xref: /linux/drivers/net/ethernet/pensando/ionic/ionic_txrx.c (revision e3b9626f09d429788d929c9b9000a069fcfc056e)
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 	desc_info = &q->info[q->tail_idx];
242 	if (desc_info->index != le16_to_cpu(comp->comp_index))
243 		return false;
244 
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 struct page *ionic_rx_page_alloc(struct ionic_queue *q,
270 					dma_addr_t *dma_addr)
271 {
272 	struct ionic_lif *lif = q->lif;
273 	struct ionic_rx_stats *stats;
274 	struct net_device *netdev;
275 	struct device *dev;
276 	struct page *page;
277 
278 	netdev = lif->netdev;
279 	dev = lif->ionic->dev;
280 	stats = q_to_rx_stats(q);
281 	page = alloc_page(GFP_ATOMIC);
282 	if (unlikely(!page)) {
283 		net_err_ratelimited("%s: Page alloc failed on %s!\n",
284 				    netdev->name, q->name);
285 		stats->alloc_err++;
286 		return NULL;
287 	}
288 
289 	*dma_addr = dma_map_page(dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE);
290 	if (unlikely(dma_mapping_error(dev, *dma_addr))) {
291 		__free_page(page);
292 		net_err_ratelimited("%s: DMA single map failed on %s!\n",
293 				    netdev->name, q->name);
294 		stats->dma_map_err++;
295 		return NULL;
296 	}
297 
298 	return page;
299 }
300 
301 static void ionic_rx_page_free(struct ionic_queue *q, struct page *page,
302 			       dma_addr_t dma_addr)
303 {
304 	struct ionic_lif *lif = q->lif;
305 	struct net_device *netdev;
306 	struct device *dev;
307 
308 	netdev = lif->netdev;
309 	dev = lif->ionic->dev;
310 
311 	if (unlikely(!page)) {
312 		net_err_ratelimited("%s: Trying to free unallocated buffer on %s!\n",
313 				    netdev->name, q->name);
314 		return;
315 	}
316 
317 	dma_unmap_page(dev, dma_addr, PAGE_SIZE, DMA_FROM_DEVICE);
318 
319 	__free_page(page);
320 }
321 
322 void ionic_rx_fill(struct ionic_queue *q)
323 {
324 	struct net_device *netdev = q->lif->netdev;
325 	struct ionic_desc_info *desc_info;
326 	struct ionic_page_info *page_info;
327 	struct ionic_rxq_sg_desc *sg_desc;
328 	struct ionic_rxq_sg_elem *sg_elem;
329 	struct ionic_rxq_desc *desc;
330 	unsigned int remain_len;
331 	unsigned int seg_len;
332 	unsigned int nfrags;
333 	unsigned int i, j;
334 	unsigned int len;
335 
336 	len = netdev->mtu + ETH_HLEN;
337 	nfrags = round_up(len, PAGE_SIZE) / PAGE_SIZE;
338 
339 	for (i = ionic_q_space_avail(q); i; i--) {
340 		remain_len = len;
341 		desc_info = &q->info[q->head_idx];
342 		desc = desc_info->desc;
343 		sg_desc = desc_info->sg_desc;
344 		page_info = &desc_info->pages[0];
345 
346 		if (page_info->page) { /* recycle the buffer */
347 			ionic_rxq_post(q, false, ionic_rx_clean, NULL);
348 			continue;
349 		}
350 
351 		/* fill main descriptor - pages[0] */
352 		desc->opcode = (nfrags > 1) ? IONIC_RXQ_DESC_OPCODE_SG :
353 					      IONIC_RXQ_DESC_OPCODE_SIMPLE;
354 		desc_info->npages = nfrags;
355 		page_info->page = ionic_rx_page_alloc(q, &page_info->dma_addr);
356 		if (unlikely(!page_info->page)) {
357 			desc->addr = 0;
358 			desc->len = 0;
359 			return;
360 		}
361 		desc->addr = cpu_to_le64(page_info->dma_addr);
362 		seg_len = min_t(unsigned int, PAGE_SIZE, len);
363 		desc->len = cpu_to_le16(seg_len);
364 		remain_len -= seg_len;
365 		page_info++;
366 
367 		/* fill sg descriptors - pages[1..n] */
368 		for (j = 0; j < nfrags - 1; j++) {
369 			if (page_info->page) /* recycle the sg buffer */
370 				continue;
371 
372 			sg_elem = &sg_desc->elems[j];
373 			page_info->page = ionic_rx_page_alloc(q, &page_info->dma_addr);
374 			if (unlikely(!page_info->page)) {
375 				sg_elem->addr = 0;
376 				sg_elem->len = 0;
377 				return;
378 			}
379 			sg_elem->addr = cpu_to_le64(page_info->dma_addr);
380 			seg_len = min_t(unsigned int, PAGE_SIZE, remain_len);
381 			sg_elem->len = cpu_to_le16(seg_len);
382 			remain_len -= seg_len;
383 			page_info++;
384 		}
385 
386 		ionic_rxq_post(q, false, ionic_rx_clean, NULL);
387 	}
388 
389 	ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
390 			 q->dbval | q->head_idx);
391 }
392 
393 static void ionic_rx_fill_cb(void *arg)
394 {
395 	ionic_rx_fill(arg);
396 }
397 
398 void ionic_rx_empty(struct ionic_queue *q)
399 {
400 	struct ionic_desc_info *desc_info;
401 	struct ionic_rxq_desc *desc;
402 	unsigned int i;
403 	u16 idx;
404 
405 	idx = q->tail_idx;
406 	while (idx != q->head_idx) {
407 		desc_info = &q->info[idx];
408 		desc = desc_info->desc;
409 		desc->addr = 0;
410 		desc->len = 0;
411 
412 		for (i = 0; i < desc_info->npages; i++) {
413 			if (likely(desc_info->pages[i].page)) {
414 				ionic_rx_page_free(q, desc_info->pages[i].page,
415 						   desc_info->pages[i].dma_addr);
416 				desc_info->pages[i].page = NULL;
417 				desc_info->pages[i].dma_addr = 0;
418 			}
419 		}
420 
421 		desc_info->cb_arg = NULL;
422 		idx = (idx + 1) & (q->num_descs - 1);
423 	}
424 }
425 
426 int ionic_tx_napi(struct napi_struct *napi, int budget)
427 {
428 	struct ionic_qcq *qcq = napi_to_qcq(napi);
429 	struct ionic_cq *cq = napi_to_cq(napi);
430 	struct ionic_dev *idev;
431 	struct ionic_lif *lif;
432 	u32 work_done = 0;
433 	u32 flags = 0;
434 
435 	lif = cq->bound_q->lif;
436 	idev = &lif->ionic->idev;
437 
438 	work_done = ionic_cq_service(cq, budget,
439 				     ionic_tx_service, NULL, NULL);
440 
441 	if (work_done < budget && napi_complete_done(napi, work_done)) {
442 		flags |= IONIC_INTR_CRED_UNMASK;
443 		DEBUG_STATS_INTR_REARM(cq->bound_intr);
444 	}
445 
446 	if (work_done || flags) {
447 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
448 		ionic_intr_credits(idev->intr_ctrl,
449 				   cq->bound_intr->index,
450 				   work_done, flags);
451 	}
452 
453 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
454 
455 	return work_done;
456 }
457 
458 int ionic_rx_napi(struct napi_struct *napi, int budget)
459 {
460 	struct ionic_qcq *qcq = napi_to_qcq(napi);
461 	struct ionic_cq *cq = napi_to_cq(napi);
462 	struct ionic_dev *idev;
463 	struct ionic_lif *lif;
464 	u32 work_done = 0;
465 	u32 flags = 0;
466 
467 	lif = cq->bound_q->lif;
468 	idev = &lif->ionic->idev;
469 
470 	work_done = ionic_cq_service(cq, budget,
471 				     ionic_rx_service, NULL, NULL);
472 
473 	if (work_done)
474 		ionic_rx_fill(cq->bound_q);
475 
476 	if (work_done < budget && napi_complete_done(napi, work_done)) {
477 		flags |= IONIC_INTR_CRED_UNMASK;
478 		DEBUG_STATS_INTR_REARM(cq->bound_intr);
479 	}
480 
481 	if (work_done || flags) {
482 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
483 		ionic_intr_credits(idev->intr_ctrl,
484 				   cq->bound_intr->index,
485 				   work_done, flags);
486 	}
487 
488 	DEBUG_STATS_NAPI_POLL(qcq, work_done);
489 
490 	return work_done;
491 }
492 
493 int ionic_txrx_napi(struct napi_struct *napi, int budget)
494 {
495 	struct ionic_qcq *qcq = napi_to_qcq(napi);
496 	struct ionic_cq *rxcq = napi_to_cq(napi);
497 	unsigned int qi = rxcq->bound_q->index;
498 	struct ionic_dev *idev;
499 	struct ionic_lif *lif;
500 	struct ionic_cq *txcq;
501 	u32 rx_work_done = 0;
502 	u32 tx_work_done = 0;
503 	u32 work_done = 0;
504 	u32 flags = 0;
505 	bool unmask;
506 
507 	lif = rxcq->bound_q->lif;
508 	idev = &lif->ionic->idev;
509 	txcq = &lif->txqcqs[qi]->cq;
510 
511 	tx_work_done = ionic_cq_service(txcq, lif->tx_budget,
512 					ionic_tx_service, NULL, NULL);
513 
514 	rx_work_done = ionic_cq_service(rxcq, budget,
515 					ionic_rx_service, NULL, NULL);
516 	if (rx_work_done)
517 		ionic_rx_fill_cb(rxcq->bound_q);
518 
519 	unmask = (rx_work_done < budget) && (tx_work_done < lif->tx_budget);
520 
521 	if (unmask && napi_complete_done(napi, rx_work_done)) {
522 		flags |= IONIC_INTR_CRED_UNMASK;
523 		DEBUG_STATS_INTR_REARM(rxcq->bound_intr);
524 		work_done = rx_work_done;
525 	} else {
526 		work_done = budget;
527 	}
528 
529 	if (work_done || flags) {
530 		flags |= IONIC_INTR_CRED_RESET_COALESCE;
531 		ionic_intr_credits(idev->intr_ctrl, rxcq->bound_intr->index,
532 				   tx_work_done + rx_work_done, flags);
533 	}
534 
535 	DEBUG_STATS_NAPI_POLL(qcq, rx_work_done);
536 	DEBUG_STATS_NAPI_POLL(qcq, tx_work_done);
537 
538 	return work_done;
539 }
540 
541 static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
542 				      void *data, size_t len)
543 {
544 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
545 	struct device *dev = q->lif->ionic->dev;
546 	dma_addr_t dma_addr;
547 
548 	dma_addr = dma_map_single(dev, data, len, DMA_TO_DEVICE);
549 	if (dma_mapping_error(dev, dma_addr)) {
550 		net_warn_ratelimited("%s: DMA single map failed on %s!\n",
551 				     q->lif->netdev->name, q->name);
552 		stats->dma_map_err++;
553 		return 0;
554 	}
555 	return dma_addr;
556 }
557 
558 static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
559 				    const skb_frag_t *frag,
560 				    size_t offset, size_t len)
561 {
562 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
563 	struct device *dev = q->lif->ionic->dev;
564 	dma_addr_t dma_addr;
565 
566 	dma_addr = skb_frag_dma_map(dev, frag, offset, len, DMA_TO_DEVICE);
567 	if (dma_mapping_error(dev, dma_addr)) {
568 		net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
569 				     q->lif->netdev->name, q->name);
570 		stats->dma_map_err++;
571 	}
572 	return dma_addr;
573 }
574 
575 static void ionic_tx_clean(struct ionic_queue *q,
576 			   struct ionic_desc_info *desc_info,
577 			   struct ionic_cq_info *cq_info,
578 			   void *cb_arg)
579 {
580 	struct ionic_txq_sg_desc *sg_desc = desc_info->sg_desc;
581 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
582 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
583 	struct ionic_txq_desc *desc = desc_info->desc;
584 	struct device *dev = q->lif->ionic->dev;
585 	u8 opcode, flags, nsge;
586 	u16 queue_index;
587 	unsigned int i;
588 	u64 addr;
589 
590 	decode_txq_desc_cmd(le64_to_cpu(desc->cmd),
591 			    &opcode, &flags, &nsge, &addr);
592 
593 	/* use unmap_single only if either this is not TSO,
594 	 * or this is first descriptor of a TSO
595 	 */
596 	if (opcode != IONIC_TXQ_DESC_OPCODE_TSO ||
597 	    flags & IONIC_TXQ_DESC_FLAG_TSO_SOT)
598 		dma_unmap_single(dev, (dma_addr_t)addr,
599 				 le16_to_cpu(desc->len), DMA_TO_DEVICE);
600 	else
601 		dma_unmap_page(dev, (dma_addr_t)addr,
602 			       le16_to_cpu(desc->len), DMA_TO_DEVICE);
603 
604 	for (i = 0; i < nsge; i++, elem++)
605 		dma_unmap_page(dev, (dma_addr_t)le64_to_cpu(elem->addr),
606 			       le16_to_cpu(elem->len), DMA_TO_DEVICE);
607 
608 	if (cb_arg) {
609 		struct sk_buff *skb = cb_arg;
610 		u32 len = skb->len;
611 
612 		queue_index = skb_get_queue_mapping(skb);
613 		if (unlikely(__netif_subqueue_stopped(q->lif->netdev,
614 						      queue_index))) {
615 			netif_wake_subqueue(q->lif->netdev, queue_index);
616 			q->wake++;
617 		}
618 		dev_kfree_skb_any(skb);
619 		stats->clean++;
620 		netdev_tx_completed_queue(q_to_ndq(q), 1, len);
621 	}
622 }
623 
624 static bool ionic_tx_service(struct ionic_cq *cq, struct ionic_cq_info *cq_info)
625 {
626 	struct ionic_txq_comp *comp = cq_info->cq_desc;
627 	struct ionic_queue *q = cq->bound_q;
628 	struct ionic_desc_info *desc_info;
629 
630 	if (!color_match(comp->color, cq->done_color))
631 		return false;
632 
633 	/* clean the related q entries, there could be
634 	 * several q entries completed for each cq completion
635 	 */
636 	do {
637 		desc_info = &q->info[q->tail_idx];
638 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
639 		ionic_tx_clean(q, desc_info, cq_info, desc_info->cb_arg);
640 		desc_info->cb = NULL;
641 		desc_info->cb_arg = NULL;
642 	} while (desc_info->index != le16_to_cpu(comp->comp_index));
643 
644 	return true;
645 }
646 
647 void ionic_tx_flush(struct ionic_cq *cq)
648 {
649 	struct ionic_dev *idev = &cq->lif->ionic->idev;
650 	u32 work_done;
651 
652 	work_done = ionic_cq_service(cq, cq->num_descs,
653 				     ionic_tx_service, NULL, NULL);
654 	if (work_done)
655 		ionic_intr_credits(idev->intr_ctrl, cq->bound_intr->index,
656 				   work_done, IONIC_INTR_CRED_RESET_COALESCE);
657 }
658 
659 void ionic_tx_empty(struct ionic_queue *q)
660 {
661 	struct ionic_desc_info *desc_info;
662 	int done = 0;
663 
664 	/* walk the not completed tx entries, if any */
665 	while (q->head_idx != q->tail_idx) {
666 		desc_info = &q->info[q->tail_idx];
667 		q->tail_idx = (q->tail_idx + 1) & (q->num_descs - 1);
668 		ionic_tx_clean(q, desc_info, NULL, desc_info->cb_arg);
669 		desc_info->cb = NULL;
670 		desc_info->cb_arg = NULL;
671 		done++;
672 	}
673 }
674 
675 static int ionic_tx_tcp_inner_pseudo_csum(struct sk_buff *skb)
676 {
677 	int err;
678 
679 	err = skb_cow_head(skb, 0);
680 	if (err)
681 		return err;
682 
683 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
684 		inner_ip_hdr(skb)->check = 0;
685 		inner_tcp_hdr(skb)->check =
686 			~csum_tcpudp_magic(inner_ip_hdr(skb)->saddr,
687 					   inner_ip_hdr(skb)->daddr,
688 					   0, IPPROTO_TCP, 0);
689 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
690 		inner_tcp_hdr(skb)->check =
691 			~csum_ipv6_magic(&inner_ipv6_hdr(skb)->saddr,
692 					 &inner_ipv6_hdr(skb)->daddr,
693 					 0, IPPROTO_TCP, 0);
694 	}
695 
696 	return 0;
697 }
698 
699 static int ionic_tx_tcp_pseudo_csum(struct sk_buff *skb)
700 {
701 	int err;
702 
703 	err = skb_cow_head(skb, 0);
704 	if (err)
705 		return err;
706 
707 	if (skb->protocol == cpu_to_be16(ETH_P_IP)) {
708 		ip_hdr(skb)->check = 0;
709 		tcp_hdr(skb)->check =
710 			~csum_tcpudp_magic(ip_hdr(skb)->saddr,
711 					   ip_hdr(skb)->daddr,
712 					   0, IPPROTO_TCP, 0);
713 	} else if (skb->protocol == cpu_to_be16(ETH_P_IPV6)) {
714 		tcp_v6_gso_csum_prep(skb);
715 	}
716 
717 	return 0;
718 }
719 
720 static void ionic_tx_tso_post(struct ionic_queue *q, struct ionic_txq_desc *desc,
721 			      struct sk_buff *skb,
722 			      dma_addr_t addr, u8 nsge, u16 len,
723 			      unsigned int hdrlen, unsigned int mss,
724 			      bool outer_csum,
725 			      u16 vlan_tci, bool has_vlan,
726 			      bool start, bool done)
727 {
728 	u8 flags = 0;
729 	u64 cmd;
730 
731 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
732 	flags |= outer_csum ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
733 	flags |= start ? IONIC_TXQ_DESC_FLAG_TSO_SOT : 0;
734 	flags |= done ? IONIC_TXQ_DESC_FLAG_TSO_EOT : 0;
735 
736 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_TSO, flags, nsge, addr);
737 	desc->cmd = cpu_to_le64(cmd);
738 	desc->len = cpu_to_le16(len);
739 	desc->vlan_tci = cpu_to_le16(vlan_tci);
740 	desc->hdr_len = cpu_to_le16(hdrlen);
741 	desc->mss = cpu_to_le16(mss);
742 
743 	if (done) {
744 		skb_tx_timestamp(skb);
745 		netdev_tx_sent_queue(q_to_ndq(q), skb->len);
746 		ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
747 	} else {
748 		ionic_txq_post(q, false, ionic_tx_clean, NULL);
749 	}
750 }
751 
752 static struct ionic_txq_desc *ionic_tx_tso_next(struct ionic_queue *q,
753 						struct ionic_txq_sg_elem **elem)
754 {
755 	struct ionic_txq_sg_desc *sg_desc = q->info[q->head_idx].txq_sg_desc;
756 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
757 
758 	*elem = sg_desc->elems;
759 	return desc;
760 }
761 
762 static int ionic_tx_tso(struct ionic_queue *q, struct sk_buff *skb)
763 {
764 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
765 	struct ionic_desc_info *rewind_desc_info;
766 	struct device *dev = q->lif->ionic->dev;
767 	struct ionic_txq_sg_elem *elem;
768 	struct ionic_txq_desc *desc;
769 	unsigned int frag_left = 0;
770 	unsigned int offset = 0;
771 	u16 abort = q->head_idx;
772 	unsigned int len_left;
773 	dma_addr_t desc_addr;
774 	unsigned int hdrlen;
775 	unsigned int nfrags;
776 	unsigned int seglen;
777 	u64 total_bytes = 0;
778 	u64 total_pkts = 0;
779 	u16 rewind = abort;
780 	unsigned int left;
781 	unsigned int len;
782 	unsigned int mss;
783 	skb_frag_t *frag;
784 	bool start, done;
785 	bool outer_csum;
786 	bool has_vlan;
787 	u16 desc_len;
788 	u8 desc_nsge;
789 	u16 vlan_tci;
790 	bool encap;
791 	int err;
792 
793 	mss = skb_shinfo(skb)->gso_size;
794 	nfrags = skb_shinfo(skb)->nr_frags;
795 	len_left = skb->len - skb_headlen(skb);
796 	outer_csum = (skb_shinfo(skb)->gso_type & SKB_GSO_GRE_CSUM) ||
797 		     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
798 	has_vlan = !!skb_vlan_tag_present(skb);
799 	vlan_tci = skb_vlan_tag_get(skb);
800 	encap = skb->encapsulation;
801 
802 	/* Preload inner-most TCP csum field with IP pseudo hdr
803 	 * calculated with IP length set to zero.  HW will later
804 	 * add in length to each TCP segment resulting from the TSO.
805 	 */
806 
807 	if (encap)
808 		err = ionic_tx_tcp_inner_pseudo_csum(skb);
809 	else
810 		err = ionic_tx_tcp_pseudo_csum(skb);
811 	if (err)
812 		return err;
813 
814 	if (encap)
815 		hdrlen = skb_inner_transport_header(skb) - skb->data +
816 			 inner_tcp_hdrlen(skb);
817 	else
818 		hdrlen = skb_transport_offset(skb) + tcp_hdrlen(skb);
819 
820 	seglen = hdrlen + mss;
821 	left = skb_headlen(skb);
822 
823 	desc = ionic_tx_tso_next(q, &elem);
824 	start = true;
825 
826 	/* Chop skb->data up into desc segments */
827 
828 	while (left > 0) {
829 		len = min(seglen, left);
830 		frag_left = seglen - len;
831 		desc_addr = ionic_tx_map_single(q, skb->data + offset, len);
832 		if (dma_mapping_error(dev, desc_addr))
833 			goto err_out_abort;
834 		desc_len = len;
835 		desc_nsge = 0;
836 		left -= len;
837 		offset += len;
838 		if (nfrags > 0 && frag_left > 0)
839 			continue;
840 		done = (nfrags == 0 && left == 0);
841 		ionic_tx_tso_post(q, desc, skb,
842 				  desc_addr, desc_nsge, desc_len,
843 				  hdrlen, mss,
844 				  outer_csum,
845 				  vlan_tci, has_vlan,
846 				  start, done);
847 		total_pkts++;
848 		total_bytes += start ? len : len + hdrlen;
849 		desc = ionic_tx_tso_next(q, &elem);
850 		start = false;
851 		seglen = mss;
852 	}
853 
854 	/* Chop skb frags into desc segments */
855 
856 	for (frag = skb_shinfo(skb)->frags; len_left; frag++) {
857 		offset = 0;
858 		left = skb_frag_size(frag);
859 		len_left -= left;
860 		nfrags--;
861 		stats->frags++;
862 
863 		while (left > 0) {
864 			if (frag_left > 0) {
865 				len = min(frag_left, left);
866 				frag_left -= len;
867 				elem->addr =
868 				    cpu_to_le64(ionic_tx_map_frag(q, frag,
869 								  offset, len));
870 				if (dma_mapping_error(dev, elem->addr))
871 					goto err_out_abort;
872 				elem->len = cpu_to_le16(len);
873 				elem++;
874 				desc_nsge++;
875 				left -= len;
876 				offset += len;
877 				if (nfrags > 0 && frag_left > 0)
878 					continue;
879 				done = (nfrags == 0 && left == 0);
880 				ionic_tx_tso_post(q, desc, skb, desc_addr,
881 						  desc_nsge, desc_len,
882 						  hdrlen, mss, outer_csum,
883 						  vlan_tci, has_vlan,
884 						  start, done);
885 				total_pkts++;
886 				total_bytes += start ? len : len + hdrlen;
887 				desc = ionic_tx_tso_next(q, &elem);
888 				start = false;
889 			} else {
890 				len = min(mss, left);
891 				frag_left = mss - len;
892 				desc_addr = ionic_tx_map_frag(q, frag,
893 							      offset, len);
894 				if (dma_mapping_error(dev, desc_addr))
895 					goto err_out_abort;
896 				desc_len = len;
897 				desc_nsge = 0;
898 				left -= len;
899 				offset += len;
900 				if (nfrags > 0 && frag_left > 0)
901 					continue;
902 				done = (nfrags == 0 && left == 0);
903 				ionic_tx_tso_post(q, desc, skb, desc_addr,
904 						  desc_nsge, desc_len,
905 						  hdrlen, mss, outer_csum,
906 						  vlan_tci, has_vlan,
907 						  start, done);
908 				total_pkts++;
909 				total_bytes += start ? len : len + hdrlen;
910 				desc = ionic_tx_tso_next(q, &elem);
911 				start = false;
912 			}
913 		}
914 	}
915 
916 	stats->pkts += total_pkts;
917 	stats->bytes += total_bytes;
918 	stats->tso++;
919 	stats->tso_bytes += total_bytes;
920 
921 	return 0;
922 
923 err_out_abort:
924 	while (rewind != q->head_idx) {
925 		rewind_desc_info = &q->info[rewind];
926 		ionic_tx_clean(q, rewind_desc_info, NULL, NULL);
927 		rewind = (rewind + 1) & (q->num_descs - 1);
928 	}
929 	q->head_idx = abort;
930 
931 	return -ENOMEM;
932 }
933 
934 static int ionic_tx_calc_csum(struct ionic_queue *q, struct sk_buff *skb)
935 {
936 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
937 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
938 	struct device *dev = q->lif->ionic->dev;
939 	dma_addr_t dma_addr;
940 	bool has_vlan;
941 	u8 flags = 0;
942 	bool encap;
943 	u64 cmd;
944 
945 	has_vlan = !!skb_vlan_tag_present(skb);
946 	encap = skb->encapsulation;
947 
948 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
949 	if (dma_mapping_error(dev, dma_addr))
950 		return -ENOMEM;
951 
952 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
953 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
954 
955 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_PARTIAL,
956 				  flags, skb_shinfo(skb)->nr_frags, dma_addr);
957 	desc->cmd = cpu_to_le64(cmd);
958 	desc->len = cpu_to_le16(skb_headlen(skb));
959 	desc->csum_start = cpu_to_le16(skb_checksum_start_offset(skb));
960 	desc->csum_offset = cpu_to_le16(skb->csum_offset);
961 	if (has_vlan) {
962 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
963 		stats->vlan_inserted++;
964 	}
965 
966 	if (skb->csum_not_inet)
967 		stats->crc32_csum++;
968 	else
969 		stats->csum++;
970 
971 	return 0;
972 }
973 
974 static int ionic_tx_calc_no_csum(struct ionic_queue *q, struct sk_buff *skb)
975 {
976 	struct ionic_txq_desc *desc = q->info[q->head_idx].txq_desc;
977 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
978 	struct device *dev = q->lif->ionic->dev;
979 	dma_addr_t dma_addr;
980 	bool has_vlan;
981 	u8 flags = 0;
982 	bool encap;
983 	u64 cmd;
984 
985 	has_vlan = !!skb_vlan_tag_present(skb);
986 	encap = skb->encapsulation;
987 
988 	dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
989 	if (dma_mapping_error(dev, dma_addr))
990 		return -ENOMEM;
991 
992 	flags |= has_vlan ? IONIC_TXQ_DESC_FLAG_VLAN : 0;
993 	flags |= encap ? IONIC_TXQ_DESC_FLAG_ENCAP : 0;
994 
995 	cmd = encode_txq_desc_cmd(IONIC_TXQ_DESC_OPCODE_CSUM_NONE,
996 				  flags, skb_shinfo(skb)->nr_frags, dma_addr);
997 	desc->cmd = cpu_to_le64(cmd);
998 	desc->len = cpu_to_le16(skb_headlen(skb));
999 	if (has_vlan) {
1000 		desc->vlan_tci = cpu_to_le16(skb_vlan_tag_get(skb));
1001 		stats->vlan_inserted++;
1002 	}
1003 
1004 	stats->csum_none++;
1005 
1006 	return 0;
1007 }
1008 
1009 static int ionic_tx_skb_frags(struct ionic_queue *q, struct sk_buff *skb)
1010 {
1011 	struct ionic_txq_sg_desc *sg_desc = q->info[q->head_idx].txq_sg_desc;
1012 	unsigned int len_left = skb->len - skb_headlen(skb);
1013 	struct ionic_txq_sg_elem *elem = sg_desc->elems;
1014 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1015 	struct device *dev = q->lif->ionic->dev;
1016 	dma_addr_t dma_addr;
1017 	skb_frag_t *frag;
1018 	u16 len;
1019 
1020 	for (frag = skb_shinfo(skb)->frags; len_left; frag++, elem++) {
1021 		len = skb_frag_size(frag);
1022 		elem->len = cpu_to_le16(len);
1023 		dma_addr = ionic_tx_map_frag(q, frag, 0, len);
1024 		if (dma_mapping_error(dev, dma_addr))
1025 			return -ENOMEM;
1026 		elem->addr = cpu_to_le64(dma_addr);
1027 		len_left -= len;
1028 		stats->frags++;
1029 	}
1030 
1031 	return 0;
1032 }
1033 
1034 static int ionic_tx(struct ionic_queue *q, struct sk_buff *skb)
1035 {
1036 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1037 	int err;
1038 
1039 	/* set up the initial descriptor */
1040 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1041 		err = ionic_tx_calc_csum(q, skb);
1042 	else
1043 		err = ionic_tx_calc_no_csum(q, skb);
1044 	if (err)
1045 		return err;
1046 
1047 	/* add frags */
1048 	err = ionic_tx_skb_frags(q, skb);
1049 	if (err)
1050 		return err;
1051 
1052 	skb_tx_timestamp(skb);
1053 	stats->pkts++;
1054 	stats->bytes += skb->len;
1055 
1056 	netdev_tx_sent_queue(q_to_ndq(q), skb->len);
1057 	ionic_txq_post(q, !netdev_xmit_more(), ionic_tx_clean, skb);
1058 
1059 	return 0;
1060 }
1061 
1062 static int ionic_tx_descs_needed(struct ionic_queue *q, struct sk_buff *skb)
1063 {
1064 	int sg_elems = q->lif->qtype_info[IONIC_QTYPE_TXQ].max_sg_elems;
1065 	struct ionic_tx_stats *stats = q_to_tx_stats(q);
1066 	int err;
1067 
1068 	/* If TSO, need roundup(skb->len/mss) descs */
1069 	if (skb_is_gso(skb))
1070 		return (skb->len / skb_shinfo(skb)->gso_size) + 1;
1071 
1072 	/* If non-TSO, just need 1 desc and nr_frags sg elems */
1073 	if (skb_shinfo(skb)->nr_frags <= sg_elems)
1074 		return 1;
1075 
1076 	/* Too many frags, so linearize */
1077 	err = skb_linearize(skb);
1078 	if (err)
1079 		return err;
1080 
1081 	stats->linearize++;
1082 
1083 	/* Need 1 desc and zero sg elems */
1084 	return 1;
1085 }
1086 
1087 static int ionic_maybe_stop_tx(struct ionic_queue *q, int ndescs)
1088 {
1089 	int stopped = 0;
1090 
1091 	if (unlikely(!ionic_q_has_space(q, ndescs))) {
1092 		netif_stop_subqueue(q->lif->netdev, q->index);
1093 		q->stop++;
1094 		stopped = 1;
1095 
1096 		/* Might race with ionic_tx_clean, check again */
1097 		smp_rmb();
1098 		if (ionic_q_has_space(q, ndescs)) {
1099 			netif_wake_subqueue(q->lif->netdev, q->index);
1100 			stopped = 0;
1101 		}
1102 	}
1103 
1104 	return stopped;
1105 }
1106 
1107 netdev_tx_t ionic_start_xmit(struct sk_buff *skb, struct net_device *netdev)
1108 {
1109 	u16 queue_index = skb_get_queue_mapping(skb);
1110 	struct ionic_lif *lif = netdev_priv(netdev);
1111 	struct ionic_queue *q;
1112 	int ndescs;
1113 	int err;
1114 
1115 	if (unlikely(!test_bit(IONIC_LIF_F_UP, lif->state))) {
1116 		dev_kfree_skb(skb);
1117 		return NETDEV_TX_OK;
1118 	}
1119 
1120 	if (unlikely(queue_index >= lif->nxqs))
1121 		queue_index = 0;
1122 	q = &lif->txqcqs[queue_index]->q;
1123 
1124 	ndescs = ionic_tx_descs_needed(q, skb);
1125 	if (ndescs < 0)
1126 		goto err_out_drop;
1127 
1128 	if (unlikely(ionic_maybe_stop_tx(q, ndescs)))
1129 		return NETDEV_TX_BUSY;
1130 
1131 	if (skb_is_gso(skb))
1132 		err = ionic_tx_tso(q, skb);
1133 	else
1134 		err = ionic_tx(q, skb);
1135 
1136 	if (err)
1137 		goto err_out_drop;
1138 
1139 	/* Stop the queue if there aren't descriptors for the next packet.
1140 	 * Since our SG lists per descriptor take care of most of the possible
1141 	 * fragmentation, we don't need to have many descriptors available.
1142 	 */
1143 	ionic_maybe_stop_tx(q, 4);
1144 
1145 	return NETDEV_TX_OK;
1146 
1147 err_out_drop:
1148 	q->stop++;
1149 	q->drop++;
1150 	dev_kfree_skb(skb);
1151 	return NETDEV_TX_OK;
1152 }
1153