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Merge pull request #942 from freechipsproject/bus-blocker-lock

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Bus blocker lock
This commit is contained in:
Wesley W. Terpstra 2017-08-08 18:03:36 -07:00 committed by GitHub
commit 49ba31ac34
1 changed files with 17 additions and 15 deletions
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32
src/main/scala/devices/tilelink/BusBlocker.scala
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@ -16,6 +16,7 @@ case class BusBlockerParams(
pmpRegisters: Int)
{
val page = 4096
val pageBits = log2Ceil(page)
val size = (((pmpRegisters * 8) + page - 1) / page) * page
require (pmpRegisters > 0)
@ -25,28 +26,29 @@ case class BusBlockerParams(
require (deviceBeatBytes > 0 && isPow2(deviceBeatBytes))
}
case class DevicePMPParams(addressBits: Int)
case class DevicePMPParams(addressBits: Int, pageBits: Int)
class DevicePMP(params: DevicePMPParams) extends GenericParameterizedBundle(params)
{
require (params.addressBits > 12)
require (params.addressBits > params.pageBits)
val l = UInt(width = 1) // locked
val a = UInt(width = 1) // LSB of A (0=disabled, 1=TOR)
val r = UInt(width = 1)
val w = UInt(width = 1)
val addr_hi = UInt(width = params.addressBits-12)
def address = Cat(addr_hi, UInt(0, width=12))
val addr_hi = UInt(width = params.addressBits-params.pageBits)
def address = Cat(addr_hi, UInt(0, width=params.pageBits))
def blockPriorAddress = l(0) && a(0)
def fields(locked: Bool): Seq[RegField] = {
def field(bits: Int, reg: UInt) =
def fields(blockAddress: Bool): Seq[RegField] = {
def field(bits: Int, reg: UInt, lock: Bool = l(0)) =
RegField(bits, RegReadFn(reg), RegWriteFn((wen, data) => {
when (wen && !locked) { reg := data }
when (wen && !lock) { reg := data }
Bool(true)
}))
Seq(
RegField(10),
field(params.addressBits-12, addr_hi),
field(params.addressBits-params.pageBits, addr_hi, l(0) || blockAddress),
RegField(56 - (params.addressBits-2)),
field(1, r),
field(1, w),
@ -59,8 +61,8 @@ class DevicePMP(params: DevicePMPParams) extends GenericParameterizedBundle(para
object DevicePMP
{
def apply(addressBits: Int) = {
val out = Wire(new DevicePMP(DevicePMPParams(addressBits)))
def apply(addressBits: Int, pageBits: Int) = {
val out = Wire(new DevicePMP(DevicePMPParams(addressBits, pageBits)))
out.l := UInt(0)
out.a := UInt(0)
out.r := UInt(0)
@ -87,9 +89,9 @@ class BusBlocker(params: BusBlockerParams)(implicit p: Parameters) extends TLBus
// We need to be able to represent +1 larger than the largest populated address
val addressBits = log2Ceil(nodeOut.edgesOut(0).manager.maxAddress+1+1)
val pmps = RegInit(Vec.fill(params.pmpRegisters) { DevicePMP(addressBits) })
val locks = (pmps.map(_.l) zip (UInt(0) +: pmps.map(_.l))) map { case (x, n) => x | n }
controlNode.regmap(0 -> (pmps zip locks).map { case (p, l) => p.fields(l(0)) }.toList.flatten)
val pmps = RegInit(Vec.fill(params.pmpRegisters) { DevicePMP(addressBits, params.pageBits) })
val blocks = pmps.tail.map(_.blockPriorAddress) :+ Bool(false)
controlNode.regmap(0 -> (pmps zip blocks).map { case (p, b) => p.fields(b) }.toList.flatten)
val in = io.in(0)
val edge = nodeIn.edgesIn(0)
@ -97,8 +99,8 @@ class BusBlocker(params: BusBlockerParams)(implicit p: Parameters) extends TLBus
// Determine if a request is allowed
val needW = in.a.bits.opcode =/= TLMessages.Get
val needR = in.a.bits.opcode =/= TLMessages.PutFullData && in.a.bits.opcode =/= TLMessages.PutPartialData
val lte = Bool(false) +: pmps.map(in.a.bits.address < _.address)
val sel = (pmps.map(_.a) zip (lte.init zip lte.tail)) map { case (a, (l, r)) => a(0) && !l && r }
val lt = Bool(false) +: pmps.map(in.a.bits.address < _.address)
val sel = (pmps.map(_.a) zip (lt.init zip lt.tail)) map { case (a, (l, r)) => a(0) && !l && r }
val ok = pmps.map(p => (p.r(0) || !needR) && (p.w(0) || !needW))
val allow = PriorityMux(sel :+ Bool(true), ok :+ Bool(false)) // no match => deny