interrupts.hh

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/*
 * Copyright (c) 2010, 2012-2013, 2016 ARM Limited
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 *
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 * property including but not limited to intellectual property relating
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 * Copyright (c) 2006 The Regents of The University of Michigan
 * All rights reserved.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 * Authors: Ali Saidi
 */

#ifndef __ARCH_ARM_INTERRUPT_HH__
#define __ARCH_ARM_INTERRUPT_HH__

#include "arch/arm/faults.hh"
#include "arch/arm/isa_traits.hh"
#include "arch/arm/miscregs.hh"
#include "arch/arm/registers.hh"
#include "arch/arm/utility.hh"
#include "cpu/thread_context.hh"
#include "debug/Interrupt.hh"
#include "params/ArmInterrupts.hh"
#include "sim/sim_object.hh"

namespace ArmISA
{

class Interrupts : public SimObject
{
  private:
    BaseCPU * cpu;

    bool interrupts[NumInterruptTypes];
    uint64_t intStatus;

  public:

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

    typedef ArmInterruptsParams Params;

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

    Interrupts(Params * p) : SimObject(p), cpu(NULL)
    {
        clearAll();
    }


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

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

        if (index != 0)
            panic("No support for other interrupt indexes\n");

        interrupts[int_num] = true;
        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 >= NumInterruptTypes)
            panic("int_num out of bounds\n");

        if (index != 0)
            panic("No support for other interrupt indexes\n");

        interrupts[int_num] = false;
        intStatus &= ~(ULL(1) << int_num);
    }

    void
    clearAll()
    {
        DPRINTF(Interrupt, "Interrupts all cleared\n");
        intStatus = 0;
        memset(interrupts, 0, sizeof(interrupts));
    }

    enum InterruptMask {
        INT_MASK_M, // masked (subject to PSTATE.{A,I,F} mask bit
        INT_MASK_T, // taken regardless of mask
        INT_MASK_P  // pending
    };

    bool takeInt(ThreadContext *tc, InterruptTypes int_type) const;

    bool
    checkInterrupts(ThreadContext *tc) const
    {
        HCR  hcr  = tc->readMiscReg(MISCREG_HCR);

        if (!(intStatus || hcr.va || hcr.vi || hcr.vf))
            return false;

        CPSR cpsr = tc->readMiscReg(MISCREG_CPSR);

        bool isHypMode   = cpsr.mode == MODE_HYP;
        bool isSecure    = inSecureState(tc);
        bool allowVIrq   = !cpsr.i && hcr.imo && !isSecure && !isHypMode;
        bool allowVFiq   = !cpsr.f && hcr.fmo && !isSecure && !isHypMode;
        bool allowVAbort = !cpsr.a && hcr.amo && !isSecure && !isHypMode;

        if ( !(intStatus || (hcr.vi && allowVIrq) || (hcr.vf && allowVFiq) ||
               (hcr.va && allowVAbort)) )
            return false;

        bool take_irq = takeInt(tc, INT_IRQ);
        bool take_fiq = takeInt(tc, INT_FIQ);
        bool take_ea =  takeInt(tc, INT_ABT);

        return ((interrupts[INT_IRQ] && take_irq)                   ||
                (interrupts[INT_FIQ] && take_fiq)                   ||
                (interrupts[INT_ABT] && take_ea)                    ||
                ((interrupts[INT_VIRT_IRQ] || hcr.vi) && allowVIrq) ||
                ((interrupts[INT_VIRT_FIQ] || hcr.vf) && allowVFiq) ||
                (hcr.va && allowVAbort)                             ||
                (interrupts[INT_RST])                               ||
                (interrupts[INT_SEV])
               );
    }

    bool
    checkWfiWake(HCR hcr, CPSR cpsr, SCR scr) const
    {
        uint64_t maskedIntStatus;
        bool     virtWake;

        maskedIntStatus = intStatus & ~((1 << INT_VIRT_IRQ) |
                                        (1 << INT_VIRT_FIQ));
        virtWake  = (hcr.vi || interrupts[INT_VIRT_IRQ]) && hcr.imo;
        virtWake |= (hcr.vf || interrupts[INT_VIRT_FIQ]) && hcr.fmo;
        virtWake |=  hcr.va                              && hcr.amo;
        virtWake &= (cpsr.mode != MODE_HYP) && !inSecureState(scr, cpsr);
        return maskedIntStatus || virtWake;
    }

    uint32_t
    getISR(HCR hcr, CPSR cpsr, SCR scr)
    {
        bool useHcrMux;
        CPSR isr = 0; // ARM ARM states ISR reg uses same bit possitions as CPSR

        useHcrMux = (cpsr.mode != MODE_HYP) && !inSecureState(scr, cpsr);
        isr.i = (useHcrMux & hcr.imo) ? (interrupts[INT_VIRT_IRQ] || hcr.vi)
                                      :  interrupts[INT_IRQ];
        isr.f = (useHcrMux & hcr.fmo) ? (interrupts[INT_VIRT_FIQ] || hcr.vf)
                                      :  interrupts[INT_FIQ];
        isr.a = (useHcrMux & hcr.amo) ?  hcr.va : interrupts[INT_ABT];
        return isr;
    }

    bool
    checkRaw(InterruptTypes interrupt) const
    {
        if (interrupt >= NumInterruptTypes)
            panic("Interrupt number out of range.\n");

        return interrupts[interrupt];
    }

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

        HCR  hcr  = tc->readMiscReg(MISCREG_HCR);
        CPSR cpsr = tc->readMiscReg(MISCREG_CPSR);

        // Calculate a few temp vars so we can work out if there's a pending
        // virtual interrupt, and if its allowed to happen
        // ARM ARM Issue C section B1.9.9, B1.9.11, and B1.9.13
        bool isHypMode   = cpsr.mode == MODE_HYP;
        bool isSecure    = inSecureState(tc);
        bool allowVIrq   = !cpsr.i && hcr.imo && !isSecure && !isHypMode;
        bool allowVFiq   = !cpsr.f && hcr.fmo && !isSecure && !isHypMode;
        bool allowVAbort = !cpsr.a && hcr.amo && !isSecure && !isHypMode;

        bool take_irq = takeInt(tc, INT_IRQ);
        bool take_fiq = takeInt(tc, INT_FIQ);
        bool take_ea =  takeInt(tc, INT_ABT);

        if (interrupts[INT_IRQ] && take_irq)
            return std::make_shared<Interrupt>();
        if ((interrupts[INT_VIRT_IRQ] || hcr.vi) && allowVIrq)
            return std::make_shared<VirtualInterrupt>();
        if (interrupts[INT_FIQ] && take_fiq)
            return std::make_shared<FastInterrupt>();
        if ((interrupts[INT_VIRT_FIQ] || hcr.vf) && allowVFiq)
            return std::make_shared<VirtualFastInterrupt>();
        if (interrupts[INT_ABT] && take_ea)
            return std::make_shared<SystemError>();
        if (hcr.va && allowVAbort)
            return std::make_shared<VirtualDataAbort>(
                0, TlbEntry::DomainType::NoAccess, false,
                ArmFault::AsynchronousExternalAbort);
        if (interrupts[INT_RST])
            return std::make_shared<Reset>();
        if (interrupts[INT_SEV])
            return std::make_shared<ArmSev>();

        panic("intStatus and interrupts not in sync\n");
    }

    void
    updateIntrInfo(ThreadContext *tc)
    {
        ; // nothing to do
    }

    void
    serialize(CheckpointOut &cp) const
    {
        SERIALIZE_ARRAY(interrupts, NumInterruptTypes);
        SERIALIZE_SCALAR(intStatus);
    }

    void
    unserialize(CheckpointIn &cp)
    {
        UNSERIALIZE_ARRAY(interrupts, NumInterruptTypes);
        UNSERIALIZE_SCALAR(intStatus);
    }
};
} // namespace ARM_ISA

#endif // __ARCH_ARM_INTERRUPT_HH__