riscv/rocket-chip
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Get I$ s1_kill signal off the critical path

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This commit is contained in:
Andrew Waterman 2017-04-02 22:26:40 -07:00 committed by Andrew Waterman
parent 744fb2e4b9
commit 43917dd59f
1 changed files with 12 additions and 16 deletions
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28
src/main/scala/rocket/ICache.scala
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@ -62,7 +62,7 @@ class ICacheModule(outer: ICache) extends LazyModuleImp(outer)
require(isPow2(coreInstBytes))
require(!usingVM || pgIdxBits >= untagBits)
val s_ready :: s_request :: s_refill_wait :: s_refill :: Nil = Enum(UInt(), 4)
val s_ready :: s_request :: s_refill :: Nil = Enum(UInt(), 3)
val state = Reg(init=s_ready)
val invalidated = Reg(Bool())
val stall = !io.resp.ready
@ -71,20 +71,18 @@ class ICacheModule(outer: ICache) extends LazyModuleImp(outer)
val s1_any_tag_hit = Wire(Bool())
val s1_valid = Reg(init=Bool(false))
val out_valid = s1_valid && !io.s1_kill && state === s_ready
val out_valid = s1_valid && state === s_ready && !io.s1_kill
val s1_idx = io.s1_paddr(untagBits-1,blockOffBits)
val s1_tag = io.s1_paddr(tagBits+untagBits-1,untagBits)
val s1_hit = out_valid && s1_any_tag_hit
val s1_miss = out_valid && !s1_any_tag_hit
val s1_miss = s1_valid && state === s_ready && !s1_any_tag_hit
val s0_valid = io.req.valid && state === s_ready && !(out_valid && stall)
val s0_valid = io.req.valid && state === s_ready && !(s1_valid && stall)
val s0_vaddr = io.req.bits.addr
s1_valid := s0_valid || out_valid && stall
when (s1_miss && state === s_ready) {
refill_addr := io.s1_paddr
}
when (s1_miss) { refill_addr := io.s1_paddr }
val refill_tag = refill_addr(tagBits+untagBits-1,untagBits)
val refill_idx = refill_addr(untagBits-1,blockOffBits)
val (_, _, refill_done, refill_cnt) = edge.count(tl_out.d)
@ -118,7 +116,7 @@ class ICacheModule(outer: ICache) extends LazyModuleImp(outer)
val s1_dout_valid = RegNext(s0_valid)
for (i <- 0 until nWays) {
val s1_vb = !io.invalidate && vb_array(Cat(UInt(i), io.s1_paddr(untagBits-1,blockOffBits))).toBool
val s1_vb = vb_array(Cat(UInt(i), io.s1_paddr(untagBits-1,blockOffBits))).toBool
val tag_out = tag_rdata(i)
val s1_tag_disparity = code.decode(tag_out).error holdUnless s1_dout_valid
s1_tag_match(i) := (tag_out(tagBits-1,0) === s1_tag) holdUnless s1_dout_valid
@ -162,18 +160,16 @@ class ICacheModule(outer: ICache) extends LazyModuleImp(outer)
// control state machine
switch (state) {
is (s_ready) {
when (s1_miss) { state := s_request }
when (s1_miss && !io.s1_kill) { state := s_request }
invalidated := Bool(false)
}
is (s_request) {
when (tl_out.a.ready) { state := s_refill_wait }
when (tl_out.a.ready) { state := s_refill }
when (io.s2_kill) { state := s_ready }
}
is (s_refill_wait) {
when (tl_out.d.valid) { state := s_refill }
}
is (s_refill) {
when (refill_done) { state := s_ready }
}
}
when (refill_done) {
assert(state === s_refill)
state := s_ready
}
}