On Mon, 5 Aug 2024 21:25:16 +0000 Mina Almasry wrote:
> +/* Protected by rtnl_lock() */
> +static DEFINE_XARRAY_FLAGS(net_devmem_dmabuf_bindings, XA_FLAGS_ALLOC1);
nit: global variable declarations before any code
> +void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding)
> +{
> + struct netdev_rx_queue *rxq;
> + unsigned long xa_idx;
> + unsigned int rxq_idx;
> +
> + if (binding->list.next)
> + list_del(&binding->list);
> +
> + xa_for_each(&binding->bound_rxqs, xa_idx, rxq) {
> + if (rxq->mp_params.mp_priv == binding) {
> + rxq->mp_params.mp_priv = NULL;
> +
> + rxq_idx = get_netdev_rx_queue_index(rxq);
> +
> + netdev_rx_queue_restart(binding->dev, rxq_idx);
Throw in a WARN_ON() around this, hopefully we'll get to addressing it
later..
> + }
> + }
> +
> + xa_erase(&net_devmem_dmabuf_bindings, binding->id);
> +
> + net_devmem_dmabuf_binding_put(binding);
> +}
> +
> +int net_devmem_bind_dmabuf_to_queue(struct net_device *dev, u32 rxq_idx,
> + struct net_devmem_dmabuf_binding *binding)
> +{
> + struct netdev_rx_queue *rxq;
> + u32 xa_idx;
> + int err;
> +
> + if (rxq_idx >= dev->real_num_rx_queues)
> + return -ERANGE;
If we prevent binding to an inactive queue we should also prevent
deactivation.
Please take a look at the (two?) callers of
ethtool_get_max_rxnfc_channel() and ethtool_get_max_rxfh_channel().
Wrap those into a new function for reading max active channel, and
take mp binds into account as well (send the refactor separately
from the series to avoid making it longer).
> + rxq = __netif_get_rx_queue(dev, rxq_idx);
> + if (rxq->mp_params.mp_priv)
> + return -EEXIST;
> +
> + err = xa_alloc(&binding->bound_rxqs, &xa_idx, rxq, xa_limit_32b,
> + GFP_KERNEL);
> + if (err)
> + return err;
> +
> + rxq->mp_params.mp_priv = binding;
> +
> + err = netdev_rx_queue_restart(dev, rxq_idx);
> + if (err)
> + goto err_xa_erase;
> +
> + return 0;
> +
> +err_xa_erase:
> + rxq->mp_params.mp_priv = NULL;
> + xa_erase(&binding->bound_rxqs, xa_idx);
> +
> + return err;
> +}
> +void dev_dmabuf_uninstall(struct net_device *dev)
> +{
> + unsigned int i, count = dev->num_rx_queues;
nit: why stash the value of num_rx_queues ?
> + struct net_devmem_dmabuf_binding *binding;
> + struct netdev_rx_queue *rxq;
> + unsigned long xa_idx;
> +
> + for (i = 0; i < count; i++) {
> + binding = dev->_rx[i].mp_params.mp_priv;
> + if (binding)
> + xa_for_each(&binding->bound_rxqs, xa_idx, rxq)
> + if (rxq == &dev->_rx[i])
> + xa_erase(&binding->bound_rxqs, xa_idx);
nit: Please use "continue", this is too deeply indented
> + nla_for_each_attr_type(attr, NETDEV_A_DMABUF_QUEUES,
> + genlmsg_data(info->genlhdr),
> + genlmsg_len(info->genlhdr), rem) {
> + err = nla_parse_nested(
> + tb, ARRAY_SIZE(netdev_queue_id_nl_policy) - 1, attr,
> + netdev_queue_id_nl_policy, info->extack);
> + if (err < 0)
> + goto err_unbind;
> +
> + rxq_idx = nla_get_u32(tb[NETDEV_A_QUEUE_ID]);
How do we know this attribute is present? NL_REQ_ATTR_CHECK()
> + err = net_devmem_bind_dmabuf_to_queue(netdev, rxq_idx, binding);
> + if (err)
> + goto err_unbind;
> + }
> +
> + list_add(&binding->list, sock_binding_list);
> +
> + nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id);
> + genlmsg_end(rsp, hdr);
> +
> + rtnl_unlock();
nit: for symmetry you should also unlock after list_add(),
netlink msg alloc and prep are before rtnl_lock()
> + return genlmsg_reply(rsp, info);
> +
> +err_unbind:
> + net_devmem_unbind_dmabuf(binding);
> +err_unlock:
> + rtnl_unlock();
> +err_genlmsg_free:
> + nlmsg_free(rsp);
> + return err;
> }
> +void netdev_nl_sock_priv_init(struct list_head *priv)
> +{
> + INIT_LIST_HEAD(priv);
> +}
> +
> +void netdev_nl_sock_priv_destroy(struct list_head *priv)
> +{
> + struct net_devmem_dmabuf_binding *binding;
> + struct net_devmem_dmabuf_binding *temp;
> +
> + list_for_each_entry_safe(binding, temp, priv, list) {
> + rtnl_lock();
> + net_devmem_unbind_dmabuf(binding);
> + rtnl_unlock();
> + }
> +}
nit: move these before the subsys_initcall.. and what it calls
