MMU now allow $ to match tag against tlb pyhsical values directly

D$ retiming
D$ directTlbHit feature added for better timings
This commit is contained in:
Dolu1990 2020-05-06 17:09:46 +02:00
parent ed4a89e4af
commit 6323caf265
10 changed files with 97 additions and 53 deletions

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@ -68,17 +68,24 @@ case class MemoryTranslatorCmd() extends Bundle{
val virtualAddress = UInt(32 bits)
val bypassTranslation = Bool
}
case class MemoryTranslatorRsp() extends Bundle{
case class MemoryTranslatorRsp(wayCount : Int) extends Bundle{
val physicalAddress = UInt(32 bits)
val isIoAccess = Bool
val allowRead, allowWrite, allowExecute = Bool
val exception = Bool
val refilling = Bool
val bypassTranslation = Bool
val ways = Vec(MemoryTranslatorRspWay(), wayCount)
}
case class MemoryTranslatorRspWay() extends Bundle{
val sel = Bool()
val physical = UInt(32 bits)
}
case class MemoryTranslatorBus() extends Bundle with IMasterSlave{
case class MemoryTranslatorBus(wayCount : Int) extends Bundle with IMasterSlave{
val cmd = MemoryTranslatorCmd()
val rsp = MemoryTranslatorRsp()
val rsp = MemoryTranslatorRsp(wayCount)
val end = Bool
val busy = Bool

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@ -28,6 +28,7 @@ case class DataCacheConfig(cacheSize : Int,
withExclusive : Boolean = false,
withInvalidate : Boolean = false,
pendingMax : Int = 32,
directTlbHit : Boolean = false,
mergeExecuteMemory : Boolean = false){
assert(!(mergeExecuteMemory && (earlyDataMux || earlyWaysHits)))
assert(!(earlyDataMux && !earlyWaysHits))
@ -124,13 +125,13 @@ case class DataCacheCpuExecuteArgs(p : DataCacheConfig) extends Bundle{
val totalyConsistent = Bool() //Only for AMO/LRSC
}
case class DataCacheCpuMemory(p : DataCacheConfig) extends Bundle with IMasterSlave{
case class DataCacheCpuMemory(p : DataCacheConfig, tlbWayCount : Int) extends Bundle with IMasterSlave{
val isValid = Bool
val isStuck = Bool
val isRemoved = Bool
val isWrite = Bool
val address = UInt(p.addressWidth bit)
val mmuBus = MemoryTranslatorBus()
val mmuBus = MemoryTranslatorBus(tlbWayCount)
override def asMaster(): Unit = {
out(isValid, isStuck, isRemoved, address)
@ -174,9 +175,9 @@ case class DataCacheCpuWriteBack(p : DataCacheConfig) extends Bundle with IMaste
}
}
case class DataCacheCpuBus(p : DataCacheConfig) extends Bundle with IMasterSlave{
case class DataCacheCpuBus(p : DataCacheConfig, tlbWayCount : Int) extends Bundle with IMasterSlave{
val execute = DataCacheCpuExecute(p)
val memory = DataCacheCpuMemory(p)
val memory = DataCacheCpuMemory(p, tlbWayCount)
val writeBack = DataCacheCpuWriteBack(p)
val redo = Bool()
@ -422,11 +423,11 @@ object DataCacheExternalAmoStates extends SpinalEnum{
}
//If external amo, mem rsp should stay
class DataCache(val p : DataCacheConfig) extends Component{
class DataCache(val p : DataCacheConfig, tlbWayCount : Int) extends Component{
import p._
val io = new Bundle{
val cpu = slave(DataCacheCpuBus(p))
val cpu = slave(DataCacheCpuBus(p, tlbWayCount))
val mem = master(DataCacheMemBus(p))
}
@ -537,11 +538,12 @@ class DataCache(val p : DataCacheConfig) extends Component{
val memCmdSent = RegInit(False) setWhen (io.mem.cmd.ready) clearWhen (!io.cpu.writeBack.isStuck)
val pending = withExclusive generate new Area{
val counter = Reg(UInt(log2Up(pendingMax) + 1 bits)) init(0)
counter := counter + U(io.mem.cmd.fire && io.mem.cmd.last) - U(io.mem.rsp.valid && io.mem.rsp.last)
val counterNext = counter + U(io.mem.cmd.fire && io.mem.cmd.last) - U(io.mem.rsp.valid && io.mem.rsp.last)
counter := counterNext
val done = counter === 0
val full = RegNext(counter.msb)
val last = counter === 1
val done = RegNext(counterNext === 0)
val full = RegNext(counter.msb) //Has margin
val last = RegNext(counterNext === 1) //Equivalent to counter === 1 but pipelined
if(!withInvalidate) {
io.cpu.execute.haltIt setWhen(full)
@ -643,7 +645,19 @@ class DataCache(val p : DataCacheConfig) extends Component{
}
}
val wayHits = earlyWaysHits generate ways.map(way => (io.cpu.memory.mmuBus.rsp.physicalAddress(tagRange) === way.tagsReadRsp.address && way.tagsReadRsp.valid))
val wayHits = earlyWaysHits generate Bits(wayCount bits)
val indirectTlbHitGen = (earlyWaysHits && !directTlbHit) generate new Area {
wayHits := B(ways.map(way => (io.cpu.memory.mmuBus.rsp.physicalAddress(tagRange) === way.tagsReadRsp.address && way.tagsReadRsp.valid)))
}
val directTlbHitGen = (earlyWaysHits && directTlbHit) generate new Area {
val wayTlbHits = for (way <- ways) yield for (tlb <- io.cpu.memory.mmuBus.rsp.ways) yield {
way.tagsReadRsp.address === tlb.physical(tagRange) && tlb.sel
}
val translatedHits = B(wayTlbHits.map(_.orR))
val bypassHits = B(ways.map(_.tagsReadRsp.address === io.cpu.memory.address(tagRange)))
wayHits := (io.cpu.memory.mmuBus.rsp.bypassTranslation ? bypassHits | translatedHits) & B(ways.map(_.tagsReadRsp.valid))
}
val dataMux = earlyDataMux generate MuxOH(wayHits, ways.map(_.dataReadRsp))
val wayInvalidate = stagePipe(stage0. wayInvalidate)
val dataColisions = if(mergeExecuteMemory){

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@ -104,7 +104,7 @@ trait InstructionCacheCommons{
val cacheMiss, error, mmuRefilling, mmuException, isUser : Bool
}
case class InstructionCacheCpuFetch(p : InstructionCacheConfig) extends Bundle with IMasterSlave with InstructionCacheCommons {
case class InstructionCacheCpuFetch(p : InstructionCacheConfig, tlbWayCount : Int) extends Bundle with IMasterSlave with InstructionCacheCommons {
val isValid = Bool()
val isStuck = Bool()
val isRemoved = Bool()
@ -112,7 +112,7 @@ case class InstructionCacheCpuFetch(p : InstructionCacheConfig) extends Bundle w
val data = Bits(p.cpuDataWidth bits)
val dataBypassValid = p.bypassGen generate Bool()
val dataBypass = p.bypassGen generate Bits(p.cpuDataWidth bits)
val mmuBus = MemoryTranslatorBus()
val mmuBus = MemoryTranslatorBus(tlbWayCount)
val physicalAddress = UInt(p.addressWidth bits)
val cacheMiss, error, mmuRefilling, mmuException, isUser = ifGen(!p.twoCycleCache)(Bool)
val haltIt = Bool() //Used to wait on the MMU rsp busy
@ -141,9 +141,9 @@ case class InstructionCacheCpuDecode(p : InstructionCacheConfig) extends Bundle
}
}
case class InstructionCacheCpuBus(p : InstructionCacheConfig) extends Bundle with IMasterSlave{
case class InstructionCacheCpuBus(p : InstructionCacheConfig, tlbWayCount : Int) extends Bundle with IMasterSlave{
val prefetch = InstructionCacheCpuPrefetch(p)
val fetch = InstructionCacheCpuFetch(p)
val fetch = InstructionCacheCpuFetch(p, tlbWayCount)
val decode = InstructionCacheCpuDecode(p)
val fill = Flow(UInt(p.addressWidth bits))
@ -277,11 +277,11 @@ case class InstructionCacheFlushBus() extends Bundle with IMasterSlave{
}
}
class InstructionCache(p : InstructionCacheConfig) extends Component{
class InstructionCache(p : InstructionCacheConfig, tlbWayCount : Int) extends Component{
import p._
val io = new Bundle{
val flush = in Bool()
val cpu = slave(InstructionCacheCpuBus(p))
val cpu = slave(InstructionCacheCpuBus(p, tlbWayCount))
val mem = master(InstructionCacheMemBus(p))
}

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@ -171,9 +171,12 @@ class DBusCachedPlugin(val config : DataCacheConfig,
import pipeline.config._
val cache = new DataCache(this.config.copy(
val cache = new DataCache(
this.config.copy(
mergeExecuteMemory = writeBack == null
))
),
tlbWayCount = mmuBus.rsp.wayCount
)
//Interconnect the plugin dBus with the cache dBus with some optional pipelining
def optionPipe[T](cond : Boolean, on : T)(f : T => T) : T = if(cond) f(on) else on

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@ -298,7 +298,6 @@ class DBusSimplePlugin(catchAddressMisaligned : Boolean = false,
object MEMORY_ADDRESS_LOW extends Stageable(UInt(2 bits))
object ALIGNEMENT_FAULT extends Stageable(Bool)
object MMU_FAULT extends Stageable(Bool)
object MMU_RSP extends Stageable(MemoryTranslatorRsp())
object MEMORY_ATOMIC extends Stageable(Bool)
object ATOMIC_HIT extends Stageable(Bool)
object MEMORY_STORE extends Stageable(Bool)
@ -393,6 +392,8 @@ class DBusSimplePlugin(catchAddressMisaligned : Boolean = false,
import pipeline._
import pipeline.config._
object MMU_RSP extends Stageable(MemoryTranslatorRsp(mmuBus.rsp.wayCount))
dBus = master(DBusSimpleBus()).setName("dBus")

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@ -124,7 +124,7 @@ class IBusCachedPlugin(resetVector : BigInt = 0x80000000l,
import pipeline.config._
pipeline plug new FetchArea(pipeline) {
val cache = new InstructionCache(IBusCachedPlugin.this.config.copy(bypassGen = tightlyGen))
val cache = new InstructionCache(IBusCachedPlugin.this.config.copy(bypassGen = tightlyGen), mmuBus.rsp.wayCount)
iBus = master(new InstructionCacheMemBus(IBusCachedPlugin.this.config)).setName("iBus")
iBus <> cache.io.mem
iBus.cmd.address.allowOverride := cache.io.mem.cmd.address

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@ -22,8 +22,8 @@ class MemoryTranslatorPlugin(tlbSize : Int,
val portsInfo = ArrayBuffer[MemoryTranslatorPort]()
override def newTranslationPort(priority : Int,args : Any): MemoryTranslatorBus = {
// val exceptionBus = pipeline.service(classOf[ExceptionService]).newExceptionPort(stage)
val port = MemoryTranslatorPort(MemoryTranslatorBus(),priority,args.asInstanceOf[MemoryTranslatorPortConfig]/*,exceptionBus*/)
val config = args.asInstanceOf[MemoryTranslatorPortConfig]
val port = MemoryTranslatorPort(MemoryTranslatorBus(0),priority, config/*,exceptionBus*/)
portsInfo += port
port.bus
}

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@ -47,7 +47,8 @@ class MmuPlugin(ioRange : UInt => Bool,
val portsInfo = ArrayBuffer[MmuPort]()
override def newTranslationPort(priority : Int,args : Any): MemoryTranslatorBus = {
val port = MmuPort(MemoryTranslatorBus(),priority,args.asInstanceOf[MmuPortConfig], portsInfo.length)
val config = args.asInstanceOf[MmuPortConfig]
val port = MmuPort(MemoryTranslatorBus(config.portTlbSize),priority, config, portsInfo.length)
portsInfo += port
port.bus
}
@ -71,7 +72,7 @@ class MmuPlugin(ioRange : UInt => Bool,
val csrService = pipeline.service(classOf[CsrInterface])
//Sorted by priority
val sortedPortsInfo = portsInfo.sortWith((a,b) => a.priority > b.priority)
val sortedPortsInfo = portsInfo.sortBy(_.priority)
case class CacheLine() extends Bundle {
val valid, exception, superPage = Bool
@ -137,6 +138,12 @@ class MmuPlugin(ioRange : UInt => Bool,
}
port.bus.rsp.isIoAccess := ioRange(port.bus.rsp.physicalAddress)
port.bus.rsp.bypassTranslation := !requireMmuLockup
for(wayId <- 0 until port.args.portTlbSize){
port.bus.rsp.ways(wayId).sel := cacheHits(wayId)
port.bus.rsp.ways(wayId).physical := cache(wayId).physicalAddress(1) @@ (cache(wayId).superPage ? port.bus.cmd.virtualAddress(21 downto 12) | cache(wayId).physicalAddress(0)) @@ port.bus.cmd.virtualAddress(11 downto 0)
}
// Avoid keeping any invalid line in the cache after an exception.
// https://github.com/riscv/riscv-linux/blob/8fe28cb58bcb235034b64cbbb7550a8a43fd88be/arch/riscv/include/asm/pgtable.h#L276
when(service(classOf[IContextSwitching]).isContextSwitching) {
@ -154,21 +161,23 @@ class MmuPlugin(ioRange : UInt => Bool,
}
val state = RegInit(State.IDLE)
val vpn = Reg(Vec(UInt(10 bits), UInt(10 bits)))
val portId = Reg(UInt(log2Up(portsInfo.length) bits))
val portSortedOh = Reg(Bits(portsInfo.length bits))
case class PTE() extends Bundle {
val V, R, W ,X, U, G, A, D = Bool()
val RSW = Bits(2 bits)
val PPN0 = UInt(10 bits)
val PPN1 = UInt(12 bits)
}
val dBusRspStaged = dBusAccess.rsp.stage()
val dBusRsp = new Area{
val pte = PTE()
pte.assignFromBits(dBusAccess.rsp.data)
val exception = !pte.V || (!pte.R && pte.W) || dBusAccess.rsp.error
pte.assignFromBits(dBusRspStaged.data)
val exception = !pte.V || (!pte.R && pte.W) || dBusRspStaged.error
val leaf = pte.R || pte.X
}
val pteBuffer = RegNextWhen(dBusRsp.pte, dBusAccess.rsp.valid && !dBusAccess.rsp.redo)
val pteBuffer = RegNextWhen(dBusRsp.pte, dBusRspStaged.valid && !dBusRspStaged.redo)
dBusAccess.cmd.valid := False
dBusAccess.cmd.write := False
@ -176,16 +185,25 @@ class MmuPlugin(ioRange : UInt => Bool,
dBusAccess.cmd.address.assignDontCare()
dBusAccess.cmd.data.assignDontCare()
dBusAccess.cmd.writeMask.assignDontCare()
val refills = OHMasking.last(B(sortedPortsInfo.map(port => port.bus.cmd.isValid && port.bus.rsp.refilling)))
switch(state){
is(State.IDLE){
for(port <- portsInfo.sortBy(_.priority)){
when(port.bus.cmd.isValid && port.bus.rsp.refilling){
vpn(1) := port.bus.cmd.virtualAddress(31 downto 22)
vpn(0) := port.bus.cmd.virtualAddress(21 downto 12)
portId := port.id
when(refills.orR){
portSortedOh := refills
state := State.L1_CMD
val address = MuxOH(refills, sortedPortsInfo.map(_.bus.cmd.virtualAddress))
vpn(1) := address(31 downto 22)
vpn(0) := address(21 downto 12)
}
}
// for(port <- portsInfo.sortBy(_.priority)){
// when(port.bus.cmd.isValid && port.bus.rsp.refilling){
// vpn(1) := port.bus.cmd.virtualAddress(31 downto 22)
// vpn(0) := port.bus.cmd.virtualAddress(21 downto 12)
// portId := port.id
// state := State.L1_CMD
// }
// }
}
is(State.L1_CMD){
dBusAccess.cmd.valid := True
@ -195,12 +213,12 @@ class MmuPlugin(ioRange : UInt => Bool,
}
}
is(State.L1_RSP){
when(dBusAccess.rsp.valid){
when(dBusRspStaged.valid){
state := State.L0_CMD
when(dBusRsp.leaf || dBusRsp.exception){
state := State.IDLE
}
when(dBusAccess.rsp.redo){
when(dBusRspStaged.redo){
state := State.L1_CMD
}
}
@ -213,22 +231,22 @@ class MmuPlugin(ioRange : UInt => Bool,
}
}
is(State.L0_RSP){
when(dBusAccess.rsp.valid) {
when(dBusRspStaged.valid) {
state := State.IDLE
when(dBusAccess.rsp.redo){
when(dBusRspStaged.redo){
state := State.L0_CMD
}
}
}
}
for(port <- ports) {
port.handle.bus.busy := state =/= State.IDLE && portId === port.id
for((port, id) <- sortedPortsInfo.zipWithIndex) {
port.bus.busy := state =/= State.IDLE && portSortedOh(id)
}
when(dBusAccess.rsp.valid && !dBusAccess.rsp.redo && (dBusRsp.leaf || dBusRsp.exception)){
for(port <- ports){
when(portId === port.id) {
when(dBusRspStaged.valid && !dBusRspStaged.redo && (dBusRsp.leaf || dBusRsp.exception)){
for((port, id) <- ports.zipWithIndex) {
when(portSortedOh(id)) {
port.entryToReplace.increment()
for ((line, lineId) <- port.cache.zipWithIndex) {
when(port.entryToReplace === lineId){

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@ -11,8 +11,7 @@ class StaticMemoryTranslatorPlugin(ioRange : UInt => Bool) extends Plugin[VexRis
val portsInfo = ArrayBuffer[StaticMemoryTranslatorPort]()
override def newTranslationPort(priority : Int,args : Any): MemoryTranslatorBus = {
// val exceptionBus = pipeline.service(classOf[ExceptionService]).newExceptionPort(stage)
val port = StaticMemoryTranslatorPort(MemoryTranslatorBus(),priority)
val port = StaticMemoryTranslatorPort(MemoryTranslatorBus(0),priority)
portsInfo += port
port.bus
}

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@ -436,13 +436,14 @@ class DBusDimension extends VexRiscvDimension("DBus") {
val dBusRspSlavePipe = r.nextBoolean() || withSmp
val relaxedMemoryTranslationRegister = r.nextBoolean()
val earlyWaysHits = r.nextBoolean() && !noWriteBack
val directTlbHit = r.nextBoolean() && mmuConfig.isInstanceOf[MmuPortConfig]
val dBusCmdMasterPipe, dBusCmdSlavePipe = false //As it create test bench issues
do{
cacheSize = 512 << r.nextInt(5)
wayCount = 1 << r.nextInt(3)
}while(cacheSize/wayCount < 512 || (catchAll && cacheSize/wayCount > 4096))
new VexRiscvPosition(s"Cached${memDataWidth}d" + "S" + cacheSize + "W" + wayCount + "BPL" + bytePerLine + (if(dBusCmdMasterPipe) "Cmp " else "") + (if(dBusCmdSlavePipe) "Csp " else "") + (if(dBusRspSlavePipe) "Rsp " else "") + (if(relaxedMemoryTranslationRegister) "Rmtr " else "") + (if(earlyWaysHits) "Ewh " else "") + (if(withAmo) "Amo " else "") + (if(withSmp) "Smp " else "")) {
new VexRiscvPosition(s"Cached${memDataWidth}d" + "S" + cacheSize + "W" + wayCount + "BPL" + bytePerLine + (if(dBusCmdMasterPipe) "Cmp " else "") + (if(dBusCmdSlavePipe) "Csp " else "") + (if(dBusRspSlavePipe) "Rsp " else "") + (if(relaxedMemoryTranslationRegister) "Rmtr " else "") + (if(earlyWaysHits) "Ewh " else "") + (if(withAmo) "Amo " else "") + (if(withSmp) "Smp " else "") + (if(directTlbHit) "Dtlb " else "")) {
override def testParam = s"DBUS=CACHED DBUS_DATA_WIDTH=$memDataWidth " + (if(withLrSc) "LRSC=yes " else "") + (if(withAmo) "AMO=yes " else "") + (if(withSmp) "DBUS_EXCLUSIVE=yes DBUS_INVALIDATE=yes " else "")
override def applyOn(config: VexRiscvConfig): Unit = {
@ -461,7 +462,8 @@ class DBusDimension extends VexRiscvDimension("DBus") {
withAmo = withAmo,
earlyWaysHits = earlyWaysHits,
withExclusive = withSmp,
withInvalidate = withSmp
withInvalidate = withSmp,
directTlbHit = directTlbHit
),
dBusCmdMasterPipe = dBusCmdMasterPipe,
dBusCmdSlavePipe = dBusCmdSlavePipe,