (fsp->status_code) {
+	case FC_COMPLETE:
+		if (fsp->cdb_status == 0) {
+			/*
+			 * good I/O status
+			 */
+			sc_cmd->result = DID_OK << 16;
+			if (fsp->scsi_resid)
+				CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
+		} else {
+			/*
+			 * transport level I/O was ok but scsi
+			 * has non zero status
+			 */
+			sc_cmd->result = (DID_OK << 16) | fsp->cdb_status;
+		}
+		break;
+	case FC_ERROR:
+		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
+			   "due to FC_ERROR\n");
+		sc_cmd->result = DID_ERROR << 16;
+		break;
+	case FC_DATA_UNDRUN:
+		if ((fsp->cdb_status == 0) && !(fsp->req_flags & FC_SRB_READ)) {
+			/*
+			 * scsi status is good but transport level
+			 * underrun.
+			 */
+			if (fsp->state & FC_SRB_RCV_STATUS) {
+				sc_cmd->result = DID_OK << 16;
+			} else {
+				FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml"
+					   " due to FC_DATA_UNDRUN (trans)\n");
+				sc_cmd->result = DID_ERROR << 16;
+			}
+		} else {
+			/*
+			 * scsi got underrun, this is an error
+			 */
+			FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
+				   "due to FC_DATA_UNDRUN (scsi)\n");
+			CMD_RESID_LEN(sc_cmd) = fsp->scsi_resid;
+			sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
+		}
+		break;
+	case FC_DATA_OVRRUN:
+		/*
+		 * overrun is an error
+		 */
+		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
+			   "due to FC_DATA_OVRRUN\n");
+		sc_cmd->result = (DID_ERROR << 16) | fsp->cdb_status;
+		break;
+	case FC_CMD_ABORTED:
+		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
+			  "due to FC_CMD_ABORTED\n");
+		sc_cmd->result = (DID_ERROR << 16) | fsp->io_status;
+		break;
+	case FC_CMD_RESET:
+		FC_FCP_DBG(fsp, "Returning DID_RESET to scsi-ml "
+			   "due to FC_CMD_RESET\n");
+		sc_cmd->result = (DID_RESET << 16);
+		break;
+	case FC_HRD_ERROR:
+		FC_FCP_DBG(fsp, "Returning DID_NO_CONNECT to scsi-ml "
+			   "due to FC_HRD_ERROR\n");
+		sc_cmd->result = (DID_NO_CONNECT << 16);
+		break;
+	case FC_CRC_ERROR:
+		FC_FCP_DBG(fsp, "Returning DID_PARITY to scsi-ml "
+			   "due to FC_CRC_ERROR\n");
+		sc_cmd->result = (DID_PARITY << 16);
+		break;
+	case FC_TIMED_OUT:
+		FC_FCP_DBG(fsp, "Returning DID_BUS_BUSY to scsi-ml "
+			   "due to FC_TIMED_OUT\n");
+		sc_cmd->result = (DID_BUS_BUSY << 16) | fsp->io_status;
+		break;
+	default:
+		FC_FCP_DBG(fsp, "Returning DID_ERROR to scsi-ml "
+			   "due to unknown error\n");
+		sc_cmd->result = (DID_ERROR << 16);
+		break;
+	}
+
+	if (lport->state != LPORT_ST_READY && fsp->status_code != FC_COMPLETE)
+		sc_cmd->result = (DID_TRANSPORT_DISRUPTED << 16);
+
+	spin_lock_irqsave(&si->scsi_queue_lock, flags);
+	list_del(&fsp->list);
+	sc_cmd->SCp.ptr = NULL;
+	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+	sc_cmd->scsi_done(sc_cmd);
+
+	/* release ref from initial allocation in queue command */
+	fc_fcp_pkt_release(fsp);
+}
+
+/**
+ * fc_eh_abort() - Abort a command
+ * @sc_cmd: The SCSI command to abort
+ *
+ * From SCSI host template.
+ * Send an ABTS to the target device and wait for the response.
+ */
+int fc_eh_abort(struct scsi_cmnd *sc_cmd)
+{
+	struct fc_fcp_pkt *fsp;
+	struct fc_lport *lport;
+	struct fc_fcp_internal *si;
+	int rc = FAILED;
+	unsigned long flags;
+	int rval;
+
+	rval = fc_block_scsi_eh(sc_cmd);
+	if (rval)
+		return rval;
+
+	lport = shost_priv(sc_cmd->device->host);
+	if (lport->state != LPORT_ST_READY)
+		return rc;
+	else if (!lport->link_up)
+		return rc;
+
+	si = fc_get_scsi_internal(lport);
+	spin_lock_irqsave(&si->scsi_queue_lock, flags);
+	fsp = CMD_SP(sc_cmd);
+	if (!fsp) {
+		/* command completed while scsi eh was setting up */
+		spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+		return SUCCESS;
+	}
+	/* grab a ref so the fsp and sc_cmd cannot be released from under us */
+	fc_fcp_pkt_hold(fsp);
+	spin_unlock_irqrestore(&si->scsi_queue_lock, flags);
+
+	if (fc_fcp_lock_pkt(fsp)) {
+		/* completed while we were waiting for timer to be deleted */
+		rc = SUCCESS;
+		goto release_pkt;
+	}
+
+	rc = fc_fcp_pkt_abort(fsp);
+	fc_fcp_unlock_pkt(fsp);
+
+release_pkt:
+	fc_fcp_pkt_release(fsp);
+	return rc;
+}
+EXPORT_SYMBOL(fc_eh_abort);
+
+/**
+ * fc_eh_device_reset() - Reset a single LUN
+ * @sc_cmd: The SCSI command which identifies the device whose
+ *	    LUN is to be reset
+ *
+ * Set from SCSI host template.
+ */
+int fc_eh_device_reset(struct scsi_cmnd *sc_cmd)
+{
+	struct fc_lport *lport;
+	struct fc_fcp_pkt *fsp;
+	struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device));
+	int rc = FAILED;
+	int rval;
+
+	rval = fc_block_scsi_eh(sc_cmd);
+	if (rval)
+		return rval;
+
+	lport = shost_priv(sc_cmd->device->host);
+
+	if (lport->state != LPORT_ST_READY)
+		return rc;
+
+	FC_SCSI_DBG(lport, "Resetting rport (%6.6x)\n", rport->port_id);
+
+	fsp = fc_fcp_pkt_alloc(lport, GFP_NOIO);
+	if (fsp == NULL) {
+		printk(KERN_WARNING "libfc: could not allocate scsi_pkt\n");
+		goto out;
+	}
+
+	/*
+	 * Build the libfc request pkt. Do not set the scsi cmnd, because
+	 * the sc passed in is not setup for execution like when sent
+	 * through the queuecommand callout.
+	 */
+	fsp->rport = rport;	/* set the remote port ptr */
+
+	/*
+	 * flush outstanding commands
+	 */
+	rc = fc_lun_reset(lport, fsp, scmd_id(sc_cmd), sc_cmd->device->lun);
+	fsp->state = FC_SRB_FREE;
+	fc_fcp_pkt_release(fsp);
+
+out:
+	return rc;
+}
+EXPORT_SYMBOL(fc_eh_device_reset);
+
+/**
+ * fc_eh_host_reset() - Reset a Scsi_Host.
+ * @sc_cmd: The SCSI command that identifies the SCSI host to be reset
+ */
+int fc_eh_host_reset(struct scsi_cmnd *sc_cmd)
+{
+	struct Scsi_Host *shost = sc_cmd->device->host;
+	struct fc_lport *lport = shost_priv(shost);
+	unsigned long wait_tmo;
+
+	FC_SCSI_DBG(lport, "Resetting host\n");
+
+	fc_block_scsi_eh(sc_cmd);
+
+	lport->tt.lport_reset(lport);
+	wait_tmo = jiffies + FC_HOST_RESET_TIMEOUT;
+	while (!fc_fcp_lport_queue_ready(lport) && time_before(jiffies,
+							       wait_tmo))
+		msleep(1000);
+
+	if (fc_fcp_lport_queue_ready(lport)) {
+		shost_printk(KERN_INFO, shost, "libfc: Host reset succeeded "
+			     "on port (%6.6x)\n", lport->port_id);
+		return SUCCESS;
+	} else {
+		shost_printk(KERN_INFO, shost, "libfc: Host reset failed, "
+			     "port (%6.6x) is not ready.\n",
+			     lport->port_id);
+		return FAILED;
+	}
+}
+EXPORT_SYMBOL(fc_eh_host_reset);
+
+/**
+ * fc_slave_alloc() - Configure the queue depth of a Scsi_Host
+ * @sdev: The SCSI device that identifies the SCSI host
+ *
+ * Configures queue depth based on host's cmd_per_len. If not set
+ * then we use the libfc default.
+ */
+int fc_slave_alloc(struct scsi_device *sdev)
+{
+	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
+
+	if (!rport || fc_remote_port_chkready(rport))
+		return -ENXIO;
+
+	scsi_change_queue_depth(sdev, FC_FCP_DFLT_QUEUE_DEPTH);
+	return 0;
+}
+EXPORT_SYMBOL(fc_slave_alloc);
+
+/**
+ * fc_fcp_destory() - Tear down the FCP layer for a given local port
+ * @lport: The local port that no longer needs the FCP layer
+ */
+void fc_fcp_destroy(struct fc_lport *lport)
+{
+	struct fc_fcp_internal *si = fc_get_scsi_internal(lport);
+
+	if (!list_empty(&si->scsi_pkt_queue))
+		printk(KERN_ERR "libfc: Leaked SCSI packets when destroying "
+		       "port (%6.6x)\n", lport->port_id);
+
+	mempool_destroy(si->scsi_pkt_pool);
+	kfree(si);
+	lport->scsi_priv = NULL;
+}
+EXPORT_SYMBOL(fc_fcp_destroy);
+
+int fc_setup_fcp(void)
+{
+	int rc = 0;
+
+	scsi_pkt_cachep = kmem_cache_create("libfc_fcp_pkt",
+					    sizeof(struct fc_fcp_pkt),
+					    0, SLAB_HWCACHE_ALIGN, NULL);
+	if (!scsi_pkt_cachep) {
+		printk(KERN_ERR "libfc: Unable to allocate SRB cache, "
+		       "module load failed!");
+		rc = -ENOMEM;
+	}
+
+	return rc;
+}
+
+void fc_destroy_fcp(void)
+{
+	if (scsi_pkt_cachep)
+		kmem_cache_destroy(scsi_pkt_cachep);
+}
+
+/**
+ * fc_fcp_init() - Initialize the FCP layer for a local port
+ * @lport: The local port to initialize the exchange layer for
+ */
+int fc_fcp_init(struct fc_lport *lport)
+{
+	int rc;
+	struct fc_fcp_internal *si;
+
+	if (!lport->tt.fcp_cmd_send)
+		lport->tt.fcp_cmd_send = fc_fcp_cmd_send;
+
+	if (!lport->tt.fcp_cleanup)
+		lport->tt.fcp_cleanup = fc_fcp_cleanup;
+
+	if (!lport->tt.fcp_abort_io)
+		lport->tt.fcp_abort_io = fc_fcp_abort_io;
+
+	si = kzalloc(sizeof(struct fc_fcp_internal), GFP_KERNEL);
+	if (!si)
+		return -ENOMEM;
+	lport->scsi_priv = si;
+	si->max_can_queue = lport->host->can_queue;
+	INIT_LIST_HEAD(&si->scsi_pkt_queue);
+	spin_lock_init(&si->scsi_queue_lock);
+
+	si->scsi_pkt_pool = mempool_create_slab_pool(2, scsi_pkt_cachep);
+	if (!si->scsi_pkt_pool) {
+		rc = -ENOMEM;
+		goto free_internal;
+	}
+	return 0;
+
+free_internal:
+	kfree(si);
+	return rc;
+}
+EXPORT_SYMBOL(fc_fcp_init);