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