[PATCH v5 6/7] nvme-fabrics: Add target support for FC transport

James Smart james.smart at broadcom.com
Wed Nov 9 08:43:36 PST 2016


Refer to nvmet_fc_rcv_abts() and nvmet_fc_rcv_rs_req() in the 
nvme-fc-driver.h and target/fc.c files. They are currently stubbed.

a) because REC/SRR is broken with exchange level routing - even on SCSI 
FCP.  T11 is addressing this.
b) even if REC/SRR - all IUs are driven via the target transport - thus 
the target transport has to be involved with recovery.

-- james


On 11/8/2016 12:02 PM, Trapp, Darren wrote:
> James,
>
> v5 mods:
> - add check in nvmet_fc_handle_ls_rqst() to ensure RS LS posted via
>    new entry point
>
> What is the new entry point here?
> Why are we using the transport to handle the recovery vs using the existing SRR mechanism in FC?
>
> Darren Trapp
> Senior Director - Engineering
> darren.trapp at cavium.com <mailto:darren.trapp at caviumnetworks.com>
> T 949-389-6273
> M 949-212-8565
> 26650 Aliso Viejo Pkwy, Aliso Viejo, CA 92656
> www.qlogic.com <http://www.qlogic.com/>
>   <http://www.qlogic.com/>
>
> On 11/6/16, 10:23 PM, "Linux-nvme on behalf of James Smart" <linux-nvme-bounces at lists.infradead.org on behalf of jsmart2021 at gmail.com> wrote:
>
>      
>      Add nvme-fabrics 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 at broadcom.com>
>      Reviewed-by: Jay Freyensee <james_p_freyensee at linux.intel.com>
>      
>      ---
>      v4 mods:
>      - added HAS_DMA to Kconfig
>      - add delete_ctrl support
>      - minor fixes in some teardown paths
>      - FC-NVME 1.11: set of transferred length, new abts and rs entry points,
>          and handling of rs ls
>      
>      v5 mods:
>      - add check in nvmet_fc_handle_ls_rqst() to ensure RS LS posted via
>        new entry point
>      
>       MAINTAINERS                  |    1 +
>       drivers/nvme/target/Kconfig  |   11 +
>       drivers/nvme/target/Makefile |    2 +
>       drivers/nvme/target/fc.c     | 2317 ++++++++++++++++++++++++++++++++++++++++++
>       4 files changed, 2331 insertions(+)
>       create mode 100644 drivers/nvme/target/fc.c
>      
>      diff --git a/MAINTAINERS b/MAINTAINERS
>      index 7ca8337..ac9d634 100644
>      --- a/MAINTAINERS
>      +++ b/MAINTAINERS
>      @@ -8667,6 +8667,7 @@ 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 at linaro.org>
>      diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
>      index 3a5b9d0..746a63e 100644
>      --- a/drivers/nvme/target/Kconfig
>      +++ b/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.
>      +
>      diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
>      index b7a0623..80b128b 100644
>      --- a/drivers/nvme/target/Makefile
>      +++ b/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
>      diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
>      new file mode 100644
>      index 0000000..f06f5de
>      --- /dev/null
>      +++ b/drivers/nvme/target/fc.c
>      @@ -0,0 +1,2317 @@
>      +/*
>      + * 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;
>      +	atomic_t			aborted;
>      +	atomic_t			active;
>      +
>      +	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;
>      +	atomic_t			connected;
>      +	atomic_t			sqtail;
>      +	atomic_t			zrspcnt;
>      +	atomic_t			rsn;
>      +	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_tgtport_put(struct nvmet_fc_tgtport *tgtport);
>      +static int nvmet_fc_tgtport_get(struct nvmet_fc_tgtport *tgtport);
>      +
>      +
>      +/* *********************** 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 = dma_map_single(tgtport->dev, iod->rspbuf,
>      +						NVME_FC_MAX_LS_BUFFER_SIZE,
>      +						DMA_TO_DEVICE);
>      +		if (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--) {
>      +		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++) {
>      +		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;
>      +		atomic_set(&fod->active, 0);
>      +		list_add_tail(&fod->fcp_list, &queue->fod_list);
>      +
>      +		fod->rspdma = dma_map_single(
>      +					tgtport->dev, &fod->rspiubuf,
>      +					sizeof(fod->rspiubuf), DMA_TO_DEVICE);
>      +		if (dma_mapping_error(tgtport->dev, fod->rspdma)) {
>      +			list_del(&fod->fcp_list);
>      +			for (fod--, i--; i >= 0; fod--, i--) {
>      +				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)
>      +			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_tgtport *tgtport,
>      +			struct nvmet_fc_tgt_queue *queue)
>      +{
>      +	static struct nvmet_fc_fcp_iod *fod;
>      +	unsigned long flags;
>      +
>      +	spin_lock_irqsave(&tgtport->lock, flags);
>      +	fod = list_first_entry_or_null(&queue->fod_list,
>      +					struct nvmet_fc_fcp_iod, fcp_list);
>      +	if (fod) {
>      +		list_del(&fod->fcp_list);
>      +		atomic_set(&fod->active, 1);
>      +		atomic_set(&fod->aborted, 0);
>      +	}
>      +	spin_unlock_irqrestore(&tgtport->lock, flags);
>      +	return fod;
>      +}
>      +
>      +
>      +static void
>      +nvmet_fc_free_fcp_iod(struct nvmet_fc_tgtport *tgtport,
>      +			struct nvmet_fc_fcp_iod *fod)
>      +{
>      +	unsigned long flags;
>      +
>      +	spin_lock_irqsave(&tgtport->lock, flags);
>      +	list_add_tail(&fod->fcp_list, &fod->queue->fod_list);
>      +	atomic_set(&fod->active, 0);
>      +	spin_unlock_irqrestore(&tgtport->lock, flags);
>      +}
>      +
>      +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;
>      +	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);
>      +	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)
>      +		WARN_ON(1);
>      +		/* should never reach here !! */
>      +}
>      +
>      +
>      +static void
>      +nvmet_fc_delete_target_queue(struct nvmet_fc_tgt_queue *queue)
>      +{
>      +	struct nvmet_fc_tgtport *tgtport = queue->assoc->tgtport;
>      +	struct nvmet_fc_fcp_iod *fod = queue->fod;
>      +	int i;
>      +	bool disconnect;
>      +
>      +	disconnect = atomic_xchg(&queue->connected, 0);
>      +
>      +	/* about outstanding io's */
>      +	for (i = 0; i < queue->sqsize; fod++, i++) {
>      +		if (atomic_read(&fod->active) && !atomic_read(&fod->aborted)) {
>      +			atomic_set(&fod->aborted, 1);
>      +			nvmet_fc_abort_op(tgtport, fod->fcpreq);
>      +		}
>      +	}
>      +
>      +	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(&nvmet_fc_tgtlock, flags);
>      +		nvmet_fc_delete_target_assoc(assoc);
>      +		nvmet_fc_tgt_a_put(assoc);
>      +		spin_lock_irqsave(&nvmet_fc_tgtlock, 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);
>      +}
>      +
>      +static void
>      +nvmet_fc_ls_rs(struct nvmet_fc_tgtport *tgtport, struct nvmet_fc_ls_iod *iod)
>      +{
>      +	struct fcnvme_ls_rs_rqst *rqst =
>      +			(struct fcnvme_ls_rs_rqst *)iod->rqstbuf;
>      +	struct fcnvme_ls_rs_acc *acc =
>      +			(struct fcnvme_ls_rs_acc *)iod->rspbuf;
>      +	struct nvmefc_tgt_fcp_req *fcpreq = iod->fcpreq;
>      +	struct nvmet_fc_fcp_iod *fod = fcpreq->nvmet_fc_private;
>      +	struct nvmet_fc_tgt_queue *queue;
>      +	int ret = 0;
>      +
>      +	memset(acc, 0, sizeof(*acc));
>      +
>      +	if (iod->rqstdatalen < sizeof(struct fcnvme_ls_rs_rqst))
>      +		ret = VERR_RS_LEN;
>      +	else if (rqst->desc_list_len !=
>      +			fcnvme_lsdesc_len(
>      +				sizeof(struct fcnvme_ls_rs_rqst)))
>      +		ret = VERR_RS_RQST_LEN;
>      +	else if (rqst->connectid.desc_tag != cpu_to_be32(FCNVME_LSDESC_CONN_ID))
>      +		ret = VERR_CONN_ID;
>      +	else if (rqst->connectid.desc_len !=
>      +			fcnvme_lsdesc_len(
>      +				sizeof(struct fcnvme_lsdesc_conn_id)))
>      +		ret = VERR_CONN_ID_LEN;
>      +	else if (rqst->rs.desc_tag !=
>      +			cpu_to_be32(FCNVME_LSDESC_RS))
>      +		ret = VERR_RS_CMD;
>      +	else if (rqst->rs.desc_len !=
>      +			fcnvme_lsdesc_len(
>      +				sizeof(struct fcnvme_lsdesc_rs)))
>      +		ret = VERR_RS_CMD_LEN;
>      +	else if (rqst->rs.r_ctl != FCNVME_RS_RCTL_DATA &&
>      +		 rqst->rs.r_ctl != FCNVME_RS_RCTL_XFER_RDY &&
>      +		 rqst->rs.r_ctl != FCNVME_RS_RCTL_RSP)
>      +		ret = VERR_RS_RCTL;
>      +	else if (be32_to_cpu(rqst->rs.relative_offset) >=
>      +				be32_to_cpu(fod->cmdiubuf.data_len))
>      +		ret = VERR_RS_RO;
>      +	else {
>      +		queue = nvmet_fc_find_target_queue(tgtport,
>      +				be64_to_cpu(rqst->connectid.connection_id));
>      +		if (!queue)
>      +			ret = VERR_NO_CONN;
>      +	}
>      +
>      +	if (ret) {
>      +		dev_err(tgtport->dev,
>      +			"RS 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_rs_acc)),
>      +			FCNVME_LS_RS);
>      +
>      +	/*
>      +	 * TODO: change I/O state and restart
>      +	 */
>      +
>      +	/* release get taken in nvmet_fc_find_target_queue */
>      +	nvmet_fc_tgt_q_get(queue);
>      +}
>      +
>      +
>      +
>      +/* *********************** 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;
>      +
>      +	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;
>      +
>      +	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;
>      +
>      +	/* Ensure RS LS came via separate callback */
>      +	if (w0->ls_cmd == FCNVME_LS_RS && !iod->fcpreq)
>      +		/* fudge the LS cmd to force a reject */
>      +		w0->ls_cmd = 0xFF;
>      +
>      +	/*
>      +	 * 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;
>      +	case FCNVME_LS_RS:
>      +		/* Set Recovery position on an I/O */
>      +		nvmet_fc_ls_rs(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);
>      +
>      +/**
>      + * nvmet_fc_rcv_abts - transport entry point called by an LLDD
>      + *                       upon the reception of an ABTS for a NVME I/O.
>      + *
>      + * The LLDD must extract the OXID/RXID information from the ABTS and
>      + * match the exchange to a corresponding NVME I/O (aka struct
>      + * nvmefc_tgt_fcp_req). The nvmet-fc layer will determine the scope of
>      + * the ABTS (exchange vs sequence) from the ABTS parameter word and
>      + * take appropriate action to the I/O state.  Upon completing the
>      + * processing, the nvmet-fc layer will invoke the LLDD's fcp_op()
>      + * callback with to send the BA_ACC/BA_RJT status;
>      + *
>      + * If this routine returns error (non-zero), the LLDD should abort
>      + * the exchange.
>      + *
>      + * @tgtport:    pointer to the (registered) target port the ABTS was
>      + *              received on.
>      + * @fcpreq:     pointer to a fcp request structure for the exchange
>      + *              the ABTS references.
>      + * @param:      value of the parameter word in the ABTS
>      + */
>      +int
>      +nvmet_fc_rcv_abts(struct nvmet_fc_target_port *tgtport,
>      +			struct nvmefc_tgt_fcp_req *fcpreq,
>      +			__be32 param)
>      +{
>      +	/* TODO */
>      +	return -EIO;
>      +}
>      +EXPORT_SYMBOL_GPL(nvmet_fc_rcv_abts);
>      +
>      +
>      +/**
>      + * nvmet_fc_rcv_rs_req - transport entry point called by an LLDD
>      + *                       upon the reception of a NVME RS LS request.
>      + *
>      + * The LLDD must extract the OXID/RXID information from the RS and
>      + * match the exchange to a corresponding NVME I/O (aka struct
>      + * nvmefc_tgt_fcp_req). The nvmet-fc layer will valdiate the LS request
>      + * and take appropriate action to the I/O state.
>      + *
>      + * 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 (non-zero), the LLDD should abort
>      + * the exchange.
>      + *
>      + * @tgtport:    pointer to the (registered) target port the RS was
>      + *              received on.
>      + * @fcpreq:     pointer to a fcp request structure for the exchange
>      + *              the RS references.
>      + * @lsreq:      pointer to a lsreq request structure to be used to reference
>      + *              the exchange corresponding to the RS LS.
>      + * @lsreqbuf:   pointer to the buffer containing the RS LS Request
>      + * @lsreqbuf_len: length, in bytes, of the received RS LS request
>      + */
>      +int
>      +nvmet_fc_rcv_rs_req(struct nvmet_fc_target_port *target_port,
>      +			struct nvmefc_tgt_fcp_req *fcpreq,
>      +			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;
>      +
>      +	if (!fcpreq)
>      +		return -ESRCH;
>      +
>      +	iod = nvmet_fc_alloc_ls_iod(tgtport);
>      +	if (!iod) {
>      +		nvmet_fc_tgtport_put(tgtport);
>      +		return -ENOENT;
>      +	}
>      +
>      +	iod->lsreq = lsreq;
>      +	iod->fcpreq = fcpreq;
>      +	memcpy(iod->rqstbuf, lsreqbuf, lsreqbuf_len);
>      +	iod->rqstdatalen = lsreqbuf_len;
>      +
>      +	schedule_work(&iod->work);
>      +
>      +	return -EIO;
>      +}
>      +EXPORT_SYMBOL_GPL(nvmet_fc_rcv_rs_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 = 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 */
>      +
>      +	if ((fod->data_sg_cnt) &&
>      +	    (fod->data_sg_cnt < fod->tgtport->ops->max_sgl_segments))
>      +		return 0;
>      +
>      +	if (fod->data_sg_cnt)
>      +		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));
>      +
>      +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;
>      +
>      +	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);
>      +	}
>      +
>      +	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) {
>      +		atomic_set(&fod->aborted, 1);
>      +		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));
>      +	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) {
>      +		if (op == NVMET_FCOP_WRITEDATA)
>      +			nvmet_req_complete(&fod->req, ret);
>      +		else /* NVMET_FCOP_READDATA or NVMET_FCOP_READDATA_RSP */ {
>      +			fcpreq->fcp_error = ret;
>      +			fcpreq->transferred_length = 0;
>      +			atomic_set(&fod->aborted, 1);
>      +			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;
>      +	struct nvme_fc_ersp_iu *ersp = &fod->rspiubuf;
>      +	struct nvme_completion *cqe = &ersp->cqe;
>      +
>      +	switch (fcpreq->op) {
>      +
>      +	case NVMET_FCOP_WRITEDATA:
>      +		if (fcpreq->fcp_error) {
>      +			nvmet_req_complete(&fod->req, fcpreq->fcp_error);
>      +			return;
>      +		}
>      +		if (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:
>      +		if (fcpreq->fcp_error) {
>      +			/* overwrite the nvmet status */
>      +			cqe->status = cpu_to_le16(fcpreq->fcp_error);
>      +		} else if (fcpreq->transferred_length !=
>      +					fcpreq->transfer_length) {
>      +			/* overwrite the nvmet status */
>      +			cqe->status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR);
>      +		} else {
>      +			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);
>      +
>      +		if (unlikely(atomic_read(&fod->aborted)))
>      +			nvmet_fc_abort_op(tgtport, fod->fcpreq);
>      +		else
>      +			nvmet_fc_xmt_fcp_rsp(tgtport, fod);
>      +
>      +		break;
>      +
>      +	case NVMET_FCOP_READDATA_RSP:
>      +		/* data no longer needed */
>      +		nvmet_fc_free_tgt_pgs(fod);
>      +
>      +		/*
>      +		 * if error, try to send a bad response
>      +		 */
>      +		if (fcpreq->fcp_error) {
>      +			/* update bytecount for any read data transferred */
>      +			fod->offset += fcpreq->transferred_length;
>      +
>      +			/* overwrite the nvmet status */
>      +			cqe->status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR);
>      +
>      +			if (unlikely(atomic_read(&fod->aborted)))
>      +				nvmet_fc_abort_op(tgtport, fod->fcpreq);
>      +			else
>      +				nvmet_fc_xmt_fcp_rsp(tgtport, fod);
>      +
>      +			break;
>      +		}
>      +
>      +		/* data transfer complete, response complete as well */
>      +
>      +		dma_sync_single_for_cpu(tgtport->dev, fod->rspdma,
>      +				sizeof(fod->rspiubuf), DMA_TO_DEVICE);
>      +		nvmet_fc_free_fcp_iod(tgtport, fod);
>      +		nvmet_fc_tgt_q_put(fod->queue);
>      +		break;
>      +
>      +	case NVMET_FCOP_RSP:
>      +	case NVMET_FCOP_ABORT:
>      +		dma_sync_single_for_cpu(tgtport->dev, fod->rspdma,
>      +				sizeof(fod->rspiubuf), DMA_TO_DEVICE);
>      +		nvmet_fc_free_fcp_iod(tgtport, fod);
>      +		nvmet_fc_tgt_q_put(fod->queue);
>      +		break;
>      +
>      +	default:
>      +		atomic_set(&fod->aborted, 1);
>      +		nvmet_fc_abort_op(tgtport, fod->fcpreq);
>      +		break;
>      +	}
>      +}
>      +
>      +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;
>      +
>      +	/* 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 {
>      +		/* snoop the last sq_head value from the last response */
>      +		fod->queue->sqhd = cqe->sq_head;
>      +
>      +		/*
>      +		 * 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_fcp_nvme_cmd_done(tgtport, fod,
>      +				NVME_SC_FC_TRANSPORT_ERROR);
>      +		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_fcp_nvme_cmd_done(tgtport, fod, NVME_SC_FC_TRANSPORT_ERROR);
>      +}
>      +
>      +/*
>      + * 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 */
>      +
>      +	fod = nvmet_fc_alloc_fcp_iod(tgtport, queue);
>      +	if (!fod) {
>      +		nvmet_fc_tgt_q_put(queue);
>      +		return -ENOENT;
>      +	}
>      +
>      +	fcpreq->nvmet_fc_private = fod;
>      +	fod->fcpreq = fcpreq;
>      +	memcpy(&fod->cmdiubuf, cmdiubuf, cmdiubuf_len);
>      +
>      +	queue_work(fod->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) {
>      +				if (nvmet_fc_tgtport_get(tgtport)) {
>      +					tgtport->port = port;
>      +					port->priv = tgtport;
>      +					ret = 0;
>      +				} else
>      +					ret = -ESHUTDOWN;
>      +			} 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");
>      --
>      2.5.0
>      
>      
>      _______________________________________________
>      Linux-nvme mailing list
>      Linux-nvme at lists.infradead.org
>      http://lists.infradead.org/mailman/listinfo/linux-nvme
>      
>
> _______________________________________________
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