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 bool ionic_txq_poke_doorbell(struct ionic_queue *q)
26 {
27 	unsigned long now, then, dif;
28 	struct netdev_queue *netdev_txq;
29 	struct net_device *netdev;
30 
31 	netdev = q->lif->netdev;
32 	netdev_txq = netdev_get_tx_queue(netdev, q->index);
33 
34 	HARD_TX_LOCK(netdev, netdev_txq, smp_processor_id());
35 
36 	if (q->tail_idx == q->head_idx) {
37 		HARD_TX_UNLOCK(netdev, netdev_txq);
38 		return false;
39 	}
40 
41 	now = READ_ONCE(jiffies);
42 	then = q->dbell_jiffies;
43 	dif = now - then;
44 
45 	if (dif > q->dbell_deadline) {
46 		ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
47 				 q->dbval | q->head_idx);
48 
49 		q->dbell_jiffies = now;
50 	}
51 
52 	HARD_TX_UNLOCK(netdev, netdev_txq);
53 
54 	return true;
55 }
56 
57 bool ionic_rxq_poke_doorbell(struct ionic_queue *q)
58 {
59 	unsigned long now, then, dif;
60 
61 	/* no lock, called from rx napi or txrx napi, nothing else can fill */
62 
63 	if (q->tail_idx == q->head_idx)
64 		return false;
65 
66 	now = READ_ONCE(jiffies);
67 	then = q->dbell_jiffies;
68 	dif = now - then;
69 
70 	if (dif > q->dbell_deadline) {
71 		ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
72 				 q->dbval | q->head_idx);
73 
74 		q->dbell_jiffies = now;
75 
76 		dif = 2 * q->dbell_deadline;
77 		if (dif > IONIC_RX_MAX_DOORBELL_DEADLINE)
78 			dif = IONIC_RX_MAX_DOORBELL_DEADLINE;
79 
80 		q->dbell_deadline = dif;
81 	}
82 
83 	return true;
84 }
85 
86 static inline struct netdev_queue *q_to_ndq(struct ionic_queue *q)
87 {
88 	return netdev_get_tx_queue(q->lif->netdev, q->index);
89 }
90 
91 static int ionic_rx_page_alloc(struct ionic_queue *q,
92 			       struct ionic_buf_info *buf_info)
93 {
94 	struct net_device *netdev = q->lif->netdev;
95 	struct ionic_rx_stats *stats;
96 	struct device *dev;
97 	struct page *page;
98 
99 	dev = q->dev;
100 	stats = q_to_rx_stats(q);
101 
102 	if (unlikely(!buf_info)) {
103 		net_err_ratelimited("%s: %s invalid buf_info in alloc\n",
104 				    netdev->name, q->name);
105 		return -EINVAL;
106 	}
107 
108 	page = alloc_pages(IONIC_PAGE_GFP_MASK, 0);
109 	if (unlikely(!page)) {
110 		net_err_ratelimited("%s: %s page alloc failed\n",
111 				    netdev->name, q->name);
112 		stats->alloc_err++;
113 		return -ENOMEM;
114 	}
115 
116 	buf_info->dma_addr = dma_map_page(dev, page, 0,
117 					  IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
118 	if (unlikely(dma_mapping_error(dev, buf_info->dma_addr))) {
119 		__free_pages(page, 0);
120 		net_err_ratelimited("%s: %s dma map failed\n",
121 				    netdev->name, q->name);
122 		stats->dma_map_err++;
123 		return -EIO;
124 	}
125 
126 	buf_info->page = page;
127 	buf_info->page_offset = 0;
128 
129 	return 0;
130 }
131 
132 static void ionic_rx_page_free(struct ionic_queue *q,
133 			       struct ionic_buf_info *buf_info)
134 {
135 	struct net_device *netdev = q->lif->netdev;
136 	struct device *dev = q->dev;
137 
138 	if (unlikely(!buf_info)) {
139 		net_err_ratelimited("%s: %s invalid buf_info in free\n",
140 				    netdev->name, q->name);
141 		return;
142 	}
143 
144 	if (!buf_info->page)
145 		return;
146 
147 	dma_unmap_page(dev, buf_info->dma_addr, IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
148 	__free_pages(buf_info->page, 0);
149 	buf_info->page = NULL;
150 }
151 
152 static bool ionic_rx_buf_recycle(struct ionic_queue *q,
153 				 struct ionic_buf_info *buf_info, u32 used)
154 {
155 	u32 size;
156 
157 	/* don't re-use pages allocated in low-mem condition */
158 	if (page_is_pfmemalloc(buf_info->page))
159 		return false;
160 
161 	/* don't re-use buffers from non-local numa nodes */
162 	if (page_to_nid(buf_info->page) != numa_mem_id())
163 		return false;
164 
165 	size = ALIGN(used, IONIC_PAGE_SPLIT_SZ);
166 	buf_info->page_offset += size;
167 	if (buf_info->page_offset >= IONIC_PAGE_SIZE)
168 		return false;
169 
170 	get_page(buf_info->page);
171 
172 	return true;
173 }
174 
175 static struct sk_buff *ionic_rx_frags(struct ionic_queue *q,
176 				      struct ionic_desc_info *desc_info,
177 				      struct ionic_rxq_comp *comp)
178 {
179 	struct net_device *netdev = q->lif->netdev;
180 	struct ionic_buf_info *buf_info;
181 	struct ionic_rx_stats *stats;
182 	struct device *dev = q->dev;
183 	struct sk_buff *skb;
184 	unsigned int i;
185 	u16 frag_len;
186 	u16 len;
187 
188 	stats = q_to_rx_stats(q);
189 
190 	buf_info = &desc_info->bufs[0];
191 	len = le16_to_cpu(comp->len);
192 
193 	prefetchw(buf_info->page);
194 
195 	skb = napi_get_frags(&q_to_qcq(q)->napi);
196 	if (unlikely(!skb)) {
197 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
198 				     netdev->name, q->name);
199 		stats->alloc_err++;
200 		return NULL;
201 	}
202 
203 	i = comp->num_sg_elems + 1;
204 	do {
205 		if (unlikely(!buf_info->page)) {
206 			dev_kfree_skb(skb);
207 			return NULL;
208 		}
209 
210 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
211 		len -= frag_len;
212 
213 		dma_sync_single_for_cpu(dev,
214 					buf_info->dma_addr + buf_info->page_offset,
215 					frag_len, DMA_FROM_DEVICE);
216 
217 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
218 				buf_info->page, buf_info->page_offset, frag_len,
219 				IONIC_PAGE_SIZE);
220 
221 		if (!ionic_rx_buf_recycle(q, buf_info, frag_len)) {
222 			dma_unmap_page(dev, buf_info->dma_addr,
223 				       IONIC_PAGE_SIZE, DMA_FROM_DEVICE);
224 			buf_info->page = NULL;
225 		}
226 
227 		buf_info++;
228 
229 		i--;
230 	} while (i > 0);
231 
232 	return skb;
233 }
234 
235 static struct sk_buff *ionic_rx_copybreak(struct ionic_queue *q,
236 					  struct ionic_desc_info *desc_info,
237 					  struct ionic_rxq_comp *comp)
238 {
239 	struct net_device *netdev = q->lif->netdev;
240 	struct ionic_buf_info *buf_info;
241 	struct ionic_rx_stats *stats;
242 	struct device *dev = q->dev;
243 	struct sk_buff *skb;
244 	u16 len;
245 
246 	stats = q_to_rx_stats(q);
247 
248 	buf_info = &desc_info->bufs[0];
249 	len = le16_to_cpu(comp->len);
250 
251 	skb = napi_alloc_skb(&q_to_qcq(q)->napi, len);
252 	if (unlikely(!skb)) {
253 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
254 				     netdev->name, q->name);
255 		stats->alloc_err++;
256 		return NULL;
257 	}
258 
259 	if (unlikely(!buf_info->page)) {
260 		dev_kfree_skb(skb);
261 		return NULL;
262 	}
263 
264 	dma_sync_single_for_cpu(dev, buf_info->dma_addr + buf_info->page_offset,
265 				len, DMA_FROM_DEVICE);
266 	skb_copy_to_linear_data(skb, page_address(buf_info->page) + buf_info->page_offset, len);
267 	dma_sync_single_for_device(dev, buf_info->dma_addr + buf_info->page_offset,
268 				   len, DMA_FROM_DEVICE);
269 
270 	skb_put(skb, len);
271 	skb->protocol = eth_type_trans(skb, q->lif->netdev);
272 
273 	return skb;
274 }
275 
276 static void ionic_rx_clean(struct ionic_queue *q,
277 			   struct ionic_desc_info *desc_info,
278 			   struct ionic_cq_info *cq_info,
279 			   void *cb_arg)
280 {
281 	struct net_device *netdev = q->lif->netdev;
282 	struct ionic_qcq *qcq = q_to_qcq(q);
283 	struct ionic_rx_stats *stats;
284 	struct ionic_rxq_comp *comp;
285 	struct sk_buff *skb;
286 
287 	comp = cq_info->cq_desc + qcq->cq.desc_size - sizeof(*comp);
288 
289 	stats = q_to_rx_stats(q);
290 
291 	if (comp->status) {
292 		stats->dropped++;
293 		return;
294 	}
295 
296 	stats->pkts++;
297 	stats->bytes += le16_to_cpu(comp->len);
298 
299 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
300 		skb = ionic_rx_copybreak(q, desc_info, comp);
301 	else
302 		skb = ionic_rx_frags(q, desc_info, comp);
303 
304 	if (unlikely(!skb)) {
305 		stats->dropped++;
306 		return;
307 	}
308 
309 	skb_record_rx_queue(skb, q->index);
310 
311 	if (likely(netdev->features & NETIF_F_RXHASH)) {
312 		switch (comp->pkt_type_color & IONIC_RXQ_COMP_PKT_TYPE_MASK) {
313 		case IONIC_PKT_TYPE_IPV4:
314 		case IONIC_PKT_TYPE_IPV6:
315 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
316 				     PKT_HASH_TYPE_L3);
317 			break;
318 		case IONIC_PKT_TYPE_IPV4_TCP:
319 		case IONIC_PKT_TYPE_IPV6_TCP:
320 		case IONIC_PKT_TYPE_IPV4_UDP:
321 		case IONIC_PKT_TYPE_IPV6_UDP:
322 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
323 				     PKT_HASH_TYPE_L4);
324 			break;
325 		}
326 	}
327 
328 	if (likely(netdev->features & NETIF_F_RXCSUM) &&
329 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_CALC)) {
330 		skb->ip_summed = CHECKSUM_COMPLETE;
331 		skb->csum = (__force __wsum)le16_to_cpu(comp->csum);
332 		stats->csum_complete++;
333 	} else {
334 		stats->csum_none++;
335 	}
336 
337 	if (unlikely((comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_TCP_BAD) ||
338 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_UDP_BAD) ||
339 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_IP_BAD)))
340 		stats->csum_error++;
341 
342 	if (likely(netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
343 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_VLAN)) {
344 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
345 				       le16_to_cpu(comp->vlan_tci));
346 		stats->vlan_stripped++;
347 	}
348 
349 	if (unlikely(q->features & IONIC_RXQ_F_HWSTAMP)) {
350 		__le64 *cq_desc_hwstamp;
351 		u64 hwstamp;
352 
353 		cq_desc_hwstamp =
354 			cq_info->cq_desc +
355 			qcq->cq.desc_size -
356 			sizeof(struct ionic_rxq_comp) -
357 			IONIC_HWSTAMP_CQ_NEGOFFSET;
358 
359 		hwstamp = le64_to_cpu(*cq_desc_hwstamp);
360 
361 		if (hwstamp != IONIC_HWSTAMP_INVALID) {
362 			skb_hwtstamps(skb)->hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
363 			stats->hwstamp_valid++;
364 		} else {
365 			stats->hwstamp_invalid++;
366 		}
367 	}
368 
369 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
370 		napi_gro_receive(&qcq->napi, skb);
371 	else
372 		napi_gro_frags(&qcq->napi);
373 }
374 
375 bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
376 {
377 	struct ionic_queue *q = cq->bound_q;
378 	struct ionic_desc_info *desc_info;
379 	struct ionic_rxq_comp *comp;
380 
381 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
382 
383 	if (!color_match(comp->pkt_type_color, cq->done_color))
384 		return false;
385 
386 	/* check for empty queue */
387 	if (q->tail_idx == q->head_idx)
388 		return false;
389 
390 	if (q->tail_idx != le16_to_cpu(comp->comp_index))
391 		return false;
392 
393 	desc_info = &q->info[q->tail_idx];
394 	q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
395 
396 	/* clean the related q entry, only one per qc completion */
397 	ionic_rx_clean(q, desc_info, cq_info, desc_info->cb_arg);
398 
399 	desc_info->cb = NULL;
400 	desc_info->cb_arg = NULL;
401 
402 	return true;
403 }
404 
405 void ionic_rx_fill(struct ionic_queue *q)
406 {
407 	struct net_device *netdev = q->lif->netdev;
408 	struct ionic_desc_info *desc_info;
409 	struct ionic_rxq_sg_desc *sg_desc;
410 	struct ionic_rxq_sg_elem *sg_elem;
411 	struct ionic_buf_info *buf_info;
412 	unsigned int fill_threshold;
413 	struct ionic_rxq_desc *desc;
414 	unsigned int remain_len;
415 	unsigned int frag_len;
416 	unsigned int nfrags;
417 	unsigned int n_fill;
418 	unsigned int i, j;
419 	unsigned int len;
420 
421 	n_fill = ionic_q_space_avail(q);
422 
423 	fill_threshold = min_t(unsigned int, IONIC_RX_FILL_THRESHOLD,
424 			       q->num_descs / IONIC_RX_FILL_DIV);
425 	if (n_fill < fill_threshold)
426 		return;
427 
428 	len = netdev->mtu + ETH_HLEN + VLAN_HLEN;
429 
430 	for (i = n_fill; i; i--) {
431 		nfrags = 0;
432 		remain_len = len;
433 		desc_info = &q->info[q->head_idx];
434 		desc = desc_info->desc;
435 		buf_info = &desc_info->bufs[0];
436 
437 		if (!buf_info->page) { /* alloc a new buffer? */
438 			if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
439 				desc->addr = 0;
440 				desc->len = 0;
441 				return;
442 			}
443 		}
444 
445 		/* fill main descriptor - buf[0] */
446 		desc->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
447 		frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset);
448 		desc->len = cpu_to_le16(frag_len);
449 		remain_len -= frag_len;
450 		buf_info++;
451 		nfrags++;
452 
453 		/* fill sg descriptors - buf[1..n] */
454 		sg_desc = desc_info->sg_desc;
455 		for (j = 0; remain_len > 0 && j < q->max_sg_elems; j++) {
456 			sg_elem = &sg_desc->elems[j];
457 			if (!buf_info->page) { /* alloc a new sg buffer? */
458 				if (unlikely(ionic_rx_page_alloc(q, buf_info))) {
459 					sg_elem->addr = 0;
460 					sg_elem->len = 0;
461 					return;
462 				}
463 			}
464 
465 			sg_elem->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset);
466 			frag_len = min_t(u16, remain_len, IONIC_PAGE_SIZE - buf_info->page_offset);
467 			sg_elem->len = cpu_to_le16(frag_len);
468 			remain_len -= frag_len;
469 			buf_info++;
470 			nfrags++;
471 		}
472 
473 		/* clear end sg element as a sentinel */
474 		if (j < q->max_sg_elems) {
475 			sg_elem = &sg_desc->elems[j];
476 			memset(sg_elem, 0, sizeof(*sg_elem));
477 		}
478 
479 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
480 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
481 		desc_info->nbufs = nfrags;
482 
483 		ionic_rxq_post(q, false, ionic_rx_clean, NULL);
484 	}
485 
486 	ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
487 			 q->dbval | q->head_idx);
488 
489 	q->dbell_deadline = IONIC_RX_MIN_DOORBELL_DEADLINE;
490 	q->dbell_jiffies = jiffies;
491 
492 	mod_timer(&q_to_qcq(q)->napi_qcq->napi_deadline,
493 		  jiffies + IONIC_NAPI_DEADLINE);
494 }
495 
496 void ionic_rx_empty(struct ionic_queue *q)
497 {
498 	struct ionic_desc_info *desc_info;
499 	struct ionic_buf_info *buf_info;
500 	unsigned int i, j;
501 
502 	for (i = 0; i < q->num_descs; i++) {
503 		desc_info = &q->info[i];
504 		for (j = 0; j < IONIC_RX_MAX_SG_ELEMS + 1; j++) {
505 			buf_info = &desc_info->bufs[j];
506 			if (buf_info->page)
507 				ionic_rx_page_free(q, buf_info);
508 		}
509 
510 		desc_info->nbufs = 0;
511 		desc_info->cb = NULL;
512 		desc_info->cb_arg = NULL;
513 	}
514 
515 	q->head_idx = 0;
516 	q->tail_idx = 0;
517 }
518 
519 static void ionic_dim_update(struct ionic_qcq *qcq, int napi_mode)
520 {
521 	struct dim_sample dim_sample;
522 	struct ionic_lif *lif;
523 	unsigned int qi;
524 	u64 pkts, bytes;
525 
526 	if (!qcq->intr.dim_coal_hw)
527 		return;
528 
529 	lif = qcq->q.lif;
530 	qi = qcq->cq.bound_q->index;
531 
532 	switch (napi_mode) {
533 	case IONIC_LIF_F_TX_DIM_INTR:
534 		pkts = lif->txqstats[qi].pkts;
535 		bytes = lif->txqstats[qi].bytes;
536 		break;
537 	case IONIC_LIF_F_RX_DIM_INTR:
538 		pkts = lif->rxqstats[qi].pkts;
539 		bytes = lif->rxqstats[qi].bytes;
540 		break;
541 	default:
542 		pkts = lif->txqstats[qi].pkts + lif->rxqstats[qi].pkts;
543 		bytes = lif->txqstats[qi].bytes + lif->rxqstats[qi].bytes;
544 		break;
545 	}
546 
547 	dim_update_sample(qcq->cq.bound_intr->rearm_count,
548 			  pkts, bytes, &dim_sample);
549 
550 	net_dim(&qcq->dim, dim_sample);
551 }
552 
553 int ionic_tx_napi(struct napi_struct *napi, int budget)
554 {
555 	struct ionic_qcq *qcq = napi_to_qcq(napi);
556 	struct ionic_cq *cq = napi_to_cq(napi);
557 	struct ionic_dev *idev;
558 	struct ionic_lif *lif;
559 	u32 work_done = 0;
560 	u32 flags = 0;
561 
562 	lif = cq->bound_q->lif;
563 	idev = &lif->ionic->idev;
564 
565 	work_done = ionic_cq_service(cq, budget,
566 				     ionic_tx_service, NULL, NULL);
567 
568 	if (work_done < budget && napi_complete_done(napi, work_done)) {
569 		ionic_dim_update(qcq, IONIC_LIF_F_TX_DIM_INTR);
570 		flags |= IONIC_INTR_CRED_UNMASK;
571 		cq->bound_intr->rearm_count++;
572 	}
573 
574 	if (work_done || flags) {
575 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
576 		ionic_intr_credits(idev->intr_ctrl,
577 				   cq->bound_intr->index,
578 				   work_done, flags);
579 	}
580 
581 	if (!work_done && ionic_txq_poke_doorbell(&qcq->q))
582 		mod_timer(&qcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
583 
584 	return work_done;
585 }
586 
587 int ionic_rx_napi(struct napi_struct *napi, int budget)
588 {
589 	struct ionic_qcq *qcq = napi_to_qcq(napi);
590 	struct ionic_cq *cq = napi_to_cq(napi);
591 	struct ionic_dev *idev;
592 	struct ionic_lif *lif;
593 	u32 work_done = 0;
594 	u32 flags = 0;
595 
596 	lif = cq->bound_q->lif;
597 	idev = &lif->ionic->idev;
598 
599 	work_done = ionic_cq_service(cq, budget,
600 				     ionic_rx_service, NULL, NULL);
601 
602 	ionic_rx_fill(cq->bound_q);
603 
604 	if (work_done < budget && napi_complete_done(napi, work_done)) {
605 		ionic_dim_update(qcq, IONIC_LIF_F_RX_DIM_INTR);
606 		flags |= IONIC_INTR_CRED_UNMASK;
607 		cq->bound_intr->rearm_count++;
608 	}
609 
610 	if (work_done || flags) {
611 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
612 		ionic_intr_credits(idev->intr_ctrl,
613 				   cq->bound_intr->index,
614 				   work_done, flags);
615 	}
616 
617 	if (!work_done && ionic_rxq_poke_doorbell(&qcq->q))
618 		mod_timer(&qcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
619 
620 	return work_done;
621 }
622 
623 int ionic_txrx_napi(struct napi_struct *napi, int budget)
624 {
625 	struct ionic_qcq *rxqcq = napi_to_qcq(napi);
626 	struct ionic_cq *rxcq = napi_to_cq(napi);
627 	unsigned int qi = rxcq->bound_q->index;
628 	struct ionic_qcq *txqcq;
629 	struct ionic_dev *idev;
630 	struct ionic_lif *lif;
631 	struct ionic_cq *txcq;
632 	bool resched = false;
633 	u32 rx_work_done = 0;
634 	u32 tx_work_done = 0;
635 	u32 flags = 0;
636 
637 	lif = rxcq->bound_q->lif;
638 	idev = &lif->ionic->idev;
639 	txqcq = lif->txqcqs[qi];
640 	txcq = &lif->txqcqs[qi]->cq;
641 
642 	tx_work_done = ionic_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT,
643 					ionic_tx_service, NULL, NULL);
644 
645 	rx_work_done = ionic_cq_service(rxcq, budget,
646 					ionic_rx_service, NULL, NULL);
647 
648 	ionic_rx_fill(rxcq->bound_q);
649 
650 	if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) {
651 		ionic_dim_update(rxqcq, 0);
652 		flags |= IONIC_INTR_CRED_UNMASK;
653 		rxcq->bound_intr->rearm_count++;
654 	}
655 
656 	if (rx_work_done || flags) {
657 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
658 		ionic_intr_credits(idev->intr_ctrl, rxcq->bound_intr->index,
659 				   tx_work_done + rx_work_done, flags);
660 	}
661 
662 	if (!rx_work_done && ionic_rxq_poke_doorbell(&rxqcq->q))
663 		resched = true;
664 	if (!tx_work_done && ionic_txq_poke_doorbell(&txqcq->q))
665 		resched = true;
666 	if (resched)
667 		mod_timer(&rxqcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
668 
669 	return rx_work_done;
670 }
671 
672 static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
673 				      void *data, size_t len)
674 {
675 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
676 	struct device *dev = q->dev;
677 	dma_addr_t dma_addr;
678 
679 	dma_addr = dma_map_single(dev, data, len, DMA_TO_DEVICE);
680 	if (dma_mapping_error(dev, dma_addr)) {
681 		net_warn_ratelimited("%s: DMA single map failed on %s!\n",
682 				     q->lif->netdev->name, q->name);
683 		stats->dma_map_err++;
684 		return 0;
685 	}
686 	return dma_addr;
687 }
688 
689 static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
690 				    const skb_frag_t *frag,
691 				    size_t offset, size_t len)
692 {
693 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
694 	struct device *dev = q->dev;
695 	dma_addr_t dma_addr;
696 
697 	dma_addr = skb_frag_dma_map(dev, frag, offset, len, DMA_TO_DEVICE);
698 	if (dma_mapping_error(dev, dma_addr)) {
699 		net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
700 				     q->lif->netdev->name, q->name);
701 		stats->dma_map_err++;
702 	}
703 	return dma_addr;
704 }
705 
706 static int ionic_tx_map_skb(struct ionic_queue *q, struct sk_buff *skb,
707 			    struct ionic_desc_info *desc_info)
708 {
709 	struct ionic_buf_info *buf_info = desc_info->bufs;
710 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
711 	struct device *dev = q->dev;
712 	dma_addr_t dma_addr;
713 	unsigned int nfrags;
714 	skb_frag_t *frag;
715 	int frag_idx;
716 
717 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
718 	if (dma_mapping_error(dev, dma_addr)) {
719 		stats->dma_map_err++;
720 		return -EIO;
721 	}
722 	buf_info->dma_addr = dma_addr;
723 	buf_info->len = skb_headlen(skb);
724 	buf_info++;
725 
726 	frag = skb_shinfo(skb)->frags;
727 	nfrags = skb_shinfo(skb)->nr_frags;
728 	for (frag_idx = 0; frag_idx < nfrags; frag_idx++, frag++) {
729 		dma_addr = ionic_tx_map_frag(q, frag, 0, skb_frag_size(frag));
730 		if (dma_mapping_error(dev, dma_addr)) {
731 			stats->dma_map_err++;
732 			goto dma_fail;
733 		}
734 		buf_info->dma_addr = dma_addr;
735 		buf_info->len = skb_frag_size(frag);
736 		buf_info++;
737 	}
738 
739 	desc_info->nbufs = 1 + nfrags;
740 
741 	return 0;
742 
743 dma_fail:
744 	/* unwind the frag mappings and the head mapping */
745 	while (frag_idx > 0) {
746 		frag_idx--;
747 		buf_info--;
748 		dma_unmap_page(dev, buf_info->dma_addr,
749 			       buf_info->len, DMA_TO_DEVICE);
750 	}
751 	dma_unmap_single(dev, buf_info->dma_addr, buf_info->len, DMA_TO_DEVICE);
752 	return -EIO;
753 }
754 
755 static void ionic_tx_desc_unmap_bufs(struct ionic_queue *q,
756 				     struct ionic_desc_info *desc_info)
757 {
758 	struct ionic_buf_info *buf_info = desc_info->bufs;
759 	struct device *dev = q->dev;
760 	unsigned int i;
761 
762 	if (!desc_info->nbufs)
763 		return;
764 
765 	dma_unmap_single(dev, (dma_addr_t)buf_info->dma_addr,
766 			 buf_info->len, DMA_TO_DEVICE);
767 	buf_info++;
768 	for (i = 1; i < desc_info->nbufs; i++, buf_info++)
769 		dma_unmap_page(dev, (dma_addr_t)buf_info->dma_addr,
770 			       buf_info->len, DMA_TO_DEVICE);
771 
772 	desc_info->nbufs = 0;
773 }
774 
775 static void ionic_tx_clean(struct ionic_queue *q,
776 			   struct ionic_desc_info *desc_info,
777 			   struct ionic_cq_info *cq_info,
778 			   void *cb_arg)
779 {
780 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
781 	struct ionic_qcq *qcq = q_to_qcq(q);
782 	struct sk_buff *skb = cb_arg;
783 	u16 qi;
784 
785 	ionic_tx_desc_unmap_bufs(q, desc_info);
786 
787 	if (!skb)
788 		return;
789 
790 	qi = skb_get_queue_mapping(skb);
791 
792 	if (unlikely(q->features & IONIC_TXQ_F_HWSTAMP)) {
793 		if (cq_info) {
794 			struct skb_shared_hwtstamps hwts = {};
795 			__le64 *cq_desc_hwstamp;
796 			u64 hwstamp;
797 
798 			cq_desc_hwstamp =
799 				cq_info->cq_desc +
800 				qcq->cq.desc_size -
801 				sizeof(struct ionic_txq_comp) -
802 				IONIC_HWSTAMP_CQ_NEGOFFSET;
803 
804 			hwstamp = le64_to_cpu(*cq_desc_hwstamp);
805 
806 			if (hwstamp != IONIC_HWSTAMP_INVALID) {
807 				hwts.hwtstamp = ionic_lif_phc_ktime(q->lif, hwstamp);
808 
809 				skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
810 				skb_tstamp_tx(skb, &hwts);
811 
812 				stats->hwstamp_valid++;
813 			} else {
814 				stats->hwstamp_invalid++;
815 			}
816 		}
817 
818 	} else if (unlikely(__netif_subqueue_stopped(q->lif->netdev, qi))) {
819 		netif_wake_subqueue(q->lif->netdev, qi);
820 	}
821 
822 	desc_info->bytes = skb->len;
823 	stats->clean++;
824 
825 	dev_consume_skb_any(skb);
826 }
827 
828 bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
829 {
830 	struct ionic_queue *q = cq->bound_q;
831 	struct ionic_desc_info *desc_info;
832 	struct ionic_txq_comp *comp;
833 	int bytes = 0;
834 	int pkts = 0;
835 	u16 index;
836 
837 	comp = cq_info->cq_desc + cq->desc_size - sizeof(*comp);
838 
839 	if (!color_match(comp->color, cq->done_color))
840 		return false;
841 
842 	/* clean the related q entries, there could be
843 	 * several q entries completed for each cq completion
844 	 */
845 	do {
846 		desc_info = &q->info[q->tail_idx];
847 		desc_info->bytes = 0;
848 		index = q->tail_idx;
849 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
850 		ionic_tx_clean(q, desc_info, cq_info, desc_info->cb_arg);
851 		if (desc_info->cb_arg) {
852 			pkts++;
853 			bytes += desc_info->bytes;
854 		}
855 		desc_info->cb = NULL;
856 		desc_info->cb_arg = NULL;
857 	} while (index != le16_to_cpu(comp->comp_index));
858 
859 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
860 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
861 
862 	return true;
863 }
864 
865 void ionic_tx_flush(struct ionic_cq *cq)
866 {
867 	struct ionic_dev *idev = &cq->lif->ionic->idev;
868 	u32 work_done;
869 
870 	work_done = ionic_cq_service(cq, cq->num_descs,
871 				     ionic_tx_service, NULL, NULL);
872 	if (work_done)
873 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
874 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
875 }
876 
877 void ionic_tx_empty(struct ionic_queue *q)
878 {
879 	struct ionic_desc_info *desc_info;
880 	int bytes = 0;
881 	int pkts = 0;
882 
883 	/* walk the not completed tx entries, if any */
884 	while (q->head_idx != q->tail_idx) {
885 		desc_info = &q->info[q->tail_idx];
886 		desc_info->bytes = 0;
887 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
888 		ionic_tx_clean(q, desc_info, NULL, desc_info->cb_arg);
889 		if (desc_info->cb_arg) {
890 			pkts++;
891 			bytes += desc_info->bytes;
892 		}
893 		desc_info->cb = NULL;
894 		desc_info->cb_arg = NULL;
895 	}
896 
897 	if (pkts && bytes && !unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
898 		netdev_tx_completed_queue(q_to_ndq(q), pkts, bytes);
899 }
900 
901 static int ionic_tx_tcp_inner_pseudo_csum(struct sk_buff *skb)
902 {
903 	int err;
904 
905 	err = skb_cow_head(skb, 0);
906 	if (err)
907 		return err;
908 
909 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
910 		inner_ip_hdr(skb)->check = 0;
911 		inner_tcp_hdr(skb)->check =
912 			~csum_tcpudp_magic(inner_ip_hdr(skb)->saddr,
913 					   inner_ip_hdr(skb)->daddr,
914 					   0, IPPROTO_TCP, 0);
915 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
916 		inner_tcp_hdr(skb)->check =
917 			~csum_ipv6_magic(&inner_ipv6_hdr(skb)->saddr,
918 					 &inner_ipv6_hdr(skb)->daddr,
919 					 0, IPPROTO_TCP, 0);
920 	}
921 
922 	return 0;
923 }
924 
925 static int ionic_tx_tcp_pseudo_csum(struct sk_buff *skb)
926 {
927 	int err;
928 
929 	err = skb_cow_head(skb, 0);
930 	if (err)
931 		return err;
932 
933 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
934 		ip_hdr(skb)->check = 0;
935 		tcp_hdr(skb)->check =
936 			~csum_tcpudp_magic(ip_hdr(skb)->saddr,
937 					   ip_hdr(skb)->daddr,
938 					   0, IPPROTO_TCP, 0);
939 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
940 		tcp_v6_gso_csum_prep(skb);
941 	}
942 
943 	return 0;
944 }
945 
946 static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
947 			      struct sk_buff *skb,
948 			      dma_addr_t addr, u8 nsge, u16 len,
949 			      unsigned int hdrlen, unsigned int mss,
950 			      bool outer_csum,
951 			      u16 vlan_tci, bool has_vlan,
952 			      bool start, bool done)
953 {
954 	u8 flags = 0;
955 	u64 cmd;
956 
957 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
958 	flags |= outer_csum ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
959 	flags |= start ? IONIC_TXQ_DESC_FLAG_TSO_SOT : 0;
960 	flags |= done ? IONIC_TXQ_DESC_FLAG_TSO_EOT : 0;
961 
962 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_TSO, flags, nsge, addr);
963 	desc->cmd = cpu_to_le64(cmd);
964 	desc->len = cpu_to_le16(len);
965 	desc->vlan_tci = cpu_to_le16(vlan_tci);
966 	desc->hdr_len = cpu_to_le16(hdrlen);
967 	desc->mss = cpu_to_le16(mss);
968 
969 	if (start) {
970 		skb_tx_timestamp(skb);
971 		if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
972 			netdev_tx_sent_queue(q_to_ndq(q), skb->len);
973 		ionic_txq_post(q, false, ionic_tx_clean, skb);
974 	} else {
975 		ionic_txq_post(q, done, NULL, NULL);
976 	}
977 }
978 
979 static int ionic_tx_tso(struct ionic_queue *q, struct sk_buff *skb)
980 {
981 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
982 	struct ionic_desc_info *desc_info;
983 	struct ionic_buf_info *buf_info;
984 	struct ionic_txq_sg_elem *elem;
985 	struct ionic_txq_desc *desc;
986 	unsigned int chunk_len;
987 	unsigned int frag_rem;
988 	unsigned int tso_rem;
989 	unsigned int seg_rem;
990 	dma_addr_t desc_addr;
991 	dma_addr_t frag_addr;
992 	unsigned int hdrlen;
993 	unsigned int len;
994 	unsigned int mss;
995 	bool start, done;
996 	bool outer_csum;
997 	bool has_vlan;
998 	u16 desc_len;
999 	u8 desc_nsge;
1000 	u16 vlan_tci;
1001 	bool encap;
1002 	int err;
1003 
1004 	desc_info = &q->info[q->head_idx];
1005 	buf_info = desc_info->bufs;
1006 
1007 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
1008 		return -EIO;
1009 
1010 	len = skb->len;
1011 	mss = skb_shinfo(skb)->gso_size;
1012 	outer_csum = (skb_shinfo(skb)->gso_type & (SKB_GSO_GRE |
1013 						   SKB_GSO_GRE_CSUM |
1014 						   SKB_GSO_IPXIP4 |
1015 						   SKB_GSO_IPXIP6 |
1016 						   SKB_GSO_UDP_TUNNEL |
1017 						   SKB_GSO_UDP_TUNNEL_CSUM));
1018 	has_vlan = !!skb_vlan_tag_present(skb);
1019 	vlan_tci = skb_vlan_tag_get(skb);
1020 	encap = skb->encapsulation;
1021 
1022 	/* Preload inner-most TCP csum field with IP pseudo hdr
1023 	 * calculated with IP length set to zero.  HW will later
1024 	 * add in length to each TCP segment resulting from the TSO.
1025 	 */
1026 
1027 	if (encap)
1028 		err = ionic_tx_tcp_inner_pseudo_csum(skb);
1029 	else
1030 		err = ionic_tx_tcp_pseudo_csum(skb);
1031 	if (err) {
1032 		/* clean up mapping from ionic_tx_map_skb */
1033 		ionic_tx_desc_unmap_bufs(q, desc_info);
1034 		return err;
1035 	}
1036 
1037 	if (encap)
1038 		hdrlen = skb_inner_tcp_all_headers(skb);
1039 	else
1040 		hdrlen = skb_tcp_all_headers(skb);
1041 
1042 	tso_rem = len;
1043 	seg_rem = min(tso_rem, hdrlen + mss);
1044 
1045 	frag_addr = 0;
1046 	frag_rem = 0;
1047 
1048 	start = true;
1049 
1050 	while (tso_rem > 0) {
1051 		desc = NULL;
1052 		elem = NULL;
1053 		desc_addr = 0;
1054 		desc_len = 0;
1055 		desc_nsge = 0;
1056 		/* use fragments until we have enough to post a single descriptor */
1057 		while (seg_rem > 0) {
1058 			/* if the fragment is exhausted then move to the next one */
1059 			if (frag_rem == 0) {
1060 				/* grab the next fragment */
1061 				frag_addr = buf_info->dma_addr;
1062 				frag_rem = buf_info->len;
1063 				buf_info++;
1064 			}
1065 			chunk_len = min(frag_rem, seg_rem);
1066 			if (!desc) {
1067 				/* fill main descriptor */
1068 				desc = desc_info->txq_desc;
1069 				elem = desc_info->txq_sg_desc->elems;
1070 				desc_addr = frag_addr;
1071 				desc_len = chunk_len;
1072 			} else {
1073 				/* fill sg descriptor */
1074 				elem->addr = cpu_to_le64(frag_addr);
1075 				elem->len = cpu_to_le16(chunk_len);
1076 				elem++;
1077 				desc_nsge++;
1078 			}
1079 			frag_addr += chunk_len;
1080 			frag_rem -= chunk_len;
1081 			tso_rem -= chunk_len;
1082 			seg_rem -= chunk_len;
1083 		}
1084 		seg_rem = min(tso_rem, mss);
1085 		done = (tso_rem == 0);
1086 		/* post descriptor */
1087 		ionic_tx_tso_post(q, desc, skb,
1088 				  desc_addr, desc_nsge, desc_len,
1089 				  hdrlen, mss, outer_csum, vlan_tci, has_vlan,
1090 				  start, done);
1091 		start = false;
1092 		/* Buffer information is stored with the first tso descriptor */
1093 		desc_info = &q->info[q->head_idx];
1094 		desc_info->nbufs = 0;
1095 	}
1096 
1097 	stats->pkts += DIV_ROUND_UP(len - hdrlen, mss);
1098 	stats->bytes += len;
1099 	stats->tso++;
1100 	stats->tso_bytes = len;
1101 
1102 	return 0;
1103 }
1104 
1105 static void ionic_tx_calc_csum(struct ionic_queue *q, struct sk_buff *skb,
1106 			       struct ionic_desc_info *desc_info)
1107 {
1108 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1109 	struct ionic_buf_info *buf_info = desc_info->bufs;
1110 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1111 	bool has_vlan;
1112 	u8 flags = 0;
1113 	bool encap;
1114 	u64 cmd;
1115 
1116 	has_vlan = !!skb_vlan_tag_present(skb);
1117 	encap = skb->encapsulation;
1118 
1119 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1120 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1121 
1122 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_PARTIAL,
1123 				  flags, skb_shinfo(skb)->nr_frags,
1124 				  buf_info->dma_addr);
1125 	desc->cmd = cpu_to_le64(cmd);
1126 	desc->len = cpu_to_le16(buf_info->len);
1127 	if (has_vlan) {
1128 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1129 		stats->vlan_inserted++;
1130 	} else {
1131 		desc->vlan_tci = 0;
1132 	}
1133 	desc->csum_start = cpu_to_le16(skb_checksum_start_offset(skb));
1134 	desc->csum_offset = cpu_to_le16(skb->csum_offset);
1135 
1136 	if (skb_csum_is_sctp(skb))
1137 		stats->crc32_csum++;
1138 	else
1139 		stats->csum++;
1140 }
1141 
1142 static void ionic_tx_calc_no_csum(struct ionic_queue *q, struct sk_buff *skb,
1143 				  struct ionic_desc_info *desc_info)
1144 {
1145 	struct ionic_txq_desc *desc = desc_info->txq_desc;
1146 	struct ionic_buf_info *buf_info = desc_info->bufs;
1147 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1148 	bool has_vlan;
1149 	u8 flags = 0;
1150 	bool encap;
1151 	u64 cmd;
1152 
1153 	has_vlan = !!skb_vlan_tag_present(skb);
1154 	encap = skb->encapsulation;
1155 
1156 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
1157 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
1158 
1159 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_NONE,
1160 				  flags, skb_shinfo(skb)->nr_frags,
1161 				  buf_info->dma_addr);
1162 	desc->cmd = cpu_to_le64(cmd);
1163 	desc->len = cpu_to_le16(buf_info->len);
1164 	if (has_vlan) {
1165 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1166 		stats->vlan_inserted++;
1167 	} else {
1168 		desc->vlan_tci = 0;
1169 	}
1170 	desc->csum_start = 0;
1171 	desc->csum_offset = 0;
1172 
1173 	stats->csum_none++;
1174 }
1175 
1176 static void ionic_tx_skb_frags(struct ionic_queue *q, struct sk_buff *skb,
1177 			       struct ionic_desc_info *desc_info)
1178 {
1179 	struct ionic_txq_sg_desc *sg_desc = desc_info->txq_sg_desc;
1180 	struct ionic_buf_info *buf_info = &desc_info->bufs[1];
1181 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
1182 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1183 	unsigned int i;
1184 
1185 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, buf_info++, elem++) {
1186 		elem->addr = cpu_to_le64(buf_info->dma_addr);
1187 		elem->len = cpu_to_le16(buf_info->len);
1188 	}
1189 
1190 	stats->frags += skb_shinfo(skb)->nr_frags;
1191 }
1192 
1193 static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
1194 {
1195 	struct ionic_desc_info *desc_info = &q->info[q->head_idx];
1196 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1197 
1198 	if (unlikely(ionic_tx_map_skb(q, skb, desc_info)))
1199 		return -EIO;
1200 
1201 	/* set up the initial descriptor */
1202 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1203 		ionic_tx_calc_csum(q, skb, desc_info);
1204 	else
1205 		ionic_tx_calc_no_csum(q, skb, desc_info);
1206 
1207 	/* add frags */
1208 	ionic_tx_skb_frags(q, skb, desc_info);
1209 
1210 	skb_tx_timestamp(skb);
1211 	stats->pkts++;
1212 	stats->bytes += skb->len;
1213 
1214 	if (!unlikely(q->features & IONIC_TXQ_F_HWSTAMP))
1215 		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
1216 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
1217 
1218 	return 0;
1219 }
1220 
1221 static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
1222 {
1223 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1224 	int ndescs;
1225 	int err;
1226 
1227 	/* Each desc is mss long max, so a descriptor for each gso_seg */
1228 	if (skb_is_gso(skb))
1229 		ndescs = skb_shinfo(skb)->gso_segs;
1230 	else
1231 		ndescs = 1;
1232 
1233 	/* If non-TSO, just need 1 desc and nr_frags sg elems */
1234 	if (skb_shinfo(skb)->nr_frags <= q->max_sg_elems)
1235 		return ndescs;
1236 
1237 	/* Too many frags, so linearize */
1238 	err = skb_linearize(skb);
1239 	if (err)
1240 		return err;
1241 
1242 	stats->linearize++;
1243 
1244 	return ndescs;
1245 }
1246 
1247 static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
1248 {
1249 	int stopped = 0;
1250 
1251 	if (unlikely(!ionic_q_has_space(q, ndescs))) {
1252 		netif_stop_subqueue(q->lif->netdev, q->index);
1253 		stopped = 1;
1254 
1255 		/* Might race with ionic_tx_clean, check again */
1256 		smp_rmb();
1257 		if (ionic_q_has_space(q, ndescs)) {
1258 			netif_wake_subqueue(q->lif->netdev, q->index);
1259 			stopped = 0;
1260 		}
1261 	}
1262 
1263 	return stopped;
1264 }
1265 
1266 static netdev_tx_t ionic_start_hwstamp_xmit(struct sk_buff *skb,
1267 					    struct net_device *netdev)
1268 {
1269 	struct ionic_lif *lif = netdev_priv(netdev);
1270 	struct ionic_queue *q = &lif->hwstamp_txq->q;
1271 	int err, ndescs;
1272 
1273 	/* Does not stop/start txq, because we post to a separate tx queue
1274 	 * for timestamping, and if a packet can't be posted immediately to
1275 	 * the timestamping queue, it is dropped.
1276 	 */
1277 
1278 	ndescs = ionic_tx_descs_needed(q, skb);
1279 	if (unlikely(ndescs < 0))
1280 		goto err_out_drop;
1281 
1282 	if (unlikely(!ionic_q_has_space(q, ndescs)))
1283 		goto err_out_drop;
1284 
1285 	skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP;
1286 	if (skb_is_gso(skb))
1287 		err = ionic_tx_tso(q, skb);
1288 	else
1289 		err = ionic_tx(q, skb);
1290 
1291 	if (err)
1292 		goto err_out_drop;
1293 
1294 	return NETDEV_TX_OK;
1295 
1296 err_out_drop:
1297 	q->drop++;
1298 	dev_kfree_skb(skb);
1299 	return NETDEV_TX_OK;
1300 }
1301 
1302 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1303 {
1304 	u16 queue_index = skb_get_queue_mapping(skb);
1305 	struct ionic_lif *lif = netdev_priv(netdev);
1306 	struct ionic_queue *q;
1307 	int ndescs;
1308 	int err;
1309 
1310 	if (unlikely(!test_bit(IONIC_LIF_F_UP, lif->state))) {
1311 		dev_kfree_skb(skb);
1312 		return NETDEV_TX_OK;
1313 	}
1314 
1315 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
1316 		if (lif->hwstamp_txq && lif->phc->ts_config_tx_mode)
1317 			return ionic_start_hwstamp_xmit(skb, netdev);
1318 
1319 	if (unlikely(queue_index >= lif->nxqs))
1320 		queue_index = 0;
1321 	q = &lif->txqcqs[queue_index]->q;
1322 
1323 	ndescs = ionic_tx_descs_needed(q, skb);
1324 	if (ndescs < 0)
1325 		goto err_out_drop;
1326 
1327 	if (unlikely(ionic_maybe_stop_tx(q, ndescs)))
1328 		return NETDEV_TX_BUSY;
1329 
1330 	if (skb_is_gso(skb))
1331 		err = ionic_tx_tso(q, skb);
1332 	else
1333 		err = ionic_tx(q, skb);
1334 
1335 	if (err)
1336 		goto err_out_drop;
1337 
1338 	/* Stop the queue if there aren't descriptors for the next packet.
1339 	 * Since our SG lists per descriptor take care of most of the possible
1340 	 * fragmentation, we don't need to have many descriptors available.
1341 	 */
1342 	ionic_maybe_stop_tx(q, 4);
1343 
1344 	return NETDEV_TX_OK;
1345 
1346 err_out_drop:
1347 	q->drop++;
1348 	dev_kfree_skb(skb);
1349 	return NETDEV_TX_OK;
1350 }
1351