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_REREG_MR]		= ib_uverbs_rereg_mr,
91 	[IB_USER_VERBS_CMD_DEREG_MR]		= ib_uverbs_dereg_mr,
92 	[IB_USER_VERBS_CMD_ALLOC_MW]		= ib_uverbs_alloc_mw,
93 	[IB_USER_VERBS_CMD_DEALLOC_MW]		= ib_uverbs_dealloc_mw,
94 	[IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
95 	[IB_USER_VERBS_CMD_CREATE_CQ]		= ib_uverbs_create_cq,
96 	[IB_USER_VERBS_CMD_RESIZE_CQ]		= ib_uverbs_resize_cq,
97 	[IB_USER_VERBS_CMD_POLL_CQ]		= ib_uverbs_poll_cq,
98 	[IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]	= ib_uverbs_req_notify_cq,
99 	[IB_USER_VERBS_CMD_DESTROY_CQ]		= ib_uverbs_destroy_cq,
100 	[IB_USER_VERBS_CMD_CREATE_QP]		= ib_uverbs_create_qp,
101 	[IB_USER_VERBS_CMD_QUERY_QP]		= ib_uverbs_query_qp,
102 	[IB_USER_VERBS_CMD_MODIFY_QP]		= ib_uverbs_modify_qp,
103 	[IB_USER_VERBS_CMD_DESTROY_QP]		= ib_uverbs_destroy_qp,
104 	[IB_USER_VERBS_CMD_POST_SEND]		= ib_uverbs_post_send,
105 	[IB_USER_VERBS_CMD_POST_RECV]		= ib_uverbs_post_recv,
106 	[IB_USER_VERBS_CMD_POST_SRQ_RECV]	= ib_uverbs_post_srq_recv,
107 	[IB_USER_VERBS_CMD_CREATE_AH]		= ib_uverbs_create_ah,
108 	[IB_USER_VERBS_CMD_DESTROY_AH]		= ib_uverbs_destroy_ah,
109 	[IB_USER_VERBS_CMD_ATTACH_MCAST]	= ib_uverbs_attach_mcast,
110 	[IB_USER_VERBS_CMD_DETACH_MCAST]	= ib_uverbs_detach_mcast,
111 	[IB_USER_VERBS_CMD_CREATE_SRQ]		= ib_uverbs_create_srq,
112 	[IB_USER_VERBS_CMD_MODIFY_SRQ]		= ib_uverbs_modify_srq,
113 	[IB_USER_VERBS_CMD_QUERY_SRQ]		= ib_uverbs_query_srq,
114 	[IB_USER_VERBS_CMD_DESTROY_SRQ]		= ib_uverbs_destroy_srq,
115 	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
116 	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
117 	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
118 	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
119 };
120 
121 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
122 				    struct ib_udata *ucore,
123 				    struct ib_udata *uhw) = {
124 	[IB_USER_VERBS_EX_CMD_CREATE_FLOW]	= ib_uverbs_ex_create_flow,
125 	[IB_USER_VERBS_EX_CMD_DESTROY_FLOW]	= ib_uverbs_ex_destroy_flow
126 };
127 
128 static void ib_uverbs_add_one(struct ib_device *device);
129 static void ib_uverbs_remove_one(struct ib_device *device);
130 
131 static void ib_uverbs_release_dev(struct kref *ref)
132 {
133 	struct ib_uverbs_device *dev =
134 		container_of(ref, struct ib_uverbs_device, ref);
135 
136 	complete(&dev->comp);
137 }
138 
139 static void ib_uverbs_release_event_file(struct kref *ref)
140 {
141 	struct ib_uverbs_event_file *file =
142 		container_of(ref, struct ib_uverbs_event_file, ref);
143 
144 	kfree(file);
145 }
146 
147 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
148 			  struct ib_uverbs_event_file *ev_file,
149 			  struct ib_ucq_object *uobj)
150 {
151 	struct ib_uverbs_event *evt, *tmp;
152 
153 	if (ev_file) {
154 		spin_lock_irq(&ev_file->lock);
155 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
156 			list_del(&evt->list);
157 			kfree(evt);
158 		}
159 		spin_unlock_irq(&ev_file->lock);
160 
161 		kref_put(&ev_file->ref, ib_uverbs_release_event_file);
162 	}
163 
164 	spin_lock_irq(&file->async_file->lock);
165 	list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
166 		list_del(&evt->list);
167 		kfree(evt);
168 	}
169 	spin_unlock_irq(&file->async_file->lock);
170 }
171 
172 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
173 			      struct ib_uevent_object *uobj)
174 {
175 	struct ib_uverbs_event *evt, *tmp;
176 
177 	spin_lock_irq(&file->async_file->lock);
178 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
179 		list_del(&evt->list);
180 		kfree(evt);
181 	}
182 	spin_unlock_irq(&file->async_file->lock);
183 }
184 
185 static void ib_uverbs_detach_umcast(struct ib_qp *qp,
186 				    struct ib_uqp_object *uobj)
187 {
188 	struct ib_uverbs_mcast_entry *mcast, *tmp;
189 
190 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
191 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
192 		list_del(&mcast->list);
193 		kfree(mcast);
194 	}
195 }
196 
197 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
198 				      struct ib_ucontext *context)
199 {
200 	struct ib_uobject *uobj, *tmp;
201 
202 	if (!context)
203 		return 0;
204 
205 	context->closing = 1;
206 
207 	list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
208 		struct ib_ah *ah = uobj->object;
209 
210 		idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
211 		ib_destroy_ah(ah);
212 		kfree(uobj);
213 	}
214 
215 	/* Remove MWs before QPs, in order to support type 2A MWs. */
216 	list_for_each_entry_safe(uobj, tmp, &context->mw_list, list) {
217 		struct ib_mw *mw = uobj->object;
218 
219 		idr_remove_uobj(&ib_uverbs_mw_idr, uobj);
220 		ib_dealloc_mw(mw);
221 		kfree(uobj);
222 	}
223 
224 	list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
225 		struct ib_flow *flow_id = uobj->object;
226 
227 		idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
228 		ib_destroy_flow(flow_id);
229 		kfree(uobj);
230 	}
231 
232 	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
233 		struct ib_qp *qp = uobj->object;
234 		struct ib_uqp_object *uqp =
235 			container_of(uobj, struct ib_uqp_object, uevent.uobject);
236 
237 		idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
238 		if (qp != qp->real_qp) {
239 			ib_close_qp(qp);
240 		} else {
241 			ib_uverbs_detach_umcast(qp, uqp);
242 			ib_destroy_qp(qp);
243 		}
244 		ib_uverbs_release_uevent(file, &uqp->uevent);
245 		kfree(uqp);
246 	}
247 
248 	list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
249 		struct ib_cq *cq = uobj->object;
250 		struct ib_uverbs_event_file *ev_file = cq->cq_context;
251 		struct ib_ucq_object *ucq =
252 			container_of(uobj, struct ib_ucq_object, uobject);
253 
254 		idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
255 		ib_destroy_cq(cq);
256 		ib_uverbs_release_ucq(file, ev_file, ucq);
257 		kfree(ucq);
258 	}
259 
260 	list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
261 		struct ib_srq *srq = uobj->object;
262 		struct ib_uevent_object *uevent =
263 			container_of(uobj, struct ib_uevent_object, uobject);
264 
265 		idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
266 		ib_destroy_srq(srq);
267 		ib_uverbs_release_uevent(file, uevent);
268 		kfree(uevent);
269 	}
270 
271 	list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
272 		struct ib_mr *mr = uobj->object;
273 
274 		idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
275 		ib_dereg_mr(mr);
276 		kfree(uobj);
277 	}
278 
279 	mutex_lock(&file->device->xrcd_tree_mutex);
280 	list_for_each_entry_safe(uobj, tmp, &context->xrcd_list, list) {
281 		struct ib_xrcd *xrcd = uobj->object;
282 		struct ib_uxrcd_object *uxrcd =
283 			container_of(uobj, struct ib_uxrcd_object, uobject);
284 
285 		idr_remove_uobj(&ib_uverbs_xrcd_idr, uobj);
286 		ib_uverbs_dealloc_xrcd(file->device, xrcd);
287 		kfree(uxrcd);
288 	}
289 	mutex_unlock(&file->device->xrcd_tree_mutex);
290 
291 	list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
292 		struct ib_pd *pd = uobj->object;
293 
294 		idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
295 		ib_dealloc_pd(pd);
296 		kfree(uobj);
297 	}
298 
299 	return context->device->dealloc_ucontext(context);
300 }
301 
302 static void ib_uverbs_release_file(struct kref *ref)
303 {
304 	struct ib_uverbs_file *file =
305 		container_of(ref, struct ib_uverbs_file, ref);
306 
307 	module_put(file->device->ib_dev->owner);
308 	kref_put(&file->device->ref, ib_uverbs_release_dev);
309 
310 	kfree(file);
311 }
312 
313 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
314 				    size_t count, loff_t *pos)
315 {
316 	struct ib_uverbs_event_file *file = filp->private_data;
317 	struct ib_uverbs_event *event;
318 	int eventsz;
319 	int ret = 0;
320 
321 	spin_lock_irq(&file->lock);
322 
323 	while (list_empty(&file->event_list)) {
324 		spin_unlock_irq(&file->lock);
325 
326 		if (filp->f_flags & O_NONBLOCK)
327 			return -EAGAIN;
328 
329 		if (wait_event_interruptible(file->poll_wait,
330 					     !list_empty(&file->event_list)))
331 			return -ERESTARTSYS;
332 
333 		spin_lock_irq(&file->lock);
334 	}
335 
336 	event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
337 
338 	if (file->is_async)
339 		eventsz = sizeof (struct ib_uverbs_async_event_desc);
340 	else
341 		eventsz = sizeof (struct ib_uverbs_comp_event_desc);
342 
343 	if (eventsz > count) {
344 		ret   = -EINVAL;
345 		event = NULL;
346 	} else {
347 		list_del(file->event_list.next);
348 		if (event->counter) {
349 			++(*event->counter);
350 			list_del(&event->obj_list);
351 		}
352 	}
353 
354 	spin_unlock_irq(&file->lock);
355 
356 	if (event) {
357 		if (copy_to_user(buf, event, eventsz))
358 			ret = -EFAULT;
359 		else
360 			ret = eventsz;
361 	}
362 
363 	kfree(event);
364 
365 	return ret;
366 }
367 
368 static unsigned int ib_uverbs_event_poll(struct file *filp,
369 					 struct poll_table_struct *wait)
370 {
371 	unsigned int pollflags = 0;
372 	struct ib_uverbs_event_file *file = filp->private_data;
373 
374 	poll_wait(filp, &file->poll_wait, wait);
375 
376 	spin_lock_irq(&file->lock);
377 	if (!list_empty(&file->event_list))
378 		pollflags = POLLIN | POLLRDNORM;
379 	spin_unlock_irq(&file->lock);
380 
381 	return pollflags;
382 }
383 
384 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
385 {
386 	struct ib_uverbs_event_file *file = filp->private_data;
387 
388 	return fasync_helper(fd, filp, on, &file->async_queue);
389 }
390 
391 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
392 {
393 	struct ib_uverbs_event_file *file = filp->private_data;
394 	struct ib_uverbs_event *entry, *tmp;
395 
396 	spin_lock_irq(&file->lock);
397 	file->is_closed = 1;
398 	list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
399 		if (entry->counter)
400 			list_del(&entry->obj_list);
401 		kfree(entry);
402 	}
403 	spin_unlock_irq(&file->lock);
404 
405 	if (file->is_async) {
406 		ib_unregister_event_handler(&file->uverbs_file->event_handler);
407 		kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
408 	}
409 	kref_put(&file->ref, ib_uverbs_release_event_file);
410 
411 	return 0;
412 }
413 
414 static const struct file_operations uverbs_event_fops = {
415 	.owner	 = THIS_MODULE,
416 	.read	 = ib_uverbs_event_read,
417 	.poll    = ib_uverbs_event_poll,
418 	.release = ib_uverbs_event_close,
419 	.fasync  = ib_uverbs_event_fasync,
420 	.llseek	 = no_llseek,
421 };
422 
423 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
424 {
425 	struct ib_uverbs_event_file    *file = cq_context;
426 	struct ib_ucq_object	       *uobj;
427 	struct ib_uverbs_event	       *entry;
428 	unsigned long			flags;
429 
430 	if (!file)
431 		return;
432 
433 	spin_lock_irqsave(&file->lock, flags);
434 	if (file->is_closed) {
435 		spin_unlock_irqrestore(&file->lock, flags);
436 		return;
437 	}
438 
439 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
440 	if (!entry) {
441 		spin_unlock_irqrestore(&file->lock, flags);
442 		return;
443 	}
444 
445 	uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
446 
447 	entry->desc.comp.cq_handle = cq->uobject->user_handle;
448 	entry->counter		   = &uobj->comp_events_reported;
449 
450 	list_add_tail(&entry->list, &file->event_list);
451 	list_add_tail(&entry->obj_list, &uobj->comp_list);
452 	spin_unlock_irqrestore(&file->lock, flags);
453 
454 	wake_up_interruptible(&file->poll_wait);
455 	kill_fasync(&file->async_queue, SIGIO, POLL_IN);
456 }
457 
458 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
459 				    __u64 element, __u64 event,
460 				    struct list_head *obj_list,
461 				    u32 *counter)
462 {
463 	struct ib_uverbs_event *entry;
464 	unsigned long flags;
465 
466 	spin_lock_irqsave(&file->async_file->lock, flags);
467 	if (file->async_file->is_closed) {
468 		spin_unlock_irqrestore(&file->async_file->lock, flags);
469 		return;
470 	}
471 
472 	entry = kmalloc(sizeof *entry, GFP_ATOMIC);
473 	if (!entry) {
474 		spin_unlock_irqrestore(&file->async_file->lock, flags);
475 		return;
476 	}
477 
478 	entry->desc.async.element    = element;
479 	entry->desc.async.event_type = event;
480 	entry->counter               = counter;
481 
482 	list_add_tail(&entry->list, &file->async_file->event_list);
483 	if (obj_list)
484 		list_add_tail(&entry->obj_list, obj_list);
485 	spin_unlock_irqrestore(&file->async_file->lock, flags);
486 
487 	wake_up_interruptible(&file->async_file->poll_wait);
488 	kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
489 }
490 
491 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
492 {
493 	struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
494 						  struct ib_ucq_object, uobject);
495 
496 	ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
497 				event->event, &uobj->async_list,
498 				&uobj->async_events_reported);
499 }
500 
501 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
502 {
503 	struct ib_uevent_object *uobj;
504 
505 	uobj = container_of(event->element.qp->uobject,
506 			    struct ib_uevent_object, uobject);
507 
508 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
509 				event->event, &uobj->event_list,
510 				&uobj->events_reported);
511 }
512 
513 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
514 {
515 	struct ib_uevent_object *uobj;
516 
517 	uobj = container_of(event->element.srq->uobject,
518 			    struct ib_uevent_object, uobject);
519 
520 	ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
521 				event->event, &uobj->event_list,
522 				&uobj->events_reported);
523 }
524 
525 void ib_uverbs_event_handler(struct ib_event_handler *handler,
526 			     struct ib_event *event)
527 {
528 	struct ib_uverbs_file *file =
529 		container_of(handler, struct ib_uverbs_file, event_handler);
530 
531 	ib_uverbs_async_handler(file, event->element.port_num, event->event,
532 				NULL, NULL);
533 }
534 
535 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
536 					int is_async)
537 {
538 	struct ib_uverbs_event_file *ev_file;
539 	struct file *filp;
540 
541 	ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL);
542 	if (!ev_file)
543 		return ERR_PTR(-ENOMEM);
544 
545 	kref_init(&ev_file->ref);
546 	spin_lock_init(&ev_file->lock);
547 	INIT_LIST_HEAD(&ev_file->event_list);
548 	init_waitqueue_head(&ev_file->poll_wait);
549 	ev_file->uverbs_file = uverbs_file;
550 	ev_file->async_queue = NULL;
551 	ev_file->is_async    = is_async;
552 	ev_file->is_closed   = 0;
553 
554 	filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
555 				  ev_file, O_RDONLY);
556 	if (IS_ERR(filp))
557 		kfree(ev_file);
558 
559 	return filp;
560 }
561 
562 /*
563  * Look up a completion event file by FD.  If lookup is successful,
564  * takes a ref to the event file struct that it returns; if
565  * unsuccessful, returns NULL.
566  */
567 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
568 {
569 	struct ib_uverbs_event_file *ev_file = NULL;
570 	struct fd f = fdget(fd);
571 
572 	if (!f.file)
573 		return NULL;
574 
575 	if (f.file->f_op != &uverbs_event_fops)
576 		goto out;
577 
578 	ev_file = f.file->private_data;
579 	if (ev_file->is_async) {
580 		ev_file = NULL;
581 		goto out;
582 	}
583 
584 	kref_get(&ev_file->ref);
585 
586 out:
587 	fdput(f);
588 	return ev_file;
589 }
590 
591 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
592 			     size_t count, loff_t *pos)
593 {
594 	struct ib_uverbs_file *file = filp->private_data;
595 	struct ib_uverbs_cmd_hdr hdr;
596 	__u32 flags;
597 
598 	if (count < sizeof hdr)
599 		return -EINVAL;
600 
601 	if (copy_from_user(&hdr, buf, sizeof hdr))
602 		return -EFAULT;
603 
604 	flags = (hdr.command &
605 		 IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
606 
607 	if (!flags) {
608 		__u32 command;
609 
610 		if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
611 					   IB_USER_VERBS_CMD_COMMAND_MASK))
612 			return -EINVAL;
613 
614 		command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
615 
616 		if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
617 		    !uverbs_cmd_table[command])
618 			return -EINVAL;
619 
620 		if (!file->ucontext &&
621 		    command != IB_USER_VERBS_CMD_GET_CONTEXT)
622 			return -EINVAL;
623 
624 		if (!(file->device->ib_dev->uverbs_cmd_mask & (1ull << command)))
625 			return -ENOSYS;
626 
627 		if (hdr.in_words * 4 != count)
628 			return -EINVAL;
629 
630 		return uverbs_cmd_table[command](file,
631 						 buf + sizeof(hdr),
632 						 hdr.in_words * 4,
633 						 hdr.out_words * 4);
634 
635 	} else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
636 		__u32 command;
637 
638 		struct ib_uverbs_ex_cmd_hdr ex_hdr;
639 		struct ib_udata ucore;
640 		struct ib_udata uhw;
641 		int err;
642 		size_t written_count = count;
643 
644 		if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
645 					   IB_USER_VERBS_CMD_COMMAND_MASK))
646 			return -EINVAL;
647 
648 		command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
649 
650 		if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
651 		    !uverbs_ex_cmd_table[command])
652 			return -ENOSYS;
653 
654 		if (!file->ucontext)
655 			return -EINVAL;
656 
657 		if (!(file->device->ib_dev->uverbs_ex_cmd_mask & (1ull << command)))
658 			return -ENOSYS;
659 
660 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
661 			return -EINVAL;
662 
663 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
664 			return -EFAULT;
665 
666 		count -= sizeof(hdr) + sizeof(ex_hdr);
667 		buf += sizeof(hdr) + sizeof(ex_hdr);
668 
669 		if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count)
670 			return -EINVAL;
671 
672 		if (ex_hdr.cmd_hdr_reserved)
673 			return -EINVAL;
674 
675 		if (ex_hdr.response) {
676 			if (!hdr.out_words && !ex_hdr.provider_out_words)
677 				return -EINVAL;
678 
679 			if (!access_ok(VERIFY_WRITE,
680 				       (void __user *) (unsigned long) ex_hdr.response,
681 				       (hdr.out_words + ex_hdr.provider_out_words) * 8))
682 				return -EFAULT;
683 		} else {
684 			if (hdr.out_words || ex_hdr.provider_out_words)
685 				return -EINVAL;
686 		}
687 
688 		INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
689 				       hdr.in_words * 8, hdr.out_words * 8);
690 
691 		INIT_UDATA_BUF_OR_NULL(&uhw,
692 				       buf + ucore.inlen,
693 				       (unsigned long) ex_hdr.response + ucore.outlen,
694 				       ex_hdr.provider_in_words * 8,
695 				       ex_hdr.provider_out_words * 8);
696 
697 		err = uverbs_ex_cmd_table[command](file,
698 						   &ucore,
699 						   &uhw);
700 
701 		if (err)
702 			return err;
703 
704 		return written_count;
705 	}
706 
707 	return -ENOSYS;
708 }
709 
710 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
711 {
712 	struct ib_uverbs_file *file = filp->private_data;
713 
714 	if (!file->ucontext)
715 		return -ENODEV;
716 	else
717 		return file->device->ib_dev->mmap(file->ucontext, vma);
718 }
719 
720 /*
721  * ib_uverbs_open() does not need the BKL:
722  *
723  *  - the ib_uverbs_device structures are properly reference counted and
724  *    everything else is purely local to the file being created, so
725  *    races against other open calls are not a problem;
726  *  - there is no ioctl method to race against;
727  *  - the open method will either immediately run -ENXIO, or all
728  *    required initialization will be done.
729  */
730 static int ib_uverbs_open(struct inode *inode, struct file *filp)
731 {
732 	struct ib_uverbs_device *dev;
733 	struct ib_uverbs_file *file;
734 	int ret;
735 
736 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
737 	if (dev)
738 		kref_get(&dev->ref);
739 	else
740 		return -ENXIO;
741 
742 	if (!try_module_get(dev->ib_dev->owner)) {
743 		ret = -ENODEV;
744 		goto err;
745 	}
746 
747 	file = kmalloc(sizeof *file, GFP_KERNEL);
748 	if (!file) {
749 		ret = -ENOMEM;
750 		goto err_module;
751 	}
752 
753 	file->device	 = dev;
754 	file->ucontext	 = NULL;
755 	file->async_file = NULL;
756 	kref_init(&file->ref);
757 	mutex_init(&file->mutex);
758 
759 	filp->private_data = file;
760 
761 	return nonseekable_open(inode, filp);
762 
763 err_module:
764 	module_put(dev->ib_dev->owner);
765 
766 err:
767 	kref_put(&dev->ref, ib_uverbs_release_dev);
768 	return ret;
769 }
770 
771 static int ib_uverbs_close(struct inode *inode, struct file *filp)
772 {
773 	struct ib_uverbs_file *file = filp->private_data;
774 
775 	ib_uverbs_cleanup_ucontext(file, file->ucontext);
776 
777 	if (file->async_file)
778 		kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
779 
780 	kref_put(&file->ref, ib_uverbs_release_file);
781 
782 	return 0;
783 }
784 
785 static const struct file_operations uverbs_fops = {
786 	.owner	 = THIS_MODULE,
787 	.write	 = ib_uverbs_write,
788 	.open	 = ib_uverbs_open,
789 	.release = ib_uverbs_close,
790 	.llseek	 = no_llseek,
791 };
792 
793 static const struct file_operations uverbs_mmap_fops = {
794 	.owner	 = THIS_MODULE,
795 	.write	 = ib_uverbs_write,
796 	.mmap    = ib_uverbs_mmap,
797 	.open	 = ib_uverbs_open,
798 	.release = ib_uverbs_close,
799 	.llseek	 = no_llseek,
800 };
801 
802 static struct ib_client uverbs_client = {
803 	.name   = "uverbs",
804 	.add    = ib_uverbs_add_one,
805 	.remove = ib_uverbs_remove_one
806 };
807 
808 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
809 			  char *buf)
810 {
811 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
812 
813 	if (!dev)
814 		return -ENODEV;
815 
816 	return sprintf(buf, "%s\n", dev->ib_dev->name);
817 }
818 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
819 
820 static ssize_t show_dev_abi_version(struct device *device,
821 				    struct device_attribute *attr, char *buf)
822 {
823 	struct ib_uverbs_device *dev = dev_get_drvdata(device);
824 
825 	if (!dev)
826 		return -ENODEV;
827 
828 	return sprintf(buf, "%d\n", dev->ib_dev->uverbs_abi_ver);
829 }
830 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
831 
832 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
833 			 __stringify(IB_USER_VERBS_ABI_VERSION));
834 
835 static dev_t overflow_maj;
836 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
837 
838 /*
839  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
840  * requesting a new major number and doubling the number of max devices we
841  * support. It's stupid, but simple.
842  */
843 static int find_overflow_devnum(void)
844 {
845 	int ret;
846 
847 	if (!overflow_maj) {
848 		ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
849 					  "infiniband_verbs");
850 		if (ret) {
851 			printk(KERN_ERR "user_verbs: couldn't register dynamic device number\n");
852 			return ret;
853 		}
854 	}
855 
856 	ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
857 	if (ret >= IB_UVERBS_MAX_DEVICES)
858 		return -1;
859 
860 	return ret;
861 }
862 
863 static void ib_uverbs_add_one(struct ib_device *device)
864 {
865 	int devnum;
866 	dev_t base;
867 	struct ib_uverbs_device *uverbs_dev;
868 
869 	if (!device->alloc_ucontext)
870 		return;
871 
872 	uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
873 	if (!uverbs_dev)
874 		return;
875 
876 	kref_init(&uverbs_dev->ref);
877 	init_completion(&uverbs_dev->comp);
878 	uverbs_dev->xrcd_tree = RB_ROOT;
879 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
880 
881 	spin_lock(&map_lock);
882 	devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
883 	if (devnum >= IB_UVERBS_MAX_DEVICES) {
884 		spin_unlock(&map_lock);
885 		devnum = find_overflow_devnum();
886 		if (devnum < 0)
887 			goto err;
888 
889 		spin_lock(&map_lock);
890 		uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
891 		base = devnum + overflow_maj;
892 		set_bit(devnum, overflow_map);
893 	} else {
894 		uverbs_dev->devnum = devnum;
895 		base = devnum + IB_UVERBS_BASE_DEV;
896 		set_bit(devnum, dev_map);
897 	}
898 	spin_unlock(&map_lock);
899 
900 	uverbs_dev->ib_dev           = device;
901 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
902 
903 	cdev_init(&uverbs_dev->cdev, NULL);
904 	uverbs_dev->cdev.owner = THIS_MODULE;
905 	uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
906 	kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
907 	if (cdev_add(&uverbs_dev->cdev, base, 1))
908 		goto err_cdev;
909 
910 	uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
911 					uverbs_dev->cdev.dev, uverbs_dev,
912 					"uverbs%d", uverbs_dev->devnum);
913 	if (IS_ERR(uverbs_dev->dev))
914 		goto err_cdev;
915 
916 	if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
917 		goto err_class;
918 	if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
919 		goto err_class;
920 
921 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
922 
923 	return;
924 
925 err_class:
926 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
927 
928 err_cdev:
929 	cdev_del(&uverbs_dev->cdev);
930 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
931 		clear_bit(devnum, dev_map);
932 	else
933 		clear_bit(devnum, overflow_map);
934 
935 err:
936 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
937 	wait_for_completion(&uverbs_dev->comp);
938 	kfree(uverbs_dev);
939 	return;
940 }
941 
942 static void ib_uverbs_remove_one(struct ib_device *device)
943 {
944 	struct ib_uverbs_device *uverbs_dev = ib_get_client_data(device, &uverbs_client);
945 
946 	if (!uverbs_dev)
947 		return;
948 
949 	dev_set_drvdata(uverbs_dev->dev, NULL);
950 	device_destroy(uverbs_class, uverbs_dev->cdev.dev);
951 	cdev_del(&uverbs_dev->cdev);
952 
953 	if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
954 		clear_bit(uverbs_dev->devnum, dev_map);
955 	else
956 		clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
957 
958 	kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
959 	wait_for_completion(&uverbs_dev->comp);
960 	kfree(uverbs_dev);
961 }
962 
963 static char *uverbs_devnode(struct device *dev, umode_t *mode)
964 {
965 	if (mode)
966 		*mode = 0666;
967 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
968 }
969 
970 static int __init ib_uverbs_init(void)
971 {
972 	int ret;
973 
974 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
975 				     "infiniband_verbs");
976 	if (ret) {
977 		printk(KERN_ERR "user_verbs: couldn't register device number\n");
978 		goto out;
979 	}
980 
981 	uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
982 	if (IS_ERR(uverbs_class)) {
983 		ret = PTR_ERR(uverbs_class);
984 		printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
985 		goto out_chrdev;
986 	}
987 
988 	uverbs_class->devnode = uverbs_devnode;
989 
990 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
991 	if (ret) {
992 		printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
993 		goto out_class;
994 	}
995 
996 	ret = ib_register_client(&uverbs_client);
997 	if (ret) {
998 		printk(KERN_ERR "user_verbs: couldn't register client\n");
999 		goto out_class;
1000 	}
1001 
1002 	return 0;
1003 
1004 out_class:
1005 	class_destroy(uverbs_class);
1006 
1007 out_chrdev:
1008 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1009 
1010 out:
1011 	return ret;
1012 }
1013 
1014 static void __exit ib_uverbs_cleanup(void)
1015 {
1016 	ib_unregister_client(&uverbs_client);
1017 	class_destroy(uverbs_class);
1018 	unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1019 	if (overflow_maj)
1020 		unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1021 	idr_destroy(&ib_uverbs_pd_idr);
1022 	idr_destroy(&ib_uverbs_mr_idr);
1023 	idr_destroy(&ib_uverbs_mw_idr);
1024 	idr_destroy(&ib_uverbs_ah_idr);
1025 	idr_destroy(&ib_uverbs_cq_idr);
1026 	idr_destroy(&ib_uverbs_qp_idr);
1027 	idr_destroy(&ib_uverbs_srq_idr);
1028 }
1029 
1030 module_init(ib_uverbs_init);
1031 module_exit(ib_uverbs_cleanup);
1032