Re: [PATCH 06/21] iommu/io-pgtable-arm-v7s: Use ias to check the valid iova in unmap

[Yong Wu]

On Mon, 2020-07-13 at 08:38 +0800, Nicolas Boichat wrote:
> On Sat, Jul 11, 2020 at 2:50 PM Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
> >
> > As title.
> >
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> >  drivers/iommu/io-pgtable-arm-v7s.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
> > index 4272fe4e17f4..01f2a8876808 100644
> > --- a/drivers/iommu/io-pgtable-arm-v7s.c
> > +++ b/drivers/iommu/io-pgtable-arm-v7s.c
> > @@ -717,7 +717,7 @@ static size_t arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova,
> >  {
> >         struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
> >
> > -       if (WARN_ON(upper_32_bits(iova)))
> > +       if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
> 
> This is a little odd as iova is unsigned long and 1ULL is unsigned long long.
> 
> Would it be better to keep the spirit of the previous test and do
> something like:
>  if (WARN_ON(iova >> data->iop.cfg.ias)) ?

Yes. Thanks. I will change it like this in next version.

Also change this in arm_v7s_map by the way.

> 
> >                 return 0;
> >
> >         return __arm_v7s_unmap(data, gather, iova, size, 1, data->pgd);
> > --
> > 2.18.0