uhd-dpdk: Add DPDK-based sockets-like library

This library makes available a userspace network stack with a
socket-like interface for applications (except the sockets pass around
pointers to buffers and use the buffers directly--It's sockets + a
put/get for buffer management). Supported services are ARP and UDP.
Destinations can be unicast or broadcast. Multicast is not currently
supported.

The implementation has two driver layers. The upper layer runs within
the caller's context. The caller will make requests through lockless
ring buffers (including socket creation and packet transmission), and
the lower layer will implement the requests and provide a response.

Currently, the lower layer runs in a separate I/O thread, and the caller
will block until it receives a response.

The I/O thread's main body is in src/uhd_dpdk_driver.c. You'll find that
all I/O thread functions are prefixed by an underscore, and user thread
functions do not.

src/uhd_dpdk.c is used to initialize uhd-dpdk and bring up the network
interfaces.

src/uhd_dpdk_fops.c and src/uhd_dpdk_udp.c are for network services.

The test is a benchmark of a flow control loop using a certain made-up
protocol with credits and sequence number tracking.

1 files changed, 32 insertions, 0 deletions

diff --git a/host/cmake/Modules/FindDPDK.cmake b/host/cmake/Modules/FindDPDK.cmake
new file mode 100644
index 000000000..4382a8cce
--- /dev/null
+++ b/host/cmake/Modules/FindDPDK.cmake
@@ -0,0 +1,32 @@
+#
+# Copyright 2018 Ettus Research, a National Instruments Company
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# - Find DPDK
+# Find the DPDK includes and client library
+# This module defines
+#  DPDK_INCLUDE_DIR, where to find rte_config.h
+#  DPDK_LIBRARIES, the libraries needed by a DPDK user
+#  DPDK_FOUND, If false, do not try to use DPDK.
+# also defined, but not for general use are
+#  DPDK_LIBRARY, where to find the DPDK library.
+
+include(FindPackageHandleStandardArgs)
+
+find_path ( DPDK_INCLUDE_DIR rte_config.h
+    PATHS ENV RTE_INCLUDE
+    PATH_SUFFIXES dpdk
+)
+
+find_library(DPDK_LIBRARY
+    PATHS $ENV{RTE_SDK_DIR}/$ENV{RTE_TARGET}/lib
+)
+
+list(APPEND DPDK_LIBRARIES dpdk)
+
+find_package_handle_standard_args(dpdk
+    DEFAULT_MSG
+    DPDK_INCLUDE_DIR
+    DPDK_LIBRARIES
+)