On Wed, Mar 06, 2024 at 02:24:36PM +0200, Jani Nikula wrote:
> Convert various pointers to struct intel_display * using _Generic().
>
> Add some macro magic to make adding new conversions easier, and somewhat
> abstract the need to cast each generic association. The cast is required
> because all associations needs to compile, regardless of the type and
> the generic selection.
>
> The use of *p in the generic selection assignment expression removes the
> need to add separate associations for const pointers.
>
> Signed-off-by: Jani Nikula <jani.nik...@intel.com>
> ---
> .../drm/i915/display/intel_display_types.h | 46 +++++++++++++++++++
> 1 file changed, 46 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index e67cd5b02e84..3f63a5a74d77 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -2183,4 +2183,50 @@ static inline int to_bpp_x16(int bpp)
> return bpp << 4;
> }
>
> +/*
> + * Conversion functions/macros from various pointer types to struct
> + * intel_display pointer.
> + */
> +static inline struct intel_display *__drm_device_to_intel_display(const
> struct drm_device *drm)
> +{
> + /*
> + * Assume there's a pointer to struct intel_display in memory right
> + * after struct drm_device.
> + */
> + struct intel_display **p = (struct intel_display **)(drm + 1);
at least this patch and the first one should be together to help the
'magic' to be understood and confirmed safe.
> +
> + return *p;
> +}
> +
> +#define __intel_connector_to_intel_display(p) \
> + __drm_device_to_intel_display((p)->base.dev)
> +#define __intel_crtc_to_intel_display(p) \
> + __drm_device_to_intel_display((p)->base.dev)
> +#define __intel_crtc_state_to_intel_display(p) \
> + __drm_device_to_intel_display((p)->uapi.crtc->dev)
> +#define __intel_digital_port_to_intel_display(p) \
> + __drm_device_to_intel_display((p)->base.base.dev)
> +#define __intel_encoder_to_intel_display(p) \
> + __drm_device_to_intel_display((p)->base.dev)
> +#define __intel_hdmi_to_intel_display(p) \
> + __drm_device_to_intel_display(hdmi_to_dig_port(p)->base.base.dev)
> +#define __intel_dp_to_intel_display(p) \
> + __drm_device_to_intel_display(dp_to_dig_port(p)->base.base.dev)
> +
> +/* Helper for generic association. Map types to conversion functions/macros.
> */
> +#define __assoc(type, p) \
> + struct type: __##type##_to_intel_display((struct type *)(p))
> +
> +/* Convert various pointer types to struct intel_display pointer. */
> +#define to_intel_display(p) \
For a moment I almost complained of this because of the generic magic,
but mostly because I had guc related code in mind where you can never
find the definition, but here it is different. the used 'to_intel_display'
can easily be searched by cscope/ctags and then you are able to see
below what are the accepted cases, so I ended up liking it.
> + _Generic(*p, \
> + __assoc(intel_connector, p), \
> + __assoc(intel_crtc, p), \
> + __assoc(intel_crtc_state, p), \
> + __assoc(intel_digital_port, p), \
> + __assoc(intel_encoder, p), \
> + __assoc(intel_hdmi, p), \
> + __assoc(intel_dp, p), \
> + __assoc(drm_device, p))
> +
> #endif /* __INTEL_DISPLAY_TYPES_H__ */
> --
> 2.39.2
>
