xref: /NextBSD/sys/ofed/drivers/net/mlx4/en_tx.c (revision 4557fabb34e865d7f40be64b39c9e34fa41dbb60)
1 /*
2  * Copyright (c) 2007, 2014 Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  *
32  */
33 
34 #include <linux/page.h>
35 #include <linux/mlx4/cq.h>
36 #include <linux/slab.h>
37 #include <linux/mlx4/qp.h>
38 #include <linux/if_vlan.h>
39 #include <linux/vmalloc.h>
40 #include <linux/moduleparam.h>
41 
42 #include <netinet/in_systm.h>
43 #include <netinet/in.h>
44 #include <netinet/if_ether.h>
45 #include <netinet/ip.h>
46 #include <netinet/ip6.h>
47 #include <netinet/tcp.h>
48 #include <netinet/tcp_lro.h>
49 #include <netinet/udp.h>
50 
51 #include "mlx4_en.h"
52 
53 enum {
54 	MAX_INLINE = 104, /* 128 - 16 - 4 - 4 */
55 	MAX_BF = 256,
56 	MIN_PKT_LEN = 17,
57 };
58 
59 static int inline_thold __read_mostly = MAX_INLINE;
60 
61 module_param_named(inline_thold, inline_thold, uint, 0444);
62 MODULE_PARM_DESC(inline_thold, "threshold for using inline data");
63 
mlx4_en_create_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring ** pring,u32 size,u16 stride,int node,int queue_idx)64 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
65 			   struct mlx4_en_tx_ring **pring, u32 size,
66 			   u16 stride, int node, int queue_idx)
67 {
68 	struct mlx4_en_dev *mdev = priv->mdev;
69 	struct mlx4_en_tx_ring *ring;
70 	uint32_t x;
71 	int tmp;
72 	int err;
73 
74 	ring = kzalloc_node(sizeof(struct mlx4_en_tx_ring), GFP_KERNEL, node);
75 	if (!ring) {
76 		ring = kzalloc(sizeof(struct mlx4_en_tx_ring), GFP_KERNEL);
77 		if (!ring) {
78 			en_err(priv, "Failed allocating TX ring\n");
79 			return -ENOMEM;
80 		}
81 	}
82 
83 	/* Create DMA descriptor TAG */
84 	if ((err = -bus_dma_tag_create(
85 	    bus_get_dma_tag(mdev->pdev->dev.bsddev),
86 	    1,					/* any alignment */
87 	    0,					/* no boundary */
88 	    BUS_SPACE_MAXADDR,			/* lowaddr */
89 	    BUS_SPACE_MAXADDR,			/* highaddr */
90 	    NULL, NULL,				/* filter, filterarg */
91 	    MLX4_EN_TX_MAX_PAYLOAD_SIZE,	/* maxsize */
92 	    MLX4_EN_TX_MAX_MBUF_FRAGS,		/* nsegments */
93 	    MLX4_EN_TX_MAX_MBUF_SIZE,		/* maxsegsize */
94 	    0,					/* flags */
95 	    NULL, NULL,				/* lockfunc, lockfuncarg */
96 	    &ring->dma_tag)))
97 		goto done;
98 
99 	ring->size = size;
100 	ring->size_mask = size - 1;
101 	ring->stride = stride;
102 	ring->inline_thold = MAX(MIN_PKT_LEN, MIN(inline_thold, MAX_INLINE));
103 	mtx_init(&ring->tx_lock.m, "mlx4 tx", NULL, MTX_DEF);
104 	mtx_init(&ring->comp_lock.m, "mlx4 comp", NULL, MTX_DEF);
105 
106 	/* Allocate the buf ring */
107 	ring->br = buf_ring_alloc(MLX4_EN_DEF_TX_QUEUE_SIZE, M_DEVBUF,
108 		M_WAITOK, &ring->tx_lock.m);
109 	if (ring->br == NULL) {
110 		en_err(priv, "Failed allocating tx_info ring\n");
111 		err = -ENOMEM;
112 		goto err_free_dma_tag;
113 	}
114 
115 	tmp = size * sizeof(struct mlx4_en_tx_info);
116 	ring->tx_info = kzalloc_node(tmp, GFP_KERNEL, node);
117 	if (!ring->tx_info) {
118 		ring->tx_info = kzalloc(tmp, GFP_KERNEL);
119 		if (!ring->tx_info) {
120 			err = -ENOMEM;
121 			goto err_ring;
122 		}
123 	}
124 
125 	/* Create DMA descriptor MAPs */
126 	for (x = 0; x != size; x++) {
127 		err = -bus_dmamap_create(ring->dma_tag, 0,
128 		    &ring->tx_info[x].dma_map);
129 		if (err != 0) {
130 			while (x--) {
131 				bus_dmamap_destroy(ring->dma_tag,
132 				    ring->tx_info[x].dma_map);
133 			}
134 			goto err_info;
135 		}
136 	}
137 
138 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
139 		 ring->tx_info, tmp);
140 
141 	ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
142 
143 	/* Allocate HW buffers on provided NUMA node */
144 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size,
145 				 2 * PAGE_SIZE);
146 	if (err) {
147 		en_err(priv, "Failed allocating hwq resources\n");
148 		goto err_dma_map;
149 	}
150 
151 	err = mlx4_en_map_buffer(&ring->wqres.buf);
152 	if (err) {
153 		en_err(priv, "Failed to map TX buffer\n");
154 		goto err_hwq_res;
155 	}
156 
157 	ring->buf = ring->wqres.buf.direct.buf;
158 
159 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d "
160 	       "buf_size:%d dma:%llx\n", ring, ring->buf, ring->size,
161 	       ring->buf_size, (unsigned long long) ring->wqres.buf.direct.map);
162 
163 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
164 				    MLX4_RESERVE_BF_QP);
165 	if (err) {
166 		en_err(priv, "failed reserving qp for TX ring\n");
167 		goto err_map;
168 	}
169 
170 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp);
171 	if (err) {
172 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
173 		goto err_reserve;
174 	}
175 	ring->qp.event = mlx4_en_sqp_event;
176 
177 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
178 	if (err) {
179 		en_dbg(DRV, priv, "working without blueflame (%d)", err);
180 		ring->bf.uar = &mdev->priv_uar;
181 		ring->bf.uar->map = mdev->uar_map;
182 		ring->bf_enabled = false;
183 	} else
184 		ring->bf_enabled = true;
185 	ring->queue_index = queue_idx;
186 	if (queue_idx < priv->num_tx_rings_p_up )
187 		CPU_SET(queue_idx, &ring->affinity_mask);
188 
189 	*pring = ring;
190 	return 0;
191 
192 err_reserve:
193 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
194 err_map:
195 	mlx4_en_unmap_buffer(&ring->wqres.buf);
196 err_hwq_res:
197 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
198 err_dma_map:
199 	for (x = 0; x != size; x++)
200 		bus_dmamap_destroy(ring->dma_tag, ring->tx_info[x].dma_map);
201 err_info:
202 	vfree(ring->tx_info);
203 err_ring:
204 	buf_ring_free(ring->br, M_DEVBUF);
205 err_free_dma_tag:
206 	bus_dma_tag_destroy(ring->dma_tag);
207 done:
208 	kfree(ring);
209 	return err;
210 }
211 
mlx4_en_destroy_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring ** pring)212 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
213 			     struct mlx4_en_tx_ring **pring)
214 {
215 	struct mlx4_en_dev *mdev = priv->mdev;
216 	struct mlx4_en_tx_ring *ring = *pring;
217 	uint32_t x;
218 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
219 
220 	buf_ring_free(ring->br, M_DEVBUF);
221 	if (ring->bf_enabled)
222 		mlx4_bf_free(mdev->dev, &ring->bf);
223 	mlx4_qp_remove(mdev->dev, &ring->qp);
224 	mlx4_qp_free(mdev->dev, &ring->qp);
225 	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
226 	mlx4_en_unmap_buffer(&ring->wqres.buf);
227 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
228 	for (x = 0; x != ring->size; x++)
229 		bus_dmamap_destroy(ring->dma_tag, ring->tx_info[x].dma_map);
230 	vfree(ring->tx_info);
231 	mtx_destroy(&ring->tx_lock.m);
232 	mtx_destroy(&ring->comp_lock.m);
233 	bus_dma_tag_destroy(ring->dma_tag);
234 	kfree(ring);
235 	*pring = NULL;
236 }
237 
mlx4_en_activate_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,int cq,int user_prio)238 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
239 			     struct mlx4_en_tx_ring *ring,
240 			     int cq, int user_prio)
241 {
242 	struct mlx4_en_dev *mdev = priv->mdev;
243 	int err;
244 
245 	ring->cqn = cq;
246 	ring->prod = 0;
247 	ring->cons = 0xffffffff;
248 	ring->last_nr_txbb = 1;
249 	ring->poll_cnt = 0;
250 	ring->blocked = 0;
251 	memset(ring->buf, 0, ring->buf_size);
252 
253 	ring->qp_state = MLX4_QP_STATE_RST;
254 	ring->doorbell_qpn = ring->qp.qpn << 8;
255 
256 	mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
257 				ring->cqn, user_prio, &ring->context);
258 	if (ring->bf_enabled)
259 		ring->context.usr_page = cpu_to_be32(ring->bf.uar->index);
260 
261 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
262 			       &ring->qp, &ring->qp_state);
263 	return err;
264 }
265 
mlx4_en_deactivate_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring)266 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
267 				struct mlx4_en_tx_ring *ring)
268 {
269 	struct mlx4_en_dev *mdev = priv->mdev;
270 
271 	mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
272 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
273 }
274 
275 static volatile struct mlx4_wqe_data_seg *
mlx4_en_store_inline_lso_data(volatile struct mlx4_wqe_data_seg * dseg,struct mbuf * mb,int len,__be32 owner_bit)276 mlx4_en_store_inline_lso_data(volatile struct mlx4_wqe_data_seg *dseg,
277     struct mbuf *mb, int len, __be32 owner_bit)
278 {
279 	uint8_t *inl = __DEVOLATILE(uint8_t *, dseg);
280 
281 	/* copy data into place */
282 	m_copydata(mb, 0, len, inl + 4);
283 	dseg += DIV_ROUND_UP(4 + len, DS_SIZE_ALIGNMENT);
284 	return (dseg);
285 }
286 
287 static void
mlx4_en_store_inline_lso_header(volatile struct mlx4_wqe_data_seg * dseg,int len,__be32 owner_bit)288 mlx4_en_store_inline_lso_header(volatile struct mlx4_wqe_data_seg *dseg,
289     int len, __be32 owner_bit)
290 {
291 }
292 
293 static void
mlx4_en_stamp_wqe(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,u32 index,u8 owner)294 mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
295     struct mlx4_en_tx_ring *ring, u32 index, u8 owner)
296 {
297 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
298 	struct mlx4_en_tx_desc *tx_desc = (struct mlx4_en_tx_desc *)
299 	    (ring->buf + (index * TXBB_SIZE));
300 	volatile __be32 *ptr = (__be32 *)tx_desc;
301 	const __be32 stamp = cpu_to_be32(STAMP_VAL |
302 	    ((u32)owner << STAMP_SHIFT));
303 	u32 i;
304 
305 	/* Stamp the freed descriptor */
306 	for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE; i += STAMP_STRIDE) {
307 		*ptr = stamp;
308 		ptr += STAMP_DWORDS;
309 	}
310 }
311 
312 static u32
mlx4_en_free_tx_desc(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,u32 index)313 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
314     struct mlx4_en_tx_ring *ring, u32 index)
315 {
316 	struct mlx4_en_tx_info *tx_info;
317 	struct mbuf *mb;
318 
319 	tx_info = &ring->tx_info[index];
320 	mb = tx_info->mb;
321 
322 	if (mb == NULL)
323 		goto done;
324 
325 	bus_dmamap_sync(ring->dma_tag, tx_info->dma_map,
326 	    BUS_DMASYNC_POSTWRITE);
327 	bus_dmamap_unload(ring->dma_tag, tx_info->dma_map);
328 
329         m_freem(mb);
330 done:
331 	return (tx_info->nr_txbb);
332 }
333 
mlx4_en_free_tx_buf(struct net_device * dev,struct mlx4_en_tx_ring * ring)334 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
335 {
336 	struct mlx4_en_priv *priv = netdev_priv(dev);
337 	int cnt = 0;
338 
339 	/* Skip last polled descriptor */
340 	ring->cons += ring->last_nr_txbb;
341 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
342 		 ring->cons, ring->prod);
343 
344 	if ((u32) (ring->prod - ring->cons) > ring->size) {
345                 en_warn(priv, "Tx consumer passed producer!\n");
346 		return 0;
347 	}
348 
349 	while (ring->cons != ring->prod) {
350 		ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
351 		    ring->cons & ring->size_mask);
352 		ring->cons += ring->last_nr_txbb;
353 		cnt++;
354 	}
355 
356 	if (cnt)
357 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
358 
359 	return cnt;
360 }
361 
362 static bool
mlx4_en_tx_ring_is_full(struct mlx4_en_tx_ring * ring)363 mlx4_en_tx_ring_is_full(struct mlx4_en_tx_ring *ring)
364 {
365 	int wqs;
366 	wqs = ring->size - (ring->prod - ring->cons);
367 	return (wqs < (HEADROOM + (2 * MLX4_EN_TX_WQE_MAX_WQEBBS)));
368 }
369 
mlx4_en_process_tx_cq(struct net_device * dev,struct mlx4_en_cq * cq)370 static int mlx4_en_process_tx_cq(struct net_device *dev,
371 				 struct mlx4_en_cq *cq)
372 {
373 	struct mlx4_en_priv *priv = netdev_priv(dev);
374 	struct mlx4_cq *mcq = &cq->mcq;
375 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
376 	struct mlx4_cqe *cqe;
377 	u16 index;
378 	u16 new_index, ring_index, stamp_index;
379 	u32 txbbs_skipped = 0;
380 	u32 txbbs_stamp = 0;
381 	u32 cons_index = mcq->cons_index;
382 	int size = cq->size;
383 	u32 size_mask = ring->size_mask;
384 	struct mlx4_cqe *buf = cq->buf;
385 	int factor = priv->cqe_factor;
386 
387 	if (!priv->port_up)
388 		return 0;
389 
390 	index = cons_index & size_mask;
391 	cqe = &buf[(index << factor) + factor];
392 	ring_index = ring->cons & size_mask;
393 	stamp_index = ring_index;
394 
395 	/* Process all completed CQEs */
396 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
397 			cons_index & size)) {
398 		/*
399 		 * make sure we read the CQE after we read the
400 		 * ownership bit
401 		 */
402 		rmb();
403 
404 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
405 			     MLX4_CQE_OPCODE_ERROR)) {
406 			en_err(priv, "CQE completed in error - vendor syndrom: 0x%x syndrom: 0x%x\n",
407 			       ((struct mlx4_err_cqe *)cqe)->
408 				       vendor_err_syndrome,
409 			       ((struct mlx4_err_cqe *)cqe)->syndrome);
410 		}
411 
412 		/* Skip over last polled CQE */
413 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
414 
415 		do {
416 			txbbs_skipped += ring->last_nr_txbb;
417 			ring_index = (ring_index + ring->last_nr_txbb) & size_mask;
418 			/* free next descriptor */
419 			ring->last_nr_txbb = mlx4_en_free_tx_desc(
420 			    priv, ring, ring_index);
421 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
422 					  !!((ring->cons + txbbs_stamp) &
423 						ring->size));
424 			stamp_index = ring_index;
425 			txbbs_stamp = txbbs_skipped;
426 		} while (ring_index != new_index);
427 
428 		++cons_index;
429 		index = cons_index & size_mask;
430 		cqe = &buf[(index << factor) + factor];
431 	}
432 
433 
434 	/*
435 	 * To prevent CQ overflow we first update CQ consumer and only then
436 	 * the ring consumer.
437 	 */
438 	mcq->cons_index = cons_index;
439 	mlx4_cq_set_ci(mcq);
440 	wmb();
441 	ring->cons += txbbs_skipped;
442 
443 	/* Wakeup Tx queue if it was stopped and ring is not full */
444 	if (unlikely(ring->blocked) && !mlx4_en_tx_ring_is_full(ring)) {
445 		ring->blocked = 0;
446 		if (atomic_fetchadd_int(&priv->blocked, -1) == 1)
447 			atomic_clear_int(&dev->if_drv_flags ,IFF_DRV_OACTIVE);
448 		ring->wake_queue++;
449 		priv->port_stats.wake_queue++;
450 	}
451 	return (0);
452 }
453 
mlx4_en_tx_irq(struct mlx4_cq * mcq)454 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
455 {
456 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
457 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
458 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
459 
460 	if (!spin_trylock(&ring->comp_lock))
461 		return;
462 	mlx4_en_process_tx_cq(cq->dev, cq);
463 	mod_timer(&cq->timer, jiffies + 1);
464 	spin_unlock(&ring->comp_lock);
465 }
466 
mlx4_en_poll_tx_cq(unsigned long data)467 void mlx4_en_poll_tx_cq(unsigned long data)
468 {
469 	struct mlx4_en_cq *cq = (struct mlx4_en_cq *) data;
470 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
471 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
472 	u32 inflight;
473 
474 	INC_PERF_COUNTER(priv->pstats.tx_poll);
475 
476 	if (!spin_trylock(&ring->comp_lock)) {
477 		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
478 		return;
479 	}
480 	mlx4_en_process_tx_cq(cq->dev, cq);
481 	inflight = (u32) (ring->prod - ring->cons - ring->last_nr_txbb);
482 
483 	/* If there are still packets in flight and the timer has not already
484 	 * been scheduled by the Tx routine then schedule it here to guarantee
485 	 * completion processing of these packets */
486 	if (inflight && priv->port_up)
487 		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
488 
489 	spin_unlock(&ring->comp_lock);
490 }
491 
mlx4_en_xmit_poll(struct mlx4_en_priv * priv,int tx_ind)492 static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind)
493 {
494 	struct mlx4_en_cq *cq = priv->tx_cq[tx_ind];
495 	struct mlx4_en_tx_ring *ring = priv->tx_ring[tx_ind];
496 
497 	/* If we don't have a pending timer, set one up to catch our recent
498 	   post in case the interface becomes idle */
499 	if (!timer_pending(&cq->timer))
500 		mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
501 
502 	/* Poll the CQ every mlx4_en_TX_MODER_POLL packets */
503 	if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)
504 		if (spin_trylock(&ring->comp_lock)) {
505 			mlx4_en_process_tx_cq(priv->dev, cq);
506 			spin_unlock(&ring->comp_lock);
507 		}
508 }
509 
510 static u16
mlx4_en_get_inline_hdr_size(struct mlx4_en_tx_ring * ring,struct mbuf * mb)511 mlx4_en_get_inline_hdr_size(struct mlx4_en_tx_ring *ring, struct mbuf *mb)
512 {
513 	u16 retval;
514 
515 	/* only copy from first fragment, if possible */
516 	retval = MIN(ring->inline_thold, mb->m_len);
517 
518 	/* check for too little data */
519 	if (unlikely(retval < MIN_PKT_LEN))
520 		retval = MIN(ring->inline_thold, mb->m_pkthdr.len);
521 	return (retval);
522 }
523 
524 static int
mlx4_en_get_header_size(struct mbuf * mb)525 mlx4_en_get_header_size(struct mbuf *mb)
526 {
527 	struct ether_vlan_header *eh;
528         struct tcphdr *th;
529         struct ip *ip;
530         int ip_hlen, tcp_hlen;
531 	struct ip6_hdr *ip6;
532 	uint16_t eth_type;
533 	int eth_hdr_len;
534 
535 	eh = mtod(mb, struct ether_vlan_header *);
536 	if (mb->m_len < ETHER_HDR_LEN)
537 		return (0);
538 	if (eh->evl_encap_proto == htons(ETHERTYPE_VLAN)) {
539 		eth_type = ntohs(eh->evl_proto);
540 		eth_hdr_len = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
541 	} else {
542 		eth_type = ntohs(eh->evl_encap_proto);
543 		eth_hdr_len = ETHER_HDR_LEN;
544 	}
545 	if (mb->m_len < eth_hdr_len)
546 		return (0);
547 	switch (eth_type) {
548 	case ETHERTYPE_IP:
549 		ip = (struct ip *)(mb->m_data + eth_hdr_len);
550 		if (mb->m_len < eth_hdr_len + sizeof(*ip))
551 			return (0);
552 		if (ip->ip_p != IPPROTO_TCP)
553 			return (0);
554 		ip_hlen = ip->ip_hl << 2;
555 		eth_hdr_len += ip_hlen;
556 		break;
557 	case ETHERTYPE_IPV6:
558 		ip6 = (struct ip6_hdr *)(mb->m_data + eth_hdr_len);
559 		if (mb->m_len < eth_hdr_len + sizeof(*ip6))
560 			return (0);
561 		if (ip6->ip6_nxt != IPPROTO_TCP)
562 			return (0);
563 		eth_hdr_len += sizeof(*ip6);
564 		break;
565 	default:
566 		return (0);
567 	}
568 	if (mb->m_len < eth_hdr_len + sizeof(*th))
569 		return (0);
570 	th = (struct tcphdr *)(mb->m_data + eth_hdr_len);
571 	tcp_hlen = th->th_off << 2;
572 	eth_hdr_len += tcp_hlen;
573 	if (mb->m_len < eth_hdr_len)
574 		return (0);
575 	return (eth_hdr_len);
576 }
577 
578 static volatile struct mlx4_wqe_data_seg *
mlx4_en_store_inline_data(volatile struct mlx4_wqe_data_seg * dseg,struct mbuf * mb,int len,__be32 owner_bit)579 mlx4_en_store_inline_data(volatile struct mlx4_wqe_data_seg *dseg,
580     struct mbuf *mb, int len, __be32 owner_bit)
581 {
582 	uint8_t *inl = __DEVOLATILE(uint8_t *, dseg);
583 	const int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - 4;
584 
585 	if (unlikely(len < MIN_PKT_LEN)) {
586 		m_copydata(mb, 0, len, inl + 4);
587 		memset(inl + 4 + len, 0, MIN_PKT_LEN - len);
588 		dseg += DIV_ROUND_UP(4 + MIN_PKT_LEN, DS_SIZE_ALIGNMENT);
589 	} else if (len <= spc) {
590 		m_copydata(mb, 0, len, inl + 4);
591 		dseg += DIV_ROUND_UP(4 + len, DS_SIZE_ALIGNMENT);
592 	} else {
593 		m_copydata(mb, 0, spc, inl + 4);
594 		m_copydata(mb, spc, len - spc, inl + 8 + spc);
595 		dseg += DIV_ROUND_UP(8 + len, DS_SIZE_ALIGNMENT);
596 	}
597 	return (dseg);
598 }
599 
600 static void
mlx4_en_store_inline_header(volatile struct mlx4_wqe_data_seg * dseg,int len,__be32 owner_bit)601 mlx4_en_store_inline_header(volatile struct mlx4_wqe_data_seg *dseg,
602     int len, __be32 owner_bit)
603 {
604 	uint8_t *inl = __DEVOLATILE(uint8_t *, dseg);
605 	const int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - 4;
606 
607 	if (unlikely(len < MIN_PKT_LEN)) {
608 		*(volatile uint32_t *)inl =
609 		    SET_BYTE_COUNT((1 << 31) | MIN_PKT_LEN);
610 	} else if (len <= spc) {
611 		*(volatile uint32_t *)inl =
612 		    SET_BYTE_COUNT((1 << 31) | len);
613 	} else {
614 		*(volatile uint32_t *)(inl + 4 + spc) =
615 		    SET_BYTE_COUNT((1 << 31) | (len - spc));
616 		wmb();
617 		*(volatile uint32_t *)inl =
618 		    SET_BYTE_COUNT((1 << 31) | spc);
619 	}
620 }
621 
622 static uint32_t hashrandom;
hashrandom_init(void * arg)623 static void hashrandom_init(void *arg)
624 {
625 	/*
626 	 * It is assumed that the random subsystem has been
627 	 * initialized when this function is called:
628 	 */
629 	hashrandom = m_ether_tcpip_hash_init();
630 }
631 SYSINIT(hashrandom_init, SI_SUB_RANDOM, SI_ORDER_ANY, &hashrandom_init, NULL);
632 
mlx4_en_select_queue(struct net_device * dev,struct mbuf * mb)633 u16 mlx4_en_select_queue(struct net_device *dev, struct mbuf *mb)
634 {
635 	struct mlx4_en_priv *priv = netdev_priv(dev);
636 	u32 rings_p_up = priv->num_tx_rings_p_up;
637 	u32 up = 0;
638 	u32 queue_index;
639 
640 #if (MLX4_EN_NUM_UP > 1)
641 	/* Obtain VLAN information if present */
642 	if (mb->m_flags & M_VLANTAG) {
643 		u32 vlan_tag = mb->m_pkthdr.ether_vtag;
644 	        up = (vlan_tag >> 13) % MLX4_EN_NUM_UP;
645 	}
646 #endif
647 	queue_index = m_ether_tcpip_hash(MBUF_HASHFLAG_L3 | MBUF_HASHFLAG_L4, mb, hashrandom);
648 
649 	return ((queue_index % rings_p_up) + (up * rings_p_up));
650 }
651 
mlx4_bf_copy(void __iomem * dst,volatile unsigned long * src,unsigned bytecnt)652 static void mlx4_bf_copy(void __iomem *dst, volatile unsigned long *src, unsigned bytecnt)
653 {
654 	__iowrite64_copy(dst, __DEVOLATILE(void *, src), bytecnt / 8);
655 }
656 
mlx4_en_mac_to_u64(u8 * addr)657 static u64 mlx4_en_mac_to_u64(u8 *addr)
658 {
659         u64 mac = 0;
660         int i;
661 
662         for (i = 0; i < ETHER_ADDR_LEN; i++) {
663                 mac <<= 8;
664                 mac |= addr[i];
665         }
666         return mac;
667 }
668 
mlx4_en_xmit(struct mlx4_en_priv * priv,int tx_ind,struct mbuf ** mbp)669 static int mlx4_en_xmit(struct mlx4_en_priv *priv, int tx_ind, struct mbuf **mbp)
670 {
671 	enum {
672 		DS_FACT = TXBB_SIZE / DS_SIZE_ALIGNMENT,
673 		CTRL_FLAGS = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE |
674 		    MLX4_WQE_CTRL_SOLICITED),
675 	};
676 	bus_dma_segment_t segs[MLX4_EN_TX_MAX_MBUF_FRAGS];
677 	volatile struct mlx4_wqe_data_seg *dseg;
678 	volatile struct mlx4_wqe_data_seg *dseg_inline;
679 	volatile struct mlx4_en_tx_desc *tx_desc;
680 	struct mlx4_en_tx_ring *ring = priv->tx_ring[tx_ind];
681 	struct ifnet *ifp = priv->dev;
682 	struct mlx4_en_tx_info *tx_info;
683 	struct mbuf *mb = *mbp;
684 	struct mbuf *m;
685 	__be32 owner_bit;
686 	int nr_segs;
687 	int pad;
688 	int err;
689 	u32 bf_size;
690 	u32 bf_prod;
691 	u32 opcode;
692 	u16 index;
693 	u16 ds_cnt;
694 	u16 ihs;
695 
696 	if (unlikely(!priv->port_up)) {
697 		err = EINVAL;
698 		goto tx_drop;
699 	}
700 
701 	/* check if TX ring is full */
702 	if (unlikely(mlx4_en_tx_ring_is_full(ring))) {
703 			/* every full native Tx ring stops queue */
704 			if (ring->blocked == 0)
705 				atomic_add_int(&priv->blocked, 1);
706 			/* Set HW-queue-is-full flag */
707 			atomic_set_int(&ifp->if_drv_flags, IFF_DRV_OACTIVE);
708 			priv->port_stats.queue_stopped++;
709 		ring->blocked = 1;
710 		priv->port_stats.queue_stopped++;
711 		ring->queue_stopped++;
712 
713 		/* Use interrupts to find out when queue opened */
714 		mlx4_en_arm_cq(priv, priv->tx_cq[tx_ind]);
715 		return (ENOBUFS);
716         }
717 
718 	/* sanity check we are not wrapping around */
719 	KASSERT(((~ring->prod) & ring->size_mask) >=
720 	    (MLX4_EN_TX_WQE_MAX_WQEBBS - 1), ("Wrapping around TX ring"));
721 
722 	/* Track current inflight packets for performance analysis */
723 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
724 			 (u32) (ring->prod - ring->cons - 1));
725 
726 	/* Track current mbuf packet header length */
727 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, mb->m_pkthdr.len);
728 
729 	/* Grab an index and try to transmit packet */
730 	owner_bit = (ring->prod & ring->size) ?
731 		cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0;
732 	index = ring->prod & ring->size_mask;
733 	tx_desc = (volatile struct mlx4_en_tx_desc *)
734 	    (ring->buf + index * TXBB_SIZE);
735 	tx_info = &ring->tx_info[index];
736 	dseg = &tx_desc->data;
737 
738 	/* send a copy of the frame to the BPF listener, if any */
739 	if (ifp != NULL && ifp->if_bpf != NULL)
740 		ETHER_BPF_MTAP(ifp, mb);
741 
742 	/* get default flags */
743 	tx_desc->ctrl.srcrb_flags = CTRL_FLAGS;
744 
745 	if (mb->m_pkthdr.csum_flags & (CSUM_IP | CSUM_TSO))
746 		tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
747 
748 	if (mb->m_pkthdr.csum_flags & (CSUM_TCP | CSUM_UDP |
749 	    CSUM_UDP_IPV6 | CSUM_TCP_IPV6 | CSUM_TSO))
750 		tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_TCP_UDP_CSUM);
751 
752 	/* do statistics */
753 	if (likely(tx_desc->ctrl.srcrb_flags != CTRL_FLAGS)) {
754 		priv->port_stats.tx_chksum_offload++;
755 		ring->tx_csum++;
756 	}
757 
758 	/* check for VLAN tag */
759 	if (mb->m_flags & M_VLANTAG) {
760 		tx_desc->ctrl.vlan_tag = cpu_to_be16(mb->m_pkthdr.ether_vtag);
761 		tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN;
762 	} else {
763 		tx_desc->ctrl.vlan_tag = 0;
764 		tx_desc->ctrl.ins_vlan = 0;
765 	}
766 
767 	/* clear immediate field */
768 	tx_desc->ctrl.imm = 0;
769 
770 	/* Handle LSO (TSO) packets */
771 	if (mb->m_pkthdr.csum_flags & CSUM_TSO) {
772 		u32 payload_len;
773 		u32 mss = mb->m_pkthdr.tso_segsz;
774 		u32 num_pkts;
775 
776 		opcode = cpu_to_be32(MLX4_OPCODE_LSO | MLX4_WQE_CTRL_RR) |
777 		    owner_bit;
778 		ihs = mlx4_en_get_header_size(mb);
779 		if (unlikely(ihs > MAX_INLINE)) {
780 			ring->oversized_packets++;
781 			err = EINVAL;
782 			goto tx_drop;
783 		}
784 		tx_desc->lso.mss_hdr_size = cpu_to_be32((mss << 16) | ihs);
785 		payload_len = mb->m_pkthdr.len - ihs;
786 		if (unlikely(payload_len == 0))
787 			num_pkts = 1;
788 		else
789 			num_pkts = DIV_ROUND_UP(payload_len, mss);
790 		ring->bytes += payload_len + (num_pkts * ihs);
791 		ring->packets += num_pkts;
792 		priv->port_stats.tso_packets++;
793 		/* store pointer to inline header */
794 		dseg_inline = dseg;
795 		/* copy data inline */
796 		dseg = mlx4_en_store_inline_lso_data(dseg,
797 		    mb, ihs, owner_bit);
798 	} else {
799 		opcode = cpu_to_be32(MLX4_OPCODE_SEND) |
800 		    owner_bit;
801 		ihs = mlx4_en_get_inline_hdr_size(ring, mb);
802 		ring->bytes += max_t (unsigned int,
803 		    mb->m_pkthdr.len, ETHER_MIN_LEN - ETHER_CRC_LEN);
804 		ring->packets++;
805 		/* store pointer to inline header */
806 		dseg_inline = dseg;
807 		/* copy data inline */
808 		dseg = mlx4_en_store_inline_data(dseg,
809 		    mb, ihs, owner_bit);
810 	}
811 	m_adj(mb, ihs);
812 
813 	/* trim off empty mbufs */
814 	while (mb->m_len == 0) {
815 		mb = m_free(mb);
816 		/* check if all data has been inlined */
817 		if (mb == NULL) {
818 			nr_segs = 0;
819 			goto skip_dma;
820 		}
821 	}
822 
823 	err = bus_dmamap_load_mbuf_sg(ring->dma_tag, tx_info->dma_map,
824 	    mb, segs, &nr_segs, BUS_DMA_NOWAIT);
825 	if (unlikely(err == EFBIG)) {
826 		/* Too many mbuf fragments */
827 		m = m_defrag(mb, M_NOWAIT);
828 		if (m == NULL) {
829 			ring->oversized_packets++;
830 			goto tx_drop;
831 		}
832 		mb = m;
833 		/* Try again */
834 		err = bus_dmamap_load_mbuf_sg(ring->dma_tag, tx_info->dma_map,
835 		    mb, segs, &nr_segs, BUS_DMA_NOWAIT);
836 	}
837 	/* catch errors */
838 	if (unlikely(err != 0)) {
839 		ring->oversized_packets++;
840 		goto tx_drop;
841 	}
842 	/* make sure all mbuf data is written to RAM */
843 	bus_dmamap_sync(ring->dma_tag, tx_info->dma_map,
844 	    BUS_DMASYNC_PREWRITE);
845 
846 skip_dma:
847 	/* compute number of DS needed */
848 	ds_cnt = (dseg - ((volatile struct mlx4_wqe_data_seg *)tx_desc)) + nr_segs;
849 
850 	/*
851 	 * Check if the next request can wrap around and fill the end
852 	 * of the current request with zero immediate data:
853 	 */
854 	pad = DIV_ROUND_UP(ds_cnt, DS_FACT);
855 	pad = (~(ring->prod + pad)) & ring->size_mask;
856 
857 	if (unlikely(pad < (MLX4_EN_TX_WQE_MAX_WQEBBS - 1))) {
858 		/*
859 		 * Compute the least number of DS blocks we need to
860 		 * pad in order to achieve a TX ring wraparound:
861 		 */
862 		pad = (DS_FACT * (pad + 1));
863 	} else {
864 		/*
865 		 * The hardware will automatically jump to the next
866 		 * TXBB. No need for padding.
867 		 */
868 		pad = 0;
869 	}
870 
871 	/* compute total number of DS blocks */
872 	ds_cnt += pad;
873 	/*
874 	 * When modifying this code, please ensure that the following
875 	 * computation is always less than or equal to 0x3F:
876 	 *
877 	 * ((MLX4_EN_TX_WQE_MAX_WQEBBS - 1) * DS_FACT) +
878 	 * (MLX4_EN_TX_WQE_MAX_WQEBBS * DS_FACT)
879 	 *
880 	 * Else the "ds_cnt" variable can become too big.
881 	 */
882 	tx_desc->ctrl.fence_size = (ds_cnt & 0x3f);
883 
884 	/* store pointer to mbuf */
885 	tx_info->mb = mb;
886 	tx_info->nr_txbb = DIV_ROUND_UP(ds_cnt, DS_FACT);
887 	bf_size = ds_cnt * DS_SIZE_ALIGNMENT;
888 	bf_prod = ring->prod;
889 
890 	/* compute end of "dseg" array */
891 	dseg += nr_segs + pad;
892 
893 	/* pad using zero immediate dseg */
894 	while (pad--) {
895 		dseg--;
896 		dseg->addr = 0;
897 		dseg->lkey = 0;
898 		wmb();
899 		dseg->byte_count = SET_BYTE_COUNT((1 << 31)|0);
900 	}
901 
902 	/* fill segment list */
903 	while (nr_segs--) {
904 		if (unlikely(segs[nr_segs].ds_len == 0)) {
905 			dseg--;
906 			dseg->addr = 0;
907 			dseg->lkey = 0;
908 			wmb();
909 			dseg->byte_count = SET_BYTE_COUNT((1 << 31)|0);
910 		} else {
911 			dseg--;
912 			dseg->addr = cpu_to_be64((uint64_t)segs[nr_segs].ds_addr);
913 			dseg->lkey = cpu_to_be32(priv->mdev->mr.key);
914 			wmb();
915 			dseg->byte_count = SET_BYTE_COUNT((uint32_t)segs[nr_segs].ds_len);
916 		}
917 	}
918 
919 	wmb();
920 
921 	/* write owner bits in reverse order */
922 	if ((opcode & cpu_to_be32(0x1F)) == cpu_to_be32(MLX4_OPCODE_LSO))
923 		mlx4_en_store_inline_lso_header(dseg_inline, ihs, owner_bit);
924 	else
925 		mlx4_en_store_inline_header(dseg_inline, ihs, owner_bit);
926 
927 	if (unlikely(priv->validate_loopback)) {
928 		/* Copy dst mac address to wqe */
929                 struct ether_header *ethh;
930                 u64 mac;
931                 u32 mac_l, mac_h;
932 
933                 ethh = mtod(mb, struct ether_header *);
934                 mac = mlx4_en_mac_to_u64(ethh->ether_dhost);
935                 if (mac) {
936                         mac_h = (u32) ((mac & 0xffff00000000ULL) >> 16);
937                         mac_l = (u32) (mac & 0xffffffff);
938                         tx_desc->ctrl.srcrb_flags |= cpu_to_be32(mac_h);
939                         tx_desc->ctrl.imm = cpu_to_be32(mac_l);
940                 }
941 	}
942 
943 	/* update producer counter */
944 	ring->prod += tx_info->nr_txbb;
945 
946 	if (ring->bf_enabled && bf_size <= MAX_BF &&
947 	    (tx_desc->ctrl.ins_vlan != MLX4_WQE_CTRL_INS_VLAN)) {
948 
949 		/* store doorbell number */
950 		*(volatile __be32 *) (&tx_desc->ctrl.vlan_tag) |= cpu_to_be32(ring->doorbell_qpn);
951 
952 		/* or in producer number for this WQE */
953 		opcode |= cpu_to_be32((bf_prod & 0xffff) << 8);
954 
955 		/*
956 		 * Ensure the new descriptor hits memory before
957 		 * setting ownership of this descriptor to HW:
958 		 */
959 		wmb();
960 		tx_desc->ctrl.owner_opcode = opcode;
961 		wmb();
962 		mlx4_bf_copy(((u8 *)ring->bf.reg) + ring->bf.offset,
963 		     (volatile unsigned long *) &tx_desc->ctrl, bf_size);
964 		wmb();
965 		ring->bf.offset ^= ring->bf.buf_size;
966 	} else {
967 		/*
968 		 * Ensure the new descriptor hits memory before
969 		 * setting ownership of this descriptor to HW:
970 		 */
971 		wmb();
972 		tx_desc->ctrl.owner_opcode = opcode;
973 		wmb();
974 		writel(cpu_to_be32(ring->doorbell_qpn),
975 		    ((u8 *)ring->bf.uar->map) + MLX4_SEND_DOORBELL);
976 	}
977 
978 	return (0);
979 tx_drop:
980 	*mbp = NULL;
981 	m_freem(mb);
982 	return (err);
983 }
984 
985 static int
mlx4_en_transmit_locked(struct ifnet * dev,int tx_ind,struct mbuf * m)986 mlx4_en_transmit_locked(struct ifnet *dev, int tx_ind, struct mbuf *m)
987 {
988 	struct mlx4_en_priv *priv = netdev_priv(dev);
989 	struct mlx4_en_tx_ring *ring;
990 	struct mbuf *next;
991 	int enqueued, err = 0;
992 
993 	ring = priv->tx_ring[tx_ind];
994 	if ((dev->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
995 	    IFF_DRV_RUNNING || priv->port_up == 0) {
996 		if (m != NULL)
997 			err = drbr_enqueue(dev, ring->br, m);
998 		return (err);
999 	}
1000 
1001 	enqueued = 0;
1002 	if (m != NULL)
1003 		/*
1004 		 * If we can't insert mbuf into drbr, try to xmit anyway.
1005 		 * We keep the error we got so we could return that after xmit.
1006 		 */
1007 		err = drbr_enqueue(dev, ring->br, m);
1008 
1009 	/* Process the queue */
1010 	while ((next = drbr_peek(dev, ring->br)) != NULL) {
1011 		if (mlx4_en_xmit(priv, tx_ind, &next) != 0) {
1012 			if (next == NULL) {
1013 				drbr_advance(dev, ring->br);
1014 			} else {
1015 				drbr_putback(dev, ring->br, next);
1016 			}
1017 			break;
1018 		}
1019 		drbr_advance(dev, ring->br);
1020 		enqueued++;
1021 		if ((dev->if_drv_flags & IFF_DRV_RUNNING) == 0)
1022 			break;
1023 	}
1024 
1025 	if (enqueued > 0)
1026 		ring->watchdog_time = ticks;
1027 
1028 	return (err);
1029 }
1030 
1031 void
mlx4_en_tx_que(void * context,int pending)1032 mlx4_en_tx_que(void *context, int pending)
1033 {
1034 	struct mlx4_en_tx_ring *ring;
1035 	struct mlx4_en_priv *priv;
1036 	struct net_device *dev;
1037 	struct mlx4_en_cq *cq;
1038 	int tx_ind;
1039 	cq = context;
1040 	dev = cq->dev;
1041 	priv = dev->if_softc;
1042 	tx_ind = cq->ring;
1043 	ring = priv->tx_ring[tx_ind];
1044         if (dev->if_drv_flags & IFF_DRV_RUNNING) {
1045 		mlx4_en_xmit_poll(priv, tx_ind);
1046 		spin_lock(&ring->tx_lock);
1047                 if (!drbr_empty(dev, ring->br))
1048 			mlx4_en_transmit_locked(dev, tx_ind, NULL);
1049 		spin_unlock(&ring->tx_lock);
1050 	}
1051 }
1052 
1053 int
mlx4_en_transmit(struct ifnet * dev,struct mbuf * m)1054 mlx4_en_transmit(struct ifnet *dev, struct mbuf *m)
1055 {
1056 	struct mlx4_en_priv *priv = netdev_priv(dev);
1057 	struct mlx4_en_tx_ring *ring;
1058 	struct mlx4_en_cq *cq;
1059 	int i, err = 0;
1060 
1061 	/* Compute which queue to use */
1062 	if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
1063 		i = m->m_pkthdr.flowid % priv->tx_ring_num;
1064 	}
1065 	else {
1066 		i = mlx4_en_select_queue(dev, m);
1067 	}
1068 
1069 	ring = priv->tx_ring[i];
1070 	if (spin_trylock(&ring->tx_lock)) {
1071 		err = mlx4_en_transmit_locked(dev, i, m);
1072 		spin_unlock(&ring->tx_lock);
1073 		/* Poll CQ here */
1074 		mlx4_en_xmit_poll(priv, i);
1075 	} else {
1076 		err = drbr_enqueue(dev, ring->br, m);
1077 		cq = priv->tx_cq[i];
1078 		taskqueue_enqueue(cq->tq, &cq->cq_task);
1079 	}
1080 
1081 	return (err);
1082 }
1083 
1084 /*
1085  * Flush ring buffers.
1086  */
1087 void
mlx4_en_qflush(struct ifnet * dev)1088 mlx4_en_qflush(struct ifnet *dev)
1089 {
1090 	struct mlx4_en_priv *priv = netdev_priv(dev);
1091 	struct mlx4_en_tx_ring *ring;
1092 	struct mbuf *m;
1093 
1094 	for (int i = 0; i < priv->tx_ring_num; i++) {
1095 		ring = priv->tx_ring[i];
1096 		spin_lock(&ring->tx_lock);
1097 		while ((m = buf_ring_dequeue_sc(ring->br)) != NULL)
1098 			m_freem(m);
1099 		spin_unlock(&ring->tx_lock);
1100 	}
1101 	if_qflush(dev);
1102 }
1103