mpm: Add LiberioDispatcherTable

2 files changed, 74 insertions, 0 deletions

diff --git a/mpm/python/usrp_mpm/CMakeLists.txt b/mpm/python/usrp_mpm/CMakeLists.txt
index ba640f7cc..7b6e6b84c 100644
--- a/mpm/python/usrp_mpm/CMakeLists.txt
+++ b/mpm/python/usrp_mpm/CMakeLists.txt
@@ -26,6 +26,8 @@ SET(USRP_MPM_TOP_FILES
     ${CMAKE_CURRENT_SOURCE_DIR}/discovery.py
     ${CMAKE_CURRENT_SOURCE_DIR}/dtoverlay.py
     ${CMAKE_CURRENT_SOURCE_DIR}/eeprom.py
+    ${CMAKE_CURRENT_SOURCE_DIR}/ethtable.py
+    ${CMAKE_CURRENT_SOURCE_DIR}/liberiotable.py
     ${CMAKE_CURRENT_SOURCE_DIR}/mpmlog.py
     ${CMAKE_CURRENT_SOURCE_DIR}/mpmtypes.py
     ${CMAKE_CURRENT_SOURCE_DIR}/mpmutils.py
diff --git a/mpm/python/usrp_mpm/liberiotable.py b/mpm/python/usrp_mpm/liberiotable.py
new file mode 100644
index 000000000..8f70c5ebe
--- /dev/null
+++ b/mpm/python/usrp_mpm/liberiotable.py
@@ -0,0 +1,72 @@
+#
+# Copyright 2017 Ettus Research, National Instruments Company
+#
+# SPDX-License-Identifier: GPL-3.0
+#
+"""
+Liberio DMA dispatcher table control
+"""
+
+from builtins import str
+from builtins import object
+from .mpmlog import get_logger
+from .uio import UIO
+
+class LiberioDispatcherTable(object):
+    """
+    Controls a Liberio DMA dispatcher table.
+
+    label -- A label that can be used by udev to find a UIO device
+    """
+
+    MTU_OFFSET = 0x80000
+
+    def __init__(self, label):
+        self.log = get_logger(label)
+        self._regs = UIO(label=label, read_only=False)
+        self.poke32 = self._regs.poke32
+        self.peek32 = self._regs.peek32
+
+    def set_route(self, sid, dma_channel, mtu):
+        """
+        Sets up routing in the Liberio dispatcher. From sid, only the
+        destination part is important. After this call, any CHDR packet with the
+        appropriate destination address will get routed to `dma_channel`.
+
+        sid -- Full SID, but only destination part matters.
+        dma_channel -- The DMA channel to which these packets should get routed.
+        mtu -- Max size of bytes per packet. This is important to get right. The
+               DMA implementation will pad packets smaller than MTU up to the
+               mtu value, so making MTU extra large is inefficient. Packets
+               larger than MTU will get chopped up. Even worse.
+        """
+        self.log.debug(
+            "Routing SID `{sid}' to DMA channel `{chan}', MTU {mtu} bytes.".format(
+                sid=str(sid), chan=dma_channel, mtu=mtu
+            )
+        )
+        def poke_and_trace(addr, data):
+            " Do a poke32() and log.trace() "
+            self.log.trace("Writing to address 0x{:04X}: 0x{:04X}".format(
+                addr, data
+            ))
+            self.poke32(addr, data)
+
+        # Poke reg for destination channel
+        # Poke reg for MTU
+        try:
+            poke_and_trace(
+                0 + 4 * sid.dst_ep,
+                dma_channel,
+            )
+            poke_and_trace(
+                self.MTU_OFFSET + 4 * sid.dst_ep,
+                int(mtu / 8),
+            )
+        except Exception as ex:
+            self.log.error(
+                "Unexpected exception while setting route: %s",
+                str(ex),
+            )
+            raise
+