drm/xen/xen_drm_front_gem.c: convert to use vm_map_pages()

Convert to use vm_map_pages() to map range of kernel memory to user vma.

Link: http://lkml.kernel.org/r/ff8e10ba778d79419c66ee8215bccf01560540fd.1552921225.git.jrdr.linux@gmail.comSigned-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/xen/xen_drm_front_gem.c

@@ -224,8 +224,7 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
 static int gem_mmap_obj(struct xen_gem_object *xen_obj,
 			struct vm_area_struct *vma)
 {
-	unsigned long addr = vma->vm_start;
-	int i;
+	int ret;
 
 	/*
 	 * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
@@ -252,18 +251,11 @@ static int gem_mmap_obj(struct xen_gem_object *xen_obj,
 	 * FIXME: as we insert all the pages now then no .fault handler must
 	 * be called, so don't provide one
 	 */
-	for (i = 0; i < xen_obj->num_pages; i++) {
-		int ret;
+	ret = vm_map_pages(vma, xen_obj->pages, xen_obj->num_pages);
+	if (ret < 0)
+		DRM_ERROR("Failed to map pages into vma: %d\n", ret);
 
-		ret = vm_insert_page(vma, addr, xen_obj->pages[i]);
-		if (ret < 0) {
-			DRM_ERROR("Failed to insert pages into vma: %d\n", ret);
 	return ret;
-		}
-
-		addr += PAGE_SIZE;
-	}
-	return 0;
 }
 
 int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)