s390/cio: use dma helpers for setting masks

Bypassing the DMA API is bad style, even when we don't expect any
actual problems. Let's utilize the right API helpers for setting the
DMA masks and check for returned errors, so that we benefit from
common sanity checks.

io_subchannel_allocate_dev() required some extra massaging, so that we
can return an errno other than -ENOMEM.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 20 insertions, 6 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index df46373d67ec..3f026021e95e 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -679,33 +679,47 @@ static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 {
 	struct ccw_device *cdev;
 	struct gen_pool *dma_pool;
+	int ret;
 
 	cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
-	if (!cdev)
+	if (!cdev) {
+		ret = -ENOMEM;
 		goto err_cdev;
+	}
 	cdev->private = kzalloc(sizeof(struct ccw_device_private),
 				GFP_KERNEL | GFP_DMA);
-	if (!cdev->private)
+	if (!cdev->private) {
+		ret = -ENOMEM;
 		goto err_priv;
-	cdev->dev.coherent_dma_mask = sch->dev.coherent_dma_mask;
+	}
+
 	cdev->dev.dma_mask = sch->dev.dma_mask;
+	ret = dma_set_coherent_mask(&cdev->dev, sch->dev.coherent_dma_mask);
+	if (ret)
+		goto err_coherent_mask;
+
 	dma_pool = cio_gp_dma_create(&cdev->dev, 1);
-	if (!dma_pool)
+	if (!dma_pool) {
+		ret = -ENOMEM;
 		goto err_dma_pool;
+	}
 	cdev->private->dma_pool = dma_pool;
 	cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
 					sizeof(*cdev->private->dma_area));
-	if (!cdev->private->dma_area)
+	if (!cdev->private->dma_area) {
+		ret = -ENOMEM;
 		goto err_dma_area;
+	}
 	return cdev;
 err_dma_area:
 	cio_gp_dma_destroy(dma_pool, &cdev->dev);
 err_dma_pool:
+err_coherent_mask:
 	kfree(cdev->private);
 err_priv:
 	kfree(cdev);
 err_cdev:
-	return ERR_PTR(-ENOMEM);
+	return ERR_PTR(ret);
 }
 
 static void ccw_device_todo(struct work_struct *work);