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

Thomas Zimmermann tzimmermann at suse.de
Mon May 22 11:46:35 PDT 2023


Hi

Am 22.05.23 um 15:20 schrieb Dmitry Baryshkov:
> 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()).

I think so. You'd need something similar to the generic fbdev emulation. 
But it's for a separate patchset. Apparently no one has complained so far.

Best regards
Thomas

> 
>>
>> 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
>>
> 
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
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