path: root/drivers/gpu/drm/amd/powerplay/hwmgr/ppevvmath.h

/*
 * Copyright 2015 Advanced Micro Devices, Inc.
 *
 * 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 */
#include <asm/div64.h>

#define SHIFT_AMOUNT 16 /* We multiply all original integers with 2^SHIFT_AMOUNT to get the fInt representation */

#define PRECISION 5 /* Change this value to change the number of decimal places in the final output - 5 is a good default */

#define SHIFTED_2 (2 << SHIFT_AMOUNT)
#define MAX (1 << (SHIFT_AMOUNT - 1)) - 1 /* 32767 - Might change in the future */

/* -------------------------------------------------------------------------------
 * NEW TYPE - fINT
 * -------------------------------------------------------------------------------
 * A variable of type fInt can be accessed in 3 ways using the dot (.) operator
 * fInt A;
 * A.full => The full number as it is. Generally not easy to read
 * A.partial.real => Only the integer portion
 * A.partial.decimal => Only the fractional portion
 */
typedef union _fInt {
    int full;
    struct _partial {
        unsigned int decimal: SHIFT_AMOUNT; /*Needs to always be unsigned*/
        int real: 32 - SHIFT_AMOUNT;
    } partial;
} fInt;

/* -------------------------------------------------------------------------------
 * Function Declarations
 *  -------------------------------------------------------------------------------
 */
fInt ConvertToFraction(int);                       /* Use this to convert an INT to a FINT */
fInt Convert_ULONG_ToFraction(uint32_t);              /* Use this to convert an uint32_t to a FINT */
fInt GetScaledFraction(int, int);                  /* Use this to convert an INT to a FINT after scaling it by a factor */
int ConvertBackToInteger(fInt);                    /* Convert a FINT back to an INT that is scaled by 1000 (i.e. last 3 digits are the decimal digits) */

fInt fNegate(fInt);                                /* Returns -1 * input fInt value */
fInt fAdd (fInt, fInt);                            /* Returns the sum of two fInt numbers */
fInt fSubtract (fInt A, fInt B);                   /* Returns A-B - Sometimes easier than Adding negative numbers */
fInt fMultiply (fInt, fInt);                       /* Returns the product of two fInt numbers */
fInt fDivide (fInt A, fInt B);                     /* Returns A/B */
fInt fGetSquare(fInt);                             /* Returns the square of a fInt number */
fInt fSqrt(fInt);                                  /* Returns the Square Root of a fInt number */

int uAbs(int);                                     /* Returns the Absolute value of the Int */
fInt fAbs(fInt);                                   /* Returns the Absolute value of the fInt */
int uPow(int base, int exponent);                  /* Returns base^exponent an INT */

void SolveQuadracticEqn(fInt, fInt, fInt, fInt[]); /* Returns the 2 roots via the array */
bool Equal(fInt, fInt);                         /* Returns true if two fInts are equal to each other */
bool GreaterThan(fInt A, fInt B);               /* Returns true if A > B */

fInt fExponential(fInt exponent);                  /* Can be used to calculate e^exponent */
fInt fNaturalLog(fInt value);                      /* Can be used to calculate ln(value) */

/* Fuse decoding functions
 * -------------------------------------------------------------------------------------
 */
fInt fDecodeLinearFuse(uint32_t fuse_value, fInt f_min, fInt f_range, uint32_t bitlength);
fInt fDecodeLogisticFuse(uint32_t fuse_value, fInt f_average, fInt f_range, uint32_t bitlength);
fInt fDecodeLeakageID (uint32_t leakageID_fuse, fInt ln_max_div_min, fInt f_min, uint32_t bitlength);

/* Internal Support Functions - Use these ONLY for testing or adding to internal functions
 * -------------------------------------------------------------------------------------
 * Some of the following functions take two INTs as their input - This is unsafe for a variety of reasons.
 */
fInt Add (int, int);                               /* Add two INTs and return Sum as FINT */
fInt Multiply (int, int);                          /* Multiply two INTs and return Product as FINT */
fInt Divide (int, int);                            /* You get the idea... */
fInt fNegate(fInt);

int uGetScaledDecimal (fInt);                      /* Internal function */
int GetReal (fInt A);                              /* Internal function */

/* Future Additions and Incomplete Functions
 * -------------------------------------------------------------------------------------
 */
int GetRoundedValue(fInt);                         /* Incomplete function - Useful only when Precision is lacking */
                                                   /* Let us say we have 2.126 but can only handle 2 decimal points. We could */
                                                   /* either chop of 6 and keep 2.12 or use this function to get 2.13, which is more accurate */

/* -------------------------------------------------------------------------------------
 * TROUBLESHOOTING INFORMATION
 * -------------------------------------------------------------------------------------
 * 1) ConvertToFraction - InputOutOfRangeException: Only accepts numbers smaller than MAX (default: 32767)
 * 2) fAdd - OutputOutOfRangeException: Output bigger than MAX (default: 32767)
 * 3) fMultiply - OutputOutOfRangeException:
 * 4) fGetSquare - OutputOutOfRangeException:
 * 5) fDivide - DivideByZeroException
 * 6) fSqrt - NegativeSquareRootException: Input cannot be a negative number
 */

/* -------------------------------------------------------------------------------------
 * START OF CODE
 * -------------------------------------------------------------------------------------
 */
fInt fExponential(fInt exponent)        /*Can be used to calculate e^exponent*/
{
    uint32_t i;
    bool bNegated = false;

    fInt fPositiveOne = ConvertToFraction(1);
    fInt fZERO = ConvertToFraction(0);

    fInt lower_bound = Divide(78, 10000);
    fInt solution = fPositiveOne; /*Starting off with baseline of 1 */
    fInt error_term;

    uint32_t k_array[11] = {55452, 27726, 13863, 6931, 4055, 2231, 1178, 606, 308, 155, 78};
    uint32_t expk_array[11] = {2560000, 160000, 40000, 20000, 15000, 12500, 11250, 10625, 10313, 10156, 10078};

    if (GreaterThan(fZERO, exponent)) {
        exponent = fNegate(exponent);
        bNegated = true;
    }

    while (GreaterThan(exponent, lower_bound)) {
        for (i = 0; i < 11; i++) {
            if (GreaterThan(exponent, GetScaledFraction(k_array[i], 10000))) {
                exponent = fSubtract(exponent, GetScaledFraction(k_array[i], 10000));
                solution = fMultiply(solution, GetScaledFraction(expk_array[i], 10000));
            }
        }
    }

    error_term = fAdd(fPositiveOne, exponent);

    solution = fMultiply(solution, error_term);

    if (bNegated)
        solution = fDivide(fPositiveOne, solution);

    return solution;
}

fInt fNaturalLog(fInt value)
{
    uint32_t i;
    fInt upper_bound = Divide(8, 1000);
    fInt fNegativeOne = ConvertToFraction(-1);
    fInt solution = ConvertToFraction(0); /*Starting off with baseline of 0 */
    fInt error_term;

    uint32_t k_array[10] = {160000, 40000, 20000, 15000, 12500, 11250, 10625, 10313, 10156, 10078};
    uint32_t logk_array[10] = {27726, 13863, 6931, 4055, 2231, 1178, 606, 308, 155, 78};

    while (GreaterThan(fAdd(value, fNegativeOne), upper_bound)) {
        for (i = 0; i < 10; i++) {
            if (GreaterThan(value, GetScaledFraction(k_array[i], 10000))) {
                value = fDivide(value, GetScaledFraction(k_array[i], 10000));
                solution = fAdd(solution, GetScaledFraction(logk_array[i], 10000));
            }
        }
    }

    error_term = fAdd(fNegativeOne, value);

    return (fAdd(solution, error_term));
}

fInt fDecodeLinearFuse(uint32_t fuse_value, fInt f_min, fInt f_range, uint32_t bitlength)
{
    fInt f_fuse_value = Convert_ULONG_ToFraction(fuse_value);
    fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);

    fInt f_decoded_value;

    f_decoded_value = fDivide(f_fuse_value, f_bit_max_value);
    f_decoded_value = fMultiply(f_decoded_value, f_range);
    f_decoded_value = fAdd(f_decoded_value, f_min);

    return f_decoded_value;
}


fInt fDecodeLogisticFuse(uint32_t fuse_value, fInt f_average, fInt f_range, uint32_t bitlength)
{
    fInt f_fuse_value = Convert_ULONG_ToFraction(fuse_value);
    fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);

    fInt f_CONSTANT_NEG13 = ConvertToFraction(-13);
    fInt f_CONSTANT1 = ConvertToFraction(1);

    fInt f_decoded_value;

    f_decoded_value = fSubtract(fDivide(f_bit_max_value, f_fuse_value), f_CONSTANT1);
    f_decoded_value = fNaturalLog(f_decoded_value);
    f_decoded_value = fMultiply(f_decoded_value, fDivide(f_range, f_CONSTANT_NEG13));
    f_decoded_value = fAdd(f_decoded_value, f_average);

    return f_decoded_value;
}

fInt fDecodeLeakageID (uint32_t leakageID_fuse, fInt ln_max_div_min, fInt f_min, uint32_t bitlength)
{
    fInt fLeakage;
    fInt f_bit_max_value = Convert_ULONG_ToFraction((uPow(2, bitlength)) - 1);

    fLeakage = fMultiply(ln_max_div_min, Convert_ULONG_ToFraction(leakageID_fuse));
    fLeakage = fDivide(fLeakage, f_bit_max_value);
    fLeakage = fExponential(fLeakage);
    fLeakage = fMultiply(fLeakage, f_min);

    return fLeakage;
}

fInt ConvertToFraction(int X) /*Add all range checking here. Is it possible to make fInt a private declaration? */
{
    fInt temp;

    if (X <= MAX)
        temp.full = (X << SHIFT_AMOUNT);
    else
        temp.full = 0;

    return temp;
}

fInt fNegate(fInt X)
{
    fInt CONSTANT_NEGONE = ConvertToFraction(-1);
    return (fMultiply(X, CONSTANT_NEGONE));
}

fInt Convert_ULONG_ToFraction(uint32_t X)
{
    fInt temp;

    if (X <= MAX)
        temp.full = (X << SHIFT_AMOUNT);
    else
        temp.full = 0;

    return temp;
}

fInt GetScaledFraction(int X, int factor)
{
    int times_shifted, factor_shifted;
    bool bNEGATED;
    fInt fValue;

    times_shifted = 0;
    factor_shifted = 0;
    bNEGATED = false;

    if (X < 0) {
        X = -1*X;
        bNEGATED = true;
    }

    if (factor < 0) {
        factor = -1*factor;

        bNEGATED = !bNEGATED; /*If bNEGATED = true due to X < 0, this will cover the case of negative cancelling negative */
    }

    if ((X > MAX) || factor > MAX) {
        if ((X/factor) <= MAX) {
            while (X > MAX) {
                X = X >> 1;
                times_shifted++;
            }

            while (factor > MAX) {
                factor = factor >> 1;
                factor_shifted++;
            }
        } else {
            fValue.full = 0;
            return fValue;
        }
    }

    if (factor == 1)
        return (ConvertToFraction(X));

    fValue = fDivide(ConvertToFraction(X * uPow(-1, bNEGATED)), ConvertToFraction(factor));

    fValue.full = fValue.full << times_shifted;
    fValue.full = fValue.full >> factor_shifted;

    return fValue;
}

/* Addition using two fInts */
fInt fAdd (fInt X, fInt Y)
{
    fInt Sum;

    Sum.full = X.full + Y.full;

    return Sum;
}

/* Addition using two fInts */
fInt fSubtract (fInt X, fInt Y)
{
    fInt Difference;

    Difference.full = X.full - Y.full;

    return Difference;
}

bool Equal(fInt A, fInt B)
{
    if (A.full == B.full)
        return true;
    else
        return false;
}

bool GreaterThan(fInt A, fInt B)
{
    if (A.full > B.full)
        return true;
    else
        return false;
}

fInt fMultiply (fInt X, fInt Y) /* Uses 64-bit integers (int64_t) */
{
    fInt Product;
    int64_t tempProduct;
    bool X_LessThanOne, Y_LessThanOne;

    X_LessThanOne = (X.partial.real == 0 && X.partial.decimal != 0 && X.full >= 0);
    Y_LessThanOne = (Y.partial.real == 0 && Y.partial.decimal != 0 && Y.full >= 0);

    /*The following is for a very specific common case: Non-zero number with ONLY fractional portion*/
    /* TEMPORARILY DISABLED - CAN BE USED TO IMPROVE PRECISION

    if (X_LessThanOne && Y_LessThanOne) {
        Product.full = X.full * Y.full;
        return Product
    }*/

    tempProduct = ((int64_t)X.full) * ((int64_t)Y.full); /*Q(16,16)*Q(16,16) = Q(32, 32) - Might become a negative number! */
    tempProduct = tempProduct >> 16; /*Remove lagging 16 bits - Will lose some precision from decimal; */
    Product.full = (int)tempProduct; /*The int64_t will lose the leading 16 bits that were part of the integer portion */

    return Product;
}

fInt fDivide (fInt X, fInt Y)
{
    fInt fZERO, fQuotient;
    int64_t longlongX, longlongY;

    fZERO = ConvertToFraction(0);

    if (Equal(Y, fZERO))
        return fZERO;

    longlongX = (int64_t)X.full;
    longlongY = (int64_t)Y.full;

    longlongX = longlongX << 16; /*Q(16,16) -> Q(32,32) */

    do_div(longlongX, longlongY); /*Q(32,32) divided by Q(16,16) = Q(16,16) Back to original format */

    fQuotient.full = (int)longlongX;
    return fQuotient;
}

int ConvertBackToInteger (fInt A) /*THIS is the function that will be used to check with the Golden settings table*/
{
    fInt fullNumber, scaledDecimal, scaledReal;

    scaledReal.full = GetReal(A) * uPow(10, PRECISION-1); /* DOUBLE CHECK THISSSS!!! */

    scaledDecimal.full = uGetScaledDecimal(A);

    fullNumber = fAdd(scaledDecimal,scaledReal);

    return fullNumber.full;
}

fInt fGetSquare(fInt A)
{
    return fMultiply(A,A);
}

/* x_new = x_old - (x_old^2 - C) / (2 * x_old) */
fInt fSqrt(fInt num)
{
    fInt F_divide_Fprime, Fprime;
    fInt test;
    fInt twoShifted;
    int seed, counter, error;
    fInt x_new, x_old, C, y;

    fInt fZERO = ConvertToFraction(0);
    /* (0 > num) is the same as (num < 0), i.e., num is negative */
    if (GreaterThan(fZERO, num) || Equal(fZERO, num))
        return fZERO;

    C = num;

    if (num.partial.real > 3000)
        seed = 60;
    else if (num.partial.real > 1000)
        seed = 30;
    else if (num.partial.real > 100)
        seed = 10;
    else
        seed = 2;

    counter = 0;

    if (Equal(num, fZERO)) /*Square Root of Zero is zero */
        return fZERO;

    twoShifted = ConvertToFraction(2);
    x_new = ConvertToFraction(seed);

    do {
        counter++;

        x_old.full = x_new.full;

        test = fGetSquare(x_old); /*1.75*1.75 is reverting back to 1 when shifted down */
        y = fSubtract(test, C); /*y = f(x) = x^2 - C; */

        Fprime = fMultiply(twoShifted, x_old);
        F_divide_Fprime = fDivide(y, Fprime);

        x_new = fSubtract(x_old, F_divide_Fprime);

        error = ConvertBackToInteger(x_new) - ConvertBackToInteger(x_old);

        if (counter > 20) /*20 is already way too many iterations. If we dont have an answer by then, we never will*/
            return x_new;

    } while (uAbs(error) > 0);

    return (x_new);
}

void SolveQuadracticEqn(fInt A, fInt B, fInt C, fInt Roots[])
{
    fInt* pRoots = &Roots[0];
    fInt temp, root_first, root_second;
    fInt f_CONSTANT10, f_CONSTANT100;

    f_CONSTANT100 = ConvertToFraction(100);
    f_CONSTANT10 = ConvertToFraction(10);

    while(GreaterThan(A, f_CONSTANT100) || GreaterThan(B, f_CONSTANT100) || GreaterThan(C, f_CONSTANT100)) {
        A = fDivide(A, f_CONSTANT10);
        B = fDivide(B, f_CONSTANT10);
        C = fDivide(C, f_CONSTANT10);
    }

    temp = fMultiply(ConvertToFraction(4), A); /* root = 4*A */
    temp = fMultiply(temp, C); /* root = 4*A*C */
    temp = fSubtract(fGetSquare(B), temp); /* root = b^2 - 4AC */
    temp = fSqrt(temp); /*root = Sqrt (b^2 - 4AC); */

    root_first = fSubtract(fNegate(B), temp); /* b - Sqrt(b^2 - 4AC) */
    root_second = fAdd(fNegate(B), temp); /* b + Sqrt(b^2 - 4AC) */

    root_first = fDivide(root_first, ConvertToFraction(2)); /* [b +- Sqrt(b^2 - 4AC)]/[2] */
    root_first = fDivide(root_first, A); /*[b +- Sqrt(b^2 - 4AC)]/[2*A] */

    root_second = fDivide(root_second, ConvertToFraction(2)); /* [b +- Sqrt(b^2 - 4AC)]/[2] */
    root_second = fDivide(root_second, A); /*[b +- Sqrt(b^2 - 4AC)]/[2*A] */

    *(pRoots + 0) = root_first;
    *(pRoots + 1) = root_second;
}

/* -----------------------------------------------------------------------------
 * SUPPORT FUNCTIONS
 * -----------------------------------------------------------------------------
 */

/* Addition using two normal ints - Temporary - Use only for testing purposes?. */
fInt Add (int X, int Y)
{
    fInt A, B, Sum;

    A.full = (X << SHIFT_AMOUNT);
    B.full = (Y << SHIFT_AMOUNT);

    Sum.full = A.full + B.full;

    return Sum;
}

/* Conversion Functions */
int GetReal (fInt A)
{
    return (A.full >> SHIFT_AMOUNT);
}

/* Temporarily Disabled */
int GetRoundedValue(fInt A) /*For now, round the 3rd decimal place */
{
    /* ROUNDING TEMPORARLY DISABLED
    int temp = A.full;

    int decimal_cutoff, decimal_mask = 0x000001FF;

    decimal_cutoff = temp & decimal_mask;


    if (decimal_cutoff > 0x147) {
        temp += 673;
    }*/

    return ConvertBackToInteger(A)/10000; /*Temporary - in case this was used somewhere else */
}

fInt Multiply (int X, int Y)
{
    fInt A, B, Product;

    A.full = X << SHIFT_AMOUNT;
    B.full = Y << SHIFT_AMOUNT;

    Product = fMultiply(A, B);

    return Product;
}
fInt Divide (int X, int Y)
{
    fInt A, B, Quotient;

    A.full = X << SHIFT_AMOUNT;
    B.full = Y << SHIFT_AMOUNT;

    Quotient = fDivide(A, B);

    return Quotient;
}

int uGetScaledDecimal (fInt A) /*Converts the fractional portion to whole integers - Costly function */
{
	int dec[PRECISION];
	int i, scaledDecimal = 0, tmp = A.partial.decimal;

	for (i = 0; i < PRECISION; i++) {
        dec[i] = tmp / (1 << SHIFT_AMOUNT);

        tmp = tmp - ((1 << SHIFT_AMOUNT)*dec[i]);

        tmp *= 10;

        scaledDecimal = scaledDecimal + dec[i]*uPow(10, PRECISION - 1 -i);
    }

    return scaledDecimal;
}

int uPow(int base, int power)
{
	if (power == 0)
		return 1;
	else
		return (base)*uPow(base, power - 1);
}

fInt fAbs(fInt A)
{
	if (A.partial.real < 0)
		return (fMultiply(A, ConvertToFraction(-1)));
	else
		return A;
}

int uAbs(int X)
{
	if (X < 0)
		return (X * -1);
	else
		return X;
}

fInt fRoundUpByStepSize(fInt A, fInt fStepSize, bool error_term)
{
    fInt solution;

    solution = fDivide(A, fStepSize);
    solution.partial.decimal = 0; /*All fractional digits changes to 0 */

    if (error_term)
        solution.partial.real += 1; /*Error term of 1 added */

    solution = fMultiply(solution, fStepSize);
    solution = fAdd(solution, fStepSize);

    return solution;
}