1/*
   2 * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
   3 *
   4 * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
   5 * All Rights Reserved.
   6 *
   7 * Author Rickard E. (Rik) Faith <faith@valinux.com>
   8 *
   9 * Permission is hereby granted, free of charge, to any person obtaining a
  10 * copy of this software and associated documentation files (the "Software"),
  11 * to deal in the Software without restriction, including without limitation
  12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13 * and/or sell copies of the Software, and to permit persons to whom the
  14 * Software is furnished to do so, subject to the following conditions:
  15 *
  16 * The above copyright notice and this permission notice (including the next
  17 * paragraph) shall be included in all copies or substantial portions of the
  18 * Software.
  19 *
  20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26 * DEALINGS IN THE SOFTWARE.
  27 */
  28
  29#include <linux/debugfs.h>
  30#include <linux/fs.h>
  31#include <linux/module.h>
  32#include <linux/moduleparam.h>
  33#include <linux/mount.h>
  34#include <linux/pseudo_fs.h>
  35#include <linux/slab.h>
  36#include <linux/srcu.h>
  37
  38#include <drm/drm_accel.h>
  39#include <drm/drm_cache.h>
  40#include <drm/drm_client.h>
  41#include <drm/drm_color_mgmt.h>
  42#include <drm/drm_drv.h>
  43#include <drm/drm_file.h>
  44#include <drm/drm_managed.h>
  45#include <drm/drm_mode_object.h>
  46#include <drm/drm_print.h>
  47#include <drm/drm_privacy_screen_machine.h>
  48
  49#include "drm_crtc_internal.h"
  50#include "drm_internal.h"
  51#include "drm_legacy.h"
  52
  53MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
  54MODULE_DESCRIPTION("DRM shared core routines");
  55MODULE_LICENSE("GPL and additional rights");
  56
  57static DEFINE_SPINLOCK(drm_minor_lock);
  58static struct idr drm_minors_idr;
  59
  60/*
  61 * If the drm core fails to init for whatever reason,
  62 * we should prevent any drivers from registering with it.
  63 * It's best to check this at drm_dev_init(), as some drivers
  64 * prefer to embed struct drm_device into their own device
  65 * structure and call drm_dev_init() themselves.
  66 */
  67static bool drm_core_init_complete;
  68
  69static struct dentry *drm_debugfs_root;
  70
  71DEFINE_STATIC_SRCU(drm_unplug_srcu);
  72
  73/*
  74 * DRM Minors
  75 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
  76 * of them is represented by a drm_minor object. Depending on the capabilities
  77 * of the device-driver, different interfaces are registered.
  78 *
  79 * Minors can be accessed via dev->$minor_name. This pointer is either
  80 * NULL or a valid drm_minor pointer and stays valid as long as the device is
  81 * valid. This means, DRM minors have the same life-time as the underlying
  82 * device. However, this doesn't mean that the minor is active. Minors are
  83 * registered and unregistered dynamically according to device-state.
  84 */
  85
  86static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
  87					     unsigned int type)
  88{
  89	switch (type) {
  90	case DRM_MINOR_PRIMARY:
  91		return &dev->primary;
  92	case DRM_MINOR_RENDER:
  93		return &dev->render;
  94	case DRM_MINOR_ACCEL:
  95		return &dev->accel;
  96	default:
  97		BUG();
  98	}
  99}
 100
 101static void drm_minor_alloc_release(struct drm_device *dev, void *data)
 102{
 103	struct drm_minor *minor = data;
 104	unsigned long flags;
 105
 106	WARN_ON(dev != minor->dev);
 107
 108	put_device(minor->kdev);
 109
 110	if (minor->type == DRM_MINOR_ACCEL) {
 111		accel_minor_remove(minor->index);
 112	} else {
 113		spin_lock_irqsave(&drm_minor_lock, flags);
 114		idr_remove(&drm_minors_idr, minor->index);
 115		spin_unlock_irqrestore(&drm_minor_lock, flags);
 116	}
 117}
 118
 119static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 120{
 121	struct drm_minor *minor;
 122	unsigned long flags;
 123	int r;
 124
 125	minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
 126	if (!minor)
 127		return -ENOMEM;
 128
 129	minor->type = type;
 130	minor->dev = dev;
 131
 132	idr_preload(GFP_KERNEL);
 133	if (type == DRM_MINOR_ACCEL) {
 134		r = accel_minor_alloc();
 135	} else {
 136		spin_lock_irqsave(&drm_minor_lock, flags);
 137		r = idr_alloc(&drm_minors_idr,
 138			NULL,
 139			64 * type,
 140			64 * (type + 1),
 141			GFP_NOWAIT);
 142		spin_unlock_irqrestore(&drm_minor_lock, flags);
 143	}
 144	idr_preload_end();
 145
 146	if (r < 0)
 147		return r;
 148
 149	minor->index = r;
 150
 151	r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
 152	if (r)
 153		return r;
 154
 155	minor->kdev = drm_sysfs_minor_alloc(minor);
 156	if (IS_ERR(minor->kdev))
 157		return PTR_ERR(minor->kdev);
 158
 159	*drm_minor_get_slot(dev, type) = minor;
 160	return 0;
 161}
 162
 163static int drm_minor_register(struct drm_device *dev, unsigned int type)
 164{
 165	struct drm_minor *minor;
 166	unsigned long flags;
 167	int ret;
 168
 169	DRM_DEBUG("\n");
 170
 171	minor = *drm_minor_get_slot(dev, type);
 172	if (!minor)
 173		return 0;
 174
 175	if (minor->type == DRM_MINOR_ACCEL) {
 176		accel_debugfs_init(minor, minor->index);
 177	} else {
 178		ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 179		if (ret) {
 180			DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 181			goto err_debugfs;
 182		}
 183	}
 184
 185	ret = device_add(minor->kdev);
 186	if (ret)
 187		goto err_debugfs;
 188
 189	/* replace NULL with @minor so lookups will succeed from now on */
 190	if (minor->type == DRM_MINOR_ACCEL) {
 191		accel_minor_replace(minor, minor->index);
 192	} else {
 193		spin_lock_irqsave(&drm_minor_lock, flags);
 194		idr_replace(&drm_minors_idr, minor, minor->index);
 195		spin_unlock_irqrestore(&drm_minor_lock, flags);
 196	}
 197
 198	DRM_DEBUG("new minor registered %d\n", minor->index);
 199	return 0;
 200
 201err_debugfs:
 202	drm_debugfs_cleanup(minor);
 203	return ret;
 204}
 205
 206static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 207{
 208	struct drm_minor *minor;
 209	unsigned long flags;
 210
 211	minor = *drm_minor_get_slot(dev, type);
 212	if (!minor || !device_is_registered(minor->kdev))
 213		return;
 214
 215	/* replace @minor with NULL so lookups will fail from now on */
 216	if (minor->type == DRM_MINOR_ACCEL) {
 217		accel_minor_replace(NULL, minor->index);
 218	} else {
 219		spin_lock_irqsave(&drm_minor_lock, flags);
 220		idr_replace(&drm_minors_idr, NULL, minor->index);
 221		spin_unlock_irqrestore(&drm_minor_lock, flags);
 222	}
 223
 224	device_del(minor->kdev);
 225	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 226	drm_debugfs_cleanup(minor);
 227}
 228
 229/*
 230 * Looks up the given minor-ID and returns the respective DRM-minor object. The
 231 * refence-count of the underlying device is increased so you must release this
 232 * object with drm_minor_release().
 233 *
 234 * As long as you hold this minor, it is guaranteed that the object and the
 235 * minor->dev pointer will stay valid! However, the device may get unplugged and
 236 * unregistered while you hold the minor.
 237 */
 238struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 239{
 240	struct drm_minor *minor;
 241	unsigned long flags;
 242
 243	spin_lock_irqsave(&drm_minor_lock, flags);
 244	minor = idr_find(&drm_minors_idr, minor_id);
 245	if (minor)
 246		drm_dev_get(minor->dev);
 247	spin_unlock_irqrestore(&drm_minor_lock, flags);
 248
 249	if (!minor) {
 250		return ERR_PTR(-ENODEV);
 251	} else if (drm_dev_is_unplugged(minor->dev)) {
 252		drm_dev_put(minor->dev);
 253		return ERR_PTR(-ENODEV);
 254	}
 255
 256	return minor;
 257}
 258
 259void drm_minor_release(struct drm_minor *minor)
 260{
 261	drm_dev_put(minor->dev);
 262}
 263
 264/**
 265 * DOC: driver instance overview
 266 *
 267 * A device instance for a drm driver is represented by &struct drm_device. This
 268 * is allocated and initialized with devm_drm_dev_alloc(), usually from
 269 * bus-specific ->probe() callbacks implemented by the driver. The driver then
 270 * needs to initialize all the various subsystems for the drm device like memory
 271 * management, vblank handling, modesetting support and initial output
 272 * configuration plus obviously initialize all the corresponding hardware bits.
 273 * Finally when everything is up and running and ready for userspace the device
 274 * instance can be published using drm_dev_register().
 275 *
 276 * There is also deprecated support for initializing device instances using
 277 * bus-specific helpers and the &drm_driver.load callback. But due to
 278 * backwards-compatibility needs the device instance have to be published too
 279 * early, which requires unpretty global locking to make safe and is therefore
 280 * only support for existing drivers not yet converted to the new scheme.
 281 *
 282 * When cleaning up a device instance everything needs to be done in reverse:
 283 * First unpublish the device instance with drm_dev_unregister(). Then clean up
 284 * any other resources allocated at device initialization and drop the driver's
 285 * reference to &drm_device using drm_dev_put().
 286 *
 287 * Note that any allocation or resource which is visible to userspace must be
 288 * released only when the final drm_dev_put() is called, and not when the
 289 * driver is unbound from the underlying physical struct &device. Best to use
 290 * &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
 291 * related functions.
 292 *
 293 * devres managed resources like devm_kmalloc() can only be used for resources
 294 * directly related to the underlying hardware device, and only used in code
 295 * paths fully protected by drm_dev_enter() and drm_dev_exit().
 296 *
 297 * Display driver example
 298 * ~~~~~~~~~~~~~~~~~~~~~~
 299 *
 300 * The following example shows a typical structure of a DRM display driver.
 301 * The example focus on the probe() function and the other functions that is
 302 * almost always present and serves as a demonstration of devm_drm_dev_alloc().
 303 *
 304 * .. code-block:: c
 305 *
 306 *	struct driver_device {
 307 *		struct drm_device drm;
 308 *		void *userspace_facing;
 309 *		struct clk *pclk;
 310 *	};
 311 *
 312 *	static const struct drm_driver driver_drm_driver = {
 313 *		[...]
 314 *	};
 315 *
 316 *	static int driver_probe(struct platform_device *pdev)
 317 *	{
 318 *		struct driver_device *priv;
 319 *		struct drm_device *drm;
 320 *		int ret;
 321 *
 322 *		priv = devm_drm_dev_alloc(&pdev->dev, &driver_drm_driver,
 323 *					  struct driver_device, drm);
 324 *		if (IS_ERR(priv))
 325 *			return PTR_ERR(priv);
 326 *		drm = &priv->drm;
 327 *
 328 *		ret = drmm_mode_config_init(drm);
 329 *		if (ret)
 330 *			return ret;
 331 *
 332 *		priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
 333 *		if (!priv->userspace_facing)
 334 *			return -ENOMEM;
 335 *
 336 *		priv->pclk = devm_clk_get(dev, "PCLK");
 337 *		if (IS_ERR(priv->pclk))
 338 *			return PTR_ERR(priv->pclk);
 339 *
 340 *		// Further setup, display pipeline etc
 341 *
 342 *		platform_set_drvdata(pdev, drm);
 343 *
 344 *		drm_mode_config_reset(drm);
 345 *
 346 *		ret = drm_dev_register(drm);
 347 *		if (ret)
 348 *			return ret;
 349 *
 350 *		drm_fbdev_generic_setup(drm, 32);
 351 *
 352 *		return 0;
 353 *	}
 354 *
 355 *	// This function is called before the devm_ resources are released
 356 *	static int driver_remove(struct platform_device *pdev)
 357 *	{
 358 *		struct drm_device *drm = platform_get_drvdata(pdev);
 359 *
 360 *		drm_dev_unregister(drm);
 361 *		drm_atomic_helper_shutdown(drm)
 362 *
 363 *		return 0;
 364 *	}
 365 *
 366 *	// This function is called on kernel restart and shutdown
 367 *	static void driver_shutdown(struct platform_device *pdev)
 368 *	{
 369 *		drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
 370 *	}
 371 *
 372 *	static int __maybe_unused driver_pm_suspend(struct device *dev)
 373 *	{
 374 *		return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
 375 *	}
 376 *
 377 *	static int __maybe_unused driver_pm_resume(struct device *dev)
 378 *	{
 379 *		drm_mode_config_helper_resume(dev_get_drvdata(dev));
 380 *
 381 *		return 0;
 382 *	}
 383 *
 384 *	static const struct dev_pm_ops driver_pm_ops = {
 385 *		SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
 386 *	};
 387 *
 388 *	static struct platform_driver driver_driver = {
 389 *		.driver = {
 390 *			[...]
 391 *			.pm = &driver_pm_ops,
 392 *		},
 393 *		.probe = driver_probe,
 394 *		.remove = driver_remove,
 395 *		.shutdown = driver_shutdown,
 396 *	};
 397 *	module_platform_driver(driver_driver);
 398 *
 399 * Drivers that want to support device unplugging (USB, DT overlay unload) should
 400 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
 401 * regions that is accessing device resources to prevent use after they're
 402 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
 403 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
 404 * drm_atomic_helper_shutdown() is called. This means that if the disable code
 405 * paths are protected, they will not run on regular driver module unload,
 406 * possibly leaving the hardware enabled.
 407 */
 408
 409/**
 410 * drm_put_dev - Unregister and release a DRM device
 411 * @dev: DRM device
 412 *
 413 * Called at module unload time or when a PCI device is unplugged.
 414 *
 415 * Cleans up all DRM device, calling drm_lastclose().
 416 *
 417 * Note: Use of this function is deprecated. It will eventually go away
 418 * completely.  Please use drm_dev_unregister() and drm_dev_put() explicitly
 419 * instead to make sure that the device isn't userspace accessible any more
 420 * while teardown is in progress, ensuring that userspace can't access an
 421 * inconsistent state.
 422 */
 423void drm_put_dev(struct drm_device *dev)
 424{
 425	DRM_DEBUG("\n");
 426
 427	if (!dev) {
 428		DRM_ERROR("cleanup called no dev\n");
 429		return;
 430	}
 431
 432	drm_dev_unregister(dev);
 433	drm_dev_put(dev);
 434}
 435EXPORT_SYMBOL(drm_put_dev);
 436
 437/**
 438 * drm_dev_enter - Enter device critical section
 439 * @dev: DRM device
 440 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
 441 *
 442 * This function marks and protects the beginning of a section that should not
 443 * be entered after the device has been unplugged. The section end is marked
 444 * with drm_dev_exit(). Calls to this function can be nested.
 445 *
 446 * Returns:
 447 * True if it is OK to enter the section, false otherwise.
 448 */
 449bool drm_dev_enter(struct drm_device *dev, int *idx)
 450{
 451	*idx = srcu_read_lock(&drm_unplug_srcu);
 452
 453	if (dev->unplugged) {
 454		srcu_read_unlock(&drm_unplug_srcu, *idx);
 455		return false;
 456	}
 457
 458	return true;
 459}
 460EXPORT_SYMBOL(drm_dev_enter);
 461
 462/**
 463 * drm_dev_exit - Exit device critical section
 464 * @idx: index returned from drm_dev_enter()
 465 *
 466 * This function marks the end of a section that should not be entered after
 467 * the device has been unplugged.
 468 */
 469void drm_dev_exit(int idx)
 470{
 471	srcu_read_unlock(&drm_unplug_srcu, idx);
 472}
 473EXPORT_SYMBOL(drm_dev_exit);
 474
 475/**
 476 * drm_dev_unplug - unplug a DRM device
 477 * @dev: DRM device
 478 *
 479 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
 480 * userspace operations. Entry-points can use drm_dev_enter() and
 481 * drm_dev_exit() to protect device resources in a race free manner. This
 482 * essentially unregisters the device like drm_dev_unregister(), but can be
 483 * called while there are still open users of @dev.
 484 */
 485void drm_dev_unplug(struct drm_device *dev)
 486{
 487	/*
 488	 * After synchronizing any critical read section is guaranteed to see
 489	 * the new value of ->unplugged, and any critical section which might
 490	 * still have seen the old value of ->unplugged is guaranteed to have
 491	 * finished.
 492	 */
 493	dev->unplugged = true;
 494	synchronize_srcu(&drm_unplug_srcu);
 495
 496	drm_dev_unregister(dev);
 497
 498	/* Clear all CPU mappings pointing to this device */
 499	unmap_mapping_range(dev->anon_inode->i_mapping, 0, 0, 1);
 500}
 501EXPORT_SYMBOL(drm_dev_unplug);
 502
 503/*
 504 * DRM internal mount
 505 * We want to be able to allocate our own "struct address_space" to control
 506 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 507 * stand-alone address_space objects, so we need an underlying inode. As there
 508 * is no way to allocate an independent inode easily, we need a fake internal
 509 * VFS mount-point.
 510 *
 511 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 512 * frees it again. You are allowed to use iget() and iput() to get references to
 513 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 514 * drm_fs_inode_free() call (which does not have to be the last iput()).
 515 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 516 * between multiple inode-users. You could, technically, call
 517 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 518 * iput(), but this way you'd end up with a new vfsmount for each inode.
 519 */
 520
 521static int drm_fs_cnt;
 522static struct vfsmount *drm_fs_mnt;
 523
 524static int drm_fs_init_fs_context(struct fs_context *fc)
 525{
 526	return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
 527}
 528
 529static struct file_system_type drm_fs_type = {
 530	.name		= "drm",
 531	.owner		= THIS_MODULE,
 532	.init_fs_context = drm_fs_init_fs_context,
 533	.kill_sb	= kill_anon_super,
 534};
 535
 536static struct inode *drm_fs_inode_new(void)
 537{
 538	struct inode *inode;
 539	int r;
 540
 541	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 542	if (r < 0) {
 543		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 544		return ERR_PTR(r);
 545	}
 546
 547	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 548	if (IS_ERR(inode))
 549		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 550
 551	return inode;
 552}
 553
 554static void drm_fs_inode_free(struct inode *inode)
 555{
 556	if (inode) {
 557		iput(inode);
 558		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 559	}
 560}
 561
 562/**
 563 * DOC: component helper usage recommendations
 564 *
 565 * DRM drivers that drive hardware where a logical device consists of a pile of
 566 * independent hardware blocks are recommended to use the :ref:`component helper
 567 * library<component>`. For consistency and better options for code reuse the
 568 * following guidelines apply:
 569 *
 570 *  - The entire device initialization procedure should be run from the
 571 *    &component_master_ops.master_bind callback, starting with
 572 *    devm_drm_dev_alloc(), then binding all components with
 573 *    component_bind_all() and finishing with drm_dev_register().
 574 *
 575 *  - The opaque pointer passed to all components through component_bind_all()
 576 *    should point at &struct drm_device of the device instance, not some driver
 577 *    specific private structure.
 578 *
 579 *  - The component helper fills the niche where further standardization of
 580 *    interfaces is not practical. When there already is, or will be, a
 581 *    standardized interface like &drm_bridge or &drm_panel, providing its own
 582 *    functions to find such components at driver load time, like
 583 *    drm_of_find_panel_or_bridge(), then the component helper should not be
 584 *    used.
 585 */
 586
 587static void drm_dev_init_release(struct drm_device *dev, void *res)
 588{
 589	drm_legacy_ctxbitmap_cleanup(dev);
 590	drm_legacy_remove_map_hash(dev);
 591	drm_fs_inode_free(dev->anon_inode);
 592
 593	put_device(dev->dev);
 594	/* Prevent use-after-free in drm_managed_release when debugging is
 595	 * enabled. Slightly awkward, but can't really be helped. */
 596	dev->dev = NULL;
 597	mutex_destroy(&dev->master_mutex);
 598	mutex_destroy(&dev->clientlist_mutex);
 599	mutex_destroy(&dev->filelist_mutex);
 600	mutex_destroy(&dev->struct_mutex);
 601	drm_legacy_destroy_members(dev);
 602}
 603
 604static int drm_dev_init(struct drm_device *dev,
 605			const struct drm_driver *driver,
 606			struct device *parent)
 607{
 608	struct inode *inode;
 609	int ret;
 610
 611	if (!drm_core_init_complete) {
 612		DRM_ERROR("DRM core is not initialized\n");
 613		return -ENODEV;
 614	}
 615
 616	if (WARN_ON(!parent))
 617		return -EINVAL;
 618
 619	kref_init(&dev->ref);
 620	dev->dev = get_device(parent);
 621	dev->driver = driver;
 622
 623	INIT_LIST_HEAD(&dev->managed.resources);
 624	spin_lock_init(&dev->managed.lock);
 625
 626	/* no per-device feature limits by default */
 627	dev->driver_features = ~0u;
 628
 629	if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL) &&
 630				(drm_core_check_feature(dev, DRIVER_RENDER) ||
 631				drm_core_check_feature(dev, DRIVER_MODESET))) {
 632		DRM_ERROR("DRM driver can't be both a compute acceleration and graphics driver\n");
 633		return -EINVAL;
 634	}
 635
 636	drm_legacy_init_members(dev);
 637	INIT_LIST_HEAD(&dev->filelist);
 638	INIT_LIST_HEAD(&dev->filelist_internal);
 639	INIT_LIST_HEAD(&dev->clientlist);
 640	INIT_LIST_HEAD(&dev->vblank_event_list);
 641
 642	spin_lock_init(&dev->event_lock);
 643	mutex_init(&dev->struct_mutex);
 644	mutex_init(&dev->filelist_mutex);
 645	mutex_init(&dev->clientlist_mutex);
 646	mutex_init(&dev->master_mutex);
 647
 648	ret = drmm_add_action_or_reset(dev, drm_dev_init_release, NULL);
 649	if (ret)
 650		return ret;
 651
 652	inode = drm_fs_inode_new();
 653	if (IS_ERR(inode)) {
 654		ret = PTR_ERR(inode);
 655		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 656		goto err;
 657	}
 658
 659	dev->anon_inode = inode;
 660
 661	if (drm_core_check_feature(dev, DRIVER_COMPUTE_ACCEL)) {
 662		ret = drm_minor_alloc(dev, DRM_MINOR_ACCEL);
 663		if (ret)
 664			goto err;
 665	} else {
 666		if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 667			ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 668			if (ret)
 669				goto err;
 670		}
 671
 672		ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
 673		if (ret)
 674			goto err;
 675	}
 676
 
 
 
 
 677	ret = drm_legacy_create_map_hash(dev);
 678	if (ret)
 679		goto err;
 680
 681	drm_legacy_ctxbitmap_init(dev);
 682
 683	if (drm_core_check_feature(dev, DRIVER_GEM)) {
 684		ret = drm_gem_init(dev);
 685		if (ret) {
 686			DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
 687			goto err;
 688		}
 689	}
 690
 691	ret = drm_dev_set_unique(dev, dev_name(parent));
 692	if (ret)
 693		goto err;
 694
 695	return 0;
 696
 697err:
 698	drm_managed_release(dev);
 699
 700	return ret;
 701}
 702
 703static void devm_drm_dev_init_release(void *data)
 704{
 705	drm_dev_put(data);
 706}
 707
 708static int devm_drm_dev_init(struct device *parent,
 709			     struct drm_device *dev,
 710			     const struct drm_driver *driver)
 711{
 712	int ret;
 713
 714	ret = drm_dev_init(dev, driver, parent);
 715	if (ret)
 716		return ret;
 717
 718	return devm_add_action_or_reset(parent,
 719					devm_drm_dev_init_release, dev);
 720}
 721
 722void *__devm_drm_dev_alloc(struct device *parent,
 723			   const struct drm_driver *driver,
 724			   size_t size, size_t offset)
 725{
 726	void *container;
 727	struct drm_device *drm;
 728	int ret;
 729
 730	container = kzalloc(size, GFP_KERNEL);
 731	if (!container)
 732		return ERR_PTR(-ENOMEM);
 733
 734	drm = container + offset;
 735	ret = devm_drm_dev_init(parent, drm, driver);
 736	if (ret) {
 737		kfree(container);
 738		return ERR_PTR(ret);
 739	}
 740	drmm_add_final_kfree(drm, container);
 741
 742	return container;
 743}
 744EXPORT_SYMBOL(__devm_drm_dev_alloc);
 745
 746/**
 747 * drm_dev_alloc - Allocate new DRM device
 748 * @driver: DRM driver to allocate device for
 749 * @parent: Parent device object
 750 *
 751 * This is the deprecated version of devm_drm_dev_alloc(), which does not support
 752 * subclassing through embedding the struct &drm_device in a driver private
 753 * structure, and which does not support automatic cleanup through devres.
 754 *
 755 * RETURNS:
 756 * Pointer to new DRM device, or ERR_PTR on failure.
 757 */
 758struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
 759				 struct device *parent)
 760{
 761	struct drm_device *dev;
 762	int ret;
 763
 764	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 765	if (!dev)
 766		return ERR_PTR(-ENOMEM);
 767
 768	ret = drm_dev_init(dev, driver, parent);
 769	if (ret) {
 770		kfree(dev);
 771		return ERR_PTR(ret);
 772	}
 773
 774	drmm_add_final_kfree(dev, dev);
 775
 776	return dev;
 777}
 778EXPORT_SYMBOL(drm_dev_alloc);
 779
 780static void drm_dev_release(struct kref *ref)
 781{
 782	struct drm_device *dev = container_of(ref, struct drm_device, ref);
 783
 784	if (dev->driver->release)
 785		dev->driver->release(dev);
 786
 787	drm_managed_release(dev);
 788
 789	kfree(dev->managed.final_kfree);
 790}
 791
 792/**
 793 * drm_dev_get - Take reference of a DRM device
 794 * @dev: device to take reference of or NULL
 795 *
 796 * This increases the ref-count of @dev by one. You *must* already own a
 797 * reference when calling this. Use drm_dev_put() to drop this reference
 798 * again.
 799 *
 800 * This function never fails. However, this function does not provide *any*
 801 * guarantee whether the device is alive or running. It only provides a
 802 * reference to the object and the memory associated with it.
 803 */
 804void drm_dev_get(struct drm_device *dev)
 805{
 806	if (dev)
 807		kref_get(&dev->ref);
 808}
 809EXPORT_SYMBOL(drm_dev_get);
 810
 811/**
 812 * drm_dev_put - Drop reference of a DRM device
 813 * @dev: device to drop reference of or NULL
 814 *
 815 * This decreases the ref-count of @dev by one. The device is destroyed if the
 816 * ref-count drops to zero.
 817 */
 818void drm_dev_put(struct drm_device *dev)
 819{
 820	if (dev)
 821		kref_put(&dev->ref, drm_dev_release);
 822}
 823EXPORT_SYMBOL(drm_dev_put);
 824
 825static int create_compat_control_link(struct drm_device *dev)
 826{
 827	struct drm_minor *minor;
 828	char *name;
 829	int ret;
 830
 831	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 832		return 0;
 833
 834	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
 835	if (!minor)
 836		return 0;
 837
 838	/*
 839	 * Some existing userspace out there uses the existing of the controlD*
 840	 * sysfs files to figure out whether it's a modeset driver. It only does
 841	 * readdir, hence a symlink is sufficient (and the least confusing
 842	 * option). Otherwise controlD* is entirely unused.
 843	 *
 844	 * Old controlD chardev have been allocated in the range
 845	 * 64-127.
 846	 */
 847	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
 848	if (!name)
 849		return -ENOMEM;
 850
 851	ret = sysfs_create_link(minor->kdev->kobj.parent,
 852				&minor->kdev->kobj,
 853				name);
 854
 855	kfree(name);
 856
 857	return ret;
 858}
 859
 860static void remove_compat_control_link(struct drm_device *dev)
 861{
 862	struct drm_minor *minor;
 863	char *name;
 864
 865	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 866		return;
 867
 868	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
 869	if (!minor)
 870		return;
 871
 872	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
 873	if (!name)
 874		return;
 875
 876	sysfs_remove_link(minor->kdev->kobj.parent, name);
 877
 878	kfree(name);
 879}
 880
 881/**
 882 * drm_dev_register - Register DRM device
 883 * @dev: Device to register
 884 * @flags: Flags passed to the driver's .load() function
 885 *
 886 * Register the DRM device @dev with the system, advertise device to user-space
 887 * and start normal device operation. @dev must be initialized via drm_dev_init()
 888 * previously.
 889 *
 890 * Never call this twice on any device!
 891 *
 892 * NOTE: To ensure backward compatibility with existing drivers method this
 893 * function calls the &drm_driver.load method after registering the device
 894 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
 895 * therefore deprecated, drivers must perform all initialization before calling
 896 * drm_dev_register().
 897 *
 898 * RETURNS:
 899 * 0 on success, negative error code on failure.
 900 */
 901int drm_dev_register(struct drm_device *dev, unsigned long flags)
 902{
 903	const struct drm_driver *driver = dev->driver;
 904	int ret;
 905
 906	if (!driver->load)
 907		drm_mode_config_validate(dev);
 908
 909	WARN_ON(!dev->managed.final_kfree);
 910
 911	if (drm_dev_needs_global_mutex(dev))
 912		mutex_lock(&drm_global_mutex);
 913
 914	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 915	if (ret)
 916		goto err_minors;
 917
 918	ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
 919	if (ret)
 920		goto err_minors;
 921
 922	ret = drm_minor_register(dev, DRM_MINOR_ACCEL);
 923	if (ret)
 924		goto err_minors;
 925
 926	ret = create_compat_control_link(dev);
 927	if (ret)
 928		goto err_minors;
 929
 930	dev->registered = true;
 931
 932	if (dev->driver->load) {
 933		ret = dev->driver->load(dev, flags);
 934		if (ret)
 935			goto err_minors;
 936	}
 937
 938	if (drm_core_check_feature(dev, DRIVER_MODESET))
 939		drm_modeset_register_all(dev);
 940
 941	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
 942		 driver->name, driver->major, driver->minor,
 943		 driver->patchlevel, driver->date,
 944		 dev->dev ? dev_name(dev->dev) : "virtual device",
 945		 dev->primary ? dev->primary->index : dev->accel->index);
 946
 947	goto out_unlock;
 948
 949err_minors:
 950	remove_compat_control_link(dev);
 951	drm_minor_unregister(dev, DRM_MINOR_ACCEL);
 952	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
 953	drm_minor_unregister(dev, DRM_MINOR_RENDER);
 954out_unlock:
 955	if (drm_dev_needs_global_mutex(dev))
 956		mutex_unlock(&drm_global_mutex);
 957	return ret;
 958}
 959EXPORT_SYMBOL(drm_dev_register);
 960
 961/**
 962 * drm_dev_unregister - Unregister DRM device
 963 * @dev: Device to unregister
 964 *
 965 * Unregister the DRM device from the system. This does the reverse of
 966 * drm_dev_register() but does not deallocate the device. The caller must call
 967 * drm_dev_put() to drop their final reference.
 968 *
 969 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
 970 * which can be called while there are still open users of @dev.
 971 *
 972 * This should be called first in the device teardown code to make sure
 973 * userspace can't access the device instance any more.
 974 */
 975void drm_dev_unregister(struct drm_device *dev)
 976{
 977	if (drm_core_check_feature(dev, DRIVER_LEGACY))
 978		drm_lastclose(dev);
 979
 980	dev->registered = false;
 981
 982	drm_client_dev_unregister(dev);
 983
 984	if (drm_core_check_feature(dev, DRIVER_MODESET))
 985		drm_modeset_unregister_all(dev);
 986
 987	if (dev->driver->unload)
 988		dev->driver->unload(dev);
 989
 990	drm_legacy_pci_agp_destroy(dev);
 991	drm_legacy_rmmaps(dev);
 992
 993	remove_compat_control_link(dev);
 994	drm_minor_unregister(dev, DRM_MINOR_ACCEL);
 995	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
 996	drm_minor_unregister(dev, DRM_MINOR_RENDER);
 997}
 998EXPORT_SYMBOL(drm_dev_unregister);
 999
1000/**
1001 * drm_dev_set_unique - Set the unique name of a DRM device
1002 * @dev: device of which to set the unique name
1003 * @name: unique name
1004 *
1005 * Sets the unique name of a DRM device using the specified string. This is
1006 * already done by drm_dev_init(), drivers should only override the default
1007 * unique name for backwards compatibility reasons.
1008 *
1009 * Return: 0 on success or a negative error code on failure.
1010 */
1011int drm_dev_set_unique(struct drm_device *dev, const char *name)
1012{
1013	drmm_kfree(dev, dev->unique);
1014	dev->unique = drmm_kstrdup(dev, name, GFP_KERNEL);
1015
1016	return dev->unique ? 0 : -ENOMEM;
1017}
1018EXPORT_SYMBOL(drm_dev_set_unique);
1019
1020/*
1021 * DRM Core
1022 * The DRM core module initializes all global DRM objects and makes them
1023 * available to drivers. Once setup, drivers can probe their respective
1024 * devices.
1025 * Currently, core management includes:
1026 *  - The "DRM-Global" key/value database
1027 *  - Global ID management for connectors
1028 *  - DRM major number allocation
1029 *  - DRM minor management
1030 *  - DRM sysfs class
1031 *  - DRM debugfs root
1032 *
1033 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1034 * interface registered on a DRM device, you can request minor numbers from DRM
1035 * core. DRM core takes care of major-number management and char-dev
1036 * registration. A stub ->open() callback forwards any open() requests to the
1037 * registered minor.
1038 */
1039
1040static int drm_stub_open(struct inode *inode, struct file *filp)
1041{
1042	const struct file_operations *new_fops;
1043	struct drm_minor *minor;
1044	int err;
1045
1046	DRM_DEBUG("\n");
1047
1048	minor = drm_minor_acquire(iminor(inode));
1049	if (IS_ERR(minor))
1050		return PTR_ERR(minor);
1051
1052	new_fops = fops_get(minor->dev->driver->fops);
1053	if (!new_fops) {
1054		err = -ENODEV;
1055		goto out;
1056	}
1057
1058	replace_fops(filp, new_fops);
1059	if (filp->f_op->open)
1060		err = filp->f_op->open(inode, filp);
1061	else
1062		err = 0;
1063
1064out:
1065	drm_minor_release(minor);
1066
1067	return err;
1068}
1069
1070static const struct file_operations drm_stub_fops = {
1071	.owner = THIS_MODULE,
1072	.open = drm_stub_open,
1073	.llseek = noop_llseek,
1074};
1075
1076static void drm_core_exit(void)
1077{
1078	drm_privacy_screen_lookup_exit();
1079	accel_core_exit();
1080	unregister_chrdev(DRM_MAJOR, "drm");
1081	debugfs_remove(drm_debugfs_root);
1082	drm_sysfs_destroy();
1083	idr_destroy(&drm_minors_idr);
1084	drm_connector_ida_destroy();
1085}
1086
1087static int __init drm_core_init(void)
1088{
1089	int ret;
1090
1091	drm_connector_ida_init();
1092	idr_init(&drm_minors_idr);
1093	drm_memcpy_init_early();
1094
1095	ret = drm_sysfs_init();
1096	if (ret < 0) {
1097		DRM_ERROR("Cannot create DRM class: %d\n", ret);
1098		goto error;
1099	}
1100
1101	drm_debugfs_root = debugfs_create_dir("dri", NULL);
1102
1103	ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
1104	if (ret < 0)
1105		goto error;
1106
1107	ret = accel_core_init();
1108	if (ret < 0)
1109		goto error;
1110
1111	drm_privacy_screen_lookup_init();
1112
1113	drm_core_init_complete = true;
1114
1115	DRM_DEBUG("Initialized\n");
1116	return 0;
1117
1118error:
1119	drm_core_exit();
1120	return ret;
1121}
1122
1123module_init(drm_core_init);
1124module_exit(drm_core_exit);