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v6.8
   1/*
   2 * \author Rickard E. (Rik) Faith <faith@valinux.com>
   3 * \author Daryll Strauss <daryll@valinux.com>
   4 * \author Gareth Hughes <gareth@valinux.com>
   5 */
   6
   7/*
   8 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
   9 *
  10 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  12 * All Rights Reserved.
  13 *
  14 * Permission is hereby granted, free of charge, to any person obtaining a
  15 * copy of this software and associated documentation files (the "Software"),
  16 * to deal in the Software without restriction, including without limitation
  17 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  18 * and/or sell copies of the Software, and to permit persons to whom the
  19 * Software is furnished to do so, subject to the following conditions:
  20 *
  21 * The above copyright notice and this permission notice (including the next
  22 * paragraph) shall be included in all copies or substantial portions of the
  23 * Software.
  24 *
  25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  28 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  31 * OTHER DEALINGS IN THE SOFTWARE.
  32 */
  33
  34#include <linux/anon_inodes.h>
  35#include <linux/dma-fence.h>
  36#include <linux/file.h>
  37#include <linux/module.h>
  38#include <linux/pci.h>
  39#include <linux/poll.h>
  40#include <linux/slab.h>
  41
  42#include <drm/drm_client.h>
  43#include <drm/drm_drv.h>
  44#include <drm/drm_file.h>
  45#include <drm/drm_gem.h>
  46#include <drm/drm_print.h>
  47
  48#include "drm_crtc_internal.h"
  49#include "drm_internal.h"
 
  50
  51/* from BKL pushdown */
  52DEFINE_MUTEX(drm_global_mutex);
  53
  54bool drm_dev_needs_global_mutex(struct drm_device *dev)
  55{
  56	/*
 
 
 
 
 
 
 
 
  57	 * The deprecated ->load callback must be called after the driver is
  58	 * already registered. This means such drivers rely on the BKL to make
  59	 * sure an open can't proceed until the driver is actually fully set up.
  60	 * Similar hilarity holds for the unload callback.
  61	 */
  62	if (dev->driver->load || dev->driver->unload)
  63		return true;
  64
  65	/*
  66	 * Drivers with the lastclose callback assume that it's synchronized
  67	 * against concurrent opens, which again needs the BKL. The proper fix
  68	 * is to use the drm_client infrastructure with proper locking for each
  69	 * client.
  70	 */
  71	if (dev->driver->lastclose)
  72		return true;
  73
  74	return false;
  75}
  76
  77/**
  78 * DOC: file operations
  79 *
  80 * Drivers must define the file operations structure that forms the DRM
  81 * userspace API entry point, even though most of those operations are
  82 * implemented in the DRM core. The resulting &struct file_operations must be
  83 * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
  84 * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
  85 * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
  86 * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
  87 * that require 32/64 bit compatibility support must provide their own
  88 * &file_operations.compat_ioctl handler that processes private ioctls and calls
  89 * drm_compat_ioctl() for core ioctls.
  90 *
  91 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
  92 * events are a generic and extensible means to send asynchronous events to
  93 * userspace through the file descriptor. They are used to send vblank event and
  94 * page flip completions by the KMS API. But drivers can also use it for their
  95 * own needs, e.g. to signal completion of rendering.
  96 *
  97 * For the driver-side event interface see drm_event_reserve_init() and
  98 * drm_send_event() as the main starting points.
  99 *
 100 * The memory mapping implementation will vary depending on how the driver
 101 * manages memory. For GEM-based drivers this is drm_gem_mmap().
 
 
 102 *
 103 * No other file operations are supported by the DRM userspace API. Overall the
 104 * following is an example &file_operations structure::
 105 *
 106 *     static const example_drm_fops = {
 107 *             .owner = THIS_MODULE,
 108 *             .open = drm_open,
 109 *             .release = drm_release,
 110 *             .unlocked_ioctl = drm_ioctl,
 111 *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
 112 *             .poll = drm_poll,
 113 *             .read = drm_read,
 114 *             .llseek = no_llseek,
 115 *             .mmap = drm_gem_mmap,
 116 *     };
 117 *
 118 * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
 119 * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
 120 * simpler.
 121 *
 122 * The driver's &file_operations must be stored in &drm_driver.fops.
 123 *
 124 * For driver-private IOCTL handling see the more detailed discussion in
 125 * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
 126 */
 127
 128/**
 129 * drm_file_alloc - allocate file context
 130 * @minor: minor to allocate on
 131 *
 132 * This allocates a new DRM file context. It is not linked into any context and
 133 * can be used by the caller freely. Note that the context keeps a pointer to
 134 * @minor, so it must be freed before @minor is.
 135 *
 136 * RETURNS:
 137 * Pointer to newly allocated context, ERR_PTR on failure.
 138 */
 139struct drm_file *drm_file_alloc(struct drm_minor *minor)
 140{
 141	static atomic64_t ident = ATOMIC_INIT(0);
 142	struct drm_device *dev = minor->dev;
 143	struct drm_file *file;
 144	int ret;
 145
 146	file = kzalloc(sizeof(*file), GFP_KERNEL);
 147	if (!file)
 148		return ERR_PTR(-ENOMEM);
 149
 150	/* Get a unique identifier for fdinfo: */
 151	file->client_id = atomic64_inc_return(&ident);
 152	rcu_assign_pointer(file->pid, get_pid(task_tgid(current)));
 153	file->minor = minor;
 154
 155	/* for compatibility root is always authenticated */
 156	file->authenticated = capable(CAP_SYS_ADMIN);
 157
 158	INIT_LIST_HEAD(&file->lhead);
 159	INIT_LIST_HEAD(&file->fbs);
 160	mutex_init(&file->fbs_lock);
 161	INIT_LIST_HEAD(&file->blobs);
 162	INIT_LIST_HEAD(&file->pending_event_list);
 163	INIT_LIST_HEAD(&file->event_list);
 164	init_waitqueue_head(&file->event_wait);
 165	file->event_space = 4096; /* set aside 4k for event buffer */
 166
 167	spin_lock_init(&file->master_lookup_lock);
 168	mutex_init(&file->event_read_lock);
 169
 170	if (drm_core_check_feature(dev, DRIVER_GEM))
 171		drm_gem_open(dev, file);
 172
 173	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 174		drm_syncobj_open(file);
 175
 176	drm_prime_init_file_private(&file->prime);
 177
 178	if (dev->driver->open) {
 179		ret = dev->driver->open(dev, file);
 180		if (ret < 0)
 181			goto out_prime_destroy;
 182	}
 183
 184	return file;
 185
 186out_prime_destroy:
 187	drm_prime_destroy_file_private(&file->prime);
 188	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 189		drm_syncobj_release(file);
 190	if (drm_core_check_feature(dev, DRIVER_GEM))
 191		drm_gem_release(dev, file);
 192	put_pid(rcu_access_pointer(file->pid));
 193	kfree(file);
 194
 195	return ERR_PTR(ret);
 196}
 197
 198static void drm_events_release(struct drm_file *file_priv)
 199{
 200	struct drm_device *dev = file_priv->minor->dev;
 201	struct drm_pending_event *e, *et;
 202	unsigned long flags;
 203
 204	spin_lock_irqsave(&dev->event_lock, flags);
 205
 206	/* Unlink pending events */
 207	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
 208				 pending_link) {
 209		list_del(&e->pending_link);
 210		e->file_priv = NULL;
 211	}
 212
 213	/* Remove unconsumed events */
 214	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
 215		list_del(&e->link);
 216		kfree(e);
 217	}
 218
 219	spin_unlock_irqrestore(&dev->event_lock, flags);
 220}
 221
 222/**
 223 * drm_file_free - free file context
 224 * @file: context to free, or NULL
 225 *
 226 * This destroys and deallocates a DRM file context previously allocated via
 227 * drm_file_alloc(). The caller must make sure to unlink it from any contexts
 228 * before calling this.
 229 *
 230 * If NULL is passed, this is a no-op.
 231 */
 232void drm_file_free(struct drm_file *file)
 233{
 234	struct drm_device *dev;
 235
 236	if (!file)
 237		return;
 238
 239	dev = file->minor->dev;
 240
 241	drm_dbg_core(dev, "comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
 242		     current->comm, task_pid_nr(current),
 243		     (long)old_encode_dev(file->minor->kdev->devt),
 244		     atomic_read(&dev->open_count));
 
 
 
 
 
 
 
 
 
 
 
 
 245
 246	drm_events_release(file);
 247
 248	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 249		drm_fb_release(file);
 250		drm_property_destroy_user_blobs(dev, file);
 251	}
 252
 253	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 254		drm_syncobj_release(file);
 255
 256	if (drm_core_check_feature(dev, DRIVER_GEM))
 257		drm_gem_release(dev, file);
 258
 
 
 259	if (drm_is_primary_client(file))
 260		drm_master_release(file);
 261
 262	if (dev->driver->postclose)
 263		dev->driver->postclose(dev, file);
 264
 265	drm_prime_destroy_file_private(&file->prime);
 266
 267	WARN_ON(!list_empty(&file->event_list));
 268
 269	put_pid(rcu_access_pointer(file->pid));
 270	kfree(file);
 271}
 272
 273static void drm_close_helper(struct file *filp)
 274{
 275	struct drm_file *file_priv = filp->private_data;
 276	struct drm_device *dev = file_priv->minor->dev;
 277
 278	mutex_lock(&dev->filelist_mutex);
 279	list_del(&file_priv->lhead);
 280	mutex_unlock(&dev->filelist_mutex);
 281
 282	drm_file_free(file_priv);
 283}
 284
 285/*
 286 * Check whether DRI will run on this CPU.
 287 *
 288 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
 289 */
 290static int drm_cpu_valid(void)
 291{
 292#if defined(__sparc__) && !defined(__sparc_v9__)
 293	return 0;		/* No cmpxchg before v9 sparc. */
 294#endif
 295	return 1;
 296}
 297
 298/*
 299 * Called whenever a process opens a drm node
 300 *
 301 * \param filp file pointer.
 302 * \param minor acquired minor-object.
 303 * \return zero on success or a negative number on failure.
 304 *
 305 * Creates and initializes a drm_file structure for the file private data in \p
 306 * filp and add it into the double linked list in \p dev.
 307 */
 308int drm_open_helper(struct file *filp, struct drm_minor *minor)
 309{
 310	struct drm_device *dev = minor->dev;
 311	struct drm_file *priv;
 312	int ret;
 313
 314	if (filp->f_flags & O_EXCL)
 315		return -EBUSY;	/* No exclusive opens */
 316	if (!drm_cpu_valid())
 317		return -EINVAL;
 318	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
 319	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
 320		return -EINVAL;
 321
 322	drm_dbg_core(dev, "comm=\"%s\", pid=%d, minor=%d\n",
 323		     current->comm, task_pid_nr(current), minor->index);
 324
 325	priv = drm_file_alloc(minor);
 326	if (IS_ERR(priv))
 327		return PTR_ERR(priv);
 328
 329	if (drm_is_primary_client(priv)) {
 330		ret = drm_master_open(priv);
 331		if (ret) {
 332			drm_file_free(priv);
 333			return ret;
 334		}
 335	}
 336
 337	filp->private_data = priv;
 338	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
 339	priv->filp = filp;
 340
 341	mutex_lock(&dev->filelist_mutex);
 342	list_add(&priv->lhead, &dev->filelist);
 343	mutex_unlock(&dev->filelist_mutex);
 344
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 345	return 0;
 346}
 347
 348/**
 349 * drm_open - open method for DRM file
 350 * @inode: device inode
 351 * @filp: file pointer.
 352 *
 353 * This function must be used by drivers as their &file_operations.open method.
 354 * It looks up the correct DRM device and instantiates all the per-file
 355 * resources for it. It also calls the &drm_driver.open driver callback.
 356 *
 357 * RETURNS:
 358 *
 359 * 0 on success or negative errno value on failure.
 360 */
 361int drm_open(struct inode *inode, struct file *filp)
 362{
 363	struct drm_device *dev;
 364	struct drm_minor *minor;
 365	int retcode;
 
 366
 367	minor = drm_minor_acquire(iminor(inode));
 368	if (IS_ERR(minor))
 369		return PTR_ERR(minor);
 370
 371	dev = minor->dev;
 372	if (drm_dev_needs_global_mutex(dev))
 373		mutex_lock(&drm_global_mutex);
 374
 375	atomic_fetch_inc(&dev->open_count);
 
 376
 377	/* share address_space across all char-devs of a single device */
 378	filp->f_mapping = dev->anon_inode->i_mapping;
 379
 380	retcode = drm_open_helper(filp, minor);
 381	if (retcode)
 382		goto err_undo;
 
 
 
 
 
 
 
 383
 384	if (drm_dev_needs_global_mutex(dev))
 385		mutex_unlock(&drm_global_mutex);
 386
 387	return 0;
 388
 389err_undo:
 390	atomic_dec(&dev->open_count);
 391	if (drm_dev_needs_global_mutex(dev))
 392		mutex_unlock(&drm_global_mutex);
 393	drm_minor_release(minor);
 394	return retcode;
 395}
 396EXPORT_SYMBOL(drm_open);
 397
 398void drm_lastclose(struct drm_device * dev)
 399{
 400	drm_dbg_core(dev, "\n");
 401
 402	if (dev->driver->lastclose)
 403		dev->driver->lastclose(dev);
 404	drm_dbg_core(dev, "driver lastclose completed\n");
 
 
 
 405
 406	drm_client_dev_restore(dev);
 407}
 408
 409/**
 410 * drm_release - release method for DRM file
 411 * @inode: device inode
 412 * @filp: file pointer.
 413 *
 414 * This function must be used by drivers as their &file_operations.release
 415 * method. It frees any resources associated with the open file, and calls the
 416 * &drm_driver.postclose driver callback. If this is the last open file for the
 417 * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
 418 *
 419 * RETURNS:
 420 *
 421 * Always succeeds and returns 0.
 422 */
 423int drm_release(struct inode *inode, struct file *filp)
 424{
 425	struct drm_file *file_priv = filp->private_data;
 426	struct drm_minor *minor = file_priv->minor;
 427	struct drm_device *dev = minor->dev;
 428
 429	if (drm_dev_needs_global_mutex(dev))
 430		mutex_lock(&drm_global_mutex);
 431
 432	drm_dbg_core(dev, "open_count = %d\n", atomic_read(&dev->open_count));
 433
 434	drm_close_helper(filp);
 435
 436	if (atomic_dec_and_test(&dev->open_count))
 437		drm_lastclose(dev);
 438
 439	if (drm_dev_needs_global_mutex(dev))
 440		mutex_unlock(&drm_global_mutex);
 441
 442	drm_minor_release(minor);
 443
 444	return 0;
 445}
 446EXPORT_SYMBOL(drm_release);
 447
 448void drm_file_update_pid(struct drm_file *filp)
 449{
 450	struct drm_device *dev;
 451	struct pid *pid, *old;
 452
 453	/*
 454	 * Master nodes need to keep the original ownership in order for
 455	 * drm_master_check_perm to keep working correctly. (See comment in
 456	 * drm_auth.c.)
 457	 */
 458	if (filp->was_master)
 459		return;
 460
 461	pid = task_tgid(current);
 462
 463	/*
 464	 * Quick unlocked check since the model is a single handover followed by
 465	 * exclusive repeated use.
 466	 */
 467	if (pid == rcu_access_pointer(filp->pid))
 468		return;
 469
 470	dev = filp->minor->dev;
 471	mutex_lock(&dev->filelist_mutex);
 472	old = rcu_replace_pointer(filp->pid, pid, 1);
 473	mutex_unlock(&dev->filelist_mutex);
 474
 475	if (pid != old) {
 476		get_pid(pid);
 477		synchronize_rcu();
 478		put_pid(old);
 479	}
 480}
 481
 482/**
 483 * drm_release_noglobal - release method for DRM file
 484 * @inode: device inode
 485 * @filp: file pointer.
 486 *
 487 * This function may be used by drivers as their &file_operations.release
 488 * method. It frees any resources associated with the open file prior to taking
 489 * the drm_global_mutex, which then calls the &drm_driver.postclose driver
 490 * callback. If this is the last open file for the DRM device also proceeds to
 491 * call the &drm_driver.lastclose driver callback.
 492 *
 493 * RETURNS:
 494 *
 495 * Always succeeds and returns 0.
 496 */
 497int drm_release_noglobal(struct inode *inode, struct file *filp)
 498{
 499	struct drm_file *file_priv = filp->private_data;
 500	struct drm_minor *minor = file_priv->minor;
 501	struct drm_device *dev = minor->dev;
 502
 503	drm_close_helper(filp);
 504
 505	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
 506		drm_lastclose(dev);
 507		mutex_unlock(&drm_global_mutex);
 508	}
 509
 510	drm_minor_release(minor);
 511
 512	return 0;
 513}
 514EXPORT_SYMBOL(drm_release_noglobal);
 515
 516/**
 517 * drm_read - read method for DRM file
 518 * @filp: file pointer
 519 * @buffer: userspace destination pointer for the read
 520 * @count: count in bytes to read
 521 * @offset: offset to read
 522 *
 523 * This function must be used by drivers as their &file_operations.read
 524 * method if they use DRM events for asynchronous signalling to userspace.
 525 * Since events are used by the KMS API for vblank and page flip completion this
 526 * means all modern display drivers must use it.
 527 *
 528 * @offset is ignored, DRM events are read like a pipe. Polling support is
 529 * provided by drm_poll().
 530 *
 531 * This function will only ever read a full event. Therefore userspace must
 532 * supply a big enough buffer to fit any event to ensure forward progress. Since
 533 * the maximum event space is currently 4K it's recommended to just use that for
 534 * safety.
 535 *
 536 * RETURNS:
 537 *
 538 * Number of bytes read (always aligned to full events, and can be 0) or a
 539 * negative error code on failure.
 540 */
 541ssize_t drm_read(struct file *filp, char __user *buffer,
 542		 size_t count, loff_t *offset)
 543{
 544	struct drm_file *file_priv = filp->private_data;
 545	struct drm_device *dev = file_priv->minor->dev;
 546	ssize_t ret;
 547
 548	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
 549	if (ret)
 550		return ret;
 551
 552	for (;;) {
 553		struct drm_pending_event *e = NULL;
 554
 555		spin_lock_irq(&dev->event_lock);
 556		if (!list_empty(&file_priv->event_list)) {
 557			e = list_first_entry(&file_priv->event_list,
 558					struct drm_pending_event, link);
 559			file_priv->event_space += e->event->length;
 560			list_del(&e->link);
 561		}
 562		spin_unlock_irq(&dev->event_lock);
 563
 564		if (e == NULL) {
 565			if (ret)
 566				break;
 567
 568			if (filp->f_flags & O_NONBLOCK) {
 569				ret = -EAGAIN;
 570				break;
 571			}
 572
 573			mutex_unlock(&file_priv->event_read_lock);
 574			ret = wait_event_interruptible(file_priv->event_wait,
 575						       !list_empty(&file_priv->event_list));
 576			if (ret >= 0)
 577				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
 578			if (ret)
 579				return ret;
 580		} else {
 581			unsigned length = e->event->length;
 582
 583			if (length > count - ret) {
 584put_back_event:
 585				spin_lock_irq(&dev->event_lock);
 586				file_priv->event_space -= length;
 587				list_add(&e->link, &file_priv->event_list);
 588				spin_unlock_irq(&dev->event_lock);
 589				wake_up_interruptible_poll(&file_priv->event_wait,
 590					EPOLLIN | EPOLLRDNORM);
 591				break;
 592			}
 593
 594			if (copy_to_user(buffer + ret, e->event, length)) {
 595				if (ret == 0)
 596					ret = -EFAULT;
 597				goto put_back_event;
 598			}
 599
 600			ret += length;
 601			kfree(e);
 602		}
 603	}
 604	mutex_unlock(&file_priv->event_read_lock);
 605
 606	return ret;
 607}
 608EXPORT_SYMBOL(drm_read);
 609
 610/**
 611 * drm_poll - poll method for DRM file
 612 * @filp: file pointer
 613 * @wait: poll waiter table
 614 *
 615 * This function must be used by drivers as their &file_operations.read method
 616 * if they use DRM events for asynchronous signalling to userspace.  Since
 617 * events are used by the KMS API for vblank and page flip completion this means
 618 * all modern display drivers must use it.
 619 *
 620 * See also drm_read().
 621 *
 622 * RETURNS:
 623 *
 624 * Mask of POLL flags indicating the current status of the file.
 625 */
 626__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
 627{
 628	struct drm_file *file_priv = filp->private_data;
 629	__poll_t mask = 0;
 630
 631	poll_wait(filp, &file_priv->event_wait, wait);
 632
 633	if (!list_empty(&file_priv->event_list))
 634		mask |= EPOLLIN | EPOLLRDNORM;
 635
 636	return mask;
 637}
 638EXPORT_SYMBOL(drm_poll);
 639
 640/**
 641 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
 642 * @dev: DRM device
 643 * @file_priv: DRM file private data
 644 * @p: tracking structure for the pending event
 645 * @e: actual event data to deliver to userspace
 646 *
 647 * This function prepares the passed in event for eventual delivery. If the event
 648 * doesn't get delivered (because the IOCTL fails later on, before queuing up
 649 * anything) then the even must be cancelled and freed using
 650 * drm_event_cancel_free(). Successfully initialized events should be sent out
 651 * using drm_send_event() or drm_send_event_locked() to signal completion of the
 652 * asynchronous event to userspace.
 653 *
 654 * If callers embedded @p into a larger structure it must be allocated with
 655 * kmalloc and @p must be the first member element.
 656 *
 657 * This is the locked version of drm_event_reserve_init() for callers which
 658 * already hold &drm_device.event_lock.
 659 *
 660 * RETURNS:
 661 *
 662 * 0 on success or a negative error code on failure.
 663 */
 664int drm_event_reserve_init_locked(struct drm_device *dev,
 665				  struct drm_file *file_priv,
 666				  struct drm_pending_event *p,
 667				  struct drm_event *e)
 668{
 669	if (file_priv->event_space < e->length)
 670		return -ENOMEM;
 671
 672	file_priv->event_space -= e->length;
 673
 674	p->event = e;
 675	list_add(&p->pending_link, &file_priv->pending_event_list);
 676	p->file_priv = file_priv;
 677
 678	return 0;
 679}
 680EXPORT_SYMBOL(drm_event_reserve_init_locked);
 681
 682/**
 683 * drm_event_reserve_init - init a DRM event and reserve space for it
 684 * @dev: DRM device
 685 * @file_priv: DRM file private data
 686 * @p: tracking structure for the pending event
 687 * @e: actual event data to deliver to userspace
 688 *
 689 * This function prepares the passed in event for eventual delivery. If the event
 690 * doesn't get delivered (because the IOCTL fails later on, before queuing up
 691 * anything) then the even must be cancelled and freed using
 692 * drm_event_cancel_free(). Successfully initialized events should be sent out
 693 * using drm_send_event() or drm_send_event_locked() to signal completion of the
 694 * asynchronous event to userspace.
 695 *
 696 * If callers embedded @p into a larger structure it must be allocated with
 697 * kmalloc and @p must be the first member element.
 698 *
 699 * Callers which already hold &drm_device.event_lock should use
 700 * drm_event_reserve_init_locked() instead.
 701 *
 702 * RETURNS:
 703 *
 704 * 0 on success or a negative error code on failure.
 705 */
 706int drm_event_reserve_init(struct drm_device *dev,
 707			   struct drm_file *file_priv,
 708			   struct drm_pending_event *p,
 709			   struct drm_event *e)
 710{
 711	unsigned long flags;
 712	int ret;
 713
 714	spin_lock_irqsave(&dev->event_lock, flags);
 715	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
 716	spin_unlock_irqrestore(&dev->event_lock, flags);
 717
 718	return ret;
 719}
 720EXPORT_SYMBOL(drm_event_reserve_init);
 721
 722/**
 723 * drm_event_cancel_free - free a DRM event and release its space
 724 * @dev: DRM device
 725 * @p: tracking structure for the pending event
 726 *
 727 * This function frees the event @p initialized with drm_event_reserve_init()
 728 * and releases any allocated space. It is used to cancel an event when the
 729 * nonblocking operation could not be submitted and needed to be aborted.
 730 */
 731void drm_event_cancel_free(struct drm_device *dev,
 732			   struct drm_pending_event *p)
 733{
 734	unsigned long flags;
 735
 736	spin_lock_irqsave(&dev->event_lock, flags);
 737	if (p->file_priv) {
 738		p->file_priv->event_space += p->event->length;
 739		list_del(&p->pending_link);
 740	}
 741	spin_unlock_irqrestore(&dev->event_lock, flags);
 742
 743	if (p->fence)
 744		dma_fence_put(p->fence);
 745
 746	kfree(p);
 747}
 748EXPORT_SYMBOL(drm_event_cancel_free);
 749
 750static void drm_send_event_helper(struct drm_device *dev,
 751			   struct drm_pending_event *e, ktime_t timestamp)
 752{
 753	assert_spin_locked(&dev->event_lock);
 754
 755	if (e->completion) {
 756		complete_all(e->completion);
 757		e->completion_release(e->completion);
 758		e->completion = NULL;
 759	}
 760
 761	if (e->fence) {
 762		if (timestamp)
 763			dma_fence_signal_timestamp(e->fence, timestamp);
 764		else
 765			dma_fence_signal(e->fence);
 766		dma_fence_put(e->fence);
 767	}
 768
 769	if (!e->file_priv) {
 770		kfree(e);
 771		return;
 772	}
 773
 774	list_del(&e->pending_link);
 775	list_add_tail(&e->link,
 776		      &e->file_priv->event_list);
 777	wake_up_interruptible_poll(&e->file_priv->event_wait,
 778		EPOLLIN | EPOLLRDNORM);
 779}
 780
 781/**
 782 * drm_send_event_timestamp_locked - send DRM event to file descriptor
 783 * @dev: DRM device
 784 * @e: DRM event to deliver
 785 * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
 786 * time domain
 787 *
 788 * This function sends the event @e, initialized with drm_event_reserve_init(),
 789 * to its associated userspace DRM file. Callers must already hold
 790 * &drm_device.event_lock.
 791 *
 792 * Note that the core will take care of unlinking and disarming events when the
 793 * corresponding DRM file is closed. Drivers need not worry about whether the
 794 * DRM file for this event still exists and can call this function upon
 795 * completion of the asynchronous work unconditionally.
 796 */
 797void drm_send_event_timestamp_locked(struct drm_device *dev,
 798				     struct drm_pending_event *e, ktime_t timestamp)
 799{
 800	drm_send_event_helper(dev, e, timestamp);
 801}
 802EXPORT_SYMBOL(drm_send_event_timestamp_locked);
 803
 804/**
 805 * drm_send_event_locked - send DRM event to file descriptor
 806 * @dev: DRM device
 807 * @e: DRM event to deliver
 808 *
 809 * This function sends the event @e, initialized with drm_event_reserve_init(),
 810 * to its associated userspace DRM file. Callers must already hold
 811 * &drm_device.event_lock, see drm_send_event() for the unlocked version.
 812 *
 813 * Note that the core will take care of unlinking and disarming events when the
 814 * corresponding DRM file is closed. Drivers need not worry about whether the
 815 * DRM file for this event still exists and can call this function upon
 816 * completion of the asynchronous work unconditionally.
 817 */
 818void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
 819{
 820	drm_send_event_helper(dev, e, 0);
 821}
 822EXPORT_SYMBOL(drm_send_event_locked);
 823
 824/**
 825 * drm_send_event - send DRM event to file descriptor
 826 * @dev: DRM device
 827 * @e: DRM event to deliver
 828 *
 829 * This function sends the event @e, initialized with drm_event_reserve_init(),
 830 * to its associated userspace DRM file. This function acquires
 831 * &drm_device.event_lock, see drm_send_event_locked() for callers which already
 832 * hold this lock.
 833 *
 834 * Note that the core will take care of unlinking and disarming events when the
 835 * corresponding DRM file is closed. Drivers need not worry about whether the
 836 * DRM file for this event still exists and can call this function upon
 837 * completion of the asynchronous work unconditionally.
 838 */
 839void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
 840{
 841	unsigned long irqflags;
 842
 843	spin_lock_irqsave(&dev->event_lock, irqflags);
 844	drm_send_event_helper(dev, e, 0);
 845	spin_unlock_irqrestore(&dev->event_lock, irqflags);
 846}
 847EXPORT_SYMBOL(drm_send_event);
 848
 849static void print_size(struct drm_printer *p, const char *stat,
 850		       const char *region, u64 sz)
 851{
 852	const char *units[] = {"", " KiB", " MiB"};
 853	unsigned u;
 854
 855	for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
 856		if (sz == 0 || !IS_ALIGNED(sz, SZ_1K))
 857			break;
 858		sz = div_u64(sz, SZ_1K);
 859	}
 860
 861	drm_printf(p, "drm-%s-%s:\t%llu%s\n", stat, region, sz, units[u]);
 862}
 863
 864/**
 865 * drm_print_memory_stats - A helper to print memory stats
 866 * @p: The printer to print output to
 867 * @stats: The collected memory stats
 868 * @supported_status: Bitmask of optional stats which are available
 869 * @region: The memory region
 870 *
 871 */
 872void drm_print_memory_stats(struct drm_printer *p,
 873			    const struct drm_memory_stats *stats,
 874			    enum drm_gem_object_status supported_status,
 875			    const char *region)
 876{
 877	print_size(p, "total", region, stats->private + stats->shared);
 878	print_size(p, "shared", region, stats->shared);
 879	print_size(p, "active", region, stats->active);
 880
 881	if (supported_status & DRM_GEM_OBJECT_RESIDENT)
 882		print_size(p, "resident", region, stats->resident);
 883
 884	if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
 885		print_size(p, "purgeable", region, stats->purgeable);
 886}
 887EXPORT_SYMBOL(drm_print_memory_stats);
 888
 889/**
 890 * drm_show_memory_stats - Helper to collect and show standard fdinfo memory stats
 891 * @p: the printer to print output to
 892 * @file: the DRM file
 893 *
 894 * Helper to iterate over GEM objects with a handle allocated in the specified
 895 * file.
 896 */
 897void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file)
 898{
 899	struct drm_gem_object *obj;
 900	struct drm_memory_stats status = {};
 901	enum drm_gem_object_status supported_status = 0;
 902	int id;
 903
 904	spin_lock(&file->table_lock);
 905	idr_for_each_entry (&file->object_idr, obj, id) {
 906		enum drm_gem_object_status s = 0;
 907		size_t add_size = (obj->funcs && obj->funcs->rss) ?
 908			obj->funcs->rss(obj) : obj->size;
 909
 910		if (obj->funcs && obj->funcs->status) {
 911			s = obj->funcs->status(obj);
 912			supported_status = DRM_GEM_OBJECT_RESIDENT |
 913					DRM_GEM_OBJECT_PURGEABLE;
 914		}
 915
 916		if (obj->handle_count > 1) {
 917			status.shared += obj->size;
 918		} else {
 919			status.private += obj->size;
 920		}
 921
 922		if (s & DRM_GEM_OBJECT_RESIDENT) {
 923			status.resident += add_size;
 924		} else {
 925			/* If already purged or not yet backed by pages, don't
 926			 * count it as purgeable:
 927			 */
 928			s &= ~DRM_GEM_OBJECT_PURGEABLE;
 929		}
 930
 931		if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true))) {
 932			status.active += add_size;
 933
 934			/* If still active, don't count as purgeable: */
 935			s &= ~DRM_GEM_OBJECT_PURGEABLE;
 936		}
 937
 938		if (s & DRM_GEM_OBJECT_PURGEABLE)
 939			status.purgeable += add_size;
 940	}
 941	spin_unlock(&file->table_lock);
 942
 943	drm_print_memory_stats(p, &status, supported_status, "memory");
 944}
 945EXPORT_SYMBOL(drm_show_memory_stats);
 946
 947/**
 948 * drm_show_fdinfo - helper for drm file fops
 949 * @m: output stream
 950 * @f: the device file instance
 951 *
 952 * Helper to implement fdinfo, for userspace to query usage stats, etc, of a
 953 * process using the GPU.  See also &drm_driver.show_fdinfo.
 954 *
 955 * For text output format description please see Documentation/gpu/drm-usage-stats.rst
 956 */
 957void drm_show_fdinfo(struct seq_file *m, struct file *f)
 958{
 959	struct drm_file *file = f->private_data;
 960	struct drm_device *dev = file->minor->dev;
 961	struct drm_printer p = drm_seq_file_printer(m);
 962
 963	drm_printf(&p, "drm-driver:\t%s\n", dev->driver->name);
 964	drm_printf(&p, "drm-client-id:\t%llu\n", file->client_id);
 965
 966	if (dev_is_pci(dev->dev)) {
 967		struct pci_dev *pdev = to_pci_dev(dev->dev);
 968
 969		drm_printf(&p, "drm-pdev:\t%04x:%02x:%02x.%d\n",
 970			   pci_domain_nr(pdev->bus), pdev->bus->number,
 971			   PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
 972	}
 973
 974	if (dev->driver->show_fdinfo)
 975		dev->driver->show_fdinfo(&p, file);
 976}
 977EXPORT_SYMBOL(drm_show_fdinfo);
 978
 979/**
 980 * mock_drm_getfile - Create a new struct file for the drm device
 981 * @minor: drm minor to wrap (e.g. #drm_device.primary)
 982 * @flags: file creation mode (O_RDWR etc)
 983 *
 984 * This create a new struct file that wraps a DRM file context around a
 985 * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
 986 * invoking userspace. The struct file may be operated on using its f_op
 987 * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
 988 * to userspace facing functions as an internal/anonymous client.
 989 *
 990 * RETURNS:
 991 * Pointer to newly created struct file, ERR_PTR on failure.
 992 */
 993struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
 994{
 995	struct drm_device *dev = minor->dev;
 996	struct drm_file *priv;
 997	struct file *file;
 998
 999	priv = drm_file_alloc(minor);
1000	if (IS_ERR(priv))
1001		return ERR_CAST(priv);
1002
1003	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
1004	if (IS_ERR(file)) {
1005		drm_file_free(priv);
1006		return file;
1007	}
1008
1009	/* Everyone shares a single global address space */
1010	file->f_mapping = dev->anon_inode->i_mapping;
1011
1012	drm_dev_get(dev);
1013	priv->filp = file;
1014
1015	return file;
1016}
1017EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
v6.2
  1/*
  2 * \author Rickard E. (Rik) Faith <faith@valinux.com>
  3 * \author Daryll Strauss <daryll@valinux.com>
  4 * \author Gareth Hughes <gareth@valinux.com>
  5 */
  6
  7/*
  8 * Created: Mon Jan  4 08:58:31 1999 by faith@valinux.com
  9 *
 10 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 12 * All Rights Reserved.
 13 *
 14 * Permission is hereby granted, free of charge, to any person obtaining a
 15 * copy of this software and associated documentation files (the "Software"),
 16 * to deal in the Software without restriction, including without limitation
 17 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 18 * and/or sell copies of the Software, and to permit persons to whom the
 19 * Software is furnished to do so, subject to the following conditions:
 20 *
 21 * The above copyright notice and this permission notice (including the next
 22 * paragraph) shall be included in all copies or substantial portions of the
 23 * Software.
 24 *
 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 28 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 31 * OTHER DEALINGS IN THE SOFTWARE.
 32 */
 33
 34#include <linux/anon_inodes.h>
 35#include <linux/dma-fence.h>
 36#include <linux/file.h>
 37#include <linux/module.h>
 38#include <linux/pci.h>
 39#include <linux/poll.h>
 40#include <linux/slab.h>
 41
 42#include <drm/drm_client.h>
 43#include <drm/drm_drv.h>
 44#include <drm/drm_file.h>
 
 45#include <drm/drm_print.h>
 46
 47#include "drm_crtc_internal.h"
 48#include "drm_internal.h"
 49#include "drm_legacy.h"
 50
 51/* from BKL pushdown */
 52DEFINE_MUTEX(drm_global_mutex);
 53
 54bool drm_dev_needs_global_mutex(struct drm_device *dev)
 55{
 56	/*
 57	 * Legacy drivers rely on all kinds of BKL locking semantics, don't
 58	 * bother. They also still need BKL locking for their ioctls, so better
 59	 * safe than sorry.
 60	 */
 61	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 62		return true;
 63
 64	/*
 65	 * The deprecated ->load callback must be called after the driver is
 66	 * already registered. This means such drivers rely on the BKL to make
 67	 * sure an open can't proceed until the driver is actually fully set up.
 68	 * Similar hilarity holds for the unload callback.
 69	 */
 70	if (dev->driver->load || dev->driver->unload)
 71		return true;
 72
 73	/*
 74	 * Drivers with the lastclose callback assume that it's synchronized
 75	 * against concurrent opens, which again needs the BKL. The proper fix
 76	 * is to use the drm_client infrastructure with proper locking for each
 77	 * client.
 78	 */
 79	if (dev->driver->lastclose)
 80		return true;
 81
 82	return false;
 83}
 84
 85/**
 86 * DOC: file operations
 87 *
 88 * Drivers must define the file operations structure that forms the DRM
 89 * userspace API entry point, even though most of those operations are
 90 * implemented in the DRM core. The resulting &struct file_operations must be
 91 * stored in the &drm_driver.fops field. The mandatory functions are drm_open(),
 92 * drm_read(), drm_ioctl() and drm_compat_ioctl() if CONFIG_COMPAT is enabled
 93 * Note that drm_compat_ioctl will be NULL if CONFIG_COMPAT=n, so there's no
 94 * need to sprinkle #ifdef into the code. Drivers which implement private ioctls
 95 * that require 32/64 bit compatibility support must provide their own
 96 * &file_operations.compat_ioctl handler that processes private ioctls and calls
 97 * drm_compat_ioctl() for core ioctls.
 98 *
 99 * In addition drm_read() and drm_poll() provide support for DRM events. DRM
100 * events are a generic and extensible means to send asynchronous events to
101 * userspace through the file descriptor. They are used to send vblank event and
102 * page flip completions by the KMS API. But drivers can also use it for their
103 * own needs, e.g. to signal completion of rendering.
104 *
105 * For the driver-side event interface see drm_event_reserve_init() and
106 * drm_send_event() as the main starting points.
107 *
108 * The memory mapping implementation will vary depending on how the driver
109 * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
110 * function, modern drivers should use one of the provided memory-manager
111 * specific implementations. For GEM-based drivers this is drm_gem_mmap().
112 *
113 * No other file operations are supported by the DRM userspace API. Overall the
114 * following is an example &file_operations structure::
115 *
116 *     static const example_drm_fops = {
117 *             .owner = THIS_MODULE,
118 *             .open = drm_open,
119 *             .release = drm_release,
120 *             .unlocked_ioctl = drm_ioctl,
121 *             .compat_ioctl = drm_compat_ioctl, // NULL if CONFIG_COMPAT=n
122 *             .poll = drm_poll,
123 *             .read = drm_read,
124 *             .llseek = no_llseek,
125 *             .mmap = drm_gem_mmap,
126 *     };
127 *
128 * For plain GEM based drivers there is the DEFINE_DRM_GEM_FOPS() macro, and for
129 * DMA based drivers there is the DEFINE_DRM_GEM_DMA_FOPS() macro to make this
130 * simpler.
131 *
132 * The driver's &file_operations must be stored in &drm_driver.fops.
133 *
134 * For driver-private IOCTL handling see the more detailed discussion in
135 * :ref:`IOCTL support in the userland interfaces chapter<drm_driver_ioctl>`.
136 */
137
138/**
139 * drm_file_alloc - allocate file context
140 * @minor: minor to allocate on
141 *
142 * This allocates a new DRM file context. It is not linked into any context and
143 * can be used by the caller freely. Note that the context keeps a pointer to
144 * @minor, so it must be freed before @minor is.
145 *
146 * RETURNS:
147 * Pointer to newly allocated context, ERR_PTR on failure.
148 */
149struct drm_file *drm_file_alloc(struct drm_minor *minor)
150{
 
151	struct drm_device *dev = minor->dev;
152	struct drm_file *file;
153	int ret;
154
155	file = kzalloc(sizeof(*file), GFP_KERNEL);
156	if (!file)
157		return ERR_PTR(-ENOMEM);
158
159	file->pid = get_pid(task_pid(current));
 
 
160	file->minor = minor;
161
162	/* for compatibility root is always authenticated */
163	file->authenticated = capable(CAP_SYS_ADMIN);
164
165	INIT_LIST_HEAD(&file->lhead);
166	INIT_LIST_HEAD(&file->fbs);
167	mutex_init(&file->fbs_lock);
168	INIT_LIST_HEAD(&file->blobs);
169	INIT_LIST_HEAD(&file->pending_event_list);
170	INIT_LIST_HEAD(&file->event_list);
171	init_waitqueue_head(&file->event_wait);
172	file->event_space = 4096; /* set aside 4k for event buffer */
173
174	spin_lock_init(&file->master_lookup_lock);
175	mutex_init(&file->event_read_lock);
176
177	if (drm_core_check_feature(dev, DRIVER_GEM))
178		drm_gem_open(dev, file);
179
180	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
181		drm_syncobj_open(file);
182
183	drm_prime_init_file_private(&file->prime);
184
185	if (dev->driver->open) {
186		ret = dev->driver->open(dev, file);
187		if (ret < 0)
188			goto out_prime_destroy;
189	}
190
191	return file;
192
193out_prime_destroy:
194	drm_prime_destroy_file_private(&file->prime);
195	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
196		drm_syncobj_release(file);
197	if (drm_core_check_feature(dev, DRIVER_GEM))
198		drm_gem_release(dev, file);
199	put_pid(file->pid);
200	kfree(file);
201
202	return ERR_PTR(ret);
203}
204
205static void drm_events_release(struct drm_file *file_priv)
206{
207	struct drm_device *dev = file_priv->minor->dev;
208	struct drm_pending_event *e, *et;
209	unsigned long flags;
210
211	spin_lock_irqsave(&dev->event_lock, flags);
212
213	/* Unlink pending events */
214	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
215				 pending_link) {
216		list_del(&e->pending_link);
217		e->file_priv = NULL;
218	}
219
220	/* Remove unconsumed events */
221	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
222		list_del(&e->link);
223		kfree(e);
224	}
225
226	spin_unlock_irqrestore(&dev->event_lock, flags);
227}
228
229/**
230 * drm_file_free - free file context
231 * @file: context to free, or NULL
232 *
233 * This destroys and deallocates a DRM file context previously allocated via
234 * drm_file_alloc(). The caller must make sure to unlink it from any contexts
235 * before calling this.
236 *
237 * If NULL is passed, this is a no-op.
238 */
239void drm_file_free(struct drm_file *file)
240{
241	struct drm_device *dev;
242
243	if (!file)
244		return;
245
246	dev = file->minor->dev;
247
248	DRM_DEBUG("comm=\"%s\", pid=%d, dev=0x%lx, open_count=%d\n",
249		  current->comm, task_pid_nr(current),
250		  (long)old_encode_dev(file->minor->kdev->devt),
251		  atomic_read(&dev->open_count));
252
253#ifdef CONFIG_DRM_LEGACY
254	if (drm_core_check_feature(dev, DRIVER_LEGACY) &&
255	    dev->driver->preclose)
256		dev->driver->preclose(dev, file);
257#endif
258
259	if (drm_core_check_feature(dev, DRIVER_LEGACY))
260		drm_legacy_lock_release(dev, file->filp);
261
262	if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
263		drm_legacy_reclaim_buffers(dev, file);
264
265	drm_events_release(file);
266
267	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
268		drm_fb_release(file);
269		drm_property_destroy_user_blobs(dev, file);
270	}
271
272	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
273		drm_syncobj_release(file);
274
275	if (drm_core_check_feature(dev, DRIVER_GEM))
276		drm_gem_release(dev, file);
277
278	drm_legacy_ctxbitmap_flush(dev, file);
279
280	if (drm_is_primary_client(file))
281		drm_master_release(file);
282
283	if (dev->driver->postclose)
284		dev->driver->postclose(dev, file);
285
286	drm_prime_destroy_file_private(&file->prime);
287
288	WARN_ON(!list_empty(&file->event_list));
289
290	put_pid(file->pid);
291	kfree(file);
292}
293
294static void drm_close_helper(struct file *filp)
295{
296	struct drm_file *file_priv = filp->private_data;
297	struct drm_device *dev = file_priv->minor->dev;
298
299	mutex_lock(&dev->filelist_mutex);
300	list_del(&file_priv->lhead);
301	mutex_unlock(&dev->filelist_mutex);
302
303	drm_file_free(file_priv);
304}
305
306/*
307 * Check whether DRI will run on this CPU.
308 *
309 * \return non-zero if the DRI will run on this CPU, or zero otherwise.
310 */
311static int drm_cpu_valid(void)
312{
313#if defined(__sparc__) && !defined(__sparc_v9__)
314	return 0;		/* No cmpxchg before v9 sparc. */
315#endif
316	return 1;
317}
318
319/*
320 * Called whenever a process opens a drm node
321 *
322 * \param filp file pointer.
323 * \param minor acquired minor-object.
324 * \return zero on success or a negative number on failure.
325 *
326 * Creates and initializes a drm_file structure for the file private data in \p
327 * filp and add it into the double linked list in \p dev.
328 */
329int drm_open_helper(struct file *filp, struct drm_minor *minor)
330{
331	struct drm_device *dev = minor->dev;
332	struct drm_file *priv;
333	int ret;
334
335	if (filp->f_flags & O_EXCL)
336		return -EBUSY;	/* No exclusive opens */
337	if (!drm_cpu_valid())
338		return -EINVAL;
339	if (dev->switch_power_state != DRM_SWITCH_POWER_ON &&
340	    dev->switch_power_state != DRM_SWITCH_POWER_DYNAMIC_OFF)
341		return -EINVAL;
342
343	DRM_DEBUG("comm=\"%s\", pid=%d, minor=%d\n", current->comm,
344		  task_pid_nr(current), minor->index);
345
346	priv = drm_file_alloc(minor);
347	if (IS_ERR(priv))
348		return PTR_ERR(priv);
349
350	if (drm_is_primary_client(priv)) {
351		ret = drm_master_open(priv);
352		if (ret) {
353			drm_file_free(priv);
354			return ret;
355		}
356	}
357
358	filp->private_data = priv;
359	filp->f_mode |= FMODE_UNSIGNED_OFFSET;
360	priv->filp = filp;
361
362	mutex_lock(&dev->filelist_mutex);
363	list_add(&priv->lhead, &dev->filelist);
364	mutex_unlock(&dev->filelist_mutex);
365
366#ifdef CONFIG_DRM_LEGACY
367#ifdef __alpha__
368	/*
369	 * Default the hose
370	 */
371	if (!dev->hose) {
372		struct pci_dev *pci_dev;
373
374		pci_dev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
375		if (pci_dev) {
376			dev->hose = pci_dev->sysdata;
377			pci_dev_put(pci_dev);
378		}
379		if (!dev->hose) {
380			struct pci_bus *b = list_entry(pci_root_buses.next,
381				struct pci_bus, node);
382			if (b)
383				dev->hose = b->sysdata;
384		}
385	}
386#endif
387#endif
388
389	return 0;
390}
391
392/**
393 * drm_open - open method for DRM file
394 * @inode: device inode
395 * @filp: file pointer.
396 *
397 * This function must be used by drivers as their &file_operations.open method.
398 * It looks up the correct DRM device and instantiates all the per-file
399 * resources for it. It also calls the &drm_driver.open driver callback.
400 *
401 * RETURNS:
402 *
403 * 0 on success or negative errno value on failure.
404 */
405int drm_open(struct inode *inode, struct file *filp)
406{
407	struct drm_device *dev;
408	struct drm_minor *minor;
409	int retcode;
410	int need_setup = 0;
411
412	minor = drm_minor_acquire(iminor(inode));
413	if (IS_ERR(minor))
414		return PTR_ERR(minor);
415
416	dev = minor->dev;
417	if (drm_dev_needs_global_mutex(dev))
418		mutex_lock(&drm_global_mutex);
419
420	if (!atomic_fetch_inc(&dev->open_count))
421		need_setup = 1;
422
423	/* share address_space across all char-devs of a single device */
424	filp->f_mapping = dev->anon_inode->i_mapping;
425
426	retcode = drm_open_helper(filp, minor);
427	if (retcode)
428		goto err_undo;
429	if (need_setup) {
430		retcode = drm_legacy_setup(dev);
431		if (retcode) {
432			drm_close_helper(filp);
433			goto err_undo;
434		}
435	}
436
437	if (drm_dev_needs_global_mutex(dev))
438		mutex_unlock(&drm_global_mutex);
439
440	return 0;
441
442err_undo:
443	atomic_dec(&dev->open_count);
444	if (drm_dev_needs_global_mutex(dev))
445		mutex_unlock(&drm_global_mutex);
446	drm_minor_release(minor);
447	return retcode;
448}
449EXPORT_SYMBOL(drm_open);
450
451void drm_lastclose(struct drm_device * dev)
452{
453	DRM_DEBUG("\n");
454
455	if (dev->driver->lastclose)
456		dev->driver->lastclose(dev);
457	DRM_DEBUG("driver lastclose completed\n");
458
459	if (drm_core_check_feature(dev, DRIVER_LEGACY))
460		drm_legacy_dev_reinit(dev);
461
462	drm_client_dev_restore(dev);
463}
464
465/**
466 * drm_release - release method for DRM file
467 * @inode: device inode
468 * @filp: file pointer.
469 *
470 * This function must be used by drivers as their &file_operations.release
471 * method. It frees any resources associated with the open file, and calls the
472 * &drm_driver.postclose driver callback. If this is the last open file for the
473 * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
474 *
475 * RETURNS:
476 *
477 * Always succeeds and returns 0.
478 */
479int drm_release(struct inode *inode, struct file *filp)
480{
481	struct drm_file *file_priv = filp->private_data;
482	struct drm_minor *minor = file_priv->minor;
483	struct drm_device *dev = minor->dev;
484
485	if (drm_dev_needs_global_mutex(dev))
486		mutex_lock(&drm_global_mutex);
487
488	DRM_DEBUG("open_count = %d\n", atomic_read(&dev->open_count));
489
490	drm_close_helper(filp);
491
492	if (atomic_dec_and_test(&dev->open_count))
493		drm_lastclose(dev);
494
495	if (drm_dev_needs_global_mutex(dev))
496		mutex_unlock(&drm_global_mutex);
497
498	drm_minor_release(minor);
499
500	return 0;
501}
502EXPORT_SYMBOL(drm_release);
503
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
504/**
505 * drm_release_noglobal - release method for DRM file
506 * @inode: device inode
507 * @filp: file pointer.
508 *
509 * This function may be used by drivers as their &file_operations.release
510 * method. It frees any resources associated with the open file prior to taking
511 * the drm_global_mutex, which then calls the &drm_driver.postclose driver
512 * callback. If this is the last open file for the DRM device also proceeds to
513 * call the &drm_driver.lastclose driver callback.
514 *
515 * RETURNS:
516 *
517 * Always succeeds and returns 0.
518 */
519int drm_release_noglobal(struct inode *inode, struct file *filp)
520{
521	struct drm_file *file_priv = filp->private_data;
522	struct drm_minor *minor = file_priv->minor;
523	struct drm_device *dev = minor->dev;
524
525	drm_close_helper(filp);
526
527	if (atomic_dec_and_mutex_lock(&dev->open_count, &drm_global_mutex)) {
528		drm_lastclose(dev);
529		mutex_unlock(&drm_global_mutex);
530	}
531
532	drm_minor_release(minor);
533
534	return 0;
535}
536EXPORT_SYMBOL(drm_release_noglobal);
537
538/**
539 * drm_read - read method for DRM file
540 * @filp: file pointer
541 * @buffer: userspace destination pointer for the read
542 * @count: count in bytes to read
543 * @offset: offset to read
544 *
545 * This function must be used by drivers as their &file_operations.read
546 * method if they use DRM events for asynchronous signalling to userspace.
547 * Since events are used by the KMS API for vblank and page flip completion this
548 * means all modern display drivers must use it.
549 *
550 * @offset is ignored, DRM events are read like a pipe. Polling support is
551 * provided by drm_poll().
552 *
553 * This function will only ever read a full event. Therefore userspace must
554 * supply a big enough buffer to fit any event to ensure forward progress. Since
555 * the maximum event space is currently 4K it's recommended to just use that for
556 * safety.
557 *
558 * RETURNS:
559 *
560 * Number of bytes read (always aligned to full events, and can be 0) or a
561 * negative error code on failure.
562 */
563ssize_t drm_read(struct file *filp, char __user *buffer,
564		 size_t count, loff_t *offset)
565{
566	struct drm_file *file_priv = filp->private_data;
567	struct drm_device *dev = file_priv->minor->dev;
568	ssize_t ret;
569
570	ret = mutex_lock_interruptible(&file_priv->event_read_lock);
571	if (ret)
572		return ret;
573
574	for (;;) {
575		struct drm_pending_event *e = NULL;
576
577		spin_lock_irq(&dev->event_lock);
578		if (!list_empty(&file_priv->event_list)) {
579			e = list_first_entry(&file_priv->event_list,
580					struct drm_pending_event, link);
581			file_priv->event_space += e->event->length;
582			list_del(&e->link);
583		}
584		spin_unlock_irq(&dev->event_lock);
585
586		if (e == NULL) {
587			if (ret)
588				break;
589
590			if (filp->f_flags & O_NONBLOCK) {
591				ret = -EAGAIN;
592				break;
593			}
594
595			mutex_unlock(&file_priv->event_read_lock);
596			ret = wait_event_interruptible(file_priv->event_wait,
597						       !list_empty(&file_priv->event_list));
598			if (ret >= 0)
599				ret = mutex_lock_interruptible(&file_priv->event_read_lock);
600			if (ret)
601				return ret;
602		} else {
603			unsigned length = e->event->length;
604
605			if (length > count - ret) {
606put_back_event:
607				spin_lock_irq(&dev->event_lock);
608				file_priv->event_space -= length;
609				list_add(&e->link, &file_priv->event_list);
610				spin_unlock_irq(&dev->event_lock);
611				wake_up_interruptible_poll(&file_priv->event_wait,
612					EPOLLIN | EPOLLRDNORM);
613				break;
614			}
615
616			if (copy_to_user(buffer + ret, e->event, length)) {
617				if (ret == 0)
618					ret = -EFAULT;
619				goto put_back_event;
620			}
621
622			ret += length;
623			kfree(e);
624		}
625	}
626	mutex_unlock(&file_priv->event_read_lock);
627
628	return ret;
629}
630EXPORT_SYMBOL(drm_read);
631
632/**
633 * drm_poll - poll method for DRM file
634 * @filp: file pointer
635 * @wait: poll waiter table
636 *
637 * This function must be used by drivers as their &file_operations.read method
638 * if they use DRM events for asynchronous signalling to userspace.  Since
639 * events are used by the KMS API for vblank and page flip completion this means
640 * all modern display drivers must use it.
641 *
642 * See also drm_read().
643 *
644 * RETURNS:
645 *
646 * Mask of POLL flags indicating the current status of the file.
647 */
648__poll_t drm_poll(struct file *filp, struct poll_table_struct *wait)
649{
650	struct drm_file *file_priv = filp->private_data;
651	__poll_t mask = 0;
652
653	poll_wait(filp, &file_priv->event_wait, wait);
654
655	if (!list_empty(&file_priv->event_list))
656		mask |= EPOLLIN | EPOLLRDNORM;
657
658	return mask;
659}
660EXPORT_SYMBOL(drm_poll);
661
662/**
663 * drm_event_reserve_init_locked - init a DRM event and reserve space for it
664 * @dev: DRM device
665 * @file_priv: DRM file private data
666 * @p: tracking structure for the pending event
667 * @e: actual event data to deliver to userspace
668 *
669 * This function prepares the passed in event for eventual delivery. If the event
670 * doesn't get delivered (because the IOCTL fails later on, before queuing up
671 * anything) then the even must be cancelled and freed using
672 * drm_event_cancel_free(). Successfully initialized events should be sent out
673 * using drm_send_event() or drm_send_event_locked() to signal completion of the
674 * asynchronous event to userspace.
675 *
676 * If callers embedded @p into a larger structure it must be allocated with
677 * kmalloc and @p must be the first member element.
678 *
679 * This is the locked version of drm_event_reserve_init() for callers which
680 * already hold &drm_device.event_lock.
681 *
682 * RETURNS:
683 *
684 * 0 on success or a negative error code on failure.
685 */
686int drm_event_reserve_init_locked(struct drm_device *dev,
687				  struct drm_file *file_priv,
688				  struct drm_pending_event *p,
689				  struct drm_event *e)
690{
691	if (file_priv->event_space < e->length)
692		return -ENOMEM;
693
694	file_priv->event_space -= e->length;
695
696	p->event = e;
697	list_add(&p->pending_link, &file_priv->pending_event_list);
698	p->file_priv = file_priv;
699
700	return 0;
701}
702EXPORT_SYMBOL(drm_event_reserve_init_locked);
703
704/**
705 * drm_event_reserve_init - init a DRM event and reserve space for it
706 * @dev: DRM device
707 * @file_priv: DRM file private data
708 * @p: tracking structure for the pending event
709 * @e: actual event data to deliver to userspace
710 *
711 * This function prepares the passed in event for eventual delivery. If the event
712 * doesn't get delivered (because the IOCTL fails later on, before queuing up
713 * anything) then the even must be cancelled and freed using
714 * drm_event_cancel_free(). Successfully initialized events should be sent out
715 * using drm_send_event() or drm_send_event_locked() to signal completion of the
716 * asynchronous event to userspace.
717 *
718 * If callers embedded @p into a larger structure it must be allocated with
719 * kmalloc and @p must be the first member element.
720 *
721 * Callers which already hold &drm_device.event_lock should use
722 * drm_event_reserve_init_locked() instead.
723 *
724 * RETURNS:
725 *
726 * 0 on success or a negative error code on failure.
727 */
728int drm_event_reserve_init(struct drm_device *dev,
729			   struct drm_file *file_priv,
730			   struct drm_pending_event *p,
731			   struct drm_event *e)
732{
733	unsigned long flags;
734	int ret;
735
736	spin_lock_irqsave(&dev->event_lock, flags);
737	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
738	spin_unlock_irqrestore(&dev->event_lock, flags);
739
740	return ret;
741}
742EXPORT_SYMBOL(drm_event_reserve_init);
743
744/**
745 * drm_event_cancel_free - free a DRM event and release its space
746 * @dev: DRM device
747 * @p: tracking structure for the pending event
748 *
749 * This function frees the event @p initialized with drm_event_reserve_init()
750 * and releases any allocated space. It is used to cancel an event when the
751 * nonblocking operation could not be submitted and needed to be aborted.
752 */
753void drm_event_cancel_free(struct drm_device *dev,
754			   struct drm_pending_event *p)
755{
756	unsigned long flags;
757
758	spin_lock_irqsave(&dev->event_lock, flags);
759	if (p->file_priv) {
760		p->file_priv->event_space += p->event->length;
761		list_del(&p->pending_link);
762	}
763	spin_unlock_irqrestore(&dev->event_lock, flags);
764
765	if (p->fence)
766		dma_fence_put(p->fence);
767
768	kfree(p);
769}
770EXPORT_SYMBOL(drm_event_cancel_free);
771
772static void drm_send_event_helper(struct drm_device *dev,
773			   struct drm_pending_event *e, ktime_t timestamp)
774{
775	assert_spin_locked(&dev->event_lock);
776
777	if (e->completion) {
778		complete_all(e->completion);
779		e->completion_release(e->completion);
780		e->completion = NULL;
781	}
782
783	if (e->fence) {
784		if (timestamp)
785			dma_fence_signal_timestamp(e->fence, timestamp);
786		else
787			dma_fence_signal(e->fence);
788		dma_fence_put(e->fence);
789	}
790
791	if (!e->file_priv) {
792		kfree(e);
793		return;
794	}
795
796	list_del(&e->pending_link);
797	list_add_tail(&e->link,
798		      &e->file_priv->event_list);
799	wake_up_interruptible_poll(&e->file_priv->event_wait,
800		EPOLLIN | EPOLLRDNORM);
801}
802
803/**
804 * drm_send_event_timestamp_locked - send DRM event to file descriptor
805 * @dev: DRM device
806 * @e: DRM event to deliver
807 * @timestamp: timestamp to set for the fence event in kernel's CLOCK_MONOTONIC
808 * time domain
809 *
810 * This function sends the event @e, initialized with drm_event_reserve_init(),
811 * to its associated userspace DRM file. Callers must already hold
812 * &drm_device.event_lock.
813 *
814 * Note that the core will take care of unlinking and disarming events when the
815 * corresponding DRM file is closed. Drivers need not worry about whether the
816 * DRM file for this event still exists and can call this function upon
817 * completion of the asynchronous work unconditionally.
818 */
819void drm_send_event_timestamp_locked(struct drm_device *dev,
820				     struct drm_pending_event *e, ktime_t timestamp)
821{
822	drm_send_event_helper(dev, e, timestamp);
823}
824EXPORT_SYMBOL(drm_send_event_timestamp_locked);
825
826/**
827 * drm_send_event_locked - send DRM event to file descriptor
828 * @dev: DRM device
829 * @e: DRM event to deliver
830 *
831 * This function sends the event @e, initialized with drm_event_reserve_init(),
832 * to its associated userspace DRM file. Callers must already hold
833 * &drm_device.event_lock, see drm_send_event() for the unlocked version.
834 *
835 * Note that the core will take care of unlinking and disarming events when the
836 * corresponding DRM file is closed. Drivers need not worry about whether the
837 * DRM file for this event still exists and can call this function upon
838 * completion of the asynchronous work unconditionally.
839 */
840void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
841{
842	drm_send_event_helper(dev, e, 0);
843}
844EXPORT_SYMBOL(drm_send_event_locked);
845
846/**
847 * drm_send_event - send DRM event to file descriptor
848 * @dev: DRM device
849 * @e: DRM event to deliver
850 *
851 * This function sends the event @e, initialized with drm_event_reserve_init(),
852 * to its associated userspace DRM file. This function acquires
853 * &drm_device.event_lock, see drm_send_event_locked() for callers which already
854 * hold this lock.
855 *
856 * Note that the core will take care of unlinking and disarming events when the
857 * corresponding DRM file is closed. Drivers need not worry about whether the
858 * DRM file for this event still exists and can call this function upon
859 * completion of the asynchronous work unconditionally.
860 */
861void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
862{
863	unsigned long irqflags;
864
865	spin_lock_irqsave(&dev->event_lock, irqflags);
866	drm_send_event_helper(dev, e, 0);
867	spin_unlock_irqrestore(&dev->event_lock, irqflags);
868}
869EXPORT_SYMBOL(drm_send_event);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
870
871/**
872 * mock_drm_getfile - Create a new struct file for the drm device
873 * @minor: drm minor to wrap (e.g. #drm_device.primary)
874 * @flags: file creation mode (O_RDWR etc)
875 *
876 * This create a new struct file that wraps a DRM file context around a
877 * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
878 * invoking userspace. The struct file may be operated on using its f_op
879 * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
880 * to userspace facing functions as an internal/anonymous client.
881 *
882 * RETURNS:
883 * Pointer to newly created struct file, ERR_PTR on failure.
884 */
885struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
886{
887	struct drm_device *dev = minor->dev;
888	struct drm_file *priv;
889	struct file *file;
890
891	priv = drm_file_alloc(minor);
892	if (IS_ERR(priv))
893		return ERR_CAST(priv);
894
895	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
896	if (IS_ERR(file)) {
897		drm_file_free(priv);
898		return file;
899	}
900
901	/* Everyone shares a single global address space */
902	file->f_mapping = dev->anon_inode->i_mapping;
903
904	drm_dev_get(dev);
905	priv->filp = file;
906
907	return file;
908}
909EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);