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_client.h>
  39#include <drm/drm_color_mgmt.h>
  40#include <drm/drm_drv.h>
  41#include <drm/drm_file.h>
  42#include <drm/drm_managed.h>
  43#include <drm/drm_mode_object.h>
  44#include <drm/drm_print.h>
  45
  46#include "drm_crtc_internal.h"
  47#include "drm_internal.h"
  48#include "drm_legacy.h"
  49
  50MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
  51MODULE_DESCRIPTION("DRM shared core routines");
  52MODULE_LICENSE("GPL and additional rights");
  53
  54static DEFINE_SPINLOCK(drm_minor_lock);
  55static struct idr drm_minors_idr;
  56
  57/*
  58 * If the drm core fails to init for whatever reason,
  59 * we should prevent any drivers from registering with it.
  60 * It's best to check this at drm_dev_init(), as some drivers
  61 * prefer to embed struct drm_device into their own device
  62 * structure and call drm_dev_init() themselves.
  63 */
  64static bool drm_core_init_complete = false;
  65
  66static struct dentry *drm_debugfs_root;
  67
  68DEFINE_STATIC_SRCU(drm_unplug_srcu);
  69
  70/*
  71 * DRM Minors
  72 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
  73 * of them is represented by a drm_minor object. Depending on the capabilities
  74 * of the device-driver, different interfaces are registered.
  75 *
  76 * Minors can be accessed via dev->$minor_name. This pointer is either
  77 * NULL or a valid drm_minor pointer and stays valid as long as the device is
  78 * valid. This means, DRM minors have the same life-time as the underlying
  79 * device. However, this doesn't mean that the minor is active. Minors are
  80 * registered and unregistered dynamically according to device-state.
  81 */
  82
  83static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
  84					     unsigned int type)
  85{
  86	switch (type) {
  87	case DRM_MINOR_PRIMARY:
  88		return &dev->primary;
  89	case DRM_MINOR_RENDER:
  90		return &dev->render;
  91	default:
  92		BUG();
  93	}
  94}
  95
  96static void drm_minor_alloc_release(struct drm_device *dev, void *data)
  97{
  98	struct drm_minor *minor = data;
  99	unsigned long flags;
 100
 101	WARN_ON(dev != minor->dev);
 102
 103	put_device(minor->kdev);
 104
 105	spin_lock_irqsave(&drm_minor_lock, flags);
 106	idr_remove(&drm_minors_idr, minor->index);
 107	spin_unlock_irqrestore(&drm_minor_lock, flags);
 108}
 109
 110static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 111{
 112	struct drm_minor *minor;
 113	unsigned long flags;
 114	int r;
 115
 116	minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
 117	if (!minor)
 118		return -ENOMEM;
 119
 120	minor->type = type;
 121	minor->dev = dev;
 122
 123	idr_preload(GFP_KERNEL);
 124	spin_lock_irqsave(&drm_minor_lock, flags);
 125	r = idr_alloc(&drm_minors_idr,
 126		      NULL,
 127		      64 * type,
 128		      64 * (type + 1),
 129		      GFP_NOWAIT);
 130	spin_unlock_irqrestore(&drm_minor_lock, flags);
 131	idr_preload_end();
 132
 133	if (r < 0)
 134		return r;
 135
 136	minor->index = r;
 137
 138	r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
 139	if (r)
 140		return r;
 141
 142	minor->kdev = drm_sysfs_minor_alloc(minor);
 143	if (IS_ERR(minor->kdev))
 144		return PTR_ERR(minor->kdev);
 145
 146	*drm_minor_get_slot(dev, type) = minor;
 147	return 0;
 148}
 149
 150static int drm_minor_register(struct drm_device *dev, unsigned int type)
 151{
 152	struct drm_minor *minor;
 153	unsigned long flags;
 154	int ret;
 155
 156	DRM_DEBUG("\n");
 157
 158	minor = *drm_minor_get_slot(dev, type);
 159	if (!minor)
 160		return 0;
 161
 162	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
 163	if (ret) {
 164		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
 165		goto err_debugfs;
 166	}
 167
 168	ret = device_add(minor->kdev);
 169	if (ret)
 170		goto err_debugfs;
 171
 172	/* replace NULL with @minor so lookups will succeed from now on */
 173	spin_lock_irqsave(&drm_minor_lock, flags);
 174	idr_replace(&drm_minors_idr, minor, minor->index);
 175	spin_unlock_irqrestore(&drm_minor_lock, flags);
 176
 177	DRM_DEBUG("new minor registered %d\n", minor->index);
 178	return 0;
 179
 180err_debugfs:
 181	drm_debugfs_cleanup(minor);
 182	return ret;
 183}
 184
 185static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
 186{
 187	struct drm_minor *minor;
 188	unsigned long flags;
 189
 190	minor = *drm_minor_get_slot(dev, type);
 191	if (!minor || !device_is_registered(minor->kdev))
 192		return;
 193
 194	/* replace @minor with NULL so lookups will fail from now on */
 195	spin_lock_irqsave(&drm_minor_lock, flags);
 196	idr_replace(&drm_minors_idr, NULL, minor->index);
 197	spin_unlock_irqrestore(&drm_minor_lock, flags);
 198
 199	device_del(minor->kdev);
 200	dev_set_drvdata(minor->kdev, NULL); /* safety belt */
 201	drm_debugfs_cleanup(minor);
 202}
 203
 204/*
 205 * Looks up the given minor-ID and returns the respective DRM-minor object. The
 206 * refence-count of the underlying device is increased so you must release this
 207 * object with drm_minor_release().
 208 *
 209 * As long as you hold this minor, it is guaranteed that the object and the
 210 * minor->dev pointer will stay valid! However, the device may get unplugged and
 211 * unregistered while you hold the minor.
 212 */
 213struct drm_minor *drm_minor_acquire(unsigned int minor_id)
 214{
 215	struct drm_minor *minor;
 216	unsigned long flags;
 217
 218	spin_lock_irqsave(&drm_minor_lock, flags);
 219	minor = idr_find(&drm_minors_idr, minor_id);
 220	if (minor)
 221		drm_dev_get(minor->dev);
 222	spin_unlock_irqrestore(&drm_minor_lock, flags);
 223
 224	if (!minor) {
 225		return ERR_PTR(-ENODEV);
 226	} else if (drm_dev_is_unplugged(minor->dev)) {
 227		drm_dev_put(minor->dev);
 228		return ERR_PTR(-ENODEV);
 229	}
 230
 231	return minor;
 232}
 233
 234void drm_minor_release(struct drm_minor *minor)
 235{
 236	drm_dev_put(minor->dev);
 237}
 238
 239/**
 240 * DOC: driver instance overview
 241 *
 242 * A device instance for a drm driver is represented by &struct drm_device. This
 243 * is initialized with drm_dev_init(), usually from bus-specific ->probe()
 244 * callbacks implemented by the driver. The driver then needs to initialize all
 245 * the various subsystems for the drm device like memory management, vblank
 246 * handling, modesetting support and intial output configuration plus obviously
 247 * initialize all the corresponding hardware bits. Finally when everything is up
 248 * and running and ready for userspace the device instance can be published
 249 * using drm_dev_register().
 250 *
 251 * There is also deprecated support for initalizing device instances using
 252 * bus-specific helpers and the &drm_driver.load callback. But due to
 253 * backwards-compatibility needs the device instance have to be published too
 254 * early, which requires unpretty global locking to make safe and is therefore
 255 * only support for existing drivers not yet converted to the new scheme.
 256 *
 257 * When cleaning up a device instance everything needs to be done in reverse:
 258 * First unpublish the device instance with drm_dev_unregister(). Then clean up
 259 * any other resources allocated at device initialization and drop the driver's
 260 * reference to &drm_device using drm_dev_put().
 261 *
 262 * Note that any allocation or resource which is visible to userspace must be
 263 * released only when the final drm_dev_put() is called, and not when the
 264 * driver is unbound from the underlying physical struct &device. Best to use
 265 * &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
 266 * related functions.
 267 *
 268 * devres managed resources like devm_kmalloc() can only be used for resources
 269 * directly related to the underlying hardware device, and only used in code
 270 * paths fully protected by drm_dev_enter() and drm_dev_exit().
 271 *
 272 * Display driver example
 273 * ~~~~~~~~~~~~~~~~~~~~~~
 274 *
 275 * The following example shows a typical structure of a DRM display driver.
 276 * The example focus on the probe() function and the other functions that is
 277 * almost always present and serves as a demonstration of devm_drm_dev_init().
 278 *
 279 * .. code-block:: c
 280 *
 281 *	struct driver_device {
 282 *		struct drm_device drm;
 283 *		void *userspace_facing;
 284 *		struct clk *pclk;
 285 *	};
 286 *
 287 *	static struct drm_driver driver_drm_driver = {
 288 *		[...]
 289 *	};
 290 *
 291 *	static int driver_probe(struct platform_device *pdev)
 292 *	{
 293 *		struct driver_device *priv;
 294 *		struct drm_device *drm;
 295 *		int ret;
 296 *
 297 *		// devm_kzalloc() can't be used here because the drm_device '
 298 *		// lifetime can exceed the device lifetime if driver unbind
 299 *		// happens when userspace still has open file descriptors.
 300 *		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 301 *		if (!priv)
 302 *			return -ENOMEM;
 303 *
 304 *		drm = &priv->drm;
 305 *
 306 *		ret = devm_drm_dev_init(&pdev->dev, drm, &driver_drm_driver);
 307 *		if (ret) {
 308 *			kfree(priv);
 309 *			return ret;
 310 *		}
 311 *		drmm_add_final_kfree(drm, priv);
 312 *
 313 *		ret = drmm_mode_config_init(drm);
 314 *		if (ret)
 315 *			return ret;
 316 *
 317 *		priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
 318 *		if (!priv->userspace_facing)
 319 *			return -ENOMEM;
 320 *
 321 *		priv->pclk = devm_clk_get(dev, "PCLK");
 322 *		if (IS_ERR(priv->pclk))
 323 *			return PTR_ERR(priv->pclk);
 324 *
 325 *		// Further setup, display pipeline etc
 326 *
 327 *		platform_set_drvdata(pdev, drm);
 328 *
 329 *		drm_mode_config_reset(drm);
 330 *
 331 *		ret = drm_dev_register(drm);
 332 *		if (ret)
 333 *			return ret;
 334 *
 335 *		drm_fbdev_generic_setup(drm, 32);
 336 *
 337 *		return 0;
 338 *	}
 339 *
 340 *	// This function is called before the devm_ resources are released
 341 *	static int driver_remove(struct platform_device *pdev)
 342 *	{
 343 *		struct drm_device *drm = platform_get_drvdata(pdev);
 344 *
 345 *		drm_dev_unregister(drm);
 346 *		drm_atomic_helper_shutdown(drm)
 347 *
 348 *		return 0;
 349 *	}
 350 *
 351 *	// This function is called on kernel restart and shutdown
 352 *	static void driver_shutdown(struct platform_device *pdev)
 353 *	{
 354 *		drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
 355 *	}
 356 *
 357 *	static int __maybe_unused driver_pm_suspend(struct device *dev)
 358 *	{
 359 *		return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
 360 *	}
 361 *
 362 *	static int __maybe_unused driver_pm_resume(struct device *dev)
 363 *	{
 364 *		drm_mode_config_helper_resume(dev_get_drvdata(dev));
 365 *
 366 *		return 0;
 367 *	}
 368 *
 369 *	static const struct dev_pm_ops driver_pm_ops = {
 370 *		SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
 371 *	};
 372 *
 373 *	static struct platform_driver driver_driver = {
 374 *		.driver = {
 375 *			[...]
 376 *			.pm = &driver_pm_ops,
 377 *		},
 378 *		.probe = driver_probe,
 379 *		.remove = driver_remove,
 380 *		.shutdown = driver_shutdown,
 381 *	};
 382 *	module_platform_driver(driver_driver);
 383 *
 384 * Drivers that want to support device unplugging (USB, DT overlay unload) should
 385 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
 386 * regions that is accessing device resources to prevent use after they're
 387 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
 388 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
 389 * drm_atomic_helper_shutdown() is called. This means that if the disable code
 390 * paths are protected, they will not run on regular driver module unload,
 391 * possibily leaving the hardware enabled.
 392 */
 393
 394/**
 395 * drm_put_dev - Unregister and release a DRM device
 396 * @dev: DRM device
 397 *
 398 * Called at module unload time or when a PCI device is unplugged.
 399 *
 400 * Cleans up all DRM device, calling drm_lastclose().
 401 *
 402 * Note: Use of this function is deprecated. It will eventually go away
 403 * completely.  Please use drm_dev_unregister() and drm_dev_put() explicitly
 404 * instead to make sure that the device isn't userspace accessible any more
 405 * while teardown is in progress, ensuring that userspace can't access an
 406 * inconsistent state.
 407 */
 408void drm_put_dev(struct drm_device *dev)
 409{
 410	DRM_DEBUG("\n");
 411
 412	if (!dev) {
 413		DRM_ERROR("cleanup called no dev\n");
 414		return;
 415	}
 416
 417	drm_dev_unregister(dev);
 418	drm_dev_put(dev);
 419}
 420EXPORT_SYMBOL(drm_put_dev);
 421
 422/**
 423 * drm_dev_enter - Enter device critical section
 424 * @dev: DRM device
 425 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
 426 *
 427 * This function marks and protects the beginning of a section that should not
 428 * be entered after the device has been unplugged. The section end is marked
 429 * with drm_dev_exit(). Calls to this function can be nested.
 430 *
 431 * Returns:
 432 * True if it is OK to enter the section, false otherwise.
 433 */
 434bool drm_dev_enter(struct drm_device *dev, int *idx)
 435{
 436	*idx = srcu_read_lock(&drm_unplug_srcu);
 437
 438	if (dev->unplugged) {
 439		srcu_read_unlock(&drm_unplug_srcu, *idx);
 440		return false;
 441	}
 442
 443	return true;
 444}
 445EXPORT_SYMBOL(drm_dev_enter);
 446
 447/**
 448 * drm_dev_exit - Exit device critical section
 449 * @idx: index returned from drm_dev_enter()
 450 *
 451 * This function marks the end of a section that should not be entered after
 452 * the device has been unplugged.
 453 */
 454void drm_dev_exit(int idx)
 455{
 456	srcu_read_unlock(&drm_unplug_srcu, idx);
 457}
 458EXPORT_SYMBOL(drm_dev_exit);
 459
 460/**
 461 * drm_dev_unplug - unplug a DRM device
 462 * @dev: DRM device
 463 *
 464 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
 465 * userspace operations. Entry-points can use drm_dev_enter() and
 466 * drm_dev_exit() to protect device resources in a race free manner. This
 467 * essentially unregisters the device like drm_dev_unregister(), but can be
 468 * called while there are still open users of @dev.
 469 */
 470void drm_dev_unplug(struct drm_device *dev)
 471{
 472	/*
 473	 * After synchronizing any critical read section is guaranteed to see
 474	 * the new value of ->unplugged, and any critical section which might
 475	 * still have seen the old value of ->unplugged is guaranteed to have
 476	 * finished.
 477	 */
 478	dev->unplugged = true;
 479	synchronize_srcu(&drm_unplug_srcu);
 480
 481	drm_dev_unregister(dev);
 
 
 
 482}
 483EXPORT_SYMBOL(drm_dev_unplug);
 484
 485/*
 486 * DRM internal mount
 487 * We want to be able to allocate our own "struct address_space" to control
 488 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
 489 * stand-alone address_space objects, so we need an underlying inode. As there
 490 * is no way to allocate an independent inode easily, we need a fake internal
 491 * VFS mount-point.
 492 *
 493 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
 494 * frees it again. You are allowed to use iget() and iput() to get references to
 495 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
 496 * drm_fs_inode_free() call (which does not have to be the last iput()).
 497 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
 498 * between multiple inode-users. You could, technically, call
 499 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
 500 * iput(), but this way you'd end up with a new vfsmount for each inode.
 501 */
 502
 503static int drm_fs_cnt;
 504static struct vfsmount *drm_fs_mnt;
 505
 506static int drm_fs_init_fs_context(struct fs_context *fc)
 507{
 508	return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
 509}
 510
 511static struct file_system_type drm_fs_type = {
 512	.name		= "drm",
 513	.owner		= THIS_MODULE,
 514	.init_fs_context = drm_fs_init_fs_context,
 515	.kill_sb	= kill_anon_super,
 516};
 517
 518static struct inode *drm_fs_inode_new(void)
 519{
 520	struct inode *inode;
 521	int r;
 522
 523	r = simple_pin_fs(&drm_fs_type, &drm_fs_mnt, &drm_fs_cnt);
 524	if (r < 0) {
 525		DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
 526		return ERR_PTR(r);
 527	}
 528
 529	inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
 530	if (IS_ERR(inode))
 531		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 532
 533	return inode;
 534}
 535
 536static void drm_fs_inode_free(struct inode *inode)
 537{
 538	if (inode) {
 539		iput(inode);
 540		simple_release_fs(&drm_fs_mnt, &drm_fs_cnt);
 541	}
 542}
 543
 544/**
 545 * DOC: component helper usage recommendations
 546 *
 547 * DRM drivers that drive hardware where a logical device consists of a pile of
 548 * independent hardware blocks are recommended to use the :ref:`component helper
 549 * library<component>`. For consistency and better options for code reuse the
 550 * following guidelines apply:
 551 *
 552 *  - The entire device initialization procedure should be run from the
 553 *    &component_master_ops.master_bind callback, starting with drm_dev_init(),
 554 *    then binding all components with component_bind_all() and finishing with
 555 *    drm_dev_register().
 556 *
 557 *  - The opaque pointer passed to all components through component_bind_all()
 558 *    should point at &struct drm_device of the device instance, not some driver
 559 *    specific private structure.
 560 *
 561 *  - The component helper fills the niche where further standardization of
 562 *    interfaces is not practical. When there already is, or will be, a
 563 *    standardized interface like &drm_bridge or &drm_panel, providing its own
 564 *    functions to find such components at driver load time, like
 565 *    drm_of_find_panel_or_bridge(), then the component helper should not be
 566 *    used.
 567 */
 568
 569static void drm_dev_init_release(struct drm_device *dev, void *res)
 570{
 571	drm_legacy_ctxbitmap_cleanup(dev);
 572	drm_legacy_remove_map_hash(dev);
 573	drm_fs_inode_free(dev->anon_inode);
 574
 575	put_device(dev->dev);
 576	/* Prevent use-after-free in drm_managed_release when debugging is
 577	 * enabled. Slightly awkward, but can't really be helped. */
 578	dev->dev = NULL;
 579	mutex_destroy(&dev->master_mutex);
 580	mutex_destroy(&dev->clientlist_mutex);
 581	mutex_destroy(&dev->filelist_mutex);
 582	mutex_destroy(&dev->struct_mutex);
 583	drm_legacy_destroy_members(dev);
 584}
 585
 586/**
 587 * drm_dev_init - Initialise new DRM device
 588 * @dev: DRM device
 589 * @driver: DRM driver
 590 * @parent: Parent device object
 591 *
 592 * Initialize a new DRM device. No device registration is done.
 593 * Call drm_dev_register() to advertice the device to user space and register it
 594 * with other core subsystems. This should be done last in the device
 595 * initialization sequence to make sure userspace can't access an inconsistent
 596 * state.
 597 *
 598 * The initial ref-count of the object is 1. Use drm_dev_get() and
 599 * drm_dev_put() to take and drop further ref-counts.
 600 *
 601 * It is recommended that drivers embed &struct drm_device into their own device
 602 * structure.
 603 *
 604 * Drivers that do not want to allocate their own device struct
 605 * embedding &struct drm_device can call drm_dev_alloc() instead. For drivers
 606 * that do embed &struct drm_device it must be placed first in the overall
 607 * structure, and the overall structure must be allocated using kmalloc(): The
 608 * drm core's release function unconditionally calls kfree() on the @dev pointer
 609 * when the final reference is released. To override this behaviour, and so
 610 * allow embedding of the drm_device inside the driver's device struct at an
 611 * arbitrary offset, you must supply a &drm_driver.release callback and control
 612 * the finalization explicitly.
 613 *
 614 * Note that drivers must call drmm_add_final_kfree() after this function has
 615 * completed successfully.
 616 *
 617 * RETURNS:
 618 * 0 on success, or error code on failure.
 619 */
 620int drm_dev_init(struct drm_device *dev,
 621		 struct drm_driver *driver,
 622		 struct device *parent)
 623{
 624	int ret;
 625
 626	if (!drm_core_init_complete) {
 627		DRM_ERROR("DRM core is not initialized\n");
 628		return -ENODEV;
 629	}
 630
 631	if (WARN_ON(!parent))
 632		return -EINVAL;
 633
 634	kref_init(&dev->ref);
 635	dev->dev = get_device(parent);
 636	dev->driver = driver;
 637
 638	INIT_LIST_HEAD(&dev->managed.resources);
 639	spin_lock_init(&dev->managed.lock);
 640
 641	/* no per-device feature limits by default */
 642	dev->driver_features = ~0u;
 643
 644	drm_legacy_init_members(dev);
 645	INIT_LIST_HEAD(&dev->filelist);
 646	INIT_LIST_HEAD(&dev->filelist_internal);
 647	INIT_LIST_HEAD(&dev->clientlist);
 648	INIT_LIST_HEAD(&dev->vblank_event_list);
 649
 650	spin_lock_init(&dev->event_lock);
 651	mutex_init(&dev->struct_mutex);
 652	mutex_init(&dev->filelist_mutex);
 653	mutex_init(&dev->clientlist_mutex);
 654	mutex_init(&dev->master_mutex);
 655
 656	ret = drmm_add_action(dev, drm_dev_init_release, NULL);
 657	if (ret)
 658		return ret;
 659
 660	dev->anon_inode = drm_fs_inode_new();
 661	if (IS_ERR(dev->anon_inode)) {
 662		ret = PTR_ERR(dev->anon_inode);
 663		DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
 664		goto err;
 665	}
 666
 667	if (drm_core_check_feature(dev, DRIVER_RENDER)) {
 668		ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
 669		if (ret)
 670			goto err;
 671	}
 672
 673	ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
 674	if (ret)
 675		goto err;
 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}
 702EXPORT_SYMBOL(drm_dev_init);
 703
 704static void devm_drm_dev_init_release(void *data)
 705{
 706	drm_dev_put(data);
 707}
 708
 709/**
 710 * devm_drm_dev_init - Resource managed drm_dev_init()
 711 * @parent: Parent device object
 712 * @dev: DRM device
 713 * @driver: DRM driver
 714 *
 715 * Managed drm_dev_init(). The DRM device initialized with this function is
 716 * automatically put on driver detach using drm_dev_put().
 717 *
 718 * Note that drivers must call drmm_add_final_kfree() after this function has
 719 * completed successfully.
 720 *
 721 * RETURNS:
 722 * 0 on success, or error code on failure.
 723 */
 724int devm_drm_dev_init(struct device *parent,
 725		      struct drm_device *dev,
 726		      struct drm_driver *driver)
 727{
 728	int ret;
 729
 730	ret = drm_dev_init(dev, driver, parent);
 731	if (ret)
 732		return ret;
 733
 734	ret = devm_add_action(parent, devm_drm_dev_init_release, dev);
 735	if (ret)
 736		devm_drm_dev_init_release(dev);
 737
 738	return ret;
 739}
 740EXPORT_SYMBOL(devm_drm_dev_init);
 741
 742void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
 
 743			   size_t size, size_t offset)
 744{
 745	void *container;
 746	struct drm_device *drm;
 747	int ret;
 748
 749	container = kzalloc(size, GFP_KERNEL);
 750	if (!container)
 751		return ERR_PTR(-ENOMEM);
 752
 753	drm = container + offset;
 754	ret = devm_drm_dev_init(parent, drm, driver);
 755	if (ret) {
 756		kfree(container);
 757		return ERR_PTR(ret);
 758	}
 759	drmm_add_final_kfree(drm, container);
 760
 761	return container;
 762}
 763EXPORT_SYMBOL(__devm_drm_dev_alloc);
 764
 765/**
 766 * drm_dev_alloc - Allocate new DRM device
 767 * @driver: DRM driver to allocate device for
 768 * @parent: Parent device object
 769 *
 770 * Allocate and initialize a new DRM device. No device registration is done.
 771 * Call drm_dev_register() to advertice the device to user space and register it
 772 * with other core subsystems. This should be done last in the device
 773 * initialization sequence to make sure userspace can't access an inconsistent
 774 * state.
 775 *
 776 * The initial ref-count of the object is 1. Use drm_dev_get() and
 777 * drm_dev_put() to take and drop further ref-counts.
 778 *
 779 * Note that for purely virtual devices @parent can be NULL.
 780 *
 781 * Drivers that wish to subclass or embed &struct drm_device into their
 782 * own struct should look at using drm_dev_init() instead.
 783 *
 784 * RETURNS:
 785 * Pointer to new DRM device, or ERR_PTR on failure.
 786 */
 787struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 788				 struct device *parent)
 789{
 790	struct drm_device *dev;
 791	int ret;
 792
 793	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 794	if (!dev)
 795		return ERR_PTR(-ENOMEM);
 796
 797	ret = drm_dev_init(dev, driver, parent);
 798	if (ret) {
 799		kfree(dev);
 800		return ERR_PTR(ret);
 801	}
 802
 803	drmm_add_final_kfree(dev, dev);
 804
 805	return dev;
 806}
 807EXPORT_SYMBOL(drm_dev_alloc);
 808
 809static void drm_dev_release(struct kref *ref)
 810{
 811	struct drm_device *dev = container_of(ref, struct drm_device, ref);
 812
 813	if (dev->driver->release)
 814		dev->driver->release(dev);
 815
 816	drm_managed_release(dev);
 817
 818	kfree(dev->managed.final_kfree);
 819}
 820
 821/**
 822 * drm_dev_get - Take reference of a DRM device
 823 * @dev: device to take reference of or NULL
 824 *
 825 * This increases the ref-count of @dev by one. You *must* already own a
 826 * reference when calling this. Use drm_dev_put() to drop this reference
 827 * again.
 828 *
 829 * This function never fails. However, this function does not provide *any*
 830 * guarantee whether the device is alive or running. It only provides a
 831 * reference to the object and the memory associated with it.
 832 */
 833void drm_dev_get(struct drm_device *dev)
 834{
 835	if (dev)
 836		kref_get(&dev->ref);
 837}
 838EXPORT_SYMBOL(drm_dev_get);
 839
 840/**
 841 * drm_dev_put - Drop reference of a DRM device
 842 * @dev: device to drop reference of or NULL
 843 *
 844 * This decreases the ref-count of @dev by one. The device is destroyed if the
 845 * ref-count drops to zero.
 846 */
 847void drm_dev_put(struct drm_device *dev)
 848{
 849	if (dev)
 850		kref_put(&dev->ref, drm_dev_release);
 851}
 852EXPORT_SYMBOL(drm_dev_put);
 853
 854static int create_compat_control_link(struct drm_device *dev)
 855{
 856	struct drm_minor *minor;
 857	char *name;
 858	int ret;
 859
 860	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 861		return 0;
 862
 863	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
 864	if (!minor)
 865		return 0;
 866
 867	/*
 868	 * Some existing userspace out there uses the existing of the controlD*
 869	 * sysfs files to figure out whether it's a modeset driver. It only does
 870	 * readdir, hence a symlink is sufficient (and the least confusing
 871	 * option). Otherwise controlD* is entirely unused.
 872	 *
 873	 * Old controlD chardev have been allocated in the range
 874	 * 64-127.
 875	 */
 876	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
 877	if (!name)
 878		return -ENOMEM;
 879
 880	ret = sysfs_create_link(minor->kdev->kobj.parent,
 881				&minor->kdev->kobj,
 882				name);
 883
 884	kfree(name);
 885
 886	return ret;
 887}
 888
 889static void remove_compat_control_link(struct drm_device *dev)
 890{
 891	struct drm_minor *minor;
 892	char *name;
 893
 894	if (!drm_core_check_feature(dev, DRIVER_MODESET))
 895		return;
 896
 897	minor = *drm_minor_get_slot(dev, DRM_MINOR_PRIMARY);
 898	if (!minor)
 899		return;
 900
 901	name = kasprintf(GFP_KERNEL, "controlD%d", minor->index + 64);
 902	if (!name)
 903		return;
 904
 905	sysfs_remove_link(minor->kdev->kobj.parent, name);
 906
 907	kfree(name);
 908}
 909
 910/**
 911 * drm_dev_register - Register DRM device
 912 * @dev: Device to register
 913 * @flags: Flags passed to the driver's .load() function
 914 *
 915 * Register the DRM device @dev with the system, advertise device to user-space
 916 * and start normal device operation. @dev must be initialized via drm_dev_init()
 917 * previously.
 918 *
 919 * Never call this twice on any device!
 920 *
 921 * NOTE: To ensure backward compatibility with existing drivers method this
 922 * function calls the &drm_driver.load method after registering the device
 923 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
 924 * therefore deprecated, drivers must perform all initialization before calling
 925 * drm_dev_register().
 926 *
 927 * RETURNS:
 928 * 0 on success, negative error code on failure.
 929 */
 930int drm_dev_register(struct drm_device *dev, unsigned long flags)
 931{
 932	struct drm_driver *driver = dev->driver;
 933	int ret;
 934
 935	if (!driver->load)
 936		drm_mode_config_validate(dev);
 937
 938	WARN_ON(!dev->managed.final_kfree);
 939
 940	if (drm_dev_needs_global_mutex(dev))
 941		mutex_lock(&drm_global_mutex);
 942
 943	ret = drm_minor_register(dev, DRM_MINOR_RENDER);
 944	if (ret)
 945		goto err_minors;
 946
 947	ret = drm_minor_register(dev, DRM_MINOR_PRIMARY);
 948	if (ret)
 949		goto err_minors;
 950
 951	ret = create_compat_control_link(dev);
 952	if (ret)
 953		goto err_minors;
 954
 955	dev->registered = true;
 956
 957	if (dev->driver->load) {
 958		ret = dev->driver->load(dev, flags);
 959		if (ret)
 960			goto err_minors;
 961	}
 962
 963	if (drm_core_check_feature(dev, DRIVER_MODESET))
 964		drm_modeset_register_all(dev);
 965
 966	ret = 0;
 967
 968	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
 969		 driver->name, driver->major, driver->minor,
 970		 driver->patchlevel, driver->date,
 971		 dev->dev ? dev_name(dev->dev) : "virtual device",
 972		 dev->primary->index);
 973
 974	goto out_unlock;
 975
 976err_minors:
 977	remove_compat_control_link(dev);
 978	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
 979	drm_minor_unregister(dev, DRM_MINOR_RENDER);
 980out_unlock:
 981	if (drm_dev_needs_global_mutex(dev))
 982		mutex_unlock(&drm_global_mutex);
 983	return ret;
 984}
 985EXPORT_SYMBOL(drm_dev_register);
 986
 987/**
 988 * drm_dev_unregister - Unregister DRM device
 989 * @dev: Device to unregister
 990 *
 991 * Unregister the DRM device from the system. This does the reverse of
 992 * drm_dev_register() but does not deallocate the device. The caller must call
 993 * drm_dev_put() to drop their final reference.
 994 *
 995 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
 996 * which can be called while there are still open users of @dev.
 997 *
 998 * This should be called first in the device teardown code to make sure
 999 * userspace can't access the device instance any more.
1000 */
1001void drm_dev_unregister(struct drm_device *dev)
1002{
1003	if (drm_core_check_feature(dev, DRIVER_LEGACY))
1004		drm_lastclose(dev);
1005
1006	dev->registered = false;
1007
1008	drm_client_dev_unregister(dev);
1009
1010	if (drm_core_check_feature(dev, DRIVER_MODESET))
1011		drm_modeset_unregister_all(dev);
1012
1013	if (dev->driver->unload)
1014		dev->driver->unload(dev);
1015
1016	if (dev->agp)
1017		drm_pci_agp_destroy(dev);
1018
1019	drm_legacy_rmmaps(dev);
1020
1021	remove_compat_control_link(dev);
1022	drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
1023	drm_minor_unregister(dev, DRM_MINOR_RENDER);
1024}
1025EXPORT_SYMBOL(drm_dev_unregister);
1026
1027/**
1028 * drm_dev_set_unique - Set the unique name of a DRM device
1029 * @dev: device of which to set the unique name
1030 * @name: unique name
1031 *
1032 * Sets the unique name of a DRM device using the specified string. This is
1033 * already done by drm_dev_init(), drivers should only override the default
1034 * unique name for backwards compatibility reasons.
1035 *
1036 * Return: 0 on success or a negative error code on failure.
1037 */
1038int drm_dev_set_unique(struct drm_device *dev, const char *name)
1039{
1040	drmm_kfree(dev, dev->unique);
1041	dev->unique = drmm_kstrdup(dev, name, GFP_KERNEL);
1042
1043	return dev->unique ? 0 : -ENOMEM;
1044}
1045EXPORT_SYMBOL(drm_dev_set_unique);
1046
1047/*
1048 * DRM Core
1049 * The DRM core module initializes all global DRM objects and makes them
1050 * available to drivers. Once setup, drivers can probe their respective
1051 * devices.
1052 * Currently, core management includes:
1053 *  - The "DRM-Global" key/value database
1054 *  - Global ID management for connectors
1055 *  - DRM major number allocation
1056 *  - DRM minor management
1057 *  - DRM sysfs class
1058 *  - DRM debugfs root
1059 *
1060 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1061 * interface registered on a DRM device, you can request minor numbers from DRM
1062 * core. DRM core takes care of major-number management and char-dev
1063 * registration. A stub ->open() callback forwards any open() requests to the
1064 * registered minor.
1065 */
1066
1067static int drm_stub_open(struct inode *inode, struct file *filp)
1068{
1069	const struct file_operations *new_fops;
1070	struct drm_minor *minor;
1071	int err;
1072
1073	DRM_DEBUG("\n");
1074
1075	minor = drm_minor_acquire(iminor(inode));
1076	if (IS_ERR(minor))
1077		return PTR_ERR(minor);
1078
1079	new_fops = fops_get(minor->dev->driver->fops);
1080	if (!new_fops) {
1081		err = -ENODEV;
1082		goto out;
1083	}
1084
1085	replace_fops(filp, new_fops);
1086	if (filp->f_op->open)
1087		err = filp->f_op->open(inode, filp);
1088	else
1089		err = 0;
1090
1091out:
1092	drm_minor_release(minor);
1093
1094	return err;
1095}
1096
1097static const struct file_operations drm_stub_fops = {
1098	.owner = THIS_MODULE,
1099	.open = drm_stub_open,
1100	.llseek = noop_llseek,
1101};
1102
1103static void drm_core_exit(void)
1104{
1105	unregister_chrdev(DRM_MAJOR, "drm");
1106	debugfs_remove(drm_debugfs_root);
1107	drm_sysfs_destroy();
1108	idr_destroy(&drm_minors_idr);
1109	drm_connector_ida_destroy();
1110}
1111
1112static int __init drm_core_init(void)
1113{
1114	int ret;
1115
1116	drm_connector_ida_init();
1117	idr_init(&drm_minors_idr);
 
1118
1119	ret = drm_sysfs_init();
1120	if (ret < 0) {
1121		DRM_ERROR("Cannot create DRM class: %d\n", ret);
1122		goto error;
1123	}
1124
1125	drm_debugfs_root = debugfs_create_dir("dri", NULL);
1126
1127	ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops);
1128	if (ret < 0)
1129		goto error;
1130
1131	drm_core_init_complete = true;
1132
1133	DRM_DEBUG("Initialized\n");
1134	return 0;
1135
1136error:
1137	drm_core_exit();
1138	return ret;
1139}
1140
1141module_init(drm_core_init);
1142module_exit(drm_core_exit);