rfnoc: Add chdr_ctrl_xport

chdr_ctrl_xport is a dumb-pipe transport for RFNoC control transactions
and management frames.

Also remove the I/O service's check on num_recv_frames and num_send_frames.
The transports may request additional virtual channels, so the send_io_if
and recv_io_if may not reserve additional frames, as they are shared with
a previously-allocated instance.

Note: this uses a mutex to force sequentual access to the
chdr_ctrl_xport. This is supposed to go away when the multi threaded
xport is done.

1 files changed, 128 insertions, 0 deletions

diff --git a/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp b/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp
new file mode 100644
index 000000000..3365dcb23
--- /dev/null
+++ b/host/lib/include/uhdlib/rfnoc/chdr_ctrl_xport.hpp
@@ -0,0 +1,128 @@
+//
+// Copyright 2019 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_RFNOC_CHDR_CTRL_XPORT_HPP
+#define INCLUDED_RFNOC_CHDR_CTRL_XPORT_HPP
+
+#include <uhdlib/rfnoc/chdr_types.hpp>
+#include <uhdlib/transport/io_service.hpp>
+#include <mutex>
+
+namespace uhd { namespace rfnoc {
+
+/*!
+ * Represents a transport for CHDR control streams and management streams
+ */
+class chdr_ctrl_xport
+{
+public:
+    using io_service   = uhd::transport::io_service;
+    using frame_buff   = uhd::transport::frame_buff;
+    using send_link_if = uhd::transport::send_link_if;
+    using recv_link_if = uhd::transport::recv_link_if;
+    using send_io_if   = uhd::transport::send_io_if;
+    using recv_io_if   = uhd::transport::recv_io_if;
+
+    using sptr = std::shared_ptr<chdr_ctrl_xport>;
+
+    /*!
+     * Make a chdr_ctrl_xport
+     *
+     * \param io_srv The I/O service that send_link and recv_link are attached to
+     * \param send_link Link to use for sending packets
+     * \param recv_link Link to use for receiving packets
+     * \param my_epid The local EPID for this transport
+     * \param num_send_frames Number of frames to reserve for TX
+     * \param num_recv_frames Number of frames to reserve for RX
+     */
+    static sptr make(io_service::sptr io_srv,
+        send_link_if::sptr send_link,
+        recv_link_if::sptr recv_link,
+        sep_id_t my_epid,
+        size_t num_send_frames,
+        size_t num_recv_frames)
+    {
+        return std::make_shared<chdr_ctrl_xport>(io_srv, send_link, recv_link, my_epid,
+            num_send_frames, num_recv_frames);
+    }
+
+    /*!
+     * Make a chdr_ctrl_xport
+     *
+     * \param io_srv The I/O service that send_link and recv_link are attached to
+     * \param send_link Link to use for sending packets
+     * \param recv_link Link to use for receiving packets
+     * \param my_epid The local EPID for this transport
+     * \param num_send_frames Number of frames to reserve for TX
+     * \param num_recv_frames Number of frames to reserve for RX
+     */
+    chdr_ctrl_xport(io_service::sptr io_srv,
+        send_link_if::sptr send_link,
+        recv_link_if::sptr recv_link,
+        sep_id_t my_epid,
+        size_t num_send_frames,
+        size_t num_recv_frames);
+
+    ~chdr_ctrl_xport() = default;
+
+    /*!
+      * Get an empty frame buffer in which to write packet contents.
+      *
+      * \param timeout_ms a positive timeout value specifies the maximum number
+                          of ms to wait, a negative value specifies to block
+                          until successful, and a value of 0 specifies no wait.
+      * \return a frame buffer, or null uptr if timeout occurs
+      */
+    frame_buff::uptr get_send_buff(int32_t timeout_ms);
+
+    /*!
+     * Release a frame buffer, allowing the driver to reuse it.
+     *
+     * \param buffer frame buffer to release for reuse by the link
+     */
+    void release_send_buff(frame_buff::uptr buff);
+
+    /*!
+     * Attempt to get a frame buffer with data from the recv link.
+     *
+     * Receives packets from the control stream.
+     *
+     * \param timeout_ms a positive timeout value specifies the maximum number
+                         of ms to wait, a negative value specifies to block
+                         until successful, and a value of 0 specifies no wait.
+     * \return a frame buffer, or null uptr if timeout occurs
+     */
+    frame_buff::uptr get_recv_buff(int32_t timeout_ms);
+
+    /*!
+     * FIXME: Remove or alter when get threaded_io_service
+     *
+     * Receives packets from the management stream.
+     */
+    frame_buff::uptr get_mgmt_buff(int32_t timeout_ms);
+
+    /*!
+     * Release a frame buffer, allowing the recv link driver to reuse it.
+     *
+     * \param buffer frame buffer to release for reuse by the link
+     */
+    void release_recv_buff(frame_buff::uptr buff);
+
+private:
+    chdr_ctrl_xport(const chdr_ctrl_xport&) = delete;
+
+    sep_id_t _my_epid;
+    send_io_if::sptr _send_if;
+    recv_io_if::sptr _ctrl_recv_if;
+    recv_io_if::sptr _mgmt_recv_if;
+
+    // FIXME: Remove this when have threaded_io_service
+    std::mutex _mutex;
+};
+
+}} // namespace uhd::rfnoc
+
+#endif /* INCLUDED_UHDLIB_RFNOC_CHDR_CTRL_XPORT_HPP */