xref: /dpdk/drivers/net/enic/enic_rxtx.c (revision 9e991f217fc8719e38a812dc280dba5f84db9f59)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2008-2017 Cisco Systems, Inc.  All rights reserved.
3  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
4  */
5 
6 #include <rte_mbuf.h>
7 #include <rte_ethdev_driver.h>
8 #include <rte_net.h>
9 #include <rte_prefetch.h>
10 
11 #include "enic_compat.h"
12 #include "rq_enet_desc.h"
13 #include "enic.h"
14 #include "enic_rxtx_common.h"
15 #include <rte_ether.h>
16 #include <rte_ip.h>
17 #include <rte_tcp.h>
18 
19 #define RTE_PMD_USE_PREFETCH
20 
21 #ifdef RTE_PMD_USE_PREFETCH
22 /*Prefetch a cache line into all cache levels. */
23 #define rte_enic_prefetch(p) rte_prefetch0(p)
24 #else
25 #define rte_enic_prefetch(p) do {} while (0)
26 #endif
27 
28 #ifdef RTE_PMD_PACKET_PREFETCH
29 #define rte_packet_prefetch(p) rte_prefetch1(p)
30 #else
31 #define rte_packet_prefetch(p) do {} while (0)
32 #endif
33 
34 /* dummy receive function to replace actual function in
35  * order to do safe reconfiguration operations.
36  */
37 uint16_t
38 enic_dummy_recv_pkts(__rte_unused void *rx_queue,
39 		     __rte_unused struct rte_mbuf **rx_pkts,
40 		     __rte_unused uint16_t nb_pkts)
41 {
42 	return 0;
43 }
44 
45 uint16_t
46 enic_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
47 	       uint16_t nb_pkts)
48 {
49 	struct vnic_rq *sop_rq = rx_queue;
50 	struct vnic_rq *data_rq;
51 	struct vnic_rq *rq;
52 	struct enic *enic = vnic_dev_priv(sop_rq->vdev);
53 	uint16_t cq_idx;
54 	uint16_t rq_idx, max_rx;
55 	uint16_t rq_num;
56 	struct rte_mbuf *nmb, *rxmb;
57 	uint16_t nb_rx = 0;
58 	struct vnic_cq *cq;
59 	volatile struct cq_desc *cqd_ptr;
60 	uint8_t color;
61 	uint8_t tnl;
62 	uint16_t seg_length;
63 	struct rte_mbuf *first_seg = sop_rq->pkt_first_seg;
64 	struct rte_mbuf *last_seg = sop_rq->pkt_last_seg;
65 
66 	cq = &enic->cq[enic_cq_rq(enic, sop_rq->index)];
67 	cq_idx = cq->to_clean;		/* index of cqd, rqd, mbuf_table */
68 	cqd_ptr = (struct cq_desc *)(cq->ring.descs) + cq_idx;
69 	color = cq->last_color;
70 
71 	data_rq = &enic->rq[sop_rq->data_queue_idx];
72 
73 	/* Receive until the end of the ring, at most. */
74 	max_rx = RTE_MIN(nb_pkts, cq->ring.desc_count - cq_idx);
75 
76 	while (max_rx) {
77 		volatile struct rq_enet_desc *rqd_ptr;
78 		struct cq_desc cqd;
79 		uint8_t packet_error;
80 		uint16_t ciflags;
81 
82 		max_rx--;
83 
84 		/* Check for pkts available */
85 		if ((cqd_ptr->type_color & CQ_DESC_COLOR_MASK_NOSHIFT) == color)
86 			break;
87 
88 		/* Get the cq descriptor and extract rq info from it */
89 		cqd = *cqd_ptr;
90 		rq_num = cqd.q_number & CQ_DESC_Q_NUM_MASK;
91 		rq_idx = cqd.completed_index & CQ_DESC_COMP_NDX_MASK;
92 
93 		rq = &enic->rq[rq_num];
94 		rqd_ptr = ((struct rq_enet_desc *)rq->ring.descs) + rq_idx;
95 
96 		/* allocate a new mbuf */
97 		nmb = rte_mbuf_raw_alloc(rq->mp);
98 		if (nmb == NULL) {
99 			rte_atomic64_inc(&enic->soft_stats.rx_nombuf);
100 			break;
101 		}
102 
103 		/* A packet error means descriptor and data are untrusted */
104 		packet_error = enic_cq_rx_check_err(&cqd);
105 
106 		/* Get the mbuf to return and replace with one just allocated */
107 		rxmb = rq->mbuf_ring[rq_idx];
108 		rq->mbuf_ring[rq_idx] = nmb;
109 		cq_idx++;
110 
111 		/* Prefetch next mbuf & desc while processing current one */
112 		cqd_ptr = (struct cq_desc *)(cq->ring.descs) + cq_idx;
113 		rte_enic_prefetch(cqd_ptr);
114 
115 		ciflags = enic_cq_rx_desc_ciflags(
116 			(struct cq_enet_rq_desc *)&cqd);
117 
118 		/* Push descriptor for newly allocated mbuf */
119 		nmb->data_off = RTE_PKTMBUF_HEADROOM;
120 		/*
121 		 * Only the address needs to be refilled. length_type of the
122 		 * descriptor it set during initialization
123 		 * (enic_alloc_rx_queue_mbufs) and does not change.
124 		 */
125 		rqd_ptr->address = rte_cpu_to_le_64(nmb->buf_iova +
126 						    RTE_PKTMBUF_HEADROOM);
127 
128 		/* Fill in the rest of the mbuf */
129 		seg_length = enic_cq_rx_desc_n_bytes(&cqd);
130 
131 		if (rq->is_sop) {
132 			first_seg = rxmb;
133 			first_seg->pkt_len = seg_length;
134 		} else {
135 			first_seg->pkt_len = (uint16_t)(first_seg->pkt_len
136 							+ seg_length);
137 			first_seg->nb_segs++;
138 			last_seg->next = rxmb;
139 		}
140 
141 		rxmb->port = enic->port_id;
142 		rxmb->data_len = seg_length;
143 
144 		rq->rx_nb_hold++;
145 
146 		if (!(enic_cq_rx_desc_eop(ciflags))) {
147 			last_seg = rxmb;
148 			continue;
149 		}
150 
151 		/*
152 		 * When overlay offload is enabled, CQ.fcoe indicates the
153 		 * packet is tunnelled.
154 		 */
155 		tnl = enic->overlay_offload &&
156 			(ciflags & CQ_ENET_RQ_DESC_FLAGS_FCOE) != 0;
157 		/* cq rx flags are only valid if eop bit is set */
158 		first_seg->packet_type =
159 			enic_cq_rx_flags_to_pkt_type(&cqd, tnl);
160 		enic_cq_rx_to_pkt_flags(&cqd, first_seg);
161 
162 		/* Wipe the outer types set by enic_cq_rx_flags_to_pkt_type() */
163 		if (tnl) {
164 			first_seg->packet_type &= ~(RTE_PTYPE_L3_MASK |
165 						    RTE_PTYPE_L4_MASK);
166 		}
167 		if (unlikely(packet_error)) {
168 			rte_pktmbuf_free(first_seg);
169 			rte_atomic64_inc(&enic->soft_stats.rx_packet_errors);
170 			continue;
171 		}
172 
173 
174 		/* prefetch mbuf data for caller */
175 		rte_packet_prefetch(RTE_PTR_ADD(first_seg->buf_addr,
176 				    RTE_PKTMBUF_HEADROOM));
177 
178 		/* store the mbuf address into the next entry of the array */
179 		rx_pkts[nb_rx++] = first_seg;
180 	}
181 	if (unlikely(cq_idx == cq->ring.desc_count)) {
182 		cq_idx = 0;
183 		cq->last_color ^= CQ_DESC_COLOR_MASK_NOSHIFT;
184 	}
185 
186 	sop_rq->pkt_first_seg = first_seg;
187 	sop_rq->pkt_last_seg = last_seg;
188 
189 	cq->to_clean = cq_idx;
190 
191 	if ((sop_rq->rx_nb_hold + data_rq->rx_nb_hold) >
192 	    sop_rq->rx_free_thresh) {
193 		if (data_rq->in_use) {
194 			data_rq->posted_index =
195 				enic_ring_add(data_rq->ring.desc_count,
196 					      data_rq->posted_index,
197 					      data_rq->rx_nb_hold);
198 			data_rq->rx_nb_hold = 0;
199 		}
200 		sop_rq->posted_index = enic_ring_add(sop_rq->ring.desc_count,
201 						     sop_rq->posted_index,
202 						     sop_rq->rx_nb_hold);
203 		sop_rq->rx_nb_hold = 0;
204 
205 		rte_mb();
206 		if (data_rq->in_use)
207 			iowrite32_relaxed(data_rq->posted_index,
208 					  &data_rq->ctrl->posted_index);
209 		rte_compiler_barrier();
210 		iowrite32_relaxed(sop_rq->posted_index,
211 				  &sop_rq->ctrl->posted_index);
212 	}
213 
214 
215 	return nb_rx;
216 }
217 
218 uint16_t
219 enic_noscatter_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
220 			 uint16_t nb_pkts)
221 {
222 	struct rte_mbuf *mb, **rx, **rxmb;
223 	uint16_t cq_idx, nb_rx, max_rx;
224 	struct cq_enet_rq_desc *cqd;
225 	struct rq_enet_desc *rqd;
226 	unsigned int port_id;
227 	struct vnic_cq *cq;
228 	struct vnic_rq *rq;
229 	struct enic *enic;
230 	uint8_t color;
231 	bool overlay;
232 	bool tnl;
233 
234 	rq = rx_queue;
235 	enic = vnic_dev_priv(rq->vdev);
236 	cq = &enic->cq[enic_cq_rq(enic, rq->index)];
237 	cq_idx = cq->to_clean;
238 
239 	/*
240 	 * Fill up the reserve of free mbufs. Below, we restock the receive
241 	 * ring with these mbufs to avoid allocation failures.
242 	 */
243 	if (rq->num_free_mbufs == 0) {
244 		if (rte_mempool_get_bulk(rq->mp, (void **)rq->free_mbufs,
245 					 ENIC_RX_BURST_MAX))
246 			return 0;
247 		rq->num_free_mbufs = ENIC_RX_BURST_MAX;
248 	}
249 
250 	/* Receive until the end of the ring, at most. */
251 	max_rx = RTE_MIN(nb_pkts, rq->num_free_mbufs);
252 	max_rx = RTE_MIN(max_rx, cq->ring.desc_count - cq_idx);
253 
254 	cqd = (struct cq_enet_rq_desc *)(cq->ring.descs) + cq_idx;
255 	color = cq->last_color;
256 	rxmb = rq->mbuf_ring + cq_idx;
257 	port_id = enic->port_id;
258 	overlay = enic->overlay_offload;
259 
260 	rx = rx_pkts;
261 	while (max_rx) {
262 		max_rx--;
263 		if ((cqd->type_color & CQ_DESC_COLOR_MASK_NOSHIFT) == color)
264 			break;
265 		if (unlikely(cqd->bytes_written_flags &
266 			     CQ_ENET_RQ_DESC_FLAGS_TRUNCATED)) {
267 			rte_pktmbuf_free(*rxmb++);
268 			rte_atomic64_inc(&enic->soft_stats.rx_packet_errors);
269 			cqd++;
270 			continue;
271 		}
272 
273 		mb = *rxmb++;
274 		/* prefetch mbuf data for caller */
275 		rte_packet_prefetch(RTE_PTR_ADD(mb->buf_addr,
276 				    RTE_PKTMBUF_HEADROOM));
277 		mb->data_len = cqd->bytes_written_flags &
278 			CQ_ENET_RQ_DESC_BYTES_WRITTEN_MASK;
279 		mb->pkt_len = mb->data_len;
280 		mb->port = port_id;
281 		tnl = overlay && (cqd->completed_index_flags &
282 				  CQ_ENET_RQ_DESC_FLAGS_FCOE) != 0;
283 		mb->packet_type =
284 			enic_cq_rx_flags_to_pkt_type((struct cq_desc *)cqd,
285 						     tnl);
286 		enic_cq_rx_to_pkt_flags((struct cq_desc *)cqd, mb);
287 		/* Wipe the outer types set by enic_cq_rx_flags_to_pkt_type() */
288 		if (tnl) {
289 			mb->packet_type &= ~(RTE_PTYPE_L3_MASK |
290 					     RTE_PTYPE_L4_MASK);
291 		}
292 		cqd++;
293 		*rx++ = mb;
294 	}
295 	/* Number of descriptors visited */
296 	nb_rx = cqd - (struct cq_enet_rq_desc *)(cq->ring.descs) - cq_idx;
297 	if (nb_rx == 0)
298 		return 0;
299 	rqd = ((struct rq_enet_desc *)rq->ring.descs) + cq_idx;
300 	rxmb = rq->mbuf_ring + cq_idx;
301 	cq_idx += nb_rx;
302 	rq->rx_nb_hold += nb_rx;
303 	if (unlikely(cq_idx == cq->ring.desc_count)) {
304 		cq_idx = 0;
305 		cq->last_color ^= CQ_DESC_COLOR_MASK_NOSHIFT;
306 	}
307 	cq->to_clean = cq_idx;
308 
309 	memcpy(rxmb, rq->free_mbufs + ENIC_RX_BURST_MAX - rq->num_free_mbufs,
310 	       sizeof(struct rte_mbuf *) * nb_rx);
311 	rq->num_free_mbufs -= nb_rx;
312 	while (nb_rx) {
313 		nb_rx--;
314 		mb = *rxmb++;
315 		mb->data_off = RTE_PKTMBUF_HEADROOM;
316 		rqd->address = mb->buf_iova + RTE_PKTMBUF_HEADROOM;
317 		rqd++;
318 	}
319 	if (rq->rx_nb_hold > rq->rx_free_thresh) {
320 		rq->posted_index = enic_ring_add(rq->ring.desc_count,
321 						 rq->posted_index,
322 						 rq->rx_nb_hold);
323 		rq->rx_nb_hold = 0;
324 		rte_wmb();
325 		iowrite32_relaxed(rq->posted_index,
326 				  &rq->ctrl->posted_index);
327 	}
328 
329 	return rx - rx_pkts;
330 }
331 
332 static inline void enic_free_wq_bufs(struct vnic_wq *wq,
333 				     uint16_t completed_index)
334 {
335 	struct rte_mbuf *buf;
336 	struct rte_mbuf *m, *free[ENIC_MAX_WQ_DESCS];
337 	unsigned int nb_to_free, nb_free = 0, i;
338 	struct rte_mempool *pool;
339 	unsigned int tail_idx;
340 	unsigned int desc_count = wq->ring.desc_count;
341 
342 	nb_to_free = enic_ring_sub(desc_count, wq->tail_idx, completed_index)
343 				   + 1;
344 	tail_idx = wq->tail_idx;
345 	pool = wq->bufs[tail_idx]->pool;
346 	for (i = 0; i < nb_to_free; i++) {
347 		buf = wq->bufs[tail_idx];
348 		m = rte_pktmbuf_prefree_seg(buf);
349 		if (unlikely(m == NULL)) {
350 			tail_idx = enic_ring_incr(desc_count, tail_idx);
351 			continue;
352 		}
353 
354 		if (likely(m->pool == pool)) {
355 			RTE_ASSERT(nb_free < ENIC_MAX_WQ_DESCS);
356 			free[nb_free++] = m;
357 		} else {
358 			rte_mempool_put_bulk(pool, (void *)free, nb_free);
359 			free[0] = m;
360 			nb_free = 1;
361 			pool = m->pool;
362 		}
363 		tail_idx = enic_ring_incr(desc_count, tail_idx);
364 	}
365 
366 	if (nb_free > 0)
367 		rte_mempool_put_bulk(pool, (void **)free, nb_free);
368 
369 	wq->tail_idx = tail_idx;
370 	wq->ring.desc_avail += nb_to_free;
371 }
372 
373 unsigned int enic_cleanup_wq(__rte_unused struct enic *enic, struct vnic_wq *wq)
374 {
375 	uint16_t completed_index;
376 
377 	completed_index = *((uint32_t *)wq->cqmsg_rz->addr) & 0xffff;
378 
379 	if (wq->last_completed_index != completed_index) {
380 		enic_free_wq_bufs(wq, completed_index);
381 		wq->last_completed_index = completed_index;
382 	}
383 	return 0;
384 }
385 
386 uint16_t enic_prep_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
387 			uint16_t nb_pkts)
388 {
389 	struct vnic_wq *wq = (struct vnic_wq *)tx_queue;
390 	int32_t ret;
391 	uint16_t i;
392 	uint64_t ol_flags;
393 	struct rte_mbuf *m;
394 
395 	for (i = 0; i != nb_pkts; i++) {
396 		m = tx_pkts[i];
397 		ol_flags = m->ol_flags;
398 		if (!(ol_flags & PKT_TX_TCP_SEG)) {
399 			if (unlikely(m->pkt_len > ENIC_TX_MAX_PKT_SIZE)) {
400 				rte_errno = EINVAL;
401 				return i;
402 			}
403 		} else {
404 			uint16_t header_len;
405 
406 			header_len = m->l2_len + m->l3_len + m->l4_len;
407 			if (m->tso_segsz + header_len > ENIC_TX_MAX_PKT_SIZE) {
408 				rte_errno = EINVAL;
409 				return i;
410 			}
411 		}
412 
413 		if (ol_flags & wq->tx_offload_notsup_mask) {
414 			rte_errno = ENOTSUP;
415 			return i;
416 		}
417 #ifdef RTE_LIBRTE_ETHDEV_DEBUG
418 		ret = rte_validate_tx_offload(m);
419 		if (ret != 0) {
420 			rte_errno = -ret;
421 			return i;
422 		}
423 #endif
424 		ret = rte_net_intel_cksum_prepare(m);
425 		if (ret != 0) {
426 			rte_errno = -ret;
427 			return i;
428 		}
429 	}
430 
431 	return i;
432 }
433 
434 uint16_t enic_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
435 	uint16_t nb_pkts)
436 {
437 	uint16_t index;
438 	unsigned int pkt_len, data_len;
439 	unsigned int nb_segs;
440 	struct rte_mbuf *tx_pkt;
441 	struct vnic_wq *wq = (struct vnic_wq *)tx_queue;
442 	struct enic *enic = vnic_dev_priv(wq->vdev);
443 	unsigned short vlan_id;
444 	uint64_t ol_flags;
445 	uint64_t ol_flags_mask;
446 	unsigned int wq_desc_avail;
447 	int head_idx;
448 	unsigned int desc_count;
449 	struct wq_enet_desc *descs, *desc_p, desc_tmp;
450 	uint16_t mss;
451 	uint8_t vlan_tag_insert;
452 	uint8_t eop, cq;
453 	uint64_t bus_addr;
454 	uint8_t offload_mode;
455 	uint16_t header_len;
456 	uint64_t tso;
457 	rte_atomic64_t *tx_oversized;
458 
459 	enic_cleanup_wq(enic, wq);
460 	wq_desc_avail = vnic_wq_desc_avail(wq);
461 	head_idx = wq->head_idx;
462 	desc_count = wq->ring.desc_count;
463 	ol_flags_mask = PKT_TX_VLAN | PKT_TX_IP_CKSUM | PKT_TX_L4_MASK;
464 	tx_oversized = &enic->soft_stats.tx_oversized;
465 
466 	nb_pkts = RTE_MIN(nb_pkts, ENIC_TX_XMIT_MAX);
467 
468 	for (index = 0; index < nb_pkts; index++) {
469 		tx_pkt = *tx_pkts++;
470 		pkt_len = tx_pkt->pkt_len;
471 		data_len = tx_pkt->data_len;
472 		ol_flags = tx_pkt->ol_flags;
473 		nb_segs = tx_pkt->nb_segs;
474 		tso = ol_flags & PKT_TX_TCP_SEG;
475 
476 		/* drop packet if it's too big to send */
477 		if (unlikely(!tso && pkt_len > ENIC_TX_MAX_PKT_SIZE)) {
478 			rte_pktmbuf_free(tx_pkt);
479 			rte_atomic64_inc(tx_oversized);
480 			continue;
481 		}
482 
483 		if (nb_segs > wq_desc_avail) {
484 			if (index > 0)
485 				goto post;
486 			goto done;
487 		}
488 
489 		mss = 0;
490 		vlan_id = tx_pkt->vlan_tci;
491 		vlan_tag_insert = !!(ol_flags & PKT_TX_VLAN);
492 		bus_addr = (dma_addr_t)
493 			   (tx_pkt->buf_iova + tx_pkt->data_off);
494 
495 		descs = (struct wq_enet_desc *)wq->ring.descs;
496 		desc_p = descs + head_idx;
497 
498 		eop = (data_len == pkt_len);
499 		offload_mode = WQ_ENET_OFFLOAD_MODE_CSUM;
500 		header_len = 0;
501 
502 		if (tso) {
503 			header_len = tx_pkt->l2_len + tx_pkt->l3_len +
504 				     tx_pkt->l4_len;
505 
506 			/* Drop if non-TCP packet or TSO seg size is too big */
507 			if (unlikely(header_len == 0 || ((tx_pkt->tso_segsz +
508 			    header_len) > ENIC_TX_MAX_PKT_SIZE))) {
509 				rte_pktmbuf_free(tx_pkt);
510 				rte_atomic64_inc(tx_oversized);
511 				continue;
512 			}
513 
514 			offload_mode = WQ_ENET_OFFLOAD_MODE_TSO;
515 			mss = tx_pkt->tso_segsz;
516 			/* For tunnel, need the size of outer+inner headers */
517 			if (ol_flags & PKT_TX_TUNNEL_MASK) {
518 				header_len += tx_pkt->outer_l2_len +
519 					tx_pkt->outer_l3_len;
520 			}
521 		}
522 
523 		if ((ol_flags & ol_flags_mask) && (header_len == 0)) {
524 			if (ol_flags & PKT_TX_IP_CKSUM)
525 				mss |= ENIC_CALC_IP_CKSUM;
526 
527 			/* Nic uses just 1 bit for UDP and TCP */
528 			switch (ol_flags & PKT_TX_L4_MASK) {
529 			case PKT_TX_TCP_CKSUM:
530 			case PKT_TX_UDP_CKSUM:
531 				mss |= ENIC_CALC_TCP_UDP_CKSUM;
532 				break;
533 			}
534 		}
535 		wq->cq_pend++;
536 		cq = 0;
537 		if (eop && wq->cq_pend >= ENIC_WQ_CQ_THRESH) {
538 			cq = 1;
539 			wq->cq_pend = 0;
540 		}
541 		wq_enet_desc_enc(&desc_tmp, bus_addr, data_len, mss, header_len,
542 				 offload_mode, eop, cq, 0, vlan_tag_insert,
543 				 vlan_id, 0);
544 
545 		*desc_p = desc_tmp;
546 		wq->bufs[head_idx] = tx_pkt;
547 		head_idx = enic_ring_incr(desc_count, head_idx);
548 		wq_desc_avail--;
549 
550 		if (!eop) {
551 			for (tx_pkt = tx_pkt->next; tx_pkt; tx_pkt =
552 			    tx_pkt->next) {
553 				data_len = tx_pkt->data_len;
554 
555 				wq->cq_pend++;
556 				cq = 0;
557 				if (tx_pkt->next == NULL) {
558 					eop = 1;
559 					if (wq->cq_pend >= ENIC_WQ_CQ_THRESH) {
560 						cq = 1;
561 						wq->cq_pend = 0;
562 					}
563 				}
564 				desc_p = descs + head_idx;
565 				bus_addr = (dma_addr_t)(tx_pkt->buf_iova
566 					   + tx_pkt->data_off);
567 				wq_enet_desc_enc((struct wq_enet_desc *)
568 						 &desc_tmp, bus_addr, data_len,
569 						 mss, 0, offload_mode, eop, cq,
570 						 0, vlan_tag_insert, vlan_id,
571 						 0);
572 
573 				*desc_p = desc_tmp;
574 				wq->bufs[head_idx] = tx_pkt;
575 				head_idx = enic_ring_incr(desc_count, head_idx);
576 				wq_desc_avail--;
577 			}
578 		}
579 	}
580  post:
581 	rte_wmb();
582 	iowrite32_relaxed(head_idx, &wq->ctrl->posted_index);
583  done:
584 	wq->ring.desc_avail = wq_desc_avail;
585 	wq->head_idx = head_idx;
586 
587 	return index;
588 }
589 
590 static void enqueue_simple_pkts(struct rte_mbuf **pkts,
591 				struct wq_enet_desc *desc,
592 				uint16_t n,
593 				struct enic *enic)
594 {
595 	struct rte_mbuf *p;
596 	uint16_t mss;
597 
598 	while (n) {
599 		n--;
600 		p = *pkts++;
601 		desc->address = p->buf_iova + p->data_off;
602 		desc->length = p->pkt_len;
603 		/* VLAN insert */
604 		desc->vlan_tag = p->vlan_tci;
605 		desc->header_length_flags &=
606 			((1 << WQ_ENET_FLAGS_EOP_SHIFT) |
607 			 (1 << WQ_ENET_FLAGS_CQ_ENTRY_SHIFT));
608 		if (p->ol_flags & PKT_TX_VLAN) {
609 			desc->header_length_flags |=
610 				1 << WQ_ENET_FLAGS_VLAN_TAG_INSERT_SHIFT;
611 		}
612 		/*
613 		 * Checksum offload. We use WQ_ENET_OFFLOAD_MODE_CSUM, which
614 		 * is 0, so no need to set offload_mode.
615 		 */
616 		mss = 0;
617 		if (p->ol_flags & PKT_TX_IP_CKSUM)
618 			mss |= ENIC_CALC_IP_CKSUM << WQ_ENET_MSS_SHIFT;
619 		if (p->ol_flags & PKT_TX_L4_MASK)
620 			mss |= ENIC_CALC_TCP_UDP_CKSUM << WQ_ENET_MSS_SHIFT;
621 		desc->mss_loopback = mss;
622 
623 		/*
624 		 * The app should not send oversized
625 		 * packets. tx_pkt_prepare includes a check as
626 		 * well. But some apps ignore the device max size and
627 		 * tx_pkt_prepare. Oversized packets cause WQ errrors
628 		 * and the NIC ends up disabling the whole WQ. So
629 		 * truncate packets..
630 		 */
631 		if (unlikely(p->pkt_len > ENIC_TX_MAX_PKT_SIZE)) {
632 			desc->length = ENIC_TX_MAX_PKT_SIZE;
633 			rte_atomic64_inc(&enic->soft_stats.tx_oversized);
634 		}
635 		desc++;
636 	}
637 }
638 
639 uint16_t enic_simple_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
640 			       uint16_t nb_pkts)
641 {
642 	unsigned int head_idx, desc_count;
643 	struct wq_enet_desc *desc;
644 	struct vnic_wq *wq;
645 	struct enic *enic;
646 	uint16_t rem, n;
647 
648 	wq = (struct vnic_wq *)tx_queue;
649 	enic = vnic_dev_priv(wq->vdev);
650 	enic_cleanup_wq(enic, wq);
651 	/* Will enqueue this many packets in this call */
652 	nb_pkts = RTE_MIN(nb_pkts, wq->ring.desc_avail);
653 	if (nb_pkts == 0)
654 		return 0;
655 
656 	head_idx = wq->head_idx;
657 	desc_count = wq->ring.desc_count;
658 
659 	/* Descriptors until the end of the ring */
660 	n = desc_count - head_idx;
661 	n = RTE_MIN(nb_pkts, n);
662 
663 	/* Save mbuf pointers to free later */
664 	memcpy(wq->bufs + head_idx, tx_pkts, sizeof(struct rte_mbuf *) * n);
665 
666 	/* Enqueue until the ring end */
667 	rem = nb_pkts - n;
668 	desc = ((struct wq_enet_desc *)wq->ring.descs) + head_idx;
669 	enqueue_simple_pkts(tx_pkts, desc, n, enic);
670 
671 	/* Wrap to the start of the ring */
672 	if (rem) {
673 		tx_pkts += n;
674 		memcpy(wq->bufs, tx_pkts, sizeof(struct rte_mbuf *) * rem);
675 		desc = (struct wq_enet_desc *)wq->ring.descs;
676 		enqueue_simple_pkts(tx_pkts, desc, rem, enic);
677 	}
678 	rte_wmb();
679 
680 	/* Update head_idx and desc_avail */
681 	wq->ring.desc_avail -= nb_pkts;
682 	head_idx += nb_pkts;
683 	if (head_idx >= desc_count)
684 		head_idx -= desc_count;
685 	wq->head_idx = head_idx;
686 	iowrite32_relaxed(head_idx, &wq->ctrl->posted_index);
687 	return nb_pkts;
688 }
689