gem5/src/dev/io_device.cc

344 lines
9.9 KiB
C++

/*
* Copyright (c) 2006 The Regents of The University of Michigan
* 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: Ali Saidi
* Nathan Binkert
*/
#include "base/chunk_generator.hh"
#include "base/trace.hh"
#include "dev/io_device.hh"
#include "sim/system.hh"
PioPort::PioPort(PioDevice *dev, System *s, std::string pname)
: SimpleTimingPort(dev->name() + pname, dev), device(dev)
{ }
Tick
PioPort::recvAtomic(PacketPtr pkt)
{
return pkt->isRead() ? device->read(pkt) : device->write(pkt);
}
void
PioPort::getDeviceAddressRanges(AddrRangeList &resp, bool &snoop)
{
snoop = false;
device->addressRanges(resp);
}
PioDevice::PioDevice(const Params *p)
: MemObject(p), platform(p->platform), sys(p->system), pioPort(NULL)
{}
PioDevice::~PioDevice()
{
if (pioPort)
delete pioPort;
}
void
PioDevice::init()
{
if (!pioPort)
panic("Pio port not connected to anything!");
pioPort->sendStatusChange(Port::RangeChange);
}
unsigned int
PioDevice::drain(Event *de)
{
unsigned int count;
count = pioPort->drain(de);
if (count)
changeState(Draining);
else
changeState(Drained);
return count;
}
BasicPioDevice::BasicPioDevice(const Params *p)
: PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
pioDelay(p->pio_latency)
{}
void
BasicPioDevice::addressRanges(AddrRangeList &range_list)
{
assert(pioSize != 0);
range_list.clear();
range_list.push_back(RangeSize(pioAddr, pioSize));
}
DmaPort::DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff)
: Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
pendingCount(0), actionInProgress(0), drainEvent(NULL),
backoffTime(0), minBackoffDelay(min_backoff),
maxBackoffDelay(max_backoff), inRetry(false), backoffEvent(this)
{ }
bool
DmaPort::recvTiming(PacketPtr pkt)
{
if (pkt->wasNacked()) {
DPRINTF(DMA, "Received nacked %s addr %#x\n",
pkt->cmdString(), pkt->getAddr());
if (backoffTime < minBackoffDelay)
backoffTime = minBackoffDelay;
else if (backoffTime < maxBackoffDelay)
backoffTime <<= 1;
reschedule(backoffEvent, curTick + backoffTime, true);
DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
pkt->reinitNacked();
queueDma(pkt, true);
} else if (pkt->senderState) {
DmaReqState *state;
backoffTime >>= 2;
DPRINTF(DMA, "Received response %s addr %#x size %#x\n",
pkt->cmdString(), pkt->getAddr(), pkt->req->getSize());
state = dynamic_cast<DmaReqState*>(pkt->senderState);
pendingCount--;
assert(pendingCount >= 0);
assert(state);
state->numBytes += pkt->req->getSize();
assert(state->totBytes >= state->numBytes);
if (state->totBytes == state->numBytes) {
if (state->completionEvent) {
if (state->delay)
schedule(state->completionEvent, curTick + state->delay);
else
state->completionEvent->process();
}
delete state;
}
delete pkt->req;
delete pkt;
if (pendingCount == 0 && drainEvent) {
drainEvent->process();
drainEvent = NULL;
}
} else {
panic("Got packet without sender state... huh?\n");
}
return true;
}
DmaDevice::DmaDevice(const Params *p)
: PioDevice(p), dmaPort(NULL)
{ }
unsigned int
DmaDevice::drain(Event *de)
{
unsigned int count;
count = pioPort->drain(de) + dmaPort->drain(de);
if (count)
changeState(Draining);
else
changeState(Drained);
return count;
}
unsigned int
DmaPort::drain(Event *de)
{
if (pendingCount == 0)
return 0;
drainEvent = de;
return 1;
}
void
DmaPort::recvRetry()
{
assert(transmitList.size());
bool result = true;
do {
PacketPtr pkt = transmitList.front();
DPRINTF(DMA, "Retry on %s addr %#x\n",
pkt->cmdString(), pkt->getAddr());
result = sendTiming(pkt);
if (result) {
DPRINTF(DMA, "-- Done\n");
transmitList.pop_front();
inRetry = false;
} else {
inRetry = true;
DPRINTF(DMA, "-- Failed, queued\n");
}
} while (!backoffTime && result && transmitList.size());
if (transmitList.size() && backoffTime && !inRetry) {
DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
if (!backoffEvent.scheduled())
schedule(backoffEvent, backoffTime + curTick);
}
DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
transmitList.size(), backoffTime, inRetry,
backoffEvent.scheduled());
}
void
DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
uint8_t *data, Tick delay)
{
assert(device->getState() == SimObject::Running);
DmaReqState *reqState = new DmaReqState(event, this, size, delay);
DPRINTF(DMA, "Starting DMA for addr: %#x size: %d sched: %d\n", addr, size,
event->scheduled());
for (ChunkGenerator gen(addr, size, peerBlockSize());
!gen.done(); gen.next()) {
Request *req = new Request(gen.addr(), gen.size(), 0);
PacketPtr pkt = new Packet(req, cmd, Packet::Broadcast);
// Increment the data pointer on a write
if (data)
pkt->dataStatic(data + gen.complete());
pkt->senderState = reqState;
assert(pendingCount >= 0);
pendingCount++;
DPRINTF(DMA, "--Queuing DMA for addr: %#x size: %d\n", gen.addr(),
gen.size());
queueDma(pkt);
}
}
void
DmaPort::queueDma(PacketPtr pkt, bool front)
{
if (front)
transmitList.push_front(pkt);
else
transmitList.push_back(pkt);
sendDma();
}
void
DmaPort::sendDma()
{
// some kind of selction between access methods
// more work is going to have to be done to make
// switching actually work
assert(transmitList.size());
PacketPtr pkt = transmitList.front();
Enums::MemoryMode state = sys->getMemoryMode();
if (state == Enums::timing) {
if (backoffEvent.scheduled() || inRetry) {
DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
return;
}
DPRINTF(DMA, "Attempting to send %s addr %#x\n",
pkt->cmdString(), pkt->getAddr());
bool result;
do {
result = sendTiming(pkt);
if (result) {
transmitList.pop_front();
DPRINTF(DMA, "-- Done\n");
} else {
inRetry = true;
DPRINTF(DMA, "-- Failed: queued\n");
}
} while (result && !backoffTime && transmitList.size());
if (transmitList.size() && backoffTime && !inRetry &&
!backoffEvent.scheduled()) {
DPRINTF(DMA, "-- Scheduling backoff timer for %d\n",
backoffTime+curTick);
schedule(backoffEvent, backoffTime + curTick);
}
} else if (state == Enums::atomic) {
transmitList.pop_front();
Tick lat;
DPRINTF(DMA, "--Sending DMA for addr: %#x size: %d\n",
pkt->req->getPaddr(), pkt->req->getSize());
lat = sendAtomic(pkt);
assert(pkt->senderState);
DmaReqState *state = dynamic_cast<DmaReqState*>(pkt->senderState);
assert(state);
state->numBytes += pkt->req->getSize();
DPRINTF(DMA, "--Received response for DMA for addr: %#x size: %d nb: %d, tot: %d sched %d\n",
pkt->req->getPaddr(), pkt->req->getSize(), state->numBytes,
state->totBytes,
state->completionEvent ? state->completionEvent->scheduled() : 0 );
if (state->totBytes == state->numBytes) {
if (state->completionEvent) {
assert(!state->completionEvent->scheduled());
schedule(state->completionEvent, curTick + lat + state->delay);
}
delete state;
delete pkt->req;
}
pendingCount--;
assert(pendingCount >= 0);
delete pkt;
if (pendingCount == 0 && drainEvent) {
drainEvent->process();
drainEvent = NULL;
}
} else
panic("Unknown memory command state.");
}
DmaDevice::~DmaDevice()
{
if (dmaPort)
delete dmaPort;
}