On Wed, 2020-07-01 at 18:17 +1000, Alexey Kardashevskiy wrote:
>
> > +#define DDW_EXT_SIZE 0
> > +#define DDW_EXT_RESET_DMA_WIN 1
> > +#define DDW_EXT_QUERY_OUT_SIZE 2
>
> #define DDW_EXT_LAST (DDW_EXT_QUERY_OUT_SIZE + 1)
> ...
>
>
> > +
> > static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> > {
> > struct iommu_table_group *table_group;
> > @@ -339,7 +343,7 @@ struct direct_window {
> > /* Dynamic DMA Window support */
> > struct ddw_query_response {
> > u32 windows_available;
> > - u32 largest_available_block;
> > + u64 largest_available_block;
> > u32 page_size;
> > u32 migration_capable;
> > };
> > @@ -875,13 +879,29 @@ static int find_existing_ddw_windows(void)
> > machine_arch_initcall(pseries, find_existing_ddw_windows);
> >
> > static int query_ddw(struct pci_dev *dev, const u32 *ddw_avail,
> > - struct ddw_query_response *query)
> > + struct ddw_query_response *query,
> > + struct device_node *parent)
> > {
> > struct device_node *dn;
> > struct pci_dn *pdn;
> > - u32 cfg_addr;
> > + u32 cfg_addr, query_out[5], ddw_ext[DDW_EXT_QUERY_OUT_SIZE + 1];
>
> ... and use DDW_EXT_LAST here.
Because of the growing nature of ddw-extensions, I intentionally let
this be (DDW_EXT_QUERY_OUT_SIZE + 1). If we create a DDW_EXT_LAST, it
will be incremented in the future if more extensions come to exist.
I mean, I previously saw no reason for allocating space for extensions
after the desired one, as they won't be used here.
>
>
> > u64 buid;
> > - int ret;
> > + int ret, out_sz;
> > +
> > + /*
> > + * From LoPAR level 2.8, "ibm,ddw-extensions" index 3 can rule how many
> > + * output parameters ibm,query-pe-dma-windows will have, ranging from
> > + * 5 to 6.
> > + */
> > +
> > + ret = of_property_read_u32_array(parent, "ibm,ddw-extensions",
> > + &ddw_ext[0],
> > + DDW_EXT_QUERY_OUT_SIZE + 1);
In this case, I made sure not to cross (DDW_EXT_QUERY_OUT_SIZE + 1)
while reading the extensions from the property.
What do you think about it?
Best regards,
Leonardo
