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-rw-r--r--src/cpu/simple/timing.cc366
-rw-r--r--src/cpu/simple/timing.hh57
2 files changed, 347 insertions, 76 deletions
diff --git a/src/cpu/simple/timing.cc b/src/cpu/simple/timing.cc
index f5eeeba60..5d37fa620 100644
--- a/src/cpu/simple/timing.cc
+++ b/src/cpu/simple/timing.cc
@@ -241,57 +241,135 @@ TimingSimpleCPU::suspendContext(int thread_num)
_status = Idle;
}
+bool
+TimingSimpleCPU::handleReadPacket(PacketPtr pkt)
+{
+ RequestPtr req = pkt->req;
+ if (req->isMmapedIpr()) {
+ Tick delay;
+ delay = TheISA::handleIprRead(thread->getTC(), pkt);
+ new IprEvent(pkt, this, nextCycle(curTick + delay));
+ _status = DcacheWaitResponse;
+ dcache_pkt = NULL;
+ } else if (!dcachePort.sendTiming(pkt)) {
+ _status = DcacheRetry;
+ dcache_pkt = pkt;
+ } else {
+ _status = DcacheWaitResponse;
+ // memory system takes ownership of packet
+ dcache_pkt = NULL;
+ }
+ return dcache_pkt == NULL;
+}
template <class T>
Fault
TimingSimpleCPU::read(Addr addr, T &data, unsigned flags)
{
- Request *req =
- new Request(/* asid */ 0, addr, sizeof(T), flags, thread->readPC(),
- _cpuId, /* thread ID */ 0);
-
- if (traceData) {
- traceData->setAddr(req->getVaddr());
- }
+ Fault fault;
+ const int asid = 0;
+ const int thread_id = 0;
+ const Addr pc = thread->readPC();
+
+ PacketPtr pkt;
+ RequestPtr req;
+
+ int block_size = dcachePort.peerBlockSize();
+ int data_size = sizeof(T);
+
+ Addr second_addr = roundDown(addr + data_size - 1, block_size);
+
+ if (second_addr > addr) {
+ Addr first_size = second_addr - addr;
+ Addr second_size = data_size - first_size;
+ // Make sure we'll only need two accesses.
+ assert(roundDown(second_addr + second_size - 1, block_size) ==
+ second_addr);
+
+ /*
+ * Do the translations. If something isn't going to work, find out
+ * before we waste time setting up anything else.
+ */
+ req = new Request(asid, addr, first_size,
+ flags, pc, _cpuId, thread_id);
+ fault = thread->translateDataReadReq(req);
+ if (fault != NoFault) {
+ delete req;
+ return fault;
+ }
+ Request *second_req =
+ new Request(asid, second_addr, second_size,
+ flags, pc, _cpuId, thread_id);
+ fault = thread->translateDataReadReq(second_req);
+ if (fault != NoFault) {
+ delete req;
+ delete second_req;
+ return fault;
+ }
- // translate to physical address
- Fault fault = thread->translateDataReadReq(req);
+ T * data_ptr = new T;
+
+ /*
+ * This is the big packet that will hold the data we've gotten so far,
+ * if any, and also act as the response we actually give to the
+ * instruction.
+ */
+ Request *orig_req =
+ new Request(asid, addr, data_size, flags, pc, _cpuId, thread_id);
+ orig_req->setPhys(req->getPaddr(), data_size, flags);
+ PacketPtr big_pkt =
+ new Packet(orig_req, MemCmd::ReadResp, Packet::Broadcast);
+ big_pkt->dataDynamic<T>(data_ptr);
+ SplitMainSenderState * main_send_state = new SplitMainSenderState;
+ big_pkt->senderState = main_send_state;
+ main_send_state->outstanding = 2;
+
+ // This is the packet we'll process now.
+ pkt = new Packet(req, MemCmd::ReadReq, Packet::Broadcast);
+ pkt->dataStatic<uint8_t>((uint8_t *)data_ptr);
+ pkt->senderState = new SplitFragmentSenderState(big_pkt, 0);
+
+ // This is the second half of the access we'll deal with later.
+ PacketPtr second_pkt =
+ new Packet(second_req, MemCmd::ReadReq, Packet::Broadcast);
+ second_pkt->dataStatic<uint8_t>((uint8_t *)data_ptr + first_size);
+ second_pkt->senderState = new SplitFragmentSenderState(big_pkt, 1);
+ if (!handleReadPacket(pkt)) {
+ main_send_state->fragments[1] = second_pkt;
+ } else {
+ handleReadPacket(second_pkt);
+ }
+ } else {
+ req = new Request(asid, addr, data_size,
+ flags, pc, _cpuId, thread_id);
- // Now do the access.
- if (fault == NoFault) {
- PacketPtr pkt =
- new Packet(req,
- (req->isLocked() ?
- MemCmd::LoadLockedReq : MemCmd::ReadReq),
- Packet::Broadcast);
- pkt->dataDynamic<T>(new T);
+ // translate to physical address
+ Fault fault = thread->translateDataReadReq(req);
- if (req->isMmapedIpr()) {
- Tick delay;
- delay = TheISA::handleIprRead(thread->getTC(), pkt);
- new IprEvent(pkt, this, nextCycle(curTick + delay));
- _status = DcacheWaitResponse;
- dcache_pkt = NULL;
- } else if (!dcachePort.sendTiming(pkt)) {
- _status = DcacheRetry;
- dcache_pkt = pkt;
- } else {
- _status = DcacheWaitResponse;
- // memory system takes ownership of packet
- dcache_pkt = NULL;
+ if (fault != NoFault) {
+ delete req;
+ return fault;
}
- // This will need a new way to tell if it has a dcache attached.
- if (req->isUncacheable())
- recordEvent("Uncached Read");
- } else {
- delete req;
+ pkt = new Packet(req,
+ (req->isLocked() ?
+ MemCmd::LoadLockedReq : MemCmd::ReadReq),
+ Packet::Broadcast);
+ pkt->dataDynamic<T>(new T);
+
+ handleReadPacket(pkt);
}
if (traceData) {
traceData->setData(data);
+ traceData->setAddr(addr);
}
- return fault;
+
+ // This will need a new way to tell if it has a dcache attached.
+ if (req->isUncacheable())
+ recordEvent("Uncached Read");
+
+ return NoFault;
}
Fault
@@ -364,26 +442,117 @@ TimingSimpleCPU::read(Addr addr, int32_t &data, unsigned flags)
return read(addr, (uint32_t&)data, flags);
}
+bool
+TimingSimpleCPU::handleWritePacket()
+{
+ RequestPtr req = dcache_pkt->req;
+ if (req->isMmapedIpr()) {
+ Tick delay;
+ delay = TheISA::handleIprWrite(thread->getTC(), dcache_pkt);
+ new IprEvent(dcache_pkt, this, nextCycle(curTick + delay));
+ _status = DcacheWaitResponse;
+ dcache_pkt = NULL;
+ } else if (!dcachePort.sendTiming(dcache_pkt)) {
+ _status = DcacheRetry;
+ } else {
+ _status = DcacheWaitResponse;
+ // memory system takes ownership of packet
+ dcache_pkt = NULL;
+ }
+ return dcache_pkt == NULL;
+}
template <class T>
Fault
TimingSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
{
- Request *req =
- new Request(/* asid */ 0, addr, sizeof(T), flags, thread->readPC(),
- _cpuId, /* thread ID */ 0);
+ const int asid = 0;
+ const int thread_id = 0;
+ bool do_access = true; // flag to suppress cache access
+ const Addr pc = thread->readPC();
+
+ RequestPtr req;
+
+ int block_size = dcachePort.peerBlockSize();
+ int data_size = sizeof(T);
+
+ Addr second_addr = roundDown(addr + data_size - 1, block_size);
+
+ if (second_addr > addr) {
+ Fault fault;
+ Addr first_size = second_addr - addr;
+ Addr second_size = data_size - first_size;
+ // Make sure we'll only need two accesses.
+ assert(roundDown(second_addr + second_size - 1, block_size) ==
+ second_addr);
+
+ req = new Request(asid, addr, first_size,
+ flags, pc, _cpuId, thread_id);
+ fault = thread->translateDataWriteReq(req);
+ if (fault != NoFault) {
+ delete req;
+ return fault;
+ }
+ RequestPtr second_req = new Request(asid, second_addr, second_size,
+ flags, pc, _cpuId, thread_id);
+ fault = thread->translateDataWriteReq(second_req);
+ if (fault != NoFault) {
+ delete req;
+ delete second_req;
+ return fault;
+ }
- if (traceData) {
- traceData->setAddr(req->getVaddr());
- }
+ if (req->isLocked() || req->isSwap() ||
+ second_req->isLocked() || second_req->isSwap()) {
+ panic("LL/SCs and swaps can't be split.");
+ }
- // translate to physical address
- Fault fault = thread->translateDataWriteReq(req);
+ T * data_ptr = new T;
+
+ /*
+ * This is the big packet that will hold the data we've gotten so far,
+ * if any, and also act as the response we actually give to the
+ * instruction.
+ */
+ RequestPtr orig_req =
+ new Request(asid, addr, data_size, flags, pc, _cpuId, thread_id);
+ orig_req->setPhys(req->getPaddr(), data_size, flags);
+ PacketPtr big_pkt =
+ new Packet(orig_req, MemCmd::WriteResp, Packet::Broadcast);
+ big_pkt->dataDynamic<T>(data_ptr);
+ big_pkt->set(data);
+ SplitMainSenderState * main_send_state = new SplitMainSenderState;
+ big_pkt->senderState = main_send_state;
+ main_send_state->outstanding = 2;
+
+ assert(dcache_pkt == NULL);
+ // This is the packet we'll process now.
+ dcache_pkt = new Packet(req, MemCmd::WriteReq, Packet::Broadcast);
+ dcache_pkt->dataStatic<uint8_t>((uint8_t *)data_ptr);
+ dcache_pkt->senderState = new SplitFragmentSenderState(big_pkt, 0);
+
+ // This is the second half of the access we'll deal with later.
+ PacketPtr second_pkt =
+ new Packet(second_req, MemCmd::WriteReq, Packet::Broadcast);
+ second_pkt->dataStatic<uint8_t>((uint8_t *)data_ptr + first_size);
+ second_pkt->senderState = new SplitFragmentSenderState(big_pkt, 1);
+ if (!handleWritePacket()) {
+ main_send_state->fragments[1] = second_pkt;
+ } else {
+ dcache_pkt = second_pkt;
+ handleWritePacket();
+ }
+ } else {
+ req = new Request(asid, addr, data_size, flags, pc, _cpuId, thread_id);
+
+ // translate to physical address
+ Fault fault = thread->translateDataWriteReq(req);
+ if (fault != NoFault) {
+ delete req;
+ return fault;
+ }
- // Now do the access.
- if (fault == NoFault) {
MemCmd cmd = MemCmd::WriteReq; // default
- bool do_access = true; // flag to suppress cache access
if (req->isLocked()) {
cmd = MemCmd::StoreCondReq;
@@ -401,38 +570,27 @@ TimingSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
assert(dcache_pkt == NULL);
dcache_pkt = new Packet(req, cmd, Packet::Broadcast);
dcache_pkt->allocate();
- dcache_pkt->set(data);
-
- if (do_access) {
- if (req->isMmapedIpr()) {
- Tick delay;
- dcache_pkt->set(htog(data));
- delay = TheISA::handleIprWrite(thread->getTC(), dcache_pkt);
- new IprEvent(dcache_pkt, this, nextCycle(curTick + delay));
- _status = DcacheWaitResponse;
- dcache_pkt = NULL;
- } else if (!dcachePort.sendTiming(dcache_pkt)) {
- _status = DcacheRetry;
- } else {
- _status = DcacheWaitResponse;
- // memory system takes ownership of packet
- dcache_pkt = NULL;
- }
- }
- // This will need a new way to tell if it's hooked up to a cache or not.
- if (req->isUncacheable())
- recordEvent("Uncached Write");
- } else {
- delete req;
+ if (req->isMmapedIpr())
+ dcache_pkt->set(htog(data));
+ else
+ dcache_pkt->set(data);
+
+ if (do_access)
+ handleWritePacket();
}
if (traceData) {
+ traceData->setAddr(req->getVaddr());
traceData->setData(data);
}
+ // This will need a new way to tell if it's hooked up to a cache or not.
+ if (req->isUncacheable())
+ recordEvent("Uncached Write");
+
// If the write needs to have a fault on the access, consider calling
// changeStatus() and changing it to "bad addr write" or something.
- return fault;
+ return NoFault;
}
Fault
@@ -721,12 +879,38 @@ TimingSimpleCPU::completeDataAccess(PacketPtr pkt)
// received a response from the dcache: complete the load or store
// instruction
assert(!pkt->isError());
- assert(_status == DcacheWaitResponse);
- _status = Running;
numCycles += tickToCycles(curTick - previousTick);
previousTick = curTick;
+ if (pkt->senderState) {
+ SplitFragmentSenderState * send_state =
+ dynamic_cast<SplitFragmentSenderState *>(pkt->senderState);
+ assert(send_state);
+ delete pkt->req;
+ delete pkt;
+ PacketPtr big_pkt = send_state->bigPkt;
+ delete send_state;
+
+ SplitMainSenderState * main_send_state =
+ dynamic_cast<SplitMainSenderState *>(big_pkt->senderState);
+ assert(main_send_state);
+ // Record the fact that this packet is no longer outstanding.
+ assert(main_send_state->outstanding != 0);
+ main_send_state->outstanding--;
+
+ if (main_send_state->outstanding) {
+ return;
+ } else {
+ delete main_send_state;
+ big_pkt->senderState = NULL;
+ pkt = big_pkt;
+ }
+ }
+
+ assert(_status == DcacheWaitResponse);
+ _status = Running;
+
Fault fault = curStaticInst->completeAcc(pkt, this, traceData);
// keep an instruction count
@@ -787,10 +971,11 @@ TimingSimpleCPU::DcachePort::recvTiming(PacketPtr pkt)
// delay processing of returned data until next CPU clock edge
Tick next_tick = cpu->nextCycle(curTick);
- if (next_tick == curTick)
+ if (next_tick == curTick) {
cpu->completeDataAccess(pkt);
- else
+ } else {
tickEvent.schedule(pkt, next_tick);
+ }
return true;
}
@@ -820,7 +1005,36 @@ TimingSimpleCPU::DcachePort::recvRetry()
assert(cpu->dcache_pkt != NULL);
assert(cpu->_status == DcacheRetry);
PacketPtr tmp = cpu->dcache_pkt;
- if (sendTiming(tmp)) {
+ if (tmp->senderState) {
+ // This is a packet from a split access.
+ SplitFragmentSenderState * send_state =
+ dynamic_cast<SplitFragmentSenderState *>(tmp->senderState);
+ assert(send_state);
+ PacketPtr big_pkt = send_state->bigPkt;
+
+ SplitMainSenderState * main_send_state =
+ dynamic_cast<SplitMainSenderState *>(big_pkt->senderState);
+ assert(main_send_state);
+
+ if (sendTiming(tmp)) {
+ // If we were able to send without retrying, record that fact
+ // and try sending the other fragment.
+ send_state->clearFromParent();
+ int other_index = main_send_state->getPendingFragment();
+ if (other_index > 0) {
+ tmp = main_send_state->fragments[other_index];
+ cpu->dcache_pkt = tmp;
+ if ((big_pkt->isRead() && cpu->handleReadPacket(tmp)) ||
+ (big_pkt->isWrite() && cpu->handleWritePacket())) {
+ main_send_state->fragments[other_index] = NULL;
+ }
+ } else {
+ cpu->_status = DcacheWaitResponse;
+ // memory system takes ownership of packet
+ cpu->dcache_pkt = NULL;
+ }
+ }
+ } else if (sendTiming(tmp)) {
cpu->_status = DcacheWaitResponse;
// memory system takes ownership of packet
cpu->dcache_pkt = NULL;
diff --git a/src/cpu/simple/timing.hh b/src/cpu/simple/timing.hh
index 0fc9b3152..b641b1302 100644
--- a/src/cpu/simple/timing.hh
+++ b/src/cpu/simple/timing.hh
@@ -49,6 +49,63 @@ class TimingSimpleCPU : public BaseSimpleCPU
private:
+ /*
+ * If an access needs to be broken into fragments, currently at most two,
+ * the the following two classes are used as the sender state of the
+ * packets so the CPU can keep track of everything. In the main packet
+ * sender state, there's an array with a spot for each fragment. If a
+ * fragment has already been accepted by the CPU, aka isn't waiting for
+ * a retry, it's pointer is NULL. After each fragment has successfully
+ * been processed, the "outstanding" counter is decremented. Once the
+ * count is zero, the entire larger access is complete.
+ */
+ class SplitMainSenderState : public Packet::SenderState
+ {
+ public:
+ int outstanding;
+ PacketPtr fragments[2];
+
+ SplitMainSenderState()
+ {
+ fragments[0] = NULL;
+ fragments[1] = NULL;
+ }
+
+ int
+ getPendingFragment()
+ {
+ if (fragments[0]) {
+ return 0;
+ } else if (fragments[1]) {
+ return 1;
+ } else {
+ return -1;
+ }
+ }
+ };
+
+ class SplitFragmentSenderState : public Packet::SenderState
+ {
+ public:
+ SplitFragmentSenderState(PacketPtr _bigPkt, int _index) :
+ bigPkt(_bigPkt), index(_index)
+ {}
+ PacketPtr bigPkt;
+ int index;
+
+ void
+ clearFromParent()
+ {
+ SplitMainSenderState * main_send_state =
+ dynamic_cast<SplitMainSenderState *>(bigPkt->senderState);
+ main_send_state->fragments[index] = NULL;
+ }
+ };
+
+ bool handleReadPacket(PacketPtr pkt);
+ // This function always implicitly uses dcache_pkt.
+ bool handleWritePacket();
+
class CpuPort : public Port
{
protected:
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-29 01:31:52 +0000