nvme-fabrics: Add host 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 FCP operations that comprise NVME
over FC operation.

The T11 definitions for FC-4 Link Services are implemented which create
NVMeOF connections.  Implements the hooks with blk-mq to then submit admin
and io requests to 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>

Author: jsmart-gh

MAINTAINERS

@@ -8665,6 +8665,7 @@ L:	linux-nvme@lists.infradead.org
 S:	Supported
 F:	include/linux/nvme-fc.h
 F:	include/linux/nvme-fc-driver.h
+F:	drivers/nvme/host/fc.c
 
 NVMEM FRAMEWORK
 M:	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

drivers/nvme/host/Kconfig

@@ -43,3 +43,20 @@ config NVME_RDMA
 	  from https://github.com/linux-nvme/nvme-cli.
 
 	  If unsure, say N.
+
+config NVME_FC
+	tristate "NVM Express over Fabrics FC host driver"
+	depends on BLOCK
+	depends on HAS_DMA
+	select NVME_CORE
+	select NVME_FABRICS
+	select SG_POOL
+	help
+	  This provides support for the NVMe over Fabrics protocol using
+	  the FC transport.  This allows you to use remote block devices
+	  exported using the NVMe protocol set.
+
+	  To configure a NVMe over Fabrics controller use the nvme-cli tool
+	  from https://github.com/linux-nvme/nvme-cli.
+
+	  If unsure, say N.

drivers/nvme/host/Makefile

@@ -2,6 +2,7 @@ obj-$(CONFIG_NVME_CORE)			+= nvme-core.o
 obj-$(CONFIG_BLK_DEV_NVME)		+= nvme.o
 obj-$(CONFIG_NVME_FABRICS)		+= nvme-fabrics.o
 obj-$(CONFIG_NVME_RDMA)			+= nvme-rdma.o
+obj-$(CONFIG_NVME_FC)			+= nvme-fc.o
 
 nvme-core-y				:= core.o
 nvme-core-$(CONFIG_BLK_DEV_NVME_SCSI)	+= scsi.o
@@ -12,3 +13,5 @@ nvme-y					+= pci.o
 nvme-fabrics-y				+= fabrics.o
 
 nvme-rdma-y				+= rdma.o
+
+nvme-fc-y				+= fc.o