Re: [PATCH RESEND] drm/via: use get_user_pages_unlocked()

[Daniel Vetter]

On Mon, Feb 27, 2017 at 09:50:08PM +0000, Lorenzo Stoakes wrote:
> Moving from get_user_pages() to get_user_pages_unlocked() simplifies the code
> and takes advantage of VM_FAULT_RETRY functionality when faulting in pages.
> 
> Signed-off-by: Lorenzo Stoakes <lstoa...@gmail.com>

Queued for 4.12, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/via/via_dmablit.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/via/via_dmablit.c 
> b/drivers/gpu/drm/via/via_dmablit.c
> index 1a3ad769f8c8..98aae9809249 100644
> --- a/drivers/gpu/drm/via/via_dmablit.c
> +++ b/drivers/gpu/drm/via/via_dmablit.c
> @@ -238,13 +238,9 @@ via_lock_all_dma_pages(drm_via_sg_info_t *vsg,  
> drm_via_dmablit_t *xfer)
>       vsg->pages = vzalloc(sizeof(struct page *) * vsg->num_pages);
>       if (NULL == vsg->pages)
>               return -ENOMEM;
> -     down_read(&current->mm->mmap_sem);
> -     ret = get_user_pages((unsigned long)xfer->mem_addr,
> -                          vsg->num_pages,
> -                          (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 
> 0,
> -                          vsg->pages, NULL);
> -
> -     up_read(&current->mm->mmap_sem);
> +     ret = get_user_pages_unlocked((unsigned long)xfer->mem_addr,
> +                     vsg->num_pages, vsg->pages,
> +                     (vsg->direction == DMA_FROM_DEVICE) ? FOLL_WRITE : 0);
>       if (ret != vsg->num_pages) {
>               if (ret < 0)
>                       return ret;
> -- 
> 2.11.1
> 

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