atomic.cc revision 8229 
1/*
2 * Copyright (c) 2002-2005 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: Steve Reinhardt
29 */
30
31#include "arch/locked_mem.hh"
32#include "arch/mmapped_ipr.hh"
33#include "arch/utility.hh"
34#include "base/bigint.hh"
35#include "config/the_isa.hh"
36#include "cpu/simple/atomic.hh"
37#include "cpu/exetrace.hh"
38#include "mem/packet.hh"
39#include "mem/packet_access.hh"
40#include "params/AtomicSimpleCPU.hh"
41#include "sim/faults.hh"
42#include "sim/system.hh"
43
44using namespace std;
45using namespace TheISA;
46
47AtomicSimpleCPU::TickEvent::TickEvent(AtomicSimpleCPU *c)
48    : Event(CPU_Tick_Pri), cpu(c)
49{
50}
51
52
53void
54AtomicSimpleCPU::TickEvent::process()
55{
56    cpu->tick();
57}
58
59const char *
60AtomicSimpleCPU::TickEvent::description() const
61{
62    return "AtomicSimpleCPU tick";
63}
64
65Port *
66AtomicSimpleCPU::getPort(const string &if_name, int idx)
67{
68    if (if_name == "dcache_port")
69        return &dcachePort;
70    else if (if_name == "icache_port")
71        return &icachePort;
72    else if (if_name == "physmem_port") {
73        hasPhysMemPort = true;
74        return &physmemPort;
75    }
76    else
77        panic("No Such Port\n");
78}
79
80void
81AtomicSimpleCPU::init()
82{
83    BaseCPU::init();
84#if FULL_SYSTEM
85    ThreadID size = threadContexts.size();
86    for (ThreadID i = 0; i < size; ++i) {
87        ThreadContext *tc = threadContexts[i];
88
89        // initialize CPU, including PC
90        TheISA::initCPU(tc, tc->contextId());
91    }
92#endif
93    if (hasPhysMemPort) {
94        bool snoop = false;
95        AddrRangeList pmAddrList;
96        physmemPort.getPeerAddressRanges(pmAddrList, snoop);
97        physMemAddr = *pmAddrList.begin();
98    }
99    // Atomic doesn't do MT right now, so contextId == threadId
100    ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
101    data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
102    data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
103}
104
105bool
106AtomicSimpleCPU::CpuPort::recvTiming(PacketPtr pkt)
107{
108    panic("AtomicSimpleCPU doesn't expect recvTiming callback!");
109    return true;
110}
111
112Tick
113AtomicSimpleCPU::CpuPort::recvAtomic(PacketPtr pkt)
114{
115    //Snooping a coherence request, just return
116    return 0;
117}
118
119void
120AtomicSimpleCPU::CpuPort::recvFunctional(PacketPtr pkt)
121{
122    //No internal storage to update, just return
123    return;
124}
125
126void
127AtomicSimpleCPU::CpuPort::recvStatusChange(Status status)
128{
129    if (status == RangeChange) {
130        if (!snoopRangeSent) {
131            snoopRangeSent = true;
132            sendStatusChange(Port::RangeChange);
133        }
134        return;
135    }
136
137    panic("AtomicSimpleCPU doesn't expect recvStatusChange callback!");
138}
139
140void
141AtomicSimpleCPU::CpuPort::recvRetry()
142{
143    panic("AtomicSimpleCPU doesn't expect recvRetry callback!");
144}
145
146void
147AtomicSimpleCPU::DcachePort::setPeer(Port *port)
148{
149    Port::setPeer(port);
150
151#if FULL_SYSTEM
152    // Update the ThreadContext's memory ports (Functional/Virtual
153    // Ports)
154    cpu->tcBase()->connectMemPorts(cpu->tcBase());
155#endif
156}
157
158AtomicSimpleCPU::AtomicSimpleCPU(AtomicSimpleCPUParams *p)
159    : BaseSimpleCPU(p), tickEvent(this), width(p->width), locked(false),
160      simulate_data_stalls(p->simulate_data_stalls),
161      simulate_inst_stalls(p->simulate_inst_stalls),
162      icachePort(name() + "-iport", this), dcachePort(name() + "-iport", this),
163      physmemPort(name() + "-iport", this), hasPhysMemPort(false)
164{
165    _status = Idle;
166
167    icachePort.snoopRangeSent = false;
168    dcachePort.snoopRangeSent = false;
169
170}
171
172
173AtomicSimpleCPU::~AtomicSimpleCPU()
174{
175    if (tickEvent.scheduled()) {
176        deschedule(tickEvent);
177    }
178}
179
180void
181AtomicSimpleCPU::serialize(ostream &os)
182{
183    SimObject::State so_state = SimObject::getState();
184    SERIALIZE_ENUM(so_state);
185    SERIALIZE_SCALAR(locked);
186    BaseSimpleCPU::serialize(os);
187    nameOut(os, csprintf("%s.tickEvent", name()));
188    tickEvent.serialize(os);
189}
190
191void
192AtomicSimpleCPU::unserialize(Checkpoint *cp, const string &section)
193{
194    SimObject::State so_state;
195    UNSERIALIZE_ENUM(so_state);
196    UNSERIALIZE_SCALAR(locked);
197    BaseSimpleCPU::unserialize(cp, section);
198    tickEvent.unserialize(cp, csprintf("%s.tickEvent", section));
199}
200
201void
202AtomicSimpleCPU::resume()
203{
204    if (_status == Idle || _status == SwitchedOut)
205        return;
206
207    DPRINTF(SimpleCPU, "Resume\n");
208    assert(system->getMemoryMode() == Enums::atomic);
209
210    changeState(SimObject::Running);
211    if (thread->status() == ThreadContext::Active) {
212        if (!tickEvent.scheduled())
213            schedule(tickEvent, nextCycle());
214    }
215    system->totalNumInsts = 0;
216}
217
218void
219AtomicSimpleCPU::switchOut()
220{
221    assert(_status == Running || _status == Idle);
222    _status = SwitchedOut;
223
224    tickEvent.squash();
225}
226
227
228void
229AtomicSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
230{
231    BaseCPU::takeOverFrom(oldCPU, &icachePort, &dcachePort);
232
233    assert(!tickEvent.scheduled());
234
235    // if any of this CPU's ThreadContexts are active, mark the CPU as
236    // running and schedule its tick event.
237    ThreadID size = threadContexts.size();
238    for (ThreadID i = 0; i < size; ++i) {
239        ThreadContext *tc = threadContexts[i];
240        if (tc->status() == ThreadContext::Active && _status != Running) {
241            _status = Running;
242            schedule(tickEvent, nextCycle());
243            break;
244        }
245    }
246    if (_status != Running) {
247        _status = Idle;
248    }
249    assert(threadContexts.size() == 1);
250    ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
251    data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
252    data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
253}
254
255
256void
257AtomicSimpleCPU::activateContext(int thread_num, int delay)
258{
259    DPRINTF(SimpleCPU, "ActivateContext %d (%d cycles)\n", thread_num, delay);
260
261    assert(thread_num == 0);
262    assert(thread);
263
264    assert(_status == Idle);
265    assert(!tickEvent.scheduled());
266
267    notIdleFraction++;
268    numCycles += tickToCycles(thread->lastActivate - thread->lastSuspend);
269
270    //Make sure ticks are still on multiples of cycles
271    schedule(tickEvent, nextCycle(curTick() + ticks(delay)));
272    _status = Running;
273}
274
275
276void
277AtomicSimpleCPU::suspendContext(int thread_num)
278{
279    DPRINTF(SimpleCPU, "SuspendContext %d\n", thread_num);
280
281    assert(thread_num == 0);
282    assert(thread);
283
284    if (_status == Idle)
285        return;
286
287    assert(_status == Running);
288
289    // tick event may not be scheduled if this gets called from inside
290    // an instruction's execution, e.g. "quiesce"
291    if (tickEvent.scheduled())
292        deschedule(tickEvent);
293
294    notIdleFraction--;
295    _status = Idle;
296}
297
298
299Fault
300AtomicSimpleCPU::readBytes(Addr addr, uint8_t * data,
301                           unsigned size, unsigned flags)
302{
303    // use the CPU's statically allocated read request and packet objects
304    Request *req = &data_read_req;
305
306    if (traceData) {
307        traceData->setAddr(addr);
308    }
309
310    //The block size of our peer.
311    unsigned blockSize = dcachePort.peerBlockSize();
312    //The size of the data we're trying to read.
313    int fullSize = size;
314
315    //The address of the second part of this access if it needs to be split
316    //across a cache line boundary.
317    Addr secondAddr = roundDown(addr + size - 1, blockSize);
318
319    if (secondAddr > addr)
320        size = secondAddr - addr;
321
322    dcache_latency = 0;
323
324    while (1) {
325        req->setVirt(0, addr, size, flags, thread->pcState().instAddr());
326
327        // translate to physical address
328        Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Read);
329
330        // Now do the access.
331        if (fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
332            Packet pkt = Packet(req,
333                    req->isLLSC() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
334                    Packet::Broadcast);
335            pkt.dataStatic(data);
336
337            if (req->isMmappedIpr())
338                dcache_latency += TheISA::handleIprRead(thread->getTC(), &pkt);
339            else {
340                if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
341                    dcache_latency += physmemPort.sendAtomic(&pkt);
342                else
343                    dcache_latency += dcachePort.sendAtomic(&pkt);
344            }
345            dcache_access = true;
346
347            assert(!pkt.isError());
348
349            if (req->isLLSC()) {
350                TheISA::handleLockedRead(thread, req);
351            }
352        }
353
354        //If there's a fault, return it
355        if (fault != NoFault) {
356            if (req->isPrefetch()) {
357                return NoFault;
358            } else {
359                return fault;
360            }
361        }
362
363        //If we don't need to access a second cache line, stop now.
364        if (secondAddr <= addr)
365        {
366            if (req->isLocked() && fault == NoFault) {
367                assert(!locked);
368                locked = true;
369            }
370            return fault;
371        }
372
373        /*
374         * Set up for accessing the second cache line.
375         */
376
377        //Move the pointer we're reading into to the correct location.
378        data += size;
379        //Adjust the size to get the remaining bytes.
380        size = addr + fullSize - secondAddr;
381        //And access the right address.
382        addr = secondAddr;
383    }
384}
385
386
387template <class T>
388Fault
389AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
390{
391    uint8_t *dataPtr = (uint8_t *)&data;
392    memset(dataPtr, 0, sizeof(data));
393    Fault fault = readBytes(addr, dataPtr, sizeof(data), flags);
394    if (fault == NoFault) {
395        data = gtoh(data);
396        if (traceData)
397            traceData->setData(data);
398    }
399    return fault;
400}
401
402#ifndef DOXYGEN_SHOULD_SKIP_THIS
403
404template
405Fault
406AtomicSimpleCPU::read(Addr addr, Twin32_t &data, unsigned flags);
407
408template
409Fault
410AtomicSimpleCPU::read(Addr addr, Twin64_t &data, unsigned flags);
411
412template
413Fault
414AtomicSimpleCPU::read(Addr addr, uint64_t &data, unsigned flags);
415
416template
417Fault
418AtomicSimpleCPU::read(Addr addr, uint32_t &data, unsigned flags);
419
420template
421Fault
422AtomicSimpleCPU::read(Addr addr, uint16_t &data, unsigned flags);
423
424template
425Fault
426AtomicSimpleCPU::read(Addr addr, uint8_t &data, unsigned flags);
427
428#endif //DOXYGEN_SHOULD_SKIP_THIS
429
430template<>
431Fault
432AtomicSimpleCPU::read(Addr addr, double &data, unsigned flags)
433{
434    return read(addr, *(uint64_t*)&data, flags);
435}
436
437template<>
438Fault
439AtomicSimpleCPU::read(Addr addr, float &data, unsigned flags)
440{
441    return read(addr, *(uint32_t*)&data, flags);
442}
443
444
445template<>
446Fault
447AtomicSimpleCPU::read(Addr addr, int32_t &data, unsigned flags)
448{
449    return read(addr, (uint32_t&)data, flags);
450}
451
452
453Fault
454AtomicSimpleCPU::writeBytes(uint8_t *data, unsigned size,
455                            Addr addr, unsigned flags, uint64_t *res)
456{
457    // use the CPU's statically allocated write request and packet objects
458    Request *req = &data_write_req;
459
460    if (traceData) {
461        traceData->setAddr(addr);
462    }
463
464    //The block size of our peer.
465    unsigned blockSize = dcachePort.peerBlockSize();
466    //The size of the data we're trying to read.
467    int fullSize = size;
468
469    //The address of the second part of this access if it needs to be split
470    //across a cache line boundary.
471    Addr secondAddr = roundDown(addr + size - 1, blockSize);
472
473    if(secondAddr > addr)
474        size = secondAddr - addr;
475
476    dcache_latency = 0;
477
478    while(1) {
479        req->setVirt(0, addr, size, flags, thread->pcState().instAddr());
480
481        // translate to physical address
482        Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Write);
483
484        // Now do the access.
485        if (fault == NoFault) {
486            MemCmd cmd = MemCmd::WriteReq; // default
487            bool do_access = true;  // flag to suppress cache access
488
489            if (req->isLLSC()) {
490                cmd = MemCmd::StoreCondReq;
491                do_access = TheISA::handleLockedWrite(thread, req);
492            } else if (req->isSwap()) {
493                cmd = MemCmd::SwapReq;
494                if (req->isCondSwap()) {
495                    assert(res);
496                    req->setExtraData(*res);
497                }
498            }
499
500            if (do_access && !req->getFlags().isSet(Request::NO_ACCESS)) {
501                Packet pkt = Packet(req, cmd, Packet::Broadcast);
502                pkt.dataStatic(data);
503
504                if (req->isMmappedIpr()) {
505                    dcache_latency +=
506                        TheISA::handleIprWrite(thread->getTC(), &pkt);
507                } else {
508                    if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
509                        dcache_latency += physmemPort.sendAtomic(&pkt);
510                    else
511                        dcache_latency += dcachePort.sendAtomic(&pkt);
512                }
513                dcache_access = true;
514                assert(!pkt.isError());
515
516                if (req->isSwap()) {
517                    assert(res);
518                    memcpy(res, pkt.getPtr<uint8_t>(), fullSize);
519                }
520            }
521
522            if (res && !req->isSwap()) {
523                *res = req->getExtraData();
524            }
525        }
526
527        //If there's a fault or we don't need to access a second cache line,
528        //stop now.
529        if (fault != NoFault || secondAddr <= addr)
530        {
531            if (req->isLocked() && fault == NoFault) {
532                assert(locked);
533                locked = false;
534            }
535            if (fault != NoFault && req->isPrefetch()) {
536                return NoFault;
537            } else {
538                return fault;
539            }
540        }
541
542        /*
543         * Set up for accessing the second cache line.
544         */
545
546        //Move the pointer we're reading into to the correct location.
547        data += size;
548        //Adjust the size to get the remaining bytes.
549        size = addr + fullSize - secondAddr;
550        //And access the right address.
551        addr = secondAddr;
552    }
553}
554
555
556template <class T>
557Fault
558AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
559{
560    uint8_t *dataPtr = (uint8_t *)&data;
561    if (traceData)
562        traceData->setData(data);
563    data = htog(data);
564
565    Fault fault = writeBytes(dataPtr, sizeof(data), addr, flags, res);
566    if (fault == NoFault && data_write_req.isSwap()) {
567        *res = gtoh((T)*res);
568    }
569    return fault;
570}
571
572
573#ifndef DOXYGEN_SHOULD_SKIP_THIS
574
575template
576Fault
577AtomicSimpleCPU::write(Twin32_t data, Addr addr,
578                       unsigned flags, uint64_t *res);
579
580template
581Fault
582AtomicSimpleCPU::write(Twin64_t data, Addr addr,
583                       unsigned flags, uint64_t *res);
584
585template
586Fault
587AtomicSimpleCPU::write(uint64_t data, Addr addr,
588                       unsigned flags, uint64_t *res);
589
590template
591Fault
592AtomicSimpleCPU::write(uint32_t data, Addr addr,
593                       unsigned flags, uint64_t *res);
594
595template
596Fault
597AtomicSimpleCPU::write(uint16_t data, Addr addr,
598                       unsigned flags, uint64_t *res);
599
600template
601Fault
602AtomicSimpleCPU::write(uint8_t data, Addr addr,
603                       unsigned flags, uint64_t *res);
604
605#endif //DOXYGEN_SHOULD_SKIP_THIS
606
607template<>
608Fault
609AtomicSimpleCPU::write(double data, Addr addr, unsigned flags, uint64_t *res)
610{
611    return write(*(uint64_t*)&data, addr, flags, res);
612}
613
614template<>
615Fault
616AtomicSimpleCPU::write(float data, Addr addr, unsigned flags, uint64_t *res)
617{
618    return write(*(uint32_t*)&data, addr, flags, res);
619}
620
621
622template<>
623Fault
624AtomicSimpleCPU::write(int32_t data, Addr addr, unsigned flags, uint64_t *res)
625{
626    return write((uint32_t)data, addr, flags, res);
627}
628
629
630void
631AtomicSimpleCPU::tick()
632{
633    DPRINTF(SimpleCPU, "Tick\n");
634
635    Tick latency = 0;
636
637    for (int i = 0; i < width || locked; ++i) {
638        numCycles++;
639
640        if (!curStaticInst || !curStaticInst->isDelayedCommit())
641            checkForInterrupts();
642
643        checkPcEventQueue();
644        // We must have just got suspended by a PC event
645        if (_status == Idle)
646            return;
647
648        Fault fault = NoFault;
649
650        TheISA::PCState pcState = thread->pcState();
651
652        bool needToFetch = !isRomMicroPC(pcState.microPC()) &&
653                           !curMacroStaticInst;
654        if (needToFetch) {
655            setupFetchRequest(&ifetch_req);
656            fault = thread->itb->translateAtomic(&ifetch_req, tc,
657                                                 BaseTLB::Execute);
658        }
659
660        if (fault == NoFault) {
661            Tick icache_latency = 0;
662            bool icache_access = false;
663            dcache_access = false; // assume no dcache access
664
665            if (needToFetch) {
666                // This is commented out because the predecoder would act like
667                // a tiny cache otherwise. It wouldn't be flushed when needed
668                // like the I cache. It should be flushed, and when that works
669                // this code should be uncommented.
670                //Fetch more instruction memory if necessary
671                //if(predecoder.needMoreBytes())
672                //{
673                    icache_access = true;
674                    Packet ifetch_pkt = Packet(&ifetch_req, MemCmd::ReadReq,
675                                               Packet::Broadcast);
676                    ifetch_pkt.dataStatic(&inst);
677
678                    if (hasPhysMemPort && ifetch_pkt.getAddr() == physMemAddr)
679                        icache_latency = physmemPort.sendAtomic(&ifetch_pkt);
680                    else
681                        icache_latency = icachePort.sendAtomic(&ifetch_pkt);
682
683                    assert(!ifetch_pkt.isError());
684
685                    // ifetch_req is initialized to read the instruction directly
686                    // into the CPU object's inst field.
687                //}
688            }
689
690            preExecute();
691
692            if (curStaticInst) {
693                fault = curStaticInst->execute(this, traceData);
694
695                // keep an instruction count
696                if (fault == NoFault)
697                    countInst();
698                else if (traceData && !DTRACE(ExecFaulting)) {
699                    delete traceData;
700                    traceData = NULL;
701                }
702
703                postExecute();
704            }
705
706            // @todo remove me after debugging with legion done
707            if (curStaticInst && (!curStaticInst->isMicroop() ||
708                        curStaticInst->isFirstMicroop()))
709                instCnt++;
710
711            Tick stall_ticks = 0;
712            if (simulate_inst_stalls && icache_access)
713                stall_ticks += icache_latency;
714
715            if (simulate_data_stalls && dcache_access)
716                stall_ticks += dcache_latency;
717
718            if (stall_ticks) {
719                Tick stall_cycles = stall_ticks / ticks(1);
720                Tick aligned_stall_ticks = ticks(stall_cycles);
721
722                if (aligned_stall_ticks < stall_ticks)
723                    aligned_stall_ticks += 1;
724
725                latency += aligned_stall_ticks;
726            }
727
728        }
729        if(fault != NoFault || !stayAtPC)
730            advancePC(fault);
731    }
732
733    // instruction takes at least one cycle
734    if (latency < ticks(1))
735        latency = ticks(1);
736
737    if (_status != Idle)
738        schedule(tickEvent, curTick() + latency);
739}
740
741
742void
743AtomicSimpleCPU::printAddr(Addr a)
744{
745    dcachePort.printAddr(a);
746}
747
748
749////////////////////////////////////////////////////////////////////////
750//
751//  AtomicSimpleCPU Simulation Object
752//
753AtomicSimpleCPU *
754AtomicSimpleCPUParams::create()
755{
756    numThreads = 1;
757#if !FULL_SYSTEM
758    if (workload.size() != 1)
759        panic("only one workload allowed");
760#endif
761    return new AtomicSimpleCPU(this);
762}
763