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/*
* Copyright (c) 2011 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: Korey Sewell
*
*/
#ifndef __CPU_INORDER_FETCH_UNIT_HH__
#define __CPU_INORDER_FETCH_UNIT_HH__
#include <vector>
#include <list>
#include <string>
#include "arch/predecoder.hh"
#include "arch/tlb.hh"
#include "config/the_isa.hh"
#include "cpu/inorder/inorder_dyn_inst.hh"
#include "cpu/inorder/pipeline_traits.hh"
#include "cpu/inorder/resource.hh"
#include "cpu/inorder/resources/cache_unit.hh"
#include "mem/packet.hh"
#include "mem/packet_access.hh"
#include "mem/port.hh"
#include "params/InOrderCPU.hh"
#include "sim/sim_object.hh"
class FetchUnit : public CacheUnit
{
public:
FetchUnit(std::string res_name, int res_id, int res_width,
int res_latency, InOrderCPU *_cpu, ThePipeline::Params *params);
virtual ~FetchUnit();
typedef ThePipeline::DynInstPtr DynInstPtr;
typedef TheISA::ExtMachInst ExtMachInst;
struct FetchBlock {
int asid;
Addr addr;
uint8_t *block;
short cnt;
bool valid;
FetchBlock(int _asid, Addr _addr)
: asid(_asid), addr(_addr), block(NULL), cnt(1), valid(false)
{ }
};
/** Actions that this resource can take on an instruction */
enum Command {
InitiateFetch,
CompleteFetch
};
ResourceRequest* getRequest(DynInstPtr _inst, int stage_num,
int res_idx, int slot_num,
unsigned cmd);
int getSlot(DynInstPtr inst);
/** Executes one of the commands from the "Command" enum */
void execute(int slot_num);
private:
void squashCacheRequest(CacheReqPtr req_ptr);
void createMachInst(std::list<FetchBlock*>::iterator fetch_it,
DynInstPtr inst);
/** After memory request is completed, then turn the fetched data
into an instruction.
*/
void processCacheCompletion(PacketPtr pkt);
/** Create request that will interface w/TLB and Memory objects */
virtual void setupMemRequest(DynInstPtr inst, CacheReqPtr cache_req,
int acc_size, int flags);
/** Align a PC to the start of an I-cache block. */
Addr cacheBlockAlignPC(Addr addr)
{
return (addr & ~(cacheBlkMask));
}
void removeAddrDependency(DynInstPtr inst);
std::list<FetchBlock*>::iterator findReplacementBlock();
std::list<FetchBlock*>::iterator findBlock(std::list<FetchBlock*>
&fetch_blocks, int asid,
Addr block_addr);
void markBlockUsed(std::list<FetchBlock*>::iterator block_it);
int instSize;
int fetchBuffSize;
TheISA::Predecoder predecoder;
/** Valid Cache Blocks*/
std::list<FetchBlock*> fetchBuffer;
/** Cache lines that are pending */
std::list<FetchBlock*> pendingFetch;
};
#endif //__CPU_FETCH_UNIT_HH__
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