1 /*
2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
6  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
7  *
8  * This software is available to you under a choice of one of two
9  * licenses.  You may choose to be licensed under the terms of the GNU
10  * General Public License (GPL) Version 2, available from the file
11  * COPYING in the main directory of this source tree, or the
12  * OpenIB.org BSD license below:
13  *
14  *     Redistribution and use in source and binary forms, with or
15  *     without modification, are permitted provided that the following
16  *     conditions are met:
17  *
18  *      - Redistributions of source code must retain the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer.
21  *
22  *      - Redistributions in binary form must reproduce the above
23  *        copyright notice, this list of conditions and the following
24  *        disclaimer in the documentation and/or other materials
25  *        provided with the distribution.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
28  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
29  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
30  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
31  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
32  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
33  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34  * SOFTWARE.
35  */
36 
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/device.h>
40 #include <linux/err.h>
41 #include <linux/fs.h>
42 #include <linux/poll.h>
43 #include <linux/sched.h>
44 #include <linux/file.h>
45 #include <linux/cdev.h>
46 #include <linux/anon_inodes.h>
47 #include <linux/slab.h>
48 #include <linux/sched/mm.h>
49 
50 #include <linux/uaccess.h>
51 
52 #include <rdma/ib.h>
53 #include <rdma/uverbs_std_types.h>
54 
55 #include "uverbs.h"
56 #include "core_priv.h"
57 #include "rdma_core.h"
58 
59 MODULE_AUTHOR("Roland Dreier");
60 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
61 MODULE_LICENSE("Dual BSD/GPL");
62 
63 enum {
64 	IB_UVERBS_MAJOR       = 231,
65 	IB_UVERBS_BASE_MINOR  = 192,
66 	IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
67 	IB_UVERBS_NUM_FIXED_MINOR = 32,
68 	IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
69 };
70 
71 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
72 
73 static dev_t dynamic_uverbs_dev;
74 static struct class *uverbs_class;
75 
76 static DEFINE_IDA(uverbs_ida);
77 static void ib_uverbs_add_one(struct ib_device *device);
78 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
79 
80 /*
81  * Must be called with the ufile->device->disassociate_srcu held, and the lock
82  * must be held until use of the ucontext is finished.
83  */
84 struct ib_ucontext *ib_uverbs_get_ucontext_file(struct ib_uverbs_file *ufile)
85 {
86 	/*
87 	 * We do not hold the hw_destroy_rwsem lock for this flow, instead
88 	 * srcu is used. It does not matter if someone races this with
89 	 * get_context, we get NULL or valid ucontext.
90 	 */
91 	struct ib_ucontext *ucontext = smp_load_acquire(&ufile->ucontext);
92 
93 	if (!srcu_dereference(ufile->device->ib_dev,
94 			      &ufile->device->disassociate_srcu))
95 		return ERR_PTR(-EIO);
96 
97 	if (!ucontext)
98 		return ERR_PTR(-EINVAL);
99 
100 	return ucontext;
101 }
102 EXPORT_SYMBOL(ib_uverbs_get_ucontext_file);
103 
104 int uverbs_dealloc_mw(struct ib_mw *mw)
105 {
106 	struct ib_pd *pd = mw->pd;
107 	int ret;
108 
109 	ret = mw->device->ops.dealloc_mw(mw);
110 	if (!ret)
111 		atomic_dec(&pd->usecnt);
112 	return ret;
113 }
114 
115 static void ib_uverbs_release_dev(struct device *device)
116 {
117 	struct ib_uverbs_device *dev =
118 			container_of(device, struct ib_uverbs_device, dev);
119 
120 	uverbs_destroy_api(dev->uapi);
121 	cleanup_srcu_struct(&dev->disassociate_srcu);
122 	kfree(dev);
123 }
124 
125 static void ib_uverbs_release_async_event_file(struct kref *ref)
126 {
127 	struct ib_uverbs_async_event_file *file =
128 		container_of(ref, struct ib_uverbs_async_event_file, ref);
129 
130 	kfree(file);
131 }
132 
133 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
134 			  struct ib_uverbs_completion_event_file *ev_file,
135 			  struct ib_ucq_object *uobj)
136 {
137 	struct ib_uverbs_event *evt, *tmp;
138 
139 	if (ev_file) {
140 		spin_lock_irq(&ev_file->ev_queue.lock);
141 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
142 			list_del(&evt->list);
143 			kfree(evt);
144 		}
145 		spin_unlock_irq(&ev_file->ev_queue.lock);
146 
147 		uverbs_uobject_put(&ev_file->uobj);
148 	}
149 
150 	spin_lock_irq(&file->async_file->ev_queue.lock);
151 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
152 		list_del(&evt->list);
153 		kfree(evt);
154 	}
155 	spin_unlock_irq(&file->async_file->ev_queue.lock);
156 }
157 
158 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
159 			      struct ib_uevent_object *uobj)
160 {
161 	struct ib_uverbs_event *evt, *tmp;
162 
163 	spin_lock_irq(&file->async_file->ev_queue.lock);
164 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
165 		list_del(&evt->list);
166 		kfree(evt);
167 	}
168 	spin_unlock_irq(&file->async_file->ev_queue.lock);
169 }
170 
171 void ib_uverbs_detach_umcast(struct ib_qp *qp,
172 			     struct ib_uqp_object *uobj)
173 {
174 	struct ib_uverbs_mcast_entry *mcast, *tmp;
175 
176 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
177 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
178 		list_del(&mcast->list);
179 		kfree(mcast);
180 	}
181 }
182 
183 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
184 {
185 	complete(&dev->comp);
186 }
187 
188 void ib_uverbs_release_file(struct kref *ref)
189 {
190 	struct ib_uverbs_file *file =
191 		container_of(ref, struct ib_uverbs_file, ref);
192 	struct ib_device *ib_dev;
193 	int srcu_key;
194 
195 	release_ufile_idr_uobject(file);
196 
197 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
198 	ib_dev = srcu_dereference(file->device->ib_dev,
199 				  &file->device->disassociate_srcu);
200 	if (ib_dev && !ib_dev->ops.disassociate_ucontext)
201 		module_put(ib_dev->owner);
202 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
203 
204 	if (atomic_dec_and_test(&file->device->refcount))
205 		ib_uverbs_comp_dev(file->device);
206 
207 	if (file->async_file)
208 		kref_put(&file->async_file->ref,
209 			 ib_uverbs_release_async_event_file);
210 	put_device(&file->device->dev);
211 
212 	if (file->disassociate_page)
213 		__free_pages(file->disassociate_page, 0);
214 	kfree(file);
215 }
216 
217 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
218 				    struct ib_uverbs_file *uverbs_file,
219 				    struct file *filp, char __user *buf,
220 				    size_t count, loff_t *pos,
221 				    size_t eventsz)
222 {
223 	struct ib_uverbs_event *event;
224 	int ret = 0;
225 
226 	spin_lock_irq(&ev_queue->lock);
227 
228 	while (list_empty(&ev_queue->event_list)) {
229 		spin_unlock_irq(&ev_queue->lock);
230 
231 		if (filp->f_flags & O_NONBLOCK)
232 			return -EAGAIN;
233 
234 		if (wait_event_interruptible(ev_queue->poll_wait,
235 					     (!list_empty(&ev_queue->event_list) ||
236 			/* The barriers built into wait_event_interruptible()
237 			 * and wake_up() guarentee this will see the null set
238 			 * without using RCU
239 			 */
240 					     !uverbs_file->device->ib_dev)))
241 			return -ERESTARTSYS;
242 
243 		/* If device was disassociated and no event exists set an error */
244 		if (list_empty(&ev_queue->event_list) &&
245 		    !uverbs_file->device->ib_dev)
246 			return -EIO;
247 
248 		spin_lock_irq(&ev_queue->lock);
249 	}
250 
251 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
252 
253 	if (eventsz > count) {
254 		ret   = -EINVAL;
255 		event = NULL;
256 	} else {
257 		list_del(ev_queue->event_list.next);
258 		if (event->counter) {
259 			++(*event->counter);
260 			list_del(&event->obj_list);
261 		}
262 	}
263 
264 	spin_unlock_irq(&ev_queue->lock);
265 
266 	if (event) {
267 		if (copy_to_user(buf, event, eventsz))
268 			ret = -EFAULT;
269 		else
270 			ret = eventsz;
271 	}
272 
273 	kfree(event);
274 
275 	return ret;
276 }
277 
278 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
279 					  size_t count, loff_t *pos)
280 {
281 	struct ib_uverbs_async_event_file *file = filp->private_data;
282 
283 	return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
284 				    buf, count, pos,
285 				    sizeof(struct ib_uverbs_async_event_desc));
286 }
287 
288 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
289 					 size_t count, loff_t *pos)
290 {
291 	struct ib_uverbs_completion_event_file *comp_ev_file =
292 		filp->private_data;
293 
294 	return ib_uverbs_event_read(&comp_ev_file->ev_queue,
295 				    comp_ev_file->uobj.ufile, filp,
296 				    buf, count, pos,
297 				    sizeof(struct ib_uverbs_comp_event_desc));
298 }
299 
300 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
301 					 struct file *filp,
302 					 struct poll_table_struct *wait)
303 {
304 	__poll_t pollflags = 0;
305 
306 	poll_wait(filp, &ev_queue->poll_wait, wait);
307 
308 	spin_lock_irq(&ev_queue->lock);
309 	if (!list_empty(&ev_queue->event_list))
310 		pollflags = EPOLLIN | EPOLLRDNORM;
311 	spin_unlock_irq(&ev_queue->lock);
312 
313 	return pollflags;
314 }
315 
316 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
317 					       struct poll_table_struct *wait)
318 {
319 	return ib_uverbs_event_poll(filp->private_data, filp, wait);
320 }
321 
322 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
323 					      struct poll_table_struct *wait)
324 {
325 	struct ib_uverbs_completion_event_file *comp_ev_file =
326 		filp->private_data;
327 
328 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
329 }
330 
331 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
332 {
333 	struct ib_uverbs_event_queue *ev_queue = filp->private_data;
334 
335 	return fasync_helper(fd, filp, on, &ev_queue->async_queue);
336 }
337 
338 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
339 {
340 	struct ib_uverbs_completion_event_file *comp_ev_file =
341 		filp->private_data;
342 
343 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
344 }
345 
346 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
347 {
348 	struct ib_uverbs_async_event_file *file = filp->private_data;
349 	struct ib_uverbs_file *uverbs_file = file->uverbs_file;
350 	struct ib_uverbs_event *entry, *tmp;
351 	int closed_already = 0;
352 
353 	mutex_lock(&uverbs_file->device->lists_mutex);
354 	spin_lock_irq(&file->ev_queue.lock);
355 	closed_already = file->ev_queue.is_closed;
356 	file->ev_queue.is_closed = 1;
357 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
358 		if (entry->counter)
359 			list_del(&entry->obj_list);
360 		kfree(entry);
361 	}
362 	spin_unlock_irq(&file->ev_queue.lock);
363 	if (!closed_already) {
364 		list_del(&file->list);
365 		ib_unregister_event_handler(&uverbs_file->event_handler);
366 	}
367 	mutex_unlock(&uverbs_file->device->lists_mutex);
368 
369 	kref_put(&uverbs_file->ref, ib_uverbs_release_file);
370 	kref_put(&file->ref, ib_uverbs_release_async_event_file);
371 
372 	return 0;
373 }
374 
375 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
376 {
377 	struct ib_uobject *uobj = filp->private_data;
378 	struct ib_uverbs_completion_event_file *file = container_of(
379 		uobj, struct ib_uverbs_completion_event_file, uobj);
380 	struct ib_uverbs_event *entry, *tmp;
381 
382 	spin_lock_irq(&file->ev_queue.lock);
383 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
384 		if (entry->counter)
385 			list_del(&entry->obj_list);
386 		kfree(entry);
387 	}
388 	file->ev_queue.is_closed = 1;
389 	spin_unlock_irq(&file->ev_queue.lock);
390 
391 	uverbs_close_fd(filp);
392 
393 	return 0;
394 }
395 
396 const struct file_operations uverbs_event_fops = {
397 	.owner	 = THIS_MODULE,
398 	.read	 = ib_uverbs_comp_event_read,
399 	.poll    = ib_uverbs_comp_event_poll,
400 	.release = ib_uverbs_comp_event_close,
401 	.fasync  = ib_uverbs_comp_event_fasync,
402 	.llseek	 = no_llseek,
403 };
404 
405 static const struct file_operations uverbs_async_event_fops = {
406 	.owner	 = THIS_MODULE,
407 	.read	 = ib_uverbs_async_event_read,
408 	.poll    = ib_uverbs_async_event_poll,
409 	.release = ib_uverbs_async_event_close,
410 	.fasync  = ib_uverbs_async_event_fasync,
411 	.llseek	 = no_llseek,
412 };
413 
414 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
415 {
416 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
417 	struct ib_ucq_object	       *uobj;
418 	struct ib_uverbs_event	       *entry;
419 	unsigned long			flags;
420 
421 	if (!ev_queue)
422 		return;
423 
424 	spin_lock_irqsave(&ev_queue->lock, flags);
425 	if (ev_queue->is_closed) {
426 		spin_unlock_irqrestore(&ev_queue->lock, flags);
427 		return;
428 	}
429 
430 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
431 	if (!entry) {
432 		spin_unlock_irqrestore(&ev_queue->lock, flags);
433 		return;
434 	}
435 
436 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
437 
438 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
439 	entry->counter		   = &uobj->comp_events_reported;
440 
441 	list_add_tail(&entry->list, &ev_queue->event_list);
442 	list_add_tail(&entry->obj_list, &uobj->comp_list);
443 	spin_unlock_irqrestore(&ev_queue->lock, flags);
444 
445 	wake_up_interruptible(&ev_queue->poll_wait);
446 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
447 }
448 
449 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
450 				    __u64 element, __u64 event,
451 				    struct list_head *obj_list,
452 				    u32 *counter)
453 {
454 	struct ib_uverbs_event *entry;
455 	unsigned long flags;
456 
457 	spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
458 	if (file->async_file->ev_queue.is_closed) {
459 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
460 		return;
461 	}
462 
463 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
464 	if (!entry) {
465 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
466 		return;
467 	}
468 
469 	entry->desc.async.element    = element;
470 	entry->desc.async.event_type = event;
471 	entry->desc.async.reserved   = 0;
472 	entry->counter               = counter;
473 
474 	list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
475 	if (obj_list)
476 		list_add_tail(&entry->obj_list, obj_list);
477 	spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
478 
479 	wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
480 	kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
481 }
482 
483 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
484 {
485 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
486 						  struct ib_ucq_object, uobject);
487 
488 	ib_uverbs_async_handler(uobj->uobject.ufile, uobj->uobject.user_handle,
489 				event->event, &uobj->async_list,
490 				&uobj->async_events_reported);
491 }
492 
493 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
494 {
495 	struct ib_uevent_object *uobj;
496 
497 	/* for XRC target qp's, check that qp is live */
498 	if (!event->element.qp->uobject)
499 		return;
500 
501 	uobj = container_of(event->element.qp->uobject,
502 			    struct ib_uevent_object, uobject);
503 
504 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
505 				event->event, &uobj->event_list,
506 				&uobj->events_reported);
507 }
508 
509 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
510 {
511 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
512 						  struct ib_uevent_object, uobject);
513 
514 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
515 				event->event, &uobj->event_list,
516 				&uobj->events_reported);
517 }
518 
519 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
520 {
521 	struct ib_uevent_object *uobj;
522 
523 	uobj = container_of(event->element.srq->uobject,
524 			    struct ib_uevent_object, uobject);
525 
526 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
527 				event->event, &uobj->event_list,
528 				&uobj->events_reported);
529 }
530 
531 void ib_uverbs_event_handler(struct ib_event_handler *handler,
532 			     struct ib_event *event)
533 {
534 	struct ib_uverbs_file *file =
535 		container_of(handler, struct ib_uverbs_file, event_handler);
536 
537 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
538 				NULL, NULL);
539 }
540 
541 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
542 {
543 	kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
544 	file->async_file = NULL;
545 }
546 
547 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
548 {
549 	spin_lock_init(&ev_queue->lock);
550 	INIT_LIST_HEAD(&ev_queue->event_list);
551 	init_waitqueue_head(&ev_queue->poll_wait);
552 	ev_queue->is_closed   = 0;
553 	ev_queue->async_queue = NULL;
554 }
555 
556 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
557 					      struct ib_device	*ib_dev)
558 {
559 	struct ib_uverbs_async_event_file *ev_file;
560 	struct file *filp;
561 
562 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
563 	if (!ev_file)
564 		return ERR_PTR(-ENOMEM);
565 
566 	ib_uverbs_init_event_queue(&ev_file->ev_queue);
567 	ev_file->uverbs_file = uverbs_file;
568 	kref_get(&ev_file->uverbs_file->ref);
569 	kref_init(&ev_file->ref);
570 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
571 				  ev_file, O_RDONLY);
572 	if (IS_ERR(filp))
573 		goto err_put_refs;
574 
575 	mutex_lock(&uverbs_file->device->lists_mutex);
576 	list_add_tail(&ev_file->list,
577 		      &uverbs_file->device->uverbs_events_file_list);
578 	mutex_unlock(&uverbs_file->device->lists_mutex);
579 
580 	WARN_ON(uverbs_file->async_file);
581 	uverbs_file->async_file = ev_file;
582 	kref_get(&uverbs_file->async_file->ref);
583 	INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
584 			      ib_dev,
585 			      ib_uverbs_event_handler);
586 	ib_register_event_handler(&uverbs_file->event_handler);
587 	/* At that point async file stuff was fully set */
588 
589 	return filp;
590 
591 err_put_refs:
592 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
593 	kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
594 	return filp;
595 }
596 
597 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
598 			  struct ib_uverbs_ex_cmd_hdr *ex_hdr, size_t count,
599 			  const struct uverbs_api_write_method *method_elm)
600 {
601 	if (method_elm->is_ex) {
602 		count -= sizeof(*hdr) + sizeof(*ex_hdr);
603 
604 		if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
605 			return -EINVAL;
606 
607 		if (hdr->in_words * 8 < method_elm->req_size)
608 			return -ENOSPC;
609 
610 		if (ex_hdr->cmd_hdr_reserved)
611 			return -EINVAL;
612 
613 		if (ex_hdr->response) {
614 			if (!hdr->out_words && !ex_hdr->provider_out_words)
615 				return -EINVAL;
616 
617 			if (hdr->out_words * 8 < method_elm->resp_size)
618 				return -ENOSPC;
619 
620 			if (!access_ok(u64_to_user_ptr(ex_hdr->response),
621 				       (hdr->out_words + ex_hdr->provider_out_words) * 8))
622 				return -EFAULT;
623 		} else {
624 			if (hdr->out_words || ex_hdr->provider_out_words)
625 				return -EINVAL;
626 		}
627 
628 		return 0;
629 	}
630 
631 	/* not extended command */
632 	if (hdr->in_words * 4 != count)
633 		return -EINVAL;
634 
635 	if (count < method_elm->req_size + sizeof(hdr)) {
636 		/*
637 		 * rdma-core v18 and v19 have a bug where they send DESTROY_CQ
638 		 * with a 16 byte write instead of 24. Old kernels didn't
639 		 * check the size so they allowed this. Now that the size is
640 		 * checked provide a compatibility work around to not break
641 		 * those userspaces.
642 		 */
643 		if (hdr->command == IB_USER_VERBS_CMD_DESTROY_CQ &&
644 		    count == 16) {
645 			hdr->in_words = 6;
646 			return 0;
647 		}
648 		return -ENOSPC;
649 	}
650 	if (hdr->out_words * 4 < method_elm->resp_size)
651 		return -ENOSPC;
652 
653 	return 0;
654 }
655 
656 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
657 			     size_t count, loff_t *pos)
658 {
659 	struct ib_uverbs_file *file = filp->private_data;
660 	const struct uverbs_api_write_method *method_elm;
661 	struct uverbs_api *uapi = file->device->uapi;
662 	struct ib_uverbs_ex_cmd_hdr ex_hdr;
663 	struct ib_uverbs_cmd_hdr hdr;
664 	struct uverbs_attr_bundle bundle;
665 	int srcu_key;
666 	ssize_t ret;
667 
668 	if (!ib_safe_file_access(filp)) {
669 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
670 			    task_tgid_vnr(current), current->comm);
671 		return -EACCES;
672 	}
673 
674 	if (count < sizeof(hdr))
675 		return -EINVAL;
676 
677 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
678 		return -EFAULT;
679 
680 	method_elm = uapi_get_method(uapi, hdr.command);
681 	if (IS_ERR(method_elm))
682 		return PTR_ERR(method_elm);
683 
684 	if (method_elm->is_ex) {
685 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
686 			return -EINVAL;
687 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
688 			return -EFAULT;
689 	}
690 
691 	ret = verify_hdr(&hdr, &ex_hdr, count, method_elm);
692 	if (ret)
693 		return ret;
694 
695 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
696 
697 	buf += sizeof(hdr);
698 
699 	memset(bundle.attr_present, 0, sizeof(bundle.attr_present));
700 	bundle.ufile = file;
701 	bundle.context = NULL; /* only valid if bundle has uobject */
702 	if (!method_elm->is_ex) {
703 		size_t in_len = hdr.in_words * 4 - sizeof(hdr);
704 		size_t out_len = hdr.out_words * 4;
705 		u64 response = 0;
706 
707 		if (method_elm->has_udata) {
708 			bundle.driver_udata.inlen =
709 				in_len - method_elm->req_size;
710 			in_len = method_elm->req_size;
711 			if (bundle.driver_udata.inlen)
712 				bundle.driver_udata.inbuf = buf + in_len;
713 			else
714 				bundle.driver_udata.inbuf = NULL;
715 		} else {
716 			memset(&bundle.driver_udata, 0,
717 			       sizeof(bundle.driver_udata));
718 		}
719 
720 		if (method_elm->has_resp) {
721 			/*
722 			 * The macros check that if has_resp is set
723 			 * then the command request structure starts
724 			 * with a '__aligned u64 response' member.
725 			 */
726 			ret = get_user(response, (const u64 __user *)buf);
727 			if (ret)
728 				goto out_unlock;
729 
730 			if (method_elm->has_udata) {
731 				bundle.driver_udata.outlen =
732 					out_len - method_elm->resp_size;
733 				out_len = method_elm->resp_size;
734 				if (bundle.driver_udata.outlen)
735 					bundle.driver_udata.outbuf =
736 						u64_to_user_ptr(response +
737 								out_len);
738 				else
739 					bundle.driver_udata.outbuf = NULL;
740 			}
741 		} else {
742 			bundle.driver_udata.outlen = 0;
743 			bundle.driver_udata.outbuf = NULL;
744 		}
745 
746 		ib_uverbs_init_udata_buf_or_null(
747 			&bundle.ucore, buf, u64_to_user_ptr(response),
748 			in_len, out_len);
749 	} else {
750 		buf += sizeof(ex_hdr);
751 
752 		ib_uverbs_init_udata_buf_or_null(&bundle.ucore, buf,
753 					u64_to_user_ptr(ex_hdr.response),
754 					hdr.in_words * 8, hdr.out_words * 8);
755 
756 		ib_uverbs_init_udata_buf_or_null(
757 			&bundle.driver_udata, buf + bundle.ucore.inlen,
758 			u64_to_user_ptr(ex_hdr.response) + bundle.ucore.outlen,
759 			ex_hdr.provider_in_words * 8,
760 			ex_hdr.provider_out_words * 8);
761 
762 	}
763 
764 	ret = method_elm->handler(&bundle);
765 out_unlock:
766 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
767 	return (ret) ? : count;
768 }
769 
770 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
771 {
772 	struct ib_uverbs_file *file = filp->private_data;
773 	struct ib_ucontext *ucontext;
774 	int ret = 0;
775 	int srcu_key;
776 
777 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
778 	ucontext = ib_uverbs_get_ucontext_file(file);
779 	if (IS_ERR(ucontext)) {
780 		ret = PTR_ERR(ucontext);
781 		goto out;
782 	}
783 
784 	ret = ucontext->device->ops.mmap(ucontext, vma);
785 out:
786 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
787 	return ret;
788 }
789 
790 /*
791  * Each time we map IO memory into user space this keeps track of the mapping.
792  * When the device is hot-unplugged we 'zap' the mmaps in user space to point
793  * to the zero page and allow the hot unplug to proceed.
794  *
795  * This is necessary for cases like PCI physical hot unplug as the actual BAR
796  * memory may vanish after this and access to it from userspace could MCE.
797  *
798  * RDMA drivers supporting disassociation must have their user space designed
799  * to cope in some way with their IO pages going to the zero page.
800  */
801 struct rdma_umap_priv {
802 	struct vm_area_struct *vma;
803 	struct list_head list;
804 };
805 
806 static const struct vm_operations_struct rdma_umap_ops;
807 
808 static void rdma_umap_priv_init(struct rdma_umap_priv *priv,
809 				struct vm_area_struct *vma)
810 {
811 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
812 
813 	priv->vma = vma;
814 	vma->vm_private_data = priv;
815 	vma->vm_ops = &rdma_umap_ops;
816 
817 	mutex_lock(&ufile->umap_lock);
818 	list_add(&priv->list, &ufile->umaps);
819 	mutex_unlock(&ufile->umap_lock);
820 }
821 
822 /*
823  * The VMA has been dup'd, initialize the vm_private_data with a new tracking
824  * struct
825  */
826 static void rdma_umap_open(struct vm_area_struct *vma)
827 {
828 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
829 	struct rdma_umap_priv *opriv = vma->vm_private_data;
830 	struct rdma_umap_priv *priv;
831 
832 	if (!opriv)
833 		return;
834 
835 	/* We are racing with disassociation */
836 	if (!down_read_trylock(&ufile->hw_destroy_rwsem))
837 		goto out_zap;
838 	/*
839 	 * Disassociation already completed, the VMA should already be zapped.
840 	 */
841 	if (!ufile->ucontext)
842 		goto out_unlock;
843 
844 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
845 	if (!priv)
846 		goto out_unlock;
847 	rdma_umap_priv_init(priv, vma);
848 
849 	up_read(&ufile->hw_destroy_rwsem);
850 	return;
851 
852 out_unlock:
853 	up_read(&ufile->hw_destroy_rwsem);
854 out_zap:
855 	/*
856 	 * We can't allow the VMA to be created with the actual IO pages, that
857 	 * would break our API contract, and it can't be stopped at this
858 	 * point, so zap it.
859 	 */
860 	vma->vm_private_data = NULL;
861 	zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
862 }
863 
864 static void rdma_umap_close(struct vm_area_struct *vma)
865 {
866 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
867 	struct rdma_umap_priv *priv = vma->vm_private_data;
868 
869 	if (!priv)
870 		return;
871 
872 	/*
873 	 * The vma holds a reference on the struct file that created it, which
874 	 * in turn means that the ib_uverbs_file is guaranteed to exist at
875 	 * this point.
876 	 */
877 	mutex_lock(&ufile->umap_lock);
878 	list_del(&priv->list);
879 	mutex_unlock(&ufile->umap_lock);
880 	kfree(priv);
881 }
882 
883 /*
884  * Once the zap_vma_ptes has been called touches to the VMA will come here and
885  * we return a dummy writable zero page for all the pfns.
886  */
887 static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
888 {
889 	struct ib_uverbs_file *ufile = vmf->vma->vm_file->private_data;
890 	struct rdma_umap_priv *priv = vmf->vma->vm_private_data;
891 	vm_fault_t ret = 0;
892 
893 	if (!priv)
894 		return VM_FAULT_SIGBUS;
895 
896 	/* Read only pages can just use the system zero page. */
897 	if (!(vmf->vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
898 		vmf->page = ZERO_PAGE(vmf->address);
899 		get_page(vmf->page);
900 		return 0;
901 	}
902 
903 	mutex_lock(&ufile->umap_lock);
904 	if (!ufile->disassociate_page)
905 		ufile->disassociate_page =
906 			alloc_pages(vmf->gfp_mask | __GFP_ZERO, 0);
907 
908 	if (ufile->disassociate_page) {
909 		/*
910 		 * This VMA is forced to always be shared so this doesn't have
911 		 * to worry about COW.
912 		 */
913 		vmf->page = ufile->disassociate_page;
914 		get_page(vmf->page);
915 	} else {
916 		ret = VM_FAULT_SIGBUS;
917 	}
918 	mutex_unlock(&ufile->umap_lock);
919 
920 	return ret;
921 }
922 
923 static const struct vm_operations_struct rdma_umap_ops = {
924 	.open = rdma_umap_open,
925 	.close = rdma_umap_close,
926 	.fault = rdma_umap_fault,
927 };
928 
929 /*
930  * Map IO memory into a process. This is to be called by drivers as part of
931  * their mmap() functions if they wish to send something like PCI-E BAR memory
932  * to userspace.
933  */
934 int rdma_user_mmap_io(struct ib_ucontext *ucontext, struct vm_area_struct *vma,
935 		      unsigned long pfn, unsigned long size, pgprot_t prot)
936 {
937 	struct ib_uverbs_file *ufile = ucontext->ufile;
938 	struct rdma_umap_priv *priv;
939 
940 	if (!(vma->vm_flags & VM_SHARED))
941 		return -EINVAL;
942 
943 	if (vma->vm_end - vma->vm_start != size)
944 		return -EINVAL;
945 
946 	/* Driver is using this wrong, must be called by ib_uverbs_mmap */
947 	if (WARN_ON(!vma->vm_file ||
948 		    vma->vm_file->private_data != ufile))
949 		return -EINVAL;
950 	lockdep_assert_held(&ufile->device->disassociate_srcu);
951 
952 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
953 	if (!priv)
954 		return -ENOMEM;
955 
956 	vma->vm_page_prot = prot;
957 	if (io_remap_pfn_range(vma, vma->vm_start, pfn, size, prot)) {
958 		kfree(priv);
959 		return -EAGAIN;
960 	}
961 
962 	rdma_umap_priv_init(priv, vma);
963 	return 0;
964 }
965 EXPORT_SYMBOL(rdma_user_mmap_io);
966 
967 void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
968 {
969 	struct rdma_umap_priv *priv, *next_priv;
970 
971 	lockdep_assert_held(&ufile->hw_destroy_rwsem);
972 
973 	while (1) {
974 		struct mm_struct *mm = NULL;
975 
976 		/* Get an arbitrary mm pointer that hasn't been cleaned yet */
977 		mutex_lock(&ufile->umap_lock);
978 		while (!list_empty(&ufile->umaps)) {
979 			int ret;
980 
981 			priv = list_first_entry(&ufile->umaps,
982 						struct rdma_umap_priv, list);
983 			mm = priv->vma->vm_mm;
984 			ret = mmget_not_zero(mm);
985 			if (!ret) {
986 				list_del_init(&priv->list);
987 				mm = NULL;
988 				continue;
989 			}
990 			break;
991 		}
992 		mutex_unlock(&ufile->umap_lock);
993 		if (!mm)
994 			return;
995 
996 		/*
997 		 * The umap_lock is nested under mmap_sem since it used within
998 		 * the vma_ops callbacks, so we have to clean the list one mm
999 		 * at a time to get the lock ordering right. Typically there
1000 		 * will only be one mm, so no big deal.
1001 		 */
1002 		down_read(&mm->mmap_sem);
1003 		if (!mmget_still_valid(mm))
1004 			goto skip_mm;
1005 		mutex_lock(&ufile->umap_lock);
1006 		list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
1007 					  list) {
1008 			struct vm_area_struct *vma = priv->vma;
1009 
1010 			if (vma->vm_mm != mm)
1011 				continue;
1012 			list_del_init(&priv->list);
1013 
1014 			zap_vma_ptes(vma, vma->vm_start,
1015 				     vma->vm_end - vma->vm_start);
1016 		}
1017 		mutex_unlock(&ufile->umap_lock);
1018 	skip_mm:
1019 		up_read(&mm->mmap_sem);
1020 		mmput(mm);
1021 	}
1022 }
1023 
1024 /*
1025  * ib_uverbs_open() does not need the BKL:
1026  *
1027  *  - the ib_uverbs_device structures are properly reference counted and
1028  *    everything else is purely local to the file being created, so
1029  *    races against other open calls are not a problem;
1030  *  - there is no ioctl method to race against;
1031  *  - the open method will either immediately run -ENXIO, or all
1032  *    required initialization will be done.
1033  */
1034 static int ib_uverbs_open(struct inode *inode, struct file *filp)
1035 {
1036 	struct ib_uverbs_device *dev;
1037 	struct ib_uverbs_file *file;
1038 	struct ib_device *ib_dev;
1039 	int ret;
1040 	int module_dependent;
1041 	int srcu_key;
1042 
1043 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
1044 	if (!atomic_inc_not_zero(&dev->refcount))
1045 		return -ENXIO;
1046 
1047 	get_device(&dev->dev);
1048 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1049 	mutex_lock(&dev->lists_mutex);
1050 	ib_dev = srcu_dereference(dev->ib_dev,
1051 				  &dev->disassociate_srcu);
1052 	if (!ib_dev) {
1053 		ret = -EIO;
1054 		goto err;
1055 	}
1056 
1057 	if (!rdma_dev_access_netns(ib_dev, current->nsproxy->net_ns)) {
1058 		ret = -EPERM;
1059 		goto err;
1060 	}
1061 
1062 	/* In case IB device supports disassociate ucontext, there is no hard
1063 	 * dependency between uverbs device and its low level device.
1064 	 */
1065 	module_dependent = !(ib_dev->ops.disassociate_ucontext);
1066 
1067 	if (module_dependent) {
1068 		if (!try_module_get(ib_dev->owner)) {
1069 			ret = -ENODEV;
1070 			goto err;
1071 		}
1072 	}
1073 
1074 	file = kzalloc(sizeof(*file), GFP_KERNEL);
1075 	if (!file) {
1076 		ret = -ENOMEM;
1077 		if (module_dependent)
1078 			goto err_module;
1079 
1080 		goto err;
1081 	}
1082 
1083 	file->device	 = dev;
1084 	kref_init(&file->ref);
1085 	mutex_init(&file->ucontext_lock);
1086 
1087 	spin_lock_init(&file->uobjects_lock);
1088 	INIT_LIST_HEAD(&file->uobjects);
1089 	init_rwsem(&file->hw_destroy_rwsem);
1090 	mutex_init(&file->umap_lock);
1091 	INIT_LIST_HEAD(&file->umaps);
1092 
1093 	filp->private_data = file;
1094 	list_add_tail(&file->list, &dev->uverbs_file_list);
1095 	mutex_unlock(&dev->lists_mutex);
1096 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1097 
1098 	setup_ufile_idr_uobject(file);
1099 
1100 	return stream_open(inode, filp);
1101 
1102 err_module:
1103 	module_put(ib_dev->owner);
1104 
1105 err:
1106 	mutex_unlock(&dev->lists_mutex);
1107 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1108 	if (atomic_dec_and_test(&dev->refcount))
1109 		ib_uverbs_comp_dev(dev);
1110 
1111 	put_device(&dev->dev);
1112 	return ret;
1113 }
1114 
1115 static int ib_uverbs_close(struct inode *inode, struct file *filp)
1116 {
1117 	struct ib_uverbs_file *file = filp->private_data;
1118 
1119 	uverbs_destroy_ufile_hw(file, RDMA_REMOVE_CLOSE);
1120 
1121 	mutex_lock(&file->device->lists_mutex);
1122 	list_del_init(&file->list);
1123 	mutex_unlock(&file->device->lists_mutex);
1124 
1125 	kref_put(&file->ref, ib_uverbs_release_file);
1126 
1127 	return 0;
1128 }
1129 
1130 static const struct file_operations uverbs_fops = {
1131 	.owner	 = THIS_MODULE,
1132 	.write	 = ib_uverbs_write,
1133 	.open	 = ib_uverbs_open,
1134 	.release = ib_uverbs_close,
1135 	.llseek	 = no_llseek,
1136 	.unlocked_ioctl = ib_uverbs_ioctl,
1137 	.compat_ioctl = ib_uverbs_ioctl,
1138 };
1139 
1140 static const struct file_operations uverbs_mmap_fops = {
1141 	.owner	 = THIS_MODULE,
1142 	.write	 = ib_uverbs_write,
1143 	.mmap    = ib_uverbs_mmap,
1144 	.open	 = ib_uverbs_open,
1145 	.release = ib_uverbs_close,
1146 	.llseek	 = no_llseek,
1147 	.unlocked_ioctl = ib_uverbs_ioctl,
1148 	.compat_ioctl = ib_uverbs_ioctl,
1149 };
1150 
1151 static struct ib_client uverbs_client = {
1152 	.name   = "uverbs",
1153 	.no_kverbs_req = true,
1154 	.add    = ib_uverbs_add_one,
1155 	.remove = ib_uverbs_remove_one
1156 };
1157 
1158 static ssize_t ibdev_show(struct device *device, struct device_attribute *attr,
1159 			  char *buf)
1160 {
1161 	struct ib_uverbs_device *dev =
1162 			container_of(device, struct ib_uverbs_device, dev);
1163 	int ret = -ENODEV;
1164 	int srcu_key;
1165 	struct ib_device *ib_dev;
1166 
1167 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1168 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1169 	if (ib_dev)
1170 		ret = sprintf(buf, "%s\n", dev_name(&ib_dev->dev));
1171 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1172 
1173 	return ret;
1174 }
1175 static DEVICE_ATTR_RO(ibdev);
1176 
1177 static ssize_t abi_version_show(struct device *device,
1178 				struct device_attribute *attr, char *buf)
1179 {
1180 	struct ib_uverbs_device *dev =
1181 			container_of(device, struct ib_uverbs_device, dev);
1182 	int ret = -ENODEV;
1183 	int srcu_key;
1184 	struct ib_device *ib_dev;
1185 
1186 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1187 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1188 	if (ib_dev)
1189 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1190 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1191 
1192 	return ret;
1193 }
1194 static DEVICE_ATTR_RO(abi_version);
1195 
1196 static struct attribute *ib_dev_attrs[] = {
1197 	&dev_attr_abi_version.attr,
1198 	&dev_attr_ibdev.attr,
1199 	NULL,
1200 };
1201 
1202 static const struct attribute_group dev_attr_group = {
1203 	.attrs = ib_dev_attrs,
1204 };
1205 
1206 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1207 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1208 
1209 static int ib_uverbs_create_uapi(struct ib_device *device,
1210 				 struct ib_uverbs_device *uverbs_dev)
1211 {
1212 	struct uverbs_api *uapi;
1213 
1214 	uapi = uverbs_alloc_api(device);
1215 	if (IS_ERR(uapi))
1216 		return PTR_ERR(uapi);
1217 
1218 	uverbs_dev->uapi = uapi;
1219 	return 0;
1220 }
1221 
1222 static void ib_uverbs_add_one(struct ib_device *device)
1223 {
1224 	int devnum;
1225 	dev_t base;
1226 	struct ib_uverbs_device *uverbs_dev;
1227 	int ret;
1228 
1229 	if (!device->ops.alloc_ucontext)
1230 		return;
1231 
1232 	uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1233 	if (!uverbs_dev)
1234 		return;
1235 
1236 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1237 	if (ret) {
1238 		kfree(uverbs_dev);
1239 		return;
1240 	}
1241 
1242 	device_initialize(&uverbs_dev->dev);
1243 	uverbs_dev->dev.class = uverbs_class;
1244 	uverbs_dev->dev.parent = device->dev.parent;
1245 	uverbs_dev->dev.release = ib_uverbs_release_dev;
1246 	uverbs_dev->groups[0] = &dev_attr_group;
1247 	uverbs_dev->dev.groups = uverbs_dev->groups;
1248 	atomic_set(&uverbs_dev->refcount, 1);
1249 	init_completion(&uverbs_dev->comp);
1250 	uverbs_dev->xrcd_tree = RB_ROOT;
1251 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1252 	mutex_init(&uverbs_dev->lists_mutex);
1253 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1254 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1255 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1256 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1257 
1258 	devnum = ida_alloc_max(&uverbs_ida, IB_UVERBS_MAX_DEVICES - 1,
1259 			       GFP_KERNEL);
1260 	if (devnum < 0)
1261 		goto err;
1262 	uverbs_dev->devnum = devnum;
1263 	if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1264 		base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1265 	else
1266 		base = IB_UVERBS_BASE_DEV + devnum;
1267 
1268 	if (ib_uverbs_create_uapi(device, uverbs_dev))
1269 		goto err_uapi;
1270 
1271 	uverbs_dev->dev.devt = base;
1272 	dev_set_name(&uverbs_dev->dev, "uverbs%d", uverbs_dev->devnum);
1273 
1274 	cdev_init(&uverbs_dev->cdev,
1275 		  device->ops.mmap ? &uverbs_mmap_fops : &uverbs_fops);
1276 	uverbs_dev->cdev.owner = THIS_MODULE;
1277 
1278 	ret = cdev_device_add(&uverbs_dev->cdev, &uverbs_dev->dev);
1279 	if (ret)
1280 		goto err_uapi;
1281 
1282 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1283 	return;
1284 
1285 err_uapi:
1286 	ida_free(&uverbs_ida, devnum);
1287 err:
1288 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1289 		ib_uverbs_comp_dev(uverbs_dev);
1290 	wait_for_completion(&uverbs_dev->comp);
1291 	put_device(&uverbs_dev->dev);
1292 	return;
1293 }
1294 
1295 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1296 					struct ib_device *ib_dev)
1297 {
1298 	struct ib_uverbs_file *file;
1299 	struct ib_uverbs_async_event_file *event_file;
1300 	struct ib_event event;
1301 
1302 	/* Pending running commands to terminate */
1303 	uverbs_disassociate_api_pre(uverbs_dev);
1304 	event.event = IB_EVENT_DEVICE_FATAL;
1305 	event.element.port_num = 0;
1306 	event.device = ib_dev;
1307 
1308 	mutex_lock(&uverbs_dev->lists_mutex);
1309 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1310 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1311 					struct ib_uverbs_file, list);
1312 		list_del_init(&file->list);
1313 		kref_get(&file->ref);
1314 
1315 		/* We must release the mutex before going ahead and calling
1316 		 * uverbs_cleanup_ufile, as it might end up indirectly calling
1317 		 * uverbs_close, for example due to freeing the resources (e.g
1318 		 * mmput).
1319 		 */
1320 		mutex_unlock(&uverbs_dev->lists_mutex);
1321 
1322 		ib_uverbs_event_handler(&file->event_handler, &event);
1323 		uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
1324 		kref_put(&file->ref, ib_uverbs_release_file);
1325 
1326 		mutex_lock(&uverbs_dev->lists_mutex);
1327 	}
1328 
1329 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1330 		event_file = list_first_entry(&uverbs_dev->
1331 					      uverbs_events_file_list,
1332 					      struct ib_uverbs_async_event_file,
1333 					      list);
1334 		spin_lock_irq(&event_file->ev_queue.lock);
1335 		event_file->ev_queue.is_closed = 1;
1336 		spin_unlock_irq(&event_file->ev_queue.lock);
1337 
1338 		list_del(&event_file->list);
1339 		ib_unregister_event_handler(
1340 			&event_file->uverbs_file->event_handler);
1341 		event_file->uverbs_file->event_handler.device =
1342 			NULL;
1343 
1344 		wake_up_interruptible(&event_file->ev_queue.poll_wait);
1345 		kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1346 	}
1347 	mutex_unlock(&uverbs_dev->lists_mutex);
1348 
1349 	uverbs_disassociate_api(uverbs_dev->uapi);
1350 }
1351 
1352 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1353 {
1354 	struct ib_uverbs_device *uverbs_dev = client_data;
1355 	int wait_clients = 1;
1356 
1357 	if (!uverbs_dev)
1358 		return;
1359 
1360 	cdev_device_del(&uverbs_dev->cdev, &uverbs_dev->dev);
1361 	ida_free(&uverbs_ida, uverbs_dev->devnum);
1362 
1363 	if (device->ops.disassociate_ucontext) {
1364 		/* We disassociate HW resources and immediately return.
1365 		 * Userspace will see a EIO errno for all future access.
1366 		 * Upon returning, ib_device may be freed internally and is not
1367 		 * valid any more.
1368 		 * uverbs_device is still available until all clients close
1369 		 * their files, then the uverbs device ref count will be zero
1370 		 * and its resources will be freed.
1371 		 * Note: At this point no more files can be opened since the
1372 		 * cdev was deleted, however active clients can still issue
1373 		 * commands and close their open files.
1374 		 */
1375 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1376 		wait_clients = 0;
1377 	}
1378 
1379 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1380 		ib_uverbs_comp_dev(uverbs_dev);
1381 	if (wait_clients)
1382 		wait_for_completion(&uverbs_dev->comp);
1383 
1384 	put_device(&uverbs_dev->dev);
1385 }
1386 
1387 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1388 {
1389 	if (mode)
1390 		*mode = 0666;
1391 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1392 }
1393 
1394 static int __init ib_uverbs_init(void)
1395 {
1396 	int ret;
1397 
1398 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1399 				     IB_UVERBS_NUM_FIXED_MINOR,
1400 				     "infiniband_verbs");
1401 	if (ret) {
1402 		pr_err("user_verbs: couldn't register device number\n");
1403 		goto out;
1404 	}
1405 
1406 	ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1407 				  IB_UVERBS_NUM_DYNAMIC_MINOR,
1408 				  "infiniband_verbs");
1409 	if (ret) {
1410 		pr_err("couldn't register dynamic device number\n");
1411 		goto out_alloc;
1412 	}
1413 
1414 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1415 	if (IS_ERR(uverbs_class)) {
1416 		ret = PTR_ERR(uverbs_class);
1417 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1418 		goto out_chrdev;
1419 	}
1420 
1421 	uverbs_class->devnode = uverbs_devnode;
1422 
1423 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1424 	if (ret) {
1425 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1426 		goto out_class;
1427 	}
1428 
1429 	ret = ib_register_client(&uverbs_client);
1430 	if (ret) {
1431 		pr_err("user_verbs: couldn't register client\n");
1432 		goto out_class;
1433 	}
1434 
1435 	return 0;
1436 
1437 out_class:
1438 	class_destroy(uverbs_class);
1439 
1440 out_chrdev:
1441 	unregister_chrdev_region(dynamic_uverbs_dev,
1442 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1443 
1444 out_alloc:
1445 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1446 				 IB_UVERBS_NUM_FIXED_MINOR);
1447 
1448 out:
1449 	return ret;
1450 }
1451 
1452 static void __exit ib_uverbs_cleanup(void)
1453 {
1454 	ib_unregister_client(&uverbs_client);
1455 	class_destroy(uverbs_class);
1456 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1457 				 IB_UVERBS_NUM_FIXED_MINOR);
1458 	unregister_chrdev_region(dynamic_uverbs_dev,
1459 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1460 }
1461 
1462 module_init(ib_uverbs_init);
1463 module_exit(ib_uverbs_cleanup);
1464