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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 
mlx4_en_create_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring ** pring,int qpn,u32 size,u16 stride,int node,int queue_index)48 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
49 			   struct mlx4_en_tx_ring **pring, int qpn, 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 	ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
70 
71 	tmp = size * sizeof(struct mlx4_en_tx_info);
72 	ring->tx_info = kmalloc_node(tmp, GFP_KERNEL | __GFP_NOWARN, node);
73 	if (!ring->tx_info) {
74 		ring->tx_info = vmalloc(tmp);
75 		if (!ring->tx_info) {
76 			err = -ENOMEM;
77 			goto err_ring;
78 		}
79 	}
80 
81 	en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
82 		 ring->tx_info, tmp);
83 
84 	ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
85 	if (!ring->bounce_buf) {
86 		ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
87 		if (!ring->bounce_buf) {
88 			err = -ENOMEM;
89 			goto err_info;
90 		}
91 	}
92 	ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
93 
94 	/* Allocate HW buffers on provided NUMA node */
95 	set_dev_node(&mdev->dev->pdev->dev, node);
96 	err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size,
97 				 2 * PAGE_SIZE);
98 	set_dev_node(&mdev->dev->pdev->dev, mdev->dev->numa_node);
99 	if (err) {
100 		en_err(priv, "Failed allocating hwq resources\n");
101 		goto err_bounce;
102 	}
103 
104 	err = mlx4_en_map_buffer(&ring->wqres.buf);
105 	if (err) {
106 		en_err(priv, "Failed to map TX buffer\n");
107 		goto err_hwq_res;
108 	}
109 
110 	ring->buf = ring->wqres.buf.direct.buf;
111 
112 	en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
113 	       ring, ring->buf, ring->size, ring->buf_size,
114 	       (unsigned long long) ring->wqres.buf.direct.map);
115 
116 	ring->qpn = qpn;
117 	err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp, GFP_KERNEL);
118 	if (err) {
119 		en_err(priv, "Failed allocating qp %d\n", ring->qpn);
120 		goto err_map;
121 	}
122 	ring->qp.event = mlx4_en_sqp_event;
123 
124 	err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
125 	if (err) {
126 		en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
127 		ring->bf.uar = &mdev->priv_uar;
128 		ring->bf.uar->map = mdev->uar_map;
129 		ring->bf_enabled = false;
130 		ring->bf_alloced = false;
131 		priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
132 	} else {
133 		ring->bf_alloced = true;
134 		ring->bf_enabled = !!(priv->pflags &
135 				      MLX4_EN_PRIV_FLAGS_BLUEFLAME);
136 	}
137 
138 	ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
139 	ring->queue_index = queue_index;
140 
141 	if (queue_index < priv->num_tx_rings_p_up)
142 		cpumask_set_cpu(cpumask_local_spread(queue_index,
143 						     priv->mdev->dev->numa_node),
144 				&ring->affinity_mask);
145 
146 	*pring = ring;
147 	return 0;
148 
149 err_map:
150 	mlx4_en_unmap_buffer(&ring->wqres.buf);
151 err_hwq_res:
152 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
153 err_bounce:
154 	kfree(ring->bounce_buf);
155 	ring->bounce_buf = NULL;
156 err_info:
157 	kvfree(ring->tx_info);
158 	ring->tx_info = NULL;
159 err_ring:
160 	kfree(ring);
161 	*pring = NULL;
162 	return err;
163 }
164 
mlx4_en_destroy_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring ** pring)165 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
166 			     struct mlx4_en_tx_ring **pring)
167 {
168 	struct mlx4_en_dev *mdev = priv->mdev;
169 	struct mlx4_en_tx_ring *ring = *pring;
170 	en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
171 
172 	if (ring->bf_alloced)
173 		mlx4_bf_free(mdev->dev, &ring->bf);
174 	mlx4_qp_remove(mdev->dev, &ring->qp);
175 	mlx4_qp_free(mdev->dev, &ring->qp);
176 	mlx4_en_unmap_buffer(&ring->wqres.buf);
177 	mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
178 	kfree(ring->bounce_buf);
179 	ring->bounce_buf = NULL;
180 	kvfree(ring->tx_info);
181 	ring->tx_info = NULL;
182 	kfree(ring);
183 	*pring = NULL;
184 }
185 
mlx4_en_activate_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,int cq,int user_prio)186 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
187 			     struct mlx4_en_tx_ring *ring,
188 			     int cq, int user_prio)
189 {
190 	struct mlx4_en_dev *mdev = priv->mdev;
191 	int err;
192 
193 	ring->cqn = cq;
194 	ring->prod = 0;
195 	ring->cons = 0xffffffff;
196 	ring->last_nr_txbb = 1;
197 	memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
198 	memset(ring->buf, 0, ring->buf_size);
199 
200 	ring->qp_state = MLX4_QP_STATE_RST;
201 	ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8);
202 	ring->mr_key = cpu_to_be32(mdev->mr.key);
203 
204 	mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
205 				ring->cqn, user_prio, &ring->context);
206 	if (ring->bf_alloced)
207 		ring->context.usr_page = cpu_to_be32(ring->bf.uar->index);
208 
209 	err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
210 			       &ring->qp, &ring->qp_state);
211 	if (!cpumask_empty(&ring->affinity_mask))
212 		netif_set_xps_queue(priv->dev, &ring->affinity_mask,
213 				    ring->queue_index);
214 
215 	return err;
216 }
217 
mlx4_en_deactivate_tx_ring(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring)218 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
219 				struct mlx4_en_tx_ring *ring)
220 {
221 	struct mlx4_en_dev *mdev = priv->mdev;
222 
223 	mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
224 		       MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
225 }
226 
mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring * ring)227 static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
228 {
229 	return ring->prod - ring->cons > ring->full_size;
230 }
231 
mlx4_en_stamp_wqe(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,int index,u8 owner)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 
mlx4_en_free_tx_desc(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,int index,u8 owner,u64 timestamp)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 
mlx4_en_free_tx_buf(struct net_device * dev,struct mlx4_en_tx_ring * ring)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 
mlx4_en_process_tx_cq(struct net_device * dev,struct mlx4_en_cq * cq)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 	int done = 0;
395 	int budget = priv->tx_work_limit;
396 	u32 last_nr_txbb;
397 	u32 ring_cons;
398 
399 	if (!priv->port_up)
400 		return true;
401 
402 	netdev_txq_bql_complete_prefetchw(ring->tx_queue);
403 
404 	index = cons_index & size_mask;
405 	cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
406 	last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb);
407 	ring_cons = ACCESS_ONCE(ring->cons);
408 	ring_index = ring_cons & size_mask;
409 	stamp_index = ring_index;
410 
411 	/* Process all completed CQEs */
412 	while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
413 			cons_index & size) && (done < budget)) {
414 		/*
415 		 * make sure we read the CQE after we read the
416 		 * ownership bit
417 		 */
418 		rmb();
419 
420 		if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
421 			     MLX4_CQE_OPCODE_ERROR)) {
422 			struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
423 
424 			en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
425 			       cqe_err->vendor_err_syndrome,
426 			       cqe_err->syndrome);
427 		}
428 
429 		/* Skip over last polled CQE */
430 		new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
431 
432 		do {
433 			u64 timestamp = 0;
434 
435 			txbbs_skipped += last_nr_txbb;
436 			ring_index = (ring_index + last_nr_txbb) & size_mask;
437 
438 			if (unlikely(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 	/* Wakeup Tx queue if this stopped, and ring is not full.
477 	 */
478 	if (netif_tx_queue_stopped(ring->tx_queue) &&
479 	    !mlx4_en_is_tx_ring_full(ring)) {
480 		netif_tx_wake_queue(ring->tx_queue);
481 		ring->wake_queue++;
482 	}
483 	return done < budget;
484 }
485 
mlx4_en_tx_irq(struct mlx4_cq * mcq)486 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
487 {
488 	struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
489 	struct mlx4_en_priv *priv = netdev_priv(cq->dev);
490 
491 	if (priv->port_up)
492 		napi_schedule(&cq->napi);
493 	else
494 		mlx4_en_arm_cq(priv, cq);
495 }
496 
497 /* TX CQ polling - called by NAPI */
mlx4_en_poll_tx_cq(struct napi_struct * napi,int budget)498 int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
499 {
500 	struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
501 	struct net_device *dev = cq->dev;
502 	struct mlx4_en_priv *priv = netdev_priv(dev);
503 	int clean_complete;
504 
505 	clean_complete = mlx4_en_process_tx_cq(dev, cq);
506 	if (!clean_complete)
507 		return budget;
508 
509 	napi_complete(napi);
510 	mlx4_en_arm_cq(priv, cq);
511 
512 	return 0;
513 }
514 
mlx4_en_bounce_to_desc(struct mlx4_en_priv * priv,struct mlx4_en_tx_ring * ring,u32 index,unsigned int desc_size)515 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
516 						      struct mlx4_en_tx_ring *ring,
517 						      u32 index,
518 						      unsigned int desc_size)
519 {
520 	u32 copy = (ring->size - index) * TXBB_SIZE;
521 	int i;
522 
523 	for (i = desc_size - copy - 4; i >= 0; i -= 4) {
524 		if ((i & (TXBB_SIZE - 1)) == 0)
525 			wmb();
526 
527 		*((u32 *) (ring->buf + i)) =
528 			*((u32 *) (ring->bounce_buf + copy + i));
529 	}
530 
531 	for (i = copy - 4; i >= 4 ; i -= 4) {
532 		if ((i & (TXBB_SIZE - 1)) == 0)
533 			wmb();
534 
535 		*((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
536 			*((u32 *) (ring->bounce_buf + i));
537 	}
538 
539 	/* Return real descriptor location */
540 	return ring->buf + index * TXBB_SIZE;
541 }
542 
543 /* Decide if skb can be inlined in tx descriptor to avoid dma mapping
544  *
545  * It seems strange we do not simply use skb_copy_bits().
546  * This would allow to inline all skbs iff skb->len <= inline_thold
547  *
548  * Note that caller already checked skb was not a gso packet
549  */
is_inline(int inline_thold,const struct sk_buff * skb,const struct skb_shared_info * shinfo,void ** pfrag)550 static bool is_inline(int inline_thold, const struct sk_buff *skb,
551 		      const struct skb_shared_info *shinfo,
552 		      void **pfrag)
553 {
554 	void *ptr;
555 
556 	if (skb->len > inline_thold || !inline_thold)
557 		return false;
558 
559 	if (shinfo->nr_frags == 1) {
560 		ptr = skb_frag_address_safe(&shinfo->frags[0]);
561 		if (unlikely(!ptr))
562 			return false;
563 		*pfrag = ptr;
564 		return true;
565 	}
566 	if (shinfo->nr_frags)
567 		return false;
568 	return true;
569 }
570 
inline_size(const struct sk_buff * skb)571 static int inline_size(const struct sk_buff *skb)
572 {
573 	if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
574 	    <= MLX4_INLINE_ALIGN)
575 		return ALIGN(skb->len + CTRL_SIZE +
576 			     sizeof(struct mlx4_wqe_inline_seg), 16);
577 	else
578 		return ALIGN(skb->len + CTRL_SIZE + 2 *
579 			     sizeof(struct mlx4_wqe_inline_seg), 16);
580 }
581 
get_real_size(const struct sk_buff * skb,const struct skb_shared_info * shinfo,struct net_device * dev,int * lso_header_size,bool * inline_ok,void ** pfrag)582 static int get_real_size(const struct sk_buff *skb,
583 			 const struct skb_shared_info *shinfo,
584 			 struct net_device *dev,
585 			 int *lso_header_size,
586 			 bool *inline_ok,
587 			 void **pfrag)
588 {
589 	struct mlx4_en_priv *priv = netdev_priv(dev);
590 	int real_size;
591 
592 	if (shinfo->gso_size) {
593 		*inline_ok = false;
594 		if (skb->encapsulation)
595 			*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
596 		else
597 			*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
598 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
599 			ALIGN(*lso_header_size + 4, DS_SIZE);
600 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
601 			/* We add a segment for the skb linear buffer only if
602 			 * it contains data */
603 			if (*lso_header_size < skb_headlen(skb))
604 				real_size += DS_SIZE;
605 			else {
606 				if (netif_msg_tx_err(priv))
607 					en_warn(priv, "Non-linear headers\n");
608 				return 0;
609 			}
610 		}
611 	} else {
612 		*lso_header_size = 0;
613 		*inline_ok = is_inline(priv->prof->inline_thold, skb,
614 				       shinfo, pfrag);
615 
616 		if (*inline_ok)
617 			real_size = inline_size(skb);
618 		else
619 			real_size = CTRL_SIZE +
620 				    (shinfo->nr_frags + 1) * DS_SIZE;
621 	}
622 
623 	return real_size;
624 }
625 
build_inline_wqe(struct mlx4_en_tx_desc * tx_desc,const struct sk_buff * skb,const struct skb_shared_info * shinfo,int real_size,u16 * vlan_tag,int tx_ind,void * fragptr)626 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc,
627 			     const struct sk_buff *skb,
628 			     const struct skb_shared_info *shinfo,
629 			     int real_size, u16 *vlan_tag,
630 			     int tx_ind, void *fragptr)
631 {
632 	struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
633 	int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
634 	unsigned int hlen = skb_headlen(skb);
635 
636 	if (skb->len <= spc) {
637 		if (likely(skb->len >= MIN_PKT_LEN)) {
638 			inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
639 		} else {
640 			inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
641 			memset(((void *)(inl + 1)) + skb->len, 0,
642 			       MIN_PKT_LEN - skb->len);
643 		}
644 		skb_copy_from_linear_data(skb, inl + 1, hlen);
645 		if (shinfo->nr_frags)
646 			memcpy(((void *)(inl + 1)) + hlen, fragptr,
647 			       skb_frag_size(&shinfo->frags[0]));
648 
649 	} else {
650 		inl->byte_count = cpu_to_be32(1 << 31 | spc);
651 		if (hlen <= spc) {
652 			skb_copy_from_linear_data(skb, inl + 1, hlen);
653 			if (hlen < spc) {
654 				memcpy(((void *)(inl + 1)) + hlen,
655 				       fragptr, spc - hlen);
656 				fragptr +=  spc - hlen;
657 			}
658 			inl = (void *) (inl + 1) + spc;
659 			memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
660 		} else {
661 			skb_copy_from_linear_data(skb, inl + 1, spc);
662 			inl = (void *) (inl + 1) + spc;
663 			skb_copy_from_linear_data_offset(skb, spc, inl + 1,
664 							 hlen - spc);
665 			if (shinfo->nr_frags)
666 				memcpy(((void *)(inl + 1)) + hlen - spc,
667 				       fragptr,
668 				       skb_frag_size(&shinfo->frags[0]));
669 		}
670 
671 		wmb();
672 		inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
673 	}
674 }
675 
mlx4_en_select_queue(struct net_device * dev,struct sk_buff * skb,void * accel_priv,select_queue_fallback_t fallback)676 u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
677 			 void *accel_priv, select_queue_fallback_t fallback)
678 {
679 	struct mlx4_en_priv *priv = netdev_priv(dev);
680 	u16 rings_p_up = priv->num_tx_rings_p_up;
681 	u8 up = 0;
682 
683 	if (dev->num_tc)
684 		return skb_tx_hash(dev, skb);
685 
686 	if (vlan_tx_tag_present(skb))
687 		up = vlan_tx_tag_get(skb) >> VLAN_PRIO_SHIFT;
688 
689 	return fallback(dev, skb) % rings_p_up + up * rings_p_up;
690 }
691 
mlx4_bf_copy(void __iomem * dst,const void * src,unsigned int bytecnt)692 static void mlx4_bf_copy(void __iomem *dst, const void *src,
693 			 unsigned int bytecnt)
694 {
695 	__iowrite64_copy(dst, src, bytecnt / 8);
696 }
697 
mlx4_en_xmit(struct sk_buff * skb,struct net_device * dev)698 netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
699 {
700 	struct skb_shared_info *shinfo = skb_shinfo(skb);
701 	struct mlx4_en_priv *priv = netdev_priv(dev);
702 	struct device *ddev = priv->ddev;
703 	struct mlx4_en_tx_ring *ring;
704 	struct mlx4_en_tx_desc *tx_desc;
705 	struct mlx4_wqe_data_seg *data;
706 	struct mlx4_en_tx_info *tx_info;
707 	int tx_ind = 0;
708 	int nr_txbb;
709 	int desc_size;
710 	int real_size;
711 	u32 index, bf_index;
712 	__be32 op_own;
713 	u16 vlan_tag = 0;
714 	int i_frag;
715 	int lso_header_size;
716 	void *fragptr = NULL;
717 	bool bounce = false;
718 	bool send_doorbell;
719 	bool stop_queue;
720 	bool inline_ok;
721 	u32 ring_cons;
722 
723 	if (!priv->port_up)
724 		goto tx_drop;
725 
726 	tx_ind = skb_get_queue_mapping(skb);
727 	ring = priv->tx_ring[tx_ind];
728 
729 	/* fetch ring->cons far ahead before needing it to avoid stall */
730 	ring_cons = ACCESS_ONCE(ring->cons);
731 
732 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
733 				  &inline_ok, &fragptr);
734 	if (unlikely(!real_size))
735 		goto tx_drop;
736 
737 	/* Align descriptor to TXBB size */
738 	desc_size = ALIGN(real_size, TXBB_SIZE);
739 	nr_txbb = desc_size / TXBB_SIZE;
740 	if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
741 		if (netif_msg_tx_err(priv))
742 			en_warn(priv, "Oversized header or SG list\n");
743 		goto tx_drop;
744 	}
745 
746 	if (vlan_tx_tag_present(skb))
747 		vlan_tag = vlan_tx_tag_get(skb);
748 
749 
750 	netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
751 
752 	/* Track current inflight packets for performance analysis */
753 	AVG_PERF_COUNTER(priv->pstats.inflight_avg,
754 			 (u32)(ring->prod - ring_cons - 1));
755 
756 	/* Packet is good - grab an index and transmit it */
757 	index = ring->prod & ring->size_mask;
758 	bf_index = ring->prod;
759 
760 	/* See if we have enough space for whole descriptor TXBB for setting
761 	 * SW ownership on next descriptor; if not, use a bounce buffer. */
762 	if (likely(index + nr_txbb <= ring->size))
763 		tx_desc = ring->buf + index * TXBB_SIZE;
764 	else {
765 		tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
766 		bounce = true;
767 	}
768 
769 	/* Save skb in tx_info ring */
770 	tx_info = &ring->tx_info[index];
771 	tx_info->skb = skb;
772 	tx_info->nr_txbb = nr_txbb;
773 
774 	data = &tx_desc->data;
775 	if (lso_header_size)
776 		data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4,
777 						      DS_SIZE));
778 
779 	/* valid only for none inline segments */
780 	tx_info->data_offset = (void *)data - (void *)tx_desc;
781 
782 	tx_info->inl = inline_ok;
783 
784 	tx_info->linear = (lso_header_size < skb_headlen(skb) &&
785 			   !inline_ok) ? 1 : 0;
786 
787 	tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
788 	data += tx_info->nr_maps - 1;
789 
790 	if (!tx_info->inl) {
791 		dma_addr_t dma = 0;
792 		u32 byte_count = 0;
793 
794 		/* Map fragments if any */
795 		for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) {
796 			const struct skb_frag_struct *frag;
797 
798 			frag = &shinfo->frags[i_frag];
799 			byte_count = skb_frag_size(frag);
800 			dma = skb_frag_dma_map(ddev, frag,
801 					       0, byte_count,
802 					       DMA_TO_DEVICE);
803 			if (dma_mapping_error(ddev, dma))
804 				goto tx_drop_unmap;
805 
806 			data->addr = cpu_to_be64(dma);
807 			data->lkey = ring->mr_key;
808 			wmb();
809 			data->byte_count = cpu_to_be32(byte_count);
810 			--data;
811 		}
812 
813 		/* Map linear part if needed */
814 		if (tx_info->linear) {
815 			byte_count = skb_headlen(skb) - lso_header_size;
816 
817 			dma = dma_map_single(ddev, skb->data +
818 					     lso_header_size, byte_count,
819 					     PCI_DMA_TODEVICE);
820 			if (dma_mapping_error(ddev, dma))
821 				goto tx_drop_unmap;
822 
823 			data->addr = cpu_to_be64(dma);
824 			data->lkey = ring->mr_key;
825 			wmb();
826 			data->byte_count = cpu_to_be32(byte_count);
827 		}
828 		/* tx completion can avoid cache line miss for common cases */
829 		tx_info->map0_dma = dma;
830 		tx_info->map0_byte_count = byte_count;
831 	}
832 
833 	/*
834 	 * For timestamping add flag to skb_shinfo and
835 	 * set flag for further reference
836 	 */
837 	tx_info->ts_requested = 0;
838 	if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON &&
839 		     shinfo->tx_flags & SKBTX_HW_TSTAMP)) {
840 		shinfo->tx_flags |= SKBTX_IN_PROGRESS;
841 		tx_info->ts_requested = 1;
842 	}
843 
844 	/* Prepare ctrl segement apart opcode+ownership, which depends on
845 	 * whether LSO is used */
846 	tx_desc->ctrl.srcrb_flags = priv->ctrl_flags;
847 	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
848 		if (!skb->encapsulation)
849 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
850 								 MLX4_WQE_CTRL_TCP_UDP_CSUM);
851 		else
852 			tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
853 		ring->tx_csum++;
854 	}
855 
856 	if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
857 		struct ethhdr *ethh;
858 
859 		/* Copy dst mac address to wqe. This allows loopback in eSwitch,
860 		 * so that VFs and PF can communicate with each other
861 		 */
862 		ethh = (struct ethhdr *)skb->data;
863 		tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
864 		tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
865 	}
866 
867 	/* Handle LSO (TSO) packets */
868 	if (lso_header_size) {
869 		int i;
870 
871 		/* Mark opcode as LSO */
872 		op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
873 			((ring->prod & ring->size) ?
874 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
875 
876 		/* Fill in the LSO prefix */
877 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
878 			shinfo->gso_size << 16 | lso_header_size);
879 
880 		/* Copy headers;
881 		 * note that we already verified that it is linear */
882 		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
883 
884 		ring->tso_packets++;
885 
886 		i = ((skb->len - lso_header_size) / shinfo->gso_size) +
887 			!!((skb->len - lso_header_size) % shinfo->gso_size);
888 		tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size;
889 		ring->packets += i;
890 	} else {
891 		/* Normal (Non LSO) packet */
892 		op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
893 			((ring->prod & ring->size) ?
894 			 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
895 		tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN);
896 		ring->packets++;
897 	}
898 	ring->bytes += tx_info->nr_bytes;
899 	netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes);
900 	AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
901 
902 	if (tx_info->inl)
903 		build_inline_wqe(tx_desc, skb, shinfo, real_size, &vlan_tag,
904 				 tx_ind, fragptr);
905 
906 	if (skb->encapsulation) {
907 		struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);
908 		if (ipv4->protocol == IPPROTO_TCP || ipv4->protocol == IPPROTO_UDP)
909 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
910 		else
911 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
912 	}
913 
914 	ring->prod += nr_txbb;
915 
916 	/* If we used a bounce buffer then copy descriptor back into place */
917 	if (unlikely(bounce))
918 		tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
919 
920 	skb_tx_timestamp(skb);
921 
922 	/* Check available TXBBs And 2K spare for prefetch */
923 	stop_queue = mlx4_en_is_tx_ring_full(ring);
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(!mlx4_en_is_tx_ring_full(ring))) {
993 			netif_tx_wake_queue(ring->tx_queue);
994 			ring->wake_queue++;
995 		}
996 	}
997 	return NETDEV_TX_OK;
998 
999 tx_drop_unmap:
1000 	en_err(priv, "DMA mapping error\n");
1001 
1002 	while (++i_frag < shinfo->nr_frags) {
1003 		++data;
1004 		dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr),
1005 			       be32_to_cpu(data->byte_count),
1006 			       PCI_DMA_TODEVICE);
1007 	}
1008 
1009 tx_drop:
1010 	dev_kfree_skb_any(skb);
1011 	priv->stats.tx_dropped++;
1012 	return NETDEV_TX_OK;
1013 }
1014 
1015