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 
53 #include "uverbs.h"
54 
55 MODULE_AUTHOR("Roland Dreier");
56 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
57 MODULE_LICENSE("Dual BSD/GPL");
58 
59 enum {
60 	IB_UVERBS_MAJOR       = 231,
61 	IB_UVERBS_BASE_MINOR  = 192,
62 	IB_UVERBS_MAX_DEVICES = 32
63 };
64 
65 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
66 
67 static struct class *uverbs_class;
68 
69 DEFINE_SPINLOCK(ib_uverbs_idr_lock);
70 DEFINE_IDR(ib_uverbs_pd_idr);
71 DEFINE_IDR(ib_uverbs_mr_idr);
72 DEFINE_IDR(ib_uverbs_mw_idr);
73 DEFINE_IDR(ib_uverbs_ah_idr);
74 DEFINE_IDR(ib_uverbs_cq_idr);
75 DEFINE_IDR(ib_uverbs_qp_idr);
76 DEFINE_IDR(ib_uverbs_srq_idr);
77 DEFINE_IDR(ib_uverbs_xrcd_idr);
78 DEFINE_IDR(ib_uverbs_rule_idr);
79 DEFINE_IDR(ib_uverbs_wq_idr);
80 DEFINE_IDR(ib_uverbs_rwq_ind_tbl_idr);
81 
82 static DEFINE_SPINLOCK(map_lock);
83 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
84 
85 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
86 				     struct ib_device *ib_dev,
87 				     const char __user *buf, int in_len,
88 				     int out_len) = {
89 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
90 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
91 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
92 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
93 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
94 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
95 	[IB_USER_VERBS_CMD_REREG_MR]		= ib_uverbs_rereg_mr,
96 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
97 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
98 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
99 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
100 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
101 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
102 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
103 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
104 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
105 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
106 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
107 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
108 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
109 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
110 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
111 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
112 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
113 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
114 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
115 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
116 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
117 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
118 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
119 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
120 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
121 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
122 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
123 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
124 };
125 
126 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
127 				    struct ib_device *ib_dev,
128 				    struct ib_udata *ucore,
129 				    struct ib_udata *uhw) = {
130 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
131 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow,
132 	[IB_USER_VERBS_EX_CMD_QUERY_DEVICE]	= ib_uverbs_ex_query_device,
133 	[IB_USER_VERBS_EX_CMD_CREATE_CQ]	= ib_uverbs_ex_create_cq,
134 	[IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
135 	[IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
136 	[IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
137 	[IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
138 	[IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
139 	[IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
140 	[IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
141 };
142 
143 static void ib_uverbs_add_one(struct ib_device *device);
144 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
145 
146 int uverbs_dealloc_mw(struct ib_mw *mw)
147 {
148 	struct ib_pd *pd = mw->pd;
149 	int ret;
150 
151 	ret = mw->device->dealloc_mw(mw);
152 	if (!ret)
153 		atomic_dec(&pd->usecnt);
154 	return ret;
155 }
156 
157 static void ib_uverbs_release_dev(struct kobject *kobj)
158 {
159 	struct ib_uverbs_device *dev =
160 		container_of(kobj, struct ib_uverbs_device, kobj);
161 
162 	cleanup_srcu_struct(&dev->disassociate_srcu);
163 	kfree(dev);
164 }
165 
166 static struct kobj_type ib_uverbs_dev_ktype = {
167 	.release = ib_uverbs_release_dev,
168 };
169 
170 static void ib_uverbs_release_event_file(struct kref *ref)
171 {
172 	struct ib_uverbs_event_file *file =
173 		container_of(ref, struct ib_uverbs_event_file, ref);
174 
175 	kfree(file);
176 }
177 
178 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
179 			  struct ib_uverbs_event_file *ev_file,
180 			  struct ib_ucq_object *uobj)
181 {
182 	struct ib_uverbs_event *evt, *tmp;
183 
184 	if (ev_file) {
185 		spin_lock_irq(&ev_file->lock);
186 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
187 			list_del(&evt->list);
188 			kfree(evt);
189 		}
190 		spin_unlock_irq(&ev_file->lock);
191 
192 		kref_put(&ev_file->ref, ib_uverbs_release_event_file);
193 	}
194 
195 	spin_lock_irq(&file->async_file->lock);
196 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
197 		list_del(&evt->list);
198 		kfree(evt);
199 	}
200 	spin_unlock_irq(&file->async_file->lock);
201 }
202 
203 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
204 			      struct ib_uevent_object *uobj)
205 {
206 	struct ib_uverbs_event *evt, *tmp;
207 
208 	spin_lock_irq(&file->async_file->lock);
209 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
210 		list_del(&evt->list);
211 		kfree(evt);
212 	}
213 	spin_unlock_irq(&file->async_file->lock);
214 }
215 
216 static void ib_uverbs_detach_umcast(struct ib_qp *qp,
217 				    struct ib_uqp_object *uobj)
218 {
219 	struct ib_uverbs_mcast_entry *mcast, *tmp;
220 
221 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
222 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
223 		list_del(&mcast->list);
224 		kfree(mcast);
225 	}
226 }
227 
228 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
229 				      struct ib_ucontext *context)
230 {
231 	struct ib_uobject *uobj, *tmp;
232 
233 	context->closing = 1;
234 
235 	list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
236 		struct ib_ah *ah = uobj->object;
237 
238 		idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
239 		ib_destroy_ah(ah);
240 		kfree(uobj);
241 	}
242 
243 	/* Remove MWs before QPs, in order to support type 2A MWs. */
244 	list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
245 		struct ib_mw *mw = uobj->object;
246 
247 		idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
248 		uverbs_dealloc_mw(mw);
249 		kfree(uobj);
250 	}
251 
252 	list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
253 		struct ib_flow *flow_id = uobj->object;
254 
255 		idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
256 		ib_destroy_flow(flow_id);
257 		kfree(uobj);
258 	}
259 
260 	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
261 		struct ib_qp *qp = uobj->object;
262 		struct ib_uqp_object *uqp =
263 			container_of(uobj, struct ib_uqp_object, uevent.uobject);
264 
265 		idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
266 		if (qp == qp->real_qp)
267 			ib_uverbs_detach_umcast(qp, uqp);
268 		ib_destroy_qp(qp);
269 		ib_uverbs_release_uevent(file, &uqp->uevent);
270 		kfree(uqp);
271 	}
272 
273 	list_for_each_entry_safe(uobj, tmp, &context->rwq_ind_tbl_list, list) {
274 		struct ib_rwq_ind_table *rwq_ind_tbl = uobj->object;
275 		struct ib_wq **ind_tbl = rwq_ind_tbl->ind_tbl;
276 
277 		idr_remove_uobj(&ib_uverbs_rwq_ind_tbl_idr, uobj);
278 		ib_destroy_rwq_ind_table(rwq_ind_tbl);
279 		kfree(ind_tbl);
280 		kfree(uobj);
281 	}
282 
283 	list_for_each_entry_safe(uobj, tmp, &context->wq_list, list) {
284 		struct ib_wq *wq = uobj->object;
285 		struct ib_uwq_object *uwq =
286 			container_of(uobj, struct ib_uwq_object, uevent.uobject);
287 
288 		idr_remove_uobj(&ib_uverbs_wq_idr, uobj);
289 		ib_destroy_wq(wq);
290 		ib_uverbs_release_uevent(file, &uwq->uevent);
291 		kfree(uwq);
292 	}
293 
294 	list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
295 		struct ib_srq *srq = uobj->object;
296 		struct ib_uevent_object *uevent =
297 			container_of(uobj, struct ib_uevent_object, uobject);
298 
299 		idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
300 		ib_destroy_srq(srq);
301 		ib_uverbs_release_uevent(file, uevent);
302 		kfree(uevent);
303 	}
304 
305 	list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
306 		struct ib_cq *cq = uobj->object;
307 		struct ib_uverbs_event_file *ev_file = cq->cq_context;
308 		struct ib_ucq_object *ucq =
309 			container_of(uobj, struct ib_ucq_object, uobject);
310 
311 		idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
312 		ib_destroy_cq(cq);
313 		ib_uverbs_release_ucq(file, ev_file, ucq);
314 		kfree(ucq);
315 	}
316 
317 	list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
318 		struct ib_mr *mr = uobj->object;
319 
320 		idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
321 		ib_dereg_mr(mr);
322 		kfree(uobj);
323 	}
324 
325 	mutex_lock(&file->device->xrcd_tree_mutex);
326 	list_for_each_entry_safe(uobj, tmp, &context->xrcd_list, list) {
327 		struct ib_xrcd *xrcd = uobj->object;
328 		struct ib_uxrcd_object *uxrcd =
329 			container_of(uobj, struct ib_uxrcd_object, uobject);
330 
331 		idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
332 		ib_uverbs_dealloc_xrcd(file->device, xrcd);
333 		kfree(uxrcd);
334 	}
335 	mutex_unlock(&file->device->xrcd_tree_mutex);
336 
337 	list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
338 		struct ib_pd *pd = uobj->object;
339 
340 		idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
341 		ib_dealloc_pd(pd);
342 		kfree(uobj);
343 	}
344 
345 	put_pid(context->tgid);
346 
347 	return context->device->dealloc_ucontext(context);
348 }
349 
350 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
351 {
352 	complete(&dev->comp);
353 }
354 
355 static void ib_uverbs_release_file(struct kref *ref)
356 {
357 	struct ib_uverbs_file *file =
358 		container_of(ref, struct ib_uverbs_file, ref);
359 	struct ib_device *ib_dev;
360 	int srcu_key;
361 
362 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
363 	ib_dev = srcu_dereference(file->device->ib_dev,
364 				  &file->device->disassociate_srcu);
365 	if (ib_dev && !ib_dev->disassociate_ucontext)
366 		module_put(ib_dev->owner);
367 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
368 
369 	if (atomic_dec_and_test(&file->device->refcount))
370 		ib_uverbs_comp_dev(file->device);
371 
372 	kfree(file);
373 }
374 
375 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
376 				    size_t count, loff_t *pos)
377 {
378 	struct ib_uverbs_event_file *file = filp->private_data;
379 	struct ib_uverbs_event *event;
380 	int eventsz;
381 	int ret = 0;
382 
383 	spin_lock_irq(&file->lock);
384 
385 	while (list_empty(&file->event_list)) {
386 		spin_unlock_irq(&file->lock);
387 
388 		if (filp->f_flags & O_NONBLOCK)
389 			return -EAGAIN;
390 
391 		if (wait_event_interruptible(file->poll_wait,
392 					     (!list_empty(&file->event_list) ||
393 			/* The barriers built into wait_event_interruptible()
394 			 * and wake_up() guarentee this will see the null set
395 			 * without using RCU
396 			 */
397 					     !file->uverbs_file->device->ib_dev)))
398 			return -ERESTARTSYS;
399 
400 		/* If device was disassociated and no event exists set an error */
401 		if (list_empty(&file->event_list) &&
402 		    !file->uverbs_file->device->ib_dev)
403 			return -EIO;
404 
405 		spin_lock_irq(&file->lock);
406 	}
407 
408 	event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
409 
410 	if (file->is_async)
411 		eventsz = sizeof (struct ib_uverbs_async_event_desc);
412 	else
413 		eventsz = sizeof (struct ib_uverbs_comp_event_desc);
414 
415 	if (eventsz > count) {
416 		ret   = -EINVAL;
417 		event = NULL;
418 	} else {
419 		list_del(file->event_list.next);
420 		if (event->counter) {
421 			++(*event->counter);
422 			list_del(&event->obj_list);
423 		}
424 	}
425 
426 	spin_unlock_irq(&file->lock);
427 
428 	if (event) {
429 		if (copy_to_user(buf, event, eventsz))
430 			ret = -EFAULT;
431 		else
432 			ret = eventsz;
433 	}
434 
435 	kfree(event);
436 
437 	return ret;
438 }
439 
440 static unsigned int ib_uverbs_event_poll(struct file *filp,
441 					 struct poll_table_struct *wait)
442 {
443 	unsigned int pollflags = 0;
444 	struct ib_uverbs_event_file *file = filp->private_data;
445 
446 	poll_wait(filp, &file->poll_wait, wait);
447 
448 	spin_lock_irq(&file->lock);
449 	if (!list_empty(&file->event_list))
450 		pollflags = POLLIN | POLLRDNORM;
451 	spin_unlock_irq(&file->lock);
452 
453 	return pollflags;
454 }
455 
456 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
457 {
458 	struct ib_uverbs_event_file *file = filp->private_data;
459 
460 	return fasync_helper(fd, filp, on, &file->async_queue);
461 }
462 
463 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
464 {
465 	struct ib_uverbs_event_file *file = filp->private_data;
466 	struct ib_uverbs_event *entry, *tmp;
467 	int closed_already = 0;
468 
469 	mutex_lock(&file->uverbs_file->device->lists_mutex);
470 	spin_lock_irq(&file->lock);
471 	closed_already = file->is_closed;
472 	file->is_closed = 1;
473 	list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
474 		if (entry->counter)
475 			list_del(&entry->obj_list);
476 		kfree(entry);
477 	}
478 	spin_unlock_irq(&file->lock);
479 	if (!closed_already) {
480 		list_del(&file->list);
481 		if (file->is_async)
482 			ib_unregister_event_handler(&file->uverbs_file->
483 				event_handler);
484 	}
485 	mutex_unlock(&file->uverbs_file->device->lists_mutex);
486 
487 	kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
488 	kref_put(&file->ref, ib_uverbs_release_event_file);
489 
490 	return 0;
491 }
492 
493 static const struct file_operations uverbs_event_fops = {
494 	.owner	 = THIS_MODULE,
495 	.read	 = ib_uverbs_event_read,
496 	.poll    = ib_uverbs_event_poll,
497 	.release = ib_uverbs_event_close,
498 	.fasync  = ib_uverbs_event_fasync,
499 	.llseek	 = no_llseek,
500 };
501 
502 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
503 {
504 	struct ib_uverbs_event_file    *file = cq_context;
505 	struct ib_ucq_object	       *uobj;
506 	struct ib_uverbs_event	       *entry;
507 	unsigned long			flags;
508 
509 	if (!file)
510 		return;
511 
512 	spin_lock_irqsave(&file->lock, flags);
513 	if (file->is_closed) {
514 		spin_unlock_irqrestore(&file->lock, flags);
515 		return;
516 	}
517 
518 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
519 	if (!entry) {
520 		spin_unlock_irqrestore(&file->lock, flags);
521 		return;
522 	}
523 
524 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
525 
526 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
527 	entry->counter		   = &uobj->comp_events_reported;
528 
529 	list_add_tail(&entry->list, &file->event_list);
530 	list_add_tail(&entry->obj_list, &uobj->comp_list);
531 	spin_unlock_irqrestore(&file->lock, flags);
532 
533 	wake_up_interruptible(&file->poll_wait);
534 	kill_fasync(&file->async_queue, SIGIO, POLL_IN);
535 }
536 
537 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
538 				    __u64 element, __u64 event,
539 				    struct list_head *obj_list,
540 				    u32 *counter)
541 {
542 	struct ib_uverbs_event *entry;
543 	unsigned long flags;
544 
545 	spin_lock_irqsave(&file->async_file->lock, flags);
546 	if (file->async_file->is_closed) {
547 		spin_unlock_irqrestore(&file->async_file->lock, flags);
548 		return;
549 	}
550 
551 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
552 	if (!entry) {
553 		spin_unlock_irqrestore(&file->async_file->lock, flags);
554 		return;
555 	}
556 
557 	entry->desc.async.element    = element;
558 	entry->desc.async.event_type = event;
559 	entry->desc.async.reserved   = 0;
560 	entry->counter               = counter;
561 
562 	list_add_tail(&entry->list, &file->async_file->event_list);
563 	if (obj_list)
564 		list_add_tail(&entry->obj_list, obj_list);
565 	spin_unlock_irqrestore(&file->async_file->lock, flags);
566 
567 	wake_up_interruptible(&file->async_file->poll_wait);
568 	kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
569 }
570 
571 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
572 {
573 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
574 						  struct ib_ucq_object, uobject);
575 
576 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
577 				event->event, &uobj->async_list,
578 				&uobj->async_events_reported);
579 }
580 
581 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
582 {
583 	struct ib_uevent_object *uobj;
584 
585 	/* for XRC target qp's, check that qp is live */
586 	if (!event->element.qp->uobject || !event->element.qp->uobject->live)
587 		return;
588 
589 	uobj = container_of(event->element.qp->uobject,
590 			    struct ib_uevent_object, uobject);
591 
592 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
593 				event->event, &uobj->event_list,
594 				&uobj->events_reported);
595 }
596 
597 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
598 {
599 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
600 						  struct ib_uevent_object, uobject);
601 
602 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
603 				event->event, &uobj->event_list,
604 				&uobj->events_reported);
605 }
606 
607 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
608 {
609 	struct ib_uevent_object *uobj;
610 
611 	uobj = container_of(event->element.srq->uobject,
612 			    struct ib_uevent_object, uobject);
613 
614 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
615 				event->event, &uobj->event_list,
616 				&uobj->events_reported);
617 }
618 
619 void ib_uverbs_event_handler(struct ib_event_handler *handler,
620 			     struct ib_event *event)
621 {
622 	struct ib_uverbs_file *file =
623 		container_of(handler, struct ib_uverbs_file, event_handler);
624 
625 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
626 				NULL, NULL);
627 }
628 
629 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
630 {
631 	kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
632 	file->async_file = NULL;
633 }
634 
635 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
636 					struct ib_device	*ib_dev,
637 					int is_async)
638 {
639 	struct ib_uverbs_event_file *ev_file;
640 	struct file *filp;
641 	int ret;
642 
643 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
644 	if (!ev_file)
645 		return ERR_PTR(-ENOMEM);
646 
647 	kref_init(&ev_file->ref);
648 	spin_lock_init(&ev_file->lock);
649 	INIT_LIST_HEAD(&ev_file->event_list);
650 	init_waitqueue_head(&ev_file->poll_wait);
651 	ev_file->uverbs_file = uverbs_file;
652 	kref_get(&ev_file->uverbs_file->ref);
653 	ev_file->async_queue = NULL;
654 	ev_file->is_closed   = 0;
655 
656 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
657 				  ev_file, O_RDONLY);
658 	if (IS_ERR(filp))
659 		goto err_put_refs;
660 
661 	mutex_lock(&uverbs_file->device->lists_mutex);
662 	list_add_tail(&ev_file->list,
663 		      &uverbs_file->device->uverbs_events_file_list);
664 	mutex_unlock(&uverbs_file->device->lists_mutex);
665 
666 	if (is_async) {
667 		WARN_ON(uverbs_file->async_file);
668 		uverbs_file->async_file = ev_file;
669 		kref_get(&uverbs_file->async_file->ref);
670 		INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
671 				      ib_dev,
672 				      ib_uverbs_event_handler);
673 		ret = ib_register_event_handler(&uverbs_file->event_handler);
674 		if (ret)
675 			goto err_put_file;
676 
677 		/* At that point async file stuff was fully set */
678 		ev_file->is_async = 1;
679 	}
680 
681 	return filp;
682 
683 err_put_file:
684 	fput(filp);
685 	kref_put(&uverbs_file->async_file->ref, ib_uverbs_release_event_file);
686 	uverbs_file->async_file = NULL;
687 	return ERR_PTR(ret);
688 
689 err_put_refs:
690 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
691 	kref_put(&ev_file->ref, ib_uverbs_release_event_file);
692 	return filp;
693 }
694 
695 /*
696  * Look up a completion event file by FD.  If lookup is successful,
697  * takes a ref to the event file struct that it returns; if
698  * unsuccessful, returns NULL.
699  */
700 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
701 {
702 	struct ib_uverbs_event_file *ev_file = NULL;
703 	struct fd f = fdget(fd);
704 
705 	if (!f.file)
706 		return NULL;
707 
708 	if (f.file->f_op != &uverbs_event_fops)
709 		goto out;
710 
711 	ev_file = f.file->private_data;
712 	if (ev_file->is_async) {
713 		ev_file = NULL;
714 		goto out;
715 	}
716 
717 	kref_get(&ev_file->ref);
718 
719 out:
720 	fdput(f);
721 	return ev_file;
722 }
723 
724 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
725 {
726 	u64 mask;
727 
728 	if (command <= IB_USER_VERBS_CMD_OPEN_QP)
729 		mask = ib_dev->uverbs_cmd_mask;
730 	else
731 		mask = ib_dev->uverbs_ex_cmd_mask;
732 
733 	if (mask & ((u64)1 << command))
734 		return 0;
735 
736 	return -1;
737 }
738 
739 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
740 			     size_t count, loff_t *pos)
741 {
742 	struct ib_uverbs_file *file = filp->private_data;
743 	struct ib_device *ib_dev;
744 	struct ib_uverbs_cmd_hdr hdr;
745 	__u32 command;
746 	__u32 flags;
747 	int srcu_key;
748 	ssize_t ret;
749 
750 	if (!ib_safe_file_access(filp)) {
751 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
752 			    task_tgid_vnr(current), current->comm);
753 		return -EACCES;
754 	}
755 
756 	if (count < sizeof hdr)
757 		return -EINVAL;
758 
759 	if (copy_from_user(&hdr, buf, sizeof hdr))
760 		return -EFAULT;
761 
762 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
763 	ib_dev = srcu_dereference(file->device->ib_dev,
764 				  &file->device->disassociate_srcu);
765 	if (!ib_dev) {
766 		ret = -EIO;
767 		goto out;
768 	}
769 
770 	if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
771 				   IB_USER_VERBS_CMD_COMMAND_MASK)) {
772 		ret = -EINVAL;
773 		goto out;
774 	}
775 
776 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
777 	if (verify_command_mask(ib_dev, command)) {
778 		ret = -EOPNOTSUPP;
779 		goto out;
780 	}
781 
782 	if (!file->ucontext &&
783 	    command != IB_USER_VERBS_CMD_GET_CONTEXT) {
784 		ret = -EINVAL;
785 		goto out;
786 	}
787 
788 	flags = (hdr.command &
789 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
790 
791 	if (!flags) {
792 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
793 		    !uverbs_cmd_table[command]) {
794 			ret = -EINVAL;
795 			goto out;
796 		}
797 
798 		if (hdr.in_words * 4 != count) {
799 			ret = -EINVAL;
800 			goto out;
801 		}
802 
803 		ret = uverbs_cmd_table[command](file, ib_dev,
804 						 buf + sizeof(hdr),
805 						 hdr.in_words * 4,
806 						 hdr.out_words * 4);
807 
808 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
809 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
810 		struct ib_udata ucore;
811 		struct ib_udata uhw;
812 		size_t written_count = count;
813 
814 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
815 		    !uverbs_ex_cmd_table[command]) {
816 			ret = -ENOSYS;
817 			goto out;
818 		}
819 
820 		if (!file->ucontext) {
821 			ret = -EINVAL;
822 			goto out;
823 		}
824 
825 		if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
826 			ret = -EINVAL;
827 			goto out;
828 		}
829 
830 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
831 			ret = -EFAULT;
832 			goto out;
833 		}
834 
835 		count -= sizeof(hdr) + sizeof(ex_hdr);
836 		buf += sizeof(hdr) + sizeof(ex_hdr);
837 
838 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
839 			ret = -EINVAL;
840 			goto out;
841 		}
842 
843 		if (ex_hdr.cmd_hdr_reserved) {
844 			ret = -EINVAL;
845 			goto out;
846 		}
847 
848 		if (ex_hdr.response) {
849 			if (!hdr.out_words && !ex_hdr.provider_out_words) {
850 				ret = -EINVAL;
851 				goto out;
852 			}
853 
854 			if (!access_ok(VERIFY_WRITE,
855 				       (void __user *) (unsigned long) ex_hdr.response,
856 				       (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
857 				ret = -EFAULT;
858 				goto out;
859 			}
860 		} else {
861 			if (hdr.out_words || ex_hdr.provider_out_words) {
862 				ret = -EINVAL;
863 				goto out;
864 			}
865 		}
866 
867 		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
868 				       hdr.in_words * 8, hdr.out_words * 8);
869 
870 		INIT_UDATA_BUF_OR_NULL(&uhw,
871 				       buf + ucore.inlen,
872 				       (unsigned long) ex_hdr.response + ucore.outlen,
873 				       ex_hdr.provider_in_words * 8,
874 				       ex_hdr.provider_out_words * 8);
875 
876 		ret = uverbs_ex_cmd_table[command](file,
877 						   ib_dev,
878 						   &ucore,
879 						   &uhw);
880 		if (!ret)
881 			ret = written_count;
882 	} else {
883 		ret = -ENOSYS;
884 	}
885 
886 out:
887 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
888 	return ret;
889 }
890 
891 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
892 {
893 	struct ib_uverbs_file *file = filp->private_data;
894 	struct ib_device *ib_dev;
895 	int ret = 0;
896 	int srcu_key;
897 
898 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
899 	ib_dev = srcu_dereference(file->device->ib_dev,
900 				  &file->device->disassociate_srcu);
901 	if (!ib_dev) {
902 		ret = -EIO;
903 		goto out;
904 	}
905 
906 	if (!file->ucontext)
907 		ret = -ENODEV;
908 	else
909 		ret = ib_dev->mmap(file->ucontext, vma);
910 out:
911 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
912 	return ret;
913 }
914 
915 /*
916  * ib_uverbs_open() does not need the BKL:
917  *
918  *  - the ib_uverbs_device structures are properly reference counted and
919  *    everything else is purely local to the file being created, so
920  *    races against other open calls are not a problem;
921  *  - there is no ioctl method to race against;
922  *  - the open method will either immediately run -ENXIO, or all
923  *    required initialization will be done.
924  */
925 static int ib_uverbs_open(struct inode *inode, struct file *filp)
926 {
927 	struct ib_uverbs_device *dev;
928 	struct ib_uverbs_file *file;
929 	struct ib_device *ib_dev;
930 	int ret;
931 	int module_dependent;
932 	int srcu_key;
933 
934 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
935 	if (!atomic_inc_not_zero(&dev->refcount))
936 		return -ENXIO;
937 
938 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
939 	mutex_lock(&dev->lists_mutex);
940 	ib_dev = srcu_dereference(dev->ib_dev,
941 				  &dev->disassociate_srcu);
942 	if (!ib_dev) {
943 		ret = -EIO;
944 		goto err;
945 	}
946 
947 	/* In case IB device supports disassociate ucontext, there is no hard
948 	 * dependency between uverbs device and its low level device.
949 	 */
950 	module_dependent = !(ib_dev->disassociate_ucontext);
951 
952 	if (module_dependent) {
953 		if (!try_module_get(ib_dev->owner)) {
954 			ret = -ENODEV;
955 			goto err;
956 		}
957 	}
958 
959 	file = kzalloc(sizeof(*file), GFP_KERNEL);
960 	if (!file) {
961 		ret = -ENOMEM;
962 		if (module_dependent)
963 			goto err_module;
964 
965 		goto err;
966 	}
967 
968 	file->device	 = dev;
969 	file->ucontext	 = NULL;
970 	file->async_file = NULL;
971 	kref_init(&file->ref);
972 	mutex_init(&file->mutex);
973 	mutex_init(&file->cleanup_mutex);
974 
975 	filp->private_data = file;
976 	kobject_get(&dev->kobj);
977 	list_add_tail(&file->list, &dev->uverbs_file_list);
978 	mutex_unlock(&dev->lists_mutex);
979 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
980 
981 	return nonseekable_open(inode, filp);
982 
983 err_module:
984 	module_put(ib_dev->owner);
985 
986 err:
987 	mutex_unlock(&dev->lists_mutex);
988 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
989 	if (atomic_dec_and_test(&dev->refcount))
990 		ib_uverbs_comp_dev(dev);
991 
992 	return ret;
993 }
994 
995 static int ib_uverbs_close(struct inode *inode, struct file *filp)
996 {
997 	struct ib_uverbs_file *file = filp->private_data;
998 	struct ib_uverbs_device *dev = file->device;
999 
1000 	mutex_lock(&file->cleanup_mutex);
1001 	if (file->ucontext) {
1002 		ib_uverbs_cleanup_ucontext(file, file->ucontext);
1003 		file->ucontext = NULL;
1004 	}
1005 	mutex_unlock(&file->cleanup_mutex);
1006 
1007 	mutex_lock(&file->device->lists_mutex);
1008 	if (!file->is_closed) {
1009 		list_del(&file->list);
1010 		file->is_closed = 1;
1011 	}
1012 	mutex_unlock(&file->device->lists_mutex);
1013 
1014 	if (file->async_file)
1015 		kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
1016 
1017 	kref_put(&file->ref, ib_uverbs_release_file);
1018 	kobject_put(&dev->kobj);
1019 
1020 	return 0;
1021 }
1022 
1023 static const struct file_operations uverbs_fops = {
1024 	.owner	 = THIS_MODULE,
1025 	.write	 = ib_uverbs_write,
1026 	.open	 = ib_uverbs_open,
1027 	.release = ib_uverbs_close,
1028 	.llseek	 = no_llseek,
1029 };
1030 
1031 static const struct file_operations uverbs_mmap_fops = {
1032 	.owner	 = THIS_MODULE,
1033 	.write	 = ib_uverbs_write,
1034 	.mmap    = ib_uverbs_mmap,
1035 	.open	 = ib_uverbs_open,
1036 	.release = ib_uverbs_close,
1037 	.llseek	 = no_llseek,
1038 };
1039 
1040 static struct ib_client uverbs_client = {
1041 	.name   = "uverbs",
1042 	.add    = ib_uverbs_add_one,
1043 	.remove = ib_uverbs_remove_one
1044 };
1045 
1046 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
1047 			  char *buf)
1048 {
1049 	int ret = -ENODEV;
1050 	int srcu_key;
1051 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
1052 	struct ib_device *ib_dev;
1053 
1054 	if (!dev)
1055 		return -ENODEV;
1056 
1057 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1058 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1059 	if (ib_dev)
1060 		ret = sprintf(buf, "%s\n", ib_dev->name);
1061 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1062 
1063 	return ret;
1064 }
1065 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1066 
1067 static ssize_t show_dev_abi_version(struct device *device,
1068 				    struct device_attribute *attr, char *buf)
1069 {
1070 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
1071 	int ret = -ENODEV;
1072 	int srcu_key;
1073 	struct ib_device *ib_dev;
1074 
1075 	if (!dev)
1076 		return -ENODEV;
1077 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1078 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1079 	if (ib_dev)
1080 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1081 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1082 
1083 	return ret;
1084 }
1085 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
1086 
1087 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1088 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1089 
1090 static dev_t overflow_maj;
1091 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
1092 
1093 /*
1094  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
1095  * requesting a new major number and doubling the number of max devices we
1096  * support. It's stupid, but simple.
1097  */
1098 static int find_overflow_devnum(void)
1099 {
1100 	int ret;
1101 
1102 	if (!overflow_maj) {
1103 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
1104 					  "infiniband_verbs");
1105 		if (ret) {
1106 			pr_err("user_verbs: couldn't register dynamic device number\n");
1107 			return ret;
1108 		}
1109 	}
1110 
1111 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
1112 	if (ret >= IB_UVERBS_MAX_DEVICES)
1113 		return -1;
1114 
1115 	return ret;
1116 }
1117 
1118 static void ib_uverbs_add_one(struct ib_device *device)
1119 {
1120 	int devnum;
1121 	dev_t base;
1122 	struct ib_uverbs_device *uverbs_dev;
1123 	int ret;
1124 
1125 	if (!device->alloc_ucontext)
1126 		return;
1127 
1128 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1129 	if (!uverbs_dev)
1130 		return;
1131 
1132 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1133 	if (ret) {
1134 		kfree(uverbs_dev);
1135 		return;
1136 	}
1137 
1138 	atomic_set(&uverbs_dev->refcount, 1);
1139 	init_completion(&uverbs_dev->comp);
1140 	uverbs_dev->xrcd_tree = RB_ROOT;
1141 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1142 	kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1143 	mutex_init(&uverbs_dev->lists_mutex);
1144 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1145 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1146 
1147 	spin_lock(&map_lock);
1148 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1149 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
1150 		spin_unlock(&map_lock);
1151 		devnum = find_overflow_devnum();
1152 		if (devnum < 0)
1153 			goto err;
1154 
1155 		spin_lock(&map_lock);
1156 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
1157 		base = devnum + overflow_maj;
1158 		set_bit(devnum, overflow_map);
1159 	} else {
1160 		uverbs_dev->devnum = devnum;
1161 		base = devnum + IB_UVERBS_BASE_DEV;
1162 		set_bit(devnum, dev_map);
1163 	}
1164 	spin_unlock(&map_lock);
1165 
1166 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1167 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1168 
1169 	cdev_init(&uverbs_dev->cdev, NULL);
1170 	uverbs_dev->cdev.owner = THIS_MODULE;
1171 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1172 	uverbs_dev->cdev.kobj.parent = &uverbs_dev->kobj;
1173 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1174 	if (cdev_add(&uverbs_dev->cdev, base, 1))
1175 		goto err_cdev;
1176 
1177 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
1178 					uverbs_dev->cdev.dev, uverbs_dev,
1179 					"uverbs%d", uverbs_dev->devnum);
1180 	if (IS_ERR(uverbs_dev->dev))
1181 		goto err_cdev;
1182 
1183 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1184 		goto err_class;
1185 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1186 		goto err_class;
1187 
1188 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1189 
1190 	return;
1191 
1192 err_class:
1193 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1194 
1195 err_cdev:
1196 	cdev_del(&uverbs_dev->cdev);
1197 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1198 		clear_bit(devnum, dev_map);
1199 	else
1200 		clear_bit(devnum, overflow_map);
1201 
1202 err:
1203 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1204 		ib_uverbs_comp_dev(uverbs_dev);
1205 	wait_for_completion(&uverbs_dev->comp);
1206 	kobject_put(&uverbs_dev->kobj);
1207 	return;
1208 }
1209 
1210 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1211 					struct ib_device *ib_dev)
1212 {
1213 	struct ib_uverbs_file *file;
1214 	struct ib_uverbs_event_file *event_file;
1215 	struct ib_event event;
1216 
1217 	/* Pending running commands to terminate */
1218 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
1219 	event.event = IB_EVENT_DEVICE_FATAL;
1220 	event.element.port_num = 0;
1221 	event.device = ib_dev;
1222 
1223 	mutex_lock(&uverbs_dev->lists_mutex);
1224 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1225 		struct ib_ucontext *ucontext;
1226 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1227 					struct ib_uverbs_file, list);
1228 		file->is_closed = 1;
1229 		list_del(&file->list);
1230 		kref_get(&file->ref);
1231 		mutex_unlock(&uverbs_dev->lists_mutex);
1232 
1233 		ib_uverbs_event_handler(&file->event_handler, &event);
1234 
1235 		mutex_lock(&file->cleanup_mutex);
1236 		ucontext = file->ucontext;
1237 		file->ucontext = NULL;
1238 		mutex_unlock(&file->cleanup_mutex);
1239 
1240 		/* At this point ib_uverbs_close cannot be running
1241 		 * ib_uverbs_cleanup_ucontext
1242 		 */
1243 		if (ucontext) {
1244 			/* We must release the mutex before going ahead and
1245 			 * calling disassociate_ucontext. disassociate_ucontext
1246 			 * might end up indirectly calling uverbs_close,
1247 			 * for example due to freeing the resources
1248 			 * (e.g mmput).
1249 			 */
1250 			ib_dev->disassociate_ucontext(ucontext);
1251 			ib_uverbs_cleanup_ucontext(file, ucontext);
1252 		}
1253 
1254 		mutex_lock(&uverbs_dev->lists_mutex);
1255 		kref_put(&file->ref, ib_uverbs_release_file);
1256 	}
1257 
1258 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1259 		event_file = list_first_entry(&uverbs_dev->
1260 					      uverbs_events_file_list,
1261 					      struct ib_uverbs_event_file,
1262 					      list);
1263 		spin_lock_irq(&event_file->lock);
1264 		event_file->is_closed = 1;
1265 		spin_unlock_irq(&event_file->lock);
1266 
1267 		list_del(&event_file->list);
1268 		if (event_file->is_async) {
1269 			ib_unregister_event_handler(&event_file->uverbs_file->
1270 						    event_handler);
1271 			event_file->uverbs_file->event_handler.device = NULL;
1272 		}
1273 
1274 		wake_up_interruptible(&event_file->poll_wait);
1275 		kill_fasync(&event_file->async_queue, SIGIO, POLL_IN);
1276 	}
1277 	mutex_unlock(&uverbs_dev->lists_mutex);
1278 }
1279 
1280 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1281 {
1282 	struct ib_uverbs_device *uverbs_dev = client_data;
1283 	int wait_clients = 1;
1284 
1285 	if (!uverbs_dev)
1286 		return;
1287 
1288 	dev_set_drvdata(uverbs_dev->dev, NULL);
1289 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1290 	cdev_del(&uverbs_dev->cdev);
1291 
1292 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1293 		clear_bit(uverbs_dev->devnum, dev_map);
1294 	else
1295 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
1296 
1297 	if (device->disassociate_ucontext) {
1298 		/* We disassociate HW resources and immediately return.
1299 		 * Userspace will see a EIO errno for all future access.
1300 		 * Upon returning, ib_device may be freed internally and is not
1301 		 * valid any more.
1302 		 * uverbs_device is still available until all clients close
1303 		 * their files, then the uverbs device ref count will be zero
1304 		 * and its resources will be freed.
1305 		 * Note: At this point no more files can be opened since the
1306 		 * cdev was deleted, however active clients can still issue
1307 		 * commands and close their open files.
1308 		 */
1309 		rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1310 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1311 		wait_clients = 0;
1312 	}
1313 
1314 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1315 		ib_uverbs_comp_dev(uverbs_dev);
1316 	if (wait_clients)
1317 		wait_for_completion(&uverbs_dev->comp);
1318 	kobject_put(&uverbs_dev->kobj);
1319 }
1320 
1321 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1322 {
1323 	if (mode)
1324 		*mode = 0666;
1325 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1326 }
1327 
1328 static int __init ib_uverbs_init(void)
1329 {
1330 	int ret;
1331 
1332 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
1333 				     "infiniband_verbs");
1334 	if (ret) {
1335 		pr_err("user_verbs: couldn't register device number\n");
1336 		goto out;
1337 	}
1338 
1339 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1340 	if (IS_ERR(uverbs_class)) {
1341 		ret = PTR_ERR(uverbs_class);
1342 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1343 		goto out_chrdev;
1344 	}
1345 
1346 	uverbs_class->devnode = uverbs_devnode;
1347 
1348 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1349 	if (ret) {
1350 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1351 		goto out_class;
1352 	}
1353 
1354 	ret = ib_register_client(&uverbs_client);
1355 	if (ret) {
1356 		pr_err("user_verbs: couldn't register client\n");
1357 		goto out_class;
1358 	}
1359 
1360 	return 0;
1361 
1362 out_class:
1363 	class_destroy(uverbs_class);
1364 
1365 out_chrdev:
1366 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1367 
1368 out:
1369 	return ret;
1370 }
1371 
1372 static void __exit ib_uverbs_cleanup(void)
1373 {
1374 	ib_unregister_client(&uverbs_client);
1375 	class_destroy(uverbs_class);
1376 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1377 	if (overflow_maj)
1378 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1379 	idr_destroy(&ib_uverbs_pd_idr);
1380 	idr_destroy(&ib_uverbs_mr_idr);
1381 	idr_destroy(&ib_uverbs_mw_idr);
1382 	idr_destroy(&ib_uverbs_ah_idr);
1383 	idr_destroy(&ib_uverbs_cq_idr);
1384 	idr_destroy(&ib_uverbs_qp_idr);
1385 	idr_destroy(&ib_uverbs_srq_idr);
1386 }
1387 
1388 module_init(ib_uverbs_init);
1389 module_exit(ib_uverbs_cleanup);
1390