[ESI] Add hostmem write support to cosim (#8059)

Adds cosim support to both the cosim BSP in PyCDE and the corresponding support in the runtime. As with hostmem reads, write only supports one client and no gearboxing.

Author: teqdruid

frontends/PyCDE/integration_test/esitester.py

@@ -114,6 +114,52 @@ def construct(ports):
     mem_data_ce.assign(hostmem_read_resp_valid)
 
 
+class WriteMem(Module):
+  """Writes a cycle count to host memory at address 0 in MMIO upon each MMIO
+  transaction."""
+  clk = Clock()
+  rst = Reset()
+
+  @generator
+  def construct(ports):
+    cmd_chan_wire = Wire(Channel(esi.MMIOReadWriteCmdType))
+    resp_ready_wire = Wire(Bits(1))
+    cmd, cmd_valid = cmd_chan_wire.unwrap(resp_ready_wire)
+    mmio_xact = cmd_valid & resp_ready_wire
+
+    write_loc_ce = mmio_xact & cmd.write & (cmd.offset == UInt(32)(0))
+    write_loc = Reg(UInt(64),
+                    clk=ports.clk,
+                    rst=ports.rst,
+                    rst_value=0,
+                    ce=write_loc_ce)
+    write_loc.assign(cmd.data.as_uint())
+
+    response_data = write_loc.as_bits()
+    response_chan, response_ready = Channel(Bits(64)).wrap(
+        response_data, cmd_valid)
+    resp_ready_wire.assign(response_ready)
+
+    mmio_rw = esi.MMIO.read_write(appid=AppID("WriteMem"))
+    mmio_rw_cmd_chan = mmio_rw.unpack(data=response_chan)['cmd']
+    cmd_chan_wire.assign(mmio_rw_cmd_chan)
+
+    tag = Counter(8)(clk=ports.clk, rst=ports.rst, increment=mmio_xact)
+
+    cycle_counter = Counter(64)(clk=ports.clk,
+                                rst=ports.rst,
+                                increment=Bits(1)(1))
+
+    hostmem_write_req, _ = esi.HostMem.wrap_write_req(
+        write_loc,
+        cycle_counter.out.as_bits(),
+        tag.out,
+        valid=mmio_xact.reg(ports.clk, ports.rst))
+
+    hostmem_write_resp = esi.HostMem.write(appid=AppID("WriteMem_hostwrite"),
+                                           req=hostmem_write_req)
+
+
 class EsiTesterTop(Module):
   clk = Clock()
   rst = Reset()
@@ -122,6 +168,7 @@ class EsiTesterTop(Module):
   def construct(ports):
     PrintfExample(clk=ports.clk, rst=ports.rst)
     ReadMem(clk=ports.clk, rst=ports.rst)
+    WriteMem(clk=ports.clk, rst=ports.rst)
 
 
 if __name__ == "__main__":

frontends/PyCDE/src/pycde/bsp/common.py

@@ -5,13 +5,13 @@
 from __future__ import annotations
 
 from ..common import Clock, Input, Output, Reset
-from ..constructs import AssignableSignal, ControlReg, NamedWire, Wire
+from ..constructs import AssignableSignal, NamedWire, Wire
 from .. import esi
 from ..module import Module, generator, modparams
 from ..signals import BitsSignal, BundleSignal, ChannelSignal
 from ..support import clog2
 from ..types import (Array, Bits, Bundle, BundledChannel, Channel,
-                     ChannelDirection, StructType, Type, UInt)
+                     ChannelDirection, StructType, UInt)
 
 from typing import Dict, List, Tuple
 import typing
@@ -266,34 +266,100 @@ class ChannelHostMemImpl(esi.ServiceImplementation):
     clk = Clock()
     rst = Reset()
 
-    UpstreamReq = StructType([
+    UpstreamReadReq = StructType([
         ("address", UInt(64)),
         ("length", UInt(32)),
         ("tag", UInt(8)),
     ])
     read = Output(
         Bundle([
-            BundledChannel("req", ChannelDirection.TO, UpstreamReq),
+            BundledChannel("req", ChannelDirection.TO, UpstreamReadReq),
             BundledChannel(
                 "resp", ChannelDirection.FROM,
                 StructType([
                     ("tag", UInt(8)),
                     ("data", Bits(read_width)),
                 ])),
         ]))
+    UpstreamWriteReq = StructType([
+        ("address", UInt(64)),
+        ("tag", UInt(8)),
+        ("data", Bits(write_width)),
+    ])
+    write = Output(
+        Bundle([
+            BundledChannel("req", ChannelDirection.TO, UpstreamWriteReq),
+            BundledChannel("ackTag", ChannelDirection.FROM, UInt(8)),
+        ]))
 
     @generator
     def generate(ports, bundles: esi._ServiceGeneratorBundles):
       read_reqs = [req for req in bundles.to_client_reqs if req.port == 'read']
       ports.read = ChannelHostMemImpl.build_tagged_read_mux(ports, read_reqs)
+      write_reqs = [
+          req for req in bundles.to_client_reqs if req.port == 'write'
+      ]
+      ports.write = ChannelHostMemImpl.build_tagged_write_mux(ports, write_reqs)
+
+    @staticmethod
+    def build_tagged_write_mux(
+        ports, reqs: List[esi._OutputBundleSetter]) -> BundleSignal:
+      """Build the write side of the HostMem service."""
+
+      # If there's no write clients, just return a no-op write bundle
+      if len(reqs) == 0:
+        req, _ = Channel(ChannelHostMemImpl.UpstreamWriteReq).wrap(
+            {
+                "address": 0,
+                "tag": 0,
+                "data": 0
+            }, 0)
+        write_bundle, _ = ChannelHostMemImpl.write.type.pack(req=req)
+        return write_bundle
+
+      # TODO: mux together multiple write clients.
+      assert len(reqs) == 1, "Only one write client supported for now."
+
+      # Build the write request channels and ack wires.
+      write_channels: List[ChannelSignal] = []
+      write_acks = []
+      for req in reqs:
+        # Get the request channel and its data type.
+        reqch = [c.channel for c in req.type.channels if c.name == 'req'][0]
+        data_type = reqch.inner_type.data
+        assert data_type == Bits(
+            write_width
+        ), f"Gearboxing not yet supported. Client {req.client_name}"
+
+        # Write acks to be filled in later.
+        write_ack = Wire(Channel(UInt(8)))
+        write_acks.append(write_ack)
+
+        # Pack up the bundle and assign the request channel.
+        write_req_bundle_type = esi.HostMem.write_req_bundle_type(data_type)
+        bundle_sig, froms = write_req_bundle_type.pack(ackTag=write_ack)
+        tagged_client_req = froms["req"]
+        req.assign(bundle_sig)
+        write_channels.append(tagged_client_req)
+
+      # TODO: re-write the tags and store the client and client tag.
+
+      # Build a channel mux for the write requests.
+      tagged_write_channel = esi.ChannelMux(write_channels)
+      upstream_write_bundle, froms = ChannelHostMemImpl.write.type.pack(
+          req=tagged_write_channel)
+      ack_tag = froms["ackTag"]
+      # TODO: decode the ack tag and assign it to the correct client.
+      write_acks[0].assign(ack_tag)
+      return upstream_write_bundle
 
     @staticmethod
     def build_tagged_read_mux(
         ports, reqs: List[esi._OutputBundleSetter]) -> BundleSignal:
       """Build the read side of the HostMem service."""
 
       if len(reqs) == 0:
-        req, req_ready = Channel(ChannelHostMemImpl.UpstreamReq).wrap(
+        req, req_ready = Channel(ChannelHostMemImpl.UpstreamReadReq).wrap(
             {
                 "tag": 0,
                 "length": 0,
@@ -305,7 +371,7 @@ def build_tagged_read_mux(
       # TODO: mux together multiple read clients.
       assert len(reqs) == 1, "Only one read client supported for now."
 
-      req = Wire(Channel(ChannelHostMemImpl.UpstreamReq))
+      req = Wire(Channel(ChannelHostMemImpl.UpstreamReadReq))
       read_bundle, froms = ChannelHostMemImpl.read.type.pack(req=req)
       resp_chan_ready = Wire(Bits(1))
       resp_data, resp_valid = froms["resp"].unwrap(resp_chan_ready)
@@ -335,7 +401,7 @@ def build_tagged_read_mux(
 
         # Assign the multiplexed read request to the upstream request.
         req.assign(
-            client_req.transform(lambda r: ChannelHostMemImpl.UpstreamReq({
+            client_req.transform(lambda r: ChannelHostMemImpl.UpstreamReadReq({
                 "address": r.address,
                 "length": 1,
                 "tag": r.tag

frontends/PyCDE/src/pycde/bsp/cosim.py

@@ -72,6 +72,12 @@ def build(ports):
                                   resp_wire.type)
       resp_wire.assign(data)
 
+      ack_wire = Wire(Channel(UInt(8)))
+      write_req = hostmem.write.unpack(ackTag=ack_wire)['req']
+      ack_tag = esi.CallService.call(esi.AppID("__cosim_hostmem_write"),
+                                     write_req, UInt(8))
+      ack_wire.assign(ack_tag)
+
   class ESI_Cosim_Top(Module):
     clk = Clock()
     rst = Input(Bits(1))

frontends/PyCDE/src/pycde/esi.py

@@ -519,24 +519,34 @@ class _HostMem(ServiceDecl):
       ("tag", UInt(8)),
   ])
 
-  WriteReqType = StructType([
-      ("address", UInt(64)),
-      ("tag", UInt(8)),
-      ("data", Any()),
-  ])
-
   def __init__(self):
     super().__init__(self.__class__)
 
+  def write_req_bundle_type(self, data_type: Type) -> Bundle:
+    """Build a write request bundle type for the given data type."""
+    write_req_type = StructType([
+        ("address", UInt(64)),
+        ("tag", UInt(8)),
+        ("data", data_type),
+    ])
+    return Bundle([
+        BundledChannel("req", ChannelDirection.FROM, write_req_type),
+        BundledChannel("ackTag", ChannelDirection.TO, UInt(8))
+    ])
+
+  def write_req_channel_type(self, data_type: Type) -> StructType:
+    """Return a write request struct type for 'data_type'."""
+    return StructType([
+        ("address", UInt(64)),
+        ("tag", UInt(8)),
+        ("data", data_type),
+    ])
+
   def wrap_write_req(self, address: UIntSignal, data: Type, tag: UIntSignal,
                      valid: BitsSignal) -> Tuple[ChannelSignal, BitsSignal]:
     """Create the proper channel type for a write request and use it to wrap the
     given request arguments. Returns the Channel signal and a ready bit."""
-    inner_type = StructType([
-        ("address", UInt(64)),
-        ("tag", UInt(8)),
-        ("data", data.type),
-    ])
+    inner_type = self.write_req_channel_type(data.type)
     return Channel(inner_type).wrap(
         inner_type({
             "address": address,
@@ -548,10 +558,10 @@ def write(self, appid: AppID, req: ChannelSignal) -> ChannelSignal:
     """Create a write request to the host memory out of a request channel."""
     self._materialize_service_decl()
 
-    write_bundle_type = Bundle([
-        BundledChannel("req", ChannelDirection.FROM, _HostMem.WriteReqType),
-        BundledChannel("ackTag", ChannelDirection.TO, UInt(8))
-    ])
+    # Extract the data type from the request channel and call the helper to get
+    # the write bundle type for the req channel.
+    req_data_type = req.type.inner_type.data
+    write_bundle_type = self.write_req_bundle_type(req_data_type)
 
     bundle = cast(
         BundleSignal,

frontends/PyCDE/src/pycde/signals.py

@@ -809,8 +809,9 @@ def unpack(self, **kwargs: ChannelSignal) -> Dict[str, ChannelSignal]:
       raise ValueError(
           f"Missing channel values for {', '.join(from_channels.keys())}")
 
-    unpack_op = esi.UnpackBundleOp([bc.channel._type for bc in to_channels],
-                                   self.value, operands)
+    with get_user_loc():
+      unpack_op = esi.UnpackBundleOp([bc.channel._type for bc in to_channels],
+                                     self.value, operands)
 
     to_channels_results = unpack_op.toChannels
     ret = {

frontends/PyCDE/src/pycde/types.py

@@ -858,9 +858,10 @@ def pack(
     if len(to_channels) > 0:
       raise ValueError(f"Missing channels: {', '.join(to_channels.keys())}")
 
-    pack_op = esi.PackBundleOp(self._type,
-                               [bc.channel._type for bc in from_channels],
-                               operands)
+    with get_user_loc():
+      pack_op = esi.PackBundleOp(self._type,
+                                 [bc.channel._type for bc in from_channels],
+                                 operands)
 
     return BundleSignal(pack_op.bundle, self), Bundle.PackSignalResults(
         [_FromCirctValue(c) for c in pack_op.fromChannels], self)

frontends/PyCDE/test/test_esi.py

@@ -308,8 +308,8 @@ def build(ports):
 # CHECK-NEXT:     [[R5:%.+]] = hwarith.constant 0 : ui256
 # CHECK-NEXT:     [[R6:%.+]] = hw.struct_create ([[R0]], [[R4]], [[R5]]) : !hw.struct<address: ui64, tag: ui8, data: ui256>
 # CHECK-NEXT:     %chanOutput_0, %ready_1 = esi.wrap.vr [[R6]], %false : !hw.struct<address: ui64, tag: ui8, data: ui256>
-# CHECK-NEXT:     [[R7:%.+]] = esi.service.req <@_HostMem::@write>(#esi.appid<"host_mem_write_req">) : !esi.bundle<[!esi.channel<!hw.struct<address: ui64, tag: ui8, data: !esi.any>> from "req", !esi.channel<ui8> to "ackTag"]>
-# CHECK-NEXT:     %ackTag = esi.bundle.unpack %chanOutput_0 from [[R7]] : !esi.bundle<[!esi.channel<!hw.struct<address: ui64, tag: ui8, data: !esi.any>> from "req", !esi.channel<ui8> to "ackTag"]>
+# CHECK-NEXT:     [[R7:%.+]] = esi.service.req <@_HostMem::@write>(#esi.appid<"host_mem_write_req">) : !esi.bundle<[!esi.channel<!hw.struct<address: ui64, tag: ui8, data: ui256>> from "req", !esi.channel<ui8> to "ackTag"]>
+# CHECK-NEXT:     %ackTag = esi.bundle.unpack %chanOutput_0 from [[R7]] : !esi.bundle<[!esi.channel<!hw.struct<address: ui64, tag: ui8, data: ui256>> from "req", !esi.channel<ui8> to "ackTag"]>
 # CHECK:        esi.service.std.hostmem @_HostMem
 @unittestmodule(esi_sys=True)
 class HostMemReq(Module):