Merge pull request #599 from davidharrishmc/dev

More coverage: CacheWay, hptw

sim/coverage-exclusions-rv64gc.do

@@ -93,6 +93,11 @@ for {set i 0} {$i < $numcacheways} {incr i} {
     # below: flushD can't go high during an icache write b/c of pipeline stall
     coverage exclude -scope /dut/core/ifu/bus/icache/icache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "exclusion-tag: cache SetValidEN"] -item e 1 -fecexprrow 4
     coverage exclude -scope /dut/core/ifu/bus/icache/icache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "exclusion-tag: cache ClearValidEN"] -item e 1 -fecexprrow 4
+    # No CMO to clear valid bits of I$
+    coverage exclude -scope /dut/core/ifu/bus/icache/icache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "// exclusion-tag: icache ClearValidBits"] 
+    coverage exclude -scope /dut/core/ifu/bus/icache/icache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "// exclusion-tag: icache ClearValidWay"] -item e 1
+    # No dirty ways in read-only I$
+    coverage exclude -scope /dut/core/ifu/bus/icache/icache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "// exclusion-tag: icache DirtyWay"] -item e 1
 }
 
 ## D$ Exclusions.
@@ -104,6 +109,8 @@ coverage exclude -scope /dut/core/lsu/bus/dcache/dcache/cachefsm -linerange [Get
 set numcacheways 4
 for {set i 0} {$i < $numcacheways} {incr i} {
     coverage exclude -scope /dut/core/lsu/bus/dcache/dcache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "exclusion-tag: dcache invalidateway"] -item bes 1 -fecexprrow 4
+    # InvalidateCacheDelay is always 0 for D$ because it is flushed, not invalidated
+    coverage exclude -scope /dut/core/lsu/bus/dcache/dcache/CacheWays[$i] -linerange [GetLineNum ../src/cache/cacheway.sv "exclusion-tag: dcache HitWay"] -item 3 1 -fecexprrow 2
 
     # FlushStage=1 will never happen when SetValidWay=1 since a pipeline stall is asserted by the cache in the fetch stage, which happens before
     # going into the WRITE_LINE state (and asserting SetValidWay). No TrapM can fire and since StallW is high, a stallM caused by WFIStallM would not cause a flushW.
@@ -246,6 +253,9 @@ coverage exclude -scope /dut/core/ifu/ifu/immu/immu/tlb/tlb/tlbcontrol -linerang
 # never reaches this when ENVCFG_ADUE_1 because HPTW updates A bit first
 coverage exclude -scope /dut/core/ifu/ifu/immu/immu/tlb/tlb/tlbcontrol -linerange [GetLineNum ../src/mmu/tlb/tlbcontrol.sv "assign PrePageFault"] -item e 1 -fecexprrow 18 
 
+
+
+
 ###############
 # HPTW exclusions
 ###############

src/cache/cache.sv

@@ -199,7 +199,7 @@ module cache import cvw::*; #(parameter cvw_t P,
   // Flush logic
   /////////////////////////////////////////////////////////////////////////////////////////////
 
-  if (!READ_ONLY_CACHE) begin:flushlogic
+  if (!READ_ONLY_CACHE) begin:flushlogic // D$ can be flushed
     // Flush address (line number)
     assign ResetOrFlushCntRst = reset | FlushCntRst;
     flopenr #(SETLEN) FlushAdrReg(clk, ResetOrFlushCntRst, FlushAdrCntEn, FlushAdrP1, NextFlushAdr);
@@ -213,7 +213,8 @@ module cache import cvw::*; #(parameter cvw_t P,
     else            assign NextFlushWay = FlushWay[NUMWAYS-1];
     assign FlushWayFlag = FlushWay[NUMWAYS-1];
   end // block: flushlogic
-  else begin:flushlogic
+  else begin:flushlogic // I$ is never flushed because it is never dirty
+    assign FlushWay = 0;
     assign FlushWayFlag = 0;
     assign FlushAdrFlag = 0;
   end

src/cache/cacheway.sv

@@ -100,7 +100,7 @@ module cacheway import cvw::*; #(parameter cvw_t P,
   /////////////////////////////////////////////////////////////////////////////////////////////
 
   assign SetValidWay = SetValid & SelData;
-  assign ClearValidWay = ClearValid & SelData;
+  assign ClearValidWay = ClearValid & SelData;                             // exclusion-tag: icache ClearValidWay
   assign SetDirtyWay = SetDirty & SelData;                                 // exclusion-tag: icache SetDirtyWay
   assign ClearDirtyWay = ClearDirty & SelData;
   assign SelectedWriteWordEn = (SetValidWay | SetDirtyWay) & ~FlushStage;  // exclusion-tag: icache SelectedWiteWordEn
@@ -121,8 +121,8 @@ module cacheway import cvw::*; #(parameter cvw_t P,
   // AND portion of distributed tag multiplexer
   assign TagWay = SelData ? ReadTag : '0; // AND part of AOMux
   assign HitDirtyWay = Dirty & ValidWay;
-  assign DirtyWay = SelDirty & HitDirtyWay;
+  assign DirtyWay = SelDirty & HitDirtyWay;                               // exclusion-tag: icache DirtyWay
-  assign HitWay = ValidWay & (ReadTag == PAdr[PA_BITS-1:OFFSETLEN+INDEXLEN]) & ~InvalidateCacheDelay;
+  assign HitWay = ValidWay & (ReadTag == PAdr[PA_BITS-1:OFFSETLEN+INDEXLEN]) & ~InvalidateCacheDelay; // exclusion-tag: dcache HitWay
 
   flop #(1) InvalidateCacheReg(clk, InvalidateCache, InvalidateCacheDelay);
 
@@ -163,7 +163,7 @@ module cacheway import cvw::*; #(parameter cvw_t P,
       ValidWay <= #1 ValidBits[CacheSetTag];
       if(InvalidateCache)                    ValidBits <= #1 '0; // exclusion-tag: dcache invalidateway
       else if (SetValidEN) ValidBits[CacheSetData] <= #1 SetValidWay;
-      else if (ClearValidEN) ValidBits[CacheSetData] <= #1 '0;
+      else if (ClearValidEN) ValidBits[CacheSetData] <= #1 '0; // exclusion-tag: icache ClearValidBits
     end
   end
 

tests/coverage/fround.S

@@ -0,0 +1,18 @@
+// fround.s
+
+#include "WALLY-init-lib.h"
+
+# run-elf.bash find this in project description
+main:
+
+    bseti t0, zero, 14  # turn on FPU
+    csrs mstatus, t0
+
+    # test fround behavior on NaN
+    li t0, 0x7FC00001
+    fmv.w.x ft0, t0
+    fround.s ft1, ft0
+    j done
+
+.align 10
+data_start:

tests/coverage/ifu.S

@@ -74,8 +74,31 @@ main:
     
     .hword 0x9C7D      // Reserved instruction from line 187 with op = 01, Instr[15:10] = 100111, Instr[6:5] = 11, and 0's everywhere else
     
+    # exercise all the cache ways
+    j way0code
 
+# stress test cache ways by loading stuff from each one and then doing fence.i to invalidate
+.align 12
+way0code:
+    jal way1code
+    fence.i
+    j done
 
+.align 12
+way1code:
+    j way2code
+
+.align 12
+way2code:
+    j way3code
+
+.align 12
+way3code:
+    j way00code
+
+.align 12
+way00code:
+    ret
     
    
     j done

tests/coverage/tlbmisc.S

@@ -133,10 +133,18 @@ main:
     li t0, 0x1000000000
     lw t1, 0(t0)
 
+    # Bad PBMT on top level PTE
+    li t0, 0x1800000000
+    lw t1, 0(t0)
+
     # Access fault on megapage
     li t0, 0x81400000
     lw t1, 0(t0)
 
+    # Access fault walking page tables at megapage level
+    li t0, 0xC0000000
+    lw t1, 0(t0)
+
     # AMO operation on page table entry that causes page fault due to malformed PBMT
     li t0, 0x81200000 
     jalr t0          # Attempt to fetch instruction from address causing faulty page walk
@@ -144,6 +152,13 @@ main:
     sfence.vma
     amoadd.w t0, t0, 0(t0)
 
+    # point top-level page table to an illegal address and verify it faults
+    li t0, 0x9000000000070000 # trap handler at non-existing memory location
+    csrw satp, t0 # should cause trap 
+    sfence.vma
+    nop
+ 
+
     # change back to default trap handler after checking everything that might cause an instruction page fault
     jal changetodefaulthandler
 
@@ -199,6 +214,9 @@ main:
     li a0, 1
     ecall
 
+
+   
+
     # wrap up
     li a0, 3 # switch back to machine mode because code at 0x80000000 may not have clean page table entry
     ecall
@@ -229,12 +247,14 @@ instructionpagefaulthandler:
     csrw mepc, ra # go back to calling function
     mret
 
-.align 4                # trap handlers must be aligned to multiple of 4
+.align 4                # trap handlers must be aligned to multiple of 16
 ipf_handler:
     # Load trap handler stack pointer tp
     csrrw tp, mscratch, tp  # swap MSCRATCH and tp
     sd t0, 0(tp)        # Save t0 and t1 on the stack
     sd t1, -8(tp)
+    li t5, 0x9000000000080010  
+    csrw satp, t5       # make sure we are pointing to the root page table 
     csrr t0, mcause     # Check the cause
     li t1, 8            # is it an ecall trap?
     andi t0, t0, 0xFC   # if CAUSE = 8, 9, or 11
@@ -251,20 +271,28 @@ ipf:
     csrrw tp, mscratch, tp  # restore tp
     mret                # return from trap
 
+.align 4                # trap handlers must be aligned to multiple of 16
+fixsatptraphandler:
+    li t5, 0x9000000000080010   # fix satp entry to normal page table root
+    csrw satp, t5
+    mret
+
 .data
 
 .align 16
 # root Page table situated at 0x80010000
 pagetable: 
-    .8byte 0x200044C1  # 0x00000000-0x7F_FFFFFFFF: PTE at 0x80011000 C1 dirty, accessed, valid
+    .8byte 0x200044C1  # VA 0x00000000-0x7F_FFFFFFFF: PTE at 0x80011000 C1 dirty, accessed, valid
     .8byte 0x00000000000010CF # misaligned terapage at 0x80_00000000
     .8byte 0x00000000000000CF # access fault terapage at 0x100_00000000
+    .8byte 0x40000000200044C1 # Bad PBMT at VA 0x180_0000000
 
 # next page table at 0x80011000
 .align 12
     .8byte 0x00000000000010CF # misaligned gigapage at 0x00000000
     .8byte 0x00000000200058C1 # PTE for pages at 0x40000000 pointing to 0x80150000
     .8byte 0x00000000200048C1 # gigapage at 0x80000000 pointing to 0x80120000
+    .8byte 0x00000000000000C1 # gigapage at VA 0xC0000000 causes access fault
  
 
 # Next page table at 0x80012000 for gigapage at 0x80000000