drm/tegra: Refactor IOMMU attach/detach

Attaching to and detaching from an IOMMU uses the same code sequence in
every driver, so factor it out into separate helpers.
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/dc.c

@@ -1837,23 +1837,13 @@ static int tegra_dc_init(struct host1x_client *client)
 	if (!dc->syncpt)
 		dev_warn(dc->dev, "failed to allocate syncpoint\n");
 
-	if (tegra->domain) {
-		dc->group = iommu_group_get(client->dev);
-
-		if (dc->group && dc->group != tegra->group) {
-			err = iommu_attach_group(tegra->domain, dc->group);
-			if (err < 0) {
-				dev_err(dc->dev,
-					"failed to attach to domain: %d\n",
-					err);
-				iommu_group_put(dc->group);
+	dc->group = host1x_client_iommu_attach(client, true);
+	if (IS_ERR(dc->group)) {
+		err = PTR_ERR(dc->group);
+		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		return err;
 	}
 
-			tegra->group = dc->group;
-		}
-	}
-
 	if (dc->soc->wgrps)
 		primary = tegra_dc_add_shared_planes(drm, dc);
 	else
@@ -1916,15 +1906,7 @@ static int tegra_dc_init(struct host1x_client *client)
 	if (!IS_ERR(primary))
 		drm_plane_cleanup(primary);
 
-	if (dc->group) {
-		if (dc->group == tegra->group) {
-			iommu_detach_group(tegra->domain, dc->group);
-			tegra->group = NULL;
-		}
-
-		iommu_group_put(dc->group);
-	}
-
+	host1x_client_iommu_detach(client, dc->group);
 	host1x_syncpt_free(dc->syncpt);
 
 	return err;
@@ -1932,9 +1914,7 @@ static int tegra_dc_init(struct host1x_client *client)
 
 static int tegra_dc_exit(struct host1x_client *client)
 {
-	struct drm_device *drm = dev_get_drvdata(client->parent);
 	struct tegra_dc *dc = host1x_client_to_dc(client);
-	struct tegra_drm *tegra = drm->dev_private;
 	int err;
 
 	devm_free_irq(dc->dev, dc->irq, dc);
@@ -1945,15 +1925,7 @@ static int tegra_dc_exit(struct host1x_client *client)
 		return err;
 	}
 
-	if (dc->group) {
-		if (dc->group == tegra->group) {
-			iommu_detach_group(tegra->domain, dc->group);
-			tegra->group = NULL;
-		}
-
-		iommu_group_put(dc->group);
-	}
-
+	host1x_client_iommu_detach(client, dc->group);
 	host1x_syncpt_free(dc->syncpt);
 
 	return 0;

drivers/gpu/drm/tegra/drm.c

@@ -1114,6 +1114,52 @@ int tegra_drm_unregister_client(struct tegra_drm *tegra,
 	return 0;
 }
 
+struct iommu_group *host1x_client_iommu_attach(struct host1x_client *client,
+					       bool shared)
+{
+	struct drm_device *drm = dev_get_drvdata(client->parent);
+	struct tegra_drm *tegra = drm->dev_private;
+	struct iommu_group *group = NULL;
+	int err;
+
+	if (tegra->domain) {
+		group = iommu_group_get(client->dev);
+		if (!group) {
+			dev_err(client->dev, "failed to get IOMMU group\n");
+			return ERR_PTR(-ENODEV);
+		}
+
+		if (!shared || (shared && (group != tegra->group))) {
+			err = iommu_attach_group(tegra->domain, group);
+			if (err < 0) {
+				iommu_group_put(group);
+				return ERR_PTR(err);
+			}
+
+			if (shared && !tegra->group)
+				tegra->group = group;
+		}
+	}
+
+	return group;
+}
+
+void host1x_client_iommu_detach(struct host1x_client *client,
+				struct iommu_group *group)
+{
+	struct drm_device *drm = dev_get_drvdata(client->parent);
+	struct tegra_drm *tegra = drm->dev_private;
+
+	if (group) {
+		if (group == tegra->group) {
+			iommu_detach_group(tegra->domain, group);
+			tegra->group = NULL;
+		}
+
+		iommu_group_put(group);
+	}
+}
+
 void *tegra_drm_alloc(struct tegra_drm *tegra, size_t size, dma_addr_t *dma)
 {
 	struct iova *alloc;

drivers/gpu/drm/tegra/drm.h

@@ -110,6 +110,10 @@ 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);
+struct iommu_group *host1x_client_iommu_attach(struct host1x_client *client,
+					       bool shared);
+void host1x_client_iommu_detach(struct host1x_client *client,
+				struct iommu_group *group);
 
 int tegra_drm_init(struct tegra_drm *tegra, struct drm_device *drm);
 int tegra_drm_exit(struct tegra_drm *tegra);

drivers/gpu/drm/tegra/gr2d.c

@@ -32,7 +32,6 @@ static int gr2d_init(struct host1x_client *client)
 	struct tegra_drm_client *drm = host1x_to_drm_client(client);
 	struct drm_device *dev = dev_get_drvdata(client->parent);
 	unsigned long flags = HOST1X_SYNCPT_HAS_BASE;
-	struct tegra_drm *tegra = dev->dev_private;
 	struct gr2d *gr2d = to_gr2d(drm);
 	int err;
 
@@ -47,22 +46,14 @@ static int gr2d_init(struct host1x_client *client)
 		goto put;
 	}
 
-	if (tegra->domain) {
-		gr2d->group = iommu_group_get(client->dev);
-
-		if (gr2d->group) {
-			err = iommu_attach_group(tegra->domain, gr2d->group);
-			if (err < 0) {
-				dev_err(client->dev,
-					"failed to attach to domain: %d\n",
-					err);
-				iommu_group_put(gr2d->group);
+	gr2d->group = host1x_client_iommu_attach(client, false);
+	if (IS_ERR(gr2d->group)) {
+		err = PTR_ERR(gr2d->group);
+		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		goto free;
 	}
-		}
-	}
 
-	err = tegra_drm_register_client(tegra, drm);
+	err = tegra_drm_register_client(dev->dev_private, drm);
 	if (err < 0) {
 		dev_err(client->dev, "failed to register client: %d\n", err);
 		goto detach;
@@ -71,10 +62,7 @@ static int gr2d_init(struct host1x_client *client)
 	return 0;
 
 detach:
-	if (gr2d->group) {
-		iommu_detach_group(tegra->domain, gr2d->group);
-		iommu_group_put(gr2d->group);
-	}
+	host1x_client_iommu_detach(client, gr2d->group);
 free:
 	host1x_syncpt_free(client->syncpts[0]);
 put:
@@ -94,14 +82,10 @@ static int gr2d_exit(struct host1x_client *client)
 	if (err < 0)
 		return err;
 
+	host1x_client_iommu_detach(client, gr2d->group);
 	host1x_syncpt_free(client->syncpts[0]);
 	host1x_channel_put(gr2d->channel);
 
-	if (gr2d->group) {
-		iommu_detach_group(tegra->domain, gr2d->group);
-		iommu_group_put(gr2d->group);
-	}
-
 	return 0;
 }
 

drivers/gpu/drm/tegra/gr3d.c

@@ -42,7 +42,6 @@ static int gr3d_init(struct host1x_client *client)
 	struct tegra_drm_client *drm = host1x_to_drm_client(client);
 	struct drm_device *dev = dev_get_drvdata(client->parent);
 	unsigned long flags = HOST1X_SYNCPT_HAS_BASE;
-	struct tegra_drm *tegra = dev->dev_private;
 	struct gr3d *gr3d = to_gr3d(drm);
 	int err;
 
@@ -57,20 +56,12 @@ static int gr3d_init(struct host1x_client *client)
 		goto put;
 	}
 
-	if (tegra->domain) {
-		gr3d->group = iommu_group_get(client->dev);
-
-		if (gr3d->group) {
-			err = iommu_attach_group(tegra->domain, gr3d->group);
-			if (err < 0) {
-				dev_err(client->dev,
-					"failed to attach to domain: %d\n",
-					err);
-				iommu_group_put(gr3d->group);
+	gr3d->group = host1x_client_iommu_attach(client, false);
+	if (IS_ERR(gr3d->group)) {
+		err = PTR_ERR(gr3d->group);
+		dev_err(client->dev, "failed to attach to domain: %d\n", err);
 		goto free;
 	}
-		}
-	}
 
 	err = tegra_drm_register_client(dev->dev_private, drm);
 	if (err < 0) {
@@ -81,10 +72,7 @@ static int gr3d_init(struct host1x_client *client)
 	return 0;
 
 detach:
-	if (gr3d->group) {
-		iommu_detach_group(tegra->domain, gr3d->group);
-		iommu_group_put(gr3d->group);
-	}
+	host1x_client_iommu_detach(client, gr3d->group);
 free:
 	host1x_syncpt_free(client->syncpts[0]);
 put:
@@ -96,7 +84,6 @@ static int gr3d_exit(struct host1x_client *client)
 {
 	struct tegra_drm_client *drm = host1x_to_drm_client(client);
 	struct drm_device *dev = dev_get_drvdata(client->parent);
-	struct tegra_drm *tegra = dev->dev_private;
 	struct gr3d *gr3d = to_gr3d(drm);
 	int err;
 
@@ -104,14 +91,10 @@ static int gr3d_exit(struct host1x_client *client)
 	if (err < 0)
 		return err;
 
+	host1x_client_iommu_detach(client, gr3d->group);
 	host1x_syncpt_free(client->syncpts[0]);
 	host1x_channel_put(gr3d->channel);
 
-	if (gr3d->group) {
-		iommu_detach_group(tegra->domain, gr3d->group);
-		iommu_group_put(gr3d->group);
-	}
-
 	return 0;
 }