1 /*
2  * Copyright (c) 2007 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 <asm/page.h>
35 #include <linux/mlx4/cq.h>
36 #include <linux/slab.h>
37 #include <linux/mlx4/qp.h>
38 #include <linux/skbuff.h>
39 #include <linux/if_vlan.h>
40 #include <linux/prefetch.h>
41 #include <linux/vmalloc.h>
42 #include <linux/tcp.h>
43 #include <linux/ip.h>
44 #include <linux/ipv6.h>
45 #include <linux/moduleparam.h>
46 
47 #include "mlx4_en.h"
48 
49 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
50 			   struct mlx4_en_tx_ring **pring, u32 size,
51 			   u16 stride, int node, int queue_index)
52 {
53 	struct mlx4_en_dev *mdev = priv->mdev;
54 	struct mlx4_en_tx_ring *ring;
55 	int tmp;
56 	int err;
57 
58 	ring = kzalloc_node(sizeof(*ring), GFP_KERNEL, node);
59 	if (!ring) {
60 		ring = kzalloc(sizeof(*ring), GFP_KERNEL);
61 		if (!ring) {
62 			en_err(priv, "Failed allocating TX ring\n");
63 			return -ENOMEM;
64 		}
65 	}
66 
67 	ring->size = size;
68 	ring->size_mask = size - 1;
69 	ring->stride = stride;
70 	ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
71 
72 	tmp = size * sizeof(struct mlx4_en_tx_info);
73 	ring->tx_info = kmalloc_node(tmp, GFP_KERNEL | __GFP_NOWARN, node);
74 	if (!ring->tx_info) {
75 		ring->tx_info = vmalloc(tmp);
76 		if (!ring->tx_info) {
77 			err = -ENOMEM;
78 			goto err_ring;
79 		}
80 	}
81 
82 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
83 		 ring->tx_info, tmp);
84 
85 	ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
86 	if (!ring->bounce_buf) {
87 		ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
88 		if (!ring->bounce_buf) {
89 			err = -ENOMEM;
90 			goto err_info;
91 		}
92 	}
93 	ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
94 
95 	/* Allocate HW buffers on provided NUMA node */
96 	set_dev_node(&mdev->dev->persist->pdev->dev, node);
97 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
98 	set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
99 	if (err) {
100 		en_err(priv, "Failed allocating hwq resources\n");
101 		goto err_bounce;
102 	}
103 
104 	ring->buf = ring->wqres.buf.direct.buf;
105 
106 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
107 	       ring, ring->buf, ring->size, ring->buf_size,
108 	       (unsigned long long) ring->wqres.buf.direct.map);
109 
110 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
111 				    MLX4_RESERVE_ETH_BF_QP);
112 	if (err) {
113 		en_err(priv, "failed reserving qp for TX ring\n");
114 		goto err_hwq_res;
115 	}
116 
117 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp, GFP_KERNEL);
118 	if (err) {
119 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
120 		goto err_reserve;
121 	}
122 	ring->qp.event = mlx4_en_sqp_event;
123 
124 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
125 	if (err) {
126 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
127 		ring->bf.uar = &mdev->priv_uar;
128 		ring->bf.uar->map = mdev->uar_map;
129 		ring->bf_enabled = false;
130 		ring->bf_alloced = false;
131 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
132 	} else {
133 		ring->bf_alloced = true;
134 		ring->bf_enabled = !!(priv->pflags &
135 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
136 	}
137 
138 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
139 	ring->queue_index = queue_index;
140 
141 	if (queue_index < priv->num_tx_rings_p_up)
142 		cpumask_set_cpu(cpumask_local_spread(queue_index,
143 						     priv->mdev->dev->numa_node),
144 				&ring->affinity_mask);
145 
146 	*pring = ring;
147 	return 0;
148 
149 err_reserve:
150 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
151 err_hwq_res:
152 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
153 err_bounce:
154 	kfree(ring->bounce_buf);
155 	ring->bounce_buf = NULL;
156 err_info:
157 	kvfree(ring->tx_info);
158 	ring->tx_info = NULL;
159 err_ring:
160 	kfree(ring);
161 	*pring = NULL;
162 	return err;
163 }
164 
165 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
166 			     struct mlx4_en_tx_ring **pring)
167 {
168 	struct mlx4_en_dev *mdev = priv->mdev;
169 	struct mlx4_en_tx_ring *ring = *pring;
170 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
171 
172 	if (ring->bf_alloced)
173 		mlx4_bf_free(mdev->dev, &ring->bf);
174 	mlx4_qp_remove(mdev->dev, &ring->qp);
175 	mlx4_qp_free(mdev->dev, &ring->qp);
176 	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
177 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
178 	kfree(ring->bounce_buf);
179 	ring->bounce_buf = NULL;
180 	kvfree(ring->tx_info);
181 	ring->tx_info = NULL;
182 	kfree(ring);
183 	*pring = NULL;
184 }
185 
186 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
187 			     struct mlx4_en_tx_ring *ring,
188 			     int cq, int user_prio)
189 {
190 	struct mlx4_en_dev *mdev = priv->mdev;
191 	int err;
192 
193 	ring->cqn = cq;
194 	ring->prod = 0;
195 	ring->cons = 0xffffffff;
196 	ring->last_nr_txbb = 1;
197 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
198 	memset(ring->buf, 0, ring->buf_size);
199 	ring->free_tx_desc = mlx4_en_free_tx_desc;
200 
201 	ring->qp_state = MLX4_QP_STATE_RST;
202 	ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8);
203 	ring->mr_key = cpu_to_be32(mdev->mr.key);
204 
205 	mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
206 				ring->cqn, user_prio, &ring->context);
207 	if (ring->bf_alloced)
208 		ring->context.usr_page =
209 			cpu_to_be32(mlx4_to_hw_uar_index(mdev->dev,
210 							 ring->bf.uar->index));
211 
212 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
213 			       &ring->qp, &ring->qp_state);
214 	if (!cpumask_empty(&ring->affinity_mask))
215 		netif_set_xps_queue(priv->dev, &ring->affinity_mask,
216 				    ring->queue_index);
217 
218 	return err;
219 }
220 
221 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
222 				struct mlx4_en_tx_ring *ring)
223 {
224 	struct mlx4_en_dev *mdev = priv->mdev;
225 
226 	mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
227 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
228 }
229 
230 static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
231 {
232 	return ring->prod - ring->cons > ring->full_size;
233 }
234 
235 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
236 			      struct mlx4_en_tx_ring *ring, int index,
237 			      u8 owner)
238 {
239 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
240 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
241 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
242 	void *end = ring->buf + ring->buf_size;
243 	__be32 *ptr = (__be32 *)tx_desc;
244 	int i;
245 
246 	/* Optimize the common case when there are no wraparounds */
247 	if (likely((void *)tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
248 		/* Stamp the freed descriptor */
249 		for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
250 		     i += STAMP_STRIDE) {
251 			*ptr = stamp;
252 			ptr += STAMP_DWORDS;
253 		}
254 	} else {
255 		/* Stamp the freed descriptor */
256 		for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
257 		     i += STAMP_STRIDE) {
258 			*ptr = stamp;
259 			ptr += STAMP_DWORDS;
260 			if ((void *)ptr >= end) {
261 				ptr = ring->buf;
262 				stamp ^= cpu_to_be32(0x80000000);
263 			}
264 		}
265 	}
266 }
267 
268 
269 u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
270 			 struct mlx4_en_tx_ring *ring,
271 			 int index, u8 owner, u64 timestamp,
272 			 int napi_mode)
273 {
274 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
275 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
276 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
277 	void *end = ring->buf + ring->buf_size;
278 	struct sk_buff *skb = tx_info->skb;
279 	int nr_maps = tx_info->nr_maps;
280 	int i;
281 
282 	/* We do not touch skb here, so prefetch skb->users location
283 	 * to speedup consume_skb()
284 	 */
285 	prefetchw(&skb->users);
286 
287 	if (unlikely(timestamp)) {
288 		struct skb_shared_hwtstamps hwts;
289 
290 		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
291 		skb_tstamp_tx(skb, &hwts);
292 	}
293 
294 	/* Optimize the common case when there are no wraparounds */
295 	if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
296 		if (!tx_info->inl) {
297 			if (tx_info->linear)
298 				dma_unmap_single(priv->ddev,
299 						tx_info->map0_dma,
300 						tx_info->map0_byte_count,
301 						PCI_DMA_TODEVICE);
302 			else
303 				dma_unmap_page(priv->ddev,
304 					       tx_info->map0_dma,
305 					       tx_info->map0_byte_count,
306 					       PCI_DMA_TODEVICE);
307 			for (i = 1; i < nr_maps; i++) {
308 				data++;
309 				dma_unmap_page(priv->ddev,
310 					(dma_addr_t)be64_to_cpu(data->addr),
311 					be32_to_cpu(data->byte_count),
312 					PCI_DMA_TODEVICE);
313 			}
314 		}
315 	} else {
316 		if (!tx_info->inl) {
317 			if ((void *) data >= end) {
318 				data = ring->buf + ((void *)data - end);
319 			}
320 
321 			if (tx_info->linear)
322 				dma_unmap_single(priv->ddev,
323 						tx_info->map0_dma,
324 						tx_info->map0_byte_count,
325 						PCI_DMA_TODEVICE);
326 			else
327 				dma_unmap_page(priv->ddev,
328 					       tx_info->map0_dma,
329 					       tx_info->map0_byte_count,
330 					       PCI_DMA_TODEVICE);
331 			for (i = 1; i < nr_maps; i++) {
332 				data++;
333 				/* Check for wraparound before unmapping */
334 				if ((void *) data >= end)
335 					data = ring->buf;
336 				dma_unmap_page(priv->ddev,
337 					(dma_addr_t)be64_to_cpu(data->addr),
338 					be32_to_cpu(data->byte_count),
339 					PCI_DMA_TODEVICE);
340 			}
341 		}
342 	}
343 	napi_consume_skb(skb, napi_mode);
344 
345 	return tx_info->nr_txbb;
346 }
347 
348 u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
349 			    struct mlx4_en_tx_ring *ring,
350 			    int index, u8 owner, u64 timestamp,
351 			    int napi_mode)
352 {
353 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
354 	struct mlx4_en_rx_alloc frame = {
355 		.page = tx_info->page,
356 		.dma = tx_info->map0_dma,
357 		.page_offset = 0,
358 		.page_size = PAGE_SIZE,
359 	};
360 
361 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
362 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
363 			       PAGE_SIZE, priv->frag_info[0].dma_dir);
364 		put_page(tx_info->page);
365 	}
366 
367 	return tx_info->nr_txbb;
368 }
369 
370 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
371 {
372 	struct mlx4_en_priv *priv = netdev_priv(dev);
373 	int cnt = 0;
374 
375 	/* Skip last polled descriptor */
376 	ring->cons += ring->last_nr_txbb;
377 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
378 		 ring->cons, ring->prod);
379 
380 	if ((u32) (ring->prod - ring->cons) > ring->size) {
381 		if (netif_msg_tx_err(priv))
382 			en_warn(priv, "Tx consumer passed producer!\n");
383 		return 0;
384 	}
385 
386 	while (ring->cons != ring->prod) {
387 		ring->last_nr_txbb = ring->free_tx_desc(priv, ring,
388 						ring->cons & ring->size_mask,
389 						!!(ring->cons & ring->size), 0,
390 						0 /* Non-NAPI caller */);
391 		ring->cons += ring->last_nr_txbb;
392 		cnt++;
393 	}
394 
395 	netdev_tx_reset_queue(ring->tx_queue);
396 
397 	if (cnt)
398 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
399 
400 	return cnt;
401 }
402 
403 static bool mlx4_en_process_tx_cq(struct net_device *dev,
404 				  struct mlx4_en_cq *cq, int napi_budget)
405 {
406 	struct mlx4_en_priv *priv = netdev_priv(dev);
407 	struct mlx4_cq *mcq = &cq->mcq;
408 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
409 	struct mlx4_cqe *cqe;
410 	u16 index;
411 	u16 new_index, ring_index, stamp_index;
412 	u32 txbbs_skipped = 0;
413 	u32 txbbs_stamp = 0;
414 	u32 cons_index = mcq->cons_index;
415 	int size = cq->size;
416 	u32 size_mask = ring->size_mask;
417 	struct mlx4_cqe *buf = cq->buf;
418 	u32 packets = 0;
419 	u32 bytes = 0;
420 	int factor = priv->cqe_factor;
421 	int done = 0;
422 	int budget = priv->tx_work_limit;
423 	u32 last_nr_txbb;
424 	u32 ring_cons;
425 
426 	if (!priv->port_up)
427 		return true;
428 
429 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
430 
431 	index = cons_index & size_mask;
432 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
433 	last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb);
434 	ring_cons = ACCESS_ONCE(ring->cons);
435 	ring_index = ring_cons & size_mask;
436 	stamp_index = ring_index;
437 
438 	/* Process all completed CQEs */
439 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
440 			cons_index & size) && (done < budget)) {
441 		/*
442 		 * make sure we read the CQE after we read the
443 		 * ownership bit
444 		 */
445 		dma_rmb();
446 
447 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
448 			     MLX4_CQE_OPCODE_ERROR)) {
449 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
450 
451 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
452 			       cqe_err->vendor_err_syndrome,
453 			       cqe_err->syndrome);
454 		}
455 
456 		/* Skip over last polled CQE */
457 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
458 
459 		do {
460 			u64 timestamp = 0;
461 
462 			txbbs_skipped += last_nr_txbb;
463 			ring_index = (ring_index + last_nr_txbb) & size_mask;
464 
465 			if (unlikely(ring->tx_info[ring_index].ts_requested))
466 				timestamp = mlx4_en_get_cqe_ts(cqe);
467 
468 			/* free next descriptor */
469 			last_nr_txbb = ring->free_tx_desc(
470 					priv, ring, ring_index,
471 					!!((ring_cons + txbbs_skipped) &
472 					ring->size), timestamp, napi_budget);
473 
474 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
475 					  !!((ring_cons + txbbs_stamp) &
476 						ring->size));
477 			stamp_index = ring_index;
478 			txbbs_stamp = txbbs_skipped;
479 			packets++;
480 			bytes += ring->tx_info[ring_index].nr_bytes;
481 		} while ((++done < budget) && (ring_index != new_index));
482 
483 		++cons_index;
484 		index = cons_index & size_mask;
485 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
486 	}
487 
488 
489 	/*
490 	 * To prevent CQ overflow we first update CQ consumer and only then
491 	 * the ring consumer.
492 	 */
493 	mcq->cons_index = cons_index;
494 	mlx4_cq_set_ci(mcq);
495 	wmb();
496 
497 	/* we want to dirty this cache line once */
498 	ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb;
499 	ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped;
500 
501 	if (ring->free_tx_desc == mlx4_en_recycle_tx_desc)
502 		return done < budget;
503 
504 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
505 
506 	/* Wakeup Tx queue if this stopped, and ring is not full.
507 	 */
508 	if (netif_tx_queue_stopped(ring->tx_queue) &&
509 	    !mlx4_en_is_tx_ring_full(ring)) {
510 		netif_tx_wake_queue(ring->tx_queue);
511 		ring->wake_queue++;
512 	}
513 	return done < budget;
514 }
515 
516 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
517 {
518 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
519 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
520 
521 	if (likely(priv->port_up))
522 		napi_schedule_irqoff(&cq->napi);
523 	else
524 		mlx4_en_arm_cq(priv, cq);
525 }
526 
527 /* TX CQ polling - called by NAPI */
528 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
529 {
530 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
531 	struct net_device *dev = cq->dev;
532 	struct mlx4_en_priv *priv = netdev_priv(dev);
533 	int clean_complete;
534 
535 	clean_complete = mlx4_en_process_tx_cq(dev, cq, budget);
536 	if (!clean_complete)
537 		return budget;
538 
539 	napi_complete(napi);
540 	mlx4_en_arm_cq(priv, cq);
541 
542 	return 0;
543 }
544 
545 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
546 						      struct mlx4_en_tx_ring *ring,
547 						      u32 index,
548 						      unsigned int desc_size)
549 {
550 	u32 copy = (ring->size - index) * TXBB_SIZE;
551 	int i;
552 
553 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
554 		if ((i & (TXBB_SIZE - 1)) == 0)
555 			wmb();
556 
557 		*((u32 *) (ring->buf + i)) =
558 			*((u32 *) (ring->bounce_buf + copy + i));
559 	}
560 
561 	for (i = copy - 4; i >= 4 ; i -= 4) {
562 		if ((i & (TXBB_SIZE - 1)) == 0)
563 			wmb();
564 
565 		*((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
566 			*((u32 *) (ring->bounce_buf + i));
567 	}
568 
569 	/* Return real descriptor location */
570 	return ring->buf + index * TXBB_SIZE;
571 }
572 
573 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
574  *
575  * It seems strange we do not simply use skb_copy_bits().
576  * This would allow to inline all skbs iff skb->len <= inline_thold
577  *
578  * Note that caller already checked skb was not a gso packet
579  */
580 static bool is_inline(int inline_thold, const struct sk_buff *skb,
581 		      const struct skb_shared_info *shinfo,
582 		      void **pfrag)
583 {
584 	void *ptr;
585 
586 	if (skb->len > inline_thold || !inline_thold)
587 		return false;
588 
589 	if (shinfo->nr_frags == 1) {
590 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
591 		if (unlikely(!ptr))
592 			return false;
593 		*pfrag = ptr;
594 		return true;
595 	}
596 	if (shinfo->nr_frags)
597 		return false;
598 	return true;
599 }
600 
601 static int inline_size(const struct sk_buff *skb)
602 {
603 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
604 	    <= MLX4_INLINE_ALIGN)
605 		return ALIGN(skb->len + CTRL_SIZE +
606 			     sizeof(struct mlx4_wqe_inline_seg), 16);
607 	else
608 		return ALIGN(skb->len + CTRL_SIZE + 2 *
609 			     sizeof(struct mlx4_wqe_inline_seg), 16);
610 }
611 
612 static int get_real_size(const struct sk_buff *skb,
613 			 const struct skb_shared_info *shinfo,
614 			 struct net_device *dev,
615 			 int *lso_header_size,
616 			 bool *inline_ok,
617 			 void **pfrag)
618 {
619 	struct mlx4_en_priv *priv = netdev_priv(dev);
620 	int real_size;
621 
622 	if (shinfo->gso_size) {
623 		*inline_ok = false;
624 		if (skb->encapsulation)
625 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
626 		else
627 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
628 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
629 			ALIGN(*lso_header_size + 4, DS_SIZE);
630 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
631 			/* We add a segment for the skb linear buffer only if
632 			 * it contains data */
633 			if (*lso_header_size < skb_headlen(skb))
634 				real_size += DS_SIZE;
635 			else {
636 				if (netif_msg_tx_err(priv))
637 					en_warn(priv, "Non-linear headers\n");
638 				return 0;
639 			}
640 		}
641 	} else {
642 		*lso_header_size = 0;
643 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
644 				       shinfo, pfrag);
645 
646 		if (*inline_ok)
647 			real_size = inline_size(skb);
648 		else
649 			real_size = CTRL_SIZE +
650 				    (shinfo->nr_frags + 1) * DS_SIZE;
651 	}
652 
653 	return real_size;
654 }
655 
656 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
657 			     const struct sk_buff *skb,
658 			     const struct skb_shared_info *shinfo,
659 			     void *fragptr)
660 {
661 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
662 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
663 	unsigned int hlen = skb_headlen(skb);
664 
665 	if (skb->len <= spc) {
666 		if (likely(skb->len >= MIN_PKT_LEN)) {
667 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
668 		} else {
669 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
670 			memset(((void *)(inl + 1)) + skb->len, 0,
671 			       MIN_PKT_LEN - skb->len);
672 		}
673 		skb_copy_from_linear_data(skb, inl + 1, hlen);
674 		if (shinfo->nr_frags)
675 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
676 			       skb_frag_size(&shinfo->frags[0]));
677 
678 	} else {
679 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
680 		if (hlen <= spc) {
681 			skb_copy_from_linear_data(skb, inl + 1, hlen);
682 			if (hlen < spc) {
683 				memcpy(((void *)(inl + 1)) + hlen,
684 				       fragptr, spc - hlen);
685 				fragptr +=  spc - hlen;
686 			}
687 			inl = (void *) (inl + 1) + spc;
688 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
689 		} else {
690 			skb_copy_from_linear_data(skb, inl + 1, spc);
691 			inl = (void *) (inl + 1) + spc;
692 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
693 							 hlen - spc);
694 			if (shinfo->nr_frags)
695 				memcpy(((void *)(inl + 1)) + hlen - spc,
696 				       fragptr,
697 				       skb_frag_size(&shinfo->frags[0]));
698 		}
699 
700 		dma_wmb();
701 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
702 	}
703 }
704 
705 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
706 			 void *accel_priv, select_queue_fallback_t fallback)
707 {
708 	struct mlx4_en_priv *priv = netdev_priv(dev);
709 	u16 rings_p_up = priv->num_tx_rings_p_up;
710 	u8 up = 0;
711 
712 	if (dev->num_tc)
713 		return skb_tx_hash(dev, skb);
714 
715 	if (skb_vlan_tag_present(skb))
716 		up = skb_vlan_tag_get(skb) >> VLAN_PRIO_SHIFT;
717 
718 	return fallback(dev, skb) % rings_p_up + up * rings_p_up;
719 }
720 
721 static void mlx4_bf_copy(void __iomem *dst, const void *src,
722 			 unsigned int bytecnt)
723 {
724 	__iowrite64_copy(dst, src, bytecnt / 8);
725 }
726 
727 void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
728 {
729 	wmb();
730 	/* Since there is no iowrite*_native() that writes the
731 	 * value as is, without byteswapping - using the one
732 	 * the doesn't do byteswapping in the relevant arch
733 	 * endianness.
734 	 */
735 #if defined(__LITTLE_ENDIAN)
736 	iowrite32(
737 #else
738 	iowrite32be(
739 #endif
740 		  ring->doorbell_qpn,
741 		  ring->bf.uar->map + MLX4_SEND_DOORBELL);
742 }
743 
744 static void mlx4_en_tx_write_desc(struct mlx4_en_tx_ring *ring,
745 				  struct mlx4_en_tx_desc *tx_desc,
746 				  union mlx4_wqe_qpn_vlan qpn_vlan,
747 				  int desc_size, int bf_index,
748 				  __be32 op_own, bool bf_ok,
749 				  bool send_doorbell)
750 {
751 	tx_desc->ctrl.qpn_vlan = qpn_vlan;
752 
753 	if (bf_ok) {
754 		op_own |= htonl((bf_index & 0xffff) << 8);
755 		/* Ensure new descriptor hits memory
756 		 * before setting ownership of this descriptor to HW
757 		 */
758 		dma_wmb();
759 		tx_desc->ctrl.owner_opcode = op_own;
760 
761 		wmb();
762 
763 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
764 			     desc_size);
765 
766 		wmb();
767 
768 		ring->bf.offset ^= ring->bf.buf_size;
769 	} else {
770 		/* Ensure new descriptor hits memory
771 		 * before setting ownership of this descriptor to HW
772 		 */
773 		dma_wmb();
774 		tx_desc->ctrl.owner_opcode = op_own;
775 		if (send_doorbell)
776 			mlx4_en_xmit_doorbell(ring);
777 		else
778 			ring->xmit_more++;
779 	}
780 }
781 
782 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
783 {
784 	struct skb_shared_info *shinfo = skb_shinfo(skb);
785 	struct mlx4_en_priv *priv = netdev_priv(dev);
786 	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
787 	struct device *ddev = priv->ddev;
788 	struct mlx4_en_tx_ring *ring;
789 	struct mlx4_en_tx_desc *tx_desc;
790 	struct mlx4_wqe_data_seg *data;
791 	struct mlx4_en_tx_info *tx_info;
792 	int tx_ind = 0;
793 	int nr_txbb;
794 	int desc_size;
795 	int real_size;
796 	u32 index, bf_index;
797 	__be32 op_own;
798 	u16 vlan_proto = 0;
799 	int i_frag;
800 	int lso_header_size;
801 	void *fragptr = NULL;
802 	bool bounce = false;
803 	bool send_doorbell;
804 	bool stop_queue;
805 	bool inline_ok;
806 	u32 ring_cons;
807 	bool bf_ok;
808 
809 	tx_ind = skb_get_queue_mapping(skb);
810 	ring = priv->tx_ring[tx_ind];
811 
812 	if (!priv->port_up)
813 		goto tx_drop;
814 
815 	/* fetch ring->cons far ahead before needing it to avoid stall */
816 	ring_cons = ACCESS_ONCE(ring->cons);
817 
818 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
819 				  &inline_ok, &fragptr);
820 	if (unlikely(!real_size))
821 		goto tx_drop_count;
822 
823 	/* Align descriptor to TXBB size */
824 	desc_size = ALIGN(real_size, TXBB_SIZE);
825 	nr_txbb = desc_size / TXBB_SIZE;
826 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
827 		if (netif_msg_tx_err(priv))
828 			en_warn(priv, "Oversized header or SG list\n");
829 		goto tx_drop_count;
830 	}
831 
832 	bf_ok = ring->bf_enabled;
833 	if (skb_vlan_tag_present(skb)) {
834 		qpn_vlan.vlan_tag = cpu_to_be16(skb_vlan_tag_get(skb));
835 		vlan_proto = be16_to_cpu(skb->vlan_proto);
836 		if (vlan_proto == ETH_P_8021AD)
837 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_SVLAN;
838 		else if (vlan_proto == ETH_P_8021Q)
839 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_CVLAN;
840 		else
841 			qpn_vlan.ins_vlan = 0;
842 		bf_ok = false;
843 	}
844 
845 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
846 
847 	/* Track current inflight packets for performance analysis */
848 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
849 			 (u32)(ring->prod - ring_cons - 1));
850 
851 	/* Packet is good - grab an index and transmit it */
852 	index = ring->prod & ring->size_mask;
853 	bf_index = ring->prod;
854 
855 	/* See if we have enough space for whole descriptor TXBB for setting
856 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
857 	if (likely(index + nr_txbb <= ring->size))
858 		tx_desc = ring->buf + index * TXBB_SIZE;
859 	else {
860 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
861 		bounce = true;
862 		bf_ok = false;
863 	}
864 
865 	/* Save skb in tx_info ring */
866 	tx_info = &ring->tx_info[index];
867 	tx_info->skb = skb;
868 	tx_info->nr_txbb = nr_txbb;
869 
870 	data = &tx_desc->data;
871 	if (lso_header_size)
872 		data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4,
873 						      DS_SIZE));
874 
875 	/* valid only for none inline segments */
876 	tx_info->data_offset = (void *)data - (void *)tx_desc;
877 
878 	tx_info->inl = inline_ok;
879 
880 	tx_info->linear = (lso_header_size < skb_headlen(skb) &&
881 			   !inline_ok) ? 1 : 0;
882 
883 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
884 	data += tx_info->nr_maps - 1;
885 
886 	if (!tx_info->inl) {
887 		dma_addr_t dma = 0;
888 		u32 byte_count = 0;
889 
890 		/* Map fragments if any */
891 		for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
892 			const struct skb_frag_struct *frag;
893 
894 			frag = &shinfo->frags[i_frag];
895 			byte_count = skb_frag_size(frag);
896 			dma = skb_frag_dma_map(ddev, frag,
897 					       0, byte_count,
898 					       DMA_TO_DEVICE);
899 			if (dma_mapping_error(ddev, dma))
900 				goto tx_drop_unmap;
901 
902 			data->addr = cpu_to_be64(dma);
903 			data->lkey = ring->mr_key;
904 			dma_wmb();
905 			data->byte_count = cpu_to_be32(byte_count);
906 			--data;
907 		}
908 
909 		/* Map linear part if needed */
910 		if (tx_info->linear) {
911 			byte_count = skb_headlen(skb) - lso_header_size;
912 
913 			dma = dma_map_single(ddev, skb->data +
914 					     lso_header_size, byte_count,
915 					     PCI_DMA_TODEVICE);
916 			if (dma_mapping_error(ddev, dma))
917 				goto tx_drop_unmap;
918 
919 			data->addr = cpu_to_be64(dma);
920 			data->lkey = ring->mr_key;
921 			dma_wmb();
922 			data->byte_count = cpu_to_be32(byte_count);
923 		}
924 		/* tx completion can avoid cache line miss for common cases */
925 		tx_info->map0_dma = dma;
926 		tx_info->map0_byte_count = byte_count;
927 	}
928 
929 	/*
930 	 * For timestamping add flag to skb_shinfo and
931 	 * set flag for further reference
932 	 */
933 	tx_info->ts_requested = 0;
934 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
935 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
936 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
937 		tx_info->ts_requested = 1;
938 	}
939 
940 	/* Prepare ctrl segement apart opcode+ownership, which depends on
941 	 * whether LSO is used */
942 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
943 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
944 		if (!skb->encapsulation)
945 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
946 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
947 		else
948 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
949 		ring->tx_csum++;
950 	}
951 
952 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
953 		struct ethhdr *ethh;
954 
955 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
956 		 * so that VFs and PF can communicate with each other
957 		 */
958 		ethh = (struct ethhdr *)skb->data;
959 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
960 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
961 	}
962 
963 	/* Handle LSO (TSO) packets */
964 	if (lso_header_size) {
965 		int i;
966 
967 		/* Mark opcode as LSO */
968 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
969 			((ring->prod & ring->size) ?
970 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
971 
972 		/* Fill in the LSO prefix */
973 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
974 			shinfo->gso_size << 16 | lso_header_size);
975 
976 		/* Copy headers;
977 		 * note that we already verified that it is linear */
978 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
979 
980 		ring->tso_packets++;
981 
982 		i = ((skb->len - lso_header_size) / shinfo->gso_size) +
983 			!!((skb->len - lso_header_size) % shinfo->gso_size);
984 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
985 		ring->packets += i;
986 	} else {
987 		/* Normal (Non LSO) packet */
988 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
989 			((ring->prod & ring->size) ?
990 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
991 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
992 		ring->packets++;
993 	}
994 	ring->bytes += tx_info->nr_bytes;
995 	netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);
996 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
997 
998 	if (tx_info->inl)
999 		build_inline_wqe(tx_desc, skb, shinfo, fragptr);
1000 
1001 	if (skb->encapsulation) {
1002 		union {
1003 			struct iphdr *v4;
1004 			struct ipv6hdr *v6;
1005 			unsigned char *hdr;
1006 		} ip;
1007 		u8 proto;
1008 
1009 		ip.hdr = skb_inner_network_header(skb);
1010 		proto = (ip.v4->version == 4) ? ip.v4->protocol :
1011 						ip.v6->nexthdr;
1012 
1013 		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
1014 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
1015 		else
1016 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
1017 	}
1018 
1019 	ring->prod += nr_txbb;
1020 
1021 	/* If we used a bounce buffer then copy descriptor back into place */
1022 	if (unlikely(bounce))
1023 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
1024 
1025 	skb_tx_timestamp(skb);
1026 
1027 	/* Check available TXBBs And 2K spare for prefetch */
1028 	stop_queue = mlx4_en_is_tx_ring_full(ring);
1029 	if (unlikely(stop_queue)) {
1030 		netif_tx_stop_queue(ring->tx_queue);
1031 		ring->queue_stopped++;
1032 	}
1033 	send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue);
1034 
1035 	real_size = (real_size / 16) & 0x3f;
1036 
1037 	bf_ok &= desc_size <= MAX_BF && send_doorbell;
1038 
1039 	if (bf_ok)
1040 		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
1041 	else
1042 		qpn_vlan.fence_size = real_size;
1043 
1044 	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, desc_size, bf_index,
1045 			      op_own, bf_ok, send_doorbell);
1046 
1047 	if (unlikely(stop_queue)) {
1048 		/* If queue was emptied after the if (stop_queue) , and before
1049 		 * the netif_tx_stop_queue() - need to wake the queue,
1050 		 * or else it will remain stopped forever.
1051 		 * Need a memory barrier to make sure ring->cons was not
1052 		 * updated before queue was stopped.
1053 		 */
1054 		smp_rmb();
1055 
1056 		ring_cons = ACCESS_ONCE(ring->cons);
1057 		if (unlikely(!mlx4_en_is_tx_ring_full(ring))) {
1058 			netif_tx_wake_queue(ring->tx_queue);
1059 			ring->wake_queue++;
1060 		}
1061 	}
1062 	return NETDEV_TX_OK;
1063 
1064 tx_drop_unmap:
1065 	en_err(priv, "DMA mapping error\n");
1066 
1067 	while (++i_frag < shinfo->nr_frags) {
1068 		++data;
1069 		dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr),
1070 			       be32_to_cpu(data->byte_count),
1071 			       PCI_DMA_TODEVICE);
1072 	}
1073 
1074 tx_drop_count:
1075 	ring->tx_dropped++;
1076 tx_drop:
1077 	dev_kfree_skb_any(skb);
1078 	return NETDEV_TX_OK;
1079 }
1080 
1081 netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_alloc *frame,
1082 			       struct net_device *dev, unsigned int length,
1083 			       int tx_ind, int *doorbell_pending)
1084 {
1085 	struct mlx4_en_priv *priv = netdev_priv(dev);
1086 	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
1087 	struct mlx4_en_tx_ring *ring;
1088 	struct mlx4_en_tx_desc *tx_desc;
1089 	struct mlx4_wqe_data_seg *data;
1090 	struct mlx4_en_tx_info *tx_info;
1091 	int index, bf_index;
1092 	bool send_doorbell;
1093 	int nr_txbb = 1;
1094 	bool stop_queue;
1095 	dma_addr_t dma;
1096 	int real_size;
1097 	__be32 op_own;
1098 	u32 ring_cons;
1099 	bool bf_ok;
1100 
1101 	BUILD_BUG_ON_MSG(ALIGN(CTRL_SIZE + DS_SIZE, TXBB_SIZE) != TXBB_SIZE,
1102 			 "mlx4_en_xmit_frame requires minimum size tx desc");
1103 
1104 	ring = priv->tx_ring[tx_ind];
1105 
1106 	if (!priv->port_up)
1107 		goto tx_drop;
1108 
1109 	if (mlx4_en_is_tx_ring_full(ring))
1110 		goto tx_drop_count;
1111 
1112 	/* fetch ring->cons far ahead before needing it to avoid stall */
1113 	ring_cons = READ_ONCE(ring->cons);
1114 
1115 	index = ring->prod & ring->size_mask;
1116 	tx_info = &ring->tx_info[index];
1117 
1118 	bf_ok = ring->bf_enabled;
1119 
1120 	/* Track current inflight packets for performance analysis */
1121 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
1122 			 (u32)(ring->prod - ring_cons - 1));
1123 
1124 	bf_index = ring->prod;
1125 	tx_desc = ring->buf + index * TXBB_SIZE;
1126 	data = &tx_desc->data;
1127 
1128 	dma = frame->dma;
1129 
1130 	tx_info->page = frame->page;
1131 	frame->page = NULL;
1132 	tx_info->map0_dma = dma;
1133 	tx_info->map0_byte_count = length;
1134 	tx_info->nr_txbb = nr_txbb;
1135 	tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
1136 	tx_info->data_offset = (void *)data - (void *)tx_desc;
1137 	tx_info->ts_requested = 0;
1138 	tx_info->nr_maps = 1;
1139 	tx_info->linear = 1;
1140 	tx_info->inl = 0;
1141 
1142 	dma_sync_single_for_device(priv->ddev, dma, length, PCI_DMA_TODEVICE);
1143 
1144 	data->addr = cpu_to_be64(dma);
1145 	data->lkey = ring->mr_key;
1146 	dma_wmb();
1147 	data->byte_count = cpu_to_be32(length);
1148 
1149 	/* tx completion can avoid cache line miss for common cases */
1150 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
1151 
1152 	op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1153 		((ring->prod & ring->size) ?
1154 		 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1155 
1156 	ring->packets++;
1157 	ring->bytes += tx_info->nr_bytes;
1158 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, length);
1159 
1160 	ring->prod += nr_txbb;
1161 
1162 	stop_queue = mlx4_en_is_tx_ring_full(ring);
1163 	send_doorbell = stop_queue ||
1164 				*doorbell_pending > MLX4_EN_DOORBELL_BUDGET;
1165 	bf_ok &= send_doorbell;
1166 
1167 	real_size = ((CTRL_SIZE + nr_txbb * DS_SIZE) / 16) & 0x3f;
1168 
1169 	if (bf_ok)
1170 		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
1171 	else
1172 		qpn_vlan.fence_size = real_size;
1173 
1174 	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, TXBB_SIZE, bf_index,
1175 			      op_own, bf_ok, send_doorbell);
1176 	*doorbell_pending = send_doorbell ? 0 : *doorbell_pending + 1;
1177 
1178 	return NETDEV_TX_OK;
1179 
1180 tx_drop_count:
1181 	ring->tx_dropped++;
1182 tx_drop:
1183 	return NETDEV_TX_BUSY;
1184 }
1185