// SPDX-License-Identifier: GPL-2.0-or-later #include <linux/netdevice.h>#include <net/netdev_queues.h>#include <net/netdev_rx_queue.h> #include "page_pool_priv.h" int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx){	struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx);	void *new_mem, *old_mem;	int err; 	if (!dev->queue_mgmt_ops || !dev->queue_mgmt_ops->ndo_queue_stop ||	    !dev->queue_mgmt_ops->ndo_queue_mem_free ||	    !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||	    !dev->queue_mgmt_ops->ndo_queue_start)		return -EOPNOTSUPP; 	ASSERT_RTNL(); 	new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);	if (!new_mem)		return -ENOMEM; 	old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);	if (!old_mem) {		err = -ENOMEM;		goto err_free_new_mem;	} 	err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);	if (err)		goto err_free_old_mem; 	err = page_pool_check_memory_provider(dev, rxq);	if (err)		goto err_free_new_queue_mem; 	err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx);	if (err)		goto err_free_new_queue_mem; 	err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx);	if (err)		goto err_start_queue; 	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem); 	kvfree(old_mem);	kvfree(new_mem); 	return 0; err_start_queue:	/* Restarting the queue with old_mem should be successful as we haven't	 * changed any of the queue configuration, and there is not much we can	 * do to recover from a failure here.	 *	 * WARN if we fail to recover the old rx queue, and at least free	 * old_mem so we don't also leak that.	 */	if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {		WARN(1,		     "Failed to restart old queue in error path. RX queue %d may be unhealthy.",		     rxq_idx);		dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);	} err_free_new_queue_mem:	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem); err_free_old_mem:	kvfree(old_mem); err_free_new_mem:	kvfree(new_mem); 	return err;}