# Copyright (c) 2021 Huawei International
# Copyright (c) 2022 EXAscale Performance SYStems (EXAPSYS)
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from m5.objects.Platform import Platform
from m5.objects.PMAChecker import PMAChecker
from m5.objects.Clint import Clint
from m5.objects.Plic import Plic
from m5.objects.RTC import RiscvRTC
from m5.objects.Uart import RiscvUart8250
from m5.objects.Terminal import Terminal
from m5.params import *
from m5.proxy import *
from m5.util.fdthelper import *

from m5.objects.PciHost import GenericPciHost


class GenericRiscvPciHost(GenericPciHost):
    type = "GenericRiscvPciHost"
    cxx_header = "dev/riscv/pci_host.hh"
    cxx_class = "gem5::GenericRiscvPciHost"
    int_base = Param.Int(
        0x10, "Base number used as interrupt line and PLIC source."
    )
    int_count = Param.Unsigned(
        4, "Maximum number of interrupts used by this host"
    )
    # This python parameter can be used in configuration scripts to turn
    # on/off the fdt dma-coherent flag when doing dtb autogeneration
    _dma_coherent = True


class HiFive(Platform):
    """HiFive Platform

    Implementation:
        This is the base class for SiFive's HiFive
        board series. It contains the CLINT and PLIC
        interrupt controllers, Uart and Disk.

        Implementation details are based on SiFive
        FU540-C000. https://sifive.cdn.prismic.io/
        sifive/b5e7a29c-d3c2-44ea-85fb-acc1df282e2
        1_FU540-C000-v1p3.pdf

    Setup:
        The following sections outline the required
        setup for a RISC-V HiFive platform. See
        configs/example/riscv/fs_linux.py for example.

    Driving CLINT:
        CLINT has an interrupt pin which increments
        mtime. It can be connected to any interrupt
        source pin which acts as the RTCCLK pin. An
        abstract RTC wrapper called RiscvRTC can be
        used.

    Attaching PLIC devices:
        PLIC handles external interrupts. Interrupt
        PioDevices should inherit from PlicIntDevice
        (PCI and DMA not yet implemented). It contains
        a parameter interrupt_id which should be used
        to call platform->postPciInt(id).

        All PLIC interrupt devices should be returned
        by _off_chip_devices(). Calling attachPlic sets
        up the PLIC interrupt source count.

    Uart:
        The HiFive platform also has an uart_int_id.
        This is because Uart8250 uses postConsoleInt
        instead of postPciInt. In the future if a Uart
        that inherits PlicIntDevice is implemented,
        this can be removed.

    Disk:
        See fs_linux.py for setup example.

    PMAChecker:
        The PMAChecker will be attached to the MMU of
        each CPU (which allows them to differ). See
        fs_linux.py for setup example.
    """

    type = "HiFive"
    cxx_header = "dev/riscv/hifive.hh"
    cxx_class = "gem5::HiFive"

    # CLINT
    clint = Param.Clint(Clint(pio_addr=0x2000000), "CLINT")

    # PLIC
    plic = Param.Plic(Plic(pio_addr=0xC000000), "PLIC")

    # PCI
    pci_host = GenericRiscvPciHost(
        conf_base=0x30000000,
        conf_size="256MB",
        conf_device_bits=12,
        pci_pio_base=0x2F000000,
        pci_mem_base=0x40000000,
    )

    # Uart
    uart = RiscvUart8250(pio_addr=0x10000000)
    # Int source ID to redirect console interrupts to
    # Set to 0 if using a pci interrupt for Uart instead
    uart_int_id = Param.Int(0xA, "PLIC Uart interrupt ID")
    terminal = Terminal()

    def _on_chip_devices(self):
        """Returns a list of on-chip peripherals"""
        return [self.clint, self.plic]

    def _off_chip_devices(self):
        """Returns a list of off-chip peripherals"""
        devices = [self.uart]
        if hasattr(self, "disk"):
            devices.append(self.disk)
        if hasattr(self, "rng"):
            devices.append(self.rng)
        return devices

    def _on_chip_ranges(self):
        """Returns a list of on-chip peripherals
        address range
        """
        return [
            AddrRange(dev.pio_addr, size=dev.pio_size)
            for dev in self._on_chip_devices()
        ]

    def _off_chip_ranges(self):
        """Returns a list of off-chip peripherals
        address range
        """
        return [
            AddrRange(dev.pio_addr, size=dev.pio_size)
            for dev in self._off_chip_devices()
        ]

    def attachPlic(self):
        """Count number of PLIC interrupt sources"""
        plic_srcs = [
            self.uart_int_id,
            self.pci_host.int_base + self.pci_host.int_count,
        ]
        for device in self._off_chip_devices():
            if hasattr(device, "interrupt_id"):
                plic_srcs.append(device.interrupt_id)
        self.plic.n_src = max(plic_srcs) + 1

    def attachOnChipIO(self, bus):
        """Attach on-chip IO devices, needs modification
        to support DMA
        """
        for device in self._on_chip_devices():
            device.pio = bus.mem_side_ports

    def attachOffChipIO(self, bus):
        """Attach off-chip IO devices, needs modification
        to support DMA
        """
        for device in self._off_chip_devices():
            device.pio = bus.mem_side_ports

    def setNumCores(self, num_cpu):
        """Sets the PLIC and CLINT to have the right number of threads and
        contexts. Assumes that the cores have a single hardware thread.
        """
        self.plic.n_contexts = num_cpu * 2
        self.clint.num_threads = num_cpu

    def generateDeviceTree(self, state):
        cpus_node = FdtNode("cpus")
        cpus_node.append(FdtPropertyWords("timebase-frequency", [10000000]))
        yield cpus_node

        node = FdtNode("soc")
        local_state = FdtState(addr_cells=2, size_cells=2)
        node.append(local_state.addrCellsProperty())
        node.append(local_state.sizeCellsProperty())
        node.append(FdtProperty("ranges"))
        node.appendCompatible(["simple-bus"])

        for subnode in self.recurseDeviceTree(local_state):
            node.append(subnode)

        yield node

    # For generating devicetree
    _cpu_count = 0

    def annotateCpuDeviceNode(self, cpu, state):
        cpu.append(FdtPropertyStrings("mmu-type", "riscv,sv48"))
        cpu.append(FdtPropertyStrings("status", "okay"))
        cpu.append(FdtPropertyStrings("riscv,isa", "rv64imafdcsu"))
        cpu.appendCompatible(["riscv"])

        int_node = FdtNode("interrupt-controller")
        int_state = FdtState(interrupt_cells=1)
        int_node.append(int_state.interruptCellsProperty())
        int_node.append(FdtProperty("interrupt-controller"))
        int_node.appendCompatible("riscv,cpu-intc")

        cpus = self.system.unproxy(self).cpu
        phandle = int_state.phandle(cpus[self._cpu_count])
        self._cpu_count += 1
        int_node.append(FdtPropertyWords("phandle", [phandle]))

        cpu.append(int_node)