Cleaned up redundant ZICBOM/Z_SUPPORTED.

This commit is contained in:
Rose Thompson 2023-11-29 15:20:49 -06:00
parent 053b094620
commit 80336493f5
2 changed files with 16 additions and 18 deletions

24
src/cache/cachefsm.sv vendored
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@ -94,7 +94,7 @@ module cachefsm import cvw::*; #(parameter cvw_t P,
assign AnyMiss = (CacheRW[0] | CacheRW[1]) & ~CacheHit & ~InvalidateCache; // exclusion-tag: cache AnyMiss
assign AnyUpdateHit = (CacheRW[0]) & CacheHit; // exclusion-tag: icache storeAMO1
assign AnyHit = AnyUpdateHit | (CacheRW[1] & CacheHit); // exclusion-tag: icache AnyUpdateHit
assign CMOWritebackHit = (CMOp[1] | CMOp[2]) & CacheHit;
assign CMOWritebackHit = (CMOp[1] | CMOp[2]) & CacheHit; // *** why does this not include dirty?
assign CMOZeroNoEviction = CMOp[3] & ~LineDirty; // (hit or miss) with no writeback store zeros now
assign CMOZeroEviction = CMOp[3] & LineDirty; // (hit or miss) with writeback dirty line
assign CMOWriteback = CMOWritebackHit | CMOZeroEviction;
@ -130,7 +130,7 @@ module cachefsm import cvw::*; #(parameter cvw_t P,
else NextState = STATE_READY;
// exclusion-tag-start: icache case
STATE_WRITEBACK: if(CacheBusAck & ~(|CMOp[3:1])) NextState = STATE_FETCH;
else if(CacheBusAck) NextState = STATE_READ_HOLD;
else if(CacheBusAck) NextState = STATE_READ_HOLD; // *** why not Ready?
else NextState = STATE_WRITEBACK;
// eviction needs a delay as the bus fsm does not correctly handle sending the write command at the same time as getting back the bus ack.
STATE_FLUSH: if(LineDirty) NextState = STATE_FLUSH_WRITEBACK;
@ -154,24 +154,24 @@ module cachefsm import cvw::*; #(parameter cvw_t P,
(CurrState == STATE_FLUSH_WRITEBACK);
// write enables internal to cache
assign SetValid = CurrState == STATE_WRITE_LINE |
(P.ZICBOZ_SUPPORTED & CurrState == STATE_READY & CMOZeroNoEviction) |
(P.ZICBOZ_SUPPORTED & CurrState == STATE_WRITEBACK & CacheBusAck & CMOp[3]);
assign ClearValid = P.ZICBOM_SUPPORTED & ((CurrState == STATE_READY & CMOp[0] & CacheHit) |
(CurrState == STATE_WRITEBACK & CMOp[2] & CacheBusAck));
(CurrState == STATE_READY & CMOZeroNoEviction) |
(CurrState == STATE_WRITEBACK & CacheBusAck & CMOp[3]);
assign ClearValid = (CurrState == STATE_READY & CMOp[0]) |
(CurrState == STATE_WRITEBACK & CMOp[2] & CacheBusAck);
// coverage off -item e 1 -fecexprrow 8
assign LRUWriteEn = (((CurrState == STATE_READY & (AnyHit | CMOZeroNoEviction)) |
(CurrState == STATE_WRITE_LINE)) & ~FlushStage) |
(P.ZICBOZ_SUPPORTED & CurrState == STATE_WRITEBACK & CMOp[3] & CacheBusAck);
(CurrState == STATE_WRITEBACK & CMOp[3] & CacheBusAck);
// exclusion-tag-start: icache flushdirtycontrols
assign SetDirty = (CurrState == STATE_READY & (AnyUpdateHit | CMOZeroNoEviction)) | // exclusion-tag: icache SetDirty
(CurrState == STATE_WRITE_LINE & (CacheRW[0])) |
(P.ZICBOZ_SUPPORTED & CurrState == STATE_WRITEBACK & (CMOp[3] & CacheBusAck));
(CurrState == STATE_WRITEBACK & (CMOp[3] & CacheBusAck));
assign ClearDirty = (CurrState == STATE_WRITE_LINE & ~(CacheRW[0])) | // exclusion-tag: icache ClearDirty
(CurrState == STATE_FLUSH & LineDirty) | // This is wrong in a multicore snoop cache protocal. Dirty must be cleared concurrently and atomically with writeback. For single core cannot clear after writeback on bus ack and change flushadr. Clears the wrong set.
// Flush and eviction controls
(P.ZICBOM_SUPPORTED & CurrState == STATE_WRITEBACK & (CMOp[1] | CMOp[2]) & CacheBusAck);
assign SelWay = (CurrState == STATE_WRITEBACK & ((~CacheBusAck & ~(CMOp[1] | CMOp[2])) | (P.ZICBOZ_SUPPORTED & CacheBusAck & CMOp[3]))) |
(CurrState == STATE_READY & ((AnyMiss & LineDirty) | (P.ZICBOZ_SUPPORTED & CMOZeroNoEviction & ~CacheHit))) |
CurrState == STATE_WRITEBACK & (CMOp[1] | CMOp[2]) & CacheBusAck;
assign SelWay = (CurrState == STATE_WRITEBACK & ((~CacheBusAck & ~(CMOp[1] | CMOp[2])) | (CacheBusAck & CMOp[3]))) |
(CurrState == STATE_READY & ((AnyMiss & LineDirty) | (CMOZeroNoEviction & ~CacheHit))) |
(CurrState == STATE_WRITE_LINE);
assign SelWriteback = (CurrState == STATE_WRITEBACK & (CMOp[1] | CMOp[2] | ~CacheBusAck)) |
(CurrState == STATE_READY & AnyMiss & LineDirty);
@ -194,7 +194,7 @@ module cachefsm import cvw::*; #(parameter cvw_t P,
assign CacheBusRW[0] = (CurrState == STATE_READY & AnyMiss & LineDirty) | // exclusion-tag: icache CacheBusW
(CurrState == STATE_WRITEBACK & ~CacheBusAck) |
(CurrState == STATE_FLUSH_WRITEBACK & ~CacheBusAck) |
(P.ZICBOM_SUPPORTED & CurrState == STATE_WRITEBACK & (CMOp[1] | CMOp[2]) & ~CacheBusAck);
(CurrState == STATE_WRITEBACK & (CMOp[1] | CMOp[2]) & ~CacheBusAck);
assign SelAdr = (CurrState == STATE_READY & (CacheRW[0] | AnyMiss | (|CMOp))) | // exclusion-tag: icache SelAdrCauses // changes if store delay hazard removed
(CurrState == STATE_FETCH) |

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@ -357,8 +357,10 @@ module controller import cvw::*; #(parameter cvw_t P) (
// Cache Management instructions
always_comb begin
CMOpD = 4'b0000; // default: not a cbo instruction
if ((P.ZICBOM_SUPPORTED | P.ZICBOZ_SUPPORTED) & CMOD) begin
if ((P.ZICBOZ_SUPPORTED) & CMOD) begin
CMOpD[3] = (InstrD[31:20] == 12'd4); // cbo.zero
end
if ((P.ZICBOM_SUPPORTED) & CMOD) begin
CMOpD[2] = (InstrD[31:20] == 12'd2); // cbo.clean
CMOpD[1] = (InstrD[31:20] == 12'd1) | ((InstrD[31:20] == 12'd0) & (ENVCFG_CBE[1:0] == 2'b01)); // cbo.flush
CMOpD[0] = (InstrD[31:20] == 12'd0) & (ENVCFG_CBE[1:0] == 2'b11); // cbo.inval
@ -425,9 +427,5 @@ module controller import cvw::*; #(parameter cvw_t P) (
// a cache cannot read or write immediately after a write
// atomic operations are also detected as MemRWD[1]
//assign StoreStallD = MemRWE[0] & ((MemRWD[1] | (MemRWD[0] & P.DCACHE_SUPPORTED)));
// *** RT: Modify for ZICBOZ
logic cboD, cboE;
assign cboE = (|CMOpE[2:0] & P.ZICBOM_SUPPORTED) | (CMOpE[3] & P.ZICBOZ_SUPPORTED);
assign cboD = (|CMOpD[2:0] & P.ZICBOM_SUPPORTED) | (CMOpD[3] & P.ZICBOZ_SUPPORTED);
assign StoreStallD = (MemRWE[0] | cboE) & ((MemRWD[1] | (MemRWD[0] & P.DCACHE_SUPPORTED) | cboD));
assign StoreStallD = (MemRWE[0] | (|CMOpE)) & ((MemRWD[1] | (MemRWD[0] & P.DCACHE_SUPPORTED) | (|CMOpD)));
endmodule