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 #include <linux/sched/mm.h>
  49
  50 #include <linux/uaccess.h>
  51
  52 #include <rdma/ib.h>
  53 #include <rdma/uverbs_std_types.h>
  54 #include <rdma/rdma_netlink.h>
  55
  56 #include "uverbs.h"
  57 #include "core_priv.h"
  58 #include "rdma_core.h"
  59
  60 MODULE_AUTHOR("Roland Dreier");
  61 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
  62 MODULE_LICENSE("Dual BSD/GPL");
  63
  64 enum {
  65         IB_UVERBS_MAJOR       = 231,
  66         IB_UVERBS_BASE_MINOR  = 192,
  67         IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
  68         IB_UVERBS_NUM_FIXED_MINOR = 32,
  69         IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
  70 };
  71
  72 #define IB_UVERBS_BASE_DEV      MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
  73
  74 static dev_t dynamic_uverbs_dev;
  75
  76 static DEFINE_IDA(uverbs_ida);
  77 static int ib_uverbs_add_one(struct ib_device *device);
  78 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
  79
  80 static char *uverbs_devnode(const struct device *dev, umode_t *mode)
  81 {
  82         if (mode)
  83                 *mode = 0666;
  84         return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
  85 }
  86
  87 static const struct class uverbs_class = {
  88         .name = "infiniband_verbs",
  89         .devnode = uverbs_devnode,
  90 };
  91
  92 /*
  93  * Must be called with the ufile->device->disassociate_srcu held, and the lock
  94  * must be held until use of the ucontext is finished.
  95  */
  96 struct ib_ucontext *ib_uverbs_get_ucontext_file(struct ib_uverbs_file *ufile)
  97 {
  98         /*
  99          * We do not hold the hw_destroy_rwsem lock for this flow, instead
 100          * srcu is used. It does not matter if someone races this with
 101          * get_context, we get NULL or valid ucontext.
 102          */
 103         struct ib_ucontext *ucontext = smp_load_acquire(&ufile->ucontext);
 104
 105         if (!srcu_dereference(ufile->device->ib_dev,
 106                               &ufile->device->disassociate_srcu))
 107                 return ERR_PTR(-EIO);
 108
 109         if (!ucontext)
 110                 return ERR_PTR(-EINVAL);
 111
 112         return ucontext;
 113 }
 114 EXPORT_SYMBOL(ib_uverbs_get_ucontext_file);
 115
 116 int uverbs_dealloc_mw(struct ib_mw *mw)
 117 {
 118         struct ib_pd *pd = mw->pd;
 119         int ret;
 120
 121         ret = mw->device->ops.dealloc_mw(mw);
 122         if (ret)
 123                 return ret;
 124
 125         atomic_dec(&pd->usecnt);
 126         kfree(mw);
 127         return ret;
 128 }
 129
 130 static void ib_uverbs_release_dev(struct device *device)
 131 {
 132         struct ib_uverbs_device *dev =
 133                         container_of(device, struct ib_uverbs_device, dev);
 134
 135         uverbs_destroy_api(dev->uapi);
 136         cleanup_srcu_struct(&dev->disassociate_srcu);
 137         mutex_destroy(&dev->lists_mutex);
 138         mutex_destroy(&dev->xrcd_tree_mutex);
 139         kfree(dev);
 140 }
 141
 142 void ib_uverbs_release_ucq(struct ib_uverbs_completion_event_file *ev_file,
 143                            struct ib_ucq_object *uobj)
 144 {
 145         struct ib_uverbs_event *evt, *tmp;
 146
 147         if (ev_file) {
 148                 spin_lock_irq(&ev_file->ev_queue.lock);
 149                 list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
 150                         list_del(&evt->list);
 151                         kfree(evt);
 152                 }
 153                 spin_unlock_irq(&ev_file->ev_queue.lock);
 154
 155                 uverbs_uobject_put(&ev_file->uobj);
 156         }
 157
 158         ib_uverbs_release_uevent(&uobj->uevent);
 159 }
 160
 161 void ib_uverbs_release_uevent(struct ib_uevent_object *uobj)
 162 {
 163         struct ib_uverbs_async_event_file *async_file = uobj->event_file;
 164         struct ib_uverbs_event *evt, *tmp;
 165
 166         if (!async_file)
 167                 return;
 168
 169         spin_lock_irq(&async_file->ev_queue.lock);
 170         list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
 171                 list_del(&evt->list);
 172                 kfree(evt);
 173         }
 174         spin_unlock_irq(&async_file->ev_queue.lock);
 175         uverbs_uobject_put(&async_file->uobj);
 176 }
 177
 178 void ib_uverbs_detach_umcast(struct ib_qp *qp,
 179                              struct ib_uqp_object *uobj)
 180 {
 181         struct ib_uverbs_mcast_entry *mcast, *tmp;
 182
 183         list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
 184                 ib_detach_mcast(qp, &mcast->gid, mcast->lid);
 185                 list_del(&mcast->list);
 186                 kfree(mcast);
 187         }
 188 }
 189
 190 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
 191 {
 192         complete(&dev->comp);
 193 }
 194
 195 void ib_uverbs_release_file(struct kref *ref)
 196 {
 197         struct ib_uverbs_file *file =
 198                 container_of(ref, struct ib_uverbs_file, ref);
 199         struct ib_device *ib_dev;
 200         int srcu_key;
 201
 202         release_ufile_idr_uobject(file);
 203
 204         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 205         ib_dev = srcu_dereference(file->device->ib_dev,
 206                                   &file->device->disassociate_srcu);
 207         if (ib_dev && !ib_dev->ops.disassociate_ucontext)
 208                 module_put(ib_dev->ops.owner);
 209         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 210
 211         if (refcount_dec_and_test(&file->device->refcount))
 212                 ib_uverbs_comp_dev(file->device);
 213
 214         if (file->default_async_file)
 215                 uverbs_uobject_put(&file->default_async_file->uobj);
 216         put_device(&file->device->dev);
 217
 218         if (file->disassociate_page)
 219                 __free_pages(file->disassociate_page, 0);
 220         mutex_destroy(&file->umap_lock);
 221         mutex_destroy(&file->ucontext_lock);
 222         kfree(file);
 223 }
 224
 225 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
 226                                     struct file *filp, char __user *buf,
 227                                     size_t count, loff_t *pos,
 228                                     size_t eventsz)
 229 {
 230         struct ib_uverbs_event *event;
 231         int ret = 0;
 232
 233         spin_lock_irq(&ev_queue->lock);
 234
 235         while (list_empty(&ev_queue->event_list)) {
 236                 if (ev_queue->is_closed) {
 237                         spin_unlock_irq(&ev_queue->lock);
 238                         return -EIO;
 239                 }
 240
 241                 spin_unlock_irq(&ev_queue->lock);
 242                 if (filp->f_flags & O_NONBLOCK)
 243                         return -EAGAIN;
 244
 245                 if (wait_event_interruptible(ev_queue->poll_wait,
 246                                              (!list_empty(&ev_queue->event_list) ||
 247                                               ev_queue->is_closed)))
 248                         return -ERESTARTSYS;
 249
 250                 spin_lock_irq(&ev_queue->lock);
 251         }
 252
 253         event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
 254
 255         if (eventsz > count) {
 256                 ret   = -EINVAL;
 257                 event = NULL;
 258         } else {
 259                 list_del(ev_queue->event_list.next);
 260                 if (event->counter) {
 261                         ++(*event->counter);
 262                         list_del(&event->obj_list);
 263                 }
 264         }
 265
 266         spin_unlock_irq(&ev_queue->lock);
 267
 268         if (event) {
 269                 if (copy_to_user(buf, event, eventsz))
 270                         ret = -EFAULT;
 271                 else
 272                         ret = eventsz;
 273         }
 274
 275         kfree(event);
 276
 277         return ret;
 278 }
 279
 280 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
 281                                           size_t count, loff_t *pos)
 282 {
 283         struct ib_uverbs_async_event_file *file = filp->private_data;
 284
 285         return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos,
 286                                     sizeof(struct ib_uverbs_async_event_desc));
 287 }
 288
 289 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
 290                                          size_t count, loff_t *pos)
 291 {
 292         struct ib_uverbs_completion_event_file *comp_ev_file =
 293                 filp->private_data;
 294
 295         return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count,
 296                                     pos,
 297                                     sizeof(struct ib_uverbs_comp_event_desc));
 298 }
 299
 300 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
 301                                          struct file *filp,
 302                                          struct poll_table_struct *wait)
 303 {
 304         __poll_t pollflags = 0;
 305
 306         poll_wait(filp, &ev_queue->poll_wait, wait);
 307
 308         spin_lock_irq(&ev_queue->lock);
 309         if (!list_empty(&ev_queue->event_list))
 310                 pollflags = EPOLLIN | EPOLLRDNORM;
 311         else if (ev_queue->is_closed)
 312                 pollflags = EPOLLERR;
 313         spin_unlock_irq(&ev_queue->lock);
 314
 315         return pollflags;
 316 }
 317
 318 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
 319                                                struct poll_table_struct *wait)
 320 {
 321         struct ib_uverbs_async_event_file *file = filp->private_data;
 322
 323         return ib_uverbs_event_poll(&file->ev_queue, filp, wait);
 324 }
 325
 326 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
 327                                               struct poll_table_struct *wait)
 328 {
 329         struct ib_uverbs_completion_event_file *comp_ev_file =
 330                 filp->private_data;
 331
 332         return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
 333 }
 334
 335 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
 336 {
 337         struct ib_uverbs_async_event_file *file = filp->private_data;
 338
 339         return fasync_helper(fd, filp, on, &file->ev_queue.async_queue);
 340 }
 341
 342 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
 343 {
 344         struct ib_uverbs_completion_event_file *comp_ev_file =
 345                 filp->private_data;
 346
 347         return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
 348 }
 349
 350 const struct file_operations uverbs_event_fops = {
 351         .owner   = THIS_MODULE,
 352         .read    = ib_uverbs_comp_event_read,
 353         .poll    = ib_uverbs_comp_event_poll,
 354         .release = uverbs_uobject_fd_release,
 355         .fasync  = ib_uverbs_comp_event_fasync,
 356         .llseek  = no_llseek,
 357 };
 358
 359 const struct file_operations uverbs_async_event_fops = {
 360         .owner   = THIS_MODULE,
 361         .read    = ib_uverbs_async_event_read,
 362         .poll    = ib_uverbs_async_event_poll,
 363         .release = uverbs_async_event_release,
 364         .fasync  = ib_uverbs_async_event_fasync,
 365         .llseek  = no_llseek,
 366 };
 367
 368 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
 369 {
 370         struct ib_uverbs_event_queue   *ev_queue = cq_context;
 371         struct ib_ucq_object           *uobj;
 372         struct ib_uverbs_event         *entry;
 373         unsigned long                   flags;
 374
 375         if (!ev_queue)
 376                 return;
 377
 378         spin_lock_irqsave(&ev_queue->lock, flags);
 379         if (ev_queue->is_closed) {
 380                 spin_unlock_irqrestore(&ev_queue->lock, flags);
 381                 return;
 382         }
 383
 384         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 385         if (!entry) {
 386                 spin_unlock_irqrestore(&ev_queue->lock, flags);
 387                 return;
 388         }
 389
 390         uobj = cq->uobject;
 391
 392         entry->desc.comp.cq_handle = cq->uobject->uevent.uobject.user_handle;
 393         entry->counter             = &uobj->comp_events_reported;
 394
 395         list_add_tail(&entry->list, &ev_queue->event_list);
 396         list_add_tail(&entry->obj_list, &uobj->comp_list);
 397         spin_unlock_irqrestore(&ev_queue->lock, flags);
 398
 399         wake_up_interruptible(&ev_queue->poll_wait);
 400         kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
 401 }
 402
 403 void ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
 404                              __u64 element, __u64 event,
 405                              struct list_head *obj_list, u32 *counter)
 406 {
 407         struct ib_uverbs_event *entry;
 408         unsigned long flags;
 409
 410         if (!async_file)
 411                 return;
 412
 413         spin_lock_irqsave(&async_file->ev_queue.lock, flags);
 414         if (async_file->ev_queue.is_closed) {
 415                 spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
 416                 return;
 417         }
 418
 419         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 420         if (!entry) {
 421                 spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
 422                 return;
 423         }
 424
 425         entry->desc.async.element = element;
 426         entry->desc.async.event_type = event;
 427         entry->desc.async.reserved = 0;
 428         entry->counter = counter;
 429
 430         list_add_tail(&entry->list, &async_file->ev_queue.event_list);
 431         if (obj_list)
 432                 list_add_tail(&entry->obj_list, obj_list);
 433         spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
 434
 435         wake_up_interruptible(&async_file->ev_queue.poll_wait);
 436         kill_fasync(&async_file->ev_queue.async_queue, SIGIO, POLL_IN);
 437 }
 438
 439 static void uverbs_uobj_event(struct ib_uevent_object *eobj,
 440                               struct ib_event *event)
 441 {
 442         ib_uverbs_async_handler(eobj->event_file,
 443                                 eobj->uobject.user_handle, event->event,
 444                                 &eobj->event_list, &eobj->events_reported);
 445 }
 446
 447 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
 448 {
 449         uverbs_uobj_event(&event->element.cq->uobject->uevent, event);
 450 }
 451
 452 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
 453 {
 454         /* for XRC target qp's, check that qp is live */
 455         if (!event->element.qp->uobject)
 456                 return;
 457
 458         uverbs_uobj_event(&event->element.qp->uobject->uevent, event);
 459 }
 460
 461 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
 462 {
 463         uverbs_uobj_event(&event->element.wq->uobject->uevent, event);
 464 }
 465
 466 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
 467 {
 468         uverbs_uobj_event(&event->element.srq->uobject->uevent, event);
 469 }
 470
 471 static void ib_uverbs_event_handler(struct ib_event_handler *handler,
 472                                     struct ib_event *event)
 473 {
 474         ib_uverbs_async_handler(
 475                 container_of(handler, struct ib_uverbs_async_event_file,
 476                              event_handler),
 477                 event->element.port_num, event->event, NULL, NULL);
 478 }
 479
 480 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
 481 {
 482         spin_lock_init(&ev_queue->lock);
 483         INIT_LIST_HEAD(&ev_queue->event_list);
 484         init_waitqueue_head(&ev_queue->poll_wait);
 485         ev_queue->is_closed   = 0;
 486         ev_queue->async_queue = NULL;
 487 }
 488
 489 void ib_uverbs_init_async_event_file(
 490         struct ib_uverbs_async_event_file *async_file)
 491 {
 492         struct ib_uverbs_file *uverbs_file = async_file->uobj.ufile;
 493         struct ib_device *ib_dev = async_file->uobj.context->device;
 494
 495         ib_uverbs_init_event_queue(&async_file->ev_queue);
 496
 497         /* The first async_event_file becomes the default one for the file. */
 498         mutex_lock(&uverbs_file->ucontext_lock);
 499         if (!uverbs_file->default_async_file) {
 500                 /* Pairs with the put in ib_uverbs_release_file */
 501                 uverbs_uobject_get(&async_file->uobj);
 502                 smp_store_release(&uverbs_file->default_async_file, async_file);
 503         }
 504         mutex_unlock(&uverbs_file->ucontext_lock);
 505
 506         INIT_IB_EVENT_HANDLER(&async_file->event_handler, ib_dev,
 507                               ib_uverbs_event_handler);
 508         ib_register_event_handler(&async_file->event_handler);
 509 }
 510
 511 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
 512                           struct ib_uverbs_ex_cmd_hdr *ex_hdr, size_t count,
 513                           const struct uverbs_api_write_method *method_elm)
 514 {
 515         if (method_elm->is_ex) {
 516                 count -= sizeof(*hdr) + sizeof(*ex_hdr);
 517
 518                 if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
 519                         return -EINVAL;
 520
 521                 if (hdr->in_words * 8 < method_elm->req_size)
 522                         return -ENOSPC;
 523
 524                 if (ex_hdr->cmd_hdr_reserved)
 525                         return -EINVAL;
 526
 527                 if (ex_hdr->response) {
 528                         if (!hdr->out_words && !ex_hdr->provider_out_words)
 529                                 return -EINVAL;
 530
 531                         if (hdr->out_words * 8 < method_elm->resp_size)
 532                                 return -ENOSPC;
 533
 534                         if (!access_ok(u64_to_user_ptr(ex_hdr->response),
 535                                        (hdr->out_words + ex_hdr->provider_out_words) * 8))
 536                                 return -EFAULT;
 537                 } else {
 538                         if (hdr->out_words || ex_hdr->provider_out_words)
 539                                 return -EINVAL;
 540                 }
 541
 542                 return 0;
 543         }
 544
 545         /* not extended command */
 546         if (hdr->in_words * 4 != count)
 547                 return -EINVAL;
 548
 549         if (count < method_elm->req_size + sizeof(*hdr)) {
 550                 /*
 551                  * rdma-core v18 and v19 have a bug where they send DESTROY_CQ
 552                  * with a 16 byte write instead of 24. Old kernels didn't
 553                  * check the size so they allowed this. Now that the size is
 554                  * checked provide a compatibility work around to not break
 555                  * those userspaces.
 556                  */
 557                 if (hdr->command == IB_USER_VERBS_CMD_DESTROY_CQ &&
 558                     count == 16) {
 559                         hdr->in_words = 6;
 560                         return 0;
 561                 }
 562                 return -ENOSPC;
 563         }
 564         if (hdr->out_words * 4 < method_elm->resp_size)
 565                 return -ENOSPC;
 566
 567         return 0;
 568 }
 569
 570 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 571                              size_t count, loff_t *pos)
 572 {
 573         struct ib_uverbs_file *file = filp->private_data;
 574         const struct uverbs_api_write_method *method_elm;
 575         struct uverbs_api *uapi = file->device->uapi;
 576         struct ib_uverbs_ex_cmd_hdr ex_hdr;
 577         struct ib_uverbs_cmd_hdr hdr;
 578         struct uverbs_attr_bundle bundle;
 579         int srcu_key;
 580         ssize_t ret;
 581
 582         if (!ib_safe_file_access(filp)) {
 583                 pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 584                             task_tgid_vnr(current), current->comm);
 585                 return -EACCES;
 586         }
 587
 588         if (count < sizeof(hdr))
 589                 return -EINVAL;
 590
 591         if (copy_from_user(&hdr, buf, sizeof(hdr)))
 592                 return -EFAULT;
 593
 594         method_elm = uapi_get_method(uapi, hdr.command);
 595         if (IS_ERR(method_elm))
 596                 return PTR_ERR(method_elm);
 597
 598         if (method_elm->is_ex) {
 599                 if (count < (sizeof(hdr) + sizeof(ex_hdr)))
 600                         return -EINVAL;
 601                 if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
 602                         return -EFAULT;
 603         }
 604
 605         ret = verify_hdr(&hdr, &ex_hdr, count, method_elm);
 606         if (ret)
 607                 return ret;
 608
 609         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 610
 611         buf += sizeof(hdr);
 612
 613         memset(bundle.attr_present, 0, sizeof(bundle.attr_present));
 614         bundle.ufile = file;
 615         bundle.context = NULL; /* only valid if bundle has uobject */
 616         bundle.uobject = NULL;
 617         if (!method_elm->is_ex) {
 618                 size_t in_len = hdr.in_words * 4 - sizeof(hdr);
 619                 size_t out_len = hdr.out_words * 4;
 620                 u64 response = 0;
 621
 622                 if (method_elm->has_udata) {
 623                         bundle.driver_udata.inlen =
 624                                 in_len - method_elm->req_size;
 625                         in_len = method_elm->req_size;
 626                         if (bundle.driver_udata.inlen)
 627                                 bundle.driver_udata.inbuf = buf + in_len;
 628                         else
 629                                 bundle.driver_udata.inbuf = NULL;
 630                 } else {
 631                         memset(&bundle.driver_udata, 0,
 632                                sizeof(bundle.driver_udata));
 633                 }
 634
 635                 if (method_elm->has_resp) {
 636                         /*
 637                          * The macros check that if has_resp is set
 638                          * then the command request structure starts
 639                          * with a '__aligned u64 response' member.
 640                          */
 641                         ret = get_user(response, (const u64 __user *)buf);
 642                         if (ret)
 643                                 goto out_unlock;
 644
 645                         if (method_elm->has_udata) {
 646                                 bundle.driver_udata.outlen =
 647                                         out_len - method_elm->resp_size;
 648                                 out_len = method_elm->resp_size;
 649                                 if (bundle.driver_udata.outlen)
 650                                         bundle.driver_udata.outbuf =
 651                                                 u64_to_user_ptr(response +
 652                                                                 out_len);
 653                                 else
 654                                         bundle.driver_udata.outbuf = NULL;
 655                         }
 656                 } else {
 657                         bundle.driver_udata.outlen = 0;
 658                         bundle.driver_udata.outbuf = NULL;
 659                 }
 660
 661                 ib_uverbs_init_udata_buf_or_null(
 662                         &bundle.ucore, buf, u64_to_user_ptr(response),
 663                         in_len, out_len);
 664         } else {
 665                 buf += sizeof(ex_hdr);
 666
 667                 ib_uverbs_init_udata_buf_or_null(&bundle.ucore, buf,
 668                                         u64_to_user_ptr(ex_hdr.response),
 669                                         hdr.in_words * 8, hdr.out_words * 8);
 670
 671                 ib_uverbs_init_udata_buf_or_null(
 672                         &bundle.driver_udata, buf + bundle.ucore.inlen,
 673                         u64_to_user_ptr(ex_hdr.response) + bundle.ucore.outlen,
 674                         ex_hdr.provider_in_words * 8,
 675                         ex_hdr.provider_out_words * 8);
 676
 677         }
 678
 679         ret = method_elm->handler(&bundle);
 680         if (bundle.uobject)
 681                 uverbs_finalize_object(bundle.uobject, UVERBS_ACCESS_NEW, true,
 682                                        !ret, &bundle);
 683 out_unlock:
 684         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 685         return (ret) ? : count;
 686 }
 687
 688 static const struct vm_operations_struct rdma_umap_ops;
 689
 690 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
 691 {
 692         struct ib_uverbs_file *file = filp->private_data;
 693         struct ib_ucontext *ucontext;
 694         int ret = 0;
 695         int srcu_key;
 696
 697         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 698         ucontext = ib_uverbs_get_ucontext_file(file);
 699         if (IS_ERR(ucontext)) {
 700                 ret = PTR_ERR(ucontext);
 701                 goto out;
 702         }
 703         vma->vm_ops = &rdma_umap_ops;
 704         ret = ucontext->device->ops.mmap(ucontext, vma);
 705 out:
 706         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 707         return ret;
 708 }
 709
 710 /*
 711  * The VMA has been dup'd, initialize the vm_private_data with a new tracking
 712  * struct
 713  */
 714 static void rdma_umap_open(struct vm_area_struct *vma)
 715 {
 716         struct ib_uverbs_file *ufile = vma->vm_file->private_data;
 717         struct rdma_umap_priv *opriv = vma->vm_private_data;
 718         struct rdma_umap_priv *priv;
 719
 720         if (!opriv)
 721                 return;
 722
 723         /* We are racing with disassociation */
 724         if (!down_read_trylock(&ufile->hw_destroy_rwsem))
 725                 goto out_zap;
 726         /*
 727          * Disassociation already completed, the VMA should already be zapped.
 728          */
 729         if (!ufile->ucontext)
 730                 goto out_unlock;
 731
 732         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 733         if (!priv)
 734                 goto out_unlock;
 735         rdma_umap_priv_init(priv, vma, opriv->entry);
 736
 737         up_read(&ufile->hw_destroy_rwsem);
 738         return;
 739
 740 out_unlock:
 741         up_read(&ufile->hw_destroy_rwsem);
 742 out_zap:
 743         /*
 744          * We can't allow the VMA to be created with the actual IO pages, that
 745          * would break our API contract, and it can't be stopped at this
 746          * point, so zap it.
 747          */
 748         vma->vm_private_data = NULL;
 749         zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
 750 }
 751
 752 static void rdma_umap_close(struct vm_area_struct *vma)
 753 {
 754         struct ib_uverbs_file *ufile = vma->vm_file->private_data;
 755         struct rdma_umap_priv *priv = vma->vm_private_data;
 756
 757         if (!priv)
 758                 return;
 759
 760         /*
 761          * The vma holds a reference on the struct file that created it, which
 762          * in turn means that the ib_uverbs_file is guaranteed to exist at
 763          * this point.
 764          */
 765         mutex_lock(&ufile->umap_lock);
 766         if (priv->entry)
 767                 rdma_user_mmap_entry_put(priv->entry);
 768
 769         list_del(&priv->list);
 770         mutex_unlock(&ufile->umap_lock);
 771         kfree(priv);
 772 }
 773
 774 /*
 775  * Once the zap_vma_ptes has been called touches to the VMA will come here and
 776  * we return a dummy writable zero page for all the pfns.
 777  */
 778 static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
 779 {
 780         struct ib_uverbs_file *ufile = vmf->vma->vm_file->private_data;
 781         struct rdma_umap_priv *priv = vmf->vma->vm_private_data;
 782         vm_fault_t ret = 0;
 783
 784         if (!priv)
 785                 return VM_FAULT_SIGBUS;
 786
 787         /* Read only pages can just use the system zero page. */
 788         if (!(vmf->vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
 789                 vmf->page = ZERO_PAGE(vmf->address);
 790                 get_page(vmf->page);
 791                 return 0;
 792         }
 793
 794         mutex_lock(&ufile->umap_lock);
 795         if (!ufile->disassociate_page)
 796                 ufile->disassociate_page =
 797                         alloc_pages(vmf->gfp_mask | __GFP_ZERO, 0);
 798
 799         if (ufile->disassociate_page) {
 800                 /*
 801                  * This VMA is forced to always be shared so this doesn't have
 802                  * to worry about COW.
 803                  */
 804                 vmf->page = ufile->disassociate_page;
 805                 get_page(vmf->page);
 806         } else {
 807                 ret = VM_FAULT_SIGBUS;
 808         }
 809         mutex_unlock(&ufile->umap_lock);
 810
 811         return ret;
 812 }
 813
 814 static const struct vm_operations_struct rdma_umap_ops = {
 815         .open = rdma_umap_open,
 816         .close = rdma_umap_close,
 817         .fault = rdma_umap_fault,
 818 };
 819
 820 void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
 821 {
 822         struct rdma_umap_priv *priv, *next_priv;
 823
 824         lockdep_assert_held(&ufile->hw_destroy_rwsem);
 825
 826         while (1) {
 827                 struct mm_struct *mm = NULL;
 828
 829                 /* Get an arbitrary mm pointer that hasn't been cleaned yet */
 830                 mutex_lock(&ufile->umap_lock);
 831                 while (!list_empty(&ufile->umaps)) {
 832                         int ret;
 833
 834                         priv = list_first_entry(&ufile->umaps,
 835                                                 struct rdma_umap_priv, list);
 836                         mm = priv->vma->vm_mm;
 837                         ret = mmget_not_zero(mm);
 838                         if (!ret) {
 839                                 list_del_init(&priv->list);
 840                                 if (priv->entry) {
 841                                         rdma_user_mmap_entry_put(priv->entry);
 842                                         priv->entry = NULL;
 843                                 }
 844                                 mm = NULL;
 845                                 continue;
 846                         }
 847                         break;
 848                 }
 849                 mutex_unlock(&ufile->umap_lock);
 850                 if (!mm)
 851                         return;
 852
 853                 /*
 854                  * The umap_lock is nested under mmap_lock since it used within
 855                  * the vma_ops callbacks, so we have to clean the list one mm
 856                  * at a time to get the lock ordering right. Typically there
 857                  * will only be one mm, so no big deal.
 858                  */
 859                 mmap_read_lock(mm);
 860                 mutex_lock(&ufile->umap_lock);
 861                 list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
 862                                           list) {
 863                         struct vm_area_struct *vma = priv->vma;
 864
 865                         if (vma->vm_mm != mm)
 866                                 continue;
 867                         list_del_init(&priv->list);
 868
 869                         zap_vma_ptes(vma, vma->vm_start,
 870                                      vma->vm_end - vma->vm_start);
 871
 872                         if (priv->entry) {
 873                                 rdma_user_mmap_entry_put(priv->entry);
 874                                 priv->entry = NULL;
 875                         }
 876                 }
 877                 mutex_unlock(&ufile->umap_lock);
 878                 mmap_read_unlock(mm);
 879                 mmput(mm);
 880         }
 881 }
 882
 883 /*
 884  * ib_uverbs_open() does not need the BKL:
 885  *
 886  *  - the ib_uverbs_device structures are properly reference counted and
 887  *    everything else is purely local to the file being created, so
 888  *    races against other open calls are not a problem;
 889  *  - there is no ioctl method to race against;
 890  *  - the open method will either immediately run -ENXIO, or all
 891  *    required initialization will be done.
 892  */
 893 static int ib_uverbs_open(struct inode *inode, struct file *filp)
 894 {
 895         struct ib_uverbs_device *dev;
 896         struct ib_uverbs_file *file;
 897         struct ib_device *ib_dev;
 898         int ret;
 899         int module_dependent;
 900         int srcu_key;
 901
 902         dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
 903         if (!refcount_inc_not_zero(&dev->refcount))
 904                 return -ENXIO;
 905
 906         get_device(&dev->dev);
 907         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
 908         mutex_lock(&dev->lists_mutex);
 909         ib_dev = srcu_dereference(dev->ib_dev,
 910                                   &dev->disassociate_srcu);
 911         if (!ib_dev) {
 912                 ret = -EIO;
 913                 goto err;
 914         }
 915
 916         if (!rdma_dev_access_netns(ib_dev, current->nsproxy->net_ns)) {
 917                 ret = -EPERM;
 918                 goto err;
 919         }
 920
 921         /* In case IB device supports disassociate ucontext, there is no hard
 922          * dependency between uverbs device and its low level device.
 923          */
 924         module_dependent = !(ib_dev->ops.disassociate_ucontext);
 925
 926         if (module_dependent) {
 927                 if (!try_module_get(ib_dev->ops.owner)) {
 928                         ret = -ENODEV;
 929                         goto err;
 930                 }
 931         }
 932
 933         file = kzalloc(sizeof(*file), GFP_KERNEL);
 934         if (!file) {
 935                 ret = -ENOMEM;
 936                 if (module_dependent)
 937                         goto err_module;
 938
 939                 goto err;
 940         }
 941
 942         file->device     = dev;
 943         kref_init(&file->ref);
 944         mutex_init(&file->ucontext_lock);
 945
 946         spin_lock_init(&file->uobjects_lock);
 947         INIT_LIST_HEAD(&file->uobjects);
 948         init_rwsem(&file->hw_destroy_rwsem);
 949         mutex_init(&file->umap_lock);
 950         INIT_LIST_HEAD(&file->umaps);
 951
 952         filp->private_data = file;
 953         list_add_tail(&file->list, &dev->uverbs_file_list);
 954         mutex_unlock(&dev->lists_mutex);
 955         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 956
 957         setup_ufile_idr_uobject(file);
 958
 959         return stream_open(inode, filp);
 960
 961 err_module:
 962         module_put(ib_dev->ops.owner);
 963
 964 err:
 965         mutex_unlock(&dev->lists_mutex);
 966         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 967         if (refcount_dec_and_test(&dev->refcount))
 968                 ib_uverbs_comp_dev(dev);
 969
 970         put_device(&dev->dev);
 971         return ret;
 972 }
 973
 974 static int ib_uverbs_close(struct inode *inode, struct file *filp)
 975 {
 976         struct ib_uverbs_file *file = filp->private_data;
 977
 978         uverbs_destroy_ufile_hw(file, RDMA_REMOVE_CLOSE);
 979
 980         mutex_lock(&file->device->lists_mutex);
 981         list_del_init(&file->list);
 982         mutex_unlock(&file->device->lists_mutex);
 983
 984         kref_put(&file->ref, ib_uverbs_release_file);
 985
 986         return 0;
 987 }
 988
 989 static const struct file_operations uverbs_fops = {
 990         .owner   = THIS_MODULE,
 991         .write   = ib_uverbs_write,
 992         .open    = ib_uverbs_open,
 993         .release = ib_uverbs_close,
 994         .llseek  = no_llseek,
 995         .unlocked_ioctl = ib_uverbs_ioctl,
 996         .compat_ioctl = compat_ptr_ioctl,
 997 };
 998
 999 static const struct file_operations uverbs_mmap_fops = {
1000         .owner   = THIS_MODULE,
1001         .write   = ib_uverbs_write,
1002         .mmap    = ib_uverbs_mmap,
1003         .open    = ib_uverbs_open,
1004         .release = ib_uverbs_close,
1005         .llseek  = no_llseek,
1006         .unlocked_ioctl = ib_uverbs_ioctl,
1007         .compat_ioctl = compat_ptr_ioctl,
1008 };
1009
1010 static int ib_uverbs_get_nl_info(struct ib_device *ibdev, void *client_data,
1011                                  struct ib_client_nl_info *res)
1012 {
1013         struct ib_uverbs_device *uverbs_dev = client_data;
1014         int ret;
1015
1016         if (res->port != -1)
1017                 return -EINVAL;
1018
1019         res->abi = ibdev->ops.uverbs_abi_ver;
1020         res->cdev = &uverbs_dev->dev;
1021
1022         /*
1023          * To support DRIVER_ID binding in userspace some of the driver need
1024          * upgrading to expose their PCI dependent revision information
1025          * through get_context instead of relying on modalias matching. When
1026          * the drivers are fixed they can drop this flag.
1027          */
1028         if (!ibdev->ops.uverbs_no_driver_id_binding) {
1029                 ret = nla_put_u32(res->nl_msg, RDMA_NLDEV_ATTR_UVERBS_DRIVER_ID,
1030                                   ibdev->ops.driver_id);
1031                 if (ret)
1032                         return ret;
1033         }
1034         return 0;
1035 }
1036
1037 static struct ib_client uverbs_client = {
1038         .name   = "uverbs",
1039         .no_kverbs_req = true,
1040         .add    = ib_uverbs_add_one,
1041         .remove = ib_uverbs_remove_one,
1042         .get_nl_info = ib_uverbs_get_nl_info,
1043 };
1044 MODULE_ALIAS_RDMA_CLIENT("uverbs");
1045
1046 static ssize_t ibdev_show(struct device *device, struct device_attribute *attr,
1047                           char *buf)
1048 {
1049         struct ib_uverbs_device *dev =
1050                         container_of(device, struct ib_uverbs_device, dev);
1051         int ret = -ENODEV;
1052         int srcu_key;
1053         struct ib_device *ib_dev;
1054
1055         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1056         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1057         if (ib_dev)
1058                 ret = sysfs_emit(buf, "%s\n", dev_name(&ib_dev->dev));
1059         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1060
1061         return ret;
1062 }
1063 static DEVICE_ATTR_RO(ibdev);
1064
1065 static ssize_t abi_version_show(struct device *device,
1066                                 struct device_attribute *attr, char *buf)
1067 {
1068         struct ib_uverbs_device *dev =
1069                         container_of(device, struct ib_uverbs_device, dev);
1070         int ret = -ENODEV;
1071         int srcu_key;
1072         struct ib_device *ib_dev;
1073
1074         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1075         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1076         if (ib_dev)
1077                 ret = sysfs_emit(buf, "%u\n", ib_dev->ops.uverbs_abi_ver);
1078         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1079
1080         return ret;
1081 }
1082 static DEVICE_ATTR_RO(abi_version);
1083
1084 static struct attribute *ib_dev_attrs[] = {
1085         &dev_attr_abi_version.attr,
1086         &dev_attr_ibdev.attr,
1087         NULL,
1088 };
1089
1090 static const struct attribute_group dev_attr_group = {
1091         .attrs = ib_dev_attrs,
1092 };
1093
1094 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1095                          __stringify(IB_USER_VERBS_ABI_VERSION));
1096
1097 static int ib_uverbs_create_uapi(struct ib_device *device,
1098                                  struct ib_uverbs_device *uverbs_dev)
1099 {
1100         struct uverbs_api *uapi;
1101
1102         uapi = uverbs_alloc_api(device);
1103         if (IS_ERR(uapi))
1104                 return PTR_ERR(uapi);
1105
1106         uverbs_dev->uapi = uapi;
1107         return 0;
1108 }
1109
1110 static int ib_uverbs_add_one(struct ib_device *device)
1111 {
1112         int devnum;
1113         dev_t base;
1114         struct ib_uverbs_device *uverbs_dev;
1115         int ret;
1116
1117         if (!device->ops.alloc_ucontext)
1118                 return -EOPNOTSUPP;
1119
1120         uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1121         if (!uverbs_dev)
1122                 return -ENOMEM;
1123
1124         ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1125         if (ret) {
1126                 kfree(uverbs_dev);
1127                 return -ENOMEM;
1128         }
1129
1130         device_initialize(&uverbs_dev->dev);
1131         uverbs_dev->dev.class = &uverbs_class;
1132         uverbs_dev->dev.parent = device->dev.parent;
1133         uverbs_dev->dev.release = ib_uverbs_release_dev;
1134         uverbs_dev->groups[0] = &dev_attr_group;
1135         uverbs_dev->dev.groups = uverbs_dev->groups;
1136         refcount_set(&uverbs_dev->refcount, 1);
1137         init_completion(&uverbs_dev->comp);
1138         uverbs_dev->xrcd_tree = RB_ROOT;
1139         mutex_init(&uverbs_dev->xrcd_tree_mutex);
1140         mutex_init(&uverbs_dev->lists_mutex);
1141         INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1142         rcu_assign_pointer(uverbs_dev->ib_dev, device);
1143         uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1144
1145         devnum = ida_alloc_max(&uverbs_ida, IB_UVERBS_MAX_DEVICES - 1,
1146                                GFP_KERNEL);
1147         if (devnum < 0) {
1148                 ret = -ENOMEM;
1149                 goto err;
1150         }
1151         uverbs_dev->devnum = devnum;
1152         if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1153                 base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1154         else
1155                 base = IB_UVERBS_BASE_DEV + devnum;
1156
1157         ret = ib_uverbs_create_uapi(device, uverbs_dev);
1158         if (ret)
1159                 goto err_uapi;
1160
1161         uverbs_dev->dev.devt = base;
1162         dev_set_name(&uverbs_dev->dev, "uverbs%d", uverbs_dev->devnum);
1163
1164         cdev_init(&uverbs_dev->cdev,
1165                   device->ops.mmap ? &uverbs_mmap_fops : &uverbs_fops);
1166         uverbs_dev->cdev.owner = THIS_MODULE;
1167
1168         ret = cdev_device_add(&uverbs_dev->cdev, &uverbs_dev->dev);
1169         if (ret)
1170                 goto err_uapi;
1171
1172         ib_set_client_data(device, &uverbs_client, uverbs_dev);
1173         return 0;
1174
1175 err_uapi:
1176         ida_free(&uverbs_ida, devnum);
1177 err:
1178         if (refcount_dec_and_test(&uverbs_dev->refcount))
1179                 ib_uverbs_comp_dev(uverbs_dev);
1180         wait_for_completion(&uverbs_dev->comp);
1181         put_device(&uverbs_dev->dev);
1182         return ret;
1183 }
1184
1185 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1186                                         struct ib_device *ib_dev)
1187 {
1188         struct ib_uverbs_file *file;
1189
1190         /* Pending running commands to terminate */
1191         uverbs_disassociate_api_pre(uverbs_dev);
1192
1193         mutex_lock(&uverbs_dev->lists_mutex);
1194         while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1195                 file = list_first_entry(&uverbs_dev->uverbs_file_list,
1196                                         struct ib_uverbs_file, list);
1197                 list_del_init(&file->list);
1198                 kref_get(&file->ref);
1199
1200                 /* We must release the mutex before going ahead and calling
1201                  * uverbs_cleanup_ufile, as it might end up indirectly calling
1202                  * uverbs_close, for example due to freeing the resources (e.g
1203                  * mmput).
1204                  */
1205                 mutex_unlock(&uverbs_dev->lists_mutex);
1206
1207                 uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
1208                 kref_put(&file->ref, ib_uverbs_release_file);
1209
1210                 mutex_lock(&uverbs_dev->lists_mutex);
1211         }
1212         mutex_unlock(&uverbs_dev->lists_mutex);
1213
1214         uverbs_disassociate_api(uverbs_dev->uapi);
1215 }
1216
1217 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1218 {
1219         struct ib_uverbs_device *uverbs_dev = client_data;
1220         int wait_clients = 1;
1221
1222         cdev_device_del(&uverbs_dev->cdev, &uverbs_dev->dev);
1223         ida_free(&uverbs_ida, uverbs_dev->devnum);
1224
1225         if (device->ops.disassociate_ucontext) {
1226                 /* We disassociate HW resources and immediately return.
1227                  * Userspace will see a EIO errno for all future access.
1228                  * Upon returning, ib_device may be freed internally and is not
1229                  * valid any more.
1230                  * uverbs_device is still available until all clients close
1231                  * their files, then the uverbs device ref count will be zero
1232                  * and its resources will be freed.
1233                  * Note: At this point no more files can be opened since the
1234                  * cdev was deleted, however active clients can still issue
1235                  * commands and close their open files.
1236                  */
1237                 ib_uverbs_free_hw_resources(uverbs_dev, device);
1238                 wait_clients = 0;
1239         }
1240
1241         if (refcount_dec_and_test(&uverbs_dev->refcount))
1242                 ib_uverbs_comp_dev(uverbs_dev);
1243         if (wait_clients)
1244                 wait_for_completion(&uverbs_dev->comp);
1245
1246         put_device(&uverbs_dev->dev);
1247 }
1248
1249 static int __init ib_uverbs_init(void)
1250 {
1251         int ret;
1252
1253         ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1254                                      IB_UVERBS_NUM_FIXED_MINOR,
1255                                      "infiniband_verbs");
1256         if (ret) {
1257                 pr_err("user_verbs: couldn't register device number\n");
1258                 goto out;
1259         }
1260
1261         ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1262                                   IB_UVERBS_NUM_DYNAMIC_MINOR,
1263                                   "infiniband_verbs");
1264         if (ret) {
1265                 pr_err("couldn't register dynamic device number\n");
1266                 goto out_alloc;
1267         }
1268
1269         ret = class_register(&uverbs_class);
1270         if (ret) {
1271                 pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1272                 goto out_chrdev;
1273         }
1274
1275         ret = class_create_file(&uverbs_class, &class_attr_abi_version.attr);
1276         if (ret) {
1277                 pr_err("user_verbs: couldn't create abi_version attribute\n");
1278                 goto out_class;
1279         }
1280
1281         ret = ib_register_client(&uverbs_client);
1282         if (ret) {
1283                 pr_err("user_verbs: couldn't register client\n");
1284                 goto out_class;
1285         }
1286
1287         return 0;
1288
1289 out_class:
1290         class_unregister(&uverbs_class);
1291
1292 out_chrdev:
1293         unregister_chrdev_region(dynamic_uverbs_dev,
1294                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1295
1296 out_alloc:
1297         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1298                                  IB_UVERBS_NUM_FIXED_MINOR);
1299
1300 out:
1301         return ret;
1302 }
1303
1304 static void __exit ib_uverbs_cleanup(void)
1305 {
1306         ib_unregister_client(&uverbs_client);
1307         class_unregister(&uverbs_class);
1308         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1309                                  IB_UVERBS_NUM_FIXED_MINOR);
1310         unregister_chrdev_region(dynamic_uverbs_dev,
1311                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1312         mmu_notifier_synchronize();
1313 }
1314
1315 module_init(ib_uverbs_init);
1316 module_exit(ib_uverbs_cleanup);