Hello Alexey, thanks for the feedback!
On Tue, 2020-09-29 at 13:57 +1000, Alexey Kardashevskiy wrote:
>
> On 12/09/2020 03:07, Leonardo Bras wrote:
> > diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> > index ffb2637dc82b..c838da3d8f32 100644
> > --- a/arch/powerpc/kernel/iommu.c
> > +++ b/arch/powerpc/kernel/iommu.c
> > @@ -655,34 +655,21 @@ static void iommu_table_reserve_pages(struct
> > iommu_table *tbl,
> > if (tbl->it_offset == 0)
> > set_bit(0, tbl->it_map);
> >
> >
> >
> >
> > + /* Check if res_start..res_end is a valid range in the table */
> > + if (res_start >= res_end || res_start < tbl->it_offset ||
> > + res_end > (tbl->it_offset + tbl->it_size)) {
> > + tbl->it_reserved_start = tbl->it_offset;
> > + tbl->it_reserved_end = tbl->it_offset;
>
>
> This silently ignores overlapped range of the reserved area and the
> window which does not seem right.
Humm, that makes sense.
Would it be better to do something like this?
if (res_start < tbl->it_offset)
res_start = tbl->it_offset;
if (res_end > (tbl->it_offset + tbl->it_size))
res_end = tbl->it_offset + tbl->it_size;
if (res_start >= res_end) {
tbl->it_reserved_start = tbl->it_offset;
tbl->it_reserved_end = tbl->it_offset;
return;
}
> > + return;
> > + }
> > +
> > tbl->it_reserved_start = res_start;
> > tbl->it_reserved_end = res_end;
> > - /* Check if res_start..res_end isn't empty and overlaps the table */
> > - if (res_start && res_end &&
> > - (tbl->it_offset + tbl->it_size < res_start ||
> > - res_end < tbl->it_offset))
> > - return;
> > -
> > for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
> > set_bit(i - tbl->it_offset, tbl->it_map);
> > }
> > +bool iommu_table_in_use(struct iommu_table *tbl)
> > +{
> > + unsigned long start = 0, end;
> > +
> > + /* ignore reserved bit0 */
> > + if (tbl->it_offset == 0)
> > + start = 1;
> > + end = tbl->it_reserved_start - tbl->it_offset;
> > + if (find_next_bit(tbl->it_map, end, start) != end)
> > + return true;
> > +
> > + start = tbl->it_reserved_end - tbl->it_offset;
> > + end = tbl->it_size;
> > + return find_next_bit(tbl->it_map, end, start) != end;
> > +
>
> Unnecessary empty line.
Sure, removing.
Thanks!
