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
16static DEFINE_IDA(nsim_bus_dev_ids);
17static LIST_HEAD(nsim_bus_dev_list);
18static DEFINE_MUTEX(nsim_bus_dev_list_lock);
19static bool nsim_bus_enable;
20
21static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
22{
23	return container_of(dev, struct nsim_bus_dev, dev);
24}
25
26static ssize_t
27nsim_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
47static ssize_t
48nsim_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
56static 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
60static ssize_t
61new_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
79static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
80
81static ssize_t
82del_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
100static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
101
102static 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
109static const struct attribute_group nsim_bus_dev_attr_group = {
110	.attrs = nsim_bus_dev_attrs,
111};
112
113static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
114	&nsim_bus_dev_attr_group,
115	NULL,
116};
117
118static void nsim_bus_dev_release(struct device *dev)
119{
120	struct nsim_bus_dev *nsim_bus_dev;
121
122	nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev);
123	kfree(nsim_bus_dev);
124}
125
126static struct device_type nsim_bus_dev_type = {
127	.groups = nsim_bus_dev_attr_groups,
128	.release = nsim_bus_dev_release,
129};
130
131static struct nsim_bus_dev *
132nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues);
133
134static ssize_t
135new_device_store(const struct bus_type *bus, const char *buf, size_t count)
136{
137	unsigned int id, port_count, num_queues;
138	struct nsim_bus_dev *nsim_bus_dev;
139	int err;
140
141	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
142	switch (err) {
143	case 1:
144		port_count = 1;
145		fallthrough;
146	case 2:
147		num_queues = 1;
148		fallthrough;
149	case 3:
150		if (id > INT_MAX) {
151			pr_err("Value of \"id\" is too big.\n");
152			return -EINVAL;
153		}
154		break;
155	default:
156		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint unit).\n");
157		return -EINVAL;
158	}
159
160	mutex_lock(&nsim_bus_dev_list_lock);
161	/* Prevent to use resource before initialization. */
162	if (!smp_load_acquire(&nsim_bus_enable)) {
163		err = -EBUSY;
164		goto err;
165	}
166
167	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
168	if (IS_ERR(nsim_bus_dev)) {
169		err = PTR_ERR(nsim_bus_dev);
170		goto err;
171	}
172
173	/* Allow using nsim_bus_dev */
174	smp_store_release(&nsim_bus_dev->init, true);
175
176	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
177	mutex_unlock(&nsim_bus_dev_list_lock);
178
179	return count;
180err:
181	mutex_unlock(&nsim_bus_dev_list_lock);
182	return err;
183}
184static BUS_ATTR_WO(new_device);
185
186static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
187
188static ssize_t
189del_device_store(const struct bus_type *bus, const char *buf, size_t count)
190{
191	struct nsim_bus_dev *nsim_bus_dev, *tmp;
192	unsigned int id;
193	int err;
194
195	err = sscanf(buf, "%u", &id);
196	switch (err) {
197	case 1:
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 deleting device is \"id\" (uint).\n");
205		return -EINVAL;
206	}
207
208	err = -ENOENT;
209	mutex_lock(&nsim_bus_dev_list_lock);
210	/* Prevent to use resource before initialization. */
211	if (!smp_load_acquire(&nsim_bus_enable)) {
212		mutex_unlock(&nsim_bus_dev_list_lock);
213		return -EBUSY;
214	}
215	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
216		if (nsim_bus_dev->dev.id != id)
217			continue;
218		list_del(&nsim_bus_dev->list);
219		nsim_bus_dev_del(nsim_bus_dev);
220		err = 0;
221		break;
222	}
223	mutex_unlock(&nsim_bus_dev_list_lock);
224	return !err ? count : err;
225}
226static BUS_ATTR_WO(del_device);
227
228static struct attribute *nsim_bus_attrs[] = {
229	&bus_attr_new_device.attr,
230	&bus_attr_del_device.attr,
231	NULL
232};
233ATTRIBUTE_GROUPS(nsim_bus);
234
235static int nsim_bus_probe(struct device *dev)
236{
237	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
238
239	return nsim_drv_probe(nsim_bus_dev);
240}
241
242static void nsim_bus_remove(struct device *dev)
243{
244	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
245
246	nsim_drv_remove(nsim_bus_dev);
247}
248
249static int nsim_num_vf(struct device *dev)
250{
251	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
252
253	return nsim_bus_dev->num_vfs;
254}
255
256static struct bus_type nsim_bus = {
257	.name		= DRV_NAME,
258	.dev_name	= DRV_NAME,
259	.bus_groups	= nsim_bus_groups,
260	.probe		= nsim_bus_probe,
261	.remove		= nsim_bus_remove,
262	.num_vf		= nsim_num_vf,
263};
264
265#define NSIM_BUS_DEV_MAX_VFS 4
266
267static struct nsim_bus_dev *
268nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queues)
269{
270	struct nsim_bus_dev *nsim_bus_dev;
271	int err;
272
273	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
274	if (!nsim_bus_dev)
275		return ERR_PTR(-ENOMEM);
276
277	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
278	if (err < 0)
279		goto err_nsim_bus_dev_free;
280	nsim_bus_dev->dev.id = err;
281	nsim_bus_dev->dev.bus = &nsim_bus;
282	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
283	nsim_bus_dev->port_count = port_count;
284	nsim_bus_dev->num_queues = num_queues;
285	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
286	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
287	/* Disallow using nsim_bus_dev */
288	smp_store_release(&nsim_bus_dev->init, false);
289
290	err = device_register(&nsim_bus_dev->dev);
291	if (err)
292		goto err_nsim_bus_dev_id_free;
293
294	return nsim_bus_dev;
295
296err_nsim_bus_dev_id_free:
297	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
298	put_device(&nsim_bus_dev->dev);
299	nsim_bus_dev = NULL;
300err_nsim_bus_dev_free:
301	kfree(nsim_bus_dev);
302	return ERR_PTR(err);
303}
304
305static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
306{
307	/* Disallow using nsim_bus_dev */
308	smp_store_release(&nsim_bus_dev->init, false);
309	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
310	device_unregister(&nsim_bus_dev->dev);
311}
312
313static struct device_driver nsim_driver = {
314	.name		= DRV_NAME,
315	.bus		= &nsim_bus,
316	.owner		= THIS_MODULE,
317};
318
319int nsim_bus_init(void)
320{
321	int err;
322
323	err = bus_register(&nsim_bus);
324	if (err)
325		return err;
326	err = driver_register(&nsim_driver);
327	if (err)
328		goto err_bus_unregister;
329	/* Allow using resources */
330	smp_store_release(&nsim_bus_enable, true);
331	return 0;
332
333err_bus_unregister:
334	bus_unregister(&nsim_bus);
335	return err;
336}
337
338void nsim_bus_exit(void)
339{
340	struct nsim_bus_dev *nsim_bus_dev, *tmp;
341
342	/* Disallow using resources */
343	smp_store_release(&nsim_bus_enable, false);
344
345	mutex_lock(&nsim_bus_dev_list_lock);
346	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
347		list_del(&nsim_bus_dev->list);
348		nsim_bus_dev_del(nsim_bus_dev);
349	}
350	mutex_unlock(&nsim_bus_dev_list_lock);
351
352	driver_unregister(&nsim_driver);
353	bus_unregister(&nsim_bus);
354}
355