vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows API

This extends iommu_table_group_ops by a set of callbacks to support
dynamic DMA windows management.

create_table() creates a TCE table with specific parameters.
it receives iommu_table_group to know nodeid in order to allocate
TCE table memory closer to the PHB. The exact format of allocated
multi-level table might be also specific to the PHB model (not
the case now though).
This callback calculated the DMA window offset on a PCI bus from @num
and stores it in a just created table.

set_window() sets the window at specified TVT index + @num on PHB.

unset_window() unsets the window from specified TVT.

This adds a free() callback to iommu_table_ops to free the memory
(potentially a tree of tables) allocated for the TCE table.

create_table() and free() are supposed to be called once per
VFIO container and set_window()/unset_window() are supposed to be
called for every group in a container.

This adds IOMMU capabilities to iommu_table_group such as default
32bit window parameters and others. This makes use of new values in
vfio_iommu_spapr_tce. IODA1/P5IOC2 do not support DDW so they do not
advertise pagemasks to the userspace.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index eaec85b63b34..f2bdfea3b68d 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -127,6 +127,8 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
 	u64 phb_id;
 	int64_t rc;
 	static int primary = 1;
+	struct iommu_table_group *table_group;
+	struct iommu_table *tbl;
 
 	pr_info(" Initializing p5ioc2 PHB %s\n", np->full_name);
 
@@ -201,7 +203,10 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
 	 * hotplug or SRIOV on P5IOC2 and therefore iommu_free_table()
 	 * should not be called for phb->p5ioc2.table_group.tables[0] ever.
 	 */
-	phb->p5ioc2.table_group.tables[0] = &phb->p5ioc2.iommu_table;
+	tbl = phb->p5ioc2.table_group.tables[0] = &phb->p5ioc2.iommu_table;
+	table_group = &phb->p5ioc2.table_group;
+	table_group->tce32_start = tbl->it_offset << tbl->it_page_shift;
+	table_group->tce32_size = tbl->it_size << tbl->it_page_shift;
 }
 
 void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)