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Merge pull request #1206 from Zain2050/main

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Fixed a bug related to Reserved Encoding in tlbcontrol.sv
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David Harris 2024-12-24 05:32:45 -08:00 committed by GitHub
commit 505adef010
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1 changed files with 4 additions and 3 deletions
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src/mmu/tlb/tlbcontrol.sv
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@ -61,6 +61,7 @@ module tlbcontrol import cvw::*; #(parameter cvw_t P, ITLB = 0) (
logic TLBAccess; logic TLBAccess;
logic ImproperPrivilege; logic ImproperPrivilege;
logic BadPBMT, BadNAPOT, BadReserved; logic BadPBMT, BadNAPOT, BadReserved;
logic ReservedEncoding;
logic InvalidAccess; logic InvalidAccess;
logic PreUpdateDA, PrePageFault; logic PreUpdateDA, PrePageFault;
@ -88,6 +89,7 @@ module tlbcontrol import cvw::*; #(parameter cvw_t P, ITLB = 0) (
assign BadPBMT = ((PTE_PBMT != 0) & ~(P.SVPBMT_SUPPORTED & ENVCFG_PBMTE)) | PTE_PBMT == 3; // PBMT must be zero if not supported; value of 3 is reserved assign BadPBMT = ((PTE_PBMT != 0) & ~(P.SVPBMT_SUPPORTED & ENVCFG_PBMTE)) | PTE_PBMT == 3; // PBMT must be zero if not supported; value of 3 is reserved
assign BadNAPOT = PTE_N & (~P.SVNAPOT_SUPPORTED | ~NAPOT4); // N must be be 0 if CVNAPOT is not supported or not 64 KiB contiguous region assign BadNAPOT = PTE_N & (~P.SVNAPOT_SUPPORTED | ~NAPOT4); // N must be be 0 if CVNAPOT is not supported or not 64 KiB contiguous region
assign BadReserved = PTE_RESERVED; // Reserved bits must be zero assign BadReserved = PTE_RESERVED; // Reserved bits must be zero
assign ReservedEncoding = PTE_W & ~PTE_R; // fault on reserved encoding with R=0, W=1 to match ImperasDV behavior
// Check whether the access is allowed, page faulting if not. // Check whether the access is allowed, page faulting if not.
if (ITLB == 1) begin:itlb // Instruction TLB fault checking if (ITLB == 1) begin:itlb // Instruction TLB fault checking
@ -95,9 +97,9 @@ module tlbcontrol import cvw::*; #(parameter cvw_t P, ITLB = 0) (
// only execute non-user mode pages. // only execute non-user mode pages.
assign ImproperPrivilege = ((PrivilegeModeW == P.U_MODE) & ~PTE_U) | ((PrivilegeModeW == P.S_MODE) & PTE_U); assign ImproperPrivilege = ((PrivilegeModeW == P.U_MODE) & ~PTE_U) | ((PrivilegeModeW == P.S_MODE) & PTE_U);
assign PreUpdateDA = ~PTE_A; assign PreUpdateDA = ~PTE_A;
assign InvalidAccess = ~PTE_X; assign InvalidAccess = ~PTE_X | ReservedEncoding;
end else begin:dtlb // Data TLB fault checking end else begin:dtlb // Data TLB fault checking
logic InvalidRead, InvalidWrite, ReservedEncoding; logic InvalidRead, InvalidWrite;
logic InvalidCBOM, InvalidCBOZ; logic InvalidCBOM, InvalidCBOZ;
// User mode may only load/store from user mode pages, and supervisor mode // User mode may only load/store from user mode pages, and supervisor mode
@ -112,7 +114,6 @@ module tlbcontrol import cvw::*; #(parameter cvw_t P, ITLB = 0) (
assign InvalidWrite = WriteAccess & ~PTE_W; assign InvalidWrite = WriteAccess & ~PTE_W;
assign InvalidCBOM = (|CMOpM[2:0]) & (~PTE_R & (~STATUS_MXR | ~PTE_X)); assign InvalidCBOM = (|CMOpM[2:0]) & (~PTE_R & (~STATUS_MXR | ~PTE_X));
assign InvalidCBOZ = CMOpM[3] & ~PTE_W; assign InvalidCBOZ = CMOpM[3] & ~PTE_W;
assign ReservedEncoding = PTE_W & ~PTE_R; // fault on reserved encoding with R=0, W=1 to match ImperasDV behavior
assign InvalidAccess = InvalidRead | InvalidWrite | InvalidCBOM | InvalidCBOZ | ReservedEncoding; assign InvalidAccess = InvalidRead | InvalidWrite | InvalidCBOM | InvalidCBOZ | ReservedEncoding;
assign PreUpdateDA = ~PTE_A | WriteAccess & ~PTE_D; assign PreUpdateDA = ~PTE_A | WriteAccess & ~PTE_D;
end end