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 		en_err(priv, "Failed allocating TX ring\n");
61 		return -ENOMEM;
62 	}
63 
64 	ring->size = size;
65 	ring->size_mask = size - 1;
66 	ring->sp_stride = stride;
67 	ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
68 
69 	tmp = size * sizeof(struct mlx4_en_tx_info);
70 	ring->tx_info = kvmalloc_node(tmp, GFP_KERNEL, node);
71 	if (!ring->tx_info) {
72 		err = -ENOMEM;
73 		goto err_ring;
74 	}
75 
76 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
77 		 ring->tx_info, tmp);
78 
79 	ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
80 	if (!ring->bounce_buf) {
81 		ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
82 		if (!ring->bounce_buf) {
83 			err = -ENOMEM;
84 			goto err_info;
85 		}
86 	}
87 	ring->buf_size = ALIGN(size * ring->sp_stride, MLX4_EN_PAGE_SIZE);
88 
89 	/* Allocate HW buffers on provided NUMA node */
90 	set_dev_node(&mdev->dev->persist->pdev->dev, node);
91 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
92 	set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
93 	if (err) {
94 		en_err(priv, "Failed allocating hwq resources\n");
95 		goto err_bounce;
96 	}
97 
98 	ring->buf = ring->sp_wqres.buf.direct.buf;
99 
100 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
101 	       ring, ring->buf, ring->size, ring->buf_size,
102 	       (unsigned long long) ring->sp_wqres.buf.direct.map);
103 
104 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
105 				    MLX4_RESERVE_ETH_BF_QP,
106 				    MLX4_RES_USAGE_DRIVER);
107 	if (err) {
108 		en_err(priv, "failed reserving qp for TX ring\n");
109 		goto err_hwq_res;
110 	}
111 
112 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->sp_qp);
113 	if (err) {
114 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
115 		goto err_reserve;
116 	}
117 	ring->sp_qp.event = mlx4_en_sqp_event;
118 
119 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
120 	if (err) {
121 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
122 		ring->bf.uar = &mdev->priv_uar;
123 		ring->bf.uar->map = mdev->uar_map;
124 		ring->bf_enabled = false;
125 		ring->bf_alloced = false;
126 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
127 	} else {
128 		ring->bf_alloced = true;
129 		ring->bf_enabled = !!(priv->pflags &
130 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
131 	}
132 
133 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
134 	ring->queue_index = queue_index;
135 
136 	if (queue_index < priv->num_tx_rings_p_up)
137 		cpumask_set_cpu(cpumask_local_spread(queue_index,
138 						     priv->mdev->dev->numa_node),
139 				&ring->sp_affinity_mask);
140 
141 	*pring = ring;
142 	return 0;
143 
144 err_reserve:
145 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
146 err_hwq_res:
147 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
148 err_bounce:
149 	kfree(ring->bounce_buf);
150 	ring->bounce_buf = NULL;
151 err_info:
152 	kvfree(ring->tx_info);
153 	ring->tx_info = NULL;
154 err_ring:
155 	kfree(ring);
156 	*pring = NULL;
157 	return err;
158 }
159 
160 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
161 			     struct mlx4_en_tx_ring **pring)
162 {
163 	struct mlx4_en_dev *mdev = priv->mdev;
164 	struct mlx4_en_tx_ring *ring = *pring;
165 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
166 
167 	if (ring->bf_alloced)
168 		mlx4_bf_free(mdev->dev, &ring->bf);
169 	mlx4_qp_remove(mdev->dev, &ring->sp_qp);
170 	mlx4_qp_free(mdev->dev, &ring->sp_qp);
171 	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
172 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
173 	kfree(ring->bounce_buf);
174 	ring->bounce_buf = NULL;
175 	kvfree(ring->tx_info);
176 	ring->tx_info = NULL;
177 	kfree(ring);
178 	*pring = NULL;
179 }
180 
181 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
182 			     struct mlx4_en_tx_ring *ring,
183 			     int cq, int user_prio)
184 {
185 	struct mlx4_en_dev *mdev = priv->mdev;
186 	int err;
187 
188 	ring->sp_cqn = cq;
189 	ring->prod = 0;
190 	ring->cons = 0xffffffff;
191 	ring->last_nr_txbb = 1;
192 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
193 	memset(ring->buf, 0, ring->buf_size);
194 	ring->free_tx_desc = mlx4_en_free_tx_desc;
195 
196 	ring->sp_qp_state = MLX4_QP_STATE_RST;
197 	ring->doorbell_qpn = cpu_to_be32(ring->sp_qp.qpn << 8);
198 	ring->mr_key = cpu_to_be32(mdev->mr.key);
199 
200 	mlx4_en_fill_qp_context(priv, ring->size, ring->sp_stride, 1, 0, ring->qpn,
201 				ring->sp_cqn, user_prio, &ring->sp_context);
202 	if (ring->bf_alloced)
203 		ring->sp_context.usr_page =
204 			cpu_to_be32(mlx4_to_hw_uar_index(mdev->dev,
205 							 ring->bf.uar->index));
206 
207 	err = mlx4_qp_to_ready(mdev->dev, &ring->sp_wqres.mtt, &ring->sp_context,
208 			       &ring->sp_qp, &ring->sp_qp_state);
209 	if (!cpumask_empty(&ring->sp_affinity_mask))
210 		netif_set_xps_queue(priv->dev, &ring->sp_affinity_mask,
211 				    ring->queue_index);
212 
213 	return err;
214 }
215 
216 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
217 				struct mlx4_en_tx_ring *ring)
218 {
219 	struct mlx4_en_dev *mdev = priv->mdev;
220 
221 	mlx4_qp_modify(mdev->dev, NULL, ring->sp_qp_state,
222 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->sp_qp);
223 }
224 
225 static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
226 {
227 	return ring->prod - ring->cons > ring->full_size;
228 }
229 
230 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
231 			      struct mlx4_en_tx_ring *ring, int index,
232 			      u8 owner)
233 {
234 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
235 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
236 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
237 	void *end = ring->buf + ring->buf_size;
238 	__be32 *ptr = (__be32 *)tx_desc;
239 	int i;
240 
241 	/* Optimize the common case when there are no wraparounds */
242 	if (likely((void *)tx_desc +
243 		   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
244 		/* Stamp the freed descriptor */
245 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
246 		     i += STAMP_STRIDE) {
247 			*ptr = stamp;
248 			ptr += STAMP_DWORDS;
249 		}
250 	} else {
251 		/* Stamp the freed descriptor */
252 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
253 		     i += STAMP_STRIDE) {
254 			*ptr = stamp;
255 			ptr += STAMP_DWORDS;
256 			if ((void *)ptr >= end) {
257 				ptr = ring->buf;
258 				stamp ^= cpu_to_be32(0x80000000);
259 			}
260 		}
261 	}
262 }
263 
264 
265 u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
266 			 struct mlx4_en_tx_ring *ring,
267 			 int index, u64 timestamp,
268 			 int napi_mode)
269 {
270 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
271 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
272 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
273 	void *end = ring->buf + ring->buf_size;
274 	struct sk_buff *skb = tx_info->skb;
275 	int nr_maps = tx_info->nr_maps;
276 	int i;
277 
278 	/* We do not touch skb here, so prefetch skb->users location
279 	 * to speedup consume_skb()
280 	 */
281 	prefetchw(&skb->users);
282 
283 	if (unlikely(timestamp)) {
284 		struct skb_shared_hwtstamps hwts;
285 
286 		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
287 		skb_tstamp_tx(skb, &hwts);
288 	}
289 
290 	if (!tx_info->inl) {
291 		if (tx_info->linear)
292 			dma_unmap_single(priv->ddev,
293 					 tx_info->map0_dma,
294 					 tx_info->map0_byte_count,
295 					 PCI_DMA_TODEVICE);
296 		else
297 			dma_unmap_page(priv->ddev,
298 				       tx_info->map0_dma,
299 				       tx_info->map0_byte_count,
300 				       PCI_DMA_TODEVICE);
301 		/* Optimize the common case when there are no wraparounds */
302 		if (likely((void *)tx_desc +
303 			   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
304 			for (i = 1; i < nr_maps; i++) {
305 				data++;
306 				dma_unmap_page(priv->ddev,
307 					(dma_addr_t)be64_to_cpu(data->addr),
308 					be32_to_cpu(data->byte_count),
309 					PCI_DMA_TODEVICE);
310 			}
311 		} else {
312 			if ((void *)data >= end)
313 				data = ring->buf + ((void *)data - end);
314 
315 			for (i = 1; i < nr_maps; i++) {
316 				data++;
317 				/* Check for wraparound before unmapping */
318 				if ((void *) data >= end)
319 					data = ring->buf;
320 				dma_unmap_page(priv->ddev,
321 					(dma_addr_t)be64_to_cpu(data->addr),
322 					be32_to_cpu(data->byte_count),
323 					PCI_DMA_TODEVICE);
324 			}
325 		}
326 	}
327 	napi_consume_skb(skb, napi_mode);
328 
329 	return tx_info->nr_txbb;
330 }
331 
332 u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
333 			    struct mlx4_en_tx_ring *ring,
334 			    int index, u64 timestamp,
335 			    int napi_mode)
336 {
337 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
338 	struct mlx4_en_rx_alloc frame = {
339 		.page = tx_info->page,
340 		.dma = tx_info->map0_dma,
341 	};
342 
343 	if (!mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
344 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
345 			       PAGE_SIZE, priv->dma_dir);
346 		put_page(tx_info->page);
347 	}
348 
349 	return tx_info->nr_txbb;
350 }
351 
352 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
353 {
354 	struct mlx4_en_priv *priv = netdev_priv(dev);
355 	int cnt = 0;
356 
357 	/* Skip last polled descriptor */
358 	ring->cons += ring->last_nr_txbb;
359 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
360 		 ring->cons, ring->prod);
361 
362 	if ((u32) (ring->prod - ring->cons) > ring->size) {
363 		if (netif_msg_tx_err(priv))
364 			en_warn(priv, "Tx consumer passed producer!\n");
365 		return 0;
366 	}
367 
368 	while (ring->cons != ring->prod) {
369 		ring->last_nr_txbb = ring->free_tx_desc(priv, ring,
370 						ring->cons & ring->size_mask,
371 						0, 0 /* Non-NAPI caller */);
372 		ring->cons += ring->last_nr_txbb;
373 		cnt++;
374 	}
375 
376 	if (ring->tx_queue)
377 		netdev_tx_reset_queue(ring->tx_queue);
378 
379 	if (cnt)
380 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
381 
382 	return cnt;
383 }
384 
385 bool mlx4_en_process_tx_cq(struct net_device *dev,
386 			   struct mlx4_en_cq *cq, int napi_budget)
387 {
388 	struct mlx4_en_priv *priv = netdev_priv(dev);
389 	struct mlx4_cq *mcq = &cq->mcq;
390 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->type][cq->ring];
391 	struct mlx4_cqe *cqe;
392 	u16 index, ring_index, stamp_index;
393 	u32 txbbs_skipped = 0;
394 	u32 txbbs_stamp = 0;
395 	u32 cons_index = mcq->cons_index;
396 	int size = cq->size;
397 	u32 size_mask = ring->size_mask;
398 	struct mlx4_cqe *buf = cq->buf;
399 	u32 packets = 0;
400 	u32 bytes = 0;
401 	int factor = priv->cqe_factor;
402 	int done = 0;
403 	int budget = priv->tx_work_limit;
404 	u32 last_nr_txbb;
405 	u32 ring_cons;
406 
407 	if (unlikely(!priv->port_up))
408 		return true;
409 
410 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
411 
412 	index = cons_index & size_mask;
413 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
414 	last_nr_txbb = READ_ONCE(ring->last_nr_txbb);
415 	ring_cons = READ_ONCE(ring->cons);
416 	ring_index = ring_cons & size_mask;
417 	stamp_index = ring_index;
418 
419 	/* Process all completed CQEs */
420 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
421 			cons_index & size) && (done < budget)) {
422 		u16 new_index;
423 
424 		/*
425 		 * make sure we read the CQE after we read the
426 		 * ownership bit
427 		 */
428 		dma_rmb();
429 
430 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
431 			     MLX4_CQE_OPCODE_ERROR)) {
432 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
433 
434 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
435 			       cqe_err->vendor_err_syndrome,
436 			       cqe_err->syndrome);
437 		}
438 
439 		/* Skip over last polled CQE */
440 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
441 
442 		do {
443 			u64 timestamp = 0;
444 
445 			txbbs_skipped += last_nr_txbb;
446 			ring_index = (ring_index + last_nr_txbb) & size_mask;
447 
448 			if (unlikely(ring->tx_info[ring_index].ts_requested))
449 				timestamp = mlx4_en_get_cqe_ts(cqe);
450 
451 			/* free next descriptor */
452 			last_nr_txbb = ring->free_tx_desc(
453 					priv, ring, ring_index,
454 					timestamp, napi_budget);
455 
456 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
457 					  !!((ring_cons + txbbs_stamp) &
458 						ring->size));
459 			stamp_index = ring_index;
460 			txbbs_stamp = txbbs_skipped;
461 			packets++;
462 			bytes += ring->tx_info[ring_index].nr_bytes;
463 		} while ((++done < budget) && (ring_index != new_index));
464 
465 		++cons_index;
466 		index = cons_index & size_mask;
467 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
468 	}
469 
470 	/*
471 	 * To prevent CQ overflow we first update CQ consumer and only then
472 	 * the ring consumer.
473 	 */
474 	mcq->cons_index = cons_index;
475 	mlx4_cq_set_ci(mcq);
476 	wmb();
477 
478 	/* we want to dirty this cache line once */
479 	WRITE_ONCE(ring->last_nr_txbb, last_nr_txbb);
480 	WRITE_ONCE(ring->cons, ring_cons + txbbs_skipped);
481 
482 	if (cq->type == TX_XDP)
483 		return done < budget;
484 
485 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
486 
487 	/* Wakeup Tx queue if this stopped, and ring is not full.
488 	 */
489 	if (netif_tx_queue_stopped(ring->tx_queue) &&
490 	    !mlx4_en_is_tx_ring_full(ring)) {
491 		netif_tx_wake_queue(ring->tx_queue);
492 		ring->wake_queue++;
493 	}
494 
495 	return done < budget;
496 }
497 
498 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
499 {
500 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
501 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
502 
503 	if (likely(priv->port_up))
504 		napi_schedule_irqoff(&cq->napi);
505 	else
506 		mlx4_en_arm_cq(priv, cq);
507 }
508 
509 /* TX CQ polling - called by NAPI */
510 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
511 {
512 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
513 	struct net_device *dev = cq->dev;
514 	struct mlx4_en_priv *priv = netdev_priv(dev);
515 	bool clean_complete;
516 
517 	clean_complete = mlx4_en_process_tx_cq(dev, cq, budget);
518 	if (!clean_complete)
519 		return budget;
520 
521 	napi_complete(napi);
522 	mlx4_en_arm_cq(priv, cq);
523 
524 	return 0;
525 }
526 
527 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
528 						      struct mlx4_en_tx_ring *ring,
529 						      u32 index,
530 						      unsigned int desc_size)
531 {
532 	u32 copy = (ring->size - index) << LOG_TXBB_SIZE;
533 	int i;
534 
535 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
536 		if ((i & (TXBB_SIZE - 1)) == 0)
537 			wmb();
538 
539 		*((u32 *) (ring->buf + i)) =
540 			*((u32 *) (ring->bounce_buf + copy + i));
541 	}
542 
543 	for (i = copy - 4; i >= 4 ; i -= 4) {
544 		if ((i & (TXBB_SIZE - 1)) == 0)
545 			wmb();
546 
547 		*((u32 *)(ring->buf + (index << LOG_TXBB_SIZE) + i)) =
548 			*((u32 *) (ring->bounce_buf + i));
549 	}
550 
551 	/* Return real descriptor location */
552 	return ring->buf + (index << LOG_TXBB_SIZE);
553 }
554 
555 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
556  *
557  * It seems strange we do not simply use skb_copy_bits().
558  * This would allow to inline all skbs iff skb->len <= inline_thold
559  *
560  * Note that caller already checked skb was not a gso packet
561  */
562 static bool is_inline(int inline_thold, const struct sk_buff *skb,
563 		      const struct skb_shared_info *shinfo,
564 		      void **pfrag)
565 {
566 	void *ptr;
567 
568 	if (skb->len > inline_thold || !inline_thold)
569 		return false;
570 
571 	if (shinfo->nr_frags == 1) {
572 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
573 		if (unlikely(!ptr))
574 			return false;
575 		*pfrag = ptr;
576 		return true;
577 	}
578 	if (shinfo->nr_frags)
579 		return false;
580 	return true;
581 }
582 
583 static int inline_size(const struct sk_buff *skb)
584 {
585 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
586 	    <= MLX4_INLINE_ALIGN)
587 		return ALIGN(skb->len + CTRL_SIZE +
588 			     sizeof(struct mlx4_wqe_inline_seg), 16);
589 	else
590 		return ALIGN(skb->len + CTRL_SIZE + 2 *
591 			     sizeof(struct mlx4_wqe_inline_seg), 16);
592 }
593 
594 static int get_real_size(const struct sk_buff *skb,
595 			 const struct skb_shared_info *shinfo,
596 			 struct net_device *dev,
597 			 int *lso_header_size,
598 			 bool *inline_ok,
599 			 void **pfrag)
600 {
601 	struct mlx4_en_priv *priv = netdev_priv(dev);
602 	int real_size;
603 
604 	if (shinfo->gso_size) {
605 		*inline_ok = false;
606 		if (skb->encapsulation)
607 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
608 		else
609 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
610 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
611 			ALIGN(*lso_header_size + 4, DS_SIZE);
612 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
613 			/* We add a segment for the skb linear buffer only if
614 			 * it contains data */
615 			if (*lso_header_size < skb_headlen(skb))
616 				real_size += DS_SIZE;
617 			else {
618 				if (netif_msg_tx_err(priv))
619 					en_warn(priv, "Non-linear headers\n");
620 				return 0;
621 			}
622 		}
623 	} else {
624 		*lso_header_size = 0;
625 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
626 				       shinfo, pfrag);
627 
628 		if (*inline_ok)
629 			real_size = inline_size(skb);
630 		else
631 			real_size = CTRL_SIZE +
632 				    (shinfo->nr_frags + 1) * DS_SIZE;
633 	}
634 
635 	return real_size;
636 }
637 
638 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
639 			     const struct sk_buff *skb,
640 			     const struct skb_shared_info *shinfo,
641 			     void *fragptr)
642 {
643 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
644 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof(*inl);
645 	unsigned int hlen = skb_headlen(skb);
646 
647 	if (skb->len <= spc) {
648 		if (likely(skb->len >= MIN_PKT_LEN)) {
649 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
650 		} else {
651 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
652 			memset(((void *)(inl + 1)) + skb->len, 0,
653 			       MIN_PKT_LEN - skb->len);
654 		}
655 		skb_copy_from_linear_data(skb, inl + 1, hlen);
656 		if (shinfo->nr_frags)
657 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
658 			       skb_frag_size(&shinfo->frags[0]));
659 
660 	} else {
661 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
662 		if (hlen <= spc) {
663 			skb_copy_from_linear_data(skb, inl + 1, hlen);
664 			if (hlen < spc) {
665 				memcpy(((void *)(inl + 1)) + hlen,
666 				       fragptr, spc - hlen);
667 				fragptr +=  spc - hlen;
668 			}
669 			inl = (void *) (inl + 1) + spc;
670 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
671 		} else {
672 			skb_copy_from_linear_data(skb, inl + 1, spc);
673 			inl = (void *) (inl + 1) + spc;
674 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
675 							 hlen - spc);
676 			if (shinfo->nr_frags)
677 				memcpy(((void *)(inl + 1)) + hlen - spc,
678 				       fragptr,
679 				       skb_frag_size(&shinfo->frags[0]));
680 		}
681 
682 		dma_wmb();
683 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
684 	}
685 }
686 
687 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
688 			 struct net_device *sb_dev,
689 			 select_queue_fallback_t fallback)
690 {
691 	struct mlx4_en_priv *priv = netdev_priv(dev);
692 	u16 rings_p_up = priv->num_tx_rings_p_up;
693 
694 	if (netdev_get_num_tc(dev))
695 		return fallback(dev, skb, NULL);
696 
697 	return fallback(dev, skb, NULL) % rings_p_up;
698 }
699 
700 static void mlx4_bf_copy(void __iomem *dst, const void *src,
701 			 unsigned int bytecnt)
702 {
703 	__iowrite64_copy(dst, src, bytecnt / 8);
704 }
705 
706 void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
707 {
708 	wmb();
709 	/* Since there is no iowrite*_native() that writes the
710 	 * value as is, without byteswapping - using the one
711 	 * the doesn't do byteswapping in the relevant arch
712 	 * endianness.
713 	 */
714 #if defined(__LITTLE_ENDIAN)
715 	iowrite32(
716 #else
717 	iowrite32be(
718 #endif
719 		  (__force u32)ring->doorbell_qpn,
720 		  ring->bf.uar->map + MLX4_SEND_DOORBELL);
721 }
722 
723 static void mlx4_en_tx_write_desc(struct mlx4_en_tx_ring *ring,
724 				  struct mlx4_en_tx_desc *tx_desc,
725 				  union mlx4_wqe_qpn_vlan qpn_vlan,
726 				  int desc_size, int bf_index,
727 				  __be32 op_own, bool bf_ok,
728 				  bool send_doorbell)
729 {
730 	tx_desc->ctrl.qpn_vlan = qpn_vlan;
731 
732 	if (bf_ok) {
733 		op_own |= htonl((bf_index & 0xffff) << 8);
734 		/* Ensure new descriptor hits memory
735 		 * before setting ownership of this descriptor to HW
736 		 */
737 		dma_wmb();
738 		tx_desc->ctrl.owner_opcode = op_own;
739 
740 		wmb();
741 
742 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
743 			     desc_size);
744 
745 		wmb();
746 
747 		ring->bf.offset ^= ring->bf.buf_size;
748 	} else {
749 		/* Ensure new descriptor hits memory
750 		 * before setting ownership of this descriptor to HW
751 		 */
752 		dma_wmb();
753 		tx_desc->ctrl.owner_opcode = op_own;
754 		if (send_doorbell)
755 			mlx4_en_xmit_doorbell(ring);
756 		else
757 			ring->xmit_more++;
758 	}
759 }
760 
761 static bool mlx4_en_build_dma_wqe(struct mlx4_en_priv *priv,
762 				  struct skb_shared_info *shinfo,
763 				  struct mlx4_wqe_data_seg *data,
764 				  struct sk_buff *skb,
765 				  int lso_header_size,
766 				  __be32 mr_key,
767 				  struct mlx4_en_tx_info *tx_info)
768 {
769 	struct device *ddev = priv->ddev;
770 	dma_addr_t dma = 0;
771 	u32 byte_count = 0;
772 	int i_frag;
773 
774 	/* Map fragments if any */
775 	for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
776 		const struct skb_frag_struct *frag;
777 
778 		frag = &shinfo->frags[i_frag];
779 		byte_count = skb_frag_size(frag);
780 		dma = skb_frag_dma_map(ddev, frag,
781 				       0, byte_count,
782 				       DMA_TO_DEVICE);
783 		if (dma_mapping_error(ddev, dma))
784 			goto tx_drop_unmap;
785 
786 		data->addr = cpu_to_be64(dma);
787 		data->lkey = mr_key;
788 		dma_wmb();
789 		data->byte_count = cpu_to_be32(byte_count);
790 		--data;
791 	}
792 
793 	/* Map linear part if needed */
794 	if (tx_info->linear) {
795 		byte_count = skb_headlen(skb) - lso_header_size;
796 
797 		dma = dma_map_single(ddev, skb->data +
798 				     lso_header_size, byte_count,
799 				     PCI_DMA_TODEVICE);
800 		if (dma_mapping_error(ddev, dma))
801 			goto tx_drop_unmap;
802 
803 		data->addr = cpu_to_be64(dma);
804 		data->lkey = mr_key;
805 		dma_wmb();
806 		data->byte_count = cpu_to_be32(byte_count);
807 	}
808 	/* tx completion can avoid cache line miss for common cases */
809 	tx_info->map0_dma = dma;
810 	tx_info->map0_byte_count = byte_count;
811 
812 	return true;
813 
814 tx_drop_unmap:
815 	en_err(priv, "DMA mapping error\n");
816 
817 	while (++i_frag < shinfo->nr_frags) {
818 		++data;
819 		dma_unmap_page(ddev, (dma_addr_t)be64_to_cpu(data->addr),
820 			       be32_to_cpu(data->byte_count),
821 			       PCI_DMA_TODEVICE);
822 	}
823 
824 	return false;
825 }
826 
827 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
828 {
829 	struct skb_shared_info *shinfo = skb_shinfo(skb);
830 	struct mlx4_en_priv *priv = netdev_priv(dev);
831 	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
832 	struct mlx4_en_tx_ring *ring;
833 	struct mlx4_en_tx_desc *tx_desc;
834 	struct mlx4_wqe_data_seg *data;
835 	struct mlx4_en_tx_info *tx_info;
836 	int tx_ind;
837 	int nr_txbb;
838 	int desc_size;
839 	int real_size;
840 	u32 index, bf_index;
841 	__be32 op_own;
842 	int lso_header_size;
843 	void *fragptr = NULL;
844 	bool bounce = false;
845 	bool send_doorbell;
846 	bool stop_queue;
847 	bool inline_ok;
848 	u8 data_offset;
849 	u32 ring_cons;
850 	bool bf_ok;
851 
852 	tx_ind = skb_get_queue_mapping(skb);
853 	ring = priv->tx_ring[TX][tx_ind];
854 
855 	if (unlikely(!priv->port_up))
856 		goto tx_drop;
857 
858 	/* fetch ring->cons far ahead before needing it to avoid stall */
859 	ring_cons = READ_ONCE(ring->cons);
860 
861 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
862 				  &inline_ok, &fragptr);
863 	if (unlikely(!real_size))
864 		goto tx_drop_count;
865 
866 	/* Align descriptor to TXBB size */
867 	desc_size = ALIGN(real_size, TXBB_SIZE);
868 	nr_txbb = desc_size >> LOG_TXBB_SIZE;
869 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
870 		if (netif_msg_tx_err(priv))
871 			en_warn(priv, "Oversized header or SG list\n");
872 		goto tx_drop_count;
873 	}
874 
875 	bf_ok = ring->bf_enabled;
876 	if (skb_vlan_tag_present(skb)) {
877 		u16 vlan_proto;
878 
879 		qpn_vlan.vlan_tag = cpu_to_be16(skb_vlan_tag_get(skb));
880 		vlan_proto = be16_to_cpu(skb->vlan_proto);
881 		if (vlan_proto == ETH_P_8021AD)
882 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_SVLAN;
883 		else if (vlan_proto == ETH_P_8021Q)
884 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_CVLAN;
885 		else
886 			qpn_vlan.ins_vlan = 0;
887 		bf_ok = false;
888 	}
889 
890 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
891 
892 	/* Track current inflight packets for performance analysis */
893 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
894 			 (u32)(ring->prod - ring_cons - 1));
895 
896 	/* Packet is good - grab an index and transmit it */
897 	index = ring->prod & ring->size_mask;
898 	bf_index = ring->prod;
899 
900 	/* See if we have enough space for whole descriptor TXBB for setting
901 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
902 	if (likely(index + nr_txbb <= ring->size))
903 		tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
904 	else {
905 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
906 		bounce = true;
907 		bf_ok = false;
908 	}
909 
910 	/* Save skb in tx_info ring */
911 	tx_info = &ring->tx_info[index];
912 	tx_info->skb = skb;
913 	tx_info->nr_txbb = nr_txbb;
914 
915 	if (!lso_header_size) {
916 		data = &tx_desc->data;
917 		data_offset = offsetof(struct mlx4_en_tx_desc, data);
918 	} else {
919 		int lso_align = ALIGN(lso_header_size + 4, DS_SIZE);
920 
921 		data = (void *)&tx_desc->lso + lso_align;
922 		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
923 	}
924 
925 	/* valid only for none inline segments */
926 	tx_info->data_offset = data_offset;
927 
928 	tx_info->inl = inline_ok;
929 
930 	tx_info->linear = lso_header_size < skb_headlen(skb) && !inline_ok;
931 
932 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
933 	data += tx_info->nr_maps - 1;
934 
935 	if (!tx_info->inl)
936 		if (!mlx4_en_build_dma_wqe(priv, shinfo, data, skb,
937 					   lso_header_size, ring->mr_key,
938 					   tx_info))
939 			goto tx_drop_count;
940 
941 	/*
942 	 * For timestamping add flag to skb_shinfo and
943 	 * set flag for further reference
944 	 */
945 	tx_info->ts_requested = 0;
946 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
947 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
948 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
949 		tx_info->ts_requested = 1;
950 	}
951 
952 	/* Prepare ctrl segement apart opcode+ownership, which depends on
953 	 * whether LSO is used */
954 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
955 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
956 		if (!skb->encapsulation)
957 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
958 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
959 		else
960 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
961 		ring->tx_csum++;
962 	}
963 
964 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
965 		struct ethhdr *ethh;
966 
967 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
968 		 * so that VFs and PF can communicate with each other
969 		 */
970 		ethh = (struct ethhdr *)skb->data;
971 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
972 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
973 	}
974 
975 	/* Handle LSO (TSO) packets */
976 	if (lso_header_size) {
977 		int i;
978 
979 		/* Mark opcode as LSO */
980 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
981 			((ring->prod & ring->size) ?
982 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
983 
984 		/* Fill in the LSO prefix */
985 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
986 			shinfo->gso_size << 16 | lso_header_size);
987 
988 		/* Copy headers;
989 		 * note that we already verified that it is linear */
990 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
991 
992 		ring->tso_packets++;
993 
994 		i = shinfo->gso_segs;
995 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
996 		ring->packets += i;
997 	} else {
998 		/* Normal (Non LSO) packet */
999 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1000 			((ring->prod & ring->size) ?
1001 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1002 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
1003 		ring->packets++;
1004 	}
1005 	ring->bytes += tx_info->nr_bytes;
1006 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
1007 
1008 	if (tx_info->inl)
1009 		build_inline_wqe(tx_desc, skb, shinfo, fragptr);
1010 
1011 	if (skb->encapsulation) {
1012 		union {
1013 			struct iphdr *v4;
1014 			struct ipv6hdr *v6;
1015 			unsigned char *hdr;
1016 		} ip;
1017 		u8 proto;
1018 
1019 		ip.hdr = skb_inner_network_header(skb);
1020 		proto = (ip.v4->version == 4) ? ip.v4->protocol :
1021 						ip.v6->nexthdr;
1022 
1023 		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
1024 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
1025 		else
1026 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
1027 	}
1028 
1029 	ring->prod += nr_txbb;
1030 
1031 	/* If we used a bounce buffer then copy descriptor back into place */
1032 	if (unlikely(bounce))
1033 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
1034 
1035 	skb_tx_timestamp(skb);
1036 
1037 	/* Check available TXBBs And 2K spare for prefetch */
1038 	stop_queue = mlx4_en_is_tx_ring_full(ring);
1039 	if (unlikely(stop_queue)) {
1040 		netif_tx_stop_queue(ring->tx_queue);
1041 		ring->queue_stopped++;
1042 	}
1043 
1044 	send_doorbell = __netdev_tx_sent_queue(ring->tx_queue,
1045 					       tx_info->nr_bytes,
1046 					       skb->xmit_more);
1047 
1048 	real_size = (real_size / 16) & 0x3f;
1049 
1050 	bf_ok &= desc_size <= MAX_BF && send_doorbell;
1051 
1052 	if (bf_ok)
1053 		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
1054 	else
1055 		qpn_vlan.fence_size = real_size;
1056 
1057 	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, desc_size, bf_index,
1058 			      op_own, bf_ok, send_doorbell);
1059 
1060 	if (unlikely(stop_queue)) {
1061 		/* If queue was emptied after the if (stop_queue) , and before
1062 		 * the netif_tx_stop_queue() - need to wake the queue,
1063 		 * or else it will remain stopped forever.
1064 		 * Need a memory barrier to make sure ring->cons was not
1065 		 * updated before queue was stopped.
1066 		 */
1067 		smp_rmb();
1068 
1069 		ring_cons = READ_ONCE(ring->cons);
1070 		if (unlikely(!mlx4_en_is_tx_ring_full(ring))) {
1071 			netif_tx_wake_queue(ring->tx_queue);
1072 			ring->wake_queue++;
1073 		}
1074 	}
1075 	return NETDEV_TX_OK;
1076 
1077 tx_drop_count:
1078 	ring->tx_dropped++;
1079 tx_drop:
1080 	dev_kfree_skb_any(skb);
1081 	return NETDEV_TX_OK;
1082 }
1083 
1084 #define MLX4_EN_XDP_TX_NRTXBB  1
1085 #define MLX4_EN_XDP_TX_REAL_SZ (((CTRL_SIZE + MLX4_EN_XDP_TX_NRTXBB * DS_SIZE) \
1086 				 / 16) & 0x3f)
1087 
1088 void mlx4_en_init_tx_xdp_ring_descs(struct mlx4_en_priv *priv,
1089 				    struct mlx4_en_tx_ring *ring)
1090 {
1091 	int i;
1092 
1093 	for (i = 0; i < ring->size; i++) {
1094 		struct mlx4_en_tx_info *tx_info = &ring->tx_info[i];
1095 		struct mlx4_en_tx_desc *tx_desc = ring->buf +
1096 			(i << LOG_TXBB_SIZE);
1097 
1098 		tx_info->map0_byte_count = PAGE_SIZE;
1099 		tx_info->nr_txbb = MLX4_EN_XDP_TX_NRTXBB;
1100 		tx_info->data_offset = offsetof(struct mlx4_en_tx_desc, data);
1101 		tx_info->ts_requested = 0;
1102 		tx_info->nr_maps = 1;
1103 		tx_info->linear = 1;
1104 		tx_info->inl = 0;
1105 
1106 		tx_desc->data.lkey = ring->mr_key;
1107 		tx_desc->ctrl.qpn_vlan.fence_size = MLX4_EN_XDP_TX_REAL_SZ;
1108 		tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
1109 	}
1110 }
1111 
1112 netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring,
1113 			       struct mlx4_en_rx_alloc *frame,
1114 			       struct mlx4_en_priv *priv, unsigned int length,
1115 			       int tx_ind, bool *doorbell_pending)
1116 {
1117 	struct mlx4_en_tx_desc *tx_desc;
1118 	struct mlx4_en_tx_info *tx_info;
1119 	struct mlx4_wqe_data_seg *data;
1120 	struct mlx4_en_tx_ring *ring;
1121 	dma_addr_t dma;
1122 	__be32 op_own;
1123 	int index;
1124 
1125 	if (unlikely(!priv->port_up))
1126 		goto tx_drop;
1127 
1128 	ring = priv->tx_ring[TX_XDP][tx_ind];
1129 
1130 	if (unlikely(mlx4_en_is_tx_ring_full(ring)))
1131 		goto tx_drop_count;
1132 
1133 	index = ring->prod & ring->size_mask;
1134 	tx_info = &ring->tx_info[index];
1135 
1136 	/* Track current inflight packets for performance analysis */
1137 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
1138 			 (u32)(ring->prod - READ_ONCE(ring->cons) - 1));
1139 
1140 	tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
1141 	data = &tx_desc->data;
1142 
1143 	dma = frame->dma;
1144 
1145 	tx_info->page = frame->page;
1146 	frame->page = NULL;
1147 	tx_info->map0_dma = dma;
1148 	tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
1149 
1150 	dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset,
1151 					 length, PCI_DMA_TODEVICE);
1152 
1153 	data->addr = cpu_to_be64(dma + frame->page_offset);
1154 	dma_wmb();
1155 	data->byte_count = cpu_to_be32(length);
1156 
1157 	/* tx completion can avoid cache line miss for common cases */
1158 
1159 	op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1160 		((ring->prod & ring->size) ?
1161 		 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1162 
1163 	rx_ring->xdp_tx++;
1164 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, length);
1165 
1166 	ring->prod += MLX4_EN_XDP_TX_NRTXBB;
1167 
1168 	/* Ensure new descriptor hits memory
1169 	 * before setting ownership of this descriptor to HW
1170 	 */
1171 	dma_wmb();
1172 	tx_desc->ctrl.owner_opcode = op_own;
1173 	ring->xmit_more++;
1174 
1175 	*doorbell_pending = true;
1176 
1177 	return NETDEV_TX_OK;
1178 
1179 tx_drop_count:
1180 	rx_ring->xdp_tx_full++;
1181 	*doorbell_pending = true;
1182 tx_drop:
1183 	return NETDEV_TX_BUSY;
1184 }
1185