xref: /linux/drivers/net/ntb_netdev.c (revision 1fc5a74b108fc90951890ec513ac81869f5eaff1)
1 // SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause
2 /*
3  * PCIe NTB Network Linux driver
4  */
5 #include <linux/etherdevice.h>
6 #include <linux/ethtool.h>
7 #include <linux/module.h>
8 #include <linux/pci.h>
9 #include <linux/ntb.h>
10 #include <linux/ntb_transport.h>
11 #include <linux/slab.h>
12 
13 #define NTB_NETDEV_VER	"0.7"
14 
15 MODULE_DESCRIPTION(KBUILD_MODNAME);
16 MODULE_VERSION(NTB_NETDEV_VER);
17 MODULE_LICENSE("Dual BSD/GPL");
18 MODULE_AUTHOR("Intel Corporation");
19 
20 /* Time in usecs for tx resource reaper */
21 static unsigned int tx_time = 1;
22 
23 /* Number of descriptors to free before resuming tx */
24 static unsigned int tx_start = 10;
25 
26 /* Number of descriptors still available before stop upper layer tx */
27 static unsigned int tx_stop = 5;
28 
29 #define NTB_NETDEV_MAX_QUEUES		64
30 #define NTB_NETDEV_DEFAULT_QUEUES	1
31 
32 struct ntb_netdev;
33 
34 struct ntb_netdev_queue {
35 	struct ntb_netdev *ntdev;
36 	struct ntb_transport_qp *qp;
37 	struct timer_list tx_timer;
38 	u16 qid;
39 };
40 
41 struct ntb_netdev {
42 	struct pci_dev *pdev;
43 	struct device *client_dev;
44 	struct net_device *ndev;
45 	unsigned int num_queues;
46 	struct ntb_netdev_queue *queues;
47 };
48 
49 #define	NTB_TX_TIMEOUT_MS	1000
50 #define	NTB_RXQ_SIZE		100
51 
ntb_netdev_update_carrier(struct ntb_netdev * dev)52 static void ntb_netdev_update_carrier(struct ntb_netdev *dev)
53 {
54 	struct net_device *ndev;
55 	bool any_up = false;
56 	unsigned int i;
57 
58 	ndev = dev->ndev;
59 
60 	for (i = 0; i < dev->num_queues; i++) {
61 		if (ntb_transport_link_query(dev->queues[i].qp)) {
62 			any_up = true;
63 			break;
64 		}
65 	}
66 
67 	if (any_up)
68 		netif_carrier_on(ndev);
69 	else
70 		netif_carrier_off(ndev);
71 }
72 
ntb_netdev_queue_rx_drain(struct ntb_netdev_queue * queue)73 static void ntb_netdev_queue_rx_drain(struct ntb_netdev_queue *queue)
74 {
75 	struct sk_buff *skb;
76 	int len;
77 
78 	while ((skb = ntb_transport_rx_remove(queue->qp, &len)))
79 		dev_kfree_skb(skb);
80 }
81 
ntb_netdev_queue_rx_fill(struct net_device * ndev,struct ntb_netdev_queue * queue)82 static int ntb_netdev_queue_rx_fill(struct net_device *ndev,
83 				    struct ntb_netdev_queue *queue)
84 {
85 	struct sk_buff *skb;
86 	int rc, i;
87 
88 	for (i = 0; i < NTB_RXQ_SIZE; i++) {
89 		skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
90 		if (!skb)
91 			return -ENOMEM;
92 
93 		rc = ntb_transport_rx_enqueue(queue->qp, skb, skb->data,
94 					      ndev->mtu + ETH_HLEN);
95 		if (rc) {
96 			dev_kfree_skb(skb);
97 			return rc;
98 		}
99 	}
100 
101 	return 0;
102 }
103 
ntb_netdev_event_handler(void * data,int link_is_up)104 static void ntb_netdev_event_handler(void *data, int link_is_up)
105 {
106 	struct ntb_netdev_queue *q = data;
107 	struct ntb_netdev *dev = q->ntdev;
108 	struct net_device *ndev;
109 
110 	ndev = dev->ndev;
111 
112 	netdev_dbg(ndev, "Event %x, Link %x, qp %u\n", link_is_up,
113 		   ntb_transport_link_query(q->qp), q->qid);
114 
115 	if (netif_running(ndev)) {
116 		if (link_is_up)
117 			netif_wake_subqueue(ndev, q->qid);
118 		else
119 			netif_stop_subqueue(ndev, q->qid);
120 	}
121 
122 	ntb_netdev_update_carrier(dev);
123 }
124 
ntb_netdev_rx_handler(struct ntb_transport_qp * qp,void * qp_data,void * data,int len)125 static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
126 				  void *data, int len)
127 {
128 	struct ntb_netdev_queue *q = qp_data;
129 	struct ntb_netdev *dev = q->ntdev;
130 	struct pcpu_sw_netstats *tstats;
131 	struct sk_buff *skb, *new_skb;
132 	struct net_device *ndev;
133 	unsigned long flags;
134 	int rc;
135 
136 	ndev = dev->ndev;
137 	skb = data;
138 	if (!skb)
139 		return;
140 
141 	netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len);
142 
143 	if (len < 0) {
144 		DEV_STATS_INC(ndev, rx_errors);
145 		DEV_STATS_INC(ndev, rx_length_errors);
146 		goto enqueue_again;
147 	}
148 
149 	tstats = this_cpu_ptr(ndev->tstats);
150 	flags = u64_stats_update_begin_irqsave(&tstats->syncp);
151 	u64_stats_inc(&tstats->rx_packets);
152 	u64_stats_add(&tstats->rx_bytes, len);
153 	u64_stats_update_end_irqrestore(&tstats->syncp, flags);
154 
155 	new_skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
156 	if (!new_skb) {
157 		DEV_STATS_INC(ndev, rx_dropped);
158 		goto enqueue_again;
159 	}
160 
161 	skb_put(skb, len);
162 	skb->protocol = eth_type_trans(skb, ndev);
163 	skb->ip_summed = CHECKSUM_NONE;
164 	skb_record_rx_queue(skb, q->qid);
165 
166 	netif_rx(skb);
167 
168 	skb = new_skb;
169 
170 enqueue_again:
171 	rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
172 	if (rc) {
173 		dev_kfree_skb_any(skb);
174 		DEV_STATS_INC(ndev, rx_errors);
175 		DEV_STATS_INC(ndev, rx_fifo_errors);
176 	}
177 }
178 
__ntb_netdev_maybe_stop_tx(struct net_device * netdev,struct ntb_netdev_queue * q,int size)179 static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev,
180 				      struct ntb_netdev_queue *q, int size)
181 {
182 	netif_stop_subqueue(netdev, q->qid);
183 
184 	/* Make sure to see the latest value of ntb_transport_tx_free_entry()
185 	 * since the queue was last started.
186 	 */
187 	smp_mb();
188 
189 	if (likely(ntb_transport_tx_free_entry(q->qp) < size)) {
190 		mod_timer(&q->tx_timer, jiffies + usecs_to_jiffies(tx_time));
191 		return -EBUSY;
192 	}
193 
194 	/* The subqueue must be kept stopped if the link is down */
195 	if (ntb_transport_link_query(q->qp))
196 		netif_start_subqueue(netdev, q->qid);
197 
198 	return 0;
199 }
200 
ntb_netdev_maybe_stop_tx(struct net_device * ndev,struct ntb_netdev_queue * q,int size)201 static int ntb_netdev_maybe_stop_tx(struct net_device *ndev,
202 				    struct ntb_netdev_queue *q, int size)
203 {
204 	if (__netif_subqueue_stopped(ndev, q->qid))
205 		return -EBUSY;
206 
207 	if (ntb_transport_tx_free_entry(q->qp) >= size)
208 		return 0;
209 
210 	return __ntb_netdev_maybe_stop_tx(ndev, q, size);
211 }
212 
ntb_netdev_tx_handler(struct ntb_transport_qp * qp,void * qp_data,void * data,int len)213 static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
214 				  void *data, int len)
215 {
216 	struct ntb_netdev_queue *q = qp_data;
217 	struct ntb_netdev *dev = q->ntdev;
218 	struct pcpu_sw_netstats *tstats;
219 	struct net_device *ndev;
220 	struct sk_buff *skb;
221 	unsigned long flags;
222 	bool registered;
223 
224 	ndev = dev->ndev;
225 	skb = data;
226 	if (!skb || !ndev)
227 		return;
228 
229 	rcu_read_lock();
230 	registered = READ_ONCE(ndev->reg_state) == NETREG_REGISTERED;
231 	if (!registered)
232 		goto free_skb;
233 
234 	if (len > 0) {
235 		/* The memcpy kthread can migrate, so pin the per-CPU update. */
236 		tstats = get_cpu_ptr(ndev->tstats);
237 		flags = u64_stats_update_begin_irqsave(&tstats->syncp);
238 		u64_stats_inc(&tstats->tx_packets);
239 		u64_stats_add(&tstats->tx_bytes, skb->len);
240 		u64_stats_update_end_irqrestore(&tstats->syncp, flags);
241 		put_cpu_ptr(ndev->tstats);
242 	} else {
243 		DEV_STATS_INC(ndev, tx_errors);
244 		DEV_STATS_INC(ndev, tx_aborted_errors);
245 	}
246 
247 free_skb:
248 	dev_kfree_skb_any(skb);
249 
250 	if (registered && ntb_transport_tx_free_entry(qp) >= tx_start) {
251 		/* Make sure anybody stopping the queue after this sees the new
252 		 * value of ntb_transport_tx_free_entry()
253 		 */
254 		smp_mb();
255 		if (__netif_subqueue_stopped(ndev, q->qid) &&
256 		    ntb_transport_link_query(q->qp))
257 			netif_wake_subqueue(ndev, q->qid);
258 	}
259 	rcu_read_unlock();
260 }
261 
262 static const struct ntb_queue_handlers ntb_netdev_handlers = {
263 	.tx_handler = ntb_netdev_tx_handler,
264 	.rx_handler = ntb_netdev_rx_handler,
265 	.event_handler = ntb_netdev_event_handler,
266 };
267 
ntb_netdev_start_xmit(struct sk_buff * skb,struct net_device * ndev)268 static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
269 					 struct net_device *ndev)
270 {
271 	struct ntb_netdev *dev = netdev_priv(ndev);
272 	u16 qid = skb_get_queue_mapping(skb);
273 	struct ntb_netdev_queue *q;
274 	int rc;
275 
276 	q = &dev->queues[qid];
277 
278 	if (unlikely(ntb_netdev_maybe_stop_tx(ndev, q, tx_stop)))
279 		return NETDEV_TX_BUSY;
280 
281 	rc = ntb_transport_tx_enqueue(q->qp, skb, skb->data, skb->len);
282 	if (rc) {
283 		if (rc == -EAGAIN || rc == -EBUSY) {
284 			netif_stop_subqueue(ndev, q->qid);
285 			mod_timer(&q->tx_timer,
286 				  jiffies + usecs_to_jiffies(tx_time));
287 			return NETDEV_TX_BUSY;
288 		}
289 
290 		goto drop;
291 	}
292 
293 	/* check for next submit */
294 	ntb_netdev_maybe_stop_tx(ndev, q, tx_stop);
295 
296 	return NETDEV_TX_OK;
297 
298 drop:
299 	dev_kfree_skb_any(skb);
300 	DEV_STATS_INC(ndev, tx_dropped);
301 	return NETDEV_TX_OK;
302 }
303 
ntb_netdev_tx_timer(struct timer_list * t)304 static void ntb_netdev_tx_timer(struct timer_list *t)
305 {
306 	struct ntb_netdev_queue *q = timer_container_of(q, t, tx_timer);
307 	struct ntb_netdev *dev = q->ntdev;
308 	struct net_device *ndev;
309 
310 	ndev = dev->ndev;
311 
312 	if (ntb_transport_tx_free_entry(q->qp) < tx_stop) {
313 		mod_timer(&q->tx_timer, jiffies + usecs_to_jiffies(tx_time));
314 	} else {
315 		/* Make sure anybody stopping the queue after this sees the new
316 		 * value of ntb_transport_tx_free_entry()
317 		 */
318 		smp_mb();
319 
320 		/* The subqueue must be kept stopped if the link is down */
321 		if (__netif_subqueue_stopped(ndev, q->qid) &&
322 		    ntb_transport_link_query(q->qp))
323 			netif_wake_subqueue(ndev, q->qid);
324 	}
325 }
326 
ntb_netdev_open(struct net_device * ndev)327 static int ntb_netdev_open(struct net_device *ndev)
328 {
329 	struct ntb_netdev *dev = netdev_priv(ndev);
330 	struct ntb_netdev_queue *queue;
331 	unsigned int q;
332 	int rc = 0;
333 
334 	/* Add some empty rx bufs for each queue */
335 	for (q = 0; q < dev->num_queues; q++) {
336 		queue = &dev->queues[q];
337 
338 		rc = ntb_netdev_queue_rx_fill(ndev, queue);
339 		if (rc)
340 			goto err;
341 
342 		timer_setup(&queue->tx_timer, ntb_netdev_tx_timer, 0);
343 	}
344 
345 	netif_carrier_off(ndev);
346 	netif_tx_stop_all_queues(ndev);
347 
348 	for (q = 0; q < dev->num_queues; q++)
349 		ntb_transport_link_up(dev->queues[q].qp);
350 
351 	return 0;
352 
353 err:
354 	for (q = 0; q < dev->num_queues; q++) {
355 		queue = &dev->queues[q];
356 		ntb_netdev_queue_rx_drain(queue);
357 	}
358 	return rc;
359 }
360 
ntb_netdev_close(struct net_device * ndev)361 static int ntb_netdev_close(struct net_device *ndev)
362 {
363 	struct ntb_netdev *dev = netdev_priv(ndev);
364 	struct ntb_netdev_queue *queue;
365 	unsigned int q;
366 
367 	netif_tx_stop_all_queues(ndev);
368 	netif_carrier_off(ndev);
369 
370 	for (q = 0; q < dev->num_queues; q++) {
371 		queue = &dev->queues[q];
372 
373 		ntb_transport_link_down(queue->qp);
374 		ntb_netdev_queue_rx_drain(queue);
375 		timer_delete_sync(&queue->tx_timer);
376 	}
377 
378 	return 0;
379 }
380 
ntb_netdev_change_mtu(struct net_device * ndev,int new_mtu)381 static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu)
382 {
383 	struct ntb_netdev *dev = netdev_priv(ndev);
384 	struct ntb_netdev_queue *queue;
385 	struct sk_buff *skb;
386 	unsigned int q, i;
387 	int len, rc = 0;
388 
389 	if (new_mtu > ntb_transport_max_size(dev->queues[0].qp) - ETH_HLEN)
390 		return -EINVAL;
391 
392 	if (!netif_running(ndev)) {
393 		WRITE_ONCE(ndev->mtu, new_mtu);
394 		return 0;
395 	}
396 
397 	/* Bring down the link and dispose of posted rx entries */
398 	for (q = 0; q < dev->num_queues; q++)
399 		ntb_transport_link_down(dev->queues[q].qp);
400 
401 	if (ndev->mtu < new_mtu) {
402 		for (q = 0; q < dev->num_queues; q++) {
403 			queue = &dev->queues[q];
404 
405 			for (i = 0;
406 			     (skb = ntb_transport_rx_remove(queue->qp, &len));
407 			     i++)
408 				dev_kfree_skb(skb);
409 
410 			for (; i; i--) {
411 				skb = netdev_alloc_skb(ndev,
412 						       new_mtu + ETH_HLEN);
413 				if (!skb) {
414 					rc = -ENOMEM;
415 					goto err;
416 				}
417 
418 				rc = ntb_transport_rx_enqueue(queue->qp, skb,
419 							      skb->data,
420 							      new_mtu +
421 							      ETH_HLEN);
422 				if (rc) {
423 					dev_kfree_skb(skb);
424 					goto err;
425 				}
426 			}
427 		}
428 	}
429 
430 	WRITE_ONCE(ndev->mtu, new_mtu);
431 
432 	for (q = 0; q < dev->num_queues; q++)
433 		ntb_transport_link_up(dev->queues[q].qp);
434 
435 	return 0;
436 
437 err:
438 	for (q = 0; q < dev->num_queues; q++) {
439 		struct ntb_netdev_queue *queue = &dev->queues[q];
440 
441 		ntb_transport_link_down(queue->qp);
442 
443 		ntb_netdev_queue_rx_drain(queue);
444 	}
445 
446 	netdev_err(ndev, "Error changing MTU, device inoperable\n");
447 	return rc;
448 }
449 
450 static const struct net_device_ops ntb_netdev_ops = {
451 	.ndo_open = ntb_netdev_open,
452 	.ndo_stop = ntb_netdev_close,
453 	.ndo_start_xmit = ntb_netdev_start_xmit,
454 	.ndo_change_mtu = ntb_netdev_change_mtu,
455 	.ndo_set_mac_address = eth_mac_addr,
456 };
457 
ntb_get_drvinfo(struct net_device * ndev,struct ethtool_drvinfo * info)458 static void ntb_get_drvinfo(struct net_device *ndev,
459 			    struct ethtool_drvinfo *info)
460 {
461 	struct ntb_netdev *dev = netdev_priv(ndev);
462 
463 	strscpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
464 	strscpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
465 	strscpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info));
466 }
467 
ntb_get_link_ksettings(struct net_device * dev,struct ethtool_link_ksettings * cmd)468 static int ntb_get_link_ksettings(struct net_device *dev,
469 				  struct ethtool_link_ksettings *cmd)
470 {
471 	ethtool_link_ksettings_zero_link_mode(cmd, supported);
472 	ethtool_link_ksettings_add_link_mode(cmd, supported, Backplane);
473 	ethtool_link_ksettings_zero_link_mode(cmd, advertising);
474 	ethtool_link_ksettings_add_link_mode(cmd, advertising, Backplane);
475 
476 	cmd->base.speed = SPEED_UNKNOWN;
477 	cmd->base.duplex = DUPLEX_FULL;
478 	cmd->base.port = PORT_OTHER;
479 	cmd->base.phy_address = 0;
480 	cmd->base.autoneg = AUTONEG_ENABLE;
481 
482 	return 0;
483 }
484 
ntb_get_channels(struct net_device * ndev,struct ethtool_channels * channels)485 static void ntb_get_channels(struct net_device *ndev,
486 			     struct ethtool_channels *channels)
487 {
488 	struct ntb_netdev *dev = netdev_priv(ndev);
489 
490 	channels->combined_count = dev->num_queues;
491 	channels->max_combined = ndev->num_tx_queues;
492 }
493 
ntb_inc_channels(struct net_device * ndev,unsigned int old,unsigned int new)494 static int ntb_inc_channels(struct net_device *ndev,
495 			    unsigned int old, unsigned int new)
496 {
497 	struct ntb_netdev *dev = netdev_priv(ndev);
498 	bool running = netif_running(ndev);
499 	struct ntb_netdev_queue *queue;
500 	unsigned int q, created;
501 	int rc;
502 
503 	created = old;
504 	for (q = old; q < new; q++) {
505 		queue = &dev->queues[q];
506 
507 		queue->ntdev = dev;
508 		queue->qid = q;
509 		queue->qp = ntb_transport_create_queue(queue, dev->client_dev,
510 						       &ntb_netdev_handlers);
511 		if (!queue->qp) {
512 			rc = -ENOSPC;
513 			goto err_new;
514 		}
515 		created++;
516 
517 		if (!running)
518 			continue;
519 
520 		timer_setup(&queue->tx_timer, ntb_netdev_tx_timer, 0);
521 
522 		rc = ntb_netdev_queue_rx_fill(ndev, queue);
523 		if (rc)
524 			goto err_new;
525 
526 		/*
527 		 * Carrier may already be on due to other QPs. Keep the new
528 		 * subqueue stopped until we get a Link Up event for this QP.
529 		 */
530 		netif_stop_subqueue(ndev, q);
531 	}
532 
533 	rc = netif_set_real_num_queues(ndev, new, new);
534 	if (rc)
535 		goto err_new;
536 
537 	dev->num_queues = new;
538 
539 	if (running)
540 		for (q = old; q < new; q++)
541 			ntb_transport_link_up(dev->queues[q].qp);
542 
543 	return 0;
544 
545 err_new:
546 	if (running) {
547 		unsigned int rollback = created;
548 
549 		while (rollback-- > old) {
550 			queue = &dev->queues[rollback];
551 			ntb_transport_link_down(queue->qp);
552 			ntb_netdev_queue_rx_drain(queue);
553 			timer_delete_sync(&queue->tx_timer);
554 		}
555 	}
556 	while (created-- > old) {
557 		queue = &dev->queues[created];
558 		ntb_transport_free_queue(queue->qp);
559 		queue->qp = NULL;
560 	}
561 	return rc;
562 }
563 
ntb_dec_channels(struct net_device * ndev,unsigned int old,unsigned int new)564 static int ntb_dec_channels(struct net_device *ndev,
565 			    unsigned int old, unsigned int new)
566 {
567 	struct ntb_netdev *dev = netdev_priv(ndev);
568 	bool running = netif_running(ndev);
569 	struct ntb_netdev_queue *queue;
570 	unsigned int q;
571 	int rc;
572 
573 	if (running)
574 		for (q = new; q < old; q++)
575 			netif_stop_subqueue(ndev, q);
576 
577 	rc = netif_set_real_num_queues(ndev, new, new);
578 	if (rc)
579 		goto err;
580 
581 	/* Publish new queue count before invalidating QP pointers */
582 	dev->num_queues = new;
583 
584 	for (q = new; q < old; q++) {
585 		queue = &dev->queues[q];
586 
587 		if (running) {
588 			ntb_transport_link_down(queue->qp);
589 			ntb_netdev_queue_rx_drain(queue);
590 			timer_delete_sync(&queue->tx_timer);
591 		}
592 
593 		ntb_transport_free_queue(queue->qp);
594 		queue->qp = NULL;
595 	}
596 
597 	/*
598 	 * It might be the case that the removed queues are the only queues that
599 	 * were up, so see if the global carrier needs to change.
600 	 */
601 	ntb_netdev_update_carrier(dev);
602 	return 0;
603 
604 err:
605 	if (running) {
606 		for (q = new; q < old; q++)
607 			netif_wake_subqueue(ndev, q);
608 	}
609 	return rc;
610 }
611 
ntb_set_channels(struct net_device * ndev,struct ethtool_channels * channels)612 static int ntb_set_channels(struct net_device *ndev,
613 			    struct ethtool_channels *channels)
614 {
615 	struct ntb_netdev *dev = netdev_priv(ndev);
616 	unsigned int new = channels->combined_count;
617 	unsigned int old = dev->num_queues;
618 
619 	if (new == old)
620 		return 0;
621 
622 	if (new < old)
623 		return ntb_dec_channels(ndev, old, new);
624 	else
625 		return ntb_inc_channels(ndev, old, new);
626 }
627 
628 static const struct ethtool_ops ntb_ethtool_ops = {
629 	.get_drvinfo = ntb_get_drvinfo,
630 	.get_link = ethtool_op_get_link,
631 	.get_link_ksettings = ntb_get_link_ksettings,
632 	.get_channels = ntb_get_channels,
633 	.set_channels = ntb_set_channels,
634 };
635 
ntb_netdev_probe(struct device * client_dev)636 static int ntb_netdev_probe(struct device *client_dev)
637 {
638 	struct ntb_dev *ntb;
639 	struct net_device *ndev;
640 	struct pci_dev *pdev;
641 	struct ntb_netdev *dev;
642 	unsigned int q;
643 	int rc;
644 
645 	ntb = dev_ntb(client_dev->parent);
646 	pdev = ntb->pdev;
647 	if (!pdev)
648 		return -ENODEV;
649 
650 	ndev = alloc_etherdev_mq(sizeof(*dev), NTB_NETDEV_MAX_QUEUES);
651 	if (!ndev)
652 		return -ENOMEM;
653 
654 	SET_NETDEV_DEV(ndev, client_dev);
655 
656 	dev = netdev_priv(ndev);
657 	dev->ndev = ndev;
658 	dev->pdev = pdev;
659 	dev->client_dev = client_dev;
660 	dev->num_queues = 0;
661 
662 	dev->queues = kzalloc_objs(*dev->queues, NTB_NETDEV_MAX_QUEUES);
663 	if (!dev->queues) {
664 		rc = -ENOMEM;
665 		goto err_free_netdev;
666 	}
667 
668 	ndev->features = NETIF_F_HIGHDMA;
669 	ndev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
670 
671 	ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
672 
673 	ndev->hw_features = ndev->features;
674 	ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS);
675 
676 	eth_random_addr(ndev->perm_addr);
677 	dev_addr_set(ndev, ndev->perm_addr);
678 
679 	ndev->netdev_ops = &ntb_netdev_ops;
680 	ndev->ethtool_ops = &ntb_ethtool_ops;
681 
682 	ndev->min_mtu = 0;
683 	ndev->max_mtu = ETH_MAX_MTU;
684 
685 	for (q = 0; q < NTB_NETDEV_DEFAULT_QUEUES; q++) {
686 		struct ntb_netdev_queue *queue = &dev->queues[q];
687 
688 		queue->ntdev = dev;
689 		queue->qid = q;
690 		queue->qp = ntb_transport_create_queue(queue, client_dev,
691 						       &ntb_netdev_handlers);
692 		if (!queue->qp)
693 			break;
694 
695 		dev->num_queues++;
696 	}
697 
698 	if (!dev->num_queues) {
699 		rc = -EIO;
700 		goto err_free_queues;
701 	}
702 
703 	rc = netif_set_real_num_queues(ndev, dev->num_queues, dev->num_queues);
704 	if (rc)
705 		goto err_free_qps;
706 
707 	ndev->mtu = ntb_transport_max_size(dev->queues[0].qp) - ETH_HLEN;
708 
709 	rc = register_netdev(ndev);
710 	if (rc)
711 		goto err_free_qps;
712 
713 	dev_set_drvdata(client_dev, ndev);
714 	dev_info(&pdev->dev, "%s created with %u queue pairs\n",
715 		 ndev->name, dev->num_queues);
716 	return 0;
717 
718 err_free_qps:
719 	for (q = 0; q < dev->num_queues; q++)
720 		ntb_transport_free_queue(dev->queues[q].qp);
721 
722 err_free_queues:
723 	kfree(dev->queues);
724 
725 err_free_netdev:
726 	free_netdev(ndev);
727 	return rc;
728 }
729 
ntb_netdev_remove(struct device * client_dev)730 static void ntb_netdev_remove(struct device *client_dev)
731 {
732 	struct net_device *ndev = dev_get_drvdata(client_dev);
733 	struct ntb_netdev *dev = netdev_priv(ndev);
734 	unsigned int q;
735 
736 	unregister_netdev(ndev);
737 	for (q = 0; q < dev->num_queues; q++)
738 		ntb_transport_free_queue(dev->queues[q].qp);
739 
740 	kfree(dev->queues);
741 	free_netdev(ndev);
742 }
743 
744 static struct ntb_transport_client ntb_netdev_client = {
745 	.driver.name = KBUILD_MODNAME,
746 	.driver.owner = THIS_MODULE,
747 	.probe = ntb_netdev_probe,
748 	.remove = ntb_netdev_remove,
749 };
750 
ntb_netdev_init_module(void)751 static int __init ntb_netdev_init_module(void)
752 {
753 	int rc;
754 
755 	rc = ntb_transport_register_client_dev(KBUILD_MODNAME);
756 	if (rc)
757 		return rc;
758 
759 	rc = ntb_transport_register_client(&ntb_netdev_client);
760 	if (rc) {
761 		ntb_transport_unregister_client_dev(KBUILD_MODNAME);
762 		return rc;
763 	}
764 
765 	return 0;
766 }
767 late_initcall(ntb_netdev_init_module);
768 
ntb_netdev_exit_module(void)769 static void __exit ntb_netdev_exit_module(void)
770 {
771 	ntb_transport_unregister_client(&ntb_netdev_client);
772 	ntb_transport_unregister_client_dev(KBUILD_MODNAME);
773 }
774 module_exit(ntb_netdev_exit_module);
775