[xenial][PATCH 10/15] powerpc/iommu/vfio_spapr_tce: Cleanup iommu_table disposal

[Jose Ricardo Ziviani]

From: Alexey Kardashevskiy <aik at ozlabs.ru>

At the moment iommu_table can be disposed by either calling
iommu_table_free() directly or it_ops::free(); the only implementation
of free() is in IODA2 - pnv_ioda2_table_free() - and it calls
iommu_table_free() anyway.

As we are going to have reference counting on tables, we need an unified
way of disposing tables.

This moves it_ops::free() call into iommu_free_table() and makes use
of the latter. The free() callback now handles only platform-specific
data.

As from now on the iommu_free_table() calls it_ops->free(), we need
to have it_ops initialized before calling iommu_free_table() so this
moves this initialization in pnv_pci_ioda2_create_table().

This should cause no behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson at redhat.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
 arch/powerpc/kernel/iommu.c               |  4 ++++
 arch/powerpc/platforms/powernv/pci-ioda.c | 10 ++++------
 drivers/vfio/vfio_iommu_spapr_tce.c       |  2 +-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 685a476..a3689fd 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -719,6 +719,9 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
 	if (!tbl)
 		return;
 
+	if (tbl->it_ops->free)
+		tbl->it_ops->free(tbl);
+
 	if (!tbl->it_map) {
 		kfree(tbl);
 		return;
@@ -745,6 +748,7 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
 	/* free table */
 	kfree(tbl);
 }
+EXPORT_SYMBOL_GPL(iommu_free_table);
 
 /* Creates TCEs for a user provided buffer.  The user buffer must be
  * contiguous real kernel storage (not vmalloc).  The address passed here
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 3c44a79..0b1bb56 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1424,7 +1424,6 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
 		iommu_group_put(pe->table_group.group);
 		BUG_ON(pe->table_group.group);
 	}
-	pnv_pci_ioda2_table_free_pages(tbl);
 	iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
 }
 
@@ -2049,7 +2048,6 @@ static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
 static void pnv_ioda2_table_free(struct iommu_table *tbl)
 {
 	pnv_pci_ioda2_table_free_pages(tbl);
-	iommu_free_table(tbl, "pnv");
 }
 
 static struct iommu_table_ops pnv_ioda2_iommu_ops = {
@@ -2326,6 +2324,8 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
 	if (!tbl)
 		return -ENOMEM;
 
+	tbl->it_ops = &pnv_ioda2_iommu_ops;
+
 	ret = pnv_pci_ioda2_table_alloc_pages(nid,
 			bus_offset, page_shift, window_size,
 			levels, tbl);
@@ -2334,8 +2334,6 @@ static long pnv_pci_ioda2_create_table(struct iommu_table_group *table_group,
 		return ret;
 	}
 
-	tbl->it_ops = &pnv_ioda2_iommu_ops;
-
 	*ptbl = tbl;
 
 	return 0;
@@ -2376,7 +2374,7 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
 	if (rc) {
 		pe_err(pe, "Failed to configure 32-bit TCE table, err %ld\n",
 				rc);
-		pnv_ioda2_table_free(tbl);
+		iommu_free_table(tbl, "");
 		return rc;
 	}
 
@@ -2464,7 +2462,7 @@ static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
 	pnv_pci_ioda2_unset_window(&pe->table_group, 0);
 	if (pe->pbus)
 		pnv_ioda_setup_bus_dma(pe, pe->pbus, false);
-	pnv_ioda2_table_free(tbl);
+	iommu_free_table(tbl, "pnv");
 }
 
 static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group)
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 59b3f62..ffab018 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -677,7 +677,7 @@ static void tce_iommu_free_table(struct tce_container *container,
 	unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 
 	tce_iommu_userspace_view_free(tbl, container->mm);
-	tbl->it_ops->free(tbl);
+	iommu_free_table(tbl, "");
 	decrement_locked_vm(container->mm, pages);
 }
 
-- 
2.7.4