xref: /linux/net/core/netdev_rx_queue.c (revision d1e879ec600f9b3bdd253167533959facfefb17b)
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 #include <net/page_pool/memory_provider.h>
7 
8 #include "page_pool_priv.h"
9 
10 int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
11 {
12 	struct netdev_rx_queue *rxq = __netif_get_rx_queue(dev, rxq_idx);
13 	const struct netdev_queue_mgmt_ops *qops = dev->queue_mgmt_ops;
14 	void *new_mem, *old_mem;
15 	int err;
16 
17 	if (!qops || !qops->ndo_queue_stop || !qops->ndo_queue_mem_free ||
18 	    !qops->ndo_queue_mem_alloc || !qops->ndo_queue_start)
19 		return -EOPNOTSUPP;
20 
21 	ASSERT_RTNL();
22 
23 	new_mem = kvzalloc(qops->ndo_queue_mem_size, GFP_KERNEL);
24 	if (!new_mem)
25 		return -ENOMEM;
26 
27 	old_mem = kvzalloc(qops->ndo_queue_mem_size, GFP_KERNEL);
28 	if (!old_mem) {
29 		err = -ENOMEM;
30 		goto err_free_new_mem;
31 	}
32 
33 	err = qops->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 	if (netif_running(dev)) {
42 		err = qops->ndo_queue_stop(dev, old_mem, rxq_idx);
43 		if (err)
44 			goto err_free_new_queue_mem;
45 
46 		err = qops->ndo_queue_start(dev, new_mem, rxq_idx);
47 		if (err)
48 			goto err_start_queue;
49 	} else {
50 		swap(new_mem, old_mem);
51 	}
52 
53 	qops->ndo_queue_mem_free(dev, old_mem);
54 
55 	kvfree(old_mem);
56 	kvfree(new_mem);
57 
58 	return 0;
59 
60 err_start_queue:
61 	/* Restarting the queue with old_mem should be successful as we haven't
62 	 * changed any of the queue configuration, and there is not much we can
63 	 * do to recover from a failure here.
64 	 *
65 	 * WARN if we fail to recover the old rx queue, and at least free
66 	 * old_mem so we don't also leak that.
67 	 */
68 	if (qops->ndo_queue_start(dev, old_mem, rxq_idx)) {
69 		WARN(1,
70 		     "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
71 		     rxq_idx);
72 		qops->ndo_queue_mem_free(dev, old_mem);
73 	}
74 
75 err_free_new_queue_mem:
76 	qops->ndo_queue_mem_free(dev, new_mem);
77 
78 err_free_old_mem:
79 	kvfree(old_mem);
80 
81 err_free_new_mem:
82 	kvfree(new_mem);
83 
84 	return err;
85 }
86 EXPORT_SYMBOL_NS_GPL(netdev_rx_queue_restart, "NETDEV_INTERNAL");
87 
88 static int __net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
89 			     struct pp_memory_provider_params *p)
90 {
91 	struct netdev_rx_queue *rxq;
92 	int ret;
93 
94 	if (ifq_idx >= dev->real_num_rx_queues)
95 		return -EINVAL;
96 	ifq_idx = array_index_nospec(ifq_idx, dev->real_num_rx_queues);
97 
98 	rxq = __netif_get_rx_queue(dev, ifq_idx);
99 	if (rxq->mp_params.mp_ops)
100 		return -EEXIST;
101 
102 	rxq->mp_params = *p;
103 	ret = netdev_rx_queue_restart(dev, ifq_idx);
104 	if (ret) {
105 		rxq->mp_params.mp_ops = NULL;
106 		rxq->mp_params.mp_priv = NULL;
107 	}
108 	return ret;
109 }
110 
111 int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
112 		    struct pp_memory_provider_params *p)
113 {
114 	int ret;
115 
116 	rtnl_lock();
117 	ret = __net_mp_open_rxq(dev, ifq_idx, p);
118 	rtnl_unlock();
119 	return ret;
120 }
121 
122 static void __net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
123 			      struct pp_memory_provider_params *old_p)
124 {
125 	struct netdev_rx_queue *rxq;
126 
127 	if (WARN_ON_ONCE(ifq_idx >= dev->real_num_rx_queues))
128 		return;
129 
130 	rxq = __netif_get_rx_queue(dev, ifq_idx);
131 
132 	/* Callers holding a netdev ref may get here after we already
133 	 * went thru shutdown via dev_memory_provider_uninstall().
134 	 */
135 	if (dev->reg_state > NETREG_REGISTERED &&
136 	    !rxq->mp_params.mp_ops)
137 		return;
138 
139 	if (WARN_ON_ONCE(rxq->mp_params.mp_ops != old_p->mp_ops ||
140 			 rxq->mp_params.mp_priv != old_p->mp_priv))
141 		return;
142 
143 	rxq->mp_params.mp_ops = NULL;
144 	rxq->mp_params.mp_priv = NULL;
145 	WARN_ON(netdev_rx_queue_restart(dev, ifq_idx));
146 }
147 
148 void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
149 		      struct pp_memory_provider_params *old_p)
150 {
151 	rtnl_lock();
152 	__net_mp_close_rxq(dev, ifq_idx, old_p);
153 	rtnl_unlock();
154 }
155