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/moduleparam.h>
45 
46 #include "mlx4_en.h"
47 
48 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
49 			   struct mlx4_en_tx_ring **pring, u32 size,
50 			   u16 stride, int node, int queue_index)
51 {
52 	struct mlx4_en_dev *mdev = priv->mdev;
53 	struct mlx4_en_tx_ring *ring;
54 	int tmp;
55 	int err;
56 
57 	ring = kzalloc_node(sizeof(*ring), GFP_KERNEL, node);
58 	if (!ring) {
59 		ring = kzalloc(sizeof(*ring), GFP_KERNEL);
60 		if (!ring) {
61 			en_err(priv, "Failed allocating TX ring\n");
62 			return -ENOMEM;
63 		}
64 	}
65 
66 	ring->size = size;
67 	ring->size_mask = size - 1;
68 	ring->stride = stride;
69 
70 	tmp = size * sizeof(struct mlx4_en_tx_info);
71 	ring->tx_info = kmalloc_node(tmp, GFP_KERNEL | __GFP_NOWARN, node);
72 	if (!ring->tx_info) {
73 		ring->tx_info = vmalloc(tmp);
74 		if (!ring->tx_info) {
75 			err = -ENOMEM;
76 			goto err_ring;
77 		}
78 	}
79 
80 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
81 		 ring->tx_info, tmp);
82 
83 	ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
84 	if (!ring->bounce_buf) {
85 		ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
86 		if (!ring->bounce_buf) {
87 			err = -ENOMEM;
88 			goto err_info;
89 		}
90 	}
91 	ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
92 
93 	/* Allocate HW buffers on provided NUMA node */
94 	set_dev_node(&mdev->dev->pdev->dev, node);
95 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size,
96 				 2 * PAGE_SIZE);
97 	set_dev_node(&mdev->dev->pdev->dev, mdev->dev->numa_node);
98 	if (err) {
99 		en_err(priv, "Failed allocating hwq resources\n");
100 		goto err_bounce;
101 	}
102 
103 	err = mlx4_en_map_buffer(&ring->wqres.buf);
104 	if (err) {
105 		en_err(priv, "Failed to map TX buffer\n");
106 		goto err_hwq_res;
107 	}
108 
109 	ring->buf = ring->wqres.buf.direct.buf;
110 
111 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
112 	       ring, ring->buf, ring->size, ring->buf_size,
113 	       (unsigned long long) ring->wqres.buf.direct.map);
114 
115 	err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
116 				    MLX4_RESERVE_ETH_BF_QP);
117 	if (err) {
118 		en_err(priv, "failed reserving qp for TX ring\n");
119 		goto err_map;
120 	}
121 
122 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp, GFP_KERNEL);
123 	if (err) {
124 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
125 		goto err_reserve;
126 	}
127 	ring->qp.event = mlx4_en_sqp_event;
128 
129 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
130 	if (err) {
131 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
132 		ring->bf.uar = &mdev->priv_uar;
133 		ring->bf.uar->map = mdev->uar_map;
134 		ring->bf_enabled = false;
135 		ring->bf_alloced = false;
136 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
137 	} else {
138 		ring->bf_alloced = true;
139 		ring->bf_enabled = !!(priv->pflags &
140 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
141 	}
142 
143 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
144 	ring->queue_index = queue_index;
145 
146 	if (queue_index < priv->num_tx_rings_p_up && cpu_online(queue_index))
147 		cpumask_set_cpu(queue_index, &ring->affinity_mask);
148 
149 	*pring = ring;
150 	return 0;
151 
152 err_reserve:
153 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
154 err_map:
155 	mlx4_en_unmap_buffer(&ring->wqres.buf);
156 err_hwq_res:
157 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
158 err_bounce:
159 	kfree(ring->bounce_buf);
160 	ring->bounce_buf = NULL;
161 err_info:
162 	kvfree(ring->tx_info);
163 	ring->tx_info = NULL;
164 err_ring:
165 	kfree(ring);
166 	*pring = NULL;
167 	return err;
168 }
169 
170 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
171 			     struct mlx4_en_tx_ring **pring)
172 {
173 	struct mlx4_en_dev *mdev = priv->mdev;
174 	struct mlx4_en_tx_ring *ring = *pring;
175 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
176 
177 	if (ring->bf_alloced)
178 		mlx4_bf_free(mdev->dev, &ring->bf);
179 	mlx4_qp_remove(mdev->dev, &ring->qp);
180 	mlx4_qp_free(mdev->dev, &ring->qp);
181 	mlx4_en_unmap_buffer(&ring->wqres.buf);
182 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
183 	kfree(ring->bounce_buf);
184 	ring->bounce_buf = NULL;
185 	kvfree(ring->tx_info);
186 	ring->tx_info = NULL;
187 	kfree(ring);
188 	*pring = NULL;
189 }
190 
191 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
192 			     struct mlx4_en_tx_ring *ring,
193 			     int cq, int user_prio)
194 {
195 	struct mlx4_en_dev *mdev = priv->mdev;
196 	int err;
197 
198 	ring->cqn = cq;
199 	ring->prod = 0;
200 	ring->cons = 0xffffffff;
201 	ring->last_nr_txbb = 1;
202 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
203 	memset(ring->buf, 0, ring->buf_size);
204 
205 	ring->qp_state = MLX4_QP_STATE_RST;
206 	ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8);
207 	ring->mr_key = cpu_to_be32(mdev->mr.key);
208 
209 	mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
210 				ring->cqn, user_prio, &ring->context);
211 	if (ring->bf_alloced)
212 		ring->context.usr_page = cpu_to_be32(ring->bf.uar->index);
213 
214 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
215 			       &ring->qp, &ring->qp_state);
216 	if (!user_prio && cpu_online(ring->queue_index))
217 		netif_set_xps_queue(priv->dev, &ring->affinity_mask,
218 				    ring->queue_index);
219 
220 	return err;
221 }
222 
223 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
224 				struct mlx4_en_tx_ring *ring)
225 {
226 	struct mlx4_en_dev *mdev = priv->mdev;
227 
228 	mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
229 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
230 }
231 
232 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
233 			      struct mlx4_en_tx_ring *ring, int index,
234 			      u8 owner)
235 {
236 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
237 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
238 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
239 	void *end = ring->buf + ring->buf_size;
240 	__be32 *ptr = (__be32 *)tx_desc;
241 	int i;
242 
243 	/* Optimize the common case when there are no wraparounds */
244 	if (likely((void *)tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
245 		/* Stamp the freed descriptor */
246 		for (i = 0; i < tx_info->nr_txbb * 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 * 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 
266 static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
267 				struct mlx4_en_tx_ring *ring,
268 				int index, u8 owner, u64 timestamp)
269 {
270 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
271 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * 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 	/* Optimize the common case when there are no wraparounds */
291 	if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
292 		if (!tx_info->inl) {
293 			if (tx_info->linear)
294 				dma_unmap_single(priv->ddev,
295 						tx_info->map0_dma,
296 						tx_info->map0_byte_count,
297 						PCI_DMA_TODEVICE);
298 			else
299 				dma_unmap_page(priv->ddev,
300 					       tx_info->map0_dma,
301 					       tx_info->map0_byte_count,
302 					       PCI_DMA_TODEVICE);
303 			for (i = 1; i < nr_maps; i++) {
304 				data++;
305 				dma_unmap_page(priv->ddev,
306 					(dma_addr_t)be64_to_cpu(data->addr),
307 					be32_to_cpu(data->byte_count),
308 					PCI_DMA_TODEVICE);
309 			}
310 		}
311 	} else {
312 		if (!tx_info->inl) {
313 			if ((void *) data >= end) {
314 				data = ring->buf + ((void *)data - end);
315 			}
316 
317 			if (tx_info->linear)
318 				dma_unmap_single(priv->ddev,
319 						tx_info->map0_dma,
320 						tx_info->map0_byte_count,
321 						PCI_DMA_TODEVICE);
322 			else
323 				dma_unmap_page(priv->ddev,
324 					       tx_info->map0_dma,
325 					       tx_info->map0_byte_count,
326 					       PCI_DMA_TODEVICE);
327 			for (i = 1; i < nr_maps; i++) {
328 				data++;
329 				/* Check for wraparound before unmapping */
330 				if ((void *) data >= end)
331 					data = ring->buf;
332 				dma_unmap_page(priv->ddev,
333 					(dma_addr_t)be64_to_cpu(data->addr),
334 					be32_to_cpu(data->byte_count),
335 					PCI_DMA_TODEVICE);
336 			}
337 		}
338 	}
339 	dev_consume_skb_any(skb);
340 	return tx_info->nr_txbb;
341 }
342 
343 
344 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
345 {
346 	struct mlx4_en_priv *priv = netdev_priv(dev);
347 	int cnt = 0;
348 
349 	/* Skip last polled descriptor */
350 	ring->cons += ring->last_nr_txbb;
351 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
352 		 ring->cons, ring->prod);
353 
354 	if ((u32) (ring->prod - ring->cons) > ring->size) {
355 		if (netif_msg_tx_err(priv))
356 			en_warn(priv, "Tx consumer passed producer!\n");
357 		return 0;
358 	}
359 
360 	while (ring->cons != ring->prod) {
361 		ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
362 						ring->cons & ring->size_mask,
363 						!!(ring->cons & ring->size), 0);
364 		ring->cons += ring->last_nr_txbb;
365 		cnt++;
366 	}
367 
368 	netdev_tx_reset_queue(ring->tx_queue);
369 
370 	if (cnt)
371 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
372 
373 	return cnt;
374 }
375 
376 static bool mlx4_en_process_tx_cq(struct net_device *dev,
377 				 struct mlx4_en_cq *cq)
378 {
379 	struct mlx4_en_priv *priv = netdev_priv(dev);
380 	struct mlx4_cq *mcq = &cq->mcq;
381 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
382 	struct mlx4_cqe *cqe;
383 	u16 index;
384 	u16 new_index, ring_index, stamp_index;
385 	u32 txbbs_skipped = 0;
386 	u32 txbbs_stamp = 0;
387 	u32 cons_index = mcq->cons_index;
388 	int size = cq->size;
389 	u32 size_mask = ring->size_mask;
390 	struct mlx4_cqe *buf = cq->buf;
391 	u32 packets = 0;
392 	u32 bytes = 0;
393 	int factor = priv->cqe_factor;
394 	u64 timestamp = 0;
395 	int done = 0;
396 	int budget = priv->tx_work_limit;
397 	u32 last_nr_txbb;
398 	u32 ring_cons;
399 
400 	if (!priv->port_up)
401 		return true;
402 
403 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
404 
405 	index = cons_index & size_mask;
406 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
407 	last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb);
408 	ring_cons = ACCESS_ONCE(ring->cons);
409 	ring_index = ring_cons & size_mask;
410 	stamp_index = ring_index;
411 
412 	/* Process all completed CQEs */
413 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
414 			cons_index & size) && (done < budget)) {
415 		/*
416 		 * make sure we read the CQE after we read the
417 		 * ownership bit
418 		 */
419 		rmb();
420 
421 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
422 			     MLX4_CQE_OPCODE_ERROR)) {
423 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
424 
425 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
426 			       cqe_err->vendor_err_syndrome,
427 			       cqe_err->syndrome);
428 		}
429 
430 		/* Skip over last polled CQE */
431 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
432 
433 		do {
434 			txbbs_skipped += last_nr_txbb;
435 			ring_index = (ring_index + last_nr_txbb) & size_mask;
436 			if (ring->tx_info[ring_index].ts_requested)
437 				timestamp = mlx4_en_get_cqe_ts(cqe);
438 
439 			/* free next descriptor */
440 			last_nr_txbb = mlx4_en_free_tx_desc(
441 					priv, ring, ring_index,
442 					!!((ring_cons + txbbs_skipped) &
443 					ring->size), timestamp);
444 
445 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
446 					  !!((ring_cons + txbbs_stamp) &
447 						ring->size));
448 			stamp_index = ring_index;
449 			txbbs_stamp = txbbs_skipped;
450 			packets++;
451 			bytes += ring->tx_info[ring_index].nr_bytes;
452 		} while ((++done < budget) && (ring_index != new_index));
453 
454 		++cons_index;
455 		index = cons_index & size_mask;
456 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
457 	}
458 
459 
460 	/*
461 	 * To prevent CQ overflow we first update CQ consumer and only then
462 	 * the ring consumer.
463 	 */
464 	mcq->cons_index = cons_index;
465 	mlx4_cq_set_ci(mcq);
466 	wmb();
467 
468 	/* we want to dirty this cache line once */
469 	ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb;
470 	ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped;
471 
472 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
473 
474 	/*
475 	 * Wakeup Tx queue if this stopped, and at least 1 packet
476 	 * was completed
477 	 */
478 	if (netif_tx_queue_stopped(ring->tx_queue) && txbbs_skipped > 0) {
479 		netif_tx_wake_queue(ring->tx_queue);
480 		ring->wake_queue++;
481 	}
482 	return done < budget;
483 }
484 
485 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
486 {
487 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
488 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
489 
490 	if (likely(priv->port_up))
491 		napi_schedule_irqoff(&cq->napi);
492 	else
493 		mlx4_en_arm_cq(priv, cq);
494 }
495 
496 /* TX CQ polling - called by NAPI */
497 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
498 {
499 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
500 	struct net_device *dev = cq->dev;
501 	struct mlx4_en_priv *priv = netdev_priv(dev);
502 	int clean_complete;
503 
504 	clean_complete = mlx4_en_process_tx_cq(dev, cq);
505 	if (!clean_complete)
506 		return budget;
507 
508 	napi_complete(napi);
509 	mlx4_en_arm_cq(priv, cq);
510 
511 	return 0;
512 }
513 
514 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
515 						      struct mlx4_en_tx_ring *ring,
516 						      u32 index,
517 						      unsigned int desc_size)
518 {
519 	u32 copy = (ring->size - index) * TXBB_SIZE;
520 	int i;
521 
522 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
523 		if ((i & (TXBB_SIZE - 1)) == 0)
524 			wmb();
525 
526 		*((u32 *) (ring->buf + i)) =
527 			*((u32 *) (ring->bounce_buf + copy + i));
528 	}
529 
530 	for (i = copy - 4; i >= 4 ; i -= 4) {
531 		if ((i & (TXBB_SIZE - 1)) == 0)
532 			wmb();
533 
534 		*((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
535 			*((u32 *) (ring->bounce_buf + i));
536 	}
537 
538 	/* Return real descriptor location */
539 	return ring->buf + index * TXBB_SIZE;
540 }
541 
542 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
543  *
544  * It seems strange we do not simply use skb_copy_bits().
545  * This would allow to inline all skbs iff skb->len <= inline_thold
546  *
547  * Note that caller already checked skb was not a gso packet
548  */
549 static bool is_inline(int inline_thold, const struct sk_buff *skb,
550 		      const struct skb_shared_info *shinfo,
551 		      void **pfrag)
552 {
553 	void *ptr;
554 
555 	if (skb->len > inline_thold || !inline_thold)
556 		return false;
557 
558 	if (shinfo->nr_frags == 1) {
559 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
560 		if (unlikely(!ptr))
561 			return false;
562 		*pfrag = ptr;
563 		return true;
564 	}
565 	if (shinfo->nr_frags)
566 		return false;
567 	return true;
568 }
569 
570 static int inline_size(const struct sk_buff *skb)
571 {
572 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
573 	    <= MLX4_INLINE_ALIGN)
574 		return ALIGN(skb->len + CTRL_SIZE +
575 			     sizeof(struct mlx4_wqe_inline_seg), 16);
576 	else
577 		return ALIGN(skb->len + CTRL_SIZE + 2 *
578 			     sizeof(struct mlx4_wqe_inline_seg), 16);
579 }
580 
581 static int get_real_size(const struct sk_buff *skb,
582 			 const struct skb_shared_info *shinfo,
583 			 struct net_device *dev,
584 			 int *lso_header_size,
585 			 bool *inline_ok,
586 			 void **pfrag)
587 {
588 	struct mlx4_en_priv *priv = netdev_priv(dev);
589 	int real_size;
590 
591 	if (shinfo->gso_size) {
592 		*inline_ok = false;
593 		if (skb->encapsulation)
594 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
595 		else
596 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
597 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
598 			ALIGN(*lso_header_size + 4, DS_SIZE);
599 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
600 			/* We add a segment for the skb linear buffer only if
601 			 * it contains data */
602 			if (*lso_header_size < skb_headlen(skb))
603 				real_size += DS_SIZE;
604 			else {
605 				if (netif_msg_tx_err(priv))
606 					en_warn(priv, "Non-linear headers\n");
607 				return 0;
608 			}
609 		}
610 	} else {
611 		*lso_header_size = 0;
612 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
613 				       shinfo, pfrag);
614 
615 		if (*inline_ok)
616 			real_size = inline_size(skb);
617 		else
618 			real_size = CTRL_SIZE +
619 				    (shinfo->nr_frags + 1) * DS_SIZE;
620 	}
621 
622 	return real_size;
623 }
624 
625 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
626 			     const struct sk_buff *skb,
627 			     const struct skb_shared_info *shinfo,
628 			     int real_size, u16 *vlan_tag,
629 			     int tx_ind, void *fragptr)
630 {
631 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
632 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
633 	unsigned int hlen = skb_headlen(skb);
634 
635 	if (skb->len <= spc) {
636 		if (likely(skb->len >= MIN_PKT_LEN)) {
637 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
638 		} else {
639 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
640 			memset(((void *)(inl + 1)) + skb->len, 0,
641 			       MIN_PKT_LEN - skb->len);
642 		}
643 		skb_copy_from_linear_data(skb, inl + 1, hlen);
644 		if (shinfo->nr_frags)
645 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
646 			       skb_frag_size(&shinfo->frags[0]));
647 
648 	} else {
649 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
650 		if (hlen <= spc) {
651 			skb_copy_from_linear_data(skb, inl + 1, hlen);
652 			if (hlen < spc) {
653 				memcpy(((void *)(inl + 1)) + hlen,
654 				       fragptr, spc - hlen);
655 				fragptr +=  spc - hlen;
656 			}
657 			inl = (void *) (inl + 1) + spc;
658 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
659 		} else {
660 			skb_copy_from_linear_data(skb, inl + 1, spc);
661 			inl = (void *) (inl + 1) + spc;
662 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
663 							 hlen - spc);
664 			if (shinfo->nr_frags)
665 				memcpy(((void *)(inl + 1)) + hlen - spc,
666 				       fragptr,
667 				       skb_frag_size(&shinfo->frags[0]));
668 		}
669 
670 		wmb();
671 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
672 	}
673 }
674 
675 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
676 			 void *accel_priv, select_queue_fallback_t fallback)
677 {
678 	struct mlx4_en_priv *priv = netdev_priv(dev);
679 	u16 rings_p_up = priv->num_tx_rings_p_up;
680 	u8 up = 0;
681 
682 	if (dev->num_tc)
683 		return skb_tx_hash(dev, skb);
684 
685 	if (vlan_tx_tag_present(skb))
686 		up = vlan_tx_tag_get(skb) >> VLAN_PRIO_SHIFT;
687 
688 	return fallback(dev, skb) % rings_p_up + up * rings_p_up;
689 }
690 
691 static void mlx4_bf_copy(void __iomem *dst, const void *src,
692 			 unsigned int bytecnt)
693 {
694 	__iowrite64_copy(dst, src, bytecnt / 8);
695 }
696 
697 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
698 {
699 	struct skb_shared_info *shinfo = skb_shinfo(skb);
700 	struct mlx4_en_priv *priv = netdev_priv(dev);
701 	struct device *ddev = priv->ddev;
702 	struct mlx4_en_tx_ring *ring;
703 	struct mlx4_en_tx_desc *tx_desc;
704 	struct mlx4_wqe_data_seg *data;
705 	struct mlx4_en_tx_info *tx_info;
706 	int tx_ind = 0;
707 	int nr_txbb;
708 	int desc_size;
709 	int real_size;
710 	u32 index, bf_index;
711 	__be32 op_own;
712 	u16 vlan_tag = 0;
713 	int i_frag;
714 	int lso_header_size;
715 	void *fragptr = NULL;
716 	bool bounce = false;
717 	bool send_doorbell;
718 	bool stop_queue;
719 	bool inline_ok;
720 	u32 ring_cons;
721 
722 	if (!priv->port_up)
723 		goto tx_drop;
724 
725 	tx_ind = skb_get_queue_mapping(skb);
726 	ring = priv->tx_ring[tx_ind];
727 
728 	/* fetch ring->cons far ahead before needing it to avoid stall */
729 	ring_cons = ACCESS_ONCE(ring->cons);
730 
731 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
732 				  &inline_ok, &fragptr);
733 	if (unlikely(!real_size))
734 		goto tx_drop;
735 
736 	/* Align descriptor to TXBB size */
737 	desc_size = ALIGN(real_size, TXBB_SIZE);
738 	nr_txbb = desc_size / TXBB_SIZE;
739 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
740 		if (netif_msg_tx_err(priv))
741 			en_warn(priv, "Oversized header or SG list\n");
742 		goto tx_drop;
743 	}
744 
745 	if (vlan_tx_tag_present(skb))
746 		vlan_tag = vlan_tx_tag_get(skb);
747 
748 
749 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
750 
751 	/* Track current inflight packets for performance analysis */
752 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
753 			 (u32)(ring->prod - ring_cons - 1));
754 
755 	/* Packet is good - grab an index and transmit it */
756 	index = ring->prod & ring->size_mask;
757 	bf_index = ring->prod;
758 
759 	/* See if we have enough space for whole descriptor TXBB for setting
760 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
761 	if (likely(index + nr_txbb <= ring->size))
762 		tx_desc = ring->buf + index * TXBB_SIZE;
763 	else {
764 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
765 		bounce = true;
766 	}
767 
768 	/* Save skb in tx_info ring */
769 	tx_info = &ring->tx_info[index];
770 	tx_info->skb = skb;
771 	tx_info->nr_txbb = nr_txbb;
772 
773 	data = &tx_desc->data;
774 	if (lso_header_size)
775 		data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4,
776 						      DS_SIZE));
777 
778 	/* valid only for none inline segments */
779 	tx_info->data_offset = (void *)data - (void *)tx_desc;
780 
781 	tx_info->inl = inline_ok;
782 
783 	tx_info->linear = (lso_header_size < skb_headlen(skb) &&
784 			   !inline_ok) ? 1 : 0;
785 
786 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
787 	data += tx_info->nr_maps - 1;
788 
789 	if (!tx_info->inl) {
790 		dma_addr_t dma = 0;
791 		u32 byte_count = 0;
792 
793 		/* Map fragments if any */
794 		for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
795 			const struct skb_frag_struct *frag;
796 
797 			frag = &shinfo->frags[i_frag];
798 			byte_count = skb_frag_size(frag);
799 			dma = skb_frag_dma_map(ddev, frag,
800 					       0, byte_count,
801 					       DMA_TO_DEVICE);
802 			if (dma_mapping_error(ddev, dma))
803 				goto tx_drop_unmap;
804 
805 			data->addr = cpu_to_be64(dma);
806 			data->lkey = ring->mr_key;
807 			wmb();
808 			data->byte_count = cpu_to_be32(byte_count);
809 			--data;
810 		}
811 
812 		/* Map linear part if needed */
813 		if (tx_info->linear) {
814 			byte_count = skb_headlen(skb) - lso_header_size;
815 
816 			dma = dma_map_single(ddev, skb->data +
817 					     lso_header_size, byte_count,
818 					     PCI_DMA_TODEVICE);
819 			if (dma_mapping_error(ddev, dma))
820 				goto tx_drop_unmap;
821 
822 			data->addr = cpu_to_be64(dma);
823 			data->lkey = ring->mr_key;
824 			wmb();
825 			data->byte_count = cpu_to_be32(byte_count);
826 		}
827 		/* tx completion can avoid cache line miss for common cases */
828 		tx_info->map0_dma = dma;
829 		tx_info->map0_byte_count = byte_count;
830 	}
831 
832 	/*
833 	 * For timestamping add flag to skb_shinfo and
834 	 * set flag for further reference
835 	 */
836 	tx_info->ts_requested = 0;
837 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
838 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
839 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
840 		tx_info->ts_requested = 1;
841 	}
842 
843 	/* Prepare ctrl segement apart opcode+ownership, which depends on
844 	 * whether LSO is used */
845 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
846 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
847 		if (!skb->encapsulation)
848 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
849 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
850 		else
851 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
852 		ring->tx_csum++;
853 	}
854 
855 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
856 		struct ethhdr *ethh;
857 
858 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
859 		 * so that VFs and PF can communicate with each other
860 		 */
861 		ethh = (struct ethhdr *)skb->data;
862 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
863 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
864 	}
865 
866 	/* Handle LSO (TSO) packets */
867 	if (lso_header_size) {
868 		int i;
869 
870 		/* Mark opcode as LSO */
871 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
872 			((ring->prod & ring->size) ?
873 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
874 
875 		/* Fill in the LSO prefix */
876 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
877 			shinfo->gso_size << 16 | lso_header_size);
878 
879 		/* Copy headers;
880 		 * note that we already verified that it is linear */
881 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
882 
883 		ring->tso_packets++;
884 
885 		i = ((skb->len - lso_header_size) / shinfo->gso_size) +
886 			!!((skb->len - lso_header_size) % shinfo->gso_size);
887 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
888 		ring->packets += i;
889 	} else {
890 		/* Normal (Non LSO) packet */
891 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
892 			((ring->prod & ring->size) ?
893 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
894 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
895 		ring->packets++;
896 	}
897 	ring->bytes += tx_info->nr_bytes;
898 	netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);
899 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
900 
901 	if (tx_info->inl)
902 		build_inline_wqe(tx_desc, skb, shinfo, real_size, &vlan_tag,
903 				 tx_ind, fragptr);
904 
905 	if (skb->encapsulation) {
906 		struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);
907 		if (ipv4->protocol == IPPROTO_TCP || ipv4->protocol == IPPROTO_UDP)
908 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
909 		else
910 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
911 	}
912 
913 	ring->prod += nr_txbb;
914 
915 	/* If we used a bounce buffer then copy descriptor back into place */
916 	if (unlikely(bounce))
917 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
918 
919 	skb_tx_timestamp(skb);
920 
921 	/* Check available TXBBs And 2K spare for prefetch */
922 	stop_queue = (int)(ring->prod - ring_cons) >
923 		      ring->size - HEADROOM - MAX_DESC_TXBBS;
924 	if (unlikely(stop_queue)) {
925 		netif_tx_stop_queue(ring->tx_queue);
926 		ring->queue_stopped++;
927 	}
928 	send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue);
929 
930 	real_size = (real_size / 16) & 0x3f;
931 
932 	if (ring->bf_enabled && desc_size <= MAX_BF && !bounce &&
933 	    !vlan_tx_tag_present(skb) && send_doorbell) {
934 		tx_desc->ctrl.bf_qpn = ring->doorbell_qpn |
935 				       cpu_to_be32(real_size);
936 
937 		op_own |= htonl((bf_index & 0xffff) << 8);
938 		/* Ensure new descriptor hits memory
939 		 * before setting ownership of this descriptor to HW
940 		 */
941 		wmb();
942 		tx_desc->ctrl.owner_opcode = op_own;
943 
944 		wmb();
945 
946 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
947 			     desc_size);
948 
949 		wmb();
950 
951 		ring->bf.offset ^= ring->bf.buf_size;
952 	} else {
953 		tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag);
954 		tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN *
955 			!!vlan_tx_tag_present(skb);
956 		tx_desc->ctrl.fence_size = real_size;
957 
958 		/* Ensure new descriptor hits memory
959 		 * before setting ownership of this descriptor to HW
960 		 */
961 		wmb();
962 		tx_desc->ctrl.owner_opcode = op_own;
963 		if (send_doorbell) {
964 			wmb();
965 			/* Since there is no iowrite*_native() that writes the
966 			 * value as is, without byteswapping - using the one
967 			 * the doesn't do byteswapping in the relevant arch
968 			 * endianness.
969 			 */
970 #if defined(__LITTLE_ENDIAN)
971 			iowrite32(
972 #else
973 			iowrite32be(
974 #endif
975 				  ring->doorbell_qpn,
976 				  ring->bf.uar->map + MLX4_SEND_DOORBELL);
977 		} else {
978 			ring->xmit_more++;
979 		}
980 	}
981 
982 	if (unlikely(stop_queue)) {
983 		/* If queue was emptied after the if (stop_queue) , and before
984 		 * the netif_tx_stop_queue() - need to wake the queue,
985 		 * or else it will remain stopped forever.
986 		 * Need a memory barrier to make sure ring->cons was not
987 		 * updated before queue was stopped.
988 		 */
989 		smp_rmb();
990 
991 		ring_cons = ACCESS_ONCE(ring->cons);
992 		if (unlikely(((int)(ring->prod - ring_cons)) <=
993 			     ring->size - HEADROOM - MAX_DESC_TXBBS)) {
994 			netif_tx_wake_queue(ring->tx_queue);
995 			ring->wake_queue++;
996 		}
997 	}
998 	return NETDEV_TX_OK;
999 
1000 tx_drop_unmap:
1001 	en_err(priv, "DMA mapping error\n");
1002 
1003 	while (++i_frag < shinfo->nr_frags) {
1004 		++data;
1005 		dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr),
1006 			       be32_to_cpu(data->byte_count),
1007 			       PCI_DMA_TODEVICE);
1008 	}
1009 
1010 tx_drop:
1011 	dev_kfree_skb_any(skb);
1012 	priv->stats.tx_dropped++;
1013 	return NETDEV_TX_OK;
1014 }
1015 
1016