Re: [PATCH v3 06/15] drm/i915/display: add display platforms structure with platform members

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

On Mon, Sep 30, 2024 at 03:31:07PM +0300, Jani Nikula wrote:
> Add a structure with a bitfield member for each platform and
> subplatform, and initialize them in platform and subplatform descs.
> 
> The structure also contains a bitmap in a union for easier manipulation
> of the bits.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  .../drm/i915/display/intel_display_device.c   |  4 ++++
>  .../drm/i915/display/intel_display_device.h   | 19 +++++++++++++++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.c b/drivers/gpu/drm/i915/display/intel_display_device.c
> index b2610217f5c5..258660b49eba 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.c
> @@ -31,6 +31,7 @@ struct stepping_desc {
>  	.step_info.size = ARRAY_SIZE(_map)
>  
>  struct subplatform_desc {
> +	struct intel_display_platforms platforms;
>  	enum intel_display_platform subplatform;
>  	const char *name;
>  	const u16 *pciidlist;
> @@ -38,10 +39,12 @@ struct subplatform_desc {
>  };
>  
>  #define SUBPLATFORM(_platform, _subplatform)				\
> +	.platforms._platform##_##_subplatform = 1,			\
>  	.subplatform = (INTEL_DISPLAY_##_platform##_##_subplatform),	\
>  	.name = #_subplatform
>  
>  struct platform_desc {
> +	struct intel_display_platforms platforms;
>  	enum intel_display_platform platform;
>  	const char *name;
>  	const struct subplatform_desc *subplatforms;
> @@ -50,6 +53,7 @@ struct platform_desc {
>  };
>  
>  #define PLATFORM(_platform)			 \
> +	.platforms._platform = 1,		 \
>  	.platform = (INTEL_DISPLAY_##_platform), \
>  	.name = #_platform
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
> index c4208c34cc31..f166d4698949 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_device.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_device.h
> @@ -6,6 +6,7 @@
>  #ifndef __INTEL_DISPLAY_DEVICE_H__
>  #define __INTEL_DISPLAY_DEVICE_H__
>  
> +#include <linux/bitops.h>
>  #include <linux/types.h>
>  
>  #include "intel_display_conversion.h"
> @@ -104,6 +105,24 @@ enum intel_display_platform {
>  
>  #undef __ENUM
>  
> +#define __MEMBER(name) unsigned long name:1;
> +#define __COUNT(x) 1 +
> +
> +#define __NUM_PLATFORMS (INTEL_DISPLAY_PLATFORMS(__COUNT) 0)
> +
> +struct intel_display_platforms {
> +	union {
> +		struct {
> +			INTEL_DISPLAY_PLATFORMS(__MEMBER);
> +		};
> +		DECLARE_BITMAP(bitmap, __NUM_PLATFORMS);
> +	};
> +};
> +
> +#undef __MEMBER
> +#undef __COUNT

why do we need the count here?
I'm afraid I didn't fully followed this macro...

> +#undef __NUM_PLATFORMS
> +
>  #define DEV_INFO_DISPLAY_FOR_EACH_FLAG(func) \
>  	/* Keep in alphabetical order */ \
>  	func(cursor_needs_physical); \
> -- 
> 2.39.5
>