5b811bf574d6948440c6951ca4903c6cc66277d9
[linux-2.6-microblaze.git] / drivers / infiniband / core / uverbs_main.c
1 /*
2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
6  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
7  *
8  * This software is available to you under a choice of one of two
9  * licenses.  You may choose to be licensed under the terms of the GNU
10  * General Public License (GPL) Version 2, available from the file
11  * COPYING in the main directory of this source tree, or the
12  * OpenIB.org BSD license below:
13  *
14  *     Redistribution and use in source and binary forms, with or
15  *     without modification, are permitted provided that the following
16  *     conditions are met:
17  *
18  *      - Redistributions of source code must retain the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer.
21  *
22  *      - Redistributions in binary form must reproduce the above
23  *        copyright notice, this list of conditions and the following
24  *        disclaimer in the documentation and/or other materials
25  *        provided with the distribution.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
28  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
29  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
30  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
31  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
32  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
33  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34  * SOFTWARE.
35  */
36
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/device.h>
40 #include <linux/err.h>
41 #include <linux/fs.h>
42 #include <linux/poll.h>
43 #include <linux/sched.h>
44 #include <linux/file.h>
45 #include <linux/cdev.h>
46 #include <linux/anon_inodes.h>
47 #include <linux/slab.h>
48
49 #include <linux/uaccess.h>
50
51 #include <rdma/ib.h>
52 #include <rdma/uverbs_std_types.h>
53
54 #include "uverbs.h"
55 #include "core_priv.h"
56 #include "rdma_core.h"
57
58 MODULE_AUTHOR("Roland Dreier");
59 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
60 MODULE_LICENSE("Dual BSD/GPL");
61
62 enum {
63         IB_UVERBS_MAJOR       = 231,
64         IB_UVERBS_BASE_MINOR  = 192,
65         IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
66         IB_UVERBS_NUM_FIXED_MINOR = 32,
67         IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
68 };
69
70 #define IB_UVERBS_BASE_DEV      MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
71
72 static dev_t dynamic_uverbs_dev;
73 static struct class *uverbs_class;
74
75 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
76
77 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
78                                      struct ib_device *ib_dev,
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_device *ib_dev,
120                                     struct ib_udata *ucore,
121                                     struct ib_udata *uhw) = {
122         [IB_USER_VERBS_EX_CMD_CREATE_FLOW]      = ib_uverbs_ex_create_flow,
123         [IB_USER_VERBS_EX_CMD_DESTROY_FLOW]     = ib_uverbs_ex_destroy_flow,
124         [IB_USER_VERBS_EX_CMD_QUERY_DEVICE]     = ib_uverbs_ex_query_device,
125         [IB_USER_VERBS_EX_CMD_CREATE_CQ]        = ib_uverbs_ex_create_cq,
126         [IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
127         [IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
128         [IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
129         [IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
130         [IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
131         [IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
132         [IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
133         [IB_USER_VERBS_EX_CMD_MODIFY_CQ]        = ib_uverbs_ex_modify_cq,
134 };
135
136 static void ib_uverbs_add_one(struct ib_device *device);
137 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
138
139 int uverbs_dealloc_mw(struct ib_mw *mw)
140 {
141         struct ib_pd *pd = mw->pd;
142         int ret;
143
144         ret = mw->device->dealloc_mw(mw);
145         if (!ret)
146                 atomic_dec(&pd->usecnt);
147         return ret;
148 }
149
150 static void ib_uverbs_release_dev(struct kobject *kobj)
151 {
152         struct ib_uverbs_device *dev =
153                 container_of(kobj, struct ib_uverbs_device, kobj);
154
155         cleanup_srcu_struct(&dev->disassociate_srcu);
156         kfree(dev);
157 }
158
159 static struct kobj_type ib_uverbs_dev_ktype = {
160         .release = ib_uverbs_release_dev,
161 };
162
163 static void ib_uverbs_release_async_event_file(struct kref *ref)
164 {
165         struct ib_uverbs_async_event_file *file =
166                 container_of(ref, struct ib_uverbs_async_event_file, ref);
167
168         kfree(file);
169 }
170
171 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
172                           struct ib_uverbs_completion_event_file *ev_file,
173                           struct ib_ucq_object *uobj)
174 {
175         struct ib_uverbs_event *evt, *tmp;
176
177         if (ev_file) {
178                 spin_lock_irq(&ev_file->ev_queue.lock);
179                 list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
180                         list_del(&evt->list);
181                         kfree(evt);
182                 }
183                 spin_unlock_irq(&ev_file->ev_queue.lock);
184
185                 uverbs_uobject_put(&ev_file->uobj_file.uobj);
186         }
187
188         spin_lock_irq(&file->async_file->ev_queue.lock);
189         list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
190                 list_del(&evt->list);
191                 kfree(evt);
192         }
193         spin_unlock_irq(&file->async_file->ev_queue.lock);
194 }
195
196 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
197                               struct ib_uevent_object *uobj)
198 {
199         struct ib_uverbs_event *evt, *tmp;
200
201         spin_lock_irq(&file->async_file->ev_queue.lock);
202         list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
203                 list_del(&evt->list);
204                 kfree(evt);
205         }
206         spin_unlock_irq(&file->async_file->ev_queue.lock);
207 }
208
209 void ib_uverbs_detach_umcast(struct ib_qp *qp,
210                              struct ib_uqp_object *uobj)
211 {
212         struct ib_uverbs_mcast_entry *mcast, *tmp;
213
214         list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
215                 ib_detach_mcast(qp, &mcast->gid, mcast->lid);
216                 list_del(&mcast->list);
217                 kfree(mcast);
218         }
219 }
220
221 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
222                                       struct ib_ucontext *context,
223                                       bool device_removed)
224 {
225         context->closing = 1;
226         uverbs_cleanup_ucontext(context, device_removed);
227         put_pid(context->tgid);
228
229         ib_rdmacg_uncharge(&context->cg_obj, context->device,
230                            RDMACG_RESOURCE_HCA_HANDLE);
231
232         return context->device->dealloc_ucontext(context);
233 }
234
235 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
236 {
237         complete(&dev->comp);
238 }
239
240 void ib_uverbs_release_file(struct kref *ref)
241 {
242         struct ib_uverbs_file *file =
243                 container_of(ref, struct ib_uverbs_file, ref);
244         struct ib_device *ib_dev;
245         int srcu_key;
246
247         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
248         ib_dev = srcu_dereference(file->device->ib_dev,
249                                   &file->device->disassociate_srcu);
250         if (ib_dev && !ib_dev->disassociate_ucontext)
251                 module_put(ib_dev->owner);
252         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
253
254         if (atomic_dec_and_test(&file->device->refcount))
255                 ib_uverbs_comp_dev(file->device);
256
257         kobject_put(&file->device->kobj);
258         kfree(file);
259 }
260
261 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
262                                     struct ib_uverbs_file *uverbs_file,
263                                     struct file *filp, char __user *buf,
264                                     size_t count, loff_t *pos,
265                                     size_t eventsz)
266 {
267         struct ib_uverbs_event *event;
268         int ret = 0;
269
270         spin_lock_irq(&ev_queue->lock);
271
272         while (list_empty(&ev_queue->event_list)) {
273                 spin_unlock_irq(&ev_queue->lock);
274
275                 if (filp->f_flags & O_NONBLOCK)
276                         return -EAGAIN;
277
278                 if (wait_event_interruptible(ev_queue->poll_wait,
279                                              (!list_empty(&ev_queue->event_list) ||
280                         /* The barriers built into wait_event_interruptible()
281                          * and wake_up() guarentee this will see the null set
282                          * without using RCU
283                          */
284                                              !uverbs_file->device->ib_dev)))
285                         return -ERESTARTSYS;
286
287                 /* If device was disassociated and no event exists set an error */
288                 if (list_empty(&ev_queue->event_list) &&
289                     !uverbs_file->device->ib_dev)
290                         return -EIO;
291
292                 spin_lock_irq(&ev_queue->lock);
293         }
294
295         event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
296
297         if (eventsz > count) {
298                 ret   = -EINVAL;
299                 event = NULL;
300         } else {
301                 list_del(ev_queue->event_list.next);
302                 if (event->counter) {
303                         ++(*event->counter);
304                         list_del(&event->obj_list);
305                 }
306         }
307
308         spin_unlock_irq(&ev_queue->lock);
309
310         if (event) {
311                 if (copy_to_user(buf, event, eventsz))
312                         ret = -EFAULT;
313                 else
314                         ret = eventsz;
315         }
316
317         kfree(event);
318
319         return ret;
320 }
321
322 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
323                                           size_t count, loff_t *pos)
324 {
325         struct ib_uverbs_async_event_file *file = filp->private_data;
326
327         return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
328                                     buf, count, pos,
329                                     sizeof(struct ib_uverbs_async_event_desc));
330 }
331
332 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
333                                          size_t count, loff_t *pos)
334 {
335         struct ib_uverbs_completion_event_file *comp_ev_file =
336                 filp->private_data;
337
338         return ib_uverbs_event_read(&comp_ev_file->ev_queue,
339                                     comp_ev_file->uobj_file.ufile, filp,
340                                     buf, count, pos,
341                                     sizeof(struct ib_uverbs_comp_event_desc));
342 }
343
344 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
345                                          struct file *filp,
346                                          struct poll_table_struct *wait)
347 {
348         __poll_t pollflags = 0;
349
350         poll_wait(filp, &ev_queue->poll_wait, wait);
351
352         spin_lock_irq(&ev_queue->lock);
353         if (!list_empty(&ev_queue->event_list))
354                 pollflags = POLLIN | POLLRDNORM;
355         spin_unlock_irq(&ev_queue->lock);
356
357         return pollflags;
358 }
359
360 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
361                                                struct poll_table_struct *wait)
362 {
363         return ib_uverbs_event_poll(filp->private_data, filp, wait);
364 }
365
366 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
367                                               struct poll_table_struct *wait)
368 {
369         struct ib_uverbs_completion_event_file *comp_ev_file =
370                 filp->private_data;
371
372         return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
373 }
374
375 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
376 {
377         struct ib_uverbs_event_queue *ev_queue = filp->private_data;
378
379         return fasync_helper(fd, filp, on, &ev_queue->async_queue);
380 }
381
382 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
383 {
384         struct ib_uverbs_completion_event_file *comp_ev_file =
385                 filp->private_data;
386
387         return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
388 }
389
390 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
391 {
392         struct ib_uverbs_async_event_file *file = filp->private_data;
393         struct ib_uverbs_file *uverbs_file = file->uverbs_file;
394         struct ib_uverbs_event *entry, *tmp;
395         int closed_already = 0;
396
397         mutex_lock(&uverbs_file->device->lists_mutex);
398         spin_lock_irq(&file->ev_queue.lock);
399         closed_already = file->ev_queue.is_closed;
400         file->ev_queue.is_closed = 1;
401         list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
402                 if (entry->counter)
403                         list_del(&entry->obj_list);
404                 kfree(entry);
405         }
406         spin_unlock_irq(&file->ev_queue.lock);
407         if (!closed_already) {
408                 list_del(&file->list);
409                 ib_unregister_event_handler(&uverbs_file->event_handler);
410         }
411         mutex_unlock(&uverbs_file->device->lists_mutex);
412
413         kref_put(&uverbs_file->ref, ib_uverbs_release_file);
414         kref_put(&file->ref, ib_uverbs_release_async_event_file);
415
416         return 0;
417 }
418
419 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
420 {
421         struct ib_uverbs_completion_event_file *file = filp->private_data;
422         struct ib_uverbs_event *entry, *tmp;
423
424         spin_lock_irq(&file->ev_queue.lock);
425         list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
426                 if (entry->counter)
427                         list_del(&entry->obj_list);
428                 kfree(entry);
429         }
430         spin_unlock_irq(&file->ev_queue.lock);
431
432         uverbs_close_fd(filp);
433
434         return 0;
435 }
436
437 const struct file_operations uverbs_event_fops = {
438         .owner   = THIS_MODULE,
439         .read    = ib_uverbs_comp_event_read,
440         .poll    = ib_uverbs_comp_event_poll,
441         .release = ib_uverbs_comp_event_close,
442         .fasync  = ib_uverbs_comp_event_fasync,
443         .llseek  = no_llseek,
444 };
445
446 static const struct file_operations uverbs_async_event_fops = {
447         .owner   = THIS_MODULE,
448         .read    = ib_uverbs_async_event_read,
449         .poll    = ib_uverbs_async_event_poll,
450         .release = ib_uverbs_async_event_close,
451         .fasync  = ib_uverbs_async_event_fasync,
452         .llseek  = no_llseek,
453 };
454
455 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
456 {
457         struct ib_uverbs_event_queue   *ev_queue = cq_context;
458         struct ib_ucq_object           *uobj;
459         struct ib_uverbs_event         *entry;
460         unsigned long                   flags;
461
462         if (!ev_queue)
463                 return;
464
465         spin_lock_irqsave(&ev_queue->lock, flags);
466         if (ev_queue->is_closed) {
467                 spin_unlock_irqrestore(&ev_queue->lock, flags);
468                 return;
469         }
470
471         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
472         if (!entry) {
473                 spin_unlock_irqrestore(&ev_queue->lock, flags);
474                 return;
475         }
476
477         uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
478
479         entry->desc.comp.cq_handle = cq->uobject->user_handle;
480         entry->counter             = &uobj->comp_events_reported;
481
482         list_add_tail(&entry->list, &ev_queue->event_list);
483         list_add_tail(&entry->obj_list, &uobj->comp_list);
484         spin_unlock_irqrestore(&ev_queue->lock, flags);
485
486         wake_up_interruptible(&ev_queue->poll_wait);
487         kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
488 }
489
490 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
491                                     __u64 element, __u64 event,
492                                     struct list_head *obj_list,
493                                     u32 *counter)
494 {
495         struct ib_uverbs_event *entry;
496         unsigned long flags;
497
498         spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
499         if (file->async_file->ev_queue.is_closed) {
500                 spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
501                 return;
502         }
503
504         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
505         if (!entry) {
506                 spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
507                 return;
508         }
509
510         entry->desc.async.element    = element;
511         entry->desc.async.event_type = event;
512         entry->desc.async.reserved   = 0;
513         entry->counter               = counter;
514
515         list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
516         if (obj_list)
517                 list_add_tail(&entry->obj_list, obj_list);
518         spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
519
520         wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
521         kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
522 }
523
524 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
525 {
526         struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
527                                                   struct ib_ucq_object, uobject);
528
529         ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
530                                 event->event, &uobj->async_list,
531                                 &uobj->async_events_reported);
532 }
533
534 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
535 {
536         struct ib_uevent_object *uobj;
537
538         /* for XRC target qp's, check that qp is live */
539         if (!event->element.qp->uobject)
540                 return;
541
542         uobj = container_of(event->element.qp->uobject,
543                             struct ib_uevent_object, uobject);
544
545         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
546                                 event->event, &uobj->event_list,
547                                 &uobj->events_reported);
548 }
549
550 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
551 {
552         struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
553                                                   struct ib_uevent_object, uobject);
554
555         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
556                                 event->event, &uobj->event_list,
557                                 &uobj->events_reported);
558 }
559
560 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
561 {
562         struct ib_uevent_object *uobj;
563
564         uobj = container_of(event->element.srq->uobject,
565                             struct ib_uevent_object, uobject);
566
567         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
568                                 event->event, &uobj->event_list,
569                                 &uobj->events_reported);
570 }
571
572 void ib_uverbs_event_handler(struct ib_event_handler *handler,
573                              struct ib_event *event)
574 {
575         struct ib_uverbs_file *file =
576                 container_of(handler, struct ib_uverbs_file, event_handler);
577
578         ib_uverbs_async_handler(file, event->element.port_num, event->event,
579                                 NULL, NULL);
580 }
581
582 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
583 {
584         kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
585         file->async_file = NULL;
586 }
587
588 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
589 {
590         spin_lock_init(&ev_queue->lock);
591         INIT_LIST_HEAD(&ev_queue->event_list);
592         init_waitqueue_head(&ev_queue->poll_wait);
593         ev_queue->is_closed   = 0;
594         ev_queue->async_queue = NULL;
595 }
596
597 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
598                                               struct ib_device  *ib_dev)
599 {
600         struct ib_uverbs_async_event_file *ev_file;
601         struct file *filp;
602
603         ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
604         if (!ev_file)
605                 return ERR_PTR(-ENOMEM);
606
607         ib_uverbs_init_event_queue(&ev_file->ev_queue);
608         ev_file->uverbs_file = uverbs_file;
609         kref_get(&ev_file->uverbs_file->ref);
610         kref_init(&ev_file->ref);
611         filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
612                                   ev_file, O_RDONLY);
613         if (IS_ERR(filp))
614                 goto err_put_refs;
615
616         mutex_lock(&uverbs_file->device->lists_mutex);
617         list_add_tail(&ev_file->list,
618                       &uverbs_file->device->uverbs_events_file_list);
619         mutex_unlock(&uverbs_file->device->lists_mutex);
620
621         WARN_ON(uverbs_file->async_file);
622         uverbs_file->async_file = ev_file;
623         kref_get(&uverbs_file->async_file->ref);
624         INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
625                               ib_dev,
626                               ib_uverbs_event_handler);
627         ib_register_event_handler(&uverbs_file->event_handler);
628         /* At that point async file stuff was fully set */
629
630         return filp;
631
632 err_put_refs:
633         kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
634         kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
635         return filp;
636 }
637
638 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
639 {
640         u64 mask;
641
642         if (command <= IB_USER_VERBS_CMD_OPEN_QP)
643                 mask = ib_dev->uverbs_cmd_mask;
644         else
645                 mask = ib_dev->uverbs_ex_cmd_mask;
646
647         if (mask & ((u64)1 << command))
648                 return 0;
649
650         return -1;
651 }
652
653 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
654                              size_t count, loff_t *pos)
655 {
656         struct ib_uverbs_file *file = filp->private_data;
657         struct ib_device *ib_dev;
658         struct ib_uverbs_cmd_hdr hdr;
659         __u32 command;
660         __u32 flags;
661         int srcu_key;
662         ssize_t ret;
663
664         if (!ib_safe_file_access(filp)) {
665                 pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
666                             task_tgid_vnr(current), current->comm);
667                 return -EACCES;
668         }
669
670         if (count < sizeof hdr)
671                 return -EINVAL;
672
673         if (copy_from_user(&hdr, buf, sizeof hdr))
674                 return -EFAULT;
675
676         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
677         ib_dev = srcu_dereference(file->device->ib_dev,
678                                   &file->device->disassociate_srcu);
679         if (!ib_dev) {
680                 ret = -EIO;
681                 goto out;
682         }
683
684         if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
685                                    IB_USER_VERBS_CMD_COMMAND_MASK)) {
686                 ret = -EINVAL;
687                 goto out;
688         }
689
690         command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
691         if (verify_command_mask(ib_dev, command)) {
692                 ret = -EOPNOTSUPP;
693                 goto out;
694         }
695
696         if (!file->ucontext &&
697             command != IB_USER_VERBS_CMD_GET_CONTEXT) {
698                 ret = -EINVAL;
699                 goto out;
700         }
701
702         flags = (hdr.command &
703                  IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
704
705         if (!flags) {
706                 if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
707                     !uverbs_cmd_table[command]) {
708                         ret = -EINVAL;
709                         goto out;
710                 }
711
712                 if (hdr.in_words * 4 != count) {
713                         ret = -EINVAL;
714                         goto out;
715                 }
716
717                 ret = uverbs_cmd_table[command](file, ib_dev,
718                                                  buf + sizeof(hdr),
719                                                  hdr.in_words * 4,
720                                                  hdr.out_words * 4);
721
722         } else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
723                 struct ib_uverbs_ex_cmd_hdr ex_hdr;
724                 struct ib_udata ucore;
725                 struct ib_udata uhw;
726                 size_t written_count = count;
727
728                 if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
729                     !uverbs_ex_cmd_table[command]) {
730                         ret = -ENOSYS;
731                         goto out;
732                 }
733
734                 if (!file->ucontext) {
735                         ret = -EINVAL;
736                         goto out;
737                 }
738
739                 if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
740                         ret = -EINVAL;
741                         goto out;
742                 }
743
744                 if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
745                         ret = -EFAULT;
746                         goto out;
747                 }
748
749                 count -= sizeof(hdr) + sizeof(ex_hdr);
750                 buf += sizeof(hdr) + sizeof(ex_hdr);
751
752                 if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
753                         ret = -EINVAL;
754                         goto out;
755                 }
756
757                 if (ex_hdr.cmd_hdr_reserved) {
758                         ret = -EINVAL;
759                         goto out;
760                 }
761
762                 if (ex_hdr.response) {
763                         if (!hdr.out_words && !ex_hdr.provider_out_words) {
764                                 ret = -EINVAL;
765                                 goto out;
766                         }
767
768                         if (!access_ok(VERIFY_WRITE,
769                                        u64_to_user_ptr(ex_hdr.response),
770                                        (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
771                                 ret = -EFAULT;
772                                 goto out;
773                         }
774                 } else {
775                         if (hdr.out_words || ex_hdr.provider_out_words) {
776                                 ret = -EINVAL;
777                                 goto out;
778                         }
779                 }
780
781                 ib_uverbs_init_udata_buf_or_null(&ucore, buf,
782                                         u64_to_user_ptr(ex_hdr.response),
783                                         hdr.in_words * 8, hdr.out_words * 8);
784
785                 ib_uverbs_init_udata_buf_or_null(&uhw,
786                                         buf + ucore.inlen,
787                                         u64_to_user_ptr(ex_hdr.response) + ucore.outlen,
788                                         ex_hdr.provider_in_words * 8,
789                                         ex_hdr.provider_out_words * 8);
790
791                 ret = uverbs_ex_cmd_table[command](file, ib_dev, &ucore, &uhw);
792                 if (!ret)
793                         ret = written_count;
794         } else {
795                 ret = -ENOSYS;
796         }
797
798 out:
799         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
800         return ret;
801 }
802
803 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
804 {
805         struct ib_uverbs_file *file = filp->private_data;
806         struct ib_device *ib_dev;
807         int ret = 0;
808         int srcu_key;
809
810         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
811         ib_dev = srcu_dereference(file->device->ib_dev,
812                                   &file->device->disassociate_srcu);
813         if (!ib_dev) {
814                 ret = -EIO;
815                 goto out;
816         }
817
818         if (!file->ucontext)
819                 ret = -ENODEV;
820         else
821                 ret = ib_dev->mmap(file->ucontext, vma);
822 out:
823         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
824         return ret;
825 }
826
827 /*
828  * ib_uverbs_open() does not need the BKL:
829  *
830  *  - the ib_uverbs_device structures are properly reference counted and
831  *    everything else is purely local to the file being created, so
832  *    races against other open calls are not a problem;
833  *  - there is no ioctl method to race against;
834  *  - the open method will either immediately run -ENXIO, or all
835  *    required initialization will be done.
836  */
837 static int ib_uverbs_open(struct inode *inode, struct file *filp)
838 {
839         struct ib_uverbs_device *dev;
840         struct ib_uverbs_file *file;
841         struct ib_device *ib_dev;
842         int ret;
843         int module_dependent;
844         int srcu_key;
845
846         dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
847         if (!atomic_inc_not_zero(&dev->refcount))
848                 return -ENXIO;
849
850         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
851         mutex_lock(&dev->lists_mutex);
852         ib_dev = srcu_dereference(dev->ib_dev,
853                                   &dev->disassociate_srcu);
854         if (!ib_dev) {
855                 ret = -EIO;
856                 goto err;
857         }
858
859         /* In case IB device supports disassociate ucontext, there is no hard
860          * dependency between uverbs device and its low level device.
861          */
862         module_dependent = !(ib_dev->disassociate_ucontext);
863
864         if (module_dependent) {
865                 if (!try_module_get(ib_dev->owner)) {
866                         ret = -ENODEV;
867                         goto err;
868                 }
869         }
870
871         file = kzalloc(sizeof(*file), GFP_KERNEL);
872         if (!file) {
873                 ret = -ENOMEM;
874                 if (module_dependent)
875                         goto err_module;
876
877                 goto err;
878         }
879
880         file->device     = dev;
881         spin_lock_init(&file->idr_lock);
882         idr_init(&file->idr);
883         file->ucontext   = NULL;
884         file->async_file = NULL;
885         kref_init(&file->ref);
886         mutex_init(&file->mutex);
887         mutex_init(&file->cleanup_mutex);
888
889         filp->private_data = file;
890         kobject_get(&dev->kobj);
891         list_add_tail(&file->list, &dev->uverbs_file_list);
892         mutex_unlock(&dev->lists_mutex);
893         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
894
895         return nonseekable_open(inode, filp);
896
897 err_module:
898         module_put(ib_dev->owner);
899
900 err:
901         mutex_unlock(&dev->lists_mutex);
902         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
903         if (atomic_dec_and_test(&dev->refcount))
904                 ib_uverbs_comp_dev(dev);
905
906         return ret;
907 }
908
909 static int ib_uverbs_close(struct inode *inode, struct file *filp)
910 {
911         struct ib_uverbs_file *file = filp->private_data;
912
913         mutex_lock(&file->cleanup_mutex);
914         if (file->ucontext) {
915                 ib_uverbs_cleanup_ucontext(file, file->ucontext, false);
916                 file->ucontext = NULL;
917         }
918         mutex_unlock(&file->cleanup_mutex);
919         idr_destroy(&file->idr);
920
921         mutex_lock(&file->device->lists_mutex);
922         if (!file->is_closed) {
923                 list_del(&file->list);
924                 file->is_closed = 1;
925         }
926         mutex_unlock(&file->device->lists_mutex);
927
928         if (file->async_file)
929                 kref_put(&file->async_file->ref,
930                          ib_uverbs_release_async_event_file);
931
932         kref_put(&file->ref, ib_uverbs_release_file);
933
934         return 0;
935 }
936
937 static const struct file_operations uverbs_fops = {
938         .owner   = THIS_MODULE,
939         .write   = ib_uverbs_write,
940         .open    = ib_uverbs_open,
941         .release = ib_uverbs_close,
942         .llseek  = no_llseek,
943 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
944         .unlocked_ioctl = ib_uverbs_ioctl,
945 #endif
946 };
947
948 static const struct file_operations uverbs_mmap_fops = {
949         .owner   = THIS_MODULE,
950         .write   = ib_uverbs_write,
951         .mmap    = ib_uverbs_mmap,
952         .open    = ib_uverbs_open,
953         .release = ib_uverbs_close,
954         .llseek  = no_llseek,
955 #if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
956         .unlocked_ioctl = ib_uverbs_ioctl,
957 #endif
958 };
959
960 static struct ib_client uverbs_client = {
961         .name   = "uverbs",
962         .add    = ib_uverbs_add_one,
963         .remove = ib_uverbs_remove_one
964 };
965
966 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
967                           char *buf)
968 {
969         int ret = -ENODEV;
970         int srcu_key;
971         struct ib_uverbs_device *dev = dev_get_drvdata(device);
972         struct ib_device *ib_dev;
973
974         if (!dev)
975                 return -ENODEV;
976
977         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
978         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
979         if (ib_dev)
980                 ret = sprintf(buf, "%s\n", ib_dev->name);
981         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
982
983         return ret;
984 }
985 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
986
987 static ssize_t show_dev_abi_version(struct device *device,
988                                     struct device_attribute *attr, char *buf)
989 {
990         struct ib_uverbs_device *dev = dev_get_drvdata(device);
991         int ret = -ENODEV;
992         int srcu_key;
993         struct ib_device *ib_dev;
994
995         if (!dev)
996                 return -ENODEV;
997         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
998         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
999         if (ib_dev)
1000                 ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
1001         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1002
1003         return ret;
1004 }
1005 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
1006
1007 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1008                          __stringify(IB_USER_VERBS_ABI_VERSION));
1009
1010 static void ib_uverbs_add_one(struct ib_device *device)
1011 {
1012         int devnum;
1013         dev_t base;
1014         struct ib_uverbs_device *uverbs_dev;
1015         int ret;
1016
1017         if (!device->alloc_ucontext)
1018                 return;
1019
1020         uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1021         if (!uverbs_dev)
1022                 return;
1023
1024         ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1025         if (ret) {
1026                 kfree(uverbs_dev);
1027                 return;
1028         }
1029
1030         atomic_set(&uverbs_dev->refcount, 1);
1031         init_completion(&uverbs_dev->comp);
1032         uverbs_dev->xrcd_tree = RB_ROOT;
1033         mutex_init(&uverbs_dev->xrcd_tree_mutex);
1034         kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1035         mutex_init(&uverbs_dev->lists_mutex);
1036         INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1037         INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1038
1039         devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1040         if (devnum >= IB_UVERBS_MAX_DEVICES)
1041                 goto err;
1042         uverbs_dev->devnum = devnum;
1043         set_bit(devnum, dev_map);
1044         if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1045                 base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1046         else
1047                 base = IB_UVERBS_BASE_DEV + devnum;
1048
1049         rcu_assign_pointer(uverbs_dev->ib_dev, device);
1050         uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1051
1052         cdev_init(&uverbs_dev->cdev, NULL);
1053         uverbs_dev->cdev.owner = THIS_MODULE;
1054         uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1055         cdev_set_parent(&uverbs_dev->cdev, &uverbs_dev->kobj);
1056         kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1057         if (cdev_add(&uverbs_dev->cdev, base, 1))
1058                 goto err_cdev;
1059
1060         uverbs_dev->dev = device_create(uverbs_class, device->dev.parent,
1061                                         uverbs_dev->cdev.dev, uverbs_dev,
1062                                         "uverbs%d", uverbs_dev->devnum);
1063         if (IS_ERR(uverbs_dev->dev))
1064                 goto err_cdev;
1065
1066         if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1067                 goto err_class;
1068         if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1069                 goto err_class;
1070
1071         if (!device->specs_root) {
1072                 const struct uverbs_object_tree_def *default_root[] = {
1073                         uverbs_default_get_objects()};
1074
1075                 uverbs_dev->specs_root = uverbs_alloc_spec_tree(1,
1076                                                                 default_root);
1077                 if (IS_ERR(uverbs_dev->specs_root))
1078                         goto err_class;
1079
1080                 device->specs_root = uverbs_dev->specs_root;
1081         }
1082
1083         ib_set_client_data(device, &uverbs_client, uverbs_dev);
1084
1085         return;
1086
1087 err_class:
1088         device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1089
1090 err_cdev:
1091         cdev_del(&uverbs_dev->cdev);
1092         clear_bit(devnum, dev_map);
1093
1094 err:
1095         if (atomic_dec_and_test(&uverbs_dev->refcount))
1096                 ib_uverbs_comp_dev(uverbs_dev);
1097         wait_for_completion(&uverbs_dev->comp);
1098         kobject_put(&uverbs_dev->kobj);
1099         return;
1100 }
1101
1102 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1103                                         struct ib_device *ib_dev)
1104 {
1105         struct ib_uverbs_file *file;
1106         struct ib_uverbs_async_event_file *event_file;
1107         struct ib_event event;
1108
1109         /* Pending running commands to terminate */
1110         synchronize_srcu(&uverbs_dev->disassociate_srcu);
1111         event.event = IB_EVENT_DEVICE_FATAL;
1112         event.element.port_num = 0;
1113         event.device = ib_dev;
1114
1115         mutex_lock(&uverbs_dev->lists_mutex);
1116         while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1117                 struct ib_ucontext *ucontext;
1118                 file = list_first_entry(&uverbs_dev->uverbs_file_list,
1119                                         struct ib_uverbs_file, list);
1120                 file->is_closed = 1;
1121                 list_del(&file->list);
1122                 kref_get(&file->ref);
1123                 mutex_unlock(&uverbs_dev->lists_mutex);
1124
1125
1126                 mutex_lock(&file->cleanup_mutex);
1127                 ucontext = file->ucontext;
1128                 file->ucontext = NULL;
1129                 mutex_unlock(&file->cleanup_mutex);
1130
1131                 /* At this point ib_uverbs_close cannot be running
1132                  * ib_uverbs_cleanup_ucontext
1133                  */
1134                 if (ucontext) {
1135                         /* We must release the mutex before going ahead and
1136                          * calling disassociate_ucontext. disassociate_ucontext
1137                          * might end up indirectly calling uverbs_close,
1138                          * for example due to freeing the resources
1139                          * (e.g mmput).
1140                          */
1141                         ib_uverbs_event_handler(&file->event_handler, &event);
1142                         ib_dev->disassociate_ucontext(ucontext);
1143                         mutex_lock(&file->cleanup_mutex);
1144                         ib_uverbs_cleanup_ucontext(file, ucontext, true);
1145                         mutex_unlock(&file->cleanup_mutex);
1146                 }
1147
1148                 mutex_lock(&uverbs_dev->lists_mutex);
1149                 kref_put(&file->ref, ib_uverbs_release_file);
1150         }
1151
1152         while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1153                 event_file = list_first_entry(&uverbs_dev->
1154                                               uverbs_events_file_list,
1155                                               struct ib_uverbs_async_event_file,
1156                                               list);
1157                 spin_lock_irq(&event_file->ev_queue.lock);
1158                 event_file->ev_queue.is_closed = 1;
1159                 spin_unlock_irq(&event_file->ev_queue.lock);
1160
1161                 list_del(&event_file->list);
1162                 ib_unregister_event_handler(
1163                         &event_file->uverbs_file->event_handler);
1164                 event_file->uverbs_file->event_handler.device =
1165                         NULL;
1166
1167                 wake_up_interruptible(&event_file->ev_queue.poll_wait);
1168                 kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1169         }
1170         mutex_unlock(&uverbs_dev->lists_mutex);
1171 }
1172
1173 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1174 {
1175         struct ib_uverbs_device *uverbs_dev = client_data;
1176         int wait_clients = 1;
1177
1178         if (!uverbs_dev)
1179                 return;
1180
1181         dev_set_drvdata(uverbs_dev->dev, NULL);
1182         device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1183         cdev_del(&uverbs_dev->cdev);
1184         clear_bit(uverbs_dev->devnum, dev_map);
1185
1186         if (device->disassociate_ucontext) {
1187                 /* We disassociate HW resources and immediately return.
1188                  * Userspace will see a EIO errno for all future access.
1189                  * Upon returning, ib_device may be freed internally and is not
1190                  * valid any more.
1191                  * uverbs_device is still available until all clients close
1192                  * their files, then the uverbs device ref count will be zero
1193                  * and its resources will be freed.
1194                  * Note: At this point no more files can be opened since the
1195                  * cdev was deleted, however active clients can still issue
1196                  * commands and close their open files.
1197                  */
1198                 rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1199                 ib_uverbs_free_hw_resources(uverbs_dev, device);
1200                 wait_clients = 0;
1201         }
1202
1203         if (atomic_dec_and_test(&uverbs_dev->refcount))
1204                 ib_uverbs_comp_dev(uverbs_dev);
1205         if (wait_clients)
1206                 wait_for_completion(&uverbs_dev->comp);
1207         if (uverbs_dev->specs_root) {
1208                 uverbs_free_spec_tree(uverbs_dev->specs_root);
1209                 device->specs_root = NULL;
1210         }
1211
1212         kobject_put(&uverbs_dev->kobj);
1213 }
1214
1215 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1216 {
1217         if (mode)
1218                 *mode = 0666;
1219         return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1220 }
1221
1222 static int __init ib_uverbs_init(void)
1223 {
1224         int ret;
1225
1226         ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1227                                      IB_UVERBS_NUM_FIXED_MINOR,
1228                                      "infiniband_verbs");
1229         if (ret) {
1230                 pr_err("user_verbs: couldn't register device number\n");
1231                 goto out;
1232         }
1233
1234         ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1235                                   IB_UVERBS_NUM_DYNAMIC_MINOR,
1236                                   "infiniband_verbs");
1237         if (ret) {
1238                 pr_err("couldn't register dynamic device number\n");
1239                 goto out_alloc;
1240         }
1241
1242         uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1243         if (IS_ERR(uverbs_class)) {
1244                 ret = PTR_ERR(uverbs_class);
1245                 pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1246                 goto out_chrdev;
1247         }
1248
1249         uverbs_class->devnode = uverbs_devnode;
1250
1251         ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1252         if (ret) {
1253                 pr_err("user_verbs: couldn't create abi_version attribute\n");
1254                 goto out_class;
1255         }
1256
1257         ret = ib_register_client(&uverbs_client);
1258         if (ret) {
1259                 pr_err("user_verbs: couldn't register client\n");
1260                 goto out_class;
1261         }
1262
1263         return 0;
1264
1265 out_class:
1266         class_destroy(uverbs_class);
1267
1268 out_chrdev:
1269         unregister_chrdev_region(dynamic_uverbs_dev,
1270                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1271
1272 out_alloc:
1273         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1274                                  IB_UVERBS_NUM_FIXED_MINOR);
1275
1276 out:
1277         return ret;
1278 }
1279
1280 static void __exit ib_uverbs_cleanup(void)
1281 {
1282         ib_unregister_client(&uverbs_client);
1283         class_destroy(uverbs_class);
1284         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1285                                  IB_UVERBS_NUM_FIXED_MINOR);
1286         unregister_chrdev_region(dynamic_uverbs_dev,
1287                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1288 }
1289
1290 module_init(ib_uverbs_init);
1291 module_exit(ib_uverbs_cleanup);