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 			return err;
57 	}
58 
59 	return 0;
60 }
61 
62 static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
63 {
64 	struct xsk_buff_pool *pool;
65 	bool if_running;
66 
67 	pool = xsk_get_pool_from_qid(adapter->netdev, qid);
68 	if (!pool)
69 		return -EINVAL;
70 
71 	if_running = netif_running(adapter->netdev) &&
72 		     ixgbe_enabled_xdp_adapter(adapter);
73 
74 	if (if_running)
75 		ixgbe_txrx_ring_disable(adapter, qid);
76 
77 	clear_bit(qid, adapter->af_xdp_zc_qps);
78 	xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
79 
80 	if (if_running)
81 		ixgbe_txrx_ring_enable(adapter, qid);
82 
83 	return 0;
84 }
85 
86 int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
87 			 struct xsk_buff_pool *pool,
88 			 u16 qid)
89 {
90 	return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
91 		ixgbe_xsk_pool_disable(adapter, qid);
92 }
93 
94 static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
95 			    struct ixgbe_ring *rx_ring,
96 			    struct xdp_buff *xdp)
97 {
98 	int err, result = IXGBE_XDP_PASS;
99 	struct bpf_prog *xdp_prog;
100 	struct xdp_frame *xdpf;
101 	u32 act;
102 
103 	rcu_read_lock();
104 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
105 	act = bpf_prog_run_xdp(xdp_prog, xdp);
106 
107 	if (likely(act == XDP_REDIRECT)) {
108 		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
109 		result = !err ? IXGBE_XDP_REDIR : IXGBE_XDP_CONSUMED;
110 		rcu_read_unlock();
111 		return result;
112 	}
113 
114 	switch (act) {
115 	case XDP_PASS:
116 		break;
117 	case XDP_TX:
118 		xdpf = xdp_convert_buff_to_frame(xdp);
119 		if (unlikely(!xdpf)) {
120 			result = IXGBE_XDP_CONSUMED;
121 			break;
122 		}
123 		result = ixgbe_xmit_xdp_ring(adapter, xdpf);
124 		break;
125 	default:
126 		bpf_warn_invalid_xdp_action(act);
127 		fallthrough;
128 	case XDP_ABORTED:
129 		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
130 		fallthrough; /* handle aborts by dropping packet */
131 	case XDP_DROP:
132 		result = IXGBE_XDP_CONSUMED;
133 		break;
134 	}
135 	rcu_read_unlock();
136 	return result;
137 }
138 
139 bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
140 {
141 	union ixgbe_adv_rx_desc *rx_desc;
142 	struct ixgbe_rx_buffer *bi;
143 	u16 i = rx_ring->next_to_use;
144 	dma_addr_t dma;
145 	bool ok = true;
146 
147 	/* nothing to do */
148 	if (!count)
149 		return true;
150 
151 	rx_desc = IXGBE_RX_DESC(rx_ring, i);
152 	bi = &rx_ring->rx_buffer_info[i];
153 	i -= rx_ring->count;
154 
155 	do {
156 		bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
157 		if (!bi->xdp) {
158 			ok = false;
159 			break;
160 		}
161 
162 		dma = xsk_buff_xdp_get_dma(bi->xdp);
163 
164 		/* Refresh the desc even if buffer_addrs didn't change
165 		 * because each write-back erases this info.
166 		 */
167 		rx_desc->read.pkt_addr = cpu_to_le64(dma);
168 
169 		rx_desc++;
170 		bi++;
171 		i++;
172 		if (unlikely(!i)) {
173 			rx_desc = IXGBE_RX_DESC(rx_ring, 0);
174 			bi = rx_ring->rx_buffer_info;
175 			i -= rx_ring->count;
176 		}
177 
178 		/* clear the length for the next_to_use descriptor */
179 		rx_desc->wb.upper.length = 0;
180 
181 		count--;
182 	} while (count);
183 
184 	i += rx_ring->count;
185 
186 	if (rx_ring->next_to_use != i) {
187 		rx_ring->next_to_use = i;
188 
189 		/* Force memory writes to complete before letting h/w
190 		 * know there are new descriptors to fetch.  (Only
191 		 * applicable for weak-ordered memory model archs,
192 		 * such as IA-64).
193 		 */
194 		wmb();
195 		writel(i, rx_ring->tail);
196 	}
197 
198 	return ok;
199 }
200 
201 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
202 					      struct ixgbe_rx_buffer *bi)
203 {
204 	unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
205 	unsigned int datasize = bi->xdp->data_end - bi->xdp->data;
206 	struct sk_buff *skb;
207 
208 	/* allocate a skb to store the frags */
209 	skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
210 			       bi->xdp->data_end - bi->xdp->data_hard_start,
211 			       GFP_ATOMIC | __GFP_NOWARN);
212 	if (unlikely(!skb))
213 		return NULL;
214 
215 	skb_reserve(skb, bi->xdp->data - bi->xdp->data_hard_start);
216 	memcpy(__skb_put(skb, datasize), bi->xdp->data, datasize);
217 	if (metasize)
218 		skb_metadata_set(skb, metasize);
219 
220 	xsk_buff_free(bi->xdp);
221 	bi->xdp = NULL;
222 	return skb;
223 }
224 
225 static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
226 {
227 	u32 ntc = rx_ring->next_to_clean + 1;
228 
229 	ntc = (ntc < rx_ring->count) ? ntc : 0;
230 	rx_ring->next_to_clean = ntc;
231 	prefetch(IXGBE_RX_DESC(rx_ring, ntc));
232 }
233 
234 int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
235 			  struct ixgbe_ring *rx_ring,
236 			  const int budget)
237 {
238 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
239 	struct ixgbe_adapter *adapter = q_vector->adapter;
240 	u16 cleaned_count = ixgbe_desc_unused(rx_ring);
241 	unsigned int xdp_res, xdp_xmit = 0;
242 	bool failure = false;
243 	struct sk_buff *skb;
244 
245 	while (likely(total_rx_packets < budget)) {
246 		union ixgbe_adv_rx_desc *rx_desc;
247 		struct ixgbe_rx_buffer *bi;
248 		unsigned int size;
249 
250 		/* return some buffers to hardware, one at a time is too slow */
251 		if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
252 			failure = failure ||
253 				  !ixgbe_alloc_rx_buffers_zc(rx_ring,
254 							     cleaned_count);
255 			cleaned_count = 0;
256 		}
257 
258 		rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
259 		size = le16_to_cpu(rx_desc->wb.upper.length);
260 		if (!size)
261 			break;
262 
263 		/* This memory barrier is needed to keep us from reading
264 		 * any other fields out of the rx_desc until we know the
265 		 * descriptor has been written back
266 		 */
267 		dma_rmb();
268 
269 		bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
270 
271 		if (unlikely(!ixgbe_test_staterr(rx_desc,
272 						 IXGBE_RXD_STAT_EOP))) {
273 			struct ixgbe_rx_buffer *next_bi;
274 
275 			xsk_buff_free(bi->xdp);
276 			bi->xdp = NULL;
277 			ixgbe_inc_ntc(rx_ring);
278 			next_bi =
279 			       &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
280 			next_bi->discard = true;
281 			continue;
282 		}
283 
284 		if (unlikely(bi->discard)) {
285 			xsk_buff_free(bi->xdp);
286 			bi->xdp = NULL;
287 			bi->discard = false;
288 			ixgbe_inc_ntc(rx_ring);
289 			continue;
290 		}
291 
292 		bi->xdp->data_end = bi->xdp->data + size;
293 		xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
294 		xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
295 
296 		if (xdp_res) {
297 			if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))
298 				xdp_xmit |= xdp_res;
299 			else
300 				xsk_buff_free(bi->xdp);
301 
302 			bi->xdp = NULL;
303 			total_rx_packets++;
304 			total_rx_bytes += size;
305 
306 			cleaned_count++;
307 			ixgbe_inc_ntc(rx_ring);
308 			continue;
309 		}
310 
311 		/* XDP_PASS path */
312 		skb = ixgbe_construct_skb_zc(rx_ring, bi);
313 		if (!skb) {
314 			rx_ring->rx_stats.alloc_rx_buff_failed++;
315 			break;
316 		}
317 
318 		cleaned_count++;
319 		ixgbe_inc_ntc(rx_ring);
320 
321 		if (eth_skb_pad(skb))
322 			continue;
323 
324 		total_rx_bytes += skb->len;
325 		total_rx_packets++;
326 
327 		ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
328 		ixgbe_rx_skb(q_vector, skb);
329 	}
330 
331 	if (xdp_xmit & IXGBE_XDP_REDIR)
332 		xdp_do_flush_map();
333 
334 	if (xdp_xmit & IXGBE_XDP_TX) {
335 		struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()];
336 
337 		/* Force memory writes to complete before letting h/w
338 		 * know there are new descriptors to fetch.
339 		 */
340 		wmb();
341 		writel(ring->next_to_use, ring->tail);
342 	}
343 
344 	u64_stats_update_begin(&rx_ring->syncp);
345 	rx_ring->stats.packets += total_rx_packets;
346 	rx_ring->stats.bytes += total_rx_bytes;
347 	u64_stats_update_end(&rx_ring->syncp);
348 	q_vector->rx.total_packets += total_rx_packets;
349 	q_vector->rx.total_bytes += total_rx_bytes;
350 
351 	if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
352 		if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
353 			xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
354 		else
355 			xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
356 
357 		return (int)total_rx_packets;
358 	}
359 	return failure ? budget : (int)total_rx_packets;
360 }
361 
362 void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
363 {
364 	struct ixgbe_rx_buffer *bi;
365 	u16 i;
366 
367 	for (i = 0; i < rx_ring->count; i++) {
368 		bi = &rx_ring->rx_buffer_info[i];
369 
370 		if (!bi->xdp)
371 			continue;
372 
373 		xsk_buff_free(bi->xdp);
374 		bi->xdp = NULL;
375 	}
376 }
377 
378 static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
379 {
380 	struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
381 	union ixgbe_adv_tx_desc *tx_desc = NULL;
382 	struct ixgbe_tx_buffer *tx_bi;
383 	bool work_done = true;
384 	struct xdp_desc desc;
385 	dma_addr_t dma;
386 	u32 cmd_type;
387 
388 	while (budget-- > 0) {
389 		if (unlikely(!ixgbe_desc_unused(xdp_ring)) ||
390 		    !netif_carrier_ok(xdp_ring->netdev)) {
391 			work_done = false;
392 			break;
393 		}
394 
395 		if (!xsk_tx_peek_desc(pool, &desc))
396 			break;
397 
398 		dma = xsk_buff_raw_get_dma(pool, desc.addr);
399 		xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
400 
401 		tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
402 		tx_bi->bytecount = desc.len;
403 		tx_bi->xdpf = NULL;
404 		tx_bi->gso_segs = 1;
405 
406 		tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
407 		tx_desc->read.buffer_addr = cpu_to_le64(dma);
408 
409 		/* put descriptor type bits */
410 		cmd_type = IXGBE_ADVTXD_DTYP_DATA |
411 			   IXGBE_ADVTXD_DCMD_DEXT |
412 			   IXGBE_ADVTXD_DCMD_IFCS;
413 		cmd_type |= desc.len | IXGBE_TXD_CMD;
414 		tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
415 		tx_desc->read.olinfo_status =
416 			cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
417 
418 		xdp_ring->next_to_use++;
419 		if (xdp_ring->next_to_use == xdp_ring->count)
420 			xdp_ring->next_to_use = 0;
421 	}
422 
423 	if (tx_desc) {
424 		ixgbe_xdp_ring_update_tail(xdp_ring);
425 		xsk_tx_release(pool);
426 	}
427 
428 	return !!budget && work_done;
429 }
430 
431 static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
432 				      struct ixgbe_tx_buffer *tx_bi)
433 {
434 	xdp_return_frame(tx_bi->xdpf);
435 	dma_unmap_single(tx_ring->dev,
436 			 dma_unmap_addr(tx_bi, dma),
437 			 dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
438 	dma_unmap_len_set(tx_bi, len, 0);
439 }
440 
441 bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
442 			    struct ixgbe_ring *tx_ring, int napi_budget)
443 {
444 	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
445 	unsigned int total_packets = 0, total_bytes = 0;
446 	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
447 	union ixgbe_adv_tx_desc *tx_desc;
448 	struct ixgbe_tx_buffer *tx_bi;
449 	u32 xsk_frames = 0;
450 
451 	tx_bi = &tx_ring->tx_buffer_info[ntc];
452 	tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
453 
454 	while (ntc != ntu) {
455 		if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
456 			break;
457 
458 		total_bytes += tx_bi->bytecount;
459 		total_packets += tx_bi->gso_segs;
460 
461 		if (tx_bi->xdpf)
462 			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
463 		else
464 			xsk_frames++;
465 
466 		tx_bi->xdpf = NULL;
467 
468 		tx_bi++;
469 		tx_desc++;
470 		ntc++;
471 		if (unlikely(ntc == tx_ring->count)) {
472 			ntc = 0;
473 			tx_bi = tx_ring->tx_buffer_info;
474 			tx_desc = IXGBE_TX_DESC(tx_ring, 0);
475 		}
476 
477 		/* issue prefetch for next Tx descriptor */
478 		prefetch(tx_desc);
479 	}
480 
481 	tx_ring->next_to_clean = ntc;
482 
483 	u64_stats_update_begin(&tx_ring->syncp);
484 	tx_ring->stats.bytes += total_bytes;
485 	tx_ring->stats.packets += total_packets;
486 	u64_stats_update_end(&tx_ring->syncp);
487 	q_vector->tx.total_bytes += total_bytes;
488 	q_vector->tx.total_packets += total_packets;
489 
490 	if (xsk_frames)
491 		xsk_tx_completed(pool, xsk_frames);
492 
493 	if (xsk_uses_need_wakeup(pool))
494 		xsk_set_tx_need_wakeup(pool);
495 
496 	return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
497 }
498 
499 int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
500 {
501 	struct ixgbe_adapter *adapter = netdev_priv(dev);
502 	struct ixgbe_ring *ring;
503 
504 	if (test_bit(__IXGBE_DOWN, &adapter->state))
505 		return -ENETDOWN;
506 
507 	if (!READ_ONCE(adapter->xdp_prog))
508 		return -ENXIO;
509 
510 	if (qid >= adapter->num_xdp_queues)
511 		return -ENXIO;
512 
513 	ring = adapter->xdp_ring[qid];
514 
515 	if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
516 		return -ENETDOWN;
517 
518 	if (!ring->xsk_pool)
519 		return -ENXIO;
520 
521 	if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
522 		u64 eics = BIT_ULL(ring->q_vector->v_idx);
523 
524 		ixgbe_irq_rearm_queues(adapter, eics);
525 	}
526 
527 	return 0;
528 }
529 
530 void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
531 {
532 	u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
533 	struct xsk_buff_pool *pool = tx_ring->xsk_pool;
534 	struct ixgbe_tx_buffer *tx_bi;
535 	u32 xsk_frames = 0;
536 
537 	while (ntc != ntu) {
538 		tx_bi = &tx_ring->tx_buffer_info[ntc];
539 
540 		if (tx_bi->xdpf)
541 			ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
542 		else
543 			xsk_frames++;
544 
545 		tx_bi->xdpf = NULL;
546 
547 		ntc++;
548 		if (ntc == tx_ring->count)
549 			ntc = 0;
550 	}
551 
552 	if (xsk_frames)
553 		xsk_tx_completed(pool, xsk_frames);
554 }
555