[Intel-gfx] [PATCH 02/11] drm/i915: Add more wrapper for fixed_point_16_16 operations

[Maarten Lankhorst]

Op 08-05-17 om 13:48 schreef Mahesh Kumar:
> This patch adds few wrapper to perform fixed_point_16_16 operations
> mul_u32_fixed_16_16_round_up : Multiplies u32 and fixed_16_16_t
> 				variables & returns u32 result with
> 				rounding-off.
> mul_fixed_16_16 : Multiplies two fixed_16_16_t variable & returns
> 				fixed_16_16
> div_round_up_fixed_16_16 : Perform division operation on fixed_16_16_t
> 				variables & return u32 result with round-off
> fixed_16_16_div_round_up_u64 : devide uint32_t variable by fixed_16_16
> 				variable and round_up the result to uint32_t.
>
> These wrappers will be used by later patches in the series.
>
> Signed-off-by: Mahesh Kumar <mahesh1.kumar at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h | 43 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 5804734d30a3..5ff0091707c0 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -152,6 +152,38 @@ static inline uint_fixed_16_16_t max_fixed_16_16(uint_fixed_16_16_t max1,
>  	return max;
>  }
>  
> +static inline uint32_t div_round_up_fixed_16_16(uint_fixed_16_16_t val,
> +						uint_fixed_16_16_t d)
> +{
> +	return DIV_ROUND_UP(val.val, d.val);
> +}
> +
> +static inline uint32_t mul_u32_fixed_16_16_round_up(uint32_t val,
> +						    uint_fixed_16_16_t mul)
> +{
> +       uint64_t intermediate_val;
> +       uint32_t result;
> +
> +       intermediate_val = (uint64_t) val * mul.val;
> +       intermediate_val = DIV_ROUND_UP_ULL(intermediate_val, 1 << 16);
> +       WARN_ON(intermediate_val >> 32);
> +       result = clamp_t(uint32_t, intermediate_val, 0, ~0);
> +       return result;
> +}
> +
> +static inline uint_fixed_16_16_t mul_fixed_16_16(uint_fixed_16_16_t val,
> +						 uint_fixed_16_16_t mul)
> +{
> +	uint64_t intermediate_val;
> +	uint_fixed_16_16_t fp;
> +
> +	intermediate_val = (uint64_t) val.val * mul.val;
> +	intermediate_val = intermediate_val >> 16;
> +	WARN_ON(intermediate_val >> 32);
> +	fp.val = clamp_t(uint32_t, intermediate_val, 0, ~0);
> +	return fp;
> +}
> +
>  static inline uint_fixed_16_16_t fixed_16_16_div(uint32_t val, uint32_t d)
>  {
>  	uint_fixed_16_16_t fp, res;
> @@ -174,6 +206,17 @@ static inline uint_fixed_16_16_t fixed_16_16_div_u64(uint32_t val, uint32_t d)
>  	return res;
>  }
>  
> +static inline uint32_t fixed_16_16_div_round_up_u64(uint32_t val,
> +						    uint_fixed_16_16_t d)
> +{
> +	uint64_t interm_val;
> +
> +	interm_val = (uint64_t)val << 16;
> +	interm_val = DIV_ROUND_UP_ULL(interm_val, d.val);
> +	WARN_ON(interm_val >> 32);
> +	return clamp_t(uint32_t, interm_val, 0, ~0);
> +}
> +
>  static inline uint_fixed_16_16_t mul_u32_fixed_16_16(uint32_t val,
>  						     uint_fixed_16_16_t mul)
>  {

I wouldn't mind if those macros would be moved later to drm core, I don't think i915 is the only one to benefit from fixed 16.16 calculations. :)

~Maarten