1 files changed, 492 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 000000000..1726bdf89
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
@@ -0,0 +1,492 @@
+/*
+ * 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 const struct fixed31_32 dc_fixpt_two_pi = { 26986075409LL };
+static const struct fixed31_32 dc_fixpt_ln2 = { 2977044471LL };
+static const struct fixed31_32 dc_fixpt_ln2_div_2 = { 1488522236LL };
+
+static inline unsigned long long abs_i64(
+	long long arg)
+{
+	if (arg > 0)
+		return (unsigned long long)arg;
+	else
+		return (unsigned long long)(-arg);
+}
+
+/*
+ * @brief
+ * result = dividend / divisor
+ * *remainder = dividend % divisor
+ */
+static inline unsigned long long complete_integer_division_u64(
+	unsigned long long dividend,
+	unsigned long long divisor,
+	unsigned long long *remainder)
+{
+	unsigned long long 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 dc_fixpt_from_fraction(long long numerator, long long denominator)
+{
+	struct fixed31_32 res;
+
+	bool arg1_negative = numerator < 0;
+	bool arg2_negative = denominator < 0;
+
+	unsigned long long arg1_value = arg1_negative ? -numerator : numerator;
+	unsigned long long arg2_value = arg2_negative ? -denominator : denominator;
+
+	unsigned long long remainder;
+
+	/* determine integer part */
+
+	unsigned long long res_value = complete_integer_division_u64(
+		arg1_value, arg2_value, &remainder);
+
+	ASSERT(res_value <= LONG_MAX);
+
+	/* determine fractional part */
+	{
+		unsigned int 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 */
+	{
+		unsigned long long summand = (remainder << 1) >= arg2_value;
+
+		ASSERT(res_value <= LLONG_MAX - summand);
+
+		res_value += summand;
+	}
+
+	res.value = (long long)res_value;
+
+	if (arg1_negative ^ arg2_negative)
+		res.value = -res.value;
+
+	return res;
+}
+
+struct fixed31_32 dc_fixpt_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;
+
+	unsigned long long arg1_value = arg1_negative ? -arg1.value : arg1.value;
+	unsigned long long arg2_value = arg2_negative ? -arg2.value : arg2.value;
+
+	unsigned long long arg1_int = GET_INTEGER_PART(arg1_value);
+	unsigned long long arg2_int = GET_INTEGER_PART(arg2_value);
+
+	unsigned long long arg1_fra = GET_FRACTIONAL_PART(arg1_value);
+	unsigned long long arg2_fra = GET_FRACTIONAL_PART(arg2_value);
+
+	unsigned long long 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 <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg2_int * arg1_fra;
+
+	ASSERT(tmp <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg1_fra * arg2_fra;
+
+	tmp = (tmp >> FIXED31_32_BITS_PER_FRACTIONAL_PART) +
+		(tmp >= (unsigned long long)dc_fixpt_half.value);
+
+	ASSERT(tmp <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	if (arg1_negative ^ arg2_negative)
+		res.value = -res.value;
+
+	return res;
+}
+
+struct fixed31_32 dc_fixpt_sqr(struct fixed31_32 arg)
+{
+	struct fixed31_32 res;
+
+	unsigned long long arg_value = abs_i64(arg.value);
+
+	unsigned long long arg_int = GET_INTEGER_PART(arg_value);
+
+	unsigned long long arg_fra = GET_FRACTIONAL_PART(arg_value);
+
+	unsigned long long 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 <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	ASSERT(tmp <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	tmp = arg_fra * arg_fra;
+
+	tmp = (tmp >> FIXED31_32_BITS_PER_FRACTIONAL_PART) +
+		(tmp >= (unsigned long long)dc_fixpt_half.value);
+
+	ASSERT(tmp <= (unsigned long long)(LLONG_MAX - res.value));
+
+	res.value += tmp;
+
+	return res;
+}
+
+struct fixed31_32 dc_fixpt_recip(struct fixed31_32 arg)
+{
+	/*
+	 * @note
+	 * Good idea to use Newton's method
+	 */
+
+	ASSERT(arg.value);
+
+	return dc_fixpt_from_fraction(
+		dc_fixpt_one.value,
+		arg.value);
+}
+
+struct fixed31_32 dc_fixpt_sinc(struct fixed31_32 arg)
+{
+	struct fixed31_32 square;
+
+	struct fixed31_32 res = dc_fixpt_one;
+
+	int n = 27;
+
+	struct fixed31_32 arg_norm = arg;
+
+	if (dc_fixpt_le(
+		dc_fixpt_two_pi,
+		dc_fixpt_abs(arg))) {
+		arg_norm = dc_fixpt_sub(
+			arg_norm,
+			dc_fixpt_mul_int(
+				dc_fixpt_two_pi,
+				(int)div64_s64(
+					arg_norm.value,
+					dc_fixpt_two_pi.value)));
+	}
+
+	square = dc_fixpt_sqr(arg_norm);
+
+	do {
+		res = dc_fixpt_sub(
+			dc_fixpt_one,
+			dc_fixpt_div_int(
+				dc_fixpt_mul(
+					square,
+					res),
+				n * (n - 1)));
+
+		n -= 2;
+	} while (n > 2);
+
+	if (arg.value != arg_norm.value)
+		res = dc_fixpt_div(
+			dc_fixpt_mul(res, arg_norm),
+			arg);
+
+	return res;
+}
+
+struct fixed31_32 dc_fixpt_sin(struct fixed31_32 arg)
+{
+	return dc_fixpt_mul(
+		arg,
+		dc_fixpt_sinc(arg));
+}
+
+struct fixed31_32 dc_fixpt_cos(struct fixed31_32 arg)
+{
+	/* TODO implement argument normalization */
+
+	const struct fixed31_32 square = dc_fixpt_sqr(arg);
+
+	struct fixed31_32 res = dc_fixpt_one;
+
+	int n = 26;
+
+	do {
+		res = dc_fixpt_sub(
+			dc_fixpt_one,
+			dc_fixpt_div_int(
+				dc_fixpt_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)
+{
+	unsigned int n = 9;
+
+	struct fixed31_32 res = dc_fixpt_from_fraction(
+		n + 2,
+		n + 1);
+	/* TODO find correct res */
+
+	ASSERT(dc_fixpt_lt(arg, dc_fixpt_one));
+
+	do
+		res = dc_fixpt_add(
+			dc_fixpt_one,
+			dc_fixpt_div_int(
+				dc_fixpt_mul(
+					arg,
+					res),
+				n));
+	while (--n != 1);
+
+	return dc_fixpt_add(
+		dc_fixpt_one,
+		dc_fixpt_mul(
+			arg,
+			res));
+}
+
+struct fixed31_32 dc_fixpt_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 (dc_fixpt_le(
+		dc_fixpt_ln2_div_2,
+		dc_fixpt_abs(arg))) {
+		int m = dc_fixpt_round(
+			dc_fixpt_div(
+				arg,
+				dc_fixpt_ln2));
+
+		struct fixed31_32 r = dc_fixpt_sub(
+			arg,
+			dc_fixpt_mul_int(
+				dc_fixpt_ln2,
+				m));
+
+		ASSERT(m != 0);
+
+		ASSERT(dc_fixpt_lt(
+			dc_fixpt_abs(r),
+			dc_fixpt_one));
+
+		if (m > 0)
+			return dc_fixpt_shl(
+				fixed31_32_exp_from_taylor_series(r),
+				(unsigned char)m);
+		else
+			return dc_fixpt_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 dc_fixpt_one;
+}
+
+struct fixed31_32 dc_fixpt_log(struct fixed31_32 arg)
+{
+	struct fixed31_32 res = dc_fixpt_neg(dc_fixpt_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 = dc_fixpt_add(
+			dc_fixpt_sub(
+				res,
+				dc_fixpt_one),
+			dc_fixpt_div(
+				arg,
+				dc_fixpt_exp(res)));
+
+		error = dc_fixpt_sub(
+			res,
+			res1);
+
+		res = res1;
+		/* TODO determine max_allowed_error based on quality of exp() */
+	} while (abs_i64(error.value) > 100ULL);
+
+	return res;
+}
+
+
+/* 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
+ * dc_fixpt_u2d19 to receive 2 bits integer part and 19 bits fractional
+ * part in 32 bits. It is used in hw programming (scaler)
+ */
+
+static inline unsigned int ux_dy(
+	long long value,
+	unsigned int integer_bits,
+	unsigned int fractional_bits)
+{
+	/* 1. create mask of integer part */
+	unsigned int result = (1 << integer_bits) - 1;
+	/* 2. mask out fractional part */
+	unsigned int 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;
+}
+
+static inline unsigned int clamp_ux_dy(
+	long long value,
+	unsigned int integer_bits,
+	unsigned int fractional_bits,
+	unsigned int min_clamp)
+{
+	unsigned int truncated_val = ux_dy(value, integer_bits, fractional_bits);
+
+	if (value >= (1LL << (integer_bits + FIXED31_32_BITS_PER_FRACTIONAL_PART)))
+		return (1 << (integer_bits + fractional_bits)) - 1;
+	else if (truncated_val > min_clamp)
+		return truncated_val;
+	else
+		return min_clamp;
+}
+
+unsigned int dc_fixpt_u4d19(struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 4, 19);
+}
+
+unsigned int dc_fixpt_u3d19(struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 3, 19);
+}
+
+unsigned int dc_fixpt_u2d19(struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 2, 19);
+}
+
+unsigned int dc_fixpt_u0d19(struct fixed31_32 arg)
+{
+	return ux_dy(arg.value, 0, 19);
+}
+
+unsigned int dc_fixpt_clamp_u0d14(struct fixed31_32 arg)
+{
+	return clamp_ux_dy(arg.value, 0, 14, 1);
+}
+
+unsigned int dc_fixpt_clamp_u0d10(struct fixed31_32 arg)
+{
+	return clamp_ux_dy(arg.value, 0, 10, 1);
+}
+
+int dc_fixpt_s4d19(struct fixed31_32 arg)
+{
+	if (arg.value < 0)
+		return -(int)ux_dy(dc_fixpt_abs(arg).value, 4, 19);
+	else
+		return ux_dy(arg.value, 4, 19);
+}