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1/*
2 * Copyright (c) 2016 Intel Corporation
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/export.h>
24#include <drm/drmP.h>
25#include <drm/drm_auth.h>
26#include <drm/drm_framebuffer.h>
27
28#include "drm_crtc_internal.h"
29
30/**
31 * DOC: overview
32 *
33 * Frame buffers are abstract memory objects that provide a source of pixels to
34 * scanout to a CRTC. Applications explicitly request the creation of frame
35 * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
36 * handle that can be passed to the KMS CRTC control, plane configuration and
37 * page flip functions.
38 *
39 * Frame buffers rely on the underlying memory manager for allocating backing
40 * storage. When creating a frame buffer applications pass a memory handle
41 * (or a list of memory handles for multi-planar formats) through the
42 * struct &drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
43 * buffer management interface this would be a GEM handle. Drivers are however
44 * free to use their own backing storage object handles, e.g. vmwgfx directly
45 * exposes special TTM handles to userspace and so expects TTM handles in the
46 * create ioctl and not GEM handles.
47 *
48 * Framebuffers are tracked with struct &drm_framebuffer. They are published
49 * using drm_framebuffer_init() - after calling that function userspace can use
50 * and access the framebuffer object. The helper function
51 * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
52 * metadata fields.
53 *
54 * The lifetime of a drm framebuffer is controlled with a reference count,
55 * drivers can grab additional references with drm_framebuffer_reference() and
56 * drop them again with drm_framebuffer_unreference(). For driver-private
57 * framebuffers for which the last reference is never dropped (e.g. for the
58 * fbdev framebuffer when the struct struct &drm_framebuffer is embedded into
59 * the fbdev helper struct) drivers can manually clean up a framebuffer at
60 * module unload time with drm_framebuffer_unregister_private(). But doing this
61 * is not recommended, and it's better to have a normal free-standing struct
62 * &drm_framebuffer.
63 */
64
65int drm_framebuffer_check_src_coords(uint32_t src_x, uint32_t src_y,
66 uint32_t src_w, uint32_t src_h,
67 const struct drm_framebuffer *fb)
68{
69 unsigned int fb_width, fb_height;
70
71 fb_width = fb->width << 16;
72 fb_height = fb->height << 16;
73
74 /* Make sure source coordinates are inside the fb. */
75 if (src_w > fb_width ||
76 src_x > fb_width - src_w ||
77 src_h > fb_height ||
78 src_y > fb_height - src_h) {
79 DRM_DEBUG_KMS("Invalid source coordinates "
80 "%u.%06ux%u.%06u+%u.%06u+%u.%06u\n",
81 src_w >> 16, ((src_w & 0xffff) * 15625) >> 10,
82 src_h >> 16, ((src_h & 0xffff) * 15625) >> 10,
83 src_x >> 16, ((src_x & 0xffff) * 15625) >> 10,
84 src_y >> 16, ((src_y & 0xffff) * 15625) >> 10);
85 return -ENOSPC;
86 }
87
88 return 0;
89}
90
91/**
92 * drm_mode_addfb - add an FB to the graphics configuration
93 * @dev: drm device for the ioctl
94 * @data: data pointer for the ioctl
95 * @file_priv: drm file for the ioctl call
96 *
97 * Add a new FB to the specified CRTC, given a user request. This is the
98 * original addfb ioctl which only supported RGB formats.
99 *
100 * Called by the user via ioctl.
101 *
102 * Returns:
103 * Zero on success, negative errno on failure.
104 */
105int drm_mode_addfb(struct drm_device *dev,
106 void *data, struct drm_file *file_priv)
107{
108 struct drm_mode_fb_cmd *or = data;
109 struct drm_mode_fb_cmd2 r = {};
110 int ret;
111
112 /* convert to new format and call new ioctl */
113 r.fb_id = or->fb_id;
114 r.width = or->width;
115 r.height = or->height;
116 r.pitches[0] = or->pitch;
117 r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
118 r.handles[0] = or->handle;
119
120 ret = drm_mode_addfb2(dev, &r, file_priv);
121 if (ret)
122 return ret;
123
124 or->fb_id = r.fb_id;
125
126 return 0;
127}
128
129static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
130{
131 const struct drm_format_info *info;
132 int i;
133
134 info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
135 if (!info) {
136 struct drm_format_name_buf format_name;
137 DRM_DEBUG_KMS("bad framebuffer format %s\n",
138 drm_get_format_name(r->pixel_format,
139 &format_name));
140 return -EINVAL;
141 }
142
143 if (r->width == 0 || r->width % info->hsub) {
144 DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
145 return -EINVAL;
146 }
147
148 if (r->height == 0 || r->height % info->vsub) {
149 DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
150 return -EINVAL;
151 }
152
153 for (i = 0; i < info->num_planes; i++) {
154 unsigned int width = r->width / (i != 0 ? info->hsub : 1);
155 unsigned int height = r->height / (i != 0 ? info->vsub : 1);
156 unsigned int cpp = info->cpp[i];
157
158 if (!r->handles[i]) {
159 DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
160 return -EINVAL;
161 }
162
163 if ((uint64_t) width * cpp > UINT_MAX)
164 return -ERANGE;
165
166 if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
167 return -ERANGE;
168
169 if (r->pitches[i] < width * cpp) {
170 DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
171 return -EINVAL;
172 }
173
174 if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
175 DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
176 r->modifier[i], i);
177 return -EINVAL;
178 }
179
180 if (r->flags & DRM_MODE_FB_MODIFIERS &&
181 r->modifier[i] != r->modifier[0]) {
182 DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
183 r->modifier[i], i);
184 return -EINVAL;
185 }
186
187 /* modifier specific checks: */
188 switch (r->modifier[i]) {
189 case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
190 /* NOTE: the pitch restriction may be lifted later if it turns
191 * out that no hw has this restriction:
192 */
193 if (r->pixel_format != DRM_FORMAT_NV12 ||
194 width % 128 || height % 32 ||
195 r->pitches[i] % 128) {
196 DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
197 return -EINVAL;
198 }
199 break;
200
201 default:
202 break;
203 }
204 }
205
206 for (i = info->num_planes; i < 4; i++) {
207 if (r->modifier[i]) {
208 DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
209 return -EINVAL;
210 }
211
212 /* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
213 if (!(r->flags & DRM_MODE_FB_MODIFIERS))
214 continue;
215
216 if (r->handles[i]) {
217 DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
218 return -EINVAL;
219 }
220
221 if (r->pitches[i]) {
222 DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
223 return -EINVAL;
224 }
225
226 if (r->offsets[i]) {
227 DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
228 return -EINVAL;
229 }
230 }
231
232 return 0;
233}
234
235struct drm_framebuffer *
236drm_internal_framebuffer_create(struct drm_device *dev,
237 const struct drm_mode_fb_cmd2 *r,
238 struct drm_file *file_priv)
239{
240 struct drm_mode_config *config = &dev->mode_config;
241 struct drm_framebuffer *fb;
242 int ret;
243
244 if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
245 DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
246 return ERR_PTR(-EINVAL);
247 }
248
249 if ((config->min_width > r->width) || (r->width > config->max_width)) {
250 DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
251 r->width, config->min_width, config->max_width);
252 return ERR_PTR(-EINVAL);
253 }
254 if ((config->min_height > r->height) || (r->height > config->max_height)) {
255 DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
256 r->height, config->min_height, config->max_height);
257 return ERR_PTR(-EINVAL);
258 }
259
260 if (r->flags & DRM_MODE_FB_MODIFIERS &&
261 !dev->mode_config.allow_fb_modifiers) {
262 DRM_DEBUG_KMS("driver does not support fb modifiers\n");
263 return ERR_PTR(-EINVAL);
264 }
265
266 ret = framebuffer_check(r);
267 if (ret)
268 return ERR_PTR(ret);
269
270 fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
271 if (IS_ERR(fb)) {
272 DRM_DEBUG_KMS("could not create framebuffer\n");
273 return fb;
274 }
275
276 return fb;
277}
278
279/**
280 * drm_mode_addfb2 - add an FB to the graphics configuration
281 * @dev: drm device for the ioctl
282 * @data: data pointer for the ioctl
283 * @file_priv: drm file for the ioctl call
284 *
285 * Add a new FB to the specified CRTC, given a user request with format. This is
286 * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
287 * and uses fourcc codes as pixel format specifiers.
288 *
289 * Called by the user via ioctl.
290 *
291 * Returns:
292 * Zero on success, negative errno on failure.
293 */
294int drm_mode_addfb2(struct drm_device *dev,
295 void *data, struct drm_file *file_priv)
296{
297 struct drm_mode_fb_cmd2 *r = data;
298 struct drm_framebuffer *fb;
299
300 if (!drm_core_check_feature(dev, DRIVER_MODESET))
301 return -EINVAL;
302
303 fb = drm_internal_framebuffer_create(dev, r, file_priv);
304 if (IS_ERR(fb))
305 return PTR_ERR(fb);
306
307 DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
308 r->fb_id = fb->base.id;
309
310 /* Transfer ownership to the filp for reaping on close */
311 mutex_lock(&file_priv->fbs_lock);
312 list_add(&fb->filp_head, &file_priv->fbs);
313 mutex_unlock(&file_priv->fbs_lock);
314
315 return 0;
316}
317
318struct drm_mode_rmfb_work {
319 struct work_struct work;
320 struct list_head fbs;
321};
322
323static void drm_mode_rmfb_work_fn(struct work_struct *w)
324{
325 struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
326
327 while (!list_empty(&arg->fbs)) {
328 struct drm_framebuffer *fb =
329 list_first_entry(&arg->fbs, typeof(*fb), filp_head);
330
331 list_del_init(&fb->filp_head);
332 drm_framebuffer_remove(fb);
333 }
334}
335
336/**
337 * drm_mode_rmfb - remove an FB from the configuration
338 * @dev: drm device for the ioctl
339 * @data: data pointer for the ioctl
340 * @file_priv: drm file for the ioctl call
341 *
342 * Remove the FB specified by the user.
343 *
344 * Called by the user via ioctl.
345 *
346 * Returns:
347 * Zero on success, negative errno on failure.
348 */
349int drm_mode_rmfb(struct drm_device *dev,
350 void *data, struct drm_file *file_priv)
351{
352 struct drm_framebuffer *fb = NULL;
353 struct drm_framebuffer *fbl = NULL;
354 uint32_t *id = data;
355 int found = 0;
356
357 if (!drm_core_check_feature(dev, DRIVER_MODESET))
358 return -EINVAL;
359
360 fb = drm_framebuffer_lookup(dev, *id);
361 if (!fb)
362 return -ENOENT;
363
364 mutex_lock(&file_priv->fbs_lock);
365 list_for_each_entry(fbl, &file_priv->fbs, filp_head)
366 if (fb == fbl)
367 found = 1;
368 if (!found) {
369 mutex_unlock(&file_priv->fbs_lock);
370 goto fail_unref;
371 }
372
373 list_del_init(&fb->filp_head);
374 mutex_unlock(&file_priv->fbs_lock);
375
376 /* drop the reference we picked up in framebuffer lookup */
377 drm_framebuffer_unreference(fb);
378
379 /*
380 * we now own the reference that was stored in the fbs list
381 *
382 * drm_framebuffer_remove may fail with -EINTR on pending signals,
383 * so run this in a separate stack as there's no way to correctly
384 * handle this after the fb is already removed from the lookup table.
385 */
386 if (drm_framebuffer_read_refcount(fb) > 1) {
387 struct drm_mode_rmfb_work arg;
388
389 INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
390 INIT_LIST_HEAD(&arg.fbs);
391 list_add_tail(&fb->filp_head, &arg.fbs);
392
393 schedule_work(&arg.work);
394 flush_work(&arg.work);
395 destroy_work_on_stack(&arg.work);
396 } else
397 drm_framebuffer_unreference(fb);
398
399 return 0;
400
401fail_unref:
402 drm_framebuffer_unreference(fb);
403 return -ENOENT;
404}
405
406/**
407 * drm_mode_getfb - get FB info
408 * @dev: drm device for the ioctl
409 * @data: data pointer for the ioctl
410 * @file_priv: drm file for the ioctl call
411 *
412 * Lookup the FB given its ID and return info about it.
413 *
414 * Called by the user via ioctl.
415 *
416 * Returns:
417 * Zero on success, negative errno on failure.
418 */
419int drm_mode_getfb(struct drm_device *dev,
420 void *data, struct drm_file *file_priv)
421{
422 struct drm_mode_fb_cmd *r = data;
423 struct drm_framebuffer *fb;
424 int ret;
425
426 if (!drm_core_check_feature(dev, DRIVER_MODESET))
427 return -EINVAL;
428
429 fb = drm_framebuffer_lookup(dev, r->fb_id);
430 if (!fb)
431 return -ENOENT;
432
433 r->height = fb->height;
434 r->width = fb->width;
435 r->depth = fb->depth;
436 r->bpp = fb->bits_per_pixel;
437 r->pitch = fb->pitches[0];
438 if (fb->funcs->create_handle) {
439 if (drm_is_current_master(file_priv) || capable(CAP_SYS_ADMIN) ||
440 drm_is_control_client(file_priv)) {
441 ret = fb->funcs->create_handle(fb, file_priv,
442 &r->handle);
443 } else {
444 /* GET_FB() is an unprivileged ioctl so we must not
445 * return a buffer-handle to non-master processes! For
446 * backwards-compatibility reasons, we cannot make
447 * GET_FB() privileged, so just return an invalid handle
448 * for non-masters. */
449 r->handle = 0;
450 ret = 0;
451 }
452 } else {
453 ret = -ENODEV;
454 }
455
456 drm_framebuffer_unreference(fb);
457
458 return ret;
459}
460
461/**
462 * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
463 * @dev: drm device for the ioctl
464 * @data: data pointer for the ioctl
465 * @file_priv: drm file for the ioctl call
466 *
467 * Lookup the FB and flush out the damaged area supplied by userspace as a clip
468 * rectangle list. Generic userspace which does frontbuffer rendering must call
469 * this ioctl to flush out the changes on manual-update display outputs, e.g.
470 * usb display-link, mipi manual update panels or edp panel self refresh modes.
471 *
472 * Modesetting drivers which always update the frontbuffer do not need to
473 * implement the corresponding ->dirty framebuffer callback.
474 *
475 * Called by the user via ioctl.
476 *
477 * Returns:
478 * Zero on success, negative errno on failure.
479 */
480int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
481 void *data, struct drm_file *file_priv)
482{
483 struct drm_clip_rect __user *clips_ptr;
484 struct drm_clip_rect *clips = NULL;
485 struct drm_mode_fb_dirty_cmd *r = data;
486 struct drm_framebuffer *fb;
487 unsigned flags;
488 int num_clips;
489 int ret;
490
491 if (!drm_core_check_feature(dev, DRIVER_MODESET))
492 return -EINVAL;
493
494 fb = drm_framebuffer_lookup(dev, r->fb_id);
495 if (!fb)
496 return -ENOENT;
497
498 num_clips = r->num_clips;
499 clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
500
501 if (!num_clips != !clips_ptr) {
502 ret = -EINVAL;
503 goto out_err1;
504 }
505
506 flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
507
508 /* If userspace annotates copy, clips must come in pairs */
509 if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
510 ret = -EINVAL;
511 goto out_err1;
512 }
513
514 if (num_clips && clips_ptr) {
515 if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
516 ret = -EINVAL;
517 goto out_err1;
518 }
519 clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
520 if (!clips) {
521 ret = -ENOMEM;
522 goto out_err1;
523 }
524
525 ret = copy_from_user(clips, clips_ptr,
526 num_clips * sizeof(*clips));
527 if (ret) {
528 ret = -EFAULT;
529 goto out_err2;
530 }
531 }
532
533 if (fb->funcs->dirty) {
534 ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
535 clips, num_clips);
536 } else {
537 ret = -ENOSYS;
538 }
539
540out_err2:
541 kfree(clips);
542out_err1:
543 drm_framebuffer_unreference(fb);
544
545 return ret;
546}
547
548/**
549 * drm_fb_release - remove and free the FBs on this file
550 * @priv: drm file for the ioctl
551 *
552 * Destroy all the FBs associated with @filp.
553 *
554 * Called by the user via ioctl.
555 *
556 * Returns:
557 * Zero on success, negative errno on failure.
558 */
559void drm_fb_release(struct drm_file *priv)
560{
561 struct drm_framebuffer *fb, *tfb;
562 struct drm_mode_rmfb_work arg;
563
564 INIT_LIST_HEAD(&arg.fbs);
565
566 /*
567 * When the file gets released that means no one else can access the fb
568 * list any more, so no need to grab fpriv->fbs_lock. And we need to
569 * avoid upsetting lockdep since the universal cursor code adds a
570 * framebuffer while holding mutex locks.
571 *
572 * Note that a real deadlock between fpriv->fbs_lock and the modeset
573 * locks is impossible here since no one else but this function can get
574 * at it any more.
575 */
576 list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
577 if (drm_framebuffer_read_refcount(fb) > 1) {
578 list_move_tail(&fb->filp_head, &arg.fbs);
579 } else {
580 list_del_init(&fb->filp_head);
581
582 /* This drops the fpriv->fbs reference. */
583 drm_framebuffer_unreference(fb);
584 }
585 }
586
587 if (!list_empty(&arg.fbs)) {
588 INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
589
590 schedule_work(&arg.work);
591 flush_work(&arg.work);
592 destroy_work_on_stack(&arg.work);
593 }
594}
595
596void drm_framebuffer_free(struct kref *kref)
597{
598 struct drm_framebuffer *fb =
599 container_of(kref, struct drm_framebuffer, base.refcount);
600 struct drm_device *dev = fb->dev;
601
602 /*
603 * The lookup idr holds a weak reference, which has not necessarily been
604 * removed at this point. Check for that.
605 */
606 drm_mode_object_unregister(dev, &fb->base);
607
608 fb->funcs->destroy(fb);
609}
610
611/**
612 * drm_framebuffer_init - initialize a framebuffer
613 * @dev: DRM device
614 * @fb: framebuffer to be initialized
615 * @funcs: ... with these functions
616 *
617 * Allocates an ID for the framebuffer's parent mode object, sets its mode
618 * functions & device file and adds it to the master fd list.
619 *
620 * IMPORTANT:
621 * This functions publishes the fb and makes it available for concurrent access
622 * by other users. Which means by this point the fb _must_ be fully set up -
623 * since all the fb attributes are invariant over its lifetime, no further
624 * locking but only correct reference counting is required.
625 *
626 * Returns:
627 * Zero on success, error code on failure.
628 */
629int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
630 const struct drm_framebuffer_funcs *funcs)
631{
632 int ret;
633
634 INIT_LIST_HEAD(&fb->filp_head);
635 fb->dev = dev;
636 fb->funcs = funcs;
637
638 ret = drm_mode_object_get_reg(dev, &fb->base, DRM_MODE_OBJECT_FB,
639 false, drm_framebuffer_free);
640 if (ret)
641 goto out;
642
643 mutex_lock(&dev->mode_config.fb_lock);
644 dev->mode_config.num_fb++;
645 list_add(&fb->head, &dev->mode_config.fb_list);
646 mutex_unlock(&dev->mode_config.fb_lock);
647
648 drm_mode_object_register(dev, &fb->base);
649out:
650 return ret;
651}
652EXPORT_SYMBOL(drm_framebuffer_init);
653
654/**
655 * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
656 * @dev: drm device
657 * @id: id of the fb object
658 *
659 * If successful, this grabs an additional reference to the framebuffer -
660 * callers need to make sure to eventually unreference the returned framebuffer
661 * again, using @drm_framebuffer_unreference.
662 */
663struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
664 uint32_t id)
665{
666 struct drm_mode_object *obj;
667 struct drm_framebuffer *fb = NULL;
668
669 obj = __drm_mode_object_find(dev, id, DRM_MODE_OBJECT_FB);
670 if (obj)
671 fb = obj_to_fb(obj);
672 return fb;
673}
674EXPORT_SYMBOL(drm_framebuffer_lookup);
675
676/**
677 * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
678 * @fb: fb to unregister
679 *
680 * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
681 * those used for fbdev. Note that the caller must hold a reference of it's own,
682 * i.e. the object may not be destroyed through this call (since it'll lead to a
683 * locking inversion).
684 *
685 * NOTE: This function is deprecated. For driver-private framebuffers it is not
686 * recommended to embed a framebuffer struct info fbdev struct, instead, a
687 * framebuffer pointer is preferred and drm_framebuffer_unreference() should be
688 * called when the framebuffer is to be cleaned up.
689 */
690void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
691{
692 struct drm_device *dev;
693
694 if (!fb)
695 return;
696
697 dev = fb->dev;
698
699 /* Mark fb as reaped and drop idr ref. */
700 drm_mode_object_unregister(dev, &fb->base);
701}
702EXPORT_SYMBOL(drm_framebuffer_unregister_private);
703
704/**
705 * drm_framebuffer_cleanup - remove a framebuffer object
706 * @fb: framebuffer to remove
707 *
708 * Cleanup framebuffer. This function is intended to be used from the drivers
709 * ->destroy callback. It can also be used to clean up driver private
710 * framebuffers embedded into a larger structure.
711 *
712 * Note that this function does not remove the fb from active usuage - if it is
713 * still used anywhere, hilarity can ensue since userspace could call getfb on
714 * the id and get back -EINVAL. Obviously no concern at driver unload time.
715 *
716 * Also, the framebuffer will not be removed from the lookup idr - for
717 * user-created framebuffers this will happen in in the rmfb ioctl. For
718 * driver-private objects (e.g. for fbdev) drivers need to explicitly call
719 * drm_framebuffer_unregister_private.
720 */
721void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
722{
723 struct drm_device *dev = fb->dev;
724
725 mutex_lock(&dev->mode_config.fb_lock);
726 list_del(&fb->head);
727 dev->mode_config.num_fb--;
728 mutex_unlock(&dev->mode_config.fb_lock);
729}
730EXPORT_SYMBOL(drm_framebuffer_cleanup);
731
732/**
733 * drm_framebuffer_remove - remove and unreference a framebuffer object
734 * @fb: framebuffer to remove
735 *
736 * Scans all the CRTCs and planes in @dev's mode_config. If they're
737 * using @fb, removes it, setting it to NULL. Then drops the reference to the
738 * passed-in framebuffer. Might take the modeset locks.
739 *
740 * Note that this function optimizes the cleanup away if the caller holds the
741 * last reference to the framebuffer. It is also guaranteed to not take the
742 * modeset locks in this case.
743 */
744void drm_framebuffer_remove(struct drm_framebuffer *fb)
745{
746 struct drm_device *dev;
747 struct drm_crtc *crtc;
748 struct drm_plane *plane;
749
750 if (!fb)
751 return;
752
753 dev = fb->dev;
754
755 WARN_ON(!list_empty(&fb->filp_head));
756
757 /*
758 * drm ABI mandates that we remove any deleted framebuffers from active
759 * useage. But since most sane clients only remove framebuffers they no
760 * longer need, try to optimize this away.
761 *
762 * Since we're holding a reference ourselves, observing a refcount of 1
763 * means that we're the last holder and can skip it. Also, the refcount
764 * can never increase from 1 again, so we don't need any barriers or
765 * locks.
766 *
767 * Note that userspace could try to race with use and instate a new
768 * usage _after_ we've cleared all current ones. End result will be an
769 * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
770 * in this manner.
771 */
772 if (drm_framebuffer_read_refcount(fb) > 1) {
773 drm_modeset_lock_all(dev);
774 /* remove from any CRTC */
775 drm_for_each_crtc(crtc, dev) {
776 if (crtc->primary->fb == fb) {
777 /* should turn off the crtc */
778 if (drm_crtc_force_disable(crtc))
779 DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
780 }
781 }
782
783 drm_for_each_plane(plane, dev) {
784 if (plane->fb == fb)
785 drm_plane_force_disable(plane);
786 }
787 drm_modeset_unlock_all(dev);
788 }
789
790 drm_framebuffer_unreference(fb);
791}
792EXPORT_SYMBOL(drm_framebuffer_remove);