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

[Oleksandr Andrushchenko]

On 11/19/18 12:42 PM, Souptick Joarder wrote:
> 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.

I used "ret" throughout the driver, so this is just to remain consistent:

grep -rnw err drivers/gpu/drm/xen/ | wc -l
0
grep -rnw ret drivers/gpu/drm/xen/ | wc -l
204

> > >        /*
> > >         * 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>