xref: /linux/net/core/netdev_queues.c (revision 1e91c98bc9a8ef8198e73151b2a118cd3748925d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #include <net/netdev_queues.h>
4 #include <net/netdev_rx_queue.h>
5 #include <net/xdp_sock_drv.h>
6 
7 #include "dev.h"
8 
9 /**
10  * netdev_queue_get_dma_dev() - get dma device for zero-copy operations
11  * @dev:	net_device
12  * @idx:	queue index
13  *
14  * Get dma device for zero-copy operations to be used for this queue.
15  * When such device is not available or valid, the function will return NULL.
16  *
17  * Return: Device or NULL on error
18  */
19 struct device *netdev_queue_get_dma_dev(struct net_device *dev, int idx)
20 {
21 	const struct netdev_queue_mgmt_ops *queue_ops = dev->queue_mgmt_ops;
22 	struct device *dma_dev;
23 
24 	if (queue_ops && queue_ops->ndo_queue_get_dma_dev)
25 		dma_dev = queue_ops->ndo_queue_get_dma_dev(dev, idx);
26 	else
27 		dma_dev = dev->dev.parent;
28 
29 	return dma_dev && dma_dev->dma_mask ? dma_dev : NULL;
30 }
31 
32 bool netdev_can_create_queue(const struct net_device *dev,
33 			     struct netlink_ext_ack *extack)
34 {
35 	if (dev->dev.parent) {
36 		NL_SET_ERR_MSG(extack, "Device is not a virtual device");
37 		return false;
38 	}
39 	if (!dev->queue_mgmt_ops ||
40 	    !dev->queue_mgmt_ops->ndo_queue_create) {
41 		NL_SET_ERR_MSG(extack, "Device does not support queue creation");
42 		return false;
43 	}
44 	if (dev->real_num_rx_queues < 1 ||
45 	    dev->real_num_tx_queues < 1) {
46 		NL_SET_ERR_MSG(extack, "Device must have at least one real queue");
47 		return false;
48 	}
49 	return true;
50 }
51 
52 bool netdev_can_lease_queue(const struct net_device *dev,
53 			    struct netlink_ext_ack *extack)
54 {
55 	if (!dev->dev.parent) {
56 		NL_SET_ERR_MSG(extack, "Lease device is a virtual device");
57 		return false;
58 	}
59 	if (!netif_device_present(dev)) {
60 		NL_SET_ERR_MSG(extack, "Lease device has been removed from the system");
61 		return false;
62 	}
63 	if (!dev->queue_mgmt_ops) {
64 		NL_SET_ERR_MSG(extack, "Lease device does not support queue management operations");
65 		return false;
66 	}
67 	return true;
68 }
69 
70 bool netdev_queue_busy(struct net_device *dev, unsigned int idx,
71 		       enum netdev_queue_type type,
72 		       struct netlink_ext_ack *extack)
73 {
74 	if (xsk_get_pool_from_qid(dev, idx)) {
75 		NL_SET_ERR_MSG(extack, "Device queue in use by AF_XDP");
76 		return true;
77 	}
78 	if (type == NETDEV_QUEUE_TYPE_TX)
79 		return false;
80 	if (netif_rxq_is_leased(dev, idx)) {
81 		NL_SET_ERR_MSG(extack, "Device queue in use due to queue leasing");
82 		return true;
83 	}
84 	if (netif_rxq_has_mp(dev, idx)) {
85 		NL_SET_ERR_MSG(extack, "Device queue in use by memory provider");
86 		return true;
87 	}
88 	return false;
89 }
90