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rocket-chip/src/main/scala/tile/LazyRoCC.scala

393 lines
12 KiB
Scala

// See LICENSE.Berkeley for license details.
// See LICENSE.SiFive for license details.
package freechips.rocketchip.tile
import Chisel._
import freechips.rocketchip.config._
import freechips.rocketchip.coreplex._
import freechips.rocketchip.diplomacy._
import freechips.rocketchip.rocket._
import freechips.rocketchip.tilelink._
import freechips.rocketchip.util.InOrderArbiter
case object RoccNPTWPorts extends Field[Int]
case object BuildRoCC extends Field[Seq[RoCCParams]]
case class RoCCParams(
opcodes: OpcodeSet,
generator: Parameters => LazyRoCC,
nPTWPorts : Int = 0,
useFPU: Boolean = false)
class RoCCInstruction extends Bundle
{
val funct = Bits(width = 7)
val rs2 = Bits(width = 5)
val rs1 = Bits(width = 5)
val xd = Bool()
val xs1 = Bool()
val xs2 = Bool()
val rd = Bits(width = 5)
val opcode = Bits(width = 7)
}
class RoCCCommand(implicit p: Parameters) extends CoreBundle()(p) {
val inst = new RoCCInstruction
val rs1 = Bits(width = xLen)
val rs2 = Bits(width = xLen)
val status = new MStatus
}
class RoCCResponse(implicit p: Parameters) extends CoreBundle()(p) {
val rd = Bits(width = 5)
val data = Bits(width = xLen)
}
class RoCCCoreIO(implicit p: Parameters) extends CoreBundle()(p) {
val cmd = Decoupled(new RoCCCommand).flip
val resp = Decoupled(new RoCCResponse)
val mem = new HellaCacheIO
val busy = Bool(OUTPUT)
val interrupt = Bool(OUTPUT)
val exception = Bool(INPUT)
override def cloneType = new RoCCCoreIO()(p).asInstanceOf[this.type]
}
/** Base classes for Diplomatic TL2 RoCC units **/
abstract class LazyRoCC(implicit p: Parameters) extends LazyModule {
val module: LazyRoCCModule
val atlNode: TLMixedNode = TLIdentityNode()
val tlNode: TLMixedNode = TLIdentityNode()
}
class RoCCIO(outer: LazyRoCC)(implicit p: Parameters) extends RoCCCoreIO()(p) {
// Should be handled differently, eventually
val ptw = Vec(p(RoccNPTWPorts), new TLBPTWIO)
val fpu_req = Decoupled(new FPInput)
val fpu_resp = Decoupled(new FPResult).flip
}
class LazyRoCCModule(outer: LazyRoCC) extends LazyModuleImp(outer) {
val io = IO(new RoCCIO(outer))
}
/** Mixins for including RoCC **/
trait HasLazyRoCC extends CanHaveSharedFPU with CanHavePTW with HasTileLinkMasterPort {
implicit val p: Parameters
val module: HasLazyRoCCModule
val roccs = p(BuildRoCC).zipWithIndex.map { case (accelParams, i) =>
accelParams.generator(p.alterPartial({
case RoccNPTWPorts => accelParams.nPTWPorts
}))}
roccs.map(_.atlNode).foreach { atl => tileBus.node :=* atl }
roccs.map(_.tlNode).foreach { tl => masterNode :=* tl }
nPTWPorts += p(BuildRoCC).map(_.nPTWPorts).foldLeft(0)(_ + _)
nDCachePorts += roccs.size
}
trait HasLazyRoCCModule extends CanHaveSharedFPUModule
with CanHavePTWModule
with HasCoreParameters
with HasTileLinkMasterPortModule {
val outer: HasLazyRoCC
val roccCore = Wire(new RoCCCoreIO()(outer.p))
val buildRocc = outer.p(BuildRoCC)
val usingRocc = !buildRocc.isEmpty
val nRocc = buildRocc.size
val nFPUPorts = buildRocc.filter(_.useFPU).size
val roccOpcodes = buildRocc.map(_.opcodes)
if(usingRocc) {
val respArb = Module(new RRArbiter(new RoCCResponse()(outer.p), nRocc))
roccCore.resp <> respArb.io.out
val cmdRouter = Module(new RoccCommandRouter(roccOpcodes)(outer.p))
cmdRouter.io.in <> roccCore.cmd
outer.roccs.zipWithIndex.foreach { case (rocc, i) =>
ptwPorts ++= rocc.module.io.ptw
rocc.module.io.cmd <> cmdRouter.io.out(i)
rocc.module.io.exception := roccCore.exception
val dcIF = Module(new SimpleHellaCacheIF()(outer.p))
dcIF.io.requestor <> rocc.module.io.mem
dcachePorts += dcIF.io.cache
respArb.io.in(i) <> Queue(rocc.module.io.resp)
}
roccCore.busy := cmdRouter.io.busy || outer.roccs.map(_.module.io.busy).reduce(_ || _)
roccCore.interrupt := outer.roccs.map(_.module.io.interrupt).reduce(_ || _)
fpuOpt foreach { fpu =>
if (usingFPU && nFPUPorts > 0) {
val fpArb = Module(new InOrderArbiter(new FPInput()(outer.p), new FPResult()(outer.p), nFPUPorts))
val fp_rocc_ios = outer.roccs.zip(buildRocc)
.filter { case (_, params) => params.useFPU }
.map { case (rocc, _) => rocc.module.io }
fpArb.io.in_req <> fp_rocc_ios.map(_.fpu_req)
fp_rocc_ios.zip(fpArb.io.in_resp).foreach {
case (rocc, arb) => rocc.fpu_resp <> arb
}
fpu.io.cp_req <> fpArb.io.out_req
fpArb.io.out_resp <> fpu.io.cp_resp
} else {
fpu.io.cp_req.valid := Bool(false)
fpu.io.cp_resp.ready := Bool(false)
}
}
}
}
class AccumulatorExample(implicit p: Parameters) extends LazyRoCC {
override lazy val module = new AccumulatorExampleModule(this)
}
class AccumulatorExampleModule(outer: AccumulatorExample, n: Int = 4)(implicit p: Parameters) extends LazyRoCCModule(outer)
with HasCoreParameters {
val regfile = Mem(n, UInt(width = xLen))
val busy = Reg(init = Vec.fill(n){Bool(false)})
val cmd = Queue(io.cmd)
val funct = cmd.bits.inst.funct
val addr = cmd.bits.rs2(log2Up(n)-1,0)
val doWrite = funct === UInt(0)
val doRead = funct === UInt(1)
val doLoad = funct === UInt(2)
val doAccum = funct === UInt(3)
val memRespTag = io.mem.resp.bits.tag(log2Up(n)-1,0)
// datapath
val addend = cmd.bits.rs1
val accum = regfile(addr)
val wdata = Mux(doWrite, addend, accum + addend)
when (cmd.fire() && (doWrite || doAccum)) {
regfile(addr) := wdata
}
when (io.mem.resp.valid) {
regfile(memRespTag) := io.mem.resp.bits.data
busy(memRespTag) := Bool(false)
}
// control
when (io.mem.req.fire()) {
busy(addr) := Bool(true)
}
val doResp = cmd.bits.inst.xd
val stallReg = busy(addr)
val stallLoad = doLoad && !io.mem.req.ready
val stallResp = doResp && !io.resp.ready
cmd.ready := !stallReg && !stallLoad && !stallResp
// command resolved if no stalls AND not issuing a load that will need a request
// PROC RESPONSE INTERFACE
io.resp.valid := cmd.valid && doResp && !stallReg && !stallLoad
// valid response if valid command, need a response, and no stalls
io.resp.bits.rd := cmd.bits.inst.rd
// Must respond with the appropriate tag or undefined behavior
io.resp.bits.data := accum
// Semantics is to always send out prior accumulator register value
io.busy := cmd.valid || busy.reduce(_||_)
// Be busy when have pending memory requests or committed possibility of pending requests
io.interrupt := Bool(false)
// Set this true to trigger an interrupt on the processor (please refer to supervisor documentation)
// MEMORY REQUEST INTERFACE
io.mem.req.valid := cmd.valid && doLoad && !stallReg && !stallResp
io.mem.req.bits.addr := addend
io.mem.req.bits.tag := addr
io.mem.req.bits.cmd := M_XRD // perform a load (M_XWR for stores)
io.mem.req.bits.typ := MT_D // D = 8 bytes, W = 4, H = 2, B = 1
io.mem.req.bits.data := Bits(0) // we're not performing any stores...
io.mem.req.bits.phys := Bool(false)
io.mem.invalidate_lr := Bool(false)
}
class TranslatorExample(implicit p: Parameters) extends LazyRoCC {
override lazy val module = new TranslatorExampleModule(this)
}
class TranslatorExampleModule(outer: TranslatorExample)(implicit p: Parameters) extends LazyRoCCModule(outer)
with HasCoreParameters {
val req_addr = Reg(UInt(width = coreMaxAddrBits))
val req_rd = Reg(io.resp.bits.rd)
val req_offset = req_addr(pgIdxBits - 1, 0)
val req_vpn = req_addr(coreMaxAddrBits - 1, pgIdxBits)
val pte = Reg(new PTE)
val s_idle :: s_ptw_req :: s_ptw_resp :: s_resp :: Nil = Enum(Bits(), 4)
val state = Reg(init = s_idle)
io.cmd.ready := (state === s_idle)
when (io.cmd.fire()) {
req_rd := io.cmd.bits.inst.rd
req_addr := io.cmd.bits.rs1
state := s_ptw_req
}
private val ptw = io.ptw(0)
when (ptw.req.fire()) { state := s_ptw_resp }
when (state === s_ptw_resp && ptw.resp.valid) {
pte := ptw.resp.bits.pte
state := s_resp
}
when (io.resp.fire()) { state := s_idle }
ptw.req.valid := (state === s_ptw_req)
ptw.req.bits.addr := req_vpn
io.resp.valid := (state === s_resp)
io.resp.bits.rd := req_rd
io.resp.bits.data := Mux(pte.leaf(), Cat(pte.ppn, req_offset), SInt(-1, xLen).asUInt)
io.busy := (state =/= s_idle)
io.interrupt := Bool(false)
io.mem.req.valid := Bool(false)
}
class CharacterCountExample(implicit p: Parameters) extends LazyRoCC {
override lazy val module = new CharacterCountExampleModule(this)
override val atlNode = TLClientNode(Seq(TLClientPortParameters(Seq(TLClientParameters("CharacterCountRoCC")))))
}
class CharacterCountExampleModule(outer: CharacterCountExample)(implicit p: Parameters) extends LazyRoCCModule(outer)
with HasCoreParameters
with HasL1CacheParameters {
val cacheParams = tileParams.icache.get
private val blockOffset = blockOffBits
private val beatOffset = log2Up(cacheDataBits/8)
val needle = Reg(UInt(width = 8))
val addr = Reg(UInt(width = coreMaxAddrBits))
val count = Reg(UInt(width = xLen))
val resp_rd = Reg(io.resp.bits.rd)
val addr_block = addr(coreMaxAddrBits - 1, blockOffset)
val offset = addr(blockOffset - 1, 0)
val next_addr = (addr_block + UInt(1)) << UInt(blockOffset)
val s_idle :: s_acq :: s_gnt :: s_check :: s_resp :: Nil = Enum(Bits(), 5)
val state = Reg(init = s_idle)
val (tl_out, edgesOut) = outer.atlNode.out(0)
val gnt = tl_out.d.bits
val recv_data = Reg(UInt(width = cacheDataBits))
val recv_beat = Reg(UInt(width = log2Up(cacheDataBeats+1)), init = UInt(0))
val data_bytes = Vec.tabulate(cacheDataBits/8) { i => recv_data(8 * (i + 1) - 1, 8 * i) }
val zero_match = data_bytes.map(_ === UInt(0))
val needle_match = data_bytes.map(_ === needle)
val first_zero = PriorityEncoder(zero_match)
val chars_found = PopCount(needle_match.zipWithIndex.map {
case (matches, i) =>
val idx = Cat(recv_beat - UInt(1), UInt(i, beatOffset))
matches && idx >= offset && UInt(i) <= first_zero
})
val zero_found = zero_match.reduce(_ || _)
val finished = Reg(Bool())
io.cmd.ready := (state === s_idle)
io.resp.valid := (state === s_resp)
io.resp.bits.rd := resp_rd
io.resp.bits.data := count
tl_out.a.valid := (state === s_acq)
tl_out.a.bits := edgesOut.Get(
fromSource = UInt(0),
toAddress = addr_block << blockOffset,
lgSize = UInt(lgCacheBlockBytes))._2
tl_out.d.ready := (state === s_gnt)
when (io.cmd.fire()) {
addr := io.cmd.bits.rs1
needle := io.cmd.bits.rs2
resp_rd := io.cmd.bits.inst.rd
count := UInt(0)
finished := Bool(false)
state := s_acq
}
when (tl_out.a.fire()) { state := s_gnt }
when (tl_out.d.fire()) {
recv_beat := recv_beat + UInt(1)
recv_data := gnt.data
state := s_check
}
when (state === s_check) {
when (!finished) {
count := count + chars_found
}
when (zero_found) { finished := Bool(true) }
when (recv_beat === UInt(cacheDataBeats)) {
addr := next_addr
state := Mux(zero_found || finished, s_resp, s_acq)
} .otherwise {
state := s_gnt
}
}
when (io.resp.fire()) { state := s_idle }
io.busy := (state =/= s_idle)
io.interrupt := Bool(false)
io.mem.req.valid := Bool(false)
// Tie off unused channels
tl_out.b.ready := Bool(true)
tl_out.c.valid := Bool(false)
tl_out.e.valid := Bool(false)
}
class OpcodeSet(val opcodes: Seq[UInt]) {
def |(set: OpcodeSet) =
new OpcodeSet(this.opcodes ++ set.opcodes)
def matches(oc: UInt) = opcodes.map(_ === oc).reduce(_ || _)
}
object OpcodeSet {
def custom0 = new OpcodeSet(Seq(Bits("b0001011")))
def custom1 = new OpcodeSet(Seq(Bits("b0101011")))
def custom2 = new OpcodeSet(Seq(Bits("b1011011")))
def custom3 = new OpcodeSet(Seq(Bits("b1111011")))
def all = custom0 | custom1 | custom2 | custom3
}
class RoccCommandRouter(opcodes: Seq[OpcodeSet])(implicit p: Parameters)
extends CoreModule()(p) {
val io = new Bundle {
val in = Decoupled(new RoCCCommand).flip
val out = Vec(opcodes.size, Decoupled(new RoCCCommand))
val busy = Bool(OUTPUT)
}
val cmd = Queue(io.in)
val cmdReadys = io.out.zip(opcodes).map { case (out, opcode) =>
val me = opcode.matches(cmd.bits.inst.opcode)
out.valid := cmd.valid && me
out.bits := cmd.bits
out.ready && me
}
cmd.ready := cmdReadys.reduce(_ || _)
io.busy := cmd.valid
assert(PopCount(cmdReadys) <= UInt(1),
"Custom opcode matched for more than one accelerator")
}