vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
This adds tce_iommu_take_ownership() and tce_iommu_release_ownership
which call in a loop iommu_take_ownership()/iommu_release_ownership()
for every table on the group. As there is just one now, no change in
behaviour is expected.
At the moment the iommu_table struct has a set_bypass() which enables/
disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code
which calls this callback when external IOMMU users such as VFIO are
about to get over a PHB.
The set_bypass() callback is not really an iommu_table function but
IOMMU/PE function. This introduces a iommu_table_group_ops struct and
adds take_ownership()/release_ownership() callbacks to it which are
called when an external user takes/releases control over the IOMMU.
This replaces set_bypass() with ownership callbacks as it is not
necessarily just bypass enabling, it can be something else/more
so let's give it more generic name.
The callbacks is implemented for IODA2 only. Other platforms (P5IOC2,
IODA1) will use the old iommu_take_ownership/iommu_release_ownership API.
The following patches will replace iommu_take_ownership/
iommu_release_ownership calls in IODA2 with full IOMMU table release/
create.
As we here and touching bypass control, this removes
pnv_pci_ioda2_setup_bypass_pe() as it does not do much
more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base
initialization to pnv_pci_ioda2_setup_dma_pe.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 3b413069..17a7752 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1919,13 +1919,8 @@
}
}
-static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
+static void pnv_pci_ioda2_set_bypass(struct pnv_ioda_pe *pe, bool enable)
{
- struct iommu_table_group_link *tgl = list_first_entry_or_null(
- &tbl->it_group_list, struct iommu_table_group_link,
- next);
- struct pnv_ioda_pe *pe = container_of(tgl->table_group,
- struct pnv_ioda_pe, table_group);
uint16_t window_id = (pe->pe_number << 1 ) + 1;
int64_t rc;
@@ -1952,19 +1947,31 @@
pe->tce_bypass_enabled = enable;
}
-static void pnv_pci_ioda2_setup_bypass_pe(struct pnv_phb *phb,
- struct pnv_ioda_pe *pe)
+#ifdef CONFIG_IOMMU_API
+static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
{
- /* TVE #1 is selected by PCI address bit 59 */
- pe->tce_bypass_base = 1ull << 59;
+ struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
+ table_group);
- /* Install set_bypass callback for VFIO */
- pe->table_group.tables[0]->set_bypass = pnv_pci_ioda2_set_bypass;
-
- /* Enable bypass by default */
- pnv_pci_ioda2_set_bypass(pe->table_group.tables[0], true);
+ iommu_take_ownership(table_group->tables[0]);
+ pnv_pci_ioda2_set_bypass(pe, false);
}
+static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group)
+{
+ struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
+ table_group);
+
+ iommu_release_ownership(table_group->tables[0]);
+ pnv_pci_ioda2_set_bypass(pe, true);
+}
+
+static struct iommu_table_group_ops pnv_pci_ioda2_ops = {
+ .take_ownership = pnv_ioda2_take_ownership,
+ .release_ownership = pnv_ioda2_release_ownership,
+};
+#endif
+
static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
struct pnv_ioda_pe *pe)
{
@@ -1979,6 +1986,9 @@
if (WARN_ON(pe->tce32_seg >= 0))
return;
+ /* TVE #1 is selected by PCI address bit 59 */
+ pe->tce_bypass_base = 1ull << 59;
+
tbl = pnv_pci_table_alloc(phb->hose->node);
iommu_register_group(&pe->table_group, phb->hose->global_number,
pe->pe_number);
@@ -2033,6 +2043,9 @@
}
tbl->it_ops = &pnv_ioda2_iommu_ops;
iommu_init_table(tbl, phb->hose->node);
+#ifdef CONFIG_IOMMU_API
+ pe->table_group.ops = &pnv_pci_ioda2_ops;
+#endif
if (pe->flags & PNV_IODA_PE_DEV) {
/*
@@ -2047,7 +2060,7 @@
/* Also create a bypass window */
if (!pnv_iommu_bypass_disabled)
- pnv_pci_ioda2_setup_bypass_pe(phb, pe);
+ pnv_pci_ioda2_set_bypass(pe, true);
return;
fail: