nvme-fabrics: Add target support for FC transport

Implements the FC-NVME T11 definition of how nvme fabric capsules are
performed on an FC fabric. Utilizes a lower-layer API to FC host adapters
to send/receive FC-4 LS operations and perform the FCP transactions
necessary to perform and FCP IO request for NVME.

The T11 definitions for FC-4 Link Services are implemented which create
NVMeOF connections.  Implements the hooks with nvmet layer to pass NVME
commands to it for processing and posting of data/response base to the
host via the different connections.
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Jay Freyensee <james_p_freyensee@linux.intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

MAINTAINERS

@@ -8666,6 +8666,7 @@ S:	Supported
 F:	include/linux/nvme-fc.h
 F:	include/linux/nvme-fc-driver.h
 F:	drivers/nvme/host/fc.c
+F:	drivers/nvme/target/fc.c
 
 NVMEM FRAMEWORK
 M:	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

drivers/nvme/target/Kconfig

@@ -34,3 +34,14 @@ config NVME_TARGET_RDMA
 	  devices over RDMA.
 
 	  If unsure, say N.
+
+config NVME_TARGET_FC
+	tristate "NVMe over Fabrics FC target driver"
+	depends on NVME_TARGET
+	depends on HAS_DMA
+	help
+	  This enables the NVMe FC target support, which allows exporting NVMe
+	  devices over FC.
+
+	  If unsure, say N.
+

drivers/nvme/target/Makefile

@@ -2,8 +2,10 @@
 obj-$(CONFIG_NVME_TARGET)		+= nvmet.o
 obj-$(CONFIG_NVME_TARGET_LOOP)		+= nvme-loop.o
 obj-$(CONFIG_NVME_TARGET_RDMA)		+= nvmet-rdma.o
+obj-$(CONFIG_NVME_TARGET_FC)		+= nvmet-fc.o
 
 nvmet-y		+= core.o configfs.o admin-cmd.o io-cmd.o fabrics-cmd.o \
 			discovery.o
 nvme-loop-y	+= loop.o
 nvmet-rdma-y	+= rdma.o
+nvmet-fc-y	+= fc.o

drivers/nvme/target/fc.c

+/*
+ * Copyright (c) 2016 Avago Technologies.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful.
+ * ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
+ * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED, EXCEPT TO
+ * THE EXTENT THAT SUCH DISCLAIMERS ARE HELD TO BE LEGALLY INVALID.
+ * See the GNU General Public License for more details, a copy of which
+ * can be found in the file COPYING included with this package
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/blk-mq.h>
+#include <linux/parser.h>
+#include <linux/random.h>
+#include <uapi/scsi/fc/fc_fs.h>
+#include <uapi/scsi/fc/fc_els.h>
+
+#include "nvmet.h"
+#include <linux/nvme-fc-driver.h>
+#include <linux/nvme-fc.h>
+
+
+/* *************************** Data Structures/Defines ****************** */
+
+
+#define NVMET_LS_CTX_COUNT		4
+
+/* for this implementation, assume small single frame rqst/rsp */
+#define NVME_FC_MAX_LS_BUFFER_SIZE		2048
+
+struct nvmet_fc_tgtport;
+struct nvmet_fc_tgt_assoc;
+
+struct nvmet_fc_ls_iod {
+	struct nvmefc_tgt_ls_req	*lsreq;
+	struct nvmefc_tgt_fcp_req	*fcpreq;	/* only if RS */
+
+	struct list_head		ls_list;	/* tgtport->ls_list */
+
+	struct nvmet_fc_tgtport		*tgtport;
+	struct nvmet_fc_tgt_assoc	*assoc;
+
+	u8				*rqstbuf;
+	u8				*rspbuf;
+	u16				rqstdatalen;
+	dma_addr_t			rspdma;
+
+	struct scatterlist		sg[2];
+
+	struct work_struct		work;
+} __aligned(sizeof(unsigned long long));
+
+#define NVMET_FC_MAX_KB_PER_XFR		256
+
+enum nvmet_fcp_datadir {
+	NVMET_FCP_NODATA,
+	NVMET_FCP_WRITE,
+	NVMET_FCP_READ,
+	NVMET_FCP_ABORTED,
+};
+
+struct nvmet_fc_fcp_iod {
+	struct nvmefc_tgt_fcp_req	*fcpreq;
+
+	struct nvme_fc_cmd_iu		cmdiubuf;
+	struct nvme_fc_ersp_iu		rspiubuf;
+	dma_addr_t			rspdma;
+	struct scatterlist		*data_sg;
+	struct scatterlist		*next_sg;
+	int				data_sg_cnt;
+	u32				next_sg_offset;
+	u32				total_length;
+	u32				offset;
+	enum nvmet_fcp_datadir		io_dir;
+	bool				active;
+	bool				abort;
+	spinlock_t			flock;
+
+	struct nvmet_req		req;
+	struct work_struct		work;
+
+	struct nvmet_fc_tgtport		*tgtport;
+	struct nvmet_fc_tgt_queue	*queue;
+
+	struct list_head		fcp_list;	/* tgtport->fcp_list */
+};
+
+struct nvmet_fc_tgtport {
+
+	struct nvmet_fc_target_port	fc_target_port;
+
+	struct list_head		tgt_list; /* nvmet_fc_target_list */
+	struct device			*dev;	/* dev for dma mapping */
+	struct nvmet_fc_target_template	*ops;
+
+	struct nvmet_fc_ls_iod		*iod;
+	spinlock_t			lock;
+	struct list_head		ls_list;
+	struct list_head		ls_busylist;
+	struct list_head		assoc_list;
+	struct ida			assoc_cnt;
+	struct nvmet_port		*port;
+	struct kref			ref;
+};
+
+struct nvmet_fc_tgt_queue {
+	bool				ninetypercent;
+	u16				qid;
+	u16				sqsize;
+	u16				ersp_ratio;
+	u16				sqhd;
+	int				cpu;
+	atomic_t			connected;
+	atomic_t			sqtail;
+	atomic_t			zrspcnt;
+	atomic_t			rsn;
+	spinlock_t			qlock;
+	struct nvmet_port		*port;
+	struct nvmet_cq			nvme_cq;
+	struct nvmet_sq			nvme_sq;
+	struct nvmet_fc_tgt_assoc	*assoc;
+	struct nvmet_fc_fcp_iod		*fod;		/* array of fcp_iods */
+	struct list_head		fod_list;
+	struct workqueue_struct		*work_q;
+	struct kref			ref;
+} __aligned(sizeof(unsigned long long));
+
+struct nvmet_fc_tgt_assoc {
+	u64				association_id;
+	u32				a_id;
+	struct nvmet_fc_tgtport		*tgtport;
+	struct list_head		a_list;
+	struct nvmet_fc_tgt_queue	*queues[NVMET_NR_QUEUES];
+	struct kref			ref;
+};
+
+
+static inline int
+nvmet_fc_iodnum(struct nvmet_fc_ls_iod *iodptr)
+{
+	return (iodptr - iodptr->tgtport->iod);
+}
+
+static inline int
+nvmet_fc_fodnum(struct nvmet_fc_fcp_iod *fodptr)
+{
+	return (fodptr - fodptr->queue->fod);
+}
+
+
+/*
+ * Association and Connection IDs:
+ *
+ * Association ID will have random number in upper 6 bytes and zero
+ *   in lower 2 bytes
+ *
+ * Connection IDs will be Association ID with QID or'd in lower 2 bytes
+ *
+ * note: Association ID = Connection ID for queue 0
+ */
+#define BYTES_FOR_QID			sizeof(u16)
+#define BYTES_FOR_QID_SHIFT		(BYTES_FOR_QID * 8)
+#define NVMET_FC_QUEUEID_MASK		((u64)((1 << BYTES_FOR_QID_SHIFT) - 1))
+
+static inline u64
+nvmet_fc_makeconnid(struct nvmet_fc_tgt_assoc *assoc, u16 qid)
+{
+	return (assoc->association_id | qid);
+}
+
+static inline u64
+nvmet_fc_getassociationid(u64 connectionid)
+{
+	return connectionid & ~NVMET_FC_QUEUEID_MASK;
+}
+
+static inline u16
+nvmet_fc_getqueueid(u64 connectionid)
+{
+	return (u16)(connectionid & NVMET_FC_QUEUEID_MASK);
+}
+
+static inline struct nvmet_fc_tgtport *
+targetport_to_tgtport(struct nvmet_fc_target_port *targetport)
+{
+	return container_of(targetport, struct nvmet_fc_tgtport,
+				 fc_target_port);
+}
+
+static inline struct nvmet_fc_fcp_iod *
+nvmet_req_to_fod(struct nvmet_req *nvme_req)
+{
+	return container_of(nvme_req, struct nvmet_fc_fcp_iod, req);
+}
+
+
+/* *************************** Globals **************************** */
+
+
+static DEFINE_SPINLOCK(nvmet_fc_tgtlock);
+
+static LIST_HEAD(nvmet_fc_target_list);
+static DEFINE_IDA(nvmet_fc_tgtport_cnt);
+
+
+static void nvmet_fc_handle_ls_rqst_work(struct work_struct *work);
+static void nvmet_fc_handle_fcp_rqst_work(struct work_struct *work);
+static void nvmet_fc_tgt_a_put(struct nvmet_fc_tgt_assoc *assoc);
+static int nvmet_fc_tgt_a_get(struct nvmet_fc_tgt_assoc *assoc);
+static void nvmet_fc_tgt_q_put(struct nvmet_fc_tgt_queue *queue);
+static int nvmet_fc_tgt_q_get(struct nvmet_fc_tgt_queue *queue);
+static void nvmet_fc_tgtport_put(struct nvmet_fc_tgtport *tgtport);
+static int nvmet_fc_tgtport_get(struct nvmet_fc_tgtport *tgtport);
+
+
+/* *********************** FC-NVME DMA Handling **************************** */
+
+/*
+ * The fcloop device passes in a NULL device pointer. Real LLD's will
+ * pass in a valid device pointer. If NULL is passed to the dma mapping
+ * routines, depending on the platform, it may or may not succeed, and
+ * may crash.
+ *
+ * As such:
+ * Wrapper all the dma routines and check the dev pointer.
+ *
+ * If simple mappings (return just a dma address, we'll noop them,
+ * returning a dma address of 0.
+ *
+ * On more complex mappings (dma_map_sg), a pseudo routine fills
+ * in the scatter list, setting all dma addresses to 0.
+ */
+
+static inline dma_addr_t
+fc_dma_map_single(struct device *dev, void *ptr, size_t size,
+		enum dma_data_direction dir)
+{
+	return dev ? dma_map_single(dev, ptr, size, dir) : (dma_addr_t)0L;
+}
+
+static inline int
+fc_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return dev ? dma_mapping_error(dev, dma_addr) : 0;
+}
+
+static inline void
+fc_dma_unmap_single(struct device *dev, dma_addr_t addr, size_t size,
+	enum dma_data_direction dir)
+{
+	if (dev)
+		dma_unmap_single(dev, addr, size, dir);
+}
+
+static inline void
+fc_dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size,
+		enum dma_data_direction dir)
+{
+	if (dev)
+		dma_sync_single_for_cpu(dev, addr, size, dir);
+}
+
+static inline void
+fc_dma_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size,
+		enum dma_data_direction dir)
+{
+	if (dev)
+		dma_sync_single_for_device(dev, addr, size, dir);
+}
+
+/* pseudo dma_map_sg call */
+static int
+fc_map_sg(struct scatterlist *sg, int nents)
+{
+	struct scatterlist *s;
+	int i;
+
+	WARN_ON(nents == 0 || sg[0].length == 0);
+
+	for_each_sg(sg, s, nents, i) {
+		s->dma_address = 0L;
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+		s->dma_length = s->length;
+#endif
+	}
+	return nents;
+}
+
+static inline int
+fc_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+		enum dma_data_direction dir)
+{
+	return dev ? dma_map_sg(dev, sg, nents, dir) : fc_map_sg(sg, nents);
+}
+
+static inline void
+fc_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+		enum dma_data_direction dir)
+{
+	if (dev)
+		dma_unmap_sg(dev, sg, nents, dir);
+}
+
+
+/* *********************** FC-NVME Port Management ************************ */
+
+
+static int
+nvmet_fc_alloc_ls_iodlist(struct nvmet_fc_tgtport *tgtport)
+{
+	struct nvmet_fc_ls_iod *iod;
+	int i;
+
+	iod = kcalloc(NVMET_LS_CTX_COUNT, sizeof(struct nvmet_fc_ls_iod),
+			GFP_KERNEL);
+	if (!iod)
+		return -ENOMEM;
+
+	tgtport->iod = iod;
+
+	for (i = 0; i < NVMET_LS_CTX_COUNT; iod++, i++) {
+		INIT_WORK(&iod->work, nvmet_fc_handle_ls_rqst_work);
+		iod->tgtport = tgtport;
+		list_add_tail(&iod->ls_list, &tgtport->ls_list);
+
+		iod->rqstbuf = kcalloc(2, NVME_FC_MAX_LS_BUFFER_SIZE,
+			GFP_KERNEL);
+		if (!iod->rqstbuf)
+			goto out_fail;
+
+		iod->rspbuf = iod->rqstbuf + NVME_FC_MAX_LS_BUFFER_SIZE;
+
+		iod->rspdma = fc_dma_map_single(tgtport->dev, iod->rspbuf,
+						NVME_FC_MAX_LS_BUFFER_SIZE,
+						DMA_TO_DEVICE);
+		if (fc_dma_mapping_error(tgtport->dev, iod->rspdma))
+			goto out_fail;
+	}
+
+	return 0;
+
+out_fail:
+	kfree(iod->rqstbuf);
+	list_del(&iod->ls_list);
+	for (iod--, i--; i >= 0; iod--, i--) {
+		fc_dma_unmap_single(tgtport->dev, iod->rspdma,
+				NVME_FC_MAX_LS_BUFFER_SIZE, DMA_TO_DEVICE);
+		kfree(iod->rqstbuf);
+		list_del(&iod->ls_list);
+	}
+
+	kfree(iod);
+
+	return -EFAULT;
+}
+
+static void
+nvmet_fc_free_ls_iodlist(struct nvmet_fc_tgtport *tgtport)
+{
+	struct nvmet_fc_ls_iod *iod = tgtport->iod;
+	int i;
+
+	for (i = 0; i < NVMET_LS_CTX_COUNT; iod++, i++) {
+		fc_dma_unmap_single(tgtport->dev,
+				iod->rspdma, NVME_FC_MAX_LS_BUFFER_SIZE,
+				DMA_TO_DEVICE);
+		kfree(iod->rqstbuf);
+		list_del(&iod->ls_list);
+	}
+	kfree(tgtport->iod);
+}
+
+static struct nvmet_fc_ls_iod *
+nvmet_fc_alloc_ls_iod(struct nvmet_fc_tgtport *tgtport)
+{
+	static struct nvmet_fc_ls_iod *iod;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	iod = list_first_entry_or_null(&tgtport->ls_list,
+					struct nvmet_fc_ls_iod, ls_list);
+	if (iod)
+		list_move_tail(&iod->ls_list, &tgtport->ls_busylist);
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+	return iod;
+}
+
+
+static void
+nvmet_fc_free_ls_iod(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_ls_iod *iod)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	list_move(&iod->ls_list, &tgtport->ls_list);
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+}
+
+static void
+nvmet_fc_prep_fcp_iodlist(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_tgt_queue *queue)
+{
+	struct nvmet_fc_fcp_iod *fod = queue->fod;
+	int i;
+
+	for (i = 0; i < queue->sqsize; fod++, i++) {
+		INIT_WORK(&fod->work, nvmet_fc_handle_fcp_rqst_work);
+		fod->tgtport = tgtport;
+		fod->queue = queue;
+		fod->active = false;
+		list_add_tail(&fod->fcp_list, &queue->fod_list);
+		spin_lock_init(&fod->flock);
+
+		fod->rspdma = fc_dma_map_single(tgtport->dev, &fod->rspiubuf,
+					sizeof(fod->rspiubuf), DMA_TO_DEVICE);
+		if (fc_dma_mapping_error(tgtport->dev, fod->rspdma)) {
+			list_del(&fod->fcp_list);
+			for (fod--, i--; i >= 0; fod--, i--) {
+				fc_dma_unmap_single(tgtport->dev, fod->rspdma,
+						sizeof(fod->rspiubuf),
+						DMA_TO_DEVICE);
+				fod->rspdma = 0L;
+				list_del(&fod->fcp_list);
+			}
+
+			return;
+		}
+	}
+}
+
+static void
+nvmet_fc_destroy_fcp_iodlist(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_tgt_queue *queue)
+{
+	struct nvmet_fc_fcp_iod *fod = queue->fod;
+	int i;
+
+	for (i = 0; i < queue->sqsize; fod++, i++) {
+		if (fod->rspdma)
+			fc_dma_unmap_single(tgtport->dev, fod->rspdma,
+				sizeof(fod->rspiubuf), DMA_TO_DEVICE);
+	}
+}
+
+static struct nvmet_fc_fcp_iod *
+nvmet_fc_alloc_fcp_iod(struct nvmet_fc_tgt_queue *queue)
+{
+	static struct nvmet_fc_fcp_iod *fod;
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->qlock, flags);
+	fod = list_first_entry_or_null(&queue->fod_list,
+					struct nvmet_fc_fcp_iod, fcp_list);
+	if (fod) {
+		list_del(&fod->fcp_list);
+		fod->active = true;
+		fod->abort = false;
+		/*
+		 * no queue reference is taken, as it was taken by the
+		 * queue lookup just prior to the allocation. The iod
+		 * will "inherit" that reference.
+		 */
+	}
+	spin_unlock_irqrestore(&queue->qlock, flags);
+	return fod;
+}
+
+
+static void
+nvmet_fc_free_fcp_iod(struct nvmet_fc_tgt_queue *queue,
+			struct nvmet_fc_fcp_iod *fod)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->qlock, flags);
+	list_add_tail(&fod->fcp_list, &fod->queue->fod_list);
+	fod->active = false;
+	spin_unlock_irqrestore(&queue->qlock, flags);
+
+	/*
+	 * release the reference taken at queue lookup and fod allocation
+	 */
+	nvmet_fc_tgt_q_put(queue);
+}
+
+static int
+nvmet_fc_queue_to_cpu(struct nvmet_fc_tgtport *tgtport, int qid)
+{
+	int cpu, idx, cnt;
+
+	if (!(tgtport->ops->target_features &
+			NVMET_FCTGTFEAT_NEEDS_CMD_CPUSCHED) ||
+	    tgtport->ops->max_hw_queues == 1)
+		return WORK_CPU_UNBOUND;
+
+	/* Simple cpu selection based on qid modulo active cpu count */
+	idx = !qid ? 0 : (qid - 1) % num_active_cpus();
+
+	/* find the n'th active cpu */
+	for (cpu = 0, cnt = 0; ; ) {
+		if (cpu_active(cpu)) {
+			if (cnt == idx)
+				break;
+			cnt++;
+		}
+		cpu = (cpu + 1) % num_possible_cpus();
+	}
+
+	return cpu;
+}
+
+static struct nvmet_fc_tgt_queue *
+nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc,
+			u16 qid, u16 sqsize)
+{
+	struct nvmet_fc_tgt_queue *queue;
+	unsigned long flags;
+	int ret;
+
+	if (qid >= NVMET_NR_QUEUES)
+		return NULL;
+
+	queue = kzalloc((sizeof(*queue) +
+				(sizeof(struct nvmet_fc_fcp_iod) * sqsize)),
+				GFP_KERNEL);
+	if (!queue)
+		return NULL;
+
+	if (!nvmet_fc_tgt_a_get(assoc))
+		goto out_free_queue;
+
+	queue->work_q = alloc_workqueue("ntfc%d.%d.%d", 0, 0,
+				assoc->tgtport->fc_target_port.port_num,
+				assoc->a_id, qid);
+	if (!queue->work_q)
+		goto out_a_put;
+
+	queue->fod = (struct nvmet_fc_fcp_iod *)&queue[1];
+	queue->qid = qid;
+	queue->sqsize = sqsize;
+	queue->assoc = assoc;
+	queue->port = assoc->tgtport->port;
+	queue->cpu = nvmet_fc_queue_to_cpu(assoc->tgtport, qid);
+	INIT_LIST_HEAD(&queue->fod_list);
+	atomic_set(&queue->connected, 0);
+	atomic_set(&queue->sqtail, 0);
+	atomic_set(&queue->rsn, 1);
+	atomic_set(&queue->zrspcnt, 0);
+	spin_lock_init(&queue->qlock);
+	kref_init(&queue->ref);
+
+	nvmet_fc_prep_fcp_iodlist(assoc->tgtport, queue);
+
+	ret = nvmet_sq_init(&queue->nvme_sq);
+	if (ret)
+		goto out_fail_iodlist;
+
+	WARN_ON(assoc->queues[qid]);
+	spin_lock_irqsave(&assoc->tgtport->lock, flags);
+	assoc->queues[qid] = queue;
+	spin_unlock_irqrestore(&assoc->tgtport->lock, flags);
+
+	return queue;
+
+out_fail_iodlist:
+	nvmet_fc_destroy_fcp_iodlist(assoc->tgtport, queue);
+	destroy_workqueue(queue->work_q);
+out_a_put:
+	nvmet_fc_tgt_a_put(assoc);
+out_free_queue:
+	kfree(queue);
+	return NULL;
+}
+
+
+static void
+nvmet_fc_tgt_queue_free(struct kref *ref)
+{
+	struct nvmet_fc_tgt_queue *queue =
+		container_of(ref, struct nvmet_fc_tgt_queue, ref);
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->assoc->tgtport->lock, flags);
+	queue->assoc->queues[queue->qid] = NULL;
+	spin_unlock_irqrestore(&queue->assoc->tgtport->lock, flags);
+
+	nvmet_fc_destroy_fcp_iodlist(queue->assoc->tgtport, queue);
+
+	nvmet_fc_tgt_a_put(queue->assoc);
+
+	destroy_workqueue(queue->work_q);
+
+	kfree(queue);
+}
+
+static void
+nvmet_fc_tgt_q_put(struct nvmet_fc_tgt_queue *queue)
+{
+	kref_put(&queue->ref, nvmet_fc_tgt_queue_free);
+}
+
+static int
+nvmet_fc_tgt_q_get(struct nvmet_fc_tgt_queue *queue)
+{
+	return kref_get_unless_zero(&queue->ref);
+}
+
+
+static void
+nvmet_fc_abort_op(struct nvmet_fc_tgtport *tgtport,
+				struct nvmefc_tgt_fcp_req *fcpreq)
+{
+	int ret;
+
+	fcpreq->op = NVMET_FCOP_ABORT;
+	fcpreq->offset = 0;
+	fcpreq->timeout = 0;
+	fcpreq->transfer_length = 0;
+	fcpreq->transferred_length = 0;
+	fcpreq->fcp_error = 0;
+	fcpreq->sg_cnt = 0;
+
+	ret = tgtport->ops->fcp_op(&tgtport->fc_target_port, fcpreq);
+	if (ret)
+		/* should never reach here !! */
+		WARN_ON(1);
+}
+
+
+static void
+nvmet_fc_delete_target_queue(struct nvmet_fc_tgt_queue *queue)
+{
+	struct nvmet_fc_fcp_iod *fod = queue->fod;
+	unsigned long flags;
+	int i;
+	bool disconnect;
+
+	disconnect = atomic_xchg(&queue->connected, 0);
+
+	spin_lock_irqsave(&queue->qlock, flags);
+	/* about outstanding io's */
+	for (i = 0; i < queue->sqsize; fod++, i++) {
+		if (fod->active) {
+			spin_lock(&fod->flock);
+			fod->abort = true;
+			spin_unlock(&fod->flock);
+		}
+	}
+	spin_unlock_irqrestore(&queue->qlock, flags);
+
+	flush_workqueue(queue->work_q);
+
+	if (disconnect)
+		nvmet_sq_destroy(&queue->nvme_sq);
+
+	nvmet_fc_tgt_q_put(queue);
+}
+
+static struct nvmet_fc_tgt_queue *
+nvmet_fc_find_target_queue(struct nvmet_fc_tgtport *tgtport,
+				u64 connection_id)
+{
+	struct nvmet_fc_tgt_assoc *assoc;
+	struct nvmet_fc_tgt_queue *queue;
+	u64 association_id = nvmet_fc_getassociationid(connection_id);
+	u16 qid = nvmet_fc_getqueueid(connection_id);
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	list_for_each_entry(assoc, &tgtport->assoc_list, a_list) {
+		if (association_id == assoc->association_id) {
+			queue = assoc->queues[qid];
+			if (queue &&
+			    (!atomic_read(&queue->connected) ||
+			     !nvmet_fc_tgt_q_get(queue)))
+				queue = NULL;
+			spin_unlock_irqrestore(&tgtport->lock, flags);
+			return queue;
+		}
+	}
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+	return NULL;
+}
+
+static struct nvmet_fc_tgt_assoc *
+nvmet_fc_alloc_target_assoc(struct nvmet_fc_tgtport *tgtport)
+{
+	struct nvmet_fc_tgt_assoc *assoc, *tmpassoc;
+	unsigned long flags;
+	u64 ran;
+	int idx;
+	bool needrandom = true;
+
+	assoc = kzalloc(sizeof(*assoc), GFP_KERNEL);
+	if (!assoc)
+		return NULL;
+
+	idx = ida_simple_get(&tgtport->assoc_cnt, 0, 0, GFP_KERNEL);
+	if (idx < 0)
+		goto out_free_assoc;
+
+	if (!nvmet_fc_tgtport_get(tgtport))
+		goto out_ida_put;
+
+	assoc->tgtport = tgtport;
+	assoc->a_id = idx;
+	INIT_LIST_HEAD(&assoc->a_list);
+	kref_init(&assoc->ref);
+
+	while (needrandom) {
+		get_random_bytes(&ran, sizeof(ran) - BYTES_FOR_QID);
+		ran = ran << BYTES_FOR_QID_SHIFT;
+
+		spin_lock_irqsave(&tgtport->lock, flags);
+		needrandom = false;
+		list_for_each_entry(tmpassoc, &tgtport->assoc_list, a_list)
+			if (ran == tmpassoc->association_id) {
+				needrandom = true;
+				break;
+			}
+		if (!needrandom) {
+			assoc->association_id = ran;
+			list_add_tail(&assoc->a_list, &tgtport->assoc_list);
+		}
+		spin_unlock_irqrestore(&tgtport->lock, flags);
+	}
+
+	return assoc;
+
+out_ida_put:
+	ida_simple_remove(&tgtport->assoc_cnt, idx);
+out_free_assoc:
+	kfree(assoc);
+	return NULL;
+}
+
+static void
+nvmet_fc_target_assoc_free(struct kref *ref)
+{
+	struct nvmet_fc_tgt_assoc *assoc =
+		container_of(ref, struct nvmet_fc_tgt_assoc, ref);
+	struct nvmet_fc_tgtport *tgtport = assoc->tgtport;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	list_del(&assoc->a_list);
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+	ida_simple_remove(&tgtport->assoc_cnt, assoc->a_id);
+	kfree(assoc);
+	nvmet_fc_tgtport_put(tgtport);
+}
+
+static void
+nvmet_fc_tgt_a_put(struct nvmet_fc_tgt_assoc *assoc)
+{
+	kref_put(&assoc->ref, nvmet_fc_target_assoc_free);
+}
+
+static int
+nvmet_fc_tgt_a_get(struct nvmet_fc_tgt_assoc *assoc)
+{
+	return kref_get_unless_zero(&assoc->ref);
+}
+
+static void
+nvmet_fc_delete_target_assoc(struct nvmet_fc_tgt_assoc *assoc)
+{
+	struct nvmet_fc_tgtport *tgtport = assoc->tgtport;
+	struct nvmet_fc_tgt_queue *queue;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	for (i = NVMET_NR_QUEUES - 1; i >= 0; i--) {
+		queue = assoc->queues[i];
+		if (queue) {
+			if (!nvmet_fc_tgt_q_get(queue))
+				continue;
+			spin_unlock_irqrestore(&tgtport->lock, flags);
+			nvmet_fc_delete_target_queue(queue);
+			nvmet_fc_tgt_q_put(queue);
+			spin_lock_irqsave(&tgtport->lock, flags);
+		}
+	}
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+
+	nvmet_fc_tgt_a_put(assoc);
+}
+
+static struct nvmet_fc_tgt_assoc *
+nvmet_fc_find_target_assoc(struct nvmet_fc_tgtport *tgtport,
+				u64 association_id)
+{
+	struct nvmet_fc_tgt_assoc *assoc;
+	struct nvmet_fc_tgt_assoc *ret = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	list_for_each_entry(assoc, &tgtport->assoc_list, a_list) {
+		if (association_id == assoc->association_id) {
+			ret = assoc;
+			nvmet_fc_tgt_a_get(assoc);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+
+	return ret;
+}
+
+
+/**
+ * nvme_fc_register_targetport - transport entry point called by an
+ *                              LLDD to register the existence of a local
+ *                              NVME subystem FC port.
+ * @pinfo:     pointer to information about the port to be registered
+ * @template:  LLDD entrypoints and operational parameters for the port
+ * @dev:       physical hardware device node port corresponds to. Will be
+ *             used for DMA mappings
+ * @portptr:   pointer to a local port pointer. Upon success, the routine
+ *             will allocate a nvme_fc_local_port structure and place its
+ *             address in the local port pointer. Upon failure, local port
+ *             pointer will be set to NULL.
+ *
+ * Returns:
+ * a completion status. Must be 0 upon success; a negative errno
+ * (ex: -ENXIO) upon failure.
+ */
+int
+nvmet_fc_register_targetport(struct nvmet_fc_port_info *pinfo,
+			struct nvmet_fc_target_template *template,
+			struct device *dev,
+			struct nvmet_fc_target_port **portptr)
+{
+	struct nvmet_fc_tgtport *newrec;
+	unsigned long flags;
+	int ret, idx;
+
+	if (!template->xmt_ls_rsp || !template->fcp_op ||
+	    !template->targetport_delete ||
+	    !template->max_hw_queues || !template->max_sgl_segments ||
+	    !template->max_dif_sgl_segments || !template->dma_boundary) {
+		ret = -EINVAL;
+		goto out_regtgt_failed;
+	}
+
+	newrec = kzalloc((sizeof(*newrec) + template->target_priv_sz),
+			 GFP_KERNEL);
+	if (!newrec) {
+		ret = -ENOMEM;
+		goto out_regtgt_failed;
+	}
+
+	idx = ida_simple_get(&nvmet_fc_tgtport_cnt, 0, 0, GFP_KERNEL);
+	if (idx < 0) {
+		ret = -ENOSPC;
+		goto out_fail_kfree;
+	}
+
+	if (!get_device(dev) && dev) {
+		ret = -ENODEV;
+		goto out_ida_put;
+	}
+
+	newrec->fc_target_port.node_name = pinfo->node_name;
+	newrec->fc_target_port.port_name = pinfo->port_name;
+	newrec->fc_target_port.private = &newrec[1];
+	newrec->fc_target_port.port_id = pinfo->port_id;
+	newrec->fc_target_port.port_num = idx;
+	INIT_LIST_HEAD(&newrec->tgt_list);
+	newrec->dev = dev;
+	newrec->ops = template;
+	spin_lock_init(&newrec->lock);
+	INIT_LIST_HEAD(&newrec->ls_list);
+	INIT_LIST_HEAD(&newrec->ls_busylist);
+	INIT_LIST_HEAD(&newrec->assoc_list);
+	kref_init(&newrec->ref);
+	ida_init(&newrec->assoc_cnt);
+
+	ret = nvmet_fc_alloc_ls_iodlist(newrec);
+	if (ret) {
+		ret = -ENOMEM;
+		goto out_free_newrec;
+	}
+
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	list_add_tail(&newrec->tgt_list, &nvmet_fc_target_list);
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+
+	*portptr = &newrec->fc_target_port;
+	return 0;
+
+out_free_newrec:
+	put_device(dev);
+out_ida_put:
+	ida_simple_remove(&nvmet_fc_tgtport_cnt, idx);
+out_fail_kfree:
+	kfree(newrec);
+out_regtgt_failed:
+	*portptr = NULL;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvmet_fc_register_targetport);
+
+
+static void
+nvmet_fc_free_tgtport(struct kref *ref)
+{
+	struct nvmet_fc_tgtport *tgtport =
+		container_of(ref, struct nvmet_fc_tgtport, ref);
+	struct device *dev = tgtport->dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	list_del(&tgtport->tgt_list);
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+
+	nvmet_fc_free_ls_iodlist(tgtport);
+
+	/* let the LLDD know we've finished tearing it down */
+	tgtport->ops->targetport_delete(&tgtport->fc_target_port);
+
+	ida_simple_remove(&nvmet_fc_tgtport_cnt,
+			tgtport->fc_target_port.port_num);
+
+	ida_destroy(&tgtport->assoc_cnt);
+
+	kfree(tgtport);
+
+	put_device(dev);
+}
+
+static void
+nvmet_fc_tgtport_put(struct nvmet_fc_tgtport *tgtport)
+{
+	kref_put(&tgtport->ref, nvmet_fc_free_tgtport);
+}
+
+static int
+nvmet_fc_tgtport_get(struct nvmet_fc_tgtport *tgtport)
+{
+	return kref_get_unless_zero(&tgtport->ref);
+}
+
+static void
+__nvmet_fc_free_assocs(struct nvmet_fc_tgtport *tgtport)
+{
+	struct nvmet_fc_tgt_assoc *assoc, *next;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tgtport->lock, flags);
+	list_for_each_entry_safe(assoc, next,
+				&tgtport->assoc_list, a_list) {
+		if (!nvmet_fc_tgt_a_get(assoc))
+			continue;
+		spin_unlock_irqrestore(&tgtport->lock, flags);
+		nvmet_fc_delete_target_assoc(assoc);
+		nvmet_fc_tgt_a_put(assoc);
+		spin_lock_irqsave(&tgtport->lock, flags);
+	}
+	spin_unlock_irqrestore(&tgtport->lock, flags);
+}
+
+/*
+ * nvmet layer has called to terminate an association
+ */
+static void
+nvmet_fc_delete_ctrl(struct nvmet_ctrl *ctrl)
+{
+	struct nvmet_fc_tgtport *tgtport, *next;
+	struct nvmet_fc_tgt_assoc *assoc;
+	struct nvmet_fc_tgt_queue *queue;
+	unsigned long flags;
+	bool found_ctrl = false;
+
+	/* this is a bit ugly, but don't want to make locks layered */
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	list_for_each_entry_safe(tgtport, next, &nvmet_fc_target_list,
+			tgt_list) {
+		if (!nvmet_fc_tgtport_get(tgtport))
+			continue;
+		spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+
+		spin_lock_irqsave(&tgtport->lock, flags);
+		list_for_each_entry(assoc, &tgtport->assoc_list, a_list) {
+			queue = assoc->queues[0];
+			if (queue && queue->nvme_sq.ctrl == ctrl) {
+				if (nvmet_fc_tgt_a_get(assoc))
+					found_ctrl = true;
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&tgtport->lock, flags);
+
+		nvmet_fc_tgtport_put(tgtport);
+
+		if (found_ctrl) {
+			nvmet_fc_delete_target_assoc(assoc);
+			nvmet_fc_tgt_a_put(assoc);
+			return;
+		}
+
+		spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	}
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+}
+
+/**
+ * nvme_fc_unregister_targetport - transport entry point called by an
+ *                              LLDD to deregister/remove a previously
+ *                              registered a local NVME subsystem FC port.
+ * @tgtport: pointer to the (registered) target port that is to be
+ *           deregistered.
+ *
+ * Returns:
+ * a completion status. Must be 0 upon success; a negative errno
+ * (ex: -ENXIO) upon failure.
+ */
+int
+nvmet_fc_unregister_targetport(struct nvmet_fc_target_port *target_port)
+{
+	struct nvmet_fc_tgtport *tgtport = targetport_to_tgtport(target_port);
+
+	/* terminate any outstanding associations */
+	__nvmet_fc_free_assocs(tgtport);
+
+	nvmet_fc_tgtport_put(tgtport);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmet_fc_unregister_targetport);
+
+
+/* *********************** FC-NVME LS Handling **************************** */
+
+
+static void
+nvmet_fc_format_rsp_hdr(void *buf, u8 ls_cmd, u32 desc_len, u8 rqst_ls_cmd)
+{
+	struct fcnvme_ls_acc_hdr *acc = buf;
+
+	acc->w0.ls_cmd = ls_cmd;
+	acc->desc_list_len = desc_len;
+	acc->rqst.desc_tag = cpu_to_be32(FCNVME_LSDESC_RQST);
+	acc->rqst.desc_len =
+			fcnvme_lsdesc_len(sizeof(struct fcnvme_lsdesc_rqst));
+	acc->rqst.w0.ls_cmd = rqst_ls_cmd;
+}
+
+static int
+nvmet_fc_format_rjt(void *buf, u16 buflen, u8 ls_cmd,
+			u8 reason, u8 explanation, u8 vendor)
+{
+	struct fcnvme_ls_rjt *rjt = buf;
+
+	nvmet_fc_format_rsp_hdr(buf, FCNVME_LSDESC_RQST,
+			fcnvme_lsdesc_len(sizeof(struct fcnvme_ls_rjt)),
+			ls_cmd);
+	rjt->rjt.desc_tag = cpu_to_be32(FCNVME_LSDESC_RJT);
+	rjt->rjt.desc_len = fcnvme_lsdesc_len(sizeof(struct fcnvme_lsdesc_rjt));
+	rjt->rjt.reason_code = reason;
+	rjt->rjt.reason_explanation = explanation;
+	rjt->rjt.vendor = vendor;
+
+	return sizeof(struct fcnvme_ls_rjt);
+}
+
+/* Validation Error indexes into the string table below */
+enum {
+	VERR_NO_ERROR		= 0,
+	VERR_CR_ASSOC_LEN	= 1,
+	VERR_CR_ASSOC_RQST_LEN	= 2,
+	VERR_CR_ASSOC_CMD	= 3,
+	VERR_CR_ASSOC_CMD_LEN	= 4,
+	VERR_ERSP_RATIO		= 5,
+	VERR_ASSOC_ALLOC_FAIL	= 6,
+	VERR_QUEUE_ALLOC_FAIL	= 7,
+	VERR_CR_CONN_LEN	= 8,
+	VERR_CR_CONN_RQST_LEN	= 9,
+	VERR_ASSOC_ID		= 10,
+	VERR_ASSOC_ID_LEN	= 11,
+	VERR_NO_ASSOC		= 12,
+	VERR_CONN_ID		= 13,
+	VERR_CONN_ID_LEN	= 14,
+	VERR_NO_CONN		= 15,
+	VERR_CR_CONN_CMD	= 16,
+	VERR_CR_CONN_CMD_LEN	= 17,
+	VERR_DISCONN_LEN	= 18,
+	VERR_DISCONN_RQST_LEN	= 19,
+	VERR_DISCONN_CMD	= 20,
+	VERR_DISCONN_CMD_LEN	= 21,
+	VERR_DISCONN_SCOPE	= 22,
+	VERR_RS_LEN		= 23,
+	VERR_RS_RQST_LEN	= 24,
+	VERR_RS_CMD		= 25,
+	VERR_RS_CMD_LEN		= 26,
+	VERR_RS_RCTL		= 27,
+	VERR_RS_RO		= 28,
+};
+
+static char *validation_errors[] = {
+	"OK",
+	"Bad CR_ASSOC Length",
+	"Bad CR_ASSOC Rqst Length",
+	"Not CR_ASSOC Cmd",
+	"Bad CR_ASSOC Cmd Length",
+	"Bad Ersp Ratio",
+	"Association Allocation Failed",
+	"Queue Allocation Failed",
+	"Bad CR_CONN Length",
+	"Bad CR_CONN Rqst Length",
+	"Not Association ID",
+	"Bad Association ID Length",
+	"No Association",
+	"Not Connection ID",
+	"Bad Connection ID Length",
+	"No Connection",
+	"Not CR_CONN Cmd",
+	"Bad CR_CONN Cmd Length",
+	"Bad DISCONN Length",
+	"Bad DISCONN Rqst Length",
+	"Not DISCONN Cmd",
+	"Bad DISCONN Cmd Length",
+	"Bad Disconnect Scope",
+	"Bad RS Length",
+	"Bad RS Rqst Length",
+	"Not RS Cmd",
+	"Bad RS Cmd Length",
+	"Bad RS R_CTL",
+	"Bad RS Relative Offset",
+};
+
+static void
+nvmet_fc_ls_create_association(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_ls_iod *iod)
+{
+	struct fcnvme_ls_cr_assoc_rqst *rqst =
+				(struct fcnvme_ls_cr_assoc_rqst *)iod->rqstbuf;
+	struct fcnvme_ls_cr_assoc_acc *acc =
+				(struct fcnvme_ls_cr_assoc_acc *)iod->rspbuf;
+	struct nvmet_fc_tgt_queue *queue;
+	int ret = 0;
+
+	memset(acc, 0, sizeof(*acc));
+
+	if (iod->rqstdatalen < sizeof(struct fcnvme_ls_cr_assoc_rqst))
+		ret = VERR_CR_ASSOC_LEN;
+	else if (rqst->desc_list_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_ls_cr_assoc_rqst)))
+		ret = VERR_CR_ASSOC_RQST_LEN;
+	else if (rqst->assoc_cmd.desc_tag !=
+			cpu_to_be32(FCNVME_LSDESC_CREATE_ASSOC_CMD))
+		ret = VERR_CR_ASSOC_CMD;
+	else if (rqst->assoc_cmd.desc_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_cr_assoc_cmd)))
+		ret = VERR_CR_ASSOC_CMD_LEN;
+	else if (!rqst->assoc_cmd.ersp_ratio ||
+		 (be16_to_cpu(rqst->assoc_cmd.ersp_ratio) >=
+				be16_to_cpu(rqst->assoc_cmd.sqsize)))
+		ret = VERR_ERSP_RATIO;
+
+	else {
+		/* new association w/ admin queue */
+		iod->assoc = nvmet_fc_alloc_target_assoc(tgtport);
+		if (!iod->assoc)
+			ret = VERR_ASSOC_ALLOC_FAIL;
+		else {
+			queue = nvmet_fc_alloc_target_queue(iod->assoc, 0,
+					be16_to_cpu(rqst->assoc_cmd.sqsize));
+			if (!queue)
+				ret = VERR_QUEUE_ALLOC_FAIL;
+		}
+	}
+
+	if (ret) {
+		dev_err(tgtport->dev,
+			"Create Association LS failed: %s\n",
+			validation_errors[ret]);
+		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
+				ELS_RJT_LOGIC,
+				ELS_EXPL_NONE, 0);
+		return;
+	}
+
+	queue->ersp_ratio = be16_to_cpu(rqst->assoc_cmd.ersp_ratio);
+	atomic_set(&queue->connected, 1);
+	queue->sqhd = 0;	/* best place to init value */
+
+	/* format a response */
+
+	iod->lsreq->rsplen = sizeof(*acc);
+
+	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_ls_cr_assoc_acc)),
+			FCNVME_LS_CREATE_ASSOCIATION);
+	acc->associd.desc_tag = cpu_to_be32(FCNVME_LSDESC_ASSOC_ID);
+	acc->associd.desc_len =
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_assoc_id));
+	acc->associd.association_id =
+			cpu_to_be64(nvmet_fc_makeconnid(iod->assoc, 0));
+	acc->connectid.desc_tag = cpu_to_be32(FCNVME_LSDESC_CONN_ID);
+	acc->connectid.desc_len =
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_conn_id));
+	acc->connectid.connection_id = acc->associd.association_id;
+}
+
+static void
+nvmet_fc_ls_create_connection(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_ls_iod *iod)
+{
+	struct fcnvme_ls_cr_conn_rqst *rqst =
+				(struct fcnvme_ls_cr_conn_rqst *)iod->rqstbuf;
+	struct fcnvme_ls_cr_conn_acc *acc =
+				(struct fcnvme_ls_cr_conn_acc *)iod->rspbuf;
+	struct nvmet_fc_tgt_queue *queue;
+	int ret = 0;
+
+	memset(acc, 0, sizeof(*acc));
+
+	if (iod->rqstdatalen < sizeof(struct fcnvme_ls_cr_conn_rqst))
+		ret = VERR_CR_CONN_LEN;
+	else if (rqst->desc_list_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_ls_cr_conn_rqst)))
+		ret = VERR_CR_CONN_RQST_LEN;
+	else if (rqst->associd.desc_tag != cpu_to_be32(FCNVME_LSDESC_ASSOC_ID))
+		ret = VERR_ASSOC_ID;
+	else if (rqst->associd.desc_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_assoc_id)))
+		ret = VERR_ASSOC_ID_LEN;
+	else if (rqst->connect_cmd.desc_tag !=
+			cpu_to_be32(FCNVME_LSDESC_CREATE_CONN_CMD))
+		ret = VERR_CR_CONN_CMD;
+	else if (rqst->connect_cmd.desc_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_cr_conn_cmd)))
+		ret = VERR_CR_CONN_CMD_LEN;
+	else if (!rqst->connect_cmd.ersp_ratio ||
+		 (be16_to_cpu(rqst->connect_cmd.ersp_ratio) >=
+				be16_to_cpu(rqst->connect_cmd.sqsize)))
+		ret = VERR_ERSP_RATIO;
+
+	else {
+		/* new io queue */
+		iod->assoc = nvmet_fc_find_target_assoc(tgtport,
+				be64_to_cpu(rqst->associd.association_id));
+		if (!iod->assoc)
+			ret = VERR_NO_ASSOC;
+		else {
+			queue = nvmet_fc_alloc_target_queue(iod->assoc,
+					be16_to_cpu(rqst->connect_cmd.qid),
+					be16_to_cpu(rqst->connect_cmd.sqsize));
+			if (!queue)
+				ret = VERR_QUEUE_ALLOC_FAIL;
+
+			/* release get taken in nvmet_fc_find_target_assoc */
+			nvmet_fc_tgt_a_put(iod->assoc);
+		}
+	}
+
+	if (ret) {
+		dev_err(tgtport->dev,
+			"Create Connection LS failed: %s\n",
+			validation_errors[ret]);
+		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
+				(ret == VERR_NO_ASSOC) ?
+						ELS_RJT_PROT : ELS_RJT_LOGIC,
+				ELS_EXPL_NONE, 0);
+		return;
+	}
+
+	queue->ersp_ratio = be16_to_cpu(rqst->connect_cmd.ersp_ratio);
+	atomic_set(&queue->connected, 1);
+	queue->sqhd = 0;	/* best place to init value */
+
+	/* format a response */
+
+	iod->lsreq->rsplen = sizeof(*acc);
+
+	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
+			fcnvme_lsdesc_len(sizeof(struct fcnvme_ls_cr_conn_acc)),
+			FCNVME_LS_CREATE_CONNECTION);
+	acc->connectid.desc_tag = cpu_to_be32(FCNVME_LSDESC_CONN_ID);
+	acc->connectid.desc_len =
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_conn_id));
+	acc->connectid.connection_id =
+			cpu_to_be64(nvmet_fc_makeconnid(iod->assoc,
+				be16_to_cpu(rqst->connect_cmd.qid)));
+}
+
+static void
+nvmet_fc_ls_disconnect(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_ls_iod *iod)
+{
+	struct fcnvme_ls_disconnect_rqst *rqst =
+			(struct fcnvme_ls_disconnect_rqst *)iod->rqstbuf;
+	struct fcnvme_ls_disconnect_acc *acc =
+			(struct fcnvme_ls_disconnect_acc *)iod->rspbuf;
+	struct nvmet_fc_tgt_queue *queue;
+	struct nvmet_fc_tgt_assoc *assoc;
+	int ret = 0;
+	bool del_assoc = false;
+
+	memset(acc, 0, sizeof(*acc));
+
+	if (iod->rqstdatalen < sizeof(struct fcnvme_ls_disconnect_rqst))
+		ret = VERR_DISCONN_LEN;
+	else if (rqst->desc_list_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_ls_disconnect_rqst)))
+		ret = VERR_DISCONN_RQST_LEN;
+	else if (rqst->associd.desc_tag != cpu_to_be32(FCNVME_LSDESC_ASSOC_ID))
+		ret = VERR_ASSOC_ID;
+	else if (rqst->associd.desc_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_assoc_id)))
+		ret = VERR_ASSOC_ID_LEN;
+	else if (rqst->discon_cmd.desc_tag !=
+			cpu_to_be32(FCNVME_LSDESC_DISCONN_CMD))
+		ret = VERR_DISCONN_CMD;
+	else if (rqst->discon_cmd.desc_len !=
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_lsdesc_disconn_cmd)))
+		ret = VERR_DISCONN_CMD_LEN;
+	else if ((rqst->discon_cmd.scope != FCNVME_DISCONN_ASSOCIATION) &&
+			(rqst->discon_cmd.scope != FCNVME_DISCONN_CONNECTION))
+		ret = VERR_DISCONN_SCOPE;
+	else {
+		/* match an active association */
+		assoc = nvmet_fc_find_target_assoc(tgtport,
+				be64_to_cpu(rqst->associd.association_id));
+		iod->assoc = assoc;
+		if (!assoc)
+			ret = VERR_NO_ASSOC;
+	}
+
+	if (ret) {
+		dev_err(tgtport->dev,
+			"Disconnect LS failed: %s\n",
+			validation_errors[ret]);
+		iod->lsreq->rsplen = nvmet_fc_format_rjt(acc,
+				NVME_FC_MAX_LS_BUFFER_SIZE, rqst->w0.ls_cmd,
+				(ret == 8) ? ELS_RJT_PROT : ELS_RJT_LOGIC,
+				ELS_EXPL_NONE, 0);
+		return;
+	}
+
+	/* format a response */
+
+	iod->lsreq->rsplen = sizeof(*acc);
+
+	nvmet_fc_format_rsp_hdr(acc, FCNVME_LS_ACC,
+			fcnvme_lsdesc_len(
+				sizeof(struct fcnvme_ls_disconnect_acc)),
+			FCNVME_LS_DISCONNECT);
+
+
+	if (rqst->discon_cmd.scope == FCNVME_DISCONN_CONNECTION) {
+		queue = nvmet_fc_find_target_queue(tgtport,
+					be64_to_cpu(rqst->discon_cmd.id));
+		if (queue) {
+			int qid = queue->qid;
+
+			nvmet_fc_delete_target_queue(queue);
+
+			/* release the get taken by find_target_queue */
+			nvmet_fc_tgt_q_put(queue);
+
+			/* tear association down if io queue terminated */
+			if (!qid)
+				del_assoc = true;
+		}
+	}
+
+	/* release get taken in nvmet_fc_find_target_assoc */
+	nvmet_fc_tgt_a_put(iod->assoc);
+
+	if (del_assoc)
+		nvmet_fc_delete_target_assoc(iod->assoc);
+}
+
+
+/* *********************** NVME Ctrl Routines **************************** */
+
+
+static void nvmet_fc_fcp_nvme_cmd_done(struct nvmet_req *nvme_req);
+
+static struct nvmet_fabrics_ops nvmet_fc_tgt_fcp_ops;
+
+static void
+nvmet_fc_xmt_ls_rsp_done(struct nvmefc_tgt_ls_req *lsreq)
+{
+	struct nvmet_fc_ls_iod *iod = lsreq->nvmet_fc_private;
+	struct nvmet_fc_tgtport *tgtport = iod->tgtport;
+
+	fc_dma_sync_single_for_cpu(tgtport->dev, iod->rspdma,
+				NVME_FC_MAX_LS_BUFFER_SIZE, DMA_TO_DEVICE);
+	nvmet_fc_free_ls_iod(tgtport, iod);
+	nvmet_fc_tgtport_put(tgtport);
+}
+
+static void
+nvmet_fc_xmt_ls_rsp(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_ls_iod *iod)
+{
+	int ret;
+
+	fc_dma_sync_single_for_device(tgtport->dev, iod->rspdma,
+				  NVME_FC_MAX_LS_BUFFER_SIZE, DMA_TO_DEVICE);
+
+	ret = tgtport->ops->xmt_ls_rsp(&tgtport->fc_target_port, iod->lsreq);
+	if (ret)
+		nvmet_fc_xmt_ls_rsp_done(iod->lsreq);
+}
+
+/*
+ * Actual processing routine for received FC-NVME LS Requests from the LLD
+ */
+static void
+nvmet_fc_handle_ls_rqst(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_ls_iod *iod)
+{
+	struct fcnvme_ls_rqst_w0 *w0 =
+			(struct fcnvme_ls_rqst_w0 *)iod->rqstbuf;
+
+	iod->lsreq->nvmet_fc_private = iod;
+	iod->lsreq->rspbuf = iod->rspbuf;
+	iod->lsreq->rspdma = iod->rspdma;
+	iod->lsreq->done = nvmet_fc_xmt_ls_rsp_done;
+	/* Be preventative. handlers will later set to valid length */
+	iod->lsreq->rsplen = 0;
+
+	iod->assoc = NULL;
+
+	/*
+	 * handlers:
+	 *   parse request input, execute the request, and format the
+	 *   LS response
+	 */
+	switch (w0->ls_cmd) {
+	case FCNVME_LS_CREATE_ASSOCIATION:
+		/* Creates Association and initial Admin Queue/Connection */
+		nvmet_fc_ls_create_association(tgtport, iod);
+		break;
+	case FCNVME_LS_CREATE_CONNECTION:
+		/* Creates an IO Queue/Connection */
+		nvmet_fc_ls_create_connection(tgtport, iod);
+		break;
+	case FCNVME_LS_DISCONNECT:
+		/* Terminate a Queue/Connection or the Association */
+		nvmet_fc_ls_disconnect(tgtport, iod);
+		break;
+	default:
+		iod->lsreq->rsplen = nvmet_fc_format_rjt(iod->rspbuf,
+				NVME_FC_MAX_LS_BUFFER_SIZE, w0->ls_cmd,
+				ELS_RJT_INVAL, ELS_EXPL_NONE, 0);
+	}
+
+	nvmet_fc_xmt_ls_rsp(tgtport, iod);
+}
+
+/*
+ * Actual processing routine for received FC-NVME LS Requests from the LLD
+ */
+static void
+nvmet_fc_handle_ls_rqst_work(struct work_struct *work)
+{
+	struct nvmet_fc_ls_iod *iod =
+		container_of(work, struct nvmet_fc_ls_iod, work);
+	struct nvmet_fc_tgtport *tgtport = iod->tgtport;
+
+	nvmet_fc_handle_ls_rqst(tgtport, iod);
+}
+
+
+/**
+ * nvmet_fc_rcv_ls_req - transport entry point called by an LLDD
+ *                       upon the reception of a NVME LS request.
+ *
+ * The nvmet-fc layer will copy payload to an internal structure for
+ * processing.  As such, upon completion of the routine, the LLDD may
+ * immediately free/reuse the LS request buffer passed in the call.
+ *
+ * If this routine returns error, the LLDD should abort the exchange.
+ *
+ * @tgtport:    pointer to the (registered) target port the LS was
+ *              received on.
+ * @lsreq:      pointer to a lsreq request structure to be used to reference
+ *              the exchange corresponding to the LS.
+ * @lsreqbuf:   pointer to the buffer containing the LS Request
+ * @lsreqbuf_len: length, in bytes, of the received LS request
+ */
+int
+nvmet_fc_rcv_ls_req(struct nvmet_fc_target_port *target_port,
+			struct nvmefc_tgt_ls_req *lsreq,
+			void *lsreqbuf, u32 lsreqbuf_len)
+{
+	struct nvmet_fc_tgtport *tgtport = targetport_to_tgtport(target_port);
+	struct nvmet_fc_ls_iod *iod;
+
+	if (lsreqbuf_len > NVME_FC_MAX_LS_BUFFER_SIZE)
+		return -E2BIG;
+
+	if (!nvmet_fc_tgtport_get(tgtport))
+		return -ESHUTDOWN;
+
+	iod = nvmet_fc_alloc_ls_iod(tgtport);
+	if (!iod) {
+		nvmet_fc_tgtport_put(tgtport);
+		return -ENOENT;
+	}
+
+	iod->lsreq = lsreq;
+	iod->fcpreq = NULL;
+	memcpy(iod->rqstbuf, lsreqbuf, lsreqbuf_len);
+	iod->rqstdatalen = lsreqbuf_len;
+
+	schedule_work(&iod->work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmet_fc_rcv_ls_req);
+
+
+/*
+ * **********************
+ * Start of FCP handling
+ * **********************
+ */
+
+static int
+nvmet_fc_alloc_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
+{
+	struct scatterlist *sg;
+	struct page *page;
+	unsigned int nent;
+	u32 page_len, length;
+	int i = 0;
+
+	length = fod->total_length;
+	nent = DIV_ROUND_UP(length, PAGE_SIZE);
+	sg = kmalloc_array(nent, sizeof(struct scatterlist), GFP_KERNEL);
+	if (!sg)
+		goto out;
+
+	sg_init_table(sg, nent);
+
+	while (length) {
+		page_len = min_t(u32, length, PAGE_SIZE);
+
+		page = alloc_page(GFP_KERNEL);
+		if (!page)
+			goto out_free_pages;
+
+		sg_set_page(&sg[i], page, page_len, 0);
+		length -= page_len;
+		i++;
+	}
+
+	fod->data_sg = sg;
+	fod->data_sg_cnt = nent;
+	fod->data_sg_cnt = fc_dma_map_sg(fod->tgtport->dev, sg, nent,
+				((fod->io_dir == NVMET_FCP_WRITE) ?
+					DMA_FROM_DEVICE : DMA_TO_DEVICE));
+				/* note: write from initiator perspective */
+
+	return 0;
+
+out_free_pages:
+	while (i > 0) {
+		i--;
+		__free_page(sg_page(&sg[i]));
+	}
+	kfree(sg);
+	fod->data_sg = NULL;
+	fod->data_sg_cnt = 0;
+out:
+	return NVME_SC_INTERNAL;
+}
+
+static void
+nvmet_fc_free_tgt_pgs(struct nvmet_fc_fcp_iod *fod)
+{
+	struct scatterlist *sg;
+	int count;
+
+	if (!fod->data_sg || !fod->data_sg_cnt)
+		return;
+
+	fc_dma_unmap_sg(fod->tgtport->dev, fod->data_sg, fod->data_sg_cnt,
+				((fod->io_dir == NVMET_FCP_WRITE) ?
+					DMA_FROM_DEVICE : DMA_TO_DEVICE));
+	for_each_sg(fod->data_sg, sg, fod->data_sg_cnt, count)
+		__free_page(sg_page(sg));
+	kfree(fod->data_sg);
+}
+
+
+static bool
+queue_90percent_full(struct nvmet_fc_tgt_queue *q, u32 sqhd)
+{
+	u32 sqtail, used;
+
+	/* egad, this is ugly. And sqtail is just a best guess */
+	sqtail = atomic_read(&q->sqtail) % q->sqsize;
+
+	used = (sqtail < sqhd) ? (sqtail + q->sqsize - sqhd) : (sqtail - sqhd);
+	return ((used * 10) >= (((u32)(q->sqsize - 1) * 9)));
+}
+
+/*
+ * Prep RSP payload.
+ * May be a NVMET_FCOP_RSP or NVMET_FCOP_READDATA_RSP op
+ */
+static void
+nvmet_fc_prep_fcp_rsp(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_fcp_iod *fod)
+{
+	struct nvme_fc_ersp_iu *ersp = &fod->rspiubuf;
+	struct nvme_common_command *sqe = &fod->cmdiubuf.sqe.common;
+	struct nvme_completion *cqe = &ersp->cqe;
+	u32 *cqewd = (u32 *)cqe;
+	bool send_ersp = false;
+	u32 rsn, rspcnt, xfr_length;
+
+	if (fod->fcpreq->op == NVMET_FCOP_READDATA_RSP)
+		xfr_length = fod->total_length;
+	else
+		xfr_length = fod->offset;
+
+	/*
+	 * check to see if we can send a 0's rsp.
+	 *   Note: to send a 0's response, the NVME-FC host transport will
+	 *   recreate the CQE. The host transport knows: sq id, SQHD (last
+	 *   seen in an ersp), and command_id. Thus it will create a
+	 *   zero-filled CQE with those known fields filled in. Transport
+	 *   must send an ersp for any condition where the cqe won't match
+	 *   this.
+	 *
+	 * Here are the FC-NVME mandated cases where we must send an ersp:
+	 *  every N responses, where N=ersp_ratio
+	 *  force fabric commands to send ersp's (not in FC-NVME but good
+	 *    practice)
+	 *  normal cmds: any time status is non-zero, or status is zero
+	 *     but words 0 or 1 are non-zero.
+	 *  the SQ is 90% or more full
+	 *  the cmd is a fused command
+	 *  transferred data length not equal to cmd iu length
+	 */
+	rspcnt = atomic_inc_return(&fod->queue->zrspcnt);
+	if (!(rspcnt % fod->queue->ersp_ratio) ||
+	    sqe->opcode == nvme_fabrics_command ||
+	    xfr_length != fod->total_length ||
+	    (le16_to_cpu(cqe->status) & 0xFFFE) || cqewd[0] || cqewd[1] ||
+	    (sqe->flags & (NVME_CMD_FUSE_FIRST | NVME_CMD_FUSE_SECOND)) ||
+	    queue_90percent_full(fod->queue, cqe->sq_head))
+		send_ersp = true;
+
+	/* re-set the fields */
+	fod->fcpreq->rspaddr = ersp;
+	fod->fcpreq->rspdma = fod->rspdma;
+
+	if (!send_ersp) {
+		memset(ersp, 0, NVME_FC_SIZEOF_ZEROS_RSP);
+		fod->fcpreq->rsplen = NVME_FC_SIZEOF_ZEROS_RSP;
+	} else {
+		ersp->iu_len = cpu_to_be16(sizeof(*ersp)/sizeof(u32));
+		rsn = atomic_inc_return(&fod->queue->rsn);
+		ersp->rsn = cpu_to_be32(rsn);
+		ersp->xfrd_len = cpu_to_be32(xfr_length);
+		fod->fcpreq->rsplen = sizeof(*ersp);
+	}
+
+	fc_dma_sync_single_for_device(tgtport->dev, fod->rspdma,
+				  sizeof(fod->rspiubuf), DMA_TO_DEVICE);
+}
+
+static void nvmet_fc_xmt_fcp_op_done(struct nvmefc_tgt_fcp_req *fcpreq);
+
+static void
+nvmet_fc_xmt_fcp_rsp(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_fcp_iod *fod)
+{
+	int ret;
+
+	fod->fcpreq->op = NVMET_FCOP_RSP;
+	fod->fcpreq->timeout = 0;
+
+	nvmet_fc_prep_fcp_rsp(tgtport, fod);
+
+	ret = tgtport->ops->fcp_op(&tgtport->fc_target_port, fod->fcpreq);
+	if (ret)
+		nvmet_fc_abort_op(tgtport, fod->fcpreq);
+}
+
+static void
+nvmet_fc_transfer_fcp_data(struct nvmet_fc_tgtport *tgtport,
+				struct nvmet_fc_fcp_iod *fod, u8 op)
+{
+	struct nvmefc_tgt_fcp_req *fcpreq = fod->fcpreq;
+	struct scatterlist *sg, *datasg;
+	u32 tlen, sg_off;
+	int ret;
+
+	fcpreq->op = op;
+	fcpreq->offset = fod->offset;
+	fcpreq->timeout = NVME_FC_TGTOP_TIMEOUT_SEC;
+	tlen = min_t(u32, (NVMET_FC_MAX_KB_PER_XFR * 1024),
+			(fod->total_length - fod->offset));
+	tlen = min_t(u32, tlen, NVME_FC_MAX_SEGMENTS * PAGE_SIZE);
+	tlen = min_t(u32, tlen, fod->tgtport->ops->max_sgl_segments
+					* PAGE_SIZE);
+	fcpreq->transfer_length = tlen;
+	fcpreq->transferred_length = 0;
+	fcpreq->fcp_error = 0;
+	fcpreq->rsplen = 0;
+
+	fcpreq->sg_cnt = 0;
+
+	datasg = fod->next_sg;
+	sg_off = fod->next_sg_offset;
+
+	for (sg = fcpreq->sg ; tlen; sg++) {
+		*sg = *datasg;
+		if (sg_off) {
+			sg->offset += sg_off;
+			sg->length -= sg_off;
+			sg->dma_address += sg_off;
+			sg_off = 0;
+		}
+		if (tlen < sg->length) {
+			sg->length = tlen;
+			fod->next_sg = datasg;
+			fod->next_sg_offset += tlen;
+		} else if (tlen == sg->length) {
+			fod->next_sg_offset = 0;
+			fod->next_sg = sg_next(datasg);
+		} else {
+			fod->next_sg_offset = 0;
+			datasg = sg_next(datasg);
+		}
+		tlen -= sg->length;
+		fcpreq->sg_cnt++;
+	}
+
+	/*
+	 * If the last READDATA request: check if LLDD supports
+	 * combined xfr with response.
+	 */
+	if ((op == NVMET_FCOP_READDATA) &&
+	    ((fod->offset + fcpreq->transfer_length) == fod->total_length) &&
+	    (tgtport->ops->target_features & NVMET_FCTGTFEAT_READDATA_RSP)) {
+		fcpreq->op = NVMET_FCOP_READDATA_RSP;
+		nvmet_fc_prep_fcp_rsp(tgtport, fod);
+	}
+
+	ret = tgtport->ops->fcp_op(&tgtport->fc_target_port, fod->fcpreq);
+	if (ret) {
+		/*
+		 * should be ok to set w/o lock as its in the thread of
+		 * execution (not an async timer routine) and doesn't
+		 * contend with any clearing action
+		 */
+		fod->abort = true;
+
+		if (op == NVMET_FCOP_WRITEDATA)
+			nvmet_req_complete(&fod->req,
+					NVME_SC_FC_TRANSPORT_ERROR);
+		else /* NVMET_FCOP_READDATA or NVMET_FCOP_READDATA_RSP */ {
+			fcpreq->fcp_error = ret;
+			fcpreq->transferred_length = 0;
+			nvmet_fc_xmt_fcp_op_done(fod->fcpreq);
+		}
+	}
+}
+
+static void
+nvmet_fc_xmt_fcp_op_done(struct nvmefc_tgt_fcp_req *fcpreq)
+{
+	struct nvmet_fc_fcp_iod *fod = fcpreq->nvmet_fc_private;
+	struct nvmet_fc_tgtport *tgtport = fod->tgtport;
+	unsigned long flags;
+	bool abort;
+
+	spin_lock_irqsave(&fod->flock, flags);
+	abort = fod->abort;
+	spin_unlock_irqrestore(&fod->flock, flags);
+
+	/* if in the middle of an io and we need to tear down */
+	if (abort && fcpreq->op != NVMET_FCOP_ABORT) {
+		/* data no longer needed */
+		nvmet_fc_free_tgt_pgs(fod);
+
+		if (fcpreq->fcp_error || abort)
+			nvmet_req_complete(&fod->req, fcpreq->fcp_error);
+
+		return;
+	}
+
+	switch (fcpreq->op) {
+
+	case NVMET_FCOP_WRITEDATA:
+		if (abort || fcpreq->fcp_error ||
+		    fcpreq->transferred_length != fcpreq->transfer_length) {
+			nvmet_req_complete(&fod->req,
+					NVME_SC_FC_TRANSPORT_ERROR);
+			return;
+		}
+
+		fod->offset += fcpreq->transferred_length;
+		if (fod->offset != fod->total_length) {
+			/* transfer the next chunk */
+			nvmet_fc_transfer_fcp_data(tgtport, fod,
+						NVMET_FCOP_WRITEDATA);
+			return;
+		}
+
+		/* data transfer complete, resume with nvmet layer */
+
+		fod->req.execute(&fod->req);
+
+		break;
+
+	case NVMET_FCOP_READDATA:
+	case NVMET_FCOP_READDATA_RSP:
+		if (abort || fcpreq->fcp_error ||
+		    fcpreq->transferred_length != fcpreq->transfer_length) {
+			/* data no longer needed */
+			nvmet_fc_free_tgt_pgs(fod);
+
+			nvmet_fc_abort_op(tgtport, fod->fcpreq);
+			return;
+		}
+
+		/* success */
+
+		if (fcpreq->op == NVMET_FCOP_READDATA_RSP) {
+			/* data no longer needed */
+			nvmet_fc_free_tgt_pgs(fod);
+			fc_dma_sync_single_for_cpu(tgtport->dev, fod->rspdma,
+					sizeof(fod->rspiubuf), DMA_TO_DEVICE);
+			nvmet_fc_free_fcp_iod(fod->queue, fod);
+			return;
+		}
+
+		fod->offset += fcpreq->transferred_length;
+		if (fod->offset != fod->total_length) {
+			/* transfer the next chunk */
+			nvmet_fc_transfer_fcp_data(tgtport, fod,
+						NVMET_FCOP_READDATA);
+			return;
+		}
+
+		/* data transfer complete, send response */
+
+		/* data no longer needed */
+		nvmet_fc_free_tgt_pgs(fod);
+
+		nvmet_fc_xmt_fcp_rsp(tgtport, fod);
+
+		break;
+
+	case NVMET_FCOP_RSP:
+	case NVMET_FCOP_ABORT:
+		fc_dma_sync_single_for_cpu(tgtport->dev, fod->rspdma,
+				sizeof(fod->rspiubuf), DMA_TO_DEVICE);
+		nvmet_fc_free_fcp_iod(fod->queue, fod);
+		break;
+
+	default:
+		nvmet_fc_free_tgt_pgs(fod);
+		nvmet_fc_abort_op(tgtport, fod->fcpreq);
+		break;
+	}
+}
+
+/*
+ * actual completion handler after execution by the nvmet layer
+ */
+static void
+__nvmet_fc_fcp_nvme_cmd_done(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_fcp_iod *fod, int status)
+{
+	struct nvme_common_command *sqe = &fod->cmdiubuf.sqe.common;
+	struct nvme_completion *cqe = &fod->rspiubuf.cqe;
+	unsigned long flags;
+	bool abort;
+
+	spin_lock_irqsave(&fod->flock, flags);
+	abort = fod->abort;
+	spin_unlock_irqrestore(&fod->flock, flags);
+
+	/* if we have a CQE, snoop the last sq_head value */
+	if (!status)
+		fod->queue->sqhd = cqe->sq_head;
+
+	if (abort) {
+		/* data no longer needed */
+		nvmet_fc_free_tgt_pgs(fod);
+
+		nvmet_fc_abort_op(tgtport, fod->fcpreq);
+		return;
+	}
+
+	/* if an error handling the cmd post initial parsing */
+	if (status) {
+		/* fudge up a failed CQE status for our transport error */
+		memset(cqe, 0, sizeof(*cqe));
+		cqe->sq_head = fod->queue->sqhd;	/* echo last cqe sqhd */
+		cqe->sq_id = cpu_to_le16(fod->queue->qid);
+		cqe->command_id = sqe->command_id;
+		cqe->status = cpu_to_le16(status);
+	} else {
+
+		/*
+		 * try to push the data even if the SQE status is non-zero.
+		 * There may be a status where data still was intended to
+		 * be moved
+		 */
+		if ((fod->io_dir == NVMET_FCP_READ) && (fod->data_sg_cnt)) {
+			/* push the data over before sending rsp */
+			nvmet_fc_transfer_fcp_data(tgtport, fod,
+						NVMET_FCOP_READDATA);
+			return;
+		}
+
+		/* writes & no data - fall thru */
+	}
+
+	/* data no longer needed */
+	nvmet_fc_free_tgt_pgs(fod);
+
+	nvmet_fc_xmt_fcp_rsp(tgtport, fod);
+}
+
+
+static void
+nvmet_fc_fcp_nvme_cmd_done(struct nvmet_req *nvme_req)
+{
+	struct nvmet_fc_fcp_iod *fod = nvmet_req_to_fod(nvme_req);
+	struct nvmet_fc_tgtport *tgtport = fod->tgtport;
+
+	__nvmet_fc_fcp_nvme_cmd_done(tgtport, fod, 0);
+}
+
+
+/*
+ * Actual processing routine for received FC-NVME LS Requests from the LLD
+ */
+void
+nvmet_fc_handle_fcp_rqst(struct nvmet_fc_tgtport *tgtport,
+			struct nvmet_fc_fcp_iod *fod)
+{
+	struct nvme_fc_cmd_iu *cmdiu = &fod->cmdiubuf;
+	int ret;
+
+	/*
+	 * Fused commands are currently not supported in the linux
+	 * implementation.
+	 *
+	 * As such, the implementation of the FC transport does not
+	 * look at the fused commands and order delivery to the upper
+	 * layer until we have both based on csn.
+	 */
+
+	fod->fcpreq->done = nvmet_fc_xmt_fcp_op_done;
+
+	fod->total_length = be32_to_cpu(cmdiu->data_len);
+	if (cmdiu->flags & FCNVME_CMD_FLAGS_WRITE) {
+		fod->io_dir = NVMET_FCP_WRITE;
+		if (!nvme_is_write(&cmdiu->sqe))
+			goto transport_error;
+	} else if (cmdiu->flags & FCNVME_CMD_FLAGS_READ) {
+		fod->io_dir = NVMET_FCP_READ;
+		if (nvme_is_write(&cmdiu->sqe))
+			goto transport_error;
+	} else {
+		fod->io_dir = NVMET_FCP_NODATA;
+		if (fod->total_length)
+			goto transport_error;
+	}
+
+	fod->req.cmd = &fod->cmdiubuf.sqe;
+	fod->req.rsp = &fod->rspiubuf.cqe;
+	fod->req.port = fod->queue->port;
+
+	/* ensure nvmet handlers will set cmd handler callback */
+	fod->req.execute = NULL;
+
+	/* clear any response payload */
+	memset(&fod->rspiubuf, 0, sizeof(fod->rspiubuf));
+
+	ret = nvmet_req_init(&fod->req,
+				&fod->queue->nvme_cq,
+				&fod->queue->nvme_sq,
+				&nvmet_fc_tgt_fcp_ops);
+	if (!ret) {	/* bad SQE content */
+		nvmet_fc_abort_op(tgtport, fod->fcpreq);
+		return;
+	}
+
+	/* keep a running counter of tail position */
+	atomic_inc(&fod->queue->sqtail);
+
+	fod->data_sg = NULL;
+	fod->data_sg_cnt = 0;
+	if (fod->total_length) {
+		ret = nvmet_fc_alloc_tgt_pgs(fod);
+		if (ret) {
+			nvmet_req_complete(&fod->req, ret);
+			return;
+		}
+	}
+	fod->req.sg = fod->data_sg;
+	fod->req.sg_cnt = fod->data_sg_cnt;
+	fod->offset = 0;
+	fod->next_sg = fod->data_sg;
+	fod->next_sg_offset = 0;
+
+	if (fod->io_dir == NVMET_FCP_WRITE) {
+		/* pull the data over before invoking nvmet layer */
+		nvmet_fc_transfer_fcp_data(tgtport, fod, NVMET_FCOP_WRITEDATA);
+		return;
+	}
+
+	/*
+	 * Reads or no data:
+	 *
+	 * can invoke the nvmet_layer now. If read data, cmd completion will
+	 * push the data
+	 */
+
+	fod->req.execute(&fod->req);
+
+	return;
+
+transport_error:
+	nvmet_fc_abort_op(tgtport, fod->fcpreq);
+}
+
+/*
+ * Actual processing routine for received FC-NVME LS Requests from the LLD
+ */
+static void
+nvmet_fc_handle_fcp_rqst_work(struct work_struct *work)
+{
+	struct nvmet_fc_fcp_iod *fod =
+		container_of(work, struct nvmet_fc_fcp_iod, work);
+	struct nvmet_fc_tgtport *tgtport = fod->tgtport;
+
+	nvmet_fc_handle_fcp_rqst(tgtport, fod);
+}
+
+/**
+ * nvmet_fc_rcv_fcp_req - transport entry point called by an LLDD
+ *                       upon the reception of a NVME FCP CMD IU.
+ *
+ * Pass a FC-NVME FCP CMD IU received from the FC link to the nvmet-fc
+ * layer for processing.
+ *
+ * The nvmet-fc layer will copy cmd payload to an internal structure for
+ * processing.  As such, upon completion of the routine, the LLDD may
+ * immediately free/reuse the CMD IU buffer passed in the call.
+ *
+ * If this routine returns error, the lldd should abort the exchange.
+ *
+ * @target_port: pointer to the (registered) target port the FCP CMD IU
+ *              was receive on.
+ * @fcpreq:     pointer to a fcpreq request structure to be used to reference
+ *              the exchange corresponding to the FCP Exchange.
+ * @cmdiubuf:   pointer to the buffer containing the FCP CMD IU
+ * @cmdiubuf_len: length, in bytes, of the received FCP CMD IU
+ */
+int
+nvmet_fc_rcv_fcp_req(struct nvmet_fc_target_port *target_port,
+			struct nvmefc_tgt_fcp_req *fcpreq,
+			void *cmdiubuf, u32 cmdiubuf_len)
+{
+	struct nvmet_fc_tgtport *tgtport = targetport_to_tgtport(target_port);
+	struct nvme_fc_cmd_iu *cmdiu = cmdiubuf;
+	struct nvmet_fc_tgt_queue *queue;
+	struct nvmet_fc_fcp_iod *fod;
+
+	/* validate iu, so the connection id can be used to find the queue */
+	if ((cmdiubuf_len != sizeof(*cmdiu)) ||
+			(cmdiu->scsi_id != NVME_CMD_SCSI_ID) ||
+			(cmdiu->fc_id != NVME_CMD_FC_ID) ||
+			(be16_to_cpu(cmdiu->iu_len) != (sizeof(*cmdiu)/4)))
+		return -EIO;
+
+
+	queue = nvmet_fc_find_target_queue(tgtport,
+				be64_to_cpu(cmdiu->connection_id));
+	if (!queue)
+		return -ENOTCONN;
+
+	/*
+	 * note: reference taken by find_target_queue
+	 * After successful fod allocation, the fod will inherit the
+	 * ownership of that reference and will remove the reference
+	 * when the fod is freed.
+	 */
+
+	fod = nvmet_fc_alloc_fcp_iod(queue);
+	if (!fod) {
+		/* release the queue lookup reference */
+		nvmet_fc_tgt_q_put(queue);
+		return -ENOENT;
+	}
+
+	fcpreq->nvmet_fc_private = fod;
+	fod->fcpreq = fcpreq;
+	/*
+	 * put all admin cmds on hw queue id 0. All io commands go to
+	 * the respective hw queue based on a modulo basis
+	 */
+	fcpreq->hwqid = queue->qid ?
+			((queue->qid - 1) % tgtport->ops->max_hw_queues) : 0;
+	memcpy(&fod->cmdiubuf, cmdiubuf, cmdiubuf_len);
+
+	queue_work_on(queue->cpu, queue->work_q, &fod->work);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvmet_fc_rcv_fcp_req);
+
+enum {
+	FCT_TRADDR_ERR		= 0,
+	FCT_TRADDR_WWNN		= 1 << 0,
+	FCT_TRADDR_WWPN		= 1 << 1,
+};
+
+struct nvmet_fc_traddr {
+	u64	nn;
+	u64	pn;
+};
+
+static const match_table_t traddr_opt_tokens = {
+	{ FCT_TRADDR_WWNN,	"nn-%s"		},
+	{ FCT_TRADDR_WWPN,	"pn-%s"		},
+	{ FCT_TRADDR_ERR,	NULL		}
+};
+
+static int
+nvmet_fc_parse_traddr(struct nvmet_fc_traddr *traddr, char *buf)
+{
+	substring_t args[MAX_OPT_ARGS];
+	char *options, *o, *p;
+	int token, ret = 0;
+	u64 token64;
+
+	options = o = kstrdup(buf, GFP_KERNEL);
+	if (!options)
+		return -ENOMEM;
+
+	while ((p = strsep(&o, ",\n")) != NULL) {
+		if (!*p)
+			continue;
+
+		token = match_token(p, traddr_opt_tokens, args);
+		switch (token) {
+		case FCT_TRADDR_WWNN:
+			if (match_u64(args, &token64)) {
+				ret = -EINVAL;
+				goto out;
+			}
+			traddr->nn = token64;
+			break;
+		case FCT_TRADDR_WWPN:
+			if (match_u64(args, &token64)) {
+				ret = -EINVAL;
+				goto out;
+			}
+			traddr->pn = token64;
+			break;
+		default:
+			pr_warn("unknown traddr token or missing value '%s'\n",
+					p);
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+out:
+	kfree(options);
+	return ret;
+}
+
+static int
+nvmet_fc_add_port(struct nvmet_port *port)
+{
+	struct nvmet_fc_tgtport *tgtport;
+	struct nvmet_fc_traddr traddr = { 0L, 0L };
+	unsigned long flags;
+	int ret;
+
+	/* validate the address info */
+	if ((port->disc_addr.trtype != NVMF_TRTYPE_FC) ||
+	    (port->disc_addr.adrfam != NVMF_ADDR_FAMILY_FC))
+		return -EINVAL;
+
+	/* map the traddr address info to a target port */
+
+	ret = nvmet_fc_parse_traddr(&traddr, port->disc_addr.traddr);
+	if (ret)
+		return ret;
+
+	ret = -ENXIO;
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	list_for_each_entry(tgtport, &nvmet_fc_target_list, tgt_list) {
+		if ((tgtport->fc_target_port.node_name == traddr.nn) &&
+		    (tgtport->fc_target_port.port_name == traddr.pn)) {
+			/* a FC port can only be 1 nvmet port id */
+			if (!tgtport->port) {
+				tgtport->port = port;
+				port->priv = tgtport;
+				ret = 0;
+			} else
+				ret = -EALREADY;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+	return ret;
+}
+
+static void
+nvmet_fc_remove_port(struct nvmet_port *port)
+{
+	struct nvmet_fc_tgtport *tgtport = port->priv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&nvmet_fc_tgtlock, flags);
+	if (tgtport->port == port) {
+		nvmet_fc_tgtport_put(tgtport);
+		tgtport->port = NULL;
+	}
+	spin_unlock_irqrestore(&nvmet_fc_tgtlock, flags);
+}
+
+static struct nvmet_fabrics_ops nvmet_fc_tgt_fcp_ops = {
+	.owner			= THIS_MODULE,
+	.type			= NVMF_TRTYPE_FC,
+	.msdbd			= 1,
+	.add_port		= nvmet_fc_add_port,
+	.remove_port		= nvmet_fc_remove_port,
+	.queue_response		= nvmet_fc_fcp_nvme_cmd_done,
+	.delete_ctrl		= nvmet_fc_delete_ctrl,
+};
+
+static int __init nvmet_fc_init_module(void)
+{
+	return nvmet_register_transport(&nvmet_fc_tgt_fcp_ops);
+}
+
+static void __exit nvmet_fc_exit_module(void)
+{
+	/* sanity check - all lports should be removed */
+	if (!list_empty(&nvmet_fc_target_list))
+		pr_warn("%s: targetport list not empty\n", __func__);
+
+	nvmet_unregister_transport(&nvmet_fc_tgt_fcp_ops);
+
+	ida_destroy(&nvmet_fc_tgtport_cnt);
+}
+
+module_init(nvmet_fc_init_module);
+module_exit(nvmet_fc_exit_module);
+
+MODULE_LICENSE("GPL v2");