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tilelink2 RegisterRouter: support undefZero

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This commit is contained in:
Wesley W. Terpstra 2016-09-16 14:54:30 -07:00
parent f0f553f227
commit dae0918c85
2 changed files with 39 additions and 28 deletions
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60
src/main/scala/uncore/tilelink2/RegMapper.scala
View File

@ -2,8 +2,8 @@
package uncore.tilelink2
import Chisel._
import chisel3.util.{Irrevocable, IrrevocableIO}
import chisel3._
import chisel3.util._
// A bus agnostic register interface to a register-based device
@ -36,6 +36,23 @@ object RegMapper
regmap.combinations(2).foreach { case Seq((reg1, _), (reg2, _)) =>
require (reg1 != reg2)
}
// Don't be an asshole...
regmap.foreach { reg => require (reg._1 >= 0) }
// Make sure registers fit
val inParams = in.bits.params
val inBits = inParams.indexBits
assert (regmap.map(_._1).max < (1 << inBits))
val out = Wire(Irrevocable(new RegMapperOutput(inParams)))
val front = Wire(Irrevocable(new RegMapperInput(inParams)))
front.bits := in.bits
// Must this device pipeline the control channel?
val pipelined = regmap.map(_._2.map(_.pipelined)).flatten.reduce(_ || _)
val depth = concurrency.getOrElse(if (pipelined) 1 else 0)
require (depth >= 0)
require (!pipelined || depth > 0)
val back = if (depth > 0) Queue(front, depth, pipe = depth == 1) else front
// Convert to and from Bits
def toBits(x: Int, tail: List[Boolean] = List.empty): List[Boolean] =
@ -44,36 +61,33 @@ object RegMapper
// Find the minimal mask that can decide the register map
val mask = AddressDecoder(regmap.map(_._1))
val maskMatch = ~UInt(mask, width = inBits)
val maskFilter = toBits(mask)
val maskBits = maskFilter.filter(x => x).size
// Calculate size and indexes into the register map
val endIndex = 1 << log2Ceil(regmap.map(_._1).max+1)
val params = RegMapperParams(log2Up(endIndex), bytes, in.bits.params.extraBits)
val regSize = 1 << maskBits
def regIndexI(x: Int) = ofBits((maskFilter zip toBits(x)).filter(_._1).map(_._2))
def regIndexU(x: UInt) = if (maskBits == 0) UInt(0) else
Cat((maskFilter zip x.toBools).filter(_._1).map(_._2).reverse)
// Protection flag for undefined registers
val iRightReg = Array.fill(regSize) { Bool(true) }
val oRightReg = Array.fill(regSize) { Bool(true) }
// Flatten the regmap into (RegIndex:Int, Offset:Int, field:RegField)
val flat = regmap.map { case (reg, fields) =>
val offsets = fields.scanLeft(0)(_ + _.width).init
val index = regIndexI(reg)
val uint = UInt(reg, width = inBits)
if (undefZero) {
iRightReg(index) = ((front.bits.index ^ uint) & maskMatch) === UInt(0)
oRightReg(index) = ((back .bits.index ^ uint) & maskMatch) === UInt(0)
}
// println("mapping 0x%x -> 0x%x for 0x%x/%d".format(reg, index, mask, maskBits))
(offsets zip fields) map { case (o, f) => (index, o, f) }
}.flatten
val out = Wire(Irrevocable(new RegMapperOutput(params)))
val front = Wire(Irrevocable(new RegMapperInput(params)))
front.bits := in.bits
// Must this device pipeline the control channel?
val pipelined = flat.map(_._3.pipelined).reduce(_ || _)
val depth = concurrency.getOrElse(if (pipelined) 1 else 0)
require (depth >= 0)
require (!pipelined || depth > 0)
val back = if (depth > 0) Queue(front, depth, pipe = depth == 1) else front
// Forward declaration of all flow control signals
val rivalid = Wire(Vec(flat.size, Bool()))
val wivalid = Wire(Vec(flat.size, Bool()))
@ -122,10 +136,10 @@ object RegMapper
}
// Is the selected register ready?
val rifireMux = Vec(rifire.map(_.reduce(_ && _)))
val wifireMux = Vec(wifire.map(_.reduce(_ && _)))
val rofireMux = Vec(rofire.map(_.reduce(_ && _)))
val wofireMux = Vec(wofire.map(_.reduce(_ && _)))
val rifireMux = Vec(rifire.zipWithIndex.map { case (seq, i) => !iRightReg(i) || seq.reduce(_ && _)})
val wifireMux = Vec(wifire.zipWithIndex.map { case (seq, i) => !iRightReg(i) || seq.reduce(_ && _)})
val rofireMux = Vec(rofire.zipWithIndex.map { case (seq, i) => !oRightReg(i) || seq.reduce(_ && _)})
val wofireMux = Vec(wofire.zipWithIndex.map { case (seq, i) => !oRightReg(i) || seq.reduce(_ && _)})
val iindex = regIndexU(front.bits.index)
val oindex = regIndexU(back .bits.index)
val iready = Mux(front.bits.read, rifireMux(iindex), wifireMux(iindex))
@ -138,8 +152,8 @@ object RegMapper
out.valid := back.valid && oready
// Which register is touched?
val frontSel = UIntToOH(iindex)
val backSel = UIntToOH(oindex)
val frontSel = UIntToOH(iindex) & Cat(iRightReg.reverse)
val backSel = UIntToOH(oindex) & Cat(oRightReg.reverse)
// Include the per-register one-hot selected criteria
for (reg <- 0 until regSize) {
@ -159,9 +173,9 @@ object RegMapper
}
out.bits.read := back.bits.read
out.bits.data := Vec(dataOut)(oindex)
out.bits.data := Mux(Vec(oRightReg)(oindex), Vec(dataOut)(oindex), UInt(0))
out.bits.extra := back.bits.extra
(endIndex, out)
out
}
}

7
src/main/scala/uncore/tilelink2/RegisterRouter.scala
View File

@ -27,7 +27,7 @@ class TLRegisterNode(address: AddressSet, concurrency: Option[Int] = None, beatB
val (sourceEnd, sourceOff) = (edge.bundle.sourceBits + sizeEnd, sizeEnd)
val (addrLoEnd, addrLoOff) = (log2Up(beatBytes) + sourceEnd, sourceEnd)
val params = RegMapperParams(log2Up(address.mask+1), beatBytes, addrLoEnd)
val params = RegMapperParams(log2Up((address.mask+1)/beatBytes), beatBytes, addrLoEnd)
val in = Wire(Decoupled(new RegMapperInput(params)))
in.bits.read := a.bits.opcode === TLMessages.Get
in.bits.index := a.bits.addr_hi
@ -36,10 +36,7 @@ class TLRegisterNode(address: AddressSet, concurrency: Option[Int] = None, beatB
in.bits.extra := Cat(edge.addr_lo(a.bits), a.bits.source, a.bits.size)
// Invoke the register map builder
val (endIndex, out) = RegMapper(beatBytes, concurrency, undefZero, in, mapping:_*)
// All registers must fit inside the device address space
require (address.mask >= (endIndex-1)*beatBytes)
val out = RegMapper(beatBytes, concurrency, undefZero, in, mapping:_*)
// No flow control needed
in.valid := a.valid