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