tegrakernel/kernel/nvidia/drivers/platform/tegra/mc/fixed_point.c

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2022-02-16 09:13:02 -06:00
/*
* Copyright (C) 2017-2018, NVIDIA CORPORATION. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <asm/bug.h>
#include "fixed_point.h"
#define FIX_PT_CHK_MATCH(chk_type, op1, op2) \
do { \
if (op1 != op2) { \
pr_err("%s: op %s do not match: %d != %d\n", \
__func__, chk_type, op1, op2); \
(*error) |= 1; \
WARN_ON(1); \
} \
} while (0)
#define FIX_PT_CHK_MATCH_PREC(prec1, prec2) \
FIX_PT_CHK_MATCH("precisions", prec1, prec2)
#define FIX_PT_CHK_MATCH_MASK(prec1, prec2) \
FIX_PT_CHK_MATCH("masks", prec1, prec2)
struct fixed_point fixed_point_init(
unsigned int int_part,
unsigned int frac_part,
unsigned int int_prec,
unsigned int frac_prec,
unsigned int *error)
{
struct fixed_point ret_fp;
unsigned int max_prec = (sizeof(unsigned int) * 8);
if (int_prec > max_prec) {
pr_err("%s: int_prec too large: %d > %d\n",
__func__, int_prec, max_prec);
(*error) |= 1;
WARN_ON(1);
} else if (int_prec == (sizeof(unsigned int) * 8))
ret_fp.int_mask = ((unsigned int)(-1));
else
ret_fp.int_mask = (1 << int_prec) - 1;
if (frac_prec > max_prec) {
pr_err("%s: frac_prec too large: %d > %d\n",
__func__, frac_prec, max_prec);
(*error) |= 1;
WARN_ON(1);
} else if (frac_prec == (sizeof(unsigned int) * 8))
ret_fp.frac_mask = ((unsigned int)(-1));
else
ret_fp.frac_mask = (1 << frac_prec) - 1;
ret_fp.int_part = int_part & ret_fp.int_mask;
ret_fp.frac_part = frac_part & ret_fp.frac_mask;
ret_fp.int_prec = int_prec;
ret_fp.frac_prec = frac_prec;
return ret_fp;
}
struct fixed_point fixed_point_shift_left(
struct fixed_point fp_arg,
unsigned int places,
unsigned int *error)
{
struct fixed_point ret_fp;
unsigned int frac_mask;
unsigned int frac_shift;
if (places == 0)
return fp_arg;
ret_fp = fixed_point_init(
0,
0,
fp_arg.int_prec,
fp_arg.frac_prec,
error);
frac_mask = (places >= fp_arg.frac_prec) ? 0 :
(((((unsigned int)(1 << places)) - 1) << (fp_arg.frac_prec - places)) &
fp_arg.frac_mask);
frac_shift = (places >= fp_arg.frac_prec) ? 0 :
(fp_arg.frac_prec - places);
ret_fp.int_part = (places < fp_arg.int_prec) ?
((fp_arg.int_part << places) & fp_arg.int_mask) : 0;
ret_fp.int_part |= ((fp_arg.frac_part & frac_mask) >> frac_shift);
ret_fp.frac_part = (places < fp_arg.frac_prec) ?
((fp_arg.frac_part << places) & fp_arg.frac_mask) : 0;
return ret_fp;
}
struct fixed_point fixed_point_shift_right(
struct fixed_point fp_arg,
unsigned int places,
unsigned int *error)
{
struct fixed_point ret_fp;
unsigned int int_mask = 0;
unsigned int frac_shift = 0;
int sign_ext = 0;
if (places == 0)
return fp_arg;
ret_fp = fixed_point_init(
0,
0,
fp_arg.int_prec,
fp_arg.frac_prec,
error);
ret_fp.int_part = (places < fp_arg.int_prec) ?
((fp_arg.int_part >> places) & fp_arg.int_mask) : 0;
if (fp_arg.int_part & (1 << (fp_arg.int_prec - 1))) { /* sign extend */
sign_ext = 1;
if (places < fp_arg.int_prec) {
ret_fp.int_part |=
((((1 << places) - 1) <<
(fp_arg.int_prec - places)) & fp_arg.int_mask);
} else {
ret_fp.int_part =
((unsigned int)(-1)) & ret_fp.int_mask;
}
}
ret_fp.frac_part = (places < fp_arg.frac_prec) ?
((fp_arg.frac_part >> places) & fp_arg.frac_mask) : 0;
if (places < fp_arg.frac_prec) {
int_mask = fp_arg.int_mask >> (fp_arg.int_prec - places);
frac_shift = fp_arg.frac_prec - places;
ret_fp.frac_part |=
(((fp_arg.int_part & int_mask) << frac_shift) &
fp_arg.frac_mask);
} else if (places < (fp_arg.int_prec + fp_arg.frac_prec)) {
int_mask = (fp_arg.int_mask << (places - fp_arg.frac_prec)) &
fp_arg.int_mask;
frac_shift = places - fp_arg.frac_prec;
ret_fp.frac_part |=
(((fp_arg.int_part & int_mask) >> frac_shift) &
fp_arg.frac_mask);
if (sign_ext) {
ret_fp.frac_part |=
(fp_arg.frac_mask <<
(fp_arg.frac_prec -
(places - fp_arg.frac_prec)));
}
} else {
if (sign_ext)
ret_fp.frac_part = fp_arg.frac_mask;
}
return ret_fp;
}
struct fixed_point fixed_point_negate(
struct fixed_point fp_arg,
unsigned int *error)
{
struct fixed_point ret_fp;
struct fixed_point fp_one;
ret_fp = fixed_point_init(
0,
0,
fp_arg.int_prec,
fp_arg.frac_prec,
error);
ret_fp.int_part = ~fp_arg.int_part;
ret_fp.frac_part = ~fp_arg.frac_part;
fp_one.int_prec = fp_arg.int_prec;
fp_one.frac_prec = fp_arg.frac_prec;
fp_one.int_mask = fp_arg.int_mask;
fp_one.frac_mask = fp_arg.frac_mask;
fp_one.int_part = 0;
fp_one.frac_part = 1;
ret_fp = fixed_point_add(ret_fp, fp_one, error);
return ret_fp;
}
struct fixed_point fixed_point_add(
struct fixed_point fp_arg1,
struct fixed_point fp_arg2,
unsigned int *error)
{
struct fixed_point ret_fp;
unsigned int frac_carry_out;
unsigned int frac1_msb;
unsigned int frac2_msb;
unsigned int sum_msb;
FIX_PT_CHK_MATCH_PREC(
fp_arg1.int_prec,
fp_arg2.int_prec);
FIX_PT_CHK_MATCH_PREC(
fp_arg1.frac_prec,
fp_arg2.frac_prec);
FIX_PT_CHK_MATCH_MASK(
fp_arg1.int_mask,
fp_arg2.int_mask);
FIX_PT_CHK_MATCH_MASK(
fp_arg1.frac_mask,
fp_arg2.frac_mask);
ret_fp = fixed_point_init(
0,
0,
fp_arg1.int_prec,
fp_arg1.frac_prec,
error);
ret_fp.frac_part = (fp_arg1.frac_part + fp_arg2.frac_part) &
fp_arg1.frac_mask;
frac1_msb = (fp_arg1.frac_part >> (fp_arg1.frac_prec - 1)) & 1;
frac2_msb = (fp_arg2.frac_part >> (fp_arg2.frac_prec - 1)) & 1;
sum_msb = (ret_fp.frac_part >> (fp_arg1.frac_prec - 1)) & 1;
frac_carry_out = ((frac1_msb & frac2_msb) |
((frac1_msb | frac2_msb) & ~sum_msb)) & 1;
ret_fp.int_part = (fp_arg1.int_part +
fp_arg2.int_part +
frac_carry_out) & fp_arg1.int_mask;
return ret_fp;
}
struct fixed_point fixed_point_sub(
struct fixed_point minuend_arg,
struct fixed_point subtrahend_arg,
unsigned int *error)
{
struct fixed_point neg_subtrahend =
fixed_point_negate(subtrahend_arg, error);
return fixed_point_add(minuend_arg, neg_subtrahend, error);
}
struct fixed_point fixed_point_mult(
struct fixed_point fp_arg1,
struct fixed_point fp_arg2,
unsigned int *error)
{
struct fixed_point ret_fp;
struct fixed_point tmp_fp1;
struct fixed_point tmp_fp2;
int i;
FIX_PT_CHK_MATCH_PREC(
fp_arg1.int_prec,
fp_arg2.int_prec);
FIX_PT_CHK_MATCH_PREC(
fp_arg1.frac_prec,
fp_arg2.frac_prec);
FIX_PT_CHK_MATCH_MASK(
fp_arg1.int_mask,
fp_arg2.int_mask);
FIX_PT_CHK_MATCH_MASK(
fp_arg1.frac_mask,
fp_arg2.frac_mask);
ret_fp = fixed_point_init(
0,
0,
fp_arg1.int_prec,
fp_arg1.frac_prec,
error);
tmp_fp2 = fp_arg2;
for (i = 0; i < fp_arg2.frac_prec; i++) {
ret_fp = fixed_point_shift_right(ret_fp, 1, error);
if (tmp_fp2.frac_part & 1)
ret_fp = fixed_point_add(ret_fp, fp_arg1, error);
tmp_fp2 = fixed_point_shift_right(tmp_fp2, 1, error);
}
ret_fp = fixed_point_shift_right(ret_fp, 1, error);
tmp_fp1 = fp_arg1;
for (i = fp_arg2.frac_prec;
i < (fp_arg2.int_prec + fp_arg2.frac_prec - 1); i++) {
if (tmp_fp2.frac_part & 1)
ret_fp = fixed_point_add(ret_fp, tmp_fp1, error);
tmp_fp2 = fixed_point_shift_right(tmp_fp2, 1, error);
tmp_fp1 = fixed_point_shift_left(tmp_fp1, 1, error);
}
if (tmp_fp2.frac_part & 1)
ret_fp = fixed_point_sub(ret_fp, tmp_fp1, error);
return ret_fp;
}
struct fixed_point fixed_point_div(
struct fixed_point dividend_arg,
struct fixed_point divisor_arg,
unsigned int *error)
{
struct fixed_point ret_fp;
struct fixed_point tmp_dividend;
struct fixed_point tmp_divisor;
struct fixed_point tmp_accum;
int negate_num = 0;
int i;
FIX_PT_CHK_MATCH_PREC(
dividend_arg.int_prec,
divisor_arg.int_prec);
FIX_PT_CHK_MATCH_PREC(
dividend_arg.frac_prec,
divisor_arg.frac_prec);
FIX_PT_CHK_MATCH_MASK(
dividend_arg.int_mask,
divisor_arg.int_mask);
FIX_PT_CHK_MATCH_MASK(
dividend_arg.frac_mask,
divisor_arg.frac_mask);
if (fixed_point_eq(divisor_arg,
fixed_point_init(
0,
0,
dividend_arg.int_prec,
dividend_arg.frac_prec,
error),
error
)
){
if (dividend_arg.int_part &
(1 << (dividend_arg.int_prec - 1))) {
ret_fp = fixed_point_init(
1 << (dividend_arg.int_prec - 1),
0,
dividend_arg.int_prec,
dividend_arg.frac_prec,
error);
} else {
ret_fp = fixed_point_init(
(1 << (dividend_arg.int_prec - 1)) - 1,
dividend_arg.frac_mask,
dividend_arg.int_prec,
dividend_arg.frac_prec,
error);
}
return ret_fp;
}
ret_fp = fixed_point_init(
0,
0,
dividend_arg.int_prec,
dividend_arg.frac_prec,
error);
tmp_accum = fixed_point_init(
0,
0,
dividend_arg.int_prec,
dividend_arg.frac_prec,
error);
if (dividend_arg.int_part & (1 << (dividend_arg.int_prec - 1))) {
tmp_dividend = fixed_point_negate(dividend_arg, error);
negate_num++;
} else {
tmp_dividend = dividend_arg;
}
if (divisor_arg.int_part & (1 << (dividend_arg.int_prec - 1))) {
tmp_divisor = fixed_point_negate(divisor_arg, error);
negate_num++;
} else {
tmp_divisor = divisor_arg;
}
negate_num = negate_num % 2;
for (i = 0;
i < (dividend_arg.int_prec + dividend_arg.frac_prec);
i++) {
struct fixed_point next_dividend_shifted =
fixed_point_shift_right(tmp_dividend,
dividend_arg.int_prec +
dividend_arg.frac_prec - i - 1,
error);
tmp_accum = fixed_point_shift_left(tmp_accum, 1, error);
tmp_accum.frac_part |= (next_dividend_shifted.frac_part & 1);
ret_fp = fixed_point_shift_left(ret_fp, 1, error);
if (fixed_point_loet(tmp_divisor, tmp_accum, error)) {
tmp_accum =
fixed_point_sub(tmp_accum, tmp_divisor, error);
ret_fp.frac_part |= 1;
}
}
for (i = 0;
i < dividend_arg.frac_prec;
i++) {
struct fixed_point next_dividend_shifted =
fixed_point_shift_left(tmp_dividend,
i + 1,
error);
tmp_accum = fixed_point_shift_left(tmp_accum, 1, error);
tmp_accum.frac_part |= (next_dividend_shifted.frac_part & 1);
ret_fp = fixed_point_shift_left(ret_fp, 1, error);
if (fixed_point_loet(tmp_divisor, tmp_accum, error)) {
tmp_accum =
fixed_point_sub(tmp_accum, tmp_divisor, error);
ret_fp.frac_part |= 1;
}
}
if (negate_num)
ret_fp = fixed_point_negate(ret_fp, error);
return ret_fp;
}
int fixed_point_lt(
struct fixed_point fp_lhs_arg,
struct fixed_point fp_rhs_arg,
unsigned int *error)
{
unsigned int int_lhs_msb;
unsigned int int_rhs_msb;
FIX_PT_CHK_MATCH_PREC(
fp_lhs_arg.int_prec,
fp_rhs_arg.int_prec);
FIX_PT_CHK_MATCH_PREC(
fp_lhs_arg.frac_prec,
fp_rhs_arg.frac_prec);
FIX_PT_CHK_MATCH_MASK(
fp_lhs_arg.int_mask,
fp_rhs_arg.int_mask);
FIX_PT_CHK_MATCH_MASK(
fp_lhs_arg.frac_mask,
fp_rhs_arg.frac_mask);
int_lhs_msb = (fp_lhs_arg.int_part >> (fp_lhs_arg.int_prec - 1)) & 1;
int_rhs_msb = (fp_rhs_arg.int_part >> (fp_rhs_arg.int_prec - 1)) & 1;
if ((int_lhs_msb == 1) && (int_rhs_msb == 0))
return 1;
if ((int_lhs_msb == 0) && (int_rhs_msb == 1))
return 0;
/* both are positive or both are negative */
if (fp_lhs_arg.int_part < fp_rhs_arg.int_part)
return 1;
if (fp_lhs_arg.int_part > fp_rhs_arg.int_part)
return 0;
if (fp_lhs_arg.frac_part < fp_rhs_arg.frac_part)
return 1;
if (fp_lhs_arg.frac_part > fp_rhs_arg.frac_part)
return 0;
/* equal */
return 0;
}
int fixed_point_gt(
struct fixed_point fp_lhs_arg,
struct fixed_point fp_rhs_arg,
unsigned int *error)
{
return fixed_point_lt(fp_rhs_arg, fp_lhs_arg, error);
}
int fixed_point_loet(
struct fixed_point fp_lhs_arg,
struct fixed_point fp_rhs_arg,
unsigned int *error)
{
return fixed_point_lt(fp_lhs_arg, fp_rhs_arg, error) |
fixed_point_eq(fp_lhs_arg, fp_rhs_arg, error);
}
int fixed_point_goet(
struct fixed_point fp_lhs_arg,
struct fixed_point fp_rhs_arg,
unsigned int *error)
{
return fixed_point_gt(fp_lhs_arg, fp_rhs_arg, error) |
fixed_point_eq(fp_lhs_arg, fp_rhs_arg, error);
}
int fixed_point_eq(
struct fixed_point fp_lhs_arg,
struct fixed_point fp_rhs_arg,
unsigned int *error)
{
FIX_PT_CHK_MATCH_PREC(
fp_lhs_arg.int_prec,
fp_rhs_arg.int_prec);
FIX_PT_CHK_MATCH_PREC(
fp_lhs_arg.frac_prec,
fp_rhs_arg.frac_prec);
FIX_PT_CHK_MATCH_MASK(
fp_lhs_arg.int_mask,
fp_rhs_arg.int_mask);
FIX_PT_CHK_MATCH_MASK(
fp_lhs_arg.frac_mask,
fp_rhs_arg.frac_mask);
if (fp_lhs_arg.int_part != fp_rhs_arg.int_part)
return 0;
if (fp_lhs_arg.frac_part != fp_rhs_arg.frac_part)
return 0;
return 1;
}
int fixed_point_to_int(
struct fixed_point fp_arg,
unsigned int *error)
{
int ret_int;
if (fp_arg.int_part & (1 << (fp_arg.int_prec - 1))) /* sign extend */
ret_int = 0 - ((int)fixed_point_negate(fp_arg, error).int_part);
else
ret_int = fp_arg.int_part;
return ret_int;
}
int fixed_point_ceil(
struct fixed_point fp_arg,
unsigned int *error)
{
int ret_int;
if (fp_arg.int_part & (1 << (fp_arg.int_prec - 1))) { /* negative */
struct fixed_point neg_fp = fixed_point_negate(fp_arg, error);
if (neg_fp.frac_part != 0)
ret_int = 0 - ((int)neg_fp.int_part) + 1;
else
ret_int = neg_fp.int_part;
} else {
if (fp_arg.frac_part != 0)
ret_int = fp_arg.int_part + 1;
else
ret_int = fp_arg.int_part;
}
return ret_int;
}
struct fixed_point fixed_point_min(
struct fixed_point fp_arg1,
struct fixed_point fp_arg2,
unsigned int *error)
{
if (fixed_point_lt(fp_arg1, fp_arg2, error))
return fp_arg1;
else
return fp_arg2;
}
struct fixed_point fixed_point_max(
struct fixed_point fp_arg1,
struct fixed_point fp_arg2,
unsigned int *error)
{
if (fixed_point_gt(fp_arg1, fp_arg2, error))
return fp_arg1;
else
return fp_arg2;
}