xref: /openbmc/linux/drivers/net/ethernet/pensando/ionic/ionic_txrx.c (revision 0760aad038b5a032c31ea124feed63d88627d2f1)
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 void ionic_rx_clean(struct ionic_queue *q,
14 			   struct ionic_desc_info *desc_info,
15 			   struct ionic_cq_info *cq_info,
16 			   void *cb_arg);
17 
18 static bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info);
19 
20 static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info);
21 
22 static inline void ionic_txq_post(struct ionic_queue *q, bool ring_dbell,
23 				  ionic_desc_cb cb_func, void *cb_arg)
24 {
25 	DEBUG_STATS_TXQ_POST(q, ring_dbell);
26 
27 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
28 }
29 
30 static inline void ionic_rxq_post(struct ionic_queue *q, bool ring_dbell,
31 				  ionic_desc_cb cb_func, void *cb_arg)
32 {
33 	ionic_q_post(q, ring_dbell, cb_func, cb_arg);
34 
35 	DEBUG_STATS_RX_BUFF_CNT(q);
36 }
37 
38 static inline struct netdev_queue *q_to_ndq(struct ionic_queue *q)
39 {
40 	return netdev_get_tx_queue(q->lif->netdev, q->index);
41 }
42 
43 static struct sk_buff *ionic_rx_skb_alloc(struct ionic_queue *q,
44 					  unsigned int len, bool frags)
45 {
46 	struct ionic_lif *lif = q->lif;
47 	struct ionic_rx_stats *stats;
48 	struct net_device *netdev;
49 	struct sk_buff *skb;
50 
51 	netdev = lif->netdev;
52 	stats = &q->lif->rxqstats[q->index];
53 
54 	if (frags)
55 		skb = napi_get_frags(&q_to_qcq(q)->napi);
56 	else
57 		skb = netdev_alloc_skb_ip_align(netdev, len);
58 
59 	if (unlikely(!skb)) {
60 		net_warn_ratelimited("%s: SKB alloc failed on %s!\n",
61 				     netdev->name, q->name);
62 		stats->alloc_err++;
63 		return NULL;
64 	}
65 
66 	return skb;
67 }
68 
69 static struct sk_buff *ionic_rx_frags(struct ionic_queue *q,
70 				      struct ionic_desc_info *desc_info,
71 				      struct ionic_cq_info *cq_info)
72 {
73 	struct ionic_rxq_comp *comp = cq_info->cq_desc;
74 	struct device *dev = q->lif->ionic->dev;
75 	struct ionic_page_info *page_info;
76 	struct sk_buff *skb;
77 	unsigned int i;
78 	u16 frag_len;
79 	u16 len;
80 
81 	page_info = &desc_info->pages[0];
82 	len = le16_to_cpu(comp->len);
83 
84 	prefetch(page_address(page_info->page) + NET_IP_ALIGN);
85 
86 	skb = ionic_rx_skb_alloc(q, len, true);
87 	if (unlikely(!skb))
88 		return NULL;
89 
90 	i = comp->num_sg_elems + 1;
91 	do {
92 		if (unlikely(!page_info->page)) {
93 			struct napi_struct *napi = &q_to_qcq(q)->napi;
94 
95 			napi->skb = NULL;
96 			dev_kfree_skb(skb);
97 			return NULL;
98 		}
99 
100 		frag_len = min(len, (u16)PAGE_SIZE);
101 		len -= frag_len;
102 
103 		dma_unmap_page(dev, dma_unmap_addr(page_info, dma_addr),
104 			       PAGE_SIZE, DMA_FROM_DEVICE);
105 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
106 				page_info->page, 0, frag_len, PAGE_SIZE);
107 		page_info->page = NULL;
108 		page_info++;
109 		i--;
110 	} while (i > 0);
111 
112 	return skb;
113 }
114 
115 static struct sk_buff *ionic_rx_copybreak(struct ionic_queue *q,
116 					  struct ionic_desc_info *desc_info,
117 					  struct ionic_cq_info *cq_info)
118 {
119 	struct ionic_rxq_comp *comp = cq_info->cq_desc;
120 	struct device *dev = q->lif->ionic->dev;
121 	struct ionic_page_info *page_info;
122 	struct sk_buff *skb;
123 	u16 len;
124 
125 	page_info = &desc_info->pages[0];
126 	len = le16_to_cpu(comp->len);
127 
128 	skb = ionic_rx_skb_alloc(q, len, false);
129 	if (unlikely(!skb))
130 		return NULL;
131 
132 	if (unlikely(!page_info->page)) {
133 		dev_kfree_skb(skb);
134 		return NULL;
135 	}
136 
137 	dma_sync_single_for_cpu(dev, dma_unmap_addr(page_info, dma_addr),
138 				len, DMA_FROM_DEVICE);
139 	skb_copy_to_linear_data(skb, page_address(page_info->page), len);
140 	dma_sync_single_for_device(dev, dma_unmap_addr(page_info, dma_addr),
141 				   len, DMA_FROM_DEVICE);
142 
143 	skb_put(skb, len);
144 	skb->protocol = eth_type_trans(skb, q->lif->netdev);
145 
146 	return skb;
147 }
148 
149 static void ionic_rx_clean(struct ionic_queue *q,
150 			   struct ionic_desc_info *desc_info,
151 			   struct ionic_cq_info *cq_info,
152 			   void *cb_arg)
153 {
154 	struct ionic_rxq_comp *comp = cq_info->cq_desc;
155 	struct ionic_qcq *qcq = q_to_qcq(q);
156 	struct ionic_rx_stats *stats;
157 	struct net_device *netdev;
158 	struct sk_buff *skb;
159 
160 	stats = q_to_rx_stats(q);
161 	netdev = q->lif->netdev;
162 
163 	if (comp->status) {
164 		stats->dropped++;
165 		return;
166 	}
167 
168 	stats->pkts++;
169 	stats->bytes += le16_to_cpu(comp->len);
170 
171 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
172 		skb = ionic_rx_copybreak(q, desc_info, cq_info);
173 	else
174 		skb = ionic_rx_frags(q, desc_info, cq_info);
175 
176 	if (unlikely(!skb)) {
177 		stats->dropped++;
178 		return;
179 	}
180 
181 	skb_record_rx_queue(skb, q->index);
182 
183 	if (likely(netdev->features & NETIF_F_RXHASH)) {
184 		switch (comp->pkt_type_color & IONIC_RXQ_COMP_PKT_TYPE_MASK) {
185 		case IONIC_PKT_TYPE_IPV4:
186 		case IONIC_PKT_TYPE_IPV6:
187 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
188 				     PKT_HASH_TYPE_L3);
189 			break;
190 		case IONIC_PKT_TYPE_IPV4_TCP:
191 		case IONIC_PKT_TYPE_IPV6_TCP:
192 		case IONIC_PKT_TYPE_IPV4_UDP:
193 		case IONIC_PKT_TYPE_IPV6_UDP:
194 			skb_set_hash(skb, le32_to_cpu(comp->rss_hash),
195 				     PKT_HASH_TYPE_L4);
196 			break;
197 		}
198 	}
199 
200 	if (likely(netdev->features & NETIF_F_RXCSUM)) {
201 		if (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_CALC) {
202 			skb->ip_summed = CHECKSUM_COMPLETE;
203 			skb->csum = (__wsum)le16_to_cpu(comp->csum);
204 			stats->csum_complete++;
205 		}
206 	} else {
207 		stats->csum_none++;
208 	}
209 
210 	if (unlikely((comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_TCP_BAD) ||
211 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_UDP_BAD) ||
212 		     (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_IP_BAD)))
213 		stats->csum_error++;
214 
215 	if (likely(netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
216 	    (comp->csum_flags & IONIC_RXQ_COMP_CSUM_F_VLAN)) {
217 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q),
218 				       le16_to_cpu(comp->vlan_tci));
219 		stats->vlan_stripped++;
220 	}
221 
222 	if (le16_to_cpu(comp->len) <= q->lif->rx_copybreak)
223 		napi_gro_receive(&qcq->napi, skb);
224 	else
225 		napi_gro_frags(&qcq->napi);
226 }
227 
228 static bool ionic_rx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
229 {
230 	struct ionic_rxq_comp *comp = cq_info->cq_desc;
231 	struct ionic_queue *q = cq->bound_q;
232 	struct ionic_desc_info *desc_info;
233 
234 	if (!color_match(comp->pkt_type_color, cq->done_color))
235 		return false;
236 
237 	/* check for empty queue */
238 	if (q->tail_idx == q->head_idx)
239 		return false;
240 
241 	if (q->tail_idx != le16_to_cpu(comp->comp_index))
242 		return false;
243 
244 	desc_info = &q->info[q->tail_idx];
245 	q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
246 
247 	/* clean the related q entry, only one per qc completion */
248 	ionic_rx_clean(q, desc_info, cq_info, desc_info->cb_arg);
249 
250 	desc_info->cb = NULL;
251 	desc_info->cb_arg = NULL;
252 
253 	return true;
254 }
255 
256 void ionic_rx_flush(struct ionic_cq *cq)
257 {
258 	struct ionic_dev *idev = &cq->lif->ionic->idev;
259 	u32 work_done;
260 
261 	work_done = ionic_cq_service(cq, cq->num_descs,
262 				     ionic_rx_service, NULL, NULL);
263 
264 	if (work_done)
265 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
266 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
267 }
268 
269 static int ionic_rx_page_alloc(struct ionic_queue *q,
270 			       struct ionic_page_info *page_info)
271 {
272 	struct ionic_lif *lif = q->lif;
273 	struct ionic_rx_stats *stats;
274 	struct net_device *netdev;
275 	struct device *dev;
276 
277 	netdev = lif->netdev;
278 	dev = lif->ionic->dev;
279 	stats = q_to_rx_stats(q);
280 
281 	if (unlikely(!page_info)) {
282 		net_err_ratelimited("%s: %s invalid page_info in alloc\n",
283 				    netdev->name, q->name);
284 		return -EINVAL;
285 	}
286 
287 	page_info->page = dev_alloc_page();
288 	if (unlikely(!page_info->page)) {
289 		net_err_ratelimited("%s: %s page alloc failed\n",
290 				    netdev->name, q->name);
291 		stats->alloc_err++;
292 		return -ENOMEM;
293 	}
294 
295 	page_info->dma_addr = dma_map_page(dev, page_info->page, 0, PAGE_SIZE,
296 					   DMA_FROM_DEVICE);
297 	if (unlikely(dma_mapping_error(dev, page_info->dma_addr))) {
298 		put_page(page_info->page);
299 		page_info->dma_addr = 0;
300 		page_info->page = NULL;
301 		net_err_ratelimited("%s: %s dma map failed\n",
302 				    netdev->name, q->name);
303 		stats->dma_map_err++;
304 		return -EIO;
305 	}
306 
307 	return 0;
308 }
309 
310 static void ionic_rx_page_free(struct ionic_queue *q,
311 			       struct ionic_page_info *page_info)
312 {
313 	struct ionic_lif *lif = q->lif;
314 	struct net_device *netdev;
315 	struct device *dev;
316 
317 	netdev = lif->netdev;
318 	dev = lif->ionic->dev;
319 
320 	if (unlikely(!page_info)) {
321 		net_err_ratelimited("%s: %s invalid page_info in free\n",
322 				    netdev->name, q->name);
323 		return;
324 	}
325 
326 	if (unlikely(!page_info->page)) {
327 		net_err_ratelimited("%s: %s invalid page in free\n",
328 				    netdev->name, q->name);
329 		return;
330 	}
331 
332 	dma_unmap_page(dev, page_info->dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
333 
334 	put_page(page_info->page);
335 	page_info->dma_addr = 0;
336 	page_info->page = NULL;
337 }
338 
339 void ionic_rx_fill(struct ionic_queue *q)
340 {
341 	struct net_device *netdev = q->lif->netdev;
342 	struct ionic_desc_info *desc_info;
343 	struct ionic_page_info *page_info;
344 	struct ionic_rxq_sg_desc *sg_desc;
345 	struct ionic_rxq_sg_elem *sg_elem;
346 	struct ionic_rxq_desc *desc;
347 	unsigned int remain_len;
348 	unsigned int seg_len;
349 	unsigned int nfrags;
350 	unsigned int i, j;
351 	unsigned int len;
352 
353 	len = netdev->mtu + ETH_HLEN;
354 	nfrags = round_up(len, PAGE_SIZE) / PAGE_SIZE;
355 
356 	for (i = ionic_q_space_avail(q); i; i--) {
357 		remain_len = len;
358 		desc_info = &q->info[q->head_idx];
359 		desc = desc_info->desc;
360 		sg_desc = desc_info->sg_desc;
361 		page_info = &desc_info->pages[0];
362 
363 		if (page_info->page) { /* recycle the buffer */
364 			ionic_rxq_post(q, false, ionic_rx_clean, NULL);
365 			continue;
366 		}
367 
368 		/* fill main descriptor - pages[0] */
369 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
370 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
371 		desc_info->npages = nfrags;
372 		if (unlikely(ionic_rx_page_alloc(q, page_info))) {
373 			desc->addr = 0;
374 			desc->len = 0;
375 			return;
376 		}
377 		desc->addr = cpu_to_le64(page_info->dma_addr);
378 		seg_len = min_t(unsigned int, PAGE_SIZE, len);
379 		desc->len = cpu_to_le16(seg_len);
380 		remain_len -= seg_len;
381 		page_info++;
382 
383 		/* fill sg descriptors - pages[1..n] */
384 		for (j = 0; j < nfrags - 1; j++) {
385 			if (page_info->page) /* recycle the sg buffer */
386 				continue;
387 
388 			sg_elem = &sg_desc->elems[j];
389 			if (unlikely(ionic_rx_page_alloc(q, page_info))) {
390 				sg_elem->addr = 0;
391 				sg_elem->len = 0;
392 				return;
393 			}
394 			sg_elem->addr = cpu_to_le64(page_info->dma_addr);
395 			seg_len = min_t(unsigned int, PAGE_SIZE, remain_len);
396 			sg_elem->len = cpu_to_le16(seg_len);
397 			remain_len -= seg_len;
398 			page_info++;
399 		}
400 
401 		ionic_rxq_post(q, false, ionic_rx_clean, NULL);
402 	}
403 
404 	ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
405 			 q->dbval | q->head_idx);
406 }
407 
408 static void ionic_rx_fill_cb(void *arg)
409 {
410 	ionic_rx_fill(arg);
411 }
412 
413 void ionic_rx_empty(struct ionic_queue *q)
414 {
415 	struct ionic_desc_info *desc_info;
416 	struct ionic_rxq_desc *desc;
417 	unsigned int i;
418 	u16 idx;
419 
420 	idx = q->tail_idx;
421 	while (idx != q->head_idx) {
422 		desc_info = &q->info[idx];
423 		desc = desc_info->desc;
424 		desc->addr = 0;
425 		desc->len = 0;
426 
427 		for (i = 0; i < desc_info->npages; i++)
428 			ionic_rx_page_free(q, &desc_info->pages[i]);
429 
430 		desc_info->cb_arg = NULL;
431 		idx = (idx + 1) & (q->num_descs - 1);
432 	}
433 }
434 
435 int ionic_tx_napi(struct napi_struct *napi, int budget)
436 {
437 	struct ionic_qcq *qcq = napi_to_qcq(napi);
438 	struct ionic_cq *cq = napi_to_cq(napi);
439 	struct ionic_dev *idev;
440 	struct ionic_lif *lif;
441 	u32 work_done = 0;
442 	u32 flags = 0;
443 
444 	lif = cq->bound_q->lif;
445 	idev = &lif->ionic->idev;
446 
447 	work_done = ionic_cq_service(cq, budget,
448 				     ionic_tx_service, NULL, NULL);
449 
450 	if (work_done < budget && napi_complete_done(napi, work_done)) {
451 		flags |= IONIC_INTR_CRED_UNMASK;
452 		DEBUG_STATS_INTR_REARM(cq->bound_intr);
453 	}
454 
455 	if (work_done || flags) {
456 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
457 		ionic_intr_credits(idev->intr_ctrl,
458 				   cq->bound_intr->index,
459 				   work_done, flags);
460 	}
461 
462 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
463 
464 	return work_done;
465 }
466 
467 int ionic_rx_napi(struct napi_struct *napi, int budget)
468 {
469 	struct ionic_qcq *qcq = napi_to_qcq(napi);
470 	struct ionic_cq *cq = napi_to_cq(napi);
471 	struct ionic_dev *idev;
472 	struct ionic_lif *lif;
473 	u32 work_done = 0;
474 	u32 flags = 0;
475 
476 	lif = cq->bound_q->lif;
477 	idev = &lif->ionic->idev;
478 
479 	work_done = ionic_cq_service(cq, budget,
480 				     ionic_rx_service, NULL, NULL);
481 
482 	if (work_done)
483 		ionic_rx_fill(cq->bound_q);
484 
485 	if (work_done < budget && napi_complete_done(napi, work_done)) {
486 		flags |= IONIC_INTR_CRED_UNMASK;
487 		DEBUG_STATS_INTR_REARM(cq->bound_intr);
488 	}
489 
490 	if (work_done || flags) {
491 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
492 		ionic_intr_credits(idev->intr_ctrl,
493 				   cq->bound_intr->index,
494 				   work_done, flags);
495 	}
496 
497 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
498 
499 	return work_done;
500 }
501 
502 int ionic_txrx_napi(struct napi_struct *napi, int budget)
503 {
504 	struct ionic_qcq *qcq = napi_to_qcq(napi);
505 	struct ionic_cq *rxcq = napi_to_cq(napi);
506 	unsigned int qi = rxcq->bound_q->index;
507 	struct ionic_dev *idev;
508 	struct ionic_lif *lif;
509 	struct ionic_cq *txcq;
510 	u32 rx_work_done = 0;
511 	u32 tx_work_done = 0;
512 	u32 flags = 0;
513 
514 	lif = rxcq->bound_q->lif;
515 	idev = &lif->ionic->idev;
516 	txcq = &lif->txqcqs[qi]->cq;
517 
518 	tx_work_done = ionic_cq_service(txcq, lif->tx_budget,
519 					ionic_tx_service, NULL, NULL);
520 
521 	rx_work_done = ionic_cq_service(rxcq, budget,
522 					ionic_rx_service, NULL, NULL);
523 	if (rx_work_done)
524 		ionic_rx_fill_cb(rxcq->bound_q);
525 
526 	if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) {
527 		flags |= IONIC_INTR_CRED_UNMASK;
528 		DEBUG_STATS_INTR_REARM(rxcq->bound_intr);
529 	}
530 
531 	if (rx_work_done || flags) {
532 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
533 		ionic_intr_credits(idev->intr_ctrl, rxcq->bound_intr->index,
534 				   tx_work_done + rx_work_done, flags);
535 	}
536 
537 	DEBUG_STATS_NAPI_POLL(qcq, rx_work_done);
538 	DEBUG_STATS_NAPI_POLL(qcq, tx_work_done);
539 
540 	return rx_work_done;
541 }
542 
543 static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
544 				      void *data, size_t len)
545 {
546 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
547 	struct device *dev = q->lif->ionic->dev;
548 	dma_addr_t dma_addr;
549 
550 	dma_addr = dma_map_single(dev, data, len, DMA_TO_DEVICE);
551 	if (dma_mapping_error(dev, dma_addr)) {
552 		net_warn_ratelimited("%s: DMA single map failed on %s!\n",
553 				     q->lif->netdev->name, q->name);
554 		stats->dma_map_err++;
555 		return 0;
556 	}
557 	return dma_addr;
558 }
559 
560 static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
561 				    const skb_frag_t *frag,
562 				    size_t offset, size_t len)
563 {
564 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
565 	struct device *dev = q->lif->ionic->dev;
566 	dma_addr_t dma_addr;
567 
568 	dma_addr = skb_frag_dma_map(dev, frag, offset, len, DMA_TO_DEVICE);
569 	if (dma_mapping_error(dev, dma_addr)) {
570 		net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
571 				     q->lif->netdev->name, q->name);
572 		stats->dma_map_err++;
573 	}
574 	return dma_addr;
575 }
576 
577 static void ionic_tx_clean(struct ionic_queue *q,
578 			   struct ionic_desc_info *desc_info,
579 			   struct ionic_cq_info *cq_info,
580 			   void *cb_arg)
581 {
582 	struct ionic_txq_sg_desc *sg_desc = desc_info->sg_desc;
583 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
584 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
585 	struct ionic_txq_desc *desc = desc_info->desc;
586 	struct device *dev = q->lif->ionic->dev;
587 	u8 opcode, flags, nsge;
588 	u16 queue_index;
589 	unsigned int i;
590 	u64 addr;
591 
592 	decode_txq_desc_cmd(le64_to_cpu(desc->cmd),
593 			    &opcode, &flags, &nsge, &addr);
594 
595 	/* use unmap_single only if either this is not TSO,
596 	 * or this is first descriptor of a TSO
597 	 */
598 	if (opcode != IONIC_TXQ_DESC_OPCODE_TSO ||
599 	    flags & IONIC_TXQ_DESC_FLAG_TSO_SOT)
600 		dma_unmap_single(dev, (dma_addr_t)addr,
601 				 le16_to_cpu(desc->len), DMA_TO_DEVICE);
602 	else
603 		dma_unmap_page(dev, (dma_addr_t)addr,
604 			       le16_to_cpu(desc->len), DMA_TO_DEVICE);
605 
606 	for (i = 0; i < nsge; i++, elem++)
607 		dma_unmap_page(dev, (dma_addr_t)le64_to_cpu(elem->addr),
608 			       le16_to_cpu(elem->len), DMA_TO_DEVICE);
609 
610 	if (cb_arg) {
611 		struct sk_buff *skb = cb_arg;
612 		u32 len = skb->len;
613 
614 		queue_index = skb_get_queue_mapping(skb);
615 		if (unlikely(__netif_subqueue_stopped(q->lif->netdev,
616 						      queue_index))) {
617 			netif_wake_subqueue(q->lif->netdev, queue_index);
618 			q->wake++;
619 		}
620 		dev_kfree_skb_any(skb);
621 		stats->clean++;
622 		netdev_tx_completed_queue(q_to_ndq(q), 1, len);
623 	}
624 }
625 
626 static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
627 {
628 	struct ionic_txq_comp *comp = cq_info->cq_desc;
629 	struct ionic_queue *q = cq->bound_q;
630 	struct ionic_desc_info *desc_info;
631 	u16 index;
632 
633 	if (!color_match(comp->color, cq->done_color))
634 		return false;
635 
636 	/* clean the related q entries, there could be
637 	 * several q entries completed for each cq completion
638 	 */
639 	do {
640 		desc_info = &q->info[q->tail_idx];
641 		index = q->tail_idx;
642 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
643 		ionic_tx_clean(q, desc_info, cq_info, desc_info->cb_arg);
644 		desc_info->cb = NULL;
645 		desc_info->cb_arg = NULL;
646 	} while (index != le16_to_cpu(comp->comp_index));
647 
648 	return true;
649 }
650 
651 void ionic_tx_flush(struct ionic_cq *cq)
652 {
653 	struct ionic_dev *idev = &cq->lif->ionic->idev;
654 	u32 work_done;
655 
656 	work_done = ionic_cq_service(cq, cq->num_descs,
657 				     ionic_tx_service, NULL, NULL);
658 	if (work_done)
659 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
660 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
661 }
662 
663 void ionic_tx_empty(struct ionic_queue *q)
664 {
665 	struct ionic_desc_info *desc_info;
666 
667 	/* walk the not completed tx entries, if any */
668 	while (q->head_idx != q->tail_idx) {
669 		desc_info = &q->info[q->tail_idx];
670 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
671 		ionic_tx_clean(q, desc_info, NULL, desc_info->cb_arg);
672 		desc_info->cb = NULL;
673 		desc_info->cb_arg = NULL;
674 	}
675 }
676 
677 static int ionic_tx_tcp_inner_pseudo_csum(struct sk_buff *skb)
678 {
679 	int err;
680 
681 	err = skb_cow_head(skb, 0);
682 	if (err)
683 		return err;
684 
685 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
686 		inner_ip_hdr(skb)->check = 0;
687 		inner_tcp_hdr(skb)->check =
688 			~csum_tcpudp_magic(inner_ip_hdr(skb)->saddr,
689 					   inner_ip_hdr(skb)->daddr,
690 					   0, IPPROTO_TCP, 0);
691 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
692 		inner_tcp_hdr(skb)->check =
693 			~csum_ipv6_magic(&inner_ipv6_hdr(skb)->saddr,
694 					 &inner_ipv6_hdr(skb)->daddr,
695 					 0, IPPROTO_TCP, 0);
696 	}
697 
698 	return 0;
699 }
700 
701 static int ionic_tx_tcp_pseudo_csum(struct sk_buff *skb)
702 {
703 	int err;
704 
705 	err = skb_cow_head(skb, 0);
706 	if (err)
707 		return err;
708 
709 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
710 		ip_hdr(skb)->check = 0;
711 		tcp_hdr(skb)->check =
712 			~csum_tcpudp_magic(ip_hdr(skb)->saddr,
713 					   ip_hdr(skb)->daddr,
714 					   0, IPPROTO_TCP, 0);
715 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
716 		tcp_v6_gso_csum_prep(skb);
717 	}
718 
719 	return 0;
720 }
721 
722 static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
723 			      struct sk_buff *skb,
724 			      dma_addr_t addr, u8 nsge, u16 len,
725 			      unsigned int hdrlen, unsigned int mss,
726 			      bool outer_csum,
727 			      u16 vlan_tci, bool has_vlan,
728 			      bool start, bool done)
729 {
730 	u8 flags = 0;
731 	u64 cmd;
732 
733 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
734 	flags |= outer_csum ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
735 	flags |= start ? IONIC_TXQ_DESC_FLAG_TSO_SOT : 0;
736 	flags |= done ? IONIC_TXQ_DESC_FLAG_TSO_EOT : 0;
737 
738 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_TSO, flags, nsge, addr);
739 	desc->cmd = cpu_to_le64(cmd);
740 	desc->len = cpu_to_le16(len);
741 	desc->vlan_tci = cpu_to_le16(vlan_tci);
742 	desc->hdr_len = cpu_to_le16(hdrlen);
743 	desc->mss = cpu_to_le16(mss);
744 
745 	if (done) {
746 		skb_tx_timestamp(skb);
747 		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
748 		ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
749 	} else {
750 		ionic_txq_post(q, false, ionic_tx_clean, NULL);
751 	}
752 }
753 
754 static struct ionic_txq_desc *ionic_tx_tso_next(struct ionic_queue *q,
755 						struct ionic_txq_sg_elem **elem)
756 {
757 	struct ionic_txq_sg_desc *sg_desc = q->info[q->head_idx].txq_sg_desc;
758 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
759 
760 	*elem = sg_desc->elems;
761 	return desc;
762 }
763 
764 static int ionic_tx_tso(struct ionic_queue *q, struct sk_buff *skb)
765 {
766 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
767 	struct ionic_desc_info *rewind_desc_info;
768 	struct device *dev = q->lif->ionic->dev;
769 	struct ionic_txq_sg_elem *elem;
770 	struct ionic_txq_desc *desc;
771 	unsigned int frag_left = 0;
772 	unsigned int offset = 0;
773 	u16 abort = q->head_idx;
774 	unsigned int len_left;
775 	dma_addr_t desc_addr;
776 	unsigned int hdrlen;
777 	unsigned int nfrags;
778 	unsigned int seglen;
779 	u64 total_bytes = 0;
780 	u64 total_pkts = 0;
781 	u16 rewind = abort;
782 	unsigned int left;
783 	unsigned int len;
784 	unsigned int mss;
785 	skb_frag_t *frag;
786 	bool start, done;
787 	bool outer_csum;
788 	bool has_vlan;
789 	u16 desc_len;
790 	u8 desc_nsge;
791 	u16 vlan_tci;
792 	bool encap;
793 	int err;
794 
795 	mss = skb_shinfo(skb)->gso_size;
796 	nfrags = skb_shinfo(skb)->nr_frags;
797 	len_left = skb->len - skb_headlen(skb);
798 	outer_csum = (skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM) ||
799 		     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
800 	has_vlan = !!skb_vlan_tag_present(skb);
801 	vlan_tci = skb_vlan_tag_get(skb);
802 	encap = skb->encapsulation;
803 
804 	/* Preload inner-most TCP csum field with IP pseudo hdr
805 	 * calculated with IP length set to zero.  HW will later
806 	 * add in length to each TCP segment resulting from the TSO.
807 	 */
808 
809 	if (encap)
810 		err = ionic_tx_tcp_inner_pseudo_csum(skb);
811 	else
812 		err = ionic_tx_tcp_pseudo_csum(skb);
813 	if (err)
814 		return err;
815 
816 	if (encap)
817 		hdrlen = skb_inner_transport_header(skb) - skb->data +
818 			 inner_tcp_hdrlen(skb);
819 	else
820 		hdrlen = skb_transport_offset(skb) + tcp_hdrlen(skb);
821 
822 	seglen = hdrlen + mss;
823 	left = skb_headlen(skb);
824 
825 	desc = ionic_tx_tso_next(q, &elem);
826 	start = true;
827 
828 	/* Chop skb->data up into desc segments */
829 
830 	while (left > 0) {
831 		len = min(seglen, left);
832 		frag_left = seglen - len;
833 		desc_addr = ionic_tx_map_single(q, skb->data + offset, len);
834 		if (dma_mapping_error(dev, desc_addr))
835 			goto err_out_abort;
836 		desc_len = len;
837 		desc_nsge = 0;
838 		left -= len;
839 		offset += len;
840 		if (nfrags > 0 && frag_left > 0)
841 			continue;
842 		done = (nfrags == 0 && left == 0);
843 		ionic_tx_tso_post(q, desc, skb,
844 				  desc_addr, desc_nsge, desc_len,
845 				  hdrlen, mss,
846 				  outer_csum,
847 				  vlan_tci, has_vlan,
848 				  start, done);
849 		total_pkts++;
850 		total_bytes += start ? len : len + hdrlen;
851 		desc = ionic_tx_tso_next(q, &elem);
852 		start = false;
853 		seglen = mss;
854 	}
855 
856 	/* Chop skb frags into desc segments */
857 
858 	for (frag = skb_shinfo(skb)->frags; len_left; frag++) {
859 		offset = 0;
860 		left = skb_frag_size(frag);
861 		len_left -= left;
862 		nfrags--;
863 		stats->frags++;
864 
865 		while (left > 0) {
866 			if (frag_left > 0) {
867 				len = min(frag_left, left);
868 				frag_left -= len;
869 				elem->addr =
870 				    cpu_to_le64(ionic_tx_map_frag(q, frag,
871 								  offset, len));
872 				if (dma_mapping_error(dev, elem->addr))
873 					goto err_out_abort;
874 				elem->len = cpu_to_le16(len);
875 				elem++;
876 				desc_nsge++;
877 				left -= len;
878 				offset += len;
879 				if (nfrags > 0 && frag_left > 0)
880 					continue;
881 				done = (nfrags == 0 && left == 0);
882 				ionic_tx_tso_post(q, desc, skb, desc_addr,
883 						  desc_nsge, desc_len,
884 						  hdrlen, mss, outer_csum,
885 						  vlan_tci, has_vlan,
886 						  start, done);
887 				total_pkts++;
888 				total_bytes += start ? len : len + hdrlen;
889 				desc = ionic_tx_tso_next(q, &elem);
890 				start = false;
891 			} else {
892 				len = min(mss, left);
893 				frag_left = mss - len;
894 				desc_addr = ionic_tx_map_frag(q, frag,
895 							      offset, len);
896 				if (dma_mapping_error(dev, desc_addr))
897 					goto err_out_abort;
898 				desc_len = len;
899 				desc_nsge = 0;
900 				left -= len;
901 				offset += len;
902 				if (nfrags > 0 && frag_left > 0)
903 					continue;
904 				done = (nfrags == 0 && left == 0);
905 				ionic_tx_tso_post(q, desc, skb, desc_addr,
906 						  desc_nsge, desc_len,
907 						  hdrlen, mss, outer_csum,
908 						  vlan_tci, has_vlan,
909 						  start, done);
910 				total_pkts++;
911 				total_bytes += start ? len : len + hdrlen;
912 				desc = ionic_tx_tso_next(q, &elem);
913 				start = false;
914 			}
915 		}
916 	}
917 
918 	stats->pkts += total_pkts;
919 	stats->bytes += total_bytes;
920 	stats->tso++;
921 	stats->tso_bytes += total_bytes;
922 
923 	return 0;
924 
925 err_out_abort:
926 	while (rewind != q->head_idx) {
927 		rewind_desc_info = &q->info[rewind];
928 		ionic_tx_clean(q, rewind_desc_info, NULL, NULL);
929 		rewind = (rewind + 1) & (q->num_descs - 1);
930 	}
931 	q->head_idx = abort;
932 
933 	return -ENOMEM;
934 }
935 
936 static int ionic_tx_calc_csum(struct ionic_queue *q, struct sk_buff *skb)
937 {
938 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
939 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
940 	struct device *dev = q->lif->ionic->dev;
941 	dma_addr_t dma_addr;
942 	bool has_vlan;
943 	u8 flags = 0;
944 	bool encap;
945 	u64 cmd;
946 
947 	has_vlan = !!skb_vlan_tag_present(skb);
948 	encap = skb->encapsulation;
949 
950 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
951 	if (dma_mapping_error(dev, dma_addr))
952 		return -ENOMEM;
953 
954 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
955 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
956 
957 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_PARTIAL,
958 				  flags, skb_shinfo(skb)->nr_frags, dma_addr);
959 	desc->cmd = cpu_to_le64(cmd);
960 	desc->len = cpu_to_le16(skb_headlen(skb));
961 	desc->csum_start = cpu_to_le16(skb_checksum_start_offset(skb));
962 	desc->csum_offset = cpu_to_le16(skb->csum_offset);
963 	if (has_vlan) {
964 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
965 		stats->vlan_inserted++;
966 	}
967 
968 	if (skb->csum_not_inet)
969 		stats->crc32_csum++;
970 	else
971 		stats->csum++;
972 
973 	return 0;
974 }
975 
976 static int ionic_tx_calc_no_csum(struct ionic_queue *q, struct sk_buff *skb)
977 {
978 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
979 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
980 	struct device *dev = q->lif->ionic->dev;
981 	dma_addr_t dma_addr;
982 	bool has_vlan;
983 	u8 flags = 0;
984 	bool encap;
985 	u64 cmd;
986 
987 	has_vlan = !!skb_vlan_tag_present(skb);
988 	encap = skb->encapsulation;
989 
990 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
991 	if (dma_mapping_error(dev, dma_addr))
992 		return -ENOMEM;
993 
994 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
995 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
996 
997 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_NONE,
998 				  flags, skb_shinfo(skb)->nr_frags, dma_addr);
999 	desc->cmd = cpu_to_le64(cmd);
1000 	desc->len = cpu_to_le16(skb_headlen(skb));
1001 	if (has_vlan) {
1002 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1003 		stats->vlan_inserted++;
1004 	}
1005 
1006 	stats->csum_none++;
1007 
1008 	return 0;
1009 }
1010 
1011 static int ionic_tx_skb_frags(struct ionic_queue *q, struct sk_buff *skb)
1012 {
1013 	struct ionic_txq_sg_desc *sg_desc = q->info[q->head_idx].txq_sg_desc;
1014 	unsigned int len_left = skb->len - skb_headlen(skb);
1015 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
1016 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1017 	struct device *dev = q->lif->ionic->dev;
1018 	dma_addr_t dma_addr;
1019 	skb_frag_t *frag;
1020 	u16 len;
1021 
1022 	for (frag = skb_shinfo(skb)->frags; len_left; frag++, elem++) {
1023 		len = skb_frag_size(frag);
1024 		elem->len = cpu_to_le16(len);
1025 		dma_addr = ionic_tx_map_frag(q, frag, 0, len);
1026 		if (dma_mapping_error(dev, dma_addr))
1027 			return -ENOMEM;
1028 		elem->addr = cpu_to_le64(dma_addr);
1029 		len_left -= len;
1030 		stats->frags++;
1031 	}
1032 
1033 	return 0;
1034 }
1035 
1036 static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
1037 {
1038 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1039 	int err;
1040 
1041 	/* set up the initial descriptor */
1042 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1043 		err = ionic_tx_calc_csum(q, skb);
1044 	else
1045 		err = ionic_tx_calc_no_csum(q, skb);
1046 	if (err)
1047 		return err;
1048 
1049 	/* add frags */
1050 	err = ionic_tx_skb_frags(q, skb);
1051 	if (err)
1052 		return err;
1053 
1054 	skb_tx_timestamp(skb);
1055 	stats->pkts++;
1056 	stats->bytes += skb->len;
1057 
1058 	netdev_tx_sent_queue(q_to_ndq(q), skb->len);
1059 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
1060 
1061 	return 0;
1062 }
1063 
1064 static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
1065 {
1066 	int sg_elems = q->lif->qtype_info[IONIC_QTYPE_TXQ].max_sg_elems;
1067 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1068 	int err;
1069 
1070 	/* If TSO, need roundup(skb->len/mss) descs */
1071 	if (skb_is_gso(skb))
1072 		return (skb->len / skb_shinfo(skb)->gso_size) + 1;
1073 
1074 	/* If non-TSO, just need 1 desc and nr_frags sg elems */
1075 	if (skb_shinfo(skb)->nr_frags <= sg_elems)
1076 		return 1;
1077 
1078 	/* Too many frags, so linearize */
1079 	err = skb_linearize(skb);
1080 	if (err)
1081 		return err;
1082 
1083 	stats->linearize++;
1084 
1085 	/* Need 1 desc and zero sg elems */
1086 	return 1;
1087 }
1088 
1089 static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
1090 {
1091 	int stopped = 0;
1092 
1093 	if (unlikely(!ionic_q_has_space(q, ndescs))) {
1094 		netif_stop_subqueue(q->lif->netdev, q->index);
1095 		q->stop++;
1096 		stopped = 1;
1097 
1098 		/* Might race with ionic_tx_clean, check again */
1099 		smp_rmb();
1100 		if (ionic_q_has_space(q, ndescs)) {
1101 			netif_wake_subqueue(q->lif->netdev, q->index);
1102 			stopped = 0;
1103 		}
1104 	}
1105 
1106 	return stopped;
1107 }
1108 
1109 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1110 {
1111 	u16 queue_index = skb_get_queue_mapping(skb);
1112 	struct ionic_lif *lif = netdev_priv(netdev);
1113 	struct ionic_queue *q;
1114 	int ndescs;
1115 	int err;
1116 
1117 	if (unlikely(!test_bit(IONIC_LIF_F_UP, lif->state))) {
1118 		dev_kfree_skb(skb);
1119 		return NETDEV_TX_OK;
1120 	}
1121 
1122 	if (unlikely(queue_index >= lif->nxqs))
1123 		queue_index = 0;
1124 	q = &lif->txqcqs[queue_index]->q;
1125 
1126 	ndescs = ionic_tx_descs_needed(q, skb);
1127 	if (ndescs < 0)
1128 		goto err_out_drop;
1129 
1130 	if (unlikely(ionic_maybe_stop_tx(q, ndescs)))
1131 		return NETDEV_TX_BUSY;
1132 
1133 	if (skb_is_gso(skb))
1134 		err = ionic_tx_tso(q, skb);
1135 	else
1136 		err = ionic_tx(q, skb);
1137 
1138 	if (err)
1139 		goto err_out_drop;
1140 
1141 	/* Stop the queue if there aren't descriptors for the next packet.
1142 	 * Since our SG lists per descriptor take care of most of the possible
1143 	 * fragmentation, we don't need to have many descriptors available.
1144 	 */
1145 	ionic_maybe_stop_tx(q, 4);
1146 
1147 	return NETDEV_TX_OK;
1148 
1149 err_out_drop:
1150 	q->stop++;
1151 	q->drop++;
1152 	dev_kfree_skb(skb);
1153 	return NETDEV_TX_OK;
1154 }
1155