riscv/rocket-chip
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clean up PTW and support PADDR_BITS < VADDR_BITS

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This commit is contained in:
Andrew Waterman 2012-11-26 20:38:45 -08:00
parent 608f65e716
commit 64674d4d39
1 changed files with 14 additions and 16 deletions
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30
rocket/src/main/scala/ptw.scala
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@ -3,7 +3,7 @@ package rocket
import Chisel._
import Node._
import Constants._
import scala.math._
import Util._
class IOTLBPTW extends Bundle {
val req = new FIFOIO()(UFix(width = VPN_BITS))
@ -35,16 +35,14 @@ class PTW(n: Int)(implicit conf: RocketConfiguration) extends Component
val bitsPerLevel = VPN_BITS/levels
require(VPN_BITS == levels * bitsPerLevel)
val count = Reg() { UFix(width = log2Up(levels)) }
val s_ready :: s_req :: s_wait :: s_done :: s_error :: Nil = Enum(5) { UFix() };
val state = Reg(resetVal = s_ready);
val r_req_vpn = Reg() { Bits() }
val r_req_dest = Reg() { Bits() }
val req_addr = Reg() { UFix() }
val r_resp_ppn = Reg() { Bits() };
val r_resp_perm = Reg() { Bits() };
val state = Reg(resetVal = s_ready)
val count = Reg{UFix(width = log2Up(levels))}
val r_req_vpn = Reg{Bits()}
val r_req_dest = Reg{Bits()}
val r_req_addr = Reg{UFix(width = PADDR_BITS.max(VADDR_BITS))}
val r_resp_perm = Reg{Bits()}
val vpn_idxs = (1 until levels).map(i => r_req_vpn((levels-i)*bitsPerLevel-1, (levels-i-1)*bitsPerLevel))
val vpn_idx = (2 until levels).foldRight(vpn_idxs(0))((i,j) => Mux(count === UFix(i-1), vpn_idxs(i-1), j))
@ -56,20 +54,19 @@ class PTW(n: Int)(implicit conf: RocketConfiguration) extends Component
when (arb.io.out.fire()) {
r_req_vpn := arb.io.out.bits
r_req_dest := arb.io.chosen
req_addr := Cat(io.dpath.ptbr(PADDR_BITS-1,PGIDX_BITS), arb.io.out.bits(VPN_BITS-1,VPN_BITS-bitsPerLevel), UFix(0,3))
r_req_addr := Cat(io.dpath.ptbr(PADDR_BITS-1,PGIDX_BITS), arb.io.out.bits(VPN_BITS-1,VPN_BITS-bitsPerLevel)) << log2Up(conf.xprlen/8)
}
when (io.mem.resp.valid) {
req_addr := Cat(io.mem.resp.bits.data(PADDR_BITS-1, PGIDX_BITS), vpn_idx, UFix(0,3)).toUFix
r_req_addr := Cat(io.mem.resp.bits.data(PADDR_BITS-1, PGIDX_BITS), vpn_idx).toUFix << log2Up(conf.xprlen/8)
r_resp_perm := io.mem.resp.bits.data(9,4);
r_resp_ppn := io.mem.resp.bits.data(PADDR_BITS-1, PGIDX_BITS);
}
io.mem.req.valid := state === s_req
io.mem.req.bits.phys := Bool(true)
io.mem.req.bits.cmd := M_XRD
io.mem.req.bits.typ := MT_D
io.mem.req.bits.addr := req_addr
io.mem.req.bits.addr := r_req_addr
io.mem.req.bits.kill := Bool(false)
val resp_val = state === s_done || state === s_error
@ -77,8 +74,9 @@ class PTW(n: Int)(implicit conf: RocketConfiguration) extends Component
val resp_ptd = io.mem.resp.bits.data(1,0) === Bits(1)
val resp_pte = io.mem.resp.bits.data(1,0) === Bits(2)
val resp_ppns = (0 until levels-1).map(i => Cat(r_resp_ppn(PPN_BITS-1, VPN_BITS-bitsPerLevel*(i+1)), r_req_vpn(VPN_BITS-1-bitsPerLevel*(i+1), 0)))
val r_resp_ppn = r_req_addr >> PGIDX_BITS
val resp_ppns = (0 until levels-1).map(i => Cat(r_resp_ppn >> VPN_BITS-bitsPerLevel*(i+1), r_req_vpn(VPN_BITS-1-bitsPerLevel*(i+1), 0)))
val resp_ppn = (0 until levels-1).foldRight(r_resp_ppn)((i,j) => Mux(count === UFix(i), resp_ppns(i), j))
for (i <- 0 until io.requestor.size) {