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/*
* Copyright (c) 2012-2013 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Copyright (c) 2005 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: Ron Dreslinski
* Steve Reinhardt
*/
/**
* @file
* GHB Prefetcher implementation.
*/
#include "base/trace.hh"
#include "debug/HWPrefetch.hh"
#include "mem/cache/prefetch/ghb.hh"
void
GHBPrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
std::list<Cycles> &delays)
{
Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1);
bool is_secure = pkt->isSecure();
int master_id = useMasterId ? pkt->req->masterId() : 0;
assert(master_id < Max_Masters);
bool same_sec_state = true;
// Avoid activating prefetch if the security state is not
// consistent across requests
if (is_secure != lastMissIsSecure[master_id] ||
is_secure != secondLastMissIsSecure[master_id])
same_sec_state = false;
int new_stride = blk_addr - lastMissAddr[master_id];
int old_stride = lastMissAddr[master_id] - secondLastMissAddr[master_id];
secondLastMissAddr[master_id] = lastMissAddr[master_id];
secondLastMissIsSecure[master_id] = lastMissIsSecure[master_id];
lastMissAddr[master_id] = blk_addr;
lastMissIsSecure[master_id] = is_secure;
if (same_sec_state && new_stride == old_stride) {
for (int d = 1; d <= degree; d++) {
Addr new_addr = blk_addr + d * new_stride;
if (pageStop && !samePage(blk_addr, new_addr)) {
// Spanned the page, so now stop
pfSpanPage += degree - d + 1;
return;
} else {
addresses.push_back(new_addr);
delays.push_back(latency);
}
}
}
}
GHBPrefetcher*
GHBPrefetcherParams::create()
{
return new GHBPrefetcher(this);
}
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