Re: [PATCH v4 1/4] drm/format-helper: Export line conversion helper for drm_panic

[Jocelyn Falempe <jfalempe@xxxxxxxxxx>]

On 16/10/2023 12:47, Thomas Zimmermann wrote:
> Hi
>
> Am 03.10.23 um 16:22 schrieb Jocelyn Falempe:
> > drm_panic will need the low-level drm_fb_xxxx_line functions.
>
> It seems like premature optimization to not use drm_fb_blit(); 
> especially since drm_panic is not performance critical.
>
> > Also add drm_fb_r1_to_xrgb8888 to render the fonts.
>
> I think we should provide a helper function that returns a pointer to 
> the correct function for each supported case. Essentially, it would move 
> that if-else branching from drm_fb_blit() into its own function.  It's 
> not typical DRM style, but cleaner than retyping the if-elses in drm_panic.
>
> Something like:
>
> typedef int (*drm_format_conv_func)(/* args here */);
>
> drm_format_conv_func  drm_format_conv(u32 dst_fourcc, u32 src_fourcc)
> {
>      // do if-else from drm_fb_blit here
>
>      return <correct-format-conv-helper>
> }
> EXPORT_SYMBOL(drm_format_conv)
>
> That would be callable from anywhere. You can integrate any helpers for 
> _R1 here as well.

Regarding the color conversion approach, I think we don't need to 
convert the whole buffer, like drm_fb_blit() or the xxxx_line() do. Just 
converting the fg_color and bg_color is enough, and then only the pixel 
size matters, when converting from R1.

So instead of having plenty of conversion functions, I will only need
R1_to_8bit(), R1_to_16bit(), R1_to_24bit() and R1_to_32bit()

I can encapsulate this in a drm_blit_from_r1(), that will also take the 
fg_color and bg_color as parameter.

If you agree with that, I will do it for the v5.

--

Jocelyn


> Best regards
> Thomas
>
> > Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/drm_format_helper.c | 88 ++++++++++++++++++++++++++---
> >   include/drm/drm_format_helper.h     |  9 +++
> >   2 files changed, 89 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_format_helper.c 
> > b/drivers/gpu/drm/drm_format_helper.c
> > index f93a4efcee90..c238e5d84f1f 100644
> > --- a/drivers/gpu/drm/drm_format_helper.c
> > +++ b/drivers/gpu/drm/drm_format_helper.c
> > @@ -270,7 +270,30 @@ void drm_fb_swab(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >       drm_fb_xfrm(dst, dst_pitch, &cpp, src, fb, clip, cached, 
> > swab_line);
> >   }
> > -EXPORT_SYMBOL(drm_fb_swab);
> > +
> > +/**
> > + * drm_fb_r1_to_32bit_line - Convert one line from monochrome to any 
> > 32bit pixel format
> > + * @dbuf: Pointer to the destination line (in any 32bit format)
> > + * @sbuf: Pointer to the source line (in monochrome)
> > + * @pixels: Number of pixels to convert.
> > + * @fg_color: Foreground color, applied when R1 is 1
> > + * @bg_color: Background color, applied when R1 is 0
> > + *
> > + * Convert monochrome to any format with 32bit pixel.
> > + * There is a limitation, as sbuf is a pointer, it can only points to 
> > a multiple
> > + * of 8 pixels in the source buffer.
> > + */
> > +void drm_fb_r1_to_32bit_line(void *dbuf, const void *sbuf, unsigned 
> > int pixels,
> > +                u32 fg_color, u32 bg_color)
> > +{
> > +    unsigned int x;
> > +    const u8 *sbuf8 = sbuf;
> > +    u32 *dubf32 = dbuf;
> > +
> > +    for (x = 0; x < pixels; x++)
> > +        dubf32[x] = (sbuf8[x / 8] & (0x80 >> (x % 8))) ? fg_color : 
> > bg_color;
> > +}
> > +EXPORT_SYMBOL(drm_fb_r1_to_32bit_line);
> >   static void drm_fb_xrgb8888_to_rgb332_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> >   {
> > @@ -320,7 +343,13 @@ void drm_fb_xrgb8888_to_rgb332(struct iosys_map 
> > *dst, const unsigned int *dst_pi
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb332);
> > -static void drm_fb_xrgb8888_to_rgb565_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb565_line - Convert one line from XRGB8888 to 
> > RGB565
> > + * @dbuf: Pointer to the destination line (in RGB565)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_rgb565_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels)
> >   {
> >       __le16 *dbuf16 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -336,6 +365,7 @@ static void drm_fb_xrgb8888_to_rgb565_line(void 
> > *dbuf, const void *sbuf, unsigne
> >           dbuf16[x] = cpu_to_le16(val16);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565_line);
> >   /* TODO: implement this helper as conversion to RGB565|BIG_ENDIAN */
> >   static void drm_fb_xrgb8888_to_rgb565_swab_line(void *dbuf, const 
> > void *sbuf,
> > @@ -396,7 +426,13 @@ void drm_fb_xrgb8888_to_rgb565(struct iosys_map 
> > *dst, const unsigned int *dst_pi
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb565);
> > -static void drm_fb_xrgb8888_to_xrgb1555_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb565_line - Convert one line from XRGB8888 to 
> > XRGB1555
> > + * @dbuf: Pointer to the destination line (in XRGB1555)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_xrgb1555_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels)
> >   {
> >       __le16 *dbuf16 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -412,6 +448,7 @@ static void drm_fb_xrgb8888_to_xrgb1555_line(void 
> > *dbuf, const void *sbuf, unsig
> >           dbuf16[x] = cpu_to_le16(val16);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb1555_line);
> >   /**
> >    * drm_fb_xrgb8888_to_xrgb1555 - Convert XRGB8888 to XRGB1555 clip 
> > buffer
> > @@ -447,7 +484,13 @@ void drm_fb_xrgb8888_to_xrgb1555(struct iosys_map 
> > *dst, const unsigned int *dst_
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb1555);
> > -static void drm_fb_xrgb8888_to_argb1555_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb565_line - Convert one line from XRGB8888 to 
> > ARGB1555
> > + * @dbuf: Pointer to the destination line (in ARGB1555)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_argb1555_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels)
> >   {
> >       __le16 *dbuf16 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -464,6 +507,7 @@ static void drm_fb_xrgb8888_to_argb1555_line(void 
> > *dbuf, const void *sbuf, unsig
> >           dbuf16[x] = cpu_to_le16(val16);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb1555_line);
> >   /**
> >    * drm_fb_xrgb8888_to_argb1555 - Convert XRGB8888 to ARGB1555 clip 
> > buffer
> > @@ -499,7 +543,13 @@ void drm_fb_xrgb8888_to_argb1555(struct iosys_map 
> > *dst, const unsigned int *dst_
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb1555);
> > -static void drm_fb_xrgb8888_to_rgba5551_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgba5551_line - Convert one line from XRGB8888 
> > to ARGB5551
> > + * @dbuf: Pointer to the destination line (in ARGB5551)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_rgba5551_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels)
> >   {
> >       __le16 *dbuf16 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -516,6 +566,7 @@ static void drm_fb_xrgb8888_to_rgba5551_line(void 
> > *dbuf, const void *sbuf, unsig
> >           dbuf16[x] = cpu_to_le16(val16);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgba5551_line);
> >   /**
> >    * drm_fb_xrgb8888_to_rgba5551 - Convert XRGB8888 to RGBA5551 clip 
> > buffer
> > @@ -551,7 +602,13 @@ void drm_fb_xrgb8888_to_rgba5551(struct iosys_map 
> > *dst, const unsigned int *dst_
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgba5551);
> > -static void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb888_line - Convert one line from XRGB8888 to 
> > RGB888
> > + * @dbuf: Pointer to the destination line (in RGB888)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels)
> >   {
> >       u8 *dbuf8 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -566,6 +623,7 @@ static void drm_fb_xrgb8888_to_rgb888_line(void 
> > *dbuf, const void *sbuf, unsigne
> >           *dbuf8++ = (pix & 0x00FF0000) >> 16;
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888_line);
> >   /**
> >    * drm_fb_xrgb8888_to_rgb888 - Convert XRGB8888 to RGB888 clip buffer
> > @@ -709,7 +767,13 @@ static void drm_fb_xrgb8888_to_xbgr8888(struct 
> > iosys_map *dst, const unsigned in
> >               drm_fb_xrgb8888_to_xbgr8888_line);
> >   }
> > -static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const 
> > void *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb888_line - Convert one line from XRGB8888 to 
> > XRGB2101010
> > + * @dbuf: Pointer to the destination line (in XRGB2101010)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> >   {
> >       __le32 *dbuf32 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -726,6 +790,7 @@ static void 
> > drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, un
> >           *dbuf32++ = cpu_to_le32(pix);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_line);
> >   /**
> >    * drm_fb_xrgb8888_to_xrgb2101010 - Convert XRGB8888 to XRGB2101010 
> > clip buffer
> > @@ -761,7 +826,13 @@ void drm_fb_xrgb8888_to_xrgb2101010(struct 
> > iosys_map *dst, const unsigned int *d
> >   }
> >   EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010);
> > -static void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const 
> > void *sbuf, unsigned int pixels)
> > +/**
> > + * drm_fb_xrgb8888_to_rgb888_line - Convert one line from XRGB8888 to 
> > ARGB2101010
> > + * @dbuf: Pointer to the destination line (in ARGB2101010)
> > + * @sbuf: Pointer to the source line (in XRGB8888)
> > + * @pixels: Number of pixels to convert.
> > + */
> > +void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels)
> >   {
> >       __le32 *dbuf32 = dbuf;
> >       const __le32 *sbuf32 = sbuf;
> > @@ -779,6 +850,7 @@ static void 
> > drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void *sbuf, un
> >           *dbuf32++ = cpu_to_le32(pix);
> >       }
> >   }
> > +EXPORT_SYMBOL(drm_fb_xrgb8888_to_argb2101010_line);
> >   /**
> >    * drm_fb_xrgb8888_to_argb2101010 - Convert XRGB8888 to ARGB2101010 
> > clip buffer
> > diff --git a/include/drm/drm_format_helper.h 
> > b/include/drm/drm_format_helper.h
> > index 291deb09475b..31ab699128d5 100644
> > --- a/include/drm/drm_format_helper.h
> > +++ b/include/drm/drm_format_helper.h
> > @@ -24,30 +24,39 @@ void drm_fb_memcpy(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >   void drm_fb_swab(struct iosys_map *dst, const unsigned int *dst_pitch,
> >            const struct iosys_map *src, const struct drm_framebuffer *fb,
> >            const struct drm_rect *clip, bool cached);
> > +void drm_fb_r1_to_32bit_line(void *dbuf, const void *sbuf, unsigned 
> > int pixels,
> > +                 u32 fg_color, u32 bg_color);
> >   void drm_fb_xrgb8888_to_rgb332(struct iosys_map *dst, const unsigned 
> > int *dst_pitch,
> >                      const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                      const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_rgb565_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels);
> >   void drm_fb_xrgb8888_to_rgb565(struct iosys_map *dst, const unsigned 
> > int *dst_pitch,
> >                      const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                      const struct drm_rect *clip, bool swab);
> > +void drm_fb_xrgb8888_to_xrgb1555_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels);
> >   void drm_fb_xrgb8888_to_xrgb1555(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                    const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                    const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_argb1555_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels);
> >   void drm_fb_xrgb8888_to_argb1555(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                    const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                    const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_rgba5551_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels);
> >   void drm_fb_xrgb8888_to_rgba5551(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                    const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                    const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_rgb888_line(void *dbuf, const void *sbuf, 
> > unsigned int pixels);
> >   void drm_fb_xrgb8888_to_rgb888(struct iosys_map *dst, const unsigned 
> > int *dst_pitch,
> >                      const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                      const struct drm_rect *clip);
> >   void drm_fb_xrgb8888_to_argb8888(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                    const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                    const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels);
> >   void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                       const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                       const struct drm_rect *clip);
> > +void drm_fb_xrgb8888_to_argb2101010_line(void *dbuf, const void 
> > *sbuf, unsigned int pixels);
> >   void drm_fb_xrgb8888_to_argb2101010(struct iosys_map *dst, const 
> > unsigned int *dst_pitch,
> >                       const struct iosys_map *src, const struct 
> > drm_framebuffer *fb,
> >                       const struct drm_rect *clip);