[Freedreno] [PATCH v3 11/12] drm/fbdev-generic: Implement dedicated fbdev I/O helpers

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Mon May 22 13:20:53 UTC 2023


On Mon, 22 May 2023 at 15:22, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Implement dedicated fbdev helpers for framebuffer I/O instead
> of using DRM's helpers. Fbdev-generic was the only caller of the
> DRM helpers, so remove them from the helper module.
>
> v2:
>         * use FB_SYS_HELPERS_DEFERRED option
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  drivers/gpu/drm/Kconfig             |   6 +-
>  drivers/gpu/drm/drm_fb_helper.c     | 107 ----------------------------
>  drivers/gpu/drm/drm_fbdev_generic.c |  47 ++++++++++--
>  include/drm/drm_fb_helper.h         |  41 -----------
>  4 files changed, 43 insertions(+), 158 deletions(-)

Looking at this patch makes me wonder if we should have implemented
fb_dirty for the MSM driver. We have drm_framebuffer_funcs::dirty()
implemented (by wrapping the drm_atomic_helper_dirtyfb()).

>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 77fb10ddd8a2..92a782827b7b 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -95,6 +95,7 @@ config DRM_KUNIT_TEST
>  config DRM_KMS_HELPER
>         tristate
>         depends on DRM
> +       select FB_SYS_HELPERS_DEFERRED if DRM_FBDEV_EMULATION
>         help
>           CRTC helpers for KMS drivers.
>
> @@ -135,11 +136,6 @@ config DRM_FBDEV_EMULATION
>         select FB_CFB_FILLRECT
>         select FB_CFB_COPYAREA
>         select FB_CFB_IMAGEBLIT
> -       select FB_DEFERRED_IO
> -       select FB_SYS_FOPS
> -       select FB_SYS_FILLRECT
> -       select FB_SYS_COPYAREA
> -       select FB_SYS_IMAGEBLIT
>         select FRAMEBUFFER_CONSOLE if !EXPERT
>         select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
>         default y
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 8724e08c518b..ba0a808f14ee 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -729,113 +729,6 @@ void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagerefli
>  }
>  EXPORT_SYMBOL(drm_fb_helper_deferred_io);
>
> -/**
> - * drm_fb_helper_sys_read - Implements struct &fb_ops.fb_read for system memory
> - * @info: fb_info struct pointer
> - * @buf: userspace buffer to read from framebuffer memory
> - * @count: number of bytes to read from framebuffer memory
> - * @ppos: read offset within framebuffer memory
> - *
> - * Returns:
> - * The number of bytes read on success, or an error code otherwise.
> - */
> -ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
> -                              size_t count, loff_t *ppos)
> -{
> -       return fb_sys_read(info, buf, count, ppos);
> -}
> -EXPORT_SYMBOL(drm_fb_helper_sys_read);
> -
> -/**
> - * drm_fb_helper_sys_write - Implements struct &fb_ops.fb_write for system memory
> - * @info: fb_info struct pointer
> - * @buf: userspace buffer to write to framebuffer memory
> - * @count: number of bytes to write to framebuffer memory
> - * @ppos: write offset within framebuffer memory
> - *
> - * Returns:
> - * The number of bytes written on success, or an error code otherwise.
> - */
> -ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
> -                               size_t count, loff_t *ppos)
> -{
> -       struct drm_fb_helper *helper = info->par;
> -       loff_t pos = *ppos;
> -       ssize_t ret;
> -       struct drm_rect damage_area;
> -
> -       ret = fb_sys_write(info, buf, count, ppos);
> -       if (ret <= 0)
> -               return ret;
> -
> -       if (helper->funcs->fb_dirty) {
> -               drm_fb_helper_memory_range_to_clip(info, pos, ret, &damage_area);
> -               drm_fb_helper_damage(helper, damage_area.x1, damage_area.y1,
> -                                    drm_rect_width(&damage_area),
> -                                    drm_rect_height(&damage_area));
> -       }
> -
> -       return ret;
> -}
> -EXPORT_SYMBOL(drm_fb_helper_sys_write);
> -
> -/**
> - * drm_fb_helper_sys_fillrect - wrapper around sys_fillrect
> - * @info: fbdev registered by the helper
> - * @rect: info about rectangle to fill
> - *
> - * A wrapper around sys_fillrect implemented by fbdev core
> - */
> -void drm_fb_helper_sys_fillrect(struct fb_info *info,
> -                               const struct fb_fillrect *rect)
> -{
> -       struct drm_fb_helper *helper = info->par;
> -
> -       sys_fillrect(info, rect);
> -
> -       if (helper->funcs->fb_dirty)
> -               drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
> -}
> -EXPORT_SYMBOL(drm_fb_helper_sys_fillrect);
> -
> -/**
> - * drm_fb_helper_sys_copyarea - wrapper around sys_copyarea
> - * @info: fbdev registered by the helper
> - * @area: info about area to copy
> - *
> - * A wrapper around sys_copyarea implemented by fbdev core
> - */
> -void drm_fb_helper_sys_copyarea(struct fb_info *info,
> -                               const struct fb_copyarea *area)
> -{
> -       struct drm_fb_helper *helper = info->par;
> -
> -       sys_copyarea(info, area);
> -
> -       if (helper->funcs->fb_dirty)
> -               drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
> -}
> -EXPORT_SYMBOL(drm_fb_helper_sys_copyarea);
> -
> -/**
> - * drm_fb_helper_sys_imageblit - wrapper around sys_imageblit
> - * @info: fbdev registered by the helper
> - * @image: info about image to blit
> - *
> - * A wrapper around sys_imageblit implemented by fbdev core
> - */
> -void drm_fb_helper_sys_imageblit(struct fb_info *info,
> -                                const struct fb_image *image)
> -{
> -       struct drm_fb_helper *helper = info->par;
> -
> -       sys_imageblit(info, image);
> -
> -       if (helper->funcs->fb_dirty)
> -               drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
> -}
> -EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
> -
>  /**
>   * drm_fb_helper_cfb_read - Implements struct &fb_ops.fb_read for I/O memory
>   * @info: fb_info struct pointer
> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
> index 8e5148bf40bb..f53fc49e34a4 100644
> --- a/drivers/gpu/drm/drm_fbdev_generic.c
> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
> @@ -34,6 +34,43 @@ static int drm_fbdev_generic_fb_release(struct fb_info *info, int user)
>         return 0;
>  }
>
> +static ssize_t drm_fbdev_generic_fb_write(struct fb_info *info, const char __user *buf,
> +                                         size_t count, loff_t *ppos)
> +{
> +       struct drm_fb_helper *helper = info->par;
> +       loff_t pos = *ppos;
> +       ssize_t ret;
> +
> +       ret = fb_sys_write(info, buf, count, ppos);
> +       if (ret > 0)
> +               drm_fb_helper_damage_range(helper, pos, ret);
> +       return ret;
> +}
> +
> +static void drm_fbdev_generic_fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
> +{
> +       struct drm_fb_helper *helper = info->par;
> +
> +       sys_fillrect(info, rect);
> +       drm_fb_helper_damage(helper, rect->dx, rect->dy, rect->width, rect->height);
> +}
> +
> +static void drm_fbdev_generic_fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
> +{
> +       struct drm_fb_helper *helper = info->par;
> +
> +       sys_copyarea(info, area);
> +       drm_fb_helper_damage(helper, area->dx, area->dy, area->width, area->height);
> +}
> +
> +static void drm_fbdev_generic_fb_imageblit(struct fb_info *info, const struct fb_image *image)
> +{
> +       struct drm_fb_helper *helper = info->par;
> +
> +       sys_imageblit(info, image);
> +       drm_fb_helper_damage(helper, image->dx, image->dy, image->width, image->height);
> +}
> +
>  static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
>  {
>         struct drm_fb_helper *fb_helper = info->par;
> @@ -56,12 +93,12 @@ static const struct fb_ops drm_fbdev_generic_fb_ops = {
>         .owner          = THIS_MODULE,
>         .fb_open        = drm_fbdev_generic_fb_open,
>         .fb_release     = drm_fbdev_generic_fb_release,
> -       .fb_read        = drm_fb_helper_sys_read,
> -       .fb_write       = drm_fb_helper_sys_write,
> +       .fb_read        = fb_sys_read,
> +       .fb_write       = drm_fbdev_generic_fb_write,
>         DRM_FB_HELPER_DEFAULT_OPS,
> -       .fb_fillrect    = drm_fb_helper_sys_fillrect,
> -       .fb_copyarea    = drm_fb_helper_sys_copyarea,
> -       .fb_imageblit   = drm_fb_helper_sys_imageblit,
> +       .fb_fillrect    = drm_fbdev_generic_fb_fillrect,
> +       .fb_copyarea    = drm_fbdev_generic_fb_copyarea,
> +       .fb_imageblit   = drm_fbdev_generic_fb_imageblit,
>         .fb_mmap        = fb_deferred_io_mmap,
>         .fb_destroy     = drm_fbdev_generic_fb_destroy,
>  };
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index 80c402f4e379..e3240d749a43 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -259,18 +259,6 @@ void drm_fb_helper_damage_range(struct drm_fb_helper *helper, off_t off, size_t
>
>  void drm_fb_helper_deferred_io(struct fb_info *info, struct list_head *pagereflist);
>
> -ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf,
> -                              size_t count, loff_t *ppos);
> -ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf,
> -                               size_t count, loff_t *ppos);
> -
> -void drm_fb_helper_sys_fillrect(struct fb_info *info,
> -                               const struct fb_fillrect *rect);
> -void drm_fb_helper_sys_copyarea(struct fb_info *info,
> -                               const struct fb_copyarea *area);
> -void drm_fb_helper_sys_imageblit(struct fb_info *info,
> -                                const struct fb_image *image);
> -
>  ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
>                                size_t count, loff_t *ppos);
>  ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user *buf,
> @@ -398,35 +386,6 @@ static inline int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper)
>         return -ENODEV;
>  }
>
> -static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info,
> -                                            char __user *buf, size_t count,
> -                                            loff_t *ppos)
> -{
> -       return -ENODEV;
> -}
> -
> -static inline ssize_t drm_fb_helper_sys_write(struct fb_info *info,
> -                                             const char __user *buf,
> -                                             size_t count, loff_t *ppos)
> -{
> -       return -ENODEV;
> -}
> -
> -static inline void drm_fb_helper_sys_fillrect(struct fb_info *info,
> -                                             const struct fb_fillrect *rect)
> -{
> -}
> -
> -static inline void drm_fb_helper_sys_copyarea(struct fb_info *info,
> -                                             const struct fb_copyarea *area)
> -{
> -}
> -
> -static inline void drm_fb_helper_sys_imageblit(struct fb_info *info,
> -                                              const struct fb_image *image)
> -{
> -}
> -
>  static inline ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
>                                              size_t count, loff_t *ppos)
>  {
> --
> 2.40.1
>


-- 
With best wishes
Dmitry


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