On Thu, Jun 25, 2020 at 02:00:04PM +0200, Thomas Zimmermann wrote:
> The blitter functions copy a framebuffer to I/O memory using one of
> the existing conversion functions.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Hm I guess reason for adding dst_pitch in the previous patch is so that
there wouldn't be a special case here. Makes sense.
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
> drivers/gpu/drm/drm_format_helper.c | 87 +++++++++++++++++++++++++++++
> include/drm/drm_format_helper.h | 8 +++
> 2 files changed, 95 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c
> index 8d5a683afea7..0e885cd34107 100644
> --- a/drivers/gpu/drm/drm_format_helper.c
> +++ b/drivers/gpu/drm/drm_format_helper.c
> @@ -344,3 +344,90 @@ void drm_fb_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
> }
> EXPORT_SYMBOL(drm_fb_xrgb8888_to_gray8);
>
> +/**
> + * drm_fb_blit_rect_dstclip - 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
> + * @dst_format: FOURCC code of the display's color format
> + * @vmap: The framebuffer memory to copy from
> + * @fb: The framebuffer to copy from
> + * @clip: Clip rectangle area to copy
> + *
> + * This function copies parts of a framebuffer to display memory. If the
> + * formats of the display and the framebuffer mismatch, the blit function
> + * will attempt to convert between them.
> + *
> + * Use drm_fb_blit_dstclip() to copy the full framebuffer.
> + *
> + * Returns:
> + * 0 on success, or
> + * -EINVAL if the color-format conversion failed, or
> + * a negative error code otherwise.
> + */
> +int drm_fb_blit_rect_dstclip(void __iomem *dst, unsigned int dst_pitch,
> + uint32_t dst_format, void *vmap,
> + struct drm_framebuffer *fb,
> + struct drm_rect *clip)
> +{
> + uint32_t fb_format = fb->format->format;
> +
> + /* treat alpha channel like filler bits */
> + if (fb_format == DRM_FORMAT_ARGB8888)
> + fb_format = DRM_FORMAT_XRGB8888;
> + if (dst_format == DRM_FORMAT_ARGB8888)
> + dst_format = DRM_FORMAT_XRGB8888;
> +
> + if (dst_format == fb_format) {
> + drm_fb_memcpy_dstclip(dst, dst_pitch, vmap, fb, clip);
> + return 0;
> +
> + } else if (dst_format == DRM_FORMAT_RGB565) {
> + if (fb_format == DRM_FORMAT_XRGB8888) {
> + drm_fb_xrgb8888_to_rgb565_dstclip(dst, dst_pitch,
> + vmap, fb, clip,
> + false);
> + return 0;
> + }
> + } else if (dst_format == DRM_FORMAT_RGB888) {
> + if (fb_format == DRM_FORMAT_XRGB8888) {
> + drm_fb_xrgb8888_to_rgb888_dstclip(dst, dst_pitch,
> + vmap, fb, clip);
> + return 0;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL(drm_fb_blit_rect_dstclip);
> +
> +/**
> + * drm_fb_blit_dstclip - Copy framebuffer to display memory
> + * @dst: The display memory to copy to
> + * @dst_pitch: Number of bytes between two consecutive scanlines within dst
> + * @dst_format: FOURCC code of the display's color format
> + * @vmap: The framebuffer memory to copy from
> + * @fb: The framebuffer to copy from
> + *
> + * This function copies a full framebuffer to display memory. If the formats
> + * of the display and the framebuffer mismatch, the copy function will
> + * attempt to convert between them.
> + *
> + * See drm_fb_blit_rect_dstclip() for more inforamtion.
> + *
> + * Returns:
> + * 0 on success, or a negative error code otherwise.
> + */
> +int drm_fb_blit_dstclip(void __iomem *dst, unsigned int dst_pitch,
> + uint32_t dst_format, void *vmap,
> + struct drm_framebuffer *fb)
I do wonder whether we shouldn't have to some safety checks for this
stuff, like maybe something like:
struct dst_info {
void __iomem *dst;
unsigned int size;
unsigned int dst_pitch;
uint32_t dst_format;
};
And then the helpers would splat a WARNING if a driver ever gets this
wrong. Thinking about this because syzkaller has found tons of little
off-by-a-bit bugs in the vt/fbcon/fbdev code, and maybe we should try to
be better :-)
But that's material for another patch, and maybe once we have a few more
helpers in this library we can figure out a nice struct to package up
these long&confusing argument lists a bit.
Cheers, Daniel
> +{
> + struct drm_rect fullscreen = {
> + .x1 = 0,
> + .x2 = fb->width,
> + .y1 = 0,
> + .y2 = fb->height,
> + };
> + return drm_fb_blit_rect_dstclip(dst, dst_pitch, dst_format, vmap, fb,
> + &fullscreen);
> +}
> +EXPORT_SYMBOL(drm_fb_blit_dstclip);
> diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h
> index 2b5036a5fbe7..4e0258a61311 100644
> --- a/include/drm/drm_format_helper.h
> +++ b/include/drm/drm_format_helper.h
> @@ -28,4 +28,12 @@ void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch
> void drm_fb_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
> struct drm_rect *clip);
>
> +int drm_fb_blit_rect_dstclip(void __iomem *dst, unsigned int dst_pitch,
> + uint32_t dst_format, void *vmap,
> + struct drm_framebuffer *fb,
> + struct drm_rect *rect);
> +int drm_fb_blit_dstclip(void __iomem *dst, unsigned int dst_pitch,
> + uint32_t dst_format, void *vmap,
> + struct drm_framebuffer *fb);
> +
> #endif /* __LINUX_DRM_FORMAT_HELPER_H */
> --
> 2.27.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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