Subject: [RFC PATCH 2/4] mdev: introduce helper to set per device dma ops

From: Jason Wang <[email-masked]>
Date: Tue, 10 Sep 2019 16:19:33 +0800

This patch introduces mdev_set_dma_ops() which allows parent to set
per device DMA ops. This help for the kernel driver to setup a correct
DMA mappings.

Signed-off-by: Jason Wang <[email-masked]>
---
 drivers/vfio/mdev/mdev_core.c | 7 +++++++
 include/linux/mdev.h          | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index b558d4cfd082..eb28552082d7 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -13,6 +13,7 @@
 #include <linux/uuid.h>
 #include <linux/sysfs.h>
 #include <linux/mdev.h>
+#include <linux/dma-mapping.h>
 
 #include "mdev_private.h"
 
@@ -27,6 +28,12 @@ static struct class_compat *mdev_bus_compat_class;
 static LIST_HEAD(mdev_list);
 static DEFINE_MUTEX(mdev_list_lock);
 
+void mdev_set_dma_ops(struct mdev_device *mdev, struct dma_map_ops *ops)
+{
+	set_dma_ops(&mdev->dev, ops);
+}
+EXPORT_SYMBOL(mdev_set_dma_ops);
+
 struct device *mdev_parent_dev(struct mdev_device *mdev)
 {
 	return mdev->parent->dev;
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 0ce30ca78db0..7195f40bf8bf 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -145,4 +145,6 @@ struct device *mdev_parent_dev(struct mdev_device *mdev);
 struct device *mdev_dev(struct mdev_device *mdev);
 struct mdev_device *mdev_from_dev(struct device *dev);
 
+void mdev_set_dma_ops(struct mdev_device *mdev, struct dma_map_ops *ops);
+
 #endif /* MDEV_H */
-- 
2.19.1