Re: [PATCH v2 2/3] drm/vkms: Add a macro for write_line functions

[Louis Chauvet <louis.chauvet@bootlin.com>]

On 26/10/24 - 12:08, Maíra Canal wrote:
> Hi Louis,
> 
> On 14/08/24 05:42, Louis Chauvet wrote:
> > As stated in [2], the write_line functions are very similar and force code
> 
> Where is [2]?
> 
> > duplication. This patch add a macro to avoid code repetition.
> > 
> > Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> > ---
> >   drivers/gpu/drm/vkms/vkms_formats.c | 107 ++++++++++--------------------------
> >   1 file changed, 30 insertions(+), 77 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> > index d1309f6d307f..a25cdf656d8a 100644
> > --- a/drivers/gpu/drm/vkms/vkms_formats.c
> > +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> > @@ -654,6 +654,31 @@ static void argb_u16_to_RGB565(u8 *out_pixel, const struct pixel_argb_u16 *in_pi
> >   	*pixel = cpu_to_le16(r << 11 | g << 5 | b);
> >   }
> > +/**
> > + * WRITE_LINE() - Generic generator for write_line functions
> > + *
> > + * This generator can only be used for format with only one plane and block_w == block_h == 1
> > + *
> > + * @function_name: Name to use for the generated function
> > + * @conversion_function: Fonction to use for the conversion from argb_u16 to the required format.
> 
> s/Fonction/Function
> 
> > + */
> > +#define WRITE_LINE(function_name, conversion_function)					\
> > +static void function_name(struct vkms_writeback_job *wb,				\
> > +			  struct pixel_argb_u16 *src_pixels, int count, int x_start,	\
> > +			  int y_start)							\
> > +{											\
> > +	u8 *dst_pixels;									\
> > +											\
> > +	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);	\
> > +											\
> > +	while (count) {									\
> > +		(conversion_function)(dst_pixels, src_pixels);				\
> > +		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];		\
> > +		src_pixels += 1;							\
> > +		count--;								\
> 
> Just a nit: What do you think about this loop?
> 
> for (; count > 0; src_pixels++, count--)
> 
> It doesn't really matter what option you pick.

I take this version, a bit shorter and not less explicit, thanks!

Thanks,
Louis Chauvet
 
> Best Regards,
> - Maíra
> 
> > +	}										\
> > +}
> > +
> >   /*
> >    * The following functions are write_line function for each pixel format supported by VKMS.
> >    *
> > @@ -667,85 +692,13 @@ static void argb_u16_to_RGB565(u8 *out_pixel, const struct pixel_argb_u16 *in_pi
> >    * [1]: https://lore.kernel.org/dri-devel/d258c8dc-78e9-4509-9037-a98f7f33b3a3@riseup.net/
> >    */
> > -static void ARGB8888_write_line(struct vkms_writeback_job *wb,
> > -				struct pixel_argb_u16 *src_pixels, int count, int x_start,
> > -				int y_start)
> > -{
> > -	u8 *dst_pixels;
> > +WRITE_LINE(ARGB8888_write_line, argb_u16_to_ARGB8888)
> > +WRITE_LINE(XRGB8888_write_line, argb_u16_to_XRGB8888)
> > -	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);
> > +WRITE_LINE(ARGB16161616_write_line, argb_u16_to_ARGB16161616)
> > +WRITE_LINE(XRGB16161616_write_line, argb_u16_to_XRGB16161616)
> > -	while (count) {
> > -		argb_u16_to_ARGB8888(dst_pixels, src_pixels);
> > -		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];
> > -		src_pixels += 1;
> > -		count--;
> > -	}
> > -}
> > -
> > -static void XRGB8888_write_line(struct vkms_writeback_job *wb,
> > -				struct pixel_argb_u16 *src_pixels, int count, int x_start,
> > -				int y_start)
> > -{
> > -	u8 *dst_pixels;
> > -
> > -	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);
> > -
> > -	while (count) {
> > -		argb_u16_to_XRGB8888(dst_pixels, src_pixels);
> > -		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];
> > -		src_pixels += 1;
> > -		count--;
> > -	}
> > -}
> > -
> > -static void ARGB16161616_write_line(struct vkms_writeback_job *wb,
> > -				    struct pixel_argb_u16 *src_pixels, int count, int x_start,
> > -				    int y_start)
> > -{
> > -	u8 *dst_pixels;
> > -
> > -	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);
> > -
> > -	while (count) {
> > -		argb_u16_to_ARGB16161616(dst_pixels, src_pixels);
> > -		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];
> > -		src_pixels += 1;
> > -		count--;
> > -	}
> > -}
> > -
> > -static void XRGB16161616_write_line(struct vkms_writeback_job *wb,
> > -				    struct pixel_argb_u16 *src_pixels, int count, int x_start,
> > -				    int y_start)
> > -{
> > -	u8 *dst_pixels;
> > -
> > -	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);
> > -
> > -	while (count) {
> > -		argb_u16_to_XRGB16161616(dst_pixels, src_pixels);
> > -		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];
> > -		src_pixels += 1;
> > -		count--;
> > -	}
> > -}
> > -
> > -static void RGB565_write_line(struct vkms_writeback_job *wb,
> > -			      struct pixel_argb_u16 *src_pixels, int count, int x_start,
> > -			      int y_start)
> > -{
> > -	u8 *dst_pixels;
> > -
> > -	packed_pixels_addr_1x1(&wb->wb_frame_info, x_start, y_start, 0, &dst_pixels);
> > -
> > -	while (count) {
> > -		argb_u16_to_RGB565(dst_pixels, src_pixels);
> > -		dst_pixels += wb->wb_frame_info.fb->format->char_per_block[0];
> > -		src_pixels += 1;
> > -		count--;
> > -	}
> > -}
> > +WRITE_LINE(RGB565_write_line, argb_u16_to_RGB565)
> >   /**
> >    * get_pixel_read_function() - Retrieve the correct read_line function for a specific
> >