[PATCH v11 04/12] vdpa: Add reset callback in vdpa_config_ops

[Xie Yongji <xieyongji@bytedance.com>]

This adds a new callback to support device specific reset
behavior. The vdpa bus driver will call the reset function
instead of setting status to zero during resetting if device
driver supports the new callback.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
---
 drivers/vhost/vdpa.c |  9 +++++++--
 include/linux/vdpa.h | 11 ++++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index b07aa161f7ad..b1c91b4db0ba 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -157,7 +157,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	struct vdpa_device *vdpa = v->vdpa;
 	const struct vdpa_config_ops *ops = vdpa->config;
 	u8 status, status_old;
-	int nvqs = v->nvqs;
+	int ret, nvqs = v->nvqs;
 	u16 i;
 
 	if (copy_from_user(&status, statusp, sizeof(status)))
@@ -172,7 +172,12 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
 	if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
 		return -EINVAL;
 
-	ops->set_status(vdpa, status);
+	if (status == 0 && ops->reset) {
+		ret = ops->reset(vdpa);
+		if (ret)
+			return ret;
+	} else
+		ops->set_status(vdpa, status);
 
 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
 		for (i = 0; i < nvqs; i++)
diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 8a645f8f4476..af7ea5ad795f 100644
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -196,6 +196,9 @@ struct vdpa_iova_range {
  *				@vdev: vdpa device
  *				Returns the iova range supported by
  *				the device.
+ * @reset:			Reset device (optional)
+ *				@vdev: vdpa device
+ *				Returns integer: success (0) or error (< 0)
  * @set_map:			Set device memory mapping (optional)
  *				Needed for device that using device
  *				specific DMA translation (on-chip IOMMU)
@@ -263,6 +266,7 @@ struct vdpa_config_ops {
 			   const void *buf, unsigned int len);
 	u32 (*get_generation)(struct vdpa_device *vdev);
 	struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
+	int (*reset)(struct vdpa_device *vdev);
 
 	/* DMA ops */
 	int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
@@ -351,12 +355,17 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
 	return vdev->dma_dev;
 }
 
-static inline void vdpa_reset(struct vdpa_device *vdev)
+static inline int vdpa_reset(struct vdpa_device *vdev)
 {
 	const struct vdpa_config_ops *ops = vdev->config;
 
 	vdev->features_valid = false;
+	if (ops->reset)
+		return ops->reset(vdev);
+
 	ops->set_status(vdev, 0);
+
+	return 0;
 }
 
 static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
-- 
2.11.0