xref: /freebsd/sys/dev/sfxge/sfxge_tx.c (revision b1f9167f94059fd55c630891d359bcff987bd7eb)
1 /*-
2  * Copyright (c) 2010-2011 Solarflare Communications, Inc.
3  * All rights reserved.
4  *
5  * This software was developed in part by Philip Paeps under contract for
6  * Solarflare Communications, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /* Theory of operation:
31  *
32  * Tx queues allocation and mapping
33  *
34  * One Tx queue with enabled checksum offload is allocated per Rx channel
35  * (event queue).  Also 2 Tx queues (one without checksum offload and one
36  * with IP checksum offload only) are allocated and bound to event queue 0.
37  * sfxge_txq_type is used as Tx queue label.
38  *
39  * So, event queue plus label mapping to Tx queue index is:
40  *	if event queue index is 0, TxQ-index = TxQ-label * [0..SFXGE_TXQ_NTYPES)
41  *	else TxQ-index = SFXGE_TXQ_NTYPES + EvQ-index - 1
42  * See sfxge_get_txq_by_label() sfxge_ev.c
43  */
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include <sys/types.h>
49 #include <sys/mbuf.h>
50 #include <sys/smp.h>
51 #include <sys/socket.h>
52 #include <sys/sysctl.h>
53 
54 #include <net/bpf.h>
55 #include <net/ethernet.h>
56 #include <net/if.h>
57 #include <net/if_vlan_var.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/ip.h>
61 #include <netinet/ip6.h>
62 #include <netinet/tcp.h>
63 
64 #include "common/efx.h"
65 
66 #include "sfxge.h"
67 #include "sfxge_tx.h"
68 
69 /* Set the block level to ensure there is space to generate a
70  * large number of descriptors for TSO.  With minimum MSS and
71  * maximum mbuf length we might need more than a ring-ful of
72  * descriptors, but this should not happen in practice except
73  * due to deliberate attack.  In that case we will truncate
74  * the output at a packet boundary.  Allow for a reasonable
75  * minimum MSS of 512.
76  */
77 #define SFXGE_TSO_MAX_DESC ((65535 / 512) * 2 + SFXGE_TX_MAPPING_MAX_SEG - 1)
78 #define SFXGE_TXQ_BLOCK_LEVEL (SFXGE_NDESCS - SFXGE_TSO_MAX_DESC)
79 
80 /* Forward declarations. */
81 static inline void sfxge_tx_qdpl_service(struct sfxge_txq *txq);
82 static void sfxge_tx_qlist_post(struct sfxge_txq *txq);
83 static void sfxge_tx_qunblock(struct sfxge_txq *txq);
84 static int sfxge_tx_queue_tso(struct sfxge_txq *txq, struct mbuf *mbuf,
85 			      const bus_dma_segment_t *dma_seg, int n_dma_seg);
86 
87 void
88 sfxge_tx_qcomplete(struct sfxge_txq *txq)
89 {
90 	struct sfxge_softc *sc;
91 	struct sfxge_evq *evq;
92 	unsigned int completed;
93 
94 	sc = txq->sc;
95 	evq = sc->evq[txq->evq_index];
96 
97 	mtx_assert(&evq->lock, MA_OWNED);
98 
99 	completed = txq->completed;
100 	while (completed != txq->pending) {
101 		struct sfxge_tx_mapping *stmp;
102 		unsigned int id;
103 
104 		id = completed++ & (SFXGE_NDESCS - 1);
105 
106 		stmp = &txq->stmp[id];
107 		if (stmp->flags & TX_BUF_UNMAP) {
108 			bus_dmamap_unload(txq->packet_dma_tag, stmp->map);
109 			if (stmp->flags & TX_BUF_MBUF) {
110 				struct mbuf *m = stmp->u.mbuf;
111 				do
112 					m = m_free(m);
113 				while (m != NULL);
114 			} else {
115 				free(stmp->u.heap_buf, M_SFXGE);
116 			}
117 			stmp->flags = 0;
118 		}
119 	}
120 	txq->completed = completed;
121 
122 	/* Check whether we need to unblock the queue. */
123 	mb();
124 	if (txq->blocked) {
125 		unsigned int level;
126 
127 		level = txq->added - txq->completed;
128 		if (level <= SFXGE_TXQ_UNBLOCK_LEVEL)
129 			sfxge_tx_qunblock(txq);
130 	}
131 }
132 
133 #ifdef SFXGE_HAVE_MQ
134 
135 /*
136  * Reorder the put list and append it to the get list.
137  */
138 static void
139 sfxge_tx_qdpl_swizzle(struct sfxge_txq *txq)
140 {
141 	struct sfxge_tx_dpl *stdp;
142 	struct mbuf *mbuf, *get_next, **get_tailp;
143 	volatile uintptr_t *putp;
144 	uintptr_t put;
145 	unsigned int count;
146 
147 	mtx_assert(&txq->lock, MA_OWNED);
148 
149 	stdp = &txq->dpl;
150 
151 	/* Acquire the put list. */
152 	putp = &stdp->std_put;
153 	put = atomic_readandclear_ptr(putp);
154 	mbuf = (void *)put;
155 
156 	if (mbuf == NULL)
157 		return;
158 
159 	/* Reverse the put list. */
160 	get_tailp = &mbuf->m_nextpkt;
161 	get_next = NULL;
162 
163 	count = 0;
164 	do {
165 		struct mbuf *put_next;
166 
167 		put_next = mbuf->m_nextpkt;
168 		mbuf->m_nextpkt = get_next;
169 		get_next = mbuf;
170 		mbuf = put_next;
171 
172 		count++;
173 	} while (mbuf != NULL);
174 
175 	/* Append the reversed put list to the get list. */
176 	KASSERT(*get_tailp == NULL, ("*get_tailp != NULL"));
177 	*stdp->std_getp = get_next;
178 	stdp->std_getp = get_tailp;
179 	stdp->std_count += count;
180 }
181 
182 #endif /* SFXGE_HAVE_MQ */
183 
184 static void
185 sfxge_tx_qreap(struct sfxge_txq *txq)
186 {
187 	mtx_assert(SFXGE_TXQ_LOCK(txq), MA_OWNED);
188 
189 	txq->reaped = txq->completed;
190 }
191 
192 static void
193 sfxge_tx_qlist_post(struct sfxge_txq *txq)
194 {
195 	unsigned int old_added;
196 	unsigned int level;
197 	int rc;
198 
199 	mtx_assert(SFXGE_TXQ_LOCK(txq), MA_OWNED);
200 
201 	KASSERT(txq->n_pend_desc != 0, ("txq->n_pend_desc == 0"));
202 	KASSERT(txq->n_pend_desc <= SFXGE_TSO_MAX_DESC,
203 		("txq->n_pend_desc too large"));
204 	KASSERT(!txq->blocked, ("txq->blocked"));
205 
206 	old_added = txq->added;
207 
208 	/* Post the fragment list. */
209 	rc = efx_tx_qpost(txq->common, txq->pend_desc, txq->n_pend_desc,
210 			  txq->reaped, &txq->added);
211 	KASSERT(rc == 0, ("efx_tx_qpost() failed"));
212 
213 	/* If efx_tx_qpost() had to refragment, our information about
214 	 * buffers to free may be associated with the wrong
215 	 * descriptors.
216 	 */
217 	KASSERT(txq->added - old_added == txq->n_pend_desc,
218 		("efx_tx_qpost() refragmented descriptors"));
219 
220 	level = txq->added - txq->reaped;
221 	KASSERT(level <= SFXGE_NDESCS, ("overfilled TX queue"));
222 
223 	/* Clear the fragment list. */
224 	txq->n_pend_desc = 0;
225 
226 	/* Have we reached the block level? */
227 	if (level < SFXGE_TXQ_BLOCK_LEVEL)
228 		return;
229 
230 	/* Reap, and check again */
231 	sfxge_tx_qreap(txq);
232 	level = txq->added - txq->reaped;
233 	if (level < SFXGE_TXQ_BLOCK_LEVEL)
234 		return;
235 
236 	txq->blocked = 1;
237 
238 	/*
239 	 * Avoid a race with completion interrupt handling that could leave
240 	 * the queue blocked.
241 	 */
242 	mb();
243 	sfxge_tx_qreap(txq);
244 	level = txq->added - txq->reaped;
245 	if (level < SFXGE_TXQ_BLOCK_LEVEL) {
246 		mb();
247 		txq->blocked = 0;
248 	}
249 }
250 
251 static int sfxge_tx_queue_mbuf(struct sfxge_txq *txq, struct mbuf *mbuf)
252 {
253 	bus_dmamap_t *used_map;
254 	bus_dmamap_t map;
255 	bus_dma_segment_t dma_seg[SFXGE_TX_MAPPING_MAX_SEG];
256 	unsigned int id;
257 	struct sfxge_tx_mapping *stmp;
258 	efx_buffer_t *desc;
259 	int n_dma_seg;
260 	int rc;
261 	int i;
262 
263 	KASSERT(!txq->blocked, ("txq->blocked"));
264 
265 	if (mbuf->m_pkthdr.csum_flags & CSUM_TSO)
266 		prefetch_read_many(mbuf->m_data);
267 
268 	if (txq->init_state != SFXGE_TXQ_STARTED) {
269 		rc = EINTR;
270 		goto reject;
271 	}
272 
273 	/* Load the packet for DMA. */
274 	id = txq->added & (SFXGE_NDESCS - 1);
275 	stmp = &txq->stmp[id];
276 	rc = bus_dmamap_load_mbuf_sg(txq->packet_dma_tag, stmp->map,
277 				     mbuf, dma_seg, &n_dma_seg, 0);
278 	if (rc == EFBIG) {
279 		/* Try again. */
280 		struct mbuf *new_mbuf = m_collapse(mbuf, M_NOWAIT,
281 						   SFXGE_TX_MAPPING_MAX_SEG);
282 		if (new_mbuf == NULL)
283 			goto reject;
284 		++txq->collapses;
285 		mbuf = new_mbuf;
286 		rc = bus_dmamap_load_mbuf_sg(txq->packet_dma_tag,
287 					     stmp->map, mbuf,
288 					     dma_seg, &n_dma_seg, 0);
289 	}
290 	if (rc != 0)
291 		goto reject;
292 
293 	/* Make the packet visible to the hardware. */
294 	bus_dmamap_sync(txq->packet_dma_tag, stmp->map, BUS_DMASYNC_PREWRITE);
295 
296 	used_map = &stmp->map;
297 
298 	if (mbuf->m_pkthdr.csum_flags & CSUM_TSO) {
299 		rc = sfxge_tx_queue_tso(txq, mbuf, dma_seg, n_dma_seg);
300 		if (rc < 0)
301 			goto reject_mapped;
302 		stmp = &txq->stmp[rc];
303 	} else {
304 		/* Add the mapping to the fragment list, and set flags
305 		 * for the buffer.
306 		 */
307 		i = 0;
308 		for (;;) {
309 			desc = &txq->pend_desc[i];
310 			desc->eb_addr = dma_seg[i].ds_addr;
311 			desc->eb_size = dma_seg[i].ds_len;
312 			if (i == n_dma_seg - 1) {
313 				desc->eb_eop = 1;
314 				break;
315 			}
316 			desc->eb_eop = 0;
317 			i++;
318 
319 			stmp->flags = 0;
320 			if (__predict_false(stmp ==
321 					    &txq->stmp[SFXGE_NDESCS - 1]))
322 				stmp = &txq->stmp[0];
323 			else
324 				stmp++;
325 		}
326 		txq->n_pend_desc = n_dma_seg;
327 	}
328 
329 	/*
330 	 * If the mapping required more than one descriptor
331 	 * then we need to associate the DMA map with the last
332 	 * descriptor, not the first.
333 	 */
334 	if (used_map != &stmp->map) {
335 		map = stmp->map;
336 		stmp->map = *used_map;
337 		*used_map = map;
338 	}
339 
340 	stmp->u.mbuf = mbuf;
341 	stmp->flags = TX_BUF_UNMAP | TX_BUF_MBUF;
342 
343 	/* Post the fragment list. */
344 	sfxge_tx_qlist_post(txq);
345 
346 	return 0;
347 
348 reject_mapped:
349 	bus_dmamap_unload(txq->packet_dma_tag, *used_map);
350 reject:
351 	/* Drop the packet on the floor. */
352 	m_freem(mbuf);
353 	++txq->drops;
354 
355 	return rc;
356 }
357 
358 #ifdef SFXGE_HAVE_MQ
359 
360 /*
361  * Drain the deferred packet list into the transmit queue.
362  */
363 static void
364 sfxge_tx_qdpl_drain(struct sfxge_txq *txq)
365 {
366 	struct sfxge_softc *sc;
367 	struct sfxge_tx_dpl *stdp;
368 	struct mbuf *mbuf, *next;
369 	unsigned int count;
370 	unsigned int pushed;
371 	int rc;
372 
373 	mtx_assert(&txq->lock, MA_OWNED);
374 
375 	sc = txq->sc;
376 	stdp = &txq->dpl;
377 	pushed = txq->added;
378 
379 	prefetch_read_many(sc->enp);
380 	prefetch_read_many(txq->common);
381 
382 	mbuf = stdp->std_get;
383 	count = stdp->std_count;
384 
385 	while (count != 0) {
386 		KASSERT(mbuf != NULL, ("mbuf == NULL"));
387 
388 		next = mbuf->m_nextpkt;
389 		mbuf->m_nextpkt = NULL;
390 
391 		ETHER_BPF_MTAP(sc->ifnet, mbuf); /* packet capture */
392 
393 		if (next != NULL)
394 			prefetch_read_many(next);
395 
396 		rc = sfxge_tx_queue_mbuf(txq, mbuf);
397 		--count;
398 		mbuf = next;
399 		if (rc != 0)
400 			continue;
401 
402 		if (txq->blocked)
403 			break;
404 
405 		/* Push the fragments to the hardware in batches. */
406 		if (txq->added - pushed >= SFXGE_TX_BATCH) {
407 			efx_tx_qpush(txq->common, txq->added);
408 			pushed = txq->added;
409 		}
410 	}
411 
412 	if (count == 0) {
413 		KASSERT(mbuf == NULL, ("mbuf != NULL"));
414 		stdp->std_get = NULL;
415 		stdp->std_count = 0;
416 		stdp->std_getp = &stdp->std_get;
417 	} else {
418 		stdp->std_get = mbuf;
419 		stdp->std_count = count;
420 	}
421 
422 	if (txq->added != pushed)
423 		efx_tx_qpush(txq->common, txq->added);
424 
425 	KASSERT(txq->blocked || stdp->std_count == 0,
426 		("queue unblocked but count is non-zero"));
427 }
428 
429 #define SFXGE_TX_QDPL_PENDING(_txq)					\
430     ((_txq)->dpl.std_put != 0)
431 
432 /*
433  * Service the deferred packet list.
434  *
435  * NOTE: drops the txq mutex!
436  */
437 static inline void
438 sfxge_tx_qdpl_service(struct sfxge_txq *txq)
439 {
440 	mtx_assert(&txq->lock, MA_OWNED);
441 
442 	do {
443 		if (SFXGE_TX_QDPL_PENDING(txq))
444 			sfxge_tx_qdpl_swizzle(txq);
445 
446 		if (!txq->blocked)
447 			sfxge_tx_qdpl_drain(txq);
448 
449 		mtx_unlock(&txq->lock);
450 	} while (SFXGE_TX_QDPL_PENDING(txq) &&
451 		 mtx_trylock(&txq->lock));
452 }
453 
454 /*
455  * Put a packet on the deferred packet list.
456  *
457  * If we are called with the txq lock held, we put the packet on the "get
458  * list", otherwise we atomically push it on the "put list".  The swizzle
459  * function takes care of ordering.
460  *
461  * The length of the put list is bounded by SFXGE_TX_MAX_DEFFERED.  We
462  * overload the csum_data field in the mbuf to keep track of this length
463  * because there is no cheap alternative to avoid races.
464  */
465 static inline int
466 sfxge_tx_qdpl_put(struct sfxge_txq *txq, struct mbuf *mbuf, int locked)
467 {
468 	struct sfxge_tx_dpl *stdp;
469 
470 	stdp = &txq->dpl;
471 
472 	KASSERT(mbuf->m_nextpkt == NULL, ("mbuf->m_nextpkt != NULL"));
473 
474 	if (locked) {
475 		mtx_assert(&txq->lock, MA_OWNED);
476 
477 		sfxge_tx_qdpl_swizzle(txq);
478 
479 		if (stdp->std_count >= SFXGE_TX_DPL_GET_PKT_LIMIT_DEFAULT)
480 			return (ENOBUFS);
481 
482 		*(stdp->std_getp) = mbuf;
483 		stdp->std_getp = &mbuf->m_nextpkt;
484 		stdp->std_count++;
485 	} else {
486 		volatile uintptr_t *putp;
487 		uintptr_t old;
488 		uintptr_t new;
489 		unsigned old_len;
490 
491 		putp = &stdp->std_put;
492 		new = (uintptr_t)mbuf;
493 
494 		do {
495 			old = *putp;
496 			if (old) {
497 				struct mbuf *mp = (struct mbuf *)old;
498 				old_len = mp->m_pkthdr.csum_data;
499 			} else
500 				old_len = 0;
501 			if (old_len >= SFXGE_TX_DPL_PUT_PKT_LIMIT_DEFAULT)
502 				return (ENOBUFS);
503 			mbuf->m_pkthdr.csum_data = old_len + 1;
504 			mbuf->m_nextpkt = (void *)old;
505 		} while (atomic_cmpset_ptr(putp, old, new) == 0);
506 	}
507 
508 	return (0);
509 }
510 
511 /*
512  * Called from if_transmit - will try to grab the txq lock and enqueue to the
513  * put list if it succeeds, otherwise will push onto the defer list.
514  */
515 int
516 sfxge_tx_packet_add(struct sfxge_txq *txq, struct mbuf *m)
517 {
518 	int locked;
519 	int rc;
520 
521 	if (!SFXGE_LINK_UP(txq->sc)) {
522 		rc = ENETDOWN;
523 		goto fail;
524 	}
525 
526 	/*
527 	 * Try to grab the txq lock.  If we are able to get the lock,
528 	 * the packet will be appended to the "get list" of the deferred
529 	 * packet list.  Otherwise, it will be pushed on the "put list".
530 	 */
531 	locked = mtx_trylock(&txq->lock);
532 
533 	if (sfxge_tx_qdpl_put(txq, m, locked) != 0) {
534 		if (locked)
535 			mtx_unlock(&txq->lock);
536 		rc = ENOBUFS;
537 		goto fail;
538 	}
539 
540 	/*
541 	 * Try to grab the lock again.
542 	 *
543 	 * If we are able to get the lock, we need to process the deferred
544 	 * packet list.  If we are not able to get the lock, another thread
545 	 * is processing the list.
546 	 */
547 	if (!locked)
548 		locked = mtx_trylock(&txq->lock);
549 
550 	if (locked) {
551 		/* Try to service the list. */
552 		sfxge_tx_qdpl_service(txq);
553 		/* Lock has been dropped. */
554 	}
555 
556 	return (0);
557 
558 fail:
559 	m_freem(m);
560 	atomic_add_long(&txq->early_drops, 1);
561 	return (rc);
562 
563 }
564 
565 static void
566 sfxge_tx_qdpl_flush(struct sfxge_txq *txq)
567 {
568 	struct sfxge_tx_dpl *stdp = &txq->dpl;
569 	struct mbuf *mbuf, *next;
570 
571 	mtx_lock(&txq->lock);
572 
573 	sfxge_tx_qdpl_swizzle(txq);
574 	for (mbuf = stdp->std_get; mbuf != NULL; mbuf = next) {
575 		next = mbuf->m_nextpkt;
576 		m_freem(mbuf);
577 	}
578 	stdp->std_get = NULL;
579 	stdp->std_count = 0;
580 	stdp->std_getp = &stdp->std_get;
581 
582 	mtx_unlock(&txq->lock);
583 }
584 
585 void
586 sfxge_if_qflush(struct ifnet *ifp)
587 {
588 	struct sfxge_softc *sc;
589 	int i;
590 
591 	sc = ifp->if_softc;
592 
593 	for (i = 0; i < SFXGE_TX_SCALE(sc); i++)
594 		sfxge_tx_qdpl_flush(sc->txq[i]);
595 }
596 
597 /*
598  * TX start -- called by the stack.
599  */
600 int
601 sfxge_if_transmit(struct ifnet *ifp, struct mbuf *m)
602 {
603 	struct sfxge_softc *sc;
604 	struct sfxge_txq *txq;
605 	int rc;
606 
607 	sc = (struct sfxge_softc *)ifp->if_softc;
608 
609 	KASSERT(ifp->if_flags & IFF_UP, ("interface not up"));
610 
611 	/* Pick the desired transmit queue. */
612 	if (m->m_pkthdr.csum_flags & (CSUM_DELAY_DATA | CSUM_TSO)) {
613 		int index = 0;
614 
615 		if (m->m_flags & M_FLOWID) {
616 			uint32_t hash = m->m_pkthdr.flowid;
617 
618 			index = sc->rx_indir_table[hash % SFXGE_RX_SCALE_MAX];
619 		}
620 		txq = sc->txq[SFXGE_TXQ_IP_TCP_UDP_CKSUM + index];
621 	} else if (m->m_pkthdr.csum_flags & CSUM_DELAY_IP) {
622 		txq = sc->txq[SFXGE_TXQ_IP_CKSUM];
623 	} else {
624 		txq = sc->txq[SFXGE_TXQ_NON_CKSUM];
625 	}
626 
627 	rc = sfxge_tx_packet_add(txq, m);
628 
629 	return (rc);
630 }
631 
632 #else /* !SFXGE_HAVE_MQ */
633 
634 static void sfxge_if_start_locked(struct ifnet *ifp)
635 {
636 	struct sfxge_softc *sc = ifp->if_softc;
637 	struct sfxge_txq *txq;
638 	struct mbuf *mbuf;
639 	unsigned int pushed[SFXGE_TXQ_NTYPES];
640 	unsigned int q_index;
641 
642 	if ((ifp->if_drv_flags & (IFF_DRV_RUNNING|IFF_DRV_OACTIVE)) !=
643 	    IFF_DRV_RUNNING)
644 		return;
645 
646 	if (!sc->port.link_up)
647 		return;
648 
649 	for (q_index = 0; q_index < SFXGE_TXQ_NTYPES; q_index++) {
650 		txq = sc->txq[q_index];
651 		pushed[q_index] = txq->added;
652 	}
653 
654 	while (!IFQ_DRV_IS_EMPTY(&ifp->if_snd)) {
655                 IFQ_DRV_DEQUEUE(&ifp->if_snd, mbuf);
656 		if (mbuf == NULL)
657 			break;
658 
659 		ETHER_BPF_MTAP(ifp, mbuf); /* packet capture */
660 
661 		/* Pick the desired transmit queue. */
662 		if (mbuf->m_pkthdr.csum_flags & (CSUM_DELAY_DATA | CSUM_TSO))
663 			q_index = SFXGE_TXQ_IP_TCP_UDP_CKSUM;
664 		else if (mbuf->m_pkthdr.csum_flags & CSUM_DELAY_IP)
665 			q_index = SFXGE_TXQ_IP_CKSUM;
666 		else
667 			q_index = SFXGE_TXQ_NON_CKSUM;
668 		txq = sc->txq[q_index];
669 
670 		if (sfxge_tx_queue_mbuf(txq, mbuf) != 0)
671 			continue;
672 
673 		if (txq->blocked) {
674 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
675 			break;
676 		}
677 
678 		/* Push the fragments to the hardware in batches. */
679 		if (txq->added - pushed[q_index] >= SFXGE_TX_BATCH) {
680 			efx_tx_qpush(txq->common, txq->added);
681 			pushed[q_index] = txq->added;
682 		}
683 	}
684 
685 	for (q_index = 0; q_index < SFXGE_TXQ_NTYPES; q_index++) {
686 		txq = sc->txq[q_index];
687 		if (txq->added != pushed[q_index])
688 			efx_tx_qpush(txq->common, txq->added);
689 	}
690 }
691 
692 void sfxge_if_start(struct ifnet *ifp)
693 {
694 	struct sfxge_softc *sc = ifp->if_softc;
695 
696 	mtx_lock(&sc->tx_lock);
697 	sfxge_if_start_locked(ifp);
698 	mtx_unlock(&sc->tx_lock);
699 }
700 
701 static inline void
702 sfxge_tx_qdpl_service(struct sfxge_txq *txq)
703 {
704 	struct sfxge_softc *sc = txq->sc;
705 	struct ifnet *ifp = sc->ifnet;
706 
707 	mtx_assert(&sc->tx_lock, MA_OWNED);
708 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
709 	sfxge_if_start_locked(ifp);
710 	mtx_unlock(&sc->tx_lock);
711 }
712 
713 #endif /* SFXGE_HAVE_MQ */
714 
715 /*
716  * Software "TSO".  Not quite as good as doing it in hardware, but
717  * still faster than segmenting in the stack.
718  */
719 
720 struct sfxge_tso_state {
721 	/* Output position */
722 	unsigned out_len;	/* Remaining length in current segment */
723 	unsigned seqnum;	/* Current sequence number */
724 	unsigned packet_space;	/* Remaining space in current packet */
725 
726 	/* Input position */
727 	unsigned dma_seg_i;	/* Current DMA segment number */
728 	uint64_t dma_addr;	/* DMA address of current position */
729 	unsigned in_len;	/* Remaining length in current mbuf */
730 
731 	const struct mbuf *mbuf; /* Input mbuf (head of chain) */
732 	u_short protocol;	/* Network protocol (after VLAN decap) */
733 	ssize_t nh_off;		/* Offset of network header */
734 	ssize_t tcph_off;	/* Offset of TCP header */
735 	unsigned header_len;	/* Number of bytes of header */
736 	int full_packet_size;	/* Number of bytes to put in each outgoing
737 				 * segment */
738 };
739 
740 static inline const struct ip *tso_iph(const struct sfxge_tso_state *tso)
741 {
742 	KASSERT(tso->protocol == htons(ETHERTYPE_IP),
743 		("tso_iph() in non-IPv4 state"));
744 	return (const struct ip *)(tso->mbuf->m_data + tso->nh_off);
745 }
746 static inline const struct ip6_hdr *tso_ip6h(const struct sfxge_tso_state *tso)
747 {
748 	KASSERT(tso->protocol == htons(ETHERTYPE_IPV6),
749 		("tso_ip6h() in non-IPv6 state"));
750 	return (const struct ip6_hdr *)(tso->mbuf->m_data + tso->nh_off);
751 }
752 static inline const struct tcphdr *tso_tcph(const struct sfxge_tso_state *tso)
753 {
754 	return (const struct tcphdr *)(tso->mbuf->m_data + tso->tcph_off);
755 }
756 
757 /* Size of preallocated TSO header buffers.  Larger blocks must be
758  * allocated from the heap.
759  */
760 #define TSOH_STD_SIZE	128
761 
762 /* At most half the descriptors in the queue at any time will refer to
763  * a TSO header buffer, since they must always be followed by a
764  * payload descriptor referring to an mbuf.
765  */
766 #define TSOH_COUNT	(SFXGE_NDESCS / 2u)
767 #define TSOH_PER_PAGE	(PAGE_SIZE / TSOH_STD_SIZE)
768 #define TSOH_PAGE_COUNT	((TSOH_COUNT + TSOH_PER_PAGE - 1) / TSOH_PER_PAGE)
769 
770 static int tso_init(struct sfxge_txq *txq)
771 {
772 	struct sfxge_softc *sc = txq->sc;
773 	int i, rc;
774 
775 	/* Allocate TSO header buffers */
776 	txq->tsoh_buffer = malloc(TSOH_PAGE_COUNT * sizeof(txq->tsoh_buffer[0]),
777 				  M_SFXGE, M_WAITOK);
778 
779 	for (i = 0; i < TSOH_PAGE_COUNT; i++) {
780 		rc = sfxge_dma_alloc(sc, PAGE_SIZE, &txq->tsoh_buffer[i]);
781 		if (rc)
782 			goto fail;
783 	}
784 
785 	return 0;
786 
787 fail:
788 	while (i-- > 0)
789 		sfxge_dma_free(&txq->tsoh_buffer[i]);
790 	free(txq->tsoh_buffer, M_SFXGE);
791 	txq->tsoh_buffer = NULL;
792 	return rc;
793 }
794 
795 static void tso_fini(struct sfxge_txq *txq)
796 {
797 	int i;
798 
799 	if (txq->tsoh_buffer) {
800 		for (i = 0; i < TSOH_PAGE_COUNT; i++)
801 			sfxge_dma_free(&txq->tsoh_buffer[i]);
802 		free(txq->tsoh_buffer, M_SFXGE);
803 	}
804 }
805 
806 static void tso_start(struct sfxge_tso_state *tso, struct mbuf *mbuf)
807 {
808 	struct ether_header *eh = mtod(mbuf, struct ether_header *);
809 
810 	tso->mbuf = mbuf;
811 
812 	/* Find network protocol and header */
813 	tso->protocol = eh->ether_type;
814 	if (tso->protocol == htons(ETHERTYPE_VLAN)) {
815 		struct ether_vlan_header *veh =
816 			mtod(mbuf, struct ether_vlan_header *);
817 		tso->protocol = veh->evl_proto;
818 		tso->nh_off = sizeof(*veh);
819 	} else {
820 		tso->nh_off = sizeof(*eh);
821 	}
822 
823 	/* Find TCP header */
824 	if (tso->protocol == htons(ETHERTYPE_IP)) {
825 		KASSERT(tso_iph(tso)->ip_p == IPPROTO_TCP,
826 			("TSO required on non-TCP packet"));
827 		tso->tcph_off = tso->nh_off + 4 * tso_iph(tso)->ip_hl;
828 	} else {
829 		KASSERT(tso->protocol == htons(ETHERTYPE_IPV6),
830 			("TSO required on non-IP packet"));
831 		KASSERT(tso_ip6h(tso)->ip6_nxt == IPPROTO_TCP,
832 			("TSO required on non-TCP packet"));
833 		tso->tcph_off = tso->nh_off + sizeof(struct ip6_hdr);
834 	}
835 
836 	/* We assume all headers are linear in the head mbuf */
837 	tso->header_len = tso->tcph_off + 4 * tso_tcph(tso)->th_off;
838 	KASSERT(tso->header_len <= mbuf->m_len, ("packet headers fragmented"));
839 	tso->full_packet_size = tso->header_len + mbuf->m_pkthdr.tso_segsz;
840 
841 	tso->seqnum = ntohl(tso_tcph(tso)->th_seq);
842 
843 	/* These flags must not be duplicated */
844 	KASSERT(!(tso_tcph(tso)->th_flags & (TH_URG | TH_SYN | TH_RST)),
845 		("incompatible TCP flag on TSO packet"));
846 
847 	tso->out_len = mbuf->m_pkthdr.len - tso->header_len;
848 }
849 
850 /*
851  * tso_fill_packet_with_fragment - form descriptors for the current fragment
852  *
853  * Form descriptors for the current fragment, until we reach the end
854  * of fragment or end-of-packet.  Return 0 on success, 1 if not enough
855  * space.
856  */
857 static void tso_fill_packet_with_fragment(struct sfxge_txq *txq,
858 					  struct sfxge_tso_state *tso)
859 {
860 	efx_buffer_t *desc;
861 	int n;
862 
863 	if (tso->in_len == 0 || tso->packet_space == 0)
864 		return;
865 
866 	KASSERT(tso->in_len > 0, ("TSO input length went negative"));
867 	KASSERT(tso->packet_space > 0, ("TSO packet space went negative"));
868 
869 	n = min(tso->in_len, tso->packet_space);
870 
871 	tso->packet_space -= n;
872 	tso->out_len -= n;
873 	tso->in_len -= n;
874 
875 	desc = &txq->pend_desc[txq->n_pend_desc++];
876 	desc->eb_addr = tso->dma_addr;
877 	desc->eb_size = n;
878 	desc->eb_eop = tso->out_len == 0 || tso->packet_space == 0;
879 
880 	tso->dma_addr += n;
881 }
882 
883 /* Callback from bus_dmamap_load() for long TSO headers. */
884 static void tso_map_long_header(void *dma_addr_ret,
885 				bus_dma_segment_t *segs, int nseg,
886 				int error)
887 {
888 	*(uint64_t *)dma_addr_ret = ((__predict_true(error == 0) &&
889 				      __predict_true(nseg == 1)) ?
890 				     segs->ds_addr : 0);
891 }
892 
893 /*
894  * tso_start_new_packet - generate a new header and prepare for the new packet
895  *
896  * Generate a new header and prepare for the new packet.  Return 0 on
897  * success, or an error code if failed to alloc header.
898  */
899 static int tso_start_new_packet(struct sfxge_txq *txq,
900 				struct sfxge_tso_state *tso,
901 				unsigned int id)
902 {
903 	struct sfxge_tx_mapping *stmp = &txq->stmp[id];
904 	struct tcphdr *tsoh_th;
905 	unsigned ip_length;
906 	caddr_t header;
907 	uint64_t dma_addr;
908 	bus_dmamap_t map;
909 	efx_buffer_t *desc;
910 	int rc;
911 
912 	/* Allocate a DMA-mapped header buffer. */
913 	if (__predict_true(tso->header_len <= TSOH_STD_SIZE)) {
914 		unsigned int page_index = (id / 2) / TSOH_PER_PAGE;
915 		unsigned int buf_index = (id / 2) % TSOH_PER_PAGE;
916 
917 		header = (txq->tsoh_buffer[page_index].esm_base +
918 			  buf_index * TSOH_STD_SIZE);
919 		dma_addr = (txq->tsoh_buffer[page_index].esm_addr +
920 			    buf_index * TSOH_STD_SIZE);
921 		map = txq->tsoh_buffer[page_index].esm_map;
922 
923 		stmp->flags = 0;
924 	} else {
925 		/* We cannot use bus_dmamem_alloc() as that may sleep */
926 		header = malloc(tso->header_len, M_SFXGE, M_NOWAIT);
927 		if (__predict_false(!header))
928 			return ENOMEM;
929 		rc = bus_dmamap_load(txq->packet_dma_tag, stmp->map,
930 				     header, tso->header_len,
931 				     tso_map_long_header, &dma_addr,
932 				     BUS_DMA_NOWAIT);
933 		if (__predict_false(dma_addr == 0)) {
934 			if (rc == 0) {
935 				/* Succeeded but got >1 segment */
936 				bus_dmamap_unload(txq->packet_dma_tag,
937 						  stmp->map);
938 				rc = EINVAL;
939 			}
940 			free(header, M_SFXGE);
941 			return rc;
942 		}
943 		map = stmp->map;
944 
945 		txq->tso_long_headers++;
946 		stmp->u.heap_buf = header;
947 		stmp->flags = TX_BUF_UNMAP;
948 	}
949 
950 	tsoh_th = (struct tcphdr *)(header + tso->tcph_off);
951 
952 	/* Copy and update the headers. */
953 	memcpy(header, tso->mbuf->m_data, tso->header_len);
954 
955 	tsoh_th->th_seq = htonl(tso->seqnum);
956 	tso->seqnum += tso->mbuf->m_pkthdr.tso_segsz;
957 	if (tso->out_len > tso->mbuf->m_pkthdr.tso_segsz) {
958 		/* This packet will not finish the TSO burst. */
959 		ip_length = tso->full_packet_size - tso->nh_off;
960 		tsoh_th->th_flags &= ~(TH_FIN | TH_PUSH);
961 	} else {
962 		/* This packet will be the last in the TSO burst. */
963 		ip_length = tso->header_len - tso->nh_off + tso->out_len;
964 	}
965 
966 	if (tso->protocol == htons(ETHERTYPE_IP)) {
967 		struct ip *tsoh_iph = (struct ip *)(header + tso->nh_off);
968 		tsoh_iph->ip_len = htons(ip_length);
969 		/* XXX We should increment ip_id, but FreeBSD doesn't
970 		 * currently allocate extra IDs for multiple segments.
971 		 */
972 	} else {
973 		struct ip6_hdr *tsoh_iph =
974 			(struct ip6_hdr *)(header + tso->nh_off);
975 		tsoh_iph->ip6_plen = htons(ip_length - sizeof(*tsoh_iph));
976 	}
977 
978 	/* Make the header visible to the hardware. */
979 	bus_dmamap_sync(txq->packet_dma_tag, map, BUS_DMASYNC_PREWRITE);
980 
981 	tso->packet_space = tso->mbuf->m_pkthdr.tso_segsz;
982 	txq->tso_packets++;
983 
984 	/* Form a descriptor for this header. */
985 	desc = &txq->pend_desc[txq->n_pend_desc++];
986 	desc->eb_addr = dma_addr;
987 	desc->eb_size = tso->header_len;
988 	desc->eb_eop = 0;
989 
990 	return 0;
991 }
992 
993 static int
994 sfxge_tx_queue_tso(struct sfxge_txq *txq, struct mbuf *mbuf,
995 		   const bus_dma_segment_t *dma_seg, int n_dma_seg)
996 {
997 	struct sfxge_tso_state tso;
998 	unsigned int id, next_id;
999 
1000 	tso_start(&tso, mbuf);
1001 
1002 	/* Grab the first payload fragment. */
1003 	if (dma_seg->ds_len == tso.header_len) {
1004 		--n_dma_seg;
1005 		KASSERT(n_dma_seg, ("no payload found in TSO packet"));
1006 		++dma_seg;
1007 		tso.in_len = dma_seg->ds_len;
1008 		tso.dma_addr = dma_seg->ds_addr;
1009 	} else {
1010 		tso.in_len = dma_seg->ds_len - tso.header_len;
1011 		tso.dma_addr = dma_seg->ds_addr + tso.header_len;
1012 	}
1013 
1014 	id = txq->added & (SFXGE_NDESCS - 1);
1015 	if (__predict_false(tso_start_new_packet(txq, &tso, id)))
1016 		return -1;
1017 
1018 	while (1) {
1019 		id = (id + 1) & (SFXGE_NDESCS - 1);
1020 		tso_fill_packet_with_fragment(txq, &tso);
1021 
1022 		/* Move onto the next fragment? */
1023 		if (tso.in_len == 0) {
1024 			--n_dma_seg;
1025 			if (n_dma_seg == 0)
1026 				break;
1027 			++dma_seg;
1028 			tso.in_len = dma_seg->ds_len;
1029 			tso.dma_addr = dma_seg->ds_addr;
1030 		}
1031 
1032 		/* End of packet? */
1033 		if (tso.packet_space == 0) {
1034 			/* If the queue is now full due to tiny MSS,
1035 			 * or we can't create another header, discard
1036 			 * the remainder of the input mbuf but do not
1037 			 * roll back the work we have done.
1038 			 */
1039 			if (txq->n_pend_desc >
1040 			    SFXGE_TSO_MAX_DESC - (1 + SFXGE_TX_MAPPING_MAX_SEG))
1041 				break;
1042 			next_id = (id + 1) & (SFXGE_NDESCS - 1);
1043 			if (__predict_false(tso_start_new_packet(txq, &tso,
1044 								 next_id)))
1045 				break;
1046 			id = next_id;
1047 		}
1048 	}
1049 
1050 	txq->tso_bursts++;
1051 	return id;
1052 }
1053 
1054 static void
1055 sfxge_tx_qunblock(struct sfxge_txq *txq)
1056 {
1057 	struct sfxge_softc *sc;
1058 	struct sfxge_evq *evq;
1059 
1060 	sc = txq->sc;
1061 	evq = sc->evq[txq->evq_index];
1062 
1063 	mtx_assert(&evq->lock, MA_OWNED);
1064 
1065 	if (txq->init_state != SFXGE_TXQ_STARTED)
1066 		return;
1067 
1068 	mtx_lock(SFXGE_TXQ_LOCK(txq));
1069 
1070 	if (txq->blocked) {
1071 		unsigned int level;
1072 
1073 		level = txq->added - txq->completed;
1074 		if (level <= SFXGE_TXQ_UNBLOCK_LEVEL)
1075 			txq->blocked = 0;
1076 	}
1077 
1078 	sfxge_tx_qdpl_service(txq);
1079 	/* note: lock has been dropped */
1080 }
1081 
1082 void
1083 sfxge_tx_qflush_done(struct sfxge_txq *txq)
1084 {
1085 
1086 	txq->flush_state = SFXGE_FLUSH_DONE;
1087 }
1088 
1089 static void
1090 sfxge_tx_qstop(struct sfxge_softc *sc, unsigned int index)
1091 {
1092 	struct sfxge_txq *txq;
1093 	struct sfxge_evq *evq;
1094 	unsigned int count;
1095 
1096 	txq = sc->txq[index];
1097 	evq = sc->evq[txq->evq_index];
1098 
1099 	mtx_lock(SFXGE_TXQ_LOCK(txq));
1100 
1101 	KASSERT(txq->init_state == SFXGE_TXQ_STARTED,
1102 	    ("txq->init_state != SFXGE_TXQ_STARTED"));
1103 
1104 	txq->init_state = SFXGE_TXQ_INITIALIZED;
1105 	txq->flush_state = SFXGE_FLUSH_PENDING;
1106 
1107 	/* Flush the transmit queue. */
1108 	efx_tx_qflush(txq->common);
1109 
1110 	mtx_unlock(SFXGE_TXQ_LOCK(txq));
1111 
1112 	count = 0;
1113 	do {
1114 		/* Spin for 100ms. */
1115 		DELAY(100000);
1116 
1117 		if (txq->flush_state != SFXGE_FLUSH_PENDING)
1118 			break;
1119 	} while (++count < 20);
1120 
1121 	mtx_lock(&evq->lock);
1122 	mtx_lock(SFXGE_TXQ_LOCK(txq));
1123 
1124 	KASSERT(txq->flush_state != SFXGE_FLUSH_FAILED,
1125 	    ("txq->flush_state == SFXGE_FLUSH_FAILED"));
1126 
1127 	txq->flush_state = SFXGE_FLUSH_DONE;
1128 
1129 	txq->blocked = 0;
1130 	txq->pending = txq->added;
1131 
1132 	sfxge_tx_qcomplete(txq);
1133 	KASSERT(txq->completed == txq->added,
1134 	    ("txq->completed != txq->added"));
1135 
1136 	sfxge_tx_qreap(txq);
1137 	KASSERT(txq->reaped == txq->completed,
1138 	    ("txq->reaped != txq->completed"));
1139 
1140 	txq->added = 0;
1141 	txq->pending = 0;
1142 	txq->completed = 0;
1143 	txq->reaped = 0;
1144 
1145 	/* Destroy the common code transmit queue. */
1146 	efx_tx_qdestroy(txq->common);
1147 	txq->common = NULL;
1148 
1149 	efx_sram_buf_tbl_clear(sc->enp, txq->buf_base_id,
1150 	    EFX_TXQ_NBUFS(SFXGE_NDESCS));
1151 
1152 	mtx_unlock(&evq->lock);
1153 	mtx_unlock(SFXGE_TXQ_LOCK(txq));
1154 }
1155 
1156 static int
1157 sfxge_tx_qstart(struct sfxge_softc *sc, unsigned int index)
1158 {
1159 	struct sfxge_txq *txq;
1160 	efsys_mem_t *esmp;
1161 	uint16_t flags;
1162 	struct sfxge_evq *evq;
1163 	int rc;
1164 
1165 	txq = sc->txq[index];
1166 	esmp = &txq->mem;
1167 	evq = sc->evq[txq->evq_index];
1168 
1169 	KASSERT(txq->init_state == SFXGE_TXQ_INITIALIZED,
1170 	    ("txq->init_state != SFXGE_TXQ_INITIALIZED"));
1171 	KASSERT(evq->init_state == SFXGE_EVQ_STARTED,
1172 	    ("evq->init_state != SFXGE_EVQ_STARTED"));
1173 
1174 	/* Program the buffer table. */
1175 	if ((rc = efx_sram_buf_tbl_set(sc->enp, txq->buf_base_id, esmp,
1176 	    EFX_TXQ_NBUFS(SFXGE_NDESCS))) != 0)
1177 		return rc;
1178 
1179 	/* Determine the kind of queue we are creating. */
1180 	switch (txq->type) {
1181 	case SFXGE_TXQ_NON_CKSUM:
1182 		flags = 0;
1183 		break;
1184 	case SFXGE_TXQ_IP_CKSUM:
1185 		flags = EFX_CKSUM_IPV4;
1186 		break;
1187 	case SFXGE_TXQ_IP_TCP_UDP_CKSUM:
1188 		flags = EFX_CKSUM_IPV4 | EFX_CKSUM_TCPUDP;
1189 		break;
1190 	default:
1191 		KASSERT(0, ("Impossible TX queue"));
1192 		flags = 0;
1193 		break;
1194 	}
1195 
1196 	/* Create the common code transmit queue. */
1197 	if ((rc = efx_tx_qcreate(sc->enp, index, txq->type, esmp,
1198 	    SFXGE_NDESCS, txq->buf_base_id, flags, evq->common,
1199 	    &txq->common)) != 0)
1200 		goto fail;
1201 
1202 	mtx_lock(SFXGE_TXQ_LOCK(txq));
1203 
1204 	/* Enable the transmit queue. */
1205 	efx_tx_qenable(txq->common);
1206 
1207 	txq->init_state = SFXGE_TXQ_STARTED;
1208 
1209 	mtx_unlock(SFXGE_TXQ_LOCK(txq));
1210 
1211 	return (0);
1212 
1213 fail:
1214 	efx_sram_buf_tbl_clear(sc->enp, txq->buf_base_id,
1215 	    EFX_TXQ_NBUFS(SFXGE_NDESCS));
1216 	return rc;
1217 }
1218 
1219 void
1220 sfxge_tx_stop(struct sfxge_softc *sc)
1221 {
1222 	const efx_nic_cfg_t *encp;
1223 	int index;
1224 
1225 	index = SFXGE_TX_SCALE(sc);
1226 	while (--index >= 0)
1227 		sfxge_tx_qstop(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM + index);
1228 
1229 	sfxge_tx_qstop(sc, SFXGE_TXQ_IP_CKSUM);
1230 
1231 	encp = efx_nic_cfg_get(sc->enp);
1232         sfxge_tx_qstop(sc, SFXGE_TXQ_NON_CKSUM);
1233 
1234 	/* Tear down the transmit module */
1235 	efx_tx_fini(sc->enp);
1236 }
1237 
1238 int
1239 sfxge_tx_start(struct sfxge_softc *sc)
1240 {
1241 	int index;
1242 	int rc;
1243 
1244 	/* Initialize the common code transmit module. */
1245 	if ((rc = efx_tx_init(sc->enp)) != 0)
1246 		return (rc);
1247 
1248 	if ((rc = sfxge_tx_qstart(sc, SFXGE_TXQ_NON_CKSUM)) != 0)
1249 		goto fail;
1250 
1251 	if ((rc = sfxge_tx_qstart(sc, SFXGE_TXQ_IP_CKSUM)) != 0)
1252 		goto fail2;
1253 
1254 	for (index = 0; index < SFXGE_TX_SCALE(sc); index++) {
1255 		if ((rc = sfxge_tx_qstart(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM +
1256 		    index)) != 0)
1257 			goto fail3;
1258 	}
1259 
1260 	return (0);
1261 
1262 fail3:
1263 	while (--index >= 0)
1264 		sfxge_tx_qstop(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM + index);
1265 
1266 	sfxge_tx_qstop(sc, SFXGE_TXQ_IP_CKSUM);
1267 
1268 fail2:
1269         sfxge_tx_qstop(sc, SFXGE_TXQ_NON_CKSUM);
1270 
1271 fail:
1272 	efx_tx_fini(sc->enp);
1273 
1274 	return (rc);
1275 }
1276 
1277 /**
1278  * Destroy a transmit queue.
1279  */
1280 static void
1281 sfxge_tx_qfini(struct sfxge_softc *sc, unsigned int index)
1282 {
1283 	struct sfxge_txq *txq;
1284 	unsigned int nmaps = SFXGE_NDESCS;
1285 
1286 	txq = sc->txq[index];
1287 
1288 	KASSERT(txq->init_state == SFXGE_TXQ_INITIALIZED,
1289 	    ("txq->init_state != SFXGE_TXQ_INITIALIZED"));
1290 
1291 	if (txq->type == SFXGE_TXQ_IP_TCP_UDP_CKSUM)
1292 		tso_fini(txq);
1293 
1294 	/* Free the context arrays. */
1295 	free(txq->pend_desc, M_SFXGE);
1296 	while (nmaps--)
1297 		bus_dmamap_destroy(txq->packet_dma_tag, txq->stmp[nmaps].map);
1298 	free(txq->stmp, M_SFXGE);
1299 
1300 	/* Release DMA memory mapping. */
1301 	sfxge_dma_free(&txq->mem);
1302 
1303 	sc->txq[index] = NULL;
1304 
1305 #ifdef SFXGE_HAVE_MQ
1306 	mtx_destroy(&txq->lock);
1307 #endif
1308 
1309 	free(txq, M_SFXGE);
1310 }
1311 
1312 static int
1313 sfxge_tx_qinit(struct sfxge_softc *sc, unsigned int txq_index,
1314     enum sfxge_txq_type type, unsigned int evq_index)
1315 {
1316 	struct sfxge_txq *txq;
1317 	struct sfxge_evq *evq;
1318 #ifdef SFXGE_HAVE_MQ
1319 	struct sfxge_tx_dpl *stdp;
1320 #endif
1321 	efsys_mem_t *esmp;
1322 	unsigned int nmaps;
1323 	int rc;
1324 
1325 	txq = malloc(sizeof(struct sfxge_txq), M_SFXGE, M_ZERO | M_WAITOK);
1326 	txq->sc = sc;
1327 
1328 	sc->txq[txq_index] = txq;
1329 	esmp = &txq->mem;
1330 
1331 	evq = sc->evq[evq_index];
1332 
1333 	/* Allocate and zero DMA space for the descriptor ring. */
1334 	if ((rc = sfxge_dma_alloc(sc, EFX_TXQ_SIZE(SFXGE_NDESCS), esmp)) != 0)
1335 		return (rc);
1336 	(void)memset(esmp->esm_base, 0, EFX_TXQ_SIZE(SFXGE_NDESCS));
1337 
1338 	/* Allocate buffer table entries. */
1339 	sfxge_sram_buf_tbl_alloc(sc, EFX_TXQ_NBUFS(SFXGE_NDESCS),
1340 				 &txq->buf_base_id);
1341 
1342 	/* Create a DMA tag for packet mappings. */
1343 	if (bus_dma_tag_create(sc->parent_dma_tag, 1, 0x1000,
1344 	    MIN(0x3FFFFFFFFFFFUL, BUS_SPACE_MAXADDR), BUS_SPACE_MAXADDR, NULL,
1345 	    NULL, 0x11000, SFXGE_TX_MAPPING_MAX_SEG, 0x1000, 0, NULL, NULL,
1346 	    &txq->packet_dma_tag) != 0) {
1347 		device_printf(sc->dev, "Couldn't allocate txq DMA tag\n");
1348 		rc = ENOMEM;
1349 		goto fail;
1350 	}
1351 
1352 	/* Allocate pending descriptor array for batching writes. */
1353 	txq->pend_desc = malloc(sizeof(efx_buffer_t) * SFXGE_NDESCS,
1354 				M_SFXGE, M_ZERO | M_WAITOK);
1355 
1356 	/* Allocate and initialise mbuf DMA mapping array. */
1357 	txq->stmp = malloc(sizeof(struct sfxge_tx_mapping) * SFXGE_NDESCS,
1358 	    M_SFXGE, M_ZERO | M_WAITOK);
1359 	for (nmaps = 0; nmaps < SFXGE_NDESCS; nmaps++) {
1360 		rc = bus_dmamap_create(txq->packet_dma_tag, 0,
1361 				       &txq->stmp[nmaps].map);
1362 		if (rc != 0)
1363 			goto fail2;
1364 	}
1365 
1366 	if (type == SFXGE_TXQ_IP_TCP_UDP_CKSUM &&
1367 	    (rc = tso_init(txq)) != 0)
1368 		goto fail3;
1369 
1370 #ifdef SFXGE_HAVE_MQ
1371 	/* Initialize the deferred packet list. */
1372 	stdp = &txq->dpl;
1373 	stdp->std_getp = &stdp->std_get;
1374 
1375 	mtx_init(&txq->lock, "txq", NULL, MTX_DEF);
1376 #endif
1377 
1378 	txq->type = type;
1379 	txq->evq_index = evq_index;
1380 	txq->txq_index = txq_index;
1381 	txq->init_state = SFXGE_TXQ_INITIALIZED;
1382 
1383 	return (0);
1384 
1385 fail3:
1386 	free(txq->pend_desc, M_SFXGE);
1387 fail2:
1388 	while (nmaps--)
1389 		bus_dmamap_destroy(txq->packet_dma_tag, txq->stmp[nmaps].map);
1390 	free(txq->stmp, M_SFXGE);
1391 	bus_dma_tag_destroy(txq->packet_dma_tag);
1392 
1393 fail:
1394 	sfxge_dma_free(esmp);
1395 
1396 	return (rc);
1397 }
1398 
1399 static const struct {
1400 	const char *name;
1401 	size_t offset;
1402 } sfxge_tx_stats[] = {
1403 #define SFXGE_TX_STAT(name, member) \
1404 	{ #name, offsetof(struct sfxge_txq, member) }
1405 	SFXGE_TX_STAT(tso_bursts, tso_bursts),
1406 	SFXGE_TX_STAT(tso_packets, tso_packets),
1407 	SFXGE_TX_STAT(tso_long_headers, tso_long_headers),
1408 	SFXGE_TX_STAT(tx_collapses, collapses),
1409 	SFXGE_TX_STAT(tx_drops, drops),
1410 	SFXGE_TX_STAT(tx_early_drops, early_drops),
1411 };
1412 
1413 static int
1414 sfxge_tx_stat_handler(SYSCTL_HANDLER_ARGS)
1415 {
1416 	struct sfxge_softc *sc = arg1;
1417 	unsigned int id = arg2;
1418 	unsigned long sum;
1419 	unsigned int index;
1420 
1421 	/* Sum across all TX queues */
1422 	sum = 0;
1423 	for (index = 0;
1424 	     index < SFXGE_TXQ_IP_TCP_UDP_CKSUM + SFXGE_TX_SCALE(sc);
1425 	     index++)
1426 		sum += *(unsigned long *)((caddr_t)sc->txq[index] +
1427 					  sfxge_tx_stats[id].offset);
1428 
1429 	return SYSCTL_OUT(req, &sum, sizeof(sum));
1430 }
1431 
1432 static void
1433 sfxge_tx_stat_init(struct sfxge_softc *sc)
1434 {
1435 	struct sysctl_ctx_list *ctx = device_get_sysctl_ctx(sc->dev);
1436 	struct sysctl_oid_list *stat_list;
1437 	unsigned int id;
1438 
1439 	stat_list = SYSCTL_CHILDREN(sc->stats_node);
1440 
1441 	for (id = 0;
1442 	     id < sizeof(sfxge_tx_stats) / sizeof(sfxge_tx_stats[0]);
1443 	     id++) {
1444 		SYSCTL_ADD_PROC(
1445 			ctx, stat_list,
1446 			OID_AUTO, sfxge_tx_stats[id].name,
1447 			CTLTYPE_ULONG|CTLFLAG_RD,
1448 			sc, id, sfxge_tx_stat_handler, "LU",
1449 			"");
1450 	}
1451 }
1452 
1453 void
1454 sfxge_tx_fini(struct sfxge_softc *sc)
1455 {
1456 	int index;
1457 
1458 	index = SFXGE_TX_SCALE(sc);
1459 	while (--index >= 0)
1460 		sfxge_tx_qfini(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM + index);
1461 
1462 	sfxge_tx_qfini(sc, SFXGE_TXQ_IP_CKSUM);
1463         sfxge_tx_qfini(sc, SFXGE_TXQ_NON_CKSUM);
1464 }
1465 
1466 
1467 int
1468 sfxge_tx_init(struct sfxge_softc *sc)
1469 {
1470 	struct sfxge_intr *intr;
1471 	int index;
1472 	int rc;
1473 
1474 	intr = &sc->intr;
1475 
1476 	KASSERT(intr->state == SFXGE_INTR_INITIALIZED,
1477 	    ("intr->state != SFXGE_INTR_INITIALIZED"));
1478 
1479 	/* Initialize the transmit queues */
1480 	if ((rc = sfxge_tx_qinit(sc, SFXGE_TXQ_NON_CKSUM,
1481 	    SFXGE_TXQ_NON_CKSUM, 0)) != 0)
1482 		goto fail;
1483 
1484 	if ((rc = sfxge_tx_qinit(sc, SFXGE_TXQ_IP_CKSUM,
1485 	    SFXGE_TXQ_IP_CKSUM, 0)) != 0)
1486 		goto fail2;
1487 
1488 	for (index = 0; index < SFXGE_TX_SCALE(sc); index++) {
1489 		if ((rc = sfxge_tx_qinit(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM + index,
1490 		    SFXGE_TXQ_IP_TCP_UDP_CKSUM, index)) != 0)
1491 			goto fail3;
1492 	}
1493 
1494 	sfxge_tx_stat_init(sc);
1495 
1496 	return (0);
1497 
1498 fail3:
1499 	sfxge_tx_qfini(sc, SFXGE_TXQ_IP_CKSUM);
1500 
1501 	while (--index >= 0)
1502 		sfxge_tx_qfini(sc, SFXGE_TXQ_IP_TCP_UDP_CKSUM + index);
1503 
1504 fail2:
1505 	sfxge_tx_qfini(sc, SFXGE_TXQ_NON_CKSUM);
1506 
1507 fail:
1508 	return (rc);
1509 }
1510