io_device.cc revision 8708 
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 "debug/BusAddrRanges.hh"
35#include "debug/DMA.hh"
36#include "dev/io_device.hh"
37#include "sim/system.hh"
38
39PioPort::PioPort(PioDevice *dev, System *s, std::string pname)
40    : SimpleTimingPort(dev->name() + pname, dev), device(dev)
41{ }
42
43
44Tick
45PioPort::recvAtomic(PacketPtr pkt)
46{
47    return pkt->isRead() ? device->read(pkt) : device->write(pkt);
48}
49
50void
51PioPort::getDeviceAddressRanges(AddrRangeList &resp, bool &snoop)
52{
53    snoop = false;
54    device->addressRanges(resp);
55    for (AddrRangeIter i = resp.begin(); i != resp.end(); i++)
56         DPRINTF(BusAddrRanges, "Adding Range %#x-%#x\n", i->start, i->end);
57}
58
59
60PioDevice::PioDevice(const Params *p)
61    : MemObject(p), platform(p->platform), sys(p->system), pioPort(NULL)
62{}
63
64PioDevice::~PioDevice()
65{
66    if (pioPort)
67        delete pioPort;
68}
69
70void
71PioDevice::init()
72{
73    if (!pioPort)
74        panic("Pio port of %s not connected to anything!", name());
75    pioPort->sendStatusChange(Port::RangeChange);
76}
77
78Port *
79PioDevice::getPort(const std::string &if_name, int idx)
80{
81    if (if_name == "pio") {
82        if (pioPort != NULL)
83            fatal("%s: pio port already connected to %s",
84                  name(), pioPort->getPeer()->name());
85        pioPort = new PioPort(this, sys);
86        return pioPort;
87    }
88    return NULL;
89}
90
91unsigned int
92PioDevice::drain(Event *de)
93{
94    unsigned int count;
95    count = pioPort->drain(de);
96    if (count)
97        changeState(Draining);
98    else
99        changeState(Drained);
100    return count;
101}
102
103BasicPioDevice::BasicPioDevice(const Params *p)
104    : PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
105      pioDelay(p->pio_latency)
106{}
107
108void
109BasicPioDevice::addressRanges(AddrRangeList &range_list)
110{
111    assert(pioSize != 0);
112    range_list.clear();
113    DPRINTF(BusAddrRanges, "registering range: %#x-%#x\n", pioAddr, pioSize);
114    range_list.push_back(RangeSize(pioAddr, pioSize));
115}
116
117
118DmaPort::DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
119                 bool recv_snoops)
120    : Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
121      pendingCount(0), actionInProgress(0), drainEvent(NULL),
122      backoffTime(0), minBackoffDelay(min_backoff),
123      maxBackoffDelay(max_backoff), inRetry(false), recvSnoops(recv_snoops),
124      snoopRangeSent(false), backoffEvent(this)
125{ }
126
127bool
128DmaPort::recvTiming(PacketPtr pkt)
129{
130    if (pkt->wasNacked()) {
131        DPRINTF(DMA, "Received nacked %s addr %#x\n",
132                pkt->cmdString(), pkt->getAddr());
133
134        if (backoffTime < minBackoffDelay)
135            backoffTime = minBackoffDelay;
136        else if (backoffTime < maxBackoffDelay)
137            backoffTime <<= 1;
138
139        device->reschedule(backoffEvent, curTick() + backoffTime, true);
140
141        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
142
143        pkt->reinitNacked();
144        queueDma(pkt, true);
145    } else if (pkt->isRequest() && recvSnoops) {
146        return true;
147    } else if (pkt->senderState) {
148        DmaReqState *state;
149        backoffTime >>= 2;
150
151        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
152                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
153        state = dynamic_cast<DmaReqState*>(pkt->senderState);
154        pendingCount--;
155
156        assert(pendingCount >= 0);
157        assert(state);
158
159        // We shouldn't ever get a block in ownership state
160        assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
161
162        state->numBytes += pkt->req->getSize();
163        assert(state->totBytes >= state->numBytes);
164        if (state->totBytes == state->numBytes) {
165            if (state->completionEvent) {
166                if (state->delay)
167                    device->schedule(state->completionEvent,
168                                     curTick() + state->delay);
169                else
170                    state->completionEvent->process();
171            }
172            delete state;
173        }
174        delete pkt->req;
175        delete pkt;
176
177        if (pendingCount == 0 && drainEvent) {
178            drainEvent->process();
179            drainEvent = NULL;
180        }
181    }  else {
182        panic("Got packet without sender state... huh?\n");
183    }
184
185    return true;
186}
187
188DmaDevice::DmaDevice(const Params *p)
189    : PioDevice(p), dmaPort(NULL)
190{ }
191
192
193unsigned int
194DmaDevice::drain(Event *de)
195{
196    unsigned int count;
197    count = pioPort->drain(de) + dmaPort->drain(de);
198    if (count)
199        changeState(Draining);
200    else
201        changeState(Drained);
202    return count;
203}
204
205unsigned int
206DmaPort::drain(Event *de)
207{
208    if (pendingCount == 0)
209        return 0;
210    drainEvent = de;
211    return 1;
212}
213
214
215void
216DmaPort::recvRetry()
217{
218    assert(transmitList.size());
219    bool result = true;
220    do {
221        PacketPtr pkt = transmitList.front();
222        DPRINTF(DMA, "Retry on %s addr %#x\n",
223                pkt->cmdString(), pkt->getAddr());
224        result = sendTiming(pkt);
225        if (result) {
226            DPRINTF(DMA, "-- Done\n");
227            transmitList.pop_front();
228            inRetry = false;
229        } else {
230            inRetry = true;
231            DPRINTF(DMA, "-- Failed, queued\n");
232        }
233    } while (!backoffTime &&  result && transmitList.size());
234
235    if (transmitList.size() && backoffTime && !inRetry) {
236        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick()+backoffTime);
237        if (!backoffEvent.scheduled())
238            device->schedule(backoffEvent, backoffTime + curTick());
239    }
240    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
241            transmitList.size(), backoffTime, inRetry,
242            backoffEvent.scheduled());
243}
244
245
246void
247DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
248                   uint8_t *data, Tick delay, Request::Flags flag)
249{
250    assert(device->getState() == SimObject::Running);
251
252    DmaReqState *reqState = new DmaReqState(event, this, size, delay);
253
254
255    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
256            event ? event->scheduled() : -1 );
257    for (ChunkGenerator gen(addr, size, peerBlockSize());
258         !gen.done(); gen.next()) {
259            Request *req = new Request(gen.addr(), gen.size(), flag);
260            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
261
262            // Increment the data pointer on a write
263            if (data)
264                pkt->dataStatic(data + gen.complete());
265
266            pkt->senderState = reqState;
267
268            assert(pendingCount >= 0);
269            pendingCount++;
270            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
271                    gen.size());
272            queueDma(pkt);
273    }
274
275}
276
277void
278DmaPort::queueDma(PacketPtr pkt, bool front)
279{
280
281    if (front)
282        transmitList.push_front(pkt);
283    else
284        transmitList.push_back(pkt);
285    sendDma();
286}
287
288
289void
290DmaPort::sendDma()
291{
292    // some kind of selction between access methods
293    // more work is going to have to be done to make
294    // switching actually work
295    assert(transmitList.size());
296    PacketPtr pkt = transmitList.front();
297
298    Enums::MemoryMode state = sys->getMemoryMode();
299    if (state == Enums::timing) {
300        if (backoffEvent.scheduled() || inRetry) {
301            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
302            return;
303        }
304
305        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
306                pkt->cmdString(), pkt->getAddr());
307
308        bool result;
309        do {
310            result = sendTiming(pkt);
311            if (result) {
312                transmitList.pop_front();
313                DPRINTF(DMA, "-- Done\n");
314            } else {
315                inRetry = true;
316                DPRINTF(DMA, "-- Failed: queued\n");
317            }
318        } while (result && !backoffTime && transmitList.size());
319
320        if (transmitList.size() && backoffTime && !inRetry &&
321                !backoffEvent.scheduled()) {
322            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
323                    backoffTime+curTick());
324            device->schedule(backoffEvent, backoffTime + curTick());
325        }
326    } else if (state == Enums::atomic) {
327        transmitList.pop_front();
328
329        Tick lat;
330        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
331                pkt->req->getPaddr(), pkt->req->getSize());
332        lat = sendAtomic(pkt);
333        assert(pkt->senderState);
334        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
335        assert(state);
336        state->numBytes += pkt->req->getSize();
337
338        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
339                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
340                state->totBytes,
341                state->completionEvent ? state->completionEvent->scheduled() : 0 );
342
343        if (state->totBytes == state->numBytes) {
344            if (state->completionEvent) {
345                assert(!state->completionEvent->scheduled());
346                device->schedule(state->completionEvent,
347                                 curTick() + lat + state->delay);
348            }
349            delete state;
350            delete pkt->req;
351        }
352        pendingCount--;
353        assert(pendingCount >= 0);
354        delete pkt;
355
356        if (pendingCount == 0 && drainEvent) {
357            drainEvent->process();
358            drainEvent = NULL;
359        }
360
361   } else
362       panic("Unknown memory command state.");
363}
364
365DmaDevice::~DmaDevice()
366{
367    if (dmaPort)
368        delete dmaPort;
369}
370
371
372Port *
373DmaDevice::getPort(const std::string &if_name, int idx)
374{
375    if (if_name == "dma") {
376        if (dmaPort != NULL)
377            fatal("%s: dma port already connected to %s",
378                  name(), dmaPort->getPeer()->name());
379        dmaPort = new DmaPort(this, sys, params()->min_backoff_delay,
380                              params()->max_backoff_delay);
381        return dmaPort;
382    }
383    return PioDevice::getPort(if_name, idx);
384}
385
386