gem5/src/cpu/inorder/resource.cc
Steve Reinhardt 214cc0fafc inorder: get rid of references to mainEventQueue.
Events need to be scheduled on the queue assigned
to the SimObject, not on the global queue (which
should be going away).
Also cleaned up a number of redundant expressions
that made the code unnecessarily verbose.
2011-01-07 21:50:29 -08:00

512 lines
13 KiB
C++

/*
* Copyright (c) 2007 MIPS Technologies, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Korey Sewell
*
*/
#include <vector>
#include <list>
#include "cpu/inorder/resource.hh"
#include "cpu/inorder/cpu.hh"
using namespace std;
Resource::Resource(string res_name, int res_id, int res_width,
int res_latency, InOrderCPU *_cpu)
: resName(res_name), id(res_id),
width(res_width), latency(res_latency), cpu(_cpu)
{
// Use to deny a instruction a resource.
deniedReq = new ResourceRequest(this, NULL, 0, 0, 0, 0);
}
Resource::~Resource()
{
delete [] resourceEvent;
delete deniedReq;
}
void
Resource::init()
{
// Set Up Resource Events to Appropriate Resource BandWidth
resourceEvent = new ResourceEvent[width];
initSlots();
}
void
Resource::initSlots()
{
// Add available slot numbers for resource
for (int slot_idx = 0; slot_idx < width; slot_idx++) {
availSlots.push_back(slot_idx);
resourceEvent[slot_idx].init(this, slot_idx);
}
}
std::string
Resource::name()
{
return cpu->name() + "." + resName;
}
int
Resource::slotsAvail()
{
return availSlots.size();
}
int
Resource::slotsInUse()
{
return width - availSlots.size();
}
void
Resource::freeSlot(int slot_idx)
{
// Put slot number on this resource's free list
availSlots.push_back(slot_idx);
// Erase Request Pointer From Request Map
std::map<int, ResReqPtr>::iterator req_it = reqMap.find(slot_idx);
assert(req_it != reqMap.end());
reqMap.erase(req_it);
}
// TODO: More efficiently search for instruction's slot within
// resource.
int
Resource::findSlot(DynInstPtr inst)
{
map<int, ResReqPtr>::iterator map_it = reqMap.begin();
map<int, ResReqPtr>::iterator map_end = reqMap.end();
int slot_num = -1;
while (map_it != map_end) {
if ((*map_it).second->getInst()->seqNum ==
inst->seqNum) {
slot_num = (*map_it).second->getSlot();
}
map_it++;
}
return slot_num;
}
int
Resource::getSlot(DynInstPtr inst)
{
int slot_num;
if (slotsAvail() != 0) {
slot_num = availSlots[0];
vector<int>::iterator vect_it = availSlots.begin();
assert(slot_num == *vect_it);
availSlots.erase(vect_it);
} else {
DPRINTF(Resource, "[tid:%i]: No slots in resource "
"available to service [sn:%i].\n", inst->readTid(),
inst->seqNum);
slot_num = -1;
map<int, ResReqPtr>::iterator map_it = reqMap.begin();
map<int, ResReqPtr>::iterator map_end = reqMap.end();
while (map_it != map_end) {
if ((*map_it).second) {
DPRINTF(Resource, "Currently Serving request from: "
"[tid:%i] [sn:%i].\n",
(*map_it).second->getInst()->readTid(),
(*map_it).second->getInst()->seqNum);
}
map_it++;
}
}
return slot_num;
}
ResReqPtr
Resource::request(DynInstPtr inst)
{
// See if the resource is already serving this instruction.
// If so, use that request;
bool try_request = false;
int slot_num = -1;
int stage_num;
ResReqPtr inst_req = findRequest(inst);
if (inst_req) {
// If some preprocessing has to be done on instruction
// that has already requested once, then handle it here.
// update the 'try_request' variable if we should
// re-execute the request.
requestAgain(inst, try_request);
slot_num = inst_req->getSlot();
stage_num = inst_req->getStageNum();
} else {
// Get new slot # for instruction
slot_num = getSlot(inst);
if (slot_num != -1) {
// Get Stage # from Schedule Entry
stage_num = inst->resSched.top()->stageNum;
unsigned cmd = inst->resSched.top()->cmd;
// Generate Resource Request
inst_req = getRequest(inst, stage_num, id, slot_num, cmd);
if (inst->staticInst) {
DPRINTF(Resource, "[tid:%i]: [sn:%i] requesting this "
"resource.\n",
inst->readTid(), inst->seqNum);
} else {
DPRINTF(Resource, "[tid:%i]: instruction requesting this "
"resource.\n",
inst->readTid());
}
reqMap[slot_num] = inst_req;
try_request = true;
}
}
if (try_request) {
// Schedule execution of resource
scheduleExecution(slot_num);
} else {
inst_req = deniedReq;
rejectRequest(inst);
}
return inst_req;
}
void
Resource::requestAgain(DynInstPtr inst, bool &do_request)
{
do_request = true;
if (inst->staticInst) {
DPRINTF(Resource, "[tid:%i]: [sn:%i] requesting this resource "
"again.\n",
inst->readTid(), inst->seqNum);
} else {
DPRINTF(Resource, "[tid:%i]: requesting this resource again.\n",
inst->readTid());
}
}
ResReqPtr
Resource::getRequest(DynInstPtr inst, int stage_num, int res_idx,
int slot_num, unsigned cmd)
{
return new ResourceRequest(this, inst, stage_num, id, slot_num,
cmd);
}
ResReqPtr
Resource::findRequest(DynInstPtr inst)
{
map<int, ResReqPtr>::iterator map_it = reqMap.begin();
map<int, ResReqPtr>::iterator map_end = reqMap.end();
bool found = false;
ResReqPtr req = NULL;
while (map_it != map_end) {
if ((*map_it).second &&
(*map_it).second->getInst() == inst) {
req = (*map_it).second;
//return (*map_it).second;
assert(found == false);
found = true;
}
map_it++;
}
return req;
//return NULL;
}
void
Resource::rejectRequest(DynInstPtr inst)
{
DPRINTF(RefCount, "[tid:%i]: Unable to grant request for [sn:%i].\n",
inst->readTid(), inst->seqNum);
}
void
Resource::execute(int slot_idx)
{
DPRINTF(Resource, "[tid:%i]: Executing %s resource.\n",
reqMap[slot_idx]->getTid(), name());
reqMap[slot_idx]->setCompleted(true);
reqMap[slot_idx]->fault = NoFault;
reqMap[slot_idx]->done();
}
void
Resource::deactivateThread(ThreadID tid)
{
// In the most basic case, deactivation means squashing everything
// from a particular thread
DynInstPtr dummy_inst = new InOrderDynInst(cpu, NULL, 0, tid, tid);
squash(dummy_inst, 0, 0, tid);
}
void
Resource::squash(DynInstPtr inst, int stage_num, InstSeqNum squash_seq_num,
ThreadID tid)
{
std::vector<int> slot_remove_list;
map<int, ResReqPtr>::iterator map_it = reqMap.begin();
map<int, ResReqPtr>::iterator map_end = reqMap.end();
while (map_it != map_end) {
ResReqPtr req_ptr = (*map_it).second;
if (req_ptr &&
req_ptr->getInst()->readTid() == tid &&
req_ptr->getInst()->seqNum > squash_seq_num) {
DPRINTF(Resource, "[tid:%i]: Squashing [sn:%i].\n",
req_ptr->getInst()->readTid(),
req_ptr->getInst()->seqNum);
req_ptr->setSquashed();
int req_slot_num = req_ptr->getSlot();
if (resourceEvent[req_slot_num].scheduled())
unscheduleEvent(req_slot_num);
// Mark request for later removal
cpu->reqRemoveList.push(req_ptr);
// Mark slot for removal from resource
slot_remove_list.push_back(req_ptr->getSlot());
}
map_it++;
}
// Now Delete Slot Entry from Req. Map
for (int i = 0; i < slot_remove_list.size(); i++) {
freeSlot(slot_remove_list[i]);
}
}
void
Resource::squashDueToMemStall(DynInstPtr inst, int stage_num,
InstSeqNum squash_seq_num,
ThreadID tid)
{
squash(inst, stage_num, squash_seq_num, tid);
}
Tick
Resource::ticks(int num_cycles)
{
return cpu->ticks(num_cycles);
}
void
Resource::scheduleExecution(int slot_num)
{
int res_latency = getLatency(slot_num);
if (res_latency >= 1) {
scheduleEvent(slot_num, res_latency);
} else {
execute(slot_num);
}
}
void
Resource::scheduleEvent(int slot_idx, int delay)
{
DPRINTF(Resource, "[tid:%i]: Scheduling event for [sn:%i] on tick %i.\n",
reqMap[slot_idx]->inst->readTid(),
reqMap[slot_idx]->inst->seqNum,
cpu->ticks(delay) + curTick);
resourceEvent[slot_idx].scheduleEvent(delay);
}
bool
Resource::scheduleEvent(DynInstPtr inst, int delay)
{
int slot_idx = findSlot(inst);
if(slot_idx != -1)
resourceEvent[slot_idx].scheduleEvent(delay);
return slot_idx;
}
void
Resource::unscheduleEvent(int slot_idx)
{
resourceEvent[slot_idx].unscheduleEvent();
}
bool
Resource::unscheduleEvent(DynInstPtr inst)
{
int slot_idx = findSlot(inst);
if(slot_idx != -1)
resourceEvent[slot_idx].unscheduleEvent();
return slot_idx;
}
int ResourceRequest::resReqID = 0;
int ResourceRequest::maxReqCount = 0;
ResourceRequest::ResourceRequest(Resource *_res, DynInstPtr _inst,
int stage_num, int res_idx, int slot_num,
unsigned _cmd)
: res(_res), inst(_inst), cmd(_cmd), stageNum(stage_num),
resIdx(res_idx), slotNum(slot_num), completed(false),
squashed(false), processing(false), memStall(false)
{
#ifdef DEBUG
reqID = resReqID++;
res->cpu->resReqCount++;
DPRINTF(ResReqCount, "Res. Req %i created. resReqCount=%i.\n", reqID,
res->cpu->resReqCount);
if (res->cpu->resReqCount > 100) {
fatal("Too many undeleted resource requests. Memory leak?\n");
}
if (res->cpu->resReqCount > maxReqCount) {
maxReqCount = res->cpu->resReqCount;
}
#endif
stagePasses = 0;
complSlotNum = -1;
}
ResourceRequest::~ResourceRequest()
{
#ifdef DEBUG
res->cpu->resReqCount--;
DPRINTF(ResReqCount, "Res. Req %i deleted. resReqCount=%i.\n", reqID,
res->cpu->resReqCount);
#endif
}
void
ResourceRequest::done(bool completed)
{
DPRINTF(Resource, "%s [slot:%i] done with request from "
"[sn:%i] [tid:%i].\n", res->name(), slotNum,
inst->seqNum, inst->readTid());
setCompleted(completed);
// Used for debugging purposes
if (completed) {
complSlotNum = slotNum;
// Would like to start a convention such as all requests deleted in
// resources/pipeline
// but a little more complex then it seems...
// For now, all COMPLETED requests deleted in resource..
// all FAILED requests deleted in pipeline stage
// *all SQUASHED requests deleted in resource
res->cpu->reqRemoveList.push(res->reqMap[slotNum]);
}
// Free Slot So Another Instruction Can Use This Resource
res->freeSlot(slotNum);
// change slot # to -1, since we check slotNum to see if request is
// still valid
slotNum = -1;
}
ResourceEvent::ResourceEvent()
: Event((Event::Priority)Resource_Event_Pri)
{ }
ResourceEvent::ResourceEvent(Resource *res, int slot_idx)
: Event((Event::Priority)Resource_Event_Pri), resource(res),
slotIdx(slot_idx)
{ }
void
ResourceEvent::init(Resource *res, int slot_idx)
{
resource = res;
slotIdx = slot_idx;
}
void
ResourceEvent::process()
{
resource->execute(slotIdx);
}
const char *
ResourceEvent::description()
{
string desc = resource->name() + " event";
return desc.c_str();
}
void
ResourceEvent::scheduleEvent(int delay)
{
InOrderCPU *cpu = resource->cpu;
Tick when = curTick + resource->ticks(delay);
if (squashed())
cpu->reschedule(this, when);
else if (!scheduled())
cpu->schedule(this, when);
}