Re: [PATCH 19/28] gpu/drm: remove the powerpc hack in drm_legacy_sg_alloc

[Daniel Vetter]

On Wed, Apr 08, 2020 at 01:59:17PM +0200, Christoph Hellwig wrote:
> If this code was broken for non-coherent caches a crude powerpc hack
> isn't going to help anyone else.  Remove the hack as it is the last
> user of __vmalloc passing a page protection flag other than PAGE_KERNEL.

Well Ben added this to make stuff work on ppc, ofc the home grown dma
layer in drm from back then isn't going to work in other places. I guess
should have at least an ack from him, in case anyone still cares about
this on ppc. Adding Ben to cc.
-Daniel

> 
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
>  drivers/gpu/drm/drm_scatter.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c
> index ca520028b2cb..f4e6184d1877 100644
> --- a/drivers/gpu/drm/drm_scatter.c
> +++ b/drivers/gpu/drm/drm_scatter.c
> @@ -43,15 +43,6 @@
>  
>  #define DEBUG_SCATTER 0
>  
> -static inline void *drm_vmalloc_dma(unsigned long size)
> -{
> -#if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE)
> -	return __vmalloc(size, GFP_KERNEL, pgprot_noncached_wc(PAGE_KERNEL));
> -#else
> -	return vmalloc_32(size);
> -#endif
> -}
> -
>  static void drm_sg_cleanup(struct drm_sg_mem * entry)
>  {
>  	struct page *page;
> @@ -126,7 +117,7 @@ int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
>  		return -ENOMEM;
>  	}
>  
> -	entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT);
> +	entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
>  	if (!entry->virtual) {
>  		kfree(entry->busaddr);
>  		kfree(entry->pagelist);
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch