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->persist->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->persist->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)
147 		cpumask_set_cpu_local_first(queue_index,
148 					    priv->mdev->dev->numa_node,
149 					    &ring->affinity_mask);
150 
151 	*pring = ring;
152 	return 0;
153 
154 err_reserve:
155 	mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
156 err_map:
157 	mlx4_en_unmap_buffer(&ring->wqres.buf);
158 err_hwq_res:
159 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
160 err_bounce:
161 	kfree(ring->bounce_buf);
162 	ring->bounce_buf = NULL;
163 err_info:
164 	kvfree(ring->tx_info);
165 	ring->tx_info = NULL;
166 err_ring:
167 	kfree(ring);
168 	*pring = NULL;
169 	return err;
170 }
171 
172 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
173 			     struct mlx4_en_tx_ring **pring)
174 {
175 	struct mlx4_en_dev *mdev = priv->mdev;
176 	struct mlx4_en_tx_ring *ring = *pring;
177 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
178 
179 	if (ring->bf_alloced)
180 		mlx4_bf_free(mdev->dev, &ring->bf);
181 	mlx4_qp_remove(mdev->dev, &ring->qp);
182 	mlx4_qp_free(mdev->dev, &ring->qp);
183 	mlx4_en_unmap_buffer(&ring->wqres.buf);
184 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
185 	kfree(ring->bounce_buf);
186 	ring->bounce_buf = NULL;
187 	kvfree(ring->tx_info);
188 	ring->tx_info = NULL;
189 	kfree(ring);
190 	*pring = NULL;
191 }
192 
193 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
194 			     struct mlx4_en_tx_ring *ring,
195 			     int cq, int user_prio)
196 {
197 	struct mlx4_en_dev *mdev = priv->mdev;
198 	int err;
199 
200 	ring->cqn = cq;
201 	ring->prod = 0;
202 	ring->cons = 0xffffffff;
203 	ring->last_nr_txbb = 1;
204 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
205 	memset(ring->buf, 0, ring->buf_size);
206 
207 	ring->qp_state = MLX4_QP_STATE_RST;
208 	ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8);
209 	ring->mr_key = cpu_to_be32(mdev->mr.key);
210 
211 	mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
212 				ring->cqn, user_prio, &ring->context);
213 	if (ring->bf_alloced)
214 		ring->context.usr_page = cpu_to_be32(ring->bf.uar->index);
215 
216 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
217 			       &ring->qp, &ring->qp_state);
218 	if (!cpumask_empty(&ring->affinity_mask))
219 		netif_set_xps_queue(priv->dev, &ring->affinity_mask,
220 				    ring->queue_index);
221 
222 	return err;
223 }
224 
225 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
226 				struct mlx4_en_tx_ring *ring)
227 {
228 	struct mlx4_en_dev *mdev = priv->mdev;
229 
230 	mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
231 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
232 }
233 
234 static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
235 			      struct mlx4_en_tx_ring *ring, int index,
236 			      u8 owner)
237 {
238 	__be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
239 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
240 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
241 	void *end = ring->buf + ring->buf_size;
242 	__be32 *ptr = (__be32 *)tx_desc;
243 	int i;
244 
245 	/* Optimize the common case when there are no wraparounds */
246 	if (likely((void *)tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
247 		/* Stamp the freed descriptor */
248 		for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
249 		     i += STAMP_STRIDE) {
250 			*ptr = stamp;
251 			ptr += STAMP_DWORDS;
252 		}
253 	} else {
254 		/* Stamp the freed descriptor */
255 		for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
256 		     i += STAMP_STRIDE) {
257 			*ptr = stamp;
258 			ptr += STAMP_DWORDS;
259 			if ((void *)ptr >= end) {
260 				ptr = ring->buf;
261 				stamp ^= cpu_to_be32(0x80000000);
262 			}
263 		}
264 	}
265 }
266 
267 
268 static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
269 				struct mlx4_en_tx_ring *ring,
270 				int index, u8 owner, u64 timestamp)
271 {
272 	struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
273 	struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
274 	struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
275 	void *end = ring->buf + ring->buf_size;
276 	struct sk_buff *skb = tx_info->skb;
277 	int nr_maps = tx_info->nr_maps;
278 	int i;
279 
280 	/* We do not touch skb here, so prefetch skb->users location
281 	 * to speedup consume_skb()
282 	 */
283 	prefetchw(&skb->users);
284 
285 	if (unlikely(timestamp)) {
286 		struct skb_shared_hwtstamps hwts;
287 
288 		mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp);
289 		skb_tstamp_tx(skb, &hwts);
290 	}
291 
292 	/* Optimize the common case when there are no wraparounds */
293 	if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
294 		if (!tx_info->inl) {
295 			if (tx_info->linear)
296 				dma_unmap_single(priv->ddev,
297 						tx_info->map0_dma,
298 						tx_info->map0_byte_count,
299 						PCI_DMA_TODEVICE);
300 			else
301 				dma_unmap_page(priv->ddev,
302 					       tx_info->map0_dma,
303 					       tx_info->map0_byte_count,
304 					       PCI_DMA_TODEVICE);
305 			for (i = 1; i < nr_maps; i++) {
306 				data++;
307 				dma_unmap_page(priv->ddev,
308 					(dma_addr_t)be64_to_cpu(data->addr),
309 					be32_to_cpu(data->byte_count),
310 					PCI_DMA_TODEVICE);
311 			}
312 		}
313 	} else {
314 		if (!tx_info->inl) {
315 			if ((void *) data >= end) {
316 				data = ring->buf + ((void *)data - end);
317 			}
318 
319 			if (tx_info->linear)
320 				dma_unmap_single(priv->ddev,
321 						tx_info->map0_dma,
322 						tx_info->map0_byte_count,
323 						PCI_DMA_TODEVICE);
324 			else
325 				dma_unmap_page(priv->ddev,
326 					       tx_info->map0_dma,
327 					       tx_info->map0_byte_count,
328 					       PCI_DMA_TODEVICE);
329 			for (i = 1; i < nr_maps; i++) {
330 				data++;
331 				/* Check for wraparound before unmapping */
332 				if ((void *) data >= end)
333 					data = ring->buf;
334 				dma_unmap_page(priv->ddev,
335 					(dma_addr_t)be64_to_cpu(data->addr),
336 					be32_to_cpu(data->byte_count),
337 					PCI_DMA_TODEVICE);
338 			}
339 		}
340 	}
341 	dev_consume_skb_any(skb);
342 	return tx_info->nr_txbb;
343 }
344 
345 
346 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
347 {
348 	struct mlx4_en_priv *priv = netdev_priv(dev);
349 	int cnt = 0;
350 
351 	/* Skip last polled descriptor */
352 	ring->cons += ring->last_nr_txbb;
353 	en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
354 		 ring->cons, ring->prod);
355 
356 	if ((u32) (ring->prod - ring->cons) > ring->size) {
357 		if (netif_msg_tx_err(priv))
358 			en_warn(priv, "Tx consumer passed producer!\n");
359 		return 0;
360 	}
361 
362 	while (ring->cons != ring->prod) {
363 		ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
364 						ring->cons & ring->size_mask,
365 						!!(ring->cons & ring->size), 0);
366 		ring->cons += ring->last_nr_txbb;
367 		cnt++;
368 	}
369 
370 	netdev_tx_reset_queue(ring->tx_queue);
371 
372 	if (cnt)
373 		en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
374 
375 	return cnt;
376 }
377 
378 static bool mlx4_en_process_tx_cq(struct net_device *dev,
379 				 struct mlx4_en_cq *cq)
380 {
381 	struct mlx4_en_priv *priv = netdev_priv(dev);
382 	struct mlx4_cq *mcq = &cq->mcq;
383 	struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
384 	struct mlx4_cqe *cqe;
385 	u16 index;
386 	u16 new_index, ring_index, stamp_index;
387 	u32 txbbs_skipped = 0;
388 	u32 txbbs_stamp = 0;
389 	u32 cons_index = mcq->cons_index;
390 	int size = cq->size;
391 	u32 size_mask = ring->size_mask;
392 	struct mlx4_cqe *buf = cq->buf;
393 	u32 packets = 0;
394 	u32 bytes = 0;
395 	int factor = priv->cqe_factor;
396 	u64 timestamp = 0;
397 	int done = 0;
398 	int budget = priv->tx_work_limit;
399 	u32 last_nr_txbb;
400 	u32 ring_cons;
401 
402 	if (!priv->port_up)
403 		return true;
404 
405 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
406 
407 	index = cons_index & size_mask;
408 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
409 	last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb);
410 	ring_cons = ACCESS_ONCE(ring->cons);
411 	ring_index = ring_cons & size_mask;
412 	stamp_index = ring_index;
413 
414 	/* Process all completed CQEs */
415 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
416 			cons_index & size) && (done < budget)) {
417 		/*
418 		 * make sure we read the CQE after we read the
419 		 * ownership bit
420 		 */
421 		dma_rmb();
422 
423 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
424 			     MLX4_CQE_OPCODE_ERROR)) {
425 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
426 
427 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
428 			       cqe_err->vendor_err_syndrome,
429 			       cqe_err->syndrome);
430 		}
431 
432 		/* Skip over last polled CQE */
433 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
434 
435 		do {
436 			txbbs_skipped += last_nr_txbb;
437 			ring_index = (ring_index + last_nr_txbb) & size_mask;
438 			if (ring->tx_info[ring_index].ts_requested)
439 				timestamp = mlx4_en_get_cqe_ts(cqe);
440 
441 			/* free next descriptor */
442 			last_nr_txbb = mlx4_en_free_tx_desc(
443 					priv, ring, ring_index,
444 					!!((ring_cons + txbbs_skipped) &
445 					ring->size), timestamp);
446 
447 			mlx4_en_stamp_wqe(priv, ring, stamp_index,
448 					  !!((ring_cons + txbbs_stamp) &
449 						ring->size));
450 			stamp_index = ring_index;
451 			txbbs_stamp = txbbs_skipped;
452 			packets++;
453 			bytes += ring->tx_info[ring_index].nr_bytes;
454 		} while ((++done < budget) && (ring_index != new_index));
455 
456 		++cons_index;
457 		index = cons_index & size_mask;
458 		cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
459 	}
460 
461 
462 	/*
463 	 * To prevent CQ overflow we first update CQ consumer and only then
464 	 * the ring consumer.
465 	 */
466 	mcq->cons_index = cons_index;
467 	mlx4_cq_set_ci(mcq);
468 	wmb();
469 
470 	/* we want to dirty this cache line once */
471 	ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb;
472 	ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped;
473 
474 	netdev_tx_completed_queue(ring->tx_queue, packets, bytes);
475 
476 	/*
477 	 * Wakeup Tx queue if this stopped, and at least 1 packet
478 	 * was completed
479 	 */
480 	if (netif_tx_queue_stopped(ring->tx_queue) && txbbs_skipped > 0) {
481 		netif_tx_wake_queue(ring->tx_queue);
482 		ring->wake_queue++;
483 	}
484 	return done < budget;
485 }
486 
487 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
488 {
489 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
490 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
491 
492 	if (likely(priv->port_up))
493 		napi_schedule_irqoff(&cq->napi);
494 	else
495 		mlx4_en_arm_cq(priv, cq);
496 }
497 
498 /* TX CQ polling - called by NAPI */
499 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
500 {
501 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
502 	struct net_device *dev = cq->dev;
503 	struct mlx4_en_priv *priv = netdev_priv(dev);
504 	int clean_complete;
505 
506 	clean_complete = mlx4_en_process_tx_cq(dev, cq);
507 	if (!clean_complete)
508 		return budget;
509 
510 	napi_complete(napi);
511 	mlx4_en_arm_cq(priv, cq);
512 
513 	return 0;
514 }
515 
516 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
517 						      struct mlx4_en_tx_ring *ring,
518 						      u32 index,
519 						      unsigned int desc_size)
520 {
521 	u32 copy = (ring->size - index) * TXBB_SIZE;
522 	int i;
523 
524 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
525 		if ((i & (TXBB_SIZE - 1)) == 0)
526 			wmb();
527 
528 		*((u32 *) (ring->buf + i)) =
529 			*((u32 *) (ring->bounce_buf + copy + i));
530 	}
531 
532 	for (i = copy - 4; i >= 4 ; i -= 4) {
533 		if ((i & (TXBB_SIZE - 1)) == 0)
534 			wmb();
535 
536 		*((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
537 			*((u32 *) (ring->bounce_buf + i));
538 	}
539 
540 	/* Return real descriptor location */
541 	return ring->buf + index * TXBB_SIZE;
542 }
543 
544 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
545  *
546  * It seems strange we do not simply use skb_copy_bits().
547  * This would allow to inline all skbs iff skb->len <= inline_thold
548  *
549  * Note that caller already checked skb was not a gso packet
550  */
551 static bool is_inline(int inline_thold, const struct sk_buff *skb,
552 		      const struct skb_shared_info *shinfo,
553 		      void **pfrag)
554 {
555 	void *ptr;
556 
557 	if (skb->len > inline_thold || !inline_thold)
558 		return false;
559 
560 	if (shinfo->nr_frags == 1) {
561 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
562 		if (unlikely(!ptr))
563 			return false;
564 		*pfrag = ptr;
565 		return true;
566 	}
567 	if (shinfo->nr_frags)
568 		return false;
569 	return true;
570 }
571 
572 static int inline_size(const struct sk_buff *skb)
573 {
574 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
575 	    <= MLX4_INLINE_ALIGN)
576 		return ALIGN(skb->len + CTRL_SIZE +
577 			     sizeof(struct mlx4_wqe_inline_seg), 16);
578 	else
579 		return ALIGN(skb->len + CTRL_SIZE + 2 *
580 			     sizeof(struct mlx4_wqe_inline_seg), 16);
581 }
582 
583 static int get_real_size(const struct sk_buff *skb,
584 			 const struct skb_shared_info *shinfo,
585 			 struct net_device *dev,
586 			 int *lso_header_size,
587 			 bool *inline_ok,
588 			 void **pfrag)
589 {
590 	struct mlx4_en_priv *priv = netdev_priv(dev);
591 	int real_size;
592 
593 	if (shinfo->gso_size) {
594 		*inline_ok = false;
595 		if (skb->encapsulation)
596 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
597 		else
598 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
599 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
600 			ALIGN(*lso_header_size + 4, DS_SIZE);
601 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
602 			/* We add a segment for the skb linear buffer only if
603 			 * it contains data */
604 			if (*lso_header_size < skb_headlen(skb))
605 				real_size += DS_SIZE;
606 			else {
607 				if (netif_msg_tx_err(priv))
608 					en_warn(priv, "Non-linear headers\n");
609 				return 0;
610 			}
611 		}
612 	} else {
613 		*lso_header_size = 0;
614 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
615 				       shinfo, pfrag);
616 
617 		if (*inline_ok)
618 			real_size = inline_size(skb);
619 		else
620 			real_size = CTRL_SIZE +
621 				    (shinfo->nr_frags + 1) * DS_SIZE;
622 	}
623 
624 	return real_size;
625 }
626 
627 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
628 			     const struct sk_buff *skb,
629 			     const struct skb_shared_info *shinfo,
630 			     int real_size, u16 *vlan_tag,
631 			     int tx_ind, void *fragptr)
632 {
633 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
634 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
635 	unsigned int hlen = skb_headlen(skb);
636 
637 	if (skb->len <= spc) {
638 		if (likely(skb->len >= MIN_PKT_LEN)) {
639 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
640 		} else {
641 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
642 			memset(((void *)(inl + 1)) + skb->len, 0,
643 			       MIN_PKT_LEN - skb->len);
644 		}
645 		skb_copy_from_linear_data(skb, inl + 1, hlen);
646 		if (shinfo->nr_frags)
647 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
648 			       skb_frag_size(&shinfo->frags[0]));
649 
650 	} else {
651 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
652 		if (hlen <= spc) {
653 			skb_copy_from_linear_data(skb, inl + 1, hlen);
654 			if (hlen < spc) {
655 				memcpy(((void *)(inl + 1)) + hlen,
656 				       fragptr, spc - hlen);
657 				fragptr +=  spc - hlen;
658 			}
659 			inl = (void *) (inl + 1) + spc;
660 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
661 		} else {
662 			skb_copy_from_linear_data(skb, inl + 1, spc);
663 			inl = (void *) (inl + 1) + spc;
664 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
665 							 hlen - spc);
666 			if (shinfo->nr_frags)
667 				memcpy(((void *)(inl + 1)) + hlen - spc,
668 				       fragptr,
669 				       skb_frag_size(&shinfo->frags[0]));
670 		}
671 
672 		dma_wmb();
673 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
674 	}
675 }
676 
677 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
678 			 void *accel_priv, select_queue_fallback_t fallback)
679 {
680 	struct mlx4_en_priv *priv = netdev_priv(dev);
681 	u16 rings_p_up = priv->num_tx_rings_p_up;
682 	u8 up = 0;
683 
684 	if (dev->num_tc)
685 		return skb_tx_hash(dev, skb);
686 
687 	if (skb_vlan_tag_present(skb))
688 		up = skb_vlan_tag_get(skb) >> VLAN_PRIO_SHIFT;
689 
690 	return fallback(dev, skb) % rings_p_up + up * rings_p_up;
691 }
692 
693 static void mlx4_bf_copy(void __iomem *dst, const void *src,
694 			 unsigned int bytecnt)
695 {
696 	__iowrite64_copy(dst, src, bytecnt / 8);
697 }
698 
699 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
700 {
701 	struct skb_shared_info *shinfo = skb_shinfo(skb);
702 	struct mlx4_en_priv *priv = netdev_priv(dev);
703 	struct device *ddev = priv->ddev;
704 	struct mlx4_en_tx_ring *ring;
705 	struct mlx4_en_tx_desc *tx_desc;
706 	struct mlx4_wqe_data_seg *data;
707 	struct mlx4_en_tx_info *tx_info;
708 	int tx_ind = 0;
709 	int nr_txbb;
710 	int desc_size;
711 	int real_size;
712 	u32 index, bf_index;
713 	__be32 op_own;
714 	u16 vlan_tag = 0;
715 	int i_frag;
716 	int lso_header_size;
717 	void *fragptr = NULL;
718 	bool bounce = false;
719 	bool send_doorbell;
720 	bool stop_queue;
721 	bool inline_ok;
722 	u32 ring_cons;
723 
724 	if (!priv->port_up)
725 		goto tx_drop;
726 
727 	tx_ind = skb_get_queue_mapping(skb);
728 	ring = priv->tx_ring[tx_ind];
729 
730 	/* fetch ring->cons far ahead before needing it to avoid stall */
731 	ring_cons = ACCESS_ONCE(ring->cons);
732 
733 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
734 				  &inline_ok, &fragptr);
735 	if (unlikely(!real_size))
736 		goto tx_drop;
737 
738 	/* Align descriptor to TXBB size */
739 	desc_size = ALIGN(real_size, TXBB_SIZE);
740 	nr_txbb = desc_size / TXBB_SIZE;
741 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
742 		if (netif_msg_tx_err(priv))
743 			en_warn(priv, "Oversized header or SG list\n");
744 		goto tx_drop;
745 	}
746 
747 	if (skb_vlan_tag_present(skb))
748 		vlan_tag = skb_vlan_tag_get(skb);
749 
750 
751 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
752 
753 	/* Track current inflight packets for performance analysis */
754 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
755 			 (u32)(ring->prod - ring_cons - 1));
756 
757 	/* Packet is good - grab an index and transmit it */
758 	index = ring->prod & ring->size_mask;
759 	bf_index = ring->prod;
760 
761 	/* See if we have enough space for whole descriptor TXBB for setting
762 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
763 	if (likely(index + nr_txbb <= ring->size))
764 		tx_desc = ring->buf + index * TXBB_SIZE;
765 	else {
766 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
767 		bounce = true;
768 	}
769 
770 	/* Save skb in tx_info ring */
771 	tx_info = &ring->tx_info[index];
772 	tx_info->skb = skb;
773 	tx_info->nr_txbb = nr_txbb;
774 
775 	data = &tx_desc->data;
776 	if (lso_header_size)
777 		data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4,
778 						      DS_SIZE));
779 
780 	/* valid only for none inline segments */
781 	tx_info->data_offset = (void *)data - (void *)tx_desc;
782 
783 	tx_info->inl = inline_ok;
784 
785 	tx_info->linear = (lso_header_size < skb_headlen(skb) &&
786 			   !inline_ok) ? 1 : 0;
787 
788 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
789 	data += tx_info->nr_maps - 1;
790 
791 	if (!tx_info->inl) {
792 		dma_addr_t dma = 0;
793 		u32 byte_count = 0;
794 
795 		/* Map fragments if any */
796 		for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
797 			const struct skb_frag_struct *frag;
798 
799 			frag = &shinfo->frags[i_frag];
800 			byte_count = skb_frag_size(frag);
801 			dma = skb_frag_dma_map(ddev, frag,
802 					       0, byte_count,
803 					       DMA_TO_DEVICE);
804 			if (dma_mapping_error(ddev, dma))
805 				goto tx_drop_unmap;
806 
807 			data->addr = cpu_to_be64(dma);
808 			data->lkey = ring->mr_key;
809 			dma_wmb();
810 			data->byte_count = cpu_to_be32(byte_count);
811 			--data;
812 		}
813 
814 		/* Map linear part if needed */
815 		if (tx_info->linear) {
816 			byte_count = skb_headlen(skb) - lso_header_size;
817 
818 			dma = dma_map_single(ddev, skb->data +
819 					     lso_header_size, byte_count,
820 					     PCI_DMA_TODEVICE);
821 			if (dma_mapping_error(ddev, dma))
822 				goto tx_drop_unmap;
823 
824 			data->addr = cpu_to_be64(dma);
825 			data->lkey = ring->mr_key;
826 			dma_wmb();
827 			data->byte_count = cpu_to_be32(byte_count);
828 		}
829 		/* tx completion can avoid cache line miss for common cases */
830 		tx_info->map0_dma = dma;
831 		tx_info->map0_byte_count = byte_count;
832 	}
833 
834 	/*
835 	 * For timestamping add flag to skb_shinfo and
836 	 * set flag for further reference
837 	 */
838 	tx_info->ts_requested = 0;
839 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
840 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
841 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
842 		tx_info->ts_requested = 1;
843 	}
844 
845 	/* Prepare ctrl segement apart opcode+ownership, which depends on
846 	 * whether LSO is used */
847 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
848 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
849 		if (!skb->encapsulation)
850 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
851 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
852 		else
853 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
854 		ring->tx_csum++;
855 	}
856 
857 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
858 		struct ethhdr *ethh;
859 
860 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
861 		 * so that VFs and PF can communicate with each other
862 		 */
863 		ethh = (struct ethhdr *)skb->data;
864 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
865 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
866 	}
867 
868 	/* Handle LSO (TSO) packets */
869 	if (lso_header_size) {
870 		int i;
871 
872 		/* Mark opcode as LSO */
873 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
874 			((ring->prod & ring->size) ?
875 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
876 
877 		/* Fill in the LSO prefix */
878 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
879 			shinfo->gso_size << 16 | lso_header_size);
880 
881 		/* Copy headers;
882 		 * note that we already verified that it is linear */
883 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
884 
885 		ring->tso_packets++;
886 
887 		i = ((skb->len - lso_header_size) / shinfo->gso_size) +
888 			!!((skb->len - lso_header_size) % shinfo->gso_size);
889 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
890 		ring->packets += i;
891 	} else {
892 		/* Normal (Non LSO) packet */
893 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
894 			((ring->prod & ring->size) ?
895 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
896 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
897 		ring->packets++;
898 	}
899 	ring->bytes += tx_info->nr_bytes;
900 	netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);
901 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
902 
903 	if (tx_info->inl)
904 		build_inline_wqe(tx_desc, skb, shinfo, real_size, &vlan_tag,
905 				 tx_ind, fragptr);
906 
907 	if (skb->encapsulation) {
908 		struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);
909 		if (ipv4->protocol == IPPROTO_TCP || ipv4->protocol == IPPROTO_UDP)
910 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
911 		else
912 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
913 	}
914 
915 	ring->prod += nr_txbb;
916 
917 	/* If we used a bounce buffer then copy descriptor back into place */
918 	if (unlikely(bounce))
919 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
920 
921 	skb_tx_timestamp(skb);
922 
923 	/* Check available TXBBs And 2K spare for prefetch */
924 	stop_queue = (int)(ring->prod - ring_cons) >
925 		      ring->size - HEADROOM - MAX_DESC_TXBBS;
926 	if (unlikely(stop_queue)) {
927 		netif_tx_stop_queue(ring->tx_queue);
928 		ring->queue_stopped++;
929 	}
930 	send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue);
931 
932 	real_size = (real_size / 16) & 0x3f;
933 
934 	if (ring->bf_enabled && desc_size <= MAX_BF && !bounce &&
935 	    !skb_vlan_tag_present(skb) && send_doorbell) {
936 		tx_desc->ctrl.bf_qpn = ring->doorbell_qpn |
937 				       cpu_to_be32(real_size);
938 
939 		op_own |= htonl((bf_index & 0xffff) << 8);
940 		/* Ensure new descriptor hits memory
941 		 * before setting ownership of this descriptor to HW
942 		 */
943 		dma_wmb();
944 		tx_desc->ctrl.owner_opcode = op_own;
945 
946 		wmb();
947 
948 		mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
949 			     desc_size);
950 
951 		wmb();
952 
953 		ring->bf.offset ^= ring->bf.buf_size;
954 	} else {
955 		tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag);
956 		tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN *
957 			!!skb_vlan_tag_present(skb);
958 		tx_desc->ctrl.fence_size = real_size;
959 
960 		/* Ensure new descriptor hits memory
961 		 * before setting ownership of this descriptor to HW
962 		 */
963 		dma_wmb();
964 		tx_desc->ctrl.owner_opcode = op_own;
965 		if (send_doorbell) {
966 			wmb();
967 			/* Since there is no iowrite*_native() that writes the
968 			 * value as is, without byteswapping - using the one
969 			 * the doesn't do byteswapping in the relevant arch
970 			 * endianness.
971 			 */
972 #if defined(__LITTLE_ENDIAN)
973 			iowrite32(
974 #else
975 			iowrite32be(
976 #endif
977 				  ring->doorbell_qpn,
978 				  ring->bf.uar->map + MLX4_SEND_DOORBELL);
979 		} else {
980 			ring->xmit_more++;
981 		}
982 	}
983 
984 	if (unlikely(stop_queue)) {
985 		/* If queue was emptied after the if (stop_queue) , and before
986 		 * the netif_tx_stop_queue() - need to wake the queue,
987 		 * or else it will remain stopped forever.
988 		 * Need a memory barrier to make sure ring->cons was not
989 		 * updated before queue was stopped.
990 		 */
991 		smp_rmb();
992 
993 		ring_cons = ACCESS_ONCE(ring->cons);
994 		if (unlikely(((int)(ring->prod - ring_cons)) <=
995 			     ring->size - HEADROOM - MAX_DESC_TXBBS)) {
996 			netif_tx_wake_queue(ring->tx_queue);
997 			ring->wake_queue++;
998 		}
999 	}
1000 	return NETDEV_TX_OK;
1001 
1002 tx_drop_unmap:
1003 	en_err(priv, "DMA mapping error\n");
1004 
1005 	while (++i_frag < shinfo->nr_frags) {
1006 		++data;
1007 		dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr),
1008 			       be32_to_cpu(data->byte_count),
1009 			       PCI_DMA_TODEVICE);
1010 	}
1011 
1012 tx_drop:
1013 	dev_kfree_skb_any(skb);
1014 	priv->stats.tx_dropped++;
1015 	return NETDEV_TX_OK;
1016 }
1017 
1018