[PATCH v4 25/28] vfio: powerpc/spapr: powerpc/powernv/ioda2: Rework ownership

[Alexey Kardashevskiy]

This uses new helpers to remove the default TCE table if the ownership is
being taken and create it otherwise. So once an external user (such as
VFIO) obtained the ownership over a group, it does not have any DMA
windows, neither default 32bit not bypass window. The external user is
expected to unprogram DMA windows on PHBs before returning ownership
back to the kernel.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 30 ++++++++++++++++++++++++++----
 drivers/vfio/vfio_iommu_spapr_tce.c       |  8 ++++++++
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 16ddaba..79a8149 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1570,11 +1570,33 @@ static void pnv_ioda2_set_ownership(struct powerpc_iommu *iommu,
 {
 	struct pnv_ioda_pe *pe = container_of(iommu, struct pnv_ioda_pe,
 						iommu);
-	if (enable)
-		iommu_take_ownership(iommu);
-	else
-		iommu_release_ownership(iommu);
+	if (enable) {
+		pnv_pci_ioda2_unset_window(&pe->iommu, 0);
+		pnv_pci_ioda2_free_table(&pe->iommu.tables[0]);
+	} else {
+		struct iommu_table *tbl = &pe->iommu.tables[0];
+		int64_t rc;
 
+		rc = pnv_pci_ioda2_create_table(&pe->iommu, 0,
+				IOMMU_PAGE_SHIFT_4K,
+				ilog2(pe->phb->ioda.m32_pci_base),
+				POWERPC_IOMMU_DEFAULT_LEVELS, tbl);
+		if (rc) {
+			pe_err(pe, "Failed to create 32-bit TCE table, err %ld",
+					rc);
+			return;
+		}
+
+		iommu_init_table(tbl, pe->phb->hose->node);
+
+		rc = pnv_pci_ioda2_set_window(&pe->iommu, 0, tbl);
+		if (rc) {
+			pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n",
+					rc);
+			pnv_pci_ioda2_free_table(tbl);
+			return;
+		}
+	}
 	pnv_pci_ioda2_set_bypass(pe, !enable);
 }
 
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index b5134b7..fdcc04c 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -820,8 +820,16 @@ static int tce_iommu_attach_group(void *iommu_data,
 			 * our physical memory via the bypass window instead of just
 			 * the pages that has been explicitly mapped into the iommu
 			 */
+			struct iommu_table tbltmp = { 0 }, *tbl = &tbltmp;
+
 			iommu->ops->set_ownership(iommu, true);
 			container->grp = iommu_group;
+
+			ret = iommu->ops->create_table(iommu, 0,
+					IOMMU_PAGE_SHIFT_4K,
+					ilog2(iommu->tce32_size), 1, tbl);
+			if (!ret)
+				ret = iommu->ops->set_window(iommu, 0, tbl);
 		} else {
 			ret = -ENODEV;
 		}
-- 
2.0.0