io_device.cc revision 5534 
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ali Saidi
29 *          Nathan Binkert
30 */
31
32#include "base/chunk_generator.hh"
33#include "base/trace.hh"
34#include "dev/io_device.hh"
35#include "sim/system.hh"
36
37
38PioPort::PioPort(PioDevice *dev, System *s, std::string pname)
39    : SimpleTimingPort(dev->name() + pname, dev), device(dev)
40{ }
41
42
43Tick
44PioPort::recvAtomic(PacketPtr pkt)
45{
46    return pkt->isRead() ? device->read(pkt) : device->write(pkt);
47}
48
49void
50PioPort::getDeviceAddressRanges(AddrRangeList &resp, bool &snoop)
51{
52    snoop = false;
53    device->addressRanges(resp);
54}
55
56
57PioDevice::PioDevice(const Params *p)
58    : MemObject(p), platform(p->platform), sys(p->system), pioPort(NULL)
59{}
60
61PioDevice::~PioDevice()
62{
63    if (pioPort)
64        delete pioPort;
65}
66
67void
68PioDevice::init()
69{
70    if (!pioPort)
71        panic("Pio port not connected to anything!");
72    pioPort->sendStatusChange(Port::RangeChange);
73}
74
75
76unsigned int
77PioDevice::drain(Event *de)
78{
79    unsigned int count;
80    count = pioPort->drain(de);
81    if (count)
82        changeState(Draining);
83    else
84        changeState(Drained);
85    return count;
86}
87
88BasicPioDevice::BasicPioDevice(const Params *p)
89    : PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
90      pioDelay(p->pio_latency)
91{}
92
93void
94BasicPioDevice::addressRanges(AddrRangeList &range_list)
95{
96    assert(pioSize != 0);
97    range_list.clear();
98    range_list.push_back(RangeSize(pioAddr, pioSize));
99}
100
101
102DmaPort::DmaPort(DmaDevice *dev, System *s)
103    : Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
104      pendingCount(0), actionInProgress(0), drainEvent(NULL),
105      backoffTime(0), inRetry(false), backoffEvent(this)
106{ }
107
108bool
109DmaPort::recvTiming(PacketPtr pkt)
110{
111    if (pkt->wasNacked()) {
112        DPRINTF(DMA, "Received nacked %s addr %#x\n",
113                pkt->cmdString(), pkt->getAddr());
114
115        if (backoffTime < device->minBackoffDelay)
116            backoffTime = device->minBackoffDelay;
117        else if (backoffTime < device->maxBackoffDelay)
118            backoffTime <<= 1;
119
120        backoffEvent.reschedule(curTick + backoffTime, true);
121
122        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
123
124        pkt->reinitNacked();
125        queueDma(pkt, true);
126    } else if (pkt->senderState) {
127        DmaReqState *state;
128        backoffTime >>= 2;
129
130        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
131                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
132        state = dynamic_cast<DmaReqState*>(pkt->senderState);
133        pendingCount--;
134
135        assert(pendingCount >= 0);
136        assert(state);
137
138        state->numBytes += pkt->req->getSize();
139        assert(state->totBytes >= state->numBytes);
140        if (state->totBytes == state->numBytes) {
141            if (state->delay)
142                state->completionEvent->schedule(state->delay + curTick);
143            else
144                state->completionEvent->process();
145            delete state;
146        }
147        delete pkt->req;
148        delete pkt;
149
150        if (pendingCount == 0 && drainEvent) {
151            drainEvent->process();
152            drainEvent = NULL;
153        }
154    }  else {
155        panic("Got packet without sender state... huh?\n");
156    }
157
158    return true;
159}
160
161DmaDevice::DmaDevice(const Params *p)
162    : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
163      maxBackoffDelay(p->max_backoff_delay)
164{ }
165
166
167unsigned int
168DmaDevice::drain(Event *de)
169{
170    unsigned int count;
171    count = pioPort->drain(de) + dmaPort->drain(de);
172    if (count)
173        changeState(Draining);
174    else
175        changeState(Drained);
176    return count;
177}
178
179unsigned int
180DmaPort::drain(Event *de)
181{
182    if (pendingCount == 0)
183        return 0;
184    drainEvent = de;
185    return 1;
186}
187
188
189void
190DmaPort::recvRetry()
191{
192    assert(transmitList.size());
193    PacketPtr pkt = transmitList.front();
194    bool result = true;
195    do {
196        DPRINTF(DMA, "Retry on %s addr %#x\n",
197                pkt->cmdString(), pkt->getAddr());
198        result = sendTiming(pkt);
199        if (result) {
200            DPRINTF(DMA, "-- Done\n");
201            transmitList.pop_front();
202            inRetry = false;
203        } else {
204            inRetry = true;
205            DPRINTF(DMA, "-- Failed, queued\n");
206        }
207    } while (!backoffTime &&  result && transmitList.size());
208
209    if (transmitList.size() && backoffTime && !inRetry) {
210        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
211        if (!backoffEvent.scheduled())
212            backoffEvent.schedule(backoffTime+curTick);
213    }
214    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
215            transmitList.size(), backoffTime, inRetry,
216            backoffEvent.scheduled());
217}
218
219
220void
221DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
222                   uint8_t *data, Tick delay)
223{
224    assert(event);
225
226    assert(device->getState() == SimObject::Running);
227
228    DmaReqState *reqState = new DmaReqState(event, this, size, delay);
229
230
231    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
232            event->scheduled());
233    for (ChunkGenerator gen(addr, size, peerBlockSize());
234         !gen.done(); gen.next()) {
235            Request *req = new Request(gen.addr(), gen.size(), 0);
236            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
237
238            // Increment the data pointer on a write
239            if (data)
240                pkt->dataStatic(data + gen.complete());
241
242            pkt->senderState = reqState;
243
244            assert(pendingCount >= 0);
245            pendingCount++;
246            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
247                    gen.size());
248            queueDma(pkt);
249    }
250
251}
252
253void
254DmaPort::queueDma(PacketPtr pkt, bool front)
255{
256
257    if (front)
258        transmitList.push_front(pkt);
259    else
260        transmitList.push_back(pkt);
261    sendDma();
262}
263
264
265void
266DmaPort::sendDma()
267{
268    // some kind of selction between access methods
269    // more work is going to have to be done to make
270    // switching actually work
271    assert(transmitList.size());
272    PacketPtr pkt = transmitList.front();
273
274    Enums::MemoryMode state = sys->getMemoryMode();
275    if (state == Enums::timing) {
276        if (backoffEvent.scheduled() || inRetry) {
277            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
278            return;
279        }
280
281        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
282                pkt->cmdString(), pkt->getAddr());
283
284        bool result;
285        do {
286            result = sendTiming(pkt);
287            if (result) {
288                transmitList.pop_front();
289                DPRINTF(DMA, "-- Done\n");
290            } else {
291                inRetry = true;
292                DPRINTF(DMA, "-- Failed: queued\n");
293            }
294        } while (result && !backoffTime && transmitList.size());
295
296        if (transmitList.size() && backoffTime && !inRetry &&
297                !backoffEvent.scheduled()) {
298            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
299                    backoffTime+curTick);
300            backoffEvent.schedule(backoffTime+curTick);
301        }
302    } else if (state == Enums::atomic) {
303        transmitList.pop_front();
304
305        Tick lat;
306        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
307                pkt->req->getPaddr(), pkt->req->getSize());
308        lat = sendAtomic(pkt);
309        assert(pkt->senderState);
310        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
311        assert(state);
312        state->numBytes += pkt->req->getSize();
313
314        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
315                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
316                state->totBytes, state->completionEvent->scheduled());
317
318        if (state->totBytes == state->numBytes) {
319            assert(!state->completionEvent->scheduled());
320            state->completionEvent->schedule(curTick + lat + state->delay);
321            delete state;
322            delete pkt->req;
323        }
324        pendingCount--;
325        assert(pendingCount >= 0);
326        delete pkt;
327
328        if (pendingCount == 0 && drainEvent) {
329            drainEvent->process();
330            drainEvent = NULL;
331        }
332
333   } else
334       panic("Unknown memory command state.");
335}
336
337DmaDevice::~DmaDevice()
338{
339    if (dmaPort)
340        delete dmaPort;
341}
342