summaryrefslogtreecommitdiffstats
path: root/drivers/net/ntb_netdev.c
blob: a9acf7156855546080e850bc07c7a5380ccc1980 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * PCIe NTB Network Linux driver
 *
 * Contact Information:
 * Jon Mason <jon.mason@intel.com>
 */
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ntb.h>
#include <linux/ntb_transport.h>

#define NTB_NETDEV_VER	"0.7"

MODULE_DESCRIPTION(KBUILD_MODNAME);
MODULE_VERSION(NTB_NETDEV_VER);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Intel Corporation");

/* Time in usecs for tx resource reaper */
static unsigned int tx_time = 1;

/* Number of descriptors to free before resuming tx */
static unsigned int tx_start = 10;

/* Number of descriptors still available before stop upper layer tx */
static unsigned int tx_stop = 5;

struct ntb_netdev {
	struct list_head list;
	struct pci_dev *pdev;
	struct net_device *ndev;
	struct ntb_transport_qp *qp;
	struct timer_list tx_timer;
};

#define	NTB_TX_TIMEOUT_MS	1000
#define	NTB_RXQ_SIZE		100

static LIST_HEAD(dev_list);

static void ntb_netdev_event_handler(void *data, int link_is_up)
{
	struct net_device *ndev = data;
	struct ntb_netdev *dev = netdev_priv(ndev);

	netdev_dbg(ndev, "Event %x, Link %x\n", link_is_up,
		   ntb_transport_link_query(dev->qp));

	if (link_is_up) {
		if (ntb_transport_link_query(dev->qp))
			netif_carrier_on(ndev);
	} else {
		netif_carrier_off(ndev);
	}
}

static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
				  void *data, int len)
{
	struct net_device *ndev = qp_data;
	struct sk_buff *skb;
	int rc;

	skb = data;
	if (!skb)
		return;

	netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len);

	if (len < 0) {
		ndev->stats.rx_errors++;
		ndev->stats.rx_length_errors++;
		goto enqueue_again;
	}

	skb_put(skb, len);
	skb->protocol = eth_type_trans(skb, ndev);
	skb->ip_summed = CHECKSUM_NONE;

	if (netif_rx(skb) == NET_RX_DROP) {
		ndev->stats.rx_errors++;
		ndev->stats.rx_dropped++;
	} else {
		ndev->stats.rx_packets++;
		ndev->stats.rx_bytes += len;
	}

	skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
	if (!skb) {
		ndev->stats.rx_errors++;
		ndev->stats.rx_frame_errors++;
		return;
	}

enqueue_again:
	rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
	if (rc) {
		dev_kfree_skb(skb);
		ndev->stats.rx_errors++;
		ndev->stats.rx_fifo_errors++;
	}
}

static int __ntb_netdev_maybe_stop_tx(struct net_device *netdev,
				      struct ntb_transport_qp *qp, int size)
{
	struct ntb_netdev *dev = netdev_priv(netdev);

	netif_stop_queue(netdev);
	/* Make sure to see the latest value of ntb_transport_tx_free_entry()
	 * since the queue was last started.
	 */
	smp_mb();

	if (likely(ntb_transport_tx_free_entry(qp) < size)) {
		mod_timer(&dev->tx_timer, jiffies + usecs_to_jiffies(tx_time));
		return -EBUSY;
	}

	netif_start_queue(netdev);
	return 0;
}

static int ntb_netdev_maybe_stop_tx(struct net_device *ndev,
				    struct ntb_transport_qp *qp, int size)
{
	if (netif_queue_stopped(ndev) ||
	    (ntb_transport_tx_free_entry(qp) >= size))
		return 0;

	return __ntb_netdev_maybe_stop_tx(ndev, qp, size);
}

static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
				  void *data, int len)
{
	struct net_device *ndev = qp_data;
	struct sk_buff *skb;
	struct ntb_netdev *dev = netdev_priv(ndev);

	skb = data;
	if (!skb || !ndev)
		return;

	if (len > 0) {
		ndev->stats.tx_packets++;
		ndev->stats.tx_bytes += skb->len;
	} else {
		ndev->stats.tx_errors++;
		ndev->stats.tx_aborted_errors++;
	}

	dev_kfree_skb(skb);

	if (ntb_transport_tx_free_entry(dev->qp) >= tx_start) {
		/* Make sure anybody stopping the queue after this sees the new
		 * value of ntb_transport_tx_free_entry()
		 */
		smp_mb();
		if (netif_queue_stopped(ndev))
			netif_wake_queue(ndev);
	}
}

static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
					 struct net_device *ndev)
{
	struct ntb_netdev *dev = netdev_priv(ndev);
	int rc;

	ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);

	rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
	if (rc)
		goto err;

	/* check for next submit */
	ntb_netdev_maybe_stop_tx(ndev, dev->qp, tx_stop);

	return NETDEV_TX_OK;

err:
	ndev->stats.tx_dropped++;
	ndev->stats.tx_errors++;
	return NETDEV_TX_BUSY;
}

static void ntb_netdev_tx_timer(unsigned long data)
{
	struct net_device *ndev = (struct net_device *)data;
	struct ntb_netdev *dev = netdev_priv(ndev);

	if (ntb_transport_tx_free_entry(dev->qp) < tx_stop) {
		mod_timer(&dev->tx_timer, jiffies + msecs_to_jiffies(tx_time));
	} else {
		/* Make sure anybody stopping the queue after this sees the new
		 * value of ntb_transport_tx_free_entry()
		 */
		smp_mb();
		if (netif_queue_stopped(ndev))
			netif_wake_queue(ndev);
	}
}

static int ntb_netdev_open(struct net_device *ndev)
{
	struct ntb_netdev *dev = netdev_priv(ndev);
	struct sk_buff *skb;
	int rc, i, len;

	/* Add some empty rx bufs */
	for (i = 0; i < NTB_RXQ_SIZE; i++) {
		skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
		if (!skb) {
			rc = -ENOMEM;
			goto err;
		}

		rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
					      ndev->mtu + ETH_HLEN);
		if (rc) {
			dev_kfree_skb(skb);
			goto err;
		}
	}

	setup_timer(&dev->tx_timer, ntb_netdev_tx_timer, (unsigned long)ndev);

	netif_carrier_off(ndev);
	ntb_transport_link_up(dev->qp);
	netif_start_queue(ndev);

	return 0;

err:
	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
		dev_kfree_skb(skb);
	return rc;
}

static int ntb_netdev_close(struct net_device *ndev)
{
	struct ntb_netdev *dev = netdev_priv(ndev);
	struct sk_buff *skb;
	int len;

	ntb_transport_link_down(dev->qp);

	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
		dev_kfree_skb(skb);

	del_timer_sync(&dev->tx_timer);

	return 0;
}

static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu)
{
	struct ntb_netdev *dev = netdev_priv(ndev);
	struct sk_buff *skb;
	int len, rc;

	if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN)
		return -EINVAL;

	if (!netif_running(ndev)) {
		ndev->mtu = new_mtu;
		return 0;
	}

	/* Bring down the link and dispose of posted rx entries */
	ntb_transport_link_down(dev->qp);

	if (ndev->mtu < new_mtu) {
		int i;

		for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++)
			dev_kfree_skb(skb);

		for (; i; i--) {
			skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN);
			if (!skb) {
				rc = -ENOMEM;
				goto err;
			}

			rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
						      new_mtu + ETH_HLEN);
			if (rc) {
				dev_kfree_skb(skb);
				goto err;
			}
		}
	}

	ndev->mtu = new_mtu;

	ntb_transport_link_up(dev->qp);

	return 0;

err:
	ntb_transport_link_down(dev->qp);

	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
		dev_kfree_skb(skb);

	netdev_err(ndev, "Error changing MTU, device inoperable\n");
	return rc;
}

static const struct net_device_ops ntb_netdev_ops = {
	.ndo_open = ntb_netdev_open,
	.ndo_stop = ntb_netdev_close,
	.ndo_start_xmit = ntb_netdev_start_xmit,
	.ndo_change_mtu = ntb_netdev_change_mtu,
	.ndo_set_mac_address = eth_mac_addr,
};

static void ntb_get_drvinfo(struct net_device *ndev,
			    struct ethtool_drvinfo *info)
{
	struct ntb_netdev *dev = netdev_priv(ndev);

	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
	strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
	strlcpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info));
}

static int ntb_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	cmd->supported = SUPPORTED_Backplane;
	cmd->advertising = ADVERTISED_Backplane;
	ethtool_cmd_speed_set(cmd, SPEED_UNKNOWN);
	cmd->duplex = DUPLEX_FULL;
	cmd->port = PORT_OTHER;
	cmd->phy_address = 0;
	cmd->transceiver = XCVR_DUMMY1;
	cmd->autoneg = AUTONEG_ENABLE;
	cmd->maxtxpkt = 0;
	cmd->maxrxpkt = 0;

	return 0;
}

static const struct ethtool_ops ntb_ethtool_ops = {
	.get_drvinfo = ntb_get_drvinfo,
	.get_link = ethtool_op_get_link,
	.get_settings = ntb_get_settings,
};

static const struct ntb_queue_handlers ntb_netdev_handlers = {
	.tx_handler = ntb_netdev_tx_handler,
	.rx_handler = ntb_netdev_rx_handler,
	.event_handler = ntb_netdev_event_handler,
};

static int ntb_netdev_probe(struct device *client_dev)
{
	struct ntb_dev *ntb;
	struct net_device *ndev;
	struct pci_dev *pdev;
	struct ntb_netdev *dev;
	int rc;

	ntb = dev_ntb(client_dev->parent);
	pdev = ntb->pdev;
	if (!pdev)
		return -ENODEV;

	ndev = alloc_etherdev(sizeof(*dev));
	if (!ndev)
		return -ENOMEM;

	dev = netdev_priv(ndev);
	dev->ndev = ndev;
	dev->pdev = pdev;
	ndev->features = NETIF_F_HIGHDMA;

	ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;

	ndev->hw_features = ndev->features;
	ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS);

	random_ether_addr(ndev->perm_addr);
	memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len);

	ndev->netdev_ops = &ntb_netdev_ops;
	ndev->ethtool_ops = &ntb_ethtool_ops;

	dev->qp = ntb_transport_create_queue(ndev, client_dev,
					     &ntb_netdev_handlers);
	if (!dev->qp) {
		rc = -EIO;
		goto err;
	}

	ndev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN;

	rc = register_netdev(ndev);
	if (rc)
		goto err1;

	list_add(&dev->list, &dev_list);
	dev_info(&pdev->dev, "%s created\n", ndev->name);
	return 0;

err1:
	ntb_transport_free_queue(dev->qp);
err:
	free_netdev(ndev);
	return rc;
}

static void ntb_netdev_remove(struct device *client_dev)
{
	struct ntb_dev *ntb;
	struct net_device *ndev;
	struct pci_dev *pdev;
	struct ntb_netdev *dev;
	bool found = false;

	ntb = dev_ntb(client_dev->parent);
	pdev = ntb->pdev;

	list_for_each_entry(dev, &dev_list, list) {
		if (dev->pdev == pdev) {
			found = true;
			break;
		}
	}
	if (!found)
		return;

	list_del(&dev->list);

	ndev = dev->ndev;

	unregister_netdev(ndev);
	ntb_transport_free_queue(dev->qp);
	free_netdev(ndev);
}

static struct ntb_transport_client ntb_netdev_client = {
	.driver.name = KBUILD_MODNAME,
	.driver.owner = THIS_MODULE,
	.probe = ntb_netdev_probe,
	.remove = ntb_netdev_remove,
};

static int __init ntb_netdev_init_module(void)
{
	int rc;

	rc = ntb_transport_register_client_dev(KBUILD_MODNAME);
	if (rc)
		return rc;
	return ntb_transport_register_client(&ntb_netdev_client);
}
module_init(ntb_netdev_init_module);

static void __exit ntb_netdev_exit_module(void)
{
	ntb_transport_unregister_client(&ntb_netdev_client);
	ntb_transport_unregister_client_dev(KBUILD_MODNAME);
}
module_exit(ntb_netdev_exit_module);
OpenPOWER on IntegriCloud