1// SPDX-License-Identifier: GPL-2.0-or-later
 2
 3#include <linux/netdevice.h>
 4#include <net/netdev_queues.h>
 5#include <net/netdev_rx_queue.h>
 6
 7#include "page_pool_priv.h"
 8
 9int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
10{
11	struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx);
12	void *new_mem, *old_mem;
13	int err;
14
15	if (!dev->queue_mgmt_ops || !dev->queue_mgmt_ops->ndo_queue_stop ||
16	    !dev->queue_mgmt_ops->ndo_queue_mem_free ||
17	    !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||
18	    !dev->queue_mgmt_ops->ndo_queue_start)
19		return -EOPNOTSUPP;
20
21	ASSERT_RTNL();
22
23	new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
24	if (!new_mem)
25		return -ENOMEM;
26
27	old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
28	if (!old_mem) {
29		err = -ENOMEM;
30		goto err_free_new_mem;
31	}
32
33	err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);
34	if (err)
35		goto err_free_old_mem;
36
37	err = page_pool_check_memory_provider(dev, rxq);
38	if (err)
39		goto err_free_new_queue_mem;
40
41	err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx);
42	if (err)
43		goto err_free_new_queue_mem;
44
45	err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx);
46	if (err)
47		goto err_start_queue;
48
49	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
50
51	kvfree(old_mem);
52	kvfree(new_mem);
53
54	return 0;
55
56err_start_queue:
57	/* Restarting the queue with old_mem should be successful as we haven't
58	 * changed any of the queue configuration, and there is not much we can
59	 * do to recover from a failure here.
60	 *
61	 * WARN if we fail to recover the old rx queue, and at least free
62	 * old_mem so we don't also leak that.
63	 */
64	if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {
65		WARN(1,
66		     "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
67		     rxq_idx);
68		dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
69	}
70
71err_free_new_queue_mem:
72	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem);
73
74err_free_old_mem:
75	kvfree(old_mem);
76
77err_free_new_mem:
78	kvfree(new_mem);
79
80	return err;
81}