[PATCH] drm/atomic: Add new reverse iterator over all plane state

[Andrey Grodzovsky]

Any DRM related changes needs to be sent to dri-devel at lists.freedesktop.org

Andrey


On 02/28/2018 04:33 AM, S, Shirish wrote:
> From: Shirish S <shirish.s at amd.com>
>
> Add reverse iterator "for_each_oldnew_plane_in_state_reverse" to
> complement "for_each_oldnew_plane_in_state" way of reading plane
> states.
>
> The plane states are required to be read in reverse order for
> amdgpu, as the z order convention followed in linux is
> opposite to how the planes are supposed to be presented to DC
> engine, which is in common to both windows and linux.
>
> Signed-off-by: Shirish S <shirish.s at amd.com>
> Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma at amd.com>
> ---
>   include/drm/drm_atomic.h | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
>
> diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
> index cf13842..b947930 100644
> --- a/include/drm/drm_atomic.h
> +++ b/include/drm/drm_atomic.h
> @@ -754,6 +754,28 @@ void drm_state_dump(struct drm_device *dev, struct drm_printer *p);
>   			      (new_plane_state) = (__state)->planes[__i].new_state, 1))
>   
>   /**
> + * for_each_oldnew_plane_in_state_reverse - iterate over all planes in an atomic
> + * update in reverse order
> + * @__state: &struct drm_atomic_state pointer
> + * @plane: &struct drm_plane iteration cursor
> + * @old_plane_state: &struct drm_plane_state iteration cursor for the old state
> + * @new_plane_state: &struct drm_plane_state iteration cursor for the new state
> + * @__i: int iteration cursor, for macro-internal use
> + *
> + * This iterates over all planes in an atomic update in reverse order,
> + * tracking both old and  new state. This is useful in places where the
> + * state delta needs to be considered, for example in atomic check functions.
> + */
> +#define for_each_oldnew_plane_in_state_reverse(__state, plane, old_plane_state, new_plane_state, __i) \
> +	(for ((__i) = ((__state)->dev->mode_config.num_total_plane - 1);	\
> +	     (__i) >= 0;						\
> +	     (__i)--)							\
> +		for_each_if ((__state)->planes[__i].ptr &&		\
> +			     ((plane) = (__state)->planes[__i].ptr,	\
> +			      (old_plane_state) = (__state)->planes[__i].old_state,\
> +			      (new_plane_state) = (__state)->planes[__i].new_state, 1)))
> +
> +/**
>    * for_each_old_plane_in_state - iterate over all planes in an atomic update
>    * @__state: &struct drm_atomic_state pointer
>    * @plane: &struct drm_plane iteration cursor