[v2,16/25] iommu: Remove ops->set_platform_dma_ops()

Commit Message

Jason Gunthorpe May 16, 2023, midnight UTC

All drivers are now using IDENTITY or PLATFORM domains for what this did,
we can remove it now. It is no longer possible to attach to a NULL domain.

Tested-by: Heiko Stuebner <[e-mail]>
Tested-by: Niklas Schnelle <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>
---
 drivers/iommu/iommu.c | 30 +++++-------------------------
 include/linux/iommu.h |  4 ----
 2 files changed, 5 insertions(+), 29 deletions(-)

Patch

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f9f11ad918f673..af8b91d15462f3 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2259,21 +2259,8 @@  static int __iommu_group_set_domain_internal(struct iommu_group *group,
 	if (group->domain == new_domain)
 		return 0;
 
-	/*
-	 * New drivers should support default domains, so set_platform_dma()
-	 * op will never be called. Otherwise the NULL domain represents some
-	 * platform specific behavior.
-	 */
-	if (!new_domain) {
-		for_each_group_device(group, gdev) {
-			const struct iommu_ops *ops = dev_iommu_ops(gdev->dev);
-
-			if (!WARN_ON(!ops->set_platform_dma_ops))
-				ops->set_platform_dma_ops(gdev->dev);
-		}
-		group->domain = NULL;
-		return 0;
-	}
+	if (WARN_ON(!new_domain))
+		return -EINVAL;
 
 	/*
 	 * Changing the domain is done by calling attach_dev() on the new
@@ -2309,19 +2296,15 @@  static int __iommu_group_set_domain_internal(struct iommu_group *group,
 	 */
 	last_gdev = gdev;
 	for_each_group_device(group, gdev) {
-		const struct iommu_ops *ops = dev_iommu_ops(gdev->dev);
-
 		/*
-		 * If set_platform_dma_ops is not present a NULL domain can
-		 * happen only for first probe, in which case we leave
-		 * group->domain as NULL and let release clean everything up.
+		 * A NULL domain can happen only for first probe, in which case
+		 * we leave group->domain as NULL and let release clean
+		 * everything up.
 		 */
 		if (group->domain)
 			WARN_ON(__iommu_device_set_domain(
 				group, gdev->dev, group->domain,
 				IOMMU_SET_DOMAIN_MUST_SUCCEED));
-		else if (ops->set_platform_dma_ops)
-			ops->set_platform_dma_ops(gdev->dev);
 		if (gdev == last_gdev)
 			break;
 	}
@@ -2935,9 +2918,6 @@  static int iommu_setup_default_domain(struct iommu_group *group,
 	/*
 	 * There are still some drivers which don't support default domains, so
 	 * we ignore the failure and leave group->default_domain NULL.
-	 *
-	 * We assume that the iommu driver starts up the device in
-	 * 'set_platform_dma_ops' mode if it does not support default domains.
 	 */
 	dom = iommu_group_alloc_default_domain(group, req_type);
 	if (!dom) {
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ddd284f8e5b768..387746f8273c99 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -231,9 +231,6 @@  struct iommu_iotlb_gather {
  * @release_device: Remove device from iommu driver handling
  * @probe_finalize: Do final setup work after the device is added to an IOMMU
  *                  group and attached to the groups domain
- * @set_platform_dma_ops: Returning control back to the platform DMA ops. This op
- *                        is to support old IOMMU drivers, new drivers should use
- *                        default domains, and the common IOMMU DMA ops.
  * @device_group: find iommu group for a particular device
  * @get_resv_regions: Request list of reserved regions for a device
  * @of_xlate: add OF master IDs to iommu grouping
@@ -265,7 +262,6 @@  struct iommu_ops {
 	struct iommu_device *(*probe_device)(struct device *dev);
 	void (*release_device)(struct device *dev);
 	void (*probe_finalize)(struct device *dev);
-	void (*set_platform_dma_ops)(struct device *dev);
 	struct iommu_group *(*device_group)(struct device *dev);
 
 	/* Request/Free a list of reserved regions for a device */