Re: [PATCH 01/12] drm/format-helper: Provide drm_fb_blit()

[Sam Ravnborg <sam@ravnborg.org>]

Hi Thomas,

On Wed, Jul 27, 2022 at 01:33:01PM +0200, Thomas Zimmermann wrote:
> Provide drm_fb_blit() that works with struct iosys_map. Update all
> users of drm_fb_blit_toio(), which required a destination buffer in
> I/O memory. The new function's interface works with multi-plane
> color formats, although the implementation only supports a single
> plane for now.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/drm_format_helper.c | 39 ++++++++++++++++++-----------
>  drivers/gpu/drm/tiny/simpledrm.c    | 18 +++++++------
>  include/drm/drm_format_helper.h     |  7 +++---
>  3 files changed, 38 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
> index c6182b5de78b..4d74d46ab155 100644
> --- a/drivers/gpu/drm/drm_format_helper.c
> +++ b/drivers/gpu/drm/drm_format_helper.c
> @@ -8,9 +8,10 @@
>   * (at your option) any later version.
>   */
>  
> +#include <linux/io.h>
> +#include <linux/iosys-map.h>
>  #include <linux/module.h>
>  #include <linux/slab.h>
> -#include <linux/io.h>
>  
>  #include <drm/drm_device.h>
>  #include <drm/drm_format_helper.h>
> @@ -545,9 +546,9 @@ void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vad
>  EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
>  
>  /**
> - * drm_fb_blit_toio - Copy parts of a framebuffer to display memory
> - * @dst:	The display memory to copy to
> - * @dst_pitch:	Number of bytes between two consecutive scanlines within dst
> + * drm_fb_blit - Copy parts of a framebuffer to display memory
> + * @dst:	Array of display-memory addresses to copy to
> + * @dst_pitch:	Array of numbers of bytes between two consecutive scanlines within dst

The rename confused me since this function continue to operate only on
io memory, but I see that this is all fixed up in later patches.
It would be nice to have this mentioned in the changelog, just in case
someone else takes a deeper look at it.

With the changelog updated:
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

See also comments below.

>   * @dst_format:	FOURCC code of the display's color format
>   * @vmap:	The framebuffer memory to copy from
>   * @fb:		The framebuffer to copy from
> @@ -557,14 +558,18 @@ EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
>   * formats of the display and the framebuffer mismatch, the blit function
>   * will attempt to convert between them.
>   *
> + * The parameters @dst, @dst_pitch and @vmap refer to arrays. Each array must
> + * have at least as many entries as there are planes in @dst_format's format. Each
> + * entry stores the value for the format's respective color plane at the same index.
> + *
>   * Returns:
>   * 0 on success, or
>   * -EINVAL if the color-format conversion failed, or
>   * a negative error code otherwise.
>   */
> -int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_format,
> -		     const void *vmap, const struct drm_framebuffer *fb,
> -		     const struct drm_rect *clip)
> +int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t dst_format,
> +		const struct iosys_map *vmap, const struct drm_framebuffer *fb,
> +		const struct drm_rect *clip)
>  {
>  	uint32_t fb_format = fb->format->format;
>  
> @@ -579,30 +584,35 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
>  		dst_format = DRM_FORMAT_XRGB2101010;
>  
>  	if (dst_format == fb_format) {
> -		drm_fb_memcpy_toio(dst, dst_pitch, vmap, fb, clip);
> +		drm_fb_memcpy_toio(dst[0].vaddr_iomem, dst_pitch[0], vmap[0].vaddr, fb, clip);
>  		return 0;
>  
>  	} else if (dst_format == DRM_FORMAT_RGB565) {
>  		if (fb_format == DRM_FORMAT_XRGB8888) {
> -			drm_fb_xrgb8888_to_rgb565_toio(dst, dst_pitch, vmap, fb, clip, false);
> +			drm_fb_xrgb8888_to_rgb565_toio(dst[0].vaddr_iomem, dst_pitch[0],
> +						       vmap[0].vaddr, fb, clip, false);
>  			return 0;
>  		}
>  	} else if (dst_format == DRM_FORMAT_RGB888) {
>  		if (fb_format == DRM_FORMAT_XRGB8888) {
> -			drm_fb_xrgb8888_to_rgb888_toio(dst, dst_pitch, vmap, fb, clip);
> +			drm_fb_xrgb8888_to_rgb888_toio(dst[0].vaddr_iomem, dst_pitch[0],
> +						       vmap[0].vaddr, fb, clip);
>  			return 0;
>  		}
>  	} else if (dst_format == DRM_FORMAT_XRGB8888) {
>  		if (fb_format == DRM_FORMAT_RGB888) {
> -			drm_fb_rgb888_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
> +			drm_fb_rgb888_to_xrgb8888_toio(dst[0].vaddr_iomem, dst_pitch[0],
> +						       vmap[0].vaddr, fb, clip);
>  			return 0;
>  		} else if (fb_format == DRM_FORMAT_RGB565) {
> -			drm_fb_rgb565_to_xrgb8888_toio(dst, dst_pitch, vmap, fb, clip);
> +			drm_fb_rgb565_to_xrgb8888_toio(dst[0].vaddr_iomem, dst_pitch[0],
> +						       vmap[0].vaddr, fb, clip);
>  			return 0;
>  		}
>  	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
>  		if (fb_format == DRM_FORMAT_XRGB8888) {
> -			drm_fb_xrgb8888_to_xrgb2101010_toio(dst, dst_pitch, vmap, fb, clip);
> +			drm_fb_xrgb8888_to_xrgb2101010_toio(dst[0].vaddr_iomem, dst_pitch[0],
> +							    vmap[0].vaddr, fb, clip);
>  			return 0;
>  		}
>  	}
> @@ -612,8 +622,7 @@ int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_for
>  
>  	return -EINVAL;
>  }
> -EXPORT_SYMBOL(drm_fb_blit_toio);
> -
> +EXPORT_SYMBOL(drm_fb_blit);
>  
>  static void drm_fb_gray8_to_mono_line(void *dbuf, const void *sbuf, unsigned int pixels)
>  {
> diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
> index 5422363690e7..1ec73bec0513 100644
> --- a/drivers/gpu/drm/tiny/simpledrm.c
> +++ b/drivers/gpu/drm/tiny/simpledrm.c
> @@ -652,9 +652,8 @@ simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
>  	struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
>  	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
>  	struct drm_framebuffer *fb = plane_state->fb;
> -	void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
>  	struct drm_device *dev = &sdev->dev;
> -	void __iomem *dst = sdev->screen_base;
> +	struct iosys_map dst;
Maybe
struct iosys_map dst = IOSYS_MAP_INIT_VADDR(sdev->screen_base);

>  	struct drm_rect src_clip, dst_clip;
>  	int idx;
>  
> @@ -670,8 +669,10 @@ simpledrm_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
>  	if (!drm_dev_enter(dev, &idx))
>  		return;
>  
> -	dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip);
> -	drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb, &src_clip);
> +	iosys_map_set_vaddr_iomem(&dst, sdev->screen_base);
> +	iosys_map_incr(&dst, drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip));
> +	drm_fb_blit(&dst, &sdev->pitch, sdev->format->format,
> +		    shadow_plane_state->data, fb, &src_clip);
>  
>  	drm_dev_exit(idx);
>  }
> @@ -699,10 +700,9 @@ simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
>  	struct simpledrm_device *sdev = simpledrm_device_of_dev(pipe->crtc.dev);
>  	struct drm_plane_state *plane_state = pipe->plane.state;
>  	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
> -	void *vmap = shadow_plane_state->data[0].vaddr; /* TODO: Use mapping abstraction */
>  	struct drm_framebuffer *fb = plane_state->fb;
>  	struct drm_device *dev = &sdev->dev;
> -	void __iomem *dst = sdev->screen_base;
> +	struct iosys_map dst;
Likewise:
struct iosys_map dst = IOSYS_MAP_INIT_VADDR(sdev->screen_base);

>  	struct drm_rect src_clip, dst_clip;
>  	int idx;
>  
> @@ -719,8 +719,10 @@ simpledrm_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
>  	if (!drm_dev_enter(dev, &idx))
>  		return;
>  
> -	dst += drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip);
> -	drm_fb_blit_toio(dst, sdev->pitch, sdev->format->format, vmap, fb, &src_clip);
> +	iosys_map_set_vaddr_iomem(&dst, sdev->screen_base);
> +	iosys_map_incr(&dst, drm_fb_clip_offset(sdev->pitch, sdev->format, &dst_clip));
> +	drm_fb_blit(&dst, &sdev->pitch, sdev->format->format,
> +		    shadow_plane_state->data, fb, &src_clip);
>  
>  	drm_dev_exit(idx);
>  }
> diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
> index 55145eca0782..21daea7fda99 100644
> --- a/include/drm/drm_format_helper.h
> +++ b/include/drm/drm_format_helper.h
> @@ -6,6 +6,7 @@
>  #ifndef __LINUX_DRM_FORMAT_HELPER_H
>  #define __LINUX_DRM_FORMAT_HELPER_H
>  
> +struct iosys_map;
>  struct drm_format_info;
>  struct drm_framebuffer;
>  struct drm_rect;
> @@ -39,9 +40,9 @@ void drm_fb_xrgb8888_to_xrgb2101010_toio(void __iomem *dst, unsigned int dst_pit
>  void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vaddr,
>  			      const struct drm_framebuffer *fb, const struct drm_rect *clip);
>  
> -int drm_fb_blit_toio(void __iomem *dst, unsigned int dst_pitch, uint32_t dst_format,
> -		     const void *vmap, const struct drm_framebuffer *fb,
> -		     const struct drm_rect *rect);
> +int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t dst_format,
> +		const struct iosys_map *vmap, const struct drm_framebuffer *fb,
> +		const struct drm_rect *rect);
>  
>  void drm_fb_xrgb8888_to_mono(void *dst, unsigned int dst_pitch, const void *src,
>  			     const struct drm_framebuffer *fb, const struct drm_rect *clip);
> -- 
> 2.37.1