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  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
 17static DEFINE_IDA(nsim_bus_dev_ids);
 18static LIST_HEAD(nsim_bus_dev_list);
 19static DEFINE_MUTEX(nsim_bus_dev_list_lock);
 20static bool nsim_bus_enable;
 21
 22static struct nsim_bus_dev *to_nsim_bus_dev(struct device *dev)
 23{
 24	return container_of(dev, struct nsim_bus_dev, dev);
 25}
 26
 27static int nsim_bus_dev_vfs_enable(struct nsim_bus_dev *nsim_bus_dev,
 28				   unsigned int num_vfs)
 29{
 30	struct nsim_dev *nsim_dev;
 31	int err = 0;
 32
 33	if (nsim_bus_dev->max_vfs < num_vfs)
 34		return -ENOMEM;
 35
 36	if (!nsim_bus_dev->vfconfigs)
 37		return -ENOMEM;
 38	nsim_bus_dev->num_vfs = num_vfs;
 39
 40	nsim_dev = dev_get_drvdata(&nsim_bus_dev->dev);
 41	if (nsim_esw_mode_is_switchdev(nsim_dev)) {
 42		err = nsim_esw_switchdev_enable(nsim_dev, NULL);
 43		if (err)
 44			nsim_bus_dev->num_vfs = 0;
 45	}
 46
 47	return err;
 48}
 49
 50void nsim_bus_dev_vfs_disable(struct nsim_bus_dev *nsim_bus_dev)
 51{
 52	struct nsim_dev *nsim_dev;
 53
 54	nsim_bus_dev->num_vfs = 0;
 55	nsim_dev = dev_get_drvdata(&nsim_bus_dev->dev);
 56	if (nsim_esw_mode_is_switchdev(nsim_dev))
 57		nsim_esw_legacy_enable(nsim_dev, NULL);
 58}
 59
 60static ssize_t
 61nsim_bus_dev_numvfs_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 num_vfs;
 66	int ret;
 67
 68	ret = kstrtouint(buf, 0, &num_vfs);
 69	if (ret)
 70		return ret;
 71
 72	mutex_lock(&nsim_bus_dev->vfs_lock);
 73	if (nsim_bus_dev->num_vfs == num_vfs)
 74		goto exit_good;
 75	if (nsim_bus_dev->num_vfs && num_vfs) {
 76		ret = -EBUSY;
 77		goto exit_unlock;
 78	}
 79
 80	if (num_vfs) {
 81		ret = nsim_bus_dev_vfs_enable(nsim_bus_dev, num_vfs);
 82		if (ret)
 83			goto exit_unlock;
 84	} else {
 85		nsim_bus_dev_vfs_disable(nsim_bus_dev);
 86	}
 87exit_good:
 88	ret = count;
 89exit_unlock:
 90	mutex_unlock(&nsim_bus_dev->vfs_lock);
 91
 92	return ret;
 93}
 94
 95static ssize_t
 96nsim_bus_dev_numvfs_show(struct device *dev,
 97			 struct device_attribute *attr, char *buf)
 98{
 99	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
100
101	return sprintf(buf, "%u\n", nsim_bus_dev->num_vfs);
102}
103
104static struct device_attribute nsim_bus_dev_numvfs_attr =
105	__ATTR(sriov_numvfs, 0664, nsim_bus_dev_numvfs_show,
106	       nsim_bus_dev_numvfs_store);
107
108ssize_t nsim_bus_dev_max_vfs_read(struct file *file,
109				  char __user *data,
110				  size_t count, loff_t *ppos)
111{
112	struct nsim_bus_dev *nsim_bus_dev = file->private_data;
113	char buf[11];
114	ssize_t len;
115
116	len = snprintf(buf, sizeof(buf), "%u\n", nsim_bus_dev->max_vfs);
117	if (len < 0)
118		return len;
119
120	return simple_read_from_buffer(data, count, ppos, buf, len);
121}
122
123ssize_t nsim_bus_dev_max_vfs_write(struct file *file,
124				   const char __user *data,
125				   size_t count, loff_t *ppos)
126{
127	struct nsim_bus_dev *nsim_bus_dev = file->private_data;
128	struct nsim_vf_config *vfconfigs;
129	ssize_t ret;
130	char buf[10];
131	u32 val;
132
133	if (*ppos != 0)
134		return 0;
135
136	if (count >= sizeof(buf))
137		return -ENOSPC;
138
139	mutex_lock(&nsim_bus_dev->vfs_lock);
140	/* Reject if VFs are configured */
141	if (nsim_bus_dev->num_vfs) {
142		ret = -EBUSY;
143		goto unlock;
144	}
145
146	ret = copy_from_user(buf, data, count);
147	if (ret) {
148		ret = -EFAULT;
149		goto unlock;
150	}
151
152	buf[count] = '\0';
153	ret = kstrtouint(buf, 10, &val);
154	if (ret) {
155		ret = -EIO;
156		goto unlock;
157	}
158
159	/* max_vfs limited by the maximum number of provided port indexes */
160	if (val > NSIM_DEV_VF_PORT_INDEX_MAX - NSIM_DEV_VF_PORT_INDEX_BASE) {
161		ret = -ERANGE;
162		goto unlock;
163	}
164
165	vfconfigs = kcalloc(val, sizeof(struct nsim_vf_config), GFP_KERNEL | __GFP_NOWARN);
166	if (!vfconfigs) {
167		ret = -ENOMEM;
168		goto unlock;
169	}
170
171	kfree(nsim_bus_dev->vfconfigs);
172	nsim_bus_dev->vfconfigs = vfconfigs;
173	nsim_bus_dev->max_vfs = val;
174	*ppos += count;
175	ret = count;
176unlock:
177	mutex_unlock(&nsim_bus_dev->vfs_lock);
178	return ret;
179}
180
181static ssize_t
182new_port_store(struct device *dev, struct device_attribute *attr,
183	       const char *buf, size_t count)
184{
185	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
186	struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
187	struct devlink *devlink;
188	unsigned int port_index;
189	int ret;
190
191	/* Prevent to use nsim_bus_dev before initialization. */
192	if (!smp_load_acquire(&nsim_bus_dev->init))
193		return -EBUSY;
194	ret = kstrtouint(buf, 0, &port_index);
195	if (ret)
196		return ret;
197
198	devlink = priv_to_devlink(nsim_dev);
199
200	mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
201	devlink_reload_disable(devlink);
202	ret = nsim_dev_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
203	devlink_reload_enable(devlink);
204	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
205	return ret ? ret : count;
206}
207
208static struct device_attribute nsim_bus_dev_new_port_attr = __ATTR_WO(new_port);
209
210static ssize_t
211del_port_store(struct device *dev, struct device_attribute *attr,
212	       const char *buf, size_t count)
213{
214	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
215	struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
216	struct devlink *devlink;
217	unsigned int port_index;
218	int ret;
219
220	/* Prevent to use nsim_bus_dev before initialization. */
221	if (!smp_load_acquire(&nsim_bus_dev->init))
222		return -EBUSY;
223	ret = kstrtouint(buf, 0, &port_index);
224	if (ret)
225		return ret;
226
227	devlink = priv_to_devlink(nsim_dev);
228
229	mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
230	devlink_reload_disable(devlink);
231	ret = nsim_dev_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
232	devlink_reload_enable(devlink);
233	mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
234	return ret ? ret : count;
235}
236
237static struct device_attribute nsim_bus_dev_del_port_attr = __ATTR_WO(del_port);
238
239static struct attribute *nsim_bus_dev_attrs[] = {
240	&nsim_bus_dev_numvfs_attr.attr,
241	&nsim_bus_dev_new_port_attr.attr,
242	&nsim_bus_dev_del_port_attr.attr,
243	NULL,
244};
245
246static const struct attribute_group nsim_bus_dev_attr_group = {
247	.attrs = nsim_bus_dev_attrs,
248};
249
250static const struct attribute_group *nsim_bus_dev_attr_groups[] = {
251	&nsim_bus_dev_attr_group,
252	NULL,
253};
254
255static void nsim_bus_dev_release(struct device *dev)
256{
257}
258
259static struct device_type nsim_bus_dev_type = {
260	.groups = nsim_bus_dev_attr_groups,
261	.release = nsim_bus_dev_release,
262};
263
264static struct nsim_bus_dev *
265nsim_bus_dev_new(unsigned int id, unsigned int port_count);
266
267static ssize_t
268new_device_store(struct bus_type *bus, const char *buf, size_t count)
269{
270	struct nsim_bus_dev *nsim_bus_dev;
271	unsigned int port_count;
272	unsigned int id;
273	int err;
274
275	err = sscanf(buf, "%u %u", &id, &port_count);
276	switch (err) {
277	case 1:
278		port_count = 1;
279		fallthrough;
280	case 2:
281		if (id > INT_MAX) {
282			pr_err("Value of \"id\" is too big.\n");
283			return -EINVAL;
284		}
285		break;
286	default:
287		pr_err("Format for adding new device is \"id port_count\" (uint uint).\n");
288		return -EINVAL;
289	}
290
291	mutex_lock(&nsim_bus_dev_list_lock);
292	/* Prevent to use resource before initialization. */
293	if (!smp_load_acquire(&nsim_bus_enable)) {
294		err = -EBUSY;
295		goto err;
296	}
297
298	nsim_bus_dev = nsim_bus_dev_new(id, port_count);
299	if (IS_ERR(nsim_bus_dev)) {
300		err = PTR_ERR(nsim_bus_dev);
301		goto err;
302	}
303
304	/* Allow using nsim_bus_dev */
305	smp_store_release(&nsim_bus_dev->init, true);
306
307	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
308	mutex_unlock(&nsim_bus_dev_list_lock);
309
310	return count;
311err:
312	mutex_unlock(&nsim_bus_dev_list_lock);
313	return err;
314}
315static BUS_ATTR_WO(new_device);
316
317static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);
318
319static ssize_t
320del_device_store(struct bus_type *bus, const char *buf, size_t count)
321{
322	struct nsim_bus_dev *nsim_bus_dev, *tmp;
323	unsigned int id;
324	int err;
325
326	err = sscanf(buf, "%u", &id);
327	switch (err) {
328	case 1:
329		if (id > INT_MAX) {
330			pr_err("Value of \"id\" is too big.\n");
331			return -EINVAL;
332		}
333		break;
334	default:
335		pr_err("Format for deleting device is \"id\" (uint).\n");
336		return -EINVAL;
337	}
338
339	err = -ENOENT;
340	mutex_lock(&nsim_bus_dev_list_lock);
341	/* Prevent to use resource before initialization. */
342	if (!smp_load_acquire(&nsim_bus_enable)) {
343		mutex_unlock(&nsim_bus_dev_list_lock);
344		return -EBUSY;
345	}
346	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
347		if (nsim_bus_dev->dev.id != id)
348			continue;
349		list_del(&nsim_bus_dev->list);
350		nsim_bus_dev_del(nsim_bus_dev);
351		err = 0;
352		break;
353	}
354	mutex_unlock(&nsim_bus_dev_list_lock);
355	return !err ? count : err;
356}
357static BUS_ATTR_WO(del_device);
358
359static struct attribute *nsim_bus_attrs[] = {
360	&bus_attr_new_device.attr,
361	&bus_attr_del_device.attr,
362	NULL
363};
364ATTRIBUTE_GROUPS(nsim_bus);
365
366static int nsim_bus_probe(struct device *dev)
367{
368	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
369
370	return nsim_dev_probe(nsim_bus_dev);
371}
372
373static int nsim_bus_remove(struct device *dev)
374{
375	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
376
377	nsim_dev_remove(nsim_bus_dev);
378	return 0;
379}
380
381static int nsim_num_vf(struct device *dev)
382{
383	struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
384
385	return nsim_bus_dev->num_vfs;
386}
387
388static struct bus_type nsim_bus = {
389	.name		= DRV_NAME,
390	.dev_name	= DRV_NAME,
391	.bus_groups	= nsim_bus_groups,
392	.probe		= nsim_bus_probe,
393	.remove		= nsim_bus_remove,
394	.num_vf		= nsim_num_vf,
395};
396
397#define NSIM_BUS_DEV_MAX_VFS 4
398
399static struct nsim_bus_dev *
400nsim_bus_dev_new(unsigned int id, unsigned int port_count)
401{
402	struct nsim_bus_dev *nsim_bus_dev;
403	int err;
404
405	nsim_bus_dev = kzalloc(sizeof(*nsim_bus_dev), GFP_KERNEL);
406	if (!nsim_bus_dev)
407		return ERR_PTR(-ENOMEM);
408
409	err = ida_alloc_range(&nsim_bus_dev_ids, id, id, GFP_KERNEL);
410	if (err < 0)
411		goto err_nsim_bus_dev_free;
412	nsim_bus_dev->dev.id = err;
413	nsim_bus_dev->dev.bus = &nsim_bus;
414	nsim_bus_dev->dev.type = &nsim_bus_dev_type;
415	nsim_bus_dev->port_count = port_count;
416	nsim_bus_dev->initial_net = current->nsproxy->net_ns;
417	nsim_bus_dev->max_vfs = NSIM_BUS_DEV_MAX_VFS;
418	mutex_init(&nsim_bus_dev->nsim_bus_reload_lock);
419	mutex_init(&nsim_bus_dev->vfs_lock);
420	/* Disallow using nsim_bus_dev */
421	smp_store_release(&nsim_bus_dev->init, false);
422
423	nsim_bus_dev->vfconfigs = kcalloc(nsim_bus_dev->max_vfs,
424					  sizeof(struct nsim_vf_config),
425					  GFP_KERNEL | __GFP_NOWARN);
426	if (!nsim_bus_dev->vfconfigs) {
427		err = -ENOMEM;
428		goto err_nsim_bus_dev_id_free;
429	}
430
431	err = device_register(&nsim_bus_dev->dev);
432	if (err)
433		goto err_nsim_vfs_free;
434
435	return nsim_bus_dev;
436
437err_nsim_vfs_free:
438	kfree(nsim_bus_dev->vfconfigs);
439err_nsim_bus_dev_id_free:
440	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
441err_nsim_bus_dev_free:
442	kfree(nsim_bus_dev);
443	return ERR_PTR(err);
444}
445
446static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev)
447{
448	/* Disallow using nsim_bus_dev */
449	smp_store_release(&nsim_bus_dev->init, false);
450	device_unregister(&nsim_bus_dev->dev);
451	ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id);
452	kfree(nsim_bus_dev->vfconfigs);
453	kfree(nsim_bus_dev);
454}
455
456static struct device_driver nsim_driver = {
457	.name		= DRV_NAME,
458	.bus		= &nsim_bus,
459	.owner		= THIS_MODULE,
460};
461
462int nsim_bus_init(void)
463{
464	int err;
465
466	err = bus_register(&nsim_bus);
467	if (err)
468		return err;
469	err = driver_register(&nsim_driver);
470	if (err)
471		goto err_bus_unregister;
472	/* Allow using resources */
473	smp_store_release(&nsim_bus_enable, true);
474	return 0;
475
476err_bus_unregister:
477	bus_unregister(&nsim_bus);
478	return err;
479}
480
481void nsim_bus_exit(void)
482{
483	struct nsim_bus_dev *nsim_bus_dev, *tmp;
484
485	/* Disallow using resources */
486	smp_store_release(&nsim_bus_enable, false);
487
488	mutex_lock(&nsim_bus_dev_list_lock);
489	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
490		list_del(&nsim_bus_dev->list);
491		nsim_bus_dev_del(nsim_bus_dev);
492	}
493	mutex_unlock(&nsim_bus_dev_list_lock);
494
495	driver_unregister(&nsim_driver);
496	bus_unregister(&nsim_bus);
497}