Re: [PATCH v2 5/9] drm/i915/display: add platforms "is" member to struct intel_display

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

On Mon, Aug 19, 2024 at 09:44:32PM +0300, Jani Nikula wrote:
11;rgb:ffff/ffff/ffff> Facilitate using display->is.HASWELL and display->is.HASWELL_ULT
> etc. for identifying platforms and subplatforms. Merge platform and
> subplatform members together.
> 
> v2:
> - Use bitmap ops
> - Add some sanity checks with warnings
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  .../gpu/drm/i915/display/intel_display_core.h |  3 ++
>  .../drm/i915/display/intel_display_device.c   | 31 +++++++++++++++++--
>  2 files changed, 32 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 0a711114ff2b..b2907894fa28 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_core.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_core.h
> @@ -286,6 +286,9 @@ struct intel_display {
>  	/* drm device backpointer */
>  	struct drm_device *drm;
>  
> +	/* Platform (and subplatform, if any) identification */
> +	struct intel_display_platforms is;

as I told, I don't have a better suggestion I'm afraid, so


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


> +
>  	/* 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 55ab1923c8b3..3d3b4ed7940e 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -1269,8 +1269,28 @@ find_subplatform_desc(struct pci_dev *pdev, const struct platform_desc *desc)
>  	return NULL;
>  }
>  
> +/* 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;
>  	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>  	const struct intel_display_device_info *info;
>  	struct intel_display_ip_ver ip_ver = {};
> @@ -1306,13 +1326,20 @@ 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) != 1);
>  	DISPLAY_RUNTIME_INFO(i915)->platform = desc->platform;
> +	display->is = 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) != 1);
>  		DISPLAY_RUNTIME_INFO(i915)->subplatform = subdesc->subplatform;
> +		display_platforms_or(&display->is, &subdesc->platforms);
> +
> +		/* Ensure platform and subplatform are distinct */
> +		drm_WARN_ON(&i915->drm, display_platforms_weight(&subdesc->platforms) == 1);
>  	}
>  
>  	if (ip_ver.ver || ip_ver.rel || ip_ver.step)
> -- 
> 2.39.2
>