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 #include <linux/indirect_call_wrapper.h>
47 
48 #include "mlx4_en.h"
49 
50 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
51 			   struct mlx4_en_tx_ring **pring, u32 size,
52 			   u16 stride, int node, int queue_index)
53 {
54 	struct mlx4_en_dev *mdev = priv->mdev;
55 	struct mlx4_en_tx_ring *ring;
56 	int tmp;
57 	int err;
58 
59 	ring = kzalloc_node(sizeof(*ring), GFP_KERNEL, node);
60 	if (!ring) {
61 		en_err(priv, "Failed allocating TX ring\n");
62 		return -ENOMEM;
63 	}
64 
65 	ring->size = size;
66 	ring->size_mask = size - 1;
67 	ring->sp_stride = stride;
68 	ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
69 
70 	tmp = size * sizeof(struct mlx4_en_tx_info);
71 	ring->tx_info = kvmalloc_node(tmp, GFP_KERNEL, node);
72 	if (!ring->tx_info) {
73 		err = -ENOMEM;
74 		goto err_ring;
75 	}
76 
77 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
78 		 ring->tx_info, tmp);
79 
80 	ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
81 	if (!ring->bounce_buf) {
82 		ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
83 		if (!ring->bounce_buf) {
84 			err = -ENOMEM;
85 			goto err_info;
86 		}
87 	}
88 	ring->buf_size = ALIGN(size * ring->sp_stride, MLX4_EN_PAGE_SIZE);
89 
90 	/* Allocate HW buffers on provided NUMA node */
91 	set_dev_node(&mdev->dev->persist->pdev->dev, node);
92 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
93 	set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
94 	if (err) {
95 		en_err(priv, "Failed allocating hwq resources\n");
96 		goto err_bounce;
97 	}
98 
99 	ring->buf = ring->sp_wqres.buf.direct.buf;
100 
101 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
102 	       ring, ring->buf, ring->size, ring->buf_size,
103 	       (unsigned long long) ring->sp_wqres.buf.direct.map);
104 
105 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
106 				    MLX4_RESERVE_ETH_BF_QP,
107 				    MLX4_RES_USAGE_DRIVER);
108 	if (err) {
109 		en_err(priv, "failed reserving qp for TX ring\n");
110 		goto err_hwq_res;
111 	}
112 
113 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->sp_qp);
114 	if (err) {
115 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
116 		goto err_reserve;
117 	}
118 	ring->sp_qp.event = mlx4_en_sqp_event;
119 
120 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
121 	if (err) {
122 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
123 		ring->bf.uar = &mdev->priv_uar;
124 		ring->bf.uar->map = mdev->uar_map;
125 		ring->bf_enabled = false;
126 		ring->bf_alloced = false;
127 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
128 	} else {
129 		ring->bf_alloced = true;
130 		ring->bf_enabled = !!(priv->pflags &
131 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
132 	}
133 
134 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
135 	ring->queue_index = queue_index;
136 
137 	if (queue_index < priv->num_tx_rings_p_up)
138 		cpumask_set_cpu(cpumask_local_spread(queue_index,
139 						     priv->mdev->dev->numa_node),
140 				&ring->sp_affinity_mask);
141 
142 	*pring = ring;
143 	return 0;
144 
145 err_reserve:
146 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
147 err_hwq_res:
148 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
149 err_bounce:
150 	kfree(ring->bounce_buf);
151 	ring->bounce_buf = NULL;
152 err_info:
153 	kvfree(ring->tx_info);
154 	ring->tx_info = NULL;
155 err_ring:
156 	kfree(ring);
157 	*pring = NULL;
158 	return err;
159 }
160 
161 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
162 			     struct mlx4_en_tx_ring **pring)
163 {
164 	struct mlx4_en_dev *mdev = priv->mdev;
165 	struct mlx4_en_tx_ring *ring = *pring;
166 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
167 
168 	if (ring->bf_alloced)
169 		mlx4_bf_free(mdev->dev, &ring->bf);
170 	mlx4_qp_remove(mdev->dev, &ring->sp_qp);
171 	mlx4_qp_free(mdev->dev, &ring->sp_qp);
172 	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
173 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
174 	kfree(ring->bounce_buf);
175 	ring->bounce_buf = NULL;
176 	kvfree(ring->tx_info);
177 	ring->tx_info = NULL;
178 	kfree(ring);
179 	*pring = NULL;
180 }
181 
182 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
183 			     struct mlx4_en_tx_ring *ring,
184 			     int cq, int user_prio)
185 {
186 	struct mlx4_en_dev *mdev = priv->mdev;
187 	int err;
188 
189 	ring->sp_cqn = cq;
190 	ring->prod = 0;
191 	ring->cons = 0xffffffff;
192 	ring->last_nr_txbb = 1;
193 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
194 	memset(ring->buf, 0, ring->buf_size);
195 	ring->free_tx_desc = mlx4_en_free_tx_desc;
196 
197 	ring->sp_qp_state = MLX4_QP_STATE_RST;
198 	ring->doorbell_qpn = cpu_to_be32(ring->sp_qp.qpn << 8);
199 	ring->mr_key = cpu_to_be32(mdev->mr.key);
200 
201 	mlx4_en_fill_qp_context(priv, ring->size, ring->sp_stride, 1, 0, ring->qpn,
202 				ring->sp_cqn, user_prio, &ring->sp_context);
203 	if (ring->bf_alloced)
204 		ring->sp_context.usr_page =
205 			cpu_to_be32(mlx4_to_hw_uar_index(mdev->dev,
206 							 ring->bf.uar->index));
207 
208 	err = mlx4_qp_to_ready(mdev->dev, &ring->sp_wqres.mtt, &ring->sp_context,
209 			       &ring->sp_qp, &ring->sp_qp_state);
210 	if (!cpumask_empty(&ring->sp_affinity_mask))
211 		netif_set_xps_queue(priv->dev, &ring->sp_affinity_mask,
212 				    ring->queue_index);
213 
214 	return err;
215 }
216 
217 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
218 				struct mlx4_en_tx_ring *ring)
219 {
220 	struct mlx4_en_dev *mdev = priv->mdev;
221 
222 	mlx4_qp_modify(mdev->dev, NULL, ring->sp_qp_state,
223 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->sp_qp);
224 }
225 
226 static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
227 {
228 	return ring->prod - ring->cons > ring->full_size;
229 }
230 
231 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
232 			      struct mlx4_en_tx_ring *ring, int index,
233 			      u8 owner)
234 {
235 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
236 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
237 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
238 	void *end = ring->buf + ring->buf_size;
239 	__be32 *ptr = (__be32 *)tx_desc;
240 	int i;
241 
242 	/* Optimize the common case when there are no wraparounds */
243 	if (likely((void *)tx_desc +
244 		   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
245 		/* Stamp the freed descriptor */
246 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
247 		     i += STAMP_STRIDE) {
248 			*ptr = stamp;
249 			ptr += STAMP_DWORDS;
250 		}
251 	} else {
252 		/* Stamp the freed descriptor */
253 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
254 		     i += STAMP_STRIDE) {
255 			*ptr = stamp;
256 			ptr += STAMP_DWORDS;
257 			if ((void *)ptr >= end) {
258 				ptr = ring->buf;
259 				stamp ^= cpu_to_be32(0x80000000);
260 			}
261 		}
262 	}
263 }
264 
265 INDIRECT_CALLABLE_DECLARE(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 u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
271 			 struct mlx4_en_tx_ring *ring,
272 			 int index, u64 timestamp,
273 			 int napi_mode)
274 {
275 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
276 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
277 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
278 	void *end = ring->buf + ring->buf_size;
279 	struct sk_buff *skb = tx_info->skb;
280 	int nr_maps = tx_info->nr_maps;
281 	int i;
282 
283 	/* We do not touch skb here, so prefetch skb->users location
284 	 * to speedup consume_skb()
285 	 */
286 	prefetchw(&skb->users);
287 
288 	if (unlikely(timestamp)) {
289 		struct skb_shared_hwtstamps hwts;
290 
291 		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
292 		skb_tstamp_tx(skb, &hwts);
293 	}
294 
295 	if (!tx_info->inl) {
296 		if (tx_info->linear)
297 			dma_unmap_single(priv->ddev,
298 					 tx_info->map0_dma,
299 					 tx_info->map0_byte_count,
300 					 PCI_DMA_TODEVICE);
301 		else
302 			dma_unmap_page(priv->ddev,
303 				       tx_info->map0_dma,
304 				       tx_info->map0_byte_count,
305 				       PCI_DMA_TODEVICE);
306 		/* Optimize the common case when there are no wraparounds */
307 		if (likely((void *)tx_desc +
308 			   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
309 			for (i = 1; i < nr_maps; i++) {
310 				data++;
311 				dma_unmap_page(priv->ddev,
312 					(dma_addr_t)be64_to_cpu(data->addr),
313 					be32_to_cpu(data->byte_count),
314 					PCI_DMA_TODEVICE);
315 			}
316 		} else {
317 			if ((void *)data >= end)
318 				data = ring->buf + ((void *)data - end);
319 
320 			for (i = 1; i < nr_maps; i++) {
321 				data++;
322 				/* Check for wraparound before unmapping */
323 				if ((void *) data >= end)
324 					data = ring->buf;
325 				dma_unmap_page(priv->ddev,
326 					(dma_addr_t)be64_to_cpu(data->addr),
327 					be32_to_cpu(data->byte_count),
328 					PCI_DMA_TODEVICE);
329 			}
330 		}
331 	}
332 	napi_consume_skb(skb, napi_mode);
333 
334 	return tx_info->nr_txbb;
335 }
336 
337 INDIRECT_CALLABLE_DECLARE(u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
338 						      struct mlx4_en_tx_ring *ring,
339 						      int index, u64 timestamp,
340 						      int napi_mode));
341 
342 u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
343 			    struct mlx4_en_tx_ring *ring,
344 			    int index, u64 timestamp,
345 			    int napi_mode)
346 {
347 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
348 	struct mlx4_en_rx_alloc frame = {
349 		.page = tx_info->page,
350 		.dma = tx_info->map0_dma,
351 	};
352 
353 	if (!napi_mode || !mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
354 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
355 			       PAGE_SIZE, priv->dma_dir);
356 		put_page(tx_info->page);
357 	}
358 
359 	return tx_info->nr_txbb;
360 }
361 
362 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
363 {
364 	struct mlx4_en_priv *priv = netdev_priv(dev);
365 	int cnt = 0;
366 
367 	/* Skip last polled descriptor */
368 	ring->cons += ring->last_nr_txbb;
369 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
370 		 ring->cons, ring->prod);
371 
372 	if ((u32) (ring->prod - ring->cons) > ring->size) {
373 		if (netif_msg_tx_err(priv))
374 			en_warn(priv, "Tx consumer passed producer!\n");
375 		return 0;
376 	}
377 
378 	while (ring->cons != ring->prod) {
379 		ring->last_nr_txbb = ring->free_tx_desc(priv, ring,
380 						ring->cons & ring->size_mask,
381 						0, 0 /* Non-NAPI caller */);
382 		ring->cons += ring->last_nr_txbb;
383 		cnt++;
384 	}
385 
386 	if (ring->tx_queue)
387 		netdev_tx_reset_queue(ring->tx_queue);
388 
389 	if (cnt)
390 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
391 
392 	return cnt;
393 }
394 
395 int mlx4_en_process_tx_cq(struct net_device *dev,
396 			  struct mlx4_en_cq *cq, int napi_budget)
397 {
398 	struct mlx4_en_priv *priv = netdev_priv(dev);
399 	struct mlx4_cq *mcq = &cq->mcq;
400 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->type][cq->ring];
401 	struct mlx4_cqe *cqe;
402 	u16 index, ring_index, stamp_index;
403 	u32 txbbs_skipped = 0;
404 	u32 txbbs_stamp = 0;
405 	u32 cons_index = mcq->cons_index;
406 	int size = cq->size;
407 	u32 size_mask = ring->size_mask;
408 	struct mlx4_cqe *buf = cq->buf;
409 	u32 packets = 0;
410 	u32 bytes = 0;
411 	int factor = priv->cqe_factor;
412 	int done = 0;
413 	int budget = priv->tx_work_limit;
414 	u32 last_nr_txbb;
415 	u32 ring_cons;
416 
417 	if (unlikely(!priv->port_up))
418 		return 0;
419 
420 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
421 
422 	index = cons_index & size_mask;
423 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
424 	last_nr_txbb = READ_ONCE(ring->last_nr_txbb);
425 	ring_cons = READ_ONCE(ring->cons);
426 	ring_index = ring_cons & size_mask;
427 	stamp_index = ring_index;
428 
429 	/* Process all completed CQEs */
430 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
431 			cons_index & size) && (done < budget)) {
432 		u16 new_index;
433 
434 		/*
435 		 * make sure we read the CQE after we read the
436 		 * ownership bit
437 		 */
438 		dma_rmb();
439 
440 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
441 			     MLX4_CQE_OPCODE_ERROR)) {
442 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
443 
444 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
445 			       cqe_err->vendor_err_syndrome,
446 			       cqe_err->syndrome);
447 		}
448 
449 		/* Skip over last polled CQE */
450 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
451 
452 		do {
453 			u64 timestamp = 0;
454 
455 			txbbs_skipped += last_nr_txbb;
456 			ring_index = (ring_index + last_nr_txbb) & size_mask;
457 
458 			if (unlikely(ring->tx_info[ring_index].ts_requested))
459 				timestamp = mlx4_en_get_cqe_ts(cqe);
460 
461 			/* free next descriptor */
462 			last_nr_txbb = INDIRECT_CALL_2(ring->free_tx_desc,
463 						       mlx4_en_free_tx_desc,
464 						       mlx4_en_recycle_tx_desc,
465 					priv, ring, ring_index,
466 					timestamp, napi_budget);
467 
468 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
469 					  !!((ring_cons + txbbs_stamp) &
470 						ring->size));
471 			stamp_index = ring_index;
472 			txbbs_stamp = txbbs_skipped;
473 			packets++;
474 			bytes += ring->tx_info[ring_index].nr_bytes;
475 		} while ((++done < budget) && (ring_index != new_index));
476 
477 		++cons_index;
478 		index = cons_index & size_mask;
479 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
480 	}
481 
482 	/*
483 	 * To prevent CQ overflow we first update CQ consumer and only then
484 	 * the ring consumer.
485 	 */
486 	mcq->cons_index = cons_index;
487 	mlx4_cq_set_ci(mcq);
488 	wmb();
489 
490 	/* we want to dirty this cache line once */
491 	WRITE_ONCE(ring->last_nr_txbb, last_nr_txbb);
492 	WRITE_ONCE(ring->cons, ring_cons + txbbs_skipped);
493 
494 	if (cq->type == TX_XDP)
495 		return done;
496 
497 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
498 
499 	/* Wakeup Tx queue if this stopped, and ring is not full.
500 	 */
501 	if (netif_tx_queue_stopped(ring->tx_queue) &&
502 	    !mlx4_en_is_tx_ring_full(ring)) {
503 		netif_tx_wake_queue(ring->tx_queue);
504 		ring->wake_queue++;
505 	}
506 
507 	return done;
508 }
509 
510 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
511 {
512 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
513 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
514 
515 	if (likely(priv->port_up))
516 		napi_schedule_irqoff(&cq->napi);
517 	else
518 		mlx4_en_arm_cq(priv, cq);
519 }
520 
521 /* TX CQ polling - called by NAPI */
522 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
523 {
524 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
525 	struct net_device *dev = cq->dev;
526 	struct mlx4_en_priv *priv = netdev_priv(dev);
527 	int work_done;
528 
529 	work_done = mlx4_en_process_tx_cq(dev, cq, budget);
530 	if (work_done >= budget)
531 		return budget;
532 
533 	if (napi_complete_done(napi, work_done))
534 		mlx4_en_arm_cq(priv, cq);
535 
536 	return 0;
537 }
538 
539 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
540 						      struct mlx4_en_tx_ring *ring,
541 						      u32 index,
542 						      unsigned int desc_size)
543 {
544 	u32 copy = (ring->size - index) << LOG_TXBB_SIZE;
545 	int i;
546 
547 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
548 		if ((i & (TXBB_SIZE - 1)) == 0)
549 			wmb();
550 
551 		*((u32 *) (ring->buf + i)) =
552 			*((u32 *) (ring->bounce_buf + copy + i));
553 	}
554 
555 	for (i = copy - 4; i >= 4 ; i -= 4) {
556 		if ((i & (TXBB_SIZE - 1)) == 0)
557 			wmb();
558 
559 		*((u32 *)(ring->buf + (index << LOG_TXBB_SIZE) + i)) =
560 			*((u32 *) (ring->bounce_buf + i));
561 	}
562 
563 	/* Return real descriptor location */
564 	return ring->buf + (index << LOG_TXBB_SIZE);
565 }
566 
567 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
568  *
569  * It seems strange we do not simply use skb_copy_bits().
570  * This would allow to inline all skbs iff skb->len <= inline_thold
571  *
572  * Note that caller already checked skb was not a gso packet
573  */
574 static bool is_inline(int inline_thold, const struct sk_buff *skb,
575 		      const struct skb_shared_info *shinfo,
576 		      void **pfrag)
577 {
578 	void *ptr;
579 
580 	if (skb->len > inline_thold || !inline_thold)
581 		return false;
582 
583 	if (shinfo->nr_frags == 1) {
584 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
585 		if (unlikely(!ptr))
586 			return false;
587 		*pfrag = ptr;
588 		return true;
589 	}
590 	if (shinfo->nr_frags)
591 		return false;
592 	return true;
593 }
594 
595 static int inline_size(const struct sk_buff *skb)
596 {
597 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
598 	    <= MLX4_INLINE_ALIGN)
599 		return ALIGN(skb->len + CTRL_SIZE +
600 			     sizeof(struct mlx4_wqe_inline_seg), 16);
601 	else
602 		return ALIGN(skb->len + CTRL_SIZE + 2 *
603 			     sizeof(struct mlx4_wqe_inline_seg), 16);
604 }
605 
606 static int get_real_size(const struct sk_buff *skb,
607 			 const struct skb_shared_info *shinfo,
608 			 struct net_device *dev,
609 			 int *lso_header_size,
610 			 bool *inline_ok,
611 			 void **pfrag)
612 {
613 	struct mlx4_en_priv *priv = netdev_priv(dev);
614 	int real_size;
615 
616 	if (shinfo->gso_size) {
617 		*inline_ok = false;
618 		if (skb->encapsulation)
619 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
620 		else
621 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
622 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
623 			ALIGN(*lso_header_size + 4, DS_SIZE);
624 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
625 			/* We add a segment for the skb linear buffer only if
626 			 * it contains data */
627 			if (*lso_header_size < skb_headlen(skb))
628 				real_size += DS_SIZE;
629 			else {
630 				if (netif_msg_tx_err(priv))
631 					en_warn(priv, "Non-linear headers\n");
632 				return 0;
633 			}
634 		}
635 	} else {
636 		*lso_header_size = 0;
637 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
638 				       shinfo, pfrag);
639 
640 		if (*inline_ok)
641 			real_size = inline_size(skb);
642 		else
643 			real_size = CTRL_SIZE +
644 				    (shinfo->nr_frags + 1) * DS_SIZE;
645 	}
646 
647 	return real_size;
648 }
649 
650 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
651 			     const struct sk_buff *skb,
652 			     const struct skb_shared_info *shinfo,
653 			     void *fragptr)
654 {
655 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
656 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof(*inl);
657 	unsigned int hlen = skb_headlen(skb);
658 
659 	if (skb->len <= spc) {
660 		if (likely(skb->len >= MIN_PKT_LEN)) {
661 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
662 		} else {
663 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
664 			memset(((void *)(inl + 1)) + skb->len, 0,
665 			       MIN_PKT_LEN - skb->len);
666 		}
667 		skb_copy_from_linear_data(skb, inl + 1, hlen);
668 		if (shinfo->nr_frags)
669 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
670 			       skb_frag_size(&shinfo->frags[0]));
671 
672 	} else {
673 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
674 		if (hlen <= spc) {
675 			skb_copy_from_linear_data(skb, inl + 1, hlen);
676 			if (hlen < spc) {
677 				memcpy(((void *)(inl + 1)) + hlen,
678 				       fragptr, spc - hlen);
679 				fragptr +=  spc - hlen;
680 			}
681 			inl = (void *) (inl + 1) + spc;
682 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
683 		} else {
684 			skb_copy_from_linear_data(skb, inl + 1, spc);
685 			inl = (void *) (inl + 1) + spc;
686 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
687 							 hlen - spc);
688 			if (shinfo->nr_frags)
689 				memcpy(((void *)(inl + 1)) + hlen - spc,
690 				       fragptr,
691 				       skb_frag_size(&shinfo->frags[0]));
692 		}
693 
694 		dma_wmb();
695 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
696 	}
697 }
698 
699 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
700 			 struct net_device *sb_dev)
701 {
702 	struct mlx4_en_priv *priv = netdev_priv(dev);
703 	u16 rings_p_up = priv->num_tx_rings_p_up;
704 
705 	if (netdev_get_num_tc(dev))
706 		return netdev_pick_tx(dev, skb, NULL);
707 
708 	return netdev_pick_tx(dev, skb, NULL) % rings_p_up;
709 }
710 
711 static void mlx4_bf_copy(void __iomem *dst, const void *src,
712 			 unsigned int bytecnt)
713 {
714 	__iowrite64_copy(dst, src, bytecnt / 8);
715 }
716 
717 void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
718 {
719 	wmb();
720 	/* Since there is no iowrite*_native() that writes the
721 	 * value as is, without byteswapping - using the one
722 	 * the doesn't do byteswapping in the relevant arch
723 	 * endianness.
724 	 */
725 #if defined(__LITTLE_ENDIAN)
726 	iowrite32(
727 #else
728 	iowrite32be(
729 #endif
730 		  (__force u32)ring->doorbell_qpn,
731 		  ring->bf.uar->map + MLX4_SEND_DOORBELL);
732 }
733 
734 static void mlx4_en_tx_write_desc(struct mlx4_en_tx_ring *ring,
735 				  struct mlx4_en_tx_desc *tx_desc,
736 				  union mlx4_wqe_qpn_vlan qpn_vlan,
737 				  int desc_size, int bf_index,
738 				  __be32 op_own, bool bf_ok,
739 				  bool send_doorbell)
740 {
741 	tx_desc->ctrl.qpn_vlan = qpn_vlan;
742 
743 	if (bf_ok) {
744 		op_own |= htonl((bf_index & 0xffff) << 8);
745 		/* Ensure new descriptor hits memory
746 		 * before setting ownership of this descriptor to HW
747 		 */
748 		dma_wmb();
749 		tx_desc->ctrl.owner_opcode = op_own;
750 
751 		wmb();
752 
753 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
754 			     desc_size);
755 
756 		wmb();
757 
758 		ring->bf.offset ^= ring->bf.buf_size;
759 	} else {
760 		/* Ensure new descriptor hits memory
761 		 * before setting ownership of this descriptor to HW
762 		 */
763 		dma_wmb();
764 		tx_desc->ctrl.owner_opcode = op_own;
765 		if (send_doorbell)
766 			mlx4_en_xmit_doorbell(ring);
767 		else
768 			ring->xmit_more++;
769 	}
770 }
771 
772 static bool mlx4_en_build_dma_wqe(struct mlx4_en_priv *priv,
773 				  struct skb_shared_info *shinfo,
774 				  struct mlx4_wqe_data_seg *data,
775 				  struct sk_buff *skb,
776 				  int lso_header_size,
777 				  __be32 mr_key,
778 				  struct mlx4_en_tx_info *tx_info)
779 {
780 	struct device *ddev = priv->ddev;
781 	dma_addr_t dma = 0;
782 	u32 byte_count = 0;
783 	int i_frag;
784 
785 	/* Map fragments if any */
786 	for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
787 		const skb_frag_t *frag = &shinfo->frags[i_frag];
788 		byte_count = skb_frag_size(frag);
789 		dma = skb_frag_dma_map(ddev, frag,
790 				       0, byte_count,
791 				       DMA_TO_DEVICE);
792 		if (dma_mapping_error(ddev, dma))
793 			goto tx_drop_unmap;
794 
795 		data->addr = cpu_to_be64(dma);
796 		data->lkey = mr_key;
797 		dma_wmb();
798 		data->byte_count = cpu_to_be32(byte_count);
799 		--data;
800 	}
801 
802 	/* Map linear part if needed */
803 	if (tx_info->linear) {
804 		byte_count = skb_headlen(skb) - lso_header_size;
805 
806 		dma = dma_map_single(ddev, skb->data +
807 				     lso_header_size, byte_count,
808 				     PCI_DMA_TODEVICE);
809 		if (dma_mapping_error(ddev, dma))
810 			goto tx_drop_unmap;
811 
812 		data->addr = cpu_to_be64(dma);
813 		data->lkey = mr_key;
814 		dma_wmb();
815 		data->byte_count = cpu_to_be32(byte_count);
816 	}
817 	/* tx completion can avoid cache line miss for common cases */
818 	tx_info->map0_dma = dma;
819 	tx_info->map0_byte_count = byte_count;
820 
821 	return true;
822 
823 tx_drop_unmap:
824 	en_err(priv, "DMA mapping error\n");
825 
826 	while (++i_frag < shinfo->nr_frags) {
827 		++data;
828 		dma_unmap_page(ddev, (dma_addr_t)be64_to_cpu(data->addr),
829 			       be32_to_cpu(data->byte_count),
830 			       PCI_DMA_TODEVICE);
831 	}
832 
833 	return false;
834 }
835 
836 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
837 {
838 	struct skb_shared_info *shinfo = skb_shinfo(skb);
839 	struct mlx4_en_priv *priv = netdev_priv(dev);
840 	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
841 	struct mlx4_en_tx_ring *ring;
842 	struct mlx4_en_tx_desc *tx_desc;
843 	struct mlx4_wqe_data_seg *data;
844 	struct mlx4_en_tx_info *tx_info;
845 	u32 __maybe_unused ring_cons;
846 	int tx_ind;
847 	int nr_txbb;
848 	int desc_size;
849 	int real_size;
850 	u32 index, bf_index;
851 	__be32 op_own;
852 	int lso_header_size;
853 	void *fragptr = NULL;
854 	bool bounce = false;
855 	bool send_doorbell;
856 	bool stop_queue;
857 	bool inline_ok;
858 	u8 data_offset;
859 	bool bf_ok;
860 
861 	tx_ind = skb_get_queue_mapping(skb);
862 	ring = priv->tx_ring[TX][tx_ind];
863 
864 	if (unlikely(!priv->port_up))
865 		goto tx_drop;
866 
867 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
868 				  &inline_ok, &fragptr);
869 	if (unlikely(!real_size))
870 		goto tx_drop_count;
871 
872 	/* Align descriptor to TXBB size */
873 	desc_size = ALIGN(real_size, TXBB_SIZE);
874 	nr_txbb = desc_size >> LOG_TXBB_SIZE;
875 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
876 		if (netif_msg_tx_err(priv))
877 			en_warn(priv, "Oversized header or SG list\n");
878 		goto tx_drop_count;
879 	}
880 
881 	bf_ok = ring->bf_enabled;
882 	if (skb_vlan_tag_present(skb)) {
883 		u16 vlan_proto;
884 
885 		qpn_vlan.vlan_tag = cpu_to_be16(skb_vlan_tag_get(skb));
886 		vlan_proto = be16_to_cpu(skb->vlan_proto);
887 		if (vlan_proto == ETH_P_8021AD)
888 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_SVLAN;
889 		else if (vlan_proto == ETH_P_8021Q)
890 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_CVLAN;
891 		else
892 			qpn_vlan.ins_vlan = 0;
893 		bf_ok = false;
894 	}
895 
896 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
897 
898 	/* Packet is good - grab an index and transmit it */
899 	index = ring->prod & ring->size_mask;
900 	bf_index = ring->prod;
901 
902 	/* See if we have enough space for whole descriptor TXBB for setting
903 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
904 	if (likely(index + nr_txbb <= ring->size))
905 		tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
906 	else {
907 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
908 		bounce = true;
909 		bf_ok = false;
910 	}
911 
912 	/* Save skb in tx_info ring */
913 	tx_info = &ring->tx_info[index];
914 	tx_info->skb = skb;
915 	tx_info->nr_txbb = nr_txbb;
916 
917 	if (!lso_header_size) {
918 		data = &tx_desc->data;
919 		data_offset = offsetof(struct mlx4_en_tx_desc, data);
920 	} else {
921 		int lso_align = ALIGN(lso_header_size + 4, DS_SIZE);
922 
923 		data = (void *)&tx_desc->lso + lso_align;
924 		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
925 	}
926 
927 	/* valid only for none inline segments */
928 	tx_info->data_offset = data_offset;
929 
930 	tx_info->inl = inline_ok;
931 
932 	tx_info->linear = lso_header_size < skb_headlen(skb) && !inline_ok;
933 
934 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
935 	data += tx_info->nr_maps - 1;
936 
937 	if (!tx_info->inl)
938 		if (!mlx4_en_build_dma_wqe(priv, shinfo, data, skb,
939 					   lso_header_size, ring->mr_key,
940 					   tx_info))
941 			goto tx_drop_count;
942 
943 	/*
944 	 * For timestamping add flag to skb_shinfo and
945 	 * set flag for further reference
946 	 */
947 	tx_info->ts_requested = 0;
948 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
949 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
950 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
951 		tx_info->ts_requested = 1;
952 	}
953 
954 	/* Prepare ctrl segement apart opcode+ownership, which depends on
955 	 * whether LSO is used */
956 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
957 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
958 		if (!skb->encapsulation)
959 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
960 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
961 		else
962 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
963 		ring->tx_csum++;
964 	}
965 
966 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
967 		struct ethhdr *ethh;
968 
969 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
970 		 * so that VFs and PF can communicate with each other
971 		 */
972 		ethh = (struct ethhdr *)skb->data;
973 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
974 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
975 	}
976 
977 	/* Handle LSO (TSO) packets */
978 	if (lso_header_size) {
979 		int i;
980 
981 		/* Mark opcode as LSO */
982 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
983 			((ring->prod & ring->size) ?
984 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
985 
986 		/* Fill in the LSO prefix */
987 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
988 			shinfo->gso_size << 16 | lso_header_size);
989 
990 		/* Copy headers;
991 		 * note that we already verified that it is linear */
992 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
993 
994 		ring->tso_packets++;
995 
996 		i = shinfo->gso_segs;
997 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
998 		ring->packets += i;
999 	} else {
1000 		/* Normal (Non LSO) packet */
1001 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1002 			((ring->prod & ring->size) ?
1003 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1004 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
1005 		ring->packets++;
1006 	}
1007 	ring->bytes += tx_info->nr_bytes;
1008 
1009 	if (tx_info->inl)
1010 		build_inline_wqe(tx_desc, skb, shinfo, fragptr);
1011 
1012 	if (skb->encapsulation) {
1013 		union {
1014 			struct iphdr *v4;
1015 			struct ipv6hdr *v6;
1016 			unsigned char *hdr;
1017 		} ip;
1018 		u8 proto;
1019 
1020 		ip.hdr = skb_inner_network_header(skb);
1021 		proto = (ip.v4->version == 4) ? ip.v4->protocol :
1022 						ip.v6->nexthdr;
1023 
1024 		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
1025 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
1026 		else
1027 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
1028 	}
1029 
1030 	ring->prod += nr_txbb;
1031 
1032 	/* If we used a bounce buffer then copy descriptor back into place */
1033 	if (unlikely(bounce))
1034 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
1035 
1036 	skb_tx_timestamp(skb);
1037 
1038 	/* Check available TXBBs And 2K spare for prefetch */
1039 	stop_queue = mlx4_en_is_tx_ring_full(ring);
1040 	if (unlikely(stop_queue)) {
1041 		netif_tx_stop_queue(ring->tx_queue);
1042 		ring->queue_stopped++;
1043 	}
1044 
1045 	send_doorbell = __netdev_tx_sent_queue(ring->tx_queue,
1046 					       tx_info->nr_bytes,
1047 					       netdev_xmit_more());
1048 
1049 	real_size = (real_size / 16) & 0x3f;
1050 
1051 	bf_ok &= desc_size <= MAX_BF && send_doorbell;
1052 
1053 	if (bf_ok)
1054 		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
1055 	else
1056 		qpn_vlan.fence_size = real_size;
1057 
1058 	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, desc_size, bf_index,
1059 			      op_own, bf_ok, send_doorbell);
1060 
1061 	if (unlikely(stop_queue)) {
1062 		/* If queue was emptied after the if (stop_queue) , and before
1063 		 * the netif_tx_stop_queue() - need to wake the queue,
1064 		 * or else it will remain stopped forever.
1065 		 * Need a memory barrier to make sure ring->cons was not
1066 		 * updated before queue was stopped.
1067 		 */
1068 		smp_rmb();
1069 
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 	tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
1137 	data = &tx_desc->data;
1138 
1139 	dma = frame->dma;
1140 
1141 	tx_info->page = frame->page;
1142 	frame->page = NULL;
1143 	tx_info->map0_dma = dma;
1144 	tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
1145 
1146 	dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset,
1147 					 length, PCI_DMA_TODEVICE);
1148 
1149 	data->addr = cpu_to_be64(dma + frame->page_offset);
1150 	dma_wmb();
1151 	data->byte_count = cpu_to_be32(length);
1152 
1153 	/* tx completion can avoid cache line miss for common cases */
1154 
1155 	op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1156 		((ring->prod & ring->size) ?
1157 		 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1158 
1159 	rx_ring->xdp_tx++;
1160 
1161 	ring->prod += MLX4_EN_XDP_TX_NRTXBB;
1162 
1163 	/* Ensure new descriptor hits memory
1164 	 * before setting ownership of this descriptor to HW
1165 	 */
1166 	dma_wmb();
1167 	tx_desc->ctrl.owner_opcode = op_own;
1168 	ring->xmit_more++;
1169 
1170 	*doorbell_pending = true;
1171 
1172 	return NETDEV_TX_OK;
1173 
1174 tx_drop_count:
1175 	rx_ring->xdp_tx_full++;
1176 	*doorbell_pending = true;
1177 tx_drop:
1178 	return NETDEV_TX_BUSY;
1179 }
1180