io_device.cc revision 4918:3214e3694fb2 
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    if (pkt->wasNacked()) {
112        DPRINTF(DMA, "Received nacked %s addr %#x\n",
113                pkt->cmdString(), pkt->getAddr());
114
115        if (backoffTime < device->minBackoffDelay)
116            backoffTime = device->minBackoffDelay;
117        else if (backoffTime < device->maxBackoffDelay)
118            backoffTime <<= 1;
119
120        backoffEvent.reschedule(curTick + backoffTime, true);
121
122        DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
123
124        pkt->reinitNacked();
125        queueDma(pkt, true);
126    } else if (pkt->senderState) {
127        DmaReqState *state;
128        backoffTime >>= 2;
129
130        DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
131                pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
132        state = dynamic_cast<DmaReqState*>(pkt->senderState);
133        pendingCount--;
134
135        assert(pendingCount >= 0);
136        assert(state);
137
138        state->numBytes += pkt->req->getSize();
139        assert(state->totBytes >= state->numBytes);
140        if (state->totBytes == state->numBytes) {
141            state->completionEvent->process();
142            delete state;
143        }
144        delete pkt->req;
145        delete pkt;
146
147        if (pendingCount == 0 && drainEvent) {
148            drainEvent->process();
149            drainEvent = NULL;
150        }
151    }  else {
152        panic("Got packet without sender state... huh?\n");
153    }
154
155    return true;
156}
157
158DmaDevice::DmaDevice(const Params *p)
159    : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
160      maxBackoffDelay(p->max_backoff_delay)
161{ }
162
163
164unsigned int
165DmaDevice::drain(Event *de)
166{
167    unsigned int count;
168    count = pioPort->drain(de) + dmaPort->drain(de);
169    if (count)
170        changeState(Draining);
171    else
172        changeState(Drained);
173    return count;
174}
175
176unsigned int
177DmaPort::drain(Event *de)
178{
179    if (pendingCount == 0)
180        return 0;
181    drainEvent = de;
182    return 1;
183}
184
185
186void
187DmaPort::recvRetry()
188{
189    assert(transmitList.size());
190    PacketPtr pkt = transmitList.front();
191    bool result = true;
192    do {
193        DPRINTF(DMA, "Retry on %s addr %#x\n",
194                pkt->cmdString(), pkt->getAddr());
195        result = sendTiming(pkt);
196        if (result) {
197            DPRINTF(DMA, "-- Done\n");
198            transmitList.pop_front();
199            inRetry = false;
200        } else {
201            inRetry = true;
202            DPRINTF(DMA, "-- Failed, queued\n");
203        }
204    } while (!backoffTime &&  result && transmitList.size());
205
206    if (transmitList.size() && backoffTime && !inRetry) {
207        DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
208        if (!backoffEvent.scheduled())
209            backoffEvent.schedule(backoffTime+curTick);
210    }
211    DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
212            transmitList.size(), backoffTime, inRetry,
213            backoffEvent.scheduled());
214}
215
216
217void
218DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
219                   uint8_t *data)
220{
221    assert(event);
222
223    assert(device->getState() == SimObject::Running);
224
225    DmaReqState *reqState = new DmaReqState(event, this, size);
226
227
228    DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
229            event->scheduled());
230    for (ChunkGenerator gen(addr, size, peerBlockSize());
231         !gen.done(); gen.next()) {
232            Request *req = new Request(gen.addr(), gen.size(), 0);
233            PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
234
235            // Increment the data pointer on a write
236            if (data)
237                pkt->dataStatic(data + gen.complete());
238
239            pkt->senderState = reqState;
240
241            assert(pendingCount >= 0);
242            pendingCount++;
243            DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
244                    gen.size());
245            queueDma(pkt);
246    }
247
248}
249
250void
251DmaPort::queueDma(PacketPtr pkt, bool front)
252{
253
254    if (front)
255        transmitList.push_front(pkt);
256    else
257        transmitList.push_back(pkt);
258    sendDma();
259}
260
261
262void
263DmaPort::sendDma()
264{
265    // some kind of selction between access methods
266    // more work is going to have to be done to make
267    // switching actually work
268    assert(transmitList.size());
269    PacketPtr pkt = transmitList.front();
270
271    Enums::MemoryMode state = sys->getMemoryMode();
272    if (state == Enums::timing) {
273        if (backoffEvent.scheduled() || inRetry) {
274            DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
275            return;
276        }
277
278        DPRINTF(DMA, "Attempting to send %s addr %#x\n",
279                pkt->cmdString(), pkt->getAddr());
280
281        bool result;
282        do {
283            result = sendTiming(pkt);
284            if (result) {
285                transmitList.pop_front();
286                DPRINTF(DMA, "-- Done\n");
287            } else {
288                inRetry = true;
289                DPRINTF(DMA, "-- Failed: queued\n");
290            }
291        } while (result && !backoffTime && transmitList.size());
292
293        if (transmitList.size() && backoffTime && !inRetry &&
294                !backoffEvent.scheduled()) {
295            DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
296                    backoffTime+curTick);
297            backoffEvent.schedule(backoffTime+curTick);
298        }
299    } else if (state == Enums::atomic) {
300        transmitList.pop_front();
301
302        Tick lat;
303        DPRINTF(DMA, "--Sending  DMA for addr: %#x size: %d\n",
304                pkt->req->getPaddr(), pkt->req->getSize());
305        lat = sendAtomic(pkt);
306        assert(pkt->senderState);
307        DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
308        assert(state);
309        state->numBytes += pkt->req->getSize();
310
311        DPRINTF(DMA, "--Received response for  DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
312                pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
313                state->totBytes, state->completionEvent->scheduled());
314
315        if (state->totBytes == state->numBytes) {
316            assert(!state->completionEvent->scheduled());
317            state->completionEvent->schedule(curTick + lat);
318            delete state;
319            delete pkt->req;
320        }
321        pendingCount--;
322        assert(pendingCount >= 0);
323        delete pkt;
324
325        if (pendingCount == 0 && drainEvent) {
326            drainEvent->process();
327            drainEvent = NULL;
328        }
329
330   } else
331       panic("Unknown memory command state.");
332}
333
334DmaDevice::~DmaDevice()
335{
336    if (dmaPort)
337        delete dmaPort;
338}
339