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 "uverbs.h"
52 
53 MODULE_AUTHOR("Roland Dreier");
54 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
55 MODULE_LICENSE("Dual BSD/GPL");
56 
57 enum {
58 	IB_UVERBS_MAJOR       = 231,
59 	IB_UVERBS_BASE_MINOR  = 192,
60 	IB_UVERBS_MAX_DEVICES = 32
61 };
62 
63 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
64 
65 static struct class *uverbs_class;
66 
67 DEFINE_SPINLOCK(ib_uverbs_idr_lock);
68 DEFINE_IDR(ib_uverbs_pd_idr);
69 DEFINE_IDR(ib_uverbs_mr_idr);
70 DEFINE_IDR(ib_uverbs_mw_idr);
71 DEFINE_IDR(ib_uverbs_ah_idr);
72 DEFINE_IDR(ib_uverbs_cq_idr);
73 DEFINE_IDR(ib_uverbs_qp_idr);
74 DEFINE_IDR(ib_uverbs_srq_idr);
75 DEFINE_IDR(ib_uverbs_xrcd_idr);
76 DEFINE_IDR(ib_uverbs_rule_idr);
77 
78 static DEFINE_SPINLOCK(map_lock);
79 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
80 
81 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
82 				     const char __user *buf, int in_len,
83 				     int out_len) = {
84 	[IB_USER_VERBS_CMD_GET_CONTEXT]		= ib_uverbs_get_context,
85 	[IB_USER_VERBS_CMD_QUERY_DEVICE]	= ib_uverbs_query_device,
86 	[IB_USER_VERBS_CMD_QUERY_PORT]		= ib_uverbs_query_port,
87 	[IB_USER_VERBS_CMD_ALLOC_PD]		= ib_uverbs_alloc_pd,
88 	[IB_USER_VERBS_CMD_DEALLOC_PD]		= ib_uverbs_dealloc_pd,
89 	[IB_USER_VERBS_CMD_REG_MR]		= ib_uverbs_reg_mr,
90 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
91 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
92 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
93 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
94 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
95 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
96 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
97 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
98 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
99 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
100 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
101 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
102 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
103 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
104 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
105 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
106 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
107 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
108 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
109 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
110 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
111 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
112 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
113 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
114 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
115 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
116 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
117 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
118 };
119 
120 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
121 				    struct ib_udata *ucore,
122 				    struct ib_udata *uhw) = {
123 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
124 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow
125 };
126 
127 static void ib_uverbs_add_one(struct ib_device *device);
128 static void ib_uverbs_remove_one(struct ib_device *device);
129 
130 static void ib_uverbs_release_dev(struct kref *ref)
131 {
132 	struct ib_uverbs_device *dev =
133 		container_of(ref, struct ib_uverbs_device, ref);
134 
135 	complete(&dev->comp);
136 }
137 
138 static void ib_uverbs_release_event_file(struct kref *ref)
139 {
140 	struct ib_uverbs_event_file *file =
141 		container_of(ref, struct ib_uverbs_event_file, ref);
142 
143 	kfree(file);
144 }
145 
146 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
147 			  struct ib_uverbs_event_file *ev_file,
148 			  struct ib_ucq_object *uobj)
149 {
150 	struct ib_uverbs_event *evt, *tmp;
151 
152 	if (ev_file) {
153 		spin_lock_irq(&ev_file->lock);
154 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
155 			list_del(&evt->list);
156 			kfree(evt);
157 		}
158 		spin_unlock_irq(&ev_file->lock);
159 
160 		kref_put(&ev_file->ref, ib_uverbs_release_event_file);
161 	}
162 
163 	spin_lock_irq(&file->async_file->lock);
164 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
165 		list_del(&evt->list);
166 		kfree(evt);
167 	}
168 	spin_unlock_irq(&file->async_file->lock);
169 }
170 
171 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
172 			      struct ib_uevent_object *uobj)
173 {
174 	struct ib_uverbs_event *evt, *tmp;
175 
176 	spin_lock_irq(&file->async_file->lock);
177 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
178 		list_del(&evt->list);
179 		kfree(evt);
180 	}
181 	spin_unlock_irq(&file->async_file->lock);
182 }
183 
184 static void ib_uverbs_detach_umcast(struct ib_qp *qp,
185 				    struct ib_uqp_object *uobj)
186 {
187 	struct ib_uverbs_mcast_entry *mcast, *tmp;
188 
189 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
190 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
191 		list_del(&mcast->list);
192 		kfree(mcast);
193 	}
194 }
195 
196 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
197 				      struct ib_ucontext *context)
198 {
199 	struct ib_uobject *uobj, *tmp;
200 
201 	if (!context)
202 		return 0;
203 
204 	context->closing = 1;
205 
206 	list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
207 		struct ib_ah *ah = uobj->object;
208 
209 		idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
210 		ib_destroy_ah(ah);
211 		kfree(uobj);
212 	}
213 
214 	/* Remove MWs before QPs, in order to support type 2A MWs. */
215 	list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
216 		struct ib_mw *mw = uobj->object;
217 
218 		idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
219 		ib_dealloc_mw(mw);
220 		kfree(uobj);
221 	}
222 
223 	list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
224 		struct ib_flow *flow_id = uobj->object;
225 
226 		idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
227 		ib_destroy_flow(flow_id);
228 		kfree(uobj);
229 	}
230 
231 	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
232 		struct ib_qp *qp = uobj->object;
233 		struct ib_uqp_object *uqp =
234 			container_of(uobj, struct ib_uqp_object, uevent.uobject);
235 
236 		idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
237 		if (qp != qp->real_qp) {
238 			ib_close_qp(qp);
239 		} else {
240 			ib_uverbs_detach_umcast(qp, uqp);
241 			ib_destroy_qp(qp);
242 		}
243 		ib_uverbs_release_uevent(file, &uqp->uevent);
244 		kfree(uqp);
245 	}
246 
247 	list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
248 		struct ib_cq *cq = uobj->object;
249 		struct ib_uverbs_event_file *ev_file = cq->cq_context;
250 		struct ib_ucq_object *ucq =
251 			container_of(uobj, struct ib_ucq_object, uobject);
252 
253 		idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
254 		ib_destroy_cq(cq);
255 		ib_uverbs_release_ucq(file, ev_file, ucq);
256 		kfree(ucq);
257 	}
258 
259 	list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
260 		struct ib_srq *srq = uobj->object;
261 		struct ib_uevent_object *uevent =
262 			container_of(uobj, struct ib_uevent_object, uobject);
263 
264 		idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
265 		ib_destroy_srq(srq);
266 		ib_uverbs_release_uevent(file, uevent);
267 		kfree(uevent);
268 	}
269 
270 	list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
271 		struct ib_mr *mr = uobj->object;
272 
273 		idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
274 		ib_dereg_mr(mr);
275 		kfree(uobj);
276 	}
277 
278 	mutex_lock(&file->device->xrcd_tree_mutex);
279 	list_for_each_entry_safe(uobj, tmp, &context->xrcd_list, list) {
280 		struct ib_xrcd *xrcd = uobj->object;
281 		struct ib_uxrcd_object *uxrcd =
282 			container_of(uobj, struct ib_uxrcd_object, uobject);
283 
284 		idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
285 		ib_uverbs_dealloc_xrcd(file->device, xrcd);
286 		kfree(uxrcd);
287 	}
288 	mutex_unlock(&file->device->xrcd_tree_mutex);
289 
290 	list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
291 		struct ib_pd *pd = uobj->object;
292 
293 		idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
294 		ib_dealloc_pd(pd);
295 		kfree(uobj);
296 	}
297 
298 	return context->device->dealloc_ucontext(context);
299 }
300 
301 static void ib_uverbs_release_file(struct kref *ref)
302 {
303 	struct ib_uverbs_file *file =
304 		container_of(ref, struct ib_uverbs_file, ref);
305 
306 	module_put(file->device->ib_dev->owner);
307 	kref_put(&file->device->ref, ib_uverbs_release_dev);
308 
309 	kfree(file);
310 }
311 
312 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
313 				    size_t count, loff_t *pos)
314 {
315 	struct ib_uverbs_event_file *file = filp->private_data;
316 	struct ib_uverbs_event *event;
317 	int eventsz;
318 	int ret = 0;
319 
320 	spin_lock_irq(&file->lock);
321 
322 	while (list_empty(&file->event_list)) {
323 		spin_unlock_irq(&file->lock);
324 
325 		if (filp->f_flags & O_NONBLOCK)
326 			return -EAGAIN;
327 
328 		if (wait_event_interruptible(file->poll_wait,
329 					     !list_empty(&file->event_list)))
330 			return -ERESTARTSYS;
331 
332 		spin_lock_irq(&file->lock);
333 	}
334 
335 	event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
336 
337 	if (file->is_async)
338 		eventsz = sizeof (struct ib_uverbs_async_event_desc);
339 	else
340 		eventsz = sizeof (struct ib_uverbs_comp_event_desc);
341 
342 	if (eventsz > count) {
343 		ret   = -EINVAL;
344 		event = NULL;
345 	} else {
346 		list_del(file->event_list.next);
347 		if (event->counter) {
348 			++(*event->counter);
349 			list_del(&event->obj_list);
350 		}
351 	}
352 
353 	spin_unlock_irq(&file->lock);
354 
355 	if (event) {
356 		if (copy_to_user(buf, event, eventsz))
357 			ret = -EFAULT;
358 		else
359 			ret = eventsz;
360 	}
361 
362 	kfree(event);
363 
364 	return ret;
365 }
366 
367 static unsigned int ib_uverbs_event_poll(struct file *filp,
368 					 struct poll_table_struct *wait)
369 {
370 	unsigned int pollflags = 0;
371 	struct ib_uverbs_event_file *file = filp->private_data;
372 
373 	poll_wait(filp, &file->poll_wait, wait);
374 
375 	spin_lock_irq(&file->lock);
376 	if (!list_empty(&file->event_list))
377 		pollflags = POLLIN | POLLRDNORM;
378 	spin_unlock_irq(&file->lock);
379 
380 	return pollflags;
381 }
382 
383 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
384 {
385 	struct ib_uverbs_event_file *file = filp->private_data;
386 
387 	return fasync_helper(fd, filp, on, &file->async_queue);
388 }
389 
390 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
391 {
392 	struct ib_uverbs_event_file *file = filp->private_data;
393 	struct ib_uverbs_event *entry, *tmp;
394 
395 	spin_lock_irq(&file->lock);
396 	file->is_closed = 1;
397 	list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
398 		if (entry->counter)
399 			list_del(&entry->obj_list);
400 		kfree(entry);
401 	}
402 	spin_unlock_irq(&file->lock);
403 
404 	if (file->is_async) {
405 		ib_unregister_event_handler(&file->uverbs_file->event_handler);
406 		kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
407 	}
408 	kref_put(&file->ref, ib_uverbs_release_event_file);
409 
410 	return 0;
411 }
412 
413 static const struct file_operations uverbs_event_fops = {
414 	.owner	 = THIS_MODULE,
415 	.read	 = ib_uverbs_event_read,
416 	.poll    = ib_uverbs_event_poll,
417 	.release = ib_uverbs_event_close,
418 	.fasync  = ib_uverbs_event_fasync,
419 	.llseek	 = no_llseek,
420 };
421 
422 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
423 {
424 	struct ib_uverbs_event_file    *file = cq_context;
425 	struct ib_ucq_object	       *uobj;
426 	struct ib_uverbs_event	       *entry;
427 	unsigned long			flags;
428 
429 	if (!file)
430 		return;
431 
432 	spin_lock_irqsave(&file->lock, flags);
433 	if (file->is_closed) {
434 		spin_unlock_irqrestore(&file->lock, flags);
435 		return;
436 	}
437 
438 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
439 	if (!entry) {
440 		spin_unlock_irqrestore(&file->lock, flags);
441 		return;
442 	}
443 
444 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
445 
446 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
447 	entry->counter		   = &uobj->comp_events_reported;
448 
449 	list_add_tail(&entry->list, &file->event_list);
450 	list_add_tail(&entry->obj_list, &uobj->comp_list);
451 	spin_unlock_irqrestore(&file->lock, flags);
452 
453 	wake_up_interruptible(&file->poll_wait);
454 	kill_fasync(&file->async_queue, SIGIO, POLL_IN);
455 }
456 
457 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
458 				    __u64 element, __u64 event,
459 				    struct list_head *obj_list,
460 				    u32 *counter)
461 {
462 	struct ib_uverbs_event *entry;
463 	unsigned long flags;
464 
465 	spin_lock_irqsave(&file->async_file->lock, flags);
466 	if (file->async_file->is_closed) {
467 		spin_unlock_irqrestore(&file->async_file->lock, flags);
468 		return;
469 	}
470 
471 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
472 	if (!entry) {
473 		spin_unlock_irqrestore(&file->async_file->lock, flags);
474 		return;
475 	}
476 
477 	entry->desc.async.element    = element;
478 	entry->desc.async.event_type = event;
479 	entry->counter               = counter;
480 
481 	list_add_tail(&entry->list, &file->async_file->event_list);
482 	if (obj_list)
483 		list_add_tail(&entry->obj_list, obj_list);
484 	spin_unlock_irqrestore(&file->async_file->lock, flags);
485 
486 	wake_up_interruptible(&file->async_file->poll_wait);
487 	kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
488 }
489 
490 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
491 {
492 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
493 						  struct ib_ucq_object, uobject);
494 
495 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
496 				event->event, &uobj->async_list,
497 				&uobj->async_events_reported);
498 }
499 
500 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
501 {
502 	struct ib_uevent_object *uobj;
503 
504 	uobj = container_of(event->element.qp->uobject,
505 			    struct ib_uevent_object, uobject);
506 
507 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
508 				event->event, &uobj->event_list,
509 				&uobj->events_reported);
510 }
511 
512 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
513 {
514 	struct ib_uevent_object *uobj;
515 
516 	uobj = container_of(event->element.srq->uobject,
517 			    struct ib_uevent_object, uobject);
518 
519 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
520 				event->event, &uobj->event_list,
521 				&uobj->events_reported);
522 }
523 
524 void ib_uverbs_event_handler(struct ib_event_handler *handler,
525 			     struct ib_event *event)
526 {
527 	struct ib_uverbs_file *file =
528 		container_of(handler, struct ib_uverbs_file, event_handler);
529 
530 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
531 				NULL, NULL);
532 }
533 
534 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
535 					int is_async)
536 {
537 	struct ib_uverbs_event_file *ev_file;
538 	struct file *filp;
539 
540 	ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL);
541 	if (!ev_file)
542 		return ERR_PTR(-ENOMEM);
543 
544 	kref_init(&ev_file->ref);
545 	spin_lock_init(&ev_file->lock);
546 	INIT_LIST_HEAD(&ev_file->event_list);
547 	init_waitqueue_head(&ev_file->poll_wait);
548 	ev_file->uverbs_file = uverbs_file;
549 	ev_file->async_queue = NULL;
550 	ev_file->is_async    = is_async;
551 	ev_file->is_closed   = 0;
552 
553 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
554 				  ev_file, O_RDONLY);
555 	if (IS_ERR(filp))
556 		kfree(ev_file);
557 
558 	return filp;
559 }
560 
561 /*
562  * Look up a completion event file by FD.  If lookup is successful,
563  * takes a ref to the event file struct that it returns; if
564  * unsuccessful, returns NULL.
565  */
566 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
567 {
568 	struct ib_uverbs_event_file *ev_file = NULL;
569 	struct fd f = fdget(fd);
570 
571 	if (!f.file)
572 		return NULL;
573 
574 	if (f.file->f_op != &uverbs_event_fops)
575 		goto out;
576 
577 	ev_file = f.file->private_data;
578 	if (ev_file->is_async) {
579 		ev_file = NULL;
580 		goto out;
581 	}
582 
583 	kref_get(&ev_file->ref);
584 
585 out:
586 	fdput(f);
587 	return ev_file;
588 }
589 
590 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
591 			     size_t count, loff_t *pos)
592 {
593 	struct ib_uverbs_file *file = filp->private_data;
594 	struct ib_uverbs_cmd_hdr hdr;
595 	__u32 flags;
596 
597 	if (count < sizeof hdr)
598 		return -EINVAL;
599 
600 	if (copy_from_user(&hdr, buf, sizeof hdr))
601 		return -EFAULT;
602 
603 	flags = (hdr.command &
604 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
605 
606 	if (!flags) {
607 		__u32 command;
608 
609 		if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
610 					   IB_USER_VERBS_CMD_COMMAND_MASK))
611 			return -EINVAL;
612 
613 		command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
614 
615 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
616 		    !uverbs_cmd_table[command])
617 			return -EINVAL;
618 
619 		if (!file->ucontext &&
620 		    command != IB_USER_VERBS_CMD_GET_CONTEXT)
621 			return -EINVAL;
622 
623 		if (!(file->device->ib_dev->uverbs_cmd_mask & (1ull << command)))
624 			return -ENOSYS;
625 
626 		if (hdr.in_words * 4 != count)
627 			return -EINVAL;
628 
629 		return uverbs_cmd_table[command](file,
630 						 buf + sizeof(hdr),
631 						 hdr.in_words * 4,
632 						 hdr.out_words * 4);
633 
634 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
635 		__u32 command;
636 
637 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
638 		struct ib_udata ucore;
639 		struct ib_udata uhw;
640 		int err;
641 		size_t written_count = count;
642 
643 		if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
644 					   IB_USER_VERBS_CMD_COMMAND_MASK))
645 			return -EINVAL;
646 
647 		command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
648 
649 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
650 		    !uverbs_ex_cmd_table[command])
651 			return -ENOSYS;
652 
653 		if (!file->ucontext)
654 			return -EINVAL;
655 
656 		if (!(file->device->ib_dev->uverbs_ex_cmd_mask & (1ull << command)))
657 			return -ENOSYS;
658 
659 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
660 			return -EINVAL;
661 
662 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
663 			return -EFAULT;
664 
665 		count -= sizeof(hdr) + sizeof(ex_hdr);
666 		buf += sizeof(hdr) + sizeof(ex_hdr);
667 
668 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count)
669 			return -EINVAL;
670 
671 		if (ex_hdr.cmd_hdr_reserved)
672 			return -EINVAL;
673 
674 		if (ex_hdr.response) {
675 			if (!hdr.out_words && !ex_hdr.provider_out_words)
676 				return -EINVAL;
677 
678 			if (!access_ok(VERIFY_WRITE,
679 				       (void __user *) (unsigned long) ex_hdr.response,
680 				       (hdr.out_words + ex_hdr.provider_out_words) * 8))
681 				return -EFAULT;
682 		} else {
683 			if (hdr.out_words || ex_hdr.provider_out_words)
684 				return -EINVAL;
685 		}
686 
687 		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
688 				       hdr.in_words * 8, hdr.out_words * 8);
689 
690 		INIT_UDATA_BUF_OR_NULL(&uhw,
691 				       buf + ucore.inlen,
692 				       (unsigned long) ex_hdr.response + ucore.outlen,
693 				       ex_hdr.provider_in_words * 8,
694 				       ex_hdr.provider_out_words * 8);
695 
696 		err = uverbs_ex_cmd_table[command](file,
697 						   &ucore,
698 						   &uhw);
699 
700 		if (err)
701 			return err;
702 
703 		return written_count;
704 	}
705 
706 	return -ENOSYS;
707 }
708 
709 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
710 {
711 	struct ib_uverbs_file *file = filp->private_data;
712 
713 	if (!file->ucontext)
714 		return -ENODEV;
715 	else
716 		return file->device->ib_dev->mmap(file->ucontext, vma);
717 }
718 
719 /*
720  * ib_uverbs_open() does not need the BKL:
721  *
722  *  - the ib_uverbs_device structures are properly reference counted and
723  *    everything else is purely local to the file being created, so
724  *    races against other open calls are not a problem;
725  *  - there is no ioctl method to race against;
726  *  - the open method will either immediately run -ENXIO, or all
727  *    required initialization will be done.
728  */
729 static int ib_uverbs_open(struct inode *inode, struct file *filp)
730 {
731 	struct ib_uverbs_device *dev;
732 	struct ib_uverbs_file *file;
733 	int ret;
734 
735 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
736 	if (dev)
737 		kref_get(&dev->ref);
738 	else
739 		return -ENXIO;
740 
741 	if (!try_module_get(dev->ib_dev->owner)) {
742 		ret = -ENODEV;
743 		goto err;
744 	}
745 
746 	file = kmalloc(sizeof *file, GFP_KERNEL);
747 	if (!file) {
748 		ret = -ENOMEM;
749 		goto err_module;
750 	}
751 
752 	file->device	 = dev;
753 	file->ucontext	 = NULL;
754 	file->async_file = NULL;
755 	kref_init(&file->ref);
756 	mutex_init(&file->mutex);
757 
758 	filp->private_data = file;
759 
760 	return nonseekable_open(inode, filp);
761 
762 err_module:
763 	module_put(dev->ib_dev->owner);
764 
765 err:
766 	kref_put(&dev->ref, ib_uverbs_release_dev);
767 	return ret;
768 }
769 
770 static int ib_uverbs_close(struct inode *inode, struct file *filp)
771 {
772 	struct ib_uverbs_file *file = filp->private_data;
773 
774 	ib_uverbs_cleanup_ucontext(file, file->ucontext);
775 
776 	if (file->async_file)
777 		kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
778 
779 	kref_put(&file->ref, ib_uverbs_release_file);
780 
781 	return 0;
782 }
783 
784 static const struct file_operations uverbs_fops = {
785 	.owner	 = THIS_MODULE,
786 	.write	 = ib_uverbs_write,
787 	.open	 = ib_uverbs_open,
788 	.release = ib_uverbs_close,
789 	.llseek	 = no_llseek,
790 };
791 
792 static const struct file_operations uverbs_mmap_fops = {
793 	.owner	 = THIS_MODULE,
794 	.write	 = ib_uverbs_write,
795 	.mmap    = ib_uverbs_mmap,
796 	.open	 = ib_uverbs_open,
797 	.release = ib_uverbs_close,
798 	.llseek	 = no_llseek,
799 };
800 
801 static struct ib_client uverbs_client = {
802 	.name   = "uverbs",
803 	.add    = ib_uverbs_add_one,
804 	.remove = ib_uverbs_remove_one
805 };
806 
807 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
808 			  char *buf)
809 {
810 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
811 
812 	if (!dev)
813 		return -ENODEV;
814 
815 	return sprintf(buf, "%s\n", dev->ib_dev->name);
816 }
817 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
818 
819 static ssize_t show_dev_abi_version(struct device *device,
820 				    struct device_attribute *attr, char *buf)
821 {
822 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
823 
824 	if (!dev)
825 		return -ENODEV;
826 
827 	return sprintf(buf, "%d\n", dev->ib_dev->uverbs_abi_ver);
828 }
829 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
830 
831 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
832 			 __stringify(IB_USER_VERBS_ABI_VERSION));
833 
834 static dev_t overflow_maj;
835 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
836 
837 /*
838  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
839  * requesting a new major number and doubling the number of max devices we
840  * support. It's stupid, but simple.
841  */
842 static int find_overflow_devnum(void)
843 {
844 	int ret;
845 
846 	if (!overflow_maj) {
847 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
848 					  "infiniband_verbs");
849 		if (ret) {
850 			printk(KERN_ERR "user_verbs: couldn't register dynamic device number\n");
851 			return ret;
852 		}
853 	}
854 
855 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
856 	if (ret >= IB_UVERBS_MAX_DEVICES)
857 		return -1;
858 
859 	return ret;
860 }
861 
862 static void ib_uverbs_add_one(struct ib_device *device)
863 {
864 	int devnum;
865 	dev_t base;
866 	struct ib_uverbs_device *uverbs_dev;
867 
868 	if (!device->alloc_ucontext)
869 		return;
870 
871 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
872 	if (!uverbs_dev)
873 		return;
874 
875 	kref_init(&uverbs_dev->ref);
876 	init_completion(&uverbs_dev->comp);
877 	uverbs_dev->xrcd_tree = RB_ROOT;
878 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
879 
880 	spin_lock(&map_lock);
881 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
882 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
883 		spin_unlock(&map_lock);
884 		devnum = find_overflow_devnum();
885 		if (devnum < 0)
886 			goto err;
887 
888 		spin_lock(&map_lock);
889 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
890 		base = devnum + overflow_maj;
891 		set_bit(devnum, overflow_map);
892 	} else {
893 		uverbs_dev->devnum = devnum;
894 		base = devnum + IB_UVERBS_BASE_DEV;
895 		set_bit(devnum, dev_map);
896 	}
897 	spin_unlock(&map_lock);
898 
899 	uverbs_dev->ib_dev           = device;
900 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
901 
902 	cdev_init(&uverbs_dev->cdev, NULL);
903 	uverbs_dev->cdev.owner = THIS_MODULE;
904 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
905 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
906 	if (cdev_add(&uverbs_dev->cdev, base, 1))
907 		goto err_cdev;
908 
909 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
910 					uverbs_dev->cdev.dev, uverbs_dev,
911 					"uverbs%d", uverbs_dev->devnum);
912 	if (IS_ERR(uverbs_dev->dev))
913 		goto err_cdev;
914 
915 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
916 		goto err_class;
917 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
918 		goto err_class;
919 
920 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
921 
922 	return;
923 
924 err_class:
925 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
926 
927 err_cdev:
928 	cdev_del(&uverbs_dev->cdev);
929 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
930 		clear_bit(devnum, dev_map);
931 	else
932 		clear_bit(devnum, overflow_map);
933 
934 err:
935 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
936 	wait_for_completion(&uverbs_dev->comp);
937 	kfree(uverbs_dev);
938 	return;
939 }
940 
941 static void ib_uverbs_remove_one(struct ib_device *device)
942 {
943 	struct ib_uverbs_device *uverbs_dev = ib_get_client_data(device, &uverbs_client);
944 
945 	if (!uverbs_dev)
946 		return;
947 
948 	dev_set_drvdata(uverbs_dev->dev, NULL);
949 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
950 	cdev_del(&uverbs_dev->cdev);
951 
952 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
953 		clear_bit(uverbs_dev->devnum, dev_map);
954 	else
955 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
956 
957 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
958 	wait_for_completion(&uverbs_dev->comp);
959 	kfree(uverbs_dev);
960 }
961 
962 static char *uverbs_devnode(struct device *dev, umode_t *mode)
963 {
964 	if (mode)
965 		*mode = 0666;
966 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
967 }
968 
969 static int __init ib_uverbs_init(void)
970 {
971 	int ret;
972 
973 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
974 				     "infiniband_verbs");
975 	if (ret) {
976 		printk(KERN_ERR "user_verbs: couldn't register device number\n");
977 		goto out;
978 	}
979 
980 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
981 	if (IS_ERR(uverbs_class)) {
982 		ret = PTR_ERR(uverbs_class);
983 		printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
984 		goto out_chrdev;
985 	}
986 
987 	uverbs_class->devnode = uverbs_devnode;
988 
989 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
990 	if (ret) {
991 		printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
992 		goto out_class;
993 	}
994 
995 	ret = ib_register_client(&uverbs_client);
996 	if (ret) {
997 		printk(KERN_ERR "user_verbs: couldn't register client\n");
998 		goto out_class;
999 	}
1000 
1001 	return 0;
1002 
1003 out_class:
1004 	class_destroy(uverbs_class);
1005 
1006 out_chrdev:
1007 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1008 
1009 out:
1010 	return ret;
1011 }
1012 
1013 static void __exit ib_uverbs_cleanup(void)
1014 {
1015 	ib_unregister_client(&uverbs_client);
1016 	class_destroy(uverbs_class);
1017 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1018 	if (overflow_maj)
1019 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1020 	idr_destroy(&ib_uverbs_pd_idr);
1021 	idr_destroy(&ib_uverbs_mr_idr);
1022 	idr_destroy(&ib_uverbs_mw_idr);
1023 	idr_destroy(&ib_uverbs_ah_idr);
1024 	idr_destroy(&ib_uverbs_cq_idr);
1025 	idr_destroy(&ib_uverbs_qp_idr);
1026 	idr_destroy(&ib_uverbs_srq_idr);
1027 }
1028 
1029 module_init(ib_uverbs_init);
1030 module_exit(ib_uverbs_cleanup);
1031