io_device.cc revision 8674:a9476951e3a2 
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        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                    schedule(state->completionEvent, 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
191
192unsigned int
193DmaDevice::drain(Event *de)
194{
195    unsigned int count;
196    count = pioPort->drain(de) + dmaPort->drain(de);
197    if (count)
198        changeState(Draining);
199    else
200        changeState(Drained);
201    return count;
202}
203
204unsigned int
205DmaPort::drain(Event *de)
206{
207    if (pendingCount == 0)
208        return 0;
209    drainEvent = de;
210    return 1;
211}
212
213
214void
215DmaPort::recvRetry()
216{
217    assert(transmitList.size());
218    bool result = true;
219    do {
220        PacketPtr pkt = transmitList.front();
221        DPRINTF(DMA, "Retry on %s addr %#x\n",
222                pkt->cmdString(), pkt->getAddr());
223        result = sendTiming(pkt);
224        if (result) {
225            DPRINTF(DMA, "-- Done\n");
226            transmitList.pop_front();
227            inRetry = false;
228        } else {
229            inRetry = true;
230            DPRINTF(DMA, "-- Failed, queued\n");
231        }
232    } while (!backoffTime &&  result && transmitList.size());
233
234    if (transmitList.size() && backoffTime && !inRetry) {
235        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick()+backoffTime);
236        if (!backoffEvent.scheduled())
237            schedule(backoffEvent, backoffTime + curTick());
238    }
239    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
240            transmitList.size(), backoffTime, inRetry,
241            backoffEvent.scheduled());
242}
243
244
245void
246DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
247                   uint8_t *data, Tick delay, Request::Flags flag)
248{
249    assert(device->getState() == SimObject::Running);
250
251    DmaReqState *reqState = new DmaReqState(event, this, size, delay);
252
253
254    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
255            event ? event->scheduled() : -1 );
256    for (ChunkGenerator gen(addr, size, peerBlockSize());
257         !gen.done(); gen.next()) {
258            Request *req = new Request(gen.addr(), gen.size(), flag);
259            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
260
261            // Increment the data pointer on a write
262            if (data)
263                pkt->dataStatic(data + gen.complete());
264
265            pkt->senderState = reqState;
266
267            assert(pendingCount >= 0);
268            pendingCount++;
269            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
270                    gen.size());
271            queueDma(pkt);
272    }
273
274}
275
276void
277DmaPort::queueDma(PacketPtr pkt, bool front)
278{
279
280    if (front)
281        transmitList.push_front(pkt);
282    else
283        transmitList.push_back(pkt);
284    sendDma();
285}
286
287
288void
289DmaPort::sendDma()
290{
291    // some kind of selction between access methods
292    // more work is going to have to be done to make
293    // switching actually work
294    assert(transmitList.size());
295    PacketPtr pkt = transmitList.front();
296
297    Enums::MemoryMode state = sys->getMemoryMode();
298    if (state == Enums::timing) {
299        if (backoffEvent.scheduled() || inRetry) {
300            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
301            return;
302        }
303
304        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
305                pkt->cmdString(), pkt->getAddr());
306
307        bool result;
308        do {
309            result = sendTiming(pkt);
310            if (result) {
311                transmitList.pop_front();
312                DPRINTF(DMA, "-- Done\n");
313            } else {
314                inRetry = true;
315                DPRINTF(DMA, "-- Failed: queued\n");
316            }
317        } while (result && !backoffTime && transmitList.size());
318
319        if (transmitList.size() && backoffTime && !inRetry &&
320                !backoffEvent.scheduled()) {
321            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
322                    backoffTime+curTick());
323            schedule(backoffEvent, backoffTime + curTick());
324        }
325    } else if (state == Enums::atomic) {
326        transmitList.pop_front();
327
328        Tick lat;
329        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
330                pkt->req->getPaddr(), pkt->req->getSize());
331        lat = sendAtomic(pkt);
332        assert(pkt->senderState);
333        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
334        assert(state);
335        state->numBytes += pkt->req->getSize();
336
337        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
338                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
339                state->totBytes,
340                state->completionEvent ? state->completionEvent->scheduled() : 0 );
341
342        if (state->totBytes == state->numBytes) {
343            if (state->completionEvent) {
344                assert(!state->completionEvent->scheduled());
345                schedule(state->completionEvent, 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