/**
* _rpmsg_virtio_get_buffer_size
*
* Returns buffer size available for sending messages.
*
* @param rvdev - pointer to rpmsg device
*
* @return - buffer size
*
*/
static int _rpmsg_virtio_get_buffer_size(struct rpmsg_virtio_device *rvdev)
{
unsigned int role = rpmsg_virtio_get_role(rvdev);
int length = 0;
#ifndef VIRTIO_SLAVE_ONLY
if (role == RPMSG_MASTER) {
/*
* If device role is Master then buffers are provided by us,
* so just provide the macro.
*/
length = RPMSG_BUFFER_SIZE - sizeof(struct rpmsg_hdr);
}
#endif /*!VIRTIO_SLAVE_ONLY*/
#ifndef VIRTIO_MASTER_ONLY
if (role == RPMSG_REMOTE) {
/*
* If other core is Master 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 (length < 0) {
length = 0;
}
}
#endif /*!VIRTIO_MASTER_ONLY*/
return length;
}
/**
* rpmsg_get_buffer_size
*
* Returns buffer size available for sending messages.
*
* @param channel - pointer to rpmsg channel
*
* @return - buffer size
*
*/
int rpmsg_get_buffer_size(struct rpmsg_channel *rp_chnl) {
struct remote_device *rdev;
int length;
if (!rp_chnl) {
return RPMSG_ERR_PARAM;
}
/* Get associated remote device for channel. */
rdev = rp_chnl->rdev;
/* Validate device state */
if (rp_chnl->state != RPMSG_CHNL_STATE_ACTIVE
|| rdev->state != RPMSG_DEV_STATE_ACTIVE) {
return RPMSG_ERR_DEV_STATE;
}
env_lock_mutex(rdev->lock);
if (rdev->role == RPMSG_REMOTE) {
/*
* If device role is Remote then buffers are provided by us
* (RPMSG Master), so just provide the macro.
*/
length = RPMSG_BUFFER_SIZE - sizeof(struct rpmsg_hdr);
} else {
/*
* If other core is Master then buffers are provided by it,
* so get the buffer size from the virtqueue.
*/
length = (int) virtqueue_get_desc_size(rdev->tvq) - sizeof(struct rpmsg_hdr);
}
env_unlock_mutex(rdev->lock);
return length;
}