riscv/rocket-chip
1
0
Fork 0
Code Releases Activity

improve tlb qor

Browse Source
This commit is contained in:
Andrew Waterman 2012-11-16 01:59:38 -08:00
parent ff8c736d94
commit a90a1790a5
1 changed files with 13 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
rocket/src/main/scala/tlb.scala
View File

@ -102,7 +102,6 @@ class TLB(entries: Int) extends Component
val tag_cam = new rocketCAM(entries, ASID_BITS+VPN_BITS);
val tag_ram = Vec(entries) { Reg() { io.ptw.resp.bits.ppn.clone } }
when (io.ptw.resp.valid) { tag_ram(r_refill_waddr) := io.ptw.resp.bits.ppn }
val lookup_tag = Cat(io.req.bits.asid, io.req.bits.vpn).toUFix
tag_cam.io.clear := io.ptw.invalidate
@ -115,13 +114,14 @@ class TLB(entries: Int) extends Component
val tag_hit_addr = OHToUFix(tag_cam.io.hits)
// permission bit arrays
val ur_array = Reg(resetVal = Bits(0, entries)) // user read permission
val uw_array = Reg(resetVal = Bits(0, entries)) // user write permission
val ux_array = Reg(resetVal = Bits(0, entries)) // user execute permission
val sr_array = Reg(resetVal = Bits(0, entries)) // supervisor read permission
val sw_array = Reg(resetVal = Bits(0, entries)) // supervisor write permission
val sx_array = Reg(resetVal = Bits(0, entries)) // supervisor execute permission
when (tag_cam.io.write) {
val ur_array = Reg{Bits()} // user read permission
val uw_array = Reg{Bits()} // user write permission
val ux_array = Reg{Bits()} // user execute permission
val sr_array = Reg{Bits()} // supervisor read permission
val sw_array = Reg{Bits()} // supervisor write permission
val sx_array = Reg{Bits()} // supervisor execute permission
when (io.ptw.resp.valid) {
tag_ram(r_refill_waddr) := io.ptw.resp.bits.ppn
val perm = (!io.ptw.resp.bits.error).toFix & io.ptw.resp.bits.perm(5,0)
ur_array := ur_array.bitSet(r_refill_waddr, perm(2))
uw_array := uw_array.bitSet(r_refill_waddr, perm(1))
@ -144,13 +144,13 @@ class TLB(entries: Int) extends Component
val tlb_miss = status_vm && !tag_hit && !bad_va
when (io.req.valid && tlb_hit) {
plru.access(tag_hit_addr)
plru.access(OHToUFix(tag_cam.io.hits))
}
io.req.ready := state === s_ready
io.resp.xcpt_ld := bad_va || tlb_hit && !Mux(status_s, sr_array(tag_hit_addr), ur_array(tag_hit_addr))
io.resp.xcpt_st := bad_va || tlb_hit && !Mux(status_s, sw_array(tag_hit_addr), uw_array(tag_hit_addr))
io.resp.xcpt_if := bad_va || tlb_hit && !Mux(status_s, sx_array(tag_hit_addr), ux_array(tag_hit_addr))
io.resp.xcpt_ld := bad_va || tlb_hit && !Mux(status_s, (sr_array & tag_cam.io.hits).orR, (ur_array & tag_cam.io.hits).orR)
io.resp.xcpt_st := bad_va || tlb_hit && !Mux(status_s, (sw_array & tag_cam.io.hits).orR, (uw_array & tag_cam.io.hits).orR)
io.resp.xcpt_if := bad_va || tlb_hit && !Mux(status_s, (sx_array & tag_cam.io.hits).orR, (ux_array & tag_cam.io.hits).orR)
io.resp.miss := tlb_miss
io.resp.ppn := Mux(status_vm && !io.req.bits.passthrough, Mux1H(tag_cam.io.hits, tag_ram), io.req.bits.vpn(PPN_BITS-1,0))
io.resp.hit_idx := tag_cam.io.hits
@ -175,7 +175,7 @@ class TLB(entries: Int) extends Component
when (state === s_wait && io.ptw.invalidate) {
state := s_wait_invalidate
}
when ((state === s_wait || state === s_wait_invalidate) && io.ptw.resp.valid) {
when (io.ptw.resp.valid) {
state := s_ready
}
}