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Finished HPTW TranslationPAdr simlification

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This commit is contained in:
David Harris 2021-07-17 19:27:24 -04:00
parent 2b1fdfbae2
commit 35b7577be2
1 changed files with 4 additions and 29 deletions
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33
wally-pipelined/src/mmu/pagetablewalker.sv
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@ -55,7 +55,7 @@ module pagetablewalker
logic DTLBWalk; // register TLBs translation miss requests logic DTLBWalk; // register TLBs translation miss requests
logic [`PPN_BITS-1:0] BasePageTablePPN; logic [`PPN_BITS-1:0] BasePageTablePPN;
logic [`PPN_BITS-1:0] CurrentPPN; logic [`PPN_BITS-1:0] CurrentPPN;
logic MemWrite; logic MemWrite;
logic Executable, Writable, Readable, Valid; logic Executable, Writable, Readable, Valid;
logic MegapageMisaligned, GigapageMisaligned, TerapageMisaligned; logic MegapageMisaligned, GigapageMisaligned, TerapageMisaligned;
logic ValidPTE, LeafPTE, ValidLeafPTE, ValidNonLeafPTE; logic ValidPTE, LeafPTE, ValidLeafPTE, ValidNonLeafPTE;
@ -119,18 +119,18 @@ module pagetablewalker
default: NextPageType = PageType; default: NextPageType = PageType;
endcase endcase
// TranslationPAdr mux // TranslationPAdr muxing
if (`XLEN==32) begin // RV32 if (`XLEN==32) begin // RV32
logic [9:0] VPN; logic [9:0] VPN;
logic [`PPN_BITS-1:0] PPN; logic [`PPN_BITS-1:0] PPN;
assign VPN = ((WalkerState == LEVEL1_SET_ADR) | (WalkerState == LEVEL1_READ)) ? TranslationVAdr[31:22] : TranslationVAdr[21:12]; // select VPN field based on HPTW state assign VPN = ((WalkerState == LEVEL1_SET_ADR) | (WalkerState == LEVEL1_READ)) ? TranslationVAdr[31:22] : TranslationVAdr[21:12]; // select VPN field based on HPTW state
assign PPN = ((WalkerState == LEVEL1_SET_ADR) | (WalkerState == LEVEL1_READ)) ? BasePageTablePPN : CurrentPPN; assign PPN = ((WalkerState == LEVEL1_SET_ADR) | (WalkerState == LEVEL1_READ)) ? BasePageTablePPN : CurrentPPN;
assign TranslationPAdr = {PPN, VPN, 2'b00}; assign TranslationPAdr = {PPN, VPN, 2'b00};
end else begin // RV64 end else begin // RV64
logic [8:0] VPN; logic [8:0] VPN;
logic [`PPN_BITS-1:0] PPN; logic [`PPN_BITS-1:0] PPN;
always_comb always_comb
case (WalkerState) case (WalkerState) // select VPN field based on HPTW state
LEVEL3_SET_ADR: VPN = TranslationVAdr[47:39]; LEVEL3_SET_ADR: VPN = TranslationVAdr[47:39];
LEVEL3_READ: VPN = TranslationVAdr[47:39]; LEVEL3_READ: VPN = TranslationVAdr[47:39];
LEVEL3: VPN = TranslationVAdr[38:30]; LEVEL3: VPN = TranslationVAdr[38:30];
@ -144,31 +144,6 @@ module pagetablewalker
assign PPN = ((WalkerState == LEVEL3_SET_ADR) | (WalkerState == LEVEL3_READ) | assign PPN = ((WalkerState == LEVEL3_SET_ADR) | (WalkerState == LEVEL3_READ) |
(SvMode != `SV48 & ((WalkerState == LEVEL2_SET_ADR) | (WalkerState == LEVEL2_READ)))) ? BasePageTablePPN : CurrentPPN; (SvMode != `SV48 & ((WalkerState == LEVEL2_SET_ADR) | (WalkerState == LEVEL2_READ)))) ? BasePageTablePPN : CurrentPPN;
assign TranslationPAdr = {PPN, VPN, 3'b000}; assign TranslationPAdr = {PPN, VPN, 3'b000};
/*
assign VPN3 = TranslationVAdr[47:39];
assign VPN2 = TranslationVAdr[38:30];
assign VPN1 = TranslationVAdr[29:21];
assign VPN0 = TranslationVAdr[20:12];
always_comb
case (WalkerState)
LEVEL3_SET_ADR: TranslationPAdr = {BasePageTablePPN, VPN3, 3'b000};
LEVEL3_READ: TranslationPAdr = {BasePageTablePPN, VPN3, 3'b000};
LEVEL3: if (NextWalkerState == LEAF) TranslationPAdr = 0; //TranslationVAdr[`PA_BITS-1:0];
else TranslationPAdr = {(SvMode == `SV48) ? CurrentPPN : BasePageTablePPN, VPN2, 3'b000};
LEVEL2_SET_ADR: TranslationPAdr = {(SvMode == `SV48) ? CurrentPPN : BasePageTablePPN, VPN2, 3'b000};
LEVEL2_READ: TranslationPAdr = {(SvMode == `SV48) ? CurrentPPN : BasePageTablePPN, VPN2, 3'b000};
LEVEL2: if (NextWalkerState == LEAF) TranslationPAdr = 0; //TranslationVAdr[`PA_BITS-1:0];
else TranslationPAdr = {CurrentPPN, VPN1, 3'b000};
LEVEL1_SET_ADR: TranslationPAdr = {CurrentPPN, VPN1, 3'b000};
LEVEL1_READ: TranslationPAdr = {CurrentPPN, VPN1, 3'b000};
LEVEL1: if (NextWalkerState == LEAF) TranslationPAdr = 0; //TranslationVAdr[`PA_BITS-1:0];
else TranslationPAdr = {CurrentPPN, VPN0, 3'b000};
LEVEL0_SET_ADR: TranslationPAdr = {CurrentPPN, VPN0, 3'b000};
LEVEL0_READ: TranslationPAdr = {CurrentPPN, VPN0, 3'b000};
LEVEL0: TranslationPAdr = 0; //TranslationVAdr[`PA_BITS-1:0];
LEAF: TranslationPAdr = 0; //TranslationVAdr[`PA_BITS-1:0];
default: TranslationPAdr = 0; // cause seg fault if this is improperly used
endcase */
end end
if (`XLEN == 32) begin if (`XLEN == 32) begin