gem5/src/mem/ruby/system/PerfectCacheMemory.hh

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/*
* Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
* 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.
*/
/*
* PerfectCacheMemory.hh
*
* Description:
*
* $Id$
*
*/
#ifndef PERFECTCACHEMEMORY_H
#define PERFECTCACHEMEMORY_H
#include "mem/ruby/common/Global.hh"
#include "mem/gems_common/Map.hh"
#include "mem/protocol/AccessPermission.hh"
#include "mem/ruby/common/Address.hh"
template<class ENTRY>
class PerfectCacheLineState {
public:
PerfectCacheLineState() { m_permission = AccessPermission_NUM; }
AccessPermission m_permission;
ENTRY m_entry;
};
template<class ENTRY>
extern inline
ostream& operator<<(ostream& out, const PerfectCacheLineState<ENTRY>& obj)
{
return out;
}
template<class ENTRY>
class PerfectCacheMemory {
public:
// Constructors
PerfectCacheMemory();
// Destructor
//~PerfectCacheMemory();
// Public Methods
static void printConfig(ostream& out);
// perform a cache access and see if we hit or not. Return true on
// a hit.
bool tryCacheAccess(const CacheMsg& msg, bool& block_stc, ENTRY*& entry);
// tests to see if an address is present in the cache
bool isTagPresent(const Address& address) const;
// Returns true if there is:
// a) a tag match on this address or there is
// b) an Invalid line in the same cache "way"
bool cacheAvail(const Address& address) const;
// find an Invalid entry and sets the tag appropriate for the address
void allocate(const Address& address);
void deallocate(const Address& address);
// Returns with the physical address of the conflicting cache line
Address cacheProbe(const Address& newAddress) const;
// looks an address up in the cache
ENTRY& lookup(const Address& address);
const ENTRY& lookup(const Address& address) const;
// Get/Set permission of cache block
AccessPermission getPermission(const Address& address) const;
void changePermission(const Address& address, AccessPermission new_perm);
// Print cache contents
void print(ostream& out) const;
private:
// Private Methods
// Private copy constructor and assignment operator
PerfectCacheMemory(const PerfectCacheMemory& obj);
PerfectCacheMemory& operator=(const PerfectCacheMemory& obj);
// Data Members (m_prefix)
Map<Address, PerfectCacheLineState<ENTRY> > m_map;
};
// Output operator declaration
//ostream& operator<<(ostream& out, const PerfectCacheMemory<ENTRY>& obj);
// ******************* Definitions *******************
// Output operator definition
template<class ENTRY>
extern inline
ostream& operator<<(ostream& out, const PerfectCacheMemory<ENTRY>& obj)
{
obj.print(out);
out << flush;
return out;
}
// ****************************************************************
template<class ENTRY>
extern inline
PerfectCacheMemory<ENTRY>::PerfectCacheMemory()
{
}
// STATIC METHODS
template<class ENTRY>
extern inline
void PerfectCacheMemory<ENTRY>::printConfig(ostream& out)
{
}
// PUBLIC METHODS
template<class ENTRY>
extern inline
bool PerfectCacheMemory<ENTRY>::tryCacheAccess(const CacheMsg& msg, bool& block_stc, ENTRY*& entry)
{
ERROR_MSG("not implemented");
}
// tests to see if an address is present in the cache
template<class ENTRY>
extern inline
bool PerfectCacheMemory<ENTRY>::isTagPresent(const Address& address) const
{
return m_map.exist(line_address(address));
}
template<class ENTRY>
extern inline
bool PerfectCacheMemory<ENTRY>::cacheAvail(const Address& address) const
{
return true;
}
// find an Invalid or already allocated entry and sets the tag
// appropriate for the address
template<class ENTRY>
extern inline
void PerfectCacheMemory<ENTRY>::allocate(const Address& address)
{
PerfectCacheLineState<ENTRY> line_state;
line_state.m_permission = AccessPermission_Busy;
line_state.m_entry = ENTRY();
m_map.add(line_address(address), line_state);
}
// deallocate entry
template<class ENTRY>
extern inline
void PerfectCacheMemory<ENTRY>::deallocate(const Address& address)
{
m_map.erase(line_address(address));
}
// Returns with the physical address of the conflicting cache line
template<class ENTRY>
extern inline
Address PerfectCacheMemory<ENTRY>::cacheProbe(const Address& newAddress) const
{
ERROR_MSG("cacheProbe called in perfect cache");
}
// looks an address up in the cache
template<class ENTRY>
extern inline
ENTRY& PerfectCacheMemory<ENTRY>::lookup(const Address& address)
{
return m_map.lookup(line_address(address)).m_entry;
}
// looks an address up in the cache
template<class ENTRY>
extern inline
const ENTRY& PerfectCacheMemory<ENTRY>::lookup(const Address& address) const
{
return m_map.lookup(line_address(address)).m_entry;
}
template<class ENTRY>
extern inline
AccessPermission PerfectCacheMemory<ENTRY>::getPermission(const Address& address) const
{
return m_map.lookup(line_address(address)).m_permission;
}
template<class ENTRY>
extern inline
void PerfectCacheMemory<ENTRY>::changePermission(const Address& address, AccessPermission new_perm)
{
Address line_address = address;
line_address.makeLineAddress();
PerfectCacheLineState<ENTRY>& line_state = m_map.lookup(line_address);
AccessPermission old_perm = line_state.m_permission;
line_state.m_permission = new_perm;
}
template<class ENTRY>
extern inline
void PerfectCacheMemory<ENTRY>::print(ostream& out) const
{
}
#endif //PERFECTCACHEMEMORY_H