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 static struct class *uverbs_class;
  76
  77 static DEFINE_IDA(uverbs_ida);
  78 static void ib_uverbs_add_one(struct ib_device *device);
  79 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
  80
  81 /*
  82  * Must be called with the ufile->device->disassociate_srcu held, and the lock
  83  * must be held until use of the ucontext is finished.
  84  */
  85 struct ib_ucontext *ib_uverbs_get_ucontext_file(struct ib_uverbs_file *ufile)
  86 {
  87         /*
  88          * We do not hold the hw_destroy_rwsem lock for this flow, instead
  89          * srcu is used. It does not matter if someone races this with
  90          * get_context, we get NULL or valid ucontext.
  91          */
  92         struct ib_ucontext *ucontext = smp_load_acquire(&ufile->ucontext);
  93
  94         if (!srcu_dereference(ufile->device->ib_dev,
  95                               &ufile->device->disassociate_srcu))
  96                 return ERR_PTR(-EIO);
  97
  98         if (!ucontext)
  99                 return ERR_PTR(-EINVAL);
 100
 101         return ucontext;
 102 }
 103 EXPORT_SYMBOL(ib_uverbs_get_ucontext_file);
 104
 105 int uverbs_dealloc_mw(struct ib_mw *mw)
 106 {
 107         struct ib_pd *pd = mw->pd;
 108         int ret;
 109
 110         ret = mw->device->ops.dealloc_mw(mw);
 111         if (!ret)
 112                 atomic_dec(&pd->usecnt);
 113         return ret;
 114 }
 115
 116 static void ib_uverbs_release_dev(struct device *device)
 117 {
 118         struct ib_uverbs_device *dev =
 119                         container_of(device, struct ib_uverbs_device, dev);
 120
 121         uverbs_destroy_api(dev->uapi);
 122         cleanup_srcu_struct(&dev->disassociate_srcu);
 123         mutex_destroy(&dev->lists_mutex);
 124         mutex_destroy(&dev->xrcd_tree_mutex);
 125         kfree(dev);
 126 }
 127
 128 static void ib_uverbs_release_async_event_file(struct kref *ref)
 129 {
 130         struct ib_uverbs_async_event_file *file =
 131                 container_of(ref, struct ib_uverbs_async_event_file, ref);
 132
 133         kfree(file);
 134 }
 135
 136 void ib_uverbs_release_ucq(struct ib_uverbs_file *file,
 137                           struct ib_uverbs_completion_event_file *ev_file,
 138                           struct ib_ucq_object *uobj)
 139 {
 140         struct ib_uverbs_event *evt, *tmp;
 141
 142         if (ev_file) {
 143                 spin_lock_irq(&ev_file->ev_queue.lock);
 144                 list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
 145                         list_del(&evt->list);
 146                         kfree(evt);
 147                 }
 148                 spin_unlock_irq(&ev_file->ev_queue.lock);
 149
 150                 uverbs_uobject_put(&ev_file->uobj);
 151         }
 152
 153         spin_lock_irq(&file->async_file->ev_queue.lock);
 154         list_for_each_entry_safe(evt, tmp, &uobj->async_list, obj_list) {
 155                 list_del(&evt->list);
 156                 kfree(evt);
 157         }
 158         spin_unlock_irq(&file->async_file->ev_queue.lock);
 159 }
 160
 161 void ib_uverbs_release_uevent(struct ib_uverbs_file *file,
 162                               struct ib_uevent_object *uobj)
 163 {
 164         struct ib_uverbs_event *evt, *tmp;
 165
 166         spin_lock_irq(&file->async_file->ev_queue.lock);
 167         list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
 168                 list_del(&evt->list);
 169                 kfree(evt);
 170         }
 171         spin_unlock_irq(&file->async_file->ev_queue.lock);
 172 }
 173
 174 void ib_uverbs_detach_umcast(struct ib_qp *qp,
 175                              struct ib_uqp_object *uobj)
 176 {
 177         struct ib_uverbs_mcast_entry *mcast, *tmp;
 178
 179         list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
 180                 ib_detach_mcast(qp, &mcast->gid, mcast->lid);
 181                 list_del(&mcast->list);
 182                 kfree(mcast);
 183         }
 184 }
 185
 186 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
 187 {
 188         complete(&dev->comp);
 189 }
 190
 191 void ib_uverbs_release_file(struct kref *ref)
 192 {
 193         struct ib_uverbs_file *file =
 194                 container_of(ref, struct ib_uverbs_file, ref);
 195         struct ib_device *ib_dev;
 196         int srcu_key;
 197
 198         release_ufile_idr_uobject(file);
 199
 200         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 201         ib_dev = srcu_dereference(file->device->ib_dev,
 202                                   &file->device->disassociate_srcu);
 203         if (ib_dev && !ib_dev->ops.disassociate_ucontext)
 204                 module_put(ib_dev->ops.owner);
 205         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 206
 207         if (atomic_dec_and_test(&file->device->refcount))
 208                 ib_uverbs_comp_dev(file->device);
 209
 210         if (file->async_file)
 211                 kref_put(&file->async_file->ref,
 212                          ib_uverbs_release_async_event_file);
 213         put_device(&file->device->dev);
 214
 215         if (file->disassociate_page)
 216                 __free_pages(file->disassociate_page, 0);
 217         mutex_destroy(&file->umap_lock);
 218         mutex_destroy(&file->ucontext_lock);
 219         kfree(file);
 220 }
 221
 222 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
 223                                     struct ib_uverbs_file *uverbs_file,
 224                                     struct file *filp, char __user *buf,
 225                                     size_t count, loff_t *pos,
 226                                     size_t eventsz)
 227 {
 228         struct ib_uverbs_event *event;
 229         int ret = 0;
 230
 231         spin_lock_irq(&ev_queue->lock);
 232
 233         while (list_empty(&ev_queue->event_list)) {
 234                 spin_unlock_irq(&ev_queue->lock);
 235
 236                 if (filp->f_flags & O_NONBLOCK)
 237                         return -EAGAIN;
 238
 239                 if (wait_event_interruptible(ev_queue->poll_wait,
 240                                              (!list_empty(&ev_queue->event_list) ||
 241                         /* The barriers built into wait_event_interruptible()
 242                          * and wake_up() guarentee this will see the null set
 243                          * without using RCU
 244                          */
 245                                              !uverbs_file->device->ib_dev)))
 246                         return -ERESTARTSYS;
 247
 248                 /* If device was disassociated and no event exists set an error */
 249                 if (list_empty(&ev_queue->event_list) &&
 250                     !uverbs_file->device->ib_dev)
 251                         return -EIO;
 252
 253                 spin_lock_irq(&ev_queue->lock);
 254         }
 255
 256         event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
 257
 258         if (eventsz > count) {
 259                 ret   = -EINVAL;
 260                 event = NULL;
 261         } else {
 262                 list_del(ev_queue->event_list.next);
 263                 if (event->counter) {
 264                         ++(*event->counter);
 265                         list_del(&event->obj_list);
 266                 }
 267         }
 268
 269         spin_unlock_irq(&ev_queue->lock);
 270
 271         if (event) {
 272                 if (copy_to_user(buf, event, eventsz))
 273                         ret = -EFAULT;
 274                 else
 275                         ret = eventsz;
 276         }
 277
 278         kfree(event);
 279
 280         return ret;
 281 }
 282
 283 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
 284                                           size_t count, loff_t *pos)
 285 {
 286         struct ib_uverbs_async_event_file *file = filp->private_data;
 287
 288         return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp,
 289                                     buf, count, pos,
 290                                     sizeof(struct ib_uverbs_async_event_desc));
 291 }
 292
 293 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
 294                                          size_t count, loff_t *pos)
 295 {
 296         struct ib_uverbs_completion_event_file *comp_ev_file =
 297                 filp->private_data;
 298
 299         return ib_uverbs_event_read(&comp_ev_file->ev_queue,
 300                                     comp_ev_file->uobj.ufile, filp,
 301                                     buf, count, pos,
 302                                     sizeof(struct ib_uverbs_comp_event_desc));
 303 }
 304
 305 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
 306                                          struct file *filp,
 307                                          struct poll_table_struct *wait)
 308 {
 309         __poll_t pollflags = 0;
 310
 311         poll_wait(filp, &ev_queue->poll_wait, wait);
 312
 313         spin_lock_irq(&ev_queue->lock);
 314         if (!list_empty(&ev_queue->event_list))
 315                 pollflags = EPOLLIN | EPOLLRDNORM;
 316         spin_unlock_irq(&ev_queue->lock);
 317
 318         return pollflags;
 319 }
 320
 321 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
 322                                                struct poll_table_struct *wait)
 323 {
 324         return ib_uverbs_event_poll(filp->private_data, filp, wait);
 325 }
 326
 327 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
 328                                               struct poll_table_struct *wait)
 329 {
 330         struct ib_uverbs_completion_event_file *comp_ev_file =
 331                 filp->private_data;
 332
 333         return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
 334 }
 335
 336 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
 337 {
 338         struct ib_uverbs_event_queue *ev_queue = filp->private_data;
 339
 340         return fasync_helper(fd, filp, on, &ev_queue->async_queue);
 341 }
 342
 343 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
 344 {
 345         struct ib_uverbs_completion_event_file *comp_ev_file =
 346                 filp->private_data;
 347
 348         return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
 349 }
 350
 351 static int ib_uverbs_async_event_close(struct inode *inode, struct file *filp)
 352 {
 353         struct ib_uverbs_async_event_file *file = filp->private_data;
 354         struct ib_uverbs_file *uverbs_file = file->uverbs_file;
 355         struct ib_uverbs_event *entry, *tmp;
 356         int closed_already = 0;
 357
 358         mutex_lock(&uverbs_file->device->lists_mutex);
 359         spin_lock_irq(&file->ev_queue.lock);
 360         closed_already = file->ev_queue.is_closed;
 361         file->ev_queue.is_closed = 1;
 362         list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
 363                 if (entry->counter)
 364                         list_del(&entry->obj_list);
 365                 kfree(entry);
 366         }
 367         spin_unlock_irq(&file->ev_queue.lock);
 368         if (!closed_already) {
 369                 list_del(&file->list);
 370                 ib_unregister_event_handler(&uverbs_file->event_handler);
 371         }
 372         mutex_unlock(&uverbs_file->device->lists_mutex);
 373
 374         kref_put(&uverbs_file->ref, ib_uverbs_release_file);
 375         kref_put(&file->ref, ib_uverbs_release_async_event_file);
 376
 377         return 0;
 378 }
 379
 380 static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
 381 {
 382         struct ib_uobject *uobj = filp->private_data;
 383         struct ib_uverbs_completion_event_file *file = container_of(
 384                 uobj, struct ib_uverbs_completion_event_file, uobj);
 385         struct ib_uverbs_event *entry, *tmp;
 386
 387         spin_lock_irq(&file->ev_queue.lock);
 388         list_for_each_entry_safe(entry, tmp, &file->ev_queue.event_list, list) {
 389                 if (entry->counter)
 390                         list_del(&entry->obj_list);
 391                 kfree(entry);
 392         }
 393         file->ev_queue.is_closed = 1;
 394         spin_unlock_irq(&file->ev_queue.lock);
 395
 396         uverbs_close_fd(filp);
 397
 398         return 0;
 399 }
 400
 401 const struct file_operations uverbs_event_fops = {
 402         .owner   = THIS_MODULE,
 403         .read    = ib_uverbs_comp_event_read,
 404         .poll    = ib_uverbs_comp_event_poll,
 405         .release = ib_uverbs_comp_event_close,
 406         .fasync  = ib_uverbs_comp_event_fasync,
 407         .llseek  = no_llseek,
 408 };
 409
 410 static const struct file_operations uverbs_async_event_fops = {
 411         .owner   = THIS_MODULE,
 412         .read    = ib_uverbs_async_event_read,
 413         .poll    = ib_uverbs_async_event_poll,
 414         .release = ib_uverbs_async_event_close,
 415         .fasync  = ib_uverbs_async_event_fasync,
 416         .llseek  = no_llseek,
 417 };
 418
 419 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
 420 {
 421         struct ib_uverbs_event_queue   *ev_queue = cq_context;
 422         struct ib_ucq_object           *uobj;
 423         struct ib_uverbs_event         *entry;
 424         unsigned long                   flags;
 425
 426         if (!ev_queue)
 427                 return;
 428
 429         spin_lock_irqsave(&ev_queue->lock, flags);
 430         if (ev_queue->is_closed) {
 431                 spin_unlock_irqrestore(&ev_queue->lock, flags);
 432                 return;
 433         }
 434
 435         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 436         if (!entry) {
 437                 spin_unlock_irqrestore(&ev_queue->lock, flags);
 438                 return;
 439         }
 440
 441         uobj = container_of(cq->uobject, struct ib_ucq_object, uobject);
 442
 443         entry->desc.comp.cq_handle = cq->uobject->user_handle;
 444         entry->counter             = &uobj->comp_events_reported;
 445
 446         list_add_tail(&entry->list, &ev_queue->event_list);
 447         list_add_tail(&entry->obj_list, &uobj->comp_list);
 448         spin_unlock_irqrestore(&ev_queue->lock, flags);
 449
 450         wake_up_interruptible(&ev_queue->poll_wait);
 451         kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
 452 }
 453
 454 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
 455                                     __u64 element, __u64 event,
 456                                     struct list_head *obj_list,
 457                                     u32 *counter)
 458 {
 459         struct ib_uverbs_event *entry;
 460         unsigned long flags;
 461
 462         spin_lock_irqsave(&file->async_file->ev_queue.lock, flags);
 463         if (file->async_file->ev_queue.is_closed) {
 464                 spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
 465                 return;
 466         }
 467
 468         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 469         if (!entry) {
 470                 spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
 471                 return;
 472         }
 473
 474         entry->desc.async.element    = element;
 475         entry->desc.async.event_type = event;
 476         entry->desc.async.reserved   = 0;
 477         entry->counter               = counter;
 478
 479         list_add_tail(&entry->list, &file->async_file->ev_queue.event_list);
 480         if (obj_list)
 481                 list_add_tail(&entry->obj_list, obj_list);
 482         spin_unlock_irqrestore(&file->async_file->ev_queue.lock, flags);
 483
 484         wake_up_interruptible(&file->async_file->ev_queue.poll_wait);
 485         kill_fasync(&file->async_file->ev_queue.async_queue, SIGIO, POLL_IN);
 486 }
 487
 488 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
 489 {
 490         struct ib_ucq_object *uobj = container_of(event->element.cq->uobject,
 491                                                   struct ib_ucq_object, uobject);
 492
 493         ib_uverbs_async_handler(uobj->uobject.ufile, uobj->uobject.user_handle,
 494                                 event->event, &uobj->async_list,
 495                                 &uobj->async_events_reported);
 496 }
 497
 498 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
 499 {
 500         struct ib_uevent_object *uobj;
 501
 502         /* for XRC target qp's, check that qp is live */
 503         if (!event->element.qp->uobject)
 504                 return;
 505
 506         uobj = container_of(event->element.qp->uobject,
 507                             struct ib_uevent_object, uobject);
 508
 509         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 510                                 event->event, &uobj->event_list,
 511                                 &uobj->events_reported);
 512 }
 513
 514 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
 515 {
 516         struct ib_uevent_object *uobj = container_of(event->element.wq->uobject,
 517                                                   struct ib_uevent_object, uobject);
 518
 519         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 520                                 event->event, &uobj->event_list,
 521                                 &uobj->events_reported);
 522 }
 523
 524 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
 525 {
 526         struct ib_uevent_object *uobj;
 527
 528         uobj = container_of(event->element.srq->uobject,
 529                             struct ib_uevent_object, uobject);
 530
 531         ib_uverbs_async_handler(context_ptr, uobj->uobject.user_handle,
 532                                 event->event, &uobj->event_list,
 533                                 &uobj->events_reported);
 534 }
 535
 536 void ib_uverbs_event_handler(struct ib_event_handler *handler,
 537                              struct ib_event *event)
 538 {
 539         struct ib_uverbs_file *file =
 540                 container_of(handler, struct ib_uverbs_file, event_handler);
 541
 542         ib_uverbs_async_handler(file, event->element.port_num, event->event,
 543                                 NULL, NULL);
 544 }
 545
 546 void ib_uverbs_free_async_event_file(struct ib_uverbs_file *file)
 547 {
 548         kref_put(&file->async_file->ref, ib_uverbs_release_async_event_file);
 549         file->async_file = NULL;
 550 }
 551
 552 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
 553 {
 554         spin_lock_init(&ev_queue->lock);
 555         INIT_LIST_HEAD(&ev_queue->event_list);
 556         init_waitqueue_head(&ev_queue->poll_wait);
 557         ev_queue->is_closed   = 0;
 558         ev_queue->async_queue = NULL;
 559 }
 560
 561 struct file *ib_uverbs_alloc_async_event_file(struct ib_uverbs_file *uverbs_file,
 562                                               struct ib_device  *ib_dev)
 563 {
 564         struct ib_uverbs_async_event_file *ev_file;
 565         struct file *filp;
 566
 567         ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL);
 568         if (!ev_file)
 569                 return ERR_PTR(-ENOMEM);
 570
 571         ib_uverbs_init_event_queue(&ev_file->ev_queue);
 572         ev_file->uverbs_file = uverbs_file;
 573         kref_get(&ev_file->uverbs_file->ref);
 574         kref_init(&ev_file->ref);
 575         filp = anon_inode_getfile("[infinibandevent]", &uverbs_async_event_fops,
 576                                   ev_file, O_RDONLY);
 577         if (IS_ERR(filp))
 578                 goto err_put_refs;
 579
 580         mutex_lock(&uverbs_file->device->lists_mutex);
 581         list_add_tail(&ev_file->list,
 582                       &uverbs_file->device->uverbs_events_file_list);
 583         mutex_unlock(&uverbs_file->device->lists_mutex);
 584
 585         WARN_ON(uverbs_file->async_file);
 586         uverbs_file->async_file = ev_file;
 587         kref_get(&uverbs_file->async_file->ref);
 588         INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler,
 589                               ib_dev,
 590                               ib_uverbs_event_handler);
 591         ib_register_event_handler(&uverbs_file->event_handler);
 592         /* At that point async file stuff was fully set */
 593
 594         return filp;
 595
 596 err_put_refs:
 597         kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file);
 598         kref_put(&ev_file->ref, ib_uverbs_release_async_event_file);
 599         return filp;
 600 }
 601
 602 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
 603                           struct ib_uverbs_ex_cmd_hdr *ex_hdr, size_t count,
 604                           const struct uverbs_api_write_method *method_elm)
 605 {
 606         if (method_elm->is_ex) {
 607                 count -= sizeof(*hdr) + sizeof(*ex_hdr);
 608
 609                 if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
 610                         return -EINVAL;
 611
 612                 if (hdr->in_words * 8 < method_elm->req_size)
 613                         return -ENOSPC;
 614
 615                 if (ex_hdr->cmd_hdr_reserved)
 616                         return -EINVAL;
 617
 618                 if (ex_hdr->response) {
 619                         if (!hdr->out_words && !ex_hdr->provider_out_words)
 620                                 return -EINVAL;
 621
 622                         if (hdr->out_words * 8 < method_elm->resp_size)
 623                                 return -ENOSPC;
 624
 625                         if (!access_ok(u64_to_user_ptr(ex_hdr->response),
 626                                        (hdr->out_words + ex_hdr->provider_out_words) * 8))
 627                                 return -EFAULT;
 628                 } else {
 629                         if (hdr->out_words || ex_hdr->provider_out_words)
 630                                 return -EINVAL;
 631                 }
 632
 633                 return 0;
 634         }
 635
 636         /* not extended command */
 637         if (hdr->in_words * 4 != count)
 638                 return -EINVAL;
 639
 640         if (count < method_elm->req_size + sizeof(hdr)) {
 641                 /*
 642                  * rdma-core v18 and v19 have a bug where they send DESTROY_CQ
 643                  * with a 16 byte write instead of 24. Old kernels didn't
 644                  * check the size so they allowed this. Now that the size is
 645                  * checked provide a compatibility work around to not break
 646                  * those userspaces.
 647                  */
 648                 if (hdr->command == IB_USER_VERBS_CMD_DESTROY_CQ &&
 649                     count == 16) {
 650                         hdr->in_words = 6;
 651                         return 0;
 652                 }
 653                 return -ENOSPC;
 654         }
 655         if (hdr->out_words * 4 < method_elm->resp_size)
 656                 return -ENOSPC;
 657
 658         return 0;
 659 }
 660
 661 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
 662                              size_t count, loff_t *pos)
 663 {
 664         struct ib_uverbs_file *file = filp->private_data;
 665         const struct uverbs_api_write_method *method_elm;
 666         struct uverbs_api *uapi = file->device->uapi;
 667         struct ib_uverbs_ex_cmd_hdr ex_hdr;
 668         struct ib_uverbs_cmd_hdr hdr;
 669         struct uverbs_attr_bundle bundle;
 670         int srcu_key;
 671         ssize_t ret;
 672
 673         if (!ib_safe_file_access(filp)) {
 674                 pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
 675                             task_tgid_vnr(current), current->comm);
 676                 return -EACCES;
 677         }
 678
 679         if (count < sizeof(hdr))
 680                 return -EINVAL;
 681
 682         if (copy_from_user(&hdr, buf, sizeof(hdr)))
 683                 return -EFAULT;
 684
 685         method_elm = uapi_get_method(uapi, hdr.command);
 686         if (IS_ERR(method_elm))
 687                 return PTR_ERR(method_elm);
 688
 689         if (method_elm->is_ex) {
 690                 if (count < (sizeof(hdr) + sizeof(ex_hdr)))
 691                         return -EINVAL;
 692                 if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
 693                         return -EFAULT;
 694         }
 695
 696         ret = verify_hdr(&hdr, &ex_hdr, count, method_elm);
 697         if (ret)
 698                 return ret;
 699
 700         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 701
 702         buf += sizeof(hdr);
 703
 704         memset(bundle.attr_present, 0, sizeof(bundle.attr_present));
 705         bundle.ufile = file;
 706         bundle.context = NULL; /* only valid if bundle has uobject */
 707         if (!method_elm->is_ex) {
 708                 size_t in_len = hdr.in_words * 4 - sizeof(hdr);
 709                 size_t out_len = hdr.out_words * 4;
 710                 u64 response = 0;
 711
 712                 if (method_elm->has_udata) {
 713                         bundle.driver_udata.inlen =
 714                                 in_len - method_elm->req_size;
 715                         in_len = method_elm->req_size;
 716                         if (bundle.driver_udata.inlen)
 717                                 bundle.driver_udata.inbuf = buf + in_len;
 718                         else
 719                                 bundle.driver_udata.inbuf = NULL;
 720                 } else {
 721                         memset(&bundle.driver_udata, 0,
 722                                sizeof(bundle.driver_udata));
 723                 }
 724
 725                 if (method_elm->has_resp) {
 726                         /*
 727                          * The macros check that if has_resp is set
 728                          * then the command request structure starts
 729                          * with a '__aligned u64 response' member.
 730                          */
 731                         ret = get_user(response, (const u64 __user *)buf);
 732                         if (ret)
 733                                 goto out_unlock;
 734
 735                         if (method_elm->has_udata) {
 736                                 bundle.driver_udata.outlen =
 737                                         out_len - method_elm->resp_size;
 738                                 out_len = method_elm->resp_size;
 739                                 if (bundle.driver_udata.outlen)
 740                                         bundle.driver_udata.outbuf =
 741                                                 u64_to_user_ptr(response +
 742                                                                 out_len);
 743                                 else
 744                                         bundle.driver_udata.outbuf = NULL;
 745                         }
 746                 } else {
 747                         bundle.driver_udata.outlen = 0;
 748                         bundle.driver_udata.outbuf = NULL;
 749                 }
 750
 751                 ib_uverbs_init_udata_buf_or_null(
 752                         &bundle.ucore, buf, u64_to_user_ptr(response),
 753                         in_len, out_len);
 754         } else {
 755                 buf += sizeof(ex_hdr);
 756
 757                 ib_uverbs_init_udata_buf_or_null(&bundle.ucore, buf,
 758                                         u64_to_user_ptr(ex_hdr.response),
 759                                         hdr.in_words * 8, hdr.out_words * 8);
 760
 761                 ib_uverbs_init_udata_buf_or_null(
 762                         &bundle.driver_udata, buf + bundle.ucore.inlen,
 763                         u64_to_user_ptr(ex_hdr.response) + bundle.ucore.outlen,
 764                         ex_hdr.provider_in_words * 8,
 765                         ex_hdr.provider_out_words * 8);
 766
 767         }
 768
 769         ret = method_elm->handler(&bundle);
 770 out_unlock:
 771         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 772         return (ret) ? : count;
 773 }
 774
 775 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
 776 {
 777         struct ib_uverbs_file *file = filp->private_data;
 778         struct ib_ucontext *ucontext;
 779         int ret = 0;
 780         int srcu_key;
 781
 782         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 783         ucontext = ib_uverbs_get_ucontext_file(file);
 784         if (IS_ERR(ucontext)) {
 785                 ret = PTR_ERR(ucontext);
 786                 goto out;
 787         }
 788
 789         ret = ucontext->device->ops.mmap(ucontext, vma);
 790 out:
 791         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 792         return ret;
 793 }
 794
 795 /*
 796  * Each time we map IO memory into user space this keeps track of the mapping.
 797  * When the device is hot-unplugged we 'zap' the mmaps in user space to point
 798  * to the zero page and allow the hot unplug to proceed.
 799  *
 800  * This is necessary for cases like PCI physical hot unplug as the actual BAR
 801  * memory may vanish after this and access to it from userspace could MCE.
 802  *
 803  * RDMA drivers supporting disassociation must have their user space designed
 804  * to cope in some way with their IO pages going to the zero page.
 805  */
 806 struct rdma_umap_priv {
 807         struct vm_area_struct *vma;
 808         struct list_head list;
 809 };
 810
 811 static const struct vm_operations_struct rdma_umap_ops;
 812
 813 static void rdma_umap_priv_init(struct rdma_umap_priv *priv,
 814                                 struct vm_area_struct *vma)
 815 {
 816         struct ib_uverbs_file *ufile = vma->vm_file->private_data;
 817
 818         priv->vma = vma;
 819         vma->vm_private_data = priv;
 820         vma->vm_ops = &rdma_umap_ops;
 821
 822         mutex_lock(&ufile->umap_lock);
 823         list_add(&priv->list, &ufile->umaps);
 824         mutex_unlock(&ufile->umap_lock);
 825 }
 826
 827 /*
 828  * The VMA has been dup'd, initialize the vm_private_data with a new tracking
 829  * struct
 830  */
 831 static void rdma_umap_open(struct vm_area_struct *vma)
 832 {
 833         struct ib_uverbs_file *ufile = vma->vm_file->private_data;
 834         struct rdma_umap_priv *opriv = vma->vm_private_data;
 835         struct rdma_umap_priv *priv;
 836
 837         if (!opriv)
 838                 return;
 839
 840         /* We are racing with disassociation */
 841         if (!down_read_trylock(&ufile->hw_destroy_rwsem))
 842                 goto out_zap;
 843         /*
 844          * Disassociation already completed, the VMA should already be zapped.
 845          */
 846         if (!ufile->ucontext)
 847                 goto out_unlock;
 848
 849         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 850         if (!priv)
 851                 goto out_unlock;
 852         rdma_umap_priv_init(priv, vma);
 853
 854         up_read(&ufile->hw_destroy_rwsem);
 855         return;
 856
 857 out_unlock:
 858         up_read(&ufile->hw_destroy_rwsem);
 859 out_zap:
 860         /*
 861          * We can't allow the VMA to be created with the actual IO pages, that
 862          * would break our API contract, and it can't be stopped at this
 863          * point, so zap it.
 864          */
 865         vma->vm_private_data = NULL;
 866         zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
 867 }
 868
 869 static void rdma_umap_close(struct vm_area_struct *vma)
 870 {
 871         struct ib_uverbs_file *ufile = vma->vm_file->private_data;
 872         struct rdma_umap_priv *priv = vma->vm_private_data;
 873
 874         if (!priv)
 875                 return;
 876
 877         /*
 878          * The vma holds a reference on the struct file that created it, which
 879          * in turn means that the ib_uverbs_file is guaranteed to exist at
 880          * this point.
 881          */
 882         mutex_lock(&ufile->umap_lock);
 883         list_del(&priv->list);
 884         mutex_unlock(&ufile->umap_lock);
 885         kfree(priv);
 886 }
 887
 888 /*
 889  * Once the zap_vma_ptes has been called touches to the VMA will come here and
 890  * we return a dummy writable zero page for all the pfns.
 891  */
 892 static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
 893 {
 894         struct ib_uverbs_file *ufile = vmf->vma->vm_file->private_data;
 895         struct rdma_umap_priv *priv = vmf->vma->vm_private_data;
 896         vm_fault_t ret = 0;
 897
 898         if (!priv)
 899                 return VM_FAULT_SIGBUS;
 900
 901         /* Read only pages can just use the system zero page. */
 902         if (!(vmf->vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
 903                 vmf->page = ZERO_PAGE(vmf->address);
 904                 get_page(vmf->page);
 905                 return 0;
 906         }
 907
 908         mutex_lock(&ufile->umap_lock);
 909         if (!ufile->disassociate_page)
 910                 ufile->disassociate_page =
 911                         alloc_pages(vmf->gfp_mask | __GFP_ZERO, 0);
 912
 913         if (ufile->disassociate_page) {
 914                 /*
 915                  * This VMA is forced to always be shared so this doesn't have
 916                  * to worry about COW.
 917                  */
 918                 vmf->page = ufile->disassociate_page;
 919                 get_page(vmf->page);
 920         } else {
 921                 ret = VM_FAULT_SIGBUS;
 922         }
 923         mutex_unlock(&ufile->umap_lock);
 924
 925         return ret;
 926 }
 927
 928 static const struct vm_operations_struct rdma_umap_ops = {
 929         .open = rdma_umap_open,
 930         .close = rdma_umap_close,
 931         .fault = rdma_umap_fault,
 932 };
 933
 934 /*
 935  * Map IO memory into a process. This is to be called by drivers as part of
 936  * their mmap() functions if they wish to send something like PCI-E BAR memory
 937  * to userspace.
 938  */
 939 int rdma_user_mmap_io(struct ib_ucontext *ucontext, struct vm_area_struct *vma,
 940                       unsigned long pfn, unsigned long size, pgprot_t prot)
 941 {
 942         struct ib_uverbs_file *ufile = ucontext->ufile;
 943         struct rdma_umap_priv *priv;
 944
 945         if (!(vma->vm_flags & VM_SHARED))
 946                 return -EINVAL;
 947
 948         if (vma->vm_end - vma->vm_start != size)
 949                 return -EINVAL;
 950
 951         /* Driver is using this wrong, must be called by ib_uverbs_mmap */
 952         if (WARN_ON(!vma->vm_file ||
 953                     vma->vm_file->private_data != ufile))
 954                 return -EINVAL;
 955         lockdep_assert_held(&ufile->device->disassociate_srcu);
 956
 957         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 958         if (!priv)
 959                 return -ENOMEM;
 960
 961         vma->vm_page_prot = prot;
 962         if (io_remap_pfn_range(vma, vma->vm_start, pfn, size, prot)) {
 963                 kfree(priv);
 964                 return -EAGAIN;
 965         }
 966
 967         rdma_umap_priv_init(priv, vma);
 968         return 0;
 969 }
 970 EXPORT_SYMBOL(rdma_user_mmap_io);
 971
 972 void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
 973 {
 974         struct rdma_umap_priv *priv, *next_priv;
 975
 976         lockdep_assert_held(&ufile->hw_destroy_rwsem);
 977
 978         while (1) {
 979                 struct mm_struct *mm = NULL;
 980
 981                 /* Get an arbitrary mm pointer that hasn't been cleaned yet */
 982                 mutex_lock(&ufile->umap_lock);
 983                 while (!list_empty(&ufile->umaps)) {
 984                         int ret;
 985
 986                         priv = list_first_entry(&ufile->umaps,
 987                                                 struct rdma_umap_priv, list);
 988                         mm = priv->vma->vm_mm;
 989                         ret = mmget_not_zero(mm);
 990                         if (!ret) {
 991                                 list_del_init(&priv->list);
 992                                 mm = NULL;
 993                                 continue;
 994                         }
 995                         break;
 996                 }
 997                 mutex_unlock(&ufile->umap_lock);
 998                 if (!mm)
 999                         return;
1000
1001                 /*
1002                  * The umap_lock is nested under mmap_sem since it used within
1003                  * the vma_ops callbacks, so we have to clean the list one mm
1004                  * at a time to get the lock ordering right. Typically there
1005                  * will only be one mm, so no big deal.
1006                  */
1007                 down_read(&mm->mmap_sem);
1008                 if (!mmget_still_valid(mm))
1009                         goto skip_mm;
1010                 mutex_lock(&ufile->umap_lock);
1011                 list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
1012                                           list) {
1013                         struct vm_area_struct *vma = priv->vma;
1014
1015                         if (vma->vm_mm != mm)
1016                                 continue;
1017                         list_del_init(&priv->list);
1018
1019                         zap_vma_ptes(vma, vma->vm_start,
1020                                      vma->vm_end - vma->vm_start);
1021                 }
1022                 mutex_unlock(&ufile->umap_lock);
1023         skip_mm:
1024                 up_read(&mm->mmap_sem);
1025                 mmput(mm);
1026         }
1027 }
1028
1029 /*
1030  * ib_uverbs_open() does not need the BKL:
1031  *
1032  *  - the ib_uverbs_device structures are properly reference counted and
1033  *    everything else is purely local to the file being created, so
1034  *    races against other open calls are not a problem;
1035  *  - there is no ioctl method to race against;
1036  *  - the open method will either immediately run -ENXIO, or all
1037  *    required initialization will be done.
1038  */
1039 static int ib_uverbs_open(struct inode *inode, struct file *filp)
1040 {
1041         struct ib_uverbs_device *dev;
1042         struct ib_uverbs_file *file;
1043         struct ib_device *ib_dev;
1044         int ret;
1045         int module_dependent;
1046         int srcu_key;
1047
1048         dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
1049         if (!atomic_inc_not_zero(&dev->refcount))
1050                 return -ENXIO;
1051
1052         get_device(&dev->dev);
1053         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1054         mutex_lock(&dev->lists_mutex);
1055         ib_dev = srcu_dereference(dev->ib_dev,
1056                                   &dev->disassociate_srcu);
1057         if (!ib_dev) {
1058                 ret = -EIO;
1059                 goto err;
1060         }
1061
1062         if (!rdma_dev_access_netns(ib_dev, current->nsproxy->net_ns)) {
1063                 ret = -EPERM;
1064                 goto err;
1065         }
1066
1067         /* In case IB device supports disassociate ucontext, there is no hard
1068          * dependency between uverbs device and its low level device.
1069          */
1070         module_dependent = !(ib_dev->ops.disassociate_ucontext);
1071
1072         if (module_dependent) {
1073                 if (!try_module_get(ib_dev->ops.owner)) {
1074                         ret = -ENODEV;
1075                         goto err;
1076                 }
1077         }
1078
1079         file = kzalloc(sizeof(*file), GFP_KERNEL);
1080         if (!file) {
1081                 ret = -ENOMEM;
1082                 if (module_dependent)
1083                         goto err_module;
1084
1085                 goto err;
1086         }
1087
1088         file->device     = dev;
1089         kref_init(&file->ref);
1090         mutex_init(&file->ucontext_lock);
1091
1092         spin_lock_init(&file->uobjects_lock);
1093         INIT_LIST_HEAD(&file->uobjects);
1094         init_rwsem(&file->hw_destroy_rwsem);
1095         mutex_init(&file->umap_lock);
1096         INIT_LIST_HEAD(&file->umaps);
1097
1098         filp->private_data = file;
1099         list_add_tail(&file->list, &dev->uverbs_file_list);
1100         mutex_unlock(&dev->lists_mutex);
1101         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1102
1103         setup_ufile_idr_uobject(file);
1104
1105         return stream_open(inode, filp);
1106
1107 err_module:
1108         module_put(ib_dev->ops.owner);
1109
1110 err:
1111         mutex_unlock(&dev->lists_mutex);
1112         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1113         if (atomic_dec_and_test(&dev->refcount))
1114                 ib_uverbs_comp_dev(dev);
1115
1116         put_device(&dev->dev);
1117         return ret;
1118 }
1119
1120 static int ib_uverbs_close(struct inode *inode, struct file *filp)
1121 {
1122         struct ib_uverbs_file *file = filp->private_data;
1123
1124         uverbs_destroy_ufile_hw(file, RDMA_REMOVE_CLOSE);
1125
1126         mutex_lock(&file->device->lists_mutex);
1127         list_del_init(&file->list);
1128         mutex_unlock(&file->device->lists_mutex);
1129
1130         kref_put(&file->ref, ib_uverbs_release_file);
1131
1132         return 0;
1133 }
1134
1135 static const struct file_operations uverbs_fops = {
1136         .owner   = THIS_MODULE,
1137         .write   = ib_uverbs_write,
1138         .open    = ib_uverbs_open,
1139         .release = ib_uverbs_close,
1140         .llseek  = no_llseek,
1141         .unlocked_ioctl = ib_uverbs_ioctl,
1142         .compat_ioctl = ib_uverbs_ioctl,
1143 };
1144
1145 static const struct file_operations uverbs_mmap_fops = {
1146         .owner   = THIS_MODULE,
1147         .write   = ib_uverbs_write,
1148         .mmap    = ib_uverbs_mmap,
1149         .open    = ib_uverbs_open,
1150         .release = ib_uverbs_close,
1151         .llseek  = no_llseek,
1152         .unlocked_ioctl = ib_uverbs_ioctl,
1153         .compat_ioctl = ib_uverbs_ioctl,
1154 };
1155
1156 static int ib_uverbs_get_nl_info(struct ib_device *ibdev, void *client_data,
1157                                  struct ib_client_nl_info *res)
1158 {
1159         struct ib_uverbs_device *uverbs_dev = client_data;
1160         int ret;
1161
1162         if (res->port != -1)
1163                 return -EINVAL;
1164
1165         res->abi = ibdev->ops.uverbs_abi_ver;
1166         res->cdev = &uverbs_dev->dev;
1167
1168         /*
1169          * To support DRIVER_ID binding in userspace some of the driver need
1170          * upgrading to expose their PCI dependent revision information
1171          * through get_context instead of relying on modalias matching. When
1172          * the drivers are fixed they can drop this flag.
1173          */
1174         if (!ibdev->ops.uverbs_no_driver_id_binding) {
1175                 ret = nla_put_u32(res->nl_msg, RDMA_NLDEV_ATTR_UVERBS_DRIVER_ID,
1176                                   ibdev->ops.driver_id);
1177                 if (ret)
1178                         return ret;
1179         }
1180         return 0;
1181 }
1182
1183 static struct ib_client uverbs_client = {
1184         .name   = "uverbs",
1185         .no_kverbs_req = true,
1186         .add    = ib_uverbs_add_one,
1187         .remove = ib_uverbs_remove_one,
1188         .get_nl_info = ib_uverbs_get_nl_info,
1189 };
1190 MODULE_ALIAS_RDMA_CLIENT("uverbs");
1191
1192 static ssize_t ibdev_show(struct device *device, struct device_attribute *attr,
1193                           char *buf)
1194 {
1195         struct ib_uverbs_device *dev =
1196                         container_of(device, struct ib_uverbs_device, dev);
1197         int ret = -ENODEV;
1198         int srcu_key;
1199         struct ib_device *ib_dev;
1200
1201         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1202         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1203         if (ib_dev)
1204                 ret = sprintf(buf, "%s\n", dev_name(&ib_dev->dev));
1205         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1206
1207         return ret;
1208 }
1209 static DEVICE_ATTR_RO(ibdev);
1210
1211 static ssize_t abi_version_show(struct device *device,
1212                                 struct device_attribute *attr, char *buf)
1213 {
1214         struct ib_uverbs_device *dev =
1215                         container_of(device, struct ib_uverbs_device, dev);
1216         int ret = -ENODEV;
1217         int srcu_key;
1218         struct ib_device *ib_dev;
1219
1220         srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1221         ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1222         if (ib_dev)
1223                 ret = sprintf(buf, "%u\n", ib_dev->ops.uverbs_abi_ver);
1224         srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1225
1226         return ret;
1227 }
1228 static DEVICE_ATTR_RO(abi_version);
1229
1230 static struct attribute *ib_dev_attrs[] = {
1231         &dev_attr_abi_version.attr,
1232         &dev_attr_ibdev.attr,
1233         NULL,
1234 };
1235
1236 static const struct attribute_group dev_attr_group = {
1237         .attrs = ib_dev_attrs,
1238 };
1239
1240 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1241                          __stringify(IB_USER_VERBS_ABI_VERSION));
1242
1243 static int ib_uverbs_create_uapi(struct ib_device *device,
1244                                  struct ib_uverbs_device *uverbs_dev)
1245 {
1246         struct uverbs_api *uapi;
1247
1248         uapi = uverbs_alloc_api(device);
1249         if (IS_ERR(uapi))
1250                 return PTR_ERR(uapi);
1251
1252         uverbs_dev->uapi = uapi;
1253         return 0;
1254 }
1255
1256 static void ib_uverbs_add_one(struct ib_device *device)
1257 {
1258         int devnum;
1259         dev_t base;
1260         struct ib_uverbs_device *uverbs_dev;
1261         int ret;
1262
1263         if (!device->ops.alloc_ucontext)
1264                 return;
1265
1266         uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1267         if (!uverbs_dev)
1268                 return;
1269
1270         ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1271         if (ret) {
1272                 kfree(uverbs_dev);
1273                 return;
1274         }
1275
1276         device_initialize(&uverbs_dev->dev);
1277         uverbs_dev->dev.class = uverbs_class;
1278         uverbs_dev->dev.parent = device->dev.parent;
1279         uverbs_dev->dev.release = ib_uverbs_release_dev;
1280         uverbs_dev->groups[0] = &dev_attr_group;
1281         uverbs_dev->dev.groups = uverbs_dev->groups;
1282         atomic_set(&uverbs_dev->refcount, 1);
1283         init_completion(&uverbs_dev->comp);
1284         uverbs_dev->xrcd_tree = RB_ROOT;
1285         mutex_init(&uverbs_dev->xrcd_tree_mutex);
1286         mutex_init(&uverbs_dev->lists_mutex);
1287         INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1288         INIT_LIST_HEAD(&uverbs_dev->uverbs_events_file_list);
1289         rcu_assign_pointer(uverbs_dev->ib_dev, device);
1290         uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1291
1292         devnum = ida_alloc_max(&uverbs_ida, IB_UVERBS_MAX_DEVICES - 1,
1293                                GFP_KERNEL);
1294         if (devnum < 0)
1295                 goto err;
1296         uverbs_dev->devnum = devnum;
1297         if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1298                 base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1299         else
1300                 base = IB_UVERBS_BASE_DEV + devnum;
1301
1302         if (ib_uverbs_create_uapi(device, uverbs_dev))
1303                 goto err_uapi;
1304
1305         uverbs_dev->dev.devt = base;
1306         dev_set_name(&uverbs_dev->dev, "uverbs%d", uverbs_dev->devnum);
1307
1308         cdev_init(&uverbs_dev->cdev,
1309                   device->ops.mmap ? &uverbs_mmap_fops : &uverbs_fops);
1310         uverbs_dev->cdev.owner = THIS_MODULE;
1311
1312         ret = cdev_device_add(&uverbs_dev->cdev, &uverbs_dev->dev);
1313         if (ret)
1314                 goto err_uapi;
1315
1316         ib_set_client_data(device, &uverbs_client, uverbs_dev);
1317         return;
1318
1319 err_uapi:
1320         ida_free(&uverbs_ida, devnum);
1321 err:
1322         if (atomic_dec_and_test(&uverbs_dev->refcount))
1323                 ib_uverbs_comp_dev(uverbs_dev);
1324         wait_for_completion(&uverbs_dev->comp);
1325         put_device(&uverbs_dev->dev);
1326         return;
1327 }
1328
1329 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1330                                         struct ib_device *ib_dev)
1331 {
1332         struct ib_uverbs_file *file;
1333         struct ib_uverbs_async_event_file *event_file;
1334         struct ib_event event;
1335
1336         /* Pending running commands to terminate */
1337         uverbs_disassociate_api_pre(uverbs_dev);
1338         event.event = IB_EVENT_DEVICE_FATAL;
1339         event.element.port_num = 0;
1340         event.device = ib_dev;
1341
1342         mutex_lock(&uverbs_dev->lists_mutex);
1343         while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1344                 file = list_first_entry(&uverbs_dev->uverbs_file_list,
1345                                         struct ib_uverbs_file, list);
1346                 list_del_init(&file->list);
1347                 kref_get(&file->ref);
1348
1349                 /* We must release the mutex before going ahead and calling
1350                  * uverbs_cleanup_ufile, as it might end up indirectly calling
1351                  * uverbs_close, for example due to freeing the resources (e.g
1352                  * mmput).
1353                  */
1354                 mutex_unlock(&uverbs_dev->lists_mutex);
1355
1356                 ib_uverbs_event_handler(&file->event_handler, &event);
1357                 uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
1358                 kref_put(&file->ref, ib_uverbs_release_file);
1359
1360                 mutex_lock(&uverbs_dev->lists_mutex);
1361         }
1362
1363         while (!list_empty(&uverbs_dev->uverbs_events_file_list)) {
1364                 event_file = list_first_entry(&uverbs_dev->
1365                                               uverbs_events_file_list,
1366                                               struct ib_uverbs_async_event_file,
1367                                               list);
1368                 spin_lock_irq(&event_file->ev_queue.lock);
1369                 event_file->ev_queue.is_closed = 1;
1370                 spin_unlock_irq(&event_file->ev_queue.lock);
1371
1372                 list_del(&event_file->list);
1373                 ib_unregister_event_handler(
1374                         &event_file->uverbs_file->event_handler);
1375                 event_file->uverbs_file->event_handler.device =
1376                         NULL;
1377
1378                 wake_up_interruptible(&event_file->ev_queue.poll_wait);
1379                 kill_fasync(&event_file->ev_queue.async_queue, SIGIO, POLL_IN);
1380         }
1381         mutex_unlock(&uverbs_dev->lists_mutex);
1382
1383         uverbs_disassociate_api(uverbs_dev->uapi);
1384 }
1385
1386 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1387 {
1388         struct ib_uverbs_device *uverbs_dev = client_data;
1389         int wait_clients = 1;
1390
1391         if (!uverbs_dev)
1392                 return;
1393
1394         cdev_device_del(&uverbs_dev->cdev, &uverbs_dev->dev);
1395         ida_free(&uverbs_ida, uverbs_dev->devnum);
1396
1397         if (device->ops.disassociate_ucontext) {
1398                 /* We disassociate HW resources and immediately return.
1399                  * Userspace will see a EIO errno for all future access.
1400                  * Upon returning, ib_device may be freed internally and is not
1401                  * valid any more.
1402                  * uverbs_device is still available until all clients close
1403                  * their files, then the uverbs device ref count will be zero
1404                  * and its resources will be freed.
1405                  * Note: At this point no more files can be opened since the
1406                  * cdev was deleted, however active clients can still issue
1407                  * commands and close their open files.
1408                  */
1409                 ib_uverbs_free_hw_resources(uverbs_dev, device);
1410                 wait_clients = 0;
1411         }
1412
1413         if (atomic_dec_and_test(&uverbs_dev->refcount))
1414                 ib_uverbs_comp_dev(uverbs_dev);
1415         if (wait_clients)
1416                 wait_for_completion(&uverbs_dev->comp);
1417
1418         put_device(&uverbs_dev->dev);
1419 }
1420
1421 static char *uverbs_devnode(struct device *dev, umode_t *mode)
1422 {
1423         if (mode)
1424                 *mode = 0666;
1425         return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1426 }
1427
1428 static int __init ib_uverbs_init(void)
1429 {
1430         int ret;
1431
1432         ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1433                                      IB_UVERBS_NUM_FIXED_MINOR,
1434                                      "infiniband_verbs");
1435         if (ret) {
1436                 pr_err("user_verbs: couldn't register device number\n");
1437                 goto out;
1438         }
1439
1440         ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1441                                   IB_UVERBS_NUM_DYNAMIC_MINOR,
1442                                   "infiniband_verbs");
1443         if (ret) {
1444                 pr_err("couldn't register dynamic device number\n");
1445                 goto out_alloc;
1446         }
1447
1448         uverbs_class = class_create(THIS_MODULE, "infiniband_verbs");
1449         if (IS_ERR(uverbs_class)) {
1450                 ret = PTR_ERR(uverbs_class);
1451                 pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1452                 goto out_chrdev;
1453         }
1454
1455         uverbs_class->devnode = uverbs_devnode;
1456
1457         ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1458         if (ret) {
1459                 pr_err("user_verbs: couldn't create abi_version attribute\n");
1460                 goto out_class;
1461         }
1462
1463         ret = ib_register_client(&uverbs_client);
1464         if (ret) {
1465                 pr_err("user_verbs: couldn't register client\n");
1466                 goto out_class;
1467         }
1468
1469         return 0;
1470
1471 out_class:
1472         class_destroy(uverbs_class);
1473
1474 out_chrdev:
1475         unregister_chrdev_region(dynamic_uverbs_dev,
1476                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1477
1478 out_alloc:
1479         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1480                                  IB_UVERBS_NUM_FIXED_MINOR);
1481
1482 out:
1483         return ret;
1484 }
1485
1486 static void __exit ib_uverbs_cleanup(void)
1487 {
1488         ib_unregister_client(&uverbs_client);
1489         class_destroy(uverbs_class);
1490         unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1491                                  IB_UVERBS_NUM_FIXED_MINOR);
1492         unregister_chrdev_region(dynamic_uverbs_dev,
1493                                  IB_UVERBS_NUM_DYNAMIC_MINOR);
1494         mmu_notifier_synchronize();
1495 }
1496
1497 module_init(ib_uverbs_init);
1498 module_exit(ib_uverbs_cleanup);