[PATCH 1/3] drm: add func to get max iomem address

[Christian König]

Am 08.02.2018 um 09:32 schrieb Chunming Zhou:
> it will be used to check if the driver needs swiotlb
>
> Change-Id: Idbe47af8f12032d4803bb3d47273e807f19169c3
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> Reviewed-by: Monk Liu <monk.liu at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com> for the whole 
series.

> ---
>   include/drm/drm_cache.h | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/include/drm/drm_cache.h b/include/drm/drm_cache.h
> index beab0f0d0cfb..442c9ba63d03 100644
> --- a/include/drm/drm_cache.h
> +++ b/include/drm/drm_cache.h
> @@ -39,6 +39,19 @@ void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
>   void drm_clflush_sg(struct sg_table *st);
>   void drm_clflush_virt_range(void *addr, unsigned long length);
>   
> +static inline u64 drm_get_max_iomem(void)
> +{
> +	struct resource *tmp;
> +	u64 max_iomem = 0;
> +
> +	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
> +		max_iomem = max(max_iomem,  tmp->end);
> +	}
> +
> +	return max_iomem;
> +}
> +
> +
>   static inline bool drm_arch_can_wc_memory(void)
>   {
>   #if defined(CONFIG_PPC) && !defined(CONFIG_NOT_COHERENT_CACHE)