/*
 * Copyright (c) 2013 ARM Limited
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 *
 * 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.
 *
 * Copyright (c) 2004-2005 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
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 */

/* @file
 * Interface for devices using PCI configuration
 */

#ifndef __DEV_PCI_DEVICE_HH__
#define __DEV_PCI_DEVICE_HH__

#include <cstring>
#include <vector>

#include "dev/dma_device.hh"
#include "dev/pci/host.hh"
#include "dev/pci/pcireg.h"
#include "params/PciDevice.hh"
#include "sim/byteswap.hh"

#define BAR_IO_MASK 0x3
#define BAR_MEM_MASK 0xF
#define BAR_IO_SPACE_BIT 0x1
#define BAR_IO_SPACE(x) ((x) & BAR_IO_SPACE_BIT)
#define BAR_NUMBER(x) (((x) - PCI0_BASE_ADDR0) >> 0x2);

/**
 * PCI device, base implementation is only config space.
 */
class PciDevice : public DmaDevice
{
  protected:
    const PciBusAddr _busAddr;

    /** The current config space.  */
    PCIConfig config;

    /** The capability list structures and base addresses
     * @{
     */
    const int PMCAP_BASE;
    const int PMCAP_ID_OFFSET;
    const int PMCAP_PC_OFFSET;
    const int PMCAP_PMCS_OFFSET;
    PMCAP pmcap;

    const int MSICAP_BASE;
    MSICAP msicap;

    const int MSIXCAP_BASE;
    const int MSIXCAP_ID_OFFSET;
    const int MSIXCAP_MXC_OFFSET;
    const int MSIXCAP_MTAB_OFFSET;
    const int MSIXCAP_MPBA_OFFSET;
    int MSIX_TABLE_OFFSET;
    int MSIX_TABLE_END;
    int MSIX_PBA_OFFSET;
    int MSIX_PBA_END;
    MSIXCAP msixcap;

    const int PXCAP_BASE;
    PXCAP pxcap;
    /** @} */

    /** MSIX Table and PBA Structures */
    std::vector<MSIXTable> msix_table;
    std::vector<MSIXPbaEntry> msix_pba;

    /** The size of the BARs */
    uint32_t BARSize[6];

    /** The current address mapping of the BARs */
    Addr BARAddrs[6];

    /** Whether the BARs are really hardwired legacy IO locations. */
    bool legacyIO[6];

    /**
     * Does the given BAR represent 32 lower bits of a 64-bit address?
     */
    bool
    isLargeBAR(int bar) const
    {
        return bits(config.baseAddr[bar], 2, 1) == 0x2;
    }

    /**
     * Does the given address lie within the space mapped by the given
     * base address register?
     */
    bool
    isBAR(Addr addr, int bar) const
    {
        assert(bar >= 0 && bar < 6);
        return BARAddrs[bar] <= addr && addr < BARAddrs[bar] + BARSize[bar];
    }

    /**
     * Which base address register (if any) maps the given address?
     * @return The BAR number (0-5 inclusive), or -1 if none.
     */
    int
    getBAR(Addr addr)
    {
        for (int i = 0; i <= 5; ++i)
            if (isBAR(addr, i))
                return i;

        return -1;
    }

    /**
     * Which base address register (if any) maps the given address?
     * @param addr The address to check.
     * @retval bar The BAR number (0-5 inclusive),
     *             only valid if return value is true.
     * @retval offs The offset from the base address,
     *              only valid if return value is true.
     * @return True iff address maps to a base address register's region.
     */
    bool
    getBAR(Addr addr, int &bar, Addr &offs)
    {
        int b = getBAR(addr);
        if (b < 0)
            return false;

        offs = addr - BARAddrs[b];
        bar = b;
        return true;
    }

  public: // Host configuration interface
    /**
     * Write to the PCI config space data that is stored locally. This may be
     * overridden by the device but at some point it will eventually call this
     * for normal operations that it does not need to override.
     * @param pkt packet containing the write the offset into config space
     */
    virtual Tick writeConfig(PacketPtr pkt);


    /**
     * Read from the PCI config space data that is stored locally. This may be
     * overridden by the device but at some point it will eventually call this
     * for normal operations that it does not need to override.
     * @param pkt packet containing the write the offset into config space
     */
    virtual Tick readConfig(PacketPtr pkt);

  protected:
    PciHost::DeviceInterface hostInterface;

    Tick pioDelay;
    Tick configDelay;

  public:
    Addr pciToDma(Addr pci_addr) const {
        return hostInterface.dmaAddr(pci_addr);
    }

    void intrPost() { hostInterface.postInt(); }
    void intrClear() { hostInterface.clearInt(); }

    uint8_t interruptLine() const { return letoh(config.interruptLine); }

    /**
     * Determine the address ranges that this device responds to.
     *
     * @return a list of non-overlapping address ranges
     */
    AddrRangeList getAddrRanges() const override;

    /**
     * Constructor for PCI Dev. This function copies data from the
     * config file object PCIConfigData and registers the device with
     * a PciHost object.
     */
    PciDevice(const PciDeviceParams *params);

    /**
     * Serialize this object to the given output stream.
     * @param os The stream to serialize to.
     */
    void serialize(CheckpointOut &cp) const override;

    /**
     * Reconstruct the state of this object from a checkpoint.
     * @param cp The checkpoint use.
     * @param section The section name of this object
     */
    void unserialize(CheckpointIn &cp) override;

    const PciBusAddr &busAddr() const { return _busAddr; }
};
#endif // __DEV_PCI_DEVICE_HH__