Add MMU MPRIV for easier machinemode emulation #60

src/main/scala/vexriscv/Pipeline.scala

@@ -7,14 +7,14 @@ import spinal.lib._
 import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
 
-trait PipelineConfig[T]
+trait PipelineThing[T]
 
 trait Pipeline {
   type T <: Pipeline
   val plugins = ArrayBuffer[Plugin[T]]()
   var stages = ArrayBuffer[Stage]()
   var unremovableStages = mutable.Set[Stage]()
-  val configs = mutable.HashMap[PipelineConfig[_], Any]()
+  val configs = mutable.HashMap[PipelineThing[_], Any]()
 //  val services = ArrayBuffer[Any]()
 
   def indexOf(stage : Stage) = stages.indexOf(stage)
@@ -37,8 +37,8 @@ trait Pipeline {
     filtered.head.asInstanceOf[T]
   }
 
-  def update[T](that : PipelineConfig[T], value : T) : Unit = configs(that) = value
+  def update[T](that : PipelineThing[T], value : T) : Unit = configs(that) = value
-  def apply[T](that : PipelineConfig[T]) : T = configs(that).asInstanceOf[T]
+  def apply[T](that : PipelineThing[T]) : T = configs(that).asInstanceOf[T]
 
   def build(): Unit ={
     plugins.foreach(_.pipeline = this.asInstanceOf[T])

src/main/scala/vexriscv/VexRiscv.scala

@@ -42,6 +42,7 @@ case class VexRiscvConfig(){
   object REGFILE_WRITE_VALID extends Stageable(Bool)
   object REGFILE_WRITE_DATA extends Stageable(Bits(32 bits))
 
+  object MPP extends PipelineThing[UInt]
 
   object SRC1   extends Stageable(Bits(32 bits))
   object SRC2   extends Stageable(Bits(32 bits))
@@ -79,7 +80,7 @@ case class VexRiscvConfig(){
 
 
 
-object RVC_GEN extends PipelineConfig[Boolean]
+object RVC_GEN extends PipelineThing[Boolean]
 class VexRiscv(val config : VexRiscvConfig) extends Component with Pipeline{
   type  T = VexRiscv
   import config._

src/main/scala/vexriscv/plugin/CsrPlugin.scala

@@ -499,6 +499,8 @@ class CsrPlugin(config: CsrPluginConfig) extends Plugin[VexRiscv] with Exception
       //User CSR
       ucycleAccess(CSR.UCYCLE, mcycle(31 downto 0))
       ucycleAccess(CSR.UCYCLEH, mcycle(63 downto 32))
+
+      pipeline.update(MPP, mstatus.MPP)
     }
 
     val supervisorCsr = ifGen(supervisorGen) {

src/main/scala/vexriscv/plugin/DBusSimplePlugin.scala

@@ -271,7 +271,7 @@ class DBusSimplePlugin(catchAddressMisaligned : Boolean = false,
     }
 
     if(memoryTranslatorPortConfig != null) {
-      mmuBus = pipeline.service(classOf[MemoryTranslator]).newTranslationPort(MemoryTranslatorPort.PRIORITY_INSTRUCTION, memoryTranslatorPortConfig)
+      mmuBus = pipeline.service(classOf[MemoryTranslator]).newTranslationPort(MemoryTranslatorPort.PRIORITY_DATA, memoryTranslatorPortConfig)
       redoBranch = pipeline.service(classOf[JumpService]).createJumpInterface(pipeline.memory)
     }
   }

src/main/scala/vexriscv/plugin/MmuPlugin.scala

@@ -87,14 +87,14 @@ class MmuPlugin(virtualRange : UInt => Bool,
 
     val csr = pipeline plug new Area{
       val status = new Area{
-        val sum, mxr = RegInit(False)
+        val sum, mxr, mprv = RegInit(False)
       }
       val satp = new Area {
         val mode = RegInit(False)
         val ppn = Reg(UInt(20 bits))
       }
 
-      for(offset <- List(CSR.MSTATUS, CSR.SSTATUS)) csrService.rw(offset, 19 -> status.mxr, 18 -> status.sum)
+      for(offset <- List(CSR.MSTATUS, CSR.SSTATUS)) csrService.rw(offset, 19 -> status.mxr, 18 -> status.sum, 17 -> status.mprv)
       csrService.rw(CSR.SATP, 31 -> satp.mode, 0 -> satp.ppn)  //TODO write only ?
     }
 
@@ -108,7 +108,10 @@ class MmuPlugin(virtualRange : UInt => Bool,
         val privilegeService = pipeline.serviceElse(classOf[PrivilegeService], PrivilegeServiceDefault())
         val entryToReplace = Counter(port.args.portTlbSize)
         val requireMmuLockup = virtualRange(port.bus.cmd.virtualAddress) && !port.bus.cmd.bypassTranslation && csr.satp.mode
-        if(!allowMachineModeMmu) requireMmuLockup clearWhen(privilegeService.isMachine())
+        if(!allowMachineModeMmu) {
+          requireMmuLockup clearWhen(!csr.status.mprv && privilegeService.isMachine())
+          if(port.priority == MmuPort.PRIORITY_DATA) requireMmuLockup clearWhen(csr.status.mprv && pipeline(config.MPP) === 3)
+        }
 
         when(requireMmuLockup) {
           port.bus.rsp.physicalAddress := cacheLine.physicalAddress(1) @@ (cacheLine.superPage ? port.bus.cmd.virtualAddress(21 downto 12) | cacheLine.physicalAddress(0)) @@ port.bus.cmd.virtualAddress(11 downto 0)