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/sched/mm.h>
45 #include <linux/sched/task.h>
46 #include <linux/file.h>
47 #include <linux/cdev.h>
48 #include <linux/anon_inodes.h>
49 #include <linux/slab.h>
50 
51 #include <linux/uaccess.h>
52 
53 #include <rdma/ib.h>
54 #include <rdma/uverbs_std_types.h>
55 
56 #include "uverbs.h"
57 #include "core_priv.h"
58 #include "rdma_core.h"
59 
60 MODULE_AUTHOR("Roland Dreier");
61 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
62 MODULE_LICENSE("Dual BSD/GPL");
63 
64 enum {
65 	IB_UVERBS_MAJOR       = 231,
66 	IB_UVERBS_BASE_MINOR  = 192,
67 	IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
68 	IB_UVERBS_NUM_FIXED_MINOR = 32,
69 	IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
70 };
71 
72 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
73 
74 static dev_t dynamic_uverbs_dev;
75 static struct class *uverbs_class;
76 
77 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
78 
79 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
80 				     struct ib_device *ib_dev,
81 				     const char __user *buf, int in_len,
82 				     int out_len) = {
83 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
84 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
85 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
86 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
87 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
88 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
89 	[IB_USER_VERBS_CMD_REREG_MR]		= ib_uverbs_rereg_mr,
90 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
91 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
92 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
93 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
94 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
95 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
96 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
97 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
98 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
99 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
100 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
101 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
102 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
103 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
104 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
105 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
106 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
107 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
108 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
109 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
110 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
111 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
112 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
113 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
114 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
115 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
116 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
117 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
118 };
119 
120 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
121 				    struct ib_device *ib_dev,
122 				    struct ib_udata *ucore,
123 				    struct ib_udata *uhw) = {
124 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
125 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow,
126 	[IB_USER_VERBS_EX_CMD_QUERY_DEVICE]	= ib_uverbs_ex_query_device,
127 	[IB_USER_VERBS_EX_CMD_CREATE_CQ]	= ib_uverbs_ex_create_cq,
128 	[IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
129 	[IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
130 	[IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
131 	[IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
132 	[IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
133 	[IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
134 	[IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
135 	[IB_USER_VERBS_EX_CMD_MODIFY_CQ]        = ib_uverbs_ex_modify_cq,
136 };
137 
138 static void ib_uverbs_add_one(struct ib_device *device);
139 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
140 
141 int uverbs_dealloc_mw(struct ib_mw *mw)
142 {
143 	struct ib_pd *pd = mw->pd;
144 	int ret;
145 
146 	ret = mw->device->dealloc_mw(mw);
147 	if (!ret)
148 		atomic_dec(&pd->usecnt);
149 	return ret;
150 }
151 
152 static void ib_uverbs_release_dev(struct kobject *kobj)
153 {
154 	struct ib_uverbs_device *dev =
155 		container_of(kobj, struct ib_uverbs_device, kobj);
156 
157 	cleanup_srcu_struct(&dev->disassociate_srcu);
158 	kfree(dev);
159 }
160 
161 static struct kobj_type ib_uverbs_dev_ktype = {
162 	.release = ib_uverbs_release_dev,
163 };
164 
165 static void ib_uverbs_release_async_event_file(struct kref *ref)
166 {
167 	struct ib_uverbs_async_event_file *file =
168 		container_of(ref, struct ib_uverbs_async_event_file, ref);
169 
170 	kfree(file);
171 }
172 
173 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
174 			  struct ib_uverbs_completion_event_file *ev_file,
175 			  struct ib_ucq_object *uobj)
176 {
177 	struct ib_uverbs_event *evt, *tmp;
178 
179 	if (ev_file) {
180 		spin_lock_irq(&ev_file->ev_queue.lock);
181 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
182 			list_del(&evt->list);
183 			kfree(evt);
184 		}
185 		spin_unlock_irq(&ev_file->ev_queue.lock);
186 
187 		uverbs_uobject_put(&ev_file->uobj_file.uobj);
188 	}
189 
190 	spin_lock_irq(&file->async_file->ev_queue.lock);
191 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
192 		list_del(&evt->list);
193 		kfree(evt);
194 	}
195 	spin_unlock_irq(&file->async_file->ev_queue.lock);
196 }
197 
198 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
199 			      struct ib_uevent_object *uobj)
200 {
201 	struct ib_uverbs_event *evt, *tmp;
202 
203 	spin_lock_irq(&file->async_file->ev_queue.lock);
204 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
205 		list_del(&evt->list);
206 		kfree(evt);
207 	}
208 	spin_unlock_irq(&file->async_file->ev_queue.lock);
209 }
210 
211 void ib_uverbs_detach_umcast(struct ib_qp *qp,
212 			     struct ib_uqp_object *uobj)
213 {
214 	struct ib_uverbs_mcast_entry *mcast, *tmp;
215 
216 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
217 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
218 		list_del(&mcast->list);
219 		kfree(mcast);
220 	}
221 }
222 
223 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
224 				      struct ib_ucontext *context,
225 				      bool device_removed)
226 {
227 	context->closing = 1;
228 	uverbs_cleanup_ucontext(context, device_removed);
229 	put_pid(context->tgid);
230 
231 	ib_rdmacg_uncharge(&context->cg_obj, context->device,
232 			   RDMACG_RESOURCE_HCA_HANDLE);
233 
234 	return context->device->dealloc_ucontext(context);
235 }
236 
237 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
238 {
239 	complete(&dev->comp);
240 }
241 
242 void ib_uverbs_release_file(struct kref *ref)
243 {
244 	struct ib_uverbs_file *file =
245 		container_of(ref, struct ib_uverbs_file, ref);
246 	struct ib_device *ib_dev;
247 	int srcu_key;
248 
249 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
250 	ib_dev = srcu_dereference(file->device->ib_dev,
251 				  &file->device->disassociate_srcu);
252 	if (ib_dev && !ib_dev->disassociate_ucontext)
253 		module_put(ib_dev->owner);
254 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
255 
256 	if (atomic_dec_and_test(&file->device->refcount))
257 		ib_uverbs_comp_dev(file->device);
258 
259 	kobject_put(&file->device->kobj);
260 	kfree(file);
261 }
262 
263 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
264 				    struct ib_uverbs_file *uverbs_file,
265 				    struct file *filp, char __user *buf,
266 				    size_t count, loff_t *pos,
267 				    size_t eventsz)
268 {
269 	struct ib_uverbs_event *event;
270 	int ret = 0;
271 
272 	spin_lock_irq(&ev_queue->lock);
273 
274 	while (list_empty(&ev_queue->event_list)) {
275 		spin_unlock_irq(&ev_queue->lock);
276 
277 		if (filp->f_flags & O_NONBLOCK)
278 			return -EAGAIN;
279 
280 		if (wait_event_interruptible(ev_queue->poll_wait,
281 					     (!list_empty(&ev_queue->event_list) ||
282 			/* The barriers built into wait_event_interruptible()
283 			 * and wake_up() guarentee this will see the null set
284 			 * without using RCU
285 			 */
286 					     !uverbs_file->device->ib_dev)))
287 			return -ERESTARTSYS;
288 
289 		/* If device was disassociated and no event exists set an error */
290 		if (list_empty(&ev_queue->event_list) &&
291 		    !uverbs_file->device->ib_dev)
292 			return -EIO;
293 
294 		spin_lock_irq(&ev_queue->lock);
295 	}
296 
297 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
298 
299 	if (eventsz > count) {
300 		ret   = -EINVAL;
301 		event = NULL;
302 	} else {
303 		list_del(ev_queue->event_list.next);
304 		if (event->counter) {
305 			++(*event->counter);
306 			list_del(&event->obj_list);
307 		}
308 	}
309 
310 	spin_unlock_irq(&ev_queue->lock);
311 
312 	if (event) {
313 		if (copy_to_user(buf, event, eventsz))
314 			ret = -EFAULT;
315 		else
316 			ret = eventsz;
317 	}
318 
319 	kfree(event);
320 
321 	return ret;
322 }
323 
324 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
325 					  size_t count, loff_t *pos)
326 {
327 	struct ib_uverbs_async_event_file *file = filp->private_data;
328 
329 	return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
330 				    buf, count, pos,
331 				    sizeof(struct ib_uverbs_async_event_desc));
332 }
333 
334 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
335 					 size_t count, loff_t *pos)
336 {
337 	struct ib_uverbs_completion_event_file *comp_ev_file =
338 		filp->private_data;
339 
340 	return ib_uverbs_event_read(&comp_ev_file->ev_queue,
341 				    comp_ev_file->uobj_file.ufile, filp,
342 				    buf, count, pos,
343 				    sizeof(struct ib_uverbs_comp_event_desc));
344 }
345 
346 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
347 					 struct file *filp,
348 					 struct poll_table_struct *wait)
349 {
350 	__poll_t pollflags = 0;
351 
352 	poll_wait(filp, &ev_queue->poll_wait, wait);
353 
354 	spin_lock_irq(&ev_queue->lock);
355 	if (!list_empty(&ev_queue->event_list))
356 		pollflags = EPOLLIN | EPOLLRDNORM;
357 	spin_unlock_irq(&ev_queue->lock);
358 
359 	return pollflags;
360 }
361 
362 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
363 					       struct poll_table_struct *wait)
364 {
365 	return ib_uverbs_event_poll(filp->private_data, filp, wait);
366 }
367 
368 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
369 					      struct poll_table_struct *wait)
370 {
371 	struct ib_uverbs_completion_event_file *comp_ev_file =
372 		filp->private_data;
373 
374 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
375 }
376 
377 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
378 {
379 	struct ib_uverbs_event_queue *ev_queue = filp->private_data;
380 
381 	return fasync_helper(fd, filp, on, &ev_queue->async_queue);
382 }
383 
384 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
385 {
386 	struct ib_uverbs_completion_event_file *comp_ev_file =
387 		filp->private_data;
388 
389 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
390 }
391 
392 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
393 {
394 	struct ib_uverbs_async_event_file *file = filp->private_data;
395 	struct ib_uverbs_file *uverbs_file = file->uverbs_file;
396 	struct ib_uverbs_event *entry, *tmp;
397 	int closed_already = 0;
398 
399 	mutex_lock(&uverbs_file->device->lists_mutex);
400 	spin_lock_irq(&file->ev_queue.lock);
401 	closed_already = file->ev_queue.is_closed;
402 	file->ev_queue.is_closed = 1;
403 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
404 		if (entry->counter)
405 			list_del(&entry->obj_list);
406 		kfree(entry);
407 	}
408 	spin_unlock_irq(&file->ev_queue.lock);
409 	if (!closed_already) {
410 		list_del(&file->list);
411 		ib_unregister_event_handler(&uverbs_file->event_handler);
412 	}
413 	mutex_unlock(&uverbs_file->device->lists_mutex);
414 
415 	kref_put(&uverbs_file->ref, ib_uverbs_release_file);
416 	kref_put(&file->ref, ib_uverbs_release_async_event_file);
417 
418 	return 0;
419 }
420 
421 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
422 {
423 	struct ib_uverbs_completion_event_file *file = filp->private_data;
424 	struct ib_uverbs_event *entry, *tmp;
425 
426 	spin_lock_irq(&file->ev_queue.lock);
427 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
428 		if (entry->counter)
429 			list_del(&entry->obj_list);
430 		kfree(entry);
431 	}
432 	spin_unlock_irq(&file->ev_queue.lock);
433 
434 	uverbs_close_fd(filp);
435 
436 	return 0;
437 }
438 
439 const struct file_operations uverbs_event_fops = {
440 	.owner	 = THIS_MODULE,
441 	.read	 = ib_uverbs_comp_event_read,
442 	.poll    = ib_uverbs_comp_event_poll,
443 	.release = ib_uverbs_comp_event_close,
444 	.fasync  = ib_uverbs_comp_event_fasync,
445 	.llseek	 = no_llseek,
446 };
447 
448 static const struct file_operations uverbs_async_event_fops = {
449 	.owner	 = THIS_MODULE,
450 	.read	 = ib_uverbs_async_event_read,
451 	.poll    = ib_uverbs_async_event_poll,
452 	.release = ib_uverbs_async_event_close,
453 	.fasync  = ib_uverbs_async_event_fasync,
454 	.llseek	 = no_llseek,
455 };
456 
457 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
458 {
459 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
460 	struct ib_ucq_object	       *uobj;
461 	struct ib_uverbs_event	       *entry;
462 	unsigned long			flags;
463 
464 	if (!ev_queue)
465 		return;
466 
467 	spin_lock_irqsave(&ev_queue->lock, flags);
468 	if (ev_queue->is_closed) {
469 		spin_unlock_irqrestore(&ev_queue->lock, flags);
470 		return;
471 	}
472 
473 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
474 	if (!entry) {
475 		spin_unlock_irqrestore(&ev_queue->lock, flags);
476 		return;
477 	}
478 
479 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
480 
481 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
482 	entry->counter		   = &uobj->comp_events_reported;
483 
484 	list_add_tail(&entry->list, &ev_queue->event_list);
485 	list_add_tail(&entry->obj_list, &uobj->comp_list);
486 	spin_unlock_irqrestore(&ev_queue->lock, flags);
487 
488 	wake_up_interruptible(&ev_queue->poll_wait);
489 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
490 }
491 
492 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
493 				    __u64 element, __u64 event,
494 				    struct list_head *obj_list,
495 				    u32 *counter)
496 {
497 	struct ib_uverbs_event *entry;
498 	unsigned long flags;
499 
500 	spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
501 	if (file->async_file->ev_queue.is_closed) {
502 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
503 		return;
504 	}
505 
506 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
507 	if (!entry) {
508 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
509 		return;
510 	}
511 
512 	entry->desc.async.element    = element;
513 	entry->desc.async.event_type = event;
514 	entry->desc.async.reserved   = 0;
515 	entry->counter               = counter;
516 
517 	list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
518 	if (obj_list)
519 		list_add_tail(&entry->obj_list, obj_list);
520 	spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
521 
522 	wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
523 	kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
524 }
525 
526 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
527 {
528 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
529 						  struct ib_ucq_object, uobject);
530 
531 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
532 				event->event, &uobj->async_list,
533 				&uobj->async_events_reported);
534 }
535 
536 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
537 {
538 	struct ib_uevent_object *uobj;
539 
540 	/* for XRC target qp's, check that qp is live */
541 	if (!event->element.qp->uobject)
542 		return;
543 
544 	uobj = container_of(event->element.qp->uobject,
545 			    struct ib_uevent_object, uobject);
546 
547 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
548 				event->event, &uobj->event_list,
549 				&uobj->events_reported);
550 }
551 
552 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
553 {
554 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
555 						  struct ib_uevent_object, uobject);
556 
557 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
558 				event->event, &uobj->event_list,
559 				&uobj->events_reported);
560 }
561 
562 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
563 {
564 	struct ib_uevent_object *uobj;
565 
566 	uobj = container_of(event->element.srq->uobject,
567 			    struct ib_uevent_object, uobject);
568 
569 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
570 				event->event, &uobj->event_list,
571 				&uobj->events_reported);
572 }
573 
574 void ib_uverbs_event_handler(struct ib_event_handler *handler,
575 			     struct ib_event *event)
576 {
577 	struct ib_uverbs_file *file =
578 		container_of(handler, struct ib_uverbs_file, event_handler);
579 
580 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
581 				NULL, NULL);
582 }
583 
584 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
585 {
586 	kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
587 	file->async_file = NULL;
588 }
589 
590 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
591 {
592 	spin_lock_init(&ev_queue->lock);
593 	INIT_LIST_HEAD(&ev_queue->event_list);
594 	init_waitqueue_head(&ev_queue->poll_wait);
595 	ev_queue->is_closed   = 0;
596 	ev_queue->async_queue = NULL;
597 }
598 
599 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
600 					      struct ib_device	*ib_dev)
601 {
602 	struct ib_uverbs_async_event_file *ev_file;
603 	struct file *filp;
604 
605 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
606 	if (!ev_file)
607 		return ERR_PTR(-ENOMEM);
608 
609 	ib_uverbs_init_event_queue(&ev_file->ev_queue);
610 	ev_file->uverbs_file = uverbs_file;
611 	kref_get(&ev_file->uverbs_file->ref);
612 	kref_init(&ev_file->ref);
613 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
614 				  ev_file, O_RDONLY);
615 	if (IS_ERR(filp))
616 		goto err_put_refs;
617 
618 	mutex_lock(&uverbs_file->device->lists_mutex);
619 	list_add_tail(&ev_file->list,
620 		      &uverbs_file->device->uverbs_events_file_list);
621 	mutex_unlock(&uverbs_file->device->lists_mutex);
622 
623 	WARN_ON(uverbs_file->async_file);
624 	uverbs_file->async_file = ev_file;
625 	kref_get(&uverbs_file->async_file->ref);
626 	INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
627 			      ib_dev,
628 			      ib_uverbs_event_handler);
629 	ib_register_event_handler(&uverbs_file->event_handler);
630 	/* At that point async file stuff was fully set */
631 
632 	return filp;
633 
634 err_put_refs:
635 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
636 	kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
637 	return filp;
638 }
639 
640 static bool verify_command_mask(struct ib_device *ib_dev,
641 				u32 command, bool extended)
642 {
643 	if (!extended)
644 		return ib_dev->uverbs_cmd_mask & BIT_ULL(command);
645 
646 	return ib_dev->uverbs_ex_cmd_mask & BIT_ULL(command);
647 }
648 
649 static bool verify_command_idx(u32 command, bool extended)
650 {
651 	if (extended)
652 		return command < ARRAY_SIZE(uverbs_ex_cmd_table) &&
653 		       uverbs_ex_cmd_table[command];
654 
655 	return command < ARRAY_SIZE(uverbs_cmd_table) &&
656 	       uverbs_cmd_table[command];
657 }
658 
659 static ssize_t process_hdr(struct ib_uverbs_cmd_hdr *hdr,
660 			   u32 *command, bool *extended)
661 {
662 	if (hdr->command & ~(u32)(IB_USER_VERBS_CMD_FLAG_EXTENDED |
663 				   IB_USER_VERBS_CMD_COMMAND_MASK))
664 		return -EINVAL;
665 
666 	*command = hdr->command & IB_USER_VERBS_CMD_COMMAND_MASK;
667 	*extended = hdr->command & IB_USER_VERBS_CMD_FLAG_EXTENDED;
668 
669 	if (!verify_command_idx(*command, *extended))
670 		return -EOPNOTSUPP;
671 
672 	return 0;
673 }
674 
675 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
676 			  struct ib_uverbs_ex_cmd_hdr *ex_hdr,
677 			  size_t count, bool extended)
678 {
679 	if (extended) {
680 		count -= sizeof(*hdr) + sizeof(*ex_hdr);
681 
682 		if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
683 			return -EINVAL;
684 
685 		if (ex_hdr->cmd_hdr_reserved)
686 			return -EINVAL;
687 
688 		if (ex_hdr->response) {
689 			if (!hdr->out_words && !ex_hdr->provider_out_words)
690 				return -EINVAL;
691 
692 			if (!access_ok(VERIFY_WRITE,
693 				       u64_to_user_ptr(ex_hdr->response),
694 				       (hdr->out_words + ex_hdr->provider_out_words) * 8))
695 				return -EFAULT;
696 		} else {
697 			if (hdr->out_words || ex_hdr->provider_out_words)
698 				return -EINVAL;
699 		}
700 
701 		return 0;
702 	}
703 
704 	/* not extended command */
705 	if (hdr->in_words * 4 != count)
706 		return -EINVAL;
707 
708 	return 0;
709 }
710 
711 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
712 			     size_t count, loff_t *pos)
713 {
714 	struct ib_uverbs_file *file = filp->private_data;
715 	struct ib_uverbs_ex_cmd_hdr ex_hdr;
716 	struct ib_device *ib_dev;
717 	struct ib_uverbs_cmd_hdr hdr;
718 	bool extended;
719 	int srcu_key;
720 	u32 command;
721 	ssize_t ret;
722 
723 	if (!ib_safe_file_access(filp)) {
724 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
725 			    task_tgid_vnr(current), current->comm);
726 		return -EACCES;
727 	}
728 
729 	if (count < sizeof(hdr))
730 		return -EINVAL;
731 
732 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
733 		return -EFAULT;
734 
735 	ret = process_hdr(&hdr, &command, &extended);
736 	if (ret)
737 		return ret;
738 
739 	if (extended) {
740 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
741 			return -EINVAL;
742 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
743 			return -EFAULT;
744 	}
745 
746 	ret = verify_hdr(&hdr, &ex_hdr, count, extended);
747 	if (ret)
748 		return ret;
749 
750 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
751 	ib_dev = srcu_dereference(file->device->ib_dev,
752 				  &file->device->disassociate_srcu);
753 	if (!ib_dev) {
754 		ret = -EIO;
755 		goto out;
756 	}
757 
758 	/*
759 	 * Must be after the ib_dev check, as once the RCU clears ib_dev ==
760 	 * NULL means ucontext == NULL
761 	 */
762 	if (!file->ucontext &&
763 	    (command != IB_USER_VERBS_CMD_GET_CONTEXT || extended)) {
764 		ret = -EINVAL;
765 		goto out;
766 	}
767 
768 	if (!verify_command_mask(ib_dev, command, extended)) {
769 		ret = -EOPNOTSUPP;
770 		goto out;
771 	}
772 
773 	buf += sizeof(hdr);
774 
775 	if (!extended) {
776 		ret = uverbs_cmd_table[command](file, ib_dev, buf,
777 						hdr.in_words * 4,
778 						hdr.out_words * 4);
779 	} else {
780 		struct ib_udata ucore;
781 		struct ib_udata uhw;
782 
783 		buf += sizeof(ex_hdr);
784 
785 		ib_uverbs_init_udata_buf_or_null(&ucore, buf,
786 					u64_to_user_ptr(ex_hdr.response),
787 					hdr.in_words * 8, hdr.out_words * 8);
788 
789 		ib_uverbs_init_udata_buf_or_null(&uhw,
790 					buf + ucore.inlen,
791 					u64_to_user_ptr(ex_hdr.response) + ucore.outlen,
792 					ex_hdr.provider_in_words * 8,
793 					ex_hdr.provider_out_words * 8);
794 
795 		ret = uverbs_ex_cmd_table[command](file, ib_dev, &ucore, &uhw);
796 		ret = (ret) ? : count;
797 	}
798 
799 out:
800 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
801 	return ret;
802 }
803 
804 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
805 {
806 	struct ib_uverbs_file *file = filp->private_data;
807 	struct ib_device *ib_dev;
808 	int ret = 0;
809 	int srcu_key;
810 
811 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
812 	ib_dev = srcu_dereference(file->device->ib_dev,
813 				  &file->device->disassociate_srcu);
814 	if (!ib_dev) {
815 		ret = -EIO;
816 		goto out;
817 	}
818 
819 	if (!file->ucontext)
820 		ret = -ENODEV;
821 	else
822 		ret = ib_dev->mmap(file->ucontext, vma);
823 out:
824 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
825 	return ret;
826 }
827 
828 /*
829  * ib_uverbs_open() does not need the BKL:
830  *
831  *  - the ib_uverbs_device structures are properly reference counted and
832  *    everything else is purely local to the file being created, so
833  *    races against other open calls are not a problem;
834  *  - there is no ioctl method to race against;
835  *  - the open method will either immediately run -ENXIO, or all
836  *    required initialization will be done.
837  */
838 static int ib_uverbs_open(struct inode *inode, struct file *filp)
839 {
840 	struct ib_uverbs_device *dev;
841 	struct ib_uverbs_file *file;
842 	struct ib_device *ib_dev;
843 	int ret;
844 	int module_dependent;
845 	int srcu_key;
846 
847 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
848 	if (!atomic_inc_not_zero(&dev->refcount))
849 		return -ENXIO;
850 
851 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
852 	mutex_lock(&dev->lists_mutex);
853 	ib_dev = srcu_dereference(dev->ib_dev,
854 				  &dev->disassociate_srcu);
855 	if (!ib_dev) {
856 		ret = -EIO;
857 		goto err;
858 	}
859 
860 	/* In case IB device supports disassociate ucontext, there is no hard
861 	 * dependency between uverbs device and its low level device.
862 	 */
863 	module_dependent = !(ib_dev->disassociate_ucontext);
864 
865 	if (module_dependent) {
866 		if (!try_module_get(ib_dev->owner)) {
867 			ret = -ENODEV;
868 			goto err;
869 		}
870 	}
871 
872 	file = kzalloc(sizeof(*file), GFP_KERNEL);
873 	if (!file) {
874 		ret = -ENOMEM;
875 		if (module_dependent)
876 			goto err_module;
877 
878 		goto err;
879 	}
880 
881 	file->device	 = dev;
882 	spin_lock_init(&file->idr_lock);
883 	idr_init(&file->idr);
884 	file->ucontext	 = NULL;
885 	file->async_file = NULL;
886 	kref_init(&file->ref);
887 	mutex_init(&file->mutex);
888 	mutex_init(&file->cleanup_mutex);
889 
890 	filp->private_data = file;
891 	kobject_get(&dev->kobj);
892 	list_add_tail(&file->list, &dev->uverbs_file_list);
893 	mutex_unlock(&dev->lists_mutex);
894 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
895 
896 	return nonseekable_open(inode, filp);
897 
898 err_module:
899 	module_put(ib_dev->owner);
900 
901 err:
902 	mutex_unlock(&dev->lists_mutex);
903 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
904 	if (atomic_dec_and_test(&dev->refcount))
905 		ib_uverbs_comp_dev(dev);
906 
907 	return ret;
908 }
909 
910 static int ib_uverbs_close(struct inode *inode, struct file *filp)
911 {
912 	struct ib_uverbs_file *file = filp->private_data;
913 
914 	mutex_lock(&file->cleanup_mutex);
915 	if (file->ucontext) {
916 		ib_uverbs_cleanup_ucontext(file, file->ucontext, false);
917 		file->ucontext = NULL;
918 	}
919 	mutex_unlock(&file->cleanup_mutex);
920 	idr_destroy(&file->idr);
921 
922 	mutex_lock(&file->device->lists_mutex);
923 	if (!file->is_closed) {
924 		list_del(&file->list);
925 		file->is_closed = 1;
926 	}
927 	mutex_unlock(&file->device->lists_mutex);
928 
929 	if (file->async_file)
930 		kref_put(&file->async_file->ref,
931 			 ib_uverbs_release_async_event_file);
932 
933 	kref_put(&file->ref, ib_uverbs_release_file);
934 
935 	return 0;
936 }
937 
938 static const struct file_operations uverbs_fops = {
939 	.owner	 = THIS_MODULE,
940 	.write	 = ib_uverbs_write,
941 	.open	 = ib_uverbs_open,
942 	.release = ib_uverbs_close,
943 	.llseek	 = no_llseek,
944 	.unlocked_ioctl = ib_uverbs_ioctl,
945 	.compat_ioctl = ib_uverbs_ioctl,
946 };
947 
948 static const struct file_operations uverbs_mmap_fops = {
949 	.owner	 = THIS_MODULE,
950 	.write	 = ib_uverbs_write,
951 	.mmap    = ib_uverbs_mmap,
952 	.open	 = ib_uverbs_open,
953 	.release = ib_uverbs_close,
954 	.llseek	 = no_llseek,
955 	.unlocked_ioctl = ib_uverbs_ioctl,
956 	.compat_ioctl = ib_uverbs_ioctl,
957 };
958 
959 static struct ib_client uverbs_client = {
960 	.name   = "uverbs",
961 	.add    = ib_uverbs_add_one,
962 	.remove = ib_uverbs_remove_one
963 };
964 
965 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
966 			  char *buf)
967 {
968 	int ret = -ENODEV;
969 	int srcu_key;
970 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
971 	struct ib_device *ib_dev;
972 
973 	if (!dev)
974 		return -ENODEV;
975 
976 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
977 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
978 	if (ib_dev)
979 		ret = sprintf(buf, "%s\n", ib_dev->name);
980 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
981 
982 	return ret;
983 }
984 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
985 
986 static ssize_t show_dev_abi_version(struct device *device,
987 				    struct device_attribute *attr, char *buf)
988 {
989 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
990 	int ret = -ENODEV;
991 	int srcu_key;
992 	struct ib_device *ib_dev;
993 
994 	if (!dev)
995 		return -ENODEV;
996 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
997 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
998 	if (ib_dev)
999 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1000 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1001 
1002 	return ret;
1003 }
1004 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
1005 
1006 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1007 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1008 
1009 static void ib_uverbs_add_one(struct ib_device *device)
1010 {
1011 	int devnum;
1012 	dev_t base;
1013 	struct ib_uverbs_device *uverbs_dev;
1014 	int ret;
1015 
1016 	if (!device->alloc_ucontext)
1017 		return;
1018 
1019 	uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1020 	if (!uverbs_dev)
1021 		return;
1022 
1023 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1024 	if (ret) {
1025 		kfree(uverbs_dev);
1026 		return;
1027 	}
1028 
1029 	atomic_set(&uverbs_dev->refcount, 1);
1030 	init_completion(&uverbs_dev->comp);
1031 	uverbs_dev->xrcd_tree = RB_ROOT;
1032 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1033 	kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1034 	mutex_init(&uverbs_dev->lists_mutex);
1035 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1036 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1037 
1038 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1039 	if (devnum >= IB_UVERBS_MAX_DEVICES)
1040 		goto err;
1041 	uverbs_dev->devnum = devnum;
1042 	set_bit(devnum, dev_map);
1043 	if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1044 		base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1045 	else
1046 		base = IB_UVERBS_BASE_DEV + devnum;
1047 
1048 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1049 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1050 
1051 	cdev_init(&uverbs_dev->cdev, NULL);
1052 	uverbs_dev->cdev.owner = THIS_MODULE;
1053 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1054 	cdev_set_parent(&uverbs_dev->cdev, &uverbs_dev->kobj);
1055 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1056 	if (cdev_add(&uverbs_dev->cdev, base, 1))
1057 		goto err_cdev;
1058 
1059 	uverbs_dev->dev = device_create(uverbs_class, device->dev.parent,
1060 					uverbs_dev->cdev.dev, uverbs_dev,
1061 					"uverbs%d", uverbs_dev->devnum);
1062 	if (IS_ERR(uverbs_dev->dev))
1063 		goto err_cdev;
1064 
1065 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1066 		goto err_class;
1067 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1068 		goto err_class;
1069 
1070 	if (!device->specs_root) {
1071 		const struct uverbs_object_tree_def *default_root[] = {
1072 			uverbs_default_get_objects()};
1073 
1074 		uverbs_dev->specs_root = uverbs_alloc_spec_tree(1,
1075 								default_root);
1076 		if (IS_ERR(uverbs_dev->specs_root))
1077 			goto err_class;
1078 
1079 		device->specs_root = uverbs_dev->specs_root;
1080 	}
1081 
1082 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1083 
1084 	return;
1085 
1086 err_class:
1087 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1088 
1089 err_cdev:
1090 	cdev_del(&uverbs_dev->cdev);
1091 	clear_bit(devnum, dev_map);
1092 
1093 err:
1094 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1095 		ib_uverbs_comp_dev(uverbs_dev);
1096 	wait_for_completion(&uverbs_dev->comp);
1097 	kobject_put(&uverbs_dev->kobj);
1098 	return;
1099 }
1100 
1101 static void ib_uverbs_disassociate_ucontext(struct ib_ucontext *ibcontext)
1102 {
1103 	struct ib_device *ib_dev = ibcontext->device;
1104 	struct task_struct *owning_process  = NULL;
1105 	struct mm_struct   *owning_mm       = NULL;
1106 
1107 	owning_process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
1108 	if (!owning_process)
1109 		return;
1110 
1111 	owning_mm = get_task_mm(owning_process);
1112 	if (!owning_mm) {
1113 		pr_info("no mm, disassociate ucontext is pending task termination\n");
1114 		while (1) {
1115 			put_task_struct(owning_process);
1116 			usleep_range(1000, 2000);
1117 			owning_process = get_pid_task(ibcontext->tgid,
1118 						      PIDTYPE_PID);
1119 			if (!owning_process ||
1120 			    owning_process->state == TASK_DEAD) {
1121 				pr_info("disassociate ucontext done, task was terminated\n");
1122 				/* in case task was dead need to release the
1123 				 * task struct.
1124 				 */
1125 				if (owning_process)
1126 					put_task_struct(owning_process);
1127 				return;
1128 			}
1129 		}
1130 	}
1131 
1132 	down_write(&owning_mm->mmap_sem);
1133 	ib_dev->disassociate_ucontext(ibcontext);
1134 	up_write(&owning_mm->mmap_sem);
1135 	mmput(owning_mm);
1136 	put_task_struct(owning_process);
1137 }
1138 
1139 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1140 					struct ib_device *ib_dev)
1141 {
1142 	struct ib_uverbs_file *file;
1143 	struct ib_uverbs_async_event_file *event_file;
1144 	struct ib_event event;
1145 
1146 	/* Pending running commands to terminate */
1147 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
1148 	event.event = IB_EVENT_DEVICE_FATAL;
1149 	event.element.port_num = 0;
1150 	event.device = ib_dev;
1151 
1152 	mutex_lock(&uverbs_dev->lists_mutex);
1153 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1154 		struct ib_ucontext *ucontext;
1155 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1156 					struct ib_uverbs_file, list);
1157 		file->is_closed = 1;
1158 		list_del(&file->list);
1159 		kref_get(&file->ref);
1160 		mutex_unlock(&uverbs_dev->lists_mutex);
1161 
1162 
1163 		mutex_lock(&file->cleanup_mutex);
1164 		ucontext = file->ucontext;
1165 		file->ucontext = NULL;
1166 		mutex_unlock(&file->cleanup_mutex);
1167 
1168 		/* At this point ib_uverbs_close cannot be running
1169 		 * ib_uverbs_cleanup_ucontext
1170 		 */
1171 		if (ucontext) {
1172 			/* We must release the mutex before going ahead and
1173 			 * calling disassociate_ucontext. disassociate_ucontext
1174 			 * might end up indirectly calling uverbs_close,
1175 			 * for example due to freeing the resources
1176 			 * (e.g mmput).
1177 			 */
1178 			ib_uverbs_event_handler(&file->event_handler, &event);
1179 			ib_uverbs_disassociate_ucontext(ucontext);
1180 			mutex_lock(&file->cleanup_mutex);
1181 			ib_uverbs_cleanup_ucontext(file, ucontext, true);
1182 			mutex_unlock(&file->cleanup_mutex);
1183 		}
1184 
1185 		mutex_lock(&uverbs_dev->lists_mutex);
1186 		kref_put(&file->ref, ib_uverbs_release_file);
1187 	}
1188 
1189 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1190 		event_file = list_first_entry(&uverbs_dev->
1191 					      uverbs_events_file_list,
1192 					      struct ib_uverbs_async_event_file,
1193 					      list);
1194 		spin_lock_irq(&event_file->ev_queue.lock);
1195 		event_file->ev_queue.is_closed = 1;
1196 		spin_unlock_irq(&event_file->ev_queue.lock);
1197 
1198 		list_del(&event_file->list);
1199 		ib_unregister_event_handler(
1200 			&event_file->uverbs_file->event_handler);
1201 		event_file->uverbs_file->event_handler.device =
1202 			NULL;
1203 
1204 		wake_up_interruptible(&event_file->ev_queue.poll_wait);
1205 		kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1206 	}
1207 	mutex_unlock(&uverbs_dev->lists_mutex);
1208 }
1209 
1210 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1211 {
1212 	struct ib_uverbs_device *uverbs_dev = client_data;
1213 	int wait_clients = 1;
1214 
1215 	if (!uverbs_dev)
1216 		return;
1217 
1218 	dev_set_drvdata(uverbs_dev->dev, NULL);
1219 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1220 	cdev_del(&uverbs_dev->cdev);
1221 	clear_bit(uverbs_dev->devnum, dev_map);
1222 
1223 	if (device->disassociate_ucontext) {
1224 		/* We disassociate HW resources and immediately return.
1225 		 * Userspace will see a EIO errno for all future access.
1226 		 * Upon returning, ib_device may be freed internally and is not
1227 		 * valid any more.
1228 		 * uverbs_device is still available until all clients close
1229 		 * their files, then the uverbs device ref count will be zero
1230 		 * and its resources will be freed.
1231 		 * Note: At this point no more files can be opened since the
1232 		 * cdev was deleted, however active clients can still issue
1233 		 * commands and close their open files.
1234 		 */
1235 		rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1236 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1237 		wait_clients = 0;
1238 	}
1239 
1240 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1241 		ib_uverbs_comp_dev(uverbs_dev);
1242 	if (wait_clients)
1243 		wait_for_completion(&uverbs_dev->comp);
1244 	if (uverbs_dev->specs_root) {
1245 		uverbs_free_spec_tree(uverbs_dev->specs_root);
1246 		device->specs_root = NULL;
1247 	}
1248 
1249 	kobject_put(&uverbs_dev->kobj);
1250 }
1251 
1252 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1253 {
1254 	if (mode)
1255 		*mode = 0666;
1256 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1257 }
1258 
1259 static int __init ib_uverbs_init(void)
1260 {
1261 	int ret;
1262 
1263 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1264 				     IB_UVERBS_NUM_FIXED_MINOR,
1265 				     "infiniband_verbs");
1266 	if (ret) {
1267 		pr_err("user_verbs: couldn't register device number\n");
1268 		goto out;
1269 	}
1270 
1271 	ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1272 				  IB_UVERBS_NUM_DYNAMIC_MINOR,
1273 				  "infiniband_verbs");
1274 	if (ret) {
1275 		pr_err("couldn't register dynamic device number\n");
1276 		goto out_alloc;
1277 	}
1278 
1279 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1280 	if (IS_ERR(uverbs_class)) {
1281 		ret = PTR_ERR(uverbs_class);
1282 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1283 		goto out_chrdev;
1284 	}
1285 
1286 	uverbs_class->devnode = uverbs_devnode;
1287 
1288 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1289 	if (ret) {
1290 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1291 		goto out_class;
1292 	}
1293 
1294 	ret = ib_register_client(&uverbs_client);
1295 	if (ret) {
1296 		pr_err("user_verbs: couldn't register client\n");
1297 		goto out_class;
1298 	}
1299 
1300 	return 0;
1301 
1302 out_class:
1303 	class_destroy(uverbs_class);
1304 
1305 out_chrdev:
1306 	unregister_chrdev_region(dynamic_uverbs_dev,
1307 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1308 
1309 out_alloc:
1310 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1311 				 IB_UVERBS_NUM_FIXED_MINOR);
1312 
1313 out:
1314 	return ret;
1315 }
1316 
1317 static void __exit ib_uverbs_cleanup(void)
1318 {
1319 	ib_unregister_client(&uverbs_client);
1320 	class_destroy(uverbs_class);
1321 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1322 				 IB_UVERBS_NUM_FIXED_MINOR);
1323 	unregister_chrdev_region(dynamic_uverbs_dev,
1324 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1325 }
1326 
1327 module_init(ib_uverbs_init);
1328 module_exit(ib_uverbs_cleanup);
1329