1 /*
2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
6  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
7  *
8  * This software is available to you under a choice of one of two
9  * licenses.  You may choose to be licensed under the terms of the GNU
10  * General Public License (GPL) Version 2, available from the file
11  * COPYING in the main directory of this source tree, or the
12  * OpenIB.org BSD license below:
13  *
14  *     Redistribution and use in source and binary forms, with or
15  *     without modification, are permitted provided that the following
16  *     conditions are met:
17  *
18  *      - Redistributions of source code must retain the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer.
21  *
22  *      - Redistributions in binary form must reproduce the above
23  *        copyright notice, this list of conditions and the following
24  *        disclaimer in the documentation and/or other materials
25  *        provided with the distribution.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
28  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
29  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
30  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
31  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
32  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
33  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34  * SOFTWARE.
35  */
36 
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/device.h>
40 #include <linux/err.h>
41 #include <linux/fs.h>
42 #include <linux/poll.h>
43 #include <linux/sched.h>
44 #include <linux/file.h>
45 #include <linux/cdev.h>
46 #include <linux/anon_inodes.h>
47 #include <linux/slab.h>
48 
49 #include <linux/uaccess.h>
50 
51 #include <rdma/ib.h>
52 #include <rdma/uverbs_std_types.h>
53 
54 #include "uverbs.h"
55 #include "core_priv.h"
56 #include "rdma_core.h"
57 
58 MODULE_AUTHOR("Roland Dreier");
59 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
60 MODULE_LICENSE("Dual BSD/GPL");
61 
62 enum {
63 	IB_UVERBS_MAJOR       = 231,
64 	IB_UVERBS_BASE_MINOR  = 192,
65 	IB_UVERBS_MAX_DEVICES = 32
66 };
67 
68 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
69 
70 static struct class *uverbs_class;
71 
72 static DEFINE_SPINLOCK(map_lock);
73 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
74 
75 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
76 				     struct ib_device *ib_dev,
77 				     const char __user *buf, int in_len,
78 				     int out_len) = {
79 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
80 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
81 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
82 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
83 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
84 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
85 	[IB_USER_VERBS_CMD_REREG_MR]		= ib_uverbs_rereg_mr,
86 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
87 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
88 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
89 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
90 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
91 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
92 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
93 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
94 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
95 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
96 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
97 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
98 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
99 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
100 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
101 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
102 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
103 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
104 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
105 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
106 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
107 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
108 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
109 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
110 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
111 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
112 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
113 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
114 };
115 
116 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
117 				    struct ib_device *ib_dev,
118 				    struct ib_udata *ucore,
119 				    struct ib_udata *uhw) = {
120 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
121 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow,
122 	[IB_USER_VERBS_EX_CMD_QUERY_DEVICE]	= ib_uverbs_ex_query_device,
123 	[IB_USER_VERBS_EX_CMD_CREATE_CQ]	= ib_uverbs_ex_create_cq,
124 	[IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
125 	[IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
126 	[IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
127 	[IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
128 	[IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
129 	[IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
130 	[IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
131 };
132 
133 static void ib_uverbs_add_one(struct ib_device *device);
134 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
135 
136 int uverbs_dealloc_mw(struct ib_mw *mw)
137 {
138 	struct ib_pd *pd = mw->pd;
139 	int ret;
140 
141 	ret = mw->device->dealloc_mw(mw);
142 	if (!ret)
143 		atomic_dec(&pd->usecnt);
144 	return ret;
145 }
146 
147 static void ib_uverbs_release_dev(struct kobject *kobj)
148 {
149 	struct ib_uverbs_device *dev =
150 		container_of(kobj, struct ib_uverbs_device, kobj);
151 
152 	cleanup_srcu_struct(&dev->disassociate_srcu);
153 	kfree(dev);
154 }
155 
156 static struct kobj_type ib_uverbs_dev_ktype = {
157 	.release = ib_uverbs_release_dev,
158 };
159 
160 static void ib_uverbs_release_async_event_file(struct kref *ref)
161 {
162 	struct ib_uverbs_async_event_file *file =
163 		container_of(ref, struct ib_uverbs_async_event_file, ref);
164 
165 	kfree(file);
166 }
167 
168 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
169 			  struct ib_uverbs_completion_event_file *ev_file,
170 			  struct ib_ucq_object *uobj)
171 {
172 	struct ib_uverbs_event *evt, *tmp;
173 
174 	if (ev_file) {
175 		spin_lock_irq(&ev_file->ev_queue.lock);
176 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
177 			list_del(&evt->list);
178 			kfree(evt);
179 		}
180 		spin_unlock_irq(&ev_file->ev_queue.lock);
181 
182 		uverbs_uobject_put(&ev_file->uobj_file.uobj);
183 	}
184 
185 	spin_lock_irq(&file->async_file->ev_queue.lock);
186 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
187 		list_del(&evt->list);
188 		kfree(evt);
189 	}
190 	spin_unlock_irq(&file->async_file->ev_queue.lock);
191 }
192 
193 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
194 			      struct ib_uevent_object *uobj)
195 {
196 	struct ib_uverbs_event *evt, *tmp;
197 
198 	spin_lock_irq(&file->async_file->ev_queue.lock);
199 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
200 		list_del(&evt->list);
201 		kfree(evt);
202 	}
203 	spin_unlock_irq(&file->async_file->ev_queue.lock);
204 }
205 
206 void ib_uverbs_detach_umcast(struct ib_qp *qp,
207 			     struct ib_uqp_object *uobj)
208 {
209 	struct ib_uverbs_mcast_entry *mcast, *tmp;
210 
211 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
212 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
213 		list_del(&mcast->list);
214 		kfree(mcast);
215 	}
216 }
217 
218 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
219 				      struct ib_ucontext *context,
220 				      bool device_removed)
221 {
222 	context->closing = 1;
223 	uverbs_cleanup_ucontext(context, device_removed);
224 	put_pid(context->tgid);
225 
226 	ib_rdmacg_uncharge(&context->cg_obj, context->device,
227 			   RDMACG_RESOURCE_HCA_HANDLE);
228 
229 	return context->device->dealloc_ucontext(context);
230 }
231 
232 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
233 {
234 	complete(&dev->comp);
235 }
236 
237 void ib_uverbs_release_file(struct kref *ref)
238 {
239 	struct ib_uverbs_file *file =
240 		container_of(ref, struct ib_uverbs_file, ref);
241 	struct ib_device *ib_dev;
242 	int srcu_key;
243 
244 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
245 	ib_dev = srcu_dereference(file->device->ib_dev,
246 				  &file->device->disassociate_srcu);
247 	if (ib_dev && !ib_dev->disassociate_ucontext)
248 		module_put(ib_dev->owner);
249 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
250 
251 	if (atomic_dec_and_test(&file->device->refcount))
252 		ib_uverbs_comp_dev(file->device);
253 
254 	kobject_put(&file->device->kobj);
255 	kfree(file);
256 }
257 
258 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
259 				    struct ib_uverbs_file *uverbs_file,
260 				    struct file *filp, char __user *buf,
261 				    size_t count, loff_t *pos,
262 				    size_t eventsz)
263 {
264 	struct ib_uverbs_event *event;
265 	int ret = 0;
266 
267 	spin_lock_irq(&ev_queue->lock);
268 
269 	while (list_empty(&ev_queue->event_list)) {
270 		spin_unlock_irq(&ev_queue->lock);
271 
272 		if (filp->f_flags & O_NONBLOCK)
273 			return -EAGAIN;
274 
275 		if (wait_event_interruptible(ev_queue->poll_wait,
276 					     (!list_empty(&ev_queue->event_list) ||
277 			/* The barriers built into wait_event_interruptible()
278 			 * and wake_up() guarentee this will see the null set
279 			 * without using RCU
280 			 */
281 					     !uverbs_file->device->ib_dev)))
282 			return -ERESTARTSYS;
283 
284 		/* If device was disassociated and no event exists set an error */
285 		if (list_empty(&ev_queue->event_list) &&
286 		    !uverbs_file->device->ib_dev)
287 			return -EIO;
288 
289 		spin_lock_irq(&ev_queue->lock);
290 	}
291 
292 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
293 
294 	if (eventsz > count) {
295 		ret   = -EINVAL;
296 		event = NULL;
297 	} else {
298 		list_del(ev_queue->event_list.next);
299 		if (event->counter) {
300 			++(*event->counter);
301 			list_del(&event->obj_list);
302 		}
303 	}
304 
305 	spin_unlock_irq(&ev_queue->lock);
306 
307 	if (event) {
308 		if (copy_to_user(buf, event, eventsz))
309 			ret = -EFAULT;
310 		else
311 			ret = eventsz;
312 	}
313 
314 	kfree(event);
315 
316 	return ret;
317 }
318 
319 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
320 					  size_t count, loff_t *pos)
321 {
322 	struct ib_uverbs_async_event_file *file = filp->private_data;
323 
324 	return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
325 				    buf, count, pos,
326 				    sizeof(struct ib_uverbs_async_event_desc));
327 }
328 
329 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
330 					 size_t count, loff_t *pos)
331 {
332 	struct ib_uverbs_completion_event_file *comp_ev_file =
333 		filp->private_data;
334 
335 	return ib_uverbs_event_read(&comp_ev_file->ev_queue,
336 				    comp_ev_file->uobj_file.ufile, filp,
337 				    buf, count, pos,
338 				    sizeof(struct ib_uverbs_comp_event_desc));
339 }
340 
341 static unsigned int ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
342 					 struct file *filp,
343 					 struct poll_table_struct *wait)
344 {
345 	unsigned int pollflags = 0;
346 
347 	poll_wait(filp, &ev_queue->poll_wait, wait);
348 
349 	spin_lock_irq(&ev_queue->lock);
350 	if (!list_empty(&ev_queue->event_list))
351 		pollflags = POLLIN | POLLRDNORM;
352 	spin_unlock_irq(&ev_queue->lock);
353 
354 	return pollflags;
355 }
356 
357 static unsigned int ib_uverbs_async_event_poll(struct file *filp,
358 					       struct poll_table_struct *wait)
359 {
360 	return ib_uverbs_event_poll(filp->private_data, filp, wait);
361 }
362 
363 static unsigned int ib_uverbs_comp_event_poll(struct file *filp,
364 					      struct poll_table_struct *wait)
365 {
366 	struct ib_uverbs_completion_event_file *comp_ev_file =
367 		filp->private_data;
368 
369 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
370 }
371 
372 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
373 {
374 	struct ib_uverbs_event_queue *ev_queue = filp->private_data;
375 
376 	return fasync_helper(fd, filp, on, &ev_queue->async_queue);
377 }
378 
379 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
380 {
381 	struct ib_uverbs_completion_event_file *comp_ev_file =
382 		filp->private_data;
383 
384 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
385 }
386 
387 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
388 {
389 	struct ib_uverbs_async_event_file *file = filp->private_data;
390 	struct ib_uverbs_file *uverbs_file = file->uverbs_file;
391 	struct ib_uverbs_event *entry, *tmp;
392 	int closed_already = 0;
393 
394 	mutex_lock(&uverbs_file->device->lists_mutex);
395 	spin_lock_irq(&file->ev_queue.lock);
396 	closed_already = file->ev_queue.is_closed;
397 	file->ev_queue.is_closed = 1;
398 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
399 		if (entry->counter)
400 			list_del(&entry->obj_list);
401 		kfree(entry);
402 	}
403 	spin_unlock_irq(&file->ev_queue.lock);
404 	if (!closed_already) {
405 		list_del(&file->list);
406 		ib_unregister_event_handler(&uverbs_file->event_handler);
407 	}
408 	mutex_unlock(&uverbs_file->device->lists_mutex);
409 
410 	kref_put(&uverbs_file->ref, ib_uverbs_release_file);
411 	kref_put(&file->ref, ib_uverbs_release_async_event_file);
412 
413 	return 0;
414 }
415 
416 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
417 {
418 	struct ib_uverbs_completion_event_file *file = filp->private_data;
419 	struct ib_uverbs_event *entry, *tmp;
420 
421 	spin_lock_irq(&file->ev_queue.lock);
422 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
423 		if (entry->counter)
424 			list_del(&entry->obj_list);
425 		kfree(entry);
426 	}
427 	spin_unlock_irq(&file->ev_queue.lock);
428 
429 	uverbs_close_fd(filp);
430 
431 	return 0;
432 }
433 
434 const struct file_operations uverbs_event_fops = {
435 	.owner	 = THIS_MODULE,
436 	.read	 = ib_uverbs_comp_event_read,
437 	.poll    = ib_uverbs_comp_event_poll,
438 	.release = ib_uverbs_comp_event_close,
439 	.fasync  = ib_uverbs_comp_event_fasync,
440 	.llseek	 = no_llseek,
441 };
442 
443 static const struct file_operations uverbs_async_event_fops = {
444 	.owner	 = THIS_MODULE,
445 	.read	 = ib_uverbs_async_event_read,
446 	.poll    = ib_uverbs_async_event_poll,
447 	.release = ib_uverbs_async_event_close,
448 	.fasync  = ib_uverbs_async_event_fasync,
449 	.llseek	 = no_llseek,
450 };
451 
452 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
453 {
454 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
455 	struct ib_ucq_object	       *uobj;
456 	struct ib_uverbs_event	       *entry;
457 	unsigned long			flags;
458 
459 	if (!ev_queue)
460 		return;
461 
462 	spin_lock_irqsave(&ev_queue->lock, flags);
463 	if (ev_queue->is_closed) {
464 		spin_unlock_irqrestore(&ev_queue->lock, flags);
465 		return;
466 	}
467 
468 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
469 	if (!entry) {
470 		spin_unlock_irqrestore(&ev_queue->lock, flags);
471 		return;
472 	}
473 
474 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
475 
476 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
477 	entry->counter		   = &uobj->comp_events_reported;
478 
479 	list_add_tail(&entry->list, &ev_queue->event_list);
480 	list_add_tail(&entry->obj_list, &uobj->comp_list);
481 	spin_unlock_irqrestore(&ev_queue->lock, flags);
482 
483 	wake_up_interruptible(&ev_queue->poll_wait);
484 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
485 }
486 
487 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
488 				    __u64 element, __u64 event,
489 				    struct list_head *obj_list,
490 				    u32 *counter)
491 {
492 	struct ib_uverbs_event *entry;
493 	unsigned long flags;
494 
495 	spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
496 	if (file->async_file->ev_queue.is_closed) {
497 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
498 		return;
499 	}
500 
501 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
502 	if (!entry) {
503 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
504 		return;
505 	}
506 
507 	entry->desc.async.element    = element;
508 	entry->desc.async.event_type = event;
509 	entry->desc.async.reserved   = 0;
510 	entry->counter               = counter;
511 
512 	list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
513 	if (obj_list)
514 		list_add_tail(&entry->obj_list, obj_list);
515 	spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
516 
517 	wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
518 	kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
519 }
520 
521 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
522 {
523 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
524 						  struct ib_ucq_object, uobject);
525 
526 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
527 				event->event, &uobj->async_list,
528 				&uobj->async_events_reported);
529 }
530 
531 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
532 {
533 	struct ib_uevent_object *uobj;
534 
535 	/* for XRC target qp's, check that qp is live */
536 	if (!event->element.qp->uobject)
537 		return;
538 
539 	uobj = container_of(event->element.qp->uobject,
540 			    struct ib_uevent_object, uobject);
541 
542 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
543 				event->event, &uobj->event_list,
544 				&uobj->events_reported);
545 }
546 
547 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
548 {
549 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
550 						  struct ib_uevent_object, uobject);
551 
552 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
553 				event->event, &uobj->event_list,
554 				&uobj->events_reported);
555 }
556 
557 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
558 {
559 	struct ib_uevent_object *uobj;
560 
561 	uobj = container_of(event->element.srq->uobject,
562 			    struct ib_uevent_object, uobject);
563 
564 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
565 				event->event, &uobj->event_list,
566 				&uobj->events_reported);
567 }
568 
569 void ib_uverbs_event_handler(struct ib_event_handler *handler,
570 			     struct ib_event *event)
571 {
572 	struct ib_uverbs_file *file =
573 		container_of(handler, struct ib_uverbs_file, event_handler);
574 
575 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
576 				NULL, NULL);
577 }
578 
579 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
580 {
581 	kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
582 	file->async_file = NULL;
583 }
584 
585 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
586 {
587 	spin_lock_init(&ev_queue->lock);
588 	INIT_LIST_HEAD(&ev_queue->event_list);
589 	init_waitqueue_head(&ev_queue->poll_wait);
590 	ev_queue->is_closed   = 0;
591 	ev_queue->async_queue = NULL;
592 }
593 
594 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
595 					      struct ib_device	*ib_dev)
596 {
597 	struct ib_uverbs_async_event_file *ev_file;
598 	struct file *filp;
599 
600 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
601 	if (!ev_file)
602 		return ERR_PTR(-ENOMEM);
603 
604 	ib_uverbs_init_event_queue(&ev_file->ev_queue);
605 	ev_file->uverbs_file = uverbs_file;
606 	kref_get(&ev_file->uverbs_file->ref);
607 	kref_init(&ev_file->ref);
608 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
609 				  ev_file, O_RDONLY);
610 	if (IS_ERR(filp))
611 		goto err_put_refs;
612 
613 	mutex_lock(&uverbs_file->device->lists_mutex);
614 	list_add_tail(&ev_file->list,
615 		      &uverbs_file->device->uverbs_events_file_list);
616 	mutex_unlock(&uverbs_file->device->lists_mutex);
617 
618 	WARN_ON(uverbs_file->async_file);
619 	uverbs_file->async_file = ev_file;
620 	kref_get(&uverbs_file->async_file->ref);
621 	INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
622 			      ib_dev,
623 			      ib_uverbs_event_handler);
624 	ib_register_event_handler(&uverbs_file->event_handler);
625 	/* At that point async file stuff was fully set */
626 
627 	return filp;
628 
629 err_put_refs:
630 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
631 	kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
632 	return filp;
633 }
634 
635 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
636 {
637 	u64 mask;
638 
639 	if (command <= IB_USER_VERBS_CMD_OPEN_QP)
640 		mask = ib_dev->uverbs_cmd_mask;
641 	else
642 		mask = ib_dev->uverbs_ex_cmd_mask;
643 
644 	if (mask & ((u64)1 << command))
645 		return 0;
646 
647 	return -1;
648 }
649 
650 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
651 			     size_t count, loff_t *pos)
652 {
653 	struct ib_uverbs_file *file = filp->private_data;
654 	struct ib_device *ib_dev;
655 	struct ib_uverbs_cmd_hdr hdr;
656 	__u32 command;
657 	__u32 flags;
658 	int srcu_key;
659 	ssize_t ret;
660 
661 	if (!ib_safe_file_access(filp)) {
662 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
663 			    task_tgid_vnr(current), current->comm);
664 		return -EACCES;
665 	}
666 
667 	if (count < sizeof hdr)
668 		return -EINVAL;
669 
670 	if (copy_from_user(&hdr, buf, sizeof hdr))
671 		return -EFAULT;
672 
673 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
674 	ib_dev = srcu_dereference(file->device->ib_dev,
675 				  &file->device->disassociate_srcu);
676 	if (!ib_dev) {
677 		ret = -EIO;
678 		goto out;
679 	}
680 
681 	if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
682 				   IB_USER_VERBS_CMD_COMMAND_MASK)) {
683 		ret = -EINVAL;
684 		goto out;
685 	}
686 
687 	command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
688 	if (verify_command_mask(ib_dev, command)) {
689 		ret = -EOPNOTSUPP;
690 		goto out;
691 	}
692 
693 	if (!file->ucontext &&
694 	    command != IB_USER_VERBS_CMD_GET_CONTEXT) {
695 		ret = -EINVAL;
696 		goto out;
697 	}
698 
699 	flags = (hdr.command &
700 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
701 
702 	if (!flags) {
703 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
704 		    !uverbs_cmd_table[command]) {
705 			ret = -EINVAL;
706 			goto out;
707 		}
708 
709 		if (hdr.in_words * 4 != count) {
710 			ret = -EINVAL;
711 			goto out;
712 		}
713 
714 		ret = uverbs_cmd_table[command](file, ib_dev,
715 						 buf + sizeof(hdr),
716 						 hdr.in_words * 4,
717 						 hdr.out_words * 4);
718 
719 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
720 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
721 		struct ib_udata ucore;
722 		struct ib_udata uhw;
723 		size_t written_count = count;
724 
725 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
726 		    !uverbs_ex_cmd_table[command]) {
727 			ret = -ENOSYS;
728 			goto out;
729 		}
730 
731 		if (!file->ucontext) {
732 			ret = -EINVAL;
733 			goto out;
734 		}
735 
736 		if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
737 			ret = -EINVAL;
738 			goto out;
739 		}
740 
741 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
742 			ret = -EFAULT;
743 			goto out;
744 		}
745 
746 		count -= sizeof(hdr) + sizeof(ex_hdr);
747 		buf += sizeof(hdr) + sizeof(ex_hdr);
748 
749 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
750 			ret = -EINVAL;
751 			goto out;
752 		}
753 
754 		if (ex_hdr.cmd_hdr_reserved) {
755 			ret = -EINVAL;
756 			goto out;
757 		}
758 
759 		if (ex_hdr.response) {
760 			if (!hdr.out_words && !ex_hdr.provider_out_words) {
761 				ret = -EINVAL;
762 				goto out;
763 			}
764 
765 			if (!access_ok(VERIFY_WRITE,
766 				       (void __user *) (unsigned long) ex_hdr.response,
767 				       (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
768 				ret = -EFAULT;
769 				goto out;
770 			}
771 		} else {
772 			if (hdr.out_words || ex_hdr.provider_out_words) {
773 				ret = -EINVAL;
774 				goto out;
775 			}
776 		}
777 
778 		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
779 				       hdr.in_words * 8, hdr.out_words * 8);
780 
781 		INIT_UDATA_BUF_OR_NULL(&uhw,
782 				       buf + ucore.inlen,
783 				       (unsigned long) ex_hdr.response + ucore.outlen,
784 				       ex_hdr.provider_in_words * 8,
785 				       ex_hdr.provider_out_words * 8);
786 
787 		ret = uverbs_ex_cmd_table[command](file,
788 						   ib_dev,
789 						   &ucore,
790 						   &uhw);
791 		if (!ret)
792 			ret = written_count;
793 	} else {
794 		ret = -ENOSYS;
795 	}
796 
797 out:
798 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
799 	return ret;
800 }
801 
802 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
803 {
804 	struct ib_uverbs_file *file = filp->private_data;
805 	struct ib_device *ib_dev;
806 	int ret = 0;
807 	int srcu_key;
808 
809 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
810 	ib_dev = srcu_dereference(file->device->ib_dev,
811 				  &file->device->disassociate_srcu);
812 	if (!ib_dev) {
813 		ret = -EIO;
814 		goto out;
815 	}
816 
817 	if (!file->ucontext)
818 		ret = -ENODEV;
819 	else
820 		ret = ib_dev->mmap(file->ucontext, vma);
821 out:
822 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
823 	return ret;
824 }
825 
826 /*
827  * ib_uverbs_open() does not need the BKL:
828  *
829  *  - the ib_uverbs_device structures are properly reference counted and
830  *    everything else is purely local to the file being created, so
831  *    races against other open calls are not a problem;
832  *  - there is no ioctl method to race against;
833  *  - the open method will either immediately run -ENXIO, or all
834  *    required initialization will be done.
835  */
836 static int ib_uverbs_open(struct inode *inode, struct file *filp)
837 {
838 	struct ib_uverbs_device *dev;
839 	struct ib_uverbs_file *file;
840 	struct ib_device *ib_dev;
841 	int ret;
842 	int module_dependent;
843 	int srcu_key;
844 
845 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
846 	if (!atomic_inc_not_zero(&dev->refcount))
847 		return -ENXIO;
848 
849 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
850 	mutex_lock(&dev->lists_mutex);
851 	ib_dev = srcu_dereference(dev->ib_dev,
852 				  &dev->disassociate_srcu);
853 	if (!ib_dev) {
854 		ret = -EIO;
855 		goto err;
856 	}
857 
858 	/* In case IB device supports disassociate ucontext, there is no hard
859 	 * dependency between uverbs device and its low level device.
860 	 */
861 	module_dependent = !(ib_dev->disassociate_ucontext);
862 
863 	if (module_dependent) {
864 		if (!try_module_get(ib_dev->owner)) {
865 			ret = -ENODEV;
866 			goto err;
867 		}
868 	}
869 
870 	file = kzalloc(sizeof(*file), GFP_KERNEL);
871 	if (!file) {
872 		ret = -ENOMEM;
873 		if (module_dependent)
874 			goto err_module;
875 
876 		goto err;
877 	}
878 
879 	file->device	 = dev;
880 	spin_lock_init(&file->idr_lock);
881 	idr_init(&file->idr);
882 	file->ucontext	 = NULL;
883 	file->async_file = NULL;
884 	kref_init(&file->ref);
885 	mutex_init(&file->mutex);
886 	mutex_init(&file->cleanup_mutex);
887 
888 	filp->private_data = file;
889 	kobject_get(&dev->kobj);
890 	list_add_tail(&file->list, &dev->uverbs_file_list);
891 	mutex_unlock(&dev->lists_mutex);
892 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
893 
894 	return nonseekable_open(inode, filp);
895 
896 err_module:
897 	module_put(ib_dev->owner);
898 
899 err:
900 	mutex_unlock(&dev->lists_mutex);
901 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
902 	if (atomic_dec_and_test(&dev->refcount))
903 		ib_uverbs_comp_dev(dev);
904 
905 	return ret;
906 }
907 
908 static int ib_uverbs_close(struct inode *inode, struct file *filp)
909 {
910 	struct ib_uverbs_file *file = filp->private_data;
911 
912 	mutex_lock(&file->cleanup_mutex);
913 	if (file->ucontext) {
914 		ib_uverbs_cleanup_ucontext(file, file->ucontext, false);
915 		file->ucontext = NULL;
916 	}
917 	mutex_unlock(&file->cleanup_mutex);
918 	idr_destroy(&file->idr);
919 
920 	mutex_lock(&file->device->lists_mutex);
921 	if (!file->is_closed) {
922 		list_del(&file->list);
923 		file->is_closed = 1;
924 	}
925 	mutex_unlock(&file->device->lists_mutex);
926 
927 	if (file->async_file)
928 		kref_put(&file->async_file->ref,
929 			 ib_uverbs_release_async_event_file);
930 
931 	kref_put(&file->ref, ib_uverbs_release_file);
932 
933 	return 0;
934 }
935 
936 static const struct file_operations uverbs_fops = {
937 	.owner	 = THIS_MODULE,
938 	.write	 = ib_uverbs_write,
939 	.open	 = ib_uverbs_open,
940 	.release = ib_uverbs_close,
941 	.llseek	 = no_llseek,
942 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
943 	.unlocked_ioctl = ib_uverbs_ioctl,
944 #endif
945 };
946 
947 static const struct file_operations uverbs_mmap_fops = {
948 	.owner	 = THIS_MODULE,
949 	.write	 = ib_uverbs_write,
950 	.mmap    = ib_uverbs_mmap,
951 	.open	 = ib_uverbs_open,
952 	.release = ib_uverbs_close,
953 	.llseek	 = no_llseek,
954 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
955 	.unlocked_ioctl = ib_uverbs_ioctl,
956 #endif
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 dev_t overflow_maj;
1010 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
1011 
1012 /*
1013  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
1014  * requesting a new major number and doubling the number of max devices we
1015  * support. It's stupid, but simple.
1016  */
1017 static int find_overflow_devnum(void)
1018 {
1019 	int ret;
1020 
1021 	if (!overflow_maj) {
1022 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
1023 					  "infiniband_verbs");
1024 		if (ret) {
1025 			pr_err("user_verbs: couldn't register dynamic device number\n");
1026 			return ret;
1027 		}
1028 	}
1029 
1030 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
1031 	if (ret >= IB_UVERBS_MAX_DEVICES)
1032 		return -1;
1033 
1034 	return ret;
1035 }
1036 
1037 static void ib_uverbs_add_one(struct ib_device *device)
1038 {
1039 	int devnum;
1040 	dev_t base;
1041 	struct ib_uverbs_device *uverbs_dev;
1042 	int ret;
1043 
1044 	if (!device->alloc_ucontext)
1045 		return;
1046 
1047 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1048 	if (!uverbs_dev)
1049 		return;
1050 
1051 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1052 	if (ret) {
1053 		kfree(uverbs_dev);
1054 		return;
1055 	}
1056 
1057 	atomic_set(&uverbs_dev->refcount, 1);
1058 	init_completion(&uverbs_dev->comp);
1059 	uverbs_dev->xrcd_tree = RB_ROOT;
1060 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1061 	kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1062 	mutex_init(&uverbs_dev->lists_mutex);
1063 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1064 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1065 
1066 	spin_lock(&map_lock);
1067 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1068 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
1069 		spin_unlock(&map_lock);
1070 		devnum = find_overflow_devnum();
1071 		if (devnum < 0)
1072 			goto err;
1073 
1074 		spin_lock(&map_lock);
1075 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
1076 		base = devnum + overflow_maj;
1077 		set_bit(devnum, overflow_map);
1078 	} else {
1079 		uverbs_dev->devnum = devnum;
1080 		base = devnum + IB_UVERBS_BASE_DEV;
1081 		set_bit(devnum, dev_map);
1082 	}
1083 	spin_unlock(&map_lock);
1084 
1085 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1086 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1087 
1088 	cdev_init(&uverbs_dev->cdev, NULL);
1089 	uverbs_dev->cdev.owner = THIS_MODULE;
1090 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1091 	cdev_set_parent(&uverbs_dev->cdev, &uverbs_dev->kobj);
1092 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1093 	if (cdev_add(&uverbs_dev->cdev, base, 1))
1094 		goto err_cdev;
1095 
1096 	uverbs_dev->dev = device_create(uverbs_class, device->dev.parent,
1097 					uverbs_dev->cdev.dev, uverbs_dev,
1098 					"uverbs%d", uverbs_dev->devnum);
1099 	if (IS_ERR(uverbs_dev->dev))
1100 		goto err_cdev;
1101 
1102 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1103 		goto err_class;
1104 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1105 		goto err_class;
1106 
1107 	if (!device->specs_root) {
1108 		const struct uverbs_object_tree_def *default_root[] = {
1109 			uverbs_default_get_objects()};
1110 
1111 		uverbs_dev->specs_root = uverbs_alloc_spec_tree(1,
1112 								default_root);
1113 		if (IS_ERR(uverbs_dev->specs_root))
1114 			goto err_class;
1115 
1116 		device->specs_root = uverbs_dev->specs_root;
1117 	}
1118 
1119 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1120 
1121 	return;
1122 
1123 err_class:
1124 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1125 
1126 err_cdev:
1127 	cdev_del(&uverbs_dev->cdev);
1128 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1129 		clear_bit(devnum, dev_map);
1130 	else
1131 		clear_bit(devnum, overflow_map);
1132 
1133 err:
1134 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1135 		ib_uverbs_comp_dev(uverbs_dev);
1136 	wait_for_completion(&uverbs_dev->comp);
1137 	kobject_put(&uverbs_dev->kobj);
1138 	return;
1139 }
1140 
1141 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1142 					struct ib_device *ib_dev)
1143 {
1144 	struct ib_uverbs_file *file;
1145 	struct ib_uverbs_async_event_file *event_file;
1146 	struct ib_event event;
1147 
1148 	/* Pending running commands to terminate */
1149 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
1150 	event.event = IB_EVENT_DEVICE_FATAL;
1151 	event.element.port_num = 0;
1152 	event.device = ib_dev;
1153 
1154 	mutex_lock(&uverbs_dev->lists_mutex);
1155 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1156 		struct ib_ucontext *ucontext;
1157 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1158 					struct ib_uverbs_file, list);
1159 		file->is_closed = 1;
1160 		list_del(&file->list);
1161 		kref_get(&file->ref);
1162 		mutex_unlock(&uverbs_dev->lists_mutex);
1163 
1164 
1165 		mutex_lock(&file->cleanup_mutex);
1166 		ucontext = file->ucontext;
1167 		file->ucontext = NULL;
1168 		mutex_unlock(&file->cleanup_mutex);
1169 
1170 		/* At this point ib_uverbs_close cannot be running
1171 		 * ib_uverbs_cleanup_ucontext
1172 		 */
1173 		if (ucontext) {
1174 			/* We must release the mutex before going ahead and
1175 			 * calling disassociate_ucontext. disassociate_ucontext
1176 			 * might end up indirectly calling uverbs_close,
1177 			 * for example due to freeing the resources
1178 			 * (e.g mmput).
1179 			 */
1180 			ib_uverbs_event_handler(&file->event_handler, &event);
1181 			ib_dev->disassociate_ucontext(ucontext);
1182 			mutex_lock(&file->cleanup_mutex);
1183 			ib_uverbs_cleanup_ucontext(file, ucontext, true);
1184 			mutex_unlock(&file->cleanup_mutex);
1185 		}
1186 
1187 		mutex_lock(&uverbs_dev->lists_mutex);
1188 		kref_put(&file->ref, ib_uverbs_release_file);
1189 	}
1190 
1191 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1192 		event_file = list_first_entry(&uverbs_dev->
1193 					      uverbs_events_file_list,
1194 					      struct ib_uverbs_async_event_file,
1195 					      list);
1196 		spin_lock_irq(&event_file->ev_queue.lock);
1197 		event_file->ev_queue.is_closed = 1;
1198 		spin_unlock_irq(&event_file->ev_queue.lock);
1199 
1200 		list_del(&event_file->list);
1201 		ib_unregister_event_handler(
1202 			&event_file->uverbs_file->event_handler);
1203 		event_file->uverbs_file->event_handler.device =
1204 			NULL;
1205 
1206 		wake_up_interruptible(&event_file->ev_queue.poll_wait);
1207 		kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1208 	}
1209 	mutex_unlock(&uverbs_dev->lists_mutex);
1210 }
1211 
1212 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1213 {
1214 	struct ib_uverbs_device *uverbs_dev = client_data;
1215 	int wait_clients = 1;
1216 
1217 	if (!uverbs_dev)
1218 		return;
1219 
1220 	dev_set_drvdata(uverbs_dev->dev, NULL);
1221 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1222 	cdev_del(&uverbs_dev->cdev);
1223 
1224 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1225 		clear_bit(uverbs_dev->devnum, dev_map);
1226 	else
1227 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
1228 
1229 	if (device->disassociate_ucontext) {
1230 		/* We disassociate HW resources and immediately return.
1231 		 * Userspace will see a EIO errno for all future access.
1232 		 * Upon returning, ib_device may be freed internally and is not
1233 		 * valid any more.
1234 		 * uverbs_device is still available until all clients close
1235 		 * their files, then the uverbs device ref count will be zero
1236 		 * and its resources will be freed.
1237 		 * Note: At this point no more files can be opened since the
1238 		 * cdev was deleted, however active clients can still issue
1239 		 * commands and close their open files.
1240 		 */
1241 		rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1242 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1243 		wait_clients = 0;
1244 	}
1245 
1246 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1247 		ib_uverbs_comp_dev(uverbs_dev);
1248 	if (wait_clients)
1249 		wait_for_completion(&uverbs_dev->comp);
1250 	if (uverbs_dev->specs_root) {
1251 		uverbs_free_spec_tree(uverbs_dev->specs_root);
1252 		device->specs_root = NULL;
1253 	}
1254 
1255 	kobject_put(&uverbs_dev->kobj);
1256 }
1257 
1258 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1259 {
1260 	if (mode)
1261 		*mode = 0666;
1262 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1263 }
1264 
1265 static int __init ib_uverbs_init(void)
1266 {
1267 	int ret;
1268 
1269 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
1270 				     "infiniband_verbs");
1271 	if (ret) {
1272 		pr_err("user_verbs: couldn't register device number\n");
1273 		goto out;
1274 	}
1275 
1276 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1277 	if (IS_ERR(uverbs_class)) {
1278 		ret = PTR_ERR(uverbs_class);
1279 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1280 		goto out_chrdev;
1281 	}
1282 
1283 	uverbs_class->devnode = uverbs_devnode;
1284 
1285 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1286 	if (ret) {
1287 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1288 		goto out_class;
1289 	}
1290 
1291 	ret = ib_register_client(&uverbs_client);
1292 	if (ret) {
1293 		pr_err("user_verbs: couldn't register client\n");
1294 		goto out_class;
1295 	}
1296 
1297 	return 0;
1298 
1299 out_class:
1300 	class_destroy(uverbs_class);
1301 
1302 out_chrdev:
1303 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1304 
1305 out:
1306 	return ret;
1307 }
1308 
1309 static void __exit ib_uverbs_cleanup(void)
1310 {
1311 	ib_unregister_client(&uverbs_client);
1312 	class_destroy(uverbs_class);
1313 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1314 	if (overflow_maj)
1315 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1316 }
1317 
1318 module_init(ib_uverbs_init);
1319 module_exit(ib_uverbs_cleanup);
1320