xref: /openbmc/linux/drivers/net/ntb_netdev.c (revision 275876e2)
1 /*
2  * This file is provided under a dual BSD/GPLv2 license.  When using or
3  *   redistributing this file, you may do so under either license.
4  *
5  *   GPL LICENSE SUMMARY
6  *
7  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
8  *
9  *   This program is free software; you can redistribute it and/or modify
10  *   it under the terms of version 2 of the GNU General Public License as
11  *   published by the Free Software Foundation.
12  *
13  *   BSD LICENSE
14  *
15  *   Copyright(c) 2012 Intel Corporation. All rights reserved.
16  *
17  *   Redistribution and use in source and binary forms, with or without
18  *   modification, are permitted provided that the following conditions
19  *   are met:
20  *
21  *     * Redistributions of source code must retain the above copyright
22  *       notice, this list of conditions and the following disclaimer.
23  *     * Redistributions in binary form must reproduce the above copy
24  *       notice, this list of conditions and the following disclaimer in
25  *       the documentation and/or other materials provided with the
26  *       distribution.
27  *     * Neither the name of Intel Corporation nor the names of its
28  *       contributors may be used to endorse or promote products derived
29  *       from this software without specific prior written permission.
30  *
31  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
34  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
37  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
41  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42  *
43  * Intel PCIe NTB Network Linux driver
44  *
45  * Contact Information:
46  * Jon Mason <jon.mason@intel.com>
47  */
48 #include <linux/etherdevice.h>
49 #include <linux/ethtool.h>
50 #include <linux/module.h>
51 #include <linux/pci.h>
52 #include <linux/ntb.h>
53 
54 #define NTB_NETDEV_VER	"0.7"
55 
56 MODULE_DESCRIPTION(KBUILD_MODNAME);
57 MODULE_VERSION(NTB_NETDEV_VER);
58 MODULE_LICENSE("Dual BSD/GPL");
59 MODULE_AUTHOR("Intel Corporation");
60 
61 struct ntb_netdev {
62 	struct list_head list;
63 	struct pci_dev *pdev;
64 	struct net_device *ndev;
65 	struct ntb_transport_qp *qp;
66 };
67 
68 #define	NTB_TX_TIMEOUT_MS	1000
69 #define	NTB_RXQ_SIZE		100
70 
71 static LIST_HEAD(dev_list);
72 
73 static void ntb_netdev_event_handler(void *data, int status)
74 {
75 	struct net_device *ndev = data;
76 	struct ntb_netdev *dev = netdev_priv(ndev);
77 
78 	netdev_dbg(ndev, "Event %x, Link %x\n", status,
79 		   ntb_transport_link_query(dev->qp));
80 
81 	switch (status) {
82 	case NTB_LINK_DOWN:
83 		netif_carrier_off(ndev);
84 		break;
85 	case NTB_LINK_UP:
86 		if (!ntb_transport_link_query(dev->qp))
87 			return;
88 
89 		netif_carrier_on(ndev);
90 		break;
91 	default:
92 		netdev_warn(ndev, "Unsupported event type %d\n", status);
93 	}
94 }
95 
96 static void ntb_netdev_rx_handler(struct ntb_transport_qp *qp, void *qp_data,
97 				  void *data, int len)
98 {
99 	struct net_device *ndev = qp_data;
100 	struct sk_buff *skb;
101 	int rc;
102 
103 	skb = data;
104 	if (!skb)
105 		return;
106 
107 	netdev_dbg(ndev, "%s: %d byte payload received\n", __func__, len);
108 
109 	skb_put(skb, len);
110 	skb->protocol = eth_type_trans(skb, ndev);
111 	skb->ip_summed = CHECKSUM_NONE;
112 
113 	if (netif_rx(skb) == NET_RX_DROP) {
114 		ndev->stats.rx_errors++;
115 		ndev->stats.rx_dropped++;
116 	} else {
117 		ndev->stats.rx_packets++;
118 		ndev->stats.rx_bytes += len;
119 	}
120 
121 	skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
122 	if (!skb) {
123 		ndev->stats.rx_errors++;
124 		ndev->stats.rx_frame_errors++;
125 		return;
126 	}
127 
128 	rc = ntb_transport_rx_enqueue(qp, skb, skb->data, ndev->mtu + ETH_HLEN);
129 	if (rc) {
130 		dev_kfree_skb(skb);
131 		ndev->stats.rx_errors++;
132 		ndev->stats.rx_fifo_errors++;
133 	}
134 }
135 
136 static void ntb_netdev_tx_handler(struct ntb_transport_qp *qp, void *qp_data,
137 				  void *data, int len)
138 {
139 	struct net_device *ndev = qp_data;
140 	struct sk_buff *skb;
141 
142 	skb = data;
143 	if (!skb || !ndev)
144 		return;
145 
146 	if (len > 0) {
147 		ndev->stats.tx_packets++;
148 		ndev->stats.tx_bytes += skb->len;
149 	} else {
150 		ndev->stats.tx_errors++;
151 		ndev->stats.tx_aborted_errors++;
152 	}
153 
154 	dev_kfree_skb(skb);
155 }
156 
157 static netdev_tx_t ntb_netdev_start_xmit(struct sk_buff *skb,
158 					 struct net_device *ndev)
159 {
160 	struct ntb_netdev *dev = netdev_priv(ndev);
161 	int rc;
162 
163 	netdev_dbg(ndev, "%s: skb len %d\n", __func__, skb->len);
164 
165 	rc = ntb_transport_tx_enqueue(dev->qp, skb, skb->data, skb->len);
166 	if (rc)
167 		goto err;
168 
169 	return NETDEV_TX_OK;
170 
171 err:
172 	ndev->stats.tx_dropped++;
173 	ndev->stats.tx_errors++;
174 	return NETDEV_TX_BUSY;
175 }
176 
177 static int ntb_netdev_open(struct net_device *ndev)
178 {
179 	struct ntb_netdev *dev = netdev_priv(ndev);
180 	struct sk_buff *skb;
181 	int rc, i, len;
182 
183 	/* Add some empty rx bufs */
184 	for (i = 0; i < NTB_RXQ_SIZE; i++) {
185 		skb = netdev_alloc_skb(ndev, ndev->mtu + ETH_HLEN);
186 		if (!skb) {
187 			rc = -ENOMEM;
188 			goto err;
189 		}
190 
191 		rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
192 					      ndev->mtu + ETH_HLEN);
193 		if (rc == -EINVAL) {
194 			dev_kfree_skb(skb);
195 			goto err;
196 		}
197 	}
198 
199 	netif_carrier_off(ndev);
200 	ntb_transport_link_up(dev->qp);
201 
202 	return 0;
203 
204 err:
205 	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
206 		dev_kfree_skb(skb);
207 	return rc;
208 }
209 
210 static int ntb_netdev_close(struct net_device *ndev)
211 {
212 	struct ntb_netdev *dev = netdev_priv(ndev);
213 	struct sk_buff *skb;
214 	int len;
215 
216 	ntb_transport_link_down(dev->qp);
217 
218 	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
219 		dev_kfree_skb(skb);
220 
221 	return 0;
222 }
223 
224 static int ntb_netdev_change_mtu(struct net_device *ndev, int new_mtu)
225 {
226 	struct ntb_netdev *dev = netdev_priv(ndev);
227 	struct sk_buff *skb;
228 	int len, rc;
229 
230 	if (new_mtu > ntb_transport_max_size(dev->qp) - ETH_HLEN)
231 		return -EINVAL;
232 
233 	if (!netif_running(ndev)) {
234 		ndev->mtu = new_mtu;
235 		return 0;
236 	}
237 
238 	/* Bring down the link and dispose of posted rx entries */
239 	ntb_transport_link_down(dev->qp);
240 
241 	if (ndev->mtu < new_mtu) {
242 		int i;
243 
244 		for (i = 0; (skb = ntb_transport_rx_remove(dev->qp, &len)); i++)
245 			dev_kfree_skb(skb);
246 
247 		for (; i; i--) {
248 			skb = netdev_alloc_skb(ndev, new_mtu + ETH_HLEN);
249 			if (!skb) {
250 				rc = -ENOMEM;
251 				goto err;
252 			}
253 
254 			rc = ntb_transport_rx_enqueue(dev->qp, skb, skb->data,
255 						      new_mtu + ETH_HLEN);
256 			if (rc) {
257 				dev_kfree_skb(skb);
258 				goto err;
259 			}
260 		}
261 	}
262 
263 	ndev->mtu = new_mtu;
264 
265 	ntb_transport_link_up(dev->qp);
266 
267 	return 0;
268 
269 err:
270 	ntb_transport_link_down(dev->qp);
271 
272 	while ((skb = ntb_transport_rx_remove(dev->qp, &len)))
273 		dev_kfree_skb(skb);
274 
275 	netdev_err(ndev, "Error changing MTU, device inoperable\n");
276 	return rc;
277 }
278 
279 static const struct net_device_ops ntb_netdev_ops = {
280 	.ndo_open = ntb_netdev_open,
281 	.ndo_stop = ntb_netdev_close,
282 	.ndo_start_xmit = ntb_netdev_start_xmit,
283 	.ndo_change_mtu = ntb_netdev_change_mtu,
284 	.ndo_set_mac_address = eth_mac_addr,
285 };
286 
287 static void ntb_get_drvinfo(struct net_device *ndev,
288 			    struct ethtool_drvinfo *info)
289 {
290 	struct ntb_netdev *dev = netdev_priv(ndev);
291 
292 	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
293 	strlcpy(info->version, NTB_NETDEV_VER, sizeof(info->version));
294 	strlcpy(info->bus_info, pci_name(dev->pdev), sizeof(info->bus_info));
295 }
296 
297 static int ntb_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
298 {
299 	cmd->supported = SUPPORTED_Backplane;
300 	cmd->advertising = ADVERTISED_Backplane;
301 	ethtool_cmd_speed_set(cmd, SPEED_UNKNOWN);
302 	cmd->duplex = DUPLEX_FULL;
303 	cmd->port = PORT_OTHER;
304 	cmd->phy_address = 0;
305 	cmd->transceiver = XCVR_DUMMY1;
306 	cmd->autoneg = AUTONEG_ENABLE;
307 	cmd->maxtxpkt = 0;
308 	cmd->maxrxpkt = 0;
309 
310 	return 0;
311 }
312 
313 static const struct ethtool_ops ntb_ethtool_ops = {
314 	.get_drvinfo = ntb_get_drvinfo,
315 	.get_link = ethtool_op_get_link,
316 	.get_settings = ntb_get_settings,
317 };
318 
319 static const struct ntb_queue_handlers ntb_netdev_handlers = {
320 	.tx_handler = ntb_netdev_tx_handler,
321 	.rx_handler = ntb_netdev_rx_handler,
322 	.event_handler = ntb_netdev_event_handler,
323 };
324 
325 static int ntb_netdev_probe(struct pci_dev *pdev)
326 {
327 	struct net_device *ndev;
328 	struct ntb_netdev *dev;
329 	int rc;
330 
331 	ndev = alloc_etherdev(sizeof(struct ntb_netdev));
332 	if (!ndev)
333 		return -ENOMEM;
334 
335 	dev = netdev_priv(ndev);
336 	dev->ndev = ndev;
337 	dev->pdev = pdev;
338 	BUG_ON(!dev->pdev);
339 	ndev->features = NETIF_F_HIGHDMA;
340 
341 	ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
342 
343 	ndev->hw_features = ndev->features;
344 	ndev->watchdog_timeo = msecs_to_jiffies(NTB_TX_TIMEOUT_MS);
345 
346 	random_ether_addr(ndev->perm_addr);
347 	memcpy(ndev->dev_addr, ndev->perm_addr, ndev->addr_len);
348 
349 	ndev->netdev_ops = &ntb_netdev_ops;
350 	ndev->ethtool_ops = &ntb_ethtool_ops;
351 
352 	dev->qp = ntb_transport_create_queue(ndev, pdev, &ntb_netdev_handlers);
353 	if (!dev->qp) {
354 		rc = -EIO;
355 		goto err;
356 	}
357 
358 	ndev->mtu = ntb_transport_max_size(dev->qp) - ETH_HLEN;
359 
360 	rc = register_netdev(ndev);
361 	if (rc)
362 		goto err1;
363 
364 	list_add(&dev->list, &dev_list);
365 	dev_info(&pdev->dev, "%s created\n", ndev->name);
366 	return 0;
367 
368 err1:
369 	ntb_transport_free_queue(dev->qp);
370 err:
371 	free_netdev(ndev);
372 	return rc;
373 }
374 
375 static void ntb_netdev_remove(struct pci_dev *pdev)
376 {
377 	struct net_device *ndev;
378 	struct ntb_netdev *dev;
379 	bool found = false;
380 
381 	list_for_each_entry(dev, &dev_list, list) {
382 		if (dev->pdev == pdev) {
383 			found = true;
384 			break;
385 		}
386 	}
387 	if (!found)
388 		return;
389 
390 	list_del(&dev->list);
391 
392 	ndev = dev->ndev;
393 
394 	unregister_netdev(ndev);
395 	ntb_transport_free_queue(dev->qp);
396 	free_netdev(ndev);
397 }
398 
399 static struct ntb_client ntb_netdev_client = {
400 	.driver.name = KBUILD_MODNAME,
401 	.driver.owner = THIS_MODULE,
402 	.probe = ntb_netdev_probe,
403 	.remove = ntb_netdev_remove,
404 };
405 
406 static int __init ntb_netdev_init_module(void)
407 {
408 	int rc;
409 
410 	rc = ntb_register_client_dev(KBUILD_MODNAME);
411 	if (rc)
412 		return rc;
413 	return ntb_register_client(&ntb_netdev_client);
414 }
415 module_init(ntb_netdev_init_module);
416 
417 static void __exit ntb_netdev_exit_module(void)
418 {
419 	ntb_unregister_client(&ntb_netdev_client);
420 	ntb_unregister_client_dev(KBUILD_MODNAME);
421 }
422 module_exit(ntb_netdev_exit_module);
423