/*
 * 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
 *          Kevin Lim
 */

#ifndef __ARCH_ALPHA_INTERRUPT_HH__
#define __ARCH_ALPHA_INTERRUPT_HH__

#include <memory>

#include "arch/alpha/faults.hh"
#include "arch/alpha/isa_traits.hh"
#include "base/compiler.hh"
#include "base/trace.hh"
#include "cpu/thread_context.hh"
#include "debug/Flow.hh"
#include "debug/Interrupt.hh"
#include "params/AlphaInterrupts.hh"
#include "sim/sim_object.hh"

namespace AlphaISA {

class Interrupts : public SimObject
{
  private:
    bool newInfoSet;
    int newIpl;
    int newSummary;
    BaseCPU * cpu;

  protected:
    uint64_t interrupts[NumInterruptLevels];
    uint64_t intstatus;

  public:
    typedef AlphaInterruptsParams Params;

    const Params *
    params() const
    {
        return dynamic_cast<const Params *>(_params);
    }

    Interrupts(Params * p) : SimObject(p), cpu(NULL)
    {
        memset(interrupts, 0, sizeof(interrupts));
        intstatus = 0;
        newInfoSet = false;
    }

    void
    setCPU(BaseCPU * _cpu)
    {
        cpu = _cpu;
    }

    void
    post(int int_num, int index)
    {
        DPRINTF(Interrupt, "Interrupt %d:%d posted\n", int_num, index);

        if (int_num < 0 || int_num >= NumInterruptLevels)
            panic("int_num out of bounds\n");

        if (index < 0 || index >= (int)sizeof(uint64_t) * 8)
            panic("int_num out of bounds\n");

        interrupts[int_num] |= 1 << index;
        intstatus |= (ULL(1) << int_num);
    }

    void
    clear(int int_num, int index)
    {
        DPRINTF(Interrupt, "Interrupt %d:%d cleared\n", int_num, index);

        if (int_num < 0 || int_num >= NumInterruptLevels)
            panic("int_num out of bounds\n");

        if (index < 0 || index >= (int)sizeof(uint64_t) * 8)
            panic("int_num out of bounds\n");

        interrupts[int_num] &= ~(1 << index);
        if (interrupts[int_num] == 0)
            intstatus &= ~(ULL(1) << int_num);
    }

    void
    clearAll()
    {
        DPRINTF(Interrupt, "Interrupts all cleared\n");

        memset(interrupts, 0, sizeof(interrupts));
        intstatus = 0;
    }

    void
    serialize(CheckpointOut &cp) const
    {
        SERIALIZE_ARRAY(interrupts, NumInterruptLevels);
        SERIALIZE_SCALAR(intstatus);
    }

    void
    unserialize(CheckpointIn &cp)
    {
        UNSERIALIZE_ARRAY(interrupts, NumInterruptLevels);
        UNSERIALIZE_SCALAR(intstatus);
    }

    bool
    checkInterrupts(ThreadContext *tc) const
    {
        if (intstatus == 0)
            return false;

        if (tc->pcState().pc() & 0x3)
            return false;

        if (tc->readMiscRegNoEffect(IPR_ASTRR))
            panic("asynchronous traps not implemented\n");

        uint64_t ipl = 0;
        uint64_t summary = 0;

        if (tc->readMiscRegNoEffect(IPR_SIRR)) {
            for (uint64_t i = INTLEVEL_SOFTWARE_MIN;
                 i < INTLEVEL_SOFTWARE_MAX; i++) {
                if (tc->readMiscRegNoEffect(IPR_SIRR) & (ULL(1) << i)) {
                    // See table 4-19 of 21164 hardware reference
                    ipl = (i - INTLEVEL_SOFTWARE_MIN) + 1;
                    summary |= (ULL(1) << i);
                }
            }
        }

        for (uint64_t i = INTLEVEL_EXTERNAL_MIN; i < INTLEVEL_EXTERNAL_MAX;
             i++) {
            if (intstatus & (ULL(1) << i)) {
                // See table 4-19 of 21164 hardware reference
                ipl = i;
                summary |= (ULL(1) << i);
            }
        }

        return ipl && ipl > tc->readMiscRegNoEffect(IPR_IPLR);
    }

    Fault
    getInterrupt(ThreadContext *tc)
    {
        assert(checkInterrupts(tc));

        uint64_t ipl = 0;
        uint64_t summary = 0;
        if (tc->readMiscRegNoEffect(IPR_SIRR)) {
            for (uint64_t i = INTLEVEL_SOFTWARE_MIN;
                 i < INTLEVEL_SOFTWARE_MAX; i++) {
                if (tc->readMiscRegNoEffect(IPR_SIRR) & (ULL(1) << i)) {
                    // See table 4-19 of 21164 hardware reference
                    ipl = (i - INTLEVEL_SOFTWARE_MIN) + 1;
                    summary |= (ULL(1) << i);
                }
            }
        }

        for (uint64_t i = INTLEVEL_EXTERNAL_MIN; i < INTLEVEL_EXTERNAL_MAX;
             i++) {
            if (intstatus & (ULL(1) << i)) {
                // See table 4-19 of 21164 hardware reference
                ipl = i;
                summary |= (ULL(1) << i);
            }
        }

        newIpl = ipl;
        newSummary = summary;
        newInfoSet = true;
        DPRINTF(Flow, "Interrupt! IPLR=%d ipl=%d summary=%x\n",
                tc->readMiscRegNoEffect(IPR_IPLR), ipl, summary);

        return std::make_shared<InterruptFault>();
    }

    void
    updateIntrInfo(ThreadContext *tc)
    {
        assert(newInfoSet);
        tc->setMiscRegNoEffect(IPR_ISR, newSummary);
        tc->setMiscRegNoEffect(IPR_INTID, newIpl);
        newInfoSet = false;
    }
};

} // namespace AlphaISA

#endif // __ARCH_ALPHA_INTERRUPT_HH__