bus.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (C) 2017 Netronome Systems, Inc.
  3 * Copyright (C) 2019 Mellanox Technologies. All rights reserved
  4 */
  5
  6#include <linux/completion.h>
  7#include <linux/device.h>
  8#include <linux/idr.h>
  9#include <linux/kernel.h>
 10#include <linux/list.h>
 11#include <linux/mutex.h>
 12#include <linux/refcount.h>
 13#include <linux/slab.h>
 14#include <linux/sysfs.h>
 15
 16#include "netdevsim.h"
 17
 18static DEFINE_IDA(nsim_bus_dev_ids);
 19static LIST_HEAD(nsim_bus_dev_list);
 20static DEFINE_MUTEX(nsim_bus_dev_list_lock);
 21static bool nsim_bus_enable;
 22static refcount_t nsim_bus_devs; /* Including the bus itself. */
 23static DECLARE_COMPLETION(nsim_bus_devs_released);
 24
 25static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
 26{
 27	return container_of(dev, struct nsim_bus_dev, dev);
 28}
 29
 30static ssize_t
 31nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
 32			  const char *buf, size_t count)
 33{
 34	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 35	unsigned int num_vfs;
 36	int ret;
 37
 38	ret = kstrtouint(buf, 0, &num_vfs);
 39	if (ret)
 40		return ret;
 41
 42	device_lock(dev);
 43	ret = -ENOENT;
 44	if (dev_get_drvdata(dev))
 45		ret = nsim_drv_configure_vfs(nsim_bus_dev, num_vfs);
 46	device_unlock(dev);
 47
 48	return ret ? ret : count;
 49}
 50
 51static ssize_t
 52nsim_bus_dev_numvfs_show(struct device *dev,
 53			 struct device_attribute *attr, char *buf)
 54{
 55	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 56
 57	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
 58}
 59
 60static struct device_attribute nsim_bus_dev_numvfs_attr =
 61	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
 62	       nsim_bus_dev_numvfs_store);
 63
 64static ssize_t
 65new_port_store(struct device *dev, struct device_attribute *attr,
 66	       const char *buf, size_t count)
 67{
 68	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
 69	u8 eth_addr[ETH_ALEN] = {};
 70	unsigned int port_index;
 71	bool addr_set = false;
 72	int ret;
 73
 74	/* Prevent to use nsim_bus_dev before initialization. */
 75	if (!smp_load_acquire(&nsim_bus_dev->init))
 76		return -EBUSY;
 77
 78	ret = sscanf(buf, "%u %hhx:%hhx:%hhx:%hhx:%hhx:%hhx", &port_index,
 79		     &eth_addr[0], &eth_addr[1], &eth_addr[2], &eth_addr[3],
 80		     &eth_addr[4], &eth_addr[5]);
 81	switch (ret) {
 82	case 7:
 83		if (!is_valid_ether_addr(eth_addr)) {
 84			pr_err("The supplied perm_addr is not a valid MAC address\n");
 85			return -EINVAL;
 86		}
 87		addr_set = true;
 88		fallthrough;
 89	case 1:
 90		break;
 91	default:
 92		pr_err("Format for adding new port is \"id [perm_addr]\" (uint MAC).\n");
 93		return -EINVAL;
 94	}
 95
 96	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index,
 97				addr_set ? eth_addr : NULL);
 98	return ret ? ret : count;
 99}
100
101static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
102
103static ssize_t
104del_port_store(struct device *dev, struct device_attribute *attr,
105	       const char *buf, size_t count)
106{
107	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
108	unsigned int port_index;
109	int ret;
110
111	/* Prevent to use nsim_bus_dev before initialization. */
112	if (!smp_load_acquire(&nsim_bus_dev->init))
113		return -EBUSY;
114	ret = kstrtouint(buf, 0, &port_index);
115	if (ret)
116		return ret;
117
118	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
119	return ret ? ret : count;
120}
121
122static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
123
124static struct attribute *nsim_bus_dev_attrs[] = {
125	&nsim_bus_dev_numvfs_attr.attr,
126	&nsim_bus_dev_new_port_attr.attr,
127	&nsim_bus_dev_del_port_attr.attr,
128	NULL,
129};
130
131static const struct attribute_group nsim_bus_dev_attr_group = {
132	.attrs = nsim_bus_dev_attrs,
133};
134
135static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
136	&nsim_bus_dev_attr_group,
137	NULL,
138};
139
140static void nsim_bus_dev_release(struct device *dev)
141{
142	struct nsim_bus_dev *nsim_bus_dev;
143
144	nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev);
145	kfree(nsim_bus_dev);
146	if (refcount_dec_and_test(&nsim_bus_devs))
147		complete(&nsim_bus_devs_released);
148}
149
150static const struct device_type nsim_bus_dev_type = {
151	.groups = nsim_bus_dev_attr_groups,
152	.release = nsim_bus_dev_release,
153};
154
155static struct nsim_bus_dev *
156nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);
157
158static ssize_t
159new_device_store(const struct bus_type *bus, const char *buf, size_t count)
160{
161	unsigned int id, port_count, num_queues;
162	struct nsim_bus_dev *nsim_bus_dev;
163	int err;
164
165	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
166	switch (err) {
167	case 1:
168		port_count = 1;
169		fallthrough;
170	case 2:
171		num_queues = 1;
172		fallthrough;
173	case 3:
174		if (id > INT_MAX) {
175			pr_err("Value of \"id\" is too big.\n");
176			return -EINVAL;
177		}
178		break;
179	default:
180		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
181		return -EINVAL;
182	}
183
184	mutex_lock(&nsim_bus_dev_list_lock);
185	/* Prevent to use resource before initialization. */
186	if (!smp_load_acquire(&nsim_bus_enable)) {
187		err = -EBUSY;
188		goto err;
189	}
190
191	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
192	if (IS_ERR(nsim_bus_dev)) {
193		err = PTR_ERR(nsim_bus_dev);
194		goto err;
195	}
196
197	refcount_inc(&nsim_bus_devs);
198	/* Allow using nsim_bus_dev */
199	smp_store_release(&nsim_bus_dev->init, true);
200
201	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
202	mutex_unlock(&nsim_bus_dev_list_lock);
203
204	return count;
205err:
206	mutex_unlock(&nsim_bus_dev_list_lock);
207	return err;
208}
209static BUS_ATTR_WO(new_device);
210
211static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
212
213static ssize_t
214del_device_store(const struct bus_type *bus, const char *buf, size_t count)
215{
216	struct nsim_bus_dev *nsim_bus_dev, *tmp;
217	unsigned int id;
218	int err;
219
220	err = sscanf(buf, "%u", &id);
221	switch (err) {
222	case 1:
223		if (id > INT_MAX) {
224			pr_err("Value of \"id\" is too big.\n");
225			return -EINVAL;
226		}
227		break;
228	default:
229		pr_err("Format for deleting device is \"id\" (uint).\n");
230		return -EINVAL;
231	}
232
233	err = -ENOENT;
234	mutex_lock(&nsim_bus_dev_list_lock);
235	/* Prevent to use resource before initialization. */
236	if (!smp_load_acquire(&nsim_bus_enable)) {
237		mutex_unlock(&nsim_bus_dev_list_lock);
238		return -EBUSY;
239	}
240	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
241		if (nsim_bus_dev->dev.id != id)
242			continue;
243		list_del(&nsim_bus_dev->list);
244		nsim_bus_dev_del(nsim_bus_dev);
245		err = 0;
246		break;
247	}
248	mutex_unlock(&nsim_bus_dev_list_lock);
249	return !err ? count : err;
250}
251static BUS_ATTR_WO(del_device);
252
253static ssize_t link_device_store(const struct bus_type *bus, const char *buf, size_t count)
254{
255	struct netdevsim *nsim_a, *nsim_b, *peer;
256	struct net_device *dev_a, *dev_b;
257	unsigned int ifidx_a, ifidx_b;
258	int netnsfd_a, netnsfd_b, err;
259	struct net *ns_a, *ns_b;
260
261	err = sscanf(buf, "%d:%u %d:%u", &netnsfd_a, &ifidx_a, &netnsfd_b,
262		     &ifidx_b);
263	if (err != 4) {
264		pr_err("Format for linking two devices is \"netnsfd_a:ifidx_a netnsfd_b:ifidx_b\" (int uint int uint).\n");
265		return -EINVAL;
266	}
267
268	ns_a = get_net_ns_by_fd(netnsfd_a);
269	if (IS_ERR(ns_a)) {
270		pr_err("Could not find netns with fd: %d\n", netnsfd_a);
271		return -EINVAL;
272	}
273
274	ns_b = get_net_ns_by_fd(netnsfd_b);
275	if (IS_ERR(ns_b)) {
276		pr_err("Could not find netns with fd: %d\n", netnsfd_b);
277		put_net(ns_a);
278		return -EINVAL;
279	}
280
281	err = -EINVAL;
282	rtnl_lock();
283	dev_a = __dev_get_by_index(ns_a, ifidx_a);
284	if (!dev_a) {
285		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
286		       ifidx_a, netnsfd_a);
287		goto out_err;
288	}
289
290	if (!netdev_is_nsim(dev_a)) {
291		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
292		       ifidx_a, netnsfd_a);
293		goto out_err;
294	}
295
296	dev_b = __dev_get_by_index(ns_b, ifidx_b);
297	if (!dev_b) {
298		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
299		       ifidx_b, netnsfd_b);
300		goto out_err;
301	}
302
303	if (!netdev_is_nsim(dev_b)) {
304		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
305		       ifidx_b, netnsfd_b);
306		goto out_err;
307	}
308
309	if (dev_a == dev_b) {
310		pr_err("Cannot link a netdevsim to itself\n");
311		goto out_err;
312	}
313
314	err = -EBUSY;
315	nsim_a = netdev_priv(dev_a);
316	peer = rtnl_dereference(nsim_a->peer);
317	if (peer) {
318		pr_err("Netdevsim %d:%u is already linked\n", netnsfd_a,
319		       ifidx_a);
320		goto out_err;
321	}
322
323	nsim_b = netdev_priv(dev_b);
324	peer = rtnl_dereference(nsim_b->peer);
325	if (peer) {
326		pr_err("Netdevsim %d:%u is already linked\n", netnsfd_b,
327		       ifidx_b);
328		goto out_err;
329	}
330
331	err = 0;
332	rcu_assign_pointer(nsim_a->peer, nsim_b);
333	rcu_assign_pointer(nsim_b->peer, nsim_a);
334
335	if (netif_running(dev_a) && netif_running(dev_b)) {
336		netif_carrier_on(dev_a);
337		netif_carrier_on(dev_b);
338	}
339
340out_err:
341	put_net(ns_b);
342	put_net(ns_a);
343	rtnl_unlock();
344
345	return !err ? count : err;
346}
347static BUS_ATTR_WO(link_device);
348
349static ssize_t unlink_device_store(const struct bus_type *bus, const char *buf, size_t count)
350{
351	struct netdevsim *nsim, *peer;
352	struct net_device *dev;
353	unsigned int ifidx;
354	int netnsfd, err;
355	struct net *ns;
356
357	err = sscanf(buf, "%u:%u", &netnsfd, &ifidx);
358	if (err != 2) {
359		pr_err("Format for unlinking a device is \"netnsfd:ifidx\" (int uint).\n");
360		return -EINVAL;
361	}
362
363	ns = get_net_ns_by_fd(netnsfd);
364	if (IS_ERR(ns)) {
365		pr_err("Could not find netns with fd: %d\n", netnsfd);
366		return -EINVAL;
367	}
368
369	err = -EINVAL;
370	rtnl_lock();
371	dev = __dev_get_by_index(ns, ifidx);
372	if (!dev) {
373		pr_err("Could not find device with ifindex %u in netnsfd %d\n",
374		       ifidx, netnsfd);
375		goto out_put_netns;
376	}
377
378	if (!netdev_is_nsim(dev)) {
379		pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
380		       ifidx, netnsfd);
381		goto out_put_netns;
382	}
383
384	nsim = netdev_priv(dev);
385	peer = rtnl_dereference(nsim->peer);
386	if (!peer)
387		goto out_put_netns;
388
389	netif_carrier_off(dev);
390	netif_carrier_off(peer->netdev);
391
392	err = 0;
393	RCU_INIT_POINTER(nsim->peer, NULL);
394	RCU_INIT_POINTER(peer->peer, NULL);
395	synchronize_net();
396	netif_tx_wake_all_queues(dev);
397	netif_tx_wake_all_queues(peer->netdev);
398
399out_put_netns:
400	put_net(ns);
401	rtnl_unlock();
402
403	return !err ? count : err;
404}
405static BUS_ATTR_WO(unlink_device);
406
407static struct attribute *nsim_bus_attrs[] = {
408	&bus_attr_new_device.attr,
409	&bus_attr_del_device.attr,
410	&bus_attr_link_device.attr,
411	&bus_attr_unlink_device.attr,
412	NULL
413};
414ATTRIBUTE_GROUPS(nsim_bus);
415
416static int nsim_bus_probe(struct device *dev)
417{
418	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
419
420	return nsim_drv_probe(nsim_bus_dev);
421}
422
423static void nsim_bus_remove(struct device *dev)
424{
425	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
426
427	nsim_drv_remove(nsim_bus_dev);
428}
429
430static int nsim_num_vf(struct device *dev)
431{
432	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
433
434	return nsim_bus_dev->num_vfs;
435}
436
437static const struct bus_type nsim_bus = {
438	.name		= DRV_NAME,
439	.dev_name	= DRV_NAME,
440	.bus_groups	= nsim_bus_groups,
441	.probe		= nsim_bus_probe,
442	.remove		= nsim_bus_remove,
443	.num_vf		= nsim_num_vf,
444};
445
446#define NSIM_BUS_DEV_MAX_VFS 4
447
448static struct nsim_bus_dev *
449nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
450{
451	struct nsim_bus_dev *nsim_bus_dev;
452	int err;
453
454	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
455	if (!nsim_bus_dev)
456		return ERR_PTR(-ENOMEM);
457
458	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
459	if (err < 0)
460		goto err_nsim_bus_dev_free;
461	nsim_bus_dev->dev.id = err;
462	nsim_bus_dev->dev.bus = &nsim_bus;
463	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
464	nsim_bus_dev->port_count = port_count;
465	nsim_bus_dev->num_queues = num_queues;
466	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
467	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
468	/* Disallow using nsim_bus_dev */
469	smp_store_release(&nsim_bus_dev->init, false);
470
471	err = device_register(&nsim_bus_dev->dev);
472	if (err)
473		goto err_nsim_bus_dev_id_free;
474
475	return nsim_bus_dev;
476
477err_nsim_bus_dev_id_free:
478	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
479	put_device(&nsim_bus_dev->dev);
480	nsim_bus_dev = NULL;
481err_nsim_bus_dev_free:
482	kfree(nsim_bus_dev);
483	return ERR_PTR(err);
484}
485
486static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
487{
488	/* Disallow using nsim_bus_dev */
489	smp_store_release(&nsim_bus_dev->init, false);
490	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
491	device_unregister(&nsim_bus_dev->dev);
492}
493
494static struct device_driver nsim_driver = {
495	.name		= DRV_NAME,
496	.bus		= &nsim_bus,
497	.owner		= THIS_MODULE,
498};
499
500int nsim_bus_init(void)
501{
502	int err;
503
504	err = bus_register(&nsim_bus);
505	if (err)
506		return err;
507	err = driver_register(&nsim_driver);
508	if (err)
509		goto err_bus_unregister;
510	refcount_set(&nsim_bus_devs, 1);
511	/* Allow using resources */
512	smp_store_release(&nsim_bus_enable, true);
513	return 0;
514
515err_bus_unregister:
516	bus_unregister(&nsim_bus);
517	return err;
518}
519
520void nsim_bus_exit(void)
521{
522	struct nsim_bus_dev *nsim_bus_dev, *tmp;
523
524	/* Disallow using resources */
525	smp_store_release(&nsim_bus_enable, false);
526	if (refcount_dec_and_test(&nsim_bus_devs))
527		complete(&nsim_bus_devs_released);
528
529	mutex_lock(&nsim_bus_dev_list_lock);
530	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
531		list_del(&nsim_bus_dev->list);
532		nsim_bus_dev_del(nsim_bus_dev);
533	}
534	mutex_unlock(&nsim_bus_dev_list_lock);
535
536	wait_for_completion(&nsim_bus_devs_released);
537
538	driver_unregister(&nsim_driver);
539	bus_unregister(&nsim_bus);
540}