gem5/src/arch/arm/locked_mem.hh
2011-04-15 10:44:06 -07:00

95 lines
3.3 KiB
C++

/*
* Copyright (c) 2006 The Regents of The University of Michigan
* Copyright (c) 2007-2008 The Florida State University
* 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: Ali Saidi
* Steve Reinhardt
* Stephen Hines
*/
#ifndef __ARCH_ARM_LOCKED_MEM_HH__
#define __ARCH_ARM_LOCKED_MEM_HH__
/**
* @file
*
* ISA-specific helper functions for locked memory accesses.
*/
#include "arch/arm/miscregs.hh"
#include "mem/request.hh"
namespace ArmISA
{
template <class XC>
inline void
handleLockedRead(XC *xc, Request *req)
{
xc->setMiscReg(MISCREG_LOCKADDR, req->getPaddr() & ~0xf);
xc->setMiscReg(MISCREG_LOCKFLAG, true);
}
template <class XC>
inline bool
handleLockedWrite(XC *xc, Request *req)
{
if (req->isSwap())
return true;
// Verify that the lock flag is still set and the address
// is correct
bool lock_flag = xc->readMiscReg(MISCREG_LOCKFLAG);
Addr lock_addr = xc->readMiscReg(MISCREG_LOCKADDR);
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(MISCREG_LOCKFLAG, false);
// 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 % 100000 == 0) {
warn("context %d: %d consecutive "
"store conditional failures\n",
xc->contextId(), stCondFailures);
}
// store conditional failed already, so don't issue it to mem
return false;
}
return true;
}
} // namespace ArmISA
#endif