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 	if (r.pixel_format == DRM_FORMAT_XRGB2101010 &&
125 	    dev->driver->driver_features & DRIVER_PREFER_XBGR_30BPP)
126 		r.pixel_format = DRM_FORMAT_XBGR2101010;
127 
128 	ret = drm_mode_addfb2(dev, &r, file_priv);
129 	if (ret)
130 		return ret;
131 
132 	or->fb_id = r.fb_id;
133 
134 	return 0;
135 }
136 
137 static int fb_plane_width(int width,
138 			  const struct drm_format_info *format, int plane)
139 {
140 	if (plane == 0)
141 		return width;
142 
143 	return DIV_ROUND_UP(width, format->hsub);
144 }
145 
146 static int fb_plane_height(int height,
147 			   const struct drm_format_info *format, int plane)
148 {
149 	if (plane == 0)
150 		return height;
151 
152 	return DIV_ROUND_UP(height, format->vsub);
153 }
154 
155 static int framebuffer_check(struct drm_device *dev,
156 			     const struct drm_mode_fb_cmd2 *r)
157 {
158 	const struct drm_format_info *info;
159 	int i;
160 
161 	/* check if the format is supported at all */
162 	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
163 	if (!info) {
164 		struct drm_format_name_buf format_name;
165 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
166 		              drm_get_format_name(r->pixel_format,
167 		                                  &format_name));
168 		return -EINVAL;
169 	}
170 
171 	/* now let the driver pick its own format info */
172 	info = drm_get_format_info(dev, r);
173 
174 	if (r->width == 0) {
175 		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
176 		return -EINVAL;
177 	}
178 
179 	if (r->height == 0) {
180 		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
181 		return -EINVAL;
182 	}
183 
184 	for (i = 0; i < info->num_planes; i++) {
185 		unsigned int width = fb_plane_width(r->width, info, i);
186 		unsigned int height = fb_plane_height(r->height, info, i);
187 		unsigned int cpp = info->cpp[i];
188 
189 		if (!r->handles[i]) {
190 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
191 			return -EINVAL;
192 		}
193 
194 		if ((uint64_t) width * cpp > UINT_MAX)
195 			return -ERANGE;
196 
197 		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
198 			return -ERANGE;
199 
200 		if (r->pitches[i] < width * cpp) {
201 			DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
202 			return -EINVAL;
203 		}
204 
205 		if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
206 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
207 				      r->modifier[i], i);
208 			return -EINVAL;
209 		}
210 
211 		if (r->flags & DRM_MODE_FB_MODIFIERS &&
212 		    r->modifier[i] != r->modifier[0]) {
213 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
214 				      r->modifier[i], i);
215 			return -EINVAL;
216 		}
217 
218 		/* modifier specific checks: */
219 		switch (r->modifier[i]) {
220 		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
221 			/* NOTE: the pitch restriction may be lifted later if it turns
222 			 * out that no hw has this restriction:
223 			 */
224 			if (r->pixel_format != DRM_FORMAT_NV12 ||
225 					width % 128 || height % 32 ||
226 					r->pitches[i] % 128) {
227 				DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
228 				return -EINVAL;
229 			}
230 			break;
231 
232 		default:
233 			break;
234 		}
235 	}
236 
237 	for (i = info->num_planes; i < 4; i++) {
238 		if (r->modifier[i]) {
239 			DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
240 			return -EINVAL;
241 		}
242 
243 		/* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
244 		if (!(r->flags & DRM_MODE_FB_MODIFIERS))
245 			continue;
246 
247 		if (r->handles[i]) {
248 			DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
249 			return -EINVAL;
250 		}
251 
252 		if (r->pitches[i]) {
253 			DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
254 			return -EINVAL;
255 		}
256 
257 		if (r->offsets[i]) {
258 			DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
259 			return -EINVAL;
260 		}
261 	}
262 
263 	return 0;
264 }
265 
266 struct drm_framebuffer *
267 drm_internal_framebuffer_create(struct drm_device *dev,
268 				const struct drm_mode_fb_cmd2 *r,
269 				struct drm_file *file_priv)
270 {
271 	struct drm_mode_config *config = &dev->mode_config;
272 	struct drm_framebuffer *fb;
273 	int ret;
274 
275 	if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
276 		DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
277 		return ERR_PTR(-EINVAL);
278 	}
279 
280 	if ((config->min_width > r->width) || (r->width > config->max_width)) {
281 		DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
282 			  r->width, config->min_width, config->max_width);
283 		return ERR_PTR(-EINVAL);
284 	}
285 	if ((config->min_height > r->height) || (r->height > config->max_height)) {
286 		DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
287 			  r->height, config->min_height, config->max_height);
288 		return ERR_PTR(-EINVAL);
289 	}
290 
291 	if (r->flags & DRM_MODE_FB_MODIFIERS &&
292 	    !dev->mode_config.allow_fb_modifiers) {
293 		DRM_DEBUG_KMS("driver does not support fb modifiers\n");
294 		return ERR_PTR(-EINVAL);
295 	}
296 
297 	ret = framebuffer_check(dev, r);
298 	if (ret)
299 		return ERR_PTR(ret);
300 
301 	fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
302 	if (IS_ERR(fb)) {
303 		DRM_DEBUG_KMS("could not create framebuffer\n");
304 		return fb;
305 	}
306 
307 	return fb;
308 }
309 
310 /**
311  * drm_mode_addfb2 - add an FB to the graphics configuration
312  * @dev: drm device for the ioctl
313  * @data: data pointer for the ioctl
314  * @file_priv: drm file for the ioctl call
315  *
316  * Add a new FB to the specified CRTC, given a user request with format. This is
317  * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
318  * and uses fourcc codes as pixel format specifiers.
319  *
320  * Called by the user via ioctl.
321  *
322  * Returns:
323  * Zero on success, negative errno on failure.
324  */
325 int drm_mode_addfb2(struct drm_device *dev,
326 		    void *data, struct drm_file *file_priv)
327 {
328 	struct drm_mode_fb_cmd2 *r = data;
329 	struct drm_framebuffer *fb;
330 
331 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
332 		return -EINVAL;
333 
334 	fb = drm_internal_framebuffer_create(dev, r, file_priv);
335 	if (IS_ERR(fb))
336 		return PTR_ERR(fb);
337 
338 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
339 	r->fb_id = fb->base.id;
340 
341 	/* Transfer ownership to the filp for reaping on close */
342 	mutex_lock(&file_priv->fbs_lock);
343 	list_add(&fb->filp_head, &file_priv->fbs);
344 	mutex_unlock(&file_priv->fbs_lock);
345 
346 	return 0;
347 }
348 
349 struct drm_mode_rmfb_work {
350 	struct work_struct work;
351 	struct list_head fbs;
352 };
353 
354 static void drm_mode_rmfb_work_fn(struct work_struct *w)
355 {
356 	struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
357 
358 	while (!list_empty(&arg->fbs)) {
359 		struct drm_framebuffer *fb =
360 			list_first_entry(&arg->fbs, typeof(*fb), filp_head);
361 
362 		list_del_init(&fb->filp_head);
363 		drm_framebuffer_remove(fb);
364 	}
365 }
366 
367 /**
368  * drm_mode_rmfb - remove an FB from the configuration
369  * @dev: drm device for the ioctl
370  * @data: data pointer for the ioctl
371  * @file_priv: drm file for the ioctl call
372  *
373  * Remove the FB specified by the user.
374  *
375  * Called by the user via ioctl.
376  *
377  * Returns:
378  * Zero on success, negative errno on failure.
379  */
380 int drm_mode_rmfb(struct drm_device *dev,
381 		   void *data, struct drm_file *file_priv)
382 {
383 	struct drm_framebuffer *fb = NULL;
384 	struct drm_framebuffer *fbl = NULL;
385 	uint32_t *id = data;
386 	int found = 0;
387 
388 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
389 		return -EINVAL;
390 
391 	fb = drm_framebuffer_lookup(dev, file_priv, *id);
392 	if (!fb)
393 		return -ENOENT;
394 
395 	mutex_lock(&file_priv->fbs_lock);
396 	list_for_each_entry(fbl, &file_priv->fbs, filp_head)
397 		if (fb == fbl)
398 			found = 1;
399 	if (!found) {
400 		mutex_unlock(&file_priv->fbs_lock);
401 		goto fail_unref;
402 	}
403 
404 	list_del_init(&fb->filp_head);
405 	mutex_unlock(&file_priv->fbs_lock);
406 
407 	/* drop the reference we picked up in framebuffer lookup */
408 	drm_framebuffer_put(fb);
409 
410 	/*
411 	 * we now own the reference that was stored in the fbs list
412 	 *
413 	 * drm_framebuffer_remove may fail with -EINTR on pending signals,
414 	 * so run this in a separate stack as there's no way to correctly
415 	 * handle this after the fb is already removed from the lookup table.
416 	 */
417 	if (drm_framebuffer_read_refcount(fb) > 1) {
418 		struct drm_mode_rmfb_work arg;
419 
420 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
421 		INIT_LIST_HEAD(&arg.fbs);
422 		list_add_tail(&fb->filp_head, &arg.fbs);
423 
424 		schedule_work(&arg.work);
425 		flush_work(&arg.work);
426 		destroy_work_on_stack(&arg.work);
427 	} else
428 		drm_framebuffer_put(fb);
429 
430 	return 0;
431 
432 fail_unref:
433 	drm_framebuffer_put(fb);
434 	return -ENOENT;
435 }
436 
437 /**
438  * drm_mode_getfb - get FB info
439  * @dev: drm device for the ioctl
440  * @data: data pointer for the ioctl
441  * @file_priv: drm file for the ioctl call
442  *
443  * Lookup the FB given its ID and return info about it.
444  *
445  * Called by the user via ioctl.
446  *
447  * Returns:
448  * Zero on success, negative errno on failure.
449  */
450 int drm_mode_getfb(struct drm_device *dev,
451 		   void *data, struct drm_file *file_priv)
452 {
453 	struct drm_mode_fb_cmd *r = data;
454 	struct drm_framebuffer *fb;
455 	int ret;
456 
457 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
458 		return -EINVAL;
459 
460 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
461 	if (!fb)
462 		return -ENOENT;
463 
464 	/* Multi-planar framebuffers need getfb2. */
465 	if (fb->format->num_planes > 1) {
466 		ret = -EINVAL;
467 		goto out;
468 	}
469 
470 	r->height = fb->height;
471 	r->width = fb->width;
472 	r->depth = fb->format->depth;
473 	r->bpp = fb->format->cpp[0] * 8;
474 	r->pitch = fb->pitches[0];
475 	if (fb->funcs->create_handle) {
476 		if (drm_is_current_master(file_priv) || capable(CAP_SYS_ADMIN) ||
477 		    drm_is_control_client(file_priv)) {
478 			ret = fb->funcs->create_handle(fb, file_priv,
479 						       &r->handle);
480 		} else {
481 			/* GET_FB() is an unprivileged ioctl so we must not
482 			 * return a buffer-handle to non-master processes! For
483 			 * backwards-compatibility reasons, we cannot make
484 			 * GET_FB() privileged, so just return an invalid handle
485 			 * for non-masters. */
486 			r->handle = 0;
487 			ret = 0;
488 		}
489 	} else {
490 		ret = -ENODEV;
491 	}
492 
493 out:
494 	drm_framebuffer_put(fb);
495 
496 	return ret;
497 }
498 
499 /**
500  * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
501  * @dev: drm device for the ioctl
502  * @data: data pointer for the ioctl
503  * @file_priv: drm file for the ioctl call
504  *
505  * Lookup the FB and flush out the damaged area supplied by userspace as a clip
506  * rectangle list. Generic userspace which does frontbuffer rendering must call
507  * this ioctl to flush out the changes on manual-update display outputs, e.g.
508  * usb display-link, mipi manual update panels or edp panel self refresh modes.
509  *
510  * Modesetting drivers which always update the frontbuffer do not need to
511  * implement the corresponding &drm_framebuffer_funcs.dirty callback.
512  *
513  * Called by the user via ioctl.
514  *
515  * Returns:
516  * Zero on success, negative errno on failure.
517  */
518 int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
519 			   void *data, struct drm_file *file_priv)
520 {
521 	struct drm_clip_rect __user *clips_ptr;
522 	struct drm_clip_rect *clips = NULL;
523 	struct drm_mode_fb_dirty_cmd *r = data;
524 	struct drm_framebuffer *fb;
525 	unsigned flags;
526 	int num_clips;
527 	int ret;
528 
529 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
530 		return -EINVAL;
531 
532 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
533 	if (!fb)
534 		return -ENOENT;
535 
536 	num_clips = r->num_clips;
537 	clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
538 
539 	if (!num_clips != !clips_ptr) {
540 		ret = -EINVAL;
541 		goto out_err1;
542 	}
543 
544 	flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
545 
546 	/* If userspace annotates copy, clips must come in pairs */
547 	if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
548 		ret = -EINVAL;
549 		goto out_err1;
550 	}
551 
552 	if (num_clips && clips_ptr) {
553 		if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
554 			ret = -EINVAL;
555 			goto out_err1;
556 		}
557 		clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
558 		if (!clips) {
559 			ret = -ENOMEM;
560 			goto out_err1;
561 		}
562 
563 		ret = copy_from_user(clips, clips_ptr,
564 				     num_clips * sizeof(*clips));
565 		if (ret) {
566 			ret = -EFAULT;
567 			goto out_err2;
568 		}
569 	}
570 
571 	if (fb->funcs->dirty) {
572 		ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
573 				       clips, num_clips);
574 	} else {
575 		ret = -ENOSYS;
576 	}
577 
578 out_err2:
579 	kfree(clips);
580 out_err1:
581 	drm_framebuffer_put(fb);
582 
583 	return ret;
584 }
585 
586 /**
587  * drm_fb_release - remove and free the FBs on this file
588  * @priv: drm file for the ioctl
589  *
590  * Destroy all the FBs associated with @filp.
591  *
592  * Called by the user via ioctl.
593  *
594  * Returns:
595  * Zero on success, negative errno on failure.
596  */
597 void drm_fb_release(struct drm_file *priv)
598 {
599 	struct drm_framebuffer *fb, *tfb;
600 	struct drm_mode_rmfb_work arg;
601 
602 	INIT_LIST_HEAD(&arg.fbs);
603 
604 	/*
605 	 * When the file gets released that means no one else can access the fb
606 	 * list any more, so no need to grab fpriv->fbs_lock. And we need to
607 	 * avoid upsetting lockdep since the universal cursor code adds a
608 	 * framebuffer while holding mutex locks.
609 	 *
610 	 * Note that a real deadlock between fpriv->fbs_lock and the modeset
611 	 * locks is impossible here since no one else but this function can get
612 	 * at it any more.
613 	 */
614 	list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
615 		if (drm_framebuffer_read_refcount(fb) > 1) {
616 			list_move_tail(&fb->filp_head, &arg.fbs);
617 		} else {
618 			list_del_init(&fb->filp_head);
619 
620 			/* This drops the fpriv->fbs reference. */
621 			drm_framebuffer_put(fb);
622 		}
623 	}
624 
625 	if (!list_empty(&arg.fbs)) {
626 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
627 
628 		schedule_work(&arg.work);
629 		flush_work(&arg.work);
630 		destroy_work_on_stack(&arg.work);
631 	}
632 }
633 
634 void drm_framebuffer_free(struct kref *kref)
635 {
636 	struct drm_framebuffer *fb =
637 			container_of(kref, struct drm_framebuffer, base.refcount);
638 	struct drm_device *dev = fb->dev;
639 
640 	/*
641 	 * The lookup idr holds a weak reference, which has not necessarily been
642 	 * removed at this point. Check for that.
643 	 */
644 	drm_mode_object_unregister(dev, &fb->base);
645 
646 	fb->funcs->destroy(fb);
647 }
648 
649 /**
650  * drm_framebuffer_init - initialize a framebuffer
651  * @dev: DRM device
652  * @fb: framebuffer to be initialized
653  * @funcs: ... with these functions
654  *
655  * Allocates an ID for the framebuffer's parent mode object, sets its mode
656  * functions & device file and adds it to the master fd list.
657  *
658  * IMPORTANT:
659  * This functions publishes the fb and makes it available for concurrent access
660  * by other users. Which means by this point the fb _must_ be fully set up -
661  * since all the fb attributes are invariant over its lifetime, no further
662  * locking but only correct reference counting is required.
663  *
664  * Returns:
665  * Zero on success, error code on failure.
666  */
667 int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
668 			 const struct drm_framebuffer_funcs *funcs)
669 {
670 	int ret;
671 
672 	if (WARN_ON_ONCE(fb->dev != dev || !fb->format))
673 		return -EINVAL;
674 
675 	INIT_LIST_HEAD(&fb->filp_head);
676 
677 	fb->funcs = funcs;
678 	strcpy(fb->comm, current->comm);
679 
680 	ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB,
681 				    false, drm_framebuffer_free);
682 	if (ret)
683 		goto out;
684 
685 	mutex_lock(&dev->mode_config.fb_lock);
686 	dev->mode_config.num_fb++;
687 	list_add(&fb->head, &dev->mode_config.fb_list);
688 	mutex_unlock(&dev->mode_config.fb_lock);
689 
690 	drm_mode_object_register(dev, &fb->base);
691 out:
692 	return ret;
693 }
694 EXPORT_SYMBOL(drm_framebuffer_init);
695 
696 /**
697  * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
698  * @dev: drm device
699  * @file_priv: drm file to check for lease against.
700  * @id: id of the fb object
701  *
702  * If successful, this grabs an additional reference to the framebuffer -
703  * callers need to make sure to eventually unreference the returned framebuffer
704  * again, using drm_framebuffer_put().
705  */
706 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
707 					       struct drm_file *file_priv,
708 					       uint32_t id)
709 {
710 	struct drm_mode_object *obj;
711 	struct drm_framebuffer *fb = NULL;
712 
713 	obj = __drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_FB);
714 	if (obj)
715 		fb = obj_to_fb(obj);
716 	return fb;
717 }
718 EXPORT_SYMBOL(drm_framebuffer_lookup);
719 
720 /**
721  * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
722  * @fb: fb to unregister
723  *
724  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
725  * those used for fbdev. Note that the caller must hold a reference of it's own,
726  * i.e. the object may not be destroyed through this call (since it'll lead to a
727  * locking inversion).
728  *
729  * NOTE: This function is deprecated. For driver-private framebuffers it is not
730  * recommended to embed a framebuffer struct info fbdev struct, instead, a
731  * framebuffer pointer is preferred and drm_framebuffer_put() should be called
732  * when the framebuffer is to be cleaned up.
733  */
734 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
735 {
736 	struct drm_device *dev;
737 
738 	if (!fb)
739 		return;
740 
741 	dev = fb->dev;
742 
743 	/* Mark fb as reaped and drop idr ref. */
744 	drm_mode_object_unregister(dev, &fb->base);
745 }
746 EXPORT_SYMBOL(drm_framebuffer_unregister_private);
747 
748 /**
749  * drm_framebuffer_cleanup - remove a framebuffer object
750  * @fb: framebuffer to remove
751  *
752  * Cleanup framebuffer. This function is intended to be used from the drivers
753  * &drm_framebuffer_funcs.destroy callback. It can also be used to clean up
754  * driver private framebuffers embedded into a larger structure.
755  *
756  * Note that this function does not remove the fb from active usage - if it is
757  * still used anywhere, hilarity can ensue since userspace could call getfb on
758  * the id and get back -EINVAL. Obviously no concern at driver unload time.
759  *
760  * Also, the framebuffer will not be removed from the lookup idr - for
761  * user-created framebuffers this will happen in in the rmfb ioctl. For
762  * driver-private objects (e.g. for fbdev) drivers need to explicitly call
763  * drm_framebuffer_unregister_private.
764  */
765 void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
766 {
767 	struct drm_device *dev = fb->dev;
768 
769 	mutex_lock(&dev->mode_config.fb_lock);
770 	list_del(&fb->head);
771 	dev->mode_config.num_fb--;
772 	mutex_unlock(&dev->mode_config.fb_lock);
773 }
774 EXPORT_SYMBOL(drm_framebuffer_cleanup);
775 
776 static int atomic_remove_fb(struct drm_framebuffer *fb)
777 {
778 	struct drm_modeset_acquire_ctx ctx;
779 	struct drm_device *dev = fb->dev;
780 	struct drm_atomic_state *state;
781 	struct drm_plane *plane;
782 	struct drm_connector *conn;
783 	struct drm_connector_state *conn_state;
784 	int i, ret;
785 	unsigned plane_mask;
786 	bool disable_crtcs = false;
787 
788 retry_disable:
789 	drm_modeset_acquire_init(&ctx, 0);
790 
791 	state = drm_atomic_state_alloc(dev);
792 	if (!state) {
793 		ret = -ENOMEM;
794 		goto out;
795 	}
796 	state->acquire_ctx = &ctx;
797 
798 retry:
799 	plane_mask = 0;
800 	ret = drm_modeset_lock_all_ctx(dev, &ctx);
801 	if (ret)
802 		goto unlock;
803 
804 	drm_for_each_plane(plane, dev) {
805 		struct drm_plane_state *plane_state;
806 
807 		if (plane->state->fb != fb)
808 			continue;
809 
810 		plane_state = drm_atomic_get_plane_state(state, plane);
811 		if (IS_ERR(plane_state)) {
812 			ret = PTR_ERR(plane_state);
813 			goto unlock;
814 		}
815 
816 		if (disable_crtcs && plane_state->crtc->primary == plane) {
817 			struct drm_crtc_state *crtc_state;
818 
819 			crtc_state = drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
820 
821 			ret = drm_atomic_add_affected_connectors(state, plane_state->crtc);
822 			if (ret)
823 				goto unlock;
824 
825 			crtc_state->active = false;
826 			ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
827 			if (ret)
828 				goto unlock;
829 		}
830 
831 		drm_atomic_set_fb_for_plane(plane_state, NULL);
832 		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
833 		if (ret)
834 			goto unlock;
835 
836 		plane_mask |= BIT(drm_plane_index(plane));
837 
838 		plane->old_fb = plane->fb;
839 	}
840 
841 	/* This list is only filled when disable_crtcs is set. */
842 	for_each_new_connector_in_state(state, conn, conn_state, i) {
843 		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
844 
845 		if (ret)
846 			goto unlock;
847 	}
848 
849 	if (plane_mask)
850 		ret = drm_atomic_commit(state);
851 
852 unlock:
853 	if (plane_mask)
854 		drm_atomic_clean_old_fb(dev, plane_mask, ret);
855 
856 	if (ret == -EDEADLK) {
857 		drm_atomic_state_clear(state);
858 		drm_modeset_backoff(&ctx);
859 		goto retry;
860 	}
861 
862 	drm_atomic_state_put(state);
863 
864 out:
865 	drm_modeset_drop_locks(&ctx);
866 	drm_modeset_acquire_fini(&ctx);
867 
868 	if (ret == -EINVAL && !disable_crtcs) {
869 		disable_crtcs = true;
870 		goto retry_disable;
871 	}
872 
873 	return ret;
874 }
875 
876 static void legacy_remove_fb(struct drm_framebuffer *fb)
877 {
878 	struct drm_device *dev = fb->dev;
879 	struct drm_crtc *crtc;
880 	struct drm_plane *plane;
881 
882 	drm_modeset_lock_all(dev);
883 	/* remove from any CRTC */
884 	drm_for_each_crtc(crtc, dev) {
885 		if (crtc->primary->fb == fb) {
886 			/* should turn off the crtc */
887 			if (drm_crtc_force_disable(crtc))
888 				DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
889 		}
890 	}
891 
892 	drm_for_each_plane(plane, dev) {
893 		if (plane->fb == fb)
894 			drm_plane_force_disable(plane);
895 	}
896 	drm_modeset_unlock_all(dev);
897 }
898 
899 /**
900  * drm_framebuffer_remove - remove and unreference a framebuffer object
901  * @fb: framebuffer to remove
902  *
903  * Scans all the CRTCs and planes in @dev's mode_config.  If they're
904  * using @fb, removes it, setting it to NULL. Then drops the reference to the
905  * passed-in framebuffer. Might take the modeset locks.
906  *
907  * Note that this function optimizes the cleanup away if the caller holds the
908  * last reference to the framebuffer. It is also guaranteed to not take the
909  * modeset locks in this case.
910  */
911 void drm_framebuffer_remove(struct drm_framebuffer *fb)
912 {
913 	struct drm_device *dev;
914 
915 	if (!fb)
916 		return;
917 
918 	dev = fb->dev;
919 
920 	WARN_ON(!list_empty(&fb->filp_head));
921 
922 	/*
923 	 * drm ABI mandates that we remove any deleted framebuffers from active
924 	 * useage. But since most sane clients only remove framebuffers they no
925 	 * longer need, try to optimize this away.
926 	 *
927 	 * Since we're holding a reference ourselves, observing a refcount of 1
928 	 * means that we're the last holder and can skip it. Also, the refcount
929 	 * can never increase from 1 again, so we don't need any barriers or
930 	 * locks.
931 	 *
932 	 * Note that userspace could try to race with use and instate a new
933 	 * usage _after_ we've cleared all current ones. End result will be an
934 	 * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
935 	 * in this manner.
936 	 */
937 	if (drm_framebuffer_read_refcount(fb) > 1) {
938 		if (drm_drv_uses_atomic_modeset(dev)) {
939 			int ret = atomic_remove_fb(fb);
940 			WARN(ret, "atomic remove_fb failed with %i\n", ret);
941 		} else
942 			legacy_remove_fb(fb);
943 	}
944 
945 	drm_framebuffer_put(fb);
946 }
947 EXPORT_SYMBOL(drm_framebuffer_remove);
948 
949 /**
950  * drm_framebuffer_plane_width - width of the plane given the first plane
951  * @width: width of the first plane
952  * @fb: the framebuffer
953  * @plane: plane index
954  *
955  * Returns:
956  * The width of @plane, given that the width of the first plane is @width.
957  */
958 int drm_framebuffer_plane_width(int width,
959 				const struct drm_framebuffer *fb, int plane)
960 {
961 	if (plane >= fb->format->num_planes)
962 		return 0;
963 
964 	return fb_plane_width(width, fb->format, plane);
965 }
966 EXPORT_SYMBOL(drm_framebuffer_plane_width);
967 
968 /**
969  * drm_framebuffer_plane_height - height of the plane given the first plane
970  * @height: height of the first plane
971  * @fb: the framebuffer
972  * @plane: plane index
973  *
974  * Returns:
975  * The height of @plane, given that the height of the first plane is @height.
976  */
977 int drm_framebuffer_plane_height(int height,
978 				 const struct drm_framebuffer *fb, int plane)
979 {
980 	if (plane >= fb->format->num_planes)
981 		return 0;
982 
983 	return fb_plane_height(height, fb->format, plane);
984 }
985 EXPORT_SYMBOL(drm_framebuffer_plane_height);
986 
987 void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
988 				const struct drm_framebuffer *fb)
989 {
990 	struct drm_format_name_buf format_name;
991 	unsigned int i;
992 
993 	drm_printf_indent(p, indent, "allocated by = %s\n", fb->comm);
994 	drm_printf_indent(p, indent, "refcount=%u\n",
995 			  drm_framebuffer_read_refcount(fb));
996 	drm_printf_indent(p, indent, "format=%s\n",
997 			  drm_get_format_name(fb->format->format, &format_name));
998 	drm_printf_indent(p, indent, "modifier=0x%llx\n", fb->modifier);
999 	drm_printf_indent(p, indent, "size=%ux%u\n", fb->width, fb->height);
1000 	drm_printf_indent(p, indent, "layers:\n");
1001 
1002 	for (i = 0; i < fb->format->num_planes; i++) {
1003 		drm_printf_indent(p, indent + 1, "size[%u]=%dx%d\n", i,
1004 				  drm_framebuffer_plane_width(fb->width, fb, i),
1005 				  drm_framebuffer_plane_height(fb->height, fb, i));
1006 		drm_printf_indent(p, indent + 1, "pitch[%u]=%u\n", i, fb->pitches[i]);
1007 		drm_printf_indent(p, indent + 1, "offset[%u]=%u\n", i, fb->offsets[i]);
1008 		drm_printf_indent(p, indent + 1, "obj[%u]:%s\n", i,
1009 				  fb->obj[i] ? "" : "(null)");
1010 		if (fb->obj[i])
1011 			drm_gem_print_info(p, indent + 2, fb->obj[i]);
1012 	}
1013 }
1014 
1015 #ifdef CONFIG_DEBUG_FS
1016 static int drm_framebuffer_info(struct seq_file *m, void *data)
1017 {
1018 	struct drm_info_node *node = m->private;
1019 	struct drm_device *dev = node->minor->dev;
1020 	struct drm_printer p = drm_seq_file_printer(m);
1021 	struct drm_framebuffer *fb;
1022 
1023 	mutex_lock(&dev->mode_config.fb_lock);
1024 	drm_for_each_fb(fb, dev) {
1025 		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
1026 		drm_framebuffer_print_info(&p, 1, fb);
1027 	}
1028 	mutex_unlock(&dev->mode_config.fb_lock);
1029 
1030 	return 0;
1031 }
1032 
1033 static const struct drm_info_list drm_framebuffer_debugfs_list[] = {
1034 	{ "framebuffer", drm_framebuffer_info, 0 },
1035 };
1036 
1037 int drm_framebuffer_debugfs_init(struct drm_minor *minor)
1038 {
1039 	return drm_debugfs_create_files(drm_framebuffer_debugfs_list,
1040 				ARRAY_SIZE(drm_framebuffer_debugfs_list),
1041 				minor->debugfs_root, minor);
1042 }
1043 #endif
1044