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/*
* Copyright (c) 2006 The Regents of The University of Michigan
* Copyright (c) 2007 MIPS Technologies, Inc.
* 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
* Kevin Lim
* Korey Sewell
*/
#include "arch/mips/interrupts.hh"
#include "arch/mips/isa_traits.hh"
#include "arch/mips/pra_constants.hh"
#include "base/trace.hh"
#include "cpu/thread_context.hh"
#include "debug/Interrupt.hh"
namespace MipsISA
{
static inline uint8_t
getCauseIP(ThreadContext *tc) {
CauseReg cause = tc->readMiscRegNoEffect(MISCREG_CAUSE);
return cause.ip;
}
static inline void
setCauseIP(ThreadContext *tc, uint8_t val) {
CauseReg cause = tc->readMiscRegNoEffect(MISCREG_CAUSE);
cause.ip = val;
tc->setMiscRegNoEffect(MISCREG_CAUSE, cause);
}
void
Interrupts::post(int int_num, ThreadContext* tc)
{
DPRINTF(Interrupt, "Interrupt %d posted\n", int_num);
if (int_num < 0 || int_num >= NumInterruptLevels)
panic("int_num out of bounds\n");
uint8_t intstatus = getCauseIP(tc);
intstatus |= 1 << int_num;
setCauseIP(tc, intstatus);
}
void
Interrupts::post(int int_num, int index)
{
fatal("Must use Thread Context when posting MIPS Interrupts in M5");
}
void
Interrupts::clear(int int_num, ThreadContext* tc)
{
DPRINTF(Interrupt, "Interrupt %d cleared\n", int_num);
if (int_num < 0 || int_num >= NumInterruptLevels)
panic("int_num out of bounds\n");
uint8_t intstatus = getCauseIP(tc);
intstatus &= ~(1 << int_num);
setCauseIP(tc, intstatus);
}
void
Interrupts::clear(int int_num, int index)
{
fatal("Must use Thread Context when clearing MIPS Interrupts in M5");
}
void
Interrupts::clearAll(ThreadContext *tc)
{
DPRINTF(Interrupt, "Interrupts all cleared\n");
uint8_t intstatus = 0;
setCauseIP(tc, intstatus);
}
void
Interrupts::clearAll()
{
fatal("Must use Thread Context when clearing MIPS Interrupts in M5");
}
bool
Interrupts::checkInterrupts(ThreadContext *tc) const
{
if (!interruptsPending(tc))
return false;
//Check if there are any outstanding interrupts
StatusReg status = tc->readMiscRegNoEffect(MISCREG_STATUS);
// Interrupts must be enabled, error level must be 0 or interrupts
// inhibited, and exception level must be 0 or interrupts inhibited
if ((status.ie == 1) && (status.erl == 0) && (status.exl == 0)) {
// Software interrupts & hardware interrupts are handled in software.
// So if any interrupt that isn't masked is detected, jump to interrupt
// handler
CauseReg cause = tc->readMiscRegNoEffect(MISCREG_CAUSE);
if (status.im && cause.ip)
return true;
}
return false;
}
Fault
Interrupts::getInterrupt(ThreadContext * tc)
{
assert(checkInterrupts(tc));
StatusReg M5_VAR_USED status = tc->readMiscRegNoEffect(MISCREG_STATUS);
CauseReg M5_VAR_USED cause = tc->readMiscRegNoEffect(MISCREG_CAUSE);
DPRINTF(Interrupt, "Interrupt! IM[7:0]=%d IP[7:0]=%d \n",
(unsigned)status.im, (unsigned)cause.ip);
return std::make_shared<InterruptFault>();
}
bool
Interrupts::onCpuTimerInterrupt(ThreadContext * tc) const
{
RegVal compare = tc->readMiscRegNoEffect(MISCREG_COMPARE);
RegVal count = tc->readMiscRegNoEffect(MISCREG_COUNT);
if (compare == count && count != 0)
return true;
return false;
}
void
Interrupts::updateIntrInfo(ThreadContext *tc)
{
//Nothing needs to be done.
}
bool
Interrupts::interruptsPending(ThreadContext *tc) const
{
//if there is a on cpu timer interrupt (i.e. Compare == Count)
//update CauseIP before proceeding to interrupt
if (onCpuTimerInterrupt(tc)) {
DPRINTF(Interrupt, "Interrupts OnCpuTimerINterrupt(tc) == true\n");
//determine timer interrupt IP #
IntCtlReg intCtl = tc->readMiscRegNoEffect(MISCREG_INTCTL);
uint8_t intStatus = getCauseIP(tc);
intStatus |= 1 << intCtl.ipti;
setCauseIP(tc, intStatus);
}
return (getCauseIP(tc) != 0);
}
}
MipsISA::Interrupts *
MipsInterruptsParams::create()
{
return new MipsISA::Interrupts(this);
}