drivers/staging/android/sync.c

   1 /*
   2  * drivers/base/sync.c
   3  *
   4  * Copyright (C) 2012 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #include <linux/debugfs.h>
  18 #include <linux/export.h>
  19 #include <linux/file.h>
  20 #include <linux/fs.h>
  21 #include <linux/kernel.h>
  22 #include <linux/poll.h>
  23 #include <linux/sched.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/slab.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/anon_inodes.h>
  28
  29 #include "sync.h"
  30
  31 #define CREATE_TRACE_POINTS
  32 #include "trace/sync.h"
  33
  34 static const struct fence_ops android_fence_ops;
  35 static const struct file_operations sync_fence_fops;
  36
  37 struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
  38                                            int size, const char *name)
  39 {
  40         struct sync_timeline *obj;
  41
  42         if (size < sizeof(struct sync_timeline))
  43                 return NULL;
  44
  45         obj = kzalloc(size, GFP_KERNEL);
  46         if (obj == NULL)
  47                 return NULL;
  48
  49         kref_init(&obj->kref);
  50         obj->ops = ops;
  51         obj->context = fence_context_alloc(1);
  52         strlcpy(obj->name, name, sizeof(obj->name));
  53
  54         INIT_LIST_HEAD(&obj->child_list_head);
  55         INIT_LIST_HEAD(&obj->active_list_head);
  56         spin_lock_init(&obj->child_list_lock);
  57
  58         sync_timeline_debug_add(obj);
  59
  60         return obj;
  61 }
  62 EXPORT_SYMBOL(sync_timeline_create);
  63
  64 static void sync_timeline_free(struct kref *kref)
  65 {
  66         struct sync_timeline *obj =
  67                 container_of(kref, struct sync_timeline, kref);
  68
  69         sync_timeline_debug_remove(obj);
  70
  71         if (obj->ops->release_obj)
  72                 obj->ops->release_obj(obj);
  73
  74         kfree(obj);
  75 }
  76
  77 static void sync_timeline_get(struct sync_timeline *obj)
  78 {
  79         kref_get(&obj->kref);
  80 }
  81
  82 static void sync_timeline_put(struct sync_timeline *obj)
  83 {
  84         kref_put(&obj->kref, sync_timeline_free);
  85 }
  86
  87 void sync_timeline_destroy(struct sync_timeline *obj)
  88 {
  89         obj->destroyed = true;
  90         /*
  91          * Ensure timeline is marked as destroyed before
  92          * changing timeline's fences status.
  93          */
  94         smp_wmb();
  95
  96         /*
  97          * signal any children that their parent is going away.
  98          */
  99         sync_timeline_signal(obj);
 100         sync_timeline_put(obj);
 101 }
 102 EXPORT_SYMBOL(sync_timeline_destroy);
 103
 104 void sync_timeline_signal(struct sync_timeline *obj)
 105 {
 106         unsigned long flags;
 107         LIST_HEAD(signaled_pts);
 108         struct sync_pt *pt, *next;
 109
 110         trace_sync_timeline(obj);
 111
 112         spin_lock_irqsave(&obj->child_list_lock, flags);
 113
 114         list_for_each_entry_safe(pt, next, &obj->active_list_head,
 115                                  active_list) {
 116                 if (fence_is_signaled_locked(&pt->base))
 117                         list_del(&pt->active_list);
 118         }
 119
 120         spin_unlock_irqrestore(&obj->child_list_lock, flags);
 121 }
 122 EXPORT_SYMBOL(sync_timeline_signal);
 123
 124 struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size)
 125 {
 126         unsigned long flags;
 127         struct sync_pt *pt;
 128
 129         if (size < sizeof(struct sync_pt))
 130                 return NULL;
 131
 132         pt = kzalloc(size, GFP_KERNEL);
 133         if (pt == NULL)
 134                 return NULL;
 135
 136         spin_lock_irqsave(&obj->child_list_lock, flags);
 137         sync_timeline_get(obj);
 138         fence_init(&pt->base, &android_fence_ops, &obj->child_list_lock,
 139                    obj->context, ++obj->value);
 140         list_add_tail(&pt->child_list, &obj->child_list_head);
 141         INIT_LIST_HEAD(&pt->active_list);
 142         spin_unlock_irqrestore(&obj->child_list_lock, flags);
 143         return pt;
 144 }
 145 EXPORT_SYMBOL(sync_pt_create);
 146
 147 void sync_pt_free(struct sync_pt *pt)
 148 {
 149         fence_put(&pt->base);
 150 }
 151 EXPORT_SYMBOL(sync_pt_free);
 152
 153 static struct sync_fence *sync_fence_alloc(int size, const char *name)
 154 {
 155         struct sync_fence *fence;
 156
 157         fence = kzalloc(size, GFP_KERNEL);
 158         if (fence == NULL)
 159                 return NULL;
 160
 161         fence->file = anon_inode_getfile("sync_fence", &sync_fence_fops,
 162                                          fence, 0);
 163         if (IS_ERR(fence->file))
 164                 goto err;
 165
 166         kref_init(&fence->kref);
 167         strlcpy(fence->name, name, sizeof(fence->name));
 168
 169         init_waitqueue_head(&fence->wq);
 170
 171         return fence;
 172
 173 err:
 174         kfree(fence);
 175         return NULL;
 176 }
 177
 178 static void fence_check_cb_func(struct fence *f, struct fence_cb *cb)
 179 {
 180         struct sync_fence_cb *check;
 181         struct sync_fence *fence;
 182
 183         check = container_of(cb, struct sync_fence_cb, cb);
 184         fence = check->fence;
 185
 186         if (atomic_dec_and_test(&fence->status))
 187                 wake_up_all(&fence->wq);
 188 }
 189
 190 /* TODO: implement a create which takes more that one sync_pt */
 191 struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
 192 {
 193         struct sync_fence *fence;
 194
 195         fence = sync_fence_alloc(offsetof(struct sync_fence, cbs[1]), name);
 196         if (fence == NULL)
 197                 return NULL;
 198
 199         fence->num_fences = 1;
 200         atomic_set(&fence->status, 1);
 201
 202         fence_get(&pt->base);
 203         fence->cbs[0].sync_pt = &pt->base;
 204         fence->cbs[0].fence = fence;
 205         if (fence_add_callback(&pt->base, &fence->cbs[0].cb,
 206                                fence_check_cb_func))
 207                 atomic_dec(&fence->status);
 208
 209         sync_fence_debug_add(fence);
 210
 211         return fence;
 212 }
 213 EXPORT_SYMBOL(sync_fence_create);
 214
 215 struct sync_fence *sync_fence_fdget(int fd)
 216 {
 217         struct file *file = fget(fd);
 218
 219         if (file == NULL)
 220                 return NULL;
 221
 222         if (file->f_op != &sync_fence_fops)
 223                 goto err;
 224
 225         return file->private_data;
 226
 227 err:
 228         fput(file);
 229         return NULL;
 230 }
 231 EXPORT_SYMBOL(sync_fence_fdget);
 232
 233 void sync_fence_put(struct sync_fence *fence)
 234 {
 235         fput(fence->file);
 236 }
 237 EXPORT_SYMBOL(sync_fence_put);
 238
 239 void sync_fence_install(struct sync_fence *fence, int fd)
 240 {
 241         fd_install(fd, fence->file);
 242 }
 243 EXPORT_SYMBOL(sync_fence_install);
 244
 245 static void sync_fence_add_pt(struct sync_fence *fence,
 246                               int *i, struct fence *pt)
 247 {
 248         fence->cbs[*i].sync_pt = pt;
 249         fence->cbs[*i].fence = fence;
 250
 251         if (!fence_add_callback(pt, &fence->cbs[*i].cb, fence_check_cb_func)) {
 252                 fence_get(pt);
 253                 (*i)++;
 254         }
 255 }
 256
 257 struct sync_fence *sync_fence_merge(const char *name,
 258                                     struct sync_fence *a, struct sync_fence *b)
 259 {
 260         int num_fences = a->num_fences + b->num_fences;
 261         struct sync_fence *fence;
 262         int i, i_a, i_b;
 263         unsigned long size = offsetof(struct sync_fence, cbs[num_fences]);
 264
 265         fence = sync_fence_alloc(size, name);
 266         if (fence == NULL)
 267                 return NULL;
 268
 269         atomic_set(&fence->status, num_fences);
 270
 271         /*
 272          * Assume sync_fence a and b are both ordered and have no
 273          * duplicates with the same context.
 274          *
 275          * If a sync_fence can only be created with sync_fence_merge
 276          * and sync_fence_create, this is a reasonable assumption.
 277          */
 278         for (i = i_a = i_b = 0; i_a < a->num_fences && i_b < b->num_fences; ) {
 279                 struct fence *pt_a = a->cbs[i_a].sync_pt;
 280                 struct fence *pt_b = b->cbs[i_b].sync_pt;
 281
 282                 if (pt_a->context < pt_b->context) {
 283                         sync_fence_add_pt(fence, &i, pt_a);
 284
 285                         i_a++;
 286                 } else if (pt_a->context > pt_b->context) {
 287                         sync_fence_add_pt(fence, &i, pt_b);
 288
 289                         i_b++;
 290                 } else {
 291                         if (pt_a->seqno - pt_b->seqno <= INT_MAX)
 292                                 sync_fence_add_pt(fence, &i, pt_a);
 293                         else
 294                                 sync_fence_add_pt(fence, &i, pt_b);
 295
 296                         i_a++;
 297                         i_b++;
 298                 }
 299         }
 300
 301         for (; i_a < a->num_fences; i_a++)
 302                 sync_fence_add_pt(fence, &i, a->cbs[i_a].sync_pt);
 303
 304         for (; i_b < b->num_fences; i_b++)
 305                 sync_fence_add_pt(fence, &i, b->cbs[i_b].sync_pt);
 306
 307         if (num_fences > i)
 308                 atomic_sub(num_fences - i, &fence->status);
 309         fence->num_fences = i;
 310
 311         sync_fence_debug_add(fence);
 312         return fence;
 313 }
 314 EXPORT_SYMBOL(sync_fence_merge);
 315
 316 int sync_fence_wake_up_wq(wait_queue_t *curr, unsigned mode,
 317                                  int wake_flags, void *key)
 318 {
 319         struct sync_fence_waiter *wait;
 320
 321         wait = container_of(curr, struct sync_fence_waiter, work);
 322         list_del_init(&wait->work.task_list);
 323
 324         wait->callback(wait->work.private, wait);
 325         return 1;
 326 }
 327
 328 int sync_fence_wait_async(struct sync_fence *fence,
 329                           struct sync_fence_waiter *waiter)
 330 {
 331         int err = atomic_read(&fence->status);
 332         unsigned long flags;
 333
 334         if (err < 0)
 335                 return err;
 336
 337         if (!err)
 338                 return 1;
 339
 340         init_waitqueue_func_entry(&waiter->work, sync_fence_wake_up_wq);
 341         waiter->work.private = fence;
 342
 343         spin_lock_irqsave(&fence->wq.lock, flags);
 344         err = atomic_read(&fence->status);
 345         if (err > 0)
 346                 __add_wait_queue_tail(&fence->wq, &waiter->work);
 347         spin_unlock_irqrestore(&fence->wq.lock, flags);
 348
 349         if (err < 0)
 350                 return err;
 351
 352         return !err;
 353 }
 354 EXPORT_SYMBOL(sync_fence_wait_async);
 355
 356 int sync_fence_cancel_async(struct sync_fence *fence,
 357                              struct sync_fence_waiter *waiter)
 358 {
 359         unsigned long flags;
 360         int ret = 0;
 361
 362         spin_lock_irqsave(&fence->wq.lock, flags);
 363         if (!list_empty(&waiter->work.task_list))
 364                 list_del_init(&waiter->work.task_list);
 365         else
 366                 ret = -ENOENT;
 367         spin_unlock_irqrestore(&fence->wq.lock, flags);
 368         return ret;
 369 }
 370 EXPORT_SYMBOL(sync_fence_cancel_async);
 371
 372 int sync_fence_wait(struct sync_fence *fence, long timeout)
 373 {
 374         long ret;
 375         int i;
 376
 377         if (timeout < 0)
 378                 timeout = MAX_SCHEDULE_TIMEOUT;
 379         else
 380                 timeout = msecs_to_jiffies(timeout);
 381
 382         trace_sync_wait(fence, 1);
 383         for (i = 0; i < fence->num_fences; ++i)
 384                 trace_sync_pt(fence->cbs[i].sync_pt);
 385         ret = wait_event_interruptible_timeout(fence->wq,
 386                                                atomic_read(&fence->status) <= 0,
 387                                                timeout);
 388         trace_sync_wait(fence, 0);
 389
 390         if (ret < 0)
 391                 return ret;
 392         else if (ret == 0) {
 393                 if (timeout) {
 394                         pr_info("fence timeout on [%p] after %dms\n", fence,
 395                                 jiffies_to_msecs(timeout));
 396                         sync_dump();
 397                 }
 398                 return -ETIME;
 399         }
 400
 401         ret = atomic_read(&fence->status);
 402         if (ret) {
 403                 pr_info("fence error %ld on [%p]\n", ret, fence);
 404                 sync_dump();
 405         }
 406         return ret;
 407 }
 408 EXPORT_SYMBOL(sync_fence_wait);
 409
 410 static const char *android_fence_get_driver_name(struct fence *fence)
 411 {
 412         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 413         struct sync_timeline *parent = sync_pt_parent(pt);
 414
 415         return parent->ops->driver_name;
 416 }
 417
 418 static const char *android_fence_get_timeline_name(struct fence *fence)
 419 {
 420         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 421         struct sync_timeline *parent = sync_pt_parent(pt);
 422
 423         return parent->name;
 424 }
 425
 426 static void android_fence_release(struct fence *fence)
 427 {
 428         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 429         struct sync_timeline *parent = sync_pt_parent(pt);
 430         unsigned long flags;
 431
 432         spin_lock_irqsave(fence->lock, flags);
 433         list_del(&pt->child_list);
 434         if (WARN_ON_ONCE(!list_empty(&pt->active_list)))
 435                 list_del(&pt->active_list);
 436         spin_unlock_irqrestore(fence->lock, flags);
 437
 438         if (parent->ops->free_pt)
 439                 parent->ops->free_pt(pt);
 440
 441         sync_timeline_put(parent);
 442         fence_free(&pt->base);
 443 }
 444
 445 static bool android_fence_signaled(struct fence *fence)
 446 {
 447         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 448         struct sync_timeline *parent = sync_pt_parent(pt);
 449         int ret;
 450
 451         ret = parent->ops->has_signaled(pt);
 452         if (ret < 0)
 453                 fence->status = ret;
 454         return ret;
 455 }
 456
 457 static bool android_fence_enable_signaling(struct fence *fence)
 458 {
 459         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 460         struct sync_timeline *parent = sync_pt_parent(pt);
 461
 462         if (android_fence_signaled(fence))
 463                 return false;
 464
 465         list_add_tail(&pt->active_list, &parent->active_list_head);
 466         return true;
 467 }
 468
 469 static int android_fence_fill_driver_data(struct fence *fence,
 470                                           void *data, int size)
 471 {
 472         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 473         struct sync_timeline *parent = sync_pt_parent(pt);
 474
 475         if (!parent->ops->fill_driver_data)
 476                 return 0;
 477         return parent->ops->fill_driver_data(pt, data, size);
 478 }
 479
 480 static void android_fence_value_str(struct fence *fence,
 481                                     char *str, int size)
 482 {
 483         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 484         struct sync_timeline *parent = sync_pt_parent(pt);
 485
 486         if (!parent->ops->pt_value_str) {
 487                 if (size)
 488                         *str = 0;
 489                 return;
 490         }
 491         parent->ops->pt_value_str(pt, str, size);
 492 }
 493
 494 static void android_fence_timeline_value_str(struct fence *fence,
 495                                              char *str, int size)
 496 {
 497         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 498         struct sync_timeline *parent = sync_pt_parent(pt);
 499
 500         if (!parent->ops->timeline_value_str) {
 501                 if (size)
 502                         *str = 0;
 503                 return;
 504         }
 505         parent->ops->timeline_value_str(parent, str, size);
 506 }
 507
 508 static const struct fence_ops android_fence_ops = {
 509         .get_driver_name = android_fence_get_driver_name,
 510         .get_timeline_name = android_fence_get_timeline_name,
 511         .enable_signaling = android_fence_enable_signaling,
 512         .signaled = android_fence_signaled,
 513         .wait = fence_default_wait,
 514         .release = android_fence_release,
 515         .fill_driver_data = android_fence_fill_driver_data,
 516         .fence_value_str = android_fence_value_str,
 517         .timeline_value_str = android_fence_timeline_value_str,
 518 };
 519
 520 static void sync_fence_free(struct kref *kref)
 521 {
 522         struct sync_fence *fence = container_of(kref, struct sync_fence, kref);
 523         int i, status = atomic_read(&fence->status);
 524
 525         for (i = 0; i < fence->num_fences; ++i) {
 526                 if (status)
 527                         fence_remove_callback(fence->cbs[i].sync_pt,
 528                                               &fence->cbs[i].cb);
 529                 fence_put(fence->cbs[i].sync_pt);
 530         }
 531
 532         kfree(fence);
 533 }
 534
 535 static int sync_fence_release(struct inode *inode, struct file *file)
 536 {
 537         struct sync_fence *fence = file->private_data;
 538
 539         sync_fence_debug_remove(fence);
 540
 541         kref_put(&fence->kref, sync_fence_free);
 542         return 0;
 543 }
 544
 545 static unsigned int sync_fence_poll(struct file *file, poll_table *wait)
 546 {
 547         struct sync_fence *fence = file->private_data;
 548         int status;
 549
 550         poll_wait(file, &fence->wq, wait);
 551
 552         status = atomic_read(&fence->status);
 553
 554         if (!status)
 555                 return POLLIN;
 556         else if (status < 0)
 557                 return POLLERR;
 558         return 0;
 559 }
 560
 561 static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
 562 {
 563         __s32 value;
 564
 565         if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
 566                 return -EFAULT;
 567
 568         return sync_fence_wait(fence, value);
 569 }
 570
 571 static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
 572 {
 573         int fd = get_unused_fd_flags(O_CLOEXEC);
 574         int err;
 575         struct sync_fence *fence2, *fence3;
 576         struct sync_merge_data data;
 577
 578         if (fd < 0)
 579                 return fd;
 580
 581         if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
 582                 err = -EFAULT;
 583                 goto err_put_fd;
 584         }
 585
 586         fence2 = sync_fence_fdget(data.fd2);
 587         if (fence2 == NULL) {
 588                 err = -ENOENT;
 589                 goto err_put_fd;
 590         }
 591
 592         data.name[sizeof(data.name) - 1] = '\0';
 593         fence3 = sync_fence_merge(data.name, fence, fence2);
 594         if (fence3 == NULL) {
 595                 err = -ENOMEM;
 596                 goto err_put_fence2;
 597         }
 598
 599         data.fence = fd;
 600         if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
 601                 err = -EFAULT;
 602                 goto err_put_fence3;
 603         }
 604
 605         sync_fence_install(fence3, fd);
 606         sync_fence_put(fence2);
 607         return 0;
 608
 609 err_put_fence3:
 610         sync_fence_put(fence3);
 611
 612 err_put_fence2:
 613         sync_fence_put(fence2);
 614
 615 err_put_fd:
 616         put_unused_fd(fd);
 617         return err;
 618 }
 619
 620 static int sync_fill_pt_info(struct fence *fence, void *data, int size)
 621 {
 622         struct sync_pt_info *info = data;
 623         int ret;
 624
 625         if (size < sizeof(struct sync_pt_info))
 626                 return -ENOMEM;
 627
 628         info->len = sizeof(struct sync_pt_info);
 629
 630         if (fence->ops->fill_driver_data) {
 631                 ret = fence->ops->fill_driver_data(fence, info->driver_data,
 632                                                    size - sizeof(*info));
 633                 if (ret < 0)
 634                         return ret;
 635
 636                 info->len += ret;
 637         }
 638
 639         strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
 640                 sizeof(info->obj_name));
 641         strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
 642                 sizeof(info->driver_name));
 643         if (fence_is_signaled(fence))
 644                 info->status = fence->status >= 0 ? 1 : fence->status;
 645         else
 646                 info->status = 0;
 647         info->timestamp_ns = ktime_to_ns(fence->timestamp);
 648
 649         return info->len;
 650 }
 651
 652 static long sync_fence_ioctl_fence_info(struct sync_fence *fence,
 653                                         unsigned long arg)
 654 {
 655         struct sync_fence_info_data *data;
 656         __u32 size;
 657         __u32 len = 0;
 658         int ret, i;
 659
 660         if (copy_from_user(&size, (void __user *)arg, sizeof(size)))
 661                 return -EFAULT;
 662
 663         if (size < sizeof(struct sync_fence_info_data))
 664                 return -EINVAL;
 665
 666         if (size > 4096)
 667                 size = 4096;
 668
 669         data = kzalloc(size, GFP_KERNEL);
 670         if (data == NULL)
 671                 return -ENOMEM;
 672
 673         strlcpy(data->name, fence->name, sizeof(data->name));
 674         data->status = atomic_read(&fence->status);
 675         if (data->status >= 0)
 676                 data->status = !data->status;
 677
 678         len = sizeof(struct sync_fence_info_data);
 679
 680         for (i = 0; i < fence->num_fences; ++i) {
 681                 struct fence *pt = fence->cbs[i].sync_pt;
 682
 683                 ret = sync_fill_pt_info(pt, (u8 *)data + len, size - len);
 684
 685                 if (ret < 0)
 686                         goto out;
 687
 688                 len += ret;
 689         }
 690
 691         data->len = len;
 692
 693         if (copy_to_user((void __user *)arg, data, len))
 694                 ret = -EFAULT;
 695         else
 696                 ret = 0;
 697
 698 out:
 699         kfree(data);
 700
 701         return ret;
 702 }
 703
 704 static long sync_fence_ioctl(struct file *file, unsigned int cmd,
 705                              unsigned long arg)
 706 {
 707         struct sync_fence *fence = file->private_data;
 708         switch (cmd) {
 709         case SYNC_IOC_WAIT:
 710                 return sync_fence_ioctl_wait(fence, arg);
 711
 712         case SYNC_IOC_MERGE:
 713                 return sync_fence_ioctl_merge(fence, arg);
 714
 715         case SYNC_IOC_FENCE_INFO:
 716                 return sync_fence_ioctl_fence_info(fence, arg);
 717
 718         default:
 719                 return -ENOTTY;
 720         }
 721 }
 722
 723 static const struct file_operations sync_fence_fops = {
 724         .release = sync_fence_release,
 725         .poll = sync_fence_poll,
 726         .unlocked_ioctl = sync_fence_ioctl,
 727         .compat_ioctl = sync_fence_ioctl,
 728 };
 729