[PATCH 2/8] drm/format-helper: Add generic conversion to 32-bit formats

[Jocelyn Falempe]

On 25/03/2025 11:31, Thomas Zimmermann wrote:
> Add drm_fb_xfrm_line_32to32() to implement conversion from 32-bit
> pixels to 32-bit pixels. The pixel-conversion is specified by the
> given callback parameter. Mark the helper as always_inline to avoid
> overhead from function calls.
> 
> Then implement all existing line-conversion functions with the new
> generic call and the respective pixel-conversion helper.

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>

> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>   drivers/gpu/drm/drm_format_helper.c | 84 +++++++----------------------
>   1 file changed, 19 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
> index 01d3ab307ac3..abd18c23cfbb 100644
> --- a/drivers/gpu/drm/drm_format_helper.c
> +++ b/drivers/gpu/drm/drm_format_helper.c
> @@ -20,6 +20,8 @@
>   #include <drm/drm_print.h>
>   #include <drm/drm_rect.h>
>   
> +#include "drm_format_internal.h"
> +
>   /**
>    * drm_format_conv_state_init - Initialize format-conversion state
>    * @state: The state to initialize
> @@ -244,6 +246,18 @@ static int drm_fb_xfrm(struct iosys_map *dst,
>   				     xfrm_line);
>   }
>   
> +static __always_inline void drm_fb_xfrm_line_32to32(void *dbuf, const void *sbuf,
> +						    unsigned int pixels,
> +						    u32 (*xfrm_pixel)(u32))
> +{
> +	__le32 *dbuf32 = dbuf;
> +	const __le32 *sbuf32 = sbuf;
> +	const __le32 *send32 = sbuf32 + pixels;
> +
> +	while (sbuf32 < send32)
> +		*dbuf32++ = cpu_to_le32(xfrm_pixel(le32_to_cpup(sbuf32++)));
> +}
> +
>   /**
>    * drm_fb_memcpy - Copy clip buffer
>    * @dst: Array of destination buffers
> @@ -755,16 +769,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_bgr888);
>   
>   static void drm_fb_xrgb8888_to_argb8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
>   {
> -	__le32 *dbuf32 = dbuf;
> -	const __le32 *sbuf32 = sbuf;
> -	unsigned int x;
> -	u32 pix;
> -
> -	for (x = 0; x < pixels; x++) {
> -		pix = le32_to_cpu(sbuf32[x]);
> -		pix |= GENMASK(31, 24); /* fill alpha bits */
> -		dbuf32[x] = cpu_to_le32(pix);
> -	}
> +	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_argb8888);
>   }
>   
>   /**
> @@ -804,19 +809,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb8888);
>   
>   static void drm_fb_xrgb8888_to_abgr8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
>   {
> -	__le32 *dbuf32 = dbuf;
> -	const __le32 *sbuf32 = sbuf;
> -	unsigned int x;
> -	u32 pix;
> -
> -	for (x = 0; x < pixels; x++) {
> -		pix = le32_to_cpu(sbuf32[x]);
> -		pix = ((pix & 0x00ff0000) >> 16) <<  0 |
> -		      ((pix & 0x0000ff00) >>  8) <<  8 |
> -		      ((pix & 0x000000ff) >>  0) << 16 |
> -		      GENMASK(31, 24); /* fill alpha bits */
> -		*dbuf32++ = cpu_to_le32(pix);
> -	}
> +	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_abgr8888);
>   }
>   
>   static void drm_fb_xrgb8888_to_abgr8888(struct iosys_map *dst, const unsigned int *dst_pitch,
> @@ -835,19 +828,7 @@ static void drm_fb_xrgb8888_to_abgr8888(struct iosys_map *dst, const unsigned in
>   
>   static void drm_fb_xrgb8888_to_xbgr8888_line(void *dbuf, const void *sbuf, unsigned int pixels)
>   {
> -	__le32 *dbuf32 = dbuf;
> -	const __le32 *sbuf32 = sbuf;
> -	unsigned int x;
> -	u32 pix;
> -
> -	for (x = 0; x < pixels; x++) {
> -		pix = le32_to_cpu(sbuf32[x]);
> -		pix = ((pix & 0x00ff0000) >> 16) <<  0 |
> -		      ((pix & 0x0000ff00) >>  8) <<  8 |
> -		      ((pix & 0x000000ff) >>  0) << 16 |
> -		      ((pix & 0xff000000) >> 24) << 24;
> -		*dbuf32++ = cpu_to_le32(pix);
> -	}
> +	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_xbgr8888);
>   }
>   
>   static void drm_fb_xrgb8888_to_xbgr8888(struct iosys_map *dst, const unsigned int *dst_pitch,
> @@ -866,20 +847,7 @@ static void drm_fb_xrgb8888_to_xbgr8888(struct iosys_map *dst, const unsigned in
>   
>   static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
>   {
> -	__le32 *dbuf32 = dbuf;
> -	const __le32 *sbuf32 = sbuf;
> -	unsigned int x;
> -	u32 val32;
> -	u32 pix;
> -
> -	for (x = 0; x < pixels; x++) {
> -		pix = le32_to_cpu(sbuf32[x]);
> -		val32 = ((pix & 0x000000FF) << 2) |
> -			((pix & 0x0000FF00) << 4) |
> -			((pix & 0x00FF0000) << 6);
> -		pix = val32 | ((val32 >> 8) & 0x00300C03);
> -		*dbuf32++ = cpu_to_le32(pix);
> -	}
> +	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_xrgb2101010);
>   }
>   
>   /**
> @@ -920,21 +888,7 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
>   
>   static void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void *sbuf, unsigned int pixels)
>   {
> -	__le32 *dbuf32 = dbuf;
> -	const __le32 *sbuf32 = sbuf;
> -	unsigned int x;
> -	u32 val32;
> -	u32 pix;
> -
> -	for (x = 0; x < pixels; x++) {
> -		pix = le32_to_cpu(sbuf32[x]);
> -		val32 = ((pix & 0x000000ff) << 2) |
> -			((pix & 0x0000ff00) << 4) |
> -			((pix & 0x00ff0000) << 6);
> -		pix = GENMASK(31, 30) | /* set alpha bits */
> -		      val32 | ((val32 >> 8) & 0x00300c03);
> -		*dbuf32++ = cpu_to_le32(pix);
> -	}
> +	drm_fb_xfrm_line_32to32(dbuf, sbuf, pixels, drm_pixel_xrgb8888_to_argb2101010);
>   }
>   
>   /**