dma_device.cc revision 9166:1d983855df2c 
1/*
2 * Copyright (c) 2012 ARM Limited
3 * All rights reserved.
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ali Saidi
41 *          Nathan Binkert
42 *          Andreas Hansson
43 */
44
45#include "base/chunk_generator.hh"
46#include "debug/DMA.hh"
47#include "debug/Drain.hh"
48#include "dev/dma_device.hh"
49#include "sim/system.hh"
50
51DmaPort::DmaPort(MemObject *dev, System *s)
52    : MasterPort(dev->name() + ".dma", dev), device(dev), sys(s),
53      masterId(s->getMasterId(dev->name())),
54      pendingCount(0), drainEvent(NULL),
55      inRetry(false)
56{ }
57
58void
59DmaPort::handleResp(PacketPtr pkt, Tick delay)
60{
61    // should always see a response with a sender state
62    assert(pkt->isResponse());
63
64    // get the DMA sender state
65    DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
66    assert(state);
67
68    DPRINTF(DMA, "Received response %s for addr: %#x size: %d nb: %d,"  \
69            " tot: %d sched %d\n",
70            pkt->cmdString(), pkt->getAddr(), pkt->req->getSize(),
71            state->numBytes, state->totBytes,
72            state->completionEvent ?
73            state->completionEvent->scheduled() : 0);
74
75    assert(pendingCount != 0);
76    pendingCount--;
77
78    // update the number of bytes received based on the request rather
79    // than the packet as the latter could be rounded up to line sizes
80    state->numBytes += pkt->req->getSize();
81    assert(state->totBytes >= state->numBytes);
82
83    // if we have reached the total number of bytes for this DMA
84    // request, then signal the completion and delete the sate
85    if (state->totBytes == state->numBytes) {
86        if (state->completionEvent) {
87            delay += state->delay;
88            if (delay)
89                device->schedule(state->completionEvent, curTick() + delay);
90            else
91                state->completionEvent->process();
92        }
93        delete state;
94    }
95
96    // delete the request that we created and also the packet
97    delete pkt->req;
98    delete pkt;
99
100    // we might be drained at this point, if so signal the drain event
101    if (pendingCount == 0 && drainEvent) {
102        drainEvent->process();
103        drainEvent = NULL;
104    }
105}
106
107bool
108DmaPort::recvTimingResp(PacketPtr pkt)
109{
110    // We shouldn't ever get a block in ownership state
111    assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
112
113    handleResp(pkt);
114
115    return true;
116}
117
118DmaDevice::DmaDevice(const Params *p)
119    : PioDevice(p), dmaPort(this, sys)
120{ }
121
122void
123DmaDevice::init()
124{
125    if (!dmaPort.isConnected())
126        panic("DMA port of %s not connected to anything!", name());
127    PioDevice::init();
128}
129
130unsigned int
131DmaDevice::drain(Event *de)
132{
133    unsigned int count = pioPort.drain(de) + dmaPort.drain(de);
134    if (count)
135        changeState(Draining);
136    else
137        changeState(Drained);
138    return count;
139}
140
141unsigned int
142DmaPort::drain(Event *de)
143{
144    if (pendingCount == 0)
145        return 0;
146    drainEvent = de;
147    DPRINTF(Drain, "DmaPort not drained\n");
148    return 1;
149}
150
151void
152DmaPort::recvRetry()
153{
154    assert(transmitList.size());
155    bool result = true;
156    do {
157        PacketPtr pkt = transmitList.front();
158        DPRINTF(DMA, "Retry on %s addr %#x\n",
159                pkt->cmdString(), pkt->getAddr());
160        result = sendTimingReq(pkt);
161        if (result) {
162            DPRINTF(DMA, "-- Done\n");
163            transmitList.pop_front();
164            inRetry = false;
165        } else {
166            inRetry = true;
167            DPRINTF(DMA, "-- Failed, queued\n");
168        }
169    } while (result && transmitList.size());
170
171    DPRINTF(DMA, "TransmitList: %d, inRetry: %d\n",
172            transmitList.size(), inRetry);
173}
174
175void
176DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
177                   uint8_t *data, Tick delay, Request::Flags flag)
178{
179    // one DMA request sender state for every action, that is then
180    // split into many requests and packets based on the block size,
181    // i.e. cache line size
182    DmaReqState *reqState = new DmaReqState(event, size, delay);
183
184    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
185            event ? event->scheduled() : -1);
186    for (ChunkGenerator gen(addr, size, peerBlockSize());
187         !gen.done(); gen.next()) {
188        Request *req = new Request(gen.addr(), gen.size(), flag, masterId);
189        PacketPtr pkt = new Packet(req, cmd);
190
191        // Increment the data pointer on a write
192        if (data)
193            pkt->dataStatic(data + gen.complete());
194
195        pkt->senderState = reqState;
196
197        DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
198                gen.size());
199        queueDma(pkt);
200    }
201}
202
203void
204DmaPort::queueDma(PacketPtr pkt)
205{
206    transmitList.push_back(pkt);
207
208    // remember that we have another packet pending, this will only be
209    // decremented once a response comes back
210    pendingCount++;
211
212    sendDma();
213}
214
215void
216DmaPort::sendDma()
217{
218    // some kind of selcetion between access methods
219    // more work is going to have to be done to make
220    // switching actually work
221    assert(transmitList.size());
222    PacketPtr pkt = transmitList.front();
223
224    Enums::MemoryMode state = sys->getMemoryMode();
225    if (state == Enums::timing) {
226        if (inRetry) {
227            DPRINTF(DMA, "Can't send immediately, waiting for retry\n");
228            return;
229        }
230
231        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
232                pkt->cmdString(), pkt->getAddr());
233
234        bool result;
235        do {
236            result = sendTimingReq(pkt);
237            if (result) {
238                transmitList.pop_front();
239                DPRINTF(DMA, "-- Done\n");
240            } else {
241                inRetry = true;
242                DPRINTF(DMA, "-- Failed: queued\n");
243            }
244        } while (result && transmitList.size());
245    } else if (state == Enums::atomic) {
246        transmitList.pop_front();
247
248        DPRINTF(DMA, "Sending  DMA for addr: %#x size: %d\n",
249                pkt->req->getPaddr(), pkt->req->getSize());
250        Tick lat = sendAtomic(pkt);
251
252        handleResp(pkt, lat);
253    } else
254        panic("Unknown memory mode.");
255}
256
257MasterPort &
258DmaDevice::getMasterPort(const std::string &if_name, int idx)
259{
260    if (if_name == "dma") {
261        return dmaPort;
262    }
263    return PioDevice::getMasterPort(if_name, idx);
264}
265