io_device.cc revision 4762:c94e103c83ad 
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
112
113    if (pkt->result == Packet::Nacked) {
114        DPRINTF(DMA, "Received nacked %s addr %#x\n",
115                pkt->cmdString(), pkt->getAddr());
116
117        if (backoffTime < device->minBackoffDelay)
118            backoffTime = device->minBackoffDelay;
119        else if (backoffTime < device->maxBackoffDelay)
120            backoffTime <<= 1;
121
122        backoffEvent.reschedule(curTick + backoffTime, true);
123
124        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
125
126        pkt->reinitNacked();
127        queueDma(pkt, true);
128    } else if (pkt->senderState) {
129        DmaReqState *state;
130        backoffTime >>= 2;
131
132        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
133                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
134        state = dynamic_cast<DmaReqState*>(pkt->senderState);
135        pendingCount--;
136
137        assert(pendingCount >= 0);
138        assert(state);
139
140        state->numBytes += pkt->req->getSize();
141        assert(state->totBytes >= state->numBytes);
142        if (state->totBytes == state->numBytes) {
143            state->completionEvent->process();
144            delete state;
145        }
146        delete pkt->req;
147        delete pkt;
148
149        if (pendingCount == 0 && drainEvent) {
150            drainEvent->process();
151            drainEvent = NULL;
152        }
153    }  else {
154        panic("Got packet without sender state... huh?\n");
155    }
156
157    return true;
158}
159
160DmaDevice::DmaDevice(const Params *p)
161    : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
162      maxBackoffDelay(p->max_backoff_delay)
163{ }
164
165
166unsigned int
167DmaDevice::drain(Event *de)
168{
169    unsigned int count;
170    count = pioPort->drain(de) + dmaPort->drain(de);
171    if (count)
172        changeState(Draining);
173    else
174        changeState(Drained);
175    return count;
176}
177
178unsigned int
179DmaPort::drain(Event *de)
180{
181    if (pendingCount == 0)
182        return 0;
183    drainEvent = de;
184    return 1;
185}
186
187
188void
189DmaPort::recvRetry()
190{
191    assert(transmitList.size());
192    PacketPtr pkt = transmitList.front();
193    bool result = true;
194    do {
195        DPRINTF(DMA, "Retry on %s addr %#x\n",
196                pkt->cmdString(), pkt->getAddr());
197        result = sendTiming(pkt);
198        if (result) {
199            DPRINTF(DMA, "-- Done\n");
200            transmitList.pop_front();
201            inRetry = false;
202        } else {
203            inRetry = true;
204            DPRINTF(DMA, "-- Failed, queued\n");
205        }
206    } while (!backoffTime &&  result && transmitList.size());
207
208    if (transmitList.size() && backoffTime && !inRetry) {
209        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
210        if (!backoffEvent.scheduled())
211            backoffEvent.schedule(backoffTime+curTick);
212    }
213    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
214            transmitList.size(), backoffTime, inRetry,
215            backoffEvent.scheduled());
216}
217
218
219void
220DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
221                   uint8_t *data)
222{
223    assert(event);
224
225    assert(device->getState() == SimObject::Running);
226
227    DmaReqState *reqState = new DmaReqState(event, this, size);
228
229
230    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
231            event->scheduled());
232    for (ChunkGenerator gen(addr, size, peerBlockSize());
233         !gen.done(); gen.next()) {
234            Request *req = new Request(gen.addr(), gen.size(), 0);
235            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
236
237            // Increment the data pointer on a write
238            if (data)
239                pkt->dataStatic(data + gen.complete());
240
241            pkt->senderState = reqState;
242
243            assert(pendingCount >= 0);
244            pendingCount++;
245            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
246                    gen.size());
247            queueDma(pkt);
248    }
249
250}
251
252void
253DmaPort::queueDma(PacketPtr pkt, bool front)
254{
255
256    if (front)
257        transmitList.push_front(pkt);
258    else
259        transmitList.push_back(pkt);
260    sendDma();
261}
262
263
264void
265DmaPort::sendDma()
266{
267    // some kind of selction between access methods
268    // more work is going to have to be done to make
269    // switching actually work
270    assert(transmitList.size());
271    PacketPtr pkt = transmitList.front();
272
273    Enums::MemoryMode state = sys->getMemoryMode();
274    if (state == Enums::timing) {
275        if (backoffEvent.scheduled() || inRetry) {
276            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
277            return;
278        }
279
280        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
281                pkt->cmdString(), pkt->getAddr());
282
283        bool result;
284        do {
285            result = sendTiming(pkt);
286            if (result) {
287                transmitList.pop_front();
288                DPRINTF(DMA, "-- Done\n");
289            } else {
290                inRetry = true;
291                DPRINTF(DMA, "-- Failed: queued\n");
292            }
293        } while (result && !backoffTime && transmitList.size());
294
295        if (transmitList.size() && backoffTime && !inRetry &&
296                !backoffEvent.scheduled()) {
297            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
298                    backoffTime+curTick);
299            backoffEvent.schedule(backoffTime+curTick);
300        }
301    } else if (state == Enums::atomic) {
302        transmitList.pop_front();
303
304        Tick lat;
305        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
306                pkt->req->getPaddr(), pkt->req->getSize());
307        lat = sendAtomic(pkt);
308        assert(pkt->senderState);
309        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
310        assert(state);
311        state->numBytes += pkt->req->getSize();
312
313        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
314                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
315                state->totBytes, state->completionEvent->scheduled());
316
317        if (state->totBytes == state->numBytes) {
318            assert(!state->completionEvent->scheduled());
319            state->completionEvent->schedule(curTick + lat);
320            delete state;
321            delete pkt->req;
322        }
323        pendingCount--;
324        assert(pendingCount >= 0);
325        delete pkt;
326
327        if (pendingCount == 0 && drainEvent) {
328            drainEvent->process();
329            drainEvent = NULL;
330        }
331
332   } else
333       panic("Unknown memory command state.");
334}
335
336DmaDevice::~DmaDevice()
337{
338    if (dmaPort)
339        delete dmaPort;
340}
341