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updated so svmode actually causes the right state tranitions. fsm now stuck in idle loop

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Kip Macsai-Goren 2021-06-22 11:21:11 -04:00
parent 9b27cd6fb7
commit 3e19eba20d
1 changed files with 32 additions and 30 deletions
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62
wally-pipelined/src/mmu/pagetablewalker.sv
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@ -225,49 +225,51 @@ module pagetablewalker (
always_comb begin
case (WalkerState)
IDLE: if (MMUTranslate) NextWalkerState = LEVEL3;
else NextWalkerState = IDLE;
LEVEL3: if (SvMode != `SV48) NextWalkerState = LEVEL2;
// 3rd level used if SV48 is enabled.
else begin
if (~MMUReady) NextWalkerState = LEVEL3;
// *** <FUTURE WORK> According to the architecture, we should
// fault upon finding a superpage that is misaligned or has 0
// access bit. The following commented line of code is
// supposed to perform that check. However, it is untested.
else if (ValidPTE && LeafPTE && ~BadTerapage) NextWalkerState = LEAF;
// else if (ValidPTE && LeafPTE) NextWalkerState = LEAF; // *** Once the above line is properly tested, delete this line.
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL2;
else NextWalkerState = FAULT;
end
LEVEL2: if (~MMUReady) NextWalkerState = LEVEL2;
IDLE: if (MMUTranslate && SvMode == `SV48) NextWalkerState = LEVEL3;
else if (MMUTranslate && SvMode == `SV39) NextWalkerState = LEVEL2;
else NextWalkerState = IDLE;
LEVEL3: if (~MMUReady) NextWalkerState = LEVEL3;
// *** <FUTURE WORK> According to the architecture, we should
// fault upon finding a superpage that is misaligned or has 0
// access bit. The following commented line of code is
// supposed to perform that check. However, it is untested.
else if (ValidPTE && LeafPTE && ~BadTerapage) NextWalkerState = LEAF;
// else if (ValidPTE && LeafPTE) NextWalkerState = LEAF; // *** Once the above line is properly tested, delete this line.
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL2;
else NextWalkerState = FAULT;
LEVEL2: if (~MMUReady) NextWalkerState = LEVEL2;
// *** <FUTURE WORK> According to the architecture, we should
// fault upon finding a superpage that is misaligned or has 0
// access bit. The following commented line of code is
// supposed to perform that check. However, it is untested.
else if (ValidPTE && LeafPTE && ~BadGigapage) NextWalkerState = LEAF;
// else if (ValidPTE && LeafPTE) NextWalkerState = LEAF; // *** Once the above line is properly tested, delete this line.
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL1;
else NextWalkerState = FAULT;
LEVEL1: if (~MMUReady) NextWalkerState = LEVEL1;
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL1;
else NextWalkerState = FAULT;
LEVEL1: if (~MMUReady) NextWalkerState = LEVEL1;
// *** <FUTURE WORK> According to the architecture, we should
// fault upon finding a superpage that is misaligned or has 0
// access bit. The following commented line of code is
// supposed to perform that check. However, it is untested.
else if (ValidPTE && LeafPTE && ~BadMegapage) NextWalkerState = LEAF;
// else if (ValidPTE && LeafPTE) NextWalkerState = LEAF; // *** Once the above line is properly tested, delete this line.
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL0;
else NextWalkerState = FAULT;
LEVEL0: if (~MMUReady) NextWalkerState = LEVEL0;
else if (ValidPTE && LeafPTE && ~AccessAlert)
NextWalkerState = LEAF;
else NextWalkerState = FAULT;
LEAF: if (MMUTranslate) NextWalkerState = LEVEL3;
else NextWalkerState = IDLE;
FAULT: if (MMUTranslate) NextWalkerState = LEVEL3;
else NextWalkerState = IDLE;
else if (ValidPTE && ~LeafPTE) NextWalkerState = LEVEL0;
else NextWalkerState = FAULT;
LEVEL0: if (~MMUReady) NextWalkerState = LEVEL0;
else if (ValidPTE && LeafPTE && ~AccessAlert) NextWalkerState = LEAF;
else NextWalkerState = FAULT;
LEAF: if (MMUTranslate) NextWalkerState = LEVEL3;
else NextWalkerState = IDLE;
FAULT: if (MMUTranslate) NextWalkerState = LEVEL3;
else NextWalkerState = IDLE;
// Default case should never happen, but is included for linter.
default: NextWalkerState = IDLE;
default: NextWalkerState = IDLE;
endcase
end