cpu: Add support for instructions that zero cache lines.
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6bed6e0352
commit
90b1775a8f
6 changed files with 51 additions and 13 deletions
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@ -90,6 +90,7 @@ BaseDynInst<Impl>::initVars()
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effAddr = 0;
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physEffAddr = 0;
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readyRegs = 0;
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memReqFlags = 0;
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status.reset();
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@ -1,5 +1,5 @@
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/*
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* Copyright (c) 2012 ARM Limited
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* Copyright (c) 2012-2013 ARM Limited
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* All rights reserved
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*
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* The license below extends only to copyright in the software and shall
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@ -361,7 +361,7 @@ class LSQUnit {
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/** Constructs a store queue entry for a given instruction. */
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SQEntry(DynInstPtr &_inst)
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: inst(_inst), req(NULL), sreqLow(NULL), sreqHigh(NULL), size(0),
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isSplit(0), canWB(0), committed(0), completed(0)
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isSplit(0), canWB(0), committed(0), completed(0), isAllZeros(0)
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{
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std::memset(data, 0, sizeof(data));
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}
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@ -384,6 +384,11 @@ class LSQUnit {
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bool committed;
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/** Whether or not the store is completed. */
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bool completed;
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/** Does this request write all zeros and thus doesn't
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* have any data attached to it. Used for cache block zero
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* style instructs (ARM DC ZVA; ALPHA WH64)
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*/
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bool isAllZeros;
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};
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private:
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@ -691,13 +696,18 @@ LSQUnit<Impl>::read(Request *req, Request *sreqLow, Request *sreqHigh,
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// Get shift amount for offset into the store's data.
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int shift_amt = req->getVaddr() - storeQueue[store_idx].inst->effAddr;
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memcpy(data, storeQueue[store_idx].data + shift_amt,
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if (storeQueue[store_idx].isAllZeros)
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memset(data, 0, req->getSize());
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else
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memcpy(data, storeQueue[store_idx].data + shift_amt,
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req->getSize());
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assert(!load_inst->memData);
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load_inst->memData = new uint8_t[64];
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memcpy(load_inst->memData,
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load_inst->memData = new uint8_t[req->getSize()];
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if (storeQueue[store_idx].isAllZeros)
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memset(load_inst->memData, 0, req->getSize());
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else
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memcpy(load_inst->memData,
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storeQueue[store_idx].data + shift_amt, req->getSize());
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DPRINTF(LSQUnit, "Forwarding from store idx %i to load to "
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@ -777,7 +787,7 @@ LSQUnit<Impl>::read(Request *req, Request *sreqLow, Request *sreqHigh,
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load_inst->seqNum, load_inst->pcState());
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assert(!load_inst->memData);
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load_inst->memData = new uint8_t[64];
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load_inst->memData = new uint8_t[req->getSize()];
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++usedPorts;
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@ -916,7 +926,9 @@ LSQUnit<Impl>::write(Request *req, Request *sreqLow, Request *sreqHigh,
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storeQueue[store_idx].sreqHigh = sreqHigh;
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unsigned size = req->getSize();
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storeQueue[store_idx].size = size;
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assert(size <= sizeof(storeQueue[store_idx].data));
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storeQueue[store_idx].isAllZeros = req->getFlags() & Request::CACHE_BLOCK_ZERO;
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assert(size <= sizeof(storeQueue[store_idx].data) ||
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(req->getFlags() & Request::CACHE_BLOCK_ZERO));
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// Split stores can only occur in ISAs with unaligned memory accesses. If
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// a store request has been split, sreqLow and sreqHigh will be non-null.
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@ -924,7 +936,8 @@ LSQUnit<Impl>::write(Request *req, Request *sreqLow, Request *sreqHigh,
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storeQueue[store_idx].isSplit = true;
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}
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memcpy(storeQueue[store_idx].data, data, size);
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if (!(req->getFlags() & Request::CACHE_BLOCK_ZERO))
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memcpy(storeQueue[store_idx].data, data, size);
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// This function only writes the data to the store queue, so no fault
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// can happen here.
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@ -816,9 +816,12 @@ LSQUnit<Impl>::writebackStores()
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storeQueue[storeWBIdx].committed = true;
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assert(!inst->memData);
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inst->memData = new uint8_t[64];
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inst->memData = new uint8_t[req->getSize()];
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memcpy(inst->memData, storeQueue[storeWBIdx].data, req->getSize());
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if (storeQueue[storeWBIdx].isAllZeros)
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memset(inst->memData, 0, req->getSize());
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else
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memcpy(inst->memData, storeQueue[storeWBIdx].data, req->getSize());
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MemCmd command =
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req->isSwap() ? MemCmd::SwapReq :
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@ -399,6 +399,16 @@ Fault
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AtomicSimpleCPU::writeMem(uint8_t *data, unsigned size,
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Addr addr, unsigned flags, uint64_t *res)
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{
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static uint8_t zero_array[64] = {};
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if (data == NULL) {
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assert(size <= 64);
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assert(flags & Request::CACHE_BLOCK_ZERO);
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// This must be a cache block cleaning request
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data = zero_array;
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}
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// use the CPU's statically allocated write request and packet objects
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Request *req = &data_write_req;
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@ -472,14 +472,20 @@ TimingSimpleCPU::writeMem(uint8_t *data, unsigned size,
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Addr addr, unsigned flags, uint64_t *res)
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{
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uint8_t *newData = new uint8_t[size];
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memcpy(newData, data, size);
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const int asid = 0;
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const ThreadID tid = 0;
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const Addr pc = thread->instAddr();
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unsigned block_size = cacheLineSize();
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BaseTLB::Mode mode = BaseTLB::Write;
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if (data == NULL) {
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assert(flags & Request::CACHE_BLOCK_ZERO);
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// This must be a cache block cleaning request
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memset(newData, 0, size);
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} else {
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memcpy(newData, data, size);
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}
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if (traceData) {
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traceData->setAddr(addr);
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}
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@ -114,6 +114,11 @@ class Request
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/** This request is made in privileged mode. */
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static const FlagsType PRIVILEGED = 0x00008000;
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/** This is a write that is targeted and zeroing an entire cache block.
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* There is no need for a read/modify/write
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*/
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static const FlagsType CACHE_BLOCK_ZERO = 0x00010000;
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/** The request should not cause a memory access. */
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static const FlagsType NO_ACCESS = 0x00080000;
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/** This request will lock or unlock the accessed memory. When used with
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