5 files changed, 125 insertions, 86 deletions

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 7e29c73e3dd4..678b5bdc79b1 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -175,7 +175,7 @@ struct iommu_table_group_ops {
 	long (*unset_window)(struct iommu_table_group *table_group,
 			int num);
 	/* Switch ownership from platform code to external user (e.g. VFIO) */
-	void (*take_ownership)(struct iommu_table_group *table_group);
+	long (*take_ownership)(struct iommu_table_group *table_group);
 	/* Switch ownership from external user (e.g. VFIO) back to core */
 	void (*release_ownership)(struct iommu_table_group *table_group);
 };
@@ -215,6 +215,8 @@ extern long iommu_tce_xchg_no_kill(struct mm_struct *mm,
 		enum dma_data_direction *direction);
 extern void iommu_tce_kill(struct iommu_table *tbl,
 		unsigned long entry, unsigned long pages);
+
+extern struct iommu_table_group_ops spapr_tce_table_group_ops;
 #else
 static inline void iommu_register_group(struct iommu_table_group *table_group,
 					int pci_domain_number,
@@ -303,8 +305,6 @@ extern int iommu_tce_check_gpa(unsigned long page_shift,
 		iommu_tce_check_gpa((tbl)->it_page_shift, (gpa)))
 
 extern void iommu_flush_tce(struct iommu_table *tbl);
-extern int iommu_take_ownership(struct iommu_table *tbl);
-extern void iommu_release_ownership(struct iommu_table *tbl);
 
 extern enum dma_data_direction iommu_tce_direction(unsigned long tce);
 extern unsigned long iommu_direction_to_tce_perm(enum dma_data_direction dir);
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ee95937bdaf1..4cd3d68784b6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1086,7 +1086,7 @@ void iommu_tce_kill(struct iommu_table *tbl,
 }
 EXPORT_SYMBOL_GPL(iommu_tce_kill);
 
-int iommu_take_ownership(struct iommu_table *tbl)
+static int iommu_take_ownership(struct iommu_table *tbl)
 {
 	unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
 	int ret = 0;
@@ -1118,9 +1118,8 @@ int iommu_take_ownership(struct iommu_table *tbl)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_take_ownership);
 
-void iommu_release_ownership(struct iommu_table *tbl)
+static void iommu_release_ownership(struct iommu_table *tbl)
 {
 	unsigned long flags, i, sz = (tbl->it_size + 7) >> 3;
 
@@ -1137,7 +1136,6 @@ void iommu_release_ownership(struct iommu_table *tbl)
 		spin_unlock(&tbl->pools[i].lock);
 	spin_unlock_irqrestore(&tbl->large_pool.lock, flags);
 }
-EXPORT_SYMBOL_GPL(iommu_release_ownership);
 
 int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
 {
@@ -1179,4 +1177,96 @@ void iommu_del_device(struct device *dev)
 	iommu_group_remove_device(dev);
 }
 EXPORT_SYMBOL_GPL(iommu_del_device);
+
+/*
+ * A simple iommu_table_group_ops which only allows reusing the existing
+ * iommu_table. This handles VFIO for POWER7 or the nested KVM.
+ * The ops does not allow creating windows and only allows reusing the existing
+ * one if it matches table_group->tce32_start/tce32_size/page_shift.
+ */
+static unsigned long spapr_tce_get_table_size(__u32 page_shift,
+					      __u64 window_size, __u32 levels)
+{
+	unsigned long size;
+
+	if (levels > 1)
+		return ~0U;
+	size = window_size >> (page_shift - 3);
+	return size;
+}
+
+static long spapr_tce_create_table(struct iommu_table_group *table_group, int num,
+				   __u32 page_shift, __u64 window_size, __u32 levels,
+				   struct iommu_table **ptbl)
+{
+	struct iommu_table *tbl = table_group->tables[0];
+
+	if (num > 0)
+		return -EPERM;
+
+	if (tbl->it_page_shift != page_shift ||
+	    tbl->it_size != (window_size >> page_shift) ||
+	    tbl->it_indirect_levels != levels - 1)
+		return -EINVAL;
+
+	*ptbl = iommu_tce_table_get(tbl);
+	return 0;
+}
+
+static long spapr_tce_set_window(struct iommu_table_group *table_group,
+				 int num, struct iommu_table *tbl)
+{
+	return tbl == table_group->tables[num] ? 0 : -EPERM;
+}
+
+static long spapr_tce_unset_window(struct iommu_table_group *table_group, int num)
+{
+	return 0;
+}
+
+static long spapr_tce_take_ownership(struct iommu_table_group *table_group)
+{
+	int i, j, rc = 0;
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = table_group->tables[i];
+
+		if (!tbl || !tbl->it_map)
+			continue;
+
+		rc = iommu_take_ownership(tbl);
+		if (!rc)
+			continue;
+		for (j = 0; j < i; ++j)
+			iommu_release_ownership(table_group->tables[j]);
+		return rc;
+	}
+	return 0;
+}
+
+static void spapr_tce_release_ownership(struct iommu_table_group *table_group)
+{
+	int i;
+
+	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
+		struct iommu_table *tbl = table_group->tables[i];
+
+		if (!tbl)
+			continue;
+
+		iommu_table_clear(tbl);
+		if (tbl->it_map)
+			iommu_release_ownership(tbl);
+	}
+}
+
+struct iommu_table_group_ops spapr_tce_table_group_ops = {
+	.get_table_size = spapr_tce_get_table_size,
+	.create_table = spapr_tce_create_table,
+	.set_window = spapr_tce_set_window,
+	.unset_window = spapr_tce_unset_window,
+	.take_ownership = spapr_tce_take_ownership,
+	.release_ownership = spapr_tce_release_ownership,
+};
+
 #endif /* CONFIG_IOMMU_API */
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 4f6e20a35aa1..c8a5caedc4c5 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1554,6 +1554,10 @@ found:
 	if (WARN_ON(!tbl))
 		return;
 
+#ifdef CONFIG_IOMMU_API
+	pe->table_group.ops = &spapr_tce_table_group_ops;
+	pe->table_group.pgsizes = SZ_4K;
+#endif
 	iommu_register_group(&pe->table_group, phb->hose->global_number,
 			pe->pe_number);
 	pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
@@ -1888,7 +1892,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
 	}
 }
 
-static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
+static long pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
 {
 	struct pnv_ioda_pe *pe = container_of(table_group, struct pnv_ioda_pe,
 						table_group);
@@ -1902,6 +1906,8 @@ static void pnv_ioda2_take_ownership(struct iommu_table_group *table_group)
 	else if (pe->pdev)
 		set_iommu_table_base(&pe->pdev->dev, NULL);
 	iommu_tce_table_put(tbl);
+
+	return 0;
 }
 
 static void pnv_ioda2_release_ownership(struct iommu_table_group *table_group)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index c74b71d4733d..8eec100a1d87 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -74,6 +74,11 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
 	if (!table_group)
 		return NULL;
 
+#ifdef CONFIG_IOMMU_API
+	table_group->ops = &spapr_tce_table_group_ops;
+	table_group->pgsizes = SZ_4K;
+#endif
+
 	table_group->tables[0] = iommu_pseries_alloc_table(node);
 	if (table_group->tables[0])
 		return table_group;
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 60a50ce8701e..c3f8ae102ece 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1190,52 +1190,6 @@ static long tce_iommu_ioctl(void *iommu_data,
 static void tce_iommu_release_ownership(struct tce_container *container,
 		struct iommu_table_group *table_group)
 {
-	int i;
-
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		struct iommu_table *tbl = container->tables[i];
-
-		if (!tbl)
-			continue;
-
-		tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
-		if (tbl->it_map)
-			iommu_release_ownership(tbl);
-
-		container->tables[i] = NULL;
-	}
-}
-
-static int tce_iommu_take_ownership(struct tce_container *container,
-		struct iommu_table_group *table_group)
-{
-	int i, j, rc = 0;
-
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		struct iommu_table *tbl = table_group->tables[i];
-
-		if (!tbl || !tbl->it_map)
-			continue;
-
-		rc = iommu_take_ownership(tbl);
-		if (rc) {
-			for (j = 0; j < i; ++j)
-				iommu_release_ownership(
-						table_group->tables[j]);
-
-			return rc;
-		}
-	}
-
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
-		container->tables[i] = table_group->tables[i];
-
-	return 0;
-}
-
-static void tce_iommu_release_ownership_ddw(struct tce_container *container,
-		struct iommu_table_group *table_group)
-{
 	long i;
 
 	if (!table_group->ops->unset_window) {
@@ -1250,18 +1204,14 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container,
 	table_group->ops->release_ownership(table_group);
 }
 
-static long tce_iommu_take_ownership_ddw(struct tce_container *container,
+static long tce_iommu_take_ownership(struct tce_container *container,
 		struct iommu_table_group *table_group)
 {
 	long i, ret = 0;
 
-	if (!table_group->ops->create_table || !table_group->ops->set_window ||
-			!table_group->ops->release_ownership) {
-		WARN_ON_ONCE(1);
-		return -EFAULT;
-	}
-
-	table_group->ops->take_ownership(table_group);
+	ret = table_group->ops->take_ownership(table_group);
+	if (ret)
+		return ret;
 
 	/* Set all windows to the new group */
 	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
@@ -1307,9 +1257,14 @@ static int tce_iommu_attach_group(void *iommu_data,
 		goto unlock_exit;
 	}
 
-	if (tce_groups_attached(container) && (!table_group->ops ||
-			!table_group->ops->take_ownership ||
-			!table_group->ops->release_ownership)) {
+	/* v2 requires full support of dynamic DMA windows */
+	if (container->v2 && table_group->max_dynamic_windows_supported == 0) {
+		ret = -EINVAL;
+		goto unlock_exit;
+	}
+
+	/* v1 reuses TCE tables and does not share them among PEs */
+	if (!container->v2 && tce_groups_attached(container)) {
 		ret = -EBUSY;
 		goto unlock_exit;
 	}
@@ -1344,29 +1299,15 @@ static int tce_iommu_attach_group(void *iommu_data,
 		goto unlock_exit;
 	}
 
-	if (!table_group->ops || !table_group->ops->take_ownership ||
-			!table_group->ops->release_ownership) {
-		if (container->v2) {
-			ret = -EPERM;
-			goto free_exit;
-		}
-		ret = tce_iommu_take_ownership(container, table_group);
-	} else {
-		if (!container->v2) {
-			ret = -EPERM;
-			goto free_exit;
-		}
-		ret = tce_iommu_take_ownership_ddw(container, table_group);
-		if (!tce_groups_attached(container) && !container->tables[0])
-			container->def_window_pending = true;
-	}
+	ret = tce_iommu_take_ownership(container, table_group);
+	if (!tce_groups_attached(container) && !container->tables[0])
+		container->def_window_pending = true;
 
 	if (!ret) {
 		tcegrp->grp = iommu_group;
 		list_add(&tcegrp->next, &container->group_list);
 	}
 
-free_exit:
 	if (ret && tcegrp)
 		kfree(tcegrp);
 
@@ -1405,10 +1346,7 @@ static void tce_iommu_detach_group(void *iommu_data,
 	table_group = iommu_group_get_iommudata(iommu_group);
 	BUG_ON(!table_group);
 
-	if (!table_group->ops || !table_group->ops->release_ownership)
-		tce_iommu_release_ownership(container, table_group);
-	else
-		tce_iommu_release_ownership_ddw(container, table_group);
+	tce_iommu_release_ownership(container, table_group);
 
 unlock_exit:
 	mutex_unlock(&container->lock);