[PATCH 02/13] drm/exynos: Use FOLL_LONGTERM for g2d cmdlists

[John Hubbard]

On 10/7/20 9:44 AM, Daniel Vetter wrote:
> The exynos g2d interface is very unusual, but it looks like the
> userptr objects are persistent. Hence they need FOLL_LONGTERM.
> 
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Jason Gunthorpe <jgg at ziepe.ca>
> Cc: Inki Dae <inki.dae at samsung.com>
> Cc: Joonyoung Shim <jy0922.shim at samsung.com>
> Cc: Seung-Woo Kim <sw0312.kim at samsung.com>
> Cc: Kyungmin Park <kyungmin.park at samsung.com>
> Cc: Kukjin Kim <kgene at kernel.org>
> Cc: Krzysztof Kozlowski <krzk at kernel.org>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: John Hubbard <jhubbard at nvidia.com>
> Cc: Jérôme Glisse <jglisse at redhat.com>
> Cc: Jan Kara <jack at suse.cz>
> Cc: Dan Williams <dan.j.williams at intel.com>
> Cc: linux-mm at kvack.org
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-samsung-soc at vger.kernel.org
> Cc: linux-media at vger.kernel.org
> ---
>   drivers/gpu/drm/exynos/exynos_drm_g2d.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> index c83f6faac9de..514fd000feb1 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> @@ -478,7 +478,8 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct g2d_data *g2d,
>   		goto err_free;
>   	}
>   
> -	ret = pin_user_pages_fast(start, npages, FOLL_FORCE | FOLL_WRITE,
> +	ret = pin_user_pages_fast(start, npages,
> +				  FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
>   				  g2d_userptr->pages);
>   	if (ret != npages) {
>   		DRM_DEV_ERROR(g2d->dev,
> 

Looks good from a pin_user_pages_fast() point of view. I'm of course not a exynos
developer, so we still need a look from one of those, ideally, but:

Reviewed-by: John Hubbard <jhubbard at nvidia.com>

thanks,
-- 
John Hubbard
NVIDIA