6 files changed, 25 insertions, 20 deletions

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 54966f538141..36c36b295ab1 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -2014,7 +2014,7 @@ static int tegra_dc_init(struct host1x_client *client)
 	if (!dc->syncpt)
 		dev_warn(dc->dev, "failed to allocate syncpoint\n");
 
-	err = host1x_client_iommu_attach(client, true);
+	err = host1x_client_iommu_attach(client);
 	if (err < 0) {
 		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		return err;
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 7480f575188d..9a1c1694604a 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -904,7 +904,7 @@ int tegra_drm_unregister_client(struct tegra_drm *tegra,
 	return 0;
 }
 
-int host1x_client_iommu_attach(struct host1x_client *client, bool shared)
+int host1x_client_iommu_attach(struct host1x_client *client)
 {
 	struct drm_device *drm = dev_get_drvdata(client->parent);
 	struct tegra_drm *tegra = drm->dev_private;
@@ -912,29 +912,30 @@ int host1x_client_iommu_attach(struct host1x_client *client, bool shared)
 	int err;
 
 	if (tegra->domain) {
+		struct iommu_domain *domain;
+
 		group = iommu_group_get(client->dev);
 		if (!group) {
 			dev_err(client->dev, "failed to get IOMMU group\n");
 			return -ENODEV;
 		}
 
-		if (!shared || (shared && (group != tegra->group))) {
 #if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
-			if (client->dev->archdata.mapping) {
-				struct dma_iommu_mapping *mapping =
-					to_dma_iommu_mapping(client->dev);
-				arm_iommu_detach_device(client->dev);
-				arm_iommu_release_mapping(mapping);
-			}
+		if (client->dev->archdata.mapping) {
+			struct dma_iommu_mapping *mapping =
+				to_dma_iommu_mapping(client->dev);
+			arm_iommu_detach_device(client->dev);
+			arm_iommu_release_mapping(mapping);
+		}
 #endif
+
+		domain = iommu_get_domain_for_dev(client->dev);
+		if (domain != tegra->domain) {
 			err = iommu_attach_group(tegra->domain, group);
 			if (err < 0) {
 				iommu_group_put(group);
 				return err;
 			}
-
-			if (shared && !tegra->group)
-				tegra->group = group;
 		}
 	}
 
@@ -947,12 +948,17 @@ void host1x_client_iommu_detach(struct host1x_client *client)
 {
 	struct drm_device *drm = dev_get_drvdata(client->parent);
 	struct tegra_drm *tegra = drm->dev_private;
+	struct iommu_domain *domain;
 
 	if (client->group) {
-		if (client->group == tegra->group) {
+		/*
+		 * Devices that are part of the same group may no longer be
+		 * attached to a domain at this point because their group may
+		 * have been detached by an earlier client.
+		 */
+		domain = iommu_get_domain_for_dev(client->dev);
+		if (domain)
 			iommu_detach_group(tegra->domain, client->group);
-			tegra->group = NULL;
-		}
 
 		iommu_group_put(client->group);
 	}
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 8b812bb52e5b..28f2820a7371 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -36,7 +36,6 @@ struct tegra_drm {
 	struct drm_device *drm;
 
 	struct iommu_domain *domain;
-	struct iommu_group *group;
 	struct mutex mm_lock;
 	struct drm_mm mm;
 
@@ -100,7 +99,7 @@ int tegra_drm_register_client(struct tegra_drm *tegra,
 			      struct tegra_drm_client *client);
 int tegra_drm_unregister_client(struct tegra_drm *tegra,
 				struct tegra_drm_client *client);
-int host1x_client_iommu_attach(struct host1x_client *client, bool shared);
+int host1x_client_iommu_attach(struct host1x_client *client);
 void host1x_client_iommu_detach(struct host1x_client *client);
 
 int tegra_drm_init(struct tegra_drm *tegra, struct drm_device *drm);
diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index 5d5af9a05c18..1fc4e56c7cc5 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -50,7 +50,7 @@ static int gr2d_init(struct host1x_client *client)
 		goto put;
 	}
 
-	err = host1x_client_iommu_attach(client, false);
+	err = host1x_client_iommu_attach(client);
 	if (err < 0) {
 		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		goto free;
diff --git a/drivers/gpu/drm/tegra/gr3d.c b/drivers/gpu/drm/tegra/gr3d.c
index c249a6bd8d51..24fae0f64032 100644
--- a/drivers/gpu/drm/tegra/gr3d.c
+++ b/drivers/gpu/drm/tegra/gr3d.c
@@ -59,7 +59,7 @@ static int gr3d_init(struct host1x_client *client)
 		goto put;
 	}
 
-	err = host1x_client_iommu_attach(client, false);
+	err = host1x_client_iommu_attach(client);
 	if (err < 0) {
 		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		goto free;
diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index d34b1ada422c..603f41ed4b81 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -187,7 +187,7 @@ static int vic_init(struct host1x_client *client)
 	struct vic *vic = to_vic(drm);
 	int err;
 
-	err = host1x_client_iommu_attach(client, false);
+	err = host1x_client_iommu_attach(client);
 	if (err < 0) {
 		dev_err(vic->dev, "failed to attach to domain: %d\n", err);
 		return err;