drm_fops.c revision 1a72d65d6291ec248cbc5f05df2487edd714aba6
1/** 2 * \file drm_fops.c 3 * File operations for DRM 4 * 5 * \author Rickard E. (Rik) Faith <faith@valinux.com> 6 * \author Daryll Strauss <daryll@valinux.com> 7 * \author Gareth Hughes <gareth@valinux.com> 8 */ 9 10/* 11 * Created: Mon Jan 4 08:58:31 1999 by faith@valinux.com 12 * 13 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 14 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 15 * All Rights Reserved. 16 * 17 * Permission is hereby granted, free of charge, to any person obtaining a 18 * copy of this software and associated documentation files (the "Software"), 19 * to deal in the Software without restriction, including without limitation 20 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 21 * and/or sell copies of the Software, and to permit persons to whom the 22 * Software is furnished to do so, subject to the following conditions: 23 * 24 * The above copyright notice and this permission notice (including the next 25 * paragraph) shall be included in all copies or substantial portions of the 26 * Software. 27 * 28 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 29 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 30 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 31 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 32 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 33 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 34 * OTHER DEALINGS IN THE SOFTWARE. 35 */ 36 37#include "drmP.h" 38#include <linux/poll.h> 39#include <linux/slab.h> 40#include <linux/smp_lock.h> 41 42/* from BKL pushdown: note that nothing else serializes idr_find() */ 43DEFINE_MUTEX(drm_global_mutex); 44 45static int drm_open_helper(struct inode *inode, struct file *filp, 46 struct drm_device * dev); 47 48static int drm_setup(struct drm_device * dev) 49{ 50 int i; 51 int ret; 52 53 if (dev->driver->firstopen) { 54 ret = dev->driver->firstopen(dev); 55 if (ret != 0) 56 return ret; 57 } 58 59 atomic_set(&dev->ioctl_count, 0); 60 atomic_set(&dev->vma_count, 0); 61 62 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) && 63 !drm_core_check_feature(dev, DRIVER_MODESET)) { 64 dev->buf_use = 0; 65 atomic_set(&dev->buf_alloc, 0); 66 67 i = drm_dma_setup(dev); 68 if (i < 0) 69 return i; 70 } 71 72 for (i = 0; i < ARRAY_SIZE(dev->counts); i++) 73 atomic_set(&dev->counts[i], 0); 74 75 dev->sigdata.lock = NULL; 76 77 dev->queue_count = 0; 78 dev->queue_reserved = 0; 79 dev->queue_slots = 0; 80 dev->queuelist = NULL; 81 dev->context_flag = 0; 82 dev->interrupt_flag = 0; 83 dev->dma_flag = 0; 84 dev->last_context = 0; 85 dev->last_switch = 0; 86 dev->last_checked = 0; 87 init_waitqueue_head(&dev->context_wait); 88 dev->if_version = 0; 89 90 dev->ctx_start = 0; 91 dev->lck_start = 0; 92 93 dev->buf_async = NULL; 94 init_waitqueue_head(&dev->buf_readers); 95 init_waitqueue_head(&dev->buf_writers); 96 97 DRM_DEBUG("\n"); 98 99 /* 100 * The kernel's context could be created here, but is now created 101 * in drm_dma_enqueue. This is more resource-efficient for 102 * hardware that does not do DMA, but may mean that 103 * drm_select_queue fails between the time the interrupt is 104 * initialized and the time the queues are initialized. 105 */ 106 107 return 0; 108} 109 110/** 111 * Open file. 112 * 113 * \param inode device inode 114 * \param filp file pointer. 115 * \return zero on success or a negative number on failure. 116 * 117 * Searches the DRM device with the same minor number, calls open_helper(), and 118 * increments the device open count. If the open count was previous at zero, 119 * i.e., it's the first that the device is open, then calls setup(). 120 */ 121int drm_open(struct inode *inode, struct file *filp) 122{ 123 struct drm_device *dev = NULL; 124 int minor_id = iminor(inode); 125 struct drm_minor *minor; 126 int retcode = 0; 127 128 minor = idr_find(&drm_minors_idr, minor_id); 129 if (!minor) 130 return -ENODEV; 131 132 if (!(dev = minor->dev)) 133 return -ENODEV; 134 135 retcode = drm_open_helper(inode, filp, dev); 136 if (!retcode) { 137 atomic_inc(&dev->counts[_DRM_STAT_OPENS]); 138 if (!dev->open_count++) 139 retcode = drm_setup(dev); 140 } 141 if (!retcode) { 142 mutex_lock(&dev->struct_mutex); 143 if (minor->type == DRM_MINOR_LEGACY) { 144 if (dev->dev_mapping == NULL) 145 dev->dev_mapping = inode->i_mapping; 146 else if (dev->dev_mapping != inode->i_mapping) 147 retcode = -ENODEV; 148 } 149 mutex_unlock(&dev->struct_mutex); 150 } 151 152 return retcode; 153} 154EXPORT_SYMBOL(drm_open); 155 156/** 157 * File \c open operation. 158 * 159 * \param inode device inode. 160 * \param filp file pointer. 161 * 162 * Puts the dev->fops corresponding to the device minor number into 163 * \p filp, call the \c open method, and restore the file operations. 164 */ 165int drm_stub_open(struct inode *inode, struct file *filp) 166{ 167 struct drm_device *dev = NULL; 168 struct drm_minor *minor; 169 int minor_id = iminor(inode); 170 int err = -ENODEV; 171 const struct file_operations *old_fops; 172 173 DRM_DEBUG("\n"); 174 175 mutex_lock(&drm_global_mutex); 176 minor = idr_find(&drm_minors_idr, minor_id); 177 if (!minor) 178 goto out; 179 180 if (!(dev = minor->dev)) 181 goto out; 182 183 old_fops = filp->f_op; 184 filp->f_op = fops_get(&dev->driver->fops); 185 if (filp->f_op == NULL) { 186 filp->f_op = old_fops; 187 goto out; 188 } 189 if (filp->f_op->open && (err = filp->f_op->open(inode, filp))) { 190 fops_put(filp->f_op); 191 filp->f_op = fops_get(old_fops); 192 } 193 fops_put(old_fops); 194 195out: 196 mutex_unlock(&drm_global_mutex); 197 return err; 198} 199 200/** 201 * Check whether DRI will run on this CPU. 202 * 203 * \return non-zero if the DRI will run on this CPU, or zero otherwise. 204 */ 205static int drm_cpu_valid(void) 206{ 207#if defined(__i386__) 208 if (boot_cpu_data.x86 == 3) 209 return 0; /* No cmpxchg on a 386 */ 210#endif 211#if defined(__sparc__) && !defined(__sparc_v9__) 212 return 0; /* No cmpxchg before v9 sparc. */ 213#endif 214 return 1; 215} 216 217/** 218 * Called whenever a process opens /dev/drm. 219 * 220 * \param inode device inode. 221 * \param filp file pointer. 222 * \param dev device. 223 * \return zero on success or a negative number on failure. 224 * 225 * Creates and initializes a drm_file structure for the file private data in \p 226 * filp and add it into the double linked list in \p dev. 227 */ 228static int drm_open_helper(struct inode *inode, struct file *filp, 229 struct drm_device * dev) 230{ 231 int minor_id = iminor(inode); 232 struct drm_file *priv; 233 int ret; 234 235 if (filp->f_flags & O_EXCL) 236 return -EBUSY; /* No exclusive opens */ 237 if (!drm_cpu_valid()) 238 return -EINVAL; 239 240 DRM_DEBUG("pid = %d, minor = %d\n", task_pid_nr(current), minor_id); 241 242 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 243 if (!priv) 244 return -ENOMEM; 245 246 filp->private_data = priv; 247 priv->filp = filp; 248 priv->uid = current_euid(); 249 priv->pid = task_pid_nr(current); 250 priv->minor = idr_find(&drm_minors_idr, minor_id); 251 priv->ioctl_count = 0; 252 /* for compatibility root is always authenticated */ 253 priv->authenticated = capable(CAP_SYS_ADMIN); 254 priv->lock_count = 0; 255 256 INIT_LIST_HEAD(&priv->lhead); 257 INIT_LIST_HEAD(&priv->fbs); 258 INIT_LIST_HEAD(&priv->event_list); 259 init_waitqueue_head(&priv->event_wait); 260 priv->event_space = 4096; /* set aside 4k for event buffer */ 261 262 if (dev->driver->driver_features & DRIVER_GEM) 263 drm_gem_open(dev, priv); 264 265 if (dev->driver->open) { 266 ret = dev->driver->open(dev, priv); 267 if (ret < 0) 268 goto out_free; 269 } 270 271 272 /* if there is no current master make this fd it */ 273 mutex_lock(&dev->struct_mutex); 274 if (!priv->minor->master) { 275 /* create a new master */ 276 priv->minor->master = drm_master_create(priv->minor); 277 if (!priv->minor->master) { 278 mutex_unlock(&dev->struct_mutex); 279 ret = -ENOMEM; 280 goto out_free; 281 } 282 283 priv->is_master = 1; 284 /* take another reference for the copy in the local file priv */ 285 priv->master = drm_master_get(priv->minor->master); 286 287 priv->authenticated = 1; 288 289 mutex_unlock(&dev->struct_mutex); 290 if (dev->driver->master_create) { 291 ret = dev->driver->master_create(dev, priv->master); 292 if (ret) { 293 mutex_lock(&dev->struct_mutex); 294 /* drop both references if this fails */ 295 drm_master_put(&priv->minor->master); 296 drm_master_put(&priv->master); 297 mutex_unlock(&dev->struct_mutex); 298 goto out_free; 299 } 300 } 301 mutex_lock(&dev->struct_mutex); 302 if (dev->driver->master_set) { 303 ret = dev->driver->master_set(dev, priv, true); 304 if (ret) { 305 /* drop both references if this fails */ 306 drm_master_put(&priv->minor->master); 307 drm_master_put(&priv->master); 308 mutex_unlock(&dev->struct_mutex); 309 goto out_free; 310 } 311 } 312 mutex_unlock(&dev->struct_mutex); 313 } else { 314 /* get a reference to the master */ 315 priv->master = drm_master_get(priv->minor->master); 316 mutex_unlock(&dev->struct_mutex); 317 } 318 319 mutex_lock(&dev->struct_mutex); 320 list_add(&priv->lhead, &dev->filelist); 321 mutex_unlock(&dev->struct_mutex); 322 323#ifdef __alpha__ 324 /* 325 * Default the hose 326 */ 327 if (!dev->hose) { 328 struct pci_dev *pci_dev; 329 pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL); 330 if (pci_dev) { 331 dev->hose = pci_dev->sysdata; 332 pci_dev_put(pci_dev); 333 } 334 if (!dev->hose) { 335 struct pci_bus *b = pci_bus_b(pci_root_buses.next); 336 if (b) 337 dev->hose = b->sysdata; 338 } 339 } 340#endif 341 342 return 0; 343 out_free: 344 kfree(priv); 345 filp->private_data = NULL; 346 return ret; 347} 348 349/** No-op. */ 350int drm_fasync(int fd, struct file *filp, int on) 351{ 352 struct drm_file *priv = filp->private_data; 353 struct drm_device *dev = priv->minor->dev; 354 355 DRM_DEBUG("fd = %d, device = 0x%lx\n", fd, 356 (long)old_encode_dev(priv->minor->device)); 357 return fasync_helper(fd, filp, on, &dev->buf_async); 358} 359EXPORT_SYMBOL(drm_fasync); 360 361/* 362 * Reclaim locked buffers; note that this may be a bad idea if the current 363 * context doesn't have the hw lock... 364 */ 365static void drm_reclaim_locked_buffers(struct drm_device *dev, struct file *f) 366{ 367 struct drm_file *file_priv = f->private_data; 368 369 if (drm_i_have_hw_lock(dev, file_priv)) { 370 dev->driver->reclaim_buffers_locked(dev, file_priv); 371 } else { 372 unsigned long _end = jiffies + 3 * DRM_HZ; 373 int locked = 0; 374 375 drm_idlelock_take(&file_priv->master->lock); 376 377 /* 378 * Wait for a while. 379 */ 380 do { 381 spin_lock_bh(&file_priv->master->lock.spinlock); 382 locked = file_priv->master->lock.idle_has_lock; 383 spin_unlock_bh(&file_priv->master->lock.spinlock); 384 if (locked) 385 break; 386 schedule(); 387 } while (!time_after_eq(jiffies, _end)); 388 389 if (!locked) { 390 DRM_ERROR("reclaim_buffers_locked() deadlock. Please rework this\n" 391 "\tdriver to use reclaim_buffers_idlelocked() instead.\n" 392 "\tI will go on reclaiming the buffers anyway.\n"); 393 } 394 395 dev->driver->reclaim_buffers_locked(dev, file_priv); 396 drm_idlelock_release(&file_priv->master->lock); 397 } 398} 399 400static void drm_master_release(struct drm_device *dev, struct file *filp) 401{ 402 struct drm_file *file_priv = filp->private_data; 403 404 if (dev->driver->reclaim_buffers_locked && 405 file_priv->master->lock.hw_lock) 406 drm_reclaim_locked_buffers(dev, filp); 407 408 if (dev->driver->reclaim_buffers_idlelocked && 409 file_priv->master->lock.hw_lock) { 410 drm_idlelock_take(&file_priv->master->lock); 411 dev->driver->reclaim_buffers_idlelocked(dev, file_priv); 412 drm_idlelock_release(&file_priv->master->lock); 413 } 414 415 416 if (drm_i_have_hw_lock(dev, file_priv)) { 417 DRM_DEBUG("File %p released, freeing lock for context %d\n", 418 filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock)); 419 drm_lock_free(&file_priv->master->lock, 420 _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock)); 421 } 422 423 if (drm_core_check_feature(dev, DRIVER_HAVE_DMA) && 424 !dev->driver->reclaim_buffers_locked) { 425 dev->driver->reclaim_buffers(dev, file_priv); 426 } 427} 428 429static void drm_events_release(struct drm_file *file_priv) 430{ 431 struct drm_device *dev = file_priv->minor->dev; 432 struct drm_pending_event *e, *et; 433 struct drm_pending_vblank_event *v, *vt; 434 unsigned long flags; 435 436 spin_lock_irqsave(&dev->event_lock, flags); 437 438 /* Remove pending flips */ 439 list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link) 440 if (v->base.file_priv == file_priv) { 441 list_del(&v->base.link); 442 drm_vblank_put(dev, v->pipe); 443 v->base.destroy(&v->base); 444 } 445 446 /* Remove unconsumed events */ 447 list_for_each_entry_safe(e, et, &file_priv->event_list, link) 448 e->destroy(e); 449 450 spin_unlock_irqrestore(&dev->event_lock, flags); 451} 452 453/** 454 * Release file. 455 * 456 * \param inode device inode 457 * \param file_priv DRM file private. 458 * \return zero on success or a negative number on failure. 459 * 460 * If the hardware lock is held then free it, and take it again for the kernel 461 * context since it's necessary to reclaim buffers. Unlink the file private 462 * data from its list and free it. Decreases the open count and if it reaches 463 * zero calls drm_lastclose(). 464 */ 465int drm_release(struct inode *inode, struct file *filp) 466{ 467 struct drm_file *file_priv = filp->private_data; 468 struct drm_device *dev = file_priv->minor->dev; 469 int retcode = 0; 470 471 mutex_lock(&drm_global_mutex); 472 473 DRM_DEBUG("open_count = %d\n", dev->open_count); 474 475 if (dev->driver->preclose) 476 dev->driver->preclose(dev, file_priv); 477 478 /* ======================================================== 479 * Begin inline drm_release 480 */ 481 482 DRM_DEBUG("pid = %d, device = 0x%lx, open_count = %d\n", 483 task_pid_nr(current), 484 (long)old_encode_dev(file_priv->minor->device), 485 dev->open_count); 486 487 /* if the master has gone away we can't do anything with the lock */ 488 if (file_priv->minor->master) 489 drm_master_release(dev, filp); 490 491 drm_events_release(file_priv); 492 493 if (dev->driver->driver_features & DRIVER_GEM) 494 drm_gem_release(dev, file_priv); 495 496 if (dev->driver->driver_features & DRIVER_MODESET) 497 drm_fb_release(file_priv); 498 499 mutex_lock(&dev->ctxlist_mutex); 500 if (!list_empty(&dev->ctxlist)) { 501 struct drm_ctx_list *pos, *n; 502 503 list_for_each_entry_safe(pos, n, &dev->ctxlist, head) { 504 if (pos->tag == file_priv && 505 pos->handle != DRM_KERNEL_CONTEXT) { 506 if (dev->driver->context_dtor) 507 dev->driver->context_dtor(dev, 508 pos->handle); 509 510 drm_ctxbitmap_free(dev, pos->handle); 511 512 list_del(&pos->head); 513 kfree(pos); 514 --dev->ctx_count; 515 } 516 } 517 } 518 mutex_unlock(&dev->ctxlist_mutex); 519 520 mutex_lock(&dev->struct_mutex); 521 522 if (file_priv->is_master) { 523 struct drm_master *master = file_priv->master; 524 struct drm_file *temp; 525 list_for_each_entry(temp, &dev->filelist, lhead) { 526 if ((temp->master == file_priv->master) && 527 (temp != file_priv)) 528 temp->authenticated = 0; 529 } 530 531 /** 532 * Since the master is disappearing, so is the 533 * possibility to lock. 534 */ 535 536 if (master->lock.hw_lock) { 537 if (dev->sigdata.lock == master->lock.hw_lock) 538 dev->sigdata.lock = NULL; 539 master->lock.hw_lock = NULL; 540 master->lock.file_priv = NULL; 541 wake_up_interruptible_all(&master->lock.lock_queue); 542 } 543 544 if (file_priv->minor->master == file_priv->master) { 545 /* drop the reference held my the minor */ 546 if (dev->driver->master_drop) 547 dev->driver->master_drop(dev, file_priv, true); 548 drm_master_put(&file_priv->minor->master); 549 } 550 } 551 552 /* drop the reference held my the file priv */ 553 drm_master_put(&file_priv->master); 554 file_priv->is_master = 0; 555 list_del(&file_priv->lhead); 556 mutex_unlock(&dev->struct_mutex); 557 558 if (dev->driver->postclose) 559 dev->driver->postclose(dev, file_priv); 560 kfree(file_priv); 561 562 /* ======================================================== 563 * End inline drm_release 564 */ 565 566 atomic_inc(&dev->counts[_DRM_STAT_CLOSES]); 567 if (!--dev->open_count) { 568 if (atomic_read(&dev->ioctl_count)) { 569 DRM_ERROR("Device busy: %d\n", 570 atomic_read(&dev->ioctl_count)); 571 retcode = -EBUSY; 572 } else 573 retcode = drm_lastclose(dev); 574 } 575 mutex_unlock(&drm_global_mutex); 576 577 return retcode; 578} 579EXPORT_SYMBOL(drm_release); 580 581static bool 582drm_dequeue_event(struct drm_file *file_priv, 583 size_t total, size_t max, struct drm_pending_event **out) 584{ 585 struct drm_device *dev = file_priv->minor->dev; 586 struct drm_pending_event *e; 587 unsigned long flags; 588 bool ret = false; 589 590 spin_lock_irqsave(&dev->event_lock, flags); 591 592 *out = NULL; 593 if (list_empty(&file_priv->event_list)) 594 goto out; 595 e = list_first_entry(&file_priv->event_list, 596 struct drm_pending_event, link); 597 if (e->event->length + total > max) 598 goto out; 599 600 file_priv->event_space += e->event->length; 601 list_del(&e->link); 602 *out = e; 603 ret = true; 604 605out: 606 spin_unlock_irqrestore(&dev->event_lock, flags); 607 return ret; 608} 609 610ssize_t drm_read(struct file *filp, char __user *buffer, 611 size_t count, loff_t *offset) 612{ 613 struct drm_file *file_priv = filp->private_data; 614 struct drm_pending_event *e; 615 size_t total; 616 ssize_t ret; 617 618 ret = wait_event_interruptible(file_priv->event_wait, 619 !list_empty(&file_priv->event_list)); 620 if (ret < 0) 621 return ret; 622 623 total = 0; 624 while (drm_dequeue_event(file_priv, total, count, &e)) { 625 if (copy_to_user(buffer + total, 626 e->event, e->event->length)) { 627 total = -EFAULT; 628 break; 629 } 630 631 total += e->event->length; 632 e->destroy(e); 633 } 634 635 return total; 636} 637EXPORT_SYMBOL(drm_read); 638 639unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait) 640{ 641 struct drm_file *file_priv = filp->private_data; 642 unsigned int mask = 0; 643 644 poll_wait(filp, &file_priv->event_wait, wait); 645 646 if (!list_empty(&file_priv->event_list)) 647 mask |= POLLIN | POLLRDNORM; 648 649 return mask; 650} 651EXPORT_SYMBOL(drm_poll); 652