Merge tag 'mediatek-drm-fixes-5.3' of https://github.com/ckhu-mediatek/linux.git-tags into drm-fixes

Mediatek memory leak drm fix for Linux 5.3

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1566264270.30493.4.camel@mtksdaap41

2 files changed, 52 insertions, 4 deletions

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 95fdbd0fbcac..7f5408cb2377 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -213,6 +213,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 	struct mtk_drm_private *private = drm->dev_private;
 	struct platform_device *pdev;
 	struct device_node *np;
+	struct device *dma_dev;
 	int ret;
 
 	if (!iommu_present(&platform_bus_type))
@@ -275,7 +276,29 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 		goto err_component_unbind;
 	}
 
-	private->dma_dev = &pdev->dev;
+	dma_dev = &pdev->dev;
+	private->dma_dev = dma_dev;
+
+	/*
+	 * Configure the DMA segment size to make sure we get contiguous IOVA
+	 * when importing PRIME buffers.
+	 */
+	if (!dma_dev->dma_parms) {
+		private->dma_parms_allocated = true;
+		dma_dev->dma_parms =
+			devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
+				     GFP_KERNEL);
+	}
+	if (!dma_dev->dma_parms) {
+		ret = -ENOMEM;
+		goto err_component_unbind;
+	}
+
+	ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dma_dev, "Failed to set DMA segment size\n");
+		goto err_unset_dma_parms;
+	}
 
 	/*
 	 * We don't use the drm_irq_install() helpers provided by the DRM
@@ -285,13 +308,16 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 	drm->irq_enabled = true;
 	ret = drm_vblank_init(drm, MAX_CRTC);
 	if (ret < 0)
-		goto err_component_unbind;
+		goto err_unset_dma_parms;
 
 	drm_kms_helper_poll_init(drm);
 	drm_mode_config_reset(drm);
 
 	return 0;
 
+err_unset_dma_parms:
+	if (private->dma_parms_allocated)
+		dma_dev->dma_parms = NULL;
 err_component_unbind:
 	component_unbind_all(drm->dev, drm);
 err_config_cleanup:
@@ -302,9 +328,14 @@ err_config_cleanup:
 
 static void mtk_drm_kms_deinit(struct drm_device *drm)
 {
+	struct mtk_drm_private *private = drm->dev_private;
+
 	drm_kms_helper_poll_fini(drm);
 	drm_atomic_helper_shutdown(drm);
 
+	if (private->dma_parms_allocated)
+		private->dma_dev->dma_parms = NULL;
+
 	component_unbind_all(drm->dev, drm);
 	drm_mode_config_cleanup(drm);
 }
@@ -320,6 +351,18 @@ static const struct file_operations mtk_drm_fops = {
 	.compat_ioctl = drm_compat_ioctl,
 };
 
+/*
+ * We need to override this because the device used to import the memory is
+ * not dev->dev, as drm_gem_prime_import() expects.
+ */
+struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
+						struct dma_buf *dma_buf)
+{
+	struct mtk_drm_private *private = dev->dev_private;
+
+	return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
+}
+
 static struct drm_driver mtk_drm_driver = {
 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
 			   DRIVER_ATOMIC,
@@ -331,7 +374,7 @@ static struct drm_driver mtk_drm_driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_export = drm_gem_prime_export,
-	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_import = mtk_drm_gem_prime_import,
 	.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
 	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
 	.gem_prime_mmap = mtk_drm_gem_mmap_buf,
@@ -524,12 +567,15 @@ static int mtk_drm_probe(struct platform_device *pdev)
 			comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
 			if (!comp) {
 				ret = -ENOMEM;
+				of_node_put(node);
 				goto err_node;
 			}
 
 			ret = mtk_ddp_comp_init(dev, node, comp, comp_id, NULL);
-			if (ret)
+			if (ret) {
+				of_node_put(node);
 				goto err_node;
+			}
 
 			private->ddp_comp[comp_id] = comp;
 		}
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
index 598ff3e70446..e03fea12ff59 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
@@ -51,6 +51,8 @@ struct mtk_drm_private {
 	} commit;
 
 	struct drm_atomic_state *suspend_state;
+
+	bool dma_parms_allocated;
 };
 
 extern struct platform_driver mtk_ddp_driver;