drm/via: use get_user_pages_unlocked()

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 <lstoakes@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170227215008.21457-1-lstoakes@gmail.com

diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c
index 1a3ad76..98aae98 100644 (file)
--- 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;