s390/virtio_ccw: avoid converting dma addresses / handles

Instead of converting virtual to physical addresses with the virt_to_dma*()
functions, use dma addresses as provided by DMA API and only add offsets to
these addresses. This makes sure that address conversion is only done by
the DMA API.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 53 insertions, 18 deletions

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index ee9c82721a7e..d7569f395559 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -72,6 +72,7 @@ struct virtio_ccw_device {
 	unsigned int config_ready;
 	void *airq_info;
 	struct vcdev_dma_area *dma_area;
+	dma32_t dma_area_addr;
 };
 
 static inline unsigned long *indicators(struct virtio_ccw_device *vcdev)
@@ -84,6 +85,36 @@ static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev)
 	return &vcdev->dma_area->indicators2;
 }
 
+/* Spec stipulates a 64 bit address */
+static inline dma64_t indicators_dma(struct virtio_ccw_device *vcdev)
+{
+	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
+
+	return dma64_add(u64_to_dma64(dma_area_addr),
+			 offsetof(struct vcdev_dma_area, indicators));
+}
+
+/* Spec stipulates a 64 bit address */
+static inline dma64_t indicators2_dma(struct virtio_ccw_device *vcdev)
+{
+	u64 dma_area_addr = dma32_to_u32(vcdev->dma_area_addr);
+
+	return dma64_add(u64_to_dma64(dma_area_addr),
+			 offsetof(struct vcdev_dma_area, indicators2));
+}
+
+static inline dma32_t config_block_dma(struct virtio_ccw_device *vcdev)
+{
+	return dma32_add(vcdev->dma_area_addr,
+			 offsetof(struct vcdev_dma_area, config_block));
+}
+
+static inline dma32_t status_dma(struct virtio_ccw_device *vcdev)
+{
+	return dma32_add(vcdev->dma_area_addr,
+			 offsetof(struct vcdev_dma_area, status));
+}
+
 struct vq_info_block_legacy {
 	dma64_t queue;
 	__u32 align;
@@ -157,6 +188,11 @@ static inline u8 *get_summary_indicator(struct airq_info *info)
 	return summary_indicators + info->summary_indicator_idx;
 }
 
+static inline dma64_t get_summary_indicator_dma(struct airq_info *info)
+{
+	return virt_to_dma64(get_summary_indicator(info));
+}
+
 #define CCW_CMD_SET_VQ 0x13
 #define CCW_CMD_VDEV_RESET 0x33
 #define CCW_CMD_SET_IND 0x43
@@ -349,9 +385,9 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 				      struct ccw1 *ccw)
 {
 	int ret;
-	unsigned long *indicatorp = NULL;
 	struct virtio_thinint_area *thinint_area = NULL;
 	struct airq_info *airq_info = vcdev->airq_info;
+	dma64_t *indicatorp = NULL;
 
 	if (vcdev->is_thinint) {
 		thinint_area = ccw_device_dma_zalloc(vcdev->cdev,
@@ -360,20 +396,20 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 		if (!thinint_area)
 			return;
 		thinint_area->summary_indicator =
-			virt_to_dma64(get_summary_indicator(airq_info));
+			get_summary_indicator_dma(airq_info);
 		thinint_area->isc = VIRTIO_AIRQ_ISC;
 		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 		ccw->count = sizeof(*thinint_area);
 	} else {
 		/* payload is the address of the indicators */
 		indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
-						   sizeof(indicators(vcdev)),
+						   sizeof(*indicatorp),
 						   &ccw->cda);
 		if (!indicatorp)
 			return;
 		*indicatorp = 0;
 		ccw->cmd_code = CCW_CMD_SET_IND;
-		ccw->count = sizeof(indicators(vcdev));
+		ccw->count = sizeof(*indicatorp);
 	}
 	/* Deregister indicators from host. */
 	*indicators(vcdev) = 0;
@@ -387,7 +423,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
 			 "Failed to deregister indicators (%d)\n", ret);
 	else if (vcdev->is_thinint)
 		virtio_ccw_drop_indicators(vcdev);
-	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(indicators(vcdev)));
+	ccw_device_dma_free(vcdev->cdev, indicatorp, sizeof(*indicatorp));
 	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));
 }
 
@@ -427,7 +463,7 @@ static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
 	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
 	ccw->flags = 0;
 	ccw->count = sizeof(struct vq_config_block);
-	ccw->cda = virt_to_dma32(&vcdev->dma_area->config_block);
+	ccw->cda = config_block_dma(vcdev);
 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
 	if (ret)
 		return ret;
@@ -627,8 +663,7 @@ static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
 	}
 	thinint_area->indicator = virt_to_dma64(indicator_addr);
 	info = vcdev->airq_info;
-	thinint_area->summary_indicator =
-		virt_to_dma64(get_summary_indicator(info));
+	thinint_area->summary_indicator = get_summary_indicator_dma(info);
 	thinint_area->isc = VIRTIO_AIRQ_ISC;
 	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
 	ccw->flags = CCW_FLAG_SLI;
@@ -689,11 +724,11 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	 * the address of the indicators.
 	*/
 	indicatorp = ccw_device_dma_zalloc(vcdev->cdev,
-					   sizeof(indicators(vcdev)),
+					   sizeof(*indicatorp),
 					   &ccw->cda);
 	if (!indicatorp)
 		goto out;
-	*indicatorp = virt_to_dma64(indicators(vcdev));
+	*indicatorp = indicators_dma(vcdev);
 	if (vcdev->is_thinint) {
 		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
 		if (ret)
@@ -705,30 +740,30 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 		*indicators(vcdev) = 0;
 		ccw->cmd_code = CCW_CMD_SET_IND;
 		ccw->flags = 0;
-		ccw->count = sizeof(indicators(vcdev));
+		ccw->count = sizeof(*indicatorp);
 		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
 		if (ret)
 			goto out;
 	}
 	/* Register indicators2 with host for config changes */
-	*indicatorp = virt_to_dma64(indicators2(vcdev));
+	*indicatorp = indicators2_dma(vcdev);
 	*indicators2(vcdev) = 0;
 	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
 	ccw->flags = 0;
-	ccw->count = sizeof(indicators2(vcdev));
+	ccw->count = sizeof(*indicatorp);
 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
 	if (ret)
 		goto out;
 
 	if (indicatorp)
 		ccw_device_dma_free(vcdev->cdev, indicatorp,
-				    sizeof(indicators(vcdev)));
+				    sizeof(*indicatorp));
 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 	return 0;
 out:
 	if (indicatorp)
 		ccw_device_dma_free(vcdev->cdev, indicatorp,
-				    sizeof(indicators(vcdev)));
+				    sizeof(*indicatorp));
 	ccw_device_dma_free(vcdev->cdev, ccw, sizeof(*ccw));
 	virtio_ccw_del_vqs(vdev);
 	return ret;
@@ -962,7 +997,7 @@ static u8 virtio_ccw_get_status(struct virtio_device *vdev)
 	ccw->cmd_code = CCW_CMD_READ_STATUS;
 	ccw->flags = 0;
 	ccw->count = sizeof(vcdev->dma_area->status);
-	ccw->cda = virt_to_dma32(&vcdev->dma_area->status);
+	ccw->cda = status_dma(vcdev);
 	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_STATUS);
 /*
  * If the channel program failed (should only happen if the device
@@ -995,7 +1030,7 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
 	 * instruction that guarantees the memory writes have
 	 * completed before ssch.
 	 */
-	ccw->cda = virt_to_dma32(&vcdev->dma_area->status);
+	ccw->cda = status_dma(vcdev);
 	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
 	/* Write failed? We assume status is unchanged. */
 	if (ret)
@@ -1332,7 +1367,7 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 	vcdev->cdev = cdev;
 	vcdev->dma_area = ccw_device_dma_zalloc(vcdev->cdev,
 						sizeof(*vcdev->dma_area),
-						NULL);
+						&vcdev->dma_area_addr);
 	if (!vcdev->dma_area) {
 		ret = -ENOMEM;
 		goto out_free;