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
  53 #include "uverbs.h"
  54 #include "core_priv.h"
  55 #include "rdma_core.h"
  56
  57 MODULE_AUTHOR("Roland Dreier");
  58 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
  59 MODULE_LICENSE("Dual BSD/GPL");
  60
  61 enum {
  62         IB_UVERBS_MAJOR       = 231,
  63         IB_UVERBS_BASE_MINOR  = 192,
  64         IB_UVERBS_MAX_DEVICES = 32
  65 };
  66
  67 #define IB_UVERBS_BASE_DEV      MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
  68
  69 static struct class *uverbs_class;
  70
  71 static DEFINE_SPINLOCK(map_lock);
  72 static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);
  73
  74 static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file *file,
  75                                      struct ib_device *ib_dev,
  76                                      const char __user *buf, int in_len,
  77                                      int out_len) = {
  78         [IB_USER_VERBS_CMD_GET_CONTEXT]         = ib_uverbs_get_context,
  79         [IB_USER_VERBS_CMD_QUERY_DEVICE]        = ib_uverbs_query_device,
  80         [IB_USER_VERBS_CMD_QUERY_PORT]          = ib_uverbs_query_port,
  81         [IB_USER_VERBS_CMD_ALLOC_PD]            = ib_uverbs_alloc_pd,
  82         [IB_USER_VERBS_CMD_DEALLOC_PD]          = ib_uverbs_dealloc_pd,
  83         [IB_USER_VERBS_CMD_REG_MR]              = ib_uverbs_reg_mr,
  84         [IB_USER_VERBS_CMD_REREG_MR]            = ib_uverbs_rereg_mr,
  85         [IB_USER_VERBS_CMD_DEREG_MR]            = ib_uverbs_dereg_mr,
  86         [IB_USER_VERBS_CMD_ALLOC_MW]            = ib_uverbs_alloc_mw,
  87         [IB_USER_VERBS_CMD_DEALLOC_MW]          = ib_uverbs_dealloc_mw,
  88         [IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL] = ib_uverbs_create_comp_channel,
  89         [IB_USER_VERBS_CMD_CREATE_CQ]           = ib_uverbs_create_cq,
  90         [IB_USER_VERBS_CMD_RESIZE_CQ]           = ib_uverbs_resize_cq,
  91         [IB_USER_VERBS_CMD_POLL_CQ]             = ib_uverbs_poll_cq,
  92         [IB_USER_VERBS_CMD_REQ_NOTIFY_CQ]       = ib_uverbs_req_notify_cq,
  93         [IB_USER_VERBS_CMD_DESTROY_CQ]          = ib_uverbs_destroy_cq,
  94         [IB_USER_VERBS_CMD_CREATE_QP]           = ib_uverbs_create_qp,
  95         [IB_USER_VERBS_CMD_QUERY_QP]            = ib_uverbs_query_qp,
  96         [IB_USER_VERBS_CMD_MODIFY_QP]           = ib_uverbs_modify_qp,
  97         [IB_USER_VERBS_CMD_DESTROY_QP]          = ib_uverbs_destroy_qp,
  98         [IB_USER_VERBS_CMD_POST_SEND]           = ib_uverbs_post_send,
  99         [IB_USER_VERBS_CMD_POST_RECV]           = ib_uverbs_post_recv,
 100         [IB_USER_VERBS_CMD_POST_SRQ_RECV]       = ib_uverbs_post_srq_recv,
 101         [IB_USER_VERBS_CMD_CREATE_AH]           = ib_uverbs_create_ah,
 102         [IB_USER_VERBS_CMD_DESTROY_AH]          = ib_uverbs_destroy_ah,
 103         [IB_USER_VERBS_CMD_ATTACH_MCAST]        = ib_uverbs_attach_mcast,
 104         [IB_USER_VERBS_CMD_DETACH_MCAST]        = ib_uverbs_detach_mcast,
 105         [IB_USER_VERBS_CMD_CREATE_SRQ]          = ib_uverbs_create_srq,
 106         [IB_USER_VERBS_CMD_MODIFY_SRQ]          = ib_uverbs_modify_srq,
 107         [IB_USER_VERBS_CMD_QUERY_SRQ]           = ib_uverbs_query_srq,
 108         [IB_USER_VERBS_CMD_DESTROY_SRQ]         = ib_uverbs_destroy_srq,
 109         [IB_USER_VERBS_CMD_OPEN_XRCD]           = ib_uverbs_open_xrcd,
 110         [IB_USER_VERBS_CMD_CLOSE_XRCD]          = ib_uverbs_close_xrcd,
 111         [IB_USER_VERBS_CMD_CREATE_XSRQ]         = ib_uverbs_create_xsrq,
 112         [IB_USER_VERBS_CMD_OPEN_QP]             = ib_uverbs_open_qp,
 113 };
 114
 115 static int (*uverbs_ex_cmd_table[])(struct ib_uverbs_file *file,
 116                                     struct ib_device *ib_dev,
 117                                     struct ib_udata *ucore,
 118                                     struct ib_udata *uhw) = {
 119         [IB_USER_VERBS_EX_CMD_CREATE_FLOW]      = ib_uverbs_ex_create_flow,
 120         [IB_USER_VERBS_EX_CMD_DESTROY_FLOW]     = ib_uverbs_ex_destroy_flow,
 121         [IB_USER_VERBS_EX_CMD_QUERY_DEVICE]     = ib_uverbs_ex_query_device,
 122         [IB_USER_VERBS_EX_CMD_CREATE_CQ]        = ib_uverbs_ex_create_cq,
 123         [IB_USER_VERBS_EX_CMD_CREATE_QP]        = ib_uverbs_ex_create_qp,
 124         [IB_USER_VERBS_EX_CMD_CREATE_WQ]        = ib_uverbs_ex_create_wq,
 125         [IB_USER_VERBS_EX_CMD_MODIFY_WQ]        = ib_uverbs_ex_modify_wq,
 126         [IB_USER_VERBS_EX_CMD_DESTROY_WQ]       = ib_uverbs_ex_destroy_wq,
 127         [IB_USER_VERBS_EX_CMD_CREATE_RWQ_IND_TBL] = ib_uverbs_ex_create_rwq_ind_table,
 128         [IB_USER_VERBS_EX_CMD_DESTROY_RWQ_IND_TBL] = ib_uverbs_ex_destroy_rwq_ind_table,
 129         [IB_USER_VERBS_EX_CMD_MODIFY_QP]        = ib_uverbs_ex_modify_qp,
 130 };
 131
 132 static void ib_uverbs_add_one(struct ib_device *device);
 133 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
 134
 135 int uverbs_dealloc_mw(struct ib_mw *mw)
 136 {
 137         struct ib_pd *pd = mw->pd;
 138         int ret;
 139
 140         ret = mw->device->dealloc_mw(mw);
 141         if (!ret)
 142                 atomic_dec(&pd->usecnt);
 143         return ret;
 144 }
 145
 146 static void ib_uverbs_release_dev(struct kobject *kobj)
 147 {
 148         struct ib_uverbs_device *dev =
 149                 container_of(kobj, struct ib_uverbs_device, kobj);
 150
 151         cleanup_srcu_struct(&dev->disassociate_srcu);
 152         kfree(dev);
 153 }
 154
 155 static struct kobj_type ib_uverbs_dev_ktype = {
 156         .release = ib_uverbs_release_dev,
 157 };
 158
 159 static void ib_uverbs_release_event_file(struct kref *ref)
 160 {
 161         struct ib_uverbs_event_file *file =
 162                 container_of(ref, struct ib_uverbs_event_file, ref);
 163
 164         kfree(file);
 165 }
 166
 167 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
 168                           struct ib_uverbs_event_file *ev_file,
 169                           struct ib_ucq_object *uobj)
 170 {
 171         struct ib_uverbs_event *evt, *tmp;
 172
 173         if (ev_file) {
 174                 spin_lock_irq(&ev_file->lock);
 175                 list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
 176                         list_del(&evt->list);
 177                         kfree(evt);
 178                 }
 179                 spin_unlock_irq(&ev_file->lock);
 180
 181                 kref_put(&ev_file->ref, ib_uverbs_release_event_file);
 182         }
 183
 184         spin_lock_irq(&file->async_file->lock);
 185         list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
 186                 list_del(&evt->list);
 187                 kfree(evt);
 188         }
 189         spin_unlock_irq(&file->async_file->lock);
 190 }
 191
 192 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
 193                               struct ib_uevent_object *uobj)
 194 {
 195         struct ib_uverbs_event *evt, *tmp;
 196
 197         spin_lock_irq(&file->async_file->lock);
 198         list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
 199                 list_del(&evt->list);
 200                 kfree(evt);
 201         }
 202         spin_unlock_irq(&file->async_file->lock);
 203 }
 204
 205 void ib_uverbs_detach_umcast(struct ib_qp *qp,
 206                              struct ib_uqp_object *uobj)
 207 {
 208         struct ib_uverbs_mcast_entry *mcast, *tmp;
 209
 210         list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
 211                 ib_detach_mcast(qp, &mcast->gid, mcast->lid);
 212                 list_del(&mcast->list);
 213                 kfree(mcast);
 214         }
 215 }
 216
 217 static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
 218                                       struct ib_ucontext *context,
 219                                       bool device_removed)
 220 {
 221         context->closing = 1;
 222         uverbs_cleanup_ucontext(context, device_removed);
 223         put_pid(context->tgid);
 224
 225         ib_rdmacg_uncharge(&context->cg_obj, context->device,
 226                            RDMACG_RESOURCE_HCA_HANDLE);
 227
 228         return context->device->dealloc_ucontext(context);
 229 }
 230
 231 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
 232 {
 233         complete(&dev->comp);
 234 }
 235
 236 static void ib_uverbs_release_file(struct kref *ref)
 237 {
 238         struct ib_uverbs_file *file =
 239                 container_of(ref, struct ib_uverbs_file, ref);
 240         struct ib_device *ib_dev;
 241         int srcu_key;
 242
 243         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 244         ib_dev = srcu_dereference(file->device->ib_dev,
 245                                   &file->device->disassociate_srcu);
 246         if (ib_dev && !ib_dev->disassociate_ucontext)
 247                 module_put(ib_dev->owner);
 248         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 249
 250         if (atomic_dec_and_test(&file->device->refcount))
 251                 ib_uverbs_comp_dev(file->device);
 252
 253         kfree(file);
 254 }
 255
 256 static ssize_t ib_uverbs_event_read(struct file *filp, char __user *buf,
 257                                     size_t count, loff_t *pos)
 258 {
 259         struct ib_uverbs_event_file *file = filp->private_data;
 260         struct ib_uverbs_event *event;
 261         int eventsz;
 262         int ret = 0;
 263
 264         spin_lock_irq(&file->lock);
 265
 266         while (list_empty(&file->event_list)) {
 267                 spin_unlock_irq(&file->lock);
 268
 269                 if (filp->f_flags & O_NONBLOCK)
 270                         return -EAGAIN;
 271
 272                 if (wait_event_interruptible(file->poll_wait,
 273                                              (!list_empty(&file->event_list) ||
 274                         /* The barriers built into wait_event_interruptible()
 275                          * and wake_up() guarentee this will see the null set
 276                          * without using RCU
 277                          */
 278                                              !file->uverbs_file->device->ib_dev)))
 279                         return -ERESTARTSYS;
 280
 281                 /* If device was disassociated and no event exists set an error */
 282                 if (list_empty(&file->event_list) &&
 283                     !file->uverbs_file->device->ib_dev)
 284                         return -EIO;
 285
 286                 spin_lock_irq(&file->lock);
 287         }
 288
 289         event = list_entry(file->event_list.next, struct ib_uverbs_event, list);
 290
 291         if (file->is_async)
 292                 eventsz = sizeof (struct ib_uverbs_async_event_desc);
 293         else
 294                 eventsz = sizeof (struct ib_uverbs_comp_event_desc);
 295
 296         if (eventsz > count) {
 297                 ret   = -EINVAL;
 298                 event = NULL;
 299         } else {
 300                 list_del(file->event_list.next);
 301                 if (event->counter) {
 302                         ++(*event->counter);
 303                         list_del(&event->obj_list);
 304                 }
 305         }
 306
 307         spin_unlock_irq(&file->lock);
 308
 309         if (event) {
 310                 if (copy_to_user(buf, event, eventsz))
 311                         ret = -EFAULT;
 312                 else
 313                         ret = eventsz;
 314         }
 315
 316         kfree(event);
 317
 318         return ret;
 319 }
 320
 321 static unsigned int ib_uverbs_event_poll(struct file *filp,
 322                                          struct poll_table_struct *wait)
 323 {
 324         unsigned int pollflags = 0;
 325         struct ib_uverbs_event_file *file = filp->private_data;
 326
 327         poll_wait(filp, &file->poll_wait, wait);
 328
 329         spin_lock_irq(&file->lock);
 330         if (!list_empty(&file->event_list))
 331                 pollflags = POLLIN | POLLRDNORM;
 332         spin_unlock_irq(&file->lock);
 333
 334         return pollflags;
 335 }
 336
 337 static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
 338 {
 339         struct ib_uverbs_event_file *file = filp->private_data;
 340
 341         return fasync_helper(fd, filp, on, &file->async_queue);
 342 }
 343
 344 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
 345 {
 346         struct ib_uverbs_event_file *file = filp->private_data;
 347         struct ib_uverbs_event *entry, *tmp;
 348         int closed_already = 0;
 349
 350         mutex_lock(&file->uverbs_file->device->lists_mutex);
 351         spin_lock_irq(&file->lock);
 352         closed_already = file->is_closed;
 353         file->is_closed = 1;
 354         list_for_each_entry_safe(entry, tmp, &file->event_list, list) {
 355                 if (entry->counter)
 356                         list_del(&entry->obj_list);
 357                 kfree(entry);
 358         }
 359         spin_unlock_irq(&file->lock);
 360         if (!closed_already) {
 361                 list_del(&file->list);
 362                 if (file->is_async)
 363                         ib_unregister_event_handler(&file->uverbs_file->
 364                                 event_handler);
 365         }
 366         mutex_unlock(&file->uverbs_file->device->lists_mutex);
 367
 368         kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
 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         .llseek  = no_llseek,
 381 };
 382
 383 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
 384 {
 385         struct ib_uverbs_event_file    *file = cq_context;
 386         struct ib_ucq_object           *uobj;
 387         struct ib_uverbs_event         *entry;
 388         unsigned long                   flags;
 389
 390         if (!file)
 391                 return;
 392
 393         spin_lock_irqsave(&file->lock, flags);
 394         if (file->is_closed) {
 395                 spin_unlock_irqrestore(&file->lock, flags);
 396                 return;
 397         }
 398
 399         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
 400         if (!entry) {
 401                 spin_unlock_irqrestore(&file->lock, flags);
 402                 return;
 403         }
 404
 405         uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
 406
 407         entry->desc.comp.cq_handle = cq->uobject->user_handle;
 408         entry->counter             = &uobj->comp_events_reported;
 409
 410         list_add_tail(&entry->list, &file->event_list);
 411         list_add_tail(&entry->obj_list, &uobj->comp_list);
 412         spin_unlock_irqrestore(&file->lock, flags);
 413
 414         wake_up_interruptible(&file->poll_wait);
 415         kill_fasync(&file->async_queue, SIGIO, POLL_IN);
 416 }
 417
 418 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
 419                                     __u64 element, __u64 event,
 420                                     struct list_head *obj_list,
 421                                     u32 *counter)
 422 {
 423         struct ib_uverbs_event *entry;
 424         unsigned long flags;
 425
 426         spin_lock_irqsave(&file->async_file->lock, flags);
 427         if (file->async_file->is_closed) {
 428                 spin_unlock_irqrestore(&file->async_file->lock, flags);
 429                 return;
 430         }
 431
 432         entry = kmalloc(sizeof *entry, GFP_ATOMIC);
 433         if (!entry) {
 434                 spin_unlock_irqrestore(&file->async_file->lock, flags);
 435                 return;
 436         }
 437
 438         entry->desc.async.element    = element;
 439         entry->desc.async.event_type = event;
 440         entry->desc.async.reserved   = 0;
 441         entry->counter               = counter;
 442
 443         list_add_tail(&entry->list, &file->async_file->event_list);
 444         if (obj_list)
 445                 list_add_tail(&entry->obj_list, obj_list);
 446         spin_unlock_irqrestore(&file->async_file->lock, flags);
 447
 448         wake_up_interruptible(&file->async_file->poll_wait);
 449         kill_fasync(&file->async_file->async_queue, SIGIO, POLL_IN);
 450 }
 451
 452 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
 453 {
 454         struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
 455                                                   struct ib_ucq_object, uobject);
 456
 457         ib_uverbs_async_handler(uobj->uverbs_file, uobj->uobject.user_handle,
 458                                 event->event, &uobj->async_list,
 459                                 &uobj->async_events_reported);
 460 }
 461
 462 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
 463 {
 464         struct ib_uevent_object *uobj;
 465
 466         /* for XRC target qp's, check that qp is live */
 467         if (!event->element.qp->uobject)
 468                 return;
 469
 470         uobj = container_of(event->element.qp->uobject,
 471                             struct ib_uevent_object, uobject);
 472
 473         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 474                                 event->event, &uobj->event_list,
 475                                 &uobj->events_reported);
 476 }
 477
 478 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
 479 {
 480         struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
 481                                                   struct ib_uevent_object, uobject);
 482
 483         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 484                                 event->event, &uobj->event_list,
 485                                 &uobj->events_reported);
 486 }
 487
 488 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
 489 {
 490         struct ib_uevent_object *uobj;
 491
 492         uobj = container_of(event->element.srq->uobject,
 493                             struct ib_uevent_object, uobject);
 494
 495         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 496                                 event->event, &uobj->event_list,
 497                                 &uobj->events_reported);
 498 }
 499
 500 void ib_uverbs_event_handler(struct ib_event_handler *handler,
 501                              struct ib_event *event)
 502 {
 503         struct ib_uverbs_file *file =
 504                 container_of(handler, struct ib_uverbs_file, event_handler);
 505
 506         ib_uverbs_async_handler(file, event->element.port_num, event->event,
 507                                 NULL, NULL);
 508 }
 509
 510 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
 511 {
 512         kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
 513         file->async_file = NULL;
 514 }
 515
 516 struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file,
 517                                         struct ib_device        *ib_dev,
 518                                         int is_async)
 519 {
 520         struct ib_uverbs_event_file *ev_file;
 521         struct file *filp;
 522         int ret;
 523
 524         ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
 525         if (!ev_file)
 526                 return ERR_PTR(-ENOMEM);
 527
 528         kref_init(&ev_file->ref);
 529         spin_lock_init(&ev_file->lock);
 530         INIT_LIST_HEAD(&ev_file->event_list);
 531         init_waitqueue_head(&ev_file->poll_wait);
 532         ev_file->uverbs_file = uverbs_file;
 533         kref_get(&ev_file->uverbs_file->ref);
 534         ev_file->async_queue = NULL;
 535         ev_file->is_closed   = 0;
 536
 537         filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops,
 538                                   ev_file, O_RDONLY);
 539         if (IS_ERR(filp))
 540                 goto err_put_refs;
 541
 542         mutex_lock(&uverbs_file->device->lists_mutex);
 543         list_add_tail(&ev_file->list,
 544                       &uverbs_file->device->uverbs_events_file_list);
 545         mutex_unlock(&uverbs_file->device->lists_mutex);
 546
 547         if (is_async) {
 548                 WARN_ON(uverbs_file->async_file);
 549                 uverbs_file->async_file = ev_file;
 550                 kref_get(&uverbs_file->async_file->ref);
 551                 INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
 552                                       ib_dev,
 553                                       ib_uverbs_event_handler);
 554                 ret = ib_register_event_handler(&uverbs_file->event_handler);
 555                 if (ret)
 556                         goto err_put_file;
 557
 558                 /* At that point async file stuff was fully set */
 559                 ev_file->is_async = 1;
 560         }
 561
 562         return filp;
 563
 564 err_put_file:
 565         fput(filp);
 566         kref_put(&uverbs_file->async_file->ref, ib_uverbs_release_event_file);
 567         uverbs_file->async_file = NULL;
 568         return ERR_PTR(ret);
 569
 570 err_put_refs:
 571         kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
 572         kref_put(&ev_file->ref, ib_uverbs_release_event_file);
 573         return filp;
 574 }
 575
 576 /*
 577  * Look up a completion event file by FD.  If lookup is successful,
 578  * takes a ref to the event file struct that it returns; if
 579  * unsuccessful, returns NULL.
 580  */
 581 struct ib_uverbs_event_file *ib_uverbs_lookup_comp_file(int fd)
 582 {
 583         struct ib_uverbs_event_file *ev_file = NULL;
 584         struct fd f = fdget(fd);
 585
 586         if (!f.file)
 587                 return NULL;
 588
 589         if (f.file->f_op != &uverbs_event_fops)
 590                 goto out;
 591
 592         ev_file = f.file->private_data;
 593         if (ev_file->is_async) {
 594                 ev_file = NULL;
 595                 goto out;
 596         }
 597
 598         kref_get(&ev_file->ref);
 599
 600 out:
 601         fdput(f);
 602         return ev_file;
 603 }
 604
 605 static int verify_command_mask(struct ib_device *ib_dev, __u32 command)
 606 {
 607         u64 mask;
 608
 609         if (command <= IB_USER_VERBS_CMD_OPEN_QP)
 610                 mask = ib_dev->uverbs_cmd_mask;
 611         else
 612                 mask = ib_dev->uverbs_ex_cmd_mask;
 613
 614         if (mask & ((u64)1 << command))
 615                 return 0;
 616
 617         return -1;
 618 }
 619
 620 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 621                              size_t count, loff_t *pos)
 622 {
 623         struct ib_uverbs_file *file = filp->private_data;
 624         struct ib_device *ib_dev;
 625         struct ib_uverbs_cmd_hdr hdr;
 626         __u32 command;
 627         __u32 flags;
 628         int srcu_key;
 629         ssize_t ret;
 630
 631         if (!ib_safe_file_access(filp)) {
 632                 pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 633                             task_tgid_vnr(current), current->comm);
 634                 return -EACCES;
 635         }
 636
 637         if (count < sizeof hdr)
 638                 return -EINVAL;
 639
 640         if (copy_from_user(&hdr, buf, sizeof hdr))
 641                 return -EFAULT;
 642
 643         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 644         ib_dev = srcu_dereference(file->device->ib_dev,
 645                                   &file->device->disassociate_srcu);
 646         if (!ib_dev) {
 647                 ret = -EIO;
 648                 goto out;
 649         }
 650
 651         if (hdr.command & ~(__u32)(IB_USER_VERBS_CMD_FLAGS_MASK |
 652                                    IB_USER_VERBS_CMD_COMMAND_MASK)) {
 653                 ret = -EINVAL;
 654                 goto out;
 655         }
 656
 657         command = hdr.command & IB_USER_VERBS_CMD_COMMAND_MASK;
 658         if (verify_command_mask(ib_dev, command)) {
 659                 ret = -EOPNOTSUPP;
 660                 goto out;
 661         }
 662
 663         if (!file->ucontext &&
 664             command != IB_USER_VERBS_CMD_GET_CONTEXT) {
 665                 ret = -EINVAL;
 666                 goto out;
 667         }
 668
 669         flags = (hdr.command &
 670                  IB_USER_VERBS_CMD_FLAGS_MASK) >> IB_USER_VERBS_CMD_FLAGS_SHIFT;
 671
 672         if (!flags) {
 673                 if (command >= ARRAY_SIZE(uverbs_cmd_table) ||
 674                     !uverbs_cmd_table[command]) {
 675                         ret = -EINVAL;
 676                         goto out;
 677                 }
 678
 679                 if (hdr.in_words * 4 != count) {
 680                         ret = -EINVAL;
 681                         goto out;
 682                 }
 683
 684                 ret = uverbs_cmd_table[command](file, ib_dev,
 685                                                  buf + sizeof(hdr),
 686                                                  hdr.in_words * 4,
 687                                                  hdr.out_words * 4);
 688
 689         } else if (flags == IB_USER_VERBS_CMD_FLAG_EXTENDED) {
 690                 struct ib_uverbs_ex_cmd_hdr ex_hdr;
 691                 struct ib_udata ucore;
 692                 struct ib_udata uhw;
 693                 size_t written_count = count;
 694
 695                 if (command >= ARRAY_SIZE(uverbs_ex_cmd_table) ||
 696                     !uverbs_ex_cmd_table[command]) {
 697                         ret = -ENOSYS;
 698                         goto out;
 699                 }
 700
 701                 if (!file->ucontext) {
 702                         ret = -EINVAL;
 703                         goto out;
 704                 }
 705
 706                 if (count < (sizeof(hdr) + sizeof(ex_hdr))) {
 707                         ret = -EINVAL;
 708                         goto out;
 709                 }
 710
 711                 if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr))) {
 712                         ret = -EFAULT;
 713                         goto out;
 714                 }
 715
 716                 count -= sizeof(hdr) + sizeof(ex_hdr);
 717                 buf += sizeof(hdr) + sizeof(ex_hdr);
 718
 719                 if ((hdr.in_words + ex_hdr.provider_in_words) * 8 != count) {
 720                         ret = -EINVAL;
 721                         goto out;
 722                 }
 723
 724                 if (ex_hdr.cmd_hdr_reserved) {
 725                         ret = -EINVAL;
 726                         goto out;
 727                 }
 728
 729                 if (ex_hdr.response) {
 730                         if (!hdr.out_words && !ex_hdr.provider_out_words) {
 731                                 ret = -EINVAL;
 732                                 goto out;
 733                         }
 734
 735                         if (!access_ok(VERIFY_WRITE,
 736                                        (void __user *) (unsigned long) ex_hdr.response,
 737                                        (hdr.out_words + ex_hdr.provider_out_words) * 8)) {
 738                                 ret = -EFAULT;
 739                                 goto out;
 740                         }
 741                 } else {
 742                         if (hdr.out_words || ex_hdr.provider_out_words) {
 743                                 ret = -EINVAL;
 744                                 goto out;
 745                         }
 746                 }
 747
 748                 INIT_UDATA_BUF_OR_NULL(&ucore, buf, (unsigned long) ex_hdr.response,
 749                                        hdr.in_words * 8, hdr.out_words * 8);
 750
 751                 INIT_UDATA_BUF_OR_NULL(&uhw,
 752                                        buf + ucore.inlen,
 753                                        (unsigned long) ex_hdr.response + ucore.outlen,
 754                                        ex_hdr.provider_in_words * 8,
 755                                        ex_hdr.provider_out_words * 8);
 756
 757                 ret = uverbs_ex_cmd_table[command](file,
 758                                                    ib_dev,
 759                                                    &ucore,
 760                                                    &uhw);
 761                 if (!ret)
 762                         ret = written_count;
 763         } else {
 764                 ret = -ENOSYS;
 765         }
 766
 767 out:
 768         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 769         return ret;
 770 }
 771
 772 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
 773 {
 774         struct ib_uverbs_file *file = filp->private_data;
 775         struct ib_device *ib_dev;
 776         int ret = 0;
 777         int srcu_key;
 778
 779         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 780         ib_dev = srcu_dereference(file->device->ib_dev,
 781                                   &file->device->disassociate_srcu);
 782         if (!ib_dev) {
 783                 ret = -EIO;
 784                 goto out;
 785         }
 786
 787         if (!file->ucontext)
 788                 ret = -ENODEV;
 789         else
 790                 ret = ib_dev->mmap(file->ucontext, vma);
 791 out:
 792         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 793         return ret;
 794 }
 795
 796 /*
 797  * ib_uverbs_open() does not need the BKL:
 798  *
 799  *  - the ib_uverbs_device structures are properly reference counted and
 800  *    everything else is purely local to the file being created, so
 801  *    races against other open calls are not a problem;
 802  *  - there is no ioctl method to race against;
 803  *  - the open method will either immediately run -ENXIO, or all
 804  *    required initialization will be done.
 805  */
 806 static int ib_uverbs_open(struct inode *inode, struct file *filp)
 807 {
 808         struct ib_uverbs_device *dev;
 809         struct ib_uverbs_file *file;
 810         struct ib_device *ib_dev;
 811         int ret;
 812         int module_dependent;
 813         int srcu_key;
 814
 815         dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
 816         if (!atomic_inc_not_zero(&dev->refcount))
 817                 return -ENXIO;
 818
 819         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
 820         mutex_lock(&dev->lists_mutex);
 821         ib_dev = srcu_dereference(dev->ib_dev,
 822                                   &dev->disassociate_srcu);
 823         if (!ib_dev) {
 824                 ret = -EIO;
 825                 goto err;
 826         }
 827
 828         /* In case IB device supports disassociate ucontext, there is no hard
 829          * dependency between uverbs device and its low level device.
 830          */
 831         module_dependent = !(ib_dev->disassociate_ucontext);
 832
 833         if (module_dependent) {
 834                 if (!try_module_get(ib_dev->owner)) {
 835                         ret = -ENODEV;
 836                         goto err;
 837                 }
 838         }
 839
 840         file = kzalloc(sizeof(*file), GFP_KERNEL);
 841         if (!file) {
 842                 ret = -ENOMEM;
 843                 if (module_dependent)
 844                         goto err_module;
 845
 846                 goto err;
 847         }
 848
 849         file->device     = dev;
 850         spin_lock_init(&file->idr_lock);
 851         idr_init(&file->idr);
 852         file->ucontext   = NULL;
 853         file->async_file = NULL;
 854         kref_init(&file->ref);
 855         mutex_init(&file->mutex);
 856         mutex_init(&file->cleanup_mutex);
 857
 858         filp->private_data = file;
 859         kobject_get(&dev->kobj);
 860         list_add_tail(&file->list, &dev->uverbs_file_list);
 861         mutex_unlock(&dev->lists_mutex);
 862         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 863
 864         return nonseekable_open(inode, filp);
 865
 866 err_module:
 867         module_put(ib_dev->owner);
 868
 869 err:
 870         mutex_unlock(&dev->lists_mutex);
 871         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 872         if (atomic_dec_and_test(&dev->refcount))
 873                 ib_uverbs_comp_dev(dev);
 874
 875         return ret;
 876 }
 877
 878 static int ib_uverbs_close(struct inode *inode, struct file *filp)
 879 {
 880         struct ib_uverbs_file *file = filp->private_data;
 881         struct ib_uverbs_device *dev = file->device;
 882
 883         mutex_lock(&file->cleanup_mutex);
 884         if (file->ucontext) {
 885                 ib_uverbs_cleanup_ucontext(file, file->ucontext, false);
 886                 file->ucontext = NULL;
 887         }
 888         mutex_unlock(&file->cleanup_mutex);
 889         idr_destroy(&file->idr);
 890
 891         mutex_lock(&file->device->lists_mutex);
 892         if (!file->is_closed) {
 893                 list_del(&file->list);
 894                 file->is_closed = 1;
 895         }
 896         mutex_unlock(&file->device->lists_mutex);
 897
 898         if (file->async_file)
 899                 kref_put(&file->async_file->ref, ib_uverbs_release_event_file);
 900
 901         kref_put(&file->ref, ib_uverbs_release_file);
 902         kobject_put(&dev->kobj);
 903
 904         return 0;
 905 }
 906
 907 static const struct file_operations uverbs_fops = {
 908         .owner   = THIS_MODULE,
 909         .write   = ib_uverbs_write,
 910         .open    = ib_uverbs_open,
 911         .release = ib_uverbs_close,
 912         .llseek  = no_llseek,
 913 };
 914
 915 static const struct file_operations uverbs_mmap_fops = {
 916         .owner   = THIS_MODULE,
 917         .write   = ib_uverbs_write,
 918         .mmap    = ib_uverbs_mmap,
 919         .open    = ib_uverbs_open,
 920         .release = ib_uverbs_close,
 921         .llseek  = no_llseek,
 922 };
 923
 924 static struct ib_client uverbs_client = {
 925         .name   = "uverbs",
 926         .add    = ib_uverbs_add_one,
 927         .remove = ib_uverbs_remove_one
 928 };
 929
 930 static ssize_t show_ibdev(struct device *device, struct device_attribute *attr,
 931                           char *buf)
 932 {
 933         int ret = -ENODEV;
 934         int srcu_key;
 935         struct ib_uverbs_device *dev = dev_get_drvdata(device);
 936         struct ib_device *ib_dev;
 937
 938         if (!dev)
 939                 return -ENODEV;
 940
 941         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
 942         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
 943         if (ib_dev)
 944                 ret = sprintf(buf, "%s\n", ib_dev->name);
 945         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 946
 947         return ret;
 948 }
 949 static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
 950
 951 static ssize_t show_dev_abi_version(struct device *device,
 952                                     struct device_attribute *attr, char *buf)
 953 {
 954         struct ib_uverbs_device *dev = dev_get_drvdata(device);
 955         int ret = -ENODEV;
 956         int srcu_key;
 957         struct ib_device *ib_dev;
 958
 959         if (!dev)
 960                 return -ENODEV;
 961         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
 962         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
 963         if (ib_dev)
 964                 ret = sprintf(buf, "%d\n", ib_dev->uverbs_abi_ver);
 965         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 966
 967         return ret;
 968 }
 969 static DEVICE_ATTR(abi_version, S_IRUGO, show_dev_abi_version, NULL);
 970
 971 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
 972                          __stringify(IB_USER_VERBS_ABI_VERSION));
 973
 974 static dev_t overflow_maj;
 975 static DECLARE_BITMAP(overflow_map, IB_UVERBS_MAX_DEVICES);
 976
 977 /*
 978  * If we have more than IB_UVERBS_MAX_DEVICES, dynamically overflow by
 979  * requesting a new major number and doubling the number of max devices we
 980  * support. It's stupid, but simple.
 981  */
 982 static int find_overflow_devnum(void)
 983 {
 984         int ret;
 985
 986         if (!overflow_maj) {
 987                 ret = alloc_chrdev_region(&overflow_maj, 0, IB_UVERBS_MAX_DEVICES,
 988                                           "infiniband_verbs");
 989                 if (ret) {
 990                         pr_err("user_verbs: couldn't register dynamic device number\n");
 991                         return ret;
 992                 }
 993         }
 994
 995         ret = find_first_zero_bit(overflow_map, IB_UVERBS_MAX_DEVICES);
 996         if (ret >= IB_UVERBS_MAX_DEVICES)
 997                 return -1;
 998
 999         return ret;
1000 }
1001
1002 static void ib_uverbs_add_one(struct ib_device *device)
1003 {
1004         int devnum;
1005         dev_t base;
1006         struct ib_uverbs_device *uverbs_dev;
1007         int ret;
1008
1009         if (!device->alloc_ucontext)
1010                 return;
1011
1012         uverbs_dev = kzalloc(sizeof *uverbs_dev, GFP_KERNEL);
1013         if (!uverbs_dev)
1014                 return;
1015
1016         ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1017         if (ret) {
1018                 kfree(uverbs_dev);
1019                 return;
1020         }
1021
1022         atomic_set(&uverbs_dev->refcount, 1);
1023         init_completion(&uverbs_dev->comp);
1024         uverbs_dev->xrcd_tree = RB_ROOT;
1025         mutex_init(&uverbs_dev->xrcd_tree_mutex);
1026         kobject_init(&uverbs_dev->kobj, &ib_uverbs_dev_ktype);
1027         mutex_init(&uverbs_dev->lists_mutex);
1028         INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1029         INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1030
1031         spin_lock(&map_lock);
1032         devnum = find_first_zero_bit(dev_map, IB_UVERBS_MAX_DEVICES);
1033         if (devnum >= IB_UVERBS_MAX_DEVICES) {
1034                 spin_unlock(&map_lock);
1035                 devnum = find_overflow_devnum();
1036                 if (devnum < 0)
1037                         goto err;
1038
1039                 spin_lock(&map_lock);
1040                 uverbs_dev->devnum = devnum + IB_UVERBS_MAX_DEVICES;
1041                 base = devnum + overflow_maj;
1042                 set_bit(devnum, overflow_map);
1043         } else {
1044                 uverbs_dev->devnum = devnum;
1045                 base = devnum + IB_UVERBS_BASE_DEV;
1046                 set_bit(devnum, dev_map);
1047         }
1048         spin_unlock(&map_lock);
1049
1050         rcu_assign_pointer(uverbs_dev->ib_dev, device);
1051         uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1052
1053         cdev_init(&uverbs_dev->cdev, NULL);
1054         uverbs_dev->cdev.owner = THIS_MODULE;
1055         uverbs_dev->cdev.ops = device->mmap ? &uverbs_mmap_fops : &uverbs_fops;
1056         uverbs_dev->cdev.kobj.parent = &uverbs_dev->kobj;
1057         kobject_set_name(&uverbs_dev->cdev.kobj, "uverbs%d", uverbs_dev->devnum);
1058         if (cdev_add(&uverbs_dev->cdev, base, 1))
1059                 goto err_cdev;
1060
1061         uverbs_dev->dev = device_create(uverbs_class, device->dev.parent,
1062                                         uverbs_dev->cdev.dev, uverbs_dev,
1063                                         "uverbs%d", uverbs_dev->devnum);
1064         if (IS_ERR(uverbs_dev->dev))
1065                 goto err_cdev;
1066
1067         if (device_create_file(uverbs_dev->dev, &dev_attr_ibdev))
1068                 goto err_class;
1069         if (device_create_file(uverbs_dev->dev, &dev_attr_abi_version))
1070                 goto err_class;
1071
1072         ib_set_client_data(device, &uverbs_client, uverbs_dev);
1073
1074         return;
1075
1076 err_class:
1077         device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1078
1079 err_cdev:
1080         cdev_del(&uverbs_dev->cdev);
1081         if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1082                 clear_bit(devnum, dev_map);
1083         else
1084                 clear_bit(devnum, overflow_map);
1085
1086 err:
1087         if (atomic_dec_and_test(&uverbs_dev->refcount))
1088                 ib_uverbs_comp_dev(uverbs_dev);
1089         wait_for_completion(&uverbs_dev->comp);
1090         kobject_put(&uverbs_dev->kobj);
1091         return;
1092 }
1093
1094 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1095                                         struct ib_device *ib_dev)
1096 {
1097         struct ib_uverbs_file *file;
1098         struct ib_uverbs_event_file *event_file;
1099         struct ib_event event;
1100
1101         /* Pending running commands to terminate */
1102         synchronize_srcu(&uverbs_dev->disassociate_srcu);
1103         event.event = IB_EVENT_DEVICE_FATAL;
1104         event.element.port_num = 0;
1105         event.device = ib_dev;
1106
1107         mutex_lock(&uverbs_dev->lists_mutex);
1108         while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1109                 struct ib_ucontext *ucontext;
1110                 file = list_first_entry(&uverbs_dev->uverbs_file_list,
1111                                         struct ib_uverbs_file, list);
1112                 file->is_closed = 1;
1113                 list_del(&file->list);
1114                 kref_get(&file->ref);
1115                 mutex_unlock(&uverbs_dev->lists_mutex);
1116
1117                 ib_uverbs_event_handler(&file->event_handler, &event);
1118
1119                 mutex_lock(&file->cleanup_mutex);
1120                 ucontext = file->ucontext;
1121                 file->ucontext = NULL;
1122                 mutex_unlock(&file->cleanup_mutex);
1123
1124                 /* At this point ib_uverbs_close cannot be running
1125                  * ib_uverbs_cleanup_ucontext
1126                  */
1127                 if (ucontext) {
1128                         /* We must release the mutex before going ahead and
1129                          * calling disassociate_ucontext. disassociate_ucontext
1130                          * might end up indirectly calling uverbs_close,
1131                          * for example due to freeing the resources
1132                          * (e.g mmput).
1133                          */
1134                         ib_dev->disassociate_ucontext(ucontext);
1135                         ib_uverbs_cleanup_ucontext(file, ucontext, true);
1136                 }
1137
1138                 mutex_lock(&uverbs_dev->lists_mutex);
1139                 kref_put(&file->ref, ib_uverbs_release_file);
1140         }
1141
1142         while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1143                 event_file = list_first_entry(&uverbs_dev->
1144                                               uverbs_events_file_list,
1145                                               struct ib_uverbs_event_file,
1146                                               list);
1147                 spin_lock_irq(&event_file->lock);
1148                 event_file->is_closed = 1;
1149                 spin_unlock_irq(&event_file->lock);
1150
1151                 list_del(&event_file->list);
1152                 if (event_file->is_async) {
1153                         ib_unregister_event_handler(&event_file->uverbs_file->
1154                                                     event_handler);
1155                         event_file->uverbs_file->event_handler.device = NULL;
1156                 }
1157
1158                 wake_up_interruptible(&event_file->poll_wait);
1159                 kill_fasync(&event_file->async_queue, SIGIO, POLL_IN);
1160         }
1161         mutex_unlock(&uverbs_dev->lists_mutex);
1162 }
1163
1164 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1165 {
1166         struct ib_uverbs_device *uverbs_dev = client_data;
1167         int wait_clients = 1;
1168
1169         if (!uverbs_dev)
1170                 return;
1171
1172         dev_set_drvdata(uverbs_dev->dev, NULL);
1173         device_destroy(uverbs_class, uverbs_dev->cdev.dev);
1174         cdev_del(&uverbs_dev->cdev);
1175
1176         if (uverbs_dev->devnum < IB_UVERBS_MAX_DEVICES)
1177                 clear_bit(uverbs_dev->devnum, dev_map);
1178         else
1179                 clear_bit(uverbs_dev->devnum - IB_UVERBS_MAX_DEVICES, overflow_map);
1180
1181         if (device->disassociate_ucontext) {
1182                 /* We disassociate HW resources and immediately return.
1183                  * Userspace will see a EIO errno for all future access.
1184                  * Upon returning, ib_device may be freed internally and is not
1185                  * valid any more.
1186                  * uverbs_device is still available until all clients close
1187                  * their files, then the uverbs device ref count will be zero
1188                  * and its resources will be freed.
1189                  * Note: At this point no more files can be opened since the
1190                  * cdev was deleted, however active clients can still issue
1191                  * commands and close their open files.
1192                  */
1193                 rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
1194                 ib_uverbs_free_hw_resources(uverbs_dev, device);
1195                 wait_clients = 0;
1196         }
1197
1198         if (atomic_dec_and_test(&uverbs_dev->refcount))
1199                 ib_uverbs_comp_dev(uverbs_dev);
1200         if (wait_clients)
1201                 wait_for_completion(&uverbs_dev->comp);
1202         kobject_put(&uverbs_dev->kobj);
1203 }
1204
1205 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1206 {
1207         if (mode)
1208                 *mode = 0666;
1209         return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1210 }
1211
1212 static int __init ib_uverbs_init(void)
1213 {
1214         int ret;
1215
1216         ret = register_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES,
1217                                      "infiniband_verbs");
1218         if (ret) {
1219                 pr_err("user_verbs: couldn't register device number\n");
1220                 goto out;
1221         }
1222
1223         uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1224         if (IS_ERR(uverbs_class)) {
1225                 ret = PTR_ERR(uverbs_class);
1226                 pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1227                 goto out_chrdev;
1228         }
1229
1230         uverbs_class->devnode = uverbs_devnode;
1231
1232         ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1233         if (ret) {
1234                 pr_err("user_verbs: couldn't create abi_version attribute\n");
1235                 goto out_class;
1236         }
1237
1238         ret = ib_register_client(&uverbs_client);
1239         if (ret) {
1240                 pr_err("user_verbs: couldn't register client\n");
1241                 goto out_class;
1242         }
1243
1244         return 0;
1245
1246 out_class:
1247         class_destroy(uverbs_class);
1248
1249 out_chrdev:
1250         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1251
1252 out:
1253         return ret;
1254 }
1255
1256 static void __exit ib_uverbs_cleanup(void)
1257 {
1258         ib_unregister_client(&uverbs_client);
1259         class_destroy(uverbs_class);
1260         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
1261         if (overflow_maj)
1262                 unregister_chrdev_region(overflow_maj, IB_UVERBS_MAX_DEVICES);
1263 }
1264
1265 module_init(ib_uverbs_init);
1266 module_exit(ib_uverbs_cleanup);