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

source code of linux/drivers/net/netdevsim/bus.c