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/*
* Copyright (c) 2006 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: Steve Reinhardt
*/
#ifndef __ARCH_MIPS_LOCKED_MEM_HH__
#define __ARCH_MIPS_LOCKED_MEM_HH__
/**
* @file
*
* ISA-specific helper functions for locked memory accesses.
*/
#include "arch/isa_traits.hh"
#include "base/misc.hh"
#include "base/trace.hh"
#include "mem/request.hh"
namespace MipsISA
{
template <class XC>
inline void
handleLockedRead(XC *xc, Request *req)
{
unsigned tid = req->getThreadNum();
xc->setMiscReg(LLAddr, req->getPaddr() & ~0xf, tid);
xc->setMiscReg(LLFlag, true, tid);
DPRINTF(LLSC, "[tid:%i]: Load-Link Flag Set & Load-Link Address set to %x.\n",
tid, req->getPaddr() & ~0xf);
}
template <class XC>
inline bool
handleLockedWrite(XC *xc, Request *req)
{
unsigned tid = req->getThreadNum();
if (req->isUncacheable()) {
// Funky Turbolaser mailbox access...don't update
// result register (see stq_c in decoder.isa)
req->setExtraData(2);
} else {
// standard store conditional
bool lock_flag = xc->readMiscReg(LLFlag, tid);
Addr lock_addr = xc->readMiscReg(LLAddr, tid);
if (!lock_flag || (req->getPaddr() & ~0xf) != lock_addr) {
// Lock flag not set or addr mismatch in CPU;
// don't even bother sending to memory system
req->setExtraData(0);
xc->setMiscReg(LLFlag, false, tid);
// the rest of this code is not architectural;
// it's just a debugging aid to help detect
// livelock by warning on long sequences of failed
// store conditionals
int stCondFailures = xc->readStCondFailures();
stCondFailures++;
xc->setStCondFailures(stCondFailures);
if (stCondFailures % 10 == 0) {
warn("%i: cpu %d: %d consecutive "
"store conditional failures\n",
curTick, xc->readCpuId(), stCondFailures);
}
if (stCondFailures == 5000) {
panic("Max (5000) Store Conditional Fails Reached. Check Code For Deadlock.\n");
}
if (!lock_flag){
DPRINTF(LLSC, "[tid:%i]: Lock Flag Set, Store Conditional Failed.\n",
tid);
} else if ((req->getPaddr() & ~0xf) != lock_addr) {
DPRINTF(LLSC, "[tid:%i]: Load-Link Address Mismatch, Store Conditional Failed.\n",
tid);
}
// store conditional failed already, so don't issue it to mem
return false;
}
}
return true;
}
} // namespace MipsISA
#endif
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