Re: [PATCH v2] RFC: framebuffer: provide generic get_fb_unmapped_area

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

On Mon, Feb 03, 2014 at 06:14:44PM +0100, Uwe Kleine-König wrote:
> This patch makes mmapping the simple-framebuffer device work on a no-MMU
> ARM target. The code is mostly taken from
> arch/blackfin/kernel/sys_bfin.c.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> Hello,
> 
> note this is only tested on this no-MMU machine and I don't know enough
> about framebuffers and mm to decide if this patch is sane. Also I'm
> a bit unsure about the size check, I just believed Geert that
> PAGE_ALIGN(info->fix.smem_len) is the right value to check against.
Do you still have this patch on your radar?

Best regards
Uwe

>  drivers/video/fbmem.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
> index 7309ac704e26..d0ccedafec8c 100644
> --- a/drivers/video/fbmem.c
> +++ b/drivers/video/fbmem.c
> @@ -1491,6 +1491,22 @@ __releases(&info->lock)
>  	return 0;
>  }
>  
> +#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
> +#define fb_get_unmapped_area get_fb_unmapped_area
> +#else
> +unsigned long fb_get_unmapped_area(struct file *filp, unsigned long orig_addr,
> +		unsigned long len, unsigned long pgoff, unsigned long flags)
> +{
> +	struct fb_info * const info = filp->private_data;
> +	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
> +
> +	if (pgoff > fb_size || len > fb_size - pgoff)
> +		return -EINVAL;
> +
> +	return (unsigned long)info->screen_base + pgoff;
> +}
> +#endif
> +
>  static const struct file_operations fb_fops = {
>  	.owner =	THIS_MODULE,
>  	.read =		fb_read,
> @@ -1502,9 +1518,7 @@ static const struct file_operations fb_fops = {
>  	.mmap =		fb_mmap,
>  	.open =		fb_open,
>  	.release =	fb_release,
> -#ifdef HAVE_ARCH_FB_UNMAPPED_AREA
> -	.get_unmapped_area = get_fb_unmapped_area,
> -#endif
> +	.get_unmapped_area = fb_get_unmapped_area,
>  #ifdef CONFIG_FB_DEFERRED_IO
>  	.fsync =	fb_deferred_io_fsync,
>  #endif
> -- 
> 1.8.5.2
> 
> 

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |