//////////////////////////////////////////
// wally-constants.vh
//
// Written: tfleming@hmc.edu 4 March 2021
// Modified: Kmacsaigoren@hmc.edu 31 May 2021
//              Added constants for checking sv mode and changed existing constants to accomodate
//              both sv48 and sv39
//
// Purpose: Specify constants nexessary for different memory virtualization modes.
//              These are specific to sv49, defined in section 4.5 of the privileged spec.
//              However, despite different constants for different modes, the hardware helps distinguish between
//              each mode.
//
// A component of the Wally configurable RISC-V project.
//
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
// OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
///////////////////////////////////////////

// constants defining different privilege modes
// defined in Table 1.1 of the privileged spec
`define M_MODE (2'b11)
`define S_MODE (2'b01)
`define U_MODE (2'b00)

// Virtual Memory Constants
`define VPN_SEGMENT_BITS (`XLEN == 32 ? 10 : 9)
`define VPN_BITS (`XLEN==32 ? (2*`VPN_SEGMENT_BITS) : (4*`VPN_SEGMENT_BITS))
`define PPN_BITS (`XLEN==32 ? 22 : 44)
`define PA_BITS (`XLEN==32 ? 34 : 56)
`define SVMODE_BITS (`XLEN==32 ? 1 : 4)
`define ASID_BASE (`XLEN==32 ? 22 : 44)
`define ASID_BITS (`XLEN==32 ? 9 : 16)

// constants to check SATP_MODE against
// defined in Table 4.3 of the privileged spec
`define NO_TRANSLATE 0
`define SV32 1
`define SV39 8
`define SV48 9

// macros to define supported modes
`define A_SUPPORTED ((`MISA >> 0) % 2 == 1)
`define C_SUPPORTED ((`MISA >> 2) % 2 == 1)
`define D_SUPPORTED ((`MISA >> 3) % 2 == 1)
`define E_SUPPORTED ((`MISA >> 4) % 2 == 1)
`define F_SUPPORTED ((`MISA >> 5) % 2 == 1)
`define I_SUPPORTED ((`MISA >> 8) % 2 == 1)
`define M_SUPPORTED ((`MISA >> 12) % 2 == 1)
`define Q_SUPPORTED ((`MISA >> 16) % 2 == 1)
`define S_SUPPORTED ((`MISA >> 18) % 2 == 1)
`define U_SUPPORTED ((`MISA >> 20) % 2 == 1)
// N-mode user-level interrupts are depricated per Andrew Waterman 1/13/21

// logarithm of XLEN, used for number of index bits to select
`define LOG_XLEN (`XLEN == 32 ? 5 : 6)

// Number of 64 bit PMP Configuration Register entries (or pairs of 32 bit entries)
`define PMPCFG_ENTRIES (`PMP_ENTRIES/8)

// Floating point constants for Quad, Double, Single, and Half precisions
`define Q_LEN 32'd128
`define Q_NE 32'd15
`define Q_NF 32'd112
`define Q_BIAS 32'd16383
`define Q_FMT 2'd3
`define D_LEN 32'd64
`define D_NE 32'd11
`define D_NF 32'd52
`define D_BIAS 32'd1023
`define D_FMT 2'd1
`define S_LEN 32'd32
`define S_NE 32'd8
`define S_NF 32'd23
`define S_BIAS 32'd127
`define S_FMT 2'd0
`define H_LEN 32'd16
`define H_NE 32'd5
`define H_NF 32'd10
`define H_BIAS 32'd15
`define H_FMT 2'd2

// Floating point length FLEN and number of exponent (NE) and fraction (NF) bits
`define FLEN (`Q_SUPPORTED ? `Q_LEN  : `D_SUPPORTED ? `D_LEN  : `S_LEN)
`define NE   (`Q_SUPPORTED ? `Q_NE   : `D_SUPPORTED ? `D_NE   : `S_NE)
`define NF   (`Q_SUPPORTED ? `Q_NF   : `D_SUPPORTED ? `D_NF   : `S_NF)
`define FMT  (`Q_SUPPORTED ? 2'd3    : `D_SUPPORTED ? 2'd1    : 2'd0)
`define BIAS (`Q_SUPPORTED ? `Q_BIAS : `D_SUPPORTED ? `D_BIAS : `S_BIAS)
/* Delete once tested dh 10/10/22

`define FLEN (`Q_SUPPORTED ? `Q_LEN  : `D_SUPPORTED ? `D_LEN  : `F_SUPPORTED ? `S_LEN  : `H_LEN)
`define NE   (`Q_SUPPORTED ? `Q_NE   : `D_SUPPORTED ? `D_NE   : `F_SUPPORTED ? `S_NE   : `H_NE)
`define NF   (`Q_SUPPORTED ? `Q_NF   : `D_SUPPORTED ? `D_NF   : `F_SUPPORTED ? `S_NF   : `H_NF) 
`define FMT  (`Q_SUPPORTED ? 2'd3       : `D_SUPPORTED ? 2'd1       : `F_SUPPORTED ? 2'd0       : 2'd2)
`define BIAS (`Q_SUPPORTED ? `Q_BIAS : `D_SUPPORTED ? `D_BIAS : `F_SUPPORTED ? `S_BIAS : `H_BIAS)*/

// Floating point constants needed for FPU paramerterization
`define FPSIZES ((32)'(`Q_SUPPORTED)+(32)'(`D_SUPPORTED)+(32)'(`F_SUPPORTED)+(32)'(`ZFH_SUPPORTED))
`define FMTBITS ((32)'(`FPSIZES>=3)+1)
`define LEN1  ((`D_SUPPORTED & (`FLEN != `D_LEN)) ? `D_LEN  : (`F_SUPPORTED & (`FLEN != `S_LEN)) ? `S_LEN  : `H_LEN)
`define NE1   ((`D_SUPPORTED & (`FLEN != `D_LEN)) ? `D_NE   : (`F_SUPPORTED & (`FLEN != `S_LEN)) ? `S_NE   : `H_NE)
`define NF1   ((`D_SUPPORTED & (`FLEN != `D_LEN)) ? `D_NF   : (`F_SUPPORTED & (`FLEN != `S_LEN)) ? `S_NF   : `H_NF)
`define FMT1  ((`D_SUPPORTED & (`FLEN != `D_LEN)) ? 2'd1    : (`F_SUPPORTED & (`FLEN != `S_LEN)) ? 2'd0    : 2'd2)
`define BIAS1 ((`D_SUPPORTED & (`FLEN != `D_LEN)) ? `D_BIAS : (`F_SUPPORTED & (`FLEN != `S_LEN)) ? `S_BIAS : `H_BIAS)
`define LEN2  ((`F_SUPPORTED & (`LEN1 != `S_LEN)) ? `S_LEN  : `H_LEN)
`define NE2   ((`F_SUPPORTED & (`LEN1 != `S_LEN)) ? `S_NE   : `H_NE)
`define NF2   ((`F_SUPPORTED & (`LEN1 != `S_LEN)) ? `S_NF   : `H_NF)
`define FMT2  ((`F_SUPPORTED & (`LEN1 != `S_LEN)) ? 2'd0    : 2'd2)
`define BIAS2 ((`F_SUPPORTED & (`LEN1 != `S_LEN)) ? `S_BIAS : `H_BIAS)

// largest length in IEU/FPU
`define CVTLEN ((`NF<`XLEN) ? (`XLEN) : (`NF))
`define LLEN ((`FLEN<`XLEN) ? (`XLEN) : (`FLEN))
`define LOGCVTLEN $unsigned($clog2(`CVTLEN+1))
`define NORMSHIFTSZ ((`QLEN+`NF+1) > (3*`NF+6) ? (`QLEN+`NF+1) : (3*`NF+6))
`define LOGNORMSHIFTSZ ($clog2(`NORMSHIFTSZ))
`define CORRSHIFTSZ ((`DIVN+1+`NF) > (3*`NF+4) ? (`DIVN+1+`NF) : (3*`NF+4))

// division constants
`define DIVN        (`NF<`XLEN ? `XLEN : `NF+3) // standard length of input
`define LOGR        (`RADIX==2 ? 32'h1 : 32'h2) // r = log(R)
`define RK          (`LOGR*`DIVCOPIES)          // r*k used for intdiv preproc
`define LOGRK       ($clog2(`RK))               // log2(r*k)
`define FPDUR       ((`DIVN+1+(`LOGR*`DIVCOPIES))/(`LOGR*`DIVCOPIES)+(`RADIX/4))
`define DURLEN      ($clog2(`FPDUR+1))
`define QLEN        (`FPDUR*`LOGR*`DIVCOPIES)
`define DIVb        (`FPDUR*`LOGR*`DIVCOPIES-1) // canonical fdiv size (b)
`define DIVBLEN     ($clog2(`DIVb+1)-1)
`define DIVa        (`DIVb+1-`XLEN)             // used for idiv on fpu