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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.
*/
#ifndef __MEM_RUBY_STOREBUFFER_STOREBUFFER_HH__
#define __MEM_RUBY_STOREBUFFER_STOREBUFFER_HH__
#include <deque>
#include <map>
#include "mem/ruby/common/TypeDefines.hh"
#include "mem/ruby/libruby.hh"
/**
* Status for write buffer accesses. The Write buffer can hit in
* fastpath, be full, or successfully enqueue the store request
*/
enum storebuffer_status_t { WB_FULL, WB_OK, WB_FLUSHING };
/**
* Status of a load match
*/
enum load_match { NO_MATCH, PARTIAL_MATCH, FULL_MATCH };
struct SBEntry
{
RubyRequest m_request;
SBEntry(RubyRequest request, void * ptr)
: m_request(request)
{
}
};
class StoreBuffer
{
public:
/// Note that the size of the Write Buffer is determined by the
/// WRITE_BUFFER_SIZE config parameter
StoreBuffer(uint32_t id, uint32_t block_bits, int storebuffer_size);
~StoreBuffer();
/// Register hitcallback back to CPU
void registerHitCallback(void (*hit_callback)(int64_t request_id));
///Adds a store entry to the write buffer
void addToStoreBuffer(RubyRequest request);
///Flushes the entire write buffer
void flushStoreBuffer();
///A pseq object calls this when Ruby completes our request
void complete(uint64_t);
/// Returns ID. If ID == -2, HIT, else it's an ID to wait on
int64_t handleLoad(RubyRequest request);
/// Used by all load insts to check whether it hits to any entry
/// in the WB. If so, the WB is flushed
load_match checkForLoadHit(RubyRequest request);
/// Used to fill the load in case of FULL_MATCH
void returnMatchedData(RubyRequest request);
/// Issue next store in line
void issueNextStore();
/// prints out the contents of the Write Buffer
void print();
/// Returns flag indicating whether we are using the write buffer
bool useStoreBuffer() { return m_use_storebuffer; }
bool storeBufferFull() { return m_storebuffer_full; }
bool storeBufferFlushing() { return m_storebuffer_flushing; }
private:
/// id of this write buffer (one per sequencer object)
uint32_t m_id;
/// number of bytes in cacheline
uint32_t m_block_size;
/// the size of the write buffer
uint32_t m_storebuffer_size;
/// mask to strip off non-cache line bits
pa_t m_block_mask;
/// list of store requests in the write buffer
std::deque<SBEntry> buffer;
/// the current length of the write buffer
uint32_t m_buffer_size;
/// whether we want to simulate the write buffer or not:
bool m_use_storebuffer;
/// indicates whether the write buffer is full or not
bool m_storebuffer_full;
/// indicates that we are currently flushing the write buffer
bool m_storebuffer_flushing;
/// indicates that automatic issue is stalled and the next store
/// to be added should issue itself
bool m_stalled_issue;
/// RubyPort to make requests to
RubyPortHandle m_port;
/// HitCallback to CPU
void (*m_hit_callback)(int64_t);
/// Map the request id to rubyrequest
std::map<uint64_t, RubyRequest> outstanding_requests;
/// current instruction counter
uint64_t iseq;
/// input into tso counter
uint64_t tso_iseq;
};
#endif // __MEM_RUBY_STOREBUFFER_STOREBUFFER_HH__
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