xref: /openbmc/linux/drivers/infiniband/core/uverbs_main.c (revision 05cf4fe738242183f1237f1b3a28b4479348c0a1)
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 #include <linux/sched/mm.h>
49 
50 #include <linux/uaccess.h>
51 
52 #include <rdma/ib.h>
53 #include <rdma/uverbs_std_types.h>
54 
55 #include "uverbs.h"
56 #include "core_priv.h"
57 #include "rdma_core.h"
58 
59 MODULE_AUTHOR("Roland Dreier");
60 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
61 MODULE_LICENSE("Dual BSD/GPL");
62 
63 enum {
64 	IB_UVERBS_MAJOR       = 231,
65 	IB_UVERBS_BASE_MINOR  = 192,
66 	IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
67 	IB_UVERBS_NUM_FIXED_MINOR = 32,
68 	IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
69 };
70 
71 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
72 
73 static dev_t dynamic_uverbs_dev;
74 static struct class *uverbs_class;
75 
76 static DEFINE_IDA(uverbs_ida);
77 
78 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
79 				     const char __user *buf, int in_len,
80 				     int out_len) = {
81 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
82 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
83 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
84 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
85 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
86 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
87 	[IB_USER_VERBS_CMD_REREG_MR]		= ib_uverbs_rereg_mr,
88 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
89 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
90 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
91 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
92 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
93 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
94 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
95 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
96 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
97 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
98 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
99 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
100 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
101 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
102 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
103 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
104 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
105 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
106 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
107 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
108 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
109 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
110 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
111 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
112 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
113 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
114 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
115 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
116 };
117 
118 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
119 				    struct ib_udata *ucore,
120 				    struct ib_udata *uhw) = {
121 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
122 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow,
123 	[IB_USER_VERBS_EX_CMD_QUERY_DEVICE]	= ib_uverbs_ex_query_device,
124 	[IB_USER_VERBS_EX_CMD_CREATE_CQ]	= ib_uverbs_ex_create_cq,
125 	[IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
126 	[IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
127 	[IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
128 	[IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
129 	[IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
130 	[IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
131 	[IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
132 	[IB_USER_VERBS_EX_CMD_MODIFY_CQ]        = ib_uverbs_ex_modify_cq,
133 };
134 
135 static void ib_uverbs_add_one(struct ib_device *device);
136 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
137 
138 /*
139  * Must be called with the ufile->device->disassociate_srcu held, and the lock
140  * must be held until use of the ucontext is finished.
141  */
142 struct ib_ucontext *ib_uverbs_get_ucontext(struct ib_uverbs_file *ufile)
143 {
144 	/*
145 	 * We do not hold the hw_destroy_rwsem lock for this flow, instead
146 	 * srcu is used. It does not matter if someone races this with
147 	 * get_context, we get NULL or valid ucontext.
148 	 */
149 	struct ib_ucontext *ucontext = smp_load_acquire(&ufile->ucontext);
150 
151 	if (!srcu_dereference(ufile->device->ib_dev,
152 			      &ufile->device->disassociate_srcu))
153 		return ERR_PTR(-EIO);
154 
155 	if (!ucontext)
156 		return ERR_PTR(-EINVAL);
157 
158 	return ucontext;
159 }
160 EXPORT_SYMBOL(ib_uverbs_get_ucontext);
161 
162 int uverbs_dealloc_mw(struct ib_mw *mw)
163 {
164 	struct ib_pd *pd = mw->pd;
165 	int ret;
166 
167 	ret = mw->device->dealloc_mw(mw);
168 	if (!ret)
169 		atomic_dec(&pd->usecnt);
170 	return ret;
171 }
172 
173 static void ib_uverbs_release_dev(struct device *device)
174 {
175 	struct ib_uverbs_device *dev =
176 			container_of(device, struct ib_uverbs_device, dev);
177 
178 	uverbs_destroy_api(dev->uapi);
179 	cleanup_srcu_struct(&dev->disassociate_srcu);
180 	kfree(dev);
181 }
182 
183 static void ib_uverbs_release_async_event_file(struct kref *ref)
184 {
185 	struct ib_uverbs_async_event_file *file =
186 		container_of(ref, struct ib_uverbs_async_event_file, ref);
187 
188 	kfree(file);
189 }
190 
191 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
192 			  struct ib_uverbs_completion_event_file *ev_file,
193 			  struct ib_ucq_object *uobj)
194 {
195 	struct ib_uverbs_event *evt, *tmp;
196 
197 	if (ev_file) {
198 		spin_lock_irq(&ev_file->ev_queue.lock);
199 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
200 			list_del(&evt->list);
201 			kfree(evt);
202 		}
203 		spin_unlock_irq(&ev_file->ev_queue.lock);
204 
205 		uverbs_uobject_put(&ev_file->uobj);
206 	}
207 
208 	spin_lock_irq(&file->async_file->ev_queue.lock);
209 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
210 		list_del(&evt->list);
211 		kfree(evt);
212 	}
213 	spin_unlock_irq(&file->async_file->ev_queue.lock);
214 }
215 
216 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
217 			      struct ib_uevent_object *uobj)
218 {
219 	struct ib_uverbs_event *evt, *tmp;
220 
221 	spin_lock_irq(&file->async_file->ev_queue.lock);
222 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
223 		list_del(&evt->list);
224 		kfree(evt);
225 	}
226 	spin_unlock_irq(&file->async_file->ev_queue.lock);
227 }
228 
229 void ib_uverbs_detach_umcast(struct ib_qp *qp,
230 			     struct ib_uqp_object *uobj)
231 {
232 	struct ib_uverbs_mcast_entry *mcast, *tmp;
233 
234 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
235 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
236 		list_del(&mcast->list);
237 		kfree(mcast);
238 	}
239 }
240 
241 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
242 {
243 	complete(&dev->comp);
244 }
245 
246 void ib_uverbs_release_file(struct kref *ref)
247 {
248 	struct ib_uverbs_file *file =
249 		container_of(ref, struct ib_uverbs_file, ref);
250 	struct ib_device *ib_dev;
251 	int srcu_key;
252 
253 	release_ufile_idr_uobject(file);
254 
255 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
256 	ib_dev = srcu_dereference(file->device->ib_dev,
257 				  &file->device->disassociate_srcu);
258 	if (ib_dev && !ib_dev->disassociate_ucontext)
259 		module_put(ib_dev->owner);
260 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
261 
262 	if (atomic_dec_and_test(&file->device->refcount))
263 		ib_uverbs_comp_dev(file->device);
264 
265 	put_device(&file->device->dev);
266 	kfree(file);
267 }
268 
269 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
270 				    struct ib_uverbs_file *uverbs_file,
271 				    struct file *filp, char __user *buf,
272 				    size_t count, loff_t *pos,
273 				    size_t eventsz)
274 {
275 	struct ib_uverbs_event *event;
276 	int ret = 0;
277 
278 	spin_lock_irq(&ev_queue->lock);
279 
280 	while (list_empty(&ev_queue->event_list)) {
281 		spin_unlock_irq(&ev_queue->lock);
282 
283 		if (filp->f_flags & O_NONBLOCK)
284 			return -EAGAIN;
285 
286 		if (wait_event_interruptible(ev_queue->poll_wait,
287 					     (!list_empty(&ev_queue->event_list) ||
288 			/* The barriers built into wait_event_interruptible()
289 			 * and wake_up() guarentee this will see the null set
290 			 * without using RCU
291 			 */
292 					     !uverbs_file->device->ib_dev)))
293 			return -ERESTARTSYS;
294 
295 		/* If device was disassociated and no event exists set an error */
296 		if (list_empty(&ev_queue->event_list) &&
297 		    !uverbs_file->device->ib_dev)
298 			return -EIO;
299 
300 		spin_lock_irq(&ev_queue->lock);
301 	}
302 
303 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
304 
305 	if (eventsz > count) {
306 		ret   = -EINVAL;
307 		event = NULL;
308 	} else {
309 		list_del(ev_queue->event_list.next);
310 		if (event->counter) {
311 			++(*event->counter);
312 			list_del(&event->obj_list);
313 		}
314 	}
315 
316 	spin_unlock_irq(&ev_queue->lock);
317 
318 	if (event) {
319 		if (copy_to_user(buf, event, eventsz))
320 			ret = -EFAULT;
321 		else
322 			ret = eventsz;
323 	}
324 
325 	kfree(event);
326 
327 	return ret;
328 }
329 
330 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
331 					  size_t count, loff_t *pos)
332 {
333 	struct ib_uverbs_async_event_file *file = filp->private_data;
334 
335 	return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
336 				    buf, count, pos,
337 				    sizeof(struct ib_uverbs_async_event_desc));
338 }
339 
340 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
341 					 size_t count, loff_t *pos)
342 {
343 	struct ib_uverbs_completion_event_file *comp_ev_file =
344 		filp->private_data;
345 
346 	return ib_uverbs_event_read(&comp_ev_file->ev_queue,
347 				    comp_ev_file->uobj.ufile, filp,
348 				    buf, count, pos,
349 				    sizeof(struct ib_uverbs_comp_event_desc));
350 }
351 
352 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
353 					 struct file *filp,
354 					 struct poll_table_struct *wait)
355 {
356 	__poll_t pollflags = 0;
357 
358 	poll_wait(filp, &ev_queue->poll_wait, wait);
359 
360 	spin_lock_irq(&ev_queue->lock);
361 	if (!list_empty(&ev_queue->event_list))
362 		pollflags = EPOLLIN | EPOLLRDNORM;
363 	spin_unlock_irq(&ev_queue->lock);
364 
365 	return pollflags;
366 }
367 
368 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
369 					       struct poll_table_struct *wait)
370 {
371 	return ib_uverbs_event_poll(filp->private_data, filp, wait);
372 }
373 
374 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
375 					      struct poll_table_struct *wait)
376 {
377 	struct ib_uverbs_completion_event_file *comp_ev_file =
378 		filp->private_data;
379 
380 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
381 }
382 
383 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
384 {
385 	struct ib_uverbs_event_queue *ev_queue = filp->private_data;
386 
387 	return fasync_helper(fd, filp, on, &ev_queue->async_queue);
388 }
389 
390 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
391 {
392 	struct ib_uverbs_completion_event_file *comp_ev_file =
393 		filp->private_data;
394 
395 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
396 }
397 
398 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
399 {
400 	struct ib_uverbs_async_event_file *file = filp->private_data;
401 	struct ib_uverbs_file *uverbs_file = file->uverbs_file;
402 	struct ib_uverbs_event *entry, *tmp;
403 	int closed_already = 0;
404 
405 	mutex_lock(&uverbs_file->device->lists_mutex);
406 	spin_lock_irq(&file->ev_queue.lock);
407 	closed_already = file->ev_queue.is_closed;
408 	file->ev_queue.is_closed = 1;
409 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
410 		if (entry->counter)
411 			list_del(&entry->obj_list);
412 		kfree(entry);
413 	}
414 	spin_unlock_irq(&file->ev_queue.lock);
415 	if (!closed_already) {
416 		list_del(&file->list);
417 		ib_unregister_event_handler(&uverbs_file->event_handler);
418 	}
419 	mutex_unlock(&uverbs_file->device->lists_mutex);
420 
421 	kref_put(&uverbs_file->ref, ib_uverbs_release_file);
422 	kref_put(&file->ref, ib_uverbs_release_async_event_file);
423 
424 	return 0;
425 }
426 
427 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
428 {
429 	struct ib_uobject *uobj = filp->private_data;
430 	struct ib_uverbs_completion_event_file *file = container_of(
431 		uobj, struct ib_uverbs_completion_event_file, uobj);
432 	struct ib_uverbs_event *entry, *tmp;
433 
434 	spin_lock_irq(&file->ev_queue.lock);
435 	list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
436 		if (entry->counter)
437 			list_del(&entry->obj_list);
438 		kfree(entry);
439 	}
440 	file->ev_queue.is_closed = 1;
441 	spin_unlock_irq(&file->ev_queue.lock);
442 
443 	uverbs_close_fd(filp);
444 
445 	return 0;
446 }
447 
448 const struct file_operations uverbs_event_fops = {
449 	.owner	 = THIS_MODULE,
450 	.read	 = ib_uverbs_comp_event_read,
451 	.poll    = ib_uverbs_comp_event_poll,
452 	.release = ib_uverbs_comp_event_close,
453 	.fasync  = ib_uverbs_comp_event_fasync,
454 	.llseek	 = no_llseek,
455 };
456 
457 static const struct file_operations uverbs_async_event_fops = {
458 	.owner	 = THIS_MODULE,
459 	.read	 = ib_uverbs_async_event_read,
460 	.poll    = ib_uverbs_async_event_poll,
461 	.release = ib_uverbs_async_event_close,
462 	.fasync  = ib_uverbs_async_event_fasync,
463 	.llseek	 = no_llseek,
464 };
465 
466 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
467 {
468 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
469 	struct ib_ucq_object	       *uobj;
470 	struct ib_uverbs_event	       *entry;
471 	unsigned long			flags;
472 
473 	if (!ev_queue)
474 		return;
475 
476 	spin_lock_irqsave(&ev_queue->lock, flags);
477 	if (ev_queue->is_closed) {
478 		spin_unlock_irqrestore(&ev_queue->lock, flags);
479 		return;
480 	}
481 
482 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
483 	if (!entry) {
484 		spin_unlock_irqrestore(&ev_queue->lock, flags);
485 		return;
486 	}
487 
488 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
489 
490 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
491 	entry->counter		   = &uobj->comp_events_reported;
492 
493 	list_add_tail(&entry->list, &ev_queue->event_list);
494 	list_add_tail(&entry->obj_list, &uobj->comp_list);
495 	spin_unlock_irqrestore(&ev_queue->lock, flags);
496 
497 	wake_up_interruptible(&ev_queue->poll_wait);
498 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
499 }
500 
501 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
502 				    __u64 element, __u64 event,
503 				    struct list_head *obj_list,
504 				    u32 *counter)
505 {
506 	struct ib_uverbs_event *entry;
507 	unsigned long flags;
508 
509 	spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
510 	if (file->async_file->ev_queue.is_closed) {
511 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
512 		return;
513 	}
514 
515 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
516 	if (!entry) {
517 		spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
518 		return;
519 	}
520 
521 	entry->desc.async.element    = element;
522 	entry->desc.async.event_type = event;
523 	entry->desc.async.reserved   = 0;
524 	entry->counter               = counter;
525 
526 	list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
527 	if (obj_list)
528 		list_add_tail(&entry->obj_list, obj_list);
529 	spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
530 
531 	wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
532 	kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
533 }
534 
535 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
536 {
537 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
538 						  struct ib_ucq_object, uobject);
539 
540 	ib_uverbs_async_handler(uobj->uobject.ufile, uobj->uobject.user_handle,
541 				event->event, &uobj->async_list,
542 				&uobj->async_events_reported);
543 }
544 
545 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
546 {
547 	struct ib_uevent_object *uobj;
548 
549 	/* for XRC target qp's, check that qp is live */
550 	if (!event->element.qp->uobject)
551 		return;
552 
553 	uobj = container_of(event->element.qp->uobject,
554 			    struct ib_uevent_object, uobject);
555 
556 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
557 				event->event, &uobj->event_list,
558 				&uobj->events_reported);
559 }
560 
561 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
562 {
563 	struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
564 						  struct ib_uevent_object, uobject);
565 
566 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
567 				event->event, &uobj->event_list,
568 				&uobj->events_reported);
569 }
570 
571 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
572 {
573 	struct ib_uevent_object *uobj;
574 
575 	uobj = container_of(event->element.srq->uobject,
576 			    struct ib_uevent_object, uobject);
577 
578 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
579 				event->event, &uobj->event_list,
580 				&uobj->events_reported);
581 }
582 
583 void ib_uverbs_event_handler(struct ib_event_handler *handler,
584 			     struct ib_event *event)
585 {
586 	struct ib_uverbs_file *file =
587 		container_of(handler, struct ib_uverbs_file, event_handler);
588 
589 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
590 				NULL, NULL);
591 }
592 
593 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
594 {
595 	kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
596 	file->async_file = NULL;
597 }
598 
599 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
600 {
601 	spin_lock_init(&ev_queue->lock);
602 	INIT_LIST_HEAD(&ev_queue->event_list);
603 	init_waitqueue_head(&ev_queue->poll_wait);
604 	ev_queue->is_closed   = 0;
605 	ev_queue->async_queue = NULL;
606 }
607 
608 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
609 					      struct ib_device	*ib_dev)
610 {
611 	struct ib_uverbs_async_event_file *ev_file;
612 	struct file *filp;
613 
614 	ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
615 	if (!ev_file)
616 		return ERR_PTR(-ENOMEM);
617 
618 	ib_uverbs_init_event_queue(&ev_file->ev_queue);
619 	ev_file->uverbs_file = uverbs_file;
620 	kref_get(&ev_file->uverbs_file->ref);
621 	kref_init(&ev_file->ref);
622 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
623 				  ev_file, O_RDONLY);
624 	if (IS_ERR(filp))
625 		goto err_put_refs;
626 
627 	mutex_lock(&uverbs_file->device->lists_mutex);
628 	list_add_tail(&ev_file->list,
629 		      &uverbs_file->device->uverbs_events_file_list);
630 	mutex_unlock(&uverbs_file->device->lists_mutex);
631 
632 	WARN_ON(uverbs_file->async_file);
633 	uverbs_file->async_file = ev_file;
634 	kref_get(&uverbs_file->async_file->ref);
635 	INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
636 			      ib_dev,
637 			      ib_uverbs_event_handler);
638 	ib_register_event_handler(&uverbs_file->event_handler);
639 	/* At that point async file stuff was fully set */
640 
641 	return filp;
642 
643 err_put_refs:
644 	kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
645 	kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
646 	return filp;
647 }
648 
649 static bool verify_command_mask(struct ib_uverbs_file *ufile, u32 command,
650 				bool extended)
651 {
652 	if (!extended)
653 		return ufile->uverbs_cmd_mask & BIT_ULL(command);
654 
655 	return ufile->uverbs_ex_cmd_mask & BIT_ULL(command);
656 }
657 
658 static bool verify_command_idx(u32 command, bool extended)
659 {
660 	if (extended)
661 		return command < ARRAY_SIZE(uverbs_ex_cmd_table) &&
662 		       uverbs_ex_cmd_table[command];
663 
664 	return command < ARRAY_SIZE(uverbs_cmd_table) &&
665 	       uverbs_cmd_table[command];
666 }
667 
668 static ssize_t process_hdr(struct ib_uverbs_cmd_hdr *hdr,
669 			   u32 *command, bool *extended)
670 {
671 	if (hdr->command & ~(u32)(IB_USER_VERBS_CMD_FLAG_EXTENDED |
672 				   IB_USER_VERBS_CMD_COMMAND_MASK))
673 		return -EINVAL;
674 
675 	*command = hdr->command & IB_USER_VERBS_CMD_COMMAND_MASK;
676 	*extended = hdr->command & IB_USER_VERBS_CMD_FLAG_EXTENDED;
677 
678 	if (!verify_command_idx(*command, *extended))
679 		return -EOPNOTSUPP;
680 
681 	return 0;
682 }
683 
684 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
685 			  struct ib_uverbs_ex_cmd_hdr *ex_hdr,
686 			  size_t count, bool extended)
687 {
688 	if (extended) {
689 		count -= sizeof(*hdr) + sizeof(*ex_hdr);
690 
691 		if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
692 			return -EINVAL;
693 
694 		if (ex_hdr->cmd_hdr_reserved)
695 			return -EINVAL;
696 
697 		if (ex_hdr->response) {
698 			if (!hdr->out_words && !ex_hdr->provider_out_words)
699 				return -EINVAL;
700 
701 			if (!access_ok(VERIFY_WRITE,
702 				       u64_to_user_ptr(ex_hdr->response),
703 				       (hdr->out_words + ex_hdr->provider_out_words) * 8))
704 				return -EFAULT;
705 		} else {
706 			if (hdr->out_words || ex_hdr->provider_out_words)
707 				return -EINVAL;
708 		}
709 
710 		return 0;
711 	}
712 
713 	/* not extended command */
714 	if (hdr->in_words * 4 != count)
715 		return -EINVAL;
716 
717 	return 0;
718 }
719 
720 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
721 			     size_t count, loff_t *pos)
722 {
723 	struct ib_uverbs_file *file = filp->private_data;
724 	struct ib_uverbs_ex_cmd_hdr ex_hdr;
725 	struct ib_uverbs_cmd_hdr hdr;
726 	bool extended;
727 	int srcu_key;
728 	u32 command;
729 	ssize_t ret;
730 
731 	if (!ib_safe_file_access(filp)) {
732 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
733 			    task_tgid_vnr(current), current->comm);
734 		return -EACCES;
735 	}
736 
737 	if (count < sizeof(hdr))
738 		return -EINVAL;
739 
740 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
741 		return -EFAULT;
742 
743 	ret = process_hdr(&hdr, &command, &extended);
744 	if (ret)
745 		return ret;
746 
747 	if (extended) {
748 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
749 			return -EINVAL;
750 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
751 			return -EFAULT;
752 	}
753 
754 	ret = verify_hdr(&hdr, &ex_hdr, count, extended);
755 	if (ret)
756 		return ret;
757 
758 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
759 
760 	if (!verify_command_mask(file, command, extended)) {
761 		ret = -EOPNOTSUPP;
762 		goto out;
763 	}
764 
765 	buf += sizeof(hdr);
766 
767 	if (!extended) {
768 		ret = uverbs_cmd_table[command](file, buf,
769 						hdr.in_words * 4,
770 						hdr.out_words * 4);
771 	} else {
772 		struct ib_udata ucore;
773 		struct ib_udata uhw;
774 
775 		buf += sizeof(ex_hdr);
776 
777 		ib_uverbs_init_udata_buf_or_null(&ucore, buf,
778 					u64_to_user_ptr(ex_hdr.response),
779 					hdr.in_words * 8, hdr.out_words * 8);
780 
781 		ib_uverbs_init_udata_buf_or_null(&uhw,
782 					buf + ucore.inlen,
783 					u64_to_user_ptr(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, &ucore, &uhw);
788 		ret = (ret) ? : count;
789 	}
790 
791 out:
792 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
793 	return ret;
794 }
795 
796 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
797 {
798 	struct ib_uverbs_file *file = filp->private_data;
799 	struct ib_ucontext *ucontext;
800 	int ret = 0;
801 	int srcu_key;
802 
803 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
804 	ucontext = ib_uverbs_get_ucontext(file);
805 	if (IS_ERR(ucontext)) {
806 		ret = PTR_ERR(ucontext);
807 		goto out;
808 	}
809 
810 	ret = ucontext->device->mmap(ucontext, vma);
811 out:
812 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
813 	return ret;
814 }
815 
816 /*
817  * Each time we map IO memory into user space this keeps track of the mapping.
818  * When the device is hot-unplugged we 'zap' the mmaps in user space to point
819  * to the zero page and allow the hot unplug to proceed.
820  *
821  * This is necessary for cases like PCI physical hot unplug as the actual BAR
822  * memory may vanish after this and access to it from userspace could MCE.
823  *
824  * RDMA drivers supporting disassociation must have their user space designed
825  * to cope in some way with their IO pages going to the zero page.
826  */
827 struct rdma_umap_priv {
828 	struct vm_area_struct *vma;
829 	struct list_head list;
830 };
831 
832 static const struct vm_operations_struct rdma_umap_ops;
833 
834 static void rdma_umap_priv_init(struct rdma_umap_priv *priv,
835 				struct vm_area_struct *vma)
836 {
837 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
838 
839 	priv->vma = vma;
840 	vma->vm_private_data = priv;
841 	vma->vm_ops = &rdma_umap_ops;
842 
843 	mutex_lock(&ufile->umap_lock);
844 	list_add(&priv->list, &ufile->umaps);
845 	mutex_unlock(&ufile->umap_lock);
846 }
847 
848 /*
849  * The VMA has been dup'd, initialize the vm_private_data with a new tracking
850  * struct
851  */
852 static void rdma_umap_open(struct vm_area_struct *vma)
853 {
854 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
855 	struct rdma_umap_priv *opriv = vma->vm_private_data;
856 	struct rdma_umap_priv *priv;
857 
858 	if (!opriv)
859 		return;
860 
861 	/* We are racing with disassociation */
862 	if (!down_read_trylock(&ufile->hw_destroy_rwsem))
863 		goto out_zap;
864 	/*
865 	 * Disassociation already completed, the VMA should already be zapped.
866 	 */
867 	if (!ufile->ucontext)
868 		goto out_unlock;
869 
870 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
871 	if (!priv)
872 		goto out_unlock;
873 	rdma_umap_priv_init(priv, vma);
874 
875 	up_read(&ufile->hw_destroy_rwsem);
876 	return;
877 
878 out_unlock:
879 	up_read(&ufile->hw_destroy_rwsem);
880 out_zap:
881 	/*
882 	 * We can't allow the VMA to be created with the actual IO pages, that
883 	 * would break our API contract, and it can't be stopped at this
884 	 * point, so zap it.
885 	 */
886 	vma->vm_private_data = NULL;
887 	zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
888 }
889 
890 static void rdma_umap_close(struct vm_area_struct *vma)
891 {
892 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
893 	struct rdma_umap_priv *priv = vma->vm_private_data;
894 
895 	if (!priv)
896 		return;
897 
898 	/*
899 	 * The vma holds a reference on the struct file that created it, which
900 	 * in turn means that the ib_uverbs_file is guaranteed to exist at
901 	 * this point.
902 	 */
903 	mutex_lock(&ufile->umap_lock);
904 	list_del(&priv->list);
905 	mutex_unlock(&ufile->umap_lock);
906 	kfree(priv);
907 }
908 
909 static const struct vm_operations_struct rdma_umap_ops = {
910 	.open = rdma_umap_open,
911 	.close = rdma_umap_close,
912 };
913 
914 static struct rdma_umap_priv *rdma_user_mmap_pre(struct ib_ucontext *ucontext,
915 						 struct vm_area_struct *vma,
916 						 unsigned long size)
917 {
918 	struct ib_uverbs_file *ufile = ucontext->ufile;
919 	struct rdma_umap_priv *priv;
920 
921 	if (vma->vm_end - vma->vm_start != size)
922 		return ERR_PTR(-EINVAL);
923 
924 	/* Driver is using this wrong, must be called by ib_uverbs_mmap */
925 	if (WARN_ON(!vma->vm_file ||
926 		    vma->vm_file->private_data != ufile))
927 		return ERR_PTR(-EINVAL);
928 	lockdep_assert_held(&ufile->device->disassociate_srcu);
929 
930 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
931 	if (!priv)
932 		return ERR_PTR(-ENOMEM);
933 	return priv;
934 }
935 
936 /*
937  * Map IO memory into a process. This is to be called by drivers as part of
938  * their mmap() functions if they wish to send something like PCI-E BAR memory
939  * to userspace.
940  */
941 int rdma_user_mmap_io(struct ib_ucontext *ucontext, struct vm_area_struct *vma,
942 		      unsigned long pfn, unsigned long size, pgprot_t prot)
943 {
944 	struct rdma_umap_priv *priv = rdma_user_mmap_pre(ucontext, vma, size);
945 
946 	if (IS_ERR(priv))
947 		return PTR_ERR(priv);
948 
949 	vma->vm_page_prot = prot;
950 	if (io_remap_pfn_range(vma, vma->vm_start, pfn, size, prot)) {
951 		kfree(priv);
952 		return -EAGAIN;
953 	}
954 
955 	rdma_umap_priv_init(priv, vma);
956 	return 0;
957 }
958 EXPORT_SYMBOL(rdma_user_mmap_io);
959 
960 /*
961  * The page case is here for a slightly different reason, the driver expects
962  * to be able to free the page it is sharing to user space when it destroys
963  * its ucontext, which means we need to zap the user space references.
964  *
965  * We could handle this differently by providing an API to allocate a shared
966  * page and then only freeing the shared page when the last ufile is
967  * destroyed.
968  */
969 int rdma_user_mmap_page(struct ib_ucontext *ucontext,
970 			struct vm_area_struct *vma, struct page *page,
971 			unsigned long size)
972 {
973 	struct rdma_umap_priv *priv = rdma_user_mmap_pre(ucontext, vma, size);
974 
975 	if (IS_ERR(priv))
976 		return PTR_ERR(priv);
977 
978 	if (remap_pfn_range(vma, vma->vm_start, page_to_pfn(page), size,
979 			    vma->vm_page_prot)) {
980 		kfree(priv);
981 		return -EAGAIN;
982 	}
983 
984 	rdma_umap_priv_init(priv, vma);
985 	return 0;
986 }
987 EXPORT_SYMBOL(rdma_user_mmap_page);
988 
989 void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
990 {
991 	struct rdma_umap_priv *priv, *next_priv;
992 
993 	lockdep_assert_held(&ufile->hw_destroy_rwsem);
994 
995 	while (1) {
996 		struct mm_struct *mm = NULL;
997 
998 		/* Get an arbitrary mm pointer that hasn't been cleaned yet */
999 		mutex_lock(&ufile->umap_lock);
1000 		if (!list_empty(&ufile->umaps)) {
1001 			mm = list_first_entry(&ufile->umaps,
1002 					      struct rdma_umap_priv, list)
1003 				     ->vma->vm_mm;
1004 			mmget(mm);
1005 		}
1006 		mutex_unlock(&ufile->umap_lock);
1007 		if (!mm)
1008 			return;
1009 
1010 		/*
1011 		 * The umap_lock is nested under mmap_sem since it used within
1012 		 * the vma_ops callbacks, so we have to clean the list one mm
1013 		 * at a time to get the lock ordering right. Typically there
1014 		 * will only be one mm, so no big deal.
1015 		 */
1016 		down_write(&mm->mmap_sem);
1017 		mutex_lock(&ufile->umap_lock);
1018 		list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
1019 					  list) {
1020 			struct vm_area_struct *vma = priv->vma;
1021 
1022 			if (vma->vm_mm != mm)
1023 				continue;
1024 			list_del_init(&priv->list);
1025 
1026 			zap_vma_ptes(vma, vma->vm_start,
1027 				     vma->vm_end - vma->vm_start);
1028 			vma->vm_flags &= ~(VM_SHARED | VM_MAYSHARE);
1029 		}
1030 		mutex_unlock(&ufile->umap_lock);
1031 		up_write(&mm->mmap_sem);
1032 		mmput(mm);
1033 	}
1034 }
1035 
1036 /*
1037  * ib_uverbs_open() does not need the BKL:
1038  *
1039  *  - the ib_uverbs_device structures are properly reference counted and
1040  *    everything else is purely local to the file being created, so
1041  *    races against other open calls are not a problem;
1042  *  - there is no ioctl method to race against;
1043  *  - the open method will either immediately run -ENXIO, or all
1044  *    required initialization will be done.
1045  */
1046 static int ib_uverbs_open(struct inode *inode, struct file *filp)
1047 {
1048 	struct ib_uverbs_device *dev;
1049 	struct ib_uverbs_file *file;
1050 	struct ib_device *ib_dev;
1051 	int ret;
1052 	int module_dependent;
1053 	int srcu_key;
1054 
1055 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
1056 	if (!atomic_inc_not_zero(&dev->refcount))
1057 		return -ENXIO;
1058 
1059 	get_device(&dev->dev);
1060 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1061 	mutex_lock(&dev->lists_mutex);
1062 	ib_dev = srcu_dereference(dev->ib_dev,
1063 				  &dev->disassociate_srcu);
1064 	if (!ib_dev) {
1065 		ret = -EIO;
1066 		goto err;
1067 	}
1068 
1069 	/* In case IB device supports disassociate ucontext, there is no hard
1070 	 * dependency between uverbs device and its low level device.
1071 	 */
1072 	module_dependent = !(ib_dev->disassociate_ucontext);
1073 
1074 	if (module_dependent) {
1075 		if (!try_module_get(ib_dev->owner)) {
1076 			ret = -ENODEV;
1077 			goto err;
1078 		}
1079 	}
1080 
1081 	file = kzalloc(sizeof(*file), GFP_KERNEL);
1082 	if (!file) {
1083 		ret = -ENOMEM;
1084 		if (module_dependent)
1085 			goto err_module;
1086 
1087 		goto err;
1088 	}
1089 
1090 	file->device	 = dev;
1091 	kref_init(&file->ref);
1092 	mutex_init(&file->ucontext_lock);
1093 
1094 	spin_lock_init(&file->uobjects_lock);
1095 	INIT_LIST_HEAD(&file->uobjects);
1096 	init_rwsem(&file->hw_destroy_rwsem);
1097 	mutex_init(&file->umap_lock);
1098 	INIT_LIST_HEAD(&file->umaps);
1099 
1100 	filp->private_data = file;
1101 	list_add_tail(&file->list, &dev->uverbs_file_list);
1102 	mutex_unlock(&dev->lists_mutex);
1103 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1104 
1105 	file->uverbs_cmd_mask = ib_dev->uverbs_cmd_mask;
1106 	file->uverbs_ex_cmd_mask = ib_dev->uverbs_ex_cmd_mask;
1107 
1108 	setup_ufile_idr_uobject(file);
1109 
1110 	return nonseekable_open(inode, filp);
1111 
1112 err_module:
1113 	module_put(ib_dev->owner);
1114 
1115 err:
1116 	mutex_unlock(&dev->lists_mutex);
1117 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1118 	if (atomic_dec_and_test(&dev->refcount))
1119 		ib_uverbs_comp_dev(dev);
1120 
1121 	put_device(&dev->dev);
1122 	return ret;
1123 }
1124 
1125 static int ib_uverbs_close(struct inode *inode, struct file *filp)
1126 {
1127 	struct ib_uverbs_file *file = filp->private_data;
1128 
1129 	uverbs_destroy_ufile_hw(file, RDMA_REMOVE_CLOSE);
1130 
1131 	mutex_lock(&file->device->lists_mutex);
1132 	list_del_init(&file->list);
1133 	mutex_unlock(&file->device->lists_mutex);
1134 
1135 	if (file->async_file)
1136 		kref_put(&file->async_file->ref,
1137 			 ib_uverbs_release_async_event_file);
1138 
1139 	kref_put(&file->ref, ib_uverbs_release_file);
1140 
1141 	return 0;
1142 }
1143 
1144 static const struct file_operations uverbs_fops = {
1145 	.owner	 = THIS_MODULE,
1146 	.write	 = ib_uverbs_write,
1147 	.open	 = ib_uverbs_open,
1148 	.release = ib_uverbs_close,
1149 	.llseek	 = no_llseek,
1150 	.unlocked_ioctl = ib_uverbs_ioctl,
1151 	.compat_ioctl = ib_uverbs_ioctl,
1152 };
1153 
1154 static const struct file_operations uverbs_mmap_fops = {
1155 	.owner	 = THIS_MODULE,
1156 	.write	 = ib_uverbs_write,
1157 	.mmap    = ib_uverbs_mmap,
1158 	.open	 = ib_uverbs_open,
1159 	.release = ib_uverbs_close,
1160 	.llseek	 = no_llseek,
1161 	.unlocked_ioctl = ib_uverbs_ioctl,
1162 	.compat_ioctl = ib_uverbs_ioctl,
1163 };
1164 
1165 static struct ib_client uverbs_client = {
1166 	.name   = "uverbs",
1167 	.add    = ib_uverbs_add_one,
1168 	.remove = ib_uverbs_remove_one
1169 };
1170 
1171 static ssize_t ibdev_show(struct device *device, struct device_attribute *attr,
1172 			  char *buf)
1173 {
1174 	struct ib_uverbs_device *dev =
1175 			container_of(device, struct ib_uverbs_device, dev);
1176 	int ret = -ENODEV;
1177 	int srcu_key;
1178 	struct ib_device *ib_dev;
1179 
1180 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1181 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1182 	if (ib_dev)
1183 		ret = sprintf(buf, "%s\n", dev_name(&ib_dev->dev));
1184 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1185 
1186 	return ret;
1187 }
1188 static DEVICE_ATTR_RO(ibdev);
1189 
1190 static ssize_t abi_version_show(struct device *device,
1191 				struct device_attribute *attr, char *buf)
1192 {
1193 	struct ib_uverbs_device *dev =
1194 			container_of(device, struct ib_uverbs_device, dev);
1195 	int ret = -ENODEV;
1196 	int srcu_key;
1197 	struct ib_device *ib_dev;
1198 
1199 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1200 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1201 	if (ib_dev)
1202 		ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1203 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1204 
1205 	return ret;
1206 }
1207 static DEVICE_ATTR_RO(abi_version);
1208 
1209 static struct attribute *ib_dev_attrs[] = {
1210 	&dev_attr_abi_version.attr,
1211 	&dev_attr_ibdev.attr,
1212 	NULL,
1213 };
1214 
1215 static const struct attribute_group dev_attr_group = {
1216 	.attrs = ib_dev_attrs,
1217 };
1218 
1219 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1220 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1221 
1222 static int ib_uverbs_create_uapi(struct ib_device *device,
1223 				 struct ib_uverbs_device *uverbs_dev)
1224 {
1225 	struct uverbs_api *uapi;
1226 
1227 	uapi = uverbs_alloc_api(device->driver_specs, device->driver_id);
1228 	if (IS_ERR(uapi))
1229 		return PTR_ERR(uapi);
1230 
1231 	uverbs_dev->uapi = uapi;
1232 	return 0;
1233 }
1234 
1235 static void ib_uverbs_add_one(struct ib_device *device)
1236 {
1237 	int devnum;
1238 	dev_t base;
1239 	struct ib_uverbs_device *uverbs_dev;
1240 	int ret;
1241 
1242 	if (!device->alloc_ucontext)
1243 		return;
1244 
1245 	uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1246 	if (!uverbs_dev)
1247 		return;
1248 
1249 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1250 	if (ret) {
1251 		kfree(uverbs_dev);
1252 		return;
1253 	}
1254 
1255 	device_initialize(&uverbs_dev->dev);
1256 	uverbs_dev->dev.class = uverbs_class;
1257 	uverbs_dev->dev.parent = device->dev.parent;
1258 	uverbs_dev->dev.release = ib_uverbs_release_dev;
1259 	uverbs_dev->groups[0] = &dev_attr_group;
1260 	uverbs_dev->dev.groups = uverbs_dev->groups;
1261 	atomic_set(&uverbs_dev->refcount, 1);
1262 	init_completion(&uverbs_dev->comp);
1263 	uverbs_dev->xrcd_tree = RB_ROOT;
1264 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1265 	mutex_init(&uverbs_dev->lists_mutex);
1266 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1267 	INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1268 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1269 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1270 
1271 	devnum = ida_alloc_max(&uverbs_ida, IB_UVERBS_MAX_DEVICES - 1,
1272 			       GFP_KERNEL);
1273 	if (devnum < 0)
1274 		goto err;
1275 	uverbs_dev->devnum = devnum;
1276 	if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1277 		base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1278 	else
1279 		base = IB_UVERBS_BASE_DEV + devnum;
1280 
1281 	if (ib_uverbs_create_uapi(device, uverbs_dev))
1282 		goto err_uapi;
1283 
1284 	uverbs_dev->dev.devt = base;
1285 	dev_set_name(&uverbs_dev->dev, "uverbs%d", uverbs_dev->devnum);
1286 
1287 	cdev_init(&uverbs_dev->cdev,
1288 		  device->mmap ? &uverbs_mmap_fops : &uverbs_fops);
1289 	uverbs_dev->cdev.owner = THIS_MODULE;
1290 
1291 	ret = cdev_device_add(&uverbs_dev->cdev, &uverbs_dev->dev);
1292 	if (ret)
1293 		goto err_uapi;
1294 
1295 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1296 	return;
1297 
1298 err_uapi:
1299 	ida_free(&uverbs_ida, devnum);
1300 err:
1301 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1302 		ib_uverbs_comp_dev(uverbs_dev);
1303 	wait_for_completion(&uverbs_dev->comp);
1304 	put_device(&uverbs_dev->dev);
1305 	return;
1306 }
1307 
1308 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1309 					struct ib_device *ib_dev)
1310 {
1311 	struct ib_uverbs_file *file;
1312 	struct ib_uverbs_async_event_file *event_file;
1313 	struct ib_event event;
1314 
1315 	/* Pending running commands to terminate */
1316 	uverbs_disassociate_api_pre(uverbs_dev);
1317 	event.event = IB_EVENT_DEVICE_FATAL;
1318 	event.element.port_num = 0;
1319 	event.device = ib_dev;
1320 
1321 	mutex_lock(&uverbs_dev->lists_mutex);
1322 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1323 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1324 					struct ib_uverbs_file, list);
1325 		list_del_init(&file->list);
1326 		kref_get(&file->ref);
1327 
1328 		/* We must release the mutex before going ahead and calling
1329 		 * uverbs_cleanup_ufile, as it might end up indirectly calling
1330 		 * uverbs_close, for example due to freeing the resources (e.g
1331 		 * mmput).
1332 		 */
1333 		mutex_unlock(&uverbs_dev->lists_mutex);
1334 
1335 		ib_uverbs_event_handler(&file->event_handler, &event);
1336 		uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
1337 		kref_put(&file->ref, ib_uverbs_release_file);
1338 
1339 		mutex_lock(&uverbs_dev->lists_mutex);
1340 	}
1341 
1342 	while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1343 		event_file = list_first_entry(&uverbs_dev->
1344 					      uverbs_events_file_list,
1345 					      struct ib_uverbs_async_event_file,
1346 					      list);
1347 		spin_lock_irq(&event_file->ev_queue.lock);
1348 		event_file->ev_queue.is_closed = 1;
1349 		spin_unlock_irq(&event_file->ev_queue.lock);
1350 
1351 		list_del(&event_file->list);
1352 		ib_unregister_event_handler(
1353 			&event_file->uverbs_file->event_handler);
1354 		event_file->uverbs_file->event_handler.device =
1355 			NULL;
1356 
1357 		wake_up_interruptible(&event_file->ev_queue.poll_wait);
1358 		kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1359 	}
1360 	mutex_unlock(&uverbs_dev->lists_mutex);
1361 
1362 	uverbs_disassociate_api(uverbs_dev->uapi);
1363 }
1364 
1365 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1366 {
1367 	struct ib_uverbs_device *uverbs_dev = client_data;
1368 	int wait_clients = 1;
1369 
1370 	if (!uverbs_dev)
1371 		return;
1372 
1373 	cdev_device_del(&uverbs_dev->cdev, &uverbs_dev->dev);
1374 	ida_free(&uverbs_ida, uverbs_dev->devnum);
1375 
1376 	if (device->disassociate_ucontext) {
1377 		/* We disassociate HW resources and immediately return.
1378 		 * Userspace will see a EIO errno for all future access.
1379 		 * Upon returning, ib_device may be freed internally and is not
1380 		 * valid any more.
1381 		 * uverbs_device is still available until all clients close
1382 		 * their files, then the uverbs device ref count will be zero
1383 		 * and its resources will be freed.
1384 		 * Note: At this point no more files can be opened since the
1385 		 * cdev was deleted, however active clients can still issue
1386 		 * commands and close their open files.
1387 		 */
1388 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1389 		wait_clients = 0;
1390 	}
1391 
1392 	if (atomic_dec_and_test(&uverbs_dev->refcount))
1393 		ib_uverbs_comp_dev(uverbs_dev);
1394 	if (wait_clients)
1395 		wait_for_completion(&uverbs_dev->comp);
1396 
1397 	put_device(&uverbs_dev->dev);
1398 }
1399 
1400 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1401 {
1402 	if (mode)
1403 		*mode = 0666;
1404 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1405 }
1406 
1407 static int __init ib_uverbs_init(void)
1408 {
1409 	int ret;
1410 
1411 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1412 				     IB_UVERBS_NUM_FIXED_MINOR,
1413 				     "infiniband_verbs");
1414 	if (ret) {
1415 		pr_err("user_verbs: couldn't register device number\n");
1416 		goto out;
1417 	}
1418 
1419 	ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1420 				  IB_UVERBS_NUM_DYNAMIC_MINOR,
1421 				  "infiniband_verbs");
1422 	if (ret) {
1423 		pr_err("couldn't register dynamic device number\n");
1424 		goto out_alloc;
1425 	}
1426 
1427 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1428 	if (IS_ERR(uverbs_class)) {
1429 		ret = PTR_ERR(uverbs_class);
1430 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1431 		goto out_chrdev;
1432 	}
1433 
1434 	uverbs_class->devnode = uverbs_devnode;
1435 
1436 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1437 	if (ret) {
1438 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1439 		goto out_class;
1440 	}
1441 
1442 	ret = ib_register_client(&uverbs_client);
1443 	if (ret) {
1444 		pr_err("user_verbs: couldn't register client\n");
1445 		goto out_class;
1446 	}
1447 
1448 	return 0;
1449 
1450 out_class:
1451 	class_destroy(uverbs_class);
1452 
1453 out_chrdev:
1454 	unregister_chrdev_region(dynamic_uverbs_dev,
1455 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1456 
1457 out_alloc:
1458 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1459 				 IB_UVERBS_NUM_FIXED_MINOR);
1460 
1461 out:
1462 	return ret;
1463 }
1464 
1465 static void __exit ib_uverbs_cleanup(void)
1466 {
1467 	ib_unregister_client(&uverbs_client);
1468 	class_destroy(uverbs_class);
1469 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1470 				 IB_UVERBS_NUM_FIXED_MINOR);
1471 	unregister_chrdev_region(dynamic_uverbs_dev,
1472 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1473 }
1474 
1475 module_init(ib_uverbs_init);
1476 module_exit(ib_uverbs_cleanup);
1477