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/bitops.h>
30#include <linux/cgroup_dmem.h>
31#include <linux/debugfs.h>
32#include <linux/export.h>
33#include <linux/fs.h>
34#include <linux/module.h>
35#include <linux/moduleparam.h>
36#include <linux/mount.h>
37#include <linux/pseudo_fs.h>
38#include <linux/sched.h>
39#include <linux/slab.h>
40#include <linux/sprintf.h>
41#include <linux/srcu.h>
42#include <linux/xarray.h>
43
44#include <drm/drm_accel.h>
45#include <drm/drm_bridge.h>
46#include <drm/drm_cache.h>
47#include <drm/drm_client_event.h>
48#include <drm/drm_color_mgmt.h>
49#include <drm/drm_drv.h>
50#include <drm/drm_file.h>
51#include <drm/drm_managed.h>
52#include <drm/drm_mode_object.h>
53#include <drm/drm_panic.h>
54#include <drm/drm_print.h>
55#include <drm/drm_privacy_screen_machine.h>
56
57#include "drm_crtc_internal.h"
58#include "drm_internal.h"
59
60MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
61MODULE_DESCRIPTION("DRM shared core routines");
62MODULE_LICENSE("GPL and additional rights");
63
64DEFINE_XARRAY_ALLOC(drm_minors_xa);
65
66/*
67 * If the drm core fails to init for whatever reason,
68 * we should prevent any drivers from registering with it.
69 * It's best to check this at drm_dev_init(), as some drivers
70 * prefer to embed struct drm_device into their own device
71 * structure and call drm_dev_init() themselves.
72 */
73static bool drm_core_init_complete;
74
75DEFINE_STATIC_SRCU(drm_unplug_srcu);
76
77/*
78 * DRM Minors
79 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
80 * of them is represented by a drm_minor object. Depending on the capabilities
81 * of the device-driver, different interfaces are registered.
82 *
83 * Minors can be accessed via dev->$minor_name. This pointer is either
84 * NULL or a valid drm_minor pointer and stays valid as long as the device is
85 * valid. This means, DRM minors have the same life-time as the underlying
86 * device. However, this doesn't mean that the minor is active. Minors are
87 * registered and unregistered dynamically according to device-state.
88 */
89
90static struct xarray *drm_minor_get_xa(enum drm_minor_type type)
91{
92 if (type == DRM_MINOR_PRIMARY || type == DRM_MINOR_RENDER)
93 return &drm_minors_xa;
94#if IS_ENABLED(CONFIG_DRM_ACCEL)
95 else if (type == DRM_MINOR_ACCEL)
96 return &accel_minors_xa;
97#endif
98 else
99 return ERR_PTR(error: -EOPNOTSUPP);
100}
101
102static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
103 enum drm_minor_type type)
104{
105 switch (type) {
106 case DRM_MINOR_PRIMARY:
107 return &dev->primary;
108 case DRM_MINOR_RENDER:
109 return &dev->render;
110 case DRM_MINOR_ACCEL:
111 return &dev->accel;
112 default:
113 BUG();
114 }
115}
116
117static void drm_minor_alloc_release(struct drm_device *dev, void *data)
118{
119 struct drm_minor *minor = data;
120
121 WARN_ON(dev != minor->dev);
122
123 put_device(dev: minor->kdev);
124
125 xa_erase(drm_minor_get_xa(type: minor->type), index: minor->index);
126}
127
128/*
129 * DRM used to support 64 devices, for backwards compatibility we need to maintain the
130 * minor allocation scheme where minors 0-63 are primary nodes, 64-127 are control nodes,
131 * and 128-191 are render nodes.
132 * After reaching the limit, we're allocating minors dynamically - first-come, first-serve.
133 * Accel nodes are using a distinct major, so the minors are allocated in continuous 0-MAX
134 * range.
135 */
136#define DRM_MINOR_LIMIT(t) ({ \
137 typeof(t) _t = (t); \
138 _t == DRM_MINOR_ACCEL ? XA_LIMIT(0, ACCEL_MAX_MINORS) : XA_LIMIT(64 * _t, 64 * _t + 63); \
139})
140#define DRM_EXTENDED_MINOR_LIMIT XA_LIMIT(192, (1 << MINORBITS) - 1)
141
142static int drm_minor_alloc(struct drm_device *dev, enum drm_minor_type type)
143{
144 struct drm_minor *minor;
145 int r;
146
147 minor = drmm_kzalloc(dev, size: sizeof(*minor), GFP_KERNEL);
148 if (!minor)
149 return -ENOMEM;
150
151 minor->type = type;
152 minor->dev = dev;
153
154 r = xa_alloc(xa: drm_minor_get_xa(type), id: &minor->index,
155 NULL, DRM_MINOR_LIMIT(type), GFP_KERNEL);
156 if (r == -EBUSY && (type == DRM_MINOR_PRIMARY || type == DRM_MINOR_RENDER))
157 r = xa_alloc(xa: &drm_minors_xa, id: &minor->index,
158 NULL, DRM_EXTENDED_MINOR_LIMIT, GFP_KERNEL);
159 if (r < 0)
160 return r;
161
162 r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
163 if (r)
164 return r;
165
166 minor->kdev = drm_sysfs_minor_alloc(minor);
167 if (IS_ERR(ptr: minor->kdev))
168 return PTR_ERR(ptr: minor->kdev);
169
170 *drm_minor_get_slot(dev, type) = minor;
171 return 0;
172}
173
174static int drm_minor_register(struct drm_device *dev, enum drm_minor_type type)
175{
176 struct drm_minor *minor;
177 void *entry;
178 int ret;
179
180 DRM_DEBUG("\n");
181
182 minor = *drm_minor_get_slot(dev, type);
183 if (!minor)
184 return 0;
185
186 if (minor->type != DRM_MINOR_ACCEL) {
187 ret = drm_debugfs_register(minor, minor_id: minor->index);
188 if (ret) {
189 DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
190 goto err_debugfs;
191 }
192 }
193
194 ret = device_add(dev: minor->kdev);
195 if (ret)
196 goto err_debugfs;
197
198 /* replace NULL with @minor so lookups will succeed from now on */
199 entry = xa_store(drm_minor_get_xa(type), index: minor->index, entry: minor, GFP_KERNEL);
200 if (xa_is_err(entry)) {
201 ret = xa_err(entry);
202 goto err_debugfs;
203 }
204 WARN_ON(entry);
205
206 DRM_DEBUG("new minor registered %d\n", minor->index);
207 return 0;
208
209err_debugfs:
210 drm_debugfs_unregister(minor);
211 return ret;
212}
213
214static void drm_minor_unregister(struct drm_device *dev, enum drm_minor_type type)
215{
216 struct drm_minor *minor;
217
218 minor = *drm_minor_get_slot(dev, type);
219 if (!minor || !device_is_registered(dev: minor->kdev))
220 return;
221
222 /* replace @minor with NULL so lookups will fail from now on */
223 xa_store(drm_minor_get_xa(type), index: minor->index, NULL, GFP_KERNEL);
224
225 device_del(dev: minor->kdev);
226 dev_set_drvdata(dev: minor->kdev, NULL); /* safety belt */
227 drm_debugfs_unregister(minor);
228}
229
230/*
231 * Looks up the given minor-ID and returns the respective DRM-minor object. The
232 * refence-count of the underlying device is increased so you must release this
233 * object with drm_minor_release().
234 *
235 * As long as you hold this minor, it is guaranteed that the object and the
236 * minor->dev pointer will stay valid! However, the device may get unplugged and
237 * unregistered while you hold the minor.
238 */
239struct drm_minor *drm_minor_acquire(struct xarray *minor_xa, unsigned int minor_id)
240{
241 struct drm_minor *minor;
242
243 xa_lock(minor_xa);
244 minor = xa_load(minor_xa, index: minor_id);
245 if (minor)
246 drm_dev_get(dev: minor->dev);
247 xa_unlock(minor_xa);
248
249 if (!minor) {
250 return ERR_PTR(error: -ENODEV);
251 } else if (drm_dev_is_unplugged(dev: minor->dev)) {
252 drm_dev_put(dev: minor->dev);
253 return ERR_PTR(error: -ENODEV);
254 }
255
256 return minor;
257}
258
259void drm_minor_release(struct drm_minor *minor)
260{
261 drm_dev_put(dev: minor->dev);
262}
263
264/**
265 * DOC: driver instance overview
266 *
267 * A device instance for a drm driver is represented by &struct drm_device. This
268 * is allocated and initialized with devm_drm_dev_alloc(), usually from
269 * bus-specific ->probe() callbacks implemented by the driver. The driver then
270 * needs to initialize all the various subsystems for the drm device like memory
271 * management, vblank handling, modesetting support and initial output
272 * configuration plus obviously initialize all the corresponding hardware bits.
273 * Finally when everything is up and running and ready for userspace the device
274 * instance can be published using drm_dev_register().
275 *
276 * There is also deprecated support for initializing device instances using
277 * bus-specific helpers and the &drm_driver.load callback. But due to
278 * backwards-compatibility needs the device instance have to be published too
279 * early, which requires unpretty global locking to make safe and is therefore
280 * only support for existing drivers not yet converted to the new scheme.
281 *
282 * When cleaning up a device instance everything needs to be done in reverse:
283 * First unpublish the device instance with drm_dev_unregister(). Then clean up
284 * any other resources allocated at device initialization and drop the driver's
285 * reference to &drm_device using drm_dev_put().
286 *
287 * Note that any allocation or resource which is visible to userspace must be
288 * released only when the final drm_dev_put() is called, and not when the
289 * driver is unbound from the underlying physical struct &device. Best to use
290 * &drm_device managed resources with drmm_add_action(), drmm_kmalloc() and
291 * related functions.
292 *
293 * devres managed resources like devm_kmalloc() can only be used for resources
294 * directly related to the underlying hardware device, and only used in code
295 * paths fully protected by drm_dev_enter() and drm_dev_exit().
296 *
297 * Display driver example
298 * ~~~~~~~~~~~~~~~~~~~~~~
299 *
300 * The following example shows a typical structure of a DRM display driver.
301 * The example focus on the probe() function and the other functions that is
302 * almost always present and serves as a demonstration of devm_drm_dev_alloc().
303 *
304 * .. code-block:: c
305 *
306 * struct driver_device {
307 * struct drm_device drm;
308 * void *userspace_facing;
309 * struct clk *pclk;
310 * };
311 *
312 * static const struct drm_driver driver_drm_driver = {
313 * [...]
314 * };
315 *
316 * static int driver_probe(struct platform_device *pdev)
317 * {
318 * struct driver_device *priv;
319 * struct drm_device *drm;
320 * int ret;
321 *
322 * priv = devm_drm_dev_alloc(&pdev->dev, &driver_drm_driver,
323 * struct driver_device, drm);
324 * if (IS_ERR(priv))
325 * return PTR_ERR(priv);
326 * drm = &priv->drm;
327 *
328 * ret = drmm_mode_config_init(drm);
329 * if (ret)
330 * return ret;
331 *
332 * priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL);
333 * if (!priv->userspace_facing)
334 * return -ENOMEM;
335 *
336 * priv->pclk = devm_clk_get(dev, "PCLK");
337 * if (IS_ERR(priv->pclk))
338 * return PTR_ERR(priv->pclk);
339 *
340 * // Further setup, display pipeline etc
341 *
342 * platform_set_drvdata(pdev, drm);
343 *
344 * drm_mode_config_reset(drm);
345 *
346 * ret = drm_dev_register(drm);
347 * if (ret)
348 * return ret;
349 *
350 * drm_fbdev_{...}_setup(drm, 32);
351 *
352 * return 0;
353 * }
354 *
355 * // This function is called before the devm_ resources are released
356 * static int driver_remove(struct platform_device *pdev)
357 * {
358 * struct drm_device *drm = platform_get_drvdata(pdev);
359 *
360 * drm_dev_unregister(drm);
361 * drm_atomic_helper_shutdown(drm)
362 *
363 * return 0;
364 * }
365 *
366 * // This function is called on kernel restart and shutdown
367 * static void driver_shutdown(struct platform_device *pdev)
368 * {
369 * drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
370 * }
371 *
372 * static int __maybe_unused driver_pm_suspend(struct device *dev)
373 * {
374 * return drm_mode_config_helper_suspend(dev_get_drvdata(dev));
375 * }
376 *
377 * static int __maybe_unused driver_pm_resume(struct device *dev)
378 * {
379 * drm_mode_config_helper_resume(dev_get_drvdata(dev));
380 *
381 * return 0;
382 * }
383 *
384 * static const struct dev_pm_ops driver_pm_ops = {
385 * SET_SYSTEM_SLEEP_PM_OPS(driver_pm_suspend, driver_pm_resume)
386 * };
387 *
388 * static struct platform_driver driver_driver = {
389 * .driver = {
390 * [...]
391 * .pm = &driver_pm_ops,
392 * },
393 * .probe = driver_probe,
394 * .remove = driver_remove,
395 * .shutdown = driver_shutdown,
396 * };
397 * module_platform_driver(driver_driver);
398 *
399 * Drivers that want to support device unplugging (USB, DT overlay unload) should
400 * use drm_dev_unplug() instead of drm_dev_unregister(). The driver must protect
401 * regions that is accessing device resources to prevent use after they're
402 * released. This is done using drm_dev_enter() and drm_dev_exit(). There is one
403 * shortcoming however, drm_dev_unplug() marks the drm_device as unplugged before
404 * drm_atomic_helper_shutdown() is called. This means that if the disable code
405 * paths are protected, they will not run on regular driver module unload,
406 * possibly leaving the hardware enabled.
407 */
408
409/**
410 * drm_put_dev - Unregister and release a DRM device
411 * @dev: DRM device
412 *
413 * Called at module unload time or when a PCI device is unplugged.
414 *
415 * Cleans up all DRM device, calling drm_lastclose().
416 *
417 * Note: Use of this function is deprecated. It will eventually go away
418 * completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
419 * instead to make sure that the device isn't userspace accessible any more
420 * while teardown is in progress, ensuring that userspace can't access an
421 * inconsistent state.
422 */
423void drm_put_dev(struct drm_device *dev)
424{
425 DRM_DEBUG("\n");
426
427 if (!dev) {
428 DRM_ERROR("cleanup called no dev\n");
429 return;
430 }
431
432 drm_dev_unregister(dev);
433 drm_dev_put(dev);
434}
435EXPORT_SYMBOL(drm_put_dev);
436
437/**
438 * drm_dev_enter - Enter device critical section
439 * @dev: DRM device
440 * @idx: Pointer to index that will be passed to the matching drm_dev_exit()
441 *
442 * This function marks and protects the beginning of a section that should not
443 * be entered after the device has been unplugged. The section end is marked
444 * with drm_dev_exit(). Calls to this function can be nested.
445 *
446 * Returns:
447 * True if it is OK to enter the section, false otherwise.
448 */
449bool drm_dev_enter(struct drm_device *dev, int *idx)
450{
451 *idx = srcu_read_lock(ssp: &drm_unplug_srcu);
452
453 if (dev->unplugged) {
454 srcu_read_unlock(ssp: &drm_unplug_srcu, idx: *idx);
455 return false;
456 }
457
458 return true;
459}
460EXPORT_SYMBOL(drm_dev_enter);
461
462/**
463 * drm_dev_exit - Exit device critical section
464 * @idx: index returned from drm_dev_enter()
465 *
466 * This function marks the end of a section that should not be entered after
467 * the device has been unplugged.
468 */
469void drm_dev_exit(int idx)
470{
471 srcu_read_unlock(ssp: &drm_unplug_srcu, idx);
472}
473EXPORT_SYMBOL(drm_dev_exit);
474
475/**
476 * drm_dev_unplug - unplug a DRM device
477 * @dev: DRM device
478 *
479 * This unplugs a hotpluggable DRM device, which makes it inaccessible to
480 * userspace operations. Entry-points can use drm_dev_enter() and
481 * drm_dev_exit() to protect device resources in a race free manner. This
482 * essentially unregisters the device like drm_dev_unregister(), but can be
483 * called while there are still open users of @dev.
484 */
485void drm_dev_unplug(struct drm_device *dev)
486{
487 /*
488 * After synchronizing any critical read section is guaranteed to see
489 * the new value of ->unplugged, and any critical section which might
490 * still have seen the old value of ->unplugged is guaranteed to have
491 * finished.
492 */
493 dev->unplugged = true;
494 synchronize_srcu(ssp: &drm_unplug_srcu);
495
496 drm_dev_unregister(dev);
497
498 /* Clear all CPU mappings pointing to this device */
499 unmap_mapping_range(mapping: dev->anon_inode->i_mapping, holebegin: 0, holelen: 0, even_cows: 1);
500}
501EXPORT_SYMBOL(drm_dev_unplug);
502
503/**
504 * drm_dev_set_dma_dev - set the DMA device for a DRM device
505 * @dev: DRM device
506 * @dma_dev: DMA device or NULL
507 *
508 * Sets the DMA device of the given DRM device. Only required if
509 * the DMA device is different from the DRM device's parent. After
510 * calling this function, the DRM device holds a reference on
511 * @dma_dev. Pass NULL to clear the DMA device.
512 */
513void drm_dev_set_dma_dev(struct drm_device *dev, struct device *dma_dev)
514{
515 dma_dev = get_device(dev: dma_dev);
516
517 put_device(dev: dev->dma_dev);
518 dev->dma_dev = dma_dev;
519}
520EXPORT_SYMBOL(drm_dev_set_dma_dev);
521
522/*
523 * Available recovery methods for wedged device. To be sent along with device
524 * wedged uevent.
525 */
526static const char *drm_get_wedge_recovery(unsigned int opt)
527{
528 switch (BIT(opt)) {
529 case DRM_WEDGE_RECOVERY_NONE:
530 return "none";
531 case DRM_WEDGE_RECOVERY_REBIND:
532 return "rebind";
533 case DRM_WEDGE_RECOVERY_BUS_RESET:
534 return "bus-reset";
535 case DRM_WEDGE_RECOVERY_VENDOR:
536 return "vendor-specific";
537 default:
538 return NULL;
539 }
540}
541
542#define WEDGE_STR_LEN 32
543#define PID_STR_LEN 15
544#define COMM_STR_LEN (TASK_COMM_LEN + 5)
545
546/**
547 * drm_dev_wedged_event - generate a device wedged uevent
548 * @dev: DRM device
549 * @method: method(s) to be used for recovery
550 * @info: optional information about the guilty task
551 *
552 * This generates a device wedged uevent for the DRM device specified by @dev.
553 * Recovery @method\(s) of choice will be sent in the uevent environment as
554 * ``WEDGED=<method1>[,..,<methodN>]`` in order of less to more side-effects.
555 * If caller is unsure about recovery or @method is unknown (0),
556 * ``WEDGED=unknown`` will be sent instead.
557 *
558 * Refer to "Device Wedging" chapter in Documentation/gpu/drm-uapi.rst for more
559 * details.
560 *
561 * Returns: 0 on success, negative error code otherwise.
562 */
563int drm_dev_wedged_event(struct drm_device *dev, unsigned long method,
564 struct drm_wedge_task_info *info)
565{
566 char event_string[WEDGE_STR_LEN], pid_string[PID_STR_LEN], comm_string[COMM_STR_LEN];
567 char *envp[] = { event_string, NULL, NULL, NULL };
568 const char *recovery = NULL;
569 unsigned int len, opt;
570
571 len = scnprintf(buf: event_string, size: sizeof(event_string), fmt: "%s", "WEDGED=");
572
573 for_each_set_bit(opt, &method, BITS_PER_TYPE(method)) {
574 recovery = drm_get_wedge_recovery(opt);
575 if (drm_WARN_ONCE(dev, !recovery, "invalid recovery method %u\n", opt))
576 break;
577
578 len += scnprintf(buf: event_string + len, size: sizeof(event_string) - len, fmt: "%s,", recovery);
579 }
580
581 if (recovery)
582 /* Get rid of trailing comma */
583 event_string[len - 1] = '\0';
584 else
585 /* Caller is unsure about recovery, do the best we can at this point. */
586 snprintf(buf: event_string, size: sizeof(event_string), fmt: "%s", "WEDGED=unknown");
587
588 drm_info(dev, "device wedged, %s\n", method == DRM_WEDGE_RECOVERY_NONE ?
589 "but recovered through reset" : "needs recovery");
590
591 if (info && (info->comm[0] != '\0') && (info->pid >= 0)) {
592 snprintf(buf: pid_string, size: sizeof(pid_string), fmt: "PID=%u", info->pid);
593 snprintf(buf: comm_string, size: sizeof(comm_string), fmt: "TASK=%s", info->comm);
594 envp[1] = pid_string;
595 envp[2] = comm_string;
596 }
597
598 return kobject_uevent_env(kobj: &dev->primary->kdev->kobj, action: KOBJ_CHANGE, envp);
599}
600EXPORT_SYMBOL(drm_dev_wedged_event);
601
602/*
603 * DRM internal mount
604 * We want to be able to allocate our own "struct address_space" to control
605 * memory-mappings in VRAM (or stolen RAM, ...). However, core MM does not allow
606 * stand-alone address_space objects, so we need an underlying inode. As there
607 * is no way to allocate an independent inode easily, we need a fake internal
608 * VFS mount-point.
609 *
610 * The drm_fs_inode_new() function allocates a new inode, drm_fs_inode_free()
611 * frees it again. You are allowed to use iget() and iput() to get references to
612 * the inode. But each drm_fs_inode_new() call must be paired with exactly one
613 * drm_fs_inode_free() call (which does not have to be the last iput()).
614 * We use drm_fs_inode_*() to manage our internal VFS mount-point and share it
615 * between multiple inode-users. You could, technically, call
616 * iget() + drm_fs_inode_free() directly after alloc and sometime later do an
617 * iput(), but this way you'd end up with a new vfsmount for each inode.
618 */
619
620static int drm_fs_cnt;
621static struct vfsmount *drm_fs_mnt;
622
623static int drm_fs_init_fs_context(struct fs_context *fc)
624{
625 return init_pseudo(fc, magic: 0x010203ff) ? 0 : -ENOMEM;
626}
627
628static struct file_system_type drm_fs_type = {
629 .name = "drm",
630 .owner = THIS_MODULE,
631 .init_fs_context = drm_fs_init_fs_context,
632 .kill_sb = kill_anon_super,
633};
634
635static struct inode *drm_fs_inode_new(void)
636{
637 struct inode *inode;
638 int r;
639
640 r = simple_pin_fs(&drm_fs_type, mount: &drm_fs_mnt, count: &drm_fs_cnt);
641 if (r < 0) {
642 DRM_ERROR("Cannot mount pseudo fs: %d\n", r);
643 return ERR_PTR(error: r);
644 }
645
646 inode = alloc_anon_inode(drm_fs_mnt->mnt_sb);
647 if (IS_ERR(ptr: inode))
648 simple_release_fs(mount: &drm_fs_mnt, count: &drm_fs_cnt);
649
650 return inode;
651}
652
653static void drm_fs_inode_free(struct inode *inode)
654{
655 if (inode) {
656 iput(inode);
657 simple_release_fs(mount: &drm_fs_mnt, count: &drm_fs_cnt);
658 }
659}
660
661/**
662 * DOC: component helper usage recommendations
663 *
664 * DRM drivers that drive hardware where a logical device consists of a pile of
665 * independent hardware blocks are recommended to use the :ref:`component helper
666 * library<component>`. For consistency and better options for code reuse the
667 * following guidelines apply:
668 *
669 * - The entire device initialization procedure should be run from the
670 * &component_master_ops.master_bind callback, starting with
671 * devm_drm_dev_alloc(), then binding all components with
672 * component_bind_all() and finishing with drm_dev_register().
673 *
674 * - The opaque pointer passed to all components through component_bind_all()
675 * should point at &struct drm_device of the device instance, not some driver
676 * specific private structure.
677 *
678 * - The component helper fills the niche where further standardization of
679 * interfaces is not practical. When there already is, or will be, a
680 * standardized interface like &drm_bridge or &drm_panel, providing its own
681 * functions to find such components at driver load time, like
682 * drm_of_find_panel_or_bridge(), then the component helper should not be
683 * used.
684 */
685
686static void drm_dev_init_release(struct drm_device *dev, void *res)
687{
688 drm_fs_inode_free(inode: dev->anon_inode);
689
690 put_device(dev: dev->dma_dev);
691 dev->dma_dev = NULL;
692 put_device(dev: dev->dev);
693 /* Prevent use-after-free in drm_managed_release when debugging is
694 * enabled. Slightly awkward, but can't really be helped. */
695 dev->dev = NULL;
696 mutex_destroy(lock: &dev->master_mutex);
697 mutex_destroy(lock: &dev->clientlist_mutex);
698 mutex_destroy(lock: &dev->filelist_mutex);
699}
700
701static int drm_dev_init(struct drm_device *dev,
702 const struct drm_driver *driver,
703 struct device *parent)
704{
705 struct inode *inode;
706 int ret;
707
708 if (!drm_core_init_complete) {
709 DRM_ERROR("DRM core is not initialized\n");
710 return -ENODEV;
711 }
712
713 if (WARN_ON(!parent))
714 return -EINVAL;
715
716 kref_init(kref: &dev->ref);
717 dev->dev = get_device(dev: parent);
718 dev->driver = driver;
719
720 INIT_LIST_HEAD(list: &dev->managed.resources);
721 spin_lock_init(&dev->managed.lock);
722
723 /* no per-device feature limits by default */
724 dev->driver_features = ~0u;
725
726 if (drm_core_check_feature(dev, feature: DRIVER_COMPUTE_ACCEL) &&
727 (drm_core_check_feature(dev, feature: DRIVER_RENDER) ||
728 drm_core_check_feature(dev, feature: DRIVER_MODESET))) {
729 DRM_ERROR("DRM driver can't be both a compute acceleration and graphics driver\n");
730 return -EINVAL;
731 }
732
733 INIT_LIST_HEAD(list: &dev->filelist);
734 INIT_LIST_HEAD(list: &dev->filelist_internal);
735 INIT_LIST_HEAD(list: &dev->clientlist);
736 INIT_LIST_HEAD(list: &dev->vblank_event_list);
737
738 spin_lock_init(&dev->event_lock);
739 mutex_init(&dev->filelist_mutex);
740 mutex_init(&dev->clientlist_mutex);
741 mutex_init(&dev->master_mutex);
742 raw_spin_lock_init(&dev->mode_config.panic_lock);
743
744 ret = drmm_add_action_or_reset(dev, drm_dev_init_release, NULL);
745 if (ret)
746 return ret;
747
748 inode = drm_fs_inode_new();
749 if (IS_ERR(ptr: inode)) {
750 ret = PTR_ERR(ptr: inode);
751 DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
752 goto err;
753 }
754
755 dev->anon_inode = inode;
756
757 if (drm_core_check_feature(dev, feature: DRIVER_COMPUTE_ACCEL)) {
758 ret = drm_minor_alloc(dev, type: DRM_MINOR_ACCEL);
759 if (ret)
760 goto err;
761 } else {
762 if (drm_core_check_feature(dev, feature: DRIVER_RENDER)) {
763 ret = drm_minor_alloc(dev, type: DRM_MINOR_RENDER);
764 if (ret)
765 goto err;
766 }
767
768 ret = drm_minor_alloc(dev, type: DRM_MINOR_PRIMARY);
769 if (ret)
770 goto err;
771 }
772
773 if (drm_core_check_feature(dev, feature: DRIVER_GEM)) {
774 ret = drm_gem_init(dev);
775 if (ret) {
776 DRM_ERROR("Cannot initialize graphics execution manager (GEM)\n");
777 goto err;
778 }
779 }
780
781 dev->unique = drmm_kstrdup(dev, s: dev_name(dev: parent), GFP_KERNEL);
782 if (!dev->unique) {
783 ret = -ENOMEM;
784 goto err;
785 }
786
787 drm_debugfs_dev_init(dev);
788
789 return 0;
790
791err:
792 drm_managed_release(dev);
793
794 return ret;
795}
796
797static void devm_drm_dev_init_release(void *data)
798{
799 drm_dev_put(dev: data);
800}
801
802static int devm_drm_dev_init(struct device *parent,
803 struct drm_device *dev,
804 const struct drm_driver *driver)
805{
806 int ret;
807
808 ret = drm_dev_init(dev, driver, parent);
809 if (ret)
810 return ret;
811
812 return devm_add_action_or_reset(parent,
813 devm_drm_dev_init_release, dev);
814}
815
816void *__devm_drm_dev_alloc(struct device *parent,
817 const struct drm_driver *driver,
818 size_t size, size_t offset)
819{
820 void *container;
821 struct drm_device *drm;
822 int ret;
823
824 container = kzalloc(size, GFP_KERNEL);
825 if (!container)
826 return ERR_PTR(error: -ENOMEM);
827
828 drm = container + offset;
829 ret = devm_drm_dev_init(parent, dev: drm, driver);
830 if (ret) {
831 kfree(objp: container);
832 return ERR_PTR(error: ret);
833 }
834 drmm_add_final_kfree(dev: drm, container);
835
836 return container;
837}
838EXPORT_SYMBOL(__devm_drm_dev_alloc);
839
840/**
841 * __drm_dev_alloc - Allocation of a &drm_device instance
842 * @parent: Parent device object
843 * @driver: DRM driver
844 * @size: the size of the struct which contains struct drm_device
845 * @offset: the offset of the &drm_device within the container.
846 *
847 * This should *NOT* be by any drivers, but is a dedicated interface for the
848 * corresponding Rust abstraction.
849 *
850 * This is the same as devm_drm_dev_alloc(), but without the corresponding
851 * resource management through the parent device, but not the same as
852 * drm_dev_alloc(), since the latter is the deprecated version, which does not
853 * support subclassing.
854 *
855 * Returns: A pointer to new DRM device, or an ERR_PTR on failure.
856 */
857void *__drm_dev_alloc(struct device *parent,
858 const struct drm_driver *driver,
859 size_t size, size_t offset)
860{
861 void *container;
862 struct drm_device *drm;
863 int ret;
864
865 container = kzalloc(size, GFP_KERNEL);
866 if (!container)
867 return ERR_PTR(error: -ENOMEM);
868
869 drm = container + offset;
870 ret = drm_dev_init(dev: drm, driver, parent);
871 if (ret) {
872 kfree(objp: container);
873 return ERR_PTR(error: ret);
874 }
875 drmm_add_final_kfree(dev: drm, container);
876
877 return container;
878}
879EXPORT_SYMBOL(__drm_dev_alloc);
880
881/**
882 * drm_dev_alloc - Allocate new DRM device
883 * @driver: DRM driver to allocate device for
884 * @parent: Parent device object
885 *
886 * This is the deprecated version of devm_drm_dev_alloc(), which does not support
887 * subclassing through embedding the struct &drm_device in a driver private
888 * structure, and which does not support automatic cleanup through devres.
889 *
890 * RETURNS:
891 * Pointer to new DRM device, or ERR_PTR on failure.
892 */
893struct drm_device *drm_dev_alloc(const struct drm_driver *driver,
894 struct device *parent)
895{
896 return __drm_dev_alloc(parent, driver, sizeof(struct drm_device), 0);
897}
898EXPORT_SYMBOL(drm_dev_alloc);
899
900static void drm_dev_release(struct kref *ref)
901{
902 struct drm_device *dev = container_of(ref, struct drm_device, ref);
903
904 /* Just in case register/unregister was never called */
905 drm_debugfs_dev_fini(dev);
906
907 if (dev->driver->release)
908 dev->driver->release(dev);
909
910 drm_managed_release(dev);
911
912 kfree(objp: dev->managed.final_kfree);
913}
914
915/**
916 * drm_dev_get - Take reference of a DRM device
917 * @dev: device to take reference of or NULL
918 *
919 * This increases the ref-count of @dev by one. You *must* already own a
920 * reference when calling this. Use drm_dev_put() to drop this reference
921 * again.
922 *
923 * This function never fails. However, this function does not provide *any*
924 * guarantee whether the device is alive or running. It only provides a
925 * reference to the object and the memory associated with it.
926 */
927void drm_dev_get(struct drm_device *dev)
928{
929 if (dev)
930 kref_get(kref: &dev->ref);
931}
932EXPORT_SYMBOL(drm_dev_get);
933
934/**
935 * drm_dev_put - Drop reference of a DRM device
936 * @dev: device to drop reference of or NULL
937 *
938 * This decreases the ref-count of @dev by one. The device is destroyed if the
939 * ref-count drops to zero.
940 */
941void drm_dev_put(struct drm_device *dev)
942{
943 if (dev)
944 kref_put(kref: &dev->ref, release: drm_dev_release);
945}
946EXPORT_SYMBOL(drm_dev_put);
947
948static void drmm_cg_unregister_region(struct drm_device *dev, void *arg)
949{
950 dmem_cgroup_unregister_region(region: arg);
951}
952
953/**
954 * drmm_cgroup_register_region - Register a region of a DRM device to cgroups
955 * @dev: device for region
956 * @region_name: Region name for registering
957 * @size: Size of region in bytes
958 *
959 * This decreases the ref-count of @dev by one. The device is destroyed if the
960 * ref-count drops to zero.
961 */
962struct dmem_cgroup_region *drmm_cgroup_register_region(struct drm_device *dev, const char *region_name, u64 size)
963{
964 struct dmem_cgroup_region *region;
965 int ret;
966
967 region = dmem_cgroup_register_region(size, name_fmt: "drm/%s/%s", dev->unique, region_name);
968 if (IS_ERR_OR_NULL(ptr: region))
969 return region;
970
971 ret = drmm_add_action_or_reset(dev, drmm_cg_unregister_region, region);
972 if (ret)
973 return ERR_PTR(error: ret);
974
975 return region;
976}
977EXPORT_SYMBOL_GPL(drmm_cgroup_register_region);
978
979static int create_compat_control_link(struct drm_device *dev)
980{
981 struct drm_minor *minor;
982 char *name;
983 int ret;
984
985 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
986 return 0;
987
988 minor = *drm_minor_get_slot(dev, type: DRM_MINOR_PRIMARY);
989 if (!minor)
990 return 0;
991
992 /*
993 * Some existing userspace out there uses the existing of the controlD*
994 * sysfs files to figure out whether it's a modeset driver. It only does
995 * readdir, hence a symlink is sufficient (and the least confusing
996 * option). Otherwise controlD* is entirely unused.
997 *
998 * Old controlD chardev have been allocated in the range
999 * 64-127.
1000 */
1001 name = kasprintf(GFP_KERNEL, fmt: "controlD%d", minor->index + 64);
1002 if (!name)
1003 return -ENOMEM;
1004
1005 ret = sysfs_create_link(kobj: minor->kdev->kobj.parent,
1006 target: &minor->kdev->kobj,
1007 name);
1008
1009 kfree(objp: name);
1010
1011 return ret;
1012}
1013
1014static void remove_compat_control_link(struct drm_device *dev)
1015{
1016 struct drm_minor *minor;
1017 char *name;
1018
1019 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
1020 return;
1021
1022 minor = *drm_minor_get_slot(dev, type: DRM_MINOR_PRIMARY);
1023 if (!minor)
1024 return;
1025
1026 name = kasprintf(GFP_KERNEL, fmt: "controlD%d", minor->index + 64);
1027 if (!name)
1028 return;
1029
1030 sysfs_remove_link(kobj: minor->kdev->kobj.parent, name);
1031
1032 kfree(objp: name);
1033}
1034
1035/**
1036 * drm_dev_register - Register DRM device
1037 * @dev: Device to register
1038 * @flags: Flags passed to the driver's .load() function
1039 *
1040 * Register the DRM device @dev with the system, advertise device to user-space
1041 * and start normal device operation. @dev must be initialized via drm_dev_init()
1042 * previously.
1043 *
1044 * Never call this twice on any device!
1045 *
1046 * NOTE: To ensure backward compatibility with existing drivers method this
1047 * function calls the &drm_driver.load method after registering the device
1048 * nodes, creating race conditions. Usage of the &drm_driver.load methods is
1049 * therefore deprecated, drivers must perform all initialization before calling
1050 * drm_dev_register().
1051 *
1052 * RETURNS:
1053 * 0 on success, negative error code on failure.
1054 */
1055int drm_dev_register(struct drm_device *dev, unsigned long flags)
1056{
1057 const struct drm_driver *driver = dev->driver;
1058 int ret;
1059
1060 if (!driver->load)
1061 drm_mode_config_validate(dev);
1062
1063 WARN_ON(!dev->managed.final_kfree);
1064
1065 if (drm_dev_needs_global_mutex(dev))
1066 mutex_lock(lock: &drm_global_mutex);
1067
1068 if (drm_core_check_feature(dev, feature: DRIVER_COMPUTE_ACCEL))
1069 accel_debugfs_register(dev);
1070 else
1071 drm_debugfs_dev_register(dev);
1072
1073 ret = drm_minor_register(dev, type: DRM_MINOR_RENDER);
1074 if (ret)
1075 goto err_minors;
1076
1077 ret = drm_minor_register(dev, type: DRM_MINOR_PRIMARY);
1078 if (ret)
1079 goto err_minors;
1080
1081 ret = drm_minor_register(dev, type: DRM_MINOR_ACCEL);
1082 if (ret)
1083 goto err_minors;
1084
1085 ret = create_compat_control_link(dev);
1086 if (ret)
1087 goto err_minors;
1088
1089 dev->registered = true;
1090
1091 if (driver->load) {
1092 ret = driver->load(dev, flags);
1093 if (ret)
1094 goto err_minors;
1095 }
1096
1097 if (drm_core_check_feature(dev, feature: DRIVER_MODESET)) {
1098 ret = drm_modeset_register_all(dev);
1099 if (ret)
1100 goto err_unload;
1101 }
1102 drm_panic_register(dev);
1103
1104 DRM_INFO("Initialized %s %d.%d.%d for %s on minor %d\n",
1105 driver->name, driver->major, driver->minor,
1106 driver->patchlevel,
1107 dev->dev ? dev_name(dev->dev) : "virtual device",
1108 dev->primary ? dev->primary->index : dev->accel->index);
1109
1110 goto out_unlock;
1111
1112err_unload:
1113 if (dev->driver->unload)
1114 dev->driver->unload(dev);
1115err_minors:
1116 remove_compat_control_link(dev);
1117 drm_minor_unregister(dev, type: DRM_MINOR_ACCEL);
1118 drm_minor_unregister(dev, type: DRM_MINOR_PRIMARY);
1119 drm_minor_unregister(dev, type: DRM_MINOR_RENDER);
1120out_unlock:
1121 if (drm_dev_needs_global_mutex(dev))
1122 mutex_unlock(lock: &drm_global_mutex);
1123 return ret;
1124}
1125EXPORT_SYMBOL(drm_dev_register);
1126
1127/**
1128 * drm_dev_unregister - Unregister DRM device
1129 * @dev: Device to unregister
1130 *
1131 * Unregister the DRM device from the system. This does the reverse of
1132 * drm_dev_register() but does not deallocate the device. The caller must call
1133 * drm_dev_put() to drop their final reference, unless it is managed with devres
1134 * (as devices allocated with devm_drm_dev_alloc() are), in which case there is
1135 * already an unwind action registered.
1136 *
1137 * A special form of unregistering for hotpluggable devices is drm_dev_unplug(),
1138 * which can be called while there are still open users of @dev.
1139 *
1140 * This should be called first in the device teardown code to make sure
1141 * userspace can't access the device instance any more.
1142 */
1143void drm_dev_unregister(struct drm_device *dev)
1144{
1145 dev->registered = false;
1146
1147 drm_panic_unregister(dev);
1148
1149 drm_client_dev_unregister(dev);
1150
1151 if (drm_core_check_feature(dev, feature: DRIVER_MODESET))
1152 drm_modeset_unregister_all(dev);
1153
1154 if (dev->driver->unload)
1155 dev->driver->unload(dev);
1156
1157 remove_compat_control_link(dev);
1158 drm_minor_unregister(dev, type: DRM_MINOR_ACCEL);
1159 drm_minor_unregister(dev, type: DRM_MINOR_PRIMARY);
1160 drm_minor_unregister(dev, type: DRM_MINOR_RENDER);
1161 drm_debugfs_dev_fini(dev);
1162}
1163EXPORT_SYMBOL(drm_dev_unregister);
1164
1165/*
1166 * DRM Core
1167 * The DRM core module initializes all global DRM objects and makes them
1168 * available to drivers. Once setup, drivers can probe their respective
1169 * devices.
1170 * Currently, core management includes:
1171 * - The "DRM-Global" key/value database
1172 * - Global ID management for connectors
1173 * - DRM major number allocation
1174 * - DRM minor management
1175 * - DRM sysfs class
1176 * - DRM debugfs root
1177 *
1178 * Furthermore, the DRM core provides dynamic char-dev lookups. For each
1179 * interface registered on a DRM device, you can request minor numbers from DRM
1180 * core. DRM core takes care of major-number management and char-dev
1181 * registration. A stub ->open() callback forwards any open() requests to the
1182 * registered minor.
1183 */
1184
1185static int drm_stub_open(struct inode *inode, struct file *filp)
1186{
1187 const struct file_operations *new_fops;
1188 struct drm_minor *minor;
1189 int err;
1190
1191 DRM_DEBUG("\n");
1192
1193 minor = drm_minor_acquire(minor_xa: &drm_minors_xa, minor_id: iminor(inode));
1194 if (IS_ERR(ptr: minor))
1195 return PTR_ERR(ptr: minor);
1196
1197 new_fops = fops_get(minor->dev->driver->fops);
1198 if (!new_fops) {
1199 err = -ENODEV;
1200 goto out;
1201 }
1202
1203 replace_fops(filp, new_fops);
1204 if (filp->f_op->open)
1205 err = filp->f_op->open(inode, filp);
1206 else
1207 err = 0;
1208
1209out:
1210 drm_minor_release(minor);
1211
1212 return err;
1213}
1214
1215static const struct file_operations drm_stub_fops = {
1216 .owner = THIS_MODULE,
1217 .open = drm_stub_open,
1218 .llseek = noop_llseek,
1219};
1220
1221static void drm_core_exit(void)
1222{
1223 drm_privacy_screen_lookup_exit();
1224 drm_panic_exit();
1225 accel_core_exit();
1226 unregister_chrdev(DRM_MAJOR, name: "drm");
1227 drm_debugfs_remove_root();
1228 drm_sysfs_destroy();
1229 WARN_ON(!xa_empty(&drm_minors_xa));
1230 drm_connector_ida_destroy();
1231}
1232
1233static int __init drm_core_init(void)
1234{
1235 int ret;
1236
1237 drm_connector_ida_init();
1238 drm_memcpy_init_early();
1239
1240 ret = drm_sysfs_init();
1241 if (ret < 0) {
1242 DRM_ERROR("Cannot create DRM class: %d\n", ret);
1243 goto error;
1244 }
1245
1246 drm_debugfs_init_root();
1247 drm_debugfs_bridge_params();
1248
1249 ret = register_chrdev(DRM_MAJOR, name: "drm", fops: &drm_stub_fops);
1250 if (ret < 0)
1251 goto error;
1252
1253 ret = accel_core_init();
1254 if (ret < 0)
1255 goto error;
1256
1257 drm_panic_init();
1258
1259 drm_privacy_screen_lookup_init();
1260
1261 drm_core_init_complete = true;
1262
1263 DRM_DEBUG("Initialized\n");
1264 return 0;
1265
1266error:
1267 drm_core_exit();
1268 return ret;
1269}
1270
1271module_init(drm_core_init);
1272module_exit(drm_core_exit);
1273