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
18 static DEFINE_IDA(nsim_bus_dev_ids);
19 static LIST_HEAD(nsim_bus_dev_list);
20 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
21 static bool nsim_bus_enable;
22 static refcount_t nsim_bus_devs; /* Including the bus itself. */
23 static DECLARE_COMPLETION(nsim_bus_devs_released);
24
to_nsim_bus_dev(struct device * dev)25 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
26 {
27 return container_of(dev, struct nsim_bus_dev, dev);
28 }
29
30 static ssize_t
nsim_bus_dev_numvfs_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)31 nsim_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
51 static ssize_t
nsim_bus_dev_numvfs_show(struct device * dev,struct device_attribute * attr,char * buf)52 nsim_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
60 static 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
64 static ssize_t
new_port_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)65 new_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 ð_addr[0], ð_addr[1], ð_addr[2], ð_addr[3],
80 ð_addr[4], ð_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
101 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
102
103 static ssize_t
del_port_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)104 del_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
122 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
123
124 static 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
131 static const struct attribute_group nsim_bus_dev_attr_group = {
132 .attrs = nsim_bus_dev_attrs,
133 };
134
135 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
136 &nsim_bus_dev_attr_group,
137 NULL,
138 };
139
nsim_bus_dev_release(struct device * dev)140 static 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
150 static const struct device_type nsim_bus_dev_type = {
151 .groups = nsim_bus_dev_attr_groups,
152 .release = nsim_bus_dev_release,
153 };
154
155 static struct nsim_bus_dev *
156 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);
157
158 static ssize_t
new_device_store(const struct bus_type * bus,const char * buf,size_t count)159 new_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;
205 err:
206 mutex_unlock(&nsim_bus_dev_list_lock);
207 return err;
208 }
209 static BUS_ATTR_WO(new_device);
210
211 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
212
213 static ssize_t
del_device_store(const struct bus_type * bus,const char * buf,size_t count)214 del_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 }
251 static BUS_ATTR_WO(del_device);
252
link_device_store(const struct bus_type * bus,const char * buf,size_t count)253 static 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 out_err:
336 put_net(ns_b);
337 put_net(ns_a);
338 rtnl_unlock();
339
340 return !err ? count : err;
341 }
342 static BUS_ATTR_WO(link_device);
343
unlink_device_store(const struct bus_type * bus,const char * buf,size_t count)344 static ssize_t unlink_device_store(const struct bus_type *bus, const char *buf, size_t count)
345 {
346 struct netdevsim *nsim, *peer;
347 struct net_device *dev;
348 unsigned int ifidx;
349 int netnsfd, err;
350 struct net *ns;
351
352 err = sscanf(buf, "%u:%u", &netnsfd, &ifidx);
353 if (err != 2) {
354 pr_err("Format for unlinking a device is \"netnsfd:ifidx\" (int uint).\n");
355 return -EINVAL;
356 }
357
358 ns = get_net_ns_by_fd(netnsfd);
359 if (IS_ERR(ns)) {
360 pr_err("Could not find netns with fd: %d\n", netnsfd);
361 return -EINVAL;
362 }
363
364 err = -EINVAL;
365 rtnl_lock();
366 dev = __dev_get_by_index(ns, ifidx);
367 if (!dev) {
368 pr_err("Could not find device with ifindex %u in netnsfd %d\n",
369 ifidx, netnsfd);
370 goto out_put_netns;
371 }
372
373 if (!netdev_is_nsim(dev)) {
374 pr_err("Device with ifindex %u in netnsfd %d is not a netdevsim\n",
375 ifidx, netnsfd);
376 goto out_put_netns;
377 }
378
379 nsim = netdev_priv(dev);
380 peer = rtnl_dereference(nsim->peer);
381 if (!peer)
382 goto out_put_netns;
383
384 err = 0;
385 RCU_INIT_POINTER(nsim->peer, NULL);
386 RCU_INIT_POINTER(peer->peer, NULL);
387 synchronize_net();
388 netif_tx_wake_all_queues(dev);
389 netif_tx_wake_all_queues(peer->netdev);
390
391 out_put_netns:
392 put_net(ns);
393 rtnl_unlock();
394
395 return !err ? count : err;
396 }
397 static BUS_ATTR_WO(unlink_device);
398
399 static struct attribute *nsim_bus_attrs[] = {
400 &bus_attr_new_device.attr,
401 &bus_attr_del_device.attr,
402 &bus_attr_link_device.attr,
403 &bus_attr_unlink_device.attr,
404 NULL
405 };
406 ATTRIBUTE_GROUPS(nsim_bus);
407
nsim_bus_probe(struct device * dev)408 static int nsim_bus_probe(struct device *dev)
409 {
410 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
411
412 return nsim_drv_probe(nsim_bus_dev);
413 }
414
nsim_bus_remove(struct device * dev)415 static void nsim_bus_remove(struct device *dev)
416 {
417 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
418
419 nsim_drv_remove(nsim_bus_dev);
420 }
421
nsim_num_vf(struct device * dev)422 static int nsim_num_vf(struct device *dev)
423 {
424 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
425
426 return nsim_bus_dev->num_vfs;
427 }
428
429 static const struct bus_type nsim_bus = {
430 .name = DRV_NAME,
431 .dev_name = DRV_NAME,
432 .bus_groups = nsim_bus_groups,
433 .probe = nsim_bus_probe,
434 .remove = nsim_bus_remove,
435 .num_vf = nsim_num_vf,
436 };
437
438 #define NSIM_BUS_DEV_MAX_VFS 4
439
440 static struct nsim_bus_dev *
nsim_bus_dev_new(unsigned int id,unsigned int port_count,unsigned int num_queues)441 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
442 {
443 struct nsim_bus_dev *nsim_bus_dev;
444 int err;
445
446 nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
447 if (!nsim_bus_dev)
448 return ERR_PTR(-ENOMEM);
449
450 err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
451 if (err < 0)
452 goto err_nsim_bus_dev_free;
453 nsim_bus_dev->dev.id = err;
454 nsim_bus_dev->dev.bus = &nsim_bus;
455 nsim_bus_dev->dev.type = &nsim_bus_dev_type;
456 nsim_bus_dev->port_count = port_count;
457 nsim_bus_dev->num_queues = num_queues;
458 nsim_bus_dev->initial_net = current->nsproxy->net_ns;
459 nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
460 /* Disallow using nsim_bus_dev */
461 smp_store_release(&nsim_bus_dev->init, false);
462
463 err = device_register(&nsim_bus_dev->dev);
464 if (err)
465 goto err_nsim_bus_dev_id_free;
466
467 return nsim_bus_dev;
468
469 err_nsim_bus_dev_id_free:
470 ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
471 put_device(&nsim_bus_dev->dev);
472 nsim_bus_dev = NULL;
473 err_nsim_bus_dev_free:
474 kfree(nsim_bus_dev);
475 return ERR_PTR(err);
476 }
477
nsim_bus_dev_del(struct nsim_bus_dev * nsim_bus_dev)478 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
479 {
480 /* Disallow using nsim_bus_dev */
481 smp_store_release(&nsim_bus_dev->init, false);
482 ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
483 device_unregister(&nsim_bus_dev->dev);
484 }
485
486 static struct device_driver nsim_driver = {
487 .name = DRV_NAME,
488 .bus = &nsim_bus,
489 .owner = THIS_MODULE,
490 };
491
nsim_bus_init(void)492 int nsim_bus_init(void)
493 {
494 int err;
495
496 err = bus_register(&nsim_bus);
497 if (err)
498 return err;
499 err = driver_register(&nsim_driver);
500 if (err)
501 goto err_bus_unregister;
502 refcount_set(&nsim_bus_devs, 1);
503 /* Allow using resources */
504 smp_store_release(&nsim_bus_enable, true);
505 return 0;
506
507 err_bus_unregister:
508 bus_unregister(&nsim_bus);
509 return err;
510 }
511
nsim_bus_exit(void)512 void nsim_bus_exit(void)
513 {
514 struct nsim_bus_dev *nsim_bus_dev, *tmp;
515
516 /* Disallow using resources */
517 smp_store_release(&nsim_bus_enable, false);
518 if (refcount_dec_and_test(&nsim_bus_devs))
519 complete(&nsim_bus_devs_released);
520
521 mutex_lock(&nsim_bus_dev_list_lock);
522 list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
523 list_del(&nsim_bus_dev->list);
524 nsim_bus_dev_del(nsim_bus_dev);
525 }
526 mutex_unlock(&nsim_bus_dev_list_lock);
527
528 wait_for_completion(&nsim_bus_devs_released);
529
530 driver_unregister(&nsim_driver);
531 bus_unregister(&nsim_bus);
532 }
533