xref: /linux/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2018 Intel Corporation. */
3 
4 #include <linux/bpf_trace.h>
5 #include <net/xdp_sock_drv.h>
6 #include <net/xdp.h>
7 
8 #include "ixgbe.h"
9 #include "ixgbe_txrx_common.h"
10 
11 struct xsk_buff_pool *ixgbe_xsk_pool(struct ixgbe_adapter *adapter,
12 				     struct ixgbe_ring *ring)
13 {
14 	bool xdp_on = READ_ONCE(adapter->xdp_prog);
15 	int qid = ring->ring_idx;
16 
17 	if (!xdp_on || !test_bit(qid, adapter->af_xdp_zc_qps))
18 		return NULL;
19 
20 	return xsk_get_pool_from_qid(adapter->netdev, qid);
21 }
22 
23 static int ixgbe_xsk_pool_enable(struct ixgbe_adapter *adapter,
24 				 struct xsk_buff_pool *pool,
25 				 u16 qid)
26 {
27 	struct net_device *netdev = adapter->netdev;
28 	bool if_running;
29 	int err;
30 
31 	if (qid >= adapter->num_rx_queues)
32 		return -EINVAL;
33 
34 	if (qid >= netdev->real_num_rx_queues ||
35 	    qid >= netdev->real_num_tx_queues)
36 		return -EINVAL;
37 
38 	err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IXGBE_RX_DMA_ATTR);
39 	if (err)
40 		return err;
41 
42 	if_running = netif_running(adapter->netdev) &&
43 		     ixgbe_enabled_xdp_adapter(adapter);
44 
45 	if (if_running)
46 		ixgbe_txrx_ring_disable(adapter, qid);
47 
48 	set_bit(qid, adapter->af_xdp_zc_qps);
49 
50 	if (if_running) {
51 		ixgbe_txrx_ring_enable(adapter, qid);
52 
53 		/* Kick start the NAPI context so that receiving will start */
54 		err = ixgbe_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
55 		if (err) {
56 			clear_bit(qid, adapter->af_xdp_zc_qps);
57 			xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
58 			return err;
59 		}
60 	}
61 
62 	return 0;
63 }
64 
65 static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
66 {
67 	struct xsk_buff_pool *pool;
68 	bool if_running;
69 
70 	pool = xsk_get_pool_from_qid(adapter->netdev, qid);
71 	if (!pool)
72 		return -EINVAL;
73 
74 	if_running = netif_running(adapter->netdev) &&
75 		     ixgbe_enabled_xdp_adapter(adapter);
76 
77 	if (if_running)
78 		ixgbe_txrx_ring_disable(adapter, qid);
79 
80 	clear_bit(qid, adapter->af_xdp_zc_qps);
81 	xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
82 
83 	if (if_running)
84 		ixgbe_txrx_ring_enable(adapter, qid);
85 
86 	return 0;
87 }
88 
89 int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
90 			 struct xsk_buff_pool *pool,
91 			 u16 qid)
92 {
93 	return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
94 		ixgbe_xsk_pool_disable(adapter, qid);
95 }
96 
97 static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
98 			    struct ixgbe_ring *rx_ring,
99 			    struct xdp_buff *xdp)
100 {
101 	int err, result = IXGBE_XDP_PASS;
102 	struct bpf_prog *xdp_prog;
103 	struct ixgbe_ring *ring;
104 	struct xdp_frame *xdpf;
105 	u32 act;
106 
107 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
108 	act = bpf_prog_run_xdp(xdp_prog, xdp);
109 
110 	if (likely(act == XDP_REDIRECT)) {
111 		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
112 		if (!err)
113 			return IXGBE_XDP_REDIR;
114 		if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
115 			result = IXGBE_XDP_EXIT;
116 		else
117 			result = IXGBE_XDP_CONSUMED;
118 		goto out_failure;
119 	}
120 
121 	switch (act) {
122 	case XDP_PASS:
123 		break;
124 	case XDP_TX:
125 		xdpf = xdp_convert_buff_to_frame(xdp);
126 		if (unlikely(!xdpf))
127 			goto out_failure;
128 		ring = ixgbe_determine_xdp_ring(adapter);
129 		if (static_branch_unlikely(&ixgbe_xdp_locking_key))
130 			spin_lock(&ring->tx_lock);
131 		result = ixgbe_xmit_xdp_ring(ring, xdpf);
132 		if (static_branch_unlikely(&ixgbe_xdp_locking_key))
133 			spin_unlock(&ring->tx_lock);
134 		if (result == IXGBE_XDP_CONSUMED)
135 			goto out_failure;
136 		break;
137 	case XDP_DROP:
138 		result = IXGBE_XDP_CONSUMED;
139 		break;
140 	default:
141 		bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
142 		fallthrough;
143 	case XDP_ABORTED:
144 		result = IXGBE_XDP_CONSUMED;
145 out_failure:
146 		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
147 	}
148 	return result;
149 }
150 
151 bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
152 {
153 	union ixgbe_adv_rx_desc *rx_desc;
154 	struct ixgbe_rx_buffer *bi;
155 	u16 i = rx_ring->next_to_use;
156 	dma_addr_t dma;
157 	bool ok = true;
158 
159 	/* nothing to do */
160 	if (!count)
161 		return true;
162 
163 	rx_desc = IXGBE_RX_DESC(rx_ring, i);
164 	bi = &rx_ring->rx_buffer_info[i];
165 	i -= rx_ring->count;
166 
167 	do {
168 		bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
169 		if (!bi->xdp) {
170 			ok = false;
171 			break;
172 		}
173 
174 		dma = xsk_buff_xdp_get_dma(bi->xdp);
175 
176 		/* Refresh the desc even if buffer_addrs didn't change
177 		 * because each write-back erases this info.
178 		 */
179 		rx_desc->read.pkt_addr = cpu_to_le64(dma);
180 
181 		rx_desc++;
182 		bi++;
183 		i++;
184 		if (unlikely(!i)) {
185 			rx_desc = IXGBE_RX_DESC(rx_ring, 0);
186 			bi = rx_ring->rx_buffer_info;
187 			i -= rx_ring->count;
188 		}
189 
190 		/* clear the length for the next_to_use descriptor */
191 		rx_desc->wb.upper.length = 0;
192 
193 		count--;
194 	} while (count);
195 
196 	i += rx_ring->count;
197 
198 	if (rx_ring->next_to_use != i) {
199 		rx_ring->next_to_use = i;
200 
201 		/* Force memory writes to complete before letting h/w
202 		 * know there are new descriptors to fetch.  (Only
203 		 * applicable for weak-ordered memory model archs,
204 		 * such as IA-64).
205 		 */
206 		wmb();
207 		writel(i, rx_ring->tail);
208 	}
209 
210 	return ok;
211 }
212 
213 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
214 					      const struct xdp_buff *xdp)
215 {
216 	unsigned int totalsize = xdp->data_end - xdp->data_meta;
217 	unsigned int metasize = xdp->data - xdp->data_meta;
218 	struct sk_buff *skb;
219 
220 	net_prefetch(xdp->data_meta);
221 
222 	/* allocate a skb to store the frags */
223 	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
224 			       GFP_ATOMIC | __GFP_NOWARN);
225 	if (unlikely(!skb))
226 		return NULL;
227 
228 	memcpy(__skb_put(skb, totalsize), xdp->data_meta,
229 	       ALIGN(totalsize, sizeof(long)));
230 
231 	if (metasize) {
232 		skb_metadata_set(skb, metasize);
233 		__skb_pull(skb, metasize);
234 	}
235 
236 	return skb;
237 }
238 
239 static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
240 {
241 	u32 ntc = rx_ring->next_to_clean + 1;
242 
243 	ntc = (ntc < rx_ring->count) ? ntc : 0;
244 	rx_ring->next_to_clean = ntc;
245 	prefetch(IXGBE_RX_DESC(rx_ring, ntc));
246 }
247 
248 int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
249 			  struct ixgbe_ring *rx_ring,
250 			  const int budget)
251 {
252 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
253 	struct ixgbe_adapter *adapter = q_vector->adapter;
254 	u16 cleaned_count = ixgbe_desc_unused(rx_ring);
255 	unsigned int xdp_res, xdp_xmit = 0;
256 	bool failure = false;
257 	struct sk_buff *skb;
258 
259 	while (likely(total_rx_packets < budget)) {
260 		union ixgbe_adv_rx_desc *rx_desc;
261 		struct ixgbe_rx_buffer *bi;
262 		unsigned int size;
263 
264 		/* return some buffers to hardware, one at a time is too slow */
265 		if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
266 			failure = failure ||
267 				  !ixgbe_alloc_rx_buffers_zc(rx_ring,
268 							     cleaned_count);
269 			cleaned_count = 0;
270 		}
271 
272 		rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
273 		size = le16_to_cpu(rx_desc->wb.upper.length);
274 		if (!size)
275 			break;
276 
277 		/* This memory barrier is needed to keep us from reading
278 		 * any other fields out of the rx_desc until we know the
279 		 * descriptor has been written back
280 		 */
281 		dma_rmb();
282 
283 		bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
284 
285 		if (unlikely(!ixgbe_test_staterr(rx_desc,
286 						 IXGBE_RXD_STAT_EOP))) {
287 			struct ixgbe_rx_buffer *next_bi;
288 
289 			xsk_buff_free(bi->xdp);
290 			bi->xdp = NULL;
291 			ixgbe_inc_ntc(rx_ring);
292 			next_bi =
293 			       &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
294 			next_bi->discard = true;
295 			continue;
296 		}
297 
298 		if (unlikely(bi->discard)) {
299 			xsk_buff_free(bi->xdp);
300 			bi->xdp = NULL;
301 			bi->discard = false;
302 			ixgbe_inc_ntc(rx_ring);
303 			continue;
304 		}
305 
306 		bi->xdp->data_end = bi->xdp->data + size;
307 		xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
308 		xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
309 
310 		if (likely(xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))) {
311 			xdp_xmit |= xdp_res;
312 		} else if (xdp_res == IXGBE_XDP_EXIT) {
313 			failure = true;
314 			break;
315 		} else if (xdp_res == IXGBE_XDP_CONSUMED) {
316 			xsk_buff_free(bi->xdp);
317 		} else if (xdp_res == IXGBE_XDP_PASS) {
318 			goto construct_skb;
319 		}
320 
321 		bi->xdp = NULL;
322 		total_rx_packets++;
323 		total_rx_bytes += size;
324 
325 		cleaned_count++;
326 		ixgbe_inc_ntc(rx_ring);
327 		continue;
328 
329 construct_skb:
330 		/* XDP_PASS path */
331 		skb = ixgbe_construct_skb_zc(rx_ring, bi->xdp);
332 		if (!skb) {
333 			rx_ring->rx_stats.alloc_rx_buff_failed++;
334 			break;
335 		}
336 
337 		xsk_buff_free(bi->xdp);
338 		bi->xdp = NULL;
339 
340 		cleaned_count++;
341 		ixgbe_inc_ntc(rx_ring);
342 
343 		if (eth_skb_pad(skb))
344 			continue;
345 
346 		total_rx_bytes += skb->len;
347 		total_rx_packets++;
348 
349 		ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
350 		ixgbe_rx_skb(q_vector, skb);
351 	}
352 
353 	if (xdp_xmit & IXGBE_XDP_REDIR)
354 		xdp_do_flush();
355 
356 	if (xdp_xmit & IXGBE_XDP_TX) {
357 		struct ixgbe_ring *ring = ixgbe_determine_xdp_ring(adapter);
358 
359 		ixgbe_xdp_ring_update_tail_locked(ring);
360 	}
361 
362 	ixgbe_update_rx_ring_stats(rx_ring, q_vector, total_rx_packets,
363 				   total_rx_bytes);
364 
365 	if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
366 		if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
367 			xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
368 		else
369 			xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
370 
371 		return (int)total_rx_packets;
372 	}
373 	return failure ? budget : (int)total_rx_packets;
374 }
375 
376 void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
377 {
378 	struct ixgbe_rx_buffer *bi;
379 	u16 i;
380 
381 	for (i = 0; i < rx_ring->count; i++) {
382 		bi = &rx_ring->rx_buffer_info[i];
383 
384 		if (!bi->xdp)
385 			continue;
386 
387 		xsk_buff_free(bi->xdp);
388 		bi->xdp = NULL;
389 	}
390 }
391 
392 static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
393 {
394 	struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
395 	union ixgbe_adv_tx_desc *tx_desc = NULL;
396 	struct ixgbe_tx_buffer *tx_bi;
397 	bool work_done = true;
398 	struct xdp_desc desc;
399 	dma_addr_t dma;
400 	u32 cmd_type;
401 
402 	while (budget-- > 0) {
403 		if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
404 			work_done = false;
405 			break;
406 		}
407 
408 		if (!netif_carrier_ok(xdp_ring->netdev))
409 			break;
410 
411 		if (!xsk_tx_peek_desc(pool, &desc))
412 			break;
413 
414 		dma = xsk_buff_raw_get_dma(pool, desc.addr);
415 		xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
416 
417 		tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
418 		tx_bi->bytecount = desc.len;
419 		tx_bi->xdpf = NULL;
420 		tx_bi->gso_segs = 1;
421 
422 		tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
423 		tx_desc->read.buffer_addr = cpu_to_le64(dma);
424 
425 		/* put descriptor type bits */
426 		cmd_type = IXGBE_ADVTXD_DTYP_DATA |
427 			   IXGBE_ADVTXD_DCMD_DEXT |
428 			   IXGBE_ADVTXD_DCMD_IFCS;
429 		cmd_type |= desc.len | IXGBE_TXD_CMD;
430 		tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
431 		tx_desc->read.olinfo_status =
432 			cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
433 
434 		xdp_ring->next_to_use++;
435 		if (xdp_ring->next_to_use == xdp_ring->count)
436 			xdp_ring->next_to_use = 0;
437 	}
438 
439 	if (tx_desc) {
440 		ixgbe_xdp_ring_update_tail(xdp_ring);
441 		xsk_tx_release(pool);
442 	}
443 
444 	return !!budget && work_done;
445 }
446 
447 static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
448 				      struct ixgbe_tx_buffer *tx_bi)
449 {
450 	xdp_return_frame(tx_bi->xdpf);
451 	dma_unmap_single(tx_ring->dev,
452 			 dma_unmap_addr(tx_bi, dma),
453 			 dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
454 	dma_unmap_len_set(tx_bi, len, 0);
455 }
456 
457 bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
458 			    struct ixgbe_ring *tx_ring, int napi_budget)
459 {
460 	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
461 	unsigned int total_packets = 0, total_bytes = 0;
462 	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
463 	union ixgbe_adv_tx_desc *tx_desc;
464 	struct ixgbe_tx_buffer *tx_bi;
465 	u32 xsk_frames = 0;
466 
467 	tx_bi = &tx_ring->tx_buffer_info[ntc];
468 	tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
469 
470 	while (ntc != ntu) {
471 		if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
472 			break;
473 
474 		total_bytes += tx_bi->bytecount;
475 		total_packets += tx_bi->gso_segs;
476 
477 		if (tx_bi->xdpf)
478 			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
479 		else
480 			xsk_frames++;
481 
482 		tx_bi->xdpf = NULL;
483 
484 		tx_bi++;
485 		tx_desc++;
486 		ntc++;
487 		if (unlikely(ntc == tx_ring->count)) {
488 			ntc = 0;
489 			tx_bi = tx_ring->tx_buffer_info;
490 			tx_desc = IXGBE_TX_DESC(tx_ring, 0);
491 		}
492 
493 		/* issue prefetch for next Tx descriptor */
494 		prefetch(tx_desc);
495 	}
496 
497 	tx_ring->next_to_clean = ntc;
498 	ixgbe_update_tx_ring_stats(tx_ring, q_vector, total_packets,
499 				   total_bytes);
500 
501 	if (xsk_frames)
502 		xsk_tx_completed(pool, xsk_frames);
503 
504 	if (xsk_uses_need_wakeup(pool))
505 		xsk_set_tx_need_wakeup(pool);
506 
507 	return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
508 }
509 
510 int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
511 {
512 	struct ixgbe_adapter *adapter = netdev_priv(dev);
513 	struct ixgbe_ring *ring;
514 
515 	if (test_bit(__IXGBE_DOWN, &adapter->state))
516 		return -ENETDOWN;
517 
518 	if (!READ_ONCE(adapter->xdp_prog))
519 		return -EINVAL;
520 
521 	if (qid >= adapter->num_xdp_queues)
522 		return -EINVAL;
523 
524 	ring = adapter->xdp_ring[qid];
525 
526 	if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
527 		return -ENETDOWN;
528 
529 	if (!ring->xsk_pool)
530 		return -EINVAL;
531 
532 	if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
533 		u64 eics = BIT_ULL(ring->q_vector->v_idx);
534 
535 		ixgbe_irq_rearm_queues(adapter, eics);
536 	}
537 
538 	return 0;
539 }
540 
541 void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
542 {
543 	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
544 	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
545 	struct ixgbe_tx_buffer *tx_bi;
546 	u32 xsk_frames = 0;
547 
548 	while (ntc != ntu) {
549 		tx_bi = &tx_ring->tx_buffer_info[ntc];
550 
551 		if (tx_bi->xdpf)
552 			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
553 		else
554 			xsk_frames++;
555 
556 		tx_bi->xdpf = NULL;
557 
558 		ntc++;
559 		if (ntc == tx_ring->count)
560 			ntc = 0;
561 	}
562 
563 	if (xsk_frames)
564 		xsk_tx_completed(pool, xsk_frames);
565 }
566