xref: /linux/drivers/net/ethernet/engleder/tsnep_xdp.c (revision f9bff0e31881d03badf191d3b0005839391f5f2b)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2022 Gerhard Engleder <gerhard@engleder-embedded.com> */
3 
4 #include <linux/if_vlan.h>
5 #include <net/xdp_sock_drv.h>
6 
7 #include "tsnep.h"
8 
9 int tsnep_xdp_setup_prog(struct tsnep_adapter *adapter, struct bpf_prog *prog,
10 			 struct netlink_ext_ack *extack)
11 {
12 	struct bpf_prog *old_prog;
13 
14 	old_prog = xchg(&adapter->xdp_prog, prog);
15 	if (old_prog)
16 		bpf_prog_put(old_prog);
17 
18 	return 0;
19 }
20 
21 static int tsnep_xdp_enable_pool(struct tsnep_adapter *adapter,
22 				 struct xsk_buff_pool *pool, u16 queue_id)
23 {
24 	struct tsnep_queue *queue;
25 	int retval;
26 
27 	if (queue_id >= adapter->num_rx_queues ||
28 	    queue_id >= adapter->num_tx_queues)
29 		return -EINVAL;
30 
31 	queue = &adapter->queue[queue_id];
32 	if (queue->rx->queue_index != queue_id ||
33 	    queue->tx->queue_index != queue_id) {
34 		netdev_err(adapter->netdev,
35 			   "XSK support only for TX/RX queue pairs\n");
36 
37 		return -EOPNOTSUPP;
38 	}
39 
40 	retval = xsk_pool_dma_map(pool, adapter->dmadev,
41 				  DMA_ATTR_SKIP_CPU_SYNC);
42 	if (retval) {
43 		netdev_err(adapter->netdev, "failed to map XSK pool\n");
44 
45 		return retval;
46 	}
47 
48 	retval = tsnep_enable_xsk(queue, pool);
49 	if (retval) {
50 		xsk_pool_dma_unmap(pool, DMA_ATTR_SKIP_CPU_SYNC);
51 
52 		return retval;
53 	}
54 
55 	return 0;
56 }
57 
58 static int tsnep_xdp_disable_pool(struct tsnep_adapter *adapter, u16 queue_id)
59 {
60 	struct xsk_buff_pool *pool;
61 	struct tsnep_queue *queue;
62 
63 	if (queue_id >= adapter->num_rx_queues ||
64 	    queue_id >= adapter->num_tx_queues)
65 		return -EINVAL;
66 
67 	pool = xsk_get_pool_from_qid(adapter->netdev, queue_id);
68 	if (!pool)
69 		return -EINVAL;
70 
71 	queue = &adapter->queue[queue_id];
72 
73 	tsnep_disable_xsk(queue);
74 
75 	xsk_pool_dma_unmap(pool, DMA_ATTR_SKIP_CPU_SYNC);
76 
77 	return 0;
78 }
79 
80 int tsnep_xdp_setup_pool(struct tsnep_adapter *adapter,
81 			 struct xsk_buff_pool *pool, u16 queue_id)
82 {
83 	return pool ? tsnep_xdp_enable_pool(adapter, pool, queue_id) :
84 		      tsnep_xdp_disable_pool(adapter, queue_id);
85 }
86