io_device.cc revision 4435 
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, AddrRangeList &snoop)
52{
53    snoop.clear();
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
104
105    if (pkt->result == Packet::Nacked) {
106        DPRINTF(DMA, "Received nacked Pkt %#x with State: %#x Addr: %#x\n",
107               pkt, pkt->senderState, pkt->getAddr());
108
109        if (backoffTime < device->minBackoffDelay)
110            backoffTime = device->minBackoffDelay;
111        else if (backoffTime < device->maxBackoffDelay)
112            backoffTime <<= 1;
113
114        if (backoffEvent.scheduled())
115            backoffEvent.reschedule(curTick + backoffTime);
116        else
117            backoffEvent.schedule(curTick + backoffTime);
118
119        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
120
121        pkt->reinitNacked();
122        queueDma(pkt, true);
123    } else if (pkt->senderState) {
124        DmaReqState *state;
125        backoffTime >>= 2;
126
127        DPRINTF(DMA, "Received response Pkt %#x with State: %#x Addr: %#x size: %#x\n",
128               pkt, pkt->senderState, pkt->getAddr(), pkt->req->getSize());
129        state = dynamic_cast<DmaReqState*>(pkt->senderState);
130        pendingCount--;
131
132        assert(pendingCount >= 0);
133        assert(state);
134
135        state->numBytes += pkt->req->getSize();
136        assert(state->totBytes >= state->numBytes);
137        if (state->totBytes == state->numBytes) {
138            state->completionEvent->process();
139            delete state;
140        }
141        delete pkt->req;
142        delete pkt;
143
144        if (pendingCount == 0 && drainEvent) {
145            drainEvent->process();
146            drainEvent = NULL;
147        }
148    }  else {
149        panic("Got packet without sender state... huh?\n");
150    }
151
152    return true;
153}
154
155DmaDevice::DmaDevice(Params *p)
156    : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
157      maxBackoffDelay(p->max_backoff_delay)
158{ }
159
160
161unsigned int
162DmaDevice::drain(Event *de)
163{
164    unsigned int count;
165    count = pioPort->drain(de) + dmaPort->drain(de);
166    if (count)
167        changeState(Draining);
168    else
169        changeState(Drained);
170    return count;
171}
172
173unsigned int
174DmaPort::drain(Event *de)
175{
176    if (pendingCount == 0)
177        return 0;
178    drainEvent = de;
179    return 1;
180}
181
182
183void
184DmaPort::recvRetry()
185{
186    assert(transmitList.size());
187    PacketPtr pkt = transmitList.front();
188    bool result = true;
189    do {
190        DPRINTF(DMA, "Retry on  Packet %#x with senderState: %#x\n",
191                   pkt, pkt->senderState);
192        result = sendTiming(pkt);
193        if (result) {
194            DPRINTF(DMA, "-- Done\n");
195            transmitList.pop_front();
196            inRetry = false;
197        } else {
198            inRetry = true;
199            DPRINTF(DMA, "-- Failed, queued\n");
200        }
201    } while (!backoffTime &&  result && transmitList.size());
202
203    if (transmitList.size() && backoffTime && !inRetry) {
204        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
205        if (!backoffEvent.scheduled())
206            backoffEvent.schedule(backoffTime+curTick);
207    }
208    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
209            transmitList.size(), backoffTime, inRetry,
210            backoffEvent.scheduled());
211}
212
213
214void
215DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
216                   uint8_t *data)
217{
218    assert(event);
219
220    assert(device->getState() == SimObject::Running);
221
222    DmaReqState *reqState = new DmaReqState(event, this, size);
223
224    for (ChunkGenerator gen(addr, size, peerBlockSize());
225         !gen.done(); gen.next()) {
226            Request *req = new Request(gen.addr(), gen.size(), 0);
227            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
228
229            // Increment the data pointer on a write
230            if (data)
231                pkt->dataStatic(data + gen.complete());
232
233            pkt->senderState = reqState;
234
235            assert(pendingCount >= 0);
236            pendingCount++;
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            backoffEvent.schedule(backoffTime+curTick);
288        }
289    } else if (state == System::Atomic) {
290        transmitList.pop_front();
291
292        Tick lat;
293        lat = sendAtomic(pkt);
294        assert(pkt->senderState);
295        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
296        assert(state);
297
298        state->numBytes += pkt->req->getSize();
299        if (state->totBytes == state->numBytes) {
300            state->completionEvent->schedule(curTick + lat);
301            delete state;
302            delete pkt->req;
303        }
304        pendingCount--;
305        assert(pendingCount >= 0);
306        delete pkt;
307
308        if (pendingCount == 0 && drainEvent) {
309            drainEvent->process();
310            drainEvent = NULL;
311        }
312
313   } else
314       panic("Unknown memory command state.");
315}
316
317DmaDevice::~DmaDevice()
318{
319    if (dmaPort)
320        delete dmaPort;
321}
322
323
324