xref: /openbmc/linux/drivers/net/netdevsim/bus.c (revision 2cf1c348)
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/slab.h>
12 #include <linux/sysfs.h>
13 
14 #include "netdevsim.h"
15 
16 static DEFINE_IDA(nsim_bus_dev_ids);
17 static LIST_HEAD(nsim_bus_dev_list);
18 static DEFINE_MUTEX(nsim_bus_dev_list_lock);
19 static bool nsim_bus_enable;
20 
21 static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
22 {
23 	return container_of(dev, struct nsim_bus_dev, dev);
24 }
25 
26 static ssize_t
27 nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
28 			  const char *buf, size_t count)
29 {
30 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
31 	unsigned int num_vfs;
32 	int ret;
33 
34 	ret = kstrtouint(buf, 0, &num_vfs);
35 	if (ret)
36 		return ret;
37 
38 	device_lock(dev);
39 	ret = -ENOENT;
40 	if (dev_get_drvdata(dev))
41 		ret = nsim_drv_configure_vfs(nsim_bus_dev, num_vfs);
42 	device_unlock(dev);
43 
44 	return ret ? ret : count;
45 }
46 
47 static ssize_t
48 nsim_bus_dev_numvfs_show(struct device *dev,
49 			 struct device_attribute *attr, char *buf)
50 {
51 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
52 
53 	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
54 }
55 
56 static struct device_attribute nsim_bus_dev_numvfs_attr =
57 	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
58 	       nsim_bus_dev_numvfs_store);
59 
60 static ssize_t
61 new_port_store(struct device *dev, struct device_attribute *attr,
62 	       const char *buf, size_t count)
63 {
64 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
65 	unsigned int port_index;
66 	int ret;
67 
68 	/* Prevent to use nsim_bus_dev before initialization. */
69 	if (!smp_load_acquire(&nsim_bus_dev->init))
70 		return -EBUSY;
71 	ret = kstrtouint(buf, 0, &port_index);
72 	if (ret)
73 		return ret;
74 
75 	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
76 		return -EBUSY;
77 
78 	if (nsim_bus_dev->in_reload) {
79 		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
80 		return -EBUSY;
81 	}
82 
83 	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
84 	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
85 	return ret ? ret : count;
86 }
87 
88 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
89 
90 static ssize_t
91 del_port_store(struct device *dev, struct device_attribute *attr,
92 	       const char *buf, size_t count)
93 {
94 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
95 	unsigned int port_index;
96 	int ret;
97 
98 	/* Prevent to use nsim_bus_dev before initialization. */
99 	if (!smp_load_acquire(&nsim_bus_dev->init))
100 		return -EBUSY;
101 	ret = kstrtouint(buf, 0, &port_index);
102 	if (ret)
103 		return ret;
104 
105 	if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
106 		return -EBUSY;
107 
108 	if (nsim_bus_dev->in_reload) {
109 		mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
110 		return -EBUSY;
111 	}
112 
113 	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
114 	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
115 	return ret ? ret : count;
116 }
117 
118 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
119 
120 static struct attribute *nsim_bus_dev_attrs[] = {
121 	&nsim_bus_dev_numvfs_attr.attr,
122 	&nsim_bus_dev_new_port_attr.attr,
123 	&nsim_bus_dev_del_port_attr.attr,
124 	NULL,
125 };
126 
127 static const struct attribute_group nsim_bus_dev_attr_group = {
128 	.attrs = nsim_bus_dev_attrs,
129 };
130 
131 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
132 	&nsim_bus_dev_attr_group,
133 	NULL,
134 };
135 
136 static void nsim_bus_dev_release(struct device *dev)
137 {
138 }
139 
140 static struct device_type nsim_bus_dev_type = {
141 	.groups = nsim_bus_dev_attr_groups,
142 	.release = nsim_bus_dev_release,
143 };
144 
145 static struct nsim_bus_dev *
146 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);
147 
148 static ssize_t
149 new_device_store(struct bus_type *bus, const char *buf, size_t count)
150 {
151 	unsigned int id, port_count, num_queues;
152 	struct nsim_bus_dev *nsim_bus_dev;
153 	int err;
154 
155 	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
156 	switch (err) {
157 	case 1:
158 		port_count = 1;
159 		fallthrough;
160 	case 2:
161 		num_queues = 1;
162 		fallthrough;
163 	case 3:
164 		if (id > INT_MAX) {
165 			pr_err("Value of \"id\" is too big.\n");
166 			return -EINVAL;
167 		}
168 		break;
169 	default:
170 		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
171 		return -EINVAL;
172 	}
173 
174 	mutex_lock(&nsim_bus_dev_list_lock);
175 	/* Prevent to use resource before initialization. */
176 	if (!smp_load_acquire(&nsim_bus_enable)) {
177 		err = -EBUSY;
178 		goto err;
179 	}
180 
181 	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
182 	if (IS_ERR(nsim_bus_dev)) {
183 		err = PTR_ERR(nsim_bus_dev);
184 		goto err;
185 	}
186 
187 	/* Allow using nsim_bus_dev */
188 	smp_store_release(&nsim_bus_dev->init, true);
189 
190 	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
191 	mutex_unlock(&nsim_bus_dev_list_lock);
192 
193 	return count;
194 err:
195 	mutex_unlock(&nsim_bus_dev_list_lock);
196 	return err;
197 }
198 static BUS_ATTR_WO(new_device);
199 
200 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
201 
202 static ssize_t
203 del_device_store(struct bus_type *bus, const char *buf, size_t count)
204 {
205 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
206 	unsigned int id;
207 	int err;
208 
209 	err = sscanf(buf, "%u", &id);
210 	switch (err) {
211 	case 1:
212 		if (id > INT_MAX) {
213 			pr_err("Value of \"id\" is too big.\n");
214 			return -EINVAL;
215 		}
216 		break;
217 	default:
218 		pr_err("Format for deleting device is \"id\" (uint).\n");
219 		return -EINVAL;
220 	}
221 
222 	err = -ENOENT;
223 	mutex_lock(&nsim_bus_dev_list_lock);
224 	/* Prevent to use resource before initialization. */
225 	if (!smp_load_acquire(&nsim_bus_enable)) {
226 		mutex_unlock(&nsim_bus_dev_list_lock);
227 		return -EBUSY;
228 	}
229 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
230 		if (nsim_bus_dev->dev.id != id)
231 			continue;
232 		list_del(&nsim_bus_dev->list);
233 		nsim_bus_dev_del(nsim_bus_dev);
234 		err = 0;
235 		break;
236 	}
237 	mutex_unlock(&nsim_bus_dev_list_lock);
238 	return !err ? count : err;
239 }
240 static BUS_ATTR_WO(del_device);
241 
242 static struct attribute *nsim_bus_attrs[] = {
243 	&bus_attr_new_device.attr,
244 	&bus_attr_del_device.attr,
245 	NULL
246 };
247 ATTRIBUTE_GROUPS(nsim_bus);
248 
249 static int nsim_bus_probe(struct device *dev)
250 {
251 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
252 
253 	return nsim_drv_probe(nsim_bus_dev);
254 }
255 
256 static void nsim_bus_remove(struct device *dev)
257 {
258 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
259 
260 	nsim_drv_remove(nsim_bus_dev);
261 }
262 
263 static int nsim_num_vf(struct device *dev)
264 {
265 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
266 
267 	return nsim_bus_dev->num_vfs;
268 }
269 
270 static struct bus_type nsim_bus = {
271 	.name		= DRV_NAME,
272 	.dev_name	= DRV_NAME,
273 	.bus_groups	= nsim_bus_groups,
274 	.probe		= nsim_bus_probe,
275 	.remove		= nsim_bus_remove,
276 	.num_vf		= nsim_num_vf,
277 };
278 
279 #define NSIM_BUS_DEV_MAX_VFS 4
280 
281 static struct nsim_bus_dev *
282 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
283 {
284 	struct nsim_bus_dev *nsim_bus_dev;
285 	int err;
286 
287 	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
288 	if (!nsim_bus_dev)
289 		return ERR_PTR(-ENOMEM);
290 
291 	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
292 	if (err < 0)
293 		goto err_nsim_bus_dev_free;
294 	nsim_bus_dev->dev.id = err;
295 	nsim_bus_dev->dev.bus = &nsim_bus;
296 	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
297 	nsim_bus_dev->port_count = port_count;
298 	nsim_bus_dev->num_queues = num_queues;
299 	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
300 	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
301 	mutex_init(&nsim_bus_dev->nsim_bus_reload_lock);
302 	/* Disallow using nsim_bus_dev */
303 	smp_store_release(&nsim_bus_dev->init, false);
304 
305 	err = device_register(&nsim_bus_dev->dev);
306 	if (err)
307 		goto err_nsim_bus_dev_id_free;
308 
309 	return nsim_bus_dev;
310 
311 err_nsim_bus_dev_id_free:
312 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
313 err_nsim_bus_dev_free:
314 	kfree(nsim_bus_dev);
315 	return ERR_PTR(err);
316 }
317 
318 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
319 {
320 	/* Disallow using nsim_bus_dev */
321 	smp_store_release(&nsim_bus_dev->init, false);
322 	device_unregister(&nsim_bus_dev->dev);
323 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
324 	kfree(nsim_bus_dev);
325 }
326 
327 static struct device_driver nsim_driver = {
328 	.name		= DRV_NAME,
329 	.bus		= &nsim_bus,
330 	.owner		= THIS_MODULE,
331 };
332 
333 int nsim_bus_init(void)
334 {
335 	int err;
336 
337 	err = bus_register(&nsim_bus);
338 	if (err)
339 		return err;
340 	err = driver_register(&nsim_driver);
341 	if (err)
342 		goto err_bus_unregister;
343 	/* Allow using resources */
344 	smp_store_release(&nsim_bus_enable, true);
345 	return 0;
346 
347 err_bus_unregister:
348 	bus_unregister(&nsim_bus);
349 	return err;
350 }
351 
352 void nsim_bus_exit(void)
353 {
354 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
355 
356 	/* Disallow using resources */
357 	smp_store_release(&nsim_bus_enable, false);
358 
359 	mutex_lock(&nsim_bus_dev_list_lock);
360 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
361 		list_del(&nsim_bus_dev->list);
362 		nsim_bus_dev_del(nsim_bus_dev);
363 	}
364 	mutex_unlock(&nsim_bus_dev_list_lock);
365 
366 	driver_unregister(&nsim_driver);
367 	bus_unregister(&nsim_bus);
368 }
369