From 09d8a1e1252eba582fd8450ee31e784b54910f7d Mon Sep 17 00:00:00 2001 From: Ali Saidi Date: Tue, 30 May 2006 18:57:42 -0400 Subject: Add a very poor implementation of dealing with retries on timing requests. It is especially slow with tracing on since it ends up being O(N^2). But it's probably going to have to change for the real bus anyway, so it should be rewritten then Change recvRetry() to not accept a packet. Sendtiming should be called again (and can respond with false or true) Removed Port Blocked/Unblocked and replaced with sendRetry(). Remove possibility of packet mangling if packet is going to be refused anyway in bridge src/cpu/simple/atomic.cc: src/cpu/simple/atomic.hh: src/cpu/simple/timing.cc: src/cpu/simple/timing.hh: Change recvRetry() to not accept a packet. Sendtiming should be called again (and can respond with false or true) src/dev/io_device.cc: src/dev/io_device.hh: Make DMA Timing requests/responses work. Change recvRetry() to not accept a packet. Sendtiming should be called again (and can respond with false or true) src/mem/bridge.cc: src/mem/bridge.hh: Change recvRetry() to not accept a packet. Sendtiming should be called again (and can respond with false or true) Removed Port Blocked/Unblocked and replaced with sendRetry(). Remove posibility of packet mangling if packet is going to be refused anyway. src/mem/bus.cc: src/mem/bus.hh: Add a very poor implementation of dealing with retries on timing requests. It is especially slow with tracing on since it ends up being O(N^2). But it's probably going to have to change for the real bus anyway, so it should be rewritten then src/mem/port.hh: Change recvRetry() to not accept a packet. Sendtiming should be called again (and can respond with false or true) Removed Blocked/Unblocked port status, their functionality is really duplicated in the recvRetry() method --HG-- extra : convert_revision : fab613404be54bfa7a4c67572bae7b559169e573 --- src/mem/bridge.cc | 93 ++++++++++++++++++++++++++----------------------------- 1 file changed, 44 insertions(+), 49 deletions(-) (limited to 'src/mem/bridge.cc') diff --git a/src/mem/bridge.cc b/src/mem/bridge.cc index 736e8dc81..5b8b9164b 100644 --- a/src/mem/bridge.cc +++ b/src/mem/bridge.cc @@ -90,7 +90,17 @@ Bridge::BridgePort::recvTiming(Packet *pkt) DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", pkt->getSrc(), pkt->getDest(), pkt->getAddr()); - if (pkt->isResponse()) { + return otherPort->queueForSendTiming(pkt); +} + + +bool +Bridge::BridgePort::queueForSendTiming(Packet *pkt) +{ + if (queueFull()) + return false; + + if (pkt->isResponse()) { // This is a response for a request we forwarded earlier. The // corresponding PacketBuffer should be stored in the packet's // senderState field. @@ -99,22 +109,16 @@ Bridge::BridgePort::recvTiming(Packet *pkt) // set up new packet dest & senderState based on values saved // from original request buf->fixResponse(pkt); + DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n", + pkt->senderState, buf); DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest()); delete buf; } - return otherPort->queueForSendTiming(pkt); -} - - -bool -Bridge::BridgePort::queueForSendTiming(Packet *pkt) -{ - if (queueFull()) - return false; - Tick readyTime = curTick + delay; PacketBuffer *buf = new PacketBuffer(pkt, readyTime); + DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n", + buf->origSenderState, buf); // If we're about to put this packet at the head of the queue, we // need to schedule an event to do the transmit. Otherwise there @@ -126,43 +130,16 @@ Bridge::BridgePort::queueForSendTiming(Packet *pkt) sendQueue.push_back(buf); - // Did we just become blocked? If yes, let other side know. - if (queueFull()) - otherPort->sendStatusChange(Port::Blocked); - return true; } - -void -Bridge::BridgePort::finishSend(PacketBuffer *buf) -{ - if (buf->expectResponse) { - // Must wait for response. We just need to count outstanding - // responses (in case we want to cap them); PacketBuffer - // pointer will be recovered on response. - ++outstandingResponses; - DPRINTF(BusBridge, " successful: awaiting response (%d)\n", - outstandingResponses); - } else { - // no response expected... deallocate packet buffer now. - DPRINTF(BusBridge, " successful: no response expected\n"); - delete buf; - } - - // If there are more packets to send, schedule event to try again. - if (!sendQueue.empty()) { - buf = sendQueue.front(); - sendEvent.schedule(std::max(buf->ready, curTick + 1)); - } -} - - void Bridge::BridgePort::trySend() { assert(!sendQueue.empty()); + bool was_full = queueFull(); + PacketBuffer *buf = sendQueue.front(); assert(buf->ready <= curTick); @@ -176,20 +153,41 @@ Bridge::BridgePort::trySend() // send successful sendQueue.pop_front(); buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it - finishSend(buf); + + if (buf->expectResponse) { + // Must wait for response. We just need to count outstanding + // responses (in case we want to cap them); PacketBuffer + // pointer will be recovered on response. + ++outstandingResponses; + DPRINTF(BusBridge, " successful: awaiting response (%d)\n", + outstandingResponses); + } else { + // no response expected... deallocate packet buffer now. + DPRINTF(BusBridge, " successful: no response expected\n"); + delete buf; + } + + // If there are more packets to send, schedule event to try again. + if (!sendQueue.empty()) { + buf = sendQueue.front(); + sendEvent.schedule(std::max(buf->ready, curTick + 1)); + } + // Let things start sending again + if (was_full) { + DPRINTF(BusBridge, "Queue was full, sending retry\n"); + otherPort->sendRetry(); + } + } else { DPRINTF(BusBridge, " unsuccessful\n"); } } -Packet * +void Bridge::BridgePort::recvRetry() { - PacketBuffer *buf = sendQueue.front(); - Packet *pkt = buf->pkt; - finishSend(buf); - return pkt; + trySend(); } /** Function called by the port when the bus is receiving a Atomic @@ -223,9 +221,6 @@ Bridge::BridgePort::recvFunctional(Packet *pkt) void Bridge::BridgePort::recvStatusChange(Port::Status status) { - if (status == Port::Blocked || status == Port::Unblocked) - return; - otherPort->sendStatusChange(status); } -- cgit v1.2.3