Cheri-research/Toooba
1
0
Fork 0
Code Issues 1 Pull Requests Actions Packages Projects Releases Wiki Activity

Delay returns (up to 10 cycles) if there is an outstanding push.

Browse Source
This commit is contained in:
Jonathan Woodruff
2022-03-14 18:45:34 +00:00
parent 37a7745f1a
commit 7b78c0ed7b
1 changed files with 13 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
src_Core/RISCY_OOO/procs/lib/Ras.bsv
View File

@@ -55,7 +55,6 @@ typedef RasIndex RasPredTrainInfo;
interface ReturnAddrStack;
interface Vector#(SupSize, RAS) ras;
method Action willPush;
method Bool pendingPush;
method Action push(CapMem pushAddr);
method Action write(CapMem pushAddr, RasIndex h);
@@ -67,10 +66,20 @@ endinterface
(* synthesize *)
module mkRas(ReturnAddrStack) provisos(NumAlias#(TExp#(TLog#(RasEntries)), RasEntries));
Vector#(RasEntries, Ehr#(2, CapMem)) stack <- replicateM(mkEhr(nullCap));
Vector#(RasEntries, Ehr#(3, Bool)) valids <- replicateM(mkEhr(False));
// head points past valid data
// to gracefully overflow, head is allowed to overflow to 0 and overwrite the oldest data
Ehr#(TAdd#(SupSize, 3), RasIndex) head <- mkEhr(0);
Bool invalidHead = !(valids[head[0]][0]);
Reg#(Bit#(6)) delay <- mkReg(0);
rule resetValidHead(invalidHead);
if (delay < 10) delay <= delay + 1;
else begin
valids[head[0]][2] <= True;
delay <= 0;
end
endrule
`ifdef SECURITY
Reg#(Bool) flushDone <- mkReg(True);
@@ -97,10 +106,11 @@ module mkRas(ReturnAddrStack) provisos(NumAlias#(TExp#(TLog#(RasEntries)), RasEn
endinterface);
end
method Bool pendingPush = False;//(pendingPushReg[0] > 0 && pendingPushDelay < 6);
method Bool pendingPush = invalidHead;
method Action push(CapMem pushAddr);
Reg#(RasIndex) h = head[valueof(SupSize) + 2];
valids[h+1][0] <= False;
`ifndef NO_SPEC_RSB_PUSH
stack[h+1][1] <= pushAddr;
$display("RAS push stack[%d] <- %x", h+1, pushAddr);
@@ -111,6 +121,7 @@ module mkRas(ReturnAddrStack) provisos(NumAlias#(TExp#(TLog#(RasEntries)), RasEn
method Action write(CapMem pushAddr, RasIndex h);
stack[h][1] <= pushAddr;
valids[h][1] <= True;
$display("RAS write stack[%d] <- %x", h, pushAddr);
endmethod