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 
14 static inline void ionic_txq_post(struct ionic_queue *q, bool ring_dbell,
15 				  ionic_desc_cb cb_func, void *cb_arg)
16 {
17 	DEBUG_STATS_TXQ_POST(q, ring_dbell);
18 
19 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
20 }
21 
22 static inline void ionic_rxq_post(struct ionic_queue *q, bool ring_dbell,
23 				  ionic_desc_cb cb_func, void *cb_arg)
24 {
25 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
26 
27 	DEBUG_STATS_RX_BUFF_CNT(q);
28 }
29 
30 static inline struct netdev_queue *q_to_ndq(struct ionic_queue *q)
31 {
32 	return netdev_get_tx_queue(q->lif->netdev, q->index);
33 }
34 
35 static void ionic_rx_buf_reset(struct ionic_buf_info *buf_info)
36 {
37 	buf_info->page = NULL;
38 	buf_info->page_offset = 0;
39 	buf_info->dma_addr = 0;
40 }
41 
42 static int ionic_rx_page_alloc(struct ionic_queue *q,
43 			       struct ionic_buf_info *buf_info)
44 {
45 	struct net_device *netdev = q->lif->netdev;
46 	struct ionic_rx_stats *stats;
47 	struct device *dev;
48 
49 	dev = q->dev;
50 	stats = q_to_rx_stats(q);
51 
52 	if (unlikely(!buf_info)) {
53 		net_err_ratelimited("%s: %s invalid buf_info in alloc\n",
54 				    netdev->name, q->name);
55 		return -EINVAL;
56 	}
57 
58 	buf_info->page = alloc_pages(IONIC_PAGE_GFP_MASK, 0);
59 	if (unlikely(!buf_info->page)) {
60 		net_err_ratelimited("%s: %s page alloc failed\n",
61 				    netdev->name, q->name);
62 		stats->alloc_err++;
63 		return -ENOMEM;
64 	}
65 	buf_info->page_offset = 0;
66 
67 	buf_info->dma_addr = dma_map_page(dev, buf_info->page, buf_info->page_offset,
68 					  IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
69 	if (unlikely(dma_mapping_error(dev, buf_info->dma_addr))) {
70 		__free_pages(buf_info->page, 0);
71 		ionic_rx_buf_reset(buf_info);
72 		net_err_ratelimited("%s: %s dma map failed\n",
73 				    netdev->name, q->name);
74 		stats->dma_map_err++;
75 		return -EIO;
76 	}
77 
78 	return 0;
79 }
80 
81 static void ionic_rx_page_free(struct ionic_queue *q,
82 			       struct ionic_buf_info *buf_info)
83 {
84 	struct net_device *netdev = q->lif->netdev;
85 	struct device *dev = q->dev;
86 
87 	if (unlikely(!buf_info)) {
88 		net_err_ratelimited("%s: %s invalid buf_info in free\n",
89 				    netdev->name, q->name);
90 		return;
91 	}
92 
93 	if (!buf_info->page)
94 		return;
95 
96 	dma_unmap_page(dev, buf_info->dma_addr, IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
97 	__free_pages(buf_info->page, 0);
98 	ionic_rx_buf_reset(buf_info);
99 }
100 
101 static bool ionic_rx_buf_recycle(struct ionic_queue *q,
102 				 struct ionic_buf_info *buf_info, u32 used)
103 {
104 	u32 size;
105 
106 	/* don't re-use pages allocated in low-mem condition */
107 	if (page_is_pfmemalloc(buf_info->page))
108 		return false;
109 
110 	/* don't re-use buffers from non-local numa nodes */
111 	if (page_to_nid(buf_info->page) != numa_mem_id())
112 		return false;
113 
114 	size = ALIGN(used, IONIC_PAGE_SPLIT_SZ);
115 	buf_info->page_offset += size;
116 	if (buf_info->page_offset >= IONIC_PAGE_SIZE)
117 		return false;
118 
119 	get_page(buf_info->page);
120 
121 	return true;
122 }
123 
124 static struct sk_buff *ionic_rx_frags(struct ionic_queue *q,
125 				      struct ionic_desc_info *desc_info,
126 				      struct ionic_rxq_comp *comp)
127 {
128 	struct net_device *netdev = q->lif->netdev;
129 	struct ionic_buf_info *buf_info;
130 	struct ionic_rx_stats *stats;
131 	struct device *dev = q->dev;
132 	struct sk_buff *skb;
133 	unsigned int i;
134 	u16 frag_len;
135 	u16 len;
136 
137 	stats = q_to_rx_stats(q);
138 
139 	buf_info = &desc_info->bufs[0];
140 	len = le16_to_cpu(comp->len);
141 
142 	prefetch(buf_info->page);
143 
144 	skb = napi_get_frags(&q_to_qcq(q)->napi);
145 	if (unlikely(!skb)) {
146 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
147 				     netdev->name, q->name);
148 		stats->alloc_err++;
149 		return NULL;
150 	}
151 
152 	i = comp->num_sg_elems + 1;
153 	do {
154 		if (unlikely(!buf_info->page)) {
155 			dev_kfree_skb(skb);
156 			return NULL;
157 		}
158 
159 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
160 		len -= frag_len;
161 
162 		dma_sync_single_for_cpu(dev,
163 					buf_info->dma_addr + buf_info->page_offset,
164 					frag_len, DMA_FROM_DEVICE);
165 
166 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
167 				buf_info->page, buf_info->page_offset, frag_len,
168 				IONIC_PAGE_SIZE);
169 
170 		if (!ionic_rx_buf_recycle(q, buf_info, frag_len)) {
171 			dma_unmap_page(dev, buf_info->dma_addr,
172 				       IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
173 			ionic_rx_buf_reset(buf_info);
174 		}
175 
176 		buf_info++;
177 
178 		i--;
179 	} while (i > 0);
180 
181 	return skb;
182 }
183 
184 static struct sk_buff *ionic_rx_copybreak(struct ionic_queue *q,
185 					  struct ionic_desc_info *desc_info,
186 					  struct ionic_rxq_comp *comp)
187 {
188 	struct net_device *netdev = q->lif->netdev;
189 	struct ionic_buf_info *buf_info;
190 	struct ionic_rx_stats *stats;
191 	struct device *dev = q->dev;
192 	struct sk_buff *skb;
193 	u16 len;
194 
195 	stats = q_to_rx_stats(q);
196 
197 	buf_info = &desc_info->bufs[0];
198 	len = le16_to_cpu(comp->len);
199 
200 	skb = napi_alloc_skb(&q_to_qcq(q)->napi, len);
201 	if (unlikely(!skb)) {
202 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
203 				     netdev->name, q->name);
204 		stats->alloc_err++;
205 		return NULL;
206 	}
207 
208 	if (unlikely(!buf_info->page)) {
209 		dev_kfree_skb(skb);
210 		return NULL;
211 	}
212 
213 	dma_sync_single_for_cpu(dev, buf_info->dma_addr + buf_info->page_offset,
214 				len, DMA_FROM_DEVICE);
215 	skb_copy_to_linear_data(skb, page_address(buf_info->page) + buf_info->page_offset, len);
216 	dma_sync_single_for_device(dev, buf_info->dma_addr + buf_info->page_offset,
217 				   len, DMA_FROM_DEVICE);
218 
219 	skb_put(skb, len);
220 	skb->protocol = eth_type_trans(skb, q->lif->netdev);
221 
222 	return skb;
223 }
224 
225 static void ionic_rx_clean(struct ionic_queue *q,
226 			   struct ionic_desc_info *desc_info,
227 			   struct ionic_cq_info *cq_info,
228 			   void *cb_arg)
229 {
230 	struct net_device *netdev = q->lif->netdev;
231 	struct ionic_qcq *qcq = q_to_qcq(q);
232 	struct ionic_rx_stats *stats;
233 	struct ionic_rxq_comp *comp;
234 	struct sk_buff *skb;
235 
236 	comp = cq_info->cq_desc + qcq->cq.desc_size - sizeof(*comp);
237 
238 	stats = q_to_rx_stats(q);
239 
240 	if (comp->status) {
241 		stats->dropped++;
242 		return;
243 	}
244 
245 	stats->pkts++;
246 	stats->bytes += le16_to_cpu(comp->len);
247 
248 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
249 		skb = ionic_rx_copybreak(q, desc_info, comp);
250 	else
251 		skb = ionic_rx_frags(q, desc_info, comp);
252 
253 	if (unlikely(!skb)) {
254 		stats->dropped++;
255 		return;
256 	}
257 
258 	skb_record_rx_queue(skb, q->index);
259 
260 	if (likely(netdev->features & NETIF_F_RXHASH)) {
261 		switch (comp->pkt_type_color & IONIC_RXQ_COMP_PKT_TYPE_MASK) {
262 		case IONIC_PKT_TYPE_IPV4:
263 		case IONIC_PKT_TYPE_IPV6:
264 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
265 				     PKT_HASH_TYPE_L3);
266 			break;
267 		case IONIC_PKT_TYPE_IPV4_TCP:
268 		case IONIC_PKT_TYPE_IPV6_TCP:
269 		case IONIC_PKT_TYPE_IPV4_UDP:
270 		case IONIC_PKT_TYPE_IPV6_UDP:
271 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
272 				     PKT_HASH_TYPE_L4);
273 			break;
274 		}
275 	}
276 
277 	if (likely(netdev->features & NETIF_F_RXCSUM) &&
278 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_CALC)) {
279 		skb->ip_summed = CHECKSUM_COMPLETE;
280 		skb->csum = (__force __wsum)le16_to_cpu(comp->csum);
281 		stats->csum_complete++;
282 	} else {
283 		stats->csum_none++;
284 	}
285 
286 	if (unlikely((comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_TCP_BAD) ||
287 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_UDP_BAD) ||
288 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_IP_BAD)))
289 		stats->csum_error++;
290 
291 	if (likely(netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
292 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_VLAN)) {
293 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
294 				       le16_to_cpu(comp->vlan_tci));
295 		stats->vlan_stripped++;
296 	}
297 
298 	if (unlikely(q->features & IONIC_RXQ_F_HWSTAMP)) {
299 		__le64 *cq_desc_hwstamp;
300 		u64 hwstamp;
301 
302 		cq_desc_hwstamp =
303 			cq_info->cq_desc +
304 			qcq->cq.desc_size -
305 			sizeof(struct ionic_rxq_comp) -
306 			IONIC_HWSTAMP_CQ_NEGOFFSET;
307 
308 		hwstamp = le64_to_cpu(*cq_desc_hwstamp);
309 
310 		if (hwstamp != IONIC_HWSTAMP_INVALID) {
311 			skb_hwtstamps(skb)->hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
312 			stats->hwstamp_valid++;
313 		} else {
314 			stats->hwstamp_invalid++;
315 		}
316 	}
317 
318 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
319 		napi_gro_receive(&qcq->napi, skb);
320 	else
321 		napi_gro_frags(&qcq->napi);
322 }
323 
324 bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
325 {
326 	struct ionic_queue *q = cq->bound_q;
327 	struct ionic_desc_info *desc_info;
328 	struct ionic_rxq_comp *comp;
329 
330 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
331 
332 	if (!color_match(comp->pkt_type_color, cq->done_color))
333 		return false;
334 
335 	/* check for empty queue */
336 	if (q->tail_idx == q->head_idx)
337 		return false;
338 
339 	if (q->tail_idx != le16_to_cpu(comp->comp_index))
340 		return false;
341 
342 	desc_info = &q->info[q->tail_idx];
343 	q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
344 
345 	/* clean the related q entry, only one per qc completion */
346 	ionic_rx_clean(q, desc_info, cq_info, desc_info->cb_arg);
347 
348 	desc_info->cb = NULL;
349 	desc_info->cb_arg = NULL;
350 
351 	return true;
352 }
353 
354 void ionic_rx_fill(struct ionic_queue *q)
355 {
356 	struct net_device *netdev = q->lif->netdev;
357 	struct ionic_desc_info *desc_info;
358 	struct ionic_rxq_sg_desc *sg_desc;
359 	struct ionic_rxq_sg_elem *sg_elem;
360 	struct ionic_buf_info *buf_info;
361 	struct ionic_rxq_desc *desc;
362 	unsigned int remain_len;
363 	unsigned int frag_len;
364 	unsigned int nfrags;
365 	unsigned int i, j;
366 	unsigned int len;
367 
368 	len = netdev->mtu + ETH_HLEN + VLAN_HLEN;
369 
370 	for (i = ionic_q_space_avail(q); i; i--) {
371 		nfrags = 0;
372 		remain_len = len;
373 		desc_info = &q->info[q->head_idx];
374 		desc = desc_info->desc;
375 		buf_info = &desc_info->bufs[0];
376 
377 		if (!buf_info->page) { /* alloc a new buffer? */
378 			if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
379 				desc->addr = 0;
380 				desc->len = 0;
381 				return;
382 			}
383 		}
384 
385 		/* fill main descriptor - buf[0] */
386 		desc->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
387 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
388 		desc->len = cpu_to_le16(frag_len);
389 		remain_len -= frag_len;
390 		buf_info++;
391 		nfrags++;
392 
393 		/* fill sg descriptors - buf[1..n] */
394 		sg_desc = desc_info->sg_desc;
395 		for (j = 0; remain_len > 0 && j < q->max_sg_elems; j++) {
396 			sg_elem = &sg_desc->elems[j];
397 			if (!buf_info->page) { /* alloc a new sg buffer? */
398 				if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
399 					sg_elem->addr = 0;
400 					sg_elem->len = 0;
401 					return;
402 				}
403 			}
404 
405 			sg_elem->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
406 			frag_len = min_t(u16, remain_len, IONIC_PAGE_SIZE - buf_info->page_offset);
407 			sg_elem->len = cpu_to_le16(frag_len);
408 			remain_len -= frag_len;
409 			buf_info++;
410 			nfrags++;
411 		}
412 
413 		/* clear end sg element as a sentinel */
414 		if (j < q->max_sg_elems) {
415 			sg_elem = &sg_desc->elems[j];
416 			memset(sg_elem, 0, sizeof(*sg_elem));
417 		}
418 
419 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
420 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
421 		desc_info->nbufs = nfrags;
422 
423 		ionic_rxq_post(q, false, ionic_rx_clean, NULL);
424 	}
425 
426 	ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
427 			 q->dbval | q->head_idx);
428 }
429 
430 void ionic_rx_empty(struct ionic_queue *q)
431 {
432 	struct ionic_desc_info *desc_info;
433 	struct ionic_buf_info *buf_info;
434 	unsigned int i, j;
435 
436 	for (i = 0; i < q->num_descs; i++) {
437 		desc_info = &q->info[i];
438 		for (j = 0; j < IONIC_RX_MAX_SG_ELEMS + 1; j++) {
439 			buf_info = &desc_info->bufs[j];
440 			if (buf_info->page)
441 				ionic_rx_page_free(q, buf_info);
442 		}
443 
444 		desc_info->nbufs = 0;
445 		desc_info->cb = NULL;
446 		desc_info->cb_arg = NULL;
447 	}
448 
449 	q->head_idx = 0;
450 	q->tail_idx = 0;
451 }
452 
453 static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode)
454 {
455 	struct dim_sample dim_sample;
456 	struct ionic_lif *lif;
457 	unsigned int qi;
458 	u64 pkts, bytes;
459 
460 	if (!qcq->intr.dim_coal_hw)
461 		return;
462 
463 	lif = qcq->q.lif;
464 	qi = qcq->cq.bound_q->index;
465 
466 	switch (napi_mode) {
467 	case IONIC_LIF_F_TX_DIM_INTR:
468 		pkts = lif->txqstats[qi].pkts;
469 		bytes = lif->txqstats[qi].bytes;
470 		break;
471 	case IONIC_LIF_F_RX_DIM_INTR:
472 		pkts = lif->rxqstats[qi].pkts;
473 		bytes = lif->rxqstats[qi].bytes;
474 		break;
475 	default:
476 		pkts = lif->txqstats[qi].pkts + lif->rxqstats[qi].pkts;
477 		bytes = lif->txqstats[qi].bytes + lif->rxqstats[qi].bytes;
478 		break;
479 	}
480 
481 	dim_update_sample(qcq->cq.bound_intr->rearm_count,
482 			  pkts, bytes, &dim_sample);
483 
484 	net_dim(&qcq->dim, dim_sample);
485 }
486 
487 int ionic_tx_napi(struct napi_struct *napi, int budget)
488 {
489 	struct ionic_qcq *qcq = napi_to_qcq(napi);
490 	struct ionic_cq *cq = napi_to_cq(napi);
491 	struct ionic_dev *idev;
492 	struct ionic_lif *lif;
493 	u32 work_done = 0;
494 	u32 flags = 0;
495 
496 	lif = cq->bound_q->lif;
497 	idev = &lif->ionic->idev;
498 
499 	work_done = ionic_cq_service(cq, budget,
500 				     ionic_tx_service, NULL, NULL);
501 
502 	if (work_done < budget && napi_complete_done(napi, work_done)) {
503 		ionic_dim_update(qcq, IONIC_LIF_F_TX_DIM_INTR);
504 		flags |= IONIC_INTR_CRED_UNMASK;
505 		cq->bound_intr->rearm_count++;
506 	}
507 
508 	if (work_done || flags) {
509 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
510 		ionic_intr_credits(idev->intr_ctrl,
511 				   cq->bound_intr->index,
512 				   work_done, flags);
513 	}
514 
515 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
516 
517 	return work_done;
518 }
519 
520 int ionic_rx_napi(struct napi_struct *napi, int budget)
521 {
522 	struct ionic_qcq *qcq = napi_to_qcq(napi);
523 	struct ionic_cq *cq = napi_to_cq(napi);
524 	struct ionic_dev *idev;
525 	struct ionic_lif *lif;
526 	u16 rx_fill_threshold;
527 	u32 work_done = 0;
528 	u32 flags = 0;
529 
530 	lif = cq->bound_q->lif;
531 	idev = &lif->ionic->idev;
532 
533 	work_done = ionic_cq_service(cq, budget,
534 				     ionic_rx_service, NULL, NULL);
535 
536 	rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD,
537 				  cq->num_descs / IONIC_RX_FILL_DIV);
538 	if (work_done && ionic_q_space_avail(cq->bound_q) >= rx_fill_threshold)
539 		ionic_rx_fill(cq->bound_q);
540 
541 	if (work_done < budget && napi_complete_done(napi, work_done)) {
542 		ionic_dim_update(qcq, IONIC_LIF_F_RX_DIM_INTR);
543 		flags |= IONIC_INTR_CRED_UNMASK;
544 		cq->bound_intr->rearm_count++;
545 	}
546 
547 	if (work_done || flags) {
548 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
549 		ionic_intr_credits(idev->intr_ctrl,
550 				   cq->bound_intr->index,
551 				   work_done, flags);
552 	}
553 
554 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
555 
556 	return work_done;
557 }
558 
559 int ionic_txrx_napi(struct napi_struct *napi, int budget)
560 {
561 	struct ionic_qcq *qcq = napi_to_qcq(napi);
562 	struct ionic_cq *rxcq = napi_to_cq(napi);
563 	unsigned int qi = rxcq->bound_q->index;
564 	struct ionic_dev *idev;
565 	struct ionic_lif *lif;
566 	struct ionic_cq *txcq;
567 	u16 rx_fill_threshold;
568 	u32 rx_work_done = 0;
569 	u32 tx_work_done = 0;
570 	u32 flags = 0;
571 
572 	lif = rxcq->bound_q->lif;
573 	idev = &lif->ionic->idev;
574 	txcq = &lif->txqcqs[qi]->cq;
575 
576 	tx_work_done = ionic_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT,
577 					ionic_tx_service, NULL, NULL);
578 
579 	rx_work_done = ionic_cq_service(rxcq, budget,
580 					ionic_rx_service, NULL, NULL);
581 
582 	rx_fill_threshold = min_t(u16, IONIC_RX_FILL_THRESHOLD,
583 				  rxcq->num_descs / IONIC_RX_FILL_DIV);
584 	if (rx_work_done && ionic_q_space_avail(rxcq->bound_q) >= rx_fill_threshold)
585 		ionic_rx_fill(rxcq->bound_q);
586 
587 	if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) {
588 		ionic_dim_update(qcq, 0);
589 		flags |= IONIC_INTR_CRED_UNMASK;
590 		rxcq->bound_intr->rearm_count++;
591 	}
592 
593 	if (rx_work_done || flags) {
594 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
595 		ionic_intr_credits(idev->intr_ctrl, rxcq->bound_intr->index,
596 				   tx_work_done + rx_work_done, flags);
597 	}
598 
599 	DEBUG_STATS_NAPI_POLL(qcq, rx_work_done);
600 	DEBUG_STATS_NAPI_POLL(qcq, tx_work_done);
601 
602 	return rx_work_done;
603 }
604 
605 static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
606 				      void *data, size_t len)
607 {
608 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
609 	struct device *dev = q->dev;
610 	dma_addr_t dma_addr;
611 
612 	dma_addr = dma_map_single(dev, data, len, DMA_TO_DEVICE);
613 	if (dma_mapping_error(dev, dma_addr)) {
614 		net_warn_ratelimited("%s: DMA single map failed on %s!\n",
615 				     q->lif->netdev->name, q->name);
616 		stats->dma_map_err++;
617 		return 0;
618 	}
619 	return dma_addr;
620 }
621 
622 static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
623 				    const skb_frag_t *frag,
624 				    size_t offset, size_t len)
625 {
626 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
627 	struct device *dev = q->dev;
628 	dma_addr_t dma_addr;
629 
630 	dma_addr = skb_frag_dma_map(dev, frag, offset, len, DMA_TO_DEVICE);
631 	if (dma_mapping_error(dev, dma_addr)) {
632 		net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
633 				     q->lif->netdev->name, q->name);
634 		stats->dma_map_err++;
635 	}
636 	return dma_addr;
637 }
638 
639 static int ionic_tx_map_skb(struct ionic_queue *q, struct sk_buff *skb,
640 			    struct ionic_desc_info *desc_info)
641 {
642 	struct ionic_buf_info *buf_info = desc_info->bufs;
643 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
644 	struct device *dev = q->dev;
645 	dma_addr_t dma_addr;
646 	unsigned int nfrags;
647 	skb_frag_t *frag;
648 	int frag_idx;
649 
650 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
651 	if (dma_mapping_error(dev, dma_addr)) {
652 		stats->dma_map_err++;
653 		return -EIO;
654 	}
655 	buf_info->dma_addr = dma_addr;
656 	buf_info->len = skb_headlen(skb);
657 	buf_info++;
658 
659 	frag = skb_shinfo(skb)->frags;
660 	nfrags = skb_shinfo(skb)->nr_frags;
661 	for (frag_idx = 0; frag_idx < nfrags; frag_idx++, frag++) {
662 		dma_addr = ionic_tx_map_frag(q, frag, 0, skb_frag_size(frag));
663 		if (dma_mapping_error(dev, dma_addr)) {
664 			stats->dma_map_err++;
665 			goto dma_fail;
666 		}
667 		buf_info->dma_addr = dma_addr;
668 		buf_info->len = skb_frag_size(frag);
669 		buf_info++;
670 	}
671 
672 	desc_info->nbufs = 1 + nfrags;
673 
674 	return 0;
675 
676 dma_fail:
677 	/* unwind the frag mappings and the head mapping */
678 	while (frag_idx > 0) {
679 		frag_idx--;
680 		buf_info--;
681 		dma_unmap_page(dev, buf_info->dma_addr,
682 			       buf_info->len, DMA_TO_DEVICE);
683 	}
684 	dma_unmap_single(dev, buf_info->dma_addr, buf_info->len, DMA_TO_DEVICE);
685 	return -EIO;
686 }
687 
688 static void ionic_tx_clean(struct ionic_queue *q,
689 			   struct ionic_desc_info *desc_info,
690 			   struct ionic_cq_info *cq_info,
691 			   void *cb_arg)
692 {
693 	struct ionic_buf_info *buf_info = desc_info->bufs;
694 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
695 	struct ionic_qcq *qcq = q_to_qcq(q);
696 	struct sk_buff *skb = cb_arg;
697 	struct device *dev = q->dev;
698 	unsigned int i;
699 	u16 qi;
700 
701 	if (desc_info->nbufs) {
702 		dma_unmap_single(dev, (dma_addr_t)buf_info->dma_addr,
703 				 buf_info->len, DMA_TO_DEVICE);
704 		buf_info++;
705 		for (i = 1; i < desc_info->nbufs; i++, buf_info++)
706 			dma_unmap_page(dev, (dma_addr_t)buf_info->dma_addr,
707 				       buf_info->len, DMA_TO_DEVICE);
708 	}
709 
710 	if (!skb)
711 		return;
712 
713 	qi = skb_get_queue_mapping(skb);
714 
715 	if (unlikely(q->features & IONIC_TXQ_F_HWSTAMP)) {
716 		if (cq_info) {
717 			struct skb_shared_hwtstamps hwts = {};
718 			__le64 *cq_desc_hwstamp;
719 			u64 hwstamp;
720 
721 			cq_desc_hwstamp =
722 				cq_info->cq_desc +
723 				qcq->cq.desc_size -
724 				sizeof(struct ionic_txq_comp) -
725 				IONIC_HWSTAMP_CQ_NEGOFFSET;
726 
727 			hwstamp = le64_to_cpu(*cq_desc_hwstamp);
728 
729 			if (hwstamp != IONIC_HWSTAMP_INVALID) {
730 				hwts.hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
731 
732 				skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
733 				skb_tstamp_tx(skb, &hwts);
734 
735 				stats->hwstamp_valid++;
736 			} else {
737 				stats->hwstamp_invalid++;
738 			}
739 		}
740 
741 	} else if (unlikely(__netif_subqueue_stopped(q->lif->netdev, qi))) {
742 		netif_wake_subqueue(q->lif->netdev, qi);
743 		q->wake++;
744 	}
745 
746 	desc_info->bytes = skb->len;
747 	stats->clean++;
748 
749 	dev_consume_skb_any(skb);
750 }
751 
752 bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
753 {
754 	struct ionic_queue *q = cq->bound_q;
755 	struct ionic_desc_info *desc_info;
756 	struct ionic_txq_comp *comp;
757 	int bytes = 0;
758 	int pkts = 0;
759 	u16 index;
760 
761 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
762 
763 	if (!color_match(comp->color, cq->done_color))
764 		return false;
765 
766 	/* clean the related q entries, there could be
767 	 * several q entries completed for each cq completion
768 	 */
769 	do {
770 		desc_info = &q->info[q->tail_idx];
771 		desc_info->bytes = 0;
772 		index = q->tail_idx;
773 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
774 		ionic_tx_clean(q, desc_info, cq_info, desc_info->cb_arg);
775 		if (desc_info->cb_arg) {
776 			pkts++;
777 			bytes += desc_info->bytes;
778 		}
779 		desc_info->cb = NULL;
780 		desc_info->cb_arg = NULL;
781 	} while (index != le16_to_cpu(comp->comp_index));
782 
783 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
784 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
785 
786 	return true;
787 }
788 
789 void ionic_tx_flush(struct ionic_cq *cq)
790 {
791 	struct ionic_dev *idev = &cq->lif->ionic->idev;
792 	u32 work_done;
793 
794 	work_done = ionic_cq_service(cq, cq->num_descs,
795 				     ionic_tx_service, NULL, NULL);
796 	if (work_done)
797 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
798 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
799 }
800 
801 void ionic_tx_empty(struct ionic_queue *q)
802 {
803 	struct ionic_desc_info *desc_info;
804 	int bytes = 0;
805 	int pkts = 0;
806 
807 	/* walk the not completed tx entries, if any */
808 	while (q->head_idx != q->tail_idx) {
809 		desc_info = &q->info[q->tail_idx];
810 		desc_info->bytes = 0;
811 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
812 		ionic_tx_clean(q, desc_info, NULL, desc_info->cb_arg);
813 		if (desc_info->cb_arg) {
814 			pkts++;
815 			bytes += desc_info->bytes;
816 		}
817 		desc_info->cb = NULL;
818 		desc_info->cb_arg = NULL;
819 	}
820 
821 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
822 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
823 }
824 
825 static int ionic_tx_tcp_inner_pseudo_csum(struct sk_buff *skb)
826 {
827 	int err;
828 
829 	err = skb_cow_head(skb, 0);
830 	if (err)
831 		return err;
832 
833 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
834 		inner_ip_hdr(skb)->check = 0;
835 		inner_tcp_hdr(skb)->check =
836 			~csum_tcpudp_magic(inner_ip_hdr(skb)->saddr,
837 					   inner_ip_hdr(skb)->daddr,
838 					   0, IPPROTO_TCP, 0);
839 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
840 		inner_tcp_hdr(skb)->check =
841 			~csum_ipv6_magic(&inner_ipv6_hdr(skb)->saddr,
842 					 &inner_ipv6_hdr(skb)->daddr,
843 					 0, IPPROTO_TCP, 0);
844 	}
845 
846 	return 0;
847 }
848 
849 static int ionic_tx_tcp_pseudo_csum(struct sk_buff *skb)
850 {
851 	int err;
852 
853 	err = skb_cow_head(skb, 0);
854 	if (err)
855 		return err;
856 
857 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
858 		ip_hdr(skb)->check = 0;
859 		tcp_hdr(skb)->check =
860 			~csum_tcpudp_magic(ip_hdr(skb)->saddr,
861 					   ip_hdr(skb)->daddr,
862 					   0, IPPROTO_TCP, 0);
863 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
864 		tcp_v6_gso_csum_prep(skb);
865 	}
866 
867 	return 0;
868 }
869 
870 static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
871 			      struct sk_buff *skb,
872 			      dma_addr_t addr, u8 nsge, u16 len,
873 			      unsigned int hdrlen, unsigned int mss,
874 			      bool outer_csum,
875 			      u16 vlan_tci, bool has_vlan,
876 			      bool start, bool done)
877 {
878 	u8 flags = 0;
879 	u64 cmd;
880 
881 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
882 	flags |= outer_csum ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
883 	flags |= start ? IONIC_TXQ_DESC_FLAG_TSO_SOT : 0;
884 	flags |= done ? IONIC_TXQ_DESC_FLAG_TSO_EOT : 0;
885 
886 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_TSO, flags, nsge, addr);
887 	desc->cmd = cpu_to_le64(cmd);
888 	desc->len = cpu_to_le16(len);
889 	desc->vlan_tci = cpu_to_le16(vlan_tci);
890 	desc->hdr_len = cpu_to_le16(hdrlen);
891 	desc->mss = cpu_to_le16(mss);
892 
893 	if (start) {
894 		skb_tx_timestamp(skb);
895 		if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
896 			netdev_tx_sent_queue(q_to_ndq(q), skb->len);
897 		ionic_txq_post(q, false, ionic_tx_clean, skb);
898 	} else {
899 		ionic_txq_post(q, done, NULL, NULL);
900 	}
901 }
902 
903 static int ionic_tx_tso(struct ionic_queue *q, struct sk_buff *skb)
904 {
905 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
906 	struct ionic_desc_info *desc_info;
907 	struct ionic_buf_info *buf_info;
908 	struct ionic_txq_sg_elem *elem;
909 	struct ionic_txq_desc *desc;
910 	unsigned int chunk_len;
911 	unsigned int frag_rem;
912 	unsigned int tso_rem;
913 	unsigned int seg_rem;
914 	dma_addr_t desc_addr;
915 	dma_addr_t frag_addr;
916 	unsigned int hdrlen;
917 	unsigned int len;
918 	unsigned int mss;
919 	bool start, done;
920 	bool outer_csum;
921 	bool has_vlan;
922 	u16 desc_len;
923 	u8 desc_nsge;
924 	u16 vlan_tci;
925 	bool encap;
926 	int err;
927 
928 	desc_info = &q->info[q->head_idx];
929 	buf_info = desc_info->bufs;
930 
931 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
932 		return -EIO;
933 
934 	len = skb->len;
935 	mss = skb_shinfo(skb)->gso_size;
936 	outer_csum = (skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM) ||
937 		     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
938 	has_vlan = !!skb_vlan_tag_present(skb);
939 	vlan_tci = skb_vlan_tag_get(skb);
940 	encap = skb->encapsulation;
941 
942 	/* Preload inner-most TCP csum field with IP pseudo hdr
943 	 * calculated with IP length set to zero.  HW will later
944 	 * add in length to each TCP segment resulting from the TSO.
945 	 */
946 
947 	if (encap)
948 		err = ionic_tx_tcp_inner_pseudo_csum(skb);
949 	else
950 		err = ionic_tx_tcp_pseudo_csum(skb);
951 	if (err)
952 		return err;
953 
954 	if (encap)
955 		hdrlen = skb_inner_transport_header(skb) - skb->data +
956 			 inner_tcp_hdrlen(skb);
957 	else
958 		hdrlen = skb_transport_offset(skb) + tcp_hdrlen(skb);
959 
960 	tso_rem = len;
961 	seg_rem = min(tso_rem, hdrlen + mss);
962 
963 	frag_addr = 0;
964 	frag_rem = 0;
965 
966 	start = true;
967 
968 	while (tso_rem > 0) {
969 		desc = NULL;
970 		elem = NULL;
971 		desc_addr = 0;
972 		desc_len = 0;
973 		desc_nsge = 0;
974 		/* use fragments until we have enough to post a single descriptor */
975 		while (seg_rem > 0) {
976 			/* if the fragment is exhausted then move to the next one */
977 			if (frag_rem == 0) {
978 				/* grab the next fragment */
979 				frag_addr = buf_info->dma_addr;
980 				frag_rem = buf_info->len;
981 				buf_info++;
982 			}
983 			chunk_len = min(frag_rem, seg_rem);
984 			if (!desc) {
985 				/* fill main descriptor */
986 				desc = desc_info->txq_desc;
987 				elem = desc_info->txq_sg_desc->elems;
988 				desc_addr = frag_addr;
989 				desc_len = chunk_len;
990 			} else {
991 				/* fill sg descriptor */
992 				elem->addr = cpu_to_le64(frag_addr);
993 				elem->len = cpu_to_le16(chunk_len);
994 				elem++;
995 				desc_nsge++;
996 			}
997 			frag_addr += chunk_len;
998 			frag_rem -= chunk_len;
999 			tso_rem -= chunk_len;
1000 			seg_rem -= chunk_len;
1001 		}
1002 		seg_rem = min(tso_rem, mss);
1003 		done = (tso_rem == 0);
1004 		/* post descriptor */
1005 		ionic_tx_tso_post(q, desc, skb,
1006 				  desc_addr, desc_nsge, desc_len,
1007 				  hdrlen, mss, outer_csum, vlan_tci, has_vlan,
1008 				  start, done);
1009 		start = false;
1010 		/* Buffer information is stored with the first tso descriptor */
1011 		desc_info = &q->info[q->head_idx];
1012 		desc_info->nbufs = 0;
1013 	}
1014 
1015 	stats->pkts += DIV_ROUND_UP(len - hdrlen, mss);
1016 	stats->bytes += len;
1017 	stats->tso++;
1018 	stats->tso_bytes = len;
1019 
1020 	return 0;
1021 }
1022 
1023 static int ionic_tx_calc_csum(struct ionic_queue *q, struct sk_buff *skb,
1024 			      struct ionic_desc_info *desc_info)
1025 {
1026 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1027 	struct ionic_buf_info *buf_info = desc_info->bufs;
1028 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1029 	bool has_vlan;
1030 	u8 flags = 0;
1031 	bool encap;
1032 	u64 cmd;
1033 
1034 	has_vlan = !!skb_vlan_tag_present(skb);
1035 	encap = skb->encapsulation;
1036 
1037 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1038 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1039 
1040 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_PARTIAL,
1041 				  flags, skb_shinfo(skb)->nr_frags,
1042 				  buf_info->dma_addr);
1043 	desc->cmd = cpu_to_le64(cmd);
1044 	desc->len = cpu_to_le16(buf_info->len);
1045 	if (has_vlan) {
1046 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1047 		stats->vlan_inserted++;
1048 	} else {
1049 		desc->vlan_tci = 0;
1050 	}
1051 	desc->csum_start = cpu_to_le16(skb_checksum_start_offset(skb));
1052 	desc->csum_offset = cpu_to_le16(skb->csum_offset);
1053 
1054 	if (skb_csum_is_sctp(skb))
1055 		stats->crc32_csum++;
1056 	else
1057 		stats->csum++;
1058 
1059 	return 0;
1060 }
1061 
1062 static int ionic_tx_calc_no_csum(struct ionic_queue *q, struct sk_buff *skb,
1063 				 struct ionic_desc_info *desc_info)
1064 {
1065 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1066 	struct ionic_buf_info *buf_info = desc_info->bufs;
1067 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1068 	bool has_vlan;
1069 	u8 flags = 0;
1070 	bool encap;
1071 	u64 cmd;
1072 
1073 	has_vlan = !!skb_vlan_tag_present(skb);
1074 	encap = skb->encapsulation;
1075 
1076 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1077 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1078 
1079 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_NONE,
1080 				  flags, skb_shinfo(skb)->nr_frags,
1081 				  buf_info->dma_addr);
1082 	desc->cmd = cpu_to_le64(cmd);
1083 	desc->len = cpu_to_le16(buf_info->len);
1084 	if (has_vlan) {
1085 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1086 		stats->vlan_inserted++;
1087 	} else {
1088 		desc->vlan_tci = 0;
1089 	}
1090 	desc->csum_start = 0;
1091 	desc->csum_offset = 0;
1092 
1093 	stats->csum_none++;
1094 
1095 	return 0;
1096 }
1097 
1098 static int ionic_tx_skb_frags(struct ionic_queue *q, struct sk_buff *skb,
1099 			      struct ionic_desc_info *desc_info)
1100 {
1101 	struct ionic_txq_sg_desc *sg_desc = desc_info->txq_sg_desc;
1102 	struct ionic_buf_info *buf_info = &desc_info->bufs[1];
1103 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
1104 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1105 	unsigned int i;
1106 
1107 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, buf_info++, elem++) {
1108 		elem->addr = cpu_to_le64(buf_info->dma_addr);
1109 		elem->len = cpu_to_le16(buf_info->len);
1110 	}
1111 
1112 	stats->frags += skb_shinfo(skb)->nr_frags;
1113 
1114 	return 0;
1115 }
1116 
1117 static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
1118 {
1119 	struct ionic_desc_info *desc_info = &q->info[q->head_idx];
1120 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1121 	int err;
1122 
1123 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
1124 		return -EIO;
1125 
1126 	/* set up the initial descriptor */
1127 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1128 		err = ionic_tx_calc_csum(q, skb, desc_info);
1129 	else
1130 		err = ionic_tx_calc_no_csum(q, skb, desc_info);
1131 	if (err)
1132 		return err;
1133 
1134 	/* add frags */
1135 	err = ionic_tx_skb_frags(q, skb, desc_info);
1136 	if (err)
1137 		return err;
1138 
1139 	skb_tx_timestamp(skb);
1140 	stats->pkts++;
1141 	stats->bytes += skb->len;
1142 
1143 	if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
1144 		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
1145 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
1146 
1147 	return 0;
1148 }
1149 
1150 static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
1151 {
1152 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1153 	int ndescs;
1154 	int err;
1155 
1156 	/* Each desc is mss long max, so a descriptor for each gso_seg */
1157 	if (skb_is_gso(skb))
1158 		ndescs = skb_shinfo(skb)->gso_segs;
1159 	else
1160 		ndescs = 1;
1161 
1162 	/* If non-TSO, just need 1 desc and nr_frags sg elems */
1163 	if (skb_shinfo(skb)->nr_frags <= q->max_sg_elems)
1164 		return ndescs;
1165 
1166 	/* Too many frags, so linearize */
1167 	err = skb_linearize(skb);
1168 	if (err)
1169 		return err;
1170 
1171 	stats->linearize++;
1172 
1173 	return ndescs;
1174 }
1175 
1176 static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
1177 {
1178 	int stopped = 0;
1179 
1180 	if (unlikely(!ionic_q_has_space(q, ndescs))) {
1181 		netif_stop_subqueue(q->lif->netdev, q->index);
1182 		q->stop++;
1183 		stopped = 1;
1184 
1185 		/* Might race with ionic_tx_clean, check again */
1186 		smp_rmb();
1187 		if (ionic_q_has_space(q, ndescs)) {
1188 			netif_wake_subqueue(q->lif->netdev, q->index);
1189 			stopped = 0;
1190 		}
1191 	}
1192 
1193 	return stopped;
1194 }
1195 
1196 static netdev_tx_t ionic_start_hwstamp_xmit(struct sk_buff *skb,
1197 					    struct net_device *netdev)
1198 {
1199 	struct ionic_lif *lif = netdev_priv(netdev);
1200 	struct ionic_queue *q = &lif->hwstamp_txq->q;
1201 	int err, ndescs;
1202 
1203 	/* Does not stop/start txq, because we post to a separate tx queue
1204 	 * for timestamping, and if a packet can't be posted immediately to
1205 	 * the timestamping queue, it is dropped.
1206 	 */
1207 
1208 	ndescs = ionic_tx_descs_needed(q, skb);
1209 	if (unlikely(ndescs < 0))
1210 		goto err_out_drop;
1211 
1212 	if (unlikely(!ionic_q_has_space(q, ndescs)))
1213 		goto err_out_drop;
1214 
1215 	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP;
1216 	if (skb_is_gso(skb))
1217 		err = ionic_tx_tso(q, skb);
1218 	else
1219 		err = ionic_tx(q, skb);
1220 
1221 	if (err)
1222 		goto err_out_drop;
1223 
1224 	return NETDEV_TX_OK;
1225 
1226 err_out_drop:
1227 	q->drop++;
1228 	dev_kfree_skb(skb);
1229 	return NETDEV_TX_OK;
1230 }
1231 
1232 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1233 {
1234 	u16 queue_index = skb_get_queue_mapping(skb);
1235 	struct ionic_lif *lif = netdev_priv(netdev);
1236 	struct ionic_queue *q;
1237 	int ndescs;
1238 	int err;
1239 
1240 	if (unlikely(!test_bit(IONIC_LIF_F_UP, lif->state))) {
1241 		dev_kfree_skb(skb);
1242 		return NETDEV_TX_OK;
1243 	}
1244 
1245 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
1246 		if (lif->hwstamp_txq && lif->phc->ts_config_tx_mode)
1247 			return ionic_start_hwstamp_xmit(skb, netdev);
1248 
1249 	if (unlikely(queue_index >= lif->nxqs))
1250 		queue_index = 0;
1251 	q = &lif->txqcqs[queue_index]->q;
1252 
1253 	ndescs = ionic_tx_descs_needed(q, skb);
1254 	if (ndescs < 0)
1255 		goto err_out_drop;
1256 
1257 	if (unlikely(ionic_maybe_stop_tx(q, ndescs)))
1258 		return NETDEV_TX_BUSY;
1259 
1260 	if (skb_is_gso(skb))
1261 		err = ionic_tx_tso(q, skb);
1262 	else
1263 		err = ionic_tx(q, skb);
1264 
1265 	if (err)
1266 		goto err_out_drop;
1267 
1268 	/* Stop the queue if there aren't descriptors for the next packet.
1269 	 * Since our SG lists per descriptor take care of most of the possible
1270 	 * fragmentation, we don't need to have many descriptors available.
1271 	 */
1272 	ionic_maybe_stop_tx(q, 4);
1273 
1274 	return NETDEV_TX_OK;
1275 
1276 err_out_drop:
1277 	q->stop++;
1278 	q->drop++;
1279 	dev_kfree_skb(skb);
1280 	return NETDEV_TX_OK;
1281 }
1282