/*
 * Copyright (c) 2015-2017 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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.
 */

#ifndef __ARCH_ARM_KVM_GIC_HH__
#define __ARCH_ARM_KVM_GIC_HH__

#include "arch/arm/system.hh"
#include "cpu/kvm/device.hh"
#include "cpu/kvm/vm.hh"
#include "dev/arm/gic_v2.hh"
#include "dev/platform.hh"

namespace gem5
{

/**
 * KVM in-kernel GIC abstraction
 *
 * This class defines a high-level interface to the KVM in-kernel GIC
 * model. It exposes an API that is similar to that of
 * software-emulated GIC models in gem5.
 */
class KvmKernelGicV2 : public BaseGicRegisters
{
  public:
    /**
     * Instantiate a KVM in-kernel GIC model.
     *
     * This constructor instantiates an in-kernel GIC model and wires
     * it up to the virtual memory system.
     *
     * @param vm KVM VM representing this system
     * @param cpu_addr GIC CPU interface base address
     * @param dist_addr GIC distributor base address
     * @param it_lines Number of interrupt lines to support
     */
    KvmKernelGicV2(KvmVM &vm, Addr cpu_addr, Addr dist_addr,
                   unsigned it_lines);
    virtual ~KvmKernelGicV2();

    KvmKernelGicV2(const KvmKernelGicV2 &other) = delete;
    KvmKernelGicV2(const KvmKernelGicV2 &&other) = delete;
    KvmKernelGicV2 &operator=(const KvmKernelGicV2 &&rhs) = delete;
    KvmKernelGicV2 &operator=(const KvmKernelGicV2 &rhs) = delete;

  public:
    /**
     * @{
     * @name In-kernel GIC API
     */

    /**
     * Raise a shared peripheral interrupt
     *
     * @param spi SPI number
     */
    void setSPI(unsigned spi);
    /**
     * Clear a shared peripheral interrupt
     *
     * @param spi SPI number
     */
    void clearSPI(unsigned spi);

    /**
     * Raise a private peripheral interrupt
     *
     * @param vcpu KVM virtual CPU number
     * @parma ppi PPI interrupt number
     */
    void setPPI(unsigned vcpu, unsigned ppi);

    /**
     * Clear a private peripheral interrupt
     *
     * @param vcpu KVM virtual CPU number
     * @parma ppi PPI interrupt number
     */
    void clearPPI(unsigned vcpu, unsigned ppi);

    /** Address range for the CPU interfaces */
    const AddrRange cpuRange;
    /** Address range for the distributor interface */
    const AddrRange distRange;

    /** BaseGicRegisters interface */
    uint32_t readDistributor(ContextID ctx, Addr daddr) override;
    uint32_t readCpu(ContextID ctx, Addr daddr) override;

    void writeDistributor(ContextID ctx, Addr daddr,
                          uint32_t data) override;
    void writeCpu(ContextID ctx, Addr daddr, uint32_t data) override;

    /* @} */

  protected:
    /**
     * Update the kernel's VGIC interrupt state
     *
     * @param type Interrupt type (KVM_ARM_IRQ_TYPE_PPI/KVM_ARM_IRQ_TYPE_SPI)
     * @param vcpu CPU id within KVM (ignored for SPIs)
     * @param irq Interrupt number
     * @param high True to signal an interrupt, false to clear it.
     */
    void setIntState(unsigned type, unsigned vcpu, unsigned irq, bool high);

    /**
     * Get value of GIC register "from" a cpu
     *
     * @param group Distributor or CPU (KVM_DEV_ARM_VGIC_GRP_{DIST,CPU}_REGS)
     * @param vcpu CPU id within KVM
     * @param offset register offset
     */
    uint32_t getGicReg(unsigned group, unsigned vcpu, unsigned offset);

    /**
     * Set value of GIC register "from" a cpu
     *
     * @param group Distributor or CPU (KVM_DEV_ARM_VGIC_GRP_{DIST,CPU}_REGS)
     * @param vcpu CPU id within KVM
     * @param offset register offset
     * @param value value to set register to
     */
    void setGicReg(unsigned group, unsigned vcpu, unsigned offset,
                   unsigned value);

    /** KVM VM in the parent system */
    KvmVM &vm;

    /** Kernel interface to the GIC */
    KvmDevice kdev;
};


struct MuxingKvmGicParams;

class MuxingKvmGic : public GicV2
{
  public: // SimObject / Serializable / Drainable
    MuxingKvmGic(const MuxingKvmGicParams &p);
    ~MuxingKvmGic();

    void startup() override;
    DrainState drain() override;
    void drainResume() override;

  public: // PioDevice
    Tick read(PacketPtr pkt) override;
    Tick write(PacketPtr pkt) override;

  public: // GicV2
    void sendInt(uint32_t num) override;
    void clearInt(uint32_t num) override;

    void sendPPInt(uint32_t num, uint32_t cpu) override;
    void clearPPInt(uint32_t num, uint32_t cpu) override;

  protected: // GicV2
    void updateIntState(int hint) override;

  protected:
    /** System this interrupt controller belongs to */
    System &system;

    /** Kernel GIC device */
    KvmKernelGicV2 *kernelGic;

  private:
    bool usingKvm;

    /** Multiplexing implementation */
    void fromGicV2ToKvm();
    void fromKvmToGicV2();

    void copyGicState(BaseGicRegisters* from, BaseGicRegisters* to);

    void copyDistRegister(BaseGicRegisters* from, BaseGicRegisters* to,
                          ContextID ctx, Addr daddr);
    void copyCpuRegister(BaseGicRegisters* from, BaseGicRegisters* to,
                         ContextID ctx, Addr daddr);

    void copyBankedDistRange(BaseGicRegisters* from, BaseGicRegisters* to,
                             Addr daddr, size_t size);
    void clearBankedDistRange(BaseGicRegisters* to,
                              Addr daddr, size_t size);
    void copyDistRange(BaseGicRegisters* from, BaseGicRegisters* to,
                       Addr daddr, size_t size);
    void clearDistRange(BaseGicRegisters* to,
                        Addr daddr, size_t size);
};

} // namespace gem5

#endif // __ARCH_ARM_KVM_GIC_HH__