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rocket-chip
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more itlb/dtlb/ptw fixes

This commit is contained in:
Rimas Avizienis 2011-11-12 15:00:45 -08:00
parent 73416f224b
commit 83d90c4dab
6 changed files with 63 additions and 27 deletions
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7
rocket/src/main/scala/cpu.scala
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@ -70,7 +70,7 @@ class rocketProc extends Component
ctrl.io.imem.resp_val := io.imem.resp_val;
dpath.io.imem.resp_data := io.imem.resp_data;
ctrl.io.xcpt_itlb := itlb.io.cpu.exception;
ctrl.io.itlb_miss := itlb.io.cpu.resp_miss;
// ctrl.io.itlb_miss := itlb.io.cpu.resp_miss;
io.imem.itlb_miss := itlb.io.cpu.resp_miss;
@ -83,7 +83,9 @@ class rocketProc extends Component
dtlb.io.cpu.req_vpn := dpath.io.dmem.req_addr(VADDR_BITS-1,PGIDX_BITS);
ctrl.io.xcpt_dtlb_ld := dtlb.io.cpu.xcpt_ld;
ctrl.io.xcpt_dtlb_st := dtlb.io.cpu.xcpt_st;
ctrl.io.dtlb_busy := dtlb.io.cpu.resp_busy;
ctrl.io.dtlb_miss := dtlb.io.cpu.resp_miss;
// io.dmem.dtlb_miss := dtlb.io.cpu.resp_miss;
// connect page table walker to TLBs, page table base register (from PCR)
// and D$ arbiter (selects between requests from pipeline and PTW, PTW has priority)
@ -98,6 +100,9 @@ class rocketProc extends Component
arb.io.cpu.req_val := ctrl.io.dmem.req_val;
arb.io.cpu.req_cmd := ctrl.io.dmem.req_cmd;
arb.io.cpu.req_type := ctrl.io.dmem.req_type;
// arb.io.cpu.dtlb_busy := dtlb.io.cpu.resp_busy;
arb.io.cpu.dtlb_miss := dtlb.io.cpu.resp_miss;
// arb.io.cpu.req_addr := dtlb.io.cpu.resp_addr;
arb.io.cpu.req_idx := dpath.io.dmem.req_addr(PGIDX_BITS-1,0);
arb.io.cpu.req_ppn := dtlb.io.cpu.resp_ppn;

8
rocket/src/main/scala/ctrl.scala
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@ -67,8 +67,9 @@ class ioCtrlAll extends Bundle()
val imem = new ioImem(List("req_val", "req_rdy", "resp_val")).flip();
val dmem = new ioDmem(List("req_val", "req_rdy", "req_cmd", "req_type", "resp_miss")).flip();
val host = new ioHost(List("start"));
val dtlb_busy = Bool('input);
val dtlb_miss = Bool('input);
val itlb_miss = Bool('input);
// val itlb_miss = Bool('input);
val xcpt_dtlb_ld = Bool('input);
val xcpt_dtlb_st = Bool('input);
val xcpt_itlb = Bool('input);
@ -497,7 +498,7 @@ class rocketCtrl extends Component
id_ren1 & id_stall_raddr1 |
(id_sel_wa === WA_RD) & id_stall_waddr |
(id_sel_wa === WA_RA) & id_stall_ra |
id_mem_val & ~io.dmem.req_rdy |
id_mem_val & (~io.dmem.req_rdy | io.dtlb_busy) |
id_sync & ~io.dmem.req_rdy |
id_console_out_val & ~io.console.rdy |
id_div_val & ~io.dpath.div_rdy |
@ -513,7 +514,8 @@ class rocketCtrl extends Component
io.dpath.stalld := ctrl_stalld.toBool;
io.dpath.killf := take_pc | io.itlb_miss | ~io.imem.resp_val;
// io.dpath.killf := take_pc | io.itlb_miss | ~io.imem.resp_val;
io.dpath.killf := take_pc | ~io.imem.resp_val;
io.dpath.killd := ctrl_killd.toBool;
io.dpath.killx := kill_ex.toBool;
io.dpath.killm := kill_mem.toBool;

47
rocket/src/main/scala/dcache.scala
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@ -7,6 +7,8 @@ import scala.math._;
// interface between D$ and processor/DTLB
class ioDmem(view: List[String] = null) extends Bundle(view) {
// val dtlb_busy = Bool('input);
val dtlb_miss = Bool('input);
val req_val = Bool('input);
val req_rdy = Bool('output);
val req_cmd = Bits(4, 'input);
@ -155,6 +157,8 @@ class rocketDCacheDM_flush(lines: Int) extends Component {
dcache.io.cpu.req_tag := Mux(flushing, r_cpu_req_tag, io.cpu.req_tag);
dcache.io.cpu.req_type := io.cpu.req_type;
dcache.io.cpu.req_data ^^ io.cpu.req_data;
// dcache.io.cpu.dtlb_busy := io.cpu.dtlb_busy;
dcache.io.cpu.dtlb_miss := io.cpu.dtlb_miss;
dcache.io.mem ^^ io.mem;
io.cpu.req_rdy := dcache.io.cpu.req_rdy && !flush_waiting;
@ -210,20 +214,22 @@ class rocketDCacheDM(lines: Int) extends Component {
r_cpu_req_tag <== io.cpu.req_tag;
}
when ((state === s_ready) && r_cpu_req_val) {
when ((state === s_ready) && r_cpu_req_val && !io.cpu.dtlb_miss) {
r_cpu_req_ppn <== io.cpu.req_ppn;
}
when (io.cpu.req_rdy) {
r_cpu_req_val <== io.cpu.req_val;
}
when (state === s_resolve_miss) {
r_cpu_req_val <== Bool(false);
when (r_req_load) {
r_cpu_resp_val <== Bool(true);
}
}
r_cpu_resp_val <== Bool(false);
otherwise {
r_cpu_req_val <== Bool(false);
}
when (((state === s_resolve_miss) && r_req_load) || (state === s_replay_load)) {
r_cpu_resp_val <== Bool(true);
}
otherwise {
r_cpu_resp_val <== Bool(false);
}
// refill counter
val rr_count = Reg(resetVal = UFix(0,2));
val rr_count_next = rr_count + UFix(1);
@ -244,7 +250,7 @@ class rocketDCacheDM(lines: Int) extends Component {
tag_array.io.d := r_cpu_req_ppn;
tag_array.io.we := tag_we;
tag_array.io.bweb := ~Bits(0,tagbits);
tag_array.io.ce := (state === s_ready) && io.cpu.req_val;
tag_array.io.ce := (state === s_ready) || (state === s_start_writeback) || (state === s_writeback);
val tag_rdata = tag_array.io.q;
// valid bit array
@ -256,8 +262,9 @@ class rocketDCacheDM(lines: Int) extends Component {
when (tag_we && r_req_flush) {
vb_array <== vb_array.bitSet(r_cpu_req_idx(PGIDX_BITS-1,offsetbits).toUFix, UFix(0,1));
}
val tag_valid = Reg(vb_array(tag_addr)).toBool;
val vb_rdata = Reg(vb_array(tag_addr).toBool);
val tag_valid = r_cpu_req_val && vb_rdata;
// val tag_valid = Reg(vb_array(tag_addr)).toBool;
val tag_match = (tag_rdata === io.cpu.req_ppn);
val addr_match = (r_cpu_req_idx(PGIDX_BITS-1,offsetbits) === p_store_idx(PGIDX_BITS-1,offsetbits));
val ldst_conflict = r_cpu_req_val && r_req_load && p_store_valid && addr_match;
@ -265,7 +272,7 @@ class rocketDCacheDM(lines: Int) extends Component {
// write the pending store data when the cache is idle, when the next command isn't a load
// or when there's a load to the same address (in which case there's a 2 cycle delay:
// once cycle to write the store data and another to read the data back)
val drain_store = p_store_valid && (!io.cpu.req_val || req_store || ldst_conflict);
val drain_store = !io.cpu.dtlb_miss && p_store_valid && (!io.cpu.req_val || req_store || ldst_conflict);
// write pending store data from a store which missed
// after the cache line refill has completed
@ -282,6 +289,11 @@ class rocketDCacheDM(lines: Int) extends Component {
p_store_type <== io.cpu.req_type;
p_store_valid <== Bool(true);
}
// cancel store if there's a DTLB miss
when (r_cpu_req_val && r_req_store && io.cpu.dtlb_miss)
{
p_store_valid <== Bool(false);
}
when (drain_store) {
p_store_valid <== Bool(false);
db_array <== db_array.bitSet(p_store_idx(PGIDX_BITS-1,offsetbits).toUFix, UFix(1,1));
@ -321,12 +333,12 @@ class rocketDCacheDM(lines: Int) extends Component {
// signal a load miss when the data isn't present in the cache and when it's in the pending store data register
// (causes the cache to block for 2 cycles and the load instruction is replayed)
val hit = tag_valid && tag_match;
val load_miss = (state === s_ready) && r_cpu_req_val && r_req_load && (!hit || (p_store_valid && addr_match));
val load_miss = !io.cpu.dtlb_miss && (state === s_ready) && r_cpu_req_val && r_req_load && (!hit || (p_store_valid && addr_match));
// output signals
// busy when there's a load to the same address as a pending store, or on a cache miss, or when executing a flush
io.cpu.req_rdy := (state === s_ready) && !ldst_conflict && (!r_cpu_req_val || (hit && !r_req_flush));
io.cpu.resp_val := ((state === s_ready) && r_cpu_req_val && r_req_load && hit && !(p_store_valid && addr_match)) ||
io.cpu.req_rdy := !io.cpu.dtlb_miss && (state === s_ready) && !ldst_conflict && (!r_cpu_req_val || (hit && !r_req_flush));
io.cpu.resp_val := !io.cpu.dtlb_miss && ((state === s_ready) && hit && r_req_load && !(p_store_valid && addr_match)) ||
((state === s_resolve_miss) && r_req_flush) ||
r_cpu_resp_val;
@ -351,6 +363,9 @@ class rocketDCacheDM(lines: Int) extends Component {
state <== s_ready;
}
is (s_ready) {
when (io.cpu.dtlb_miss) {
state <== s_ready;
}
when (ldst_conflict) {
state <== s_replay_load;
}

13
rocket/src/main/scala/dtlb.scala
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@ -20,6 +20,7 @@ class ioDTLB_CPU(view: List[String] = null) extends Bundle(view)
val req_asid = Bits(ASID_BITS, 'input);
val req_vpn = UFix(VPN_BITS, 'input);
// lookup responses
val resp_busy = Bool('output);
val resp_miss = Bool('output);
// val resp_val = Bool('output);
val resp_ppn = UFix(PPN_BITS, 'output);
@ -62,6 +63,7 @@ class rocketDTLB(entries: Int) extends Component
val req_load = (r_cpu_req_cmd === M_XRD);
val req_store = (r_cpu_req_cmd === M_XWR);
val req_flush = (r_cpu_req_cmd === M_FLA);
// val req_amo = io.cpu.req_cmd(3).toBool;
val lookup_tag = Cat(r_cpu_req_asid, r_cpu_req_vpn);
@ -117,8 +119,8 @@ class rocketDTLB(entries: Int) extends Component
val repl_waddr = Mux(invalid_entry, ie_addr, repl_count).toUFix;
val lookup_hit = (state === s_ready) && r_cpu_req_val && tag_hit;
val lookup_miss = (state === s_ready) && r_cpu_req_val && !tag_hit;
val lookup_hit = (state === s_ready) && r_cpu_req_val && !req_flush && tag_hit;
val lookup_miss = (state === s_ready) && r_cpu_req_val && !req_flush && !tag_hit;
val tlb_hit = status_vm && lookup_hit;
val tlb_miss = status_vm && lookup_miss;
@ -143,9 +145,12 @@ class rocketDTLB(entries: Int) extends Component
((status_s && !sw_array(tag_hit_addr).toBool) ||
(status_u && !uw_array(tag_hit_addr).toBool));
io.cpu.req_rdy := (state === s_ready);
io.cpu.req_rdy := Mux(status_vm, (state === s_ready) && !tlb_miss, Bool(true));
io.cpu.resp_busy := tlb_miss || (state != s_ready);
io.cpu.resp_miss := tlb_miss;
io.cpu.resp_ppn := Mux(status_vm, tag_ram(tag_hit_addr), r_cpu_req_vpn(PPN_BITS-1,0)).toUFix;
io.cpu.resp_ppn :=
Mux(status_vm, Mux(req_flush, Bits(0,PPN_BITS), tag_ram(tag_hit_addr)),
r_cpu_req_vpn(PPN_BITS-1,0)).toUFix;
io.ptw.req_val := (state === s_request);
io.ptw.req_vpn := r_refill_tag(VPN_BITS-1,0);

13
rocket/src/main/scala/icache.scala
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@ -81,7 +81,7 @@ class rocketICacheDM(lines: Int) extends Component {
when (io.cpu.req_val && io.cpu.req_rdy) {
r_cpu_req_idx <== io.cpu.req_idx;
}
when (state === s_ready) {
when (state === s_ready && r_cpu_req_val && !io.cpu.itlb_miss) {
r_cpu_req_ppn <== io.cpu.req_ppn;
}
when (io.cpu.req_rdy) {
@ -140,7 +140,9 @@ class rocketICacheDM(lines: Int) extends Component {
data_array.io.d := io.mem.resp_data;
data_array.io.we := io.mem.resp_val;
data_array.io.bweb := ~Bits(0,128);
data_array.io.ce := Bool(true); // FIXME
// data_array.io.ce := Bool(true); // FIXME
data_array.io.ce := (io.cpu.req_rdy && io.cpu.req_val) || (state === s_resolve_miss);
val data_array_rdata = data_array.io.q;
// output signals
@ -162,7 +164,12 @@ class rocketICacheDM(lines: Int) extends Component {
state <== s_ready;
}
is (s_ready) {
when (!io.cpu.itlb_miss && r_cpu_req_val && !(tag_valid && tag_match)) { state <== s_request; }
when (io.cpu.itlb_miss) {
state <== s_ready;
}
when (r_cpu_req_val && !(tag_valid && tag_match)) {
state <== s_request;
}
}
is (s_request)
{

2
rocket/src/main/scala/ptw.scala
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@ -28,6 +28,8 @@ class rocketDmemArbiter extends Component
io.mem.req_ppn := Mux(r_ptw_req_val, r_ptw_req_ppn, io.cpu.req_ppn);
io.mem.req_data := io.cpu.req_data;
io.mem.req_tag := Mux(io.ptw.req_val, Bits(0,5), io.cpu.req_tag);
// io.mem.dtlb_busy := io.cpu.dtlb_busy;
io.mem.dtlb_miss := io.cpu.dtlb_miss;
io.ptw.req_rdy := io.mem.req_rdy;
io.cpu.req_rdy := io.mem.req_rdy && !io.ptw.req_val;