[PATCH 6/7] drm/exynos: Add exynos drm specific fb_mmap function

[Inki Dae]

> -----Original Message-----
> From: Prathyush K [mailto:prathyush.k at samsung.com]
> Sent: Wednesday, July 11, 2012 6:40 PM
> To: dri-devel at lists.freedesktop.org
> Cc: prathyush at chromium.org; m.szyprowski at samsung.com;
inki.dae at samsung.com;
> subash.ramaswamy at linaro.org
> Subject: [PATCH 6/7] drm/exynos: Add exynos drm specific fb_mmap function
> 
> This patch adds a exynos drm specific implementation of fb_mmap
> which supports mapping a non-contiguous buffer to user space.
> This new function does not assume that the frame buffer is contiguous
> and calls dma_mmap_writecombine for mapping the buffer to user space.
> dma_mmap_writecombine will be able to map a contiguous buffer as well
> as non-contig buffer depending on whether an IOMMU mapping is created
> for drm or not.
> 
> Signed-off-by: Prathyush K <prathyush.k at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c |   16 ++++++++++++++++
>  1 files changed, 16 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index d5586cc..b53e638 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -46,8 +46,24 @@ struct exynos_drm_fbdev {
>  	struct exynos_drm_gem_obj	*exynos_gem_obj;
>  };
> 
> +static int exynos_drm_fb_mmap(struct fb_info *info,
> +			      struct vm_area_struct *vma)
> +{
> +	if ((vma->vm_end - vma->vm_start) > info->fix.smem_len)
> +		return -EINVAL;
> +
> +	vma->vm_pgoff = 0;
> +	vma->vm_flags |= VM_IO | VM_RESERVED;
> +	if (dma_mmap_writecombine(info->device, vma, info->screen_base,
> +			info->fix.smem_start, vma->vm_end - vma->vm_start))
> +		return -EAGAIN;
> +
> +	return 0;
> +}
> +

Ok, it's good feature. actually the physically non-contiguous gem buffer
allocated for console framebuffer has to be mapped with user space.

Thanks.

>  static struct fb_ops exynos_drm_fb_ops = {
>  	.owner		= THIS_MODULE,
> +	.fb_mmap	= exynos_drm_fb_mmap,
>  	.fb_fillrect	= cfb_fillrect,
>  	.fb_copyarea	= cfb_copyarea,
>  	.fb_imageblit	= cfb_imageblit,
> --
> 1.7.0.4