1/* Broadcom NetXtreme-C/E network driver.
2 *
3 * Copyright (c) 2016-2017 Broadcom Limited
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation.
8 */
9#include <linux/kernel.h>
10#include <linux/errno.h>
11#include <linux/pci.h>
12#include <linux/netdevice.h>
13#include <linux/etherdevice.h>
14#include <linux/if_vlan.h>
15#include <linux/bpf.h>
16#include <linux/bpf_trace.h>
17#include <linux/filter.h>
18#include "bnxt_hsi.h"
19#include "bnxt.h"
20#include "bnxt_xdp.h"
21
22void bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
23 dma_addr_t mapping, u32 len, u16 rx_prod)
24{
25 struct bnxt_sw_tx_bd *tx_buf;
26 struct tx_bd *txbd;
27 u32 flags;
28 u16 prod;
29
30 prod = txr->tx_prod;
31 tx_buf = &txr->tx_buf_ring[prod];
32 tx_buf->rx_prod = rx_prod;
33
34 txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
35 flags = (len << TX_BD_LEN_SHIFT) | (1 << TX_BD_FLAGS_BD_CNT_SHIFT) |
36 TX_BD_FLAGS_PACKET_END | bnxt_lhint_arr[len >> 9];
37 txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
38 txbd->tx_bd_opaque = prod;
39 txbd->tx_bd_haddr = cpu_to_le64(mapping);
40
41 prod = NEXT_TX(prod);
42 txr->tx_prod = prod;
43}
44
45void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
46{
47 struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
48 struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
49 struct bnxt_sw_tx_bd *tx_buf;
50 u16 tx_cons = txr->tx_cons;
51 u16 last_tx_cons = tx_cons;
52 u16 rx_prod;
53 int i;
54
55 for (i = 0; i < nr_pkts; i++) {
56 last_tx_cons = tx_cons;
57 tx_cons = NEXT_TX(tx_cons);
58 }
59 txr->tx_cons = tx_cons;
60 if (bnxt_tx_avail(bp, txr) == bp->tx_ring_size) {
61 rx_prod = rxr->rx_prod;
62 } else {
63 tx_buf = &txr->tx_buf_ring[last_tx_cons];
64 rx_prod = tx_buf->rx_prod;
65 }
66 bnxt_db_write(bp, &rxr->rx_db, rx_prod);
67}
68
69/* returns the following:
70 * true - packet consumed by XDP and new buffer is allocated.
71 * false - packet should be passed to the stack.
72 */
73bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
74 struct page *page, u8 **data_ptr, unsigned int *len, u8 *event)
75{
76 struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
77 struct bnxt_tx_ring_info *txr;
78 struct bnxt_sw_rx_bd *rx_buf;
79 struct pci_dev *pdev;
80 struct xdp_buff xdp;
81 dma_addr_t mapping;
82 void *orig_data;
83 u32 tx_avail;
84 u32 offset;
85 u32 act;
86
87 if (!xdp_prog)
88 return false;
89
90 pdev = bp->pdev;
91 txr = rxr->bnapi->tx_ring;
92 rx_buf = &rxr->rx_buf_ring[cons];
93 offset = bp->rx_offset;
94
95 xdp.data_hard_start = *data_ptr - offset;
96 xdp.data = *data_ptr;
97 xdp_set_data_meta_invalid(&xdp);
98 xdp.data_end = *data_ptr + *len;
99 xdp.rxq = &rxr->xdp_rxq;
100 orig_data = xdp.data;
101 mapping = rx_buf->mapping - bp->rx_dma_offset;
102
103 dma_sync_single_for_cpu(&pdev->dev, mapping + offset, *len, bp->rx_dir);
104
105 rcu_read_lock();
106 act = bpf_prog_run_xdp(xdp_prog, &xdp);
107 rcu_read_unlock();
108
109 tx_avail = bnxt_tx_avail(bp, txr);
110 /* If the tx ring is not full, we must not update the rx producer yet
111 * because we may still be transmitting on some BDs.
112 */
113 if (tx_avail != bp->tx_ring_size)
114 *event &= ~BNXT_RX_EVENT;
115
116 *len = xdp.data_end - xdp.data;
117 if (orig_data != xdp.data) {
118 offset = xdp.data - xdp.data_hard_start;
119 *data_ptr = xdp.data_hard_start + offset;
120 }
121 switch (act) {
122 case XDP_PASS:
123 return false;
124
125 case XDP_TX:
126 if (tx_avail < 1) {
127 trace_xdp_exception(bp->dev, xdp_prog, act);
128 bnxt_reuse_rx_data(rxr, cons, page);
129 return true;
130 }
131
132 *event = BNXT_TX_EVENT;
133 dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
134 bp->rx_dir);
135 bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
136 NEXT_RX(rxr->rx_prod));
137 bnxt_reuse_rx_data(rxr, cons, page);
138 return true;
139 default:
140 bpf_warn_invalid_xdp_action(act);
141 /* Fall thru */
142 case XDP_ABORTED:
143 trace_xdp_exception(bp->dev, xdp_prog, act);
144 /* Fall thru */
145 case XDP_DROP:
146 bnxt_reuse_rx_data(rxr, cons, page);
147 break;
148 }
149 return true;
150}
151
152/* Under rtnl_lock */
153static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
154{
155 struct net_device *dev = bp->dev;
156 int tx_xdp = 0, rc, tc;
157 struct bpf_prog *old;
158
159 if (prog && bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
160 netdev_warn(dev, "MTU %d larger than largest XDP supported MTU %d.\n",
161 bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
162 return -EOPNOTSUPP;
163 }
164 if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
165 netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
166 return -EOPNOTSUPP;
167 }
168 if (prog)
169 tx_xdp = bp->rx_nr_rings;
170
171 tc = netdev_get_num_tc(dev);
172 if (!tc)
173 tc = 1;
174 rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
175 true, tc, tx_xdp);
176 if (rc) {
177 netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
178 return rc;
179 }
180 if (netif_running(dev))
181 bnxt_close_nic(bp, true, false);
182
183 old = xchg(&bp->xdp_prog, prog);
184 if (old)
185 bpf_prog_put(old);
186
187 if (prog) {
188 bnxt_set_rx_skb_mode(bp, true);
189 } else {
190 int rx, tx;
191
192 bnxt_set_rx_skb_mode(bp, false);
193 bnxt_get_max_rings(bp, &rx, &tx, true);
194 if (rx > 1) {
195 bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
196 bp->dev->hw_features |= NETIF_F_LRO;
197 }
198 }
199 bp->tx_nr_rings_xdp = tx_xdp;
200 bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
201 bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
202 bnxt_set_tpa_flags(bp);
203 bnxt_set_ring_params(bp);
204
205 if (netif_running(dev))
206 return bnxt_open_nic(bp, true, false);
207
208 return 0;
209}
210
211int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
212{
213 struct bnxt *bp = netdev_priv(dev);
214 int rc;
215
216 switch (xdp->command) {
217 case XDP_SETUP_PROG:
218 rc = bnxt_xdp_set(bp, xdp->prog);
219 break;
220 case XDP_QUERY_PROG:
221 xdp->prog_id = bp->xdp_prog ? bp->xdp_prog->aux->id : 0;
222 rc = 0;
223 break;
224 default:
225 rc = -EINVAL;
226 break;
227 }
228 return rc;
229}
230