xref: /openbmc/linux/drivers/net/netdevsim/bus.c (revision 20e2fc42)
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 
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 int nsim_bus_dev_vfs_enable(struct nsim_bus_dev *nsim_bus_dev,
27 				   unsigned int num_vfs)
28 {
29 	nsim_bus_dev->vfconfigs = kcalloc(num_vfs,
30 					  sizeof(struct nsim_vf_config),
31 					  GFP_KERNEL);
32 	if (!nsim_bus_dev->vfconfigs)
33 		return -ENOMEM;
34 	nsim_bus_dev->num_vfs = num_vfs;
35 
36 	return 0;
37 }
38 
39 static void nsim_bus_dev_vfs_disable(struct nsim_bus_dev *nsim_bus_dev)
40 {
41 	kfree(nsim_bus_dev->vfconfigs);
42 	nsim_bus_dev->vfconfigs = NULL;
43 	nsim_bus_dev->num_vfs = 0;
44 }
45 
46 static ssize_t
47 nsim_bus_dev_numvfs_store(struct device *dev, struct device_attribute *attr,
48 			  const char *buf, size_t count)
49 {
50 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
51 	unsigned int num_vfs;
52 	int ret;
53 
54 	ret = kstrtouint(buf, 0, &num_vfs);
55 	if (ret)
56 		return ret;
57 
58 	rtnl_lock();
59 	if (nsim_bus_dev->num_vfs == num_vfs)
60 		goto exit_good;
61 	if (nsim_bus_dev->num_vfs && num_vfs) {
62 		ret = -EBUSY;
63 		goto exit_unlock;
64 	}
65 
66 	if (num_vfs) {
67 		ret = nsim_bus_dev_vfs_enable(nsim_bus_dev, num_vfs);
68 		if (ret)
69 			goto exit_unlock;
70 	} else {
71 		nsim_bus_dev_vfs_disable(nsim_bus_dev);
72 	}
73 exit_good:
74 	ret = count;
75 exit_unlock:
76 	rtnl_unlock();
77 
78 	return ret;
79 }
80 
81 static ssize_t
82 nsim_bus_dev_numvfs_show(struct device *dev,
83 			 struct device_attribute *attr, char *buf)
84 {
85 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
86 
87 	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
88 }
89 
90 static struct device_attribute nsim_bus_dev_numvfs_attr =
91 	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
92 	       nsim_bus_dev_numvfs_store);
93 
94 static ssize_t
95 new_port_store(struct device *dev, struct device_attribute *attr,
96 	       const char *buf, size_t count)
97 {
98 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
99 	unsigned int port_index;
100 	int ret;
101 
102 	ret = kstrtouint(buf, 0, &port_index);
103 	if (ret)
104 		return ret;
105 	ret = nsim_dev_port_add(nsim_bus_dev, port_index);
106 	return ret ? ret : count;
107 }
108 
109 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
110 
111 static ssize_t
112 del_port_store(struct device *dev, struct device_attribute *attr,
113 	       const char *buf, size_t count)
114 {
115 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
116 	unsigned int port_index;
117 	int ret;
118 
119 	ret = kstrtouint(buf, 0, &port_index);
120 	if (ret)
121 		return ret;
122 	ret = nsim_dev_port_del(nsim_bus_dev, port_index);
123 	return ret ? ret : count;
124 }
125 
126 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
127 
128 static struct attribute *nsim_bus_dev_attrs[] = {
129 	&nsim_bus_dev_numvfs_attr.attr,
130 	&nsim_bus_dev_new_port_attr.attr,
131 	&nsim_bus_dev_del_port_attr.attr,
132 	NULL,
133 };
134 
135 static const struct attribute_group nsim_bus_dev_attr_group = {
136 	.attrs = nsim_bus_dev_attrs,
137 };
138 
139 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
140 	&nsim_bus_dev_attr_group,
141 	NULL,
142 };
143 
144 static void nsim_bus_dev_release(struct device *dev)
145 {
146 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
147 
148 	nsim_bus_dev_vfs_disable(nsim_bus_dev);
149 }
150 
151 static struct device_type nsim_bus_dev_type = {
152 	.groups = nsim_bus_dev_attr_groups,
153 	.release = nsim_bus_dev_release,
154 };
155 
156 static struct nsim_bus_dev *
157 nsim_bus_dev_new(unsigned int id, unsigned int port_count);
158 
159 static ssize_t
160 new_device_store(struct bus_type *bus, const char *buf, size_t count)
161 {
162 	struct nsim_bus_dev *nsim_bus_dev;
163 	unsigned int port_count;
164 	unsigned int id;
165 	int err;
166 
167 	err = sscanf(buf, "%u %u", &id, &port_count);
168 	switch (err) {
169 	case 1:
170 		port_count = 1;
171 		/* fall through */
172 	case 2:
173 		if (id > INT_MAX) {
174 			pr_err("Value of \"id\" is too big.\n");
175 			return -EINVAL;
176 		}
177 		break;
178 	default:
179 		pr_err("Format for adding new device is \"id port_count\" (uint uint).\n");
180 		return -EINVAL;
181 	}
182 	nsim_bus_dev = nsim_bus_dev_new(id, port_count);
183 	if (IS_ERR(nsim_bus_dev))
184 		return PTR_ERR(nsim_bus_dev);
185 
186 	mutex_lock(&nsim_bus_dev_list_lock);
187 	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
188 	mutex_unlock(&nsim_bus_dev_list_lock);
189 
190 	return count;
191 }
192 static BUS_ATTR_WO(new_device);
193 
194 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
195 
196 static ssize_t
197 del_device_store(struct bus_type *bus, const char *buf, size_t count)
198 {
199 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
200 	unsigned int id;
201 	int err;
202 
203 	err = sscanf(buf, "%u", &id);
204 	switch (err) {
205 	case 1:
206 		if (id > INT_MAX) {
207 			pr_err("Value of \"id\" is too big.\n");
208 			return -EINVAL;
209 		}
210 		break;
211 	default:
212 		pr_err("Format for deleting device is \"id\" (uint).\n");
213 		return -EINVAL;
214 	}
215 
216 	err = -ENOENT;
217 	mutex_lock(&nsim_bus_dev_list_lock);
218 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
219 		if (nsim_bus_dev->dev.id != id)
220 			continue;
221 		list_del(&nsim_bus_dev->list);
222 		nsim_bus_dev_del(nsim_bus_dev);
223 		err = 0;
224 		break;
225 	}
226 	mutex_unlock(&nsim_bus_dev_list_lock);
227 	return !err ? count : err;
228 }
229 static BUS_ATTR_WO(del_device);
230 
231 static struct attribute *nsim_bus_attrs[] = {
232 	&bus_attr_new_device.attr,
233 	&bus_attr_del_device.attr,
234 	NULL
235 };
236 ATTRIBUTE_GROUPS(nsim_bus);
237 
238 static int nsim_bus_probe(struct device *dev)
239 {
240 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
241 
242 	return nsim_dev_probe(nsim_bus_dev);
243 }
244 
245 static int nsim_bus_remove(struct device *dev)
246 {
247 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
248 
249 	nsim_dev_remove(nsim_bus_dev);
250 	return 0;
251 }
252 
253 static int nsim_num_vf(struct device *dev)
254 {
255 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
256 
257 	return nsim_bus_dev->num_vfs;
258 }
259 
260 static struct bus_type nsim_bus = {
261 	.name		= DRV_NAME,
262 	.dev_name	= DRV_NAME,
263 	.bus_groups	= nsim_bus_groups,
264 	.probe		= nsim_bus_probe,
265 	.remove		= nsim_bus_remove,
266 	.num_vf		= nsim_num_vf,
267 };
268 
269 static struct nsim_bus_dev *
270 nsim_bus_dev_new(unsigned int id, unsigned int port_count)
271 {
272 	struct nsim_bus_dev *nsim_bus_dev;
273 	int err;
274 
275 	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
276 	if (!nsim_bus_dev)
277 		return ERR_PTR(-ENOMEM);
278 
279 	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
280 	if (err < 0)
281 		goto err_nsim_bus_dev_free;
282 	nsim_bus_dev->dev.id = err;
283 	nsim_bus_dev->dev.bus = &nsim_bus;
284 	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
285 	nsim_bus_dev->port_count = port_count;
286 
287 	err = device_register(&nsim_bus_dev->dev);
288 	if (err)
289 		goto err_nsim_bus_dev_id_free;
290 	return nsim_bus_dev;
291 
292 err_nsim_bus_dev_id_free:
293 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
294 err_nsim_bus_dev_free:
295 	kfree(nsim_bus_dev);
296 	return ERR_PTR(err);
297 }
298 
299 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
300 {
301 	device_unregister(&nsim_bus_dev->dev);
302 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
303 	kfree(nsim_bus_dev);
304 }
305 
306 static struct device_driver nsim_driver = {
307 	.name		= DRV_NAME,
308 	.bus		= &nsim_bus,
309 	.owner		= THIS_MODULE,
310 };
311 
312 int nsim_bus_init(void)
313 {
314 	int err;
315 
316 	err = bus_register(&nsim_bus);
317 	if (err)
318 		return err;
319 	err = driver_register(&nsim_driver);
320 	if (err)
321 		goto err_bus_unregister;
322 	return 0;
323 
324 err_bus_unregister:
325 	bus_unregister(&nsim_bus);
326 	return err;
327 }
328 
329 void nsim_bus_exit(void)
330 {
331 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
332 
333 	mutex_lock(&nsim_bus_dev_list_lock);
334 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
335 		list_del(&nsim_bus_dev->list);
336 		nsim_bus_dev_del(nsim_bus_dev);
337 	}
338 	mutex_unlock(&nsim_bus_dev_list_lock);
339 	driver_unregister(&nsim_driver);
340 	bus_unregister(&nsim_bus);
341 }
342