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/device.h>
7 #include <linux/idr.h>
8 #include <linux/kernel.h>
9 #include <linux/list.h>
10 #include <linux/mutex.h>
11 #include <linux/rtnetlink.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14
15 #include "netdevsim.h"
16
17 static DEFINE_IDA(nsim_bus_dev_ids);
18 static LIST_HEAD(nsim_bus_dev_list);
19 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
20 static bool nsim_bus_enable;
21
to_nsim_bus_dev(struct device * dev)22 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
23 {
24 return container_of(dev, struct nsim_bus_dev, dev);
25 }
26
nsim_bus_dev_vfs_enable(struct nsim_bus_dev * nsim_bus_dev,unsigned int num_vfs)27 static int nsim_bus_dev_vfs_enable(struct nsim_bus_dev *nsim_bus_dev,
28 unsigned int num_vfs)
29 {
30 nsim_bus_dev->vfconfigs = kcalloc(num_vfs,
31 sizeof(struct nsim_vf_config),
32 GFP_KERNEL | __GFP_NOWARN);
33 if (!nsim_bus_dev->vfconfigs)
34 return -ENOMEM;
35 nsim_bus_dev->num_vfs = num_vfs;
36
37 return 0;
38 }
39
nsim_bus_dev_vfs_disable(struct nsim_bus_dev * nsim_bus_dev)40 static void nsim_bus_dev_vfs_disable(struct nsim_bus_dev *nsim_bus_dev)
41 {
42 kfree(nsim_bus_dev->vfconfigs);
43 nsim_bus_dev->vfconfigs = NULL;
44 nsim_bus_dev->num_vfs = 0;
45 }
46
47 static ssize_t
nsim_bus_dev_numvfs_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)48 nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
49 const char *buf, size_t count)
50 {
51 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
52 unsigned int num_vfs;
53 int ret;
54
55 ret = kstrtouint(buf, 0, &num_vfs);
56 if (ret)
57 return ret;
58
59 rtnl_lock();
60 if (nsim_bus_dev->num_vfs == num_vfs)
61 goto exit_good;
62 if (nsim_bus_dev->num_vfs && num_vfs) {
63 ret = -EBUSY;
64 goto exit_unlock;
65 }
66
67 if (num_vfs) {
68 ret = nsim_bus_dev_vfs_enable(nsim_bus_dev, num_vfs);
69 if (ret)
70 goto exit_unlock;
71 } else {
72 nsim_bus_dev_vfs_disable(nsim_bus_dev);
73 }
74 exit_good:
75 ret = count;
76 exit_unlock:
77 rtnl_unlock();
78
79 return ret;
80 }
81
82 static ssize_t
nsim_bus_dev_numvfs_show(struct device * dev,struct device_attribute * attr,char * buf)83 nsim_bus_dev_numvfs_show(struct device *dev,
84 struct device_attribute *attr, char *buf)
85 {
86 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
87
88 return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
89 }
90
91 static struct device_attribute nsim_bus_dev_numvfs_attr =
92 __ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
93 nsim_bus_dev_numvfs_store);
94
95 static ssize_t
new_port_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)96 new_port_store(struct device *dev, struct device_attribute *attr,
97 const char *buf, size_t count)
98 {
99 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
100 struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
101 struct devlink *devlink;
102 unsigned int port_index;
103 int ret;
104
105 /* Prevent to use nsim_bus_dev before initialization. */
106 if (!smp_load_acquire(&nsim_bus_dev->init))
107 return -EBUSY;
108 ret = kstrtouint(buf, 0, &port_index);
109 if (ret)
110 return ret;
111
112 devlink = priv_to_devlink(nsim_dev);
113
114 mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
115 devlink_reload_disable(devlink);
116 ret = nsim_dev_port_add(nsim_bus_dev, port_index);
117 devlink_reload_enable(devlink);
118 mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
119 return ret ? ret : count;
120 }
121
122 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
123
124 static ssize_t
del_port_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)125 del_port_store(struct device *dev, struct device_attribute *attr,
126 const char *buf, size_t count)
127 {
128 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
129 struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
130 struct devlink *devlink;
131 unsigned int port_index;
132 int ret;
133
134 /* Prevent to use nsim_bus_dev before initialization. */
135 if (!smp_load_acquire(&nsim_bus_dev->init))
136 return -EBUSY;
137 ret = kstrtouint(buf, 0, &port_index);
138 if (ret)
139 return ret;
140
141 devlink = priv_to_devlink(nsim_dev);
142
143 mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
144 devlink_reload_disable(devlink);
145 ret = nsim_dev_port_del(nsim_bus_dev, port_index);
146 devlink_reload_enable(devlink);
147 mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
148 return ret ? ret : count;
149 }
150
151 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
152
153 static struct attribute *nsim_bus_dev_attrs[] = {
154 &nsim_bus_dev_numvfs_attr.attr,
155 &nsim_bus_dev_new_port_attr.attr,
156 &nsim_bus_dev_del_port_attr.attr,
157 NULL,
158 };
159
160 static const struct attribute_group nsim_bus_dev_attr_group = {
161 .attrs = nsim_bus_dev_attrs,
162 };
163
164 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
165 &nsim_bus_dev_attr_group,
166 NULL,
167 };
168
nsim_bus_dev_release(struct device * dev)169 static void nsim_bus_dev_release(struct device *dev)
170 {
171 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
172
173 nsim_bus_dev_vfs_disable(nsim_bus_dev);
174 }
175
176 static struct device_type nsim_bus_dev_type = {
177 .groups = nsim_bus_dev_attr_groups,
178 .release = nsim_bus_dev_release,
179 };
180
181 static struct nsim_bus_dev *
182 nsim_bus_dev_new(unsigned int id, unsigned int port_count);
183
184 static ssize_t
new_device_store(struct bus_type * bus,const char * buf,size_t count)185 new_device_store(struct bus_type *bus, const char *buf, size_t count)
186 {
187 struct nsim_bus_dev *nsim_bus_dev;
188 unsigned int port_count;
189 unsigned int id;
190 int err;
191
192 err = sscanf(buf, "%u %u", &id, &port_count);
193 switch (err) {
194 case 1:
195 port_count = 1;
196 fallthrough;
197 case 2:
198 if (id > INT_MAX) {
199 pr_err("Value of \"id\" is too big.\n");
200 return -EINVAL;
201 }
202 break;
203 default:
204 pr_err("Format for adding new device is \"id port_count\" (uint uint).\n");
205 return -EINVAL;
206 }
207
208 mutex_lock(&nsim_bus_dev_list_lock);
209 /* Prevent to use resource before initialization. */
210 if (!smp_load_acquire(&nsim_bus_enable)) {
211 err = -EBUSY;
212 goto err;
213 }
214
215 nsim_bus_dev = nsim_bus_dev_new(id, port_count);
216 if (IS_ERR(nsim_bus_dev)) {
217 err = PTR_ERR(nsim_bus_dev);
218 goto err;
219 }
220
221 /* Allow using nsim_bus_dev */
222 smp_store_release(&nsim_bus_dev->init, true);
223
224 list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
225 mutex_unlock(&nsim_bus_dev_list_lock);
226
227 return count;
228 err:
229 mutex_unlock(&nsim_bus_dev_list_lock);
230 return err;
231 }
232 static BUS_ATTR_WO(new_device);
233
234 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
235
236 static ssize_t
del_device_store(struct bus_type * bus,const char * buf,size_t count)237 del_device_store(struct bus_type *bus, const char *buf, size_t count)
238 {
239 struct nsim_bus_dev *nsim_bus_dev, *tmp;
240 unsigned int id;
241 int err;
242
243 err = sscanf(buf, "%u", &id);
244 switch (err) {
245 case 1:
246 if (id > INT_MAX) {
247 pr_err("Value of \"id\" is too big.\n");
248 return -EINVAL;
249 }
250 break;
251 default:
252 pr_err("Format for deleting device is \"id\" (uint).\n");
253 return -EINVAL;
254 }
255
256 err = -ENOENT;
257 mutex_lock(&nsim_bus_dev_list_lock);
258 /* Prevent to use resource before initialization. */
259 if (!smp_load_acquire(&nsim_bus_enable)) {
260 mutex_unlock(&nsim_bus_dev_list_lock);
261 return -EBUSY;
262 }
263 list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
264 if (nsim_bus_dev->dev.id != id)
265 continue;
266 list_del(&nsim_bus_dev->list);
267 nsim_bus_dev_del(nsim_bus_dev);
268 err = 0;
269 break;
270 }
271 mutex_unlock(&nsim_bus_dev_list_lock);
272 return !err ? count : err;
273 }
274 static BUS_ATTR_WO(del_device);
275
276 static struct attribute *nsim_bus_attrs[] = {
277 &bus_attr_new_device.attr,
278 &bus_attr_del_device.attr,
279 NULL
280 };
281 ATTRIBUTE_GROUPS(nsim_bus);
282
nsim_bus_probe(struct device * dev)283 static int nsim_bus_probe(struct device *dev)
284 {
285 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
286
287 return nsim_dev_probe(nsim_bus_dev);
288 }
289
nsim_bus_remove(struct device * dev)290 static int nsim_bus_remove(struct device *dev)
291 {
292 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
293
294 nsim_dev_remove(nsim_bus_dev);
295 return 0;
296 }
297
nsim_num_vf(struct device * dev)298 static int nsim_num_vf(struct device *dev)
299 {
300 struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
301
302 return nsim_bus_dev->num_vfs;
303 }
304
305 static struct bus_type nsim_bus = {
306 .name = DRV_NAME,
307 .dev_name = DRV_NAME,
308 .bus_groups = nsim_bus_groups,
309 .probe = nsim_bus_probe,
310 .remove = nsim_bus_remove,
311 .num_vf = nsim_num_vf,
312 };
313
314 static struct nsim_bus_dev *
nsim_bus_dev_new(unsigned int id,unsigned int port_count)315 nsim_bus_dev_new(unsigned int id, unsigned int port_count)
316 {
317 struct nsim_bus_dev *nsim_bus_dev;
318 int err;
319
320 nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
321 if (!nsim_bus_dev)
322 return ERR_PTR(-ENOMEM);
323
324 err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
325 if (err < 0)
326 goto err_nsim_bus_dev_free;
327 nsim_bus_dev->dev.id = err;
328 nsim_bus_dev->dev.bus = &nsim_bus;
329 nsim_bus_dev->dev.type = &nsim_bus_dev_type;
330 nsim_bus_dev->port_count = port_count;
331 nsim_bus_dev->initial_net = current->nsproxy->net_ns;
332 mutex_init(&nsim_bus_dev->nsim_bus_reload_lock);
333 /* Disallow using nsim_bus_dev */
334 smp_store_release(&nsim_bus_dev->init, false);
335
336 err = device_register(&nsim_bus_dev->dev);
337 if (err)
338 goto err_nsim_bus_dev_id_free;
339 return nsim_bus_dev;
340
341 err_nsim_bus_dev_id_free:
342 ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
343 err_nsim_bus_dev_free:
344 kfree(nsim_bus_dev);
345 return ERR_PTR(err);
346 }
347
nsim_bus_dev_del(struct nsim_bus_dev * nsim_bus_dev)348 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
349 {
350 /* Disallow using nsim_bus_dev */
351 smp_store_release(&nsim_bus_dev->init, false);
352 device_unregister(&nsim_bus_dev->dev);
353 ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
354 kfree(nsim_bus_dev);
355 }
356
357 static struct device_driver nsim_driver = {
358 .name = DRV_NAME,
359 .bus = &nsim_bus,
360 .owner = THIS_MODULE,
361 };
362
nsim_bus_init(void)363 int nsim_bus_init(void)
364 {
365 int err;
366
367 err = bus_register(&nsim_bus);
368 if (err)
369 return err;
370 err = driver_register(&nsim_driver);
371 if (err)
372 goto err_bus_unregister;
373 /* Allow using resources */
374 smp_store_release(&nsim_bus_enable, true);
375 return 0;
376
377 err_bus_unregister:
378 bus_unregister(&nsim_bus);
379 return err;
380 }
381
nsim_bus_exit(void)382 void nsim_bus_exit(void)
383 {
384 struct nsim_bus_dev *nsim_bus_dev, *tmp;
385
386 /* Disallow using resources */
387 smp_store_release(&nsim_bus_enable, false);
388
389 mutex_lock(&nsim_bus_dev_list_lock);
390 list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
391 list_del(&nsim_bus_dev->list);
392 nsim_bus_dev_del(nsim_bus_dev);
393 }
394 mutex_unlock(&nsim_bus_dev_list_lock);
395
396 driver_unregister(&nsim_driver);
397 bus_unregister(&nsim_bus);
398 }
399