From ace743ae91538d5b658038517df1c488aa5544bd Mon Sep 17 00:00:00 2001
From: Ross Thompson <ross1728@gmail.com>
Date: Mon, 21 Feb 2022 16:54:38 -0600
Subject: [PATCH] Changed HPTWRead/HPTWWrite to be HPTWRW to be similar to
 MemRW.

---
 pipelined/src/lsu/lsuvirtmen.sv |  7 +++----
 pipelined/src/mmu/hptw.sv       | 13 ++++++-------
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/pipelined/src/lsu/lsuvirtmen.sv b/pipelined/src/lsu/lsuvirtmen.sv
index 25edad54..d4043a1d 100644
--- a/pipelined/src/lsu/lsuvirtmen.sv
+++ b/pipelined/src/lsu/lsuvirtmen.sv
@@ -71,13 +71,12 @@ module lsuvirtmem(
 
   logic                       AnyCPUReqM;
   logic [`PA_BITS-1:0]        HPTWAdr;
-  logic                       HPTWRead;
+  logic [1:0]                 HPTWRW;
   logic [2:0]                 HPTWSize;
   logic                       SelReplayCPURequest;
   logic [11:0]                PreLSUAdrE;  
   logic                       ITLBMissOrDAFaultF, ITLBMissOrDAFaultNoTrapF;
   logic                       DTLBMissOrDAFaultM, DTLBMissOrDAFaultNoTrapM;  
-  logic                       HPTWWrite;
 
   assign AnyCPUReqM = (|MemRWM) | (|AtomicM);
   assign ITLBMissOrDAFaultF = ITLBMissF | (`HPTW_WRITES_SUPPORTED & InstrDAPageFaultF);
@@ -93,10 +92,10 @@ module lsuvirtmem(
     .STATUS_MXR, .STATUS_SUM, .STATUS_MPRV, .STATUS_MPP, .PrivilegeModeW,
     .ITLBMissOrDAFaultNoTrapF, .DTLBMissOrDAFaultNoTrapM,
     .PTE, .PageType, .ITLBWriteF, .DTLBWriteM, .HPTWReadPTE(ReadDataM),
-    .DCacheStallM, .HPTWAdr, .HPTWRead, .HPTWWrite, .HPTWSize);
+    .DCacheStallM, .HPTWAdr, .HPTWRW, .HPTWSize);
 
   // multiplex the outputs to LSU
-  mux2 #(2) rwmux(MemRWM, {HPTWRead, HPTWWrite}, SelHPTW, PreLSURWM);
+  mux2 #(2) rwmux(MemRWM, HPTWRW, SelHPTW, PreLSURWM);
   mux2 #(3) sizemux(Funct3M, HPTWSize, SelHPTW, LSUFunct3M);
   mux2 #(7) funct7mux(Funct7M, 7'b0, SelHPTW, LSUFunct7M);    
   mux2 #(2) atomicmux(AtomicM, 2'b00, SelHPTW, LSUAtomicM);
diff --git a/pipelined/src/mmu/hptw.sv b/pipelined/src/mmu/hptw.sv
index 968b10c8..f3e156b3 100644
--- a/pipelined/src/mmu/hptw.sv
+++ b/pipelined/src/mmu/hptw.sv
@@ -48,8 +48,7 @@ module hptw
    output logic [1:0]          PageType, // page type to TLBs
    (* mark_debug = "true" *) output logic ITLBWriteF, DTLBWriteM, // write TLB with new entry
    output logic [`PA_BITS-1:0] HPTWAdr,
-   output logic                HPTWRead, // HPTW requesting to read memory
-   output logic                HPTWWrite,
+   output logic [1:0]          HPTWRW, // HPTW requesting to read memory
    output logic [2:0]          HPTWSize // 32 or 64 bit access.
 );
 
@@ -90,7 +89,7 @@ module hptw
 
 	// State flops
 	flopenr #(1) TLBMissMReg(clk, reset, StartWalk, DTLBMissOrDAFaultNoTrapM, DTLBWalk); // when walk begins, record whether it was for DTLB (or record 0 for ITLB)
-	assign PRegEn = HPTWRead & ~DCacheStallM;
+	assign PRegEn = HPTWRW[1] & ~DCacheStallM;
   
 	flopenr #(`XLEN) PTEReg(clk, reset, PRegEn | UpdatePTE, NextPTE, PTE); // Capture page table entry from data cache
 
@@ -120,7 +119,7 @@ module hptw
     assign NextPTE = UpdatePTE ? {PTE[`XLEN-1:8], (SetDirty | PTE[7]), 1'b1, PTE[5:0]} : HPTWReadPTE; 
     flopenr #(`PA_BITS) HPTWAdrWriteReg(clk, reset, SaveHPTWAdr, HPTWReadAdr, HPTWWriteAdr);
     assign SaveHPTWAdr = WalkerState == L0_ADR;
-    assign SelHPTWWriteAdr = UpdatePTE | HPTWWrite;
+    assign SelHPTWWriteAdr = UpdatePTE | HPTWRW[0];
     mux2 #(`PA_BITS) HPTWWriteAdrMux(HPTWReadAdr, HPTWWriteAdr, SelHPTWWriteAdr, HPTWAdr); 
     
 
@@ -157,19 +156,19 @@ module hptw
     // However any other fault should not cause the update.
     assign DAPageFault = ValidLeafPTE & (~Accessed | SetDirty) & ~OtherPageFault;
 
-    assign HPTWWrite = (WalkerState == UPDATE_PTE);
+    assign HPTWRW[0] = (WalkerState == UPDATE_PTE);
     assign UpdatePTE = WalkerState == LEAF & DAPageFault;
   end else begin // block: hptwwrites
     assign NextPTE = HPTWReadPTE;
     assign HPTWAdr = HPTWReadAdr;
     assign DAPageFault = '0;
     assign UpdatePTE = '0;
-    assign HPTWWrite = '0;
+    assign HPTWRW[0] = '0;
   end
 
 	// Enable and select signals based on states
 	assign StartWalk = (WalkerState == IDLE) & TLBMiss;
-	assign HPTWRead = (WalkerState == L3_RD) | (WalkerState == L2_RD) | (WalkerState == L1_RD) | (WalkerState == L0_RD);
+	assign HPTWRW[1] = (WalkerState == L3_RD) | (WalkerState == L2_RD) | (WalkerState == L1_RD) | (WalkerState == L0_RD);
 	assign DTLBWriteM = (WalkerState == LEAF & ~DAPageFault) & DTLBWalk;
 	assign ITLBWriteF = (WalkerState == LEAF & ~DAPageFault) & ~DTLBWalk;