xref: /openbmc/linux/drivers/gpu/drm/drm_framebuffer.c (revision 9977a8c3497a8f7f7f951994f298a8e4d961234f)
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 #include <drm/drm_atomic.h>
28 #include <drm/drm_print.h>
29 
30 #include "drm_internal.h"
31 #include "drm_crtc_internal.h"
32 
33 /**
34  * DOC: overview
35  *
36  * Frame buffers are abstract memory objects that provide a source of pixels to
37  * scanout to a CRTC. Applications explicitly request the creation of frame
38  * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
39  * handle that can be passed to the KMS CRTC control, plane configuration and
40  * page flip functions.
41  *
42  * Frame buffers rely on the underlying memory manager for allocating backing
43  * storage. When creating a frame buffer applications pass a memory handle
44  * (or a list of memory handles for multi-planar formats) through the
45  * &struct drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
46  * buffer management interface this would be a GEM handle.  Drivers are however
47  * free to use their own backing storage object handles, e.g. vmwgfx directly
48  * exposes special TTM handles to userspace and so expects TTM handles in the
49  * create ioctl and not GEM handles.
50  *
51  * Framebuffers are tracked with &struct drm_framebuffer. They are published
52  * using drm_framebuffer_init() - after calling that function userspace can use
53  * and access the framebuffer object. The helper function
54  * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
55  * metadata fields.
56  *
57  * The lifetime of a drm framebuffer is controlled with a reference count,
58  * drivers can grab additional references with drm_framebuffer_get() and drop
59  * them again with drm_framebuffer_put(). For driver-private framebuffers for
60  * which the last reference is never dropped (e.g. for the fbdev framebuffer
61  * when the struct &struct drm_framebuffer is embedded into the fbdev helper
62  * struct) drivers can manually clean up a framebuffer at module unload time
63  * with drm_framebuffer_unregister_private(). But doing this is not
64  * recommended, and it's better to have a normal free-standing &struct
65  * drm_framebuffer.
66  */
67 
68 int drm_framebuffer_check_src_coords(uint32_t src_x, uint32_t src_y,
69 				     uint32_t src_w, uint32_t src_h,
70 				     const struct drm_framebuffer *fb)
71 {
72 	unsigned int fb_width, fb_height;
73 
74 	fb_width = fb->width << 16;
75 	fb_height = fb->height << 16;
76 
77 	/* Make sure source coordinates are inside the fb. */
78 	if (src_w > fb_width ||
79 	    src_x > fb_width - src_w ||
80 	    src_h > fb_height ||
81 	    src_y > fb_height - src_h) {
82 		DRM_DEBUG_KMS("Invalid source coordinates "
83 			      "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
84 			      src_w >> 16, ((src_w & 0xffff) * 15625) >> 10,
85 			      src_h >> 16, ((src_h & 0xffff) * 15625) >> 10,
86 			      src_x >> 16, ((src_x & 0xffff) * 15625) >> 10,
87 			      src_y >> 16, ((src_y & 0xffff) * 15625) >> 10,
88 			      fb->width, fb->height);
89 		return -ENOSPC;
90 	}
91 
92 	return 0;
93 }
94 
95 /**
96  * drm_mode_addfb - add an FB to the graphics configuration
97  * @dev: drm device for the ioctl
98  * @data: data pointer for the ioctl
99  * @file_priv: drm file for the ioctl call
100  *
101  * Add a new FB to the specified CRTC, given a user request. This is the
102  * original addfb ioctl which only supported RGB formats.
103  *
104  * Called by the user via ioctl.
105  *
106  * Returns:
107  * Zero on success, negative errno on failure.
108  */
109 int drm_mode_addfb(struct drm_device *dev,
110 		   void *data, struct drm_file *file_priv)
111 {
112 	struct drm_mode_fb_cmd *or = data;
113 	struct drm_mode_fb_cmd2 r = {};
114 	int ret;
115 
116 	/* convert to new format and call new ioctl */
117 	r.fb_id = or->fb_id;
118 	r.width = or->width;
119 	r.height = or->height;
120 	r.pitches[0] = or->pitch;
121 	r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
122 	r.handles[0] = or->handle;
123 
124 	ret = drm_mode_addfb2(dev, &r, file_priv);
125 	if (ret)
126 		return ret;
127 
128 	or->fb_id = r.fb_id;
129 
130 	return 0;
131 }
132 
133 static int fb_plane_width(int width,
134 			  const struct drm_format_info *format, int plane)
135 {
136 	if (plane == 0)
137 		return width;
138 
139 	return DIV_ROUND_UP(width, format->hsub);
140 }
141 
142 static int fb_plane_height(int height,
143 			   const struct drm_format_info *format, int plane)
144 {
145 	if (plane == 0)
146 		return height;
147 
148 	return DIV_ROUND_UP(height, format->vsub);
149 }
150 
151 static int framebuffer_check(struct drm_device *dev,
152 			     const struct drm_mode_fb_cmd2 *r)
153 {
154 	const struct drm_format_info *info;
155 	int i;
156 
157 	/* check if the format is supported at all */
158 	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
159 	if (!info) {
160 		struct drm_format_name_buf format_name;
161 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
162 		              drm_get_format_name(r->pixel_format,
163 		                                  &format_name));
164 		return -EINVAL;
165 	}
166 
167 	/* now let the driver pick its own format info */
168 	info = drm_get_format_info(dev, r);
169 
170 	if (r->width == 0) {
171 		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
172 		return -EINVAL;
173 	}
174 
175 	if (r->height == 0) {
176 		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
177 		return -EINVAL;
178 	}
179 
180 	for (i = 0; i < info->num_planes; i++) {
181 		unsigned int width = fb_plane_width(r->width, info, i);
182 		unsigned int height = fb_plane_height(r->height, info, i);
183 		unsigned int cpp = info->cpp[i];
184 
185 		if (!r->handles[i]) {
186 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
187 			return -EINVAL;
188 		}
189 
190 		if ((uint64_t) width * cpp > UINT_MAX)
191 			return -ERANGE;
192 
193 		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
194 			return -ERANGE;
195 
196 		if (r->pitches[i] < width * cpp) {
197 			DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
198 			return -EINVAL;
199 		}
200 
201 		if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
202 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
203 				      r->modifier[i], i);
204 			return -EINVAL;
205 		}
206 
207 		if (r->flags & DRM_MODE_FB_MODIFIERS &&
208 		    r->modifier[i] != r->modifier[0]) {
209 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
210 				      r->modifier[i], i);
211 			return -EINVAL;
212 		}
213 
214 		/* modifier specific checks: */
215 		switch (r->modifier[i]) {
216 		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
217 			/* NOTE: the pitch restriction may be lifted later if it turns
218 			 * out that no hw has this restriction:
219 			 */
220 			if (r->pixel_format != DRM_FORMAT_NV12 ||
221 					width % 128 || height % 32 ||
222 					r->pitches[i] % 128) {
223 				DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
224 				return -EINVAL;
225 			}
226 			break;
227 
228 		default:
229 			break;
230 		}
231 	}
232 
233 	for (i = info->num_planes; i < 4; i++) {
234 		if (r->modifier[i]) {
235 			DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
236 			return -EINVAL;
237 		}
238 
239 		/* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
240 		if (!(r->flags & DRM_MODE_FB_MODIFIERS))
241 			continue;
242 
243 		if (r->handles[i]) {
244 			DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
245 			return -EINVAL;
246 		}
247 
248 		if (r->pitches[i]) {
249 			DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
250 			return -EINVAL;
251 		}
252 
253 		if (r->offsets[i]) {
254 			DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
255 			return -EINVAL;
256 		}
257 	}
258 
259 	return 0;
260 }
261 
262 struct drm_framebuffer *
263 drm_internal_framebuffer_create(struct drm_device *dev,
264 				const struct drm_mode_fb_cmd2 *r,
265 				struct drm_file *file_priv)
266 {
267 	struct drm_mode_config *config = &dev->mode_config;
268 	struct drm_framebuffer *fb;
269 	int ret;
270 
271 	if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
272 		DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
273 		return ERR_PTR(-EINVAL);
274 	}
275 
276 	if ((config->min_width > r->width) || (r->width > config->max_width)) {
277 		DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
278 			  r->width, config->min_width, config->max_width);
279 		return ERR_PTR(-EINVAL);
280 	}
281 	if ((config->min_height > r->height) || (r->height > config->max_height)) {
282 		DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
283 			  r->height, config->min_height, config->max_height);
284 		return ERR_PTR(-EINVAL);
285 	}
286 
287 	if (r->flags & DRM_MODE_FB_MODIFIERS &&
288 	    !dev->mode_config.allow_fb_modifiers) {
289 		DRM_DEBUG_KMS("driver does not support fb modifiers\n");
290 		return ERR_PTR(-EINVAL);
291 	}
292 
293 	ret = framebuffer_check(dev, r);
294 	if (ret)
295 		return ERR_PTR(ret);
296 
297 	fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
298 	if (IS_ERR(fb)) {
299 		DRM_DEBUG_KMS("could not create framebuffer\n");
300 		return fb;
301 	}
302 
303 	return fb;
304 }
305 
306 /**
307  * drm_mode_addfb2 - add an FB to the graphics configuration
308  * @dev: drm device for the ioctl
309  * @data: data pointer for the ioctl
310  * @file_priv: drm file for the ioctl call
311  *
312  * Add a new FB to the specified CRTC, given a user request with format. This is
313  * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
314  * and uses fourcc codes as pixel format specifiers.
315  *
316  * Called by the user via ioctl.
317  *
318  * Returns:
319  * Zero on success, negative errno on failure.
320  */
321 int drm_mode_addfb2(struct drm_device *dev,
322 		    void *data, struct drm_file *file_priv)
323 {
324 	struct drm_mode_fb_cmd2 *r = data;
325 	struct drm_framebuffer *fb;
326 
327 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
328 		return -EINVAL;
329 
330 	fb = drm_internal_framebuffer_create(dev, r, file_priv);
331 	if (IS_ERR(fb))
332 		return PTR_ERR(fb);
333 
334 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
335 	r->fb_id = fb->base.id;
336 
337 	/* Transfer ownership to the filp for reaping on close */
338 	mutex_lock(&file_priv->fbs_lock);
339 	list_add(&fb->filp_head, &file_priv->fbs);
340 	mutex_unlock(&file_priv->fbs_lock);
341 
342 	return 0;
343 }
344 
345 struct drm_mode_rmfb_work {
346 	struct work_struct work;
347 	struct list_head fbs;
348 };
349 
350 static void drm_mode_rmfb_work_fn(struct work_struct *w)
351 {
352 	struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
353 
354 	while (!list_empty(&arg->fbs)) {
355 		struct drm_framebuffer *fb =
356 			list_first_entry(&arg->fbs, typeof(*fb), filp_head);
357 
358 		list_del_init(&fb->filp_head);
359 		drm_framebuffer_remove(fb);
360 	}
361 }
362 
363 /**
364  * drm_mode_rmfb - remove an FB from the configuration
365  * @dev: drm device for the ioctl
366  * @data: data pointer for the ioctl
367  * @file_priv: drm file for the ioctl call
368  *
369  * Remove the FB specified by the user.
370  *
371  * Called by the user via ioctl.
372  *
373  * Returns:
374  * Zero on success, negative errno on failure.
375  */
376 int drm_mode_rmfb(struct drm_device *dev,
377 		   void *data, struct drm_file *file_priv)
378 {
379 	struct drm_framebuffer *fb = NULL;
380 	struct drm_framebuffer *fbl = NULL;
381 	uint32_t *id = data;
382 	int found = 0;
383 
384 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
385 		return -EINVAL;
386 
387 	fb = drm_framebuffer_lookup(dev, file_priv, *id);
388 	if (!fb)
389 		return -ENOENT;
390 
391 	mutex_lock(&file_priv->fbs_lock);
392 	list_for_each_entry(fbl, &file_priv->fbs, filp_head)
393 		if (fb == fbl)
394 			found = 1;
395 	if (!found) {
396 		mutex_unlock(&file_priv->fbs_lock);
397 		goto fail_unref;
398 	}
399 
400 	list_del_init(&fb->filp_head);
401 	mutex_unlock(&file_priv->fbs_lock);
402 
403 	/* drop the reference we picked up in framebuffer lookup */
404 	drm_framebuffer_put(fb);
405 
406 	/*
407 	 * we now own the reference that was stored in the fbs list
408 	 *
409 	 * drm_framebuffer_remove may fail with -EINTR on pending signals,
410 	 * so run this in a separate stack as there's no way to correctly
411 	 * handle this after the fb is already removed from the lookup table.
412 	 */
413 	if (drm_framebuffer_read_refcount(fb) > 1) {
414 		struct drm_mode_rmfb_work arg;
415 
416 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
417 		INIT_LIST_HEAD(&arg.fbs);
418 		list_add_tail(&fb->filp_head, &arg.fbs);
419 
420 		schedule_work(&arg.work);
421 		flush_work(&arg.work);
422 		destroy_work_on_stack(&arg.work);
423 	} else
424 		drm_framebuffer_put(fb);
425 
426 	return 0;
427 
428 fail_unref:
429 	drm_framebuffer_put(fb);
430 	return -ENOENT;
431 }
432 
433 /**
434  * drm_mode_getfb - get FB info
435  * @dev: drm device for the ioctl
436  * @data: data pointer for the ioctl
437  * @file_priv: drm file for the ioctl call
438  *
439  * Lookup the FB given its ID and return info about it.
440  *
441  * Called by the user via ioctl.
442  *
443  * Returns:
444  * Zero on success, negative errno on failure.
445  */
446 int drm_mode_getfb(struct drm_device *dev,
447 		   void *data, struct drm_file *file_priv)
448 {
449 	struct drm_mode_fb_cmd *r = data;
450 	struct drm_framebuffer *fb;
451 	int ret;
452 
453 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
454 		return -EINVAL;
455 
456 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
457 	if (!fb)
458 		return -ENOENT;
459 
460 	r->height = fb->height;
461 	r->width = fb->width;
462 	r->depth = fb->format->depth;
463 	r->bpp = fb->format->cpp[0] * 8;
464 	r->pitch = fb->pitches[0];
465 	if (fb->funcs->create_handle) {
466 		if (drm_is_current_master(file_priv) || capable(CAP_SYS_ADMIN) ||
467 		    drm_is_control_client(file_priv)) {
468 			ret = fb->funcs->create_handle(fb, file_priv,
469 						       &r->handle);
470 		} else {
471 			/* GET_FB() is an unprivileged ioctl so we must not
472 			 * return a buffer-handle to non-master processes! For
473 			 * backwards-compatibility reasons, we cannot make
474 			 * GET_FB() privileged, so just return an invalid handle
475 			 * for non-masters. */
476 			r->handle = 0;
477 			ret = 0;
478 		}
479 	} else {
480 		ret = -ENODEV;
481 	}
482 
483 	drm_framebuffer_put(fb);
484 
485 	return ret;
486 }
487 
488 /**
489  * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
490  * @dev: drm device for the ioctl
491  * @data: data pointer for the ioctl
492  * @file_priv: drm file for the ioctl call
493  *
494  * Lookup the FB and flush out the damaged area supplied by userspace as a clip
495  * rectangle list. Generic userspace which does frontbuffer rendering must call
496  * this ioctl to flush out the changes on manual-update display outputs, e.g.
497  * usb display-link, mipi manual update panels or edp panel self refresh modes.
498  *
499  * Modesetting drivers which always update the frontbuffer do not need to
500  * implement the corresponding &drm_framebuffer_funcs.dirty callback.
501  *
502  * Called by the user via ioctl.
503  *
504  * Returns:
505  * Zero on success, negative errno on failure.
506  */
507 int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
508 			   void *data, struct drm_file *file_priv)
509 {
510 	struct drm_clip_rect __user *clips_ptr;
511 	struct drm_clip_rect *clips = NULL;
512 	struct drm_mode_fb_dirty_cmd *r = data;
513 	struct drm_framebuffer *fb;
514 	unsigned flags;
515 	int num_clips;
516 	int ret;
517 
518 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
519 		return -EINVAL;
520 
521 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
522 	if (!fb)
523 		return -ENOENT;
524 
525 	num_clips = r->num_clips;
526 	clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
527 
528 	if (!num_clips != !clips_ptr) {
529 		ret = -EINVAL;
530 		goto out_err1;
531 	}
532 
533 	flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
534 
535 	/* If userspace annotates copy, clips must come in pairs */
536 	if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
537 		ret = -EINVAL;
538 		goto out_err1;
539 	}
540 
541 	if (num_clips && clips_ptr) {
542 		if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
543 			ret = -EINVAL;
544 			goto out_err1;
545 		}
546 		clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
547 		if (!clips) {
548 			ret = -ENOMEM;
549 			goto out_err1;
550 		}
551 
552 		ret = copy_from_user(clips, clips_ptr,
553 				     num_clips * sizeof(*clips));
554 		if (ret) {
555 			ret = -EFAULT;
556 			goto out_err2;
557 		}
558 	}
559 
560 	if (fb->funcs->dirty) {
561 		ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
562 				       clips, num_clips);
563 	} else {
564 		ret = -ENOSYS;
565 	}
566 
567 out_err2:
568 	kfree(clips);
569 out_err1:
570 	drm_framebuffer_put(fb);
571 
572 	return ret;
573 }
574 
575 /**
576  * drm_fb_release - remove and free the FBs on this file
577  * @priv: drm file for the ioctl
578  *
579  * Destroy all the FBs associated with @filp.
580  *
581  * Called by the user via ioctl.
582  *
583  * Returns:
584  * Zero on success, negative errno on failure.
585  */
586 void drm_fb_release(struct drm_file *priv)
587 {
588 	struct drm_framebuffer *fb, *tfb;
589 	struct drm_mode_rmfb_work arg;
590 
591 	INIT_LIST_HEAD(&arg.fbs);
592 
593 	/*
594 	 * When the file gets released that means no one else can access the fb
595 	 * list any more, so no need to grab fpriv->fbs_lock. And we need to
596 	 * avoid upsetting lockdep since the universal cursor code adds a
597 	 * framebuffer while holding mutex locks.
598 	 *
599 	 * Note that a real deadlock between fpriv->fbs_lock and the modeset
600 	 * locks is impossible here since no one else but this function can get
601 	 * at it any more.
602 	 */
603 	list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
604 		if (drm_framebuffer_read_refcount(fb) > 1) {
605 			list_move_tail(&fb->filp_head, &arg.fbs);
606 		} else {
607 			list_del_init(&fb->filp_head);
608 
609 			/* This drops the fpriv->fbs reference. */
610 			drm_framebuffer_put(fb);
611 		}
612 	}
613 
614 	if (!list_empty(&arg.fbs)) {
615 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
616 
617 		schedule_work(&arg.work);
618 		flush_work(&arg.work);
619 		destroy_work_on_stack(&arg.work);
620 	}
621 }
622 
623 void drm_framebuffer_free(struct kref *kref)
624 {
625 	struct drm_framebuffer *fb =
626 			container_of(kref, struct drm_framebuffer, base.refcount);
627 	struct drm_device *dev = fb->dev;
628 
629 	/*
630 	 * The lookup idr holds a weak reference, which has not necessarily been
631 	 * removed at this point. Check for that.
632 	 */
633 	drm_mode_object_unregister(dev, &fb->base);
634 
635 	fb->funcs->destroy(fb);
636 }
637 
638 /**
639  * drm_framebuffer_init - initialize a framebuffer
640  * @dev: DRM device
641  * @fb: framebuffer to be initialized
642  * @funcs: ... with these functions
643  *
644  * Allocates an ID for the framebuffer's parent mode object, sets its mode
645  * functions & device file and adds it to the master fd list.
646  *
647  * IMPORTANT:
648  * This functions publishes the fb and makes it available for concurrent access
649  * by other users. Which means by this point the fb _must_ be fully set up -
650  * since all the fb attributes are invariant over its lifetime, no further
651  * locking but only correct reference counting is required.
652  *
653  * Returns:
654  * Zero on success, error code on failure.
655  */
656 int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
657 			 const struct drm_framebuffer_funcs *funcs)
658 {
659 	int ret;
660 
661 	if (WARN_ON_ONCE(fb->dev != dev || !fb->format))
662 		return -EINVAL;
663 
664 	INIT_LIST_HEAD(&fb->filp_head);
665 
666 	fb->funcs = funcs;
667 	strcpy(fb->comm, current->comm);
668 
669 	ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB,
670 				    false, drm_framebuffer_free);
671 	if (ret)
672 		goto out;
673 
674 	mutex_lock(&dev->mode_config.fb_lock);
675 	dev->mode_config.num_fb++;
676 	list_add(&fb->head, &dev->mode_config.fb_list);
677 	mutex_unlock(&dev->mode_config.fb_lock);
678 
679 	drm_mode_object_register(dev, &fb->base);
680 out:
681 	return ret;
682 }
683 EXPORT_SYMBOL(drm_framebuffer_init);
684 
685 /**
686  * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
687  * @dev: drm device
688  * @file_priv: drm file to check for lease against.
689  * @id: id of the fb object
690  *
691  * If successful, this grabs an additional reference to the framebuffer -
692  * callers need to make sure to eventually unreference the returned framebuffer
693  * again, using drm_framebuffer_put().
694  */
695 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
696 					       struct drm_file *file_priv,
697 					       uint32_t id)
698 {
699 	struct drm_mode_object *obj;
700 	struct drm_framebuffer *fb = NULL;
701 
702 	obj = __drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_FB);
703 	if (obj)
704 		fb = obj_to_fb(obj);
705 	return fb;
706 }
707 EXPORT_SYMBOL(drm_framebuffer_lookup);
708 
709 /**
710  * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
711  * @fb: fb to unregister
712  *
713  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
714  * those used for fbdev. Note that the caller must hold a reference of it's own,
715  * i.e. the object may not be destroyed through this call (since it'll lead to a
716  * locking inversion).
717  *
718  * NOTE: This function is deprecated. For driver-private framebuffers it is not
719  * recommended to embed a framebuffer struct info fbdev struct, instead, a
720  * framebuffer pointer is preferred and drm_framebuffer_put() should be called
721  * when the framebuffer is to be cleaned up.
722  */
723 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
724 {
725 	struct drm_device *dev;
726 
727 	if (!fb)
728 		return;
729 
730 	dev = fb->dev;
731 
732 	/* Mark fb as reaped and drop idr ref. */
733 	drm_mode_object_unregister(dev, &fb->base);
734 }
735 EXPORT_SYMBOL(drm_framebuffer_unregister_private);
736 
737 /**
738  * drm_framebuffer_cleanup - remove a framebuffer object
739  * @fb: framebuffer to remove
740  *
741  * Cleanup framebuffer. This function is intended to be used from the drivers
742  * &drm_framebuffer_funcs.destroy callback. It can also be used to clean up
743  * driver private framebuffers embedded into a larger structure.
744  *
745  * Note that this function does not remove the fb from active usage - if it is
746  * still used anywhere, hilarity can ensue since userspace could call getfb on
747  * the id and get back -EINVAL. Obviously no concern at driver unload time.
748  *
749  * Also, the framebuffer will not be removed from the lookup idr - for
750  * user-created framebuffers this will happen in in the rmfb ioctl. For
751  * driver-private objects (e.g. for fbdev) drivers need to explicitly call
752  * drm_framebuffer_unregister_private.
753  */
754 void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
755 {
756 	struct drm_device *dev = fb->dev;
757 
758 	mutex_lock(&dev->mode_config.fb_lock);
759 	list_del(&fb->head);
760 	dev->mode_config.num_fb--;
761 	mutex_unlock(&dev->mode_config.fb_lock);
762 }
763 EXPORT_SYMBOL(drm_framebuffer_cleanup);
764 
765 static int atomic_remove_fb(struct drm_framebuffer *fb)
766 {
767 	struct drm_modeset_acquire_ctx ctx;
768 	struct drm_device *dev = fb->dev;
769 	struct drm_atomic_state *state;
770 	struct drm_plane *plane;
771 	struct drm_connector *conn;
772 	struct drm_connector_state *conn_state;
773 	int i, ret;
774 	unsigned plane_mask;
775 	bool disable_crtcs = false;
776 
777 retry_disable:
778 	drm_modeset_acquire_init(&ctx, 0);
779 
780 	state = drm_atomic_state_alloc(dev);
781 	if (!state) {
782 		ret = -ENOMEM;
783 		goto out;
784 	}
785 	state->acquire_ctx = &ctx;
786 
787 retry:
788 	plane_mask = 0;
789 	ret = drm_modeset_lock_all_ctx(dev, &ctx);
790 	if (ret)
791 		goto unlock;
792 
793 	drm_for_each_plane(plane, dev) {
794 		struct drm_plane_state *plane_state;
795 
796 		if (plane->state->fb != fb)
797 			continue;
798 
799 		plane_state = drm_atomic_get_plane_state(state, plane);
800 		if (IS_ERR(plane_state)) {
801 			ret = PTR_ERR(plane_state);
802 			goto unlock;
803 		}
804 
805 		if (disable_crtcs && plane_state->crtc->primary == plane) {
806 			struct drm_crtc_state *crtc_state;
807 
808 			crtc_state = drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
809 
810 			ret = drm_atomic_add_affected_connectors(state, plane_state->crtc);
811 			if (ret)
812 				goto unlock;
813 
814 			crtc_state->active = false;
815 			ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
816 			if (ret)
817 				goto unlock;
818 		}
819 
820 		drm_atomic_set_fb_for_plane(plane_state, NULL);
821 		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
822 		if (ret)
823 			goto unlock;
824 
825 		plane_mask |= BIT(drm_plane_index(plane));
826 
827 		plane->old_fb = plane->fb;
828 	}
829 
830 	/* This list is only filled when disable_crtcs is set. */
831 	for_each_new_connector_in_state(state, conn, conn_state, i) {
832 		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
833 
834 		if (ret)
835 			goto unlock;
836 	}
837 
838 	if (plane_mask)
839 		ret = drm_atomic_commit(state);
840 
841 unlock:
842 	if (plane_mask)
843 		drm_atomic_clean_old_fb(dev, plane_mask, ret);
844 
845 	if (ret == -EDEADLK) {
846 		drm_atomic_state_clear(state);
847 		drm_modeset_backoff(&ctx);
848 		goto retry;
849 	}
850 
851 	drm_atomic_state_put(state);
852 
853 out:
854 	drm_modeset_drop_locks(&ctx);
855 	drm_modeset_acquire_fini(&ctx);
856 
857 	if (ret == -EINVAL && !disable_crtcs) {
858 		disable_crtcs = true;
859 		goto retry_disable;
860 	}
861 
862 	return ret;
863 }
864 
865 static void legacy_remove_fb(struct drm_framebuffer *fb)
866 {
867 	struct drm_device *dev = fb->dev;
868 	struct drm_crtc *crtc;
869 	struct drm_plane *plane;
870 
871 	drm_modeset_lock_all(dev);
872 	/* remove from any CRTC */
873 	drm_for_each_crtc(crtc, dev) {
874 		if (crtc->primary->fb == fb) {
875 			/* should turn off the crtc */
876 			if (drm_crtc_force_disable(crtc))
877 				DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
878 		}
879 	}
880 
881 	drm_for_each_plane(plane, dev) {
882 		if (plane->fb == fb)
883 			drm_plane_force_disable(plane);
884 	}
885 	drm_modeset_unlock_all(dev);
886 }
887 
888 /**
889  * drm_framebuffer_remove - remove and unreference a framebuffer object
890  * @fb: framebuffer to remove
891  *
892  * Scans all the CRTCs and planes in @dev's mode_config.  If they're
893  * using @fb, removes it, setting it to NULL. Then drops the reference to the
894  * passed-in framebuffer. Might take the modeset locks.
895  *
896  * Note that this function optimizes the cleanup away if the caller holds the
897  * last reference to the framebuffer. It is also guaranteed to not take the
898  * modeset locks in this case.
899  */
900 void drm_framebuffer_remove(struct drm_framebuffer *fb)
901 {
902 	struct drm_device *dev;
903 
904 	if (!fb)
905 		return;
906 
907 	dev = fb->dev;
908 
909 	WARN_ON(!list_empty(&fb->filp_head));
910 
911 	/*
912 	 * drm ABI mandates that we remove any deleted framebuffers from active
913 	 * useage. But since most sane clients only remove framebuffers they no
914 	 * longer need, try to optimize this away.
915 	 *
916 	 * Since we're holding a reference ourselves, observing a refcount of 1
917 	 * means that we're the last holder and can skip it. Also, the refcount
918 	 * can never increase from 1 again, so we don't need any barriers or
919 	 * locks.
920 	 *
921 	 * Note that userspace could try to race with use and instate a new
922 	 * usage _after_ we've cleared all current ones. End result will be an
923 	 * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
924 	 * in this manner.
925 	 */
926 	if (drm_framebuffer_read_refcount(fb) > 1) {
927 		if (drm_drv_uses_atomic_modeset(dev)) {
928 			int ret = atomic_remove_fb(fb);
929 			WARN(ret, "atomic remove_fb failed with %i\n", ret);
930 		} else
931 			legacy_remove_fb(fb);
932 	}
933 
934 	drm_framebuffer_put(fb);
935 }
936 EXPORT_SYMBOL(drm_framebuffer_remove);
937 
938 /**
939  * drm_framebuffer_plane_width - width of the plane given the first plane
940  * @width: width of the first plane
941  * @fb: the framebuffer
942  * @plane: plane index
943  *
944  * Returns:
945  * The width of @plane, given that the width of the first plane is @width.
946  */
947 int drm_framebuffer_plane_width(int width,
948 				const struct drm_framebuffer *fb, int plane)
949 {
950 	if (plane >= fb->format->num_planes)
951 		return 0;
952 
953 	return fb_plane_width(width, fb->format, plane);
954 }
955 EXPORT_SYMBOL(drm_framebuffer_plane_width);
956 
957 /**
958  * drm_framebuffer_plane_height - height of the plane given the first plane
959  * @height: height of the first plane
960  * @fb: the framebuffer
961  * @plane: plane index
962  *
963  * Returns:
964  * The height of @plane, given that the height of the first plane is @height.
965  */
966 int drm_framebuffer_plane_height(int height,
967 				 const struct drm_framebuffer *fb, int plane)
968 {
969 	if (plane >= fb->format->num_planes)
970 		return 0;
971 
972 	return fb_plane_height(height, fb->format, plane);
973 }
974 EXPORT_SYMBOL(drm_framebuffer_plane_height);
975 
976 void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
977 				const struct drm_framebuffer *fb)
978 {
979 	struct drm_format_name_buf format_name;
980 	unsigned int i;
981 
982 	drm_printf_indent(p, indent, "allocated by = %s\n", fb->comm);
983 	drm_printf_indent(p, indent, "refcount=%u\n",
984 			  drm_framebuffer_read_refcount(fb));
985 	drm_printf_indent(p, indent, "format=%s\n",
986 			  drm_get_format_name(fb->format->format, &format_name));
987 	drm_printf_indent(p, indent, "modifier=0x%llx\n", fb->modifier);
988 	drm_printf_indent(p, indent, "size=%ux%u\n", fb->width, fb->height);
989 	drm_printf_indent(p, indent, "layers:\n");
990 
991 	for (i = 0; i < fb->format->num_planes; i++) {
992 		drm_printf_indent(p, indent + 1, "size[%u]=%dx%d\n", i,
993 				  drm_framebuffer_plane_width(fb->width, fb, i),
994 				  drm_framebuffer_plane_height(fb->height, fb, i));
995 		drm_printf_indent(p, indent + 1, "pitch[%u]=%u\n", i, fb->pitches[i]);
996 		drm_printf_indent(p, indent + 1, "offset[%u]=%u\n", i, fb->offsets[i]);
997 		drm_printf_indent(p, indent + 1, "obj[%u]:%s\n", i,
998 				  fb->obj[i] ? "" : "(null)");
999 		if (fb->obj[i])
1000 			drm_gem_print_info(p, indent + 2, fb->obj[i]);
1001 	}
1002 }
1003 
1004 #ifdef CONFIG_DEBUG_FS
1005 static int drm_framebuffer_info(struct seq_file *m, void *data)
1006 {
1007 	struct drm_info_node *node = m->private;
1008 	struct drm_device *dev = node->minor->dev;
1009 	struct drm_printer p = drm_seq_file_printer(m);
1010 	struct drm_framebuffer *fb;
1011 
1012 	mutex_lock(&dev->mode_config.fb_lock);
1013 	drm_for_each_fb(fb, dev) {
1014 		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
1015 		drm_framebuffer_print_info(&p, 1, fb);
1016 	}
1017 	mutex_unlock(&dev->mode_config.fb_lock);
1018 
1019 	return 0;
1020 }
1021 
1022 static const struct drm_info_list drm_framebuffer_debugfs_list[] = {
1023 	{ "framebuffer", drm_framebuffer_info, 0 },
1024 };
1025 
1026 int drm_framebuffer_debugfs_init(struct drm_minor *minor)
1027 {
1028 	return drm_debugfs_create_files(drm_framebuffer_debugfs_list,
1029 				ARRAY_SIZE(drm_framebuffer_debugfs_list),
1030 				minor->debugfs_root, minor);
1031 }
1032 #endif
1033