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# Authors: Matteo Andreozzi

from m5.params import *
from AbstractMemory import AbstractMemory
from QoSTurnaround import *

# QoS Queue Selection policy used to select packets among same-QoS queues
class QoSQPolicy(Enum): vals = ["fifo", "lifo", "lrg"]

class QoSMemCtrl(AbstractMemory):
    type = 'QoSMemCtrl'
    cxx_header = "mem/qos/mem_ctrl.hh"
    cxx_class = 'QoS::MemCtrl'
    abstract = True

    ##### QoS support parameters ####

    # Number of priorities in the system
    qos_priorities = Param.Unsigned(1, "QoS priorities")

    # QoS scheduler policy: tags request with QoS priority value
    qos_policy = Param.QoSPolicy(NULL,
        "Memory Controller Requests QoS arbitration policy")

    # Select QoS driven turnaround policy
    # (direction switch triggered by highest priority buffer content)
    qos_turnaround_policy = Param.QoSTurnaroundPolicy(NULL,
        "Selects QoS driven turnaround policy")

    # QoS Queue Select policy: selects packets among same priority level
    # (only supported in QoSMemSinkCtrl)
    qos_q_policy = Param.QoSQPolicy('fifo',
        "Memory Controller Requests same-QoS selection policy")

    # flag to select QoS syncronised scheduling
    # (calls the scheduler on all masters at every packet arrival)
    qos_syncro_scheduler = Param.Bool(False,
        "Enables QoS syncronized scheduling")

    # flag to enable QoS priority escalation
    qos_priority_escalation = Param.Bool(False,
        "Enables QoS priority escalation")

    # Master ID to be mapped to service parameters in QoS schedulers
    qos_masters = VectorParam.String(['']* 16,
        "Master Names to be mapped to service parameters in QoS scheduler")