1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 2017 - 2019 Pensando Systems, Inc */
3 
4 #include <linux/ip.h>
5 #include <linux/ipv6.h>
6 #include <linux/if_vlan.h>
7 #include <net/ip6_checksum.h>
8 
9 #include "ionic.h"
10 #include "ionic_lif.h"
11 #include "ionic_txrx.h"
12 
13 static inline void ionic_txq_post(struct ionic_queue *q, bool ring_dbell,
14 				  ionic_desc_cb cb_func, void *cb_arg)
15 {
16 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
17 }
18 
19 static inline void ionic_rxq_post(struct ionic_queue *q, bool ring_dbell,
20 				  ionic_desc_cb cb_func, void *cb_arg)
21 {
22 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
23 }
24 
25 static inline struct netdev_queue *q_to_ndq(struct ionic_queue *q)
26 {
27 	return netdev_get_tx_queue(q->lif->netdev, q->index);
28 }
29 
30 static int ionic_rx_page_alloc(struct ionic_queue *q,
31 			       struct ionic_buf_info *buf_info)
32 {
33 	struct net_device *netdev = q->lif->netdev;
34 	struct ionic_rx_stats *stats;
35 	struct device *dev;
36 	struct page *page;
37 
38 	dev = q->dev;
39 	stats = q_to_rx_stats(q);
40 
41 	if (unlikely(!buf_info)) {
42 		net_err_ratelimited("%s: %s invalid buf_info in alloc\n",
43 				    netdev->name, q->name);
44 		return -EINVAL;
45 	}
46 
47 	page = alloc_pages(IONIC_PAGE_GFP_MASK, 0);
48 	if (unlikely(!page)) {
49 		net_err_ratelimited("%s: %s page alloc failed\n",
50 				    netdev->name, q->name);
51 		stats->alloc_err++;
52 		return -ENOMEM;
53 	}
54 
55 	buf_info->dma_addr = dma_map_page(dev, page, 0,
56 					  IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
57 	if (unlikely(dma_mapping_error(dev, buf_info->dma_addr))) {
58 		__free_pages(page, 0);
59 		net_err_ratelimited("%s: %s dma map failed\n",
60 				    netdev->name, q->name);
61 		stats->dma_map_err++;
62 		return -EIO;
63 	}
64 
65 	buf_info->page = page;
66 	buf_info->page_offset = 0;
67 
68 	return 0;
69 }
70 
71 static void ionic_rx_page_free(struct ionic_queue *q,
72 			       struct ionic_buf_info *buf_info)
73 {
74 	struct net_device *netdev = q->lif->netdev;
75 	struct device *dev = q->dev;
76 
77 	if (unlikely(!buf_info)) {
78 		net_err_ratelimited("%s: %s invalid buf_info in free\n",
79 				    netdev->name, q->name);
80 		return;
81 	}
82 
83 	if (!buf_info->page)
84 		return;
85 
86 	dma_unmap_page(dev, buf_info->dma_addr, IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
87 	__free_pages(buf_info->page, 0);
88 	buf_info->page = NULL;
89 }
90 
91 static bool ionic_rx_buf_recycle(struct ionic_queue *q,
92 				 struct ionic_buf_info *buf_info, u32 used)
93 {
94 	u32 size;
95 
96 	/* don't re-use pages allocated in low-mem condition */
97 	if (page_is_pfmemalloc(buf_info->page))
98 		return false;
99 
100 	/* don't re-use buffers from non-local numa nodes */
101 	if (page_to_nid(buf_info->page) != numa_mem_id())
102 		return false;
103 
104 	size = ALIGN(used, IONIC_PAGE_SPLIT_SZ);
105 	buf_info->page_offset += size;
106 	if (buf_info->page_offset >= IONIC_PAGE_SIZE)
107 		return false;
108 
109 	get_page(buf_info->page);
110 
111 	return true;
112 }
113 
114 static struct sk_buff *ionic_rx_frags(struct ionic_queue *q,
115 				      struct ionic_desc_info *desc_info,
116 				      struct ionic_rxq_comp *comp)
117 {
118 	struct net_device *netdev = q->lif->netdev;
119 	struct ionic_buf_info *buf_info;
120 	struct ionic_rx_stats *stats;
121 	struct device *dev = q->dev;
122 	struct sk_buff *skb;
123 	unsigned int i;
124 	u16 frag_len;
125 	u16 len;
126 
127 	stats = q_to_rx_stats(q);
128 
129 	buf_info = &desc_info->bufs[0];
130 	len = le16_to_cpu(comp->len);
131 
132 	prefetchw(buf_info->page);
133 
134 	skb = napi_get_frags(&q_to_qcq(q)->napi);
135 	if (unlikely(!skb)) {
136 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
137 				     netdev->name, q->name);
138 		stats->alloc_err++;
139 		return NULL;
140 	}
141 
142 	i = comp->num_sg_elems + 1;
143 	do {
144 		if (unlikely(!buf_info->page)) {
145 			dev_kfree_skb(skb);
146 			return NULL;
147 		}
148 
149 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
150 		len -= frag_len;
151 
152 		dma_sync_single_for_cpu(dev,
153 					buf_info->dma_addr + buf_info->page_offset,
154 					frag_len, DMA_FROM_DEVICE);
155 
156 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
157 				buf_info->page, buf_info->page_offset, frag_len,
158 				IONIC_PAGE_SIZE);
159 
160 		if (!ionic_rx_buf_recycle(q, buf_info, frag_len)) {
161 			dma_unmap_page(dev, buf_info->dma_addr,
162 				       IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
163 			buf_info->page = NULL;
164 		}
165 
166 		buf_info++;
167 
168 		i--;
169 	} while (i > 0);
170 
171 	return skb;
172 }
173 
174 static struct sk_buff *ionic_rx_copybreak(struct ionic_queue *q,
175 					  struct ionic_desc_info *desc_info,
176 					  struct ionic_rxq_comp *comp)
177 {
178 	struct net_device *netdev = q->lif->netdev;
179 	struct ionic_buf_info *buf_info;
180 	struct ionic_rx_stats *stats;
181 	struct device *dev = q->dev;
182 	struct sk_buff *skb;
183 	u16 len;
184 
185 	stats = q_to_rx_stats(q);
186 
187 	buf_info = &desc_info->bufs[0];
188 	len = le16_to_cpu(comp->len);
189 
190 	skb = napi_alloc_skb(&q_to_qcq(q)->napi, len);
191 	if (unlikely(!skb)) {
192 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
193 				     netdev->name, q->name);
194 		stats->alloc_err++;
195 		return NULL;
196 	}
197 
198 	if (unlikely(!buf_info->page)) {
199 		dev_kfree_skb(skb);
200 		return NULL;
201 	}
202 
203 	dma_sync_single_for_cpu(dev, buf_info->dma_addr + buf_info->page_offset,
204 				len, DMA_FROM_DEVICE);
205 	skb_copy_to_linear_data(skb, page_address(buf_info->page) + buf_info->page_offset, len);
206 	dma_sync_single_for_device(dev, buf_info->dma_addr + buf_info->page_offset,
207 				   len, DMA_FROM_DEVICE);
208 
209 	skb_put(skb, len);
210 	skb->protocol = eth_type_trans(skb, q->lif->netdev);
211 
212 	return skb;
213 }
214 
215 static void ionic_rx_clean(struct ionic_queue *q,
216 			   struct ionic_desc_info *desc_info,
217 			   struct ionic_cq_info *cq_info,
218 			   void *cb_arg)
219 {
220 	struct net_device *netdev = q->lif->netdev;
221 	struct ionic_qcq *qcq = q_to_qcq(q);
222 	struct ionic_rx_stats *stats;
223 	struct ionic_rxq_comp *comp;
224 	struct sk_buff *skb;
225 
226 	comp = cq_info->cq_desc + qcq->cq.desc_size - sizeof(*comp);
227 
228 	stats = q_to_rx_stats(q);
229 
230 	if (comp->status) {
231 		stats->dropped++;
232 		return;
233 	}
234 
235 	stats->pkts++;
236 	stats->bytes += le16_to_cpu(comp->len);
237 
238 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
239 		skb = ionic_rx_copybreak(q, desc_info, comp);
240 	else
241 		skb = ionic_rx_frags(q, desc_info, comp);
242 
243 	if (unlikely(!skb)) {
244 		stats->dropped++;
245 		return;
246 	}
247 
248 	skb_record_rx_queue(skb, q->index);
249 
250 	if (likely(netdev->features & NETIF_F_RXHASH)) {
251 		switch (comp->pkt_type_color & IONIC_RXQ_COMP_PKT_TYPE_MASK) {
252 		case IONIC_PKT_TYPE_IPV4:
253 		case IONIC_PKT_TYPE_IPV6:
254 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
255 				     PKT_HASH_TYPE_L3);
256 			break;
257 		case IONIC_PKT_TYPE_IPV4_TCP:
258 		case IONIC_PKT_TYPE_IPV6_TCP:
259 		case IONIC_PKT_TYPE_IPV4_UDP:
260 		case IONIC_PKT_TYPE_IPV6_UDP:
261 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
262 				     PKT_HASH_TYPE_L4);
263 			break;
264 		}
265 	}
266 
267 	if (likely(netdev->features & NETIF_F_RXCSUM) &&
268 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_CALC)) {
269 		skb->ip_summed = CHECKSUM_COMPLETE;
270 		skb->csum = (__force __wsum)le16_to_cpu(comp->csum);
271 		stats->csum_complete++;
272 	} else {
273 		stats->csum_none++;
274 	}
275 
276 	if (unlikely((comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_TCP_BAD) ||
277 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_UDP_BAD) ||
278 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_IP_BAD)))
279 		stats->csum_error++;
280 
281 	if (likely(netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
282 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_VLAN)) {
283 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
284 				       le16_to_cpu(comp->vlan_tci));
285 		stats->vlan_stripped++;
286 	}
287 
288 	if (unlikely(q->features & IONIC_RXQ_F_HWSTAMP)) {
289 		__le64 *cq_desc_hwstamp;
290 		u64 hwstamp;
291 
292 		cq_desc_hwstamp =
293 			cq_info->cq_desc +
294 			qcq->cq.desc_size -
295 			sizeof(struct ionic_rxq_comp) -
296 			IONIC_HWSTAMP_CQ_NEGOFFSET;
297 
298 		hwstamp = le64_to_cpu(*cq_desc_hwstamp);
299 
300 		if (hwstamp != IONIC_HWSTAMP_INVALID) {
301 			skb_hwtstamps(skb)->hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
302 			stats->hwstamp_valid++;
303 		} else {
304 			stats->hwstamp_invalid++;
305 		}
306 	}
307 
308 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
309 		napi_gro_receive(&qcq->napi, skb);
310 	else
311 		napi_gro_frags(&qcq->napi);
312 }
313 
314 bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
315 {
316 	struct ionic_queue *q = cq->bound_q;
317 	struct ionic_desc_info *desc_info;
318 	struct ionic_rxq_comp *comp;
319 
320 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
321 
322 	if (!color_match(comp->pkt_type_color, cq->done_color))
323 		return false;
324 
325 	/* check for empty queue */
326 	if (q->tail_idx == q->head_idx)
327 		return false;
328 
329 	if (q->tail_idx != le16_to_cpu(comp->comp_index))
330 		return false;
331 
332 	desc_info = &q->info[q->tail_idx];
333 	q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
334 
335 	/* clean the related q entry, only one per qc completion */
336 	ionic_rx_clean(q, desc_info, cq_info, desc_info->cb_arg);
337 
338 	desc_info->cb = NULL;
339 	desc_info->cb_arg = NULL;
340 
341 	return true;
342 }
343 
344 void ionic_rx_fill(struct ionic_queue *q)
345 {
346 	struct net_device *netdev = q->lif->netdev;
347 	struct ionic_desc_info *desc_info;
348 	struct ionic_rxq_sg_desc *sg_desc;
349 	struct ionic_rxq_sg_elem *sg_elem;
350 	struct ionic_buf_info *buf_info;
351 	unsigned int fill_threshold;
352 	struct ionic_rxq_desc *desc;
353 	unsigned int remain_len;
354 	unsigned int frag_len;
355 	unsigned int nfrags;
356 	unsigned int n_fill;
357 	unsigned int i, j;
358 	unsigned int len;
359 
360 	n_fill = ionic_q_space_avail(q);
361 
362 	fill_threshold = min_t(unsigned int, IONIC_RX_FILL_THRESHOLD,
363 			       q->num_descs / IONIC_RX_FILL_DIV);
364 	if (n_fill < fill_threshold)
365 		return;
366 
367 	len = netdev->mtu + ETH_HLEN + VLAN_HLEN;
368 
369 	for (i = n_fill; i; i--) {
370 		nfrags = 0;
371 		remain_len = len;
372 		desc_info = &q->info[q->head_idx];
373 		desc = desc_info->desc;
374 		buf_info = &desc_info->bufs[0];
375 
376 		if (!buf_info->page) { /* alloc a new buffer? */
377 			if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
378 				desc->addr = 0;
379 				desc->len = 0;
380 				return;
381 			}
382 		}
383 
384 		/* fill main descriptor - buf[0] */
385 		desc->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
386 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
387 		desc->len = cpu_to_le16(frag_len);
388 		remain_len -= frag_len;
389 		buf_info++;
390 		nfrags++;
391 
392 		/* fill sg descriptors - buf[1..n] */
393 		sg_desc = desc_info->sg_desc;
394 		for (j = 0; remain_len > 0 && j < q->max_sg_elems; j++) {
395 			sg_elem = &sg_desc->elems[j];
396 			if (!buf_info->page) { /* alloc a new sg buffer? */
397 				if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
398 					sg_elem->addr = 0;
399 					sg_elem->len = 0;
400 					return;
401 				}
402 			}
403 
404 			sg_elem->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
405 			frag_len = min_t(u16, remain_len, IONIC_PAGE_SIZE - buf_info->page_offset);
406 			sg_elem->len = cpu_to_le16(frag_len);
407 			remain_len -= frag_len;
408 			buf_info++;
409 			nfrags++;
410 		}
411 
412 		/* clear end sg element as a sentinel */
413 		if (j < q->max_sg_elems) {
414 			sg_elem = &sg_desc->elems[j];
415 			memset(sg_elem, 0, sizeof(*sg_elem));
416 		}
417 
418 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
419 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
420 		desc_info->nbufs = nfrags;
421 
422 		ionic_rxq_post(q, false, ionic_rx_clean, NULL);
423 	}
424 
425 	ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
426 			 q->dbval | q->head_idx);
427 }
428 
429 void ionic_rx_empty(struct ionic_queue *q)
430 {
431 	struct ionic_desc_info *desc_info;
432 	struct ionic_buf_info *buf_info;
433 	unsigned int i, j;
434 
435 	for (i = 0; i < q->num_descs; i++) {
436 		desc_info = &q->info[i];
437 		for (j = 0; j < IONIC_RX_MAX_SG_ELEMS + 1; j++) {
438 			buf_info = &desc_info->bufs[j];
439 			if (buf_info->page)
440 				ionic_rx_page_free(q, buf_info);
441 		}
442 
443 		desc_info->nbufs = 0;
444 		desc_info->cb = NULL;
445 		desc_info->cb_arg = NULL;
446 	}
447 
448 	q->head_idx = 0;
449 	q->tail_idx = 0;
450 }
451 
452 static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode)
453 {
454 	struct dim_sample dim_sample;
455 	struct ionic_lif *lif;
456 	unsigned int qi;
457 	u64 pkts, bytes;
458 
459 	if (!qcq->intr.dim_coal_hw)
460 		return;
461 
462 	lif = qcq->q.lif;
463 	qi = qcq->cq.bound_q->index;
464 
465 	switch (napi_mode) {
466 	case IONIC_LIF_F_TX_DIM_INTR:
467 		pkts = lif->txqstats[qi].pkts;
468 		bytes = lif->txqstats[qi].bytes;
469 		break;
470 	case IONIC_LIF_F_RX_DIM_INTR:
471 		pkts = lif->rxqstats[qi].pkts;
472 		bytes = lif->rxqstats[qi].bytes;
473 		break;
474 	default:
475 		pkts = lif->txqstats[qi].pkts + lif->rxqstats[qi].pkts;
476 		bytes = lif->txqstats[qi].bytes + lif->rxqstats[qi].bytes;
477 		break;
478 	}
479 
480 	dim_update_sample(qcq->cq.bound_intr->rearm_count,
481 			  pkts, bytes, &dim_sample);
482 
483 	net_dim(&qcq->dim, dim_sample);
484 }
485 
486 int ionic_tx_napi(struct napi_struct *napi, int budget)
487 {
488 	struct ionic_qcq *qcq = napi_to_qcq(napi);
489 	struct ionic_cq *cq = napi_to_cq(napi);
490 	struct ionic_dev *idev;
491 	struct ionic_lif *lif;
492 	u32 work_done = 0;
493 	u32 flags = 0;
494 
495 	lif = cq->bound_q->lif;
496 	idev = &lif->ionic->idev;
497 
498 	work_done = ionic_cq_service(cq, budget,
499 				     ionic_tx_service, NULL, NULL);
500 
501 	if (work_done < budget && napi_complete_done(napi, work_done)) {
502 		ionic_dim_update(qcq, IONIC_LIF_F_TX_DIM_INTR);
503 		flags |= IONIC_INTR_CRED_UNMASK;
504 		cq->bound_intr->rearm_count++;
505 	}
506 
507 	if (work_done || flags) {
508 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
509 		ionic_intr_credits(idev->intr_ctrl,
510 				   cq->bound_intr->index,
511 				   work_done, flags);
512 	}
513 
514 	return work_done;
515 }
516 
517 int ionic_rx_napi(struct napi_struct *napi, int budget)
518 {
519 	struct ionic_qcq *qcq = napi_to_qcq(napi);
520 	struct ionic_cq *cq = napi_to_cq(napi);
521 	struct ionic_dev *idev;
522 	struct ionic_lif *lif;
523 	u32 work_done = 0;
524 	u32 flags = 0;
525 
526 	lif = cq->bound_q->lif;
527 	idev = &lif->ionic->idev;
528 
529 	work_done = ionic_cq_service(cq, budget,
530 				     ionic_rx_service, NULL, NULL);
531 
532 	ionic_rx_fill(cq->bound_q);
533 
534 	if (work_done < budget && napi_complete_done(napi, work_done)) {
535 		ionic_dim_update(qcq, IONIC_LIF_F_RX_DIM_INTR);
536 		flags |= IONIC_INTR_CRED_UNMASK;
537 		cq->bound_intr->rearm_count++;
538 	}
539 
540 	if (work_done || flags) {
541 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
542 		ionic_intr_credits(idev->intr_ctrl,
543 				   cq->bound_intr->index,
544 				   work_done, flags);
545 	}
546 
547 	return work_done;
548 }
549 
550 int ionic_txrx_napi(struct napi_struct *napi, int budget)
551 {
552 	struct ionic_qcq *qcq = napi_to_qcq(napi);
553 	struct ionic_cq *rxcq = napi_to_cq(napi);
554 	unsigned int qi = rxcq->bound_q->index;
555 	struct ionic_dev *idev;
556 	struct ionic_lif *lif;
557 	struct ionic_cq *txcq;
558 	u32 rx_work_done = 0;
559 	u32 tx_work_done = 0;
560 	u32 flags = 0;
561 
562 	lif = rxcq->bound_q->lif;
563 	idev = &lif->ionic->idev;
564 	txcq = &lif->txqcqs[qi]->cq;
565 
566 	tx_work_done = ionic_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT,
567 					ionic_tx_service, NULL, NULL);
568 
569 	rx_work_done = ionic_cq_service(rxcq, budget,
570 					ionic_rx_service, NULL, NULL);
571 
572 	ionic_rx_fill(rxcq->bound_q);
573 
574 	if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) {
575 		ionic_dim_update(qcq, 0);
576 		flags |= IONIC_INTR_CRED_UNMASK;
577 		rxcq->bound_intr->rearm_count++;
578 	}
579 
580 	if (rx_work_done || flags) {
581 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
582 		ionic_intr_credits(idev->intr_ctrl, rxcq->bound_intr->index,
583 				   tx_work_done + rx_work_done, flags);
584 	}
585 
586 	return rx_work_done;
587 }
588 
589 static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
590 				      void *data, size_t len)
591 {
592 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
593 	struct device *dev = q->dev;
594 	dma_addr_t dma_addr;
595 
596 	dma_addr = dma_map_single(dev, data, len, DMA_TO_DEVICE);
597 	if (dma_mapping_error(dev, dma_addr)) {
598 		net_warn_ratelimited("%s: DMA single map failed on %s!\n",
599 				     q->lif->netdev->name, q->name);
600 		stats->dma_map_err++;
601 		return 0;
602 	}
603 	return dma_addr;
604 }
605 
606 static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
607 				    const skb_frag_t *frag,
608 				    size_t offset, size_t len)
609 {
610 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
611 	struct device *dev = q->dev;
612 	dma_addr_t dma_addr;
613 
614 	dma_addr = skb_frag_dma_map(dev, frag, offset, len, DMA_TO_DEVICE);
615 	if (dma_mapping_error(dev, dma_addr)) {
616 		net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
617 				     q->lif->netdev->name, q->name);
618 		stats->dma_map_err++;
619 	}
620 	return dma_addr;
621 }
622 
623 static int ionic_tx_map_skb(struct ionic_queue *q, struct sk_buff *skb,
624 			    struct ionic_desc_info *desc_info)
625 {
626 	struct ionic_buf_info *buf_info = desc_info->bufs;
627 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
628 	struct device *dev = q->dev;
629 	dma_addr_t dma_addr;
630 	unsigned int nfrags;
631 	skb_frag_t *frag;
632 	int frag_idx;
633 
634 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
635 	if (dma_mapping_error(dev, dma_addr)) {
636 		stats->dma_map_err++;
637 		return -EIO;
638 	}
639 	buf_info->dma_addr = dma_addr;
640 	buf_info->len = skb_headlen(skb);
641 	buf_info++;
642 
643 	frag = skb_shinfo(skb)->frags;
644 	nfrags = skb_shinfo(skb)->nr_frags;
645 	for (frag_idx = 0; frag_idx < nfrags; frag_idx++, frag++) {
646 		dma_addr = ionic_tx_map_frag(q, frag, 0, skb_frag_size(frag));
647 		if (dma_mapping_error(dev, dma_addr)) {
648 			stats->dma_map_err++;
649 			goto dma_fail;
650 		}
651 		buf_info->dma_addr = dma_addr;
652 		buf_info->len = skb_frag_size(frag);
653 		buf_info++;
654 	}
655 
656 	desc_info->nbufs = 1 + nfrags;
657 
658 	return 0;
659 
660 dma_fail:
661 	/* unwind the frag mappings and the head mapping */
662 	while (frag_idx > 0) {
663 		frag_idx--;
664 		buf_info--;
665 		dma_unmap_page(dev, buf_info->dma_addr,
666 			       buf_info->len, DMA_TO_DEVICE);
667 	}
668 	dma_unmap_single(dev, buf_info->dma_addr, buf_info->len, DMA_TO_DEVICE);
669 	return -EIO;
670 }
671 
672 static void ionic_tx_desc_unmap_bufs(struct ionic_queue *q,
673 				     struct ionic_desc_info *desc_info)
674 {
675 	struct ionic_buf_info *buf_info = desc_info->bufs;
676 	struct device *dev = q->dev;
677 	unsigned int i;
678 
679 	if (!desc_info->nbufs)
680 		return;
681 
682 	dma_unmap_single(dev, (dma_addr_t)buf_info->dma_addr,
683 			 buf_info->len, DMA_TO_DEVICE);
684 	buf_info++;
685 	for (i = 1; i < desc_info->nbufs; i++, buf_info++)
686 		dma_unmap_page(dev, (dma_addr_t)buf_info->dma_addr,
687 			       buf_info->len, DMA_TO_DEVICE);
688 
689 	desc_info->nbufs = 0;
690 }
691 
692 static void ionic_tx_clean(struct ionic_queue *q,
693 			   struct ionic_desc_info *desc_info,
694 			   struct ionic_cq_info *cq_info,
695 			   void *cb_arg)
696 {
697 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
698 	struct ionic_qcq *qcq = q_to_qcq(q);
699 	struct sk_buff *skb = cb_arg;
700 	u16 qi;
701 
702 	ionic_tx_desc_unmap_bufs(q, desc_info);
703 
704 	if (!skb)
705 		return;
706 
707 	qi = skb_get_queue_mapping(skb);
708 
709 	if (unlikely(q->features & IONIC_TXQ_F_HWSTAMP)) {
710 		if (cq_info) {
711 			struct skb_shared_hwtstamps hwts = {};
712 			__le64 *cq_desc_hwstamp;
713 			u64 hwstamp;
714 
715 			cq_desc_hwstamp =
716 				cq_info->cq_desc +
717 				qcq->cq.desc_size -
718 				sizeof(struct ionic_txq_comp) -
719 				IONIC_HWSTAMP_CQ_NEGOFFSET;
720 
721 			hwstamp = le64_to_cpu(*cq_desc_hwstamp);
722 
723 			if (hwstamp != IONIC_HWSTAMP_INVALID) {
724 				hwts.hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
725 
726 				skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
727 				skb_tstamp_tx(skb, &hwts);
728 
729 				stats->hwstamp_valid++;
730 			} else {
731 				stats->hwstamp_invalid++;
732 			}
733 		}
734 
735 	} else if (unlikely(__netif_subqueue_stopped(q->lif->netdev, qi))) {
736 		netif_wake_subqueue(q->lif->netdev, qi);
737 	}
738 
739 	desc_info->bytes = skb->len;
740 	stats->clean++;
741 
742 	dev_consume_skb_any(skb);
743 }
744 
745 bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
746 {
747 	struct ionic_queue *q = cq->bound_q;
748 	struct ionic_desc_info *desc_info;
749 	struct ionic_txq_comp *comp;
750 	int bytes = 0;
751 	int pkts = 0;
752 	u16 index;
753 
754 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
755 
756 	if (!color_match(comp->color, cq->done_color))
757 		return false;
758 
759 	/* clean the related q entries, there could be
760 	 * several q entries completed for each cq completion
761 	 */
762 	do {
763 		desc_info = &q->info[q->tail_idx];
764 		desc_info->bytes = 0;
765 		index = q->tail_idx;
766 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
767 		ionic_tx_clean(q, desc_info, cq_info, desc_info->cb_arg);
768 		if (desc_info->cb_arg) {
769 			pkts++;
770 			bytes += desc_info->bytes;
771 		}
772 		desc_info->cb = NULL;
773 		desc_info->cb_arg = NULL;
774 	} while (index != le16_to_cpu(comp->comp_index));
775 
776 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
777 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
778 
779 	return true;
780 }
781 
782 void ionic_tx_flush(struct ionic_cq *cq)
783 {
784 	struct ionic_dev *idev = &cq->lif->ionic->idev;
785 	u32 work_done;
786 
787 	work_done = ionic_cq_service(cq, cq->num_descs,
788 				     ionic_tx_service, NULL, NULL);
789 	if (work_done)
790 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
791 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
792 }
793 
794 void ionic_tx_empty(struct ionic_queue *q)
795 {
796 	struct ionic_desc_info *desc_info;
797 	int bytes = 0;
798 	int pkts = 0;
799 
800 	/* walk the not completed tx entries, if any */
801 	while (q->head_idx != q->tail_idx) {
802 		desc_info = &q->info[q->tail_idx];
803 		desc_info->bytes = 0;
804 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
805 		ionic_tx_clean(q, desc_info, NULL, desc_info->cb_arg);
806 		if (desc_info->cb_arg) {
807 			pkts++;
808 			bytes += desc_info->bytes;
809 		}
810 		desc_info->cb = NULL;
811 		desc_info->cb_arg = NULL;
812 	}
813 
814 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
815 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
816 }
817 
818 static int ionic_tx_tcp_inner_pseudo_csum(struct sk_buff *skb)
819 {
820 	int err;
821 
822 	err = skb_cow_head(skb, 0);
823 	if (err)
824 		return err;
825 
826 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
827 		inner_ip_hdr(skb)->check = 0;
828 		inner_tcp_hdr(skb)->check =
829 			~csum_tcpudp_magic(inner_ip_hdr(skb)->saddr,
830 					   inner_ip_hdr(skb)->daddr,
831 					   0, IPPROTO_TCP, 0);
832 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
833 		inner_tcp_hdr(skb)->check =
834 			~csum_ipv6_magic(&inner_ipv6_hdr(skb)->saddr,
835 					 &inner_ipv6_hdr(skb)->daddr,
836 					 0, IPPROTO_TCP, 0);
837 	}
838 
839 	return 0;
840 }
841 
842 static int ionic_tx_tcp_pseudo_csum(struct sk_buff *skb)
843 {
844 	int err;
845 
846 	err = skb_cow_head(skb, 0);
847 	if (err)
848 		return err;
849 
850 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
851 		ip_hdr(skb)->check = 0;
852 		tcp_hdr(skb)->check =
853 			~csum_tcpudp_magic(ip_hdr(skb)->saddr,
854 					   ip_hdr(skb)->daddr,
855 					   0, IPPROTO_TCP, 0);
856 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
857 		tcp_v6_gso_csum_prep(skb);
858 	}
859 
860 	return 0;
861 }
862 
863 static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
864 			      struct sk_buff *skb,
865 			      dma_addr_t addr, u8 nsge, u16 len,
866 			      unsigned int hdrlen, unsigned int mss,
867 			      bool outer_csum,
868 			      u16 vlan_tci, bool has_vlan,
869 			      bool start, bool done)
870 {
871 	u8 flags = 0;
872 	u64 cmd;
873 
874 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
875 	flags |= outer_csum ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
876 	flags |= start ? IONIC_TXQ_DESC_FLAG_TSO_SOT : 0;
877 	flags |= done ? IONIC_TXQ_DESC_FLAG_TSO_EOT : 0;
878 
879 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_TSO, flags, nsge, addr);
880 	desc->cmd = cpu_to_le64(cmd);
881 	desc->len = cpu_to_le16(len);
882 	desc->vlan_tci = cpu_to_le16(vlan_tci);
883 	desc->hdr_len = cpu_to_le16(hdrlen);
884 	desc->mss = cpu_to_le16(mss);
885 
886 	if (start) {
887 		skb_tx_timestamp(skb);
888 		if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
889 			netdev_tx_sent_queue(q_to_ndq(q), skb->len);
890 		ionic_txq_post(q, false, ionic_tx_clean, skb);
891 	} else {
892 		ionic_txq_post(q, done, NULL, NULL);
893 	}
894 }
895 
896 static int ionic_tx_tso(struct ionic_queue *q, struct sk_buff *skb)
897 {
898 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
899 	struct ionic_desc_info *desc_info;
900 	struct ionic_buf_info *buf_info;
901 	struct ionic_txq_sg_elem *elem;
902 	struct ionic_txq_desc *desc;
903 	unsigned int chunk_len;
904 	unsigned int frag_rem;
905 	unsigned int tso_rem;
906 	unsigned int seg_rem;
907 	dma_addr_t desc_addr;
908 	dma_addr_t frag_addr;
909 	unsigned int hdrlen;
910 	unsigned int len;
911 	unsigned int mss;
912 	bool start, done;
913 	bool outer_csum;
914 	bool has_vlan;
915 	u16 desc_len;
916 	u8 desc_nsge;
917 	u16 vlan_tci;
918 	bool encap;
919 	int err;
920 
921 	desc_info = &q->info[q->head_idx];
922 	buf_info = desc_info->bufs;
923 
924 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
925 		return -EIO;
926 
927 	len = skb->len;
928 	mss = skb_shinfo(skb)->gso_size;
929 	outer_csum = (skb_shinfo(skb)->gso_type & (SKB_GSO_GRE |
930 						   SKB_GSO_GRE_CSUM |
931 						   SKB_GSO_IPXIP4 |
932 						   SKB_GSO_IPXIP6 |
933 						   SKB_GSO_UDP_TUNNEL |
934 						   SKB_GSO_UDP_TUNNEL_CSUM));
935 	has_vlan = !!skb_vlan_tag_present(skb);
936 	vlan_tci = skb_vlan_tag_get(skb);
937 	encap = skb->encapsulation;
938 
939 	/* Preload inner-most TCP csum field with IP pseudo hdr
940 	 * calculated with IP length set to zero.  HW will later
941 	 * add in length to each TCP segment resulting from the TSO.
942 	 */
943 
944 	if (encap)
945 		err = ionic_tx_tcp_inner_pseudo_csum(skb);
946 	else
947 		err = ionic_tx_tcp_pseudo_csum(skb);
948 	if (err) {
949 		/* clean up mapping from ionic_tx_map_skb */
950 		ionic_tx_desc_unmap_bufs(q, desc_info);
951 		return err;
952 	}
953 
954 	if (encap)
955 		hdrlen = skb_inner_tcp_all_headers(skb);
956 	else
957 		hdrlen = skb_tcp_all_headers(skb);
958 
959 	tso_rem = len;
960 	seg_rem = min(tso_rem, hdrlen + mss);
961 
962 	frag_addr = 0;
963 	frag_rem = 0;
964 
965 	start = true;
966 
967 	while (tso_rem > 0) {
968 		desc = NULL;
969 		elem = NULL;
970 		desc_addr = 0;
971 		desc_len = 0;
972 		desc_nsge = 0;
973 		/* use fragments until we have enough to post a single descriptor */
974 		while (seg_rem > 0) {
975 			/* if the fragment is exhausted then move to the next one */
976 			if (frag_rem == 0) {
977 				/* grab the next fragment */
978 				frag_addr = buf_info->dma_addr;
979 				frag_rem = buf_info->len;
980 				buf_info++;
981 			}
982 			chunk_len = min(frag_rem, seg_rem);
983 			if (!desc) {
984 				/* fill main descriptor */
985 				desc = desc_info->txq_desc;
986 				elem = desc_info->txq_sg_desc->elems;
987 				desc_addr = frag_addr;
988 				desc_len = chunk_len;
989 			} else {
990 				/* fill sg descriptor */
991 				elem->addr = cpu_to_le64(frag_addr);
992 				elem->len = cpu_to_le16(chunk_len);
993 				elem++;
994 				desc_nsge++;
995 			}
996 			frag_addr += chunk_len;
997 			frag_rem -= chunk_len;
998 			tso_rem -= chunk_len;
999 			seg_rem -= chunk_len;
1000 		}
1001 		seg_rem = min(tso_rem, mss);
1002 		done = (tso_rem == 0);
1003 		/* post descriptor */
1004 		ionic_tx_tso_post(q, desc, skb,
1005 				  desc_addr, desc_nsge, desc_len,
1006 				  hdrlen, mss, outer_csum, vlan_tci, has_vlan,
1007 				  start, done);
1008 		start = false;
1009 		/* Buffer information is stored with the first tso descriptor */
1010 		desc_info = &q->info[q->head_idx];
1011 		desc_info->nbufs = 0;
1012 	}
1013 
1014 	stats->pkts += DIV_ROUND_UP(len - hdrlen, mss);
1015 	stats->bytes += len;
1016 	stats->tso++;
1017 	stats->tso_bytes = len;
1018 
1019 	return 0;
1020 }
1021 
1022 static void ionic_tx_calc_csum(struct ionic_queue *q, struct sk_buff *skb,
1023 			       struct ionic_desc_info *desc_info)
1024 {
1025 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1026 	struct ionic_buf_info *buf_info = desc_info->bufs;
1027 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1028 	bool has_vlan;
1029 	u8 flags = 0;
1030 	bool encap;
1031 	u64 cmd;
1032 
1033 	has_vlan = !!skb_vlan_tag_present(skb);
1034 	encap = skb->encapsulation;
1035 
1036 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1037 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1038 
1039 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_PARTIAL,
1040 				  flags, skb_shinfo(skb)->nr_frags,
1041 				  buf_info->dma_addr);
1042 	desc->cmd = cpu_to_le64(cmd);
1043 	desc->len = cpu_to_le16(buf_info->len);
1044 	if (has_vlan) {
1045 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1046 		stats->vlan_inserted++;
1047 	} else {
1048 		desc->vlan_tci = 0;
1049 	}
1050 	desc->csum_start = cpu_to_le16(skb_checksum_start_offset(skb));
1051 	desc->csum_offset = cpu_to_le16(skb->csum_offset);
1052 
1053 	if (skb_csum_is_sctp(skb))
1054 		stats->crc32_csum++;
1055 	else
1056 		stats->csum++;
1057 }
1058 
1059 static void ionic_tx_calc_no_csum(struct ionic_queue *q, struct sk_buff *skb,
1060 				  struct ionic_desc_info *desc_info)
1061 {
1062 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1063 	struct ionic_buf_info *buf_info = desc_info->bufs;
1064 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1065 	bool has_vlan;
1066 	u8 flags = 0;
1067 	bool encap;
1068 	u64 cmd;
1069 
1070 	has_vlan = !!skb_vlan_tag_present(skb);
1071 	encap = skb->encapsulation;
1072 
1073 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1074 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1075 
1076 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_NONE,
1077 				  flags, skb_shinfo(skb)->nr_frags,
1078 				  buf_info->dma_addr);
1079 	desc->cmd = cpu_to_le64(cmd);
1080 	desc->len = cpu_to_le16(buf_info->len);
1081 	if (has_vlan) {
1082 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1083 		stats->vlan_inserted++;
1084 	} else {
1085 		desc->vlan_tci = 0;
1086 	}
1087 	desc->csum_start = 0;
1088 	desc->csum_offset = 0;
1089 
1090 	stats->csum_none++;
1091 }
1092 
1093 static void ionic_tx_skb_frags(struct ionic_queue *q, struct sk_buff *skb,
1094 			       struct ionic_desc_info *desc_info)
1095 {
1096 	struct ionic_txq_sg_desc *sg_desc = desc_info->txq_sg_desc;
1097 	struct ionic_buf_info *buf_info = &desc_info->bufs[1];
1098 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
1099 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1100 	unsigned int i;
1101 
1102 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, buf_info++, elem++) {
1103 		elem->addr = cpu_to_le64(buf_info->dma_addr);
1104 		elem->len = cpu_to_le16(buf_info->len);
1105 	}
1106 
1107 	stats->frags += skb_shinfo(skb)->nr_frags;
1108 }
1109 
1110 static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
1111 {
1112 	struct ionic_desc_info *desc_info = &q->info[q->head_idx];
1113 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1114 
1115 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
1116 		return -EIO;
1117 
1118 	/* set up the initial descriptor */
1119 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1120 		ionic_tx_calc_csum(q, skb, desc_info);
1121 	else
1122 		ionic_tx_calc_no_csum(q, skb, desc_info);
1123 
1124 	/* add frags */
1125 	ionic_tx_skb_frags(q, skb, desc_info);
1126 
1127 	skb_tx_timestamp(skb);
1128 	stats->pkts++;
1129 	stats->bytes += skb->len;
1130 
1131 	if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
1132 		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
1133 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
1134 
1135 	return 0;
1136 }
1137 
1138 static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
1139 {
1140 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1141 	int ndescs;
1142 	int err;
1143 
1144 	/* Each desc is mss long max, so a descriptor for each gso_seg */
1145 	if (skb_is_gso(skb))
1146 		ndescs = skb_shinfo(skb)->gso_segs;
1147 	else
1148 		ndescs = 1;
1149 
1150 	/* If non-TSO, just need 1 desc and nr_frags sg elems */
1151 	if (skb_shinfo(skb)->nr_frags <= q->max_sg_elems)
1152 		return ndescs;
1153 
1154 	/* Too many frags, so linearize */
1155 	err = skb_linearize(skb);
1156 	if (err)
1157 		return err;
1158 
1159 	stats->linearize++;
1160 
1161 	return ndescs;
1162 }
1163 
1164 static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
1165 {
1166 	int stopped = 0;
1167 
1168 	if (unlikely(!ionic_q_has_space(q, ndescs))) {
1169 		netif_stop_subqueue(q->lif->netdev, q->index);
1170 		stopped = 1;
1171 
1172 		/* Might race with ionic_tx_clean, check again */
1173 		smp_rmb();
1174 		if (ionic_q_has_space(q, ndescs)) {
1175 			netif_wake_subqueue(q->lif->netdev, q->index);
1176 			stopped = 0;
1177 		}
1178 	}
1179 
1180 	return stopped;
1181 }
1182 
1183 static netdev_tx_t ionic_start_hwstamp_xmit(struct sk_buff *skb,
1184 					    struct net_device *netdev)
1185 {
1186 	struct ionic_lif *lif = netdev_priv(netdev);
1187 	struct ionic_queue *q = &lif->hwstamp_txq->q;
1188 	int err, ndescs;
1189 
1190 	/* Does not stop/start txq, because we post to a separate tx queue
1191 	 * for timestamping, and if a packet can't be posted immediately to
1192 	 * the timestamping queue, it is dropped.
1193 	 */
1194 
1195 	ndescs = ionic_tx_descs_needed(q, skb);
1196 	if (unlikely(ndescs < 0))
1197 		goto err_out_drop;
1198 
1199 	if (unlikely(!ionic_q_has_space(q, ndescs)))
1200 		goto err_out_drop;
1201 
1202 	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP;
1203 	if (skb_is_gso(skb))
1204 		err = ionic_tx_tso(q, skb);
1205 	else
1206 		err = ionic_tx(q, skb);
1207 
1208 	if (err)
1209 		goto err_out_drop;
1210 
1211 	return NETDEV_TX_OK;
1212 
1213 err_out_drop:
1214 	q->drop++;
1215 	dev_kfree_skb(skb);
1216 	return NETDEV_TX_OK;
1217 }
1218 
1219 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1220 {
1221 	u16 queue_index = skb_get_queue_mapping(skb);
1222 	struct ionic_lif *lif = netdev_priv(netdev);
1223 	struct ionic_queue *q;
1224 	int ndescs;
1225 	int err;
1226 
1227 	if (unlikely(!test_bit(IONIC_LIF_F_UP, lif->state))) {
1228 		dev_kfree_skb(skb);
1229 		return NETDEV_TX_OK;
1230 	}
1231 
1232 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
1233 		if (lif->hwstamp_txq && lif->phc->ts_config_tx_mode)
1234 			return ionic_start_hwstamp_xmit(skb, netdev);
1235 
1236 	if (unlikely(queue_index >= lif->nxqs))
1237 		queue_index = 0;
1238 	q = &lif->txqcqs[queue_index]->q;
1239 
1240 	ndescs = ionic_tx_descs_needed(q, skb);
1241 	if (ndescs < 0)
1242 		goto err_out_drop;
1243 
1244 	if (unlikely(ionic_maybe_stop_tx(q, ndescs)))
1245 		return NETDEV_TX_BUSY;
1246 
1247 	if (skb_is_gso(skb))
1248 		err = ionic_tx_tso(q, skb);
1249 	else
1250 		err = ionic_tx(q, skb);
1251 
1252 	if (err)
1253 		goto err_out_drop;
1254 
1255 	/* Stop the queue if there aren't descriptors for the next packet.
1256 	 * Since our SG lists per descriptor take care of most of the possible
1257 	 * fragmentation, we don't need to have many descriptors available.
1258 	 */
1259 	ionic_maybe_stop_tx(q, 4);
1260 
1261 	return NETDEV_TX_OK;
1262 
1263 err_out_drop:
1264 	q->drop++;
1265 	dev_kfree_skb(skb);
1266 	return NETDEV_TX_OK;
1267 }
1268