xref: /openbmc/linux/drivers/net/netdevsim/bus.c (revision 77423a62)
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 	ret = nsim_drv_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
76 	return ret ? ret : count;
77 }
78 
79 static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
80 
81 static ssize_t
82 del_port_store(struct device *dev, struct device_attribute *attr,
83 	       const char *buf, size_t count)
84 {
85 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
86 	unsigned int port_index;
87 	int ret;
88 
89 	/* Prevent to use nsim_bus_dev before initialization. */
90 	if (!smp_load_acquire(&nsim_bus_dev->init))
91 		return -EBUSY;
92 	ret = kstrtouint(buf, 0, &port_index);
93 	if (ret)
94 		return ret;
95 
96 	ret = nsim_drv_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
97 	return ret ? ret : count;
98 }
99 
100 static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
101 
102 static struct attribute *nsim_bus_dev_attrs[] = {
103 	&nsim_bus_dev_numvfs_attr.attr,
104 	&nsim_bus_dev_new_port_attr.attr,
105 	&nsim_bus_dev_del_port_attr.attr,
106 	NULL,
107 };
108 
109 static const struct attribute_group nsim_bus_dev_attr_group = {
110 	.attrs = nsim_bus_dev_attrs,
111 };
112 
113 static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
114 	&nsim_bus_dev_attr_group,
115 	NULL,
116 };
117 
118 static void nsim_bus_dev_release(struct device *dev)
119 {
120 }
121 
122 static struct device_type nsim_bus_dev_type = {
123 	.groups = nsim_bus_dev_attr_groups,
124 	.release = nsim_bus_dev_release,
125 };
126 
127 static struct nsim_bus_dev *
128 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);
129 
130 static ssize_t
131 new_device_store(struct bus_type *bus, const char *buf, size_t count)
132 {
133 	unsigned int id, port_count, num_queues;
134 	struct nsim_bus_dev *nsim_bus_dev;
135 	int err;
136 
137 	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
138 	switch (err) {
139 	case 1:
140 		port_count = 1;
141 		fallthrough;
142 	case 2:
143 		num_queues = 1;
144 		fallthrough;
145 	case 3:
146 		if (id > INT_MAX) {
147 			pr_err("Value of \"id\" is too big.\n");
148 			return -EINVAL;
149 		}
150 		break;
151 	default:
152 		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
153 		return -EINVAL;
154 	}
155 
156 	mutex_lock(&nsim_bus_dev_list_lock);
157 	/* Prevent to use resource before initialization. */
158 	if (!smp_load_acquire(&nsim_bus_enable)) {
159 		err = -EBUSY;
160 		goto err;
161 	}
162 
163 	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
164 	if (IS_ERR(nsim_bus_dev)) {
165 		err = PTR_ERR(nsim_bus_dev);
166 		goto err;
167 	}
168 
169 	/* Allow using nsim_bus_dev */
170 	smp_store_release(&nsim_bus_dev->init, true);
171 
172 	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
173 	mutex_unlock(&nsim_bus_dev_list_lock);
174 
175 	return count;
176 err:
177 	mutex_unlock(&nsim_bus_dev_list_lock);
178 	return err;
179 }
180 static BUS_ATTR_WO(new_device);
181 
182 static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
183 
184 static ssize_t
185 del_device_store(struct bus_type *bus, const char *buf, size_t count)
186 {
187 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
188 	unsigned int id;
189 	int err;
190 
191 	err = sscanf(buf, "%u", &id);
192 	switch (err) {
193 	case 1:
194 		if (id > INT_MAX) {
195 			pr_err("Value of \"id\" is too big.\n");
196 			return -EINVAL;
197 		}
198 		break;
199 	default:
200 		pr_err("Format for deleting device is \"id\" (uint).\n");
201 		return -EINVAL;
202 	}
203 
204 	err = -ENOENT;
205 	mutex_lock(&nsim_bus_dev_list_lock);
206 	/* Prevent to use resource before initialization. */
207 	if (!smp_load_acquire(&nsim_bus_enable)) {
208 		mutex_unlock(&nsim_bus_dev_list_lock);
209 		return -EBUSY;
210 	}
211 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
212 		if (nsim_bus_dev->dev.id != id)
213 			continue;
214 		list_del(&nsim_bus_dev->list);
215 		nsim_bus_dev_del(nsim_bus_dev);
216 		err = 0;
217 		break;
218 	}
219 	mutex_unlock(&nsim_bus_dev_list_lock);
220 	return !err ? count : err;
221 }
222 static BUS_ATTR_WO(del_device);
223 
224 static struct attribute *nsim_bus_attrs[] = {
225 	&bus_attr_new_device.attr,
226 	&bus_attr_del_device.attr,
227 	NULL
228 };
229 ATTRIBUTE_GROUPS(nsim_bus);
230 
231 static int nsim_bus_probe(struct device *dev)
232 {
233 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
234 
235 	return nsim_drv_probe(nsim_bus_dev);
236 }
237 
238 static void nsim_bus_remove(struct device *dev)
239 {
240 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
241 
242 	nsim_drv_remove(nsim_bus_dev);
243 }
244 
245 static int nsim_num_vf(struct device *dev)
246 {
247 	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
248 
249 	return nsim_bus_dev->num_vfs;
250 }
251 
252 static struct bus_type nsim_bus = {
253 	.name		= DRV_NAME,
254 	.dev_name	= DRV_NAME,
255 	.bus_groups	= nsim_bus_groups,
256 	.probe		= nsim_bus_probe,
257 	.remove		= nsim_bus_remove,
258 	.num_vf		= nsim_num_vf,
259 };
260 
261 #define NSIM_BUS_DEV_MAX_VFS 4
262 
263 static struct nsim_bus_dev *
264 nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
265 {
266 	struct nsim_bus_dev *nsim_bus_dev;
267 	int err;
268 
269 	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
270 	if (!nsim_bus_dev)
271 		return ERR_PTR(-ENOMEM);
272 
273 	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
274 	if (err < 0)
275 		goto err_nsim_bus_dev_free;
276 	nsim_bus_dev->dev.id = err;
277 	nsim_bus_dev->dev.bus = &nsim_bus;
278 	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
279 	nsim_bus_dev->port_count = port_count;
280 	nsim_bus_dev->num_queues = num_queues;
281 	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
282 	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
283 	/* Disallow using nsim_bus_dev */
284 	smp_store_release(&nsim_bus_dev->init, false);
285 
286 	err = device_register(&nsim_bus_dev->dev);
287 	if (err)
288 		goto err_nsim_bus_dev_id_free;
289 
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 	/* Disallow using nsim_bus_dev */
302 	smp_store_release(&nsim_bus_dev->init, false);
303 	device_unregister(&nsim_bus_dev->dev);
304 	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
305 	kfree(nsim_bus_dev);
306 }
307 
308 static struct device_driver nsim_driver = {
309 	.name		= DRV_NAME,
310 	.bus		= &nsim_bus,
311 	.owner		= THIS_MODULE,
312 };
313 
314 int nsim_bus_init(void)
315 {
316 	int err;
317 
318 	err = bus_register(&nsim_bus);
319 	if (err)
320 		return err;
321 	err = driver_register(&nsim_driver);
322 	if (err)
323 		goto err_bus_unregister;
324 	/* Allow using resources */
325 	smp_store_release(&nsim_bus_enable, true);
326 	return 0;
327 
328 err_bus_unregister:
329 	bus_unregister(&nsim_bus);
330 	return err;
331 }
332 
333 void nsim_bus_exit(void)
334 {
335 	struct nsim_bus_dev *nsim_bus_dev, *tmp;
336 
337 	/* Disallow using resources */
338 	smp_store_release(&nsim_bus_enable, false);
339 
340 	mutex_lock(&nsim_bus_dev_list_lock);
341 	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
342 		list_del(&nsim_bus_dev->list);
343 		nsim_bus_dev_del(nsim_bus_dev);
344 	}
345 	mutex_unlock(&nsim_bus_dev_list_lock);
346 
347 	driver_unregister(&nsim_driver);
348 	bus_unregister(&nsim_bus);
349 }
350