rpmsg: Add API for retrieving message buffer sizes

Add an RPMsg API to get the buffer sizes supported by the backing transport layer. Add hooks so that transport layers can register functions to provide this data. Signed-off-by: Andrew Davis <[email protected]>
OpenAMP · Mar 15, 2024 · 78e7e58 · 78e7e58
1 parent 79b795e
commit 78e7e58
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diff --git a/lib/include/openamp/rpmsg.h b/lib/include/openamp/rpmsg.h
@@ -121,6 +121,12 @@ struct rpmsg_device_ops {
 
 	/** Release RPMsg TX buffer */
 	int (*release_tx_buffer)(struct rpmsg_device *rdev, void *txbuf);
+
+	/** Get RPMsg RX buffer size */
+	int (*get_rx_buffer_size)(struct rpmsg_device *rdev);
+
+	/** Get RPMsg TX buffer size */
+	int (*get_tx_buffer_size)(struct rpmsg_device *rdev);
 };
 
 /** @brief Representation of a RPMsg device */
@@ -404,6 +410,24 @@ void *rpmsg_get_tx_payload_buffer(struct rpmsg_endpoint *ept,
  */
 int rpmsg_release_tx_buffer(struct rpmsg_endpoint *ept, void *txbuf);
 
+/**
+ * @brief Get RPMsg Tx buffer size
+ *
+ * @param ept	The rpmsg endpoint
+ *
+ * @return Next available Tx buffer size, 0 for failure
+ */
+int rpmsg_get_tx_buffer_size(struct rpmsg_endpoint *ept);
+
+/**
+ * @brief Get RPMsg Rx buffer size
+ *
+ * @param ept	The rpmsg endpoint
+ *
+ * @return Next available Rx buffer size, 0 for failure
+ */
+int rpmsg_get_rx_buffer_size(struct rpmsg_endpoint *ept);
+
 /**
  * @brief Send a message in tx buffer reserved by
  * rpmsg_get_tx_payload_buffer() across to the remote processor.

diff --git a/lib/rpmsg/rpmsg.c b/lib/rpmsg/rpmsg.c
@@ -208,6 +208,36 @@ void *rpmsg_get_tx_payload_buffer(struct rpmsg_endpoint *ept,
 	return NULL;
 }
 
+int rpmsg_get_tx_buffer_size(struct rpmsg_endpoint *ept)
+{
+	struct rpmsg_device *rdev;
+
+	if (!ept || !ept->rdev)
+		return 0;
+
+	rdev = ept->rdev;
+
+	if (rdev->ops.get_tx_buffer_size)
+		return rdev->ops.get_tx_buffer_size(rdev);
+
+	return 0;
+}
+
+int rpmsg_get_rx_buffer_size(struct rpmsg_endpoint *ept)
+{
+	struct rpmsg_device *rdev;
+
+	if (!ept || !ept->rdev)
+		return 0;
+
+	rdev = ept->rdev;
+
+	if (rdev->ops.get_rx_buffer_size)
+		return rdev->ops.get_rx_buffer_size(rdev);
+
+	return 0;
+}
+
 int rpmsg_send_offchannel_nocopy(struct rpmsg_endpoint *ept, uint32_t src,
 				 uint32_t dst, const void *data, int len)
 {