diff --git a/src/privileged/csr.sv b/src/privileged/csr.sv index 1478b5fc0..f44785287 100644 --- a/src/privileged/csr.sv +++ b/src/privileged/csr.sv @@ -55,7 +55,7 @@ module csr #(parameter input logic [4:0] SetFflagsM, // Set floating point flag bits in FCSR input logic [1:0] NextPrivilegeModeM, // STATUS bits updated based on next privilege mode input logic [1:0] PrivilegeModeW, // current privilege mode - input logic [`LOG_XLEN-1:0] CauseM, // Trap cause + input logic [3:0] CauseM, // Trap cause input logic SelHPTW, // hardware page table walker active, so base endianness on supervisor mode // inputs for performance counters input logic LoadStallD, @@ -79,7 +79,7 @@ module csr #(parameter // outputs from CSRs output logic [1:0] STATUS_MPP, output logic STATUS_SPP, STATUS_TSR, STATUS_TVM, - output logic [`XLEN-1:0] MEDELEG_REGW, + output logic [15:0] MEDELEG_REGW, output logic [`XLEN-1:0] SATP_REGW, output logic [11:0] MIP_REGW, MIE_REGW, MIDELEG_REGW, output logic STATUS_MIE, STATUS_SIE, @@ -107,7 +107,8 @@ module csr #(parameter logic WriteMSTATUSM, WriteMSTATUSHM, WriteSSTATUSM; logic CSRMWriteM, CSRSWriteM, CSRUWriteM; logic WriteFRMM, WriteFFLAGSM; - logic [`XLEN-1:0] UnalignedNextEPCM, NextEPCM, NextCauseM, NextMtvalM; + logic [`XLEN-1:0] UnalignedNextEPCM, NextEPCM, NextMtvalM; + logic [4:0] NextCauseM; logic [11:0] CSRAdrM; logic IllegalCSRCAccessM, IllegalCSRMAccessM, IllegalCSRSAccessM, IllegalCSRUAccessM; logic InsufficientCSRPrivilegeM; @@ -153,7 +154,7 @@ module csr #(parameter logic VectoredM; logic [`XLEN-1:0] TVecPlusCauseM; assign VectoredM = InterruptM & (TVecM[1:0] == 2'b01); - assign TVecPlusCauseM = {TVecAlignedM[`XLEN-1:6], CauseM[3:0], 2'b00}; // 64-byte alignment allows concatenation rather than addition + assign TVecPlusCauseM = {TVecAlignedM[`XLEN-1:6], CauseM, 2'b00}; // 64-byte alignment allows concatenation rather than addition mux2 #(`XLEN) trapvecmux(TVecAlignedM, TVecPlusCauseM, VectoredM, TrapVectorM); end else assign TrapVectorM = TVecAlignedM; @@ -196,7 +197,7 @@ module csr #(parameter assign CSRAdrM = InstrM[31:20]; assign UnalignedNextEPCM = TrapM ? ((wfiM & IntPendingM) ? PCM+4 : PCM) : CSRWriteValM; assign NextEPCM = `C_SUPPORTED ? {UnalignedNextEPCM[`XLEN-1:1], 1'b0} : {UnalignedNextEPCM[`XLEN-1:2], 2'b00}; // 3.1.15 alignment - assign NextCauseM = TrapM ? {InterruptM, {(`XLEN-`LOG_XLEN-1){1'b0}}, CauseM}: CSRWriteValM; + assign NextCauseM = TrapM ? {InterruptM, CauseM}: {CSRWriteValM[`XLEN-1], CSRWriteValM[3:0]}; assign NextMtvalM = TrapM ? NextFaultMtvalM : CSRWriteValM; assign CSRMWriteM = CSRWriteM & (PrivilegeModeW == `M_MODE); assign CSRSWriteM = CSRWriteM & (|PrivilegeModeW); diff --git a/src/privileged/csrm.sv b/src/privileged/csrm.sv index daf7e1012..9f00f3a68 100644 --- a/src/privileged/csrm.sv +++ b/src/privileged/csrm.sv @@ -69,20 +69,21 @@ module csrm #(parameter DSCRATCH1 = 12'h7B3, // Constants ZERO = {(`XLEN){1'b0}}, - MEDELEG_MASK = ~(ZERO | `XLEN'b1 << 11), + MEDELEG_MASK = 16'hB3FF, MIDELEG_MASK = 12'h222 // we choose to not make machine interrupts delegable ) ( input logic clk, reset, input logic InstrValidNotFlushedM, input logic CSRMWriteM, MTrapM, input logic [11:0] CSRAdrM, - input logic [`XLEN-1:0] NextEPCM, NextCauseM, NextMtvalM, MSTATUS_REGW, MSTATUSH_REGW, + input logic [`XLEN-1:0] NextEPCM, NextMtvalM, MSTATUS_REGW, MSTATUSH_REGW, + input logic [4:0] NextCauseM, input logic [`XLEN-1:0] CSRWriteValM, input logic [11:0] MIP_REGW, MIE_REGW, output logic [`XLEN-1:0] CSRMReadValM, MTVEC_REGW, output logic [`XLEN-1:0] MEPC_REGW, output logic [31:0] MCOUNTEREN_REGW, MCOUNTINHIBIT_REGW, - output logic [`XLEN-1:0] MEDELEG_REGW, + output logic [15:0] MEDELEG_REGW, output logic [11:0] MIDELEG_REGW, output var logic [7:0] PMPCFG_ARRAY_REGW[`PMP_ENTRIES-1:0], output var logic [`PA_BITS-3:0] PMPADDR_ARRAY_REGW [`PMP_ENTRIES-1:0], @@ -91,8 +92,8 @@ module csrm #(parameter ); logic [`XLEN-1:0] MISA_REGW, MHARTID_REGW; - logic [`XLEN-1:0] MSCRATCH_REGW; - logic [`XLEN-1:0] MCAUSE_REGW, MTVAL_REGW; + logic [`XLEN-1:0] MSCRATCH_REGW, MTVAL_REGW; + logic [4:0] MCAUSE_REGW; logic WriteMTVECM, WriteMEDELEGM, WriteMIDELEGM; logic WriteMSCRATCHM, WriteMEPCM, WriteMCAUSEM, WriteMTVALM; logic WriteMCOUNTERENM, WriteMCOUNTINHIBITM; @@ -150,13 +151,13 @@ module csrm #(parameter // CSRs flopenr #(`XLEN) MTVECreg(clk, reset, WriteMTVECM, {CSRWriteValM[`XLEN-1:2], 1'b0, CSRWriteValM[0]}, MTVEC_REGW); if (`S_SUPPORTED) begin:deleg // DELEG registers should exist - flopenr #(`XLEN) MEDELEGreg(clk, reset, WriteMEDELEGM, CSRWriteValM & MEDELEG_MASK, MEDELEG_REGW); - flopenr #(12) MIDELEGreg(clk, reset, WriteMIDELEGM, CSRWriteValM[11:0] & MIDELEG_MASK, MIDELEG_REGW); + flopenr #(16) MEDELEGreg(clk, reset, WriteMEDELEGM, CSRWriteValM[15:0] & MEDELEG_MASK, MEDELEG_REGW); + flopenr #(12) MIDELEGreg(clk, reset, WriteMIDELEGM, CSRWriteValM[11:0] & MIDELEG_MASK, MIDELEG_REGW); end else assign {MEDELEG_REGW, MIDELEG_REGW} = 0; flopenr #(`XLEN) MSCRATCHreg(clk, reset, WriteMSCRATCHM, CSRWriteValM, MSCRATCH_REGW); flopenr #(`XLEN) MEPCreg(clk, reset, WriteMEPCM, NextEPCM, MEPC_REGW); - flopenr #(`XLEN) MCAUSEreg(clk, reset, WriteMCAUSEM, NextCauseM, MCAUSE_REGW); + flopenr #(5) MCAUSEreg(clk, reset, WriteMCAUSEM, NextCauseM, MCAUSE_REGW); if(`QEMU) assign MTVAL_REGW = `XLEN'b0; // MTVAL tied to 0 in QEMU configuration else flopenr #(`XLEN) MTVALreg(clk, reset, WriteMTVALM, NextMtvalM, MTVAL_REGW); flopenr #(32) MCOUNTINHIBITreg(clk, reset, WriteMCOUNTINHIBITM, CSRWriteValM[31:0], MCOUNTINHIBIT_REGW); @@ -192,13 +193,13 @@ module csrm #(parameter MSTATUS: CSRMReadValM = MSTATUS_REGW; MSTATUSH: CSRMReadValM = MSTATUSH_REGW; MTVEC: CSRMReadValM = MTVEC_REGW; - MEDELEG: CSRMReadValM = MEDELEG_REGW; + MEDELEG: CSRMReadValM = {{(`XLEN-16){1'b0}}, MEDELEG_REGW}; MIDELEG: CSRMReadValM = {{(`XLEN-12){1'b0}}, MIDELEG_REGW}; MIP: CSRMReadValM = {{(`XLEN-12){1'b0}}, MIP_REGW}; MIE: CSRMReadValM = {{(`XLEN-12){1'b0}}, MIE_REGW}; MSCRATCH: CSRMReadValM = MSCRATCH_REGW; MEPC: CSRMReadValM = MEPC_REGW; - MCAUSE: CSRMReadValM = MCAUSE_REGW; + MCAUSE: CSRMReadValM = {MCAUSE_REGW[4], {(`XLEN-5){1'b0}}, MCAUSE_REGW[3:0]}; MTVAL: CSRMReadValM = MTVAL_REGW; MTINST: CSRMReadValM = 0; // implemented as trivial zero MCOUNTEREN:CSRMReadValM = {{(`XLEN-32){1'b0}}, MCOUNTEREN_REGW}; diff --git a/src/privileged/csrs.sv b/src/privileged/csrs.sv index 3d75ef73e..598eed155 100644 --- a/src/privileged/csrs.sv +++ b/src/privileged/csrs.sv @@ -48,7 +48,8 @@ module csrs #(parameter input logic InstrValidNotFlushedM, input logic CSRSWriteM, STrapM, input logic [11:0] CSRAdrM, - input logic [`XLEN-1:0] NextEPCM, NextCauseM, NextMtvalM, SSTATUS_REGW, + input logic [`XLEN-1:0] NextEPCM, NextMtvalM, SSTATUS_REGW, + input logic [4:0] NextCauseM, input logic STATUS_TVM, input logic MCOUNTEREN_TM, // TM bit (1) of MCOUNTEREN; cause illegal instruction when trying to access STIMECMP if clear input logic [`XLEN-1:0] CSRWriteValM, @@ -73,7 +74,7 @@ module csrs #(parameter logic WriteSCAUSEM, WriteSTVALM, WriteSATPM, WriteSCOUNTERENM; logic WriteSTIMECMPM, WriteSTIMECMPHM; logic [`XLEN-1:0] SSCRATCH_REGW, STVAL_REGW; - logic [`XLEN-1:0] SCAUSE_REGW; + logic [4:0] SCAUSE_REGW; logic [63:0] STIMECMP_REGW; // write enables @@ -93,7 +94,7 @@ module csrs #(parameter flopenr #(`XLEN) STVECreg(clk, reset, WriteSTVECM, {CSRWriteValM[`XLEN-1:2], 1'b0, CSRWriteValM[0]}, STVEC_REGW); flopenr #(`XLEN) SSCRATCHreg(clk, reset, WriteSSCRATCHM, CSRWriteValM, SSCRATCH_REGW); flopenr #(`XLEN) SEPCreg(clk, reset, WriteSEPCM, NextEPCM, SEPC_REGW); - flopenr #(`XLEN) SCAUSEreg(clk, reset, WriteSCAUSEM, NextCauseM, SCAUSE_REGW); + flopenr #(5) SCAUSEreg(clk, reset, WriteSCAUSEM, NextCauseM, SCAUSE_REGW); flopenr #(`XLEN) STVALreg(clk, reset, WriteSTVALM, NextMtvalM, STVAL_REGW); if (`VIRTMEM_SUPPORTED) flopenr #(`XLEN) SATPreg(clk, reset, WriteSATPM, CSRWriteValM, SATP_REGW); @@ -126,7 +127,7 @@ module csrs #(parameter SIE: CSRSReadValM = {{(`XLEN-12){1'b0}}, MIE_REGW & 12'h222 & MIDELEG_REGW}; // only read supervisor fields SSCRATCH: CSRSReadValM = SSCRATCH_REGW; SEPC: CSRSReadValM = SEPC_REGW; - SCAUSE: CSRSReadValM = SCAUSE_REGW; + SCAUSE: CSRSReadValM = {SCAUSE_REGW[4], {(`XLEN-5){1'b0}}, SCAUSE_REGW[3:0]}; STVAL: CSRSReadValM = STVAL_REGW; SATP: if (`VIRTMEM_SUPPORTED & (PrivilegeModeW == `M_MODE | ~STATUS_TVM)) CSRSReadValM = SATP_REGW; else begin diff --git a/src/privileged/privileged.sv b/src/privileged/privileged.sv index 1975db10e..6fa8dcf98 100644 --- a/src/privileged/privileged.sv +++ b/src/privileged/privileged.sv @@ -96,8 +96,8 @@ module privileged ( output logic WFIStallM // Stall in Memory stage for WFI until interrupt or timeout ); - logic [`LOG_XLEN-1:0] CauseM; // trap cause - logic [`XLEN-1:0] MEDELEG_REGW; // exception delegation CSR + logic [3:0] CauseM; // trap cause + logic [15:0] MEDELEG_REGW; // exception delegation CSR logic [11:0] MIDELEG_REGW; // interrupt delegation CSR logic sretM, mretM; // supervisor / machine return instruction logic IllegalCSRAccessM; // Illegal access to CSR diff --git a/src/privileged/trap.sv b/src/privileged/trap.sv index d50b5fb48..ace63b48b 100644 --- a/src/privileged/trap.sv +++ b/src/privileged/trap.sv @@ -38,7 +38,7 @@ module trap ( input logic wfiM, // wait for interrupt instruction input logic [1:0] PrivilegeModeW, // current privilege mode input logic [11:0] MIP_REGW, MIE_REGW, MIDELEG_REGW, // interrupt pending, enabled, and delegate CSRs - input logic [`XLEN-1:0] MEDELEG_REGW, // exception delegation SR + input logic [15:0] MEDELEG_REGW, // exception delegation SR input logic STATUS_MIE, STATUS_SIE, // machine/supervisor interrupt enables input logic InstrValidM, // current instruction is valid, not flushed input logic CommittedM, CommittedF, // LSU/IFU has committed to a bus operation that can't be interrupted @@ -49,7 +49,7 @@ module trap ( output logic IntPendingM, // Interrupt is pending, might occur if enabled output logic DelegateM, // Delegate trap to supervisor handler output logic WFIStallM, // Stall due to WFI instruction - output logic [`LOG_XLEN-1:0] CauseM // trap cause + output logic [3:0] CauseM // trap cause ); logic MIntGlobalEnM, SIntGlobalEnM; // Global interupt enables @@ -72,7 +72,7 @@ module trap ( assign EnabledIntsM = ({12{MIntGlobalEnM}} & PendingIntsM & ~MIDELEG_REGW | {12{SIntGlobalEnM}} & PendingIntsM & MIDELEG_REGW); assign ValidIntsM = {12{~Committed}} & EnabledIntsM; assign InterruptM = (|ValidIntsM) & InstrValidM; // suppress interrupt if the memory system has partially processed a request. - assign DelegateM = `S_SUPPORTED & (InterruptM ? MIDELEG_REGW[CauseM[3:0]] : MEDELEG_REGW[CauseM]) & + assign DelegateM = `S_SUPPORTED & (InterruptM ? MIDELEG_REGW[CauseM] : MEDELEG_REGW[CauseM]) & (PrivilegeModeW == `U_MODE | PrivilegeModeW == `S_MODE); assign WFIStallM = wfiM & ~IntPendingM; @@ -109,7 +109,7 @@ module trap ( else if (IllegalInstrFaultM) CauseM = 2; else if (InstrMisalignedFaultM) CauseM = 0; else if (BreakpointFaultM) CauseM = 3; - else if (EcallFaultM) CauseM = {{(`LOG_XLEN-4){1'b0}}, {2'b10}, PrivilegeModeW}; + else if (EcallFaultM) CauseM = {2'b10, PrivilegeModeW}; else if (LoadMisalignedFaultM) CauseM = 4; else if (StoreAmoMisalignedFaultM) CauseM = 6; else if (LoadPageFaultM) CauseM = 13;