summaryrefslogtreecommitdiff
path: root/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
blob: fcc262064766a2d432c9006c7206c2e3fca438cf (plain)
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
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
/* 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 <net/page_pool.h>
#include "bnxt_hsi.h"
#include "bnxt.h"
#include "bnxt_xdp.h"

struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp,
				   struct bnxt_tx_ring_info *txr,
				   dma_addr_t mapping, u32 len)
{
	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];

	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;
	return tx_buf;
}

static 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;

	tx_buf = bnxt_xmit_bd(bp, txr, mapping, len);
	tx_buf->rx_prod = rx_prod;
	tx_buf->action = XDP_TX;
}

static void __bnxt_xmit_xdp_redirect(struct bnxt *bp,
				     struct bnxt_tx_ring_info *txr,
				     dma_addr_t mapping, u32 len,
				     struct xdp_frame *xdpf)
{
	struct bnxt_sw_tx_bd *tx_buf;

	tx_buf = bnxt_xmit_bd(bp, txr, mapping, len);
	tx_buf->action = XDP_REDIRECT;
	tx_buf->xdpf = xdpf;
	dma_unmap_addr_set(tx_buf, mapping, mapping);
	dma_unmap_len_set(tx_buf, len, 0);
}

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;
	bool rx_doorbell_needed = false;
	struct bnxt_sw_tx_bd *tx_buf;
	u16 tx_cons = txr->tx_cons;
	u16 last_tx_cons = tx_cons;
	int i;

	for (i = 0; i < nr_pkts; i++) {
		tx_buf = &txr->tx_buf_ring[tx_cons];

		if (tx_buf->action == XDP_REDIRECT) {
			struct pci_dev *pdev = bp->pdev;

			dma_unmap_single(&pdev->dev,
					 dma_unmap_addr(tx_buf, mapping),
					 dma_unmap_len(tx_buf, len),
					 PCI_DMA_TODEVICE);
			xdp_return_frame(tx_buf->xdpf);
			tx_buf->action = 0;
			tx_buf->xdpf = NULL;
		} else if (tx_buf->action == XDP_TX) {
			rx_doorbell_needed = true;
			last_tx_cons = tx_cons;
		}
		tx_cons = NEXT_TX(tx_cons);
	}
	txr->tx_cons = tx_cons;
	if (rx_doorbell_needed) {
		tx_buf = &txr->tx_buf_ring[last_tx_cons];
		bnxt_db_write(bp, &rxr->rx_db, tx_buf->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;
	rx_buf = &rxr->rx_buf_ring[cons];
	offset = bp->rx_offset;

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

	txr = rxr->bnapi->tx_ring;
	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;
	xdp.frame_sz = PAGE_SIZE; /* BNXT_RX_PAGE_MODE(bp) when XDP enabled */
	orig_data = xdp.data;

	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;
	case XDP_REDIRECT:
		/* if we are calling this here then we know that the
		 * redirect is coming from a frame received by the
		 * bnxt_en driver.
		 */
		dma_unmap_page_attrs(&pdev->dev, mapping,
				     PAGE_SIZE, bp->rx_dir,
				     DMA_ATTR_WEAK_ORDERING);

		/* if we are unable to allocate a new buffer, abort and reuse */
		if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) {
			trace_xdp_exception(bp->dev, xdp_prog, act);
			bnxt_reuse_rx_data(rxr, cons, page);
			return true;
		}

		if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) {
			trace_xdp_exception(bp->dev, xdp_prog, act);
			page_pool_recycle_direct(rxr->page_pool, page);
			return true;
		}

		*event |= BNXT_REDIRECT_EVENT;
		break;
	default:
		bpf_warn_invalid_xdp_action(act);
		fallthrough;
	case XDP_ABORTED:
		trace_xdp_exception(bp->dev, xdp_prog, act);
		fallthrough;
	case XDP_DROP:
		bnxt_reuse_rx_data(rxr, cons, page);
		break;
	}
	return true;
}

int bnxt_xdp_xmit(struct net_device *dev, int num_frames,
		  struct xdp_frame **frames, u32 flags)
{
	struct bnxt *bp = netdev_priv(dev);
	struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog);
	struct pci_dev *pdev = bp->pdev;
	struct bnxt_tx_ring_info *txr;
	dma_addr_t mapping;
	int drops = 0;
	int ring;
	int i;

	if (!test_bit(BNXT_STATE_OPEN, &bp->state) ||
	    !bp->tx_nr_rings_xdp ||
	    !xdp_prog)
		return -EINVAL;

	ring = smp_processor_id() % bp->tx_nr_rings_xdp;
	txr = &bp->tx_ring[ring];

	for (i = 0; i < num_frames; i++) {
		struct xdp_frame *xdp = frames[i];

		if (!txr || !bnxt_tx_avail(bp, txr) ||
		    !(bp->bnapi[ring]->flags & BNXT_NAPI_FLAG_XDP)) {
			xdp_return_frame_rx_napi(xdp);
			drops++;
			continue;
		}

		mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len,
					 DMA_TO_DEVICE);

		if (dma_mapping_error(&pdev->dev, mapping)) {
			xdp_return_frame_rx_napi(xdp);
			drops++;
			continue;
		}
		__bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp);
	}

	if (flags & XDP_XMIT_FLUSH) {
		/* Sync BD data before updating doorbell */
		wmb();
		bnxt_db_write(bp, &txr->tx_db, txr->tx_prod);
	}

	return num_frames - drops;
}

/* 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;
	default:
		rc = -EINVAL;
		break;
	}
	return rc;
}