drivers/gpu/drm/amd/display/dc/basics/bw_fixed.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/amd/display/dc/basics/bw_fixed.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/amd/display/dc/basics/bw_fixed.c
Extension
.c
Size
4742 bytes
Lines
189
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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 <= MAX_I64 - summand);

		res_value += summand;
	}

	res.value = (int64_t)(res_value);

	if (arg1_negative ^ arg2_negative)
		res.value = -res.value;
	return res;
}

struct bw_fixed bw_floor2(const struct bw_fixed arg,
			  const struct bw_fixed significance)
{
	struct bw_fixed result;
	int64_t multiplicand;

	multiplicand = div64_s64(arg.value, abs_i64(significance.value));
	result.value = abs_i64(significance.value) * multiplicand;
	ASSERT(abs_i64(result.value) <= abs_i64(arg.value));
	return result;
}

struct bw_fixed bw_ceil2(const struct bw_fixed arg,
			 const struct bw_fixed significance)
{
	struct bw_fixed result;
	int64_t multiplicand;

	multiplicand = div64_s64(arg.value, abs_i64(significance.value));
	result.value = abs_i64(significance.value) * multiplicand;
	if (abs_i64(result.value) < abs_i64(arg.value)) {
		if (arg.value < 0)
			result.value -= abs_i64(significance.value);
		else
			result.value += abs_i64(significance.value);
	}
	return result;
}

struct bw_fixed bw_mul(const struct bw_fixed arg1, const struct bw_fixed arg2)
{
	struct bw_fixed res;

	bool arg1_negative = arg1.value < 0;
	bool arg2_negative = arg2.value < 0;

	uint64_t arg1_value = abs_i64(arg1.value);
	uint64_t arg2_value = abs_i64(arg2.value);

	uint64_t arg1_int = BW_FIXED_GET_INTEGER_PART(arg1_value);
	uint64_t arg2_int = BW_FIXED_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 <= BW_FIXED_MAX_I32);

	res.value <<= BW_FIXED_BITS_PER_FRACTIONAL_PART;

	tmp = arg1_int * arg2_fra;

	ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));

	res.value += tmp;

	tmp = arg2_int * arg1_fra;

	ASSERT(tmp <= (uint64_t)(MAX_I64 - res.value));

	res.value += tmp;

	tmp = arg1_fra * arg2_fra;

Annotation

Implementation Notes