1 files changed, 567 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c b/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
new file mode 100644
index 000000000000..26936892c6f5
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
@@ -0,0 +1,567 @@
+/*
+ * Copyright 2012-15 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.
+ *
+ * Authors: AMD
+ *
+ */
+
+#include "dm_services.h"
+#include "include/fixed31_32.h"
+
+static inline uint64_t abs_i64(
+	int64_t arg)
+{
+	if (arg > 0)
+		return (uint64_t)arg;
+	else
+		return (uint64_t)(-arg);
+}
+
+/*
+ * @brief
+ * result = dividend / divisor
+ * *remainder = dividend % divisor
+ */
+static inline uint64_t complete_integer_division_u64(
+	uint64_t dividend,
+	uint64_t divisor,
+	uint64_t *remainder)
+{
+	uint64_t result;
+
+	ASSERT(divisor);
+
+	result = div64_u64_rem(dividend, divisor, remainder);
+
+	return result;
+}
+
+
+#define FRACTIONAL_PART_MASK \
+	((1ULL << FIXED31_32_BITS_PER_FRACTIONAL_PART) - 1)
+
+#define GET_INTEGER_PART(x) \
+	((x) >> FIXED31_32_BITS_PER_FRACTIONAL_PART)
+
+#define GET_FRACTIONAL_PART(x) \
+	(FRACTIONAL_PART_MASK & (x))
+
+struct fixed31_32 dal_fixed31_32_from_fraction(
+	int64_t numerator,
+	int64_t denominator)
+{
+	struct fixed31_32 res;
+
+	bool arg1_negative = numerator < 0;
+	bool arg2_negative = denominator < 0;
+
+	uint64_t arg1_value = arg1_negative ? -numerator : numerator;
+	uint64_t arg2_value = arg2_negative ? -denominator : denominator;
+
+	uint64_t remainder;
+
+	/* determine integer part */
+
+	uint64_t res_value = complete_integer_division_u64(
+		arg1_value, arg2_value, &remainder);
+
+	ASSERT(res_value <= LONG_MAX);
+
+	/* determine fractional part */
+	{
+		uint32_t i = FIXED31_32_BITS_PER_FRACTIONAL_PART;
+
+		do {
+			remainder <<= 1;
+
+			res_value <<= 1;
+
+			if (remainder >= arg2_value) {
+				res_value |= 1;
+				remainder -= arg2_value;
+			}
+		} while (--i != 0);
+	}
+
+	/* round up LSB */
+	{
+		uint64_t summand = (remainder << 1) >= arg2_value;
+
+		ASSERT(res_value <= LLONG_MAX - summand);
+
+		res_value += summand;
+	}
+
+	res.value = (int64_t)res_value;
+
+	if (arg1_negative ^ arg2_negative)
+		res.value = -res.value;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_from_int_nonconst(
+	int64_t arg)
+{
+	struct fixed31_32 res;
+
+	ASSERT((LONG_MIN <= arg) && (arg <= LONG_MAX));
+
+	res.value = arg << FIXED31_32_BITS_PER_FRACTIONAL_PART;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_shl(
+	struct fixed31_32 arg,
+	uint8_t shift)
+{
+	struct fixed31_32 res;
+
+	ASSERT(((arg.value >= 0) && (arg.value <= LLONG_MAX >> shift)) ||
+		((arg.value < 0) && (arg.value >= LLONG_MIN >> shift)));
+
+	res.value = arg.value << shift;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_add(
+	struct fixed31_32 arg1,
+	struct fixed31_32 arg2)
+{
+	struct fixed31_32 res;
+
+	ASSERT(((arg1.value >= 0) && (LLONG_MAX - arg1.value >= arg2.value)) ||
+		((arg1.value < 0) && (LLONG_MIN - arg1.value <= arg2.value)));
+
+	res.value = arg1.value + arg2.value;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_sub(
+	struct fixed31_32 arg1,
+	struct fixed31_32 arg2)
+{
+	struct fixed31_32 res;
+
+	ASSERT(((arg2.value >= 0) && (LLONG_MIN + arg2.value <= arg1.value)) ||
+		((arg2.value < 0) && (LLONG_MAX + arg2.value >= arg1.value)));
+
+	res.value = arg1.value - arg2.value;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_mul(
+	struct fixed31_32 arg1,
+	struct fixed31_32 arg2)
+{
+	struct fixed31_32 res;
+
+	bool arg1_negative = arg1.value < 0;
+	bool arg2_negative = arg2.value < 0;
+
+	uint64_t arg1_value = arg1_negative ? -arg1.value : arg1.value;
+	uint64_t arg2_value = arg2_negative ? -arg2.value : arg2.value;
+
+	uint64_t arg1_int = GET_INTEGER_PART(arg1_value);
+	uint64_t arg2_int = GET_INTEGER_PART(arg2_value);
+
+	uint64_t arg1_fra = GET_FRACTIONAL_PART(arg1_value);
+	uint64_t arg2_fra = GET_FRACTIONAL_PART(arg2_value);
+
+	uint64_t tmp;
+
+	res.value = arg1_int * arg2_int;
+
+	ASSERT(res.value <= LONG_MAX);
+
+	res.value <<= FIXED31_32_BITS_PER_FRACTIONAL_PART;
+
+	tmp = arg1_int * arg2_fra;
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg2_int * arg1_fra;
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg1_fra * arg2_fra;
+
+	tmp = (tmp >> FIXED31_32_BITS_PER_FRACTIONAL_PART) +
+		(tmp >= (uint64_t)dal_fixed31_32_half.value);
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	if (arg1_negative ^ arg2_negative)
+		res.value = -res.value;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_sqr(
+	struct fixed31_32 arg)
+{
+	struct fixed31_32 res;
+
+	uint64_t arg_value = abs_i64(arg.value);
+
+	uint64_t arg_int = GET_INTEGER_PART(arg_value);
+
+	uint64_t arg_fra = GET_FRACTIONAL_PART(arg_value);
+
+	uint64_t tmp;
+
+	res.value = arg_int * arg_int;
+
+	ASSERT(res.value <= LONG_MAX);
+
+	res.value <<= FIXED31_32_BITS_PER_FRACTIONAL_PART;
+
+	tmp = arg_int * arg_fra;
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg_fra * arg_fra;
+
+	tmp = (tmp >> FIXED31_32_BITS_PER_FRACTIONAL_PART) +
+		(tmp >= (uint64_t)dal_fixed31_32_half.value);
+
+	ASSERT(tmp <= (uint64_t)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_recip(
+	struct fixed31_32 arg)
+{
+	/*
+	 * @note
+	 * Good idea to use Newton's method
+	 */
+
+	ASSERT(arg.value);
+
+	return dal_fixed31_32_from_fraction(
+		dal_fixed31_32_one.value,
+		arg.value);
+}
+
+struct fixed31_32 dal_fixed31_32_sinc(
+	struct fixed31_32 arg)
+{
+	struct fixed31_32 square;
+
+	struct fixed31_32 res = dal_fixed31_32_one;
+
+	int32_t n = 27;
+
+	struct fixed31_32 arg_norm = arg;
+
+	if (dal_fixed31_32_le(
+		dal_fixed31_32_two_pi,
+		dal_fixed31_32_abs(arg))) {
+		arg_norm = dal_fixed31_32_sub(
+			arg_norm,
+			dal_fixed31_32_mul_int(
+				dal_fixed31_32_two_pi,
+				(int32_t)div64_s64(
+					arg_norm.value,
+					dal_fixed31_32_two_pi.value)));
+	}
+
+	square = dal_fixed31_32_sqr(arg_norm);
+
+	do {
+		res = dal_fixed31_32_sub(
+			dal_fixed31_32_one,
+			dal_fixed31_32_div_int(
+				dal_fixed31_32_mul(
+					square,
+					res),
+				n * (n - 1)));
+
+		n -= 2;
+	} while (n > 2);
+
+	if (arg.value != arg_norm.value)
+		res = dal_fixed31_32_div(
+			dal_fixed31_32_mul(res, arg_norm),
+			arg);
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_sin(
+	struct fixed31_32 arg)
+{
+	return dal_fixed31_32_mul(
+		arg,
+		dal_fixed31_32_sinc(arg));
+}
+
+struct fixed31_32 dal_fixed31_32_cos(
+	struct fixed31_32 arg)
+{
+	/* TODO implement argument normalization */
+
+	const struct fixed31_32 square = dal_fixed31_32_sqr(arg);
+
+	struct fixed31_32 res = dal_fixed31_32_one;
+
+	int32_t n = 26;
+
+	do {
+		res = dal_fixed31_32_sub(
+			dal_fixed31_32_one,
+			dal_fixed31_32_div_int(
+				dal_fixed31_32_mul(
+					square,
+					res),
+				n * (n - 1)));
+
+		n -= 2;
+	} while (n != 0);
+
+	return res;
+}
+
+/*
+ * @brief
+ * result = exp(arg),
+ * where abs(arg) < 1
+ *
+ * Calculated as Taylor series.
+ */
+static struct fixed31_32 fixed31_32_exp_from_taylor_series(
+	struct fixed31_32 arg)
+{
+	uint32_t n = 9;
+
+	struct fixed31_32 res = dal_fixed31_32_from_fraction(
+		n + 2,
+		n + 1);
+	/* TODO find correct res */
+
+	ASSERT(dal_fixed31_32_lt(arg, dal_fixed31_32_one));
+
+	do
+		res = dal_fixed31_32_add(
+			dal_fixed31_32_one,
+			dal_fixed31_32_div_int(
+				dal_fixed31_32_mul(
+					arg,
+					res),
+				n));
+	while (--n != 1);
+
+	return dal_fixed31_32_add(
+		dal_fixed31_32_one,
+		dal_fixed31_32_mul(
+			arg,
+			res));
+}
+
+struct fixed31_32 dal_fixed31_32_exp(
+	struct fixed31_32 arg)
+{
+	/*
+	 * @brief
+	 * Main equation is:
+	 * exp(x) = exp(r + m * ln(2)) = (1 << m) * exp(r),
+	 * where m = round(x / ln(2)), r = x - m * ln(2)
+	 */
+
+	if (dal_fixed31_32_le(
+		dal_fixed31_32_ln2_div_2,
+		dal_fixed31_32_abs(arg))) {
+		int32_t m = dal_fixed31_32_round(
+			dal_fixed31_32_div(
+				arg,
+				dal_fixed31_32_ln2));
+
+		struct fixed31_32 r = dal_fixed31_32_sub(
+			arg,
+			dal_fixed31_32_mul_int(
+				dal_fixed31_32_ln2,
+				m));
+
+		ASSERT(m != 0);
+
+		ASSERT(dal_fixed31_32_lt(
+			dal_fixed31_32_abs(r),
+			dal_fixed31_32_one));
+
+		if (m > 0)
+			return dal_fixed31_32_shl(
+				fixed31_32_exp_from_taylor_series(r),
+				(uint8_t)m);
+		else
+			return dal_fixed31_32_div_int(
+				fixed31_32_exp_from_taylor_series(r),
+				1LL << -m);
+	} else if (arg.value != 0)
+		return fixed31_32_exp_from_taylor_series(arg);
+	else
+		return dal_fixed31_32_one;
+}
+
+struct fixed31_32 dal_fixed31_32_log(
+	struct fixed31_32 arg)
+{
+	struct fixed31_32 res = dal_fixed31_32_neg(dal_fixed31_32_one);
+	/* TODO improve 1st estimation */
+
+	struct fixed31_32 error;
+
+	ASSERT(arg.value > 0);
+	/* TODO if arg is negative, return NaN */
+	/* TODO if arg is zero, return -INF */
+
+	do {
+		struct fixed31_32 res1 = dal_fixed31_32_add(
+			dal_fixed31_32_sub(
+				res,
+				dal_fixed31_32_one),
+			dal_fixed31_32_div(
+				arg,
+				dal_fixed31_32_exp(res)));
+
+		error = dal_fixed31_32_sub(
+			res,
+			res1);
+
+		res = res1;
+		/* TODO determine max_allowed_error based on quality of exp() */
+	} while (abs_i64(error.value) > 100ULL);
+
+	return res;
+}
+
+struct fixed31_32 dal_fixed31_32_pow(
+	struct fixed31_32 arg1,
+	struct fixed31_32 arg2)
+{
+	return dal_fixed31_32_exp(
+		dal_fixed31_32_mul(
+			dal_fixed31_32_log(arg1),
+			arg2));
+}
+
+int32_t dal_fixed31_32_floor(
+	struct fixed31_32 arg)
+{
+	uint64_t arg_value = abs_i64(arg.value);
+
+	if (arg.value >= 0)
+		return (int32_t)GET_INTEGER_PART(arg_value);
+	else
+		return -(int32_t)GET_INTEGER_PART(arg_value);
+}
+
+int32_t dal_fixed31_32_round(
+	struct fixed31_32 arg)
+{
+	uint64_t arg_value = abs_i64(arg.value);
+
+	const int64_t summand = dal_fixed31_32_half.value;
+
+	ASSERT(LLONG_MAX - (int64_t)arg_value >= summand);
+
+	arg_value += summand;
+
+	if (arg.value >= 0)
+		return (int32_t)GET_INTEGER_PART(arg_value);
+	else
+		return -(int32_t)GET_INTEGER_PART(arg_value);
+}
+
+int32_t dal_fixed31_32_ceil(
+	struct fixed31_32 arg)
+{
+	uint64_t arg_value = abs_i64(arg.value);
+
+	const int64_t summand = dal_fixed31_32_one.value -
+		dal_fixed31_32_epsilon.value;
+
+	ASSERT(LLONG_MAX - (int64_t)arg_value >= summand);
+
+	arg_value += summand;
+
+	if (arg.value >= 0)
+		return (int32_t)GET_INTEGER_PART(arg_value);
+	else
+		return -(int32_t)GET_INTEGER_PART(arg_value);
+}
+
+/* this function is a generic helper to translate fixed point value to
+ * specified integer format that will consist of integer_bits integer part and
+ * fractional_bits fractional part. For example it is used in
+ * dal_fixed31_32_u2d19 to receive 2 bits integer part and 19 bits fractional
+ * part in 32 bits. It is used in hw programming (scaler)
+ */
+
+static inline uint32_t ux_dy(
+	int64_t value,
+	uint32_t integer_bits,
+	uint32_t fractional_bits)
+{
+	/* 1. create mask of integer part */
+	uint32_t result = (1 << integer_bits) - 1;
+	/* 2. mask out fractional part */
+	uint32_t fractional_part = FRACTIONAL_PART_MASK & value;
+	/* 3. shrink fixed point integer part to be of integer_bits width*/
+	result &= GET_INTEGER_PART(value);
+	/* 4. make space for fractional part to be filled in after integer */
+	result <<= fractional_bits;
+	/* 5. shrink fixed point fractional part to of fractional_bits width*/
+	fractional_part >>= FIXED31_32_BITS_PER_FRACTIONAL_PART - fractional_bits;
+	/* 6. merge the result */
+	return result | fractional_part;
+}
+
+uint32_t dal_fixed31_32_u2d19(
+	struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 2, 19);
+}
+
+uint32_t dal_fixed31_32_u0d19(
+	struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 0, 19);
+}