Re: [PATCH v4 07/15] drm/i915/display: add platform member to struct intel_display

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Oct 21, 2024 at 04:54:08PM +0300, Jani Nikula wrote:
> Facilitate using display->platform.haswell and
> display->platform.haswell_ult etc. for identifying platforms and
> subplatforms.
> 
> Merge the platform and subplatform bitmaps together, and check that
> there's no overlap.
> 
> v4:
> - Lower case, s/is/platform/
> 
> v3:
> - Fix sanity check on display->is after merging subplatform members
> 
> v2:
> - Use bitmap ops
> - Add some sanity checks with warnings
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> ---
>  .../gpu/drm/i915/display/intel_display_core.h |  3 ++
>  .../drm/i915/display/intel_display_device.c   | 35 +++++++++++++++++--
>  2 files changed, 36 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h b/drivers/gpu/drm/i915/display/intel_display_core.h
> index 45697af25fa9..45b7c6900adc 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_core.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_core.h
> @@ -284,6 +284,9 @@ struct intel_display {
>  	/* drm device backpointer */
>  	struct drm_device *drm;
>  
> +	/* Platform (and subplatform, if any) identification */
> +	struct intel_display_platforms platform;
> +
>  	/* Display functions */
>  	struct {
>  		/* Top level crtc-ish functions */
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index 0e835f714bf5..c124df204166 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -1525,6 +1525,25 @@ static enum intel_step get_pre_gmdid_step(struct intel_display *display,
>  	return step;
>  }
>  
> +/* Size of the entire bitmap, not the number of platforms */
> +static unsigned int display_platforms_num_bits(void)
> +{
> +	return sizeof(((struct intel_display_platforms *)0)->bitmap) * BITS_PER_BYTE;
> +}
> +
> +/* Number of platform bits set */
> +static unsigned int display_platforms_weight(const struct intel_display_platforms *p)
> +{
> +	return bitmap_weight(p->bitmap, display_platforms_num_bits());
> +}
> +
> +/* Merge the subplatform information from src to dst */
> +static void display_platforms_or(struct intel_display_platforms *dst,
> +				 const struct intel_display_platforms *src)
> +{
> +	bitmap_or(dst->bitmap, dst->bitmap, src->bitmap, display_platforms_num_bits());
> +}
> +
>  void intel_display_device_probe(struct drm_i915_private *i915)
>  {
>  	struct intel_display *display = &i915->display;
> @@ -1564,13 +1583,25 @@ void intel_display_device_probe(struct drm_i915_private *i915)
>  	       &DISPLAY_INFO(i915)->__runtime_defaults,
>  	       sizeof(*DISPLAY_RUNTIME_INFO(i915)));
>  
> -	drm_WARN_ON(&i915->drm, !desc->platform || !desc->name);
> +	drm_WARN_ON(&i915->drm, !desc->platform || !desc->name ||
> +		    !display_platforms_weight(&desc->platforms));
>  	DISPLAY_RUNTIME_INFO(i915)->platform = desc->platform;
>  
> +	display->platform = desc->platforms;
> +
>  	subdesc = find_subplatform_desc(pdev, desc);
>  	if (subdesc) {
> -		drm_WARN_ON(&i915->drm, !subdesc->subplatform || !subdesc->name);
> +		drm_WARN_ON(&i915->drm, !subdesc->subplatform || !subdesc->name ||
> +			    !display_platforms_weight(&subdesc->platforms));
>  		DISPLAY_RUNTIME_INFO(i915)->subplatform = subdesc->subplatform;
> +
> +		display_platforms_or(&display->platform, &subdesc->platforms);
> +
> +		/* Ensure platform and subplatform are distinct */
> +		drm_WARN_ON(&i915->drm,
> +			    display_platforms_weight(&display->platform) !=
> +			    display_platforms_weight(&desc->platforms) +
> +			    display_platforms_weight(&subdesc->platforms));
>  	}
>  
>  	if (ip_ver.ver || ip_ver.rel || ip_ver.step) {
> -- 
> 2.39.5
>