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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.
*/
#include "arch/mips/interrupts.hh"
#include "arch/mips/pra_constants.hh"
#include "base/trace.hh"
#include "cpu/thread_context.hh"
#include "debug/Interrupt.hh"
namespace gem5
{
namespace MipsISA
{
enum InterruptLevels
{
INTLEVEL_SOFTWARE_MIN = 4,
INTLEVEL_SOFTWARE_MAX = 19,
INTLEVEL_EXTERNAL_MIN = 20,
INTLEVEL_EXTERNAL_MAX = 34,
INTLEVEL_IRQ0 = 20,
INTLEVEL_IRQ1 = 21,
INTINDEX_ETHERNET = 0,
INTINDEX_SCSI = 1,
INTLEVEL_IRQ2 = 22,
INTLEVEL_IRQ3 = 23,
INTLEVEL_SERIAL = 33,
NumInterruptLevels = INTLEVEL_EXTERNAL_MAX
};
static inline uint8_t
getCauseIP(ThreadContext *tc)
{
CauseReg cause = tc->readMiscRegNoEffect(misc_reg::Cause);
return cause.ip;
}
static inline void
setCauseIP(ThreadContext *tc, uint8_t val)
{
CauseReg cause = tc->readMiscRegNoEffect(misc_reg::Cause);
cause.ip = val;
tc->setMiscRegNoEffect(misc_reg::Cause, cause);
}
void
Interrupts::post(int int_num)
{
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)
{
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()
{
DPRINTF(Interrupt, "Interrupts all cleared\n");
uint8_t intstatus = 0;
setCauseIP(tc, intstatus);
}
bool
Interrupts::checkInterrupts() const
{
if (!interruptsPending())
return false;
//Check if there are any outstanding interrupts
StatusReg status = tc->readMiscRegNoEffect(misc_reg::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(misc_reg::Cause);
if (status.im && cause.ip)
return true;
}
return false;
}
Fault
Interrupts::getInterrupt()
{
assert(checkInterrupts());
[[maybe_unused]] StatusReg status =
tc->readMiscRegNoEffect(misc_reg::Status);
[[maybe_unused]] CauseReg cause = tc->readMiscRegNoEffect(misc_reg::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() const
{
RegVal compare = tc->readMiscRegNoEffect(misc_reg::Compare);
RegVal count = tc->readMiscRegNoEffect(misc_reg::Count);
if (compare == count && count != 0)
return true;
return false;
}
void Interrupts::updateIntrInfo() {} // Nothing needs to be done.
bool
Interrupts::interruptsPending() const
{
//if there is a on cpu timer interrupt (i.e. Compare == Count)
//update CauseIP before proceeding to interrupt
if (onCpuTimerInterrupt()) {
DPRINTF(Interrupt, "Interrupts OnCpuTimerInterrupt() == true\n");
//determine timer interrupt IP #
IntCtlReg intCtl = tc->readMiscRegNoEffect(misc_reg::Intctl);
uint8_t intStatus = getCauseIP(tc);
intStatus |= 1 << intCtl.ipti;
setCauseIP(tc, intStatus);
}
return (getCauseIP(tc) != 0);
}
} // namespace MipsISA
} // namespace gem5