io_device.cc revision 8229:78bf55f23338 
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
37PioPort::PioPort(PioDevice *dev, System *s, std::string pname)
38    : SimpleTimingPort(dev->name() + pname, dev), device(dev)
39{ }
40
41
42Tick
43PioPort::recvAtomic(PacketPtr pkt)
44{
45    return pkt->isRead() ? device->read(pkt) : device->write(pkt);
46}
47
48void
49PioPort::getDeviceAddressRanges(AddrRangeList &resp, bool &snoop)
50{
51    snoop = false;
52    device->addressRanges(resp);
53    for (AddrRangeIter i = resp.begin(); i != resp.end(); i++)
54         DPRINTF(BusAddrRanges, "Adding Range %#x-%#x\n", i->start, i->end);
55}
56
57
58PioDevice::PioDevice(const Params *p)
59    : MemObject(p), platform(p->platform), sys(p->system), pioPort(NULL)
60{}
61
62PioDevice::~PioDevice()
63{
64    if (pioPort)
65        delete pioPort;
66}
67
68void
69PioDevice::init()
70{
71    if (!pioPort)
72        panic("Pio port not connected to anything!");
73    pioPort->sendStatusChange(Port::RangeChange);
74}
75
76
77unsigned int
78PioDevice::drain(Event *de)
79{
80    unsigned int count;
81    count = pioPort->drain(de);
82    if (count)
83        changeState(Draining);
84    else
85        changeState(Drained);
86    return count;
87}
88
89BasicPioDevice::BasicPioDevice(const Params *p)
90    : PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
91      pioDelay(p->pio_latency)
92{}
93
94void
95BasicPioDevice::addressRanges(AddrRangeList &range_list)
96{
97    assert(pioSize != 0);
98    range_list.clear();
99    DPRINTF(BusAddrRanges, "registering range: %#x-%#x\n", pioAddr, pioSize);
100    range_list.push_back(RangeSize(pioAddr, pioSize));
101}
102
103
104DmaPort::DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff)
105    : Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
106      pendingCount(0), actionInProgress(0), drainEvent(NULL),
107      backoffTime(0), minBackoffDelay(min_backoff),
108      maxBackoffDelay(max_backoff), inRetry(false), backoffEvent(this)
109{ }
110
111bool
112DmaPort::recvTiming(PacketPtr pkt)
113{
114    if (pkt->wasNacked()) {
115        DPRINTF(DMA, "Received nacked %s addr %#x\n",
116                pkt->cmdString(), pkt->getAddr());
117
118        if (backoffTime < minBackoffDelay)
119            backoffTime = minBackoffDelay;
120        else if (backoffTime < maxBackoffDelay)
121            backoffTime <<= 1;
122
123        reschedule(backoffEvent, curTick() + backoffTime, true);
124
125        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
126
127        pkt->reinitNacked();
128        queueDma(pkt, true);
129    } else if (pkt->senderState) {
130        DmaReqState *state;
131        backoffTime >>= 2;
132
133        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
134                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
135        state = dynamic_cast<DmaReqState*>(pkt->senderState);
136        pendingCount--;
137
138        assert(pendingCount >= 0);
139        assert(state);
140
141        // We shouldn't ever get a block in ownership state
142        assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
143
144        state->numBytes += pkt->req->getSize();
145        assert(state->totBytes >= state->numBytes);
146        if (state->totBytes == state->numBytes) {
147            if (state->completionEvent) {
148                if (state->delay)
149                    schedule(state->completionEvent, curTick() + state->delay);
150                else
151                    state->completionEvent->process();
152            }
153            delete state;
154        }
155        delete pkt->req;
156        delete pkt;
157
158        if (pendingCount == 0 && drainEvent) {
159            drainEvent->process();
160            drainEvent = NULL;
161        }
162    }  else {
163        panic("Got packet without sender state... huh?\n");
164    }
165
166    return true;
167}
168
169DmaDevice::DmaDevice(const Params *p)
170    : PioDevice(p), dmaPort(NULL)
171{ }
172
173
174unsigned int
175DmaDevice::drain(Event *de)
176{
177    unsigned int count;
178    count = pioPort->drain(de) + dmaPort->drain(de);
179    if (count)
180        changeState(Draining);
181    else
182        changeState(Drained);
183    return count;
184}
185
186unsigned int
187DmaPort::drain(Event *de)
188{
189    if (pendingCount == 0)
190        return 0;
191    drainEvent = de;
192    return 1;
193}
194
195
196void
197DmaPort::recvRetry()
198{
199    assert(transmitList.size());
200    bool result = true;
201    do {
202        PacketPtr pkt = transmitList.front();
203        DPRINTF(DMA, "Retry on %s addr %#x\n",
204                pkt->cmdString(), pkt->getAddr());
205        result = sendTiming(pkt);
206        if (result) {
207            DPRINTF(DMA, "-- Done\n");
208            transmitList.pop_front();
209            inRetry = false;
210        } else {
211            inRetry = true;
212            DPRINTF(DMA, "-- Failed, queued\n");
213        }
214    } while (!backoffTime &&  result && transmitList.size());
215
216    if (transmitList.size() && backoffTime && !inRetry) {
217        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick()+backoffTime);
218        if (!backoffEvent.scheduled())
219            schedule(backoffEvent, backoffTime + curTick());
220    }
221    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
222            transmitList.size(), backoffTime, inRetry,
223            backoffEvent.scheduled());
224}
225
226
227void
228DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
229                   uint8_t *data, Tick delay, Request::Flags flag)
230{
231    assert(device->getState() == SimObject::Running);
232
233    DmaReqState *reqState = new DmaReqState(event, this, size, delay);
234
235
236    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
237            event ? event->scheduled() : -1 );
238    for (ChunkGenerator gen(addr, size, peerBlockSize());
239         !gen.done(); gen.next()) {
240            Request *req = new Request(gen.addr(), gen.size(), flag);
241            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
242
243            // Increment the data pointer on a write
244            if (data)
245                pkt->dataStatic(data + gen.complete());
246
247            pkt->senderState = reqState;
248
249            assert(pendingCount >= 0);
250            pendingCount++;
251            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
252                    gen.size());
253            queueDma(pkt);
254    }
255
256}
257
258void
259DmaPort::queueDma(PacketPtr pkt, bool front)
260{
261
262    if (front)
263        transmitList.push_front(pkt);
264    else
265        transmitList.push_back(pkt);
266    sendDma();
267}
268
269
270void
271DmaPort::sendDma()
272{
273    // some kind of selction between access methods
274    // more work is going to have to be done to make
275    // switching actually work
276    assert(transmitList.size());
277    PacketPtr pkt = transmitList.front();
278
279    Enums::MemoryMode state = sys->getMemoryMode();
280    if (state == Enums::timing) {
281        if (backoffEvent.scheduled() || inRetry) {
282            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
283            return;
284        }
285
286        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
287                pkt->cmdString(), pkt->getAddr());
288
289        bool result;
290        do {
291            result = sendTiming(pkt);
292            if (result) {
293                transmitList.pop_front();
294                DPRINTF(DMA, "-- Done\n");
295            } else {
296                inRetry = true;
297                DPRINTF(DMA, "-- Failed: queued\n");
298            }
299        } while (result && !backoffTime && transmitList.size());
300
301        if (transmitList.size() && backoffTime && !inRetry &&
302                !backoffEvent.scheduled()) {
303            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
304                    backoffTime+curTick());
305            schedule(backoffEvent, backoffTime + curTick());
306        }
307    } else if (state == Enums::atomic) {
308        transmitList.pop_front();
309
310        Tick lat;
311        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
312                pkt->req->getPaddr(), pkt->req->getSize());
313        lat = sendAtomic(pkt);
314        assert(pkt->senderState);
315        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
316        assert(state);
317        state->numBytes += pkt->req->getSize();
318
319        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
320                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
321                state->totBytes,
322                state->completionEvent ? state->completionEvent->scheduled() : 0 );
323
324        if (state->totBytes == state->numBytes) {
325            if (state->completionEvent) {
326                assert(!state->completionEvent->scheduled());
327                schedule(state->completionEvent, curTick() + lat + state->delay);
328            }
329            delete state;
330            delete pkt->req;
331        }
332        pendingCount--;
333        assert(pendingCount >= 0);
334        delete pkt;
335
336        if (pendingCount == 0 && drainEvent) {
337            drainEvent->process();
338            drainEvent = NULL;
339        }
340
341   } else
342       panic("Unknown memory command state.");
343}
344
345DmaDevice::~DmaDevice()
346{
347    if (dmaPort)
348        delete dmaPort;
349}
350