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

@@ -166,13 +166,37 @@ 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);
+int rpmsg_virtio_get_tx_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 Get rpmsg virtio Tx buffer size
+ *
+ * This function is same as rpmsg_virtio_get_tx_buffer_size(), keep it here
+ * to maintain the forward compatibility.
+ *
+ * @param rdev Pointer to the rpmsg device.
+ *
+ * @return Next available buffer size for text, negative value for failure.
+ */
+static inline int rpmsg_virtio_get_buffer_size(struct rpmsg_device *rdev)
+{
+ return rpmsg_virtio_get_tx_buffer_size(rdev);
+}
 
 /**
  * @brief Initialize rpmsg virtio device

lib/rpmsg/rpmsg_internal.h

@@ -34,6 +34,17 @@ extern "C" {
  ((struct rpmsg_hdr *)((unsigned char *)(p) - sizeof(struct rpmsg_hdr)))
 #define RPMSG_LOCATE_DATA(p) ((unsigned char *)(p) + sizeof(struct rpmsg_hdr))
 
+/**
+ * enum rpmsg_buffer_type - rpmsg buffer type
+ *
+ * @RPMSG_BUFFER_RX: rpmsg rx buffer type
+ * @RPMSG_BUFFER_TX: rpmsg tx buffer type
+ */
+enum rpmsg_buffer_type {
+ RPMSG_BUFFER_RX = 0,
+ RPMSG_BUFFER_TX = 1,
+};
+
 /**
  * enum rpmsg_ns_flags - dynamic name service announcement flags
  *

lib/rpmsg/rpmsg_virtio.c

@@ -273,13 +273,15 @@ 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,
+ enum rpmsg_buffer_type type)
 {
  unsigned int role = rpmsg_virtio_get_role(rvdev);
  int length = 0;
@@ -290,7 +292,10 @@ 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);
+ if (type == RPMSG_BUFFER_TX)
+ length = rvdev->config.h2r_buf_size;
+ else if (type == RPMSG_BUFFER_RX)
+ length = rvdev->config.r2h_buf_size - sizeof(struct rpmsg_hdr);
  }
 #endif /*!VIRTIO_DEVICE_ONLY*/
 
@@ -300,9 +305,12 @@ static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev)
  * If other core is host then buffers are provided by it,
  * so get the buffer size from the virtqueue.
  */
- length =
- (int)virtqueue_get_desc_size(rvdev->svq) -
- sizeof(struct rpmsg_hdr);
+ if (type == RPMSG_BUFFER_TX)
+ length = (int)virtqueue_get_desc_size(rvdev->svq) -
+ sizeof(struct rpmsg_hdr);
+ else if (type == RPMSG_BUFFER_RX)
+ length = (int)virtqueue_get_desc_size(rvdev->rvq) -
+ sizeof(struct rpmsg_hdr);
  }
 #endif /*!VIRTIO_DRIVER_ONLY*/
 
@@ -661,7 +669,7 @@ static int rpmsg_virtio_ns_callback(struct rpmsg_endpoint *ept, void *data,
  return RPMSG_SUCCESS;
 }
 
-int rpmsg_virtio_get_buffer_size(struct rpmsg_device *rdev)
+int rpmsg_virtio_get_tx_buffer_size(struct rpmsg_device *rdev)
 {
  int size;
  struct rpmsg_virtio_device *rvdev;
@@ -670,7 +678,21 @@ 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, RPMSG_BUFFER_TX);
+ 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, RPMSG_BUFFER_RX);
  metal_mutex_release(&rdev->lock);
  return size;
 }