riscv/rocket-chip
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Replace ICacheBufferWays parameter with I$ constructor argument

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This commit is contained in:
Andrew Waterman 2016-07-14 12:38:54 -07:00
parent 3d0b92afd7
commit e6aab368a4
2 changed files with 19 additions and 36 deletions
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32
rocket/src/main/scala/frontend.scala
View File

@ -37,7 +37,7 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
val mem = new ClientUncachedTileLinkIO
}
val icache = Module(new ICache)
val icache = Module(new ICache(latency = 2))
val tlb = Module(new TLB)
val s1_pc_ = Reg(UInt(width=vaddrBitsExtended))
@ -50,12 +50,10 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
val s2_btb_resp_bits = Reg(new BTBResp)
val s2_xcpt_if = Reg(init=Bool(false))
val s2_speculative = Reg(init=Bool(false))
val s2_resp_valid = Wire(Bool())
val s2_resp_data = Wire(UInt(width = rowBits))
val ntpc = ~(~s1_pc | (coreInstBytes*fetchWidth-1)) + UInt(coreInstBytes*fetchWidth)
val predicted_npc = Wire(init = ntpc)
val icmiss = s2_valid && !s2_resp_valid
val icmiss = s2_valid && !icache.io.resp.valid
val npc = Mux(icmiss, s2_pc, predicted_npc).toUInt
val s0_same_block = Wire(init = !icmiss && !io.cpu.req.valid && ((ntpc & rowBytes) === (s1_pc & rowBytes)))
@ -110,30 +108,16 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
icache.io.s1_ppn := tlb.io.resp.ppn
icache.io.s1_kill := io.cpu.req.valid || tlb.io.resp.miss || tlb.io.resp.xcpt_if || icmiss || io.cpu.flush_tlb
icache.io.s2_kill := s2_speculative
icache.io.resp.ready := !stall && !s1_same_block
io.cpu.resp.valid := s2_valid && (s2_resp_valid || s2_speculative || s2_xcpt_if)
io.cpu.resp.valid := s2_valid && (icache.io.resp.valid || s2_speculative || s2_xcpt_if)
io.cpu.resp.bits.pc := s2_pc
io.cpu.npc := Mux(io.cpu.req.valid, io.cpu.req.bits.pc, npc)
// if the ways are buffered, we don't need to buffer again
if (p(ICacheBufferWays)) {
icache.io.resp.ready := !stall && !s1_same_block
s2_resp_valid := icache.io.resp.valid
s2_resp_data := icache.io.resp.bits.datablock
} else {
val icbuf = Module(new Queue(new ICacheResp, 1, pipe=true))
icbuf.io.enq <> icache.io.resp
icbuf.io.deq.ready := !stall && !s1_same_block
s2_resp_valid := icbuf.io.deq.valid
s2_resp_data := icbuf.io.deq.bits.datablock
}
require(fetchWidth * coreInstBytes <= rowBytes)
val fetch_data =
if (fetchWidth * coreInstBytes == rowBytes) s2_resp_data
else s2_resp_data >> (s2_pc(log2Up(rowBytes)-1,log2Up(fetchWidth*coreInstBytes)) << log2Up(fetchWidth*coreInstBits))
val fetch_data = // TODO zero-width
if (fetchWidth * coreInstBytes == rowBytes) icache.io.resp.bits.datablock
else icache.io.resp.bits.datablock >> (s2_pc(log2Up(rowBytes)-1,log2Up(fetchWidth*coreInstBytes)) << log2Up(fetchWidth*coreInstBits))
for (i <- 0 until fetchWidth) {
io.cpu.resp.bits.data(i) := fetch_data(i*coreInstBits+coreInstBits-1, i*coreInstBits)
@ -143,7 +127,7 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
val msk_pc = if (fetchWidth == 1) all_ones else all_ones << s2_pc(log2Up(fetchWidth) -1+2,2)
io.cpu.resp.bits.mask := msk_pc
io.cpu.resp.bits.xcpt_if := s2_xcpt_if
io.cpu.resp.bits.replay := s2_speculative && !s2_resp_valid && !s2_xcpt_if
io.cpu.resp.bits.replay := s2_speculative && !icache.io.resp.valid && !s2_xcpt_if
io.cpu.btb_resp.valid := s2_btb_resp_valid
io.cpu.btb_resp.bits := s2_btb_resp_bits

23
rocket/src/main/scala/icache.scala
View File

@ -7,8 +7,6 @@ import uncore.util._
import Util._
import cde.{Parameters, Field}
case object ICacheBufferWays extends Field[Boolean]
trait HasL1CacheParameters extends HasCacheParameters with HasCoreParameters {
val outerDataBeats = p(TLKey(p(TLId))).dataBeats
val outerDataBits = p(TLKey(p(TLId))).dataBitsPerBeat
@ -25,7 +23,7 @@ class ICacheResp(implicit p: Parameters) extends CoreBundle()(p) with HasL1Cache
val datablock = Bits(width = rowBits)
}
class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CacheParameters {
class ICache(latency: Int)(implicit p: Parameters) extends CoreModule()(p) with HasL1CacheParameters {
val io = new Bundle {
val req = Valid(new ICacheReq).flip
val s1_ppn = UInt(INPUT, ppnBits) // delayed one cycle w.r.t. req
@ -126,15 +124,16 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
}
// output signals
if (p(ICacheBufferWays)) {
val s2_hit = RegEnable(s1_hit, !stall)
val s2_tag_hit = RegEnable(s1_tag_hit, !stall)
val s2_dout = RegEnable(s1_dout, !stall)
io.resp.bits.datablock := Mux1H(s2_tag_hit, s2_dout)
io.resp.valid := s2_hit
} else {
io.resp.bits.datablock := Mux1H(s1_tag_hit, s1_dout)
io.resp.valid := s1_hit
latency match {
case 1 =>
io.resp.bits.datablock := Mux1H(s1_tag_hit, s1_dout)
io.resp.valid := s1_hit
case 2 =>
val s2_hit = RegEnable(s1_hit, !stall)
val s2_tag_hit = RegEnable(s1_tag_hit, !stall)
val s2_dout = RegEnable(s1_dout, !stall)
io.resp.bits.datablock := Mux1H(s2_tag_hit, s2_dout)
io.resp.valid := s2_hit
}
io.mem.acquire.valid := state === s_request && !io.s2_kill
io.mem.acquire.bits := GetBlock(addr_block = refill_addr >> blockOffBits)