xref: /titanic_52/usr/src/uts/common/io/nge/nge_tx.c (revision bfed486ad8de8b8ebc6345a8e10accae08bf2f45)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include "nge.h"
28 
29 #define	TXD_OWN		0x80000000
30 #define	TXD_ERR		0x40000000
31 #define	TXD_END		0x20000000
32 #define	TXD_BCNT_MSK	0x00003FFF
33 
34 
35 #undef	NGE_DBG
36 #define	NGE_DBG		NGE_DBG_SEND
37 
38 #define	NGE_TXSWD_RECYCLE(sd)	{\
39 					(sd)->mp = NULL; \
40 					(sd)->frags = 0; \
41 					(sd)->mp_hndl.head = NULL; \
42 					(sd)->mp_hndl.tail = NULL; \
43 					(sd)->flags = HOST_OWN; \
44 				}
45 
46 
47 static size_t nge_tx_dmah_pop(nge_dmah_list_t *, nge_dmah_list_t *, size_t);
48 static void nge_tx_dmah_push(nge_dmah_list_t *, nge_dmah_list_t *);
49 
50 
51 void nge_tx_recycle_all(nge_t *ngep);
52 #pragma	no_inline(nge_tx_recycle_all)
53 
54 void
55 nge_tx_recycle_all(nge_t *ngep)
56 {
57 	send_ring_t *srp;
58 	sw_tx_sbd_t *ssbdp;
59 	nge_dmah_node_t	*dmah;
60 	uint32_t slot;
61 	uint32_t nslots;
62 
63 	srp = ngep->send;
64 	nslots = srp->desc.nslots;
65 
66 	for (slot = 0; slot < nslots; ++slot) {
67 
68 		ssbdp = srp->sw_sbds + slot;
69 
70 		DMA_ZERO(ssbdp->desc);
71 
72 		if (ssbdp->mp != NULL)	{
73 
74 			for (dmah = ssbdp->mp_hndl.head; dmah != NULL;
75 			    dmah = dmah->next)
76 				(void) ddi_dma_unbind_handle(dmah->hndl);
77 
78 			freemsg(ssbdp->mp);
79 		}
80 
81 		NGE_TXSWD_RECYCLE(ssbdp);
82 	}
83 }
84 
85 static size_t
86 nge_tx_dmah_pop(nge_dmah_list_t *src, nge_dmah_list_t *dst, size_t num)
87 {
88 	nge_dmah_node_t	*node;
89 
90 	for (node = src->head; node != NULL && --num != 0; node = node->next)
91 		;
92 
93 	if (num == 0)	{
94 
95 		dst->head = src->head;
96 		dst->tail = node;
97 
98 		if ((src->head = node->next) == NULL)
99 			src->tail = NULL;
100 
101 		node->next = NULL;
102 	}
103 
104 	return (num);
105 }
106 
107 static void
108 nge_tx_dmah_push(nge_dmah_list_t *src, nge_dmah_list_t *dst)
109 {
110 	if (dst->tail != NULL)
111 		dst->tail->next = src->head;
112 	else
113 		dst->head = src->head;
114 
115 	dst->tail = src->tail;
116 }
117 
118 static void
119 nge_tx_desc_sync(nge_t *ngep, uint32_t start_index, uint32_t bds, uint_t type)
120 {
121 	send_ring_t *srp = ngep->send;
122 	const size_t txd_size = ngep->desc_attr.txd_size;
123 	const uint64_t end = srp->desc.nslots * txd_size;
124 	uint64_t start;
125 	uint64_t num;
126 
127 	start = start_index * txd_size;
128 	num = bds * txd_size;
129 
130 	if (start + num <= end)
131 		(void) ddi_dma_sync(srp->desc.dma_hdl, start, num, type);
132 	else	{
133 
134 		(void) ddi_dma_sync(srp->desc.dma_hdl, start, 0, type);
135 		(void) ddi_dma_sync(srp->desc.dma_hdl, 0, start + num - end,
136 		    type);
137 	}
138 }
139 
140 /*
141  * Reclaim the resource after tx's completion
142  */
143 void
144 nge_tx_recycle(nge_t *ngep, boolean_t is_intr)
145 {
146 	int resched;
147 	uint32_t stflg;
148 	size_t len;
149 	uint32_t free;
150 	uint32_t slot;
151 	uint32_t used;
152 	uint32_t next;
153 	uint32_t nslots;
154 	mblk_t *mp;
155 	sw_tx_sbd_t *ssbdp;
156 	void *hw_sbd_p;
157 	send_ring_t *srp;
158 	nge_dmah_node_t *dme;
159 	nge_dmah_list_t dmah;
160 
161 	srp = ngep->send;
162 
163 	if (is_intr) {
164 		if (mutex_tryenter(srp->tc_lock) == 0)
165 			return;
166 	} else
167 		mutex_enter(srp->tc_lock);
168 	mutex_enter(srp->tx_lock);
169 
170 	next = srp->tx_next;
171 	used = srp->tx_flow;
172 	free = srp->tx_free;
173 
174 	mutex_exit(srp->tx_lock);
175 
176 	slot = srp->tc_next;
177 	nslots = srp->desc.nslots;
178 
179 	used = nslots - free - used;
180 
181 	ASSERT(slot == NEXT_INDEX(next, free, nslots));
182 
183 	if (used > srp->tx_hwmark)
184 		used = srp->tx_hwmark;
185 
186 	nge_tx_desc_sync(ngep, slot, used, DDI_DMA_SYNC_FORKERNEL);
187 
188 	/*
189 	 * Look through the send ring by bd's status part
190 	 * to find all the bds which has been transmitted sucessfully
191 	 * then reclaim all resouces associated with these bds
192 	 */
193 
194 	mp = NULL;
195 	dmah.head = NULL;
196 	dmah.tail = NULL;
197 
198 	for (free = 0; used-- != 0; slot = NEXT(slot, nslots), ++free)	{
199 
200 		ssbdp = &srp->sw_sbds[slot];
201 		hw_sbd_p = DMA_VPTR(ssbdp->desc);
202 
203 		if (ssbdp->flags == HOST_OWN)
204 			break;
205 		stflg = ngep->desc_attr.txd_check(hw_sbd_p, &len);
206 		if ((stflg & TXD_OWN) != 0)
207 			break;
208 		DMA_ZERO(ssbdp->desc);
209 		if (ssbdp->mp != NULL)	{
210 			ssbdp->mp->b_next = mp;
211 			mp = ssbdp->mp;
212 
213 			if (ssbdp->mp_hndl.head != NULL)
214 				nge_tx_dmah_push(&ssbdp->mp_hndl, &dmah);
215 		}
216 
217 		NGE_TXSWD_RECYCLE(ssbdp);
218 	}
219 
220 	/*
221 	 * We're about to release one or more places :-)
222 	 * These ASSERTions check that our invariants still hold:
223 	 * there must always be at least one free place
224 	 * at this point, there must be at least one place NOT free
225 	 * we're not about to free more places than were claimed!
226 	 */
227 
228 	mutex_enter(srp->tx_lock);
229 
230 	srp->tx_free += free;
231 	ngep->watchdog = (srp->desc.nslots - srp->tx_free != 0);
232 
233 	srp->tc_next = slot;
234 
235 	ASSERT(srp->tx_free <= nslots);
236 	ASSERT(srp->tc_next == NEXT_INDEX(srp->tx_next, srp->tx_free, nslots));
237 
238 	resched = (ngep->resched_needed != 0 && srp->tx_hwmark <= srp->tx_free);
239 
240 	mutex_exit(srp->tx_lock);
241 	mutex_exit(srp->tc_lock);
242 
243 	/* unbind/free mblks */
244 
245 	for (dme = dmah.head; dme != NULL; dme = dme->next)
246 		(void) ddi_dma_unbind_handle(dme->hndl);
247 
248 	mutex_enter(&srp->dmah_lock);
249 	nge_tx_dmah_push(&dmah, &srp->dmah_free);
250 	mutex_exit(&srp->dmah_lock);
251 
252 	freemsgchain(mp);
253 
254 	/*
255 	 * up to this place, we maybe have reclaim some resouce
256 	 * if there is a requirement to report to gld, report this.
257 	 */
258 
259 	if (resched)
260 		(void) ddi_intr_trigger_softint(ngep->resched_hdl, NULL);
261 }
262 
263 static uint32_t
264 nge_tx_alloc(nge_t *ngep, uint32_t num)
265 {
266 	uint32_t start;
267 	send_ring_t *srp;
268 
269 	start = (uint32_t)-1;
270 	srp = ngep->send;
271 
272 	mutex_enter(srp->tx_lock);
273 
274 	if (srp->tx_free < srp->tx_lwmark)	{
275 
276 		mutex_exit(srp->tx_lock);
277 		nge_tx_recycle(ngep, B_FALSE);
278 		mutex_enter(srp->tx_lock);
279 	}
280 
281 	if (srp->tx_free >= num)	{
282 
283 		start = srp->tx_next;
284 
285 		srp->tx_next = NEXT_INDEX(start, num, srp->desc.nslots);
286 		srp->tx_free -= num;
287 		srp->tx_flow += num;
288 	}
289 
290 	mutex_exit(srp->tx_lock);
291 	return (start);
292 }
293 
294 static void
295 nge_tx_start(nge_t *ngep, uint32_t slotnum)
296 {
297 	nge_mode_cntl mode_cntl;
298 	send_ring_t *srp;
299 
300 	srp = ngep->send;
301 
302 	/*
303 	 * Because there can be multiple concurrent threads in
304 	 * transit through this code, we only want to notify the
305 	 * hardware once the last one is departing ...
306 	 */
307 
308 	mutex_enter(srp->tx_lock);
309 
310 	srp->tx_flow -= slotnum;
311 	if (srp->tx_flow == 0) {
312 
313 		/*
314 		 * Bump the watchdog counter, thus guaranteeing that it's
315 		 * nonzero (watchdog activated).  Note that non-synchonised
316 		 * access here means we may race with the reclaim() code
317 		 * above, but the outcome will be harmless.  At worst, the
318 		 * counter may not get reset on a partial reclaim; but the
319 		 * large trigger threshold makes false positives unlikely
320 		 */
321 		ngep->watchdog ++;
322 
323 		mode_cntl.mode_val = nge_reg_get32(ngep, NGE_MODE_CNTL);
324 		mode_cntl.mode_bits.txdm = NGE_SET;
325 		mode_cntl.mode_bits.tx_rcom_en = NGE_SET;
326 		nge_reg_put32(ngep, NGE_MODE_CNTL, mode_cntl.mode_val);
327 	}
328 	mutex_exit(srp->tx_lock);
329 }
330 
331 static enum send_status
332 nge_send_copy(nge_t *ngep, mblk_t *mp, send_ring_t *srp);
333 #pragma	inline(nge_send_copy)
334 
335 static enum send_status
336 nge_send_copy(nge_t *ngep, mblk_t *mp, send_ring_t *srp)
337 {
338 	size_t totlen;
339 	size_t mblen;
340 	uint32_t flags;
341 	uint32_t bds;
342 	uint32_t start_index;
343 	char *txb;
344 	mblk_t *bp;
345 	void *hw_sbd_p;
346 	sw_tx_sbd_t *ssbdp;
347 
348 	hcksum_retrieve(mp, NULL, NULL, NULL, NULL,
349 	    NULL, NULL, &flags);
350 	bds = 0x1;
351 
352 	if ((uint32_t)-1 == (start_index = nge_tx_alloc(ngep, bds)))
353 		return (SEND_COPY_FAIL);
354 
355 	ASSERT(start_index < srp->desc.nslots);
356 
357 	/*
358 	 * up to this point, there's nothing that can fail,
359 	 * so we can go straight to claiming our
360 	 * already-reserved place son the train.
361 	 *
362 	 * This is the point of no return!
363 	 */
364 
365 	bp = mp;
366 	totlen = 0;
367 	ssbdp = &srp->sw_sbds[start_index];
368 	ASSERT(ssbdp->flags == HOST_OWN);
369 
370 	txb = DMA_VPTR(ssbdp->pbuf);
371 	totlen = 0;
372 	for (; bp != NULL; bp = bp->b_cont) {
373 		if ((mblen = MBLKL(bp)) == 0)
374 			continue;
375 		if ((totlen += mblen) <= ngep->max_sdu) {
376 			bcopy(bp->b_rptr, txb, mblen);
377 			txb += mblen;
378 		}
379 	}
380 
381 	DMA_SYNC(ssbdp->pbuf, DDI_DMA_SYNC_FORDEV);
382 
383 	/* Fill & sync hw desc */
384 
385 	hw_sbd_p = DMA_VPTR(ssbdp->desc);
386 
387 	ngep->desc_attr.txd_fill(hw_sbd_p, &ssbdp->pbuf.cookie, totlen,
388 	    flags, B_TRUE);
389 	nge_tx_desc_sync(ngep, start_index, bds, DDI_DMA_SYNC_FORDEV);
390 
391 	ssbdp->flags = CONTROLER_OWN;
392 
393 	nge_tx_start(ngep, bds);
394 
395 	/*
396 	 * The return status indicates that the message can be freed
397 	 * right away, as we've already copied the contents ...
398 	 */
399 
400 	freemsg(mp);
401 	return (SEND_COPY_SUCESS);
402 }
403 
404 /*
405  * static enum send_status
406  * nge_send_mapped(nge_t *ngep, mblk_t *mp, size_t fragno);
407  * #pragma	inline(nge_send_mapped)
408  */
409 
410 static enum send_status
411 nge_send_mapped(nge_t *ngep, mblk_t *mp, size_t fragno)
412 {
413 	int err;
414 	boolean_t end;
415 	uint32_t i;
416 	uint32_t j;
417 	uint32_t ncookies;
418 	uint32_t slot;
419 	uint32_t nslots;
420 	uint32_t mblen;
421 	uint32_t flags;
422 	uint32_t start_index;
423 	uint32_t end_index;
424 	mblk_t *bp;
425 	void *hw_sbd_p;
426 	send_ring_t *srp;
427 	nge_dmah_node_t *dmah;
428 	nge_dmah_node_t	*dmer;
429 	nge_dmah_list_t dmah_list;
430 	ddi_dma_cookie_t cookie[NGE_MAX_COOKIES * NGE_MAP_FRAGS];
431 
432 	srp = ngep->send;
433 	nslots = srp->desc.nslots;
434 
435 	mutex_enter(&srp->dmah_lock);
436 	err = nge_tx_dmah_pop(&srp->dmah_free, &dmah_list, fragno);
437 	mutex_exit(&srp->dmah_lock);
438 
439 	if (err != 0)	{
440 
441 		return (SEND_MAP_FAIL);
442 	}
443 
444 	/*
445 	 * Pre-scan the message chain, noting the total number of bytes,
446 	 * the number of fragments by pre-doing dma addr bind
447 	 * if the fragment is larger than NGE_COPY_SIZE.
448 	 * This way has the following advantages:
449 	 * 1. Acquire the detailed information of resouce
450 	 *	need to send the message
451 	 *
452 	 * 2. If can not pre-apply enough resouce, fails  at once
453 	 *	and the driver will chose copy way to send out the
454 	 *	message
455 	 */
456 
457 	slot = 0;
458 	dmah = dmah_list.head;
459 
460 	hcksum_retrieve(mp, NULL, NULL, NULL, NULL, NULL, NULL, &flags);
461 
462 	for (bp = mp; bp != NULL; bp = bp->b_cont)	{
463 
464 		mblen = MBLKL(bp);
465 		if (mblen == 0)
466 			continue;
467 
468 		err = ddi_dma_addr_bind_handle(dmah->hndl,
469 		    NULL, (caddr_t)bp->b_rptr, mblen,
470 		    DDI_DMA_STREAMING | DDI_DMA_WRITE,
471 		    DDI_DMA_DONTWAIT, NULL, cookie + slot, &ncookies);
472 
473 		/*
474 		 * If there can not map successfully, it is uncessary
475 		 * sending the message by map way. Sending the message
476 		 * by copy way.
477 		 *
478 		 * By referring to intel's suggestion, it is better
479 		 * the number of cookies should be less than 4.
480 		 */
481 		if (err != DDI_DMA_MAPPED || ncookies > NGE_MAX_COOKIES) {
482 			NGE_DEBUG(("err(%x) map tx bulk fails"
483 			    " cookie(%x), ncookies(%x)",
484 			    err, cookie[slot].dmac_laddress, ncookies));
485 			goto map_fail;
486 		}
487 
488 		/*
489 		 * Check How many bds a cookie will consume
490 		 */
491 		for (end_index = slot + ncookies;
492 		    ++slot != end_index;
493 		    ddi_dma_nextcookie(dmah->hndl, cookie + slot))
494 			;
495 
496 		dmah = dmah->next;
497 	}
498 
499 	/*
500 	 * Now allocate tx descriptors and fill them
501 	 * IMPORTANT:
502 	 *	Up to the point where it claims a place, It is impossibel
503 	 * 	to fail.
504 	 *
505 	 * In this version, there's no setup to be done here, and there's
506 	 * nothing that can fail, so we can go straight to claiming our
507 	 * already-reserved places on the train.
508 	 *
509 	 * This is the point of no return!
510 	 */
511 
512 
513 	if ((uint32_t)-1 == (start_index = nge_tx_alloc(ngep, slot)))
514 		goto map_fail;
515 
516 	ASSERT(start_index < nslots);
517 
518 	/* fill&sync hw desc, going in reverse order */
519 
520 	end = B_TRUE;
521 	end_index = NEXT_INDEX(start_index, slot - 1, nslots);
522 
523 	for (i = slot - 1, j = end_index; start_index - j != 0;
524 	    j = PREV(j, nslots), --i)	{
525 
526 		hw_sbd_p = DMA_VPTR(srp->sw_sbds[j].desc);
527 		ngep->desc_attr.txd_fill(hw_sbd_p, cookie + i,
528 		    cookie[i].dmac_size, 0, end);
529 
530 		end = B_FALSE;
531 	}
532 
533 	hw_sbd_p = DMA_VPTR(srp->sw_sbds[j].desc);
534 	ngep->desc_attr.txd_fill(hw_sbd_p, cookie + i, cookie[i].dmac_size,
535 	    flags, end);
536 
537 	nge_tx_desc_sync(ngep, start_index, slot, DDI_DMA_SYNC_FORDEV);
538 
539 	/* fill sw desc */
540 
541 	for (j = start_index; end_index - j != 0; j = NEXT(j, nslots)) {
542 
543 		srp->sw_sbds[j].flags = CONTROLER_OWN;
544 	}
545 
546 	srp->sw_sbds[j].mp = mp;
547 	srp->sw_sbds[j].mp_hndl = dmah_list;
548 	srp->sw_sbds[j].frags = (uint32_t)fragno;
549 	srp->sw_sbds[j].flags = CONTROLER_OWN;
550 
551 	nge_tx_start(ngep, slot);
552 
553 	/*
554 	 * The return status indicates that the message can not be freed
555 	 * right away, until we can make assure the message has been sent
556 	 * out sucessfully.
557 	 */
558 	return (SEND_MAP_SUCCESS);
559 
560 map_fail:
561 	for (dmer = dmah_list.head; dmah - dmer != 0; dmer = dmer->next)
562 		(void) ddi_dma_unbind_handle(dmer->hndl);
563 
564 	mutex_enter(&srp->dmah_lock);
565 	nge_tx_dmah_push(&dmah_list, &srp->dmah_free);
566 	mutex_exit(&srp->dmah_lock);
567 
568 	return (SEND_MAP_FAIL);
569 }
570 
571 static boolean_t
572 nge_send(nge_t *ngep, mblk_t *mp)
573 {
574 	mblk_t *bp;
575 	send_ring_t *srp;
576 	enum send_status status;
577 	uint32_t mblen = 0;
578 	uint32_t frags = 0;
579 	nge_statistics_t *nstp = &ngep->statistics;
580 	nge_sw_statistics_t *sw_stp = &nstp->sw_statistics;
581 
582 	ASSERT(mp != NULL);
583 	ASSERT(ngep->nge_mac_state == NGE_MAC_STARTED);
584 
585 	srp = ngep->send;
586 	/*
587 	 * 1.Check the number of the fragments of the messages
588 	 * If the total number is larger than 3,
589 	 * Chose copy way
590 	 *
591 	 * 2. Check the length of the message whether is larger than
592 	 * NGE_TX_COPY_SIZE, if so, choose the map way.
593 	 */
594 	for (frags = 0, bp = mp; bp != NULL; bp = bp->b_cont) {
595 		if (MBLKL(bp) == 0)
596 			continue;
597 		frags++;
598 		mblen += MBLKL(bp);
599 	}
600 	if (mblen > (ngep->max_sdu) || mblen == 0) {
601 		freemsg(mp);
602 		return (B_TRUE);
603 	}
604 
605 	if ((mblen > ngep->param_txbcopy_threshold) &&
606 	    (srp->tx_free > frags * NGE_MAX_COOKIES)) {
607 		status = nge_send_mapped(ngep, mp, frags);
608 		if (status == SEND_MAP_FAIL)
609 			status = nge_send_copy(ngep, mp, srp);
610 	} else {
611 		status = nge_send_copy(ngep, mp, srp);
612 	}
613 	if (status == SEND_COPY_FAIL) {
614 		nge_tx_recycle(ngep, B_FALSE);
615 		status = nge_send_copy(ngep, mp, srp);
616 		if (status == SEND_COPY_FAIL) {
617 			ngep->resched_needed = 1;
618 			NGE_DEBUG(("nge_send: send fail!"));
619 			return (B_FALSE);
620 		}
621 	}
622 	/* Update the software statistics */
623 	sw_stp->obytes += mblen + ETHERFCSL;
624 	sw_stp->xmit_count ++;
625 
626 	return (B_TRUE);
627 }
628 
629 /*
630  * nge_m_tx : Send a chain of packets.
631  */
632 mblk_t *
633 nge_m_tx(void *arg, mblk_t *mp)
634 {
635 	nge_t *ngep = arg;
636 	mblk_t *next;
637 
638 	rw_enter(ngep->rwlock, RW_READER);
639 	ASSERT(mp != NULL);
640 	if (ngep->nge_chip_state != NGE_CHIP_RUNNING) {
641 		freemsgchain(mp);
642 		mp = NULL;
643 	}
644 	while (mp != NULL) {
645 		next = mp->b_next;
646 		mp->b_next = NULL;
647 
648 		if (!nge_send(ngep, mp)) {
649 			mp->b_next = next;
650 			break;
651 		}
652 
653 		mp = next;
654 	}
655 	rw_exit(ngep->rwlock);
656 
657 	return (mp);
658 }
659 
660 /* ARGSUSED */
661 uint_t
662 nge_reschedule(caddr_t args1, caddr_t args2)
663 {
664 	nge_t *ngep;
665 	uint_t rslt;
666 
667 	ngep = (nge_t *)args1;
668 	rslt = DDI_INTR_UNCLAIMED;
669 
670 	/*
671 	 * when softintr is trigged, checking whether this
672 	 * is caused by our expected interrupt
673 	 */
674 	if (ngep->nge_mac_state == NGE_MAC_STARTED &&
675 	    ngep->resched_needed == 1) {
676 		ngep->resched_needed = 0;
677 		++ngep->statistics.sw_statistics.tx_resched;
678 		mac_tx_update(ngep->mh);
679 		rslt = DDI_INTR_CLAIMED;
680 	}
681 	return (rslt);
682 }
683 
684 uint32_t
685 nge_hot_txd_check(const void *hwd, size_t *len)
686 {
687 	uint32_t err_flag;
688 	const hot_tx_bd * htbdp;
689 
690 	htbdp = hwd;
691 	err_flag = htbdp->control_status.cntl_val & ~TXD_BCNT_MSK;
692 
693 	*len = htbdp->control_status.status_bits.bcnt;
694 	return (err_flag);
695 }
696 
697 uint32_t
698 nge_sum_txd_check(const void *hwd, size_t *len)
699 {
700 	uint32_t err_flag;
701 	const sum_tx_bd * htbdp;
702 
703 	htbdp = hwd;
704 	err_flag = htbdp->control_status.cntl_val & ~TXD_BCNT_MSK;
705 
706 	*len = htbdp->control_status.status_bits.bcnt;
707 	return (err_flag);
708 }
709 
710 
711 /*
712  * Filling the contents of Tx's data descriptor
713  * before transmitting.
714  */
715 
716 void
717 nge_hot_txd_fill(void *hwdesc, const ddi_dma_cookie_t *cookie,
718 	size_t length, uint32_t sum_flag, boolean_t end)
719 {
720 	hot_tx_bd * hw_sbd_p = hwdesc;
721 
722 	hw_sbd_p->host_buf_addr_hi = cookie->dmac_laddress >> 32;
723 	hw_sbd_p->host_buf_addr_lo = cookie->dmac_laddress;
724 
725 	/*
726 	 * Setting the length of the packet
727 	 * Note: the length filled in the part should be
728 	 * the original length subtract 1;
729 	 */
730 
731 	hw_sbd_p->control_status.control_sum_bits.bcnt = length - 1;
732 
733 	/* setting ip checksum */
734 	if (sum_flag & HCK_IPV4_HDRCKSUM)
735 		hw_sbd_p->control_status.control_sum_bits.ip_hsum
736 		    = NGE_SET;
737 	/* setting tcp checksum */
738 	if (sum_flag & HCK_FULLCKSUM)
739 		hw_sbd_p->control_status.control_sum_bits.tcp_hsum
740 		    = NGE_SET;
741 	/*
742 	 * indicating the end of BDs
743 	 */
744 	if (end)
745 		hw_sbd_p->control_status.control_sum_bits.end = NGE_SET;
746 
747 	membar_producer();
748 
749 	/* pass desc to HW */
750 	hw_sbd_p->control_status.control_sum_bits.own = NGE_SET;
751 }
752 
753 void
754 nge_sum_txd_fill(void *hwdesc, const ddi_dma_cookie_t *cookie,
755 	size_t length, uint32_t sum_flag, boolean_t end)
756 {
757 	sum_tx_bd * hw_sbd_p = hwdesc;
758 
759 	hw_sbd_p->host_buf_addr = cookie->dmac_address;
760 
761 	/*
762 	 * Setting the length of the packet
763 	 * Note: the length filled in the part should be
764 	 * the original length subtract 1;
765 	 */
766 
767 	hw_sbd_p->control_status.control_sum_bits.bcnt = length - 1;
768 
769 	/* setting ip checksum */
770 	if (sum_flag & HCK_IPV4_HDRCKSUM)
771 		hw_sbd_p->control_status.control_sum_bits.ip_hsum
772 		    = NGE_SET;
773 	/* setting tcp checksum */
774 	if (sum_flag & HCK_FULLCKSUM)
775 		hw_sbd_p->control_status.control_sum_bits.tcp_hsum
776 		    = NGE_SET;
777 	/*
778 	 * indicating the end of BDs
779 	 */
780 	if (end)
781 		hw_sbd_p->control_status.control_sum_bits.end = NGE_SET;
782 
783 	membar_producer();
784 
785 	/* pass desc to HW */
786 	hw_sbd_p->control_status.control_sum_bits.own = NGE_SET;
787 }
788