Re: [Xen-devel] [PATCH 5/9] drm/xen/xen_drm_front_gem.c: Convert to use vm_insert_range

[Souptick Joarder]

On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
<andr2000@xxxxxxxxx> wrote:
>
> On 11/15/18 5:49 PM, Souptick Joarder wrote:
> > Convert to use vm_insert_range() to map range of kernel
> > memory to user vma.
> >
> > Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
> > Reviewed-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/xen/xen_drm_front_gem.c | 20 ++++++--------------
> >   1 file changed, 6 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > index 47ff019..a3eade6 100644
> > --- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
> > @@ -225,8 +225,7 @@ struct drm_gem_object *
> >   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 err;
> I would love to keep ret, not err

Sure, will add it in v2.
But I think, err is more appropriate here.

> >
> >       /*
> >        * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
> > @@ -247,18 +246,11 @@ 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_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;
> > +     err = vm_insert_range(vma, vma->vm_start, xen_obj->pages,
> > +                             xen_obj->num_pages);
> > +     if (err < 0)
> > +             DRM_ERROR("Failed to insert pages into vma: %d\n", err);
> > +     return err;
> >   }
> >
> >   int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>
> With the above fixed,
>
> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
>