[v4,12/13] drm/fbdev-generic: Implement dedicated fbdev I/O helpers
Thomas Zimmermann
tzimmermann at suse.de
Fri May 26 12:44:13 UTC 2023
Hi
Am 24.05.23 um 22:23 schrieb Sui Jingfeng:
> Tested-by: Sui Jingfeng <suijingfeng at loongson.cn>
>
>
> This version works fine, I have tested it On LoongArch with
> drm/loongson(v14) as it is most handy for me.
>
> Also because it using fbdev-generic. fbdev of IGT report no error. Then
> I run fbtest from geert[1],
>
>
> Before apply your patch:
>
>
> Benchmarking... 10x10 squares: 468.39 Mpixels/s
> Benchmarking... 20x20 squares: 985.02 Mpixels/s
> Benchmarking... 50x50 squares: 2247.22 Mpixels/s
> Benchmarking... 100x100 squares: 2242.30 Mpixels/s
> Benchmarking... 200x200 squares: 2883.18 Mpixels/s
> Benchmarking... 500x500 squares: 3642.18 Mpixels/s
> Benchmarking... 1000x1000 squares: 3992.77 Mpixels/s
> Benchmarking... R5 circles: 261.90 Mpixels/s
> Benchmarking... R10 circles: 596.27 Mpixels/s
> Benchmarking... R25 circles: 1513.96 Mpixels/s
> Benchmarking... R50 circles: 1965.07 Mpixels/s
> Benchmarking... R100 circles: 2470.75 Mpixels/s
> Benchmarking... R250 circles: 3288.00 Mpixels/s
> Benchmarking... R500 circles: 3705.66 Mpixels/s
>
>
> After apply your patch:
>
>
> Benchmarking... 10x10 squares: 477.04 Mpixels/s
> Benchmarking... 20x20 squares: 1021.07 Mpixels/s
> Benchmarking... 50x50 squares: 2315.70 Mpixels/s
> Benchmarking... 100x100 squares: 2267.69 Mpixels/s
> Benchmarking... 200x200 squares: 3006.28 Mpixels/s
> Benchmarking... 500x500 squares: 3761.44 Mpixels/s
> Benchmarking... 1000x1000 squares: 4112.49 Mpixels/s
> Benchmarking... R5 circles: 269.19 Mpixels/s
> Benchmarking... R10 circles: 620.77 Mpixels/s
> Benchmarking... R25 circles: 1559.02 Mpixels/s
> Benchmarking... R50 circles: 2027.36 Mpixels/s
> Benchmarking... R100 circles: 2574.42 Mpixels/s
> Benchmarking... R250 circles: 3363.28 Mpixels/s
> Benchmarking... R500 circles: 3815.51 Mpixels/s
>
>
> It seems that this bring a little bit performance gain.
Thanks for testing. I can't really tell why the code is now faster. All
the patch really does is to eliminate an intermediate cross-module
function call and the pointer derefs. This, apparently, already has an
impact.
Best regards
Thomas
>
> Directly operate on video RAM is slower than have a shadow in system RAM.
>
> I also test this patch in intel i3-8100 @ 3.6Ghz, the results show that
> i915 is a bit slower.
>
> Because it operate directly on device memory.
>
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/geert/fbtest.git
>
>
> On 2023/5/24 17:21, Thomas Zimmermann wrote:
>> Implement dedicated fbdev helpers for framebuffer I/O instead
>> of using DRM's helpers. Use an fbdev generator macro for
>> deferred I/O to create the callbacks. Fbdev-generic was the
>> only caller of the DRM helpers, so remove them from the helper
>> module.
>>
>> v4:
>> * generate deferred-I/O helpers
>> * use initializer macros for fb_ops
>> 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 | 11 ++-
>> include/drm/drm_fb_helper.h | 41 -----------
>> 4 files changed, 6 insertions(+), 159 deletions(-)
>>
>> 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 cb03099fd2e3..bab6b252f02a 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -736,113 +736,6 @@ 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..98ae703848a0 100644
>> --- a/drivers/gpu/drm/drm_fbdev_generic.c
>> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
>> @@ -34,6 +34,10 @@ static int drm_fbdev_generic_fb_release(struct
>> fb_info *info, int user)
>> return 0;
>> }
>> +FB_GEN_DEFAULT_DEFERRED_SYS_OPS(drm_fbdev_generic,
>> + drm_fb_helper_damage_range,
>> + drm_fb_helper_damage_area);
>> +
>> static void drm_fbdev_generic_fb_destroy(struct fb_info *info)
>> {
>> struct drm_fb_helper *fb_helper = info->par;
>> @@ -56,13 +60,8 @@ 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_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),
>> 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_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 7d5804882be7..b50fd0c0b713 100644
>> --- a/include/drm/drm_fb_helper.h
>> +++ b/include/drm/drm_fb_helper.h
>> @@ -258,18 +258,6 @@ void drm_fb_helper_damage_area(struct fb_info
>> *info, u32 x, u32 y, u32 width, u3
>> 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,
>> @@ -397,35 +385,6 @@ 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)
>> {
--
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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