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[tilelink2] Fuzzer: Allow noise-making to be parameterized. Better comments.

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This commit is contained in:
Henry Cook 2016-09-13 12:25:57 -07:00
parent 05100c12a7
commit e318c29d48
1 changed files with 43 additions and 13 deletions
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56
src/main/scala/uncore/tilelink2/Fuzzer.scala
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@ -50,15 +50,39 @@ object LFSR64
}
}
object NoiseMaker
trait HasNoiseMakerIO
{
def apply(wide: Int, increment: Bool = Bool(true)): UInt = {
val lfsrs = Seq.fill((wide+63)/64) { LFSR64(increment) }
Cat(lfsrs)(wide-1,0)
val io = new Bundle {
val inc = Bool(INPUT)
val random = UInt(OUTPUT)
}
}
class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
class LFSRNoiseMaker(wide: Int) extends Module with HasNoiseMakerIO
{
val lfsrs = Seq.fill((wide+63)/64) { LFSR64(io.inc) }
io.random := Cat(lfsrs)(wide-1,0)
}
object LFSRNoiseMaker {
def apply(wide: Int, increment: Bool = Bool(true)): UInt = {
val nm = Module(new LFSRNoiseMaker(wide))
nm.io.inc := increment
nm.io.random
}
}
/** TLFuzzer drives test traffic over TL2 links. It generates a sequence of randomized
* requests, and issues legal ones into the DUT. TODO: Currently the fuzzer only generates
* memory operations, not permissions transfers.
* @param nOperations is the total number of operations that the fuzzer must complete for the test to pass
* @param inFlight is the number of operations that can be in-flight to the DUT concurrently
* @param noiseMaker is a function that supplies a random UInt of a given width every time inc is true
*/
class TLFuzzer(
nOperations: Int,
inFlight: Int = 32,
noiseMaker: (Int, Bool) => UInt = LFSRNoiseMaker.apply _) extends LazyModule
{
val node = TLClientNode(TLClientParameters(sourceId = IdRange(0,inFlight)))
@ -70,6 +94,8 @@ class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
val out = io.out(0)
val edge = node.edgesOut(0)
// Extract useful parameters from the TL edge
val endAddress = edge.manager.maxAddress + 1
val maxTransfer = edge.manager.maxTransfer
val beatBytes = edge.manager.beatBytes
@ -111,14 +137,15 @@ class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
// Increment random number generation for the following subfields
val inc = Wire(Bool())
val inc_beat = Wire(Bool())
val arth_op = NoiseMaker(3, inc)
val log_op = NoiseMaker(2, inc)
val amo_size = UInt(2) + NoiseMaker(1, inc) // word or dword
val size = NoiseMaker(sizeBits, inc)
val addr = NoiseMaker(addressBits, inc) & ~UIntToOH1(size, addressBits)
val mask = NoiseMaker(beatBytes, inc_beat) & edge.mask(addr, size)
val data = NoiseMaker(dataBits, inc_beat)
val arth_op = noiseMaker(3, inc)
val log_op = noiseMaker(2, inc)
val amo_size = UInt(2) + noiseMaker(1, inc) // word or dword
val size = noiseMaker(sizeBits, inc)
val addr = noiseMaker(addressBits, inc) & ~UIntToOH1(size, addressBits)
val mask = noiseMaker(beatBytes, inc_beat) & edge.mask(addr, size)
val data = noiseMaker(dataBits, inc_beat)
// Actually generate specific TL messages when it is legal to do so
val (glegal, gbits) = edge.Get(src, addr, size)
val (pflegal, pfbits) = if(edge.manager.anySupportPutFull) {
edge.Put(src, addr, size, data)
@ -136,7 +163,8 @@ class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
edge.Hint(src, addr, size, UInt(0))
} else { (glegal, gbits) }
val a_type_sel = NoiseMaker(3, inc)
// Pick a specific message to try to send
val a_type_sel = noiseMaker(3, inc)
val legal = MuxLookup(a_type_sel, glegal, Seq(
UInt("b000") -> glegal,
@ -154,6 +182,7 @@ class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
UInt("b100") -> lbits,
UInt("b101") -> hbits))
// Wire both the used and un-used channel signals
out.a.valid := legal && alloc.valid && num_reqs =/= UInt(0)
out.a.bits := bits
out.b.ready := Bool(true)
@ -161,6 +190,7 @@ class TLFuzzer(nOperations: Int, inFlight: Int = 32) extends LazyModule
out.d.ready := Bool(true)
out.e.valid := Bool(false)
// Increment the various progress-tracking states
inc := !legal || req_done
inc_beat := !legal || out.a.fire()