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 
49 #include <linux/uaccess.h>
50 
51 #include <rdma/ib.h>
52 #include <rdma/uverbs_std_types.h>
53 
54 #include "uverbs.h"
55 #include "core_priv.h"
56 #include "rdma_core.h"
57 
58 MODULE_AUTHOR("Roland Dreier");
59 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
60 MODULE_LICENSE("Dual BSD/GPL");
61 
62 enum {
63 	IB_UVERBS_MAJOR       = 231,
64 	IB_UVERBS_BASE_MINOR  = 192,
65 	IB_UVERBS_MAX_DEVICES = 32
66 };
67 
68 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
69 
70 static struct class *uverbs_class;
71 
72 static DEFINE_SPINLOCK(map_lock);
73 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
74 
75 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
76 				     struct ib_device *ib_dev,
77 				     const char __user *buf, int in_len,
78 				     int out_len) = {
79 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
80 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
81 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
82 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
83 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
84 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
85 	[IB_USER_VERBS_CMD_REREG_MR]		= ib_uverbs_rereg_mr,
86 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
87 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
88 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
89 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
90 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
91 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
92 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
93 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
94 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
95 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
96 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
97 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
98 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
99 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
100 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
101 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
102 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
103 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
104 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
105 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
106 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
107 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
108 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
109 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
110 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
111 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
112 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
113 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
114 };
115 
116 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
117 				    struct ib_device *ib_dev,
118 				    struct ib_udata *ucore,
119 				    struct ib_udata *uhw) = {
120 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
121 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow,
122 	[IB_USER_VERBS_EX_CMD_QUERY_DEVICE]	= ib_uverbs_ex_query_device,
123 	[IB_USER_VERBS_EX_CMD_CREATE_CQ]	= ib_uverbs_ex_create_cq,
124 	[IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
125 	[IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
126 	[IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
127 	[IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
128 	[IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
129 	[IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
130 	[IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
131 	[IB_USER_VERBS_EX_CMD_MODIFY_CQ]        = ib_uverbs_ex_modify_cq,
132 };
133 
134 static void ib_uverbs_add_one(struct ib_device *device);
135 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
136 
137 int uverbs_dealloc_mw(struct ib_mw *mw)
138 {
139 	struct ib_pd *pd = mw->pd;
140 	int ret;
141 
142 	ret = mw->device->dealloc_mw(mw);
143 	if (!ret)
144 		atomic_dec(&pd->usecnt);
145 	return ret;
146 }
147 
148 static void ib_uverbs_release_dev(struct kobject *kobj)
149 {
150 	struct ib_uverbs_device *dev =
151 		container_of(kobj, struct ib_uverbs_device, kobj);
152 
153 	cleanup_srcu_struct(&dev->disassociate_srcu);
154 	kfree(dev);
155 }
156 
157 static struct kobj_type ib_uverbs_dev_ktype = {
158 	.release = ib_uverbs_release_dev,
159 };
160 
161 static void ib_uverbs_release_async_event_file(struct kref *ref)
162 {
163 	struct ib_uverbs_async_event_file *file =
164 		container_of(ref, struct ib_uverbs_async_event_file, ref);
165 
166 	kfree(file);
167 }
168 
169 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
170 			  struct ib_uverbs_completion_event_file *ev_file,
171 			  struct ib_ucq_object *uobj)
172 {
173 	struct ib_uverbs_event *evt, *tmp;
174 
175 	if (ev_file) {
176 		spin_lock_irq(&ev_file->ev_queue.lock);
177 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
178 			list_del(&evt->list);
179 			kfree(evt);
180 		}
181 		spin_unlock_irq(&ev_file->ev_queue.lock);
182 
183 		uverbs_uobject_put(&ev_file->uobj_file.uobj);
184 	}
185 
186 	spin_lock_irq(&file->async_file->ev_queue.lock);
187 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
188 		list_del(&evt->list);
189 		kfree(evt);
190 	}
191 	spin_unlock_irq(&file->async_file->ev_queue.lock);
192 }
193 
194 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
195 			      struct ib_uevent_object *uobj)
196 {
197 	struct ib_uverbs_event *evt, *tmp;
198 
199 	spin_lock_irq(&file->async_file->ev_queue.lock);
200 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
201 		list_del(&evt->list);
202 		kfree(evt);
203 	}
204 	spin_unlock_irq(&file->async_file->ev_queue.lock);
205 }
206 
207 void ib_uverbs_detach_umcast(struct ib_qp *qp,
208 			     struct ib_uqp_object *uobj)
209 {
210 	struct ib_uverbs_mcast_entry *mcast, *tmp;
211 
212 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
213 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
214 		list_del(&mcast->list);
215 		kfree(mcast);
216 	}
217 }
218 
219 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
220 				      struct ib_ucontext *context,
221 				      bool device_removed)
222 {
223 	context->closing = 1;
224 	uverbs_cleanup_ucontext(context, device_removed);
225 	put_pid(context->tgid);
226 
227 	ib_rdmacg_uncharge(&context->cg_obj, context->device,
228 			   RDMACG_RESOURCE_HCA_HANDLE);
229 
230 	return context->device->dealloc_ucontext(context);
231 }
232 
233 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
234 {
235 	complete(&dev->comp);
236 }
237 
238 void ib_uverbs_release_file(struct kref *ref)
239 {
240 	struct ib_uverbs_file *file =
241 		container_of(ref, struct ib_uverbs_file, ref);
242 	struct ib_device *ib_dev;
243 	int srcu_key;
244 
245 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
246 	ib_dev = srcu_dereference(file->device->ib_dev,
247 				  &file->device->disassociate_srcu);
248 	if (ib_dev && !ib_dev->disassociate_ucontext)
249 		module_put(ib_dev->owner);
250 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
251 
252 	if (atomic_dec_and_test(&file->device->refcount))
253 		ib_uverbs_comp_dev(file->device);
254 
255 	kobject_put(&file->device->kobj);
256 	kfree(file);
257 }
258 
259 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
260 				    struct ib_uverbs_file *uverbs_file,
261 				    struct file *filp, char __user *buf,
262 				    size_t count, loff_t *pos,
263 				    size_t eventsz)
264 {
265 	struct ib_uverbs_event *event;
266 	int ret = 0;
267 
268 	spin_lock_irq(&ev_queue->lock);
269 
270 	while (list_empty(&ev_queue->event_list)) {
271 		spin_unlock_irq(&ev_queue->lock);
272 
273 		if (filp->f_flags & O_NONBLOCK)
274 			return -EAGAIN;
275 
276 		if (wait_event_interruptible(ev_queue->poll_wait,
277 					     (!list_empty(&ev_queue->event_list) ||
278 			/* The barriers built into wait_event_interruptible()
279 			 * and wake_up() guarentee this will see the null set
280 			 * without using RCU
281 			 */
282 					     !uverbs_file->device->ib_dev)))
283 			return -ERESTARTSYS;
284 
285 		/* If device was disassociated and no event exists set an error */
286 		if (list_empty(&ev_queue->event_list) &&
287 		    !uverbs_file->device->ib_dev)
288 			return -EIO;
289 
290 		spin_lock_irq(&ev_queue->lock);
291 	}
292 
293 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
294 
295 	if (eventsz > count) {
296 		ret   = -EINVAL;
297 		event = NULL;
298 	} else {
299 		list_del(ev_queue->event_list.next);
300 		if (event->counter) {
301 			++(*event->counter);
302 			list_del(&event->obj_list);
303 		}
304 	}
305 
306 	spin_unlock_irq(&ev_queue->lock);
307 
308 	if (event) {
309 		if (copy_to_user(buf, event, eventsz))
310 			ret = -EFAULT;
311 		else
312 			ret = eventsz;
313 	}
314 
315 	kfree(event);
316 
317 	return ret;
318 }
319 
320 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
321 					  size_t count, loff_t *pos)
322 {
323 	struct ib_uverbs_async_event_file *file = filp->private_data;
324 
325 	return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
326 				    buf, count, pos,
327 				    sizeof(struct ib_uverbs_async_event_desc));
328 }
329 
330 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
331 					 size_t count, loff_t *pos)
332 {
333 	struct ib_uverbs_completion_event_file *comp_ev_file =
334 		filp->private_data;
335 
336 	return ib_uverbs_event_read(&comp_ev_file->ev_queue,
337 				    comp_ev_file->uobj_file.ufile, filp,
338 				    buf, count, pos,
339 				    sizeof(struct ib_uverbs_comp_event_desc));
340 }
341 
342 static unsigned int ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
343 					 struct file *filp,
344 					 struct poll_table_struct *wait)
345 {
346 	unsigned int pollflags = 0;
347 
348 	poll_wait(filp, &ev_queue->poll_wait, wait);
349 
350 	spin_lock_irq(&ev_queue->lock);
351 	if (!list_empty(&ev_queue->event_list))
352 		pollflags = POLLIN | POLLRDNORM;
353 	spin_unlock_irq(&ev_queue->lock);
354 
355 	return pollflags;
356 }
357 
358 static unsigned int ib_uverbs_async_event_poll(struct file *filp,
359 					       struct poll_table_struct *wait)
360 {
361 	return ib_uverbs_event_poll(filp->private_data, filp, wait);
362 }
363 
364 static unsigned int ib_uverbs_comp_event_poll(struct file *filp,
365 					      struct poll_table_struct *wait)
366 {
367 	struct ib_uverbs_completion_event_file *comp_ev_file =
368 		filp->private_data;
369 
370 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
371 }
372 
373 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
374 {
375 	struct ib_uverbs_event_queue *ev_queue = filp->private_data;
376 
377 	return fasync_helper(fd, filp, on, &ev_queue->async_queue);
378 }
379 
380 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
381 {
382 	struct ib_uverbs_completion_event_file *comp_ev_file =
383 		filp->private_data;
384 
385 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
386 }
387 
388 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
389 {
390 	struct ib_uverbs_async_event_file *file = filp->private_data;
391 	struct ib_uverbs_file *uverbs_file = file->uverbs_file;
392 	struct ib_uverbs_event *entry, *tmp;
393 	int closed_already = 0;
394 
395 	mutex_lock(&uverbs_file->device->lists_mutex);
396 	spin_lock_irq(&file->ev_queue.lock);
397 	closed_already = file->ev_queue.is_closed;
398 	file->ev_queue.is_closed = 1;
399 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
400 		if (entry->counter)
401 			list_del(&entry->obj_list);
402 		kfree(entry);
403 	}
404 	spin_unlock_irq(&file->ev_queue.lock);
405 	if (!closed_already) {
406 		list_del(&file->list);
407 		ib_unregister_event_handler(&uverbs_file->event_handler);
408 	}
409 	mutex_unlock(&uverbs_file->device->lists_mutex);
410 
411 	kref_put(&uverbs_file->ref, ib_uverbs_release_file);
412 	kref_put(&file->ref, ib_uverbs_release_async_event_file);
413 
414 	return 0;
415 }
416 
417 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
418 {
419 	struct ib_uverbs_completion_event_file *file = filp->private_data;
420 	struct ib_uverbs_event *entry, *tmp;
421 
422 	spin_lock_irq(&file->ev_queue.lock);
423 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
424 		if (entry->counter)
425 			list_del(&entry->obj_list);
426 		kfree(entry);
427 	}
428 	spin_unlock_irq(&file->ev_queue.lock);
429 
430 	uverbs_close_fd(filp);
431 
432 	return 0;
433 }
434 
435 const struct file_operations uverbs_event_fops = {
436 	.owner	 = THIS_MODULE,
437 	.read	 = ib_uverbs_comp_event_read,
438 	.poll    = ib_uverbs_comp_event_poll,
439 	.release = ib_uverbs_comp_event_close,
440 	.fasync  = ib_uverbs_comp_event_fasync,
441 	.llseek	 = no_llseek,
442 };
443 
444 static const struct file_operations uverbs_async_event_fops = {
445 	.owner	 = THIS_MODULE,
446 	.read	 = ib_uverbs_async_event_read,
447 	.poll    = ib_uverbs_async_event_poll,
448 	.release = ib_uverbs_async_event_close,
449 	.fasync  = ib_uverbs_async_event_fasync,
450 	.llseek	 = no_llseek,
451 };
452 
453 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
454 {
455 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
456 	struct ib_ucq_object	       *uobj;
457 	struct ib_uverbs_event	       *entry;
458 	unsigned long			flags;
459 
460 	if (!ev_queue)
461 		return;
462 
463 	spin_lock_irqsave(&ev_queue->lock, flags);
464 	if (ev_queue->is_closed) {
465 		spin_unlock_irqrestore(&ev_queue->lock, flags);
466 		return;
467 	}
468 
469 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
470 	if (!entry) {
471 		spin_unlock_irqrestore(&ev_queue->lock, flags);
472 		return;
473 	}
474 
475 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
476 
477 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
478 	entry->counter		   = &uobj->comp_events_reported;
479 
480 	list_add_tail(&entry->list, &ev_queue->event_list);
481 	list_add_tail(&entry->obj_list, &uobj->comp_list);
482 	spin_unlock_irqrestore(&ev_queue->lock, flags);
483 
484 	wake_up_interruptible(&ev_queue->poll_wait);
485 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
486 }
487 
488 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
489 				    __u64 element, __u64 event,
490 				    struct list_head *obj_list,
491 				    u32 *counter)
492 {
493 	struct ib_uverbs_event *entry;
494 	unsigned long flags;
495 
496 	spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
497 	if (file->async_file->ev_queue.is_closed) {
498 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
499 		return;
500 	}
501 
502 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
503 	if (!entry) {
504 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
505 		return;
506 	}
507 
508 	entry->desc.async.element    = element;
509 	entry->desc.async.event_type = event;
510 	entry->desc.async.reserved   = 0;
511 	entry->counter               = counter;
512 
513 	list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
514 	if (obj_list)
515 		list_add_tail(&entry->obj_list, obj_list);
516 	spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
517 
518 	wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
519 	kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
520 }
521 
522 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
523 {
524 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
525 						  struct ib_ucq_object, uobject);
526 
527 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
528 				event->event, &uobj->async_list,
529 				&uobj->async_events_reported);
530 }
531 
532 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
533 {
534 	struct ib_uevent_object *uobj;
535 
536 	/* for XRC target qp's, check that qp is live */
537 	if (!event->element.qp->uobject)
538 		return;
539 
540 	uobj = container_of(event->element.qp->uobject,
541 			    struct ib_uevent_object, uobject);
542 
543 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
544 				event->event, &uobj->event_list,
545 				&uobj->events_reported);
546 }
547 
548 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
549 {
550 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
551 						  struct ib_uevent_object, uobject);
552 
553 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
554 				event->event, &uobj->event_list,
555 				&uobj->events_reported);
556 }
557 
558 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
559 {
560 	struct ib_uevent_object *uobj;
561 
562 	uobj = container_of(event->element.srq->uobject,
563 			    struct ib_uevent_object, uobject);
564 
565 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
566 				event->event, &uobj->event_list,
567 				&uobj->events_reported);
568 }
569 
570 void ib_uverbs_event_handler(struct ib_event_handler *handler,
571 			     struct ib_event *event)
572 {
573 	struct ib_uverbs_file *file =
574 		container_of(handler, struct ib_uverbs_file, event_handler);
575 
576 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
577 				NULL, NULL);
578 }
579 
580 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
581 {
582 	kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
583 	file->async_file = NULL;
584 }
585 
586 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
587 {
588 	spin_lock_init(&ev_queue->lock);
589 	INIT_LIST_HEAD(&ev_queue->event_list);
590 	init_waitqueue_head(&ev_queue->poll_wait);
591 	ev_queue->is_closed   = 0;
592 	ev_queue->async_queue = NULL;
593 }
594 
595 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
596 					      struct ib_device	*ib_dev)
597 {
598 	struct ib_uverbs_async_event_file *ev_file;
599 	struct file *filp;
600 
601 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
602 	if (!ev_file)
603 		return ERR_PTR(-ENOMEM);
604 
605 	ib_uverbs_init_event_queue(&ev_file->ev_queue);
606 	ev_file->uverbs_file = uverbs_file;
607 	kref_get(&ev_file->uverbs_file->ref);
608 	kref_init(&ev_file->ref);
609 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
610 				  ev_file, O_RDONLY);
611 	if (IS_ERR(filp))
612 		goto err_put_refs;
613 
614 	mutex_lock(&uverbs_file->device->lists_mutex);
615 	list_add_tail(&ev_file->list,
616 		      &uverbs_file->device->uverbs_events_file_list);
617 	mutex_unlock(&uverbs_file->device->lists_mutex);
618 
619 	WARN_ON(uverbs_file->async_file);
620 	uverbs_file->async_file = ev_file;
621 	kref_get(&uverbs_file->async_file->ref);
622 	INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
623 			      ib_dev,
624 			      ib_uverbs_event_handler);
625 	ib_register_event_handler(&uverbs_file->event_handler);
626 	/* At that point async file stuff was fully set */
627 
628 	return filp;
629 
630 err_put_refs:
631 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
632 	kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
633 	return filp;
634 }
635 
636 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
637 {
638 	u64 mask;
639 
640 	if (command <= IB_USER_VERBS_CMD_OPEN_QP)
641 		mask = ib_dev->uverbs_cmd_mask;
642 	else
643 		mask = ib_dev->uverbs_ex_cmd_mask;
644 
645 	if (mask & ((u64)1 << command))
646 		return 0;
647 
648 	return -1;
649 }
650 
651 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
652 			     size_t count, loff_t *pos)
653 {
654 	struct ib_uverbs_file *file = filp->private_data;
655 	struct ib_device *ib_dev;
656 	struct ib_uverbs_cmd_hdr hdr;
657 	__u32 command;
658 	__u32 flags;
659 	int srcu_key;
660 	ssize_t ret;
661 
662 	if (!ib_safe_file_access(filp)) {
663 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
664 			    task_tgid_vnr(current), current->comm);
665 		return -EACCES;
666 	}
667 
668 	if (count < sizeof hdr)
669 		return -EINVAL;
670 
671 	if (copy_from_user(&hdr, buf, sizeof hdr))
672 		return -EFAULT;
673 
674 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
675 	ib_dev = srcu_dereference(file->device->ib_dev,
676 				  &file->device->disassociate_srcu);
677 	if (!ib_dev) {
678 		ret = -EIO;
679 		goto out;
680 	}
681 
682 	if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
683 				   IB_USER_VERBS_CMD_COMMAND_MASK)) {
684 		ret = -EINVAL;
685 		goto out;
686 	}
687 
688 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
689 	if (verify_command_mask(ib_dev, command)) {
690 		ret = -EOPNOTSUPP;
691 		goto out;
692 	}
693 
694 	if (!file->ucontext &&
695 	    command != IB_USER_VERBS_CMD_GET_CONTEXT) {
696 		ret = -EINVAL;
697 		goto out;
698 	}
699 
700 	flags = (hdr.command &
701 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
702 
703 	if (!flags) {
704 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
705 		    !uverbs_cmd_table[command]) {
706 			ret = -EINVAL;
707 			goto out;
708 		}
709 
710 		if (hdr.in_words * 4 != count) {
711 			ret = -EINVAL;
712 			goto out;
713 		}
714 
715 		ret = uverbs_cmd_table[command](file, ib_dev,
716 						 buf + sizeof(hdr),
717 						 hdr.in_words * 4,
718 						 hdr.out_words * 4);
719 
720 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
721 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
722 		struct ib_udata ucore;
723 		struct ib_udata uhw;
724 		size_t written_count = count;
725 
726 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
727 		    !uverbs_ex_cmd_table[command]) {
728 			ret = -ENOSYS;
729 			goto out;
730 		}
731 
732 		if (!file->ucontext) {
733 			ret = -EINVAL;
734 			goto out;
735 		}
736 
737 		if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
738 			ret = -EINVAL;
739 			goto out;
740 		}
741 
742 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
743 			ret = -EFAULT;
744 			goto out;
745 		}
746 
747 		count -= sizeof(hdr) + sizeof(ex_hdr);
748 		buf += sizeof(hdr) + sizeof(ex_hdr);
749 
750 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
751 			ret = -EINVAL;
752 			goto out;
753 		}
754 
755 		if (ex_hdr.cmd_hdr_reserved) {
756 			ret = -EINVAL;
757 			goto out;
758 		}
759 
760 		if (ex_hdr.response) {
761 			if (!hdr.out_words && !ex_hdr.provider_out_words) {
762 				ret = -EINVAL;
763 				goto out;
764 			}
765 
766 			if (!access_ok(VERIFY_WRITE,
767 				       u64_to_user_ptr(ex_hdr.response),
768 				       (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
769 				ret = -EFAULT;
770 				goto out;
771 			}
772 		} else {
773 			if (hdr.out_words || ex_hdr.provider_out_words) {
774 				ret = -EINVAL;
775 				goto out;
776 			}
777 		}
778 
779 		ib_uverbs_init_udata_buf_or_null(&ucore, buf,
780 					u64_to_user_ptr(ex_hdr.response),
781 					hdr.in_words * 8, hdr.out_words * 8);
782 
783 		ib_uverbs_init_udata_buf_or_null(&uhw,
784 					buf + ucore.inlen,
785 					u64_to_user_ptr(ex_hdr.response) + ucore.outlen,
786 					ex_hdr.provider_in_words * 8,
787 					ex_hdr.provider_out_words * 8);
788 
789 		ret = uverbs_ex_cmd_table[command](file, ib_dev, &ucore, &uhw);
790 		if (!ret)
791 			ret = written_count;
792 	} else {
793 		ret = -ENOSYS;
794 	}
795 
796 out:
797 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
798 	return ret;
799 }
800 
801 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
802 {
803 	struct ib_uverbs_file *file = filp->private_data;
804 	struct ib_device *ib_dev;
805 	int ret = 0;
806 	int srcu_key;
807 
808 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
809 	ib_dev = srcu_dereference(file->device->ib_dev,
810 				  &file->device->disassociate_srcu);
811 	if (!ib_dev) {
812 		ret = -EIO;
813 		goto out;
814 	}
815 
816 	if (!file->ucontext)
817 		ret = -ENODEV;
818 	else
819 		ret = ib_dev->mmap(file->ucontext, vma);
820 out:
821 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
822 	return ret;
823 }
824 
825 /*
826  * ib_uverbs_open() does not need the BKL:
827  *
828  *  - the ib_uverbs_device structures are properly reference counted and
829  *    everything else is purely local to the file being created, so
830  *    races against other open calls are not a problem;
831  *  - there is no ioctl method to race against;
832  *  - the open method will either immediately run -ENXIO, or all
833  *    required initialization will be done.
834  */
835 static int ib_uverbs_open(struct inode *inode, struct file *filp)
836 {
837 	struct ib_uverbs_device *dev;
838 	struct ib_uverbs_file *file;
839 	struct ib_device *ib_dev;
840 	int ret;
841 	int module_dependent;
842 	int srcu_key;
843 
844 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
845 	if (!atomic_inc_not_zero(&dev->refcount))
846 		return -ENXIO;
847 
848 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
849 	mutex_lock(&dev->lists_mutex);
850 	ib_dev = srcu_dereference(dev->ib_dev,
851 				  &dev->disassociate_srcu);
852 	if (!ib_dev) {
853 		ret = -EIO;
854 		goto err;
855 	}
856 
857 	/* In case IB device supports disassociate ucontext, there is no hard
858 	 * dependency between uverbs device and its low level device.
859 	 */
860 	module_dependent = !(ib_dev->disassociate_ucontext);
861 
862 	if (module_dependent) {
863 		if (!try_module_get(ib_dev->owner)) {
864 			ret = -ENODEV;
865 			goto err;
866 		}
867 	}
868 
869 	file = kzalloc(sizeof(*file), GFP_KERNEL);
870 	if (!file) {
871 		ret = -ENOMEM;
872 		if (module_dependent)
873 			goto err_module;
874 
875 		goto err;
876 	}
877 
878 	file->device	 = dev;
879 	spin_lock_init(&file->idr_lock);
880 	idr_init(&file->idr);
881 	file->ucontext	 = NULL;
882 	file->async_file = NULL;
883 	kref_init(&file->ref);
884 	mutex_init(&file->mutex);
885 	mutex_init(&file->cleanup_mutex);
886 
887 	filp->private_data = file;
888 	kobject_get(&dev->kobj);
889 	list_add_tail(&file->list, &dev->uverbs_file_list);
890 	mutex_unlock(&dev->lists_mutex);
891 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
892 
893 	return nonseekable_open(inode, filp);
894 
895 err_module:
896 	module_put(ib_dev->owner);
897 
898 err:
899 	mutex_unlock(&dev->lists_mutex);
900 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
901 	if (atomic_dec_and_test(&dev->refcount))
902 		ib_uverbs_comp_dev(dev);
903 
904 	return ret;
905 }
906 
907 static int ib_uverbs_close(struct inode *inode, struct file *filp)
908 {
909 	struct ib_uverbs_file *file = filp->private_data;
910 
911 	mutex_lock(&file->cleanup_mutex);
912 	if (file->ucontext) {
913 		ib_uverbs_cleanup_ucontext(file, file->ucontext, false);
914 		file->ucontext = NULL;
915 	}
916 	mutex_unlock(&file->cleanup_mutex);
917 	idr_destroy(&file->idr);
918 
919 	mutex_lock(&file->device->lists_mutex);
920 	if (!file->is_closed) {
921 		list_del(&file->list);
922 		file->is_closed = 1;
923 	}
924 	mutex_unlock(&file->device->lists_mutex);
925 
926 	if (file->async_file)
927 		kref_put(&file->async_file->ref,
928 			 ib_uverbs_release_async_event_file);
929 
930 	kref_put(&file->ref, ib_uverbs_release_file);
931 
932 	return 0;
933 }
934 
935 static const struct file_operations uverbs_fops = {
936 	.owner	 = THIS_MODULE,
937 	.write	 = ib_uverbs_write,
938 	.open	 = ib_uverbs_open,
939 	.release = ib_uverbs_close,
940 	.llseek	 = no_llseek,
941 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
942 	.unlocked_ioctl = ib_uverbs_ioctl,
943 #endif
944 };
945 
946 static const struct file_operations uverbs_mmap_fops = {
947 	.owner	 = THIS_MODULE,
948 	.write	 = ib_uverbs_write,
949 	.mmap    = ib_uverbs_mmap,
950 	.open	 = ib_uverbs_open,
951 	.release = ib_uverbs_close,
952 	.llseek	 = no_llseek,
953 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
954 	.unlocked_ioctl = ib_uverbs_ioctl,
955 #endif
956 };
957 
958 static struct ib_client uverbs_client = {
959 	.name   = "uverbs",
960 	.add    = ib_uverbs_add_one,
961 	.remove = ib_uverbs_remove_one
962 };
963 
964 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
965 			  char *buf)
966 {
967 	int ret = -ENODEV;
968 	int srcu_key;
969 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
970 	struct ib_device *ib_dev;
971 
972 	if (!dev)
973 		return -ENODEV;
974 
975 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
976 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
977 	if (ib_dev)
978 		ret = sprintf(buf, "%s\n", ib_dev->name);
979 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
980 
981 	return ret;
982 }
983 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
984 
985 static ssize_t show_dev_abi_version(struct device *device,
986 				    struct device_attribute *attr, char *buf)
987 {
988 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
989 	int ret = -ENODEV;
990 	int srcu_key;
991 	struct ib_device *ib_dev;
992 
993 	if (!dev)
994 		return -ENODEV;
995 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
996 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
997 	if (ib_dev)
998 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
999 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1000 
1001 	return ret;
1002 }
1003 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
1004 
1005 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1006 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1007 
1008 static dev_t overflow_maj;
1009 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
1010 
1011 /*
1012  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
1013  * requesting a new major number and doubling the number of max devices we
1014  * support. It's stupid, but simple.
1015  */
1016 static int find_overflow_devnum(void)
1017 {
1018 	int ret;
1019 
1020 	if (!overflow_maj) {
1021 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
1022 					  "infiniband_verbs");
1023 		if (ret) {
1024 			pr_err("user_verbs: couldn't register dynamic device number\n");
1025 			return ret;
1026 		}
1027 	}
1028 
1029 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
1030 	if (ret >= IB_UVERBS_MAX_DEVICES)
1031 		return -1;
1032 
1033 	return ret;
1034 }
1035 
1036 static void ib_uverbs_add_one(struct ib_device *device)
1037 {
1038 	int devnum;
1039 	dev_t base;
1040 	struct ib_uverbs_device *uverbs_dev;
1041 	int ret;
1042 
1043 	if (!device->alloc_ucontext)
1044 		return;
1045 
1046 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1047 	if (!uverbs_dev)
1048 		return;
1049 
1050 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1051 	if (ret) {
1052 		kfree(uverbs_dev);
1053 		return;
1054 	}
1055 
1056 	atomic_set(&uverbs_dev->refcount, 1);
1057 	init_completion(&uverbs_dev->comp);
1058 	uverbs_dev->xrcd_tree = RB_ROOT;
1059 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1060 	kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1061 	mutex_init(&uverbs_dev->lists_mutex);
1062 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1063 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1064 
1065 	spin_lock(&map_lock);
1066 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1067 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
1068 		spin_unlock(&map_lock);
1069 		devnum = find_overflow_devnum();
1070 		if (devnum < 0)
1071 			goto err;
1072 
1073 		spin_lock(&map_lock);
1074 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
1075 		base = devnum + overflow_maj;
1076 		set_bit(devnum, overflow_map);
1077 	} else {
1078 		uverbs_dev->devnum = devnum;
1079 		base = devnum + IB_UVERBS_BASE_DEV;
1080 		set_bit(devnum, dev_map);
1081 	}
1082 	spin_unlock(&map_lock);
1083 
1084 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1085 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1086 
1087 	cdev_init(&uverbs_dev->cdev, NULL);
1088 	uverbs_dev->cdev.owner = THIS_MODULE;
1089 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1090 	cdev_set_parent(&uverbs_dev->cdev, &uverbs_dev->kobj);
1091 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1092 	if (cdev_add(&uverbs_dev->cdev, base, 1))
1093 		goto err_cdev;
1094 
1095 	uverbs_dev->dev = device_create(uverbs_class, device->dev.parent,
1096 					uverbs_dev->cdev.dev, uverbs_dev,
1097 					"uverbs%d", uverbs_dev->devnum);
1098 	if (IS_ERR(uverbs_dev->dev))
1099 		goto err_cdev;
1100 
1101 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1102 		goto err_class;
1103 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1104 		goto err_class;
1105 
1106 	if (!device->specs_root) {
1107 		const struct uverbs_object_tree_def *default_root[] = {
1108 			uverbs_default_get_objects()};
1109 
1110 		uverbs_dev->specs_root = uverbs_alloc_spec_tree(1,
1111 								default_root);
1112 		if (IS_ERR(uverbs_dev->specs_root))
1113 			goto err_class;
1114 
1115 		device->specs_root = uverbs_dev->specs_root;
1116 	}
1117 
1118 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1119 
1120 	return;
1121 
1122 err_class:
1123 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1124 
1125 err_cdev:
1126 	cdev_del(&uverbs_dev->cdev);
1127 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1128 		clear_bit(devnum, dev_map);
1129 	else
1130 		clear_bit(devnum, overflow_map);
1131 
1132 err:
1133 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1134 		ib_uverbs_comp_dev(uverbs_dev);
1135 	wait_for_completion(&uverbs_dev->comp);
1136 	kobject_put(&uverbs_dev->kobj);
1137 	return;
1138 }
1139 
1140 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1141 					struct ib_device *ib_dev)
1142 {
1143 	struct ib_uverbs_file *file;
1144 	struct ib_uverbs_async_event_file *event_file;
1145 	struct ib_event event;
1146 
1147 	/* Pending running commands to terminate */
1148 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
1149 	event.event = IB_EVENT_DEVICE_FATAL;
1150 	event.element.port_num = 0;
1151 	event.device = ib_dev;
1152 
1153 	mutex_lock(&uverbs_dev->lists_mutex);
1154 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1155 		struct ib_ucontext *ucontext;
1156 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1157 					struct ib_uverbs_file, list);
1158 		file->is_closed = 1;
1159 		list_del(&file->list);
1160 		kref_get(&file->ref);
1161 		mutex_unlock(&uverbs_dev->lists_mutex);
1162 
1163 
1164 		mutex_lock(&file->cleanup_mutex);
1165 		ucontext = file->ucontext;
1166 		file->ucontext = NULL;
1167 		mutex_unlock(&file->cleanup_mutex);
1168 
1169 		/* At this point ib_uverbs_close cannot be running
1170 		 * ib_uverbs_cleanup_ucontext
1171 		 */
1172 		if (ucontext) {
1173 			/* We must release the mutex before going ahead and
1174 			 * calling disassociate_ucontext. disassociate_ucontext
1175 			 * might end up indirectly calling uverbs_close,
1176 			 * for example due to freeing the resources
1177 			 * (e.g mmput).
1178 			 */
1179 			ib_uverbs_event_handler(&file->event_handler, &event);
1180 			ib_dev->disassociate_ucontext(ucontext);
1181 			mutex_lock(&file->cleanup_mutex);
1182 			ib_uverbs_cleanup_ucontext(file, ucontext, true);
1183 			mutex_unlock(&file->cleanup_mutex);
1184 		}
1185 
1186 		mutex_lock(&uverbs_dev->lists_mutex);
1187 		kref_put(&file->ref, ib_uverbs_release_file);
1188 	}
1189 
1190 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1191 		event_file = list_first_entry(&uverbs_dev->
1192 					      uverbs_events_file_list,
1193 					      struct ib_uverbs_async_event_file,
1194 					      list);
1195 		spin_lock_irq(&event_file->ev_queue.lock);
1196 		event_file->ev_queue.is_closed = 1;
1197 		spin_unlock_irq(&event_file->ev_queue.lock);
1198 
1199 		list_del(&event_file->list);
1200 		ib_unregister_event_handler(
1201 			&event_file->uverbs_file->event_handler);
1202 		event_file->uverbs_file->event_handler.device =
1203 			NULL;
1204 
1205 		wake_up_interruptible(&event_file->ev_queue.poll_wait);
1206 		kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1207 	}
1208 	mutex_unlock(&uverbs_dev->lists_mutex);
1209 }
1210 
1211 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1212 {
1213 	struct ib_uverbs_device *uverbs_dev = client_data;
1214 	int wait_clients = 1;
1215 
1216 	if (!uverbs_dev)
1217 		return;
1218 
1219 	dev_set_drvdata(uverbs_dev->dev, NULL);
1220 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1221 	cdev_del(&uverbs_dev->cdev);
1222 
1223 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1224 		clear_bit(uverbs_dev->devnum, dev_map);
1225 	else
1226 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
1227 
1228 	if (device->disassociate_ucontext) {
1229 		/* We disassociate HW resources and immediately return.
1230 		 * Userspace will see a EIO errno for all future access.
1231 		 * Upon returning, ib_device may be freed internally and is not
1232 		 * valid any more.
1233 		 * uverbs_device is still available until all clients close
1234 		 * their files, then the uverbs device ref count will be zero
1235 		 * and its resources will be freed.
1236 		 * Note: At this point no more files can be opened since the
1237 		 * cdev was deleted, however active clients can still issue
1238 		 * commands and close their open files.
1239 		 */
1240 		rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1241 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1242 		wait_clients = 0;
1243 	}
1244 
1245 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1246 		ib_uverbs_comp_dev(uverbs_dev);
1247 	if (wait_clients)
1248 		wait_for_completion(&uverbs_dev->comp);
1249 	if (uverbs_dev->specs_root) {
1250 		uverbs_free_spec_tree(uverbs_dev->specs_root);
1251 		device->specs_root = NULL;
1252 	}
1253 
1254 	kobject_put(&uverbs_dev->kobj);
1255 }
1256 
1257 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1258 {
1259 	if (mode)
1260 		*mode = 0666;
1261 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1262 }
1263 
1264 static int __init ib_uverbs_init(void)
1265 {
1266 	int ret;
1267 
1268 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
1269 				     "infiniband_verbs");
1270 	if (ret) {
1271 		pr_err("user_verbs: couldn't register device number\n");
1272 		goto out;
1273 	}
1274 
1275 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1276 	if (IS_ERR(uverbs_class)) {
1277 		ret = PTR_ERR(uverbs_class);
1278 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1279 		goto out_chrdev;
1280 	}
1281 
1282 	uverbs_class->devnode = uverbs_devnode;
1283 
1284 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1285 	if (ret) {
1286 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1287 		goto out_class;
1288 	}
1289 
1290 	ret = ib_register_client(&uverbs_client);
1291 	if (ret) {
1292 		pr_err("user_verbs: couldn't register client\n");
1293 		goto out_class;
1294 	}
1295 
1296 	return 0;
1297 
1298 out_class:
1299 	class_destroy(uverbs_class);
1300 
1301 out_chrdev:
1302 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1303 
1304 out:
1305 	return ret;
1306 }
1307 
1308 static void __exit ib_uverbs_cleanup(void)
1309 {
1310 	ib_unregister_client(&uverbs_client);
1311 	class_destroy(uverbs_class);
1312 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1313 	if (overflow_maj)
1314 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1315 }
1316 
1317 module_init(ib_uverbs_init);
1318 module_exit(ib_uverbs_cleanup);
1319