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/indirect_call_wrapper.h>
46 #include <net/ipv6.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 - MLX4_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(MLX4_TX_BOUNCE_BUFFER_SIZE,
81 					GFP_KERNEL, node);
82 	if (!ring->bounce_buf) {
83 		ring->bounce_buf = kmalloc(MLX4_TX_BOUNCE_BUFFER_SIZE,
84 					   GFP_KERNEL);
85 		if (!ring->bounce_buf) {
86 			err = -ENOMEM;
87 			goto err_info;
88 		}
89 	}
90 	ring->buf_size = ALIGN(size * ring->sp_stride, MLX4_EN_PAGE_SIZE);
91 
92 	/* Allocate HW buffers on provided NUMA node */
93 	set_dev_node(&mdev->dev->persist->pdev->dev, node);
94 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
95 	set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
96 	if (err) {
97 		en_err(priv, "Failed allocating hwq resources\n");
98 		goto err_bounce;
99 	}
100 
101 	ring->buf = ring->sp_wqres.buf.direct.buf;
102 
103 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
104 	       ring, ring->buf, ring->size, ring->buf_size,
105 	       (unsigned long long) ring->sp_wqres.buf.direct.map);
106 
107 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
108 				    MLX4_RESERVE_ETH_BF_QP,
109 				    MLX4_RES_USAGE_DRIVER);
110 	if (err) {
111 		en_err(priv, "failed reserving qp for TX ring\n");
112 		goto err_hwq_res;
113 	}
114 
115 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->sp_qp);
116 	if (err) {
117 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
118 		goto err_reserve;
119 	}
120 	ring->sp_qp.event = mlx4_en_sqp_event;
121 
122 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
123 	if (err) {
124 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
125 		ring->bf.uar = &mdev->priv_uar;
126 		ring->bf.uar->map = mdev->uar_map;
127 		ring->bf_enabled = false;
128 		ring->bf_alloced = false;
129 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
130 	} else {
131 		ring->bf_alloced = true;
132 		ring->bf_enabled = !!(priv->pflags &
133 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
134 	}
135 	ring->doorbell_address = ring->bf.uar->map + MLX4_SEND_DOORBELL;
136 
137 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
138 	ring->queue_index = queue_index;
139 
140 	if (queue_index < priv->num_tx_rings_p_up)
141 		cpumask_set_cpu(cpumask_local_spread(queue_index,
142 						     priv->mdev->dev->numa_node),
143 				&ring->sp_affinity_mask);
144 
145 	*pring = ring;
146 	return 0;
147 
148 err_reserve:
149 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
150 err_hwq_res:
151 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
152 err_bounce:
153 	kfree(ring->bounce_buf);
154 	ring->bounce_buf = NULL;
155 err_info:
156 	kvfree(ring->tx_info);
157 	ring->tx_info = NULL;
158 err_ring:
159 	kfree(ring);
160 	*pring = NULL;
161 	return err;
162 }
163 
164 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
165 			     struct mlx4_en_tx_ring **pring)
166 {
167 	struct mlx4_en_dev *mdev = priv->mdev;
168 	struct mlx4_en_tx_ring *ring = *pring;
169 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
170 
171 	if (ring->bf_alloced)
172 		mlx4_bf_free(mdev->dev, &ring->bf);
173 	mlx4_qp_remove(mdev->dev, &ring->sp_qp);
174 	mlx4_qp_free(mdev->dev, &ring->sp_qp);
175 	mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
176 	mlx4_free_hwq_res(mdev->dev, &ring->sp_wqres, ring->buf_size);
177 	kfree(ring->bounce_buf);
178 	ring->bounce_buf = NULL;
179 	kvfree(ring->tx_info);
180 	ring->tx_info = NULL;
181 	kfree(ring);
182 	*pring = NULL;
183 }
184 
185 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
186 			     struct mlx4_en_tx_ring *ring,
187 			     int cq, int user_prio)
188 {
189 	struct mlx4_en_dev *mdev = priv->mdev;
190 	int err;
191 
192 	ring->sp_cqn = cq;
193 	ring->prod = 0;
194 	ring->cons = 0xffffffff;
195 	ring->last_nr_txbb = 1;
196 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
197 	memset(ring->buf, 0, ring->buf_size);
198 	ring->free_tx_desc = mlx4_en_free_tx_desc;
199 
200 	ring->sp_qp_state = MLX4_QP_STATE_RST;
201 	ring->doorbell_qpn = cpu_to_be32(ring->sp_qp.qpn << 8);
202 	ring->mr_key = cpu_to_be32(mdev->mr.key);
203 
204 	mlx4_en_fill_qp_context(priv, ring->size, ring->sp_stride, 1, 0, ring->qpn,
205 				ring->sp_cqn, user_prio, &ring->sp_context);
206 	if (ring->bf_alloced)
207 		ring->sp_context.usr_page =
208 			cpu_to_be32(mlx4_to_hw_uar_index(mdev->dev,
209 							 ring->bf.uar->index));
210 
211 	err = mlx4_qp_to_ready(mdev->dev, &ring->sp_wqres.mtt, &ring->sp_context,
212 			       &ring->sp_qp, &ring->sp_qp_state);
213 	if (!cpumask_empty(&ring->sp_affinity_mask))
214 		netif_set_xps_queue(priv->dev, &ring->sp_affinity_mask,
215 				    ring->queue_index);
216 
217 	return err;
218 }
219 
220 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
221 				struct mlx4_en_tx_ring *ring)
222 {
223 	struct mlx4_en_dev *mdev = priv->mdev;
224 
225 	mlx4_qp_modify(mdev->dev, NULL, ring->sp_qp_state,
226 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->sp_qp);
227 }
228 
229 static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
230 {
231 	u32 used = READ_ONCE(ring->prod) - READ_ONCE(ring->cons);
232 
233 	return used > ring->full_size;
234 }
235 
236 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
237 			      struct mlx4_en_tx_ring *ring, int index,
238 			      u8 owner)
239 {
240 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
241 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
242 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
243 	void *end = ring->buf + ring->buf_size;
244 	__be32 *ptr = (__be32 *)tx_desc;
245 	int i;
246 
247 	/* Optimize the common case when there are no wraparounds */
248 	if (likely((void *)tx_desc +
249 		   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
250 		/* Stamp the freed descriptor */
251 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
252 		     i += STAMP_STRIDE) {
253 			*ptr = stamp;
254 			ptr += STAMP_DWORDS;
255 		}
256 	} else {
257 		/* Stamp the freed descriptor */
258 		for (i = 0; i < tx_info->nr_txbb << LOG_TXBB_SIZE;
259 		     i += STAMP_STRIDE) {
260 			*ptr = stamp;
261 			ptr += STAMP_DWORDS;
262 			if ((void *)ptr >= end) {
263 				ptr = ring->buf;
264 				stamp ^= cpu_to_be32(0x80000000);
265 			}
266 		}
267 	}
268 }
269 
270 INDIRECT_CALLABLE_DECLARE(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 u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
276 			 struct mlx4_en_tx_ring *ring,
277 			 int index, u64 timestamp,
278 			 int napi_mode)
279 {
280 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
281 	struct mlx4_en_tx_desc *tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
282 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
283 	void *end = ring->buf + ring->buf_size;
284 	struct sk_buff *skb = tx_info->skb;
285 	int nr_maps = tx_info->nr_maps;
286 	int i;
287 
288 	/* We do not touch skb here, so prefetch skb->users location
289 	 * to speedup consume_skb()
290 	 */
291 	prefetchw(&skb->users);
292 
293 	if (unlikely(timestamp)) {
294 		struct skb_shared_hwtstamps hwts;
295 
296 		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
297 		skb_tstamp_tx(skb, &hwts);
298 	}
299 
300 	if (!tx_info->inl) {
301 		if (tx_info->linear)
302 			dma_unmap_single(priv->ddev,
303 					 tx_info->map0_dma,
304 					 tx_info->map0_byte_count,
305 					 DMA_TO_DEVICE);
306 		else
307 			dma_unmap_page(priv->ddev,
308 				       tx_info->map0_dma,
309 				       tx_info->map0_byte_count,
310 				       DMA_TO_DEVICE);
311 		/* Optimize the common case when there are no wraparounds */
312 		if (likely((void *)tx_desc +
313 			   (tx_info->nr_txbb << LOG_TXBB_SIZE) <= end)) {
314 			for (i = 1; i < nr_maps; i++) {
315 				data++;
316 				dma_unmap_page(priv->ddev,
317 					(dma_addr_t)be64_to_cpu(data->addr),
318 					be32_to_cpu(data->byte_count),
319 					DMA_TO_DEVICE);
320 			}
321 		} else {
322 			if ((void *)data >= end)
323 				data = ring->buf + ((void *)data - end);
324 
325 			for (i = 1; i < nr_maps; i++) {
326 				data++;
327 				/* Check for wraparound before unmapping */
328 				if ((void *) data >= end)
329 					data = ring->buf;
330 				dma_unmap_page(priv->ddev,
331 					(dma_addr_t)be64_to_cpu(data->addr),
332 					be32_to_cpu(data->byte_count),
333 					DMA_TO_DEVICE);
334 			}
335 		}
336 	}
337 	napi_consume_skb(skb, napi_mode);
338 
339 	return tx_info->nr_txbb;
340 }
341 
342 INDIRECT_CALLABLE_DECLARE(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 u32 mlx4_en_recycle_tx_desc(struct mlx4_en_priv *priv,
348 			    struct mlx4_en_tx_ring *ring,
349 			    int index, u64 timestamp,
350 			    int napi_mode)
351 {
352 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
353 	struct mlx4_en_rx_alloc frame = {
354 		.page = tx_info->page,
355 		.dma = tx_info->map0_dma,
356 	};
357 
358 	if (!napi_mode || !mlx4_en_rx_recycle(ring->recycle_ring, &frame)) {
359 		dma_unmap_page(priv->ddev, tx_info->map0_dma,
360 			       PAGE_SIZE, priv->dma_dir);
361 		put_page(tx_info->page);
362 	}
363 
364 	return tx_info->nr_txbb;
365 }
366 
367 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
368 {
369 	struct mlx4_en_priv *priv = netdev_priv(dev);
370 	int cnt = 0;
371 
372 	/* Skip last polled descriptor */
373 	ring->cons += ring->last_nr_txbb;
374 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
375 		 ring->cons, ring->prod);
376 
377 	if ((u32) (ring->prod - ring->cons) > ring->size) {
378 		if (netif_msg_tx_err(priv))
379 			en_warn(priv, "Tx consumer passed producer!\n");
380 		return 0;
381 	}
382 
383 	while (ring->cons != ring->prod) {
384 		ring->last_nr_txbb = ring->free_tx_desc(priv, ring,
385 						ring->cons & ring->size_mask,
386 						0, 0 /* Non-NAPI caller */);
387 		ring->cons += ring->last_nr_txbb;
388 		cnt++;
389 	}
390 
391 	if (ring->tx_queue)
392 		netdev_tx_reset_queue(ring->tx_queue);
393 
394 	if (cnt)
395 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
396 
397 	return cnt;
398 }
399 
400 static void mlx4_en_handle_err_cqe(struct mlx4_en_priv *priv, struct mlx4_err_cqe *err_cqe,
401 				   u16 cqe_index, struct mlx4_en_tx_ring *ring)
402 {
403 	struct mlx4_en_dev *mdev = priv->mdev;
404 	struct mlx4_en_tx_info *tx_info;
405 	struct mlx4_en_tx_desc *tx_desc;
406 	u16 wqe_index;
407 	int desc_size;
408 
409 	en_err(priv, "CQE error - cqn 0x%x, ci 0x%x, vendor syndrome: 0x%x syndrome: 0x%x\n",
410 	       ring->sp_cqn, cqe_index, err_cqe->vendor_err_syndrome, err_cqe->syndrome);
411 	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, err_cqe, sizeof(*err_cqe),
412 		       false);
413 
414 	wqe_index = be16_to_cpu(err_cqe->wqe_index) & ring->size_mask;
415 	tx_info = &ring->tx_info[wqe_index];
416 	desc_size = tx_info->nr_txbb << LOG_TXBB_SIZE;
417 	en_err(priv, "Related WQE - qpn 0x%x, wqe index 0x%x, wqe size 0x%x\n", ring->qpn,
418 	       wqe_index, desc_size);
419 	tx_desc = ring->buf + (wqe_index << LOG_TXBB_SIZE);
420 	print_hex_dump(KERN_WARNING, "", DUMP_PREFIX_OFFSET, 16, 1, tx_desc, desc_size, false);
421 
422 	if (test_and_set_bit(MLX4_EN_STATE_FLAG_RESTARTING, &priv->state))
423 		return;
424 
425 	en_err(priv, "Scheduling port restart\n");
426 	queue_work(mdev->workqueue, &priv->restart_task);
427 }
428 
429 int mlx4_en_process_tx_cq(struct net_device *dev,
430 			  struct mlx4_en_cq *cq, int napi_budget)
431 {
432 	struct mlx4_en_priv *priv = netdev_priv(dev);
433 	struct mlx4_cq *mcq = &cq->mcq;
434 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->type][cq->ring];
435 	struct mlx4_cqe *cqe;
436 	u16 index, ring_index, stamp_index;
437 	u32 txbbs_skipped = 0;
438 	u32 txbbs_stamp = 0;
439 	u32 cons_index = mcq->cons_index;
440 	int size = cq->size;
441 	u32 size_mask = ring->size_mask;
442 	struct mlx4_cqe *buf = cq->buf;
443 	u32 packets = 0;
444 	u32 bytes = 0;
445 	int factor = priv->cqe_factor;
446 	int done = 0;
447 	int budget = priv->tx_work_limit;
448 	u32 last_nr_txbb;
449 	u32 ring_cons;
450 
451 	if (unlikely(!priv->port_up))
452 		return 0;
453 
454 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
455 
456 	index = cons_index & size_mask;
457 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
458 	last_nr_txbb = READ_ONCE(ring->last_nr_txbb);
459 	ring_cons = READ_ONCE(ring->cons);
460 	ring_index = ring_cons & size_mask;
461 	stamp_index = ring_index;
462 
463 	/* Process all completed CQEs */
464 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
465 			cons_index & size) && (done < budget)) {
466 		u16 new_index;
467 
468 		/*
469 		 * make sure we read the CQE after we read the
470 		 * ownership bit
471 		 */
472 		dma_rmb();
473 
474 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
475 			     MLX4_CQE_OPCODE_ERROR))
476 			if (!test_and_set_bit(MLX4_EN_TX_RING_STATE_RECOVERING, &ring->state))
477 				mlx4_en_handle_err_cqe(priv, (struct mlx4_err_cqe *)cqe, index,
478 						       ring);
479 
480 		/* Skip over last polled CQE */
481 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
482 
483 		do {
484 			u64 timestamp = 0;
485 
486 			txbbs_skipped += last_nr_txbb;
487 			ring_index = (ring_index + last_nr_txbb) & size_mask;
488 
489 			if (unlikely(ring->tx_info[ring_index].ts_requested))
490 				timestamp = mlx4_en_get_cqe_ts(cqe);
491 
492 			/* free next descriptor */
493 			last_nr_txbb = INDIRECT_CALL_2(ring->free_tx_desc,
494 						       mlx4_en_free_tx_desc,
495 						       mlx4_en_recycle_tx_desc,
496 					priv, ring, ring_index,
497 					timestamp, napi_budget);
498 
499 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
500 					  !!((ring_cons + txbbs_stamp) &
501 						ring->size));
502 			stamp_index = ring_index;
503 			txbbs_stamp = txbbs_skipped;
504 			packets++;
505 			bytes += ring->tx_info[ring_index].nr_bytes;
506 		} while ((++done < budget) && (ring_index != new_index));
507 
508 		++cons_index;
509 		index = cons_index & size_mask;
510 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
511 	}
512 
513 	/*
514 	 * To prevent CQ overflow we first update CQ consumer and only then
515 	 * the ring consumer.
516 	 */
517 	mcq->cons_index = cons_index;
518 	mlx4_cq_set_ci(mcq);
519 	wmb();
520 
521 	/* we want to dirty this cache line once */
522 	WRITE_ONCE(ring->last_nr_txbb, last_nr_txbb);
523 	WRITE_ONCE(ring->cons, ring_cons + txbbs_skipped);
524 
525 	if (cq->type == TX_XDP)
526 		return done;
527 
528 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
529 
530 	/* Wakeup Tx queue if this stopped, and ring is not full.
531 	 */
532 	if (netif_tx_queue_stopped(ring->tx_queue) &&
533 	    !mlx4_en_is_tx_ring_full(ring)) {
534 		netif_tx_wake_queue(ring->tx_queue);
535 		ring->wake_queue++;
536 	}
537 
538 	return done;
539 }
540 
541 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
542 {
543 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
544 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
545 
546 	if (likely(priv->port_up))
547 		napi_schedule_irqoff(&cq->napi);
548 	else
549 		mlx4_en_arm_cq(priv, cq);
550 }
551 
552 /* TX CQ polling - called by NAPI */
553 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
554 {
555 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
556 	struct net_device *dev = cq->dev;
557 	struct mlx4_en_priv *priv = netdev_priv(dev);
558 	int work_done;
559 
560 	work_done = mlx4_en_process_tx_cq(dev, cq, budget);
561 	if (work_done >= budget)
562 		return budget;
563 
564 	if (napi_complete_done(napi, work_done))
565 		mlx4_en_arm_cq(priv, cq);
566 
567 	return 0;
568 }
569 
570 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
571 						      struct mlx4_en_tx_ring *ring,
572 						      u32 index,
573 						      unsigned int desc_size)
574 {
575 	u32 copy = (ring->size - index) << LOG_TXBB_SIZE;
576 	int i;
577 
578 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
579 		if ((i & (TXBB_SIZE - 1)) == 0)
580 			wmb();
581 
582 		*((u32 *) (ring->buf + i)) =
583 			*((u32 *) (ring->bounce_buf + copy + i));
584 	}
585 
586 	for (i = copy - 4; i >= 4 ; i -= 4) {
587 		if ((i & (TXBB_SIZE - 1)) == 0)
588 			wmb();
589 
590 		*((u32 *)(ring->buf + (index << LOG_TXBB_SIZE) + i)) =
591 			*((u32 *) (ring->bounce_buf + i));
592 	}
593 
594 	/* Return real descriptor location */
595 	return ring->buf + (index << LOG_TXBB_SIZE);
596 }
597 
598 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
599  *
600  * It seems strange we do not simply use skb_copy_bits().
601  * This would allow to inline all skbs iff skb->len <= inline_thold
602  *
603  * Note that caller already checked skb was not a gso packet
604  */
605 static bool is_inline(int inline_thold, const struct sk_buff *skb,
606 		      const struct skb_shared_info *shinfo,
607 		      void **pfrag)
608 {
609 	void *ptr;
610 
611 	if (skb->len > inline_thold || !inline_thold)
612 		return false;
613 
614 	if (shinfo->nr_frags == 1) {
615 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
616 		if (unlikely(!ptr))
617 			return false;
618 		*pfrag = ptr;
619 		return true;
620 	}
621 	if (shinfo->nr_frags)
622 		return false;
623 	return true;
624 }
625 
626 static int inline_size(const struct sk_buff *skb)
627 {
628 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
629 	    <= MLX4_INLINE_ALIGN)
630 		return ALIGN(skb->len + CTRL_SIZE +
631 			     sizeof(struct mlx4_wqe_inline_seg), 16);
632 	else
633 		return ALIGN(skb->len + CTRL_SIZE + 2 *
634 			     sizeof(struct mlx4_wqe_inline_seg), 16);
635 }
636 
637 static int get_real_size(const struct sk_buff *skb,
638 			 const struct skb_shared_info *shinfo,
639 			 struct net_device *dev,
640 			 int *lso_header_size,
641 			 bool *inline_ok,
642 			 void **pfrag,
643 			 int *hopbyhop)
644 {
645 	struct mlx4_en_priv *priv = netdev_priv(dev);
646 	int real_size;
647 
648 	if (shinfo->gso_size) {
649 		*inline_ok = false;
650 		*hopbyhop = 0;
651 		if (skb->encapsulation) {
652 			*lso_header_size = skb_inner_tcp_all_headers(skb);
653 		} else {
654 			/* Detects large IPV6 TCP packets and prepares for removal of
655 			 * HBH header that has been pushed by ip6_xmit(),
656 			 * mainly so that tcpdump can dissect them.
657 			 */
658 			if (ipv6_has_hopopt_jumbo(skb))
659 				*hopbyhop = sizeof(struct hop_jumbo_hdr);
660 			*lso_header_size = skb_tcp_all_headers(skb);
661 		}
662 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
663 			ALIGN(*lso_header_size - *hopbyhop + 4, DS_SIZE);
664 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
665 			/* We add a segment for the skb linear buffer only if
666 			 * it contains data */
667 			if (*lso_header_size < skb_headlen(skb))
668 				real_size += DS_SIZE;
669 			else {
670 				if (netif_msg_tx_err(priv))
671 					en_warn(priv, "Non-linear headers\n");
672 				return 0;
673 			}
674 		}
675 	} else {
676 		*lso_header_size = 0;
677 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
678 				       shinfo, pfrag);
679 
680 		if (*inline_ok)
681 			real_size = inline_size(skb);
682 		else
683 			real_size = CTRL_SIZE +
684 				    (shinfo->nr_frags + 1) * DS_SIZE;
685 	}
686 
687 	return real_size;
688 }
689 
690 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
691 			     const struct sk_buff *skb,
692 			     const struct skb_shared_info *shinfo,
693 			     void *fragptr)
694 {
695 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
696 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof(*inl);
697 	unsigned int hlen = skb_headlen(skb);
698 
699 	if (skb->len <= spc) {
700 		if (likely(skb->len >= MIN_PKT_LEN)) {
701 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
702 		} else {
703 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
704 			memset(inl->data + skb->len, 0,
705 			       MIN_PKT_LEN - skb->len);
706 		}
707 		skb_copy_from_linear_data(skb, inl->data, hlen);
708 		if (shinfo->nr_frags)
709 			memcpy(inl->data + hlen, fragptr,
710 			       skb_frag_size(&shinfo->frags[0]));
711 
712 	} else {
713 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
714 		if (hlen <= spc) {
715 			skb_copy_from_linear_data(skb, inl->data, hlen);
716 			if (hlen < spc) {
717 				memcpy(inl->data + hlen,
718 				       fragptr, spc - hlen);
719 				fragptr +=  spc - hlen;
720 			}
721 			inl = (void *)inl->data + spc;
722 			memcpy(inl->data, fragptr, skb->len - spc);
723 		} else {
724 			skb_copy_from_linear_data(skb, inl->data, spc);
725 			inl = (void *)inl->data + spc;
726 			skb_copy_from_linear_data_offset(skb, spc, inl->data,
727 							 hlen - spc);
728 			if (shinfo->nr_frags)
729 				memcpy(inl->data + hlen - spc,
730 				       fragptr,
731 				       skb_frag_size(&shinfo->frags[0]));
732 		}
733 
734 		dma_wmb();
735 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
736 	}
737 }
738 
739 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
740 			 struct net_device *sb_dev)
741 {
742 	struct mlx4_en_priv *priv = netdev_priv(dev);
743 	u16 rings_p_up = priv->num_tx_rings_p_up;
744 
745 	if (netdev_get_num_tc(dev))
746 		return netdev_pick_tx(dev, skb, NULL);
747 
748 	return netdev_pick_tx(dev, skb, NULL) % rings_p_up;
749 }
750 
751 static void mlx4_bf_copy(void __iomem *dst, const void *src,
752 			 unsigned int bytecnt)
753 {
754 	__iowrite64_copy(dst, src, bytecnt / 8);
755 }
756 
757 void mlx4_en_xmit_doorbell(struct mlx4_en_tx_ring *ring)
758 {
759 	wmb();
760 	/* Since there is no iowrite*_native() that writes the
761 	 * value as is, without byteswapping - using the one
762 	 * the doesn't do byteswapping in the relevant arch
763 	 * endianness.
764 	 */
765 #if defined(__LITTLE_ENDIAN)
766 	iowrite32(
767 #else
768 	iowrite32be(
769 #endif
770 		  (__force u32)ring->doorbell_qpn, ring->doorbell_address);
771 }
772 
773 static void mlx4_en_tx_write_desc(struct mlx4_en_tx_ring *ring,
774 				  struct mlx4_en_tx_desc *tx_desc,
775 				  union mlx4_wqe_qpn_vlan qpn_vlan,
776 				  int desc_size, int bf_index,
777 				  __be32 op_own, bool bf_ok,
778 				  bool send_doorbell)
779 {
780 	tx_desc->ctrl.qpn_vlan = qpn_vlan;
781 
782 	if (bf_ok) {
783 		op_own |= htonl((bf_index & 0xffff) << 8);
784 		/* Ensure new descriptor hits memory
785 		 * before setting ownership of this descriptor to HW
786 		 */
787 		dma_wmb();
788 		tx_desc->ctrl.owner_opcode = op_own;
789 
790 		wmb();
791 
792 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
793 			     desc_size);
794 
795 		wmb();
796 
797 		ring->bf.offset ^= ring->bf.buf_size;
798 	} else {
799 		/* Ensure new descriptor hits memory
800 		 * before setting ownership of this descriptor to HW
801 		 */
802 		dma_wmb();
803 		tx_desc->ctrl.owner_opcode = op_own;
804 		if (send_doorbell)
805 			mlx4_en_xmit_doorbell(ring);
806 		else
807 			ring->xmit_more++;
808 	}
809 }
810 
811 static bool mlx4_en_build_dma_wqe(struct mlx4_en_priv *priv,
812 				  struct skb_shared_info *shinfo,
813 				  struct mlx4_wqe_data_seg *data,
814 				  struct sk_buff *skb,
815 				  int lso_header_size,
816 				  __be32 mr_key,
817 				  struct mlx4_en_tx_info *tx_info)
818 {
819 	struct device *ddev = priv->ddev;
820 	dma_addr_t dma = 0;
821 	u32 byte_count = 0;
822 	int i_frag;
823 
824 	/* Map fragments if any */
825 	for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
826 		const skb_frag_t *frag = &shinfo->frags[i_frag];
827 		byte_count = skb_frag_size(frag);
828 		dma = skb_frag_dma_map(ddev, frag,
829 				       0, byte_count,
830 				       DMA_TO_DEVICE);
831 		if (dma_mapping_error(ddev, dma))
832 			goto tx_drop_unmap;
833 
834 		data->addr = cpu_to_be64(dma);
835 		data->lkey = mr_key;
836 		dma_wmb();
837 		data->byte_count = cpu_to_be32(byte_count);
838 		--data;
839 	}
840 
841 	/* Map linear part if needed */
842 	if (tx_info->linear) {
843 		byte_count = skb_headlen(skb) - lso_header_size;
844 
845 		dma = dma_map_single(ddev, skb->data +
846 				     lso_header_size, byte_count,
847 				     DMA_TO_DEVICE);
848 		if (dma_mapping_error(ddev, dma))
849 			goto tx_drop_unmap;
850 
851 		data->addr = cpu_to_be64(dma);
852 		data->lkey = mr_key;
853 		dma_wmb();
854 		data->byte_count = cpu_to_be32(byte_count);
855 	}
856 	/* tx completion can avoid cache line miss for common cases */
857 	tx_info->map0_dma = dma;
858 	tx_info->map0_byte_count = byte_count;
859 
860 	return true;
861 
862 tx_drop_unmap:
863 	en_err(priv, "DMA mapping error\n");
864 
865 	while (++i_frag < shinfo->nr_frags) {
866 		++data;
867 		dma_unmap_page(ddev, (dma_addr_t)be64_to_cpu(data->addr),
868 			       be32_to_cpu(data->byte_count),
869 			       DMA_TO_DEVICE);
870 	}
871 
872 	return false;
873 }
874 
875 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
876 {
877 	struct skb_shared_info *shinfo = skb_shinfo(skb);
878 	struct mlx4_en_priv *priv = netdev_priv(dev);
879 	union mlx4_wqe_qpn_vlan	qpn_vlan = {};
880 	struct mlx4_en_tx_ring *ring;
881 	struct mlx4_en_tx_desc *tx_desc;
882 	struct mlx4_wqe_data_seg *data;
883 	struct mlx4_en_tx_info *tx_info;
884 	u32 __maybe_unused ring_cons;
885 	int tx_ind;
886 	int nr_txbb;
887 	int desc_size;
888 	int real_size;
889 	u32 index, bf_index;
890 	struct ipv6hdr *h6;
891 	__be32 op_own;
892 	int lso_header_size;
893 	void *fragptr = NULL;
894 	bool bounce = false;
895 	bool send_doorbell;
896 	bool stop_queue;
897 	bool inline_ok;
898 	u8 data_offset;
899 	int hopbyhop;
900 	bool bf_ok;
901 
902 	tx_ind = skb_get_queue_mapping(skb);
903 	ring = priv->tx_ring[TX][tx_ind];
904 
905 	if (unlikely(!priv->port_up))
906 		goto tx_drop;
907 
908 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
909 				  &inline_ok, &fragptr, &hopbyhop);
910 	if (unlikely(!real_size))
911 		goto tx_drop_count;
912 
913 	/* Align descriptor to TXBB size */
914 	desc_size = ALIGN(real_size, TXBB_SIZE);
915 	nr_txbb = desc_size >> LOG_TXBB_SIZE;
916 
917 	bf_ok = ring->bf_enabled;
918 	if (skb_vlan_tag_present(skb)) {
919 		u16 vlan_proto;
920 
921 		qpn_vlan.vlan_tag = cpu_to_be16(skb_vlan_tag_get(skb));
922 		vlan_proto = be16_to_cpu(skb->vlan_proto);
923 		if (vlan_proto == ETH_P_8021AD)
924 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_SVLAN;
925 		else if (vlan_proto == ETH_P_8021Q)
926 			qpn_vlan.ins_vlan = MLX4_WQE_CTRL_INS_CVLAN;
927 		else
928 			qpn_vlan.ins_vlan = 0;
929 		bf_ok = false;
930 	}
931 
932 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
933 
934 	/* Packet is good - grab an index and transmit it */
935 	index = ring->prod & ring->size_mask;
936 	bf_index = ring->prod;
937 
938 	/* See if we have enough space for whole descriptor TXBB for setting
939 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
940 	if (likely(index + nr_txbb <= ring->size))
941 		tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
942 	else {
943 		if (unlikely(nr_txbb > MLX4_MAX_DESC_TXBBS)) {
944 			if (netif_msg_tx_err(priv))
945 				en_warn(priv, "Oversized header or SG list\n");
946 			goto tx_drop_count;
947 		}
948 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
949 		bounce = true;
950 		bf_ok = false;
951 	}
952 
953 	/* Save skb in tx_info ring */
954 	tx_info = &ring->tx_info[index];
955 	tx_info->skb = skb;
956 	tx_info->nr_txbb = nr_txbb;
957 
958 	if (!lso_header_size) {
959 		data = &tx_desc->data;
960 		data_offset = offsetof(struct mlx4_en_tx_desc, data);
961 	} else {
962 		int lso_align = ALIGN(lso_header_size - hopbyhop + 4, DS_SIZE);
963 
964 		data = (void *)&tx_desc->lso + lso_align;
965 		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
966 	}
967 
968 	/* valid only for none inline segments */
969 	tx_info->data_offset = data_offset;
970 
971 	tx_info->inl = inline_ok;
972 
973 	tx_info->linear = lso_header_size < skb_headlen(skb) && !inline_ok;
974 
975 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
976 	data += tx_info->nr_maps - 1;
977 
978 	if (!tx_info->inl)
979 		if (!mlx4_en_build_dma_wqe(priv, shinfo, data, skb,
980 					   lso_header_size, ring->mr_key,
981 					   tx_info))
982 			goto tx_drop_count;
983 
984 	/*
985 	 * For timestamping add flag to skb_shinfo and
986 	 * set flag for further reference
987 	 */
988 	tx_info->ts_requested = 0;
989 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
990 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
991 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
992 		tx_info->ts_requested = 1;
993 	}
994 
995 	/* Prepare ctrl segement apart opcode+ownership, which depends on
996 	 * whether LSO is used */
997 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
998 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
999 		if (!skb->encapsulation)
1000 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
1001 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
1002 		else
1003 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
1004 		ring->tx_csum++;
1005 	}
1006 
1007 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
1008 		struct ethhdr *ethh;
1009 
1010 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
1011 		 * so that VFs and PF can communicate with each other
1012 		 */
1013 		ethh = (struct ethhdr *)skb->data;
1014 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
1015 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
1016 	}
1017 
1018 	/* Handle LSO (TSO) packets */
1019 	if (lso_header_size) {
1020 		int i;
1021 
1022 		/* Mark opcode as LSO */
1023 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
1024 			((ring->prod & ring->size) ?
1025 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1026 
1027 		lso_header_size -= hopbyhop;
1028 		/* Fill in the LSO prefix */
1029 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
1030 			shinfo->gso_size << 16 | lso_header_size);
1031 
1032 
1033 		if (unlikely(hopbyhop)) {
1034 			/* remove the HBH header.
1035 			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
1036 			 */
1037 			memcpy(tx_desc->lso.header, skb->data, ETH_HLEN + sizeof(*h6));
1038 			h6 = (struct ipv6hdr *)((char *)tx_desc->lso.header + ETH_HLEN);
1039 			h6->nexthdr = IPPROTO_TCP;
1040 			/* Copy the TCP header after the IPv6 one */
1041 			memcpy(h6 + 1,
1042 			       skb->data + ETH_HLEN + sizeof(*h6) +
1043 					sizeof(struct hop_jumbo_hdr),
1044 			       tcp_hdrlen(skb));
1045 			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
1046 		} else {
1047 			/* Copy headers;
1048 			 * note that we already verified that it is linear
1049 			 */
1050 			memcpy(tx_desc->lso.header, skb->data, lso_header_size);
1051 		}
1052 		ring->tso_packets++;
1053 
1054 		i = shinfo->gso_segs;
1055 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
1056 		ring->packets += i;
1057 	} else {
1058 		/* Normal (Non LSO) packet */
1059 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1060 			((ring->prod & ring->size) ?
1061 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1062 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
1063 		ring->packets++;
1064 	}
1065 	ring->bytes += tx_info->nr_bytes;
1066 
1067 	if (tx_info->inl)
1068 		build_inline_wqe(tx_desc, skb, shinfo, fragptr);
1069 
1070 	if (skb->encapsulation) {
1071 		union {
1072 			struct iphdr *v4;
1073 			struct ipv6hdr *v6;
1074 			unsigned char *hdr;
1075 		} ip;
1076 		u8 proto;
1077 
1078 		ip.hdr = skb_inner_network_header(skb);
1079 		proto = (ip.v4->version == 4) ? ip.v4->protocol :
1080 						ip.v6->nexthdr;
1081 
1082 		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
1083 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
1084 		else
1085 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
1086 	}
1087 
1088 	WRITE_ONCE(ring->prod, ring->prod + nr_txbb);
1089 
1090 	/* If we used a bounce buffer then copy descriptor back into place */
1091 	if (unlikely(bounce))
1092 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
1093 
1094 	skb_tx_timestamp(skb);
1095 
1096 	/* Check available TXBBs And 2K spare for prefetch */
1097 	stop_queue = mlx4_en_is_tx_ring_full(ring);
1098 	if (unlikely(stop_queue)) {
1099 		netif_tx_stop_queue(ring->tx_queue);
1100 		ring->queue_stopped++;
1101 	}
1102 
1103 	send_doorbell = __netdev_tx_sent_queue(ring->tx_queue,
1104 					       tx_info->nr_bytes,
1105 					       netdev_xmit_more());
1106 
1107 	real_size = (real_size / 16) & 0x3f;
1108 
1109 	bf_ok &= desc_size <= MAX_BF && send_doorbell;
1110 
1111 	if (bf_ok)
1112 		qpn_vlan.bf_qpn = ring->doorbell_qpn | cpu_to_be32(real_size);
1113 	else
1114 		qpn_vlan.fence_size = real_size;
1115 
1116 	mlx4_en_tx_write_desc(ring, tx_desc, qpn_vlan, desc_size, bf_index,
1117 			      op_own, bf_ok, send_doorbell);
1118 
1119 	if (unlikely(stop_queue)) {
1120 		/* If queue was emptied after the if (stop_queue) , and before
1121 		 * the netif_tx_stop_queue() - need to wake the queue,
1122 		 * or else it will remain stopped forever.
1123 		 * Need a memory barrier to make sure ring->cons was not
1124 		 * updated before queue was stopped.
1125 		 */
1126 		smp_rmb();
1127 
1128 		if (unlikely(!mlx4_en_is_tx_ring_full(ring))) {
1129 			netif_tx_wake_queue(ring->tx_queue);
1130 			ring->wake_queue++;
1131 		}
1132 	}
1133 	return NETDEV_TX_OK;
1134 
1135 tx_drop_count:
1136 	ring->tx_dropped++;
1137 tx_drop:
1138 	dev_kfree_skb_any(skb);
1139 	return NETDEV_TX_OK;
1140 }
1141 
1142 #define MLX4_EN_XDP_TX_NRTXBB  1
1143 #define MLX4_EN_XDP_TX_REAL_SZ (((CTRL_SIZE + MLX4_EN_XDP_TX_NRTXBB * DS_SIZE) \
1144 				 / 16) & 0x3f)
1145 
1146 void mlx4_en_init_tx_xdp_ring_descs(struct mlx4_en_priv *priv,
1147 				    struct mlx4_en_tx_ring *ring)
1148 {
1149 	int i;
1150 
1151 	for (i = 0; i < ring->size; i++) {
1152 		struct mlx4_en_tx_info *tx_info = &ring->tx_info[i];
1153 		struct mlx4_en_tx_desc *tx_desc = ring->buf +
1154 			(i << LOG_TXBB_SIZE);
1155 
1156 		tx_info->map0_byte_count = PAGE_SIZE;
1157 		tx_info->nr_txbb = MLX4_EN_XDP_TX_NRTXBB;
1158 		tx_info->data_offset = offsetof(struct mlx4_en_tx_desc, data);
1159 		tx_info->ts_requested = 0;
1160 		tx_info->nr_maps = 1;
1161 		tx_info->linear = 1;
1162 		tx_info->inl = 0;
1163 
1164 		tx_desc->data.lkey = ring->mr_key;
1165 		tx_desc->ctrl.qpn_vlan.fence_size = MLX4_EN_XDP_TX_REAL_SZ;
1166 		tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
1167 	}
1168 }
1169 
1170 netdev_tx_t mlx4_en_xmit_frame(struct mlx4_en_rx_ring *rx_ring,
1171 			       struct mlx4_en_rx_alloc *frame,
1172 			       struct mlx4_en_priv *priv, unsigned int length,
1173 			       int tx_ind, bool *doorbell_pending)
1174 {
1175 	struct mlx4_en_tx_desc *tx_desc;
1176 	struct mlx4_en_tx_info *tx_info;
1177 	struct mlx4_wqe_data_seg *data;
1178 	struct mlx4_en_tx_ring *ring;
1179 	dma_addr_t dma;
1180 	__be32 op_own;
1181 	int index;
1182 
1183 	if (unlikely(!priv->port_up))
1184 		goto tx_drop;
1185 
1186 	ring = priv->tx_ring[TX_XDP][tx_ind];
1187 
1188 	if (unlikely(mlx4_en_is_tx_ring_full(ring)))
1189 		goto tx_drop_count;
1190 
1191 	index = ring->prod & ring->size_mask;
1192 	tx_info = &ring->tx_info[index];
1193 
1194 	tx_desc = ring->buf + (index << LOG_TXBB_SIZE);
1195 	data = &tx_desc->data;
1196 
1197 	dma = frame->dma;
1198 
1199 	tx_info->page = frame->page;
1200 	frame->page = NULL;
1201 	tx_info->map0_dma = dma;
1202 	tx_info->nr_bytes = max_t(unsigned int, length, ETH_ZLEN);
1203 
1204 	dma_sync_single_range_for_device(priv->ddev, dma, frame->page_offset,
1205 					 length, DMA_TO_DEVICE);
1206 
1207 	data->addr = cpu_to_be64(dma + frame->page_offset);
1208 	dma_wmb();
1209 	data->byte_count = cpu_to_be32(length);
1210 
1211 	/* tx completion can avoid cache line miss for common cases */
1212 
1213 	op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
1214 		((ring->prod & ring->size) ?
1215 		 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
1216 
1217 	rx_ring->xdp_tx++;
1218 
1219 	WRITE_ONCE(ring->prod, ring->prod + MLX4_EN_XDP_TX_NRTXBB);
1220 
1221 	/* Ensure new descriptor hits memory
1222 	 * before setting ownership of this descriptor to HW
1223 	 */
1224 	dma_wmb();
1225 	tx_desc->ctrl.owner_opcode = op_own;
1226 	ring->xmit_more++;
1227 
1228 	*doorbell_pending = true;
1229 
1230 	return NETDEV_TX_OK;
1231 
1232 tx_drop_count:
1233 	rx_ring->xdp_tx_full++;
1234 	*doorbell_pending = true;
1235 tx_drop:
1236 	return NETDEV_TX_BUSY;
1237 }
1238