rdma/siw: addition to kernel build environment

Broken up commit to add the Soft iWarp RDMA driver.

Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

MAINTAINERS

@@ -14558,6 +14558,13 @@ M:	Chris Boot <bootc@bootc.net>
 S:	Maintained
 F:	drivers/leds/leds-net48xx.c
 
+SOFT-IWARP DRIVER (siw)
+M:	Bernard Metzler <bmt@zurich.ibm.com>
+L:	linux-rdma@vger.kernel.org
+S:	Supported
+F:	drivers/infiniband/sw/siw/
+F:	include/uapi/rdma/siw-abi.h
+
 SOFT-ROCE DRIVER (rxe)
 M:	Moni Shoua <monis@mellanox.com>
 L:	linux-rdma@vger.kernel.org

drivers/infiniband/Kconfig

@@ -96,6 +96,7 @@ source "drivers/infiniband/hw/hfi1/Kconfig"
 source "drivers/infiniband/hw/qedr/Kconfig"
 source "drivers/infiniband/sw/rdmavt/Kconfig"
 source "drivers/infiniband/sw/rxe/Kconfig"
+source "drivers/infiniband/sw/siw/Kconfig"
 endif
 
 source "drivers/infiniband/ulp/ipoib/Kconfig"

drivers/infiniband/sw/Makefile

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_INFINIBAND_RDMAVT)		+= rdmavt/
 obj-$(CONFIG_RDMA_RXE)			+= rxe/
+obj-$(CONFIG_RDMA_SIW)			+= siw/

drivers/infiniband/sw/siw/Kconfig

@@ -0,0 +1,17 @@
+config RDMA_SIW
+	tristate "Software RDMA over TCP/IP (iWARP) driver"
+	depends on INET && INFINIBAND && CRYPTO_CRC32
+	help
+	This driver implements the iWARP RDMA transport over
+	the Linux TCP/IP network stack. It enables a system with a
+	standard Ethernet adapter to interoperate with a iWARP
+	adapter or with another system running the SIW driver.
+	(See also RXE which is a similar software driver for RoCE.)
+
+	The driver interfaces with the Linux RDMA stack and
+	implements both a kernel and user space RDMA verbs API.
+	The user space verbs API requires a support
+	library named libsiw which is loaded by the generic user
+	space verbs API, libibverbs. To implement RDMA over
+	TCP/IP, the driver further interfaces with the Linux
+	in-kernel TCP socket layer.

drivers/infiniband/sw/siw/Makefile

@@ -0,0 +1,11 @@
+obj-$(CONFIG_RDMA_SIW) += siw.o
+
+siw-y := \
+	siw_cm.o \
+	siw_cq.o \
+	siw_main.o \
+	siw_mem.o \
+	siw_qp.o \
+	siw_qp_tx.o \
+	siw_qp_rx.o \
+	siw_verbs.o