1/*-
2 * Copyright (c) 2015 Mellanox Technologies. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD: stable/10/sys/dev/mlx5/mlx5_en/mlx5_en_tx.c 362313 2020-06-18 10:41:51Z hselasky $
26 */
27
28#include "en.h"
29#include <machine/atomic.h>
30
31static inline bool
32mlx5e_do_send_cqe(struct mlx5e_sq *sq)
33{
34	sq->cev_counter++;
35	/* interleave the CQEs */
36	if (sq->cev_counter >= sq->cev_factor) {
37		sq->cev_counter = 0;
38		return (1);
39	}
40	return (0);
41}
42
43void
44mlx5e_send_nop(struct mlx5e_sq *sq, u32 ds_cnt)
45{
46	u16 pi = sq->pc & sq->wq.sz_m1;
47	struct mlx5e_tx_wqe *wqe = mlx5_wq_cyc_get_wqe(&sq->wq, pi);
48
49	memset(&wqe->ctrl, 0, sizeof(wqe->ctrl));
50
51	wqe->ctrl.opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_NOP);
52	wqe->ctrl.qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);
53	if (mlx5e_do_send_cqe(sq))
54		wqe->ctrl.fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
55	else
56		wqe->ctrl.fm_ce_se = 0;
57
58	/* Copy data for doorbell */
59	memcpy(sq->doorbell.d32, &wqe->ctrl, sizeof(sq->doorbell.d32));
60
61	sq->mbuf[pi].mbuf = NULL;
62	sq->mbuf[pi].num_bytes = 0;
63	sq->mbuf[pi].num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS);
64	sq->pc += sq->mbuf[pi].num_wqebbs;
65}
66
67#if (__FreeBSD_version >= 1100000)
68static uint32_t mlx5e_hash_value;
69
70static void
71mlx5e_hash_init(void *arg)
72{
73	mlx5e_hash_value = m_ether_tcpip_hash_init();
74}
75
76/* Make kernel call mlx5e_hash_init after the random stack finished initializing */
77SYSINIT(mlx5e_hash_init, SI_SUB_RANDOM, SI_ORDER_ANY, &mlx5e_hash_init, NULL);
78#endif
79
80static struct mlx5e_sq *
81mlx5e_select_queue(struct ifnet *ifp, struct mbuf *mb)
82{
83	struct mlx5e_priv *priv = ifp->if_softc;
84	struct mlx5e_channel * volatile *ppch;
85	struct mlx5e_channel *pch;
86	u32 ch;
87	u32 tc;
88
89	ppch = priv->channel;
90
91	/* check if channels are successfully opened */
92	if (unlikely(ppch == NULL))
93		return (NULL);
94
95	/* obtain VLAN information if present */
96	if (mb->m_flags & M_VLANTAG) {
97		tc = (mb->m_pkthdr.ether_vtag >> 13);
98		if (tc >= priv->num_tc)
99			tc = priv->default_vlan_prio;
100	} else {
101		tc = priv->default_vlan_prio;
102	}
103
104	ch = priv->params.num_channels;
105
106	/* check if flowid is set */
107	if (M_HASHTYPE_GET(mb) != M_HASHTYPE_NONE) {
108#ifdef RSS
109		u32 temp;
110
111		if (rss_hash2bucket(mb->m_pkthdr.flowid,
112		    M_HASHTYPE_GET(mb), &temp) == 0)
113			ch = temp % ch;
114		else
115#endif
116			ch = (mb->m_pkthdr.flowid % 128) % ch;
117	} else {
118#if (__FreeBSD_version >= 1100000)
119		ch = m_ether_tcpip_hash(MBUF_HASHFLAG_L3 |
120		    MBUF_HASHFLAG_L4, mb, mlx5e_hash_value) % ch;
121#else
122		/*
123		 * m_ether_tcpip_hash not present in stable, so just
124		 * throw unhashed mbufs on queue 0
125		 */
126		ch = 0;
127#endif
128	}
129
130	/* check if channel is allocated and not stopped */
131	pch = ppch[ch];
132	if (likely(pch != NULL && pch->sq[tc].stopped == 0))
133		return (&pch->sq[tc]);
134	return (NULL);
135}
136
137static inline u16
138mlx5e_get_inline_hdr_size(struct mlx5e_sq *sq, struct mbuf *mb)
139{
140
141	switch(sq->min_inline_mode) {
142	case MLX5_INLINE_MODE_NONE:
143		/*
144		 * When inline mode is NONE, we do not need to copy
145		 * headers into WQEs, except when vlan tag framing is
146		 * requested. Hardware might offload vlan tagging on
147		 * transmit. This is a separate capability, which is
148		 * known to be disabled on ConnectX-5 due to a hardware
149		 * bug RM 931383. If vlan_inline_cap is not present and
150		 * the packet has vlan tag, fall back to inlining.
151		 */
152		if ((mb->m_flags & M_VLANTAG) != 0 &&
153		    sq->vlan_inline_cap == 0)
154			break;
155		return (0);
156	case MLX5_INLINE_MODE_L2:
157		/*
158		 * Due to hardware limitations, when trust mode is
159		 * DSCP, the hardware may request MLX5_INLINE_MODE_L2
160		 * while it really needs all L2 headers and the 4 first
161		 * bytes of the IP header (which include the
162		 * TOS/traffic-class).
163		 *
164		 * To avoid doing a firmware command for querying the
165		 * trust state and parsing the mbuf for doing
166		 * unnecessary checks (VLAN/eth_type) in the fast path,
167		 * we are going for the worth case (22 Bytes) if
168		 * the mb->m_pkthdr.len allows it.
169		 */
170		if (mb->m_pkthdr.len > ETHER_HDR_LEN +
171		    ETHER_VLAN_ENCAP_LEN + 4)
172			return (MIN(sq->max_inline, ETHER_HDR_LEN +
173			    ETHER_VLAN_ENCAP_LEN + 4));
174		break;
175	}
176	return (MIN(sq->max_inline, mb->m_pkthdr.len));
177}
178
179/*
180 * This function parse IPv4 and IPv6 packets looking for TCP and UDP
181 * headers.
182 *
183 * The return value indicates the number of bytes from the beginning
184 * of the packet until the first byte after the TCP or UDP header. If
185 * this function returns zero, the parsing failed.
186 */
187static int
188mlx5e_get_header_size(const struct mbuf *mb)
189{
190	const struct ether_vlan_header *eh;
191	const struct tcphdr *th;
192	const struct ip *ip;
193	int ip_hlen, tcp_hlen;
194	const struct ip6_hdr *ip6;
195	uint16_t eth_type;
196	int eth_hdr_len;
197
198	eh = mtod(mb, const struct ether_vlan_header *);
199	if (unlikely(mb->m_len < ETHER_HDR_LEN))
200		return (0);
201	if (eh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
202		if (unlikely(mb->m_len < (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN)))
203			return (0);
204		eth_type = ntohs(eh->evl_proto);
205		eth_hdr_len = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
206	} else {
207		eth_type = ntohs(eh->evl_encap_proto);
208		eth_hdr_len = ETHER_HDR_LEN;
209	}
210	switch (eth_type) {
211	case ETHERTYPE_IP:
212		ip = (const struct ip *)(mb->m_data + eth_hdr_len);
213		if (unlikely(mb->m_len < eth_hdr_len + sizeof(*ip)))
214			return (0);
215		if (ip->ip_p != IPPROTO_TCP)
216			return (0);
217		ip_hlen = ip->ip_hl << 2;
218		eth_hdr_len += ip_hlen;
219		break;
220	case ETHERTYPE_IPV6:
221		ip6 = (const struct ip6_hdr *)(mb->m_data + eth_hdr_len);
222		if (unlikely(mb->m_len < eth_hdr_len + sizeof(*ip6)))
223			return (0);
224		if (ip6->ip6_nxt != IPPROTO_TCP)
225			return (0);
226		eth_hdr_len += sizeof(*ip6);
227		break;
228	default:
229		return (0);
230	}
231	if (unlikely(mb->m_len < eth_hdr_len + sizeof(*th))) {
232		const struct mbuf *m_th = mb->m_next;
233		if (unlikely(mb->m_len != eth_hdr_len ||
234		    m_th == NULL || m_th->m_len < sizeof(*th)))
235			return (0);
236		th = (const struct tcphdr *)(m_th->m_data);
237	} else {
238		th = (const struct tcphdr *)(mb->m_data + eth_hdr_len);
239	}
240	tcp_hlen = th->th_off << 2;
241	eth_hdr_len += tcp_hlen;
242	/*
243	 * m_copydata() will be used on the remaining header which
244	 * does not need to reside within the first m_len bytes of
245	 * data:
246	 */
247	if (unlikely(mb->m_pkthdr.len < eth_hdr_len))
248		return (0);
249	return (eth_hdr_len);
250}
251
252/*
253 * The return value is not going back to the stack because of
254 * the drbr
255 */
256static int
257mlx5e_sq_xmit(struct mlx5e_sq *sq, struct mbuf **mbp)
258{
259	bus_dma_segment_t segs[MLX5E_MAX_TX_MBUF_FRAGS];
260	struct mlx5_wqe_data_seg *dseg;
261	struct mlx5e_tx_wqe *wqe;
262	struct ifnet *ifp;
263	int nsegs;
264	int err;
265	int x;
266	struct mbuf *mb = *mbp;
267	u16 ds_cnt;
268	u16 ihs;
269	u16 pi;
270	u8 opcode;
271
272	/*
273	 * Return ENOBUFS if the queue is full, this may trigger reinsertion
274	 * of the mbuf into the drbr (see mlx5e_xmit_locked)
275	 */
276	if (unlikely(!mlx5e_sq_has_room_for(sq, 2 * MLX5_SEND_WQE_MAX_WQEBBS))) {
277		sq->stats.enobuf++;
278		return (ENOBUFS);
279	}
280
281	/* Align SQ edge with NOPs to avoid WQE wrap around */
282	pi = ((~sq->pc) & sq->wq.sz_m1);
283	if (pi < (MLX5_SEND_WQE_MAX_WQEBBS - 1)) {
284		/* Send one multi NOP message instead of many */
285		mlx5e_send_nop(sq, (pi + 1) * MLX5_SEND_WQEBB_NUM_DS);
286		pi = ((~sq->pc) & sq->wq.sz_m1);
287		if (pi < (MLX5_SEND_WQE_MAX_WQEBBS - 1)) {
288			sq->stats.enobuf++;
289			return (ENOMEM);
290		}
291	}
292
293	/* Setup local variables */
294	pi = sq->pc & sq->wq.sz_m1;
295	wqe = mlx5_wq_cyc_get_wqe(&sq->wq, pi);
296	ifp = sq->ifp;
297
298	memset(wqe, 0, sizeof(*wqe));
299
300	/* Send a copy of the frame to the BPF listener, if any */
301	if (ifp != NULL && ifp->if_bpf != NULL)
302		ETHER_BPF_MTAP(ifp, mb);
303
304	if (mb->m_pkthdr.csum_flags & (CSUM_IP | CSUM_TSO)) {
305		wqe->eth.cs_flags |= MLX5_ETH_WQE_L3_CSUM;
306	}
307	if (mb->m_pkthdr.csum_flags & (CSUM_TCP | CSUM_UDP | CSUM_UDP_IPV6 | CSUM_TCP_IPV6 | CSUM_TSO)) {
308		wqe->eth.cs_flags |= MLX5_ETH_WQE_L4_CSUM;
309	}
310	if (wqe->eth.cs_flags == 0) {
311		sq->stats.csum_offload_none++;
312	}
313	if (mb->m_pkthdr.csum_flags & CSUM_TSO) {
314		u32 payload_len;
315		u32 mss = mb->m_pkthdr.tso_segsz;
316		u32 num_pkts;
317
318		wqe->eth.mss = cpu_to_be16(mss);
319		opcode = MLX5_OPCODE_LSO;
320		ihs = mlx5e_get_header_size(mb);
321		payload_len = mb->m_pkthdr.len - ihs;
322		if (payload_len == 0)
323			num_pkts = 1;
324		else
325			num_pkts = DIV_ROUND_UP(payload_len, mss);
326		sq->mbuf[pi].num_bytes = payload_len + (num_pkts * ihs);
327
328		sq->stats.tso_packets++;
329		sq->stats.tso_bytes += payload_len;
330	} else {
331		opcode = MLX5_OPCODE_SEND;
332		ihs = mlx5e_get_inline_hdr_size(sq, mb);
333		sq->mbuf[pi].num_bytes = max_t (unsigned int,
334		    mb->m_pkthdr.len, ETHER_MIN_LEN - ETHER_CRC_LEN);
335	}
336	if (ihs == 0) {
337		if ((mb->m_flags & M_VLANTAG) != 0) {
338			wqe->eth.vlan_cmd = htons(0x8000); /* bit 0 CVLAN */
339			wqe->eth.vlan_hdr = htons(mb->m_pkthdr.ether_vtag);
340		} else {
341			wqe->eth.inline_hdr_sz = 0;
342		}
343	} else {
344		if ((mb->m_flags & M_VLANTAG) != 0) {
345			struct ether_vlan_header *eh = (struct ether_vlan_header
346			    *)wqe->eth.inline_hdr_start;
347
348			/* Range checks */
349			if (ihs > (MLX5E_MAX_TX_INLINE - ETHER_VLAN_ENCAP_LEN))
350				ihs = (MLX5E_MAX_TX_INLINE -
351				    ETHER_VLAN_ENCAP_LEN);
352			else if (ihs < ETHER_HDR_LEN) {
353				err = EINVAL;
354				goto tx_drop;
355			}
356			m_copydata(mb, 0, ETHER_HDR_LEN, (caddr_t)eh);
357			m_adj(mb, ETHER_HDR_LEN);
358			/* Insert 4 bytes VLAN tag into data stream */
359			eh->evl_proto = eh->evl_encap_proto;
360			eh->evl_encap_proto = htons(ETHERTYPE_VLAN);
361			eh->evl_tag = htons(mb->m_pkthdr.ether_vtag);
362			/* Copy rest of header data, if any */
363			m_copydata(mb, 0, ihs - ETHER_HDR_LEN, (caddr_t)(eh +
364			    1));
365			m_adj(mb, ihs - ETHER_HDR_LEN);
366			/* Extend header by 4 bytes */
367			ihs += ETHER_VLAN_ENCAP_LEN;
368		} else {
369			m_copydata(mb, 0, ihs, wqe->eth.inline_hdr_start);
370			m_adj(mb, ihs);
371		}
372		wqe->eth.inline_hdr_sz = cpu_to_be16(ihs);
373	}
374
375	ds_cnt = sizeof(*wqe) / MLX5_SEND_WQE_DS;
376	if (ihs > sizeof(wqe->eth.inline_hdr_start)) {
377		ds_cnt += DIV_ROUND_UP(ihs - sizeof(wqe->eth.inline_hdr_start),
378		    MLX5_SEND_WQE_DS);
379	}
380	dseg = ((struct mlx5_wqe_data_seg *)&wqe->ctrl) + ds_cnt;
381
382	/* Trim off empty mbufs */
383	while (mb->m_len == 0) {
384		mb = m_free(mb);
385		/* Check if all data has been inlined */
386		if (mb == NULL)
387			goto skip_dma;
388	}
389
390	err = bus_dmamap_load_mbuf_sg(sq->dma_tag, sq->mbuf[pi].dma_map,
391	    mb, segs, &nsegs, BUS_DMA_NOWAIT);
392	if (err == EFBIG) {
393		/*
394		 * Update *mbp before defrag in case it was trimmed in the
395		 * loop above
396		 */
397		*mbp = mb;
398		/* Update statistics */
399		sq->stats.defragged++;
400		/* Too many mbuf fragments */
401		mb = m_defrag(*mbp, M_NOWAIT);
402		if (mb == NULL) {
403			mb = *mbp;
404			goto tx_drop;
405		}
406		/* Try again */
407		err = bus_dmamap_load_mbuf_sg(sq->dma_tag, sq->mbuf[pi].dma_map,
408		    mb, segs, &nsegs, BUS_DMA_NOWAIT);
409	}
410	/* Catch errors */
411	if (err != 0)
412		goto tx_drop;
413
414	for (x = 0; x != nsegs; x++) {
415		if (segs[x].ds_len == 0)
416			continue;
417		dseg->addr = cpu_to_be64((uint64_t)segs[x].ds_addr);
418		dseg->lkey = sq->mkey_be;
419		dseg->byte_count = cpu_to_be32((uint32_t)segs[x].ds_len);
420		dseg++;
421	}
422skip_dma:
423	ds_cnt = (dseg - ((struct mlx5_wqe_data_seg *)&wqe->ctrl));
424
425	wqe->ctrl.opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | opcode);
426	wqe->ctrl.qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_cnt);
427	if (mlx5e_do_send_cqe(sq))
428		wqe->ctrl.fm_ce_se = MLX5_WQE_CTRL_CQ_UPDATE;
429	else
430		wqe->ctrl.fm_ce_se = 0;
431
432	/* Copy data for doorbell */
433	memcpy(sq->doorbell.d32, &wqe->ctrl, sizeof(sq->doorbell.d32));
434
435	/* Store pointer to mbuf */
436	sq->mbuf[pi].mbuf = mb;
437	sq->mbuf[pi].num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS);
438	sq->pc += sq->mbuf[pi].num_wqebbs;
439
440	/* Make sure all mbuf data is written to RAM */
441	if (mb != NULL)
442		bus_dmamap_sync(sq->dma_tag, sq->mbuf[pi].dma_map, BUS_DMASYNC_PREWRITE);
443
444	sq->stats.packets++;
445	*mbp = NULL;	/* safety clear */
446	return (0);
447
448tx_drop:
449	sq->stats.dropped++;
450	*mbp = NULL;
451	m_freem(mb);
452	return err;
453}
454
455static void
456mlx5e_poll_tx_cq(struct mlx5e_sq *sq, int budget)
457{
458	u16 sqcc;
459
460	/*
461	 * sq->cc must be updated only after mlx5_cqwq_update_db_record(),
462	 * otherwise a cq overrun may occur
463	 */
464	sqcc = sq->cc;
465
466	while (budget > 0) {
467		struct mlx5_cqe64 *cqe;
468		struct mbuf *mb;
469		u16 x;
470		u16 ci;
471
472		cqe = mlx5e_get_cqe(&sq->cq);
473		if (!cqe)
474			break;
475
476		mlx5_cqwq_pop(&sq->cq.wq);
477
478		/* update budget according to the event factor */
479		budget -= sq->cev_factor;
480
481		for (x = 0; x != sq->cev_factor; x++) {
482			ci = sqcc & sq->wq.sz_m1;
483			mb = sq->mbuf[ci].mbuf;
484			sq->mbuf[ci].mbuf = NULL;	/* Safety clear */
485
486			if (mb == NULL) {
487				if (sq->mbuf[ci].num_bytes == 0) {
488					/* NOP */
489					sq->stats.nop++;
490				}
491			} else {
492				bus_dmamap_sync(sq->dma_tag, sq->mbuf[ci].dma_map,
493				    BUS_DMASYNC_POSTWRITE);
494				bus_dmamap_unload(sq->dma_tag, sq->mbuf[ci].dma_map);
495
496				/* Free transmitted mbuf */
497				m_freem(mb);
498			}
499			sqcc += sq->mbuf[ci].num_wqebbs;
500		}
501	}
502
503	mlx5_cqwq_update_db_record(&sq->cq.wq);
504
505	/* Ensure cq space is freed before enabling more cqes */
506	wmb();
507
508	sq->cc = sqcc;
509
510	if (sq->sq_tq != NULL &&
511	    atomic_cmpset_int(&sq->queue_state, MLX5E_SQ_FULL, MLX5E_SQ_READY))
512		taskqueue_enqueue(sq->sq_tq, &sq->sq_task);
513}
514
515static int
516mlx5e_xmit_locked(struct ifnet *ifp, struct mlx5e_sq *sq, struct mbuf *mb)
517{
518	struct mbuf *next;
519	int err = 0;
520
521	if (likely(mb != NULL)) {
522		/*
523		 * If we can't insert mbuf into drbr, try to xmit anyway.
524		 * We keep the error we got so we could return that after xmit.
525		 */
526		err = drbr_enqueue(ifp, sq->br, mb);
527	}
528
529	/*
530	 * Check if the network interface is closed or if the SQ is
531	 * being stopped:
532	 */
533	if (unlikely((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
534	    sq->stopped != 0))
535		return (err);
536
537	/* Process the queue */
538	while ((next = drbr_peek(ifp, sq->br)) != NULL) {
539		if (mlx5e_sq_xmit(sq, &next) != 0) {
540			if (next != NULL) {
541				drbr_putback(ifp, sq->br, next);
542				atomic_store_rel_int(&sq->queue_state, MLX5E_SQ_FULL);
543				break;
544			}
545		}
546		drbr_advance(ifp, sq->br);
547	}
548	/* Check if we need to write the doorbell */
549	if (likely(sq->doorbell.d64 != 0)) {
550		mlx5e_tx_notify_hw(sq, sq->doorbell.d32, 0);
551		sq->doorbell.d64 = 0;
552	}
553	/*
554	 * Check if we need to start the event timer which flushes the
555	 * transmit ring on timeout:
556	 */
557	if (unlikely(sq->cev_next_state == MLX5E_CEV_STATE_INITIAL &&
558	    sq->cev_factor != 1)) {
559		/* start the timer */
560		mlx5e_sq_cev_timeout(sq);
561	} else {
562		/* don't send NOPs yet */
563		sq->cev_next_state = MLX5E_CEV_STATE_HOLD_NOPS;
564	}
565	return (err);
566}
567
568static int
569mlx5e_xmit_locked_no_br(struct ifnet *ifp, struct mlx5e_sq *sq, struct mbuf *mb)
570{
571	int err = 0;
572
573	if (unlikely((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
574	    sq->stopped != 0)) {
575		m_freem(mb);
576		return (ENETDOWN);
577	}
578
579	/* Do transmit */
580	if (mlx5e_sq_xmit(sq, &mb) != 0) {
581		/* NOTE: m_freem() is NULL safe */
582		m_freem(mb);
583		err = ENOBUFS;
584	}
585
586	/* Check if we need to write the doorbell */
587	if (likely(sq->doorbell.d64 != 0)) {
588		mlx5e_tx_notify_hw(sq, sq->doorbell.d32, 0);
589		sq->doorbell.d64 = 0;
590	}
591
592	/*
593	 * Check if we need to start the event timer which flushes the
594	 * transmit ring on timeout:
595	 */
596	if (unlikely(sq->cev_next_state == MLX5E_CEV_STATE_INITIAL &&
597	    sq->cev_factor != 1)) {
598		/* start the timer */
599		mlx5e_sq_cev_timeout(sq);
600	} else {
601		/* don't send NOPs yet */
602		sq->cev_next_state = MLX5E_CEV_STATE_HOLD_NOPS;
603	}
604	return (err);
605}
606
607int
608mlx5e_xmit(struct ifnet *ifp, struct mbuf *mb)
609{
610	struct mlx5e_sq *sq;
611	int ret;
612
613	sq = mlx5e_select_queue(ifp, mb);
614	if (unlikely(sq == NULL)) {
615		/* Invalid send queue */
616		m_freem(mb);
617		return (ENXIO);
618	}
619
620	if (unlikely(sq->br == NULL)) {
621		/* rate limited traffic */
622		mtx_lock(&sq->lock);
623		ret = mlx5e_xmit_locked_no_br(ifp, sq, mb);
624		mtx_unlock(&sq->lock);
625	} else if (mtx_trylock(&sq->lock)) {
626		ret = mlx5e_xmit_locked(ifp, sq, mb);
627		mtx_unlock(&sq->lock);
628	} else {
629		ret = drbr_enqueue(ifp, sq->br, mb);
630		taskqueue_enqueue(sq->sq_tq, &sq->sq_task);
631	}
632
633	return (ret);
634}
635
636void
637mlx5e_tx_cq_comp(struct mlx5_core_cq *mcq)
638{
639	struct mlx5e_sq *sq = container_of(mcq, struct mlx5e_sq, cq.mcq);
640
641	mtx_lock(&sq->comp_lock);
642	mlx5e_poll_tx_cq(sq, MLX5E_BUDGET_MAX);
643	mlx5e_cq_arm(&sq->cq, MLX5_GET_DOORBELL_LOCK(&sq->priv->doorbell_lock));
644	mtx_unlock(&sq->comp_lock);
645}
646
647void
648mlx5e_tx_que(void *context, int pending)
649{
650	struct mlx5e_sq *sq = context;
651	struct ifnet *ifp = sq->ifp;
652
653	if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
654		mtx_lock(&sq->lock);
655		if (!drbr_empty(ifp, sq->br))
656			mlx5e_xmit_locked(ifp, sq, NULL);
657		mtx_unlock(&sq->lock);
658	}
659}
660