src/python/gem5/prebuilt/riscvmatched/riscvmatched_cache.py

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from gem5.components.cachehierarchies.abstract_cache_hierarchy import (
    AbstractCacheHierarchy,
)
from gem5.components.cachehierarchies.classic.abstract_classic_cache_hierarchy import (
    AbstractClassicCacheHierarchy,
)
from gem5.components.cachehierarchies.abstract_two_level_cache_hierarchy import (
    AbstractTwoLevelCacheHierarchy,
)
from gem5.components.cachehierarchies.classic.caches.l1dcache import L1DCache
from gem5.components.cachehierarchies.classic.caches.l1icache import L1ICache
from gem5.components.cachehierarchies.classic.caches.l2cache import L2Cache
from gem5.components.cachehierarchies.classic.caches.mmu_cache import MMUCache
from gem5.components.boards.abstract_board import AbstractBoard
from gem5.isas import ISA
from m5.objects import Cache, L2XBar, BaseXBar, SystemXBar, BadAddr, Port

from gem5.utils.override import *


class RISCVMatchedCacheHierarchy(
    AbstractClassicCacheHierarchy, AbstractTwoLevelCacheHierarchy
):
    """

    A cache setup where each core has a private L1 Data and Instruction Cache,
    and a private L2 cache.
    The HiFive board has a partially inclusive cache hierarchy, hence this hierarchy is chosen.
    The details of the cache hierarchy are in Table 7, page 36 of the datasheet.

    - L1 Instruction Cache:
        - 32 KiB 4-way set associative
    - L1 Data Cache
        - 32 KiB 8-way set associative
    - L2 Cache
        - 2 MiB 16-way set associative

    """

    def __init__(
        self,
        l2_size: str,
    ) -> None:
        """
        :param l2_size: The size of the L2 Cache (e.g., "256kB").
        :type l2_size: str
        """
        AbstractClassicCacheHierarchy.__init__(self=self)
        AbstractTwoLevelCacheHierarchy.__init__(
            self,
            l1i_size="32kB",
            l1i_assoc=4,
            l1d_size="32kB",
            l1d_assoc=8,
            l2_size=l2_size,
            l2_assoc=16,
        )

        self.membus = SystemXBar(width=64)
        self.membus.badaddr_responder = BadAddr()
        self.membus.default = self.membus.badaddr_responder.pio

    @overrides(AbstractClassicCacheHierarchy)
    def get_mem_side_port(self) -> Port:
        return self.membus.mem_side_ports

    @overrides(AbstractClassicCacheHierarchy)
    def get_cpu_side_port(self) -> Port:
        return self.membus.cpu_side_ports

    @overrides(AbstractCacheHierarchy)
    def incorporate_cache(self, board: AbstractBoard) -> None:

        # Set up the system port for functional access from the simulator.
        board.connect_system_port(self.membus.cpu_side_ports)

        for cntr in board.get_memory().get_memory_controllers():
            cntr.port = self.membus.mem_side_ports

        self.l1icaches = [
            L1ICache(size=self._l1i_size, assoc=self._l1i_assoc)
            for i in range(board.get_processor().get_num_cores())
        ]
        self.l1dcaches = [
            L1DCache(size=self._l1d_size, assoc=self._l1d_assoc)
            for i in range(board.get_processor().get_num_cores())
        ]
        self.l2buses = [
            L2XBar() for i in range(board.get_processor().get_num_cores())
        ]
        self.l2caches = [
            L2Cache(size=self._l2_size, assoc=self._l2_assoc)
            for i in range(board.get_processor().get_num_cores())
        ]
        # ITLB Page walk caches
        self.iptw_caches = [
            MMUCache(size="4KiB")
            for _ in range(board.get_processor().get_num_cores())
        ]
        # DTLB Page walk caches
        self.dptw_caches = [
            MMUCache(size="4KiB")
            for _ in range(board.get_processor().get_num_cores())
        ]

        if board.has_coherent_io():
            self._setup_io_cache(board)

        for i, cpu in enumerate(board.get_processor().get_cores()):

            cpu.connect_icache(self.l1icaches[i].cpu_side)
            cpu.connect_dcache(self.l1dcaches[i].cpu_side)

            self.l1icaches[i].mem_side = self.l2buses[i].cpu_side_ports
            self.l1dcaches[i].mem_side = self.l2buses[i].cpu_side_ports
            self.iptw_caches[i].mem_side = self.l2buses[i].cpu_side_ports
            self.dptw_caches[i].mem_side = self.l2buses[i].cpu_side_ports

            self.l2buses[i].mem_side_ports = self.l2caches[i].cpu_side

            self.membus.cpu_side_ports = self.l2caches[i].mem_side

            cpu.connect_walker_ports(
                self.iptw_caches[i].cpu_side, self.dptw_caches[i].cpu_side
            )

            if board.get_processor().get_isa() == ISA.X86:
                int_req_port = self.membus.mem_side_ports
                int_resp_port = self.membus.cpu_side_ports
                cpu.connect_interrupt(int_req_port, int_resp_port)
            else:
                cpu.connect_interrupt()

    def _setup_io_cache(self, board: AbstractBoard) -> None:
        """Create a cache for coherent I/O connections"""
        self.iocache = Cache(
            assoc=8,
            tag_latency=50,
            data_latency=50,
            response_latency=50,
            mshrs=20,
            size="1kB",
            tgts_per_mshr=12,
            addr_ranges=board.mem_ranges,
        )
        self.iocache.mem_side = self.membus.cpu_side_ports
        self.iocache.cpu_side = board.get_mem_side_coherent_io_port()