riscv/rocket-chip
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Support larger I$ sets when VM is disabled

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This commit is contained in:
Andrew Waterman 2016-05-23 17:51:08 -07:00
parent 3b35c7470e
commit f14d87e327
2 changed files with 14 additions and 15 deletions
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2
rocket/src/main/scala/frontend.scala
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@ -103,7 +103,7 @@ class Frontend(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePa
io.mem <> icache.io.mem
icache.io.req.valid := !stall && !s0_same_block
icache.io.req.bits.idx := io.cpu.npc
icache.io.req.bits.addr := io.cpu.npc
icache.io.invalidate := io.cpu.flush_icache
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

27
rocket/src/main/scala/icache.scala
View File

@ -14,8 +14,8 @@ trait HasL1CacheParameters extends HasCacheParameters with HasCoreParameters {
val refillCycles = refillCyclesPerBeat*outerDataBeats
}
class ICacheReq(implicit p: Parameters) extends CoreBundle()(p) {
val idx = UInt(width = pgIdxBits)
class ICacheReq(implicit p: Parameters) extends CoreBundle()(p) with HasL1CacheParameters {
val addr = UInt(width = vaddrBits)
}
class ICacheResp(implicit p: Parameters) extends CoreBundle()(p) with HasL1CacheParameters {
@ -35,7 +35,7 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
}
require(isPow2(nSets) && isPow2(nWays))
require(isPow2(coreInstBytes))
require(pgIdxBits >= untagBits)
require(!usingVM || pgIdxBits >= untagBits)
val s_ready :: s_request :: s_refill_wait :: s_refill :: Nil = Enum(UInt(), 4)
val state = Reg(init=s_ready)
@ -47,27 +47,26 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
val s1_any_tag_hit = Wire(Bool())
val s1_valid = Reg(init=Bool(false))
val s1_pgoff = Reg(UInt(width = pgIdxBits))
val s1_addr = Cat(io.s1_ppn, s1_pgoff).toUInt
val s1_tag = s1_addr(tagBits+untagBits-1,untagBits)
val s1_vaddr = Reg(UInt())
val s1_paddr = Cat(io.s1_ppn, s1_vaddr(pgIdxBits-1,0)).toUInt
val s1_tag = s1_paddr(tagBits+untagBits-1,untagBits)
val s0_valid = io.req.valid || s1_valid && stall
val s0_pgoff = Mux(s1_valid && stall, s1_pgoff, io.req.bits.idx)
val s0_vaddr = Mux(s1_valid && stall, s1_vaddr, io.req.bits.addr)
s1_valid := io.req.valid && rdy || s1_valid && stall && !io.s1_kill
when (io.req.valid && rdy) {
s1_pgoff := io.req.bits.idx
s1_vaddr := io.req.bits.addr
}
val out_valid = s1_valid && !io.s1_kill && state === s_ready
val s1_idx = s1_addr(untagBits-1,blockOffBits)
val s1_offset = s1_addr(blockOffBits-1,0)
val s1_idx = s1_vaddr(untagBits-1,blockOffBits)
val s1_hit = out_valid && s1_any_tag_hit
val s1_miss = out_valid && !s1_any_tag_hit
rdy := state === s_ready && !s1_miss
when (s1_valid && state === s_ready && s1_miss) {
refill_addr := s1_addr
refill_addr := s1_paddr
}
val refill_tag = refill_addr(tagBits+untagBits-1,untagBits)
@ -79,7 +78,7 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
val repl_way = if (isDM) UInt(0) else LFSR16(s1_miss)(log2Up(nWays)-1,0)
val entagbits = code.width(tagBits)
val tag_array = SeqMem(nSets, Vec(nWays, Bits(width = entagbits)))
val tag_rdata = tag_array.read(s0_pgoff(untagBits-1,blockOffBits), !refill_done && s0_valid)
val tag_rdata = tag_array.read(s0_vaddr(untagBits-1,blockOffBits), !refill_done && s0_valid)
when (refill_done) {
val tag = code.encode(refill_tag).toUInt
tag_array.write(s1_idx, Vec.fill(nWays)(tag), Vec.tabulate(nWays)(repl_way === _))
@ -102,7 +101,7 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
val s1_dout = Wire(Vec(nWays, Bits(width = rowBits)))
for (i <- 0 until nWays) {
val s1_vb = !io.invalidate && vb_array(Cat(UInt(i), s1_pgoff(untagBits-1,blockOffBits))).toBool
val s1_vb = !io.invalidate && vb_array(Cat(UInt(i), s1_vaddr(untagBits-1,blockOffBits))).toBool
val tag_out = tag_rdata(i)
val s1_tag_disparity = code.decode(tag_out).error
s1_tag_match(i) := tag_out(tagBits-1,0) === s1_tag
@ -119,7 +118,7 @@ class ICache(implicit p: Parameters) extends CoreModule()(p) with HasL1CachePara
if(refillCycles > 1) data_array.write(Cat(s1_idx, refill_cnt), e_d)
else data_array.write(s1_idx, e_d)
}
val s0_raddr = s0_pgoff(untagBits-1,blockOffBits-(if(refillCycles > 1) refill_cnt.getWidth else 0))
val s0_raddr = s0_vaddr(untagBits-1,blockOffBits-(if(refillCycles > 1) refill_cnt.getWidth else 0))
s1_dout(i) := data_array.read(s0_raddr, !wen && s0_valid)
}