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
54 MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
55 MODULE_DESCRIPTION("DRM shared core routines");
56 MODULE_LICENSE("GPL and additional rights");
57
58 DEFINE_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 */
67 static bool drm_core_init_complete;
68
69 static struct dentry *drm_debugfs_root;
70
71 DEFINE_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
drm_minor_get_xa(enum drm_minor_type type)86 static 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
drm_minor_get_slot(struct drm_device * dev,enum drm_minor_type type)98 static 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
drm_minor_alloc_release(struct drm_device * dev,void * data)113 static 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
drm_minor_alloc(struct drm_device * dev,enum drm_minor_type type)138 static 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
drm_minor_register(struct drm_device * dev,enum drm_minor_type type)170 static 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
206 err_debugfs:
207 drm_debugfs_unregister(minor);
208 return ret;
209 }
210
drm_minor_unregister(struct drm_device * dev,enum drm_minor_type type)211 static 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 */
drm_minor_acquire(struct xarray * minor_xa,unsigned int minor_id)236 struct 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
drm_minor_release(struct drm_minor * minor)256 void 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 */
drm_put_dev(struct drm_device * dev)420 void 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 }
432 EXPORT_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 */
drm_dev_enter(struct drm_device * dev,int * idx)446 bool 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 }
457 EXPORT_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 */
drm_dev_exit(int idx)466 void drm_dev_exit(int idx)
467 {
468 srcu_read_unlock(&drm_unplug_srcu, idx);
469 }
470 EXPORT_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 */
drm_dev_unplug(struct drm_device * dev)482 void 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 }
498 EXPORT_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
518 static int drm_fs_cnt;
519 static struct vfsmount *drm_fs_mnt;
520
drm_fs_init_fs_context(struct fs_context * fc)521 static int drm_fs_init_fs_context(struct fs_context *fc)
522 {
523 return init_pseudo(fc, 0x010203ff) ? 0 : -ENOMEM;
524 }
525
526 static 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
drm_fs_inode_new(void)533 static 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
drm_fs_inode_free(struct inode * inode)551 static 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
drm_dev_init_release(struct drm_device * dev,void * res)584 static 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
drm_dev_init(struct drm_device * dev,const struct drm_driver * driver,struct device * parent)598 static 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
692 err:
693 drm_managed_release(dev);
694
695 return ret;
696 }
697
devm_drm_dev_init_release(void * data)698 static void devm_drm_dev_init_release(void *data)
699 {
700 drm_dev_put(data);
701 }
702
devm_drm_dev_init(struct device * parent,struct drm_device * dev,const struct drm_driver * driver)703 static 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
__devm_drm_dev_alloc(struct device * parent,const struct drm_driver * driver,size_t size,size_t offset)717 void *__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 }
739 EXPORT_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 */
drm_dev_alloc(const struct drm_driver * driver,struct device * parent)753 struct 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 }
773 EXPORT_SYMBOL(drm_dev_alloc);
774
drm_dev_release(struct kref * ref)775 static 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 */
drm_dev_get(struct drm_device * dev)802 void drm_dev_get(struct drm_device *dev)
803 {
804 if (dev)
805 kref_get(&dev->ref);
806 }
807 EXPORT_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 */
drm_dev_put(struct drm_device * dev)816 void drm_dev_put(struct drm_device *dev)
817 {
818 if (dev)
819 kref_put(&dev->ref, drm_dev_release);
820 }
821 EXPORT_SYMBOL(drm_dev_put);
822
create_compat_control_link(struct drm_device * dev)823 static 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
remove_compat_control_link(struct drm_device * dev)858 static 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 */
drm_dev_register(struct drm_device * dev,unsigned long flags)899 int 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
956 err_unload:
957 if (dev->driver->unload)
958 dev->driver->unload(dev);
959 err_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);
964 out_unlock:
965 if (drm_dev_needs_global_mutex(dev))
966 mutex_unlock(&drm_global_mutex);
967 return ret;
968 }
969 EXPORT_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 */
drm_dev_unregister(struct drm_device * dev)987 void 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 }
1007 EXPORT_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
drm_stub_open(struct inode * inode,struct file * filp)1029 static 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
1053 out:
1054 drm_minor_release(minor);
1055
1056 return err;
1057 }
1058
1059 static const struct file_operations drm_stub_fops = {
1060 .owner = THIS_MODULE,
1061 .open = drm_stub_open,
1062 .llseek = noop_llseek,
1063 };
1064
drm_core_exit(void)1065 static 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
drm_core_init(void)1077 static 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
1109 error:
1110 drm_core_exit();
1111 return ret;
1112 }
1113
1114 module_init(drm_core_init);
1115 module_exit(drm_core_exit);
1116