On Mon, 2021-07-19 at 16:04 +0200, Frederic Barrat wrote:
>
>
> On 16/07/2021 10:27, Leonardo Bras wrote:
> > Creates a helper to allow allocating a new iommu_table without the
> > need
> > to reallocate the iommu_group.
> >
> > This will be helpful for replacing the iommu_table for the new DMA
> > window,
> > after we remove the old one with iommu_tce_table_put().
> >
> > Signed-off-by: Leonardo Bras <leobra...@gmail.com>
> > Reviewed-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> > ---
> > arch/powerpc/platforms/pseries/iommu.c | 25 ++++++++++++++-------
> > ----
> > 1 file changed, 14 insertions(+), 11 deletions(-)
> >
> > diff --git a/arch/powerpc/platforms/pseries/iommu.c
> > b/arch/powerpc/platforms/pseries/iommu.c
> > index b1b8d12bab39..33d82865d6e6 100644
> > --- a/arch/powerpc/platforms/pseries/iommu.c
> > +++ b/arch/powerpc/platforms/pseries/iommu.c
> > @@ -53,28 +53,31 @@ enum {
> > DDW_EXT_QUERY_OUT_SIZE = 2
> > };
> >
> > -static struct iommu_table_group *iommu_pseries_alloc_group(int
> > node)
> > +static struct iommu_table *iommu_pseries_alloc_table(int node)
> > {
> > - struct iommu_table_group *table_group;
> > struct iommu_table *tbl;
> >
> > - table_group = kzalloc_node(sizeof(struct
> > iommu_table_group), GFP_KERNEL,
> > - node);
> > - if (!table_group)
> > - return NULL;
> > -
> > tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
> > node);
> > if (!tbl)
> > - goto free_group;
> > + return NULL;
> >
> > INIT_LIST_HEAD_RCU(&tbl->it_group_list);
> > kref_init(&tbl->it_kref);
> > + return tbl;
> > +}
> >
> > - table_group->tables[0] = tbl;
> > +static struct iommu_table_group *iommu_pseries_alloc_group(int
> > node)
> > +{
> > + struct iommu_table_group *table_group;
> > +
> > + table_group = kzalloc_node(sizeof(*table_group),
> > GFP_KERNEL, node);
> > + if (!table_group)
> > + return NULL;
> >
> > - return table_group;
> > + table_group->tables[0] = iommu_pseries_alloc_table(node);
> > + if (table_group->tables[0])
> > + return table_group;
>
>
> Nitpick: for readability, we'd usually expect the error path to be
> detected with the if statement and keep going on the good path, and
> here
> the code does the opposite. No big deal though, so
>
> Reviewed-by: Frederic Barrat <fbar...@linux.ibm.com>
>
>
Thanks for the tip and review!
Best regards,
Leonardo Bras
> >
> > -free_group:
> > kfree(table_group);
> > return NULL;
> > }
> >
