io_device.cc revision 8832 
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
50AddrRangeList
51PioPort::getAddrRanges()
52{
53    return device->getAddrRanges();
54}
55
56
57PioDevice::PioDevice(const Params *p)
58    : MemObject(p), 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 of %s not connected to anything!", name());
72    pioPort->sendRangeChange();
73}
74
75Port *
76PioDevice::getPort(const std::string &if_name, int idx)
77{
78    if (if_name == "pio") {
79        if (pioPort != NULL)
80            fatal("%s: pio port already connected to %s",
81                  name(), pioPort->getPeer()->name());
82        pioPort = new PioPort(this, sys);
83        return pioPort;
84    }
85    return NULL;
86}
87
88unsigned int
89PioDevice::drain(Event *de)
90{
91    unsigned int count;
92    count = pioPort->drain(de);
93    if (count)
94        changeState(Draining);
95    else
96        changeState(Drained);
97    return count;
98}
99
100BasicPioDevice::BasicPioDevice(const Params *p)
101    : PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
102      pioDelay(p->pio_latency)
103{}
104
105AddrRangeList
106BasicPioDevice::getAddrRanges()
107{
108    assert(pioSize != 0);
109    AddrRangeList ranges;
110    DPRINTF(BusAddrRanges, "registering range: %#x-%#x\n", pioAddr, pioSize);
111    ranges.push_back(RangeSize(pioAddr, pioSize));
112    return ranges;
113}
114
115
116DmaPort::DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
117                 bool recv_snoops)
118    : Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
119      masterId(s->getMasterId(dev->name())),
120      pendingCount(0), actionInProgress(0), drainEvent(NULL),
121      backoffTime(0), minBackoffDelay(min_backoff),
122      maxBackoffDelay(max_backoff), inRetry(false), recvSnoops(recv_snoops),
123      backoffEvent(this)
124{ }
125
126bool
127DmaPort::recvTiming(PacketPtr pkt)
128{
129    if (pkt->wasNacked()) {
130        DPRINTF(DMA, "Received nacked %s addr %#x\n",
131                pkt->cmdString(), pkt->getAddr());
132
133        if (backoffTime < minBackoffDelay)
134            backoffTime = minBackoffDelay;
135        else if (backoffTime < maxBackoffDelay)
136            backoffTime <<= 1;
137
138        device->reschedule(backoffEvent, curTick() + backoffTime, true);
139
140        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
141
142        pkt->reinitNacked();
143        queueDma(pkt, true);
144    } else if (pkt->isRequest() && recvSnoops) {
145        return true;
146    } else if (pkt->senderState) {
147        DmaReqState *state;
148        backoffTime >>= 2;
149
150        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
151                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
152        state = dynamic_cast<DmaReqState*>(pkt->senderState);
153        pendingCount--;
154
155        assert(pendingCount >= 0);
156        assert(state);
157
158        // We shouldn't ever get a block in ownership state
159        assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
160
161        state->numBytes += pkt->req->getSize();
162        assert(state->totBytes >= state->numBytes);
163        if (state->totBytes == state->numBytes) {
164            if (state->completionEvent) {
165                if (state->delay)
166                    device->schedule(state->completionEvent,
167                                     curTick() + state->delay);
168                else
169                    state->completionEvent->process();
170            }
171            delete state;
172        }
173        delete pkt->req;
174        delete pkt;
175
176        if (pendingCount == 0 && drainEvent) {
177            drainEvent->process();
178            drainEvent = NULL;
179        }
180    }  else {
181        panic("Got packet without sender state... huh?\n");
182    }
183
184    return true;
185}
186
187DmaDevice::DmaDevice(const Params *p)
188    : PioDevice(p), dmaPort(NULL)
189{ }
190
191unsigned int
192DmaDevice::drain(Event *de)
193{
194    unsigned int count;
195    count = pioPort->drain(de) + dmaPort->drain(de);
196    if (count)
197        changeState(Draining);
198    else
199        changeState(Drained);
200    return count;
201}
202
203unsigned int
204DmaPort::drain(Event *de)
205{
206    if (pendingCount == 0)
207        return 0;
208    drainEvent = de;
209    return 1;
210}
211
212
213void
214DmaPort::recvRetry()
215{
216    assert(transmitList.size());
217    bool result = true;
218    do {
219        PacketPtr pkt = transmitList.front();
220        DPRINTF(DMA, "Retry on %s addr %#x\n",
221                pkt->cmdString(), pkt->getAddr());
222        result = sendTiming(pkt);
223        if (result) {
224            DPRINTF(DMA, "-- Done\n");
225            transmitList.pop_front();
226            inRetry = false;
227        } else {
228            inRetry = true;
229            DPRINTF(DMA, "-- Failed, queued\n");
230        }
231    } while (!backoffTime &&  result && transmitList.size());
232
233    if (transmitList.size() && backoffTime && !inRetry) {
234        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick()+backoffTime);
235        if (!backoffEvent.scheduled())
236            device->schedule(backoffEvent, backoffTime + curTick());
237    }
238    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
239            transmitList.size(), backoffTime, inRetry,
240            backoffEvent.scheduled());
241}
242
243
244void
245DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
246                   uint8_t *data, Tick delay, Request::Flags flag)
247{
248    assert(device->getState() == SimObject::Running);
249
250    DmaReqState *reqState = new DmaReqState(event, this, size, delay);
251
252
253    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
254            event ? event->scheduled() : -1 );
255    for (ChunkGenerator gen(addr, size, peerBlockSize());
256         !gen.done(); gen.next()) {
257            Request *req = new Request(gen.addr(), gen.size(), flag, masterId);
258            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
259
260            // Increment the data pointer on a write
261            if (data)
262                pkt->dataStatic(data + gen.complete());
263
264            pkt->senderState = reqState;
265
266            assert(pendingCount >= 0);
267            pendingCount++;
268            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
269                    gen.size());
270            queueDma(pkt);
271    }
272
273}
274
275void
276DmaPort::queueDma(PacketPtr pkt, bool front)
277{
278
279    if (front)
280        transmitList.push_front(pkt);
281    else
282        transmitList.push_back(pkt);
283    sendDma();
284}
285
286
287void
288DmaPort::sendDma()
289{
290    // some kind of selction between access methods
291    // more work is going to have to be done to make
292    // switching actually work
293    assert(transmitList.size());
294    PacketPtr pkt = transmitList.front();
295
296    Enums::MemoryMode state = sys->getMemoryMode();
297    if (state == Enums::timing) {
298        if (backoffEvent.scheduled() || inRetry) {
299            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
300            return;
301        }
302
303        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
304                pkt->cmdString(), pkt->getAddr());
305
306        bool result;
307        do {
308            result = sendTiming(pkt);
309            if (result) {
310                transmitList.pop_front();
311                DPRINTF(DMA, "-- Done\n");
312            } else {
313                inRetry = true;
314                DPRINTF(DMA, "-- Failed: queued\n");
315            }
316        } while (result && !backoffTime && transmitList.size());
317
318        if (transmitList.size() && backoffTime && !inRetry &&
319                !backoffEvent.scheduled()) {
320            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
321                    backoffTime+curTick());
322            device->schedule(backoffEvent, backoffTime + curTick());
323        }
324    } else if (state == Enums::atomic) {
325        transmitList.pop_front();
326
327        Tick lat;
328        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
329                pkt->req->getPaddr(), pkt->req->getSize());
330        lat = sendAtomic(pkt);
331        assert(pkt->senderState);
332        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
333        assert(state);
334        state->numBytes += pkt->req->getSize();
335
336        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
337                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
338                state->totBytes,
339                state->completionEvent ? state->completionEvent->scheduled() : 0 );
340
341        if (state->totBytes == state->numBytes) {
342            if (state->completionEvent) {
343                assert(!state->completionEvent->scheduled());
344                device->schedule(state->completionEvent,
345                                 curTick() + lat + state->delay);
346            }
347            delete state;
348            delete pkt->req;
349        }
350        pendingCount--;
351        assert(pendingCount >= 0);
352        delete pkt;
353
354        if (pendingCount == 0 && drainEvent) {
355            drainEvent->process();
356            drainEvent = NULL;
357        }
358
359   } else
360       panic("Unknown memory command state.");
361}
362
363DmaDevice::~DmaDevice()
364{
365    if (dmaPort)
366        delete dmaPort;
367}
368
369
370Port *
371DmaDevice::getPort(const std::string &if_name, int idx)
372{
373    if (if_name == "dma") {
374        if (dmaPort != NULL)
375            fatal("%s: dma port already connected to %s",
376                  name(), dmaPort->getPeer()->name());
377        dmaPort = new DmaPort(this, sys, params()->min_backoff_delay,
378                              params()->max_backoff_delay);
379        return dmaPort;
380    }
381    return PioDevice::getPort(if_name, idx);
382}
383
384