openamp: add new API rpmsg_virtio_get_rx_buffer_size()

This API can be used by the endpoint callback to limit the rx
buffer usage range.

Signed-off-by: Guiding Li <liguiding1@xiaomi.com>
Signed-off-by: Bowen Wang <wangbowen6@xiaomi.com>

lib/include/openamp/rpmsg_virtio.h

@@ -166,14 +166,23 @@ rpmsg_virtio_create_virtqueues(struct rpmsg_virtio_device *rvdev,
 }
 
 /**
- * @brief Get rpmsg virtio buffer size
+ * @brief Get rpmsg virtio Tx buffer size
  *
  * @param rdev Pointer to the rpmsg device
  *
  * @return Next available buffer size for text, negative value for failure
  */
 int rpmsg_virtio_get_buffer_size(struct rpmsg_device *rdev);
 
+/**
+ * @brief Get rpmsg virtio Rx buffer size
+ *
+ * @param rdev Pointer to the rpmsg device
+ *
+ * @return Next available buffer size for text, negative value for failure
+ */
+int rpmsg_virtio_get_rx_buffer_size(struct rpmsg_device *rdev);
+
 /**
  * @brief Initialize rpmsg virtio device
  *

lib/rpmsg/rpmsg_virtio.c

@@ -273,13 +273,14 @@ static int rpmsg_virtio_wait_remote_ready(struct rpmsg_virtio_device *rvdev)
 /**
  * @internal
  *
- * @brief Returns buffer size available for sending messages.
+ * @brief Returns buffer size available for sending/receiving messages.
  *
  * @param rvdev Pointer to rpmsg device
+ * @param tx Tx or Rx buffer
  *
  * @return Buffer size
  */
-static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev)
+static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev, bool tx)
 {
  unsigned int role = rpmsg_virtio_get_role(rvdev);
  int length = 0;
@@ -290,7 +291,9 @@ static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev)
  * If device role is host then buffers are provided by us,
  * so just provide the macro.
  */
- length = rvdev->config.h2r_buf_size - sizeof(struct rpmsg_hdr);
+ length =
+ tx ? rvdev->config.h2r_buf_size : rvdev->config.r2h_buf_size
+ - sizeof(struct rpmsg_hdr);
  }
 #endif /*!VIRTIO_DEVICE_ONLY*/
 
@@ -301,7 +304,7 @@ static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev)
  * so get the buffer size from the virtqueue.
  */
  length =
- (int)virtqueue_get_desc_size(rvdev->svq) -
+ (int)virtqueue_get_desc_size(tx ? rvdev->svq : rvdev->rvq) -
  sizeof(struct rpmsg_hdr);
  }
 #endif /*!VIRTIO_DRIVER_ONLY*/
@@ -670,7 +673,21 @@ int rpmsg_virtio_get_buffer_size(struct rpmsg_device *rdev)
  return RPMSG_ERR_PARAM;
  metal_mutex_acquire(&rdev->lock);
  rvdev = (struct rpmsg_virtio_device *)rdev;
- size = _rpmsg_virtio_get_buffer_size(rvdev);
+ size = _rpmsg_virtio_get_buffer_size(rvdev, true);
+ metal_mutex_release(&rdev->lock);
+ return size;
+}
+
+int rpmsg_virtio_get_rx_buffer_size(struct rpmsg_device *rdev)
+{
+ int size;
+ struct rpmsg_virtio_device *rvdev;
+
+ if (!rdev)
+ return RPMSG_ERR_PARAM;
+ metal_mutex_acquire(&rdev->lock);
+ rvdev = (struct rpmsg_virtio_device *)rdev;
+ size = _rpmsg_virtio_get_buffer_size(rvdev, false);
  metal_mutex_release(&rdev->lock);
  return size;
 }