IB/uverbs: BKL is not needed for ib_uverbs_open()
[linux-2.6] / 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  * $Id: uverbs_main.c 2733 2005-06-28 19:14:34Z roland $
37  */
38
39 #include <linux/module.h>
40 #include <linux/init.h>
41 #include <linux/device.h>
42 #include <linux/err.h>
43 #include <linux/fs.h>
44 #include <linux/poll.h>
45 #include <linux/file.h>
46 #include <linux/mount.h>
47 #include <linux/cdev.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 #define INFINIBANDEVENTFS_MAGIC 0x49426576      /* "IBev" */
58
59 enum {
60         IB_UVERBS_MAJOR       = 231,
61         IB_UVERBS_BASE_MINOR  = 192,
62         IB_UVERBS_MAX_DEVICES = 32
63 };
64
65 #define IB_UVERBS_BASE_DEV      MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
66
67 static struct class *uverbs_class;
68
69 DEFINE_SPINLOCK(ib_uverbs_idr_lock);
70 DEFINE_IDR(ib_uverbs_pd_idr);
71 DEFINE_IDR(ib_uverbs_mr_idr);
72 DEFINE_IDR(ib_uverbs_mw_idr);
73 DEFINE_IDR(ib_uverbs_ah_idr);
74 DEFINE_IDR(ib_uverbs_cq_idr);
75 DEFINE_IDR(ib_uverbs_qp_idr);
76 DEFINE_IDR(ib_uverbs_srq_idr);
77
78 static spinlock_t map_lock;
79 static struct ib_uverbs_device *dev_table[IB_UVERBS_MAX_DEVICES];
80 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
81
82 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
83                                      const char __user *buf, int in_len,
84                                      int out_len) = {
85         [IB_USER_VERBS_CMD_GET_CONTEXT]         = ib_uverbs_get_context,
86         [IB_USER_VERBS_CMD_QUERY_DEVICE]        = ib_uverbs_query_device,
87         [IB_USER_VERBS_CMD_QUERY_PORT]          = ib_uverbs_query_port,
88         [IB_USER_VERBS_CMD_ALLOC_PD]            = ib_uverbs_alloc_pd,
89         [IB_USER_VERBS_CMD_DEALLOC_PD]          = ib_uverbs_dealloc_pd,
90         [IB_USER_VERBS_CMD_REG_MR]              = ib_uverbs_reg_mr,
91         [IB_USER_VERBS_CMD_DEREG_MR]            = ib_uverbs_dereg_mr,
92         [IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
93         [IB_USER_VERBS_CMD_CREATE_CQ]           = ib_uverbs_create_cq,
94         [IB_USER_VERBS_CMD_RESIZE_CQ]           = ib_uverbs_resize_cq,
95         [IB_USER_VERBS_CMD_POLL_CQ]             = ib_uverbs_poll_cq,
96         [IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]       = ib_uverbs_req_notify_cq,
97         [IB_USER_VERBS_CMD_DESTROY_CQ]          = ib_uverbs_destroy_cq,
98         [IB_USER_VERBS_CMD_CREATE_QP]           = ib_uverbs_create_qp,
99         [IB_USER_VERBS_CMD_QUERY_QP]            = ib_uverbs_query_qp,
100         [IB_USER_VERBS_CMD_MODIFY_QP]           = ib_uverbs_modify_qp,
101         [IB_USER_VERBS_CMD_DESTROY_QP]          = ib_uverbs_destroy_qp,
102         [IB_USER_VERBS_CMD_POST_SEND]           = ib_uverbs_post_send,
103         [IB_USER_VERBS_CMD_POST_RECV]           = ib_uverbs_post_recv,
104         [IB_USER_VERBS_CMD_POST_SRQ_RECV]       = ib_uverbs_post_srq_recv,
105         [IB_USER_VERBS_CMD_CREATE_AH]           = ib_uverbs_create_ah,
106         [IB_USER_VERBS_CMD_DESTROY_AH]          = ib_uverbs_destroy_ah,
107         [IB_USER_VERBS_CMD_ATTACH_MCAST]        = ib_uverbs_attach_mcast,
108         [IB_USER_VERBS_CMD_DETACH_MCAST]        = ib_uverbs_detach_mcast,
109         [IB_USER_VERBS_CMD_CREATE_SRQ]          = ib_uverbs_create_srq,
110         [IB_USER_VERBS_CMD_MODIFY_SRQ]          = ib_uverbs_modify_srq,
111         [IB_USER_VERBS_CMD_QUERY_SRQ]           = ib_uverbs_query_srq,
112         [IB_USER_VERBS_CMD_DESTROY_SRQ]         = ib_uverbs_destroy_srq,
113 };
114
115 static struct vfsmount *uverbs_event_mnt;
116
117 static void ib_uverbs_add_one(struct ib_device *device);
118 static void ib_uverbs_remove_one(struct ib_device *device);
119
120 static void ib_uverbs_release_dev(struct kref *ref)
121 {
122         struct ib_uverbs_device *dev =
123                 container_of(ref, struct ib_uverbs_device, ref);
124
125         complete(&dev->comp);
126 }
127
128 static void ib_uverbs_release_event_file(struct kref *ref)
129 {
130         struct ib_uverbs_event_file *file =
131                 container_of(ref, struct ib_uverbs_event_file, ref);
132
133         kfree(file);
134 }
135
136 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
137                           struct ib_uverbs_event_file *ev_file,
138                           struct ib_ucq_object *uobj)
139 {
140         struct ib_uverbs_event *evt, *tmp;
141
142         if (ev_file) {
143                 spin_lock_irq(&ev_file->lock);
144                 list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
145                         list_del(&evt->list);
146                         kfree(evt);
147                 }
148                 spin_unlock_irq(&ev_file->lock);
149
150                 kref_put(&ev_file->ref, ib_uverbs_release_event_file);
151         }
152
153         spin_lock_irq(&file->async_file->lock);
154         list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
155                 list_del(&evt->list);
156                 kfree(evt);
157         }
158         spin_unlock_irq(&file->async_file->lock);
159 }
160
161 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
162                               struct ib_uevent_object *uobj)
163 {
164         struct ib_uverbs_event *evt, *tmp;
165
166         spin_lock_irq(&file->async_file->lock);
167         list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
168                 list_del(&evt->list);
169                 kfree(evt);
170         }
171         spin_unlock_irq(&file->async_file->lock);
172 }
173
174 static void ib_uverbs_detach_umcast(struct ib_qp *qp,
175                                     struct ib_uqp_object *uobj)
176 {
177         struct ib_uverbs_mcast_entry *mcast, *tmp;
178
179         list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
180                 ib_detach_mcast(qp, &mcast->gid, mcast->lid);
181                 list_del(&mcast->list);
182                 kfree(mcast);
183         }
184 }
185
186 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
187                                       struct ib_ucontext *context)
188 {
189         struct ib_uobject *uobj, *tmp;
190
191         if (!context)
192                 return 0;
193
194         context->closing = 1;
195
196         list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
197                 struct ib_ah *ah = uobj->object;
198
199                 idr_remove_uobj(&ib_uverbs_ah_idr, uobj);
200                 ib_destroy_ah(ah);
201                 kfree(uobj);
202         }
203
204         list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
205                 struct ib_qp *qp = uobj->object;
206                 struct ib_uqp_object *uqp =
207                         container_of(uobj, struct ib_uqp_object, uevent.uobject);
208
209                 idr_remove_uobj(&ib_uverbs_qp_idr, uobj);
210                 ib_uverbs_detach_umcast(qp, uqp);
211                 ib_destroy_qp(qp);
212                 ib_uverbs_release_uevent(file, &uqp->uevent);
213                 kfree(uqp);
214         }
215
216         list_for_each_entry_safe(uobj, tmp, &context->cq_list, list) {
217                 struct ib_cq *cq = uobj->object;
218                 struct ib_uverbs_event_file *ev_file = cq->cq_context;
219                 struct ib_ucq_object *ucq =
220                         container_of(uobj, struct ib_ucq_object, uobject);
221
222                 idr_remove_uobj(&ib_uverbs_cq_idr, uobj);
223                 ib_destroy_cq(cq);
224                 ib_uverbs_release_ucq(file, ev_file, ucq);
225                 kfree(ucq);
226         }
227
228         list_for_each_entry_safe(uobj, tmp, &context->srq_list, list) {
229                 struct ib_srq *srq = uobj->object;
230                 struct ib_uevent_object *uevent =
231                         container_of(uobj, struct ib_uevent_object, uobject);
232
233                 idr_remove_uobj(&ib_uverbs_srq_idr, uobj);
234                 ib_destroy_srq(srq);
235                 ib_uverbs_release_uevent(file, uevent);
236                 kfree(uevent);
237         }
238
239         /* XXX Free MWs */
240
241         list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
242                 struct ib_mr *mr = uobj->object;
243
244                 idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
245                 ib_dereg_mr(mr);
246                 kfree(uobj);
247         }
248
249         list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
250                 struct ib_pd *pd = uobj->object;
251
252                 idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
253                 ib_dealloc_pd(pd);
254                 kfree(uobj);
255         }
256
257         return context->device->dealloc_ucontext(context);
258 }
259
260 static void ib_uverbs_release_file(struct kref *ref)
261 {
262         struct ib_uverbs_file *file =
263                 container_of(ref, struct ib_uverbs_file, ref);
264
265         module_put(file->device->ib_dev->owner);
266         kref_put(&file->device->ref, ib_uverbs_release_dev);
267
268         kfree(file);
269 }
270
271 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
272                                     size_t count, loff_t *pos)
273 {
274         struct ib_uverbs_event_file *file = filp->private_data;
275         struct ib_uverbs_event *event;
276         int eventsz;
277         int ret = 0;
278
279         spin_lock_irq(&file->lock);
280
281         while (list_empty(&file->event_list)) {
282                 spin_unlock_irq(&file->lock);
283
284                 if (filp->f_flags & O_NONBLOCK)
285                         return -EAGAIN;
286
287                 if (wait_event_interruptible(file->poll_wait,
288                                              !list_empty(&file->event_list)))
289                         return -ERESTARTSYS;
290
291                 spin_lock_irq(&file->lock);
292         }
293
294         event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
295
296         if (file->is_async)
297                 eventsz = sizeof (struct ib_uverbs_async_event_desc);
298         else
299                 eventsz = sizeof (struct ib_uverbs_comp_event_desc);
300
301         if (eventsz > count) {
302                 ret   = -EINVAL;
303                 event = NULL;
304         } else {
305                 list_del(file->event_list.next);
306                 if (event->counter) {
307                         ++(*event->counter);
308                         list_del(&event->obj_list);
309                 }
310         }
311
312         spin_unlock_irq(&file->lock);
313
314         if (event) {
315                 if (copy_to_user(buf, event, eventsz))
316                         ret = -EFAULT;
317                 else
318                         ret = eventsz;
319         }
320
321         kfree(event);
322
323         return ret;
324 }
325
326 static unsigned int ib_uverbs_event_poll(struct file *filp,
327                                          struct poll_table_struct *wait)
328 {
329         unsigned int pollflags = 0;
330         struct ib_uverbs_event_file *file = filp->private_data;
331
332         poll_wait(filp, &file->poll_wait, wait);
333
334         spin_lock_irq(&file->lock);
335         if (!list_empty(&file->event_list))
336                 pollflags = POLLIN | POLLRDNORM;
337         spin_unlock_irq(&file->lock);
338
339         return pollflags;
340 }
341
342 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
343 {
344         struct ib_uverbs_event_file *file = filp->private_data;
345
346         return fasync_helper(fd, filp, on, &file->async_queue);
347 }
348
349 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
350 {
351         struct ib_uverbs_event_file *file = filp->private_data;
352         struct ib_uverbs_event *entry, *tmp;
353
354         spin_lock_irq(&file->lock);
355         file->is_closed = 1;
356         list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
357                 if (entry->counter)
358                         list_del(&entry->obj_list);
359                 kfree(entry);
360         }
361         spin_unlock_irq(&file->lock);
362
363         ib_uverbs_event_fasync(-1, filp, 0);
364
365         if (file->is_async) {
366                 ib_unregister_event_handler(&file->uverbs_file->event_handler);
367                 kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
368         }
369         kref_put(&file->ref, ib_uverbs_release_event_file);
370
371         return 0;
372 }
373
374 static const struct file_operations uverbs_event_fops = {
375         .owner   = THIS_MODULE,
376         .read    = ib_uverbs_event_read,
377         .poll    = ib_uverbs_event_poll,
378         .release = ib_uverbs_event_close,
379         .fasync  = ib_uverbs_event_fasync
380 };
381
382 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
383 {
384         struct ib_uverbs_event_file    *file = cq_context;
385         struct ib_ucq_object           *uobj;
386         struct ib_uverbs_event         *entry;
387         unsigned long                   flags;
388
389         if (!file)
390                 return;
391
392         spin_lock_irqsave(&file->lock, flags);
393         if (file->is_closed) {
394                 spin_unlock_irqrestore(&file->lock, flags);
395                 return;
396         }
397
398         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
399         if (!entry) {
400                 spin_unlock_irqrestore(&file->lock, flags);
401                 return;
402         }
403
404         uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
405
406         entry->desc.comp.cq_handle = cq->uobject->user_handle;
407         entry->counter             = &uobj->comp_events_reported;
408
409         list_add_tail(&entry->list, &file->event_list);
410         list_add_tail(&entry->obj_list, &uobj->comp_list);
411         spin_unlock_irqrestore(&file->lock, flags);
412
413         wake_up_interruptible(&file->poll_wait);
414         kill_fasync(&file->async_queue, SIGIO, POLL_IN);
415 }
416
417 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
418                                     __u64 element, __u64 event,
419                                     struct list_head *obj_list,
420                                     u32 *counter)
421 {
422         struct ib_uverbs_event *entry;
423         unsigned long flags;
424
425         spin_lock_irqsave(&file->async_file->lock, flags);
426         if (!file->async_file->is_closed) {
427                 spin_unlock_irqrestore(&file->async_file->lock, flags);
428                 return;
429         }
430
431         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
432         if (!entry) {
433                 spin_unlock_irqrestore(&file->async_file->lock, flags);
434                 return;
435         }
436
437         entry->desc.async.element    = element;
438         entry->desc.async.event_type = event;
439         entry->counter               = counter;
440
441         list_add_tail(&entry->list, &file->async_file->event_list);
442         if (obj_list)
443                 list_add_tail(&entry->obj_list, obj_list);
444         spin_unlock_irqrestore(&file->async_file->lock, flags);
445
446         wake_up_interruptible(&file->async_file->poll_wait);
447         kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
448 }
449
450 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
451 {
452         struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
453                                                   struct ib_ucq_object, uobject);
454
455         ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
456                                 event->event, &uobj->async_list,
457                                 &uobj->async_events_reported);
458 }
459
460 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
461 {
462         struct ib_uevent_object *uobj;
463
464         uobj = container_of(event->element.qp->uobject,
465                             struct ib_uevent_object, uobject);
466
467         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
468                                 event->event, &uobj->event_list,
469                                 &uobj->events_reported);
470 }
471
472 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
473 {
474         struct ib_uevent_object *uobj;
475
476         uobj = container_of(event->element.srq->uobject,
477                             struct ib_uevent_object, uobject);
478
479         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
480                                 event->event, &uobj->event_list,
481                                 &uobj->events_reported);
482 }
483
484 void ib_uverbs_event_handler(struct ib_event_handler *handler,
485                              struct ib_event *event)
486 {
487         struct ib_uverbs_file *file =
488                 container_of(handler, struct ib_uverbs_file, event_handler);
489
490         ib_uverbs_async_handler(file, event->element.port_num, event->event,
491                                 NULL, NULL);
492 }
493
494 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
495                                         int is_async, int *fd)
496 {
497         struct ib_uverbs_event_file *ev_file;
498         struct file *filp;
499         int ret;
500
501         ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL);
502         if (!ev_file)
503                 return ERR_PTR(-ENOMEM);
504
505         kref_init(&ev_file->ref);
506         spin_lock_init(&ev_file->lock);
507         INIT_LIST_HEAD(&ev_file->event_list);
508         init_waitqueue_head(&ev_file->poll_wait);
509         ev_file->uverbs_file = uverbs_file;
510         ev_file->async_queue = NULL;
511         ev_file->is_async    = is_async;
512         ev_file->is_closed   = 0;
513
514         *fd = get_unused_fd();
515         if (*fd < 0) {
516                 ret = *fd;
517                 goto err;
518         }
519
520         /*
521          * fops_get() can't fail here, because we're coming from a
522          * system call on a uverbs file, which will already have a
523          * module reference.
524          */
525         filp = alloc_file(uverbs_event_mnt, dget(uverbs_event_mnt->mnt_root),
526                           FMODE_READ, fops_get(&uverbs_event_fops));
527         if (!filp) {
528                 ret = -ENFILE;
529                 goto err_fd;
530         }
531
532         filp->private_data = ev_file;
533
534         return filp;
535
536 err_fd:
537         put_unused_fd(*fd);
538
539 err:
540         kfree(ev_file);
541         return ERR_PTR(ret);
542 }
543
544 /*
545  * Look up a completion event file by FD.  If lookup is successful,
546  * takes a ref to the event file struct that it returns; if
547  * unsuccessful, returns NULL.
548  */
549 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
550 {
551         struct ib_uverbs_event_file *ev_file = NULL;
552         struct file *filp;
553
554         filp = fget(fd);
555         if (!filp)
556                 return NULL;
557
558         if (filp->f_op != &uverbs_event_fops)
559                 goto out;
560
561         ev_file = filp->private_data;
562         if (ev_file->is_async) {
563                 ev_file = NULL;
564                 goto out;
565         }
566
567         kref_get(&ev_file->ref);
568
569 out:
570         fput(filp);
571         return ev_file;
572 }
573
574 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
575                              size_t count, loff_t *pos)
576 {
577         struct ib_uverbs_file *file = filp->private_data;
578         struct ib_uverbs_cmd_hdr hdr;
579
580         if (count < sizeof hdr)
581                 return -EINVAL;
582
583         if (copy_from_user(&hdr, buf, sizeof hdr))
584                 return -EFAULT;
585
586         if (hdr.in_words * 4 != count)
587                 return -EINVAL;
588
589         if (hdr.command < 0                             ||
590             hdr.command >= ARRAY_SIZE(uverbs_cmd_table) ||
591             !uverbs_cmd_table[hdr.command]              ||
592             !(file->device->ib_dev->uverbs_cmd_mask & (1ull << hdr.command)))
593                 return -EINVAL;
594
595         if (!file->ucontext &&
596             hdr.command != IB_USER_VERBS_CMD_GET_CONTEXT)
597                 return -EINVAL;
598
599         return uverbs_cmd_table[hdr.command](file, buf + sizeof hdr,
600                                              hdr.in_words * 4, hdr.out_words * 4);
601 }
602
603 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
604 {
605         struct ib_uverbs_file *file = filp->private_data;
606
607         if (!file->ucontext)
608                 return -ENODEV;
609         else
610                 return file->device->ib_dev->mmap(file->ucontext, vma);
611 }
612
613 /*
614  * ib_uverbs_open() does not need the BKL:
615  *
616  *  - dev_table[] accesses are protected by map_lock, the
617  *    ib_uverbs_device structures are properly reference counted, and
618  *    everything else is purely local to the file being created, so
619  *    races against other open calls are not a problem;
620  *  - there is no ioctl method to race against;
621  *  - the device is added to dev_table[] as the last part of module
622  *    initialization, the open method will either immediately run
623  *    -ENXIO, or all required initialization will be done.
624  */
625 static int ib_uverbs_open(struct inode *inode, struct file *filp)
626 {
627         struct ib_uverbs_device *dev;
628         struct ib_uverbs_file *file;
629         int ret;
630
631         spin_lock(&map_lock);
632         dev = dev_table[iminor(inode) - IB_UVERBS_BASE_MINOR];
633         if (dev)
634                 kref_get(&dev->ref);
635         spin_unlock(&map_lock);
636
637         if (!dev)
638                 return -ENXIO;
639
640         if (!try_module_get(dev->ib_dev->owner)) {
641                 ret = -ENODEV;
642                 goto err;
643         }
644
645         file = kmalloc(sizeof *file, GFP_KERNEL);
646         if (!file) {
647                 ret = -ENOMEM;
648                 goto err_module;
649         }
650
651         file->device     = dev;
652         file->ucontext   = NULL;
653         file->async_file = NULL;
654         kref_init(&file->ref);
655         mutex_init(&file->mutex);
656
657         filp->private_data = file;
658
659         return 0;
660
661 err_module:
662         module_put(dev->ib_dev->owner);
663
664 err:
665         kref_put(&dev->ref, ib_uverbs_release_dev);
666         return ret;
667 }
668
669 static int ib_uverbs_close(struct inode *inode, struct file *filp)
670 {
671         struct ib_uverbs_file *file = filp->private_data;
672
673         ib_uverbs_cleanup_ucontext(file, file->ucontext);
674
675         if (file->async_file)
676                 kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
677
678         kref_put(&file->ref, ib_uverbs_release_file);
679
680         return 0;
681 }
682
683 static const struct file_operations uverbs_fops = {
684         .owner   = THIS_MODULE,
685         .write   = ib_uverbs_write,
686         .open    = ib_uverbs_open,
687         .release = ib_uverbs_close
688 };
689
690 static const struct file_operations uverbs_mmap_fops = {
691         .owner   = THIS_MODULE,
692         .write   = ib_uverbs_write,
693         .mmap    = ib_uverbs_mmap,
694         .open    = ib_uverbs_open,
695         .release = ib_uverbs_close
696 };
697
698 static struct ib_client uverbs_client = {
699         .name   = "uverbs",
700         .add    = ib_uverbs_add_one,
701         .remove = ib_uverbs_remove_one
702 };
703
704 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
705                           char *buf)
706 {
707         struct ib_uverbs_device *dev = dev_get_drvdata(device);
708
709         if (!dev)
710                 return -ENODEV;
711
712         return sprintf(buf, "%s\n", dev->ib_dev->name);
713 }
714 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
715
716 static ssize_t show_dev_abi_version(struct device *device,
717                                     struct device_attribute *attr, char *buf)
718 {
719         struct ib_uverbs_device *dev = dev_get_drvdata(device);
720
721         if (!dev)
722                 return -ENODEV;
723
724         return sprintf(buf, "%d\n", dev->ib_dev->uverbs_abi_ver);
725 }
726 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
727
728 static ssize_t show_abi_version(struct class *class, char *buf)
729 {
730         return sprintf(buf, "%d\n", IB_USER_VERBS_ABI_VERSION);
731 }
732 static CLASS_ATTR(abi_version, S_IRUGO, show_abi_version, NULL);
733
734 static void ib_uverbs_add_one(struct ib_device *device)
735 {
736         struct ib_uverbs_device *uverbs_dev;
737
738         if (!device->alloc_ucontext)
739                 return;
740
741         uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
742         if (!uverbs_dev)
743                 return;
744
745         kref_init(&uverbs_dev->ref);
746         init_completion(&uverbs_dev->comp);
747
748         spin_lock(&map_lock);
749         uverbs_dev->devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
750         if (uverbs_dev->devnum >= IB_UVERBS_MAX_DEVICES) {
751                 spin_unlock(&map_lock);
752                 goto err;
753         }
754         set_bit(uverbs_dev->devnum, dev_map);
755         spin_unlock(&map_lock);
756
757         uverbs_dev->ib_dev           = device;
758         uverbs_dev->num_comp_vectors = device->num_comp_vectors;
759
760         uverbs_dev->cdev = cdev_alloc();
761         if (!uverbs_dev->cdev)
762                 goto err;
763         uverbs_dev->cdev->owner = THIS_MODULE;
764         uverbs_dev->cdev->ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
765         kobject_set_name(&uverbs_dev->cdev->kobj, "uverbs%d", uverbs_dev->devnum);
766         if (cdev_add(uverbs_dev->cdev, IB_UVERBS_BASE_DEV + uverbs_dev->devnum, 1))
767                 goto err_cdev;
768
769         uverbs_dev->dev = device_create(uverbs_class, device->dma_device,
770                                         uverbs_dev->cdev->dev,
771                                         "uverbs%d", uverbs_dev->devnum);
772         if (IS_ERR(uverbs_dev->dev))
773                 goto err_cdev;
774
775         dev_set_drvdata(uverbs_dev->dev, uverbs_dev);
776
777         if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
778                 goto err_class;
779         if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
780                 goto err_class;
781
782         spin_lock(&map_lock);
783         dev_table[uverbs_dev->devnum] = uverbs_dev;
784         spin_unlock(&map_lock);
785
786         ib_set_client_data(device, &uverbs_client, uverbs_dev);
787
788         return;
789
790 err_class:
791         device_destroy(uverbs_class, uverbs_dev->cdev->dev);
792
793 err_cdev:
794         cdev_del(uverbs_dev->cdev);
795         clear_bit(uverbs_dev->devnum, dev_map);
796
797 err:
798         kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
799         wait_for_completion(&uverbs_dev->comp);
800         kfree(uverbs_dev);
801         return;
802 }
803
804 static void ib_uverbs_remove_one(struct ib_device *device)
805 {
806         struct ib_uverbs_device *uverbs_dev = ib_get_client_data(device, &uverbs_client);
807
808         if (!uverbs_dev)
809                 return;
810
811         dev_set_drvdata(uverbs_dev->dev, NULL);
812         device_destroy(uverbs_class, uverbs_dev->cdev->dev);
813         cdev_del(uverbs_dev->cdev);
814
815         spin_lock(&map_lock);
816         dev_table[uverbs_dev->devnum] = NULL;
817         spin_unlock(&map_lock);
818
819         clear_bit(uverbs_dev->devnum, dev_map);
820
821         kref_put(&uverbs_dev->ref, ib_uverbs_release_dev);
822         wait_for_completion(&uverbs_dev->comp);
823         kfree(uverbs_dev);
824 }
825
826 static int uverbs_event_get_sb(struct file_system_type *fs_type, int flags,
827                                const char *dev_name, void *data,
828                                struct vfsmount *mnt)
829 {
830         return get_sb_pseudo(fs_type, "infinibandevent:", NULL,
831                              INFINIBANDEVENTFS_MAGIC, mnt);
832 }
833
834 static struct file_system_type uverbs_event_fs = {
835         /* No owner field so module can be unloaded */
836         .name    = "infinibandeventfs",
837         .get_sb  = uverbs_event_get_sb,
838         .kill_sb = kill_litter_super
839 };
840
841 static int __init ib_uverbs_init(void)
842 {
843         int ret;
844
845         spin_lock_init(&map_lock);
846
847         ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
848                                      "infiniband_verbs");
849         if (ret) {
850                 printk(KERN_ERR "user_verbs: couldn't register device number\n");
851                 goto out;
852         }
853
854         uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
855         if (IS_ERR(uverbs_class)) {
856                 ret = PTR_ERR(uverbs_class);
857                 printk(KERN_ERR "user_verbs: couldn't create class infiniband_verbs\n");
858                 goto out_chrdev;
859         }
860
861         ret = class_create_file(uverbs_class, &class_attr_abi_version);
862         if (ret) {
863                 printk(KERN_ERR "user_verbs: couldn't create abi_version attribute\n");
864                 goto out_class;
865         }
866
867         ret = register_filesystem(&uverbs_event_fs);
868         if (ret) {
869                 printk(KERN_ERR "user_verbs: couldn't register infinibandeventfs\n");
870                 goto out_class;
871         }
872
873         uverbs_event_mnt = kern_mount(&uverbs_event_fs);
874         if (IS_ERR(uverbs_event_mnt)) {
875                 ret = PTR_ERR(uverbs_event_mnt);
876                 printk(KERN_ERR "user_verbs: couldn't mount infinibandeventfs\n");
877                 goto out_fs;
878         }
879
880         ret = ib_register_client(&uverbs_client);
881         if (ret) {
882                 printk(KERN_ERR "user_verbs: couldn't register client\n");
883                 goto out_mnt;
884         }
885
886         return 0;
887
888 out_mnt:
889         mntput(uverbs_event_mnt);
890
891 out_fs:
892         unregister_filesystem(&uverbs_event_fs);
893
894 out_class:
895         class_destroy(uverbs_class);
896
897 out_chrdev:
898         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
899
900 out:
901         return ret;
902 }
903
904 static void __exit ib_uverbs_cleanup(void)
905 {
906         ib_unregister_client(&uverbs_client);
907         mntput(uverbs_event_mnt);
908         unregister_filesystem(&uverbs_event_fs);
909         class_destroy(uverbs_class);
910         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
911         idr_destroy(&ib_uverbs_pd_idr);
912         idr_destroy(&ib_uverbs_mr_idr);
913         idr_destroy(&ib_uverbs_mw_idr);
914         idr_destroy(&ib_uverbs_ah_idr);
915         idr_destroy(&ib_uverbs_cq_idr);
916         idr_destroy(&ib_uverbs_qp_idr);
917         idr_destroy(&ib_uverbs_srq_idr);
918 }
919
920 module_init(ib_uverbs_init);
921 module_exit(ib_uverbs_cleanup);