DMASequencer.cc revision 11025 
1/*
2 * Copyright (c) 2008 Mark D. Hill and David A. Wood
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
29#include <memory>
30
31#include "debug/Config.hh"
32#include "debug/Drain.hh"
33#include "debug/RubyDma.hh"
34#include "debug/RubyStats.hh"
35#include "mem/protocol/SequencerMsg.hh"
36#include "mem/ruby/system/DMASequencer.hh"
37#include "mem/ruby/system/System.hh"
38#include "sim/system.hh"
39
40DMASequencer::DMASequencer(const Params *p)
41    : MemObject(p), m_ruby_system(p->ruby_system), m_version(p->version),
42      m_controller(NULL), m_mandatory_q_ptr(NULL),
43      m_usingRubyTester(p->using_ruby_tester),
44      slave_port(csprintf("%s.slave", name()), this, 0, p->ruby_system,
45                 p->ruby_system->getAccessBackingStore()),
46      system(p->system), retry(false)
47{
48    assert(m_version != -1);
49}
50
51void
52DMASequencer::init()
53{
54    MemObject::init();
55    assert(m_controller != NULL);
56    m_mandatory_q_ptr = m_controller->getMandatoryQueue();
57    m_mandatory_q_ptr->setSender(this);
58    m_is_busy = false;
59    m_data_block_mask = ~ (~0 << RubySystem::getBlockSizeBits());
60
61    slave_port.sendRangeChange();
62}
63
64BaseSlavePort &
65DMASequencer::getSlavePort(const std::string &if_name, PortID idx)
66{
67    // used by the CPUs to connect the caches to the interconnect, and
68    // for the x86 case also the interrupt master
69    if (if_name != "slave") {
70        // pass it along to our super class
71        return MemObject::getSlavePort(if_name, idx);
72    } else {
73        return slave_port;
74    }
75}
76
77DMASequencer::MemSlavePort::MemSlavePort(const std::string &_name,
78    DMASequencer *_port, PortID id, RubySystem* _ruby_system,
79    bool _access_backing_store)
80    : QueuedSlavePort(_name, _port, queue, id), queue(*_port, *this),
81      m_ruby_system(_ruby_system), access_backing_store(_access_backing_store)
82{
83    DPRINTF(RubyDma, "Created slave memport on ruby sequencer %s\n", _name);
84}
85
86bool
87DMASequencer::MemSlavePort::recvTimingReq(PacketPtr pkt)
88{
89    DPRINTF(RubyDma, "Timing request for address %#x on port %d\n",
90            pkt->getAddr(), id);
91    DMASequencer *seq = static_cast<DMASequencer *>(&owner);
92
93    if (pkt->memInhibitAsserted())
94        panic("DMASequencer should never see an inhibited request\n");
95
96    assert(isPhysMemAddress(pkt->getAddr()));
97    assert(getOffset(pkt->getAddr()) + pkt->getSize() <=
98           RubySystem::getBlockSizeBytes());
99
100    // Submit the ruby request
101    RequestStatus requestStatus = seq->makeRequest(pkt);
102
103    // If the request successfully issued then we should return true.
104    // Otherwise, we need to tell the port to retry at a later point
105    // and return false.
106    if (requestStatus == RequestStatus_Issued) {
107        DPRINTF(RubyDma, "Request %s 0x%x issued\n", pkt->cmdString(),
108                pkt->getAddr());
109        return true;
110    }
111
112    // Unless one is using the ruby tester, record the stalled M5 port for
113    // later retry when the sequencer becomes free.
114    if (!seq->m_usingRubyTester) {
115        seq->retry = true;
116    }
117
118    DPRINTF(RubyDma, "Request for address %#x did not issued because %s\n",
119            pkt->getAddr(), RequestStatus_to_string(requestStatus));
120
121    return false;
122}
123
124void
125DMASequencer::ruby_hit_callback(PacketPtr pkt)
126{
127    DPRINTF(RubyDma, "Hit callback for %s 0x%x\n", pkt->cmdString(),
128            pkt->getAddr());
129
130    // The packet was destined for memory and has not yet been turned
131    // into a response
132    assert(system->isMemAddr(pkt->getAddr()));
133    assert(pkt->isRequest());
134    slave_port.hitCallback(pkt);
135
136    // If we had to stall the slave ports, wake it up because
137    // the sequencer likely has free resources now.
138    if (retry) {
139        retry = false;
140        DPRINTF(RubyDma,"Sequencer may now be free.  SendRetry to port %s\n",
141                slave_port.name());
142        slave_port.sendRetryReq();
143    }
144
145    testDrainComplete();
146}
147
148void
149DMASequencer::testDrainComplete()
150{
151    //If we weren't able to drain before, we might be able to now.
152    if (drainState() == DrainState::Draining) {
153        unsigned int drainCount = outstandingCount();
154        DPRINTF(Drain, "Drain count: %u\n", drainCount);
155        if (drainCount == 0) {
156            DPRINTF(Drain, "DMASequencer done draining, signaling drain done\n");
157            signalDrainDone();
158        }
159    }
160}
161
162DrainState
163DMASequencer::drain()
164{
165    if (isDeadlockEventScheduled()) {
166        descheduleDeadlockEvent();
167    }
168
169    // If the DMASequencer is not empty, then it needs to clear all outstanding
170    // requests before it should call signalDrainDone()
171    DPRINTF(Config, "outstanding count %d\n", outstandingCount());
172
173    // Set status
174    if (outstandingCount() > 0) {
175        DPRINTF(Drain, "DMASequencer not drained\n");
176        return DrainState::Draining;
177    } else {
178        return DrainState::Drained;
179    }
180}
181
182void
183DMASequencer::MemSlavePort::hitCallback(PacketPtr pkt)
184{
185    bool needsResponse = pkt->needsResponse();
186    assert(!pkt->isLLSC());
187    assert(!pkt->isFlush());
188
189    DPRINTF(RubyDma, "Hit callback needs response %d\n", needsResponse);
190
191    // turn packet around to go back to requester if response expected
192
193    if (access_backing_store) {
194        m_ruby_system->getPhysMem()->access(pkt);
195    } else if (needsResponse) {
196        pkt->makeResponse();
197    }
198
199    if (needsResponse) {
200        DPRINTF(RubyDma, "Sending packet back over port\n");
201        // send next cycle
202        DMASequencer *seq = static_cast<DMASequencer *>(&owner);
203        RubySystem *rs = seq->m_ruby_system;
204        schedTimingResp(pkt, curTick() + rs->clockPeriod());
205    } else {
206        delete pkt;
207    }
208
209    DPRINTF(RubyDma, "Hit callback done!\n");
210}
211
212bool
213DMASequencer::MemSlavePort::isPhysMemAddress(Addr addr) const
214{
215    DMASequencer *seq = static_cast<DMASequencer *>(&owner);
216    return seq->system->isMemAddr(addr);
217}
218
219RequestStatus
220DMASequencer::makeRequest(PacketPtr pkt)
221{
222    if (m_is_busy) {
223        return RequestStatus_BufferFull;
224    }
225
226    Addr paddr = pkt->getAddr();
227    uint8_t* data =  pkt->getPtr<uint8_t>();
228    int len = pkt->getSize();
229    bool write = pkt->isWrite();
230
231    assert(!m_is_busy);  // only support one outstanding DMA request
232    m_is_busy = true;
233
234    active_request.start_paddr = paddr;
235    active_request.write = write;
236    active_request.data = data;
237    active_request.len = len;
238    active_request.bytes_completed = 0;
239    active_request.bytes_issued = 0;
240    active_request.pkt = pkt;
241
242    std::shared_ptr<SequencerMsg> msg =
243        std::make_shared<SequencerMsg>(clockEdge());
244    msg->getPhysicalAddress() = paddr;
245    msg->getLineAddress() = makeLineAddress(msg->getPhysicalAddress());
246    msg->getType() = write ? SequencerRequestType_ST : SequencerRequestType_LD;
247    int offset = paddr & m_data_block_mask;
248
249    msg->getLen() = (offset + len) <= RubySystem::getBlockSizeBytes() ?
250        len : RubySystem::getBlockSizeBytes() - offset;
251
252    if (write && (data != NULL)) {
253        if (active_request.data != NULL) {
254            msg->getDataBlk().setData(data, offset, msg->getLen());
255        }
256    }
257
258    assert(m_mandatory_q_ptr != NULL);
259    m_mandatory_q_ptr->enqueue(msg);
260    active_request.bytes_issued += msg->getLen();
261
262    return RequestStatus_Issued;
263}
264
265void
266DMASequencer::issueNext()
267{
268    assert(m_is_busy);
269    active_request.bytes_completed = active_request.bytes_issued;
270    if (active_request.len == active_request.bytes_completed) {
271        //
272        // Must unset the busy flag before calling back the dma port because
273        // the callback may cause a previously nacked request to be reissued
274        //
275        DPRINTF(RubyDma, "DMA request completed\n");
276        m_is_busy = false;
277        ruby_hit_callback(active_request.pkt);
278        return;
279    }
280
281    std::shared_ptr<SequencerMsg> msg =
282        std::make_shared<SequencerMsg>(clockEdge());
283    msg->getPhysicalAddress() = active_request.start_paddr +
284                                active_request.bytes_completed;
285
286    assert((msg->getPhysicalAddress() & m_data_block_mask) == 0);
287    msg->getLineAddress() = makeLineAddress(msg->getPhysicalAddress());
288
289    msg->getType() = (active_request.write ? SequencerRequestType_ST :
290                     SequencerRequestType_LD);
291
292    msg->getLen() =
293        (active_request.len -
294         active_request.bytes_completed < RubySystem::getBlockSizeBytes() ?
295         active_request.len - active_request.bytes_completed :
296         RubySystem::getBlockSizeBytes());
297
298    if (active_request.write) {
299        msg->getDataBlk().
300            setData(&active_request.data[active_request.bytes_completed],
301                    0, msg->getLen());
302    }
303
304    assert(m_mandatory_q_ptr != NULL);
305    m_mandatory_q_ptr->enqueue(msg);
306    active_request.bytes_issued += msg->getLen();
307    DPRINTF(RubyDma,
308            "DMA request bytes issued %d, bytes completed %d, total len %d\n",
309            active_request.bytes_issued, active_request.bytes_completed,
310            active_request.len);
311}
312
313void
314DMASequencer::dataCallback(const DataBlock & dblk)
315{
316    assert(m_is_busy);
317    int len = active_request.bytes_issued - active_request.bytes_completed;
318    int offset = 0;
319    if (active_request.bytes_completed == 0)
320        offset = active_request.start_paddr & m_data_block_mask;
321    assert(!active_request.write);
322    if (active_request.data != NULL) {
323        memcpy(&active_request.data[active_request.bytes_completed],
324               dblk.getData(offset, len), len);
325    }
326    issueNext();
327}
328
329void
330DMASequencer::ackCallback()
331{
332    issueNext();
333}
334
335void
336DMASequencer::recordRequestType(DMASequencerRequestType requestType)
337{
338    DPRINTF(RubyStats, "Recorded statistic: %s\n",
339            DMASequencerRequestType_to_string(requestType));
340}
341
342DMASequencer *
343DMASequencerParams::create()
344{
345    return new DMASequencer(this);
346}
347