Re: [Intel-gfx] [PATCH v5 02/13] fbdev: Add initializer macros for struct fb_ops

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 30.05.23 um 17:02 schrieb Thomas Zimmermann:
> For framebuffers in I/O and system memory, add macros that set
> struct fb_ops to the respective callback functions.
>
> For deferred I/O, add macros that generate callback functions with
> damage handling. Add initializer macros that set struct fb_ops to
> the generated callbacks.
>
> These macros can remove a lot boilerplate code from fbdev drivers.
> The drivers are supposed to use the macro that is required for its
> framebuffer. Each macro is split into smaller helpers, so that
> drivers with non-standard callbacks can pick and customize callbacks
> as needed. There are individual helper macros for read/write, mmap
> and drawing.
>
> v5:
> 	* fix whitespace errors (Jingfeng)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> ---
>   include/linux/fb.h | 112 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 112 insertions(+)
>
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index 2cf8efcb9e32..ce6823e157e6 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -538,9 +538,31 @@ extern ssize_t fb_io_read(struct fb_info *info, char __user *buf,
>   extern ssize_t fb_io_write(struct fb_info *info, const char __user *buf,
>   			   size_t count, loff_t *ppos);
>   
> +/*
> + * Initializes struct fb_ops for framebuffers in I/O memory.
> + */
> +
> +#define __FB_DEFAULT_IO_OPS_RDWR \
> +	.fb_read	= fb_io_read, \
> +	.fb_write	= fb_io_write
> +
> +#define __FB_DEFAULT_IO_OPS_DRAW \
> +	.fb_fillrect	= cfb_fillrect, \
> +	.fb_copyarea	= cfb_copyarea, \
> +	.fb_imageblit	= cfb_imageblit
> +
> +#define __FB_DEFAULT_IO_OPS_MMAP \
> +	.fb_mmap	= NULL // default implementation

// style comment in a macro? That's usually a very bad idea.

Christian.

> +
> +#define FB_DEFAULT_IO_OPS \
> +	__FB_DEFAULT_IO_OPS_RDWR, \
> +	__FB_DEFAULT_IO_OPS_DRAW, \
> +	__FB_DEFAULT_IO_OPS_MMAP
> +
>   /*
>    * Drawing operations where framebuffer is in system RAM
>    */
> +
>   extern void sys_fillrect(struct fb_info *info, const struct fb_fillrect *rect);
>   extern void sys_copyarea(struct fb_info *info, const struct fb_copyarea *area);
>   extern void sys_imageblit(struct fb_info *info, const struct fb_image *image);
> @@ -549,6 +571,27 @@ extern ssize_t fb_sys_read(struct fb_info *info, char __user *buf,
>   extern ssize_t fb_sys_write(struct fb_info *info, const char __user *buf,
>   			    size_t count, loff_t *ppos);
>   
> +/*
> + * Initializes struct fb_ops for framebuffers in system memory.
> + */
> +
> +#define __FB_DEFAULT_SYS_OPS_RDWR \
> +	.fb_read	= fb_sys_read, \
> +	.fb_write	= fb_sys_write
> +
> +#define __FB_DEFAULT_SYS_OPS_DRAW \
> +	.fb_fillrect	= sys_fillrect, \
> +	.fb_copyarea	= sys_copyarea, \
> +	.fb_imageblit	= sys_imageblit
> +
> +#define __FB_DEFAULT_SYS_OPS_MMAP \
> +	.fb_mmap	= NULL // default implementation
> +
> +#define FB_DEFAULT_SYS_OPS \
> +	__FB_DEFAULT_SYS_OPS_RDWR, \
> +	__FB_DEFAULT_SYS_OPS_DRAW, \
> +	__FB_DEFAULT_SYS_OPS_MMAP
> +
>   /* drivers/video/fbmem.c */
>   extern int register_framebuffer(struct fb_info *fb_info);
>   extern void unregister_framebuffer(struct fb_info *fb_info);
> @@ -604,6 +647,75 @@ extern void fb_deferred_io_cleanup(struct fb_info *info);
>   extern int fb_deferred_io_fsync(struct file *file, loff_t start,
>   				loff_t end, int datasync);
>   
> +/*
> + * Generate callbacks for deferred I/O
> + */
> +
> +#define __FB_GEN_DEFAULT_DEFERRED_OPS_RDWR(__prefix, __damage_range, __mode) \
> +	static ssize_t __prefix ## _defio_read(struct fb_info *info, char __user *buf, \
> +					       size_t count, loff_t *ppos) \
> +	{ \
> +		return fb_ ## __mode ## _read(info, buf, count, ppos); \
> +	} \
> +	static ssize_t __prefix ## _defio_write(struct fb_info *info, const char __user *buf, \
> +						size_t count, loff_t *ppos) \
> +	{ \
> +		unsigned long offset = *ppos; \
> +		ssize_t ret = fb_ ## __mode ## _write(info, buf, count, ppos); \
> +		if (ret > 0) \
> +			__damage_range(info, offset, ret); \
> +		return ret; \
> +	}
> +
> +#define __FB_GEN_DEFAULT_DEFERRED_OPS_DRAW(__prefix, __damage_area, __mode) \
> +	static void __prefix ## _defio_fillrect(struct fb_info *info, \
> +						const struct fb_fillrect *rect) \
> +	{ \
> +		__mode ## _fillrect(info, rect); \
> +		__damage_area(info, rect->dx, rect->dy, rect->width, rect->height); \
> +	} \
> +	static void __prefix ## _defio_copyarea(struct fb_info *info, \
> +						const struct fb_copyarea *area) \
> +	{ \
> +		__mode ## _copyarea(info, area); \
> +		__damage_area(info, area->dx, area->dy, area->width, area->height); \
> +	} \
> +	static void __prefix ## _defio_imageblit(struct fb_info *info, \
> +						 const struct fb_image *image) \
> +	{ \
> +		__mode ## _imageblit(info, image); \
> +		__damage_area(info, image->dx, image->dy, image->width, image->height); \
> +	}
> +
> +#define FB_GEN_DEFAULT_DEFERRED_IO_OPS(__prefix, __damage_range, __damage_area) \
> +	__FB_GEN_DEFAULT_DEFERRED_OPS_RDWR(__prefix, __damage_range, io) \
> +	__FB_GEN_DEFAULT_DEFERRED_OPS_DRAW(__prefix, __damage_area, cfb)
> +
> +#define FB_GEN_DEFAULT_DEFERRED_SYS_OPS(__prefix, __damage_range, __damage_area) \
> +	__FB_GEN_DEFAULT_DEFERRED_OPS_RDWR(__prefix, __damage_range, sys) \
> +	__FB_GEN_DEFAULT_DEFERRED_OPS_DRAW(__prefix, __damage_area, sys)
> +
> +/*
> + * Initializes struct fb_ops for deferred I/O.
> + */
> +
> +#define __FB_DEFAULT_DEFERRED_OPS_RDWR(__prefix) \
> +	.fb_read	= __prefix ## _defio_read, \
> +	.fb_write	= __prefix ## _defio_write
> +
> +#define __FB_DEFAULT_DEFERRED_OPS_DRAW(__prefix) \
> +	.fb_fillrect	= __prefix ## _defio_fillrect, \
> +	.fb_copyarea	= __prefix ## _defio_copyarea, \
> +	.fb_imageblit	= __prefix ## _defio_imageblit
> +
> +#define __FB_DEFAULT_DEFERRED_OPS_MMAP(__prefix) \
> +	.fb_mmap	= fb_deferred_io_mmap
> +
> +#define FB_DEFAULT_DEFERRED_OPS(__prefix) \
> +	__FB_DEFAULT_DEFERRED_OPS_RDWR(__prefix), \
> +	__FB_DEFAULT_DEFERRED_OPS_DRAW(__prefix), \
> +	__FB_DEFAULT_DEFERRED_OPS_MMAP(__prefix)
> +
>   static inline bool fb_be_math(struct fb_info *info)
>   {
>   #ifdef CONFIG_FB_FOREIGN_ENDIAN