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authorGabe Black <gblack@eecs.umich.edu>2007-08-26 20:27:11 -0700
committerGabe Black <gblack@eecs.umich.edu>2007-08-26 20:27:11 -0700
commite7e2d5ce9072808d94d5fe399e6c4262d92b7923 (patch)
tree53a28ee1349088de6fa589e0f0a4119fb619ba82
parente056e49c4562108eeb7abbbeb1ee8acb096fe363 (diff)
downloadgem5-e7e2d5ce9072808d94d5fe399e6c4262d92b7923.tar.xz
Simple CPU: Added code that will split requests that cross block boundaries into multiple memory access.
--HG-- extra : convert_revision : 600f79f32ef30a6e1db951503bcfe8cd332858d1
-rw-r--r--src/cpu/simple/atomic.cc223
1 files changed, 149 insertions, 74 deletions
diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index 86deb84e6..8a05d800e 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -285,46 +285,81 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
{
// use the CPU's statically allocated read request and packet objects
Request *req = &data_read_req;
- req->setVirt(0, addr, sizeof(T), flags, thread->readPC());
if (traceData) {
traceData->setAddr(addr);
}
- // translate to physical address
- Fault fault = thread->translateDataReadReq(req);
-
- // Now do the access.
- if (fault == NoFault) {
- Packet pkt =
- Packet(req,
- req->isLocked() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
- Packet::Broadcast);
- pkt.dataStatic(&data);
-
- if (req->isMmapedIpr())
- dcache_latency = TheISA::handleIprRead(thread->getTC(), &pkt);
- else {
- if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
- dcache_latency = physmemPort.sendAtomic(&pkt);
- else
- dcache_latency = dcachePort.sendAtomic(&pkt);
- }
- dcache_access = true;
- assert(!pkt.isError());
+ //The block size of our peer.
+ int blockSize = dcachePort.peerBlockSize();
+ //The size of the data we're trying to read.
+ int dataSize = sizeof(T);
+
+ uint8_t * dataPtr = (uint8_t *)&data;
+
+ //The address of the second part of this access if it needs to be split
+ //across a cache line boundary.
+ Addr secondAddr = roundDown(addr + dataSize - 1, blockSize);
+
+ if(secondAddr > addr)
+ dataSize = secondAddr - addr;
+
+ dcache_latency = 0;
- data = gtoh(data);
+ while(1) {
+ req->setVirt(0, addr, dataSize, flags, thread->readPC());
- if (req->isLocked()) {
- TheISA::handleLockedRead(thread, req);
+ // translate to physical address
+ Fault fault = thread->translateDataReadReq(req);
+
+ // Now do the access.
+ if (fault == NoFault) {
+ Packet pkt = Packet(req,
+ req->isLocked() ? MemCmd::LoadLockedReq : MemCmd::ReadReq,
+ Packet::Broadcast);
+ pkt.dataStatic(dataPtr);
+
+ if (req->isMmapedIpr())
+ dcache_latency += TheISA::handleIprRead(thread->getTC(), &pkt);
+ else {
+ if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
+ dcache_latency += physmemPort.sendAtomic(&pkt);
+ else
+ dcache_latency += dcachePort.sendAtomic(&pkt);
+ }
+ dcache_access = true;
+ assert(!pkt.isError());
+
+ if (req->isLocked()) {
+ TheISA::handleLockedRead(thread, req);
+ }
+ }
+
+ // This will need a new way to tell if it has a dcache attached.
+ if (req->isUncacheable())
+ recordEvent("Uncached Read");
+
+ //If there's a fault, return it
+ if (fault != NoFault)
+ return fault;
+ //If we don't need to access a second cache line, stop now.
+ if (secondAddr <= addr)
+ {
+ data = gtoh(data);
+ return fault;
}
- }
- // This will need a new way to tell if it has a dcache attached.
- if (req->isUncacheable())
- recordEvent("Uncached Read");
+ /*
+ * Set up for accessing the second cache line.
+ */
- return fault;
+ //Move the pointer we're reading into to the correct location.
+ dataPtr += dataSize;
+ //Adjust the size to get the remaining bytes.
+ dataSize = addr + sizeof(T) - secondAddr;
+ //And access the right address.
+ addr = secondAddr;
+ }
}
#ifndef DOXYGEN_SHOULD_SKIP_THIS
@@ -384,65 +419,105 @@ AtomicSimpleCPU::write(T data, Addr addr, unsigned flags, uint64_t *res)
{
// use the CPU's statically allocated write request and packet objects
Request *req = &data_write_req;
- req->setVirt(0, addr, sizeof(T), flags, thread->readPC());
if (traceData) {
traceData->setAddr(addr);
}
- // translate to physical address
- Fault fault = thread->translateDataWriteReq(req);
-
- // 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;
- do_access = TheISA::handleLockedWrite(thread, req);
- } else if (req->isSwap()) {
- cmd = MemCmd::SwapReq;
- if (req->isCondSwap()) {
- assert(res);
- req->setExtraData(*res);
- }
- }
+ //The block size of our peer.
+ int blockSize = dcachePort.peerBlockSize();
+ //The size of the data we're trying to read.
+ int dataSize = sizeof(T);
- if (do_access) {
- Packet pkt = Packet(req, cmd, Packet::Broadcast);
- pkt.dataStatic(&data);
+ uint8_t * dataPtr = (uint8_t *)&data;
- if (req->isMmapedIpr()) {
- dcache_latency = TheISA::handleIprWrite(thread->getTC(), &pkt);
- } else {
- data = htog(data);
- if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
- dcache_latency = physmemPort.sendAtomic(&pkt);
- else
- dcache_latency = dcachePort.sendAtomic(&pkt);
+ //The address of the second part of this access if it needs to be split
+ //across a cache line boundary.
+ Addr secondAddr = roundDown(addr + dataSize - 1, blockSize);
+
+ if(secondAddr > addr)
+ dataSize = secondAddr - addr;
+
+ dcache_latency = 0;
+
+ while(1) {
+ req->setVirt(0, addr, dataSize, flags, thread->readPC());
+
+ // translate to physical address
+ Fault fault = thread->translateDataWriteReq(req);
+
+ // 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;
+ do_access = TheISA::handleLockedWrite(thread, req);
+ } else if (req->isSwap()) {
+ cmd = MemCmd::SwapReq;
+ if (req->isCondSwap()) {
+ assert(res);
+ req->setExtraData(*res);
+ }
}
- dcache_access = true;
- assert(!pkt.isError());
- if (req->isSwap()) {
- assert(res);
- *res = pkt.get<T>();
+ if (do_access) {
+ Packet pkt = Packet(req, cmd, Packet::Broadcast);
+ pkt.dataStatic(dataPtr);
+
+ if (req->isMmapedIpr()) {
+ dcache_latency +=
+ TheISA::handleIprWrite(thread->getTC(), &pkt);
+ } else {
+ //XXX This needs to be outside of the loop in order to
+ //work properly for cache line boundary crossing
+ //accesses in transendian simulations.
+ data = htog(data);
+ if (hasPhysMemPort && pkt.getAddr() == physMemAddr)
+ dcache_latency += physmemPort.sendAtomic(&pkt);
+ else
+ dcache_latency += dcachePort.sendAtomic(&pkt);
+ }
+ dcache_access = true;
+ assert(!pkt.isError());
+
+ if (req->isSwap()) {
+ assert(res);
+ *res = pkt.get<T>();
+ }
+ }
+
+ if (res && !req->isSwap()) {
+ *res = req->getExtraData();
}
}
- if (res && !req->isSwap()) {
- *res = req->getExtraData();
+ // 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 there's a fault or we don't need to access a second cache line,
+ //stop now.
+ if (fault != NoFault || secondAddr <= addr)
+ {
+ // 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;
}
- }
- // This will need a new way to tell if it's hooked up to a cache or not.
- if (req->isUncacheable())
- recordEvent("Uncached Write");
+ /*
+ * Set up for accessing the second cache line.
+ */
- // 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;
+ //Move the pointer we're reading into to the correct location.
+ dataPtr += dataSize;
+ //Adjust the size to get the remaining bytes.
+ dataSize = addr + sizeof(T) - secondAddr;
+ //And access the right address.
+ addr = secondAddr;
+ }
}