xref: /openbmc/linux/drivers/infiniband/core/uverbs_main.c (revision c51d39010a1bccc9c1294e2d7c00005aefeb2b5c)
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 <asm/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 };
141 
142 static void ib_uverbs_add_one(struct ib_device *device);
143 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
144 
145 int uverbs_dealloc_mw(struct ib_mw *mw)
146 {
147 	struct ib_pd *pd = mw->pd;
148 	int ret;
149 
150 	ret = mw->device->dealloc_mw(mw);
151 	if (!ret)
152 		atomic_dec(&pd->usecnt);
153 	return ret;
154 }
155 
156 static void ib_uverbs_release_dev(struct kobject *kobj)
157 {
158 	struct ib_uverbs_device *dev =
159 		container_of(kobj, struct ib_uverbs_device, kobj);
160 
161 	cleanup_srcu_struct(&dev->disassociate_srcu);
162 	kfree(dev);
163 }
164 
165 static struct kobj_type ib_uverbs_dev_ktype = {
166 	.release = ib_uverbs_release_dev,
167 };
168 
169 static void ib_uverbs_release_event_file(struct kref *ref)
170 {
171 	struct ib_uverbs_event_file *file =
172 		container_of(ref, struct ib_uverbs_event_file, ref);
173 
174 	kfree(file);
175 }
176 
177 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
178 			  struct ib_uverbs_event_file *ev_file,
179 			  struct ib_ucq_object *uobj)
180 {
181 	struct ib_uverbs_event *evt, *tmp;
182 
183 	if (ev_file) {
184 		spin_lock_irq(&ev_file->lock);
185 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
186 			list_del(&evt->list);
187 			kfree(evt);
188 		}
189 		spin_unlock_irq(&ev_file->lock);
190 
191 		kref_put(&ev_file->ref, ib_uverbs_release_event_file);
192 	}
193 
194 	spin_lock_irq(&file->async_file->lock);
195 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
196 		list_del(&evt->list);
197 		kfree(evt);
198 	}
199 	spin_unlock_irq(&file->async_file->lock);
200 }
201 
202 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
203 			      struct ib_uevent_object *uobj)
204 {
205 	struct ib_uverbs_event *evt, *tmp;
206 
207 	spin_lock_irq(&file->async_file->lock);
208 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
209 		list_del(&evt->list);
210 		kfree(evt);
211 	}
212 	spin_unlock_irq(&file->async_file->lock);
213 }
214 
215 static void ib_uverbs_detach_umcast(struct ib_qp *qp,
216 				    struct ib_uqp_object *uobj)
217 {
218 	struct ib_uverbs_mcast_entry *mcast, *tmp;
219 
220 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
221 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
222 		list_del(&mcast->list);
223 		kfree(mcast);
224 	}
225 }
226 
227 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
228 				      struct ib_ucontext *context)
229 {
230 	struct ib_uobject *uobj, *tmp;
231 
232 	context->closing = 1;
233 
234 	list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
235 		struct ib_ah *ah = uobj->object;
236 
237 		idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
238 		ib_destroy_ah(ah);
239 		kfree(uobj);
240 	}
241 
242 	/* Remove MWs before QPs, in order to support type 2A MWs. */
243 	list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
244 		struct ib_mw *mw = uobj->object;
245 
246 		idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
247 		uverbs_dealloc_mw(mw);
248 		kfree(uobj);
249 	}
250 
251 	list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
252 		struct ib_flow *flow_id = uobj->object;
253 
254 		idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
255 		ib_destroy_flow(flow_id);
256 		kfree(uobj);
257 	}
258 
259 	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
260 		struct ib_qp *qp = uobj->object;
261 		struct ib_uqp_object *uqp =
262 			container_of(uobj, struct ib_uqp_object, uevent.uobject);
263 
264 		idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
265 		if (qp == qp->real_qp)
266 			ib_uverbs_detach_umcast(qp, uqp);
267 		ib_destroy_qp(qp);
268 		ib_uverbs_release_uevent(file, &uqp->uevent);
269 		kfree(uqp);
270 	}
271 
272 	list_for_each_entry_safe(uobj, tmp, &context->rwq_ind_tbl_list, list) {
273 		struct ib_rwq_ind_table *rwq_ind_tbl = uobj->object;
274 		struct ib_wq **ind_tbl = rwq_ind_tbl->ind_tbl;
275 
276 		idr_remove_uobj(&ib_uverbs_rwq_ind_tbl_idr, uobj);
277 		ib_destroy_rwq_ind_table(rwq_ind_tbl);
278 		kfree(ind_tbl);
279 		kfree(uobj);
280 	}
281 
282 	list_for_each_entry_safe(uobj, tmp, &context->wq_list, list) {
283 		struct ib_wq *wq = uobj->object;
284 		struct ib_uwq_object *uwq =
285 			container_of(uobj, struct ib_uwq_object, uevent.uobject);
286 
287 		idr_remove_uobj(&ib_uverbs_wq_idr, uobj);
288 		ib_destroy_wq(wq);
289 		ib_uverbs_release_uevent(file, &uwq->uevent);
290 		kfree(uwq);
291 	}
292 
293 	list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
294 		struct ib_srq *srq = uobj->object;
295 		struct ib_uevent_object *uevent =
296 			container_of(uobj, struct ib_uevent_object, uobject);
297 
298 		idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
299 		ib_destroy_srq(srq);
300 		ib_uverbs_release_uevent(file, uevent);
301 		kfree(uevent);
302 	}
303 
304 	list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
305 		struct ib_cq *cq = uobj->object;
306 		struct ib_uverbs_event_file *ev_file = cq->cq_context;
307 		struct ib_ucq_object *ucq =
308 			container_of(uobj, struct ib_ucq_object, uobject);
309 
310 		idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
311 		ib_destroy_cq(cq);
312 		ib_uverbs_release_ucq(file, ev_file, ucq);
313 		kfree(ucq);
314 	}
315 
316 	list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
317 		struct ib_mr *mr = uobj->object;
318 
319 		idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
320 		ib_dereg_mr(mr);
321 		kfree(uobj);
322 	}
323 
324 	mutex_lock(&file->device->xrcd_tree_mutex);
325 	list_for_each_entry_safe(uobj, tmp, &context->xrcd_list, list) {
326 		struct ib_xrcd *xrcd = uobj->object;
327 		struct ib_uxrcd_object *uxrcd =
328 			container_of(uobj, struct ib_uxrcd_object, uobject);
329 
330 		idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
331 		ib_uverbs_dealloc_xrcd(file->device, xrcd);
332 		kfree(uxrcd);
333 	}
334 	mutex_unlock(&file->device->xrcd_tree_mutex);
335 
336 	list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
337 		struct ib_pd *pd = uobj->object;
338 
339 		idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
340 		ib_dealloc_pd(pd);
341 		kfree(uobj);
342 	}
343 
344 	put_pid(context->tgid);
345 
346 	return context->device->dealloc_ucontext(context);
347 }
348 
349 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
350 {
351 	complete(&dev->comp);
352 }
353 
354 static void ib_uverbs_release_file(struct kref *ref)
355 {
356 	struct ib_uverbs_file *file =
357 		container_of(ref, struct ib_uverbs_file, ref);
358 	struct ib_device *ib_dev;
359 	int srcu_key;
360 
361 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
362 	ib_dev = srcu_dereference(file->device->ib_dev,
363 				  &file->device->disassociate_srcu);
364 	if (ib_dev && !ib_dev->disassociate_ucontext)
365 		module_put(ib_dev->owner);
366 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
367 
368 	if (atomic_dec_and_test(&file->device->refcount))
369 		ib_uverbs_comp_dev(file->device);
370 
371 	kfree(file);
372 }
373 
374 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
375 				    size_t count, loff_t *pos)
376 {
377 	struct ib_uverbs_event_file *file = filp->private_data;
378 	struct ib_uverbs_event *event;
379 	int eventsz;
380 	int ret = 0;
381 
382 	spin_lock_irq(&file->lock);
383 
384 	while (list_empty(&file->event_list)) {
385 		spin_unlock_irq(&file->lock);
386 
387 		if (filp->f_flags & O_NONBLOCK)
388 			return -EAGAIN;
389 
390 		if (wait_event_interruptible(file->poll_wait,
391 					     (!list_empty(&file->event_list) ||
392 			/* The barriers built into wait_event_interruptible()
393 			 * and wake_up() guarentee this will see the null set
394 			 * without using RCU
395 			 */
396 					     !file->uverbs_file->device->ib_dev)))
397 			return -ERESTARTSYS;
398 
399 		/* If device was disassociated and no event exists set an error */
400 		if (list_empty(&file->event_list) &&
401 		    !file->uverbs_file->device->ib_dev)
402 			return -EIO;
403 
404 		spin_lock_irq(&file->lock);
405 	}
406 
407 	event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
408 
409 	if (file->is_async)
410 		eventsz = sizeof (struct ib_uverbs_async_event_desc);
411 	else
412 		eventsz = sizeof (struct ib_uverbs_comp_event_desc);
413 
414 	if (eventsz > count) {
415 		ret   = -EINVAL;
416 		event = NULL;
417 	} else {
418 		list_del(file->event_list.next);
419 		if (event->counter) {
420 			++(*event->counter);
421 			list_del(&event->obj_list);
422 		}
423 	}
424 
425 	spin_unlock_irq(&file->lock);
426 
427 	if (event) {
428 		if (copy_to_user(buf, event, eventsz))
429 			ret = -EFAULT;
430 		else
431 			ret = eventsz;
432 	}
433 
434 	kfree(event);
435 
436 	return ret;
437 }
438 
439 static unsigned int ib_uverbs_event_poll(struct file *filp,
440 					 struct poll_table_struct *wait)
441 {
442 	unsigned int pollflags = 0;
443 	struct ib_uverbs_event_file *file = filp->private_data;
444 
445 	poll_wait(filp, &file->poll_wait, wait);
446 
447 	spin_lock_irq(&file->lock);
448 	if (!list_empty(&file->event_list))
449 		pollflags = POLLIN | POLLRDNORM;
450 	spin_unlock_irq(&file->lock);
451 
452 	return pollflags;
453 }
454 
455 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
456 {
457 	struct ib_uverbs_event_file *file = filp->private_data;
458 
459 	return fasync_helper(fd, filp, on, &file->async_queue);
460 }
461 
462 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
463 {
464 	struct ib_uverbs_event_file *file = filp->private_data;
465 	struct ib_uverbs_event *entry, *tmp;
466 	int closed_already = 0;
467 
468 	mutex_lock(&file->uverbs_file->device->lists_mutex);
469 	spin_lock_irq(&file->lock);
470 	closed_already = file->is_closed;
471 	file->is_closed = 1;
472 	list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
473 		if (entry->counter)
474 			list_del(&entry->obj_list);
475 		kfree(entry);
476 	}
477 	spin_unlock_irq(&file->lock);
478 	if (!closed_already) {
479 		list_del(&file->list);
480 		if (file->is_async)
481 			ib_unregister_event_handler(&file->uverbs_file->
482 				event_handler);
483 	}
484 	mutex_unlock(&file->uverbs_file->device->lists_mutex);
485 
486 	kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
487 	kref_put(&file->ref, ib_uverbs_release_event_file);
488 
489 	return 0;
490 }
491 
492 static const struct file_operations uverbs_event_fops = {
493 	.owner	 = THIS_MODULE,
494 	.read	 = ib_uverbs_event_read,
495 	.poll    = ib_uverbs_event_poll,
496 	.release = ib_uverbs_event_close,
497 	.fasync  = ib_uverbs_event_fasync,
498 	.llseek	 = no_llseek,
499 };
500 
501 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
502 {
503 	struct ib_uverbs_event_file    *file = cq_context;
504 	struct ib_ucq_object	       *uobj;
505 	struct ib_uverbs_event	       *entry;
506 	unsigned long			flags;
507 
508 	if (!file)
509 		return;
510 
511 	spin_lock_irqsave(&file->lock, flags);
512 	if (file->is_closed) {
513 		spin_unlock_irqrestore(&file->lock, flags);
514 		return;
515 	}
516 
517 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
518 	if (!entry) {
519 		spin_unlock_irqrestore(&file->lock, flags);
520 		return;
521 	}
522 
523 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
524 
525 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
526 	entry->counter		   = &uobj->comp_events_reported;
527 
528 	list_add_tail(&entry->list, &file->event_list);
529 	list_add_tail(&entry->obj_list, &uobj->comp_list);
530 	spin_unlock_irqrestore(&file->lock, flags);
531 
532 	wake_up_interruptible(&file->poll_wait);
533 	kill_fasync(&file->async_queue, SIGIO, POLL_IN);
534 }
535 
536 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
537 				    __u64 element, __u64 event,
538 				    struct list_head *obj_list,
539 				    u32 *counter)
540 {
541 	struct ib_uverbs_event *entry;
542 	unsigned long flags;
543 
544 	spin_lock_irqsave(&file->async_file->lock, flags);
545 	if (file->async_file->is_closed) {
546 		spin_unlock_irqrestore(&file->async_file->lock, flags);
547 		return;
548 	}
549 
550 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
551 	if (!entry) {
552 		spin_unlock_irqrestore(&file->async_file->lock, flags);
553 		return;
554 	}
555 
556 	entry->desc.async.element    = element;
557 	entry->desc.async.event_type = event;
558 	entry->desc.async.reserved   = 0;
559 	entry->counter               = counter;
560 
561 	list_add_tail(&entry->list, &file->async_file->event_list);
562 	if (obj_list)
563 		list_add_tail(&entry->obj_list, obj_list);
564 	spin_unlock_irqrestore(&file->async_file->lock, flags);
565 
566 	wake_up_interruptible(&file->async_file->poll_wait);
567 	kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
568 }
569 
570 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
571 {
572 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
573 						  struct ib_ucq_object, uobject);
574 
575 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
576 				event->event, &uobj->async_list,
577 				&uobj->async_events_reported);
578 }
579 
580 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
581 {
582 	struct ib_uevent_object *uobj;
583 
584 	/* for XRC target qp's, check that qp is live */
585 	if (!event->element.qp->uobject || !event->element.qp->uobject->live)
586 		return;
587 
588 	uobj = container_of(event->element.qp->uobject,
589 			    struct ib_uevent_object, uobject);
590 
591 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
592 				event->event, &uobj->event_list,
593 				&uobj->events_reported);
594 }
595 
596 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
597 {
598 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
599 						  struct ib_uevent_object, uobject);
600 
601 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
602 				event->event, &uobj->event_list,
603 				&uobj->events_reported);
604 }
605 
606 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
607 {
608 	struct ib_uevent_object *uobj;
609 
610 	uobj = container_of(event->element.srq->uobject,
611 			    struct ib_uevent_object, uobject);
612 
613 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
614 				event->event, &uobj->event_list,
615 				&uobj->events_reported);
616 }
617 
618 void ib_uverbs_event_handler(struct ib_event_handler *handler,
619 			     struct ib_event *event)
620 {
621 	struct ib_uverbs_file *file =
622 		container_of(handler, struct ib_uverbs_file, event_handler);
623 
624 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
625 				NULL, NULL);
626 }
627 
628 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
629 {
630 	kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
631 	file->async_file = NULL;
632 }
633 
634 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
635 					struct ib_device	*ib_dev,
636 					int is_async)
637 {
638 	struct ib_uverbs_event_file *ev_file;
639 	struct file *filp;
640 	int ret;
641 
642 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
643 	if (!ev_file)
644 		return ERR_PTR(-ENOMEM);
645 
646 	kref_init(&ev_file->ref);
647 	spin_lock_init(&ev_file->lock);
648 	INIT_LIST_HEAD(&ev_file->event_list);
649 	init_waitqueue_head(&ev_file->poll_wait);
650 	ev_file->uverbs_file = uverbs_file;
651 	kref_get(&ev_file->uverbs_file->ref);
652 	ev_file->async_queue = NULL;
653 	ev_file->is_closed   = 0;
654 
655 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
656 				  ev_file, O_RDONLY);
657 	if (IS_ERR(filp))
658 		goto err_put_refs;
659 
660 	mutex_lock(&uverbs_file->device->lists_mutex);
661 	list_add_tail(&ev_file->list,
662 		      &uverbs_file->device->uverbs_events_file_list);
663 	mutex_unlock(&uverbs_file->device->lists_mutex);
664 
665 	if (is_async) {
666 		WARN_ON(uverbs_file->async_file);
667 		uverbs_file->async_file = ev_file;
668 		kref_get(&uverbs_file->async_file->ref);
669 		INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
670 				      ib_dev,
671 				      ib_uverbs_event_handler);
672 		ret = ib_register_event_handler(&uverbs_file->event_handler);
673 		if (ret)
674 			goto err_put_file;
675 
676 		/* At that point async file stuff was fully set */
677 		ev_file->is_async = 1;
678 	}
679 
680 	return filp;
681 
682 err_put_file:
683 	fput(filp);
684 	kref_put(&uverbs_file->async_file->ref, ib_uverbs_release_event_file);
685 	uverbs_file->async_file = NULL;
686 	return ERR_PTR(ret);
687 
688 err_put_refs:
689 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
690 	kref_put(&ev_file->ref, ib_uverbs_release_event_file);
691 	return filp;
692 }
693 
694 /*
695  * Look up a completion event file by FD.  If lookup is successful,
696  * takes a ref to the event file struct that it returns; if
697  * unsuccessful, returns NULL.
698  */
699 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
700 {
701 	struct ib_uverbs_event_file *ev_file = NULL;
702 	struct fd f = fdget(fd);
703 
704 	if (!f.file)
705 		return NULL;
706 
707 	if (f.file->f_op != &uverbs_event_fops)
708 		goto out;
709 
710 	ev_file = f.file->private_data;
711 	if (ev_file->is_async) {
712 		ev_file = NULL;
713 		goto out;
714 	}
715 
716 	kref_get(&ev_file->ref);
717 
718 out:
719 	fdput(f);
720 	return ev_file;
721 }
722 
723 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
724 {
725 	u64 mask;
726 
727 	if (command <= IB_USER_VERBS_CMD_OPEN_QP)
728 		mask = ib_dev->uverbs_cmd_mask;
729 	else
730 		mask = ib_dev->uverbs_ex_cmd_mask;
731 
732 	if (mask & ((u64)1 << command))
733 		return 0;
734 
735 	return -1;
736 }
737 
738 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
739 			     size_t count, loff_t *pos)
740 {
741 	struct ib_uverbs_file *file = filp->private_data;
742 	struct ib_device *ib_dev;
743 	struct ib_uverbs_cmd_hdr hdr;
744 	__u32 command;
745 	__u32 flags;
746 	int srcu_key;
747 	ssize_t ret;
748 
749 	if (WARN_ON_ONCE(!ib_safe_file_access(filp)))
750 		return -EACCES;
751 
752 	if (count < sizeof hdr)
753 		return -EINVAL;
754 
755 	if (copy_from_user(&hdr, buf, sizeof hdr))
756 		return -EFAULT;
757 
758 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
759 	ib_dev = srcu_dereference(file->device->ib_dev,
760 				  &file->device->disassociate_srcu);
761 	if (!ib_dev) {
762 		ret = -EIO;
763 		goto out;
764 	}
765 
766 	if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
767 				   IB_USER_VERBS_CMD_COMMAND_MASK)) {
768 		ret = -EINVAL;
769 		goto out;
770 	}
771 
772 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
773 	if (verify_command_mask(ib_dev, command)) {
774 		ret = -EOPNOTSUPP;
775 		goto out;
776 	}
777 
778 	if (!file->ucontext &&
779 	    command != IB_USER_VERBS_CMD_GET_CONTEXT) {
780 		ret = -EINVAL;
781 		goto out;
782 	}
783 
784 	flags = (hdr.command &
785 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
786 
787 	if (!flags) {
788 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
789 		    !uverbs_cmd_table[command]) {
790 			ret = -EINVAL;
791 			goto out;
792 		}
793 
794 		if (hdr.in_words * 4 != count) {
795 			ret = -EINVAL;
796 			goto out;
797 		}
798 
799 		ret = uverbs_cmd_table[command](file, ib_dev,
800 						 buf + sizeof(hdr),
801 						 hdr.in_words * 4,
802 						 hdr.out_words * 4);
803 
804 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
805 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
806 		struct ib_udata ucore;
807 		struct ib_udata uhw;
808 		size_t written_count = count;
809 
810 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
811 		    !uverbs_ex_cmd_table[command]) {
812 			ret = -ENOSYS;
813 			goto out;
814 		}
815 
816 		if (!file->ucontext) {
817 			ret = -EINVAL;
818 			goto out;
819 		}
820 
821 		if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
822 			ret = -EINVAL;
823 			goto out;
824 		}
825 
826 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
827 			ret = -EFAULT;
828 			goto out;
829 		}
830 
831 		count -= sizeof(hdr) + sizeof(ex_hdr);
832 		buf += sizeof(hdr) + sizeof(ex_hdr);
833 
834 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
835 			ret = -EINVAL;
836 			goto out;
837 		}
838 
839 		if (ex_hdr.cmd_hdr_reserved) {
840 			ret = -EINVAL;
841 			goto out;
842 		}
843 
844 		if (ex_hdr.response) {
845 			if (!hdr.out_words && !ex_hdr.provider_out_words) {
846 				ret = -EINVAL;
847 				goto out;
848 			}
849 
850 			if (!access_ok(VERIFY_WRITE,
851 				       (void __user *) (unsigned long) ex_hdr.response,
852 				       (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
853 				ret = -EFAULT;
854 				goto out;
855 			}
856 		} else {
857 			if (hdr.out_words || ex_hdr.provider_out_words) {
858 				ret = -EINVAL;
859 				goto out;
860 			}
861 		}
862 
863 		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
864 				       hdr.in_words * 8, hdr.out_words * 8);
865 
866 		INIT_UDATA_BUF_OR_NULL(&uhw,
867 				       buf + ucore.inlen,
868 				       (unsigned long) ex_hdr.response + ucore.outlen,
869 				       ex_hdr.provider_in_words * 8,
870 				       ex_hdr.provider_out_words * 8);
871 
872 		ret = uverbs_ex_cmd_table[command](file,
873 						   ib_dev,
874 						   &ucore,
875 						   &uhw);
876 		if (!ret)
877 			ret = written_count;
878 	} else {
879 		ret = -ENOSYS;
880 	}
881 
882 out:
883 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
884 	return ret;
885 }
886 
887 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
888 {
889 	struct ib_uverbs_file *file = filp->private_data;
890 	struct ib_device *ib_dev;
891 	int ret = 0;
892 	int srcu_key;
893 
894 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
895 	ib_dev = srcu_dereference(file->device->ib_dev,
896 				  &file->device->disassociate_srcu);
897 	if (!ib_dev) {
898 		ret = -EIO;
899 		goto out;
900 	}
901 
902 	if (!file->ucontext)
903 		ret = -ENODEV;
904 	else
905 		ret = ib_dev->mmap(file->ucontext, vma);
906 out:
907 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
908 	return ret;
909 }
910 
911 /*
912  * ib_uverbs_open() does not need the BKL:
913  *
914  *  - the ib_uverbs_device structures are properly reference counted and
915  *    everything else is purely local to the file being created, so
916  *    races against other open calls are not a problem;
917  *  - there is no ioctl method to race against;
918  *  - the open method will either immediately run -ENXIO, or all
919  *    required initialization will be done.
920  */
921 static int ib_uverbs_open(struct inode *inode, struct file *filp)
922 {
923 	struct ib_uverbs_device *dev;
924 	struct ib_uverbs_file *file;
925 	struct ib_device *ib_dev;
926 	int ret;
927 	int module_dependent;
928 	int srcu_key;
929 
930 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
931 	if (!atomic_inc_not_zero(&dev->refcount))
932 		return -ENXIO;
933 
934 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
935 	mutex_lock(&dev->lists_mutex);
936 	ib_dev = srcu_dereference(dev->ib_dev,
937 				  &dev->disassociate_srcu);
938 	if (!ib_dev) {
939 		ret = -EIO;
940 		goto err;
941 	}
942 
943 	/* In case IB device supports disassociate ucontext, there is no hard
944 	 * dependency between uverbs device and its low level device.
945 	 */
946 	module_dependent = !(ib_dev->disassociate_ucontext);
947 
948 	if (module_dependent) {
949 		if (!try_module_get(ib_dev->owner)) {
950 			ret = -ENODEV;
951 			goto err;
952 		}
953 	}
954 
955 	file = kzalloc(sizeof(*file), GFP_KERNEL);
956 	if (!file) {
957 		ret = -ENOMEM;
958 		if (module_dependent)
959 			goto err_module;
960 
961 		goto err;
962 	}
963 
964 	file->device	 = dev;
965 	file->ucontext	 = NULL;
966 	file->async_file = NULL;
967 	kref_init(&file->ref);
968 	mutex_init(&file->mutex);
969 	mutex_init(&file->cleanup_mutex);
970 
971 	filp->private_data = file;
972 	kobject_get(&dev->kobj);
973 	list_add_tail(&file->list, &dev->uverbs_file_list);
974 	mutex_unlock(&dev->lists_mutex);
975 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
976 
977 	return nonseekable_open(inode, filp);
978 
979 err_module:
980 	module_put(ib_dev->owner);
981 
982 err:
983 	mutex_unlock(&dev->lists_mutex);
984 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
985 	if (atomic_dec_and_test(&dev->refcount))
986 		ib_uverbs_comp_dev(dev);
987 
988 	return ret;
989 }
990 
991 static int ib_uverbs_close(struct inode *inode, struct file *filp)
992 {
993 	struct ib_uverbs_file *file = filp->private_data;
994 	struct ib_uverbs_device *dev = file->device;
995 
996 	mutex_lock(&file->cleanup_mutex);
997 	if (file->ucontext) {
998 		ib_uverbs_cleanup_ucontext(file, file->ucontext);
999 		file->ucontext = NULL;
1000 	}
1001 	mutex_unlock(&file->cleanup_mutex);
1002 
1003 	mutex_lock(&file->device->lists_mutex);
1004 	if (!file->is_closed) {
1005 		list_del(&file->list);
1006 		file->is_closed = 1;
1007 	}
1008 	mutex_unlock(&file->device->lists_mutex);
1009 
1010 	if (file->async_file)
1011 		kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
1012 
1013 	kref_put(&file->ref, ib_uverbs_release_file);
1014 	kobject_put(&dev->kobj);
1015 
1016 	return 0;
1017 }
1018 
1019 static const struct file_operations uverbs_fops = {
1020 	.owner	 = THIS_MODULE,
1021 	.write	 = ib_uverbs_write,
1022 	.open	 = ib_uverbs_open,
1023 	.release = ib_uverbs_close,
1024 	.llseek	 = no_llseek,
1025 };
1026 
1027 static const struct file_operations uverbs_mmap_fops = {
1028 	.owner	 = THIS_MODULE,
1029 	.write	 = ib_uverbs_write,
1030 	.mmap    = ib_uverbs_mmap,
1031 	.open	 = ib_uverbs_open,
1032 	.release = ib_uverbs_close,
1033 	.llseek	 = no_llseek,
1034 };
1035 
1036 static struct ib_client uverbs_client = {
1037 	.name   = "uverbs",
1038 	.add    = ib_uverbs_add_one,
1039 	.remove = ib_uverbs_remove_one
1040 };
1041 
1042 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
1043 			  char *buf)
1044 {
1045 	int ret = -ENODEV;
1046 	int srcu_key;
1047 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
1048 	struct ib_device *ib_dev;
1049 
1050 	if (!dev)
1051 		return -ENODEV;
1052 
1053 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1054 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1055 	if (ib_dev)
1056 		ret = sprintf(buf, "%s\n", ib_dev->name);
1057 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1058 
1059 	return ret;
1060 }
1061 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
1062 
1063 static ssize_t show_dev_abi_version(struct device *device,
1064 				    struct device_attribute *attr, char *buf)
1065 {
1066 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
1067 	int ret = -ENODEV;
1068 	int srcu_key;
1069 	struct ib_device *ib_dev;
1070 
1071 	if (!dev)
1072 		return -ENODEV;
1073 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1074 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1075 	if (ib_dev)
1076 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1077 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1078 
1079 	return ret;
1080 }
1081 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
1082 
1083 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1084 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1085 
1086 static dev_t overflow_maj;
1087 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
1088 
1089 /*
1090  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
1091  * requesting a new major number and doubling the number of max devices we
1092  * support. It's stupid, but simple.
1093  */
1094 static int find_overflow_devnum(void)
1095 {
1096 	int ret;
1097 
1098 	if (!overflow_maj) {
1099 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
1100 					  "infiniband_verbs");
1101 		if (ret) {
1102 			pr_err("user_verbs: couldn't register dynamic device number\n");
1103 			return ret;
1104 		}
1105 	}
1106 
1107 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
1108 	if (ret >= IB_UVERBS_MAX_DEVICES)
1109 		return -1;
1110 
1111 	return ret;
1112 }
1113 
1114 static void ib_uverbs_add_one(struct ib_device *device)
1115 {
1116 	int devnum;
1117 	dev_t base;
1118 	struct ib_uverbs_device *uverbs_dev;
1119 	int ret;
1120 
1121 	if (!device->alloc_ucontext)
1122 		return;
1123 
1124 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1125 	if (!uverbs_dev)
1126 		return;
1127 
1128 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1129 	if (ret) {
1130 		kfree(uverbs_dev);
1131 		return;
1132 	}
1133 
1134 	atomic_set(&uverbs_dev->refcount, 1);
1135 	init_completion(&uverbs_dev->comp);
1136 	uverbs_dev->xrcd_tree = RB_ROOT;
1137 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1138 	kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1139 	mutex_init(&uverbs_dev->lists_mutex);
1140 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1141 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1142 
1143 	spin_lock(&map_lock);
1144 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1145 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
1146 		spin_unlock(&map_lock);
1147 		devnum = find_overflow_devnum();
1148 		if (devnum < 0)
1149 			goto err;
1150 
1151 		spin_lock(&map_lock);
1152 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
1153 		base = devnum + overflow_maj;
1154 		set_bit(devnum, overflow_map);
1155 	} else {
1156 		uverbs_dev->devnum = devnum;
1157 		base = devnum + IB_UVERBS_BASE_DEV;
1158 		set_bit(devnum, dev_map);
1159 	}
1160 	spin_unlock(&map_lock);
1161 
1162 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1163 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1164 
1165 	cdev_init(&uverbs_dev->cdev, NULL);
1166 	uverbs_dev->cdev.owner = THIS_MODULE;
1167 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1168 	uverbs_dev->cdev.kobj.parent = &uverbs_dev->kobj;
1169 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1170 	if (cdev_add(&uverbs_dev->cdev, base, 1))
1171 		goto err_cdev;
1172 
1173 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
1174 					uverbs_dev->cdev.dev, uverbs_dev,
1175 					"uverbs%d", uverbs_dev->devnum);
1176 	if (IS_ERR(uverbs_dev->dev))
1177 		goto err_cdev;
1178 
1179 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1180 		goto err_class;
1181 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1182 		goto err_class;
1183 
1184 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1185 
1186 	return;
1187 
1188 err_class:
1189 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1190 
1191 err_cdev:
1192 	cdev_del(&uverbs_dev->cdev);
1193 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1194 		clear_bit(devnum, dev_map);
1195 	else
1196 		clear_bit(devnum, overflow_map);
1197 
1198 err:
1199 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1200 		ib_uverbs_comp_dev(uverbs_dev);
1201 	wait_for_completion(&uverbs_dev->comp);
1202 	kobject_put(&uverbs_dev->kobj);
1203 	return;
1204 }
1205 
1206 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1207 					struct ib_device *ib_dev)
1208 {
1209 	struct ib_uverbs_file *file;
1210 	struct ib_uverbs_event_file *event_file;
1211 	struct ib_event event;
1212 
1213 	/* Pending running commands to terminate */
1214 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
1215 	event.event = IB_EVENT_DEVICE_FATAL;
1216 	event.element.port_num = 0;
1217 	event.device = ib_dev;
1218 
1219 	mutex_lock(&uverbs_dev->lists_mutex);
1220 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1221 		struct ib_ucontext *ucontext;
1222 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1223 					struct ib_uverbs_file, list);
1224 		file->is_closed = 1;
1225 		list_del(&file->list);
1226 		kref_get(&file->ref);
1227 		mutex_unlock(&uverbs_dev->lists_mutex);
1228 
1229 		ib_uverbs_event_handler(&file->event_handler, &event);
1230 
1231 		mutex_lock(&file->cleanup_mutex);
1232 		ucontext = file->ucontext;
1233 		file->ucontext = NULL;
1234 		mutex_unlock(&file->cleanup_mutex);
1235 
1236 		/* At this point ib_uverbs_close cannot be running
1237 		 * ib_uverbs_cleanup_ucontext
1238 		 */
1239 		if (ucontext) {
1240 			/* We must release the mutex before going ahead and
1241 			 * calling disassociate_ucontext. disassociate_ucontext
1242 			 * might end up indirectly calling uverbs_close,
1243 			 * for example due to freeing the resources
1244 			 * (e.g mmput).
1245 			 */
1246 			ib_dev->disassociate_ucontext(ucontext);
1247 			ib_uverbs_cleanup_ucontext(file, ucontext);
1248 		}
1249 
1250 		mutex_lock(&uverbs_dev->lists_mutex);
1251 		kref_put(&file->ref, ib_uverbs_release_file);
1252 	}
1253 
1254 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1255 		event_file = list_first_entry(&uverbs_dev->
1256 					      uverbs_events_file_list,
1257 					      struct ib_uverbs_event_file,
1258 					      list);
1259 		spin_lock_irq(&event_file->lock);
1260 		event_file->is_closed = 1;
1261 		spin_unlock_irq(&event_file->lock);
1262 
1263 		list_del(&event_file->list);
1264 		if (event_file->is_async) {
1265 			ib_unregister_event_handler(&event_file->uverbs_file->
1266 						    event_handler);
1267 			event_file->uverbs_file->event_handler.device = NULL;
1268 		}
1269 
1270 		wake_up_interruptible(&event_file->poll_wait);
1271 		kill_fasync(&event_file->async_queue, SIGIO, POLL_IN);
1272 	}
1273 	mutex_unlock(&uverbs_dev->lists_mutex);
1274 }
1275 
1276 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1277 {
1278 	struct ib_uverbs_device *uverbs_dev = client_data;
1279 	int wait_clients = 1;
1280 
1281 	if (!uverbs_dev)
1282 		return;
1283 
1284 	dev_set_drvdata(uverbs_dev->dev, NULL);
1285 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1286 	cdev_del(&uverbs_dev->cdev);
1287 
1288 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1289 		clear_bit(uverbs_dev->devnum, dev_map);
1290 	else
1291 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
1292 
1293 	if (device->disassociate_ucontext) {
1294 		/* We disassociate HW resources and immediately return.
1295 		 * Userspace will see a EIO errno for all future access.
1296 		 * Upon returning, ib_device may be freed internally and is not
1297 		 * valid any more.
1298 		 * uverbs_device is still available until all clients close
1299 		 * their files, then the uverbs device ref count will be zero
1300 		 * and its resources will be freed.
1301 		 * Note: At this point no more files can be opened since the
1302 		 * cdev was deleted, however active clients can still issue
1303 		 * commands and close their open files.
1304 		 */
1305 		rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1306 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1307 		wait_clients = 0;
1308 	}
1309 
1310 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1311 		ib_uverbs_comp_dev(uverbs_dev);
1312 	if (wait_clients)
1313 		wait_for_completion(&uverbs_dev->comp);
1314 	kobject_put(&uverbs_dev->kobj);
1315 }
1316 
1317 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1318 {
1319 	if (mode)
1320 		*mode = 0666;
1321 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1322 }
1323 
1324 static int __init ib_uverbs_init(void)
1325 {
1326 	int ret;
1327 
1328 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
1329 				     "infiniband_verbs");
1330 	if (ret) {
1331 		pr_err("user_verbs: couldn't register device number\n");
1332 		goto out;
1333 	}
1334 
1335 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1336 	if (IS_ERR(uverbs_class)) {
1337 		ret = PTR_ERR(uverbs_class);
1338 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1339 		goto out_chrdev;
1340 	}
1341 
1342 	uverbs_class->devnode = uverbs_devnode;
1343 
1344 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1345 	if (ret) {
1346 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1347 		goto out_class;
1348 	}
1349 
1350 	ret = ib_register_client(&uverbs_client);
1351 	if (ret) {
1352 		pr_err("user_verbs: couldn't register client\n");
1353 		goto out_class;
1354 	}
1355 
1356 	return 0;
1357 
1358 out_class:
1359 	class_destroy(uverbs_class);
1360 
1361 out_chrdev:
1362 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1363 
1364 out:
1365 	return ret;
1366 }
1367 
1368 static void __exit ib_uverbs_cleanup(void)
1369 {
1370 	ib_unregister_client(&uverbs_client);
1371 	class_destroy(uverbs_class);
1372 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1373 	if (overflow_maj)
1374 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1375 	idr_destroy(&ib_uverbs_pd_idr);
1376 	idr_destroy(&ib_uverbs_mr_idr);
1377 	idr_destroy(&ib_uverbs_mw_idr);
1378 	idr_destroy(&ib_uverbs_ah_idr);
1379 	idr_destroy(&ib_uverbs_cq_idr);
1380 	idr_destroy(&ib_uverbs_qp_idr);
1381 	idr_destroy(&ib_uverbs_srq_idr);
1382 }
1383 
1384 module_init(ib_uverbs_init);
1385 module_exit(ib_uverbs_cleanup);
1386