aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
blob: 0184ef6f05a7440068952ee9b196f6943a716cbe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/* Broadcom NetXtreme-C/E network driver.
 *
 * Copyright (c) 2016-2017 Broadcom Limited
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/filter.h>
#include "bnxt_hsi.h"
#include "bnxt.h"
#include "bnxt_xdp.h"

void bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
		   dma_addr_t mapping, u32 len, u16 rx_prod)
{
	struct bnxt_sw_tx_bd *tx_buf;
	struct tx_bd *txbd;
	u32 flags;
	u16 prod;

	prod = txr->tx_prod;
	tx_buf = &txr->tx_buf_ring[prod];
	tx_buf->rx_prod = rx_prod;

	txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
	flags = (len << TX_BD_LEN_SHIFT) | (1 << TX_BD_FLAGS_BD_CNT_SHIFT) |
		TX_BD_FLAGS_PACKET_END | bnxt_lhint_arr[len >> 9];
	txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
	txbd->tx_bd_opaque = prod;
	txbd->tx_bd_haddr = cpu_to_le64(mapping);

	prod = NEXT_TX(prod);
	txr->tx_prod = prod;
}

void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
{
	struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
	struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
	struct bnxt_sw_tx_bd *tx_buf;
	u16 tx_cons = txr->tx_cons;
	u16 last_tx_cons = tx_cons;
	u16 rx_prod;
	int i;

	for (i = 0; i < nr_pkts; i++) {
		last_tx_cons = tx_cons;
		tx_cons = NEXT_TX(tx_cons);
	}
	txr->tx_cons = tx_cons;
	if (bnxt_tx_avail(bp, txr) == bp->tx_ring_size) {
		rx_prod = rxr->rx_prod;
	} else {
		tx_buf = &txr->tx_buf_ring[last_tx_cons];
		rx_prod = tx_buf->rx_prod;
	}
	bnxt_db_write(bp, &rxr->rx_db, rx_prod);
}

/* returns the following:
 * true    - packet consumed by XDP and new buffer is allocated.
 * false   - packet should be passed to the stack.
 */
bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
		 struct page *page, u8 **data_ptr, unsigned int *len, u8 *event)
{
	struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
	struct bnxt_tx_ring_info *txr;
	struct bnxt_sw_rx_bd *rx_buf;
	struct pci_dev *pdev;
	struct xdp_buff xdp;
	dma_addr_t mapping;
	void *orig_data;
	u32 tx_avail;
	u32 offset;
	u32 act;

	if (!xdp_prog)
		return false;

	pdev = bp->pdev;
	txr = rxr->bnapi->tx_ring;
	rx_buf = &rxr->rx_buf_ring[cons];
	offset = bp->rx_offset;

	xdp.data_hard_start = *data_ptr - offset;
	xdp.data = *data_ptr;
	xdp_set_data_meta_invalid(&xdp);
	xdp.data_end = *data_ptr + *len;
	xdp.rxq = &rxr->xdp_rxq;
	orig_data = xdp.data;
	mapping = rx_buf->mapping - bp->rx_dma_offset;

	dma_sync_single_for_cpu(&pdev->dev, mapping + offset, *len, bp->rx_dir);

	rcu_read_lock();
	act = bpf_prog_run_xdp(xdp_prog, &xdp);
	rcu_read_unlock();

	tx_avail = bnxt_tx_avail(bp, txr);
	/* If the tx ring is not full, we must not update the rx producer yet
	 * because we may still be transmitting on some BDs.
	 */
	if (tx_avail != bp->tx_ring_size)
		*event &= ~BNXT_RX_EVENT;

	*len = xdp.data_end - xdp.data;
	if (orig_data != xdp.data) {
		offset = xdp.data - xdp.data_hard_start;
		*data_ptr = xdp.data_hard_start + offset;
	}
	switch (act) {
	case XDP_PASS:
		return false;

	case XDP_TX:
		if (tx_avail < 1) {
			trace_xdp_exception(bp->dev, xdp_prog, act);
			bnxt_reuse_rx_data(rxr, cons, page);
			return true;
		}

		*event = BNXT_TX_EVENT;
		dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
					   bp->rx_dir);
		bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
			      NEXT_RX(rxr->rx_prod));
		bnxt_reuse_rx_data(rxr, cons, page);
		return true;
	default:
		bpf_warn_invalid_xdp_action(act);
		/* Fall thru */
	case XDP_ABORTED:
		trace_xdp_exception(bp->dev, xdp_prog, act);
		/* Fall thru */
	case XDP_DROP:
		bnxt_reuse_rx_data(rxr, cons, page);
		break;
	}
	return true;
}

/* Under rtnl_lock */
static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
{
	struct net_device *dev = bp->dev;
	int tx_xdp = 0, rc, tc;
	struct bpf_prog *old;

	if (prog && bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
		netdev_warn(dev, "MTU %d larger than largest XDP supported MTU %d.\n",
			    bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
		return -EOPNOTSUPP;
	}
	if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
		netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
		return -EOPNOTSUPP;
	}
	if (prog)
		tx_xdp = bp->rx_nr_rings;

	tc = netdev_get_num_tc(dev);
	if (!tc)
		tc = 1;
	rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
			      true, tc, tx_xdp);
	if (rc) {
		netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
		return rc;
	}
	if (netif_running(dev))
		bnxt_close_nic(bp, true, false);

	old = xchg(&bp->xdp_prog, prog);
	if (old)
		bpf_prog_put(old);

	if (prog) {
		bnxt_set_rx_skb_mode(bp, true);
	} else {
		int rx, tx;

		bnxt_set_rx_skb_mode(bp, false);
		bnxt_get_max_rings(bp, &rx, &tx, true);
		if (rx > 1) {
			bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
			bp->dev->hw_features |= NETIF_F_LRO;
		}
	}
	bp->tx_nr_rings_xdp = tx_xdp;
	bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
	bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
	bnxt_set_tpa_flags(bp);
	bnxt_set_ring_params(bp);

	if (netif_running(dev))
		return bnxt_open_nic(bp, true, false);

	return 0;
}

int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
	struct bnxt *bp = netdev_priv(dev);
	int rc;

	switch (xdp->command) {
	case XDP_SETUP_PROG:
		rc = bnxt_xdp_set(bp, xdp->prog);
		break;
	case XDP_QUERY_PROG:
		xdp->prog_id = bp->xdp_prog ? bp->xdp_prog->aux->id : 0;
		rc = 0;
		break;
	default:
		rc = -EINVAL;
		break;
	}
	return rc;
}