io_device.cc revision 4870:fcc39d001154 
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/builder.hh"
36#include "sim/system.hh"
37
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}
56
57
58PioDevice::~PioDevice()
59{
60    if (pioPort)
61        delete pioPort;
62}
63
64void
65PioDevice::init()
66{
67    if (!pioPort)
68        panic("Pio port not connected to anything!");
69    pioPort->sendStatusChange(Port::RangeChange);
70}
71
72
73unsigned int
74PioDevice::drain(Event *de)
75{
76    unsigned int count;
77    count = pioPort->drain(de);
78    if (count)
79        changeState(Draining);
80    else
81        changeState(Drained);
82    return count;
83}
84
85void
86BasicPioDevice::addressRanges(AddrRangeList &range_list)
87{
88    assert(pioSize != 0);
89    range_list.clear();
90    range_list.push_back(RangeSize(pioAddr, pioSize));
91}
92
93
94DmaPort::DmaPort(DmaDevice *dev, System *s)
95    : Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
96      pendingCount(0), actionInProgress(0), drainEvent(NULL),
97      backoffTime(0), inRetry(false), backoffEvent(this)
98{ }
99
100bool
101DmaPort::recvTiming(PacketPtr pkt)
102{
103    if (pkt->wasNacked()) {
104        DPRINTF(DMA, "Received nacked Pkt %#x with State: %#x Addr: %#x\n",
105               pkt, pkt->senderState, pkt->getAddr());
106
107        if (backoffTime < device->minBackoffDelay)
108            backoffTime = device->minBackoffDelay;
109        else if (backoffTime < device->maxBackoffDelay)
110            backoffTime <<= 1;
111
112        backoffEvent.reschedule(curTick + backoffTime, true);
113
114        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
115
116        pkt->reinitNacked();
117        queueDma(pkt, true);
118    } else if (pkt->senderState) {
119        DmaReqState *state;
120        backoffTime >>= 2;
121
122        DPRINTF(DMA, "Received response Pkt %#x with State: %#x Addr: %#x size: %#x\n",
123               pkt, pkt->senderState, pkt->getAddr(), pkt->req->getSize());
124        state = dynamic_cast<DmaReqState*>(pkt->senderState);
125        pendingCount--;
126
127        assert(pendingCount >= 0);
128        assert(state);
129
130        state->numBytes += pkt->req->getSize();
131        assert(state->totBytes >= state->numBytes);
132        if (state->totBytes == state->numBytes) {
133            state->completionEvent->process();
134            delete state;
135        }
136        delete pkt->req;
137        delete pkt;
138
139        if (pendingCount == 0 && drainEvent) {
140            drainEvent->process();
141            drainEvent = NULL;
142        }
143    }  else {
144        panic("Got packet without sender state... huh?\n");
145    }
146
147    return true;
148}
149
150DmaDevice::DmaDevice(Params *p)
151    : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
152      maxBackoffDelay(p->max_backoff_delay)
153{ }
154
155
156unsigned int
157DmaDevice::drain(Event *de)
158{
159    unsigned int count;
160    count = pioPort->drain(de) + dmaPort->drain(de);
161    if (count)
162        changeState(Draining);
163    else
164        changeState(Drained);
165    return count;
166}
167
168unsigned int
169DmaPort::drain(Event *de)
170{
171    if (pendingCount == 0)
172        return 0;
173    drainEvent = de;
174    return 1;
175}
176
177
178void
179DmaPort::recvRetry()
180{
181    assert(transmitList.size());
182    PacketPtr pkt = transmitList.front();
183    bool result = true;
184    do {
185        DPRINTF(DMA, "Retry on  Packet %#x with senderState: %#x\n",
186                   pkt, pkt->senderState);
187        result = sendTiming(pkt);
188        if (result) {
189            DPRINTF(DMA, "-- Done\n");
190            transmitList.pop_front();
191            inRetry = false;
192        } else {
193            inRetry = true;
194            DPRINTF(DMA, "-- Failed, queued\n");
195        }
196    } while (!backoffTime &&  result && transmitList.size());
197
198    if (transmitList.size() && backoffTime && !inRetry) {
199        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
200        if (!backoffEvent.scheduled())
201            backoffEvent.schedule(backoffTime+curTick);
202    }
203    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
204            transmitList.size(), backoffTime, inRetry,
205            backoffEvent.scheduled());
206}
207
208
209void
210DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
211                   uint8_t *data)
212{
213    assert(event);
214
215    assert(device->getState() == SimObject::Running);
216
217    DmaReqState *reqState = new DmaReqState(event, this, size);
218
219
220    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
221            event->scheduled());
222    for (ChunkGenerator gen(addr, size, peerBlockSize());
223         !gen.done(); gen.next()) {
224            Request *req = new Request(gen.addr(), gen.size(), 0);
225            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
226
227            // Increment the data pointer on a write
228            if (data)
229                pkt->dataStatic(data + gen.complete());
230
231            pkt->senderState = reqState;
232
233            assert(pendingCount >= 0);
234            pendingCount++;
235            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
236                    gen.size());
237            queueDma(pkt);
238    }
239
240}
241
242void
243DmaPort::queueDma(PacketPtr pkt, bool front)
244{
245
246    if (front)
247        transmitList.push_front(pkt);
248    else
249        transmitList.push_back(pkt);
250    sendDma();
251}
252
253
254void
255DmaPort::sendDma()
256{
257    // some kind of selction between access methods
258    // more work is going to have to be done to make
259    // switching actually work
260    assert(transmitList.size());
261    PacketPtr pkt = transmitList.front();
262
263    System::MemoryMode state = sys->getMemoryMode();
264    if (state == System::Timing) {
265        if (backoffEvent.scheduled() || inRetry) {
266            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
267            return;
268        }
269
270        DPRINTF(DMA, "Attempting to send Packet %#x with addr: %#x\n",
271                pkt, pkt->getAddr());
272
273        bool result;
274        do {
275            result = sendTiming(pkt);
276            if (result) {
277                transmitList.pop_front();
278                DPRINTF(DMA, "-- Done\n");
279            } else {
280                inRetry = true;
281                DPRINTF(DMA, "-- Failed: queued\n");
282            }
283        } while (result && !backoffTime && transmitList.size());
284
285        if (transmitList.size() && backoffTime && !inRetry &&
286                !backoffEvent.scheduled()) {
287            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
288                    backoffTime+curTick);
289            backoffEvent.schedule(backoffTime+curTick);
290        }
291    } else if (state == System::Atomic) {
292        transmitList.pop_front();
293
294        Tick lat;
295        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
296                pkt->req->getPaddr(), pkt->req->getSize());
297        lat = sendAtomic(pkt);
298        assert(pkt->senderState);
299        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
300        assert(state);
301        state->numBytes += pkt->req->getSize();
302
303        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
304                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
305                state->totBytes, state->completionEvent->scheduled());
306
307        if (state->totBytes == state->numBytes) {
308            assert(!state->completionEvent->scheduled());
309            state->completionEvent->schedule(curTick + lat);
310            delete state;
311            delete pkt->req;
312        }
313        pendingCount--;
314        assert(pendingCount >= 0);
315        delete pkt;
316
317        if (pendingCount == 0 && drainEvent) {
318            drainEvent->process();
319            drainEvent = NULL;
320        }
321
322   } else
323       panic("Unknown memory command state.");
324}
325
326DmaDevice::~DmaDevice()
327{
328    if (dmaPort)
329        delete dmaPort;
330}
331
332
333