DMA: Split the DMA device and IO device into seperate files

This patch moves the DMA device to its own set of files, splitting it
from the IO device. There are no behavioural changes associated with
this patch.

The patch also grabs the opportunity to do some very minor tidying up,
including some white space removal and pruning some redundant
parameters.

Besides the immediate benefits of the separation-of-concerns, this
patch also makes upcoming changes more streamlined as it split the
devices that are only slaves and the DMA device that also acts as a
master.

--HG--
rename : src/dev/io_device.cc => src/dev/dma_device.cc
rename : src/dev/io_device.hh => src/dev/dma_device.hh

1 files changed, 310 insertions, 0 deletions

diff --git a/src/dev/dma_device.cc b/src/dev/dma_device.cc
new file mode 100644
index 000000000..401f910ac
--- /dev/null
+++ b/src/dev/dma_device.cc
@@ -0,0 +1,310 @@
+/*
+ * Copyright (c) 2012 ARM Limited
+ * All rights reserved.
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * Copyright (c) 2006 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Ali Saidi
+ *          Nathan Binkert
+ */
+
+#include "base/chunk_generator.hh"
+#include "debug/DMA.hh"
+#include "dev/dma_device.hh"
+#include "sim/system.hh"
+
+DmaPort::DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff)
+    : MasterPort(dev->name() + "-dma", dev), device(dev), sys(s),
+      masterId(s->getMasterId(dev->name())),
+      pendingCount(0), actionInProgress(0), drainEvent(NULL),
+      backoffTime(0), minBackoffDelay(min_backoff),
+      maxBackoffDelay(max_backoff), inRetry(false),
+      backoffEvent(this)
+{ }
+
+bool
+DmaPort::recvTimingResp(PacketPtr pkt)
+{
+    if (pkt->wasNacked()) {
+        DPRINTF(DMA, "Received nacked %s addr %#x\n",
+                pkt->cmdString(), pkt->getAddr());
+
+        if (backoffTime < minBackoffDelay)
+            backoffTime = minBackoffDelay;
+        else if (backoffTime < maxBackoffDelay)
+            backoffTime <<= 1;
+
+        device->reschedule(backoffEvent, curTick() + backoffTime, true);
+
+        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
+
+        pkt->reinitNacked();
+        queueDma(pkt, true);
+    } else if (pkt->senderState) {
+        DmaReqState *state;
+        backoffTime >>= 2;
+
+        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
+                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
+        state = dynamic_cast<DmaReqState*>(pkt->senderState);
+        pendingCount--;
+
+        assert(pendingCount >= 0);
+        assert(state);
+
+        // We shouldn't ever get a block in ownership state
+        assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
+
+        state->numBytes += pkt->req->getSize();
+        assert(state->totBytes >= state->numBytes);
+        if (state->totBytes == state->numBytes) {
+            if (state->completionEvent) {
+                if (state->delay)
+                    device->schedule(state->completionEvent,
+                                     curTick() + state->delay);
+                else
+                    state->completionEvent->process();
+            }
+            delete state;
+        }
+        delete pkt->req;
+        delete pkt;
+
+        if (pendingCount == 0 && drainEvent) {
+            drainEvent->process();
+            drainEvent = NULL;
+        }
+    }  else {
+        panic("Got packet without sender state... huh?\n");
+    }
+
+    return true;
+}
+
+DmaDevice::DmaDevice(const Params *p)
+    : PioDevice(p), dmaPort(this, sys, params()->min_backoff_delay,
+                            params()->max_backoff_delay)
+{ }
+
+void
+DmaDevice::init()
+{
+    if (!dmaPort.isConnected())
+        panic("DMA port of %s not connected to anything!", name());
+    PioDevice::init();
+}
+
+unsigned int
+DmaDevice::drain(Event *de)
+{
+    unsigned int count;
+    count = pioPort.drain(de) + dmaPort.drain(de);
+    if (count)
+        changeState(Draining);
+    else
+        changeState(Drained);
+    return count;
+}
+
+unsigned int
+DmaPort::drain(Event *de)
+{
+    if (pendingCount == 0)
+        return 0;
+    drainEvent = de;
+    return 1;
+}
+
+void
+DmaPort::recvRetry()
+{
+    assert(transmitList.size());
+    bool result = true;
+    do {
+        PacketPtr pkt = transmitList.front();
+        DPRINTF(DMA, "Retry on %s addr %#x\n",
+                pkt->cmdString(), pkt->getAddr());
+        result = sendTimingReq(pkt);
+        if (result) {
+            DPRINTF(DMA, "-- Done\n");
+            transmitList.pop_front();
+            inRetry = false;
+        } else {
+            inRetry = true;
+            DPRINTF(DMA, "-- Failed, queued\n");
+        }
+    } while (!backoffTime &&  result && transmitList.size());
+
+    if (transmitList.size() && backoffTime && !inRetry) {
+        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick()+backoffTime);
+        if (!backoffEvent.scheduled())
+            device->schedule(backoffEvent, backoffTime + curTick());
+    }
+    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
+            transmitList.size(), backoffTime, inRetry,
+            backoffEvent.scheduled());
+}
+
+void
+DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
+                   uint8_t *data, Tick delay, Request::Flags flag)
+{
+    assert(device->getState() == SimObject::Running);
+
+    DmaReqState *reqState = new DmaReqState(event, size, delay);
+
+
+    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
+            event ? event->scheduled() : -1 );
+    for (ChunkGenerator gen(addr, size, peerBlockSize());
+         !gen.done(); gen.next()) {
+            Request *req = new Request(gen.addr(), gen.size(), flag, masterId);
+            PacketPtr pkt = new Packet(req, cmd);
+
+            // Increment the data pointer on a write
+            if (data)
+                pkt->dataStatic(data + gen.complete());
+
+            pkt->senderState = reqState;
+
+            assert(pendingCount >= 0);
+            pendingCount++;
+            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
+                    gen.size());
+            queueDma(pkt);
+    }
+
+}
+
+void
+DmaPort::queueDma(PacketPtr pkt, bool front)
+{
+
+    if (front)
+        transmitList.push_front(pkt);
+    else
+        transmitList.push_back(pkt);
+    sendDma();
+}
+
+void
+DmaPort::sendDma()
+{
+    // some kind of selction between access methods
+    // more work is going to have to be done to make
+    // switching actually work
+    assert(transmitList.size());
+    PacketPtr pkt = transmitList.front();
+
+    Enums::MemoryMode state = sys->getMemoryMode();
+    if (state == Enums::timing) {
+        if (backoffEvent.scheduled() || inRetry) {
+            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
+            return;
+        }
+
+        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
+                pkt->cmdString(), pkt->getAddr());
+
+        bool result;
+        do {
+            result = sendTimingReq(pkt);
+            if (result) {
+                transmitList.pop_front();
+                DPRINTF(DMA, "-- Done\n");
+            } else {
+                inRetry = true;
+                DPRINTF(DMA, "-- Failed: queued\n");
+            }
+        } while (result && !backoffTime && transmitList.size());
+
+        if (transmitList.size() && backoffTime && !inRetry &&
+                !backoffEvent.scheduled()) {
+            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
+                    backoffTime+curTick());
+            device->schedule(backoffEvent, backoffTime + curTick());
+        }
+    } else if (state == Enums::atomic) {
+        transmitList.pop_front();
+
+        Tick lat;
+        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
+                pkt->req->getPaddr(), pkt->req->getSize());
+        lat = sendAtomic(pkt);
+        assert(pkt->senderState);
+        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
+        assert(state);
+        state->numBytes += pkt->req->getSize();
+
+        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
+                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
+                state->totBytes,
+                state->completionEvent ? state->completionEvent->scheduled() : 0 );
+
+        if (state->totBytes == state->numBytes) {
+            if (state->completionEvent) {
+                assert(!state->completionEvent->scheduled());
+                device->schedule(state->completionEvent,
+                                 curTick() + lat + state->delay);
+            }
+            delete state;
+            delete pkt->req;
+        }
+        pendingCount--;
+        assert(pendingCount >= 0);
+        delete pkt;
+
+        if (pendingCount == 0 && drainEvent) {
+            drainEvent->process();
+            drainEvent = NULL;
+        }
+
+   } else
+       panic("Unknown memory command state.");
+}
+
+DmaDevice::~DmaDevice()
+{
+}
+
+MasterPort &
+DmaDevice::getMasterPort(const std::string &if_name, int idx)
+{
+    if (if_name == "dma") {
+        return dmaPort;
+    }
+    return PioDevice::getMasterPort(if_name, idx);
+}