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 "debug/ExecFaulting.hh"
39#include "debug/SimpleCPU.hh"
40#include "mem/packet.hh"
41#include "mem/packet_access.hh"
42#include "params/AtomicSimpleCPU.hh"
43#include "sim/faults.hh"
44#include "sim/system.hh"
45#include "sim/full_system.hh"
46
47using namespace std;
48using namespace TheISA;
49
50AtomicSimpleCPU::TickEvent::TickEvent(AtomicSimpleCPU *c)
51 : Event(CPU_Tick_Pri), cpu(c)
52{
53}
54
55
56void
57AtomicSimpleCPU::TickEvent::process()
58{
59 cpu->tick();
60}
61
62const char *
63AtomicSimpleCPU::TickEvent::description() const
64{
65 return "AtomicSimpleCPU tick";
66}
67
68Port *
69AtomicSimpleCPU::getPort(const string &if_name, int idx)
70{
71 if (if_name == "dcache_port")
72 return &dcachePort;
73 else if (if_name == "icache_port")
74 return &icachePort;
75 else if (if_name == "physmem_port") {
76 hasPhysMemPort = true;
77 return &physmemPort;
78 }
79 else
80 panic("No Such Port\n");
81}
82
83void
84AtomicSimpleCPU::init()
85{
86 BaseCPU::init();
87 if (FullSystem) {
88 ThreadID size = threadContexts.size();
89 for (ThreadID i = 0; i < size; ++i) {
90 ThreadContext *tc = threadContexts[i];
91 // initialize CPU, including PC
92 TheISA::initCPU(tc, tc->contextId());
93 }
94 }
95
96 // Initialise the ThreadContext's memory proxies
97 tcBase()->initMemProxies(tcBase());
98
99 if (hasPhysMemPort) {
100 AddrRangeList pmAddrList = physmemPort.getPeer()->getAddrRanges();
101 physMemAddr = *pmAddrList.begin();
102 }
103 // Atomic doesn't do MT right now, so contextId == threadId
104 ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
105 data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
106 data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
107}
108
109AtomicSimpleCPU::AtomicSimpleCPU(AtomicSimpleCPUParams *p)
110 : BaseSimpleCPU(p), tickEvent(this), width(p->width), locked(false),
111 simulate_data_stalls(p->simulate_data_stalls),
112 simulate_inst_stalls(p->simulate_inst_stalls),
113 icachePort(name() + "-iport", this), dcachePort(name() + "-iport", this),
114 physmemPort(name() + "-iport", this), hasPhysMemPort(false)
115{
116 _status = Idle;
117}
118
119
120AtomicSimpleCPU::~AtomicSimpleCPU()
121{
122 if (tickEvent.scheduled()) {
123 deschedule(tickEvent);
124 }
125}
126
127void
128AtomicSimpleCPU::serialize(ostream &os)
129{
130 SimObject::State so_state = SimObject::getState();
131 SERIALIZE_ENUM(so_state);
132 SERIALIZE_SCALAR(locked);
133 BaseSimpleCPU::serialize(os);
134 nameOut(os, csprintf("%s.tickEvent", name()));
135 tickEvent.serialize(os);
136}
137
138void
139AtomicSimpleCPU::unserialize(Checkpoint *cp, const string &section)
140{
141 SimObject::State so_state;
142 UNSERIALIZE_ENUM(so_state);
143 UNSERIALIZE_SCALAR(locked);
144 BaseSimpleCPU::unserialize(cp, section);
145 tickEvent.unserialize(cp, csprintf("%s.tickEvent", section));
146}
147
148void
149AtomicSimpleCPU::resume()
150{
151 if (_status == Idle || _status == SwitchedOut)
152 return;
153
154 DPRINTF(SimpleCPU, "Resume\n");
155 assert(system->getMemoryMode() == Enums::atomic);
156
157 changeState(SimObject::Running);
158 if (thread->status() == ThreadContext::Active) {
159 if (!tickEvent.scheduled())
160 schedule(tickEvent, nextCycle());
161 }
162 system->totalNumInsts = 0;
163}
164
165void
166AtomicSimpleCPU::switchOut()
167{
168 assert(_status == Running || _status == Idle);
169 _status = SwitchedOut;
170
171 tickEvent.squash();
172}
173
174
175void
176AtomicSimpleCPU::takeOverFrom(BaseCPU *oldCPU)
177{
178 BaseCPU::takeOverFrom(oldCPU);
179
180 assert(!tickEvent.scheduled());
181
182 // if any of this CPU's ThreadContexts are active, mark the CPU as
183 // running and schedule its tick event.
184 ThreadID size = threadContexts.size();
185 for (ThreadID i = 0; i < size; ++i) {
186 ThreadContext *tc = threadContexts[i];
187 if (tc->status() == ThreadContext::Active && _status != Running) {
188 _status = Running;
189 schedule(tickEvent, nextCycle());
190 break;
191 }
192 }
193 if (_status != Running) {
194 _status = Idle;
195 }
196 assert(threadContexts.size() == 1);
197 ifetch_req.setThreadContext(_cpuId, 0); // Add thread ID if we add MT
198 data_read_req.setThreadContext(_cpuId, 0); // Add thread ID here too
199 data_write_req.setThreadContext(_cpuId, 0); // Add thread ID here too
200}
201
202
203void
204AtomicSimpleCPU::activateContext(ThreadID thread_num, int delay)
205{
206 DPRINTF(SimpleCPU, "ActivateContext %d (%d cycles)\n", thread_num, delay);
207
208 assert(thread_num == 0);
209 assert(thread);
210
211 assert(_status == Idle);
212 assert(!tickEvent.scheduled());
213
214 notIdleFraction++;
215 numCycles += tickToCycles(thread->lastActivate - thread->lastSuspend);
216
217 //Make sure ticks are still on multiples of cycles
218 schedule(tickEvent, nextCycle(curTick() + ticks(delay)));
219 _status = Running;
220}
221
222
223void
224AtomicSimpleCPU::suspendContext(ThreadID thread_num)
225{
226 DPRINTF(SimpleCPU, "SuspendContext %d\n", thread_num);
227
228 assert(thread_num == 0);
229 assert(thread);
230
231 if (_status == Idle)
232 return;
233
234 assert(_status == Running);
235
236 // tick event may not be scheduled if this gets called from inside
237 // an instruction's execution, e.g. "quiesce"
238 if (tickEvent.scheduled())
239 deschedule(tickEvent);
240
241 notIdleFraction--;
242 _status = Idle;
243}
244
245
246Fault
247AtomicSimpleCPU::readMem(Addr addr, uint8_t * data,
248 unsigned size, unsigned flags)
249{
250 // use the CPU's statically allocated read request and packet objects
251 Request *req = &data_read_req;
252
253 if (traceData) {
254 traceData->setAddr(addr);
255 }
256
257 //The block size of our peer.
258 unsigned blockSize = dcachePort.peerBlockSize();
259 //The size of the data we're trying to read.
260 int fullSize = size;
261
262 //The address of the second part of this access if it needs to be split
263 //across a cache line boundary.
264 Addr secondAddr = roundDown(addr + size - 1, blockSize);
265
266 if (secondAddr > addr)
267 size = secondAddr - addr;
268
269 dcache_latency = 0;
270
271 while (1) {
272 req->setVirt(0, addr, size, flags, dataMasterId(), thread->pcState().instAddr());
273
274 // translate to physical address
275 Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Read);
276
277 // Now do the access.
278 if (fault == NoFault && !req->getFlags().isSet(Request::NO_ACCESS)) {
279 Packet pkt = Packet(req,
280 req->isLLSC() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
281 Packet::Broadcast);
282 pkt.dataStatic(data);
283
284 if (req->isMmappedIpr())
285 dcache_latency += TheISA::handleIprRead(thread->getTC(), &pkt);
286 else {
287 if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
288 dcache_latency += physmemPort.sendAtomic(&pkt);
289 else
290 dcache_latency += dcachePort.sendAtomic(&pkt);
291 }
292 dcache_access = true;
293
294 assert(!pkt.isError());
295
296 if (req->isLLSC()) {
297 TheISA::handleLockedRead(thread, req);
298 }
299 }
300
301 //If there's a fault, return it
302 if (fault != NoFault) {
303 if (req->isPrefetch()) {
304 return NoFault;
305 } else {
306 return fault;
307 }
308 }
309
310 //If we don't need to access a second cache line, stop now.
311 if (secondAddr <= addr)
312 {
313 if (req->isLocked() && fault == NoFault) {
314 assert(!locked);
315 locked = true;
316 }
317 return fault;
318 }
319
320 /*
321 * Set up for accessing the second cache line.
322 */
323
324 //Move the pointer we're reading into to the correct location.
325 data += size;
326 //Adjust the size to get the remaining bytes.
327 size = addr + fullSize - secondAddr;
328 //And access the right address.
329 addr = secondAddr;
330 }
331}
332
333
334Fault
335AtomicSimpleCPU::writeMem(uint8_t *data, unsigned size,
336 Addr addr, unsigned flags, uint64_t *res)
337{
338 // use the CPU's statically allocated write request and packet objects
339 Request *req = &data_write_req;
340
341 if (traceData) {
342 traceData->setAddr(addr);
343 }
344
345 //The block size of our peer.
346 unsigned blockSize = dcachePort.peerBlockSize();
347 //The size of the data we're trying to read.
348 int fullSize = size;
349
350 //The address of the second part of this access if it needs to be split
351 //across a cache line boundary.
352 Addr secondAddr = roundDown(addr + size - 1, blockSize);
353
354 if(secondAddr > addr)
355 size = secondAddr - addr;
356
357 dcache_latency = 0;
358
359 while(1) {
360 req->setVirt(0, addr, size, flags, dataMasterId(), thread->pcState().instAddr());
361
362 // translate to physical address
363 Fault fault = thread->dtb->translateAtomic(req, tc, BaseTLB::Write);
364
365 // Now do the access.
366 if (fault == NoFault) {
367 MemCmd cmd = MemCmd::WriteReq; // default
368 bool do_access = true; // flag to suppress cache access
369
370 if (req->isLLSC()) {
371 cmd = MemCmd::StoreCondReq;
372 do_access = TheISA::handleLockedWrite(thread, req);
373 } else if (req->isSwap()) {
374 cmd = MemCmd::SwapReq;
375 if (req->isCondSwap()) {
376 assert(res);
377 req->setExtraData(*res);
378 }
379 }
380
381 if (do_access && !req->getFlags().isSet(Request::NO_ACCESS)) {
382 Packet pkt = Packet(req, cmd, Packet::Broadcast);
383 pkt.dataStatic(data);
384
385 if (req->isMmappedIpr()) {
386 dcache_latency +=
387 TheISA::handleIprWrite(thread->getTC(), &pkt);
388 } else {
389 if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
390 dcache_latency += physmemPort.sendAtomic(&pkt);
391 else
392 dcache_latency += dcachePort.sendAtomic(&pkt);
393 }
394 dcache_access = true;
395 assert(!pkt.isError());
396
397 if (req->isSwap()) {
398 assert(res);
399 memcpy(res, pkt.getPtr<uint8_t>(), fullSize);
400 }
401 }
402
403 if (res && !req->isSwap()) {
404 *res = req->getExtraData();
405 }
406 }
407
408 //If there's a fault or we don't need to access a second cache line,
409 //stop now.
410 if (fault != NoFault || secondAddr <= addr)
411 {
412 if (req->isLocked() && fault == NoFault) {
413 assert(locked);
414 locked = false;
415 }
416 if (fault != NoFault && req->isPrefetch()) {
417 return NoFault;
418 } else {
419 return fault;
420 }
421 }
422
423 /*
424 * Set up for accessing the second cache line.
425 */
426
427 //Move the pointer we're reading into to the correct location.
428 data += size;
429 //Adjust the size to get the remaining bytes.
430 size = addr + fullSize - secondAddr;
431 //And access the right address.
432 addr = secondAddr;
433 }
434}
435
436
437void
438AtomicSimpleCPU::tick()
439{
440 DPRINTF(SimpleCPU, "Tick\n");
441
442 Tick latency = 0;
443
444 for (int i = 0; i < width || locked; ++i) {
445 numCycles++;
446
447 if (!curStaticInst || !curStaticInst->isDelayedCommit())
448 checkForInterrupts();
449
450 checkPcEventQueue();
451 // We must have just got suspended by a PC event
452 if (_status == Idle)
453 return;
454
455 Fault fault = NoFault;
456
457 TheISA::PCState pcState = thread->pcState();
458
459 bool needToFetch = !isRomMicroPC(pcState.microPC()) &&
460 !curMacroStaticInst;
461 if (needToFetch) {
462 setupFetchRequest(&ifetch_req);
463 fault = thread->itb->translateAtomic(&ifetch_req, tc,
464 BaseTLB::Execute);
465 }
466
467 if (fault == NoFault) {
468 Tick icache_latency = 0;
469 bool icache_access = false;
470 dcache_access = false; // assume no dcache access
471
472 if (needToFetch) {
473 // This is commented out because the predecoder would act like
474 // a tiny cache otherwise. It wouldn't be flushed when needed
475 // like the I cache. It should be flushed, and when that works
476 // this code should be uncommented.
477 //Fetch more instruction memory if necessary
478 //if(predecoder.needMoreBytes())
479 //{
480 icache_access = true;
481 Packet ifetch_pkt = Packet(&ifetch_req, MemCmd::ReadReq,
482 Packet::Broadcast);
483 ifetch_pkt.dataStatic(&inst);
484
485 if (hasPhysMemPort && ifetch_pkt.getAddr() == physMemAddr)
486 icache_latency = physmemPort.sendAtomic(&ifetch_pkt);
487 else
488 icache_latency = icachePort.sendAtomic(&ifetch_pkt);
489
490 assert(!ifetch_pkt.isError());
491
492 // ifetch_req is initialized to read the instruction directly
493 // into the CPU object's inst field.
494 //}
495 }
496
497 preExecute();
498
499 if (curStaticInst) {
500 fault = curStaticInst->execute(this, traceData);
501
502 // keep an instruction count
503 if (fault == NoFault)
504 countInst();
505 else if (traceData && !DTRACE(ExecFaulting)) {
506 delete traceData;
507 traceData = NULL;
508 }
509
510 postExecute();
511 }
512
513 // @todo remove me after debugging with legion done
514 if (curStaticInst && (!curStaticInst->isMicroop() ||
515 curStaticInst->isFirstMicroop()))
516 instCnt++;
517
518 Tick stall_ticks = 0;
519 if (simulate_inst_stalls && icache_access)
520 stall_ticks += icache_latency;
521
522 if (simulate_data_stalls && dcache_access)
523 stall_ticks += dcache_latency;
524
525 if (stall_ticks) {
526 Tick stall_cycles = stall_ticks / ticks(1);
527 Tick aligned_stall_ticks = ticks(stall_cycles);
528
529 if (aligned_stall_ticks < stall_ticks)
530 aligned_stall_ticks += 1;
531
532 latency += aligned_stall_ticks;
533 }
534
535 }
536 if(fault != NoFault || !stayAtPC)
537 advancePC(fault);
538 }
539
540 // instruction takes at least one cycle
541 if (latency < ticks(1))
542 latency = ticks(1);
543
544 if (_status != Idle)
545 schedule(tickEvent, curTick() + latency);
546}
547
548
549void
550AtomicSimpleCPU::printAddr(Addr a)
551{
552 dcachePort.printAddr(a);
553}
554
555
556////////////////////////////////////////////////////////////////////////
557//
558// AtomicSimpleCPU Simulation Object
559//
560AtomicSimpleCPU *
561AtomicSimpleCPUParams::create()
562{
563 numThreads = 1;
564 if (!FullSystem && workload.size() != 1)
565 panic("only one workload allowed");
566 return new AtomicSimpleCPU(this);
567}