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/*
* Copyright (c) 2016 Advanced Micro Devices, Inc.
* Copyright (c) 2003-2005 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.
*/
#include "sim/syscall_desc.hh"
#include "base/types.hh"
#include "sim/eventq.hh"
#include "sim/syscall_debug_macros.hh"
namespace gem5
{
class ThreadContext;
void
SyscallDesc::doSyscall(ThreadContext *tc)
{
DPRINTF_SYSCALL(Base, "Calling %s...\n", dumper(name(), tc));
SyscallReturn retval = executor(this, tc);
if (retval.needsRetry()) {
// Suspend this ThreadContext while the syscall is pending.
tc->suspend();
DPRINTF_SYSCALL(Base, "%s needs retry.\n", name());
setupRetry(tc);
return;
}
handleReturn(tc, retval);
}
void
SyscallDesc::retrySyscall(ThreadContext *tc)
{
DPRINTF_SYSCALL(Base, "Retrying %s...\n", dumper(name(), tc));
SyscallReturn retval = executor(this, tc);
if (retval.needsRetry()) {
DPRINTF_SYSCALL(Base, "%s still needs retry.\n", name());
setupRetry(tc);
return;
}
// We're done retrying, so reactivate this ThreadContext.
tc->activate();
handleReturn(tc, retval);
}
void
SyscallDesc::setupRetry(ThreadContext *tc)
{
// Create an event which will retry the system call later.
auto retry = [this, tc]() { retrySyscall(tc); };
auto *event = new EventFunctionWrapper(retry, name(), true);
// Schedule it in about 100 CPU cycles. That will give other contexts
// a chance to execute a bit of code before trying again.
auto *cpu = tc->getCpuPtr();
curEventQueue()->schedule(event,
curTick() + cpu->cyclesToTicks(Cycles(100)));
}
void
SyscallDesc::handleReturn(ThreadContext *tc, const SyscallReturn &ret)
{
if (ret.suppressed()) {
DPRINTF_SYSCALL(Base, "No return value.\n", name());
} else {
returnInto(tc, ret);
DPRINTF_SYSCALL(Base, "Returned %d.\n", ret.encodedValue());
}
}
} // namespace gem5