kernel/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_init(&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->cbs[0].sync_pt = &pt->base;
 203         fence->cbs[0].fence = fence;
 204         if (fence_add_callback(&pt->base, &fence->cbs[0].cb,
 205                                fence_check_cb_func))
 206                 atomic_dec(&fence->status);
 207
 208         sync_fence_debug_add(fence);
 209
 210         return fence;
 211 }
 212 EXPORT_SYMBOL(sync_fence_create);
 213
 214 struct sync_fence *sync_fence_fdget(int fd)
 215 {
 216         struct file *file = fget(fd);
 217
 218         if (file == NULL)
 219                 return NULL;
 220
 221         if (file->f_op != &sync_fence_fops)
 222                 goto err;
 223
 224         return file->private_data;
 225
 226 err:
 227         fput(file);
 228         return NULL;
 229 }
 230 EXPORT_SYMBOL(sync_fence_fdget);
 231
 232 void sync_fence_put(struct sync_fence *fence)
 233 {
 234         fput(fence->file);
 235 }
 236 EXPORT_SYMBOL(sync_fence_put);
 237
 238 void sync_fence_install(struct sync_fence *fence, int fd)
 239 {
 240         fd_install(fd, fence->file);
 241 }
 242 EXPORT_SYMBOL(sync_fence_install);
 243
 244 static void sync_fence_add_pt(struct sync_fence *fence,
 245                               int *i, struct fence *pt)
 246 {
 247         fence->cbs[*i].sync_pt = pt;
 248         fence->cbs[*i].fence = fence;
 249
 250         if (!fence_add_callback(pt, &fence->cbs[*i].cb, fence_check_cb_func)) {
 251                 fence_get(pt);
 252                 (*i)++;
 253         }
 254 }
 255
 256 struct sync_fence *sync_fence_merge(const char *name,
 257                                     struct sync_fence *a, struct sync_fence *b)
 258 {
 259         int num_fences = a->num_fences + b->num_fences;
 260         struct sync_fence *fence;
 261         int i, i_a, i_b;
 262         unsigned long size = offsetof(struct sync_fence, cbs[num_fences]);
 263
 264         fence = sync_fence_alloc(size, name);
 265         if (fence == NULL)
 266                 return NULL;
 267
 268         atomic_set(&fence->status, num_fences);
 269
 270         /*
 271          * Assume sync_fence a and b are both ordered and have no
 272          * duplicates with the same context.
 273          *
 274          * If a sync_fence can only be created with sync_fence_merge
 275          * and sync_fence_create, this is a reasonable assumption.
 276          */
 277         for (i = i_a = i_b = 0; i_a < a->num_fences && i_b < b->num_fences; ) {
 278                 struct fence *pt_a = a->cbs[i_a].sync_pt;
 279                 struct fence *pt_b = b->cbs[i_b].sync_pt;
 280
 281                 if (pt_a->context < pt_b->context) {
 282                         sync_fence_add_pt(fence, &i, pt_a);
 283
 284                         i_a++;
 285                 } else if (pt_a->context > pt_b->context) {
 286                         sync_fence_add_pt(fence, &i, pt_b);
 287
 288                         i_b++;
 289                 } else {
 290                         if (pt_a->seqno - pt_b->seqno <= INT_MAX)
 291                                 sync_fence_add_pt(fence, &i, pt_a);
 292                         else
 293                                 sync_fence_add_pt(fence, &i, pt_b);
 294
 295                         i_a++;
 296                         i_b++;
 297                 }
 298         }
 299
 300         for (; i_a < a->num_fences; i_a++)
 301                 sync_fence_add_pt(fence, &i, a->cbs[i_a].sync_pt);
 302
 303         for (; i_b < b->num_fences; i_b++)
 304                 sync_fence_add_pt(fence, &i, b->cbs[i_b].sync_pt);
 305
 306         if (num_fences > i)
 307                 atomic_sub(num_fences - i, &fence->status);
 308         fence->num_fences = i;
 309
 310         sync_fence_debug_add(fence);
 311         return fence;
 312 }
 313 EXPORT_SYMBOL(sync_fence_merge);
 314
 315 int sync_fence_wake_up_wq(wait_queue_t *curr, unsigned mode,
 316                                  int wake_flags, void *key)
 317 {
 318         struct sync_fence_waiter *wait;
 319
 320         wait = container_of(curr, struct sync_fence_waiter, work);
 321         list_del_init(&wait->work.task_list);
 322
 323         wait->callback(wait->work.private, wait);
 324         return 1;
 325 }
 326
 327 int sync_fence_wait_async(struct sync_fence *fence,
 328                           struct sync_fence_waiter *waiter)
 329 {
 330         int err = atomic_read(&fence->status);
 331         unsigned long flags;
 332
 333         if (err < 0)
 334                 return err;
 335
 336         if (!err)
 337                 return 1;
 338
 339         init_waitqueue_func_entry(&waiter->work, sync_fence_wake_up_wq);
 340         waiter->work.private = fence;
 341
 342         spin_lock_irqsave(&fence->wq.lock, flags);
 343         err = atomic_read(&fence->status);
 344         if (err > 0)
 345                 __add_wait_queue_tail(&fence->wq, &waiter->work);
 346         spin_unlock_irqrestore(&fence->wq.lock, flags);
 347
 348         if (err < 0)
 349                 return err;
 350
 351         return !err;
 352 }
 353 EXPORT_SYMBOL(sync_fence_wait_async);
 354
 355 int sync_fence_cancel_async(struct sync_fence *fence,
 356                              struct sync_fence_waiter *waiter)
 357 {
 358         unsigned long flags;
 359         int ret = 0;
 360
 361         spin_lock_irqsave(&fence->wq.lock, flags);
 362         if (!list_empty(&waiter->work.task_list))
 363                 list_del_init(&waiter->work.task_list);
 364         else
 365                 ret = -ENOENT;
 366         spin_unlock_irqrestore(&fence->wq.lock, flags);
 367         return ret;
 368 }
 369 EXPORT_SYMBOL(sync_fence_cancel_async);
 370
 371 int sync_fence_wait(struct sync_fence *fence, long timeout)
 372 {
 373         long ret;
 374         int i;
 375
 376         if (timeout < 0)
 377                 timeout = MAX_SCHEDULE_TIMEOUT;
 378         else
 379                 timeout = msecs_to_jiffies(timeout);
 380
 381         trace_sync_wait(fence, 1);
 382         for (i = 0; i < fence->num_fences; ++i)
 383                 trace_sync_pt(fence->cbs[i].sync_pt);
 384         ret = wait_event_interruptible_timeout(fence->wq,
 385                                                atomic_read(&fence->status) <= 0,
 386                                                timeout);
 387         trace_sync_wait(fence, 0);
 388
 389         if (ret < 0) {
 390                 return ret;
 391         } else if (ret == 0) {
 392                 if (timeout) {
 393                         pr_info("fence timeout on [%p] after %dms\n", fence,
 394                                 jiffies_to_msecs(timeout));
 395                         sync_dump();
 396                 }
 397                 return -ETIME;
 398         }
 399
 400         ret = atomic_read(&fence->status);
 401         if (ret) {
 402                 pr_info("fence error %ld on [%p]\n", ret, fence);
 403                 sync_dump();
 404         }
 405         return ret;
 406 }
 407 EXPORT_SYMBOL(sync_fence_wait);
 408
 409 static const char *android_fence_get_driver_name(struct fence *fence)
 410 {
 411         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 412         struct sync_timeline *parent = sync_pt_parent(pt);
 413
 414         return parent->ops->driver_name;
 415 }
 416
 417 static const char *android_fence_get_timeline_name(struct fence *fence)
 418 {
 419         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 420         struct sync_timeline *parent = sync_pt_parent(pt);
 421
 422         return parent->name;
 423 }
 424
 425 static void android_fence_release(struct fence *fence)
 426 {
 427         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 428         struct sync_timeline *parent = sync_pt_parent(pt);
 429         unsigned long flags;
 430
 431         spin_lock_irqsave(fence->lock, flags);
 432         list_del(&pt->child_list);
 433         if (WARN_ON_ONCE(!list_empty(&pt->active_list)))
 434                 list_del(&pt->active_list);
 435         spin_unlock_irqrestore(fence->lock, flags);
 436
 437         if (parent->ops->free_pt)
 438                 parent->ops->free_pt(pt);
 439
 440         sync_timeline_put(parent);
 441         fence_free(&pt->base);
 442 }
 443
 444 static bool android_fence_signaled(struct fence *fence)
 445 {
 446         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 447         struct sync_timeline *parent = sync_pt_parent(pt);
 448         int ret;
 449
 450         ret = parent->ops->has_signaled(pt);
 451         if (ret < 0)
 452                 fence->status = ret;
 453         return ret;
 454 }
 455
 456 static bool android_fence_enable_signaling(struct fence *fence)
 457 {
 458         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 459         struct sync_timeline *parent = sync_pt_parent(pt);
 460
 461         if (android_fence_signaled(fence))
 462                 return false;
 463
 464         list_add_tail(&pt->active_list, &parent->active_list_head);
 465         return true;
 466 }
 467
 468 static int android_fence_fill_driver_data(struct fence *fence,
 469                                           void *data, int size)
 470 {
 471         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 472         struct sync_timeline *parent = sync_pt_parent(pt);
 473
 474         if (!parent->ops->fill_driver_data)
 475                 return 0;
 476         return parent->ops->fill_driver_data(pt, data, size);
 477 }
 478
 479 static void android_fence_value_str(struct fence *fence,
 480                                     char *str, int size)
 481 {
 482         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 483         struct sync_timeline *parent = sync_pt_parent(pt);
 484
 485         if (!parent->ops->pt_value_str) {
 486                 if (size)
 487                         *str = 0;
 488                 return;
 489         }
 490         parent->ops->pt_value_str(pt, str, size);
 491 }
 492
 493 static void android_fence_timeline_value_str(struct fence *fence,
 494                                              char *str, int size)
 495 {
 496         struct sync_pt *pt = container_of(fence, struct sync_pt, base);
 497         struct sync_timeline *parent = sync_pt_parent(pt);
 498
 499         if (!parent->ops->timeline_value_str) {
 500                 if (size)
 501                         *str = 0;
 502                 return;
 503         }
 504         parent->ops->timeline_value_str(parent, str, size);
 505 }
 506
 507 static const struct fence_ops android_fence_ops = {
 508         .get_driver_name = android_fence_get_driver_name,
 509         .get_timeline_name = android_fence_get_timeline_name,
 510         .enable_signaling = android_fence_enable_signaling,
 511         .signaled = android_fence_signaled,
 512         .wait = fence_default_wait,
 513         .release = android_fence_release,
 514         .fill_driver_data = android_fence_fill_driver_data,
 515         .fence_value_str = android_fence_value_str,
 516         .timeline_value_str = android_fence_timeline_value_str,
 517 };
 518
 519 static void sync_fence_free(struct kref *kref)
 520 {
 521         struct sync_fence *fence = container_of(kref, struct sync_fence, kref);
 522         int i, status = atomic_read(&fence->status);
 523
 524         for (i = 0; i < fence->num_fences; ++i) {
 525                 if (status)
 526                         fence_remove_callback(fence->cbs[i].sync_pt,
 527                                               &fence->cbs[i].cb);
 528                 fence_put(fence->cbs[i].sync_pt);
 529         }
 530
 531         kfree(fence);
 532 }
 533
 534 static int sync_fence_release(struct inode *inode, struct file *file)
 535 {
 536         struct sync_fence *fence = file->private_data;
 537
 538         sync_fence_debug_remove(fence);
 539
 540         kref_put(&fence->kref, sync_fence_free);
 541         return 0;
 542 }
 543
 544 static unsigned int sync_fence_poll(struct file *file, poll_table *wait)
 545 {
 546         struct sync_fence *fence = file->private_data;
 547         int status;
 548
 549         poll_wait(file, &fence->wq, wait);
 550
 551         status = atomic_read(&fence->status);
 552
 553         if (!status)
 554                 return POLLIN;
 555         else if (status < 0)
 556                 return POLLERR;
 557         return 0;
 558 }
 559
 560 static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
 561 {
 562         __s32 value;
 563
 564         if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
 565                 return -EFAULT;
 566
 567         return sync_fence_wait(fence, value);
 568 }
 569
 570 static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
 571 {
 572         int fd = get_unused_fd_flags(O_CLOEXEC);
 573         int err;
 574         struct sync_fence *fence2, *fence3;
 575         struct sync_merge_data data;
 576
 577         if (fd < 0)
 578                 return fd;
 579
 580         if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
 581                 err = -EFAULT;
 582                 goto err_put_fd;
 583         }
 584
 585         fence2 = sync_fence_fdget(data.fd2);
 586         if (fence2 == NULL) {
 587                 err = -ENOENT;
 588                 goto err_put_fd;
 589         }
 590
 591         data.name[sizeof(data.name) - 1] = '\0';
 592         fence3 = sync_fence_merge(data.name, fence, fence2);
 593         if (fence3 == NULL) {
 594                 err = -ENOMEM;
 595                 goto err_put_fence2;
 596         }
 597
 598         data.fence = fd;
 599         if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
 600                 err = -EFAULT;
 601                 goto err_put_fence3;
 602         }
 603
 604         sync_fence_install(fence3, fd);
 605         sync_fence_put(fence2);
 606         return 0;
 607
 608 err_put_fence3:
 609         sync_fence_put(fence3);
 610
 611 err_put_fence2:
 612         sync_fence_put(fence2);
 613
 614 err_put_fd:
 615         put_unused_fd(fd);
 616         return err;
 617 }
 618
 619 static int sync_fill_pt_info(struct fence *fence, void *data, int size)
 620 {
 621         struct sync_pt_info *info = data;
 622         int ret;
 623
 624         if (size < sizeof(struct sync_pt_info))
 625                 return -ENOMEM;
 626
 627         info->len = sizeof(struct sync_pt_info);
 628
 629         if (fence->ops->fill_driver_data) {
 630                 ret = fence->ops->fill_driver_data(fence, info->driver_data,
 631                                                    size - sizeof(*info));
 632                 if (ret < 0)
 633                         return ret;
 634
 635                 info->len += ret;
 636         }
 637
 638         strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
 639                 sizeof(info->obj_name));
 640         strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
 641                 sizeof(info->driver_name));
 642         if (fence_is_signaled(fence))
 643                 info->status = fence->status >= 0 ? 1 : fence->status;
 644         else
 645                 info->status = 0;
 646         info->timestamp_ns = ktime_to_ns(fence->timestamp);
 647
 648         return info->len;
 649 }
 650
 651 static long sync_fence_ioctl_fence_info(struct sync_fence *fence,
 652                                         unsigned long arg)
 653 {
 654         struct sync_fence_info_data *data;
 655         __u32 size;
 656         __u32 len = 0;
 657         int ret, i;
 658
 659         if (copy_from_user(&size, (void __user *)arg, sizeof(size)))
 660                 return -EFAULT;
 661
 662         if (size < sizeof(struct sync_fence_info_data))
 663                 return -EINVAL;
 664
 665         if (size > 4096)
 666                 size = 4096;
 667
 668         data = kzalloc(size, GFP_KERNEL);
 669         if (data == NULL)
 670                 return -ENOMEM;
 671
 672         strlcpy(data->name, fence->name, sizeof(data->name));
 673         data->status = atomic_read(&fence->status);
 674         if (data->status >= 0)
 675                 data->status = !data->status;
 676
 677         len = sizeof(struct sync_fence_info_data);
 678
 679         for (i = 0; i < fence->num_fences; ++i) {
 680                 struct fence *pt = fence->cbs[i].sync_pt;
 681
 682                 ret = sync_fill_pt_info(pt, (u8 *)data + len, size - len);
 683
 684                 if (ret < 0)
 685                         goto out;
 686
 687                 len += ret;
 688         }
 689
 690         data->len = len;
 691
 692         if (copy_to_user((void __user *)arg, data, len))
 693                 ret = -EFAULT;
 694         else
 695                 ret = 0;
 696
 697 out:
 698         kfree(data);
 699
 700         return ret;
 701 }
 702
 703 static long sync_fence_ioctl(struct file *file, unsigned int cmd,
 704                              unsigned long arg)
 705 {
 706         struct sync_fence *fence = file->private_data;
 707
 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