openamp: add new ops wait_notified() support

This can avoid looping check tx buffer

Signed-off-by: Guiding Li <[email protected]>

lib/include/openamp/remoteproc.h

@@ -433,6 +433,18 @@ struct remoteproc_ops {
 					  metal_phys_addr_t da,
 					  void *va, size_t size,
 					  struct remoteproc_mem *buf);
+	/**
+	 * wait_notified
+	 *
+	 * Wait for remote notified, when there is no TX buffer anymore.
+	 * Set to NULL means use usleep to TX buffer available.
+	 *
+	 * @rproc - pointer to remoteproc instance
+	 * @id    - the notifyid
+	 *
+	 * return 0 means there is notify available, otherwise negative value.
+	 */
+	int (*wait_notified)(struct remoteproc *rproc, uint32_t id);
 };
 
 /* Remoteproc error codes */

lib/include/openamp/remoteproc_virtio.h

@@ -22,6 +22,7 @@ extern "C" {
 
 /* define vdev notification function user should implement */
 typedef int (*rpvdev_notify_func)(void *priv, uint32_t id);
+typedef int (*rpvdev_wait_notified_func)(void *priv, uint32_t id);
 
 /**
  * struct remoteproc_virtio
@@ -37,6 +38,7 @@ struct remoteproc_virtio {
 	void *vdev_rsc;
 	struct metal_io_region *vdev_rsc_io;
 	rpvdev_notify_func notify;
+	rpvdev_wait_notified_func wait_notified;
 	struct virtio_device vdev;
 	struct metal_list node;
 };
@@ -62,6 +64,7 @@ rproc_virtio_create_vdev(unsigned int role, unsigned int notifyid,
 			 void *rsc, struct metal_io_region *rsc_io,
 			 void *priv,
 			 rpvdev_notify_func notify,
+			 rpvdev_wait_notified_func wait_notified,
 			 virtio_dev_reset_cb rst_cb);
 
 /**

lib/include/openamp/rpmsg.h

@@ -42,6 +42,7 @@ extern "C" {
 #define RPMSG_ERR_BUFF_SIZE		(RPMSG_ERROR_BASE - 5)
 #define RPMSG_ERR_INIT			(RPMSG_ERROR_BASE - 6)
 #define RPMSG_ERR_ADDR			(RPMSG_ERROR_BASE - 7)
+#define RPMSG_ERR_NXIO			(RPMSG_ERROR_BASE - 8)
 
 struct rpmsg_endpoint;
 struct rpmsg_device;

lib/include/openamp/rpmsg_virtio.h

@@ -125,6 +125,15 @@ rpmsg_virtio_create_virtqueues(struct rpmsg_virtio_device *rvdev,
 					callbacks);
 }
 
+static inline int
+rpmsg_virtio_wait_notified(struct rpmsg_virtio_device *rvdev,
+					struct virtqueue *vq)
+{
+	return rvdev->vdev->func->wait_notified ?
+			rvdev->vdev->func->wait_notified(rvdev->vdev, vq) :
+			RPMSG_ERR_NXIO;
+}
+
 /**
  * rpmsg_virtio_get_buffer_size - get rpmsg virtio buffer size
  *

lib/include/openamp/virtio.h

@@ -137,6 +137,7 @@ struct virtio_dispatch {
 			     void *src, int length);
 	void (*reset_device)(struct virtio_device *dev);
 	void (*notify)(struct virtqueue *vq);
+	int (*wait_notified)(struct virtio_device *dev, struct virtqueue *vq);
 };
 
 int virtio_create_virtqueues(struct virtio_device *vdev, unsigned int flags,

lib/remoteproc/remoteproc.c

@@ -880,6 +880,16 @@ static int remoteproc_virtio_notify(void *priv, uint32_t id)
 	return 0;
 }
 
+static int remoteproc_virtio_wait_notified(void *priv, uint32_t id)
+{
+	struct remoteproc *rproc = priv;
+
+	if (rproc->ops->wait_notified)
+		return rproc->ops->wait_notified(rproc, id);
+
+	return 0;
+}
+
 struct virtio_device *
 remoteproc_create_virtio(struct remoteproc *rproc,
 			 int vdev_id, unsigned int role,
@@ -918,6 +928,7 @@ remoteproc_create_virtio(struct remoteproc *rproc,
 	vdev = rproc_virtio_create_vdev(role, notifyid,
 					vdev_rsc, vdev_rsc_io, rproc,
 					remoteproc_virtio_notify,
+					remoteproc_virtio_wait_notified,
 					rst_cb);
 	if (!vdev) {
 		metal_mutex_release(&rproc->lock);

lib/remoteproc/remoteproc_virtio.c

@@ -30,6 +30,19 @@ static void rproc_virtio_virtqueue_notify(struct virtqueue *vq)
 	rpvdev->notify(rpvdev->priv, vring_info->notifyid);
 }
 
+static int rproc_virtio_wait_notified(struct virtio_device *vdev,
+				struct virtqueue *vq)
+{
+	struct remoteproc_virtio *rpvdev;
+	struct virtio_vring_info *vring_info;
+	unsigned int vq_id = vq->vq_queue_index;
+
+	rpvdev = metal_container_of(vdev, struct remoteproc_virtio, vdev);
+	vring_info = &vdev->vrings_info[vq_id];
+
+	return rpvdev->wait_notified(rpvdev->priv, vring_info->notifyid);
+}
+
 static unsigned char rproc_virtio_get_status(struct virtio_device *vdev)
 {
 	struct remoteproc_virtio *rpvdev;
@@ -179,6 +192,7 @@ static const struct virtio_dispatch remoteproc_virtio_dispatch_funcs = {
 	.get_features = rproc_virtio_get_features,
 	.read_config = rproc_virtio_read_config,
 	.notify = rproc_virtio_virtqueue_notify,
+	.wait_notified = rproc_virtio_wait_notified,
 #ifndef VIRTIO_SLAVE_ONLY
 	/*
 	 * We suppose here that the vdev is in a shared memory so that can
@@ -198,6 +212,7 @@ rproc_virtio_create_vdev(unsigned int role, unsigned int notifyid,
 			 void *rsc, struct metal_io_region *rsc_io,
 			 void *priv,
 			 rpvdev_notify_func notify,
+			 rpvdev_wait_notified_func wait_notified,
 			 virtio_dev_reset_cb rst_cb)
 {
 	struct remoteproc_virtio *rpvdev;
@@ -233,6 +248,7 @@ rproc_virtio_create_vdev(unsigned int role, unsigned int notifyid,
 	}
 
 	rpvdev->notify = notify;
+	rpvdev->wait_notified = wait_notified;
 	rpvdev->priv = priv;
 	vdev->vrings_info = vrings_info;
 	/* Assuming the shared memory has been mapped and registered if

lib/rpmsg/rpmsg_virtio.c

@@ -346,6 +346,13 @@ static void *rpmsg_virtio_get_tx_payload_buffer(struct rpmsg_device *rdev,
 		metal_mutex_release(&rdev->lock);
 		if (rp_hdr || !tick_count)
 			break;
+
+		status = rpmsg_virtio_wait_notified(rvdev, rvdev->rvq);
+		if (status == RPMSG_SUCCESS)
+			continue;
+		else if (status != RPMSG_ERR_NXIO)
+			break;
+
 		metal_sleep_usec(RPMSG_TICKS_PER_INTERVAL);
 		tick_count--;
 	}