dpdk: Add new DPDK stack to integrate with I/O services

docs: Update DPDK docs with new parameters:
Parameter names have had their hyphens changed to underscores, and
the I/O CPU argument is now named after the lcores and reflects
the naming used by DPDK.

transport: Add new udp_dpdk_link, based atop the new APIs:
This link is tightly coupled with the DPDK I/O service. The link class
carries all the address information to communicate with the other
host, and it can send packets directly through the DPDK NIC ports.

However, for receiving packets, the I/O service must pull the packets
from the DMA queue and attach them to the appropriate link object.
The link object merely formats the frame_buff object underneath, which
is embedded in the rte_mbuf container. For get_recv_buff, the link
will pull buffers only from its internal queue (the one filled by the
I/O service).

transport: Add DPDK-specific I/O service:
The I/O service is split into two parts, the user threads and the
I/O worker threads. The user threads submit requests through
various appropriate queues, and the I/O threads perform all the
I/O on their behalf. This includes routing UDP packets to the
correct receiver and getting the MAC address of a destination (by
performing the ARP request and handling the ARP replies).

The DPDK context stores I/O services. The context spawns all I/O
services on init(), and I/O services can be fetched from the dpdk_ctx
object by using a port ID.

I/O service clients:
The clients have two lockless ring buffers. One is to get a buffer
from the I/O service; the other is to release a buffer back to the
I/O service. Threads sleeping on buffer I/O are kept in a separate
list from the service queue and are processed in the course of doing
RX or TX.

The list nodes are embedded in the dpdk_io_if, and the head of the
list is on the dpdk_io_service. The I/O service will transfer the
embedded wait_req to the list if it cannot acquire the mutex to
complete the condition for waking.

Co-authored-by: Martin Braun <martin.braun@ettus.com>
Co-authored-by: Ciro Nishiguchi <ciro.nishiguchi@ni.com>
Co-authored-by: Brent Stapleton <brent.stapleton@ettus.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/host/tests/dpdk_port_test.cpp b/host/tests/dpdk_port_test.cpp
index 7ef386c52..8f6b20c34 100644
--- a/host/tests/dpdk_port_test.cpp
+++ b/host/tests/dpdk_port_test.cpp
@@ -6,6 +6,8 @@
 
 #include <uhdlib/transport/dpdk/common.hpp>
 #include <uhdlib/transport/dpdk/service_queue.hpp>
+#include <uhdlib/transport/dpdk_io_service.hpp>
+#include <uhdlib/transport/udp_dpdk_link.hpp>
 #include <boost/program_options.hpp>
 #include <iostream>
 #include <memory>
@@ -101,6 +103,46 @@ int main(int argc, char **argv)
     service_thread.join();
     std::cout << "PASS: Service thread terminated" << std::endl;
     delete queue;
+
+    std::cout << "Starting up ARP thread..." << std::endl;
+    std::vector<uhd::transport::dpdk::dpdk_port*> ports;
+    ports.push_back(port);
+    //auto io_srv = uhd::transport::dpdk_io_service::make(1, ports, 16);
+    auto io_srv = ctx->get_io_service(1);
+
+    // Create link
+    std::cout << "Creating UDP link..." << std::endl;
+    uhd::transport::link_params_t params;
+    params.recv_frame_size = 8000;
+    params.send_frame_size = 8000;
+    params.num_recv_frames = 511;
+    params.num_send_frames = 511;
+    params.recv_buff_size = params.recv_frame_size*params.num_recv_frames;
+    params.send_buff_size = params.send_frame_size*params.num_send_frames;
+    auto link = uhd::transport::udp_dpdk_link::make("192.168.10.2", "49600", params);
+
+    // Attach link
+    std::cout << "Attaching UDP send link..." << std::endl;
+    io_srv->attach_send_link(link);
+    struct ether_addr dest_mac;
+    link->get_remote_mac(dest_mac);
+    char mac_str[20];
+    ether_format_addr(mac_str, 20, &dest_mac);
+    std::cout << "Remote MAC address is " << mac_str << std::endl;
+    std::cout << std::endl;
+    std::cout << "Attaching UDP recv link..." << std::endl;
+    io_srv->attach_recv_link(link);
+    std::cout << "Press any key to quit..." << std::endl;
+    std::cin.get();
+
+    // Shut down
+    std::cout << "Detaching UDP send link..." << std::endl;
+    io_srv->detach_send_link(link);
+    std::cout << "Detaching UDP recv link..." << std::endl;
+    io_srv->detach_recv_link(link);
+    std::cout << "Shutting down I/O service..." << std::endl;
+    io_srv.reset();
+    std::cout << "Shutting down context..." << std::endl;
     ctx.reset();
     return 0;
 }