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_atomic_uapi.h>
29 #include <drm/drm_print.h>
30 #include <drm/drm_util.h>
31 
32 #include "drm_internal.h"
33 #include "drm_crtc_internal.h"
34 
35 /**
36  * DOC: overview
37  *
38  * Frame buffers are abstract memory objects that provide a source of pixels to
39  * scanout to a CRTC. Applications explicitly request the creation of frame
40  * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
41  * handle that can be passed to the KMS CRTC control, plane configuration and
42  * page flip functions.
43  *
44  * Frame buffers rely on the underlying memory manager for allocating backing
45  * storage. When creating a frame buffer applications pass a memory handle
46  * (or a list of memory handles for multi-planar formats) through the
47  * &struct drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
48  * buffer management interface this would be a GEM handle.  Drivers are however
49  * free to use their own backing storage object handles, e.g. vmwgfx directly
50  * exposes special TTM handles to userspace and so expects TTM handles in the
51  * create ioctl and not GEM handles.
52  *
53  * Framebuffers are tracked with &struct drm_framebuffer. They are published
54  * using drm_framebuffer_init() - after calling that function userspace can use
55  * and access the framebuffer object. The helper function
56  * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
57  * metadata fields.
58  *
59  * The lifetime of a drm framebuffer is controlled with a reference count,
60  * drivers can grab additional references with drm_framebuffer_get() and drop
61  * them again with drm_framebuffer_put(). For driver-private framebuffers for
62  * which the last reference is never dropped (e.g. for the fbdev framebuffer
63  * when the struct &struct drm_framebuffer is embedded into the fbdev helper
64  * struct) drivers can manually clean up a framebuffer at module unload time
65  * with drm_framebuffer_unregister_private(). But doing this is not
66  * recommended, and it's better to have a normal free-standing &struct
67  * drm_framebuffer.
68  */
69 
70 int drm_framebuffer_check_src_coords(uint32_t src_x, uint32_t src_y,
71 				     uint32_t src_w, uint32_t src_h,
72 				     const struct drm_framebuffer *fb)
73 {
74 	unsigned int fb_width, fb_height;
75 
76 	fb_width = fb->width << 16;
77 	fb_height = fb->height << 16;
78 
79 	/* Make sure source coordinates are inside the fb. */
80 	if (src_w > fb_width ||
81 	    src_x > fb_width - src_w ||
82 	    src_h > fb_height ||
83 	    src_y > fb_height - src_h) {
84 		DRM_DEBUG_KMS("Invalid source coordinates "
85 			      "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
86 			      src_w >> 16, ((src_w & 0xffff) * 15625) >> 10,
87 			      src_h >> 16, ((src_h & 0xffff) * 15625) >> 10,
88 			      src_x >> 16, ((src_x & 0xffff) * 15625) >> 10,
89 			      src_y >> 16, ((src_y & 0xffff) * 15625) >> 10,
90 			      fb->width, fb->height);
91 		return -ENOSPC;
92 	}
93 
94 	return 0;
95 }
96 
97 /**
98  * drm_mode_addfb - add an FB to the graphics configuration
99  * @dev: drm device for the ioctl
100  * @or: pointer to request structure
101  * @file_priv: drm file
102  *
103  * Add a new FB to the specified CRTC, given a user request. This is the
104  * original addfb ioctl which only supported RGB formats.
105  *
106  * Called by the user via ioctl, or by an in-kernel client.
107  *
108  * Returns:
109  * Zero on success, negative errno on failure.
110  */
111 int drm_mode_addfb(struct drm_device *dev, struct drm_mode_fb_cmd *or,
112 		   struct drm_file *file_priv)
113 {
114 	struct drm_mode_fb_cmd2 r = {};
115 	int ret;
116 
117 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
118 		return -EOPNOTSUPP;
119 
120 	r.pixel_format = drm_driver_legacy_fb_format(dev, or->bpp, or->depth);
121 	if (r.pixel_format == DRM_FORMAT_INVALID) {
122 		DRM_DEBUG("bad {bpp:%d, depth:%d}\n", or->bpp, or->depth);
123 		return -EINVAL;
124 	}
125 
126 	/* convert to new format and call new ioctl */
127 	r.fb_id = or->fb_id;
128 	r.width = or->width;
129 	r.height = or->height;
130 	r.pitches[0] = or->pitch;
131 	r.handles[0] = or->handle;
132 
133 	ret = drm_mode_addfb2(dev, &r, file_priv);
134 	if (ret)
135 		return ret;
136 
137 	or->fb_id = r.fb_id;
138 
139 	return 0;
140 }
141 
142 int drm_mode_addfb_ioctl(struct drm_device *dev,
143 			 void *data, struct drm_file *file_priv)
144 {
145 	return drm_mode_addfb(dev, data, file_priv);
146 }
147 
148 static int fb_plane_width(int width,
149 			  const struct drm_format_info *format, int plane)
150 {
151 	if (plane == 0)
152 		return width;
153 
154 	return DIV_ROUND_UP(width, format->hsub);
155 }
156 
157 static int fb_plane_height(int height,
158 			   const struct drm_format_info *format, int plane)
159 {
160 	if (plane == 0)
161 		return height;
162 
163 	return DIV_ROUND_UP(height, format->vsub);
164 }
165 
166 static int framebuffer_check(struct drm_device *dev,
167 			     const struct drm_mode_fb_cmd2 *r)
168 {
169 	const struct drm_format_info *info;
170 	int i;
171 
172 	/* check if the format is supported at all */
173 	info = __drm_format_info(r->pixel_format);
174 	if (!info) {
175 		struct drm_format_name_buf format_name;
176 
177 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
178 			      drm_get_format_name(r->pixel_format,
179 						  &format_name));
180 		return -EINVAL;
181 	}
182 
183 	/* now let the driver pick its own format info */
184 	info = drm_get_format_info(dev, r);
185 
186 	if (r->width == 0) {
187 		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
188 		return -EINVAL;
189 	}
190 
191 	if (r->height == 0) {
192 		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
193 		return -EINVAL;
194 	}
195 
196 	for (i = 0; i < info->num_planes; i++) {
197 		unsigned int width = fb_plane_width(r->width, info, i);
198 		unsigned int height = fb_plane_height(r->height, info, i);
199 		unsigned int block_size = info->char_per_block[i];
200 		u64 min_pitch = drm_format_info_min_pitch(info, i, width);
201 
202 		if (!block_size && (r->modifier[i] == DRM_FORMAT_MOD_LINEAR)) {
203 			DRM_DEBUG_KMS("Format requires non-linear modifier for plane %d\n", i);
204 			return -EINVAL;
205 		}
206 
207 		if (!r->handles[i]) {
208 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
209 			return -EINVAL;
210 		}
211 
212 		if (min_pitch > UINT_MAX)
213 			return -ERANGE;
214 
215 		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
216 			return -ERANGE;
217 
218 		if (block_size && r->pitches[i] < min_pitch) {
219 			DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
220 			return -EINVAL;
221 		}
222 
223 		if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
224 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
225 				      r->modifier[i], i);
226 			return -EINVAL;
227 		}
228 
229 		if (r->flags & DRM_MODE_FB_MODIFIERS &&
230 		    r->modifier[i] != r->modifier[0]) {
231 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
232 				      r->modifier[i], i);
233 			return -EINVAL;
234 		}
235 
236 		/* modifier specific checks: */
237 		switch (r->modifier[i]) {
238 		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
239 			/* NOTE: the pitch restriction may be lifted later if it turns
240 			 * out that no hw has this restriction:
241 			 */
242 			if (r->pixel_format != DRM_FORMAT_NV12 ||
243 					width % 128 || height % 32 ||
244 					r->pitches[i] % 128) {
245 				DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
246 				return -EINVAL;
247 			}
248 			break;
249 
250 		default:
251 			break;
252 		}
253 	}
254 
255 	for (i = info->num_planes; i < 4; i++) {
256 		if (r->modifier[i]) {
257 			DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
258 			return -EINVAL;
259 		}
260 
261 		/* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
262 		if (!(r->flags & DRM_MODE_FB_MODIFIERS))
263 			continue;
264 
265 		if (r->handles[i]) {
266 			DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
267 			return -EINVAL;
268 		}
269 
270 		if (r->pitches[i]) {
271 			DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
272 			return -EINVAL;
273 		}
274 
275 		if (r->offsets[i]) {
276 			DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
277 			return -EINVAL;
278 		}
279 	}
280 
281 	return 0;
282 }
283 
284 struct drm_framebuffer *
285 drm_internal_framebuffer_create(struct drm_device *dev,
286 				const struct drm_mode_fb_cmd2 *r,
287 				struct drm_file *file_priv)
288 {
289 	struct drm_mode_config *config = &dev->mode_config;
290 	struct drm_framebuffer *fb;
291 	int ret;
292 
293 	if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
294 		DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
295 		return ERR_PTR(-EINVAL);
296 	}
297 
298 	if ((config->min_width > r->width) || (r->width > config->max_width)) {
299 		DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
300 			  r->width, config->min_width, config->max_width);
301 		return ERR_PTR(-EINVAL);
302 	}
303 	if ((config->min_height > r->height) || (r->height > config->max_height)) {
304 		DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
305 			  r->height, config->min_height, config->max_height);
306 		return ERR_PTR(-EINVAL);
307 	}
308 
309 	if (r->flags & DRM_MODE_FB_MODIFIERS &&
310 	    !dev->mode_config.allow_fb_modifiers) {
311 		DRM_DEBUG_KMS("driver does not support fb modifiers\n");
312 		return ERR_PTR(-EINVAL);
313 	}
314 
315 	ret = framebuffer_check(dev, r);
316 	if (ret)
317 		return ERR_PTR(ret);
318 
319 	fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
320 	if (IS_ERR(fb)) {
321 		DRM_DEBUG_KMS("could not create framebuffer\n");
322 		return fb;
323 	}
324 
325 	return fb;
326 }
327 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_internal_framebuffer_create);
328 
329 /**
330  * drm_mode_addfb2 - add an FB to the graphics configuration
331  * @dev: drm device for the ioctl
332  * @data: data pointer for the ioctl
333  * @file_priv: drm file for the ioctl call
334  *
335  * Add a new FB to the specified CRTC, given a user request with format. This is
336  * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
337  * and uses fourcc codes as pixel format specifiers.
338  *
339  * Called by the user via ioctl.
340  *
341  * Returns:
342  * Zero on success, negative errno on failure.
343  */
344 int drm_mode_addfb2(struct drm_device *dev,
345 		    void *data, struct drm_file *file_priv)
346 {
347 	struct drm_mode_fb_cmd2 *r = data;
348 	struct drm_framebuffer *fb;
349 
350 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
351 		return -EOPNOTSUPP;
352 
353 	fb = drm_internal_framebuffer_create(dev, r, file_priv);
354 	if (IS_ERR(fb))
355 		return PTR_ERR(fb);
356 
357 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
358 	r->fb_id = fb->base.id;
359 
360 	/* Transfer ownership to the filp for reaping on close */
361 	mutex_lock(&file_priv->fbs_lock);
362 	list_add(&fb->filp_head, &file_priv->fbs);
363 	mutex_unlock(&file_priv->fbs_lock);
364 
365 	return 0;
366 }
367 
368 int drm_mode_addfb2_ioctl(struct drm_device *dev,
369 			  void *data, struct drm_file *file_priv)
370 {
371 #ifdef __BIG_ENDIAN
372 	if (!dev->mode_config.quirk_addfb_prefer_host_byte_order) {
373 		/*
374 		 * Drivers must set the
375 		 * quirk_addfb_prefer_host_byte_order quirk to make
376 		 * the drm_mode_addfb() compat code work correctly on
377 		 * bigendian machines.
378 		 *
379 		 * If they don't they interpret pixel_format values
380 		 * incorrectly for bug compatibility, which in turn
381 		 * implies the ADDFB2 ioctl does not work correctly
382 		 * then.  So block it to make userspace fallback to
383 		 * ADDFB.
384 		 */
385 		DRM_DEBUG_KMS("addfb2 broken on bigendian");
386 		return -EOPNOTSUPP;
387 	}
388 #endif
389 	return drm_mode_addfb2(dev, data, file_priv);
390 }
391 
392 struct drm_mode_rmfb_work {
393 	struct work_struct work;
394 	struct list_head fbs;
395 };
396 
397 static void drm_mode_rmfb_work_fn(struct work_struct *w)
398 {
399 	struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
400 
401 	while (!list_empty(&arg->fbs)) {
402 		struct drm_framebuffer *fb =
403 			list_first_entry(&arg->fbs, typeof(*fb), filp_head);
404 
405 		list_del_init(&fb->filp_head);
406 		drm_framebuffer_remove(fb);
407 	}
408 }
409 
410 /**
411  * drm_mode_rmfb - remove an FB from the configuration
412  * @dev: drm device
413  * @fb_id: id of framebuffer to remove
414  * @file_priv: drm file
415  *
416  * Remove the specified FB.
417  *
418  * Called by the user via ioctl, or by an in-kernel client.
419  *
420  * Returns:
421  * Zero on success, negative errno on failure.
422  */
423 int drm_mode_rmfb(struct drm_device *dev, u32 fb_id,
424 		  struct drm_file *file_priv)
425 {
426 	struct drm_framebuffer *fb = NULL;
427 	struct drm_framebuffer *fbl = NULL;
428 	int found = 0;
429 
430 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
431 		return -EOPNOTSUPP;
432 
433 	fb = drm_framebuffer_lookup(dev, file_priv, fb_id);
434 	if (!fb)
435 		return -ENOENT;
436 
437 	mutex_lock(&file_priv->fbs_lock);
438 	list_for_each_entry(fbl, &file_priv->fbs, filp_head)
439 		if (fb == fbl)
440 			found = 1;
441 	if (!found) {
442 		mutex_unlock(&file_priv->fbs_lock);
443 		goto fail_unref;
444 	}
445 
446 	list_del_init(&fb->filp_head);
447 	mutex_unlock(&file_priv->fbs_lock);
448 
449 	/* drop the reference we picked up in framebuffer lookup */
450 	drm_framebuffer_put(fb);
451 
452 	/*
453 	 * we now own the reference that was stored in the fbs list
454 	 *
455 	 * drm_framebuffer_remove may fail with -EINTR on pending signals,
456 	 * so run this in a separate stack as there's no way to correctly
457 	 * handle this after the fb is already removed from the lookup table.
458 	 */
459 	if (drm_framebuffer_read_refcount(fb) > 1) {
460 		struct drm_mode_rmfb_work arg;
461 
462 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
463 		INIT_LIST_HEAD(&arg.fbs);
464 		list_add_tail(&fb->filp_head, &arg.fbs);
465 
466 		schedule_work(&arg.work);
467 		flush_work(&arg.work);
468 		destroy_work_on_stack(&arg.work);
469 	} else
470 		drm_framebuffer_put(fb);
471 
472 	return 0;
473 
474 fail_unref:
475 	drm_framebuffer_put(fb);
476 	return -ENOENT;
477 }
478 
479 int drm_mode_rmfb_ioctl(struct drm_device *dev,
480 			void *data, struct drm_file *file_priv)
481 {
482 	uint32_t *fb_id = data;
483 
484 	return drm_mode_rmfb(dev, *fb_id, file_priv);
485 }
486 
487 /**
488  * drm_mode_getfb - get FB info
489  * @dev: drm device for the ioctl
490  * @data: data pointer for the ioctl
491  * @file_priv: drm file for the ioctl call
492  *
493  * Lookup the FB given its ID and return info about it.
494  *
495  * Called by the user via ioctl.
496  *
497  * Returns:
498  * Zero on success, negative errno on failure.
499  */
500 int drm_mode_getfb(struct drm_device *dev,
501 		   void *data, struct drm_file *file_priv)
502 {
503 	struct drm_mode_fb_cmd *r = data;
504 	struct drm_framebuffer *fb;
505 	int ret;
506 
507 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
508 		return -EOPNOTSUPP;
509 
510 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
511 	if (!fb)
512 		return -ENOENT;
513 
514 	/* Multi-planar framebuffers need getfb2. */
515 	if (fb->format->num_planes > 1) {
516 		ret = -EINVAL;
517 		goto out;
518 	}
519 
520 	if (!fb->funcs->create_handle) {
521 		ret = -ENODEV;
522 		goto out;
523 	}
524 
525 	r->height = fb->height;
526 	r->width = fb->width;
527 	r->depth = fb->format->depth;
528 	r->bpp = fb->format->cpp[0] * 8;
529 	r->pitch = fb->pitches[0];
530 
531 	/* GET_FB() is an unprivileged ioctl so we must not return a
532 	 * buffer-handle to non-master processes! For
533 	 * backwards-compatibility reasons, we cannot make GET_FB() privileged,
534 	 * so just return an invalid handle for non-masters.
535 	 */
536 	if (!drm_is_current_master(file_priv) && !capable(CAP_SYS_ADMIN)) {
537 		r->handle = 0;
538 		ret = 0;
539 		goto out;
540 	}
541 
542 	ret = fb->funcs->create_handle(fb, file_priv, &r->handle);
543 
544 out:
545 	drm_framebuffer_put(fb);
546 
547 	return ret;
548 }
549 
550 /**
551  * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
552  * @dev: drm device for the ioctl
553  * @data: data pointer for the ioctl
554  * @file_priv: drm file for the ioctl call
555  *
556  * Lookup the FB and flush out the damaged area supplied by userspace as a clip
557  * rectangle list. Generic userspace which does frontbuffer rendering must call
558  * this ioctl to flush out the changes on manual-update display outputs, e.g.
559  * usb display-link, mipi manual update panels or edp panel self refresh modes.
560  *
561  * Modesetting drivers which always update the frontbuffer do not need to
562  * implement the corresponding &drm_framebuffer_funcs.dirty callback.
563  *
564  * Called by the user via ioctl.
565  *
566  * Returns:
567  * Zero on success, negative errno on failure.
568  */
569 int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
570 			   void *data, struct drm_file *file_priv)
571 {
572 	struct drm_clip_rect __user *clips_ptr;
573 	struct drm_clip_rect *clips = NULL;
574 	struct drm_mode_fb_dirty_cmd *r = data;
575 	struct drm_framebuffer *fb;
576 	unsigned flags;
577 	int num_clips;
578 	int ret;
579 
580 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
581 		return -EOPNOTSUPP;
582 
583 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
584 	if (!fb)
585 		return -ENOENT;
586 
587 	num_clips = r->num_clips;
588 	clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
589 
590 	if (!num_clips != !clips_ptr) {
591 		ret = -EINVAL;
592 		goto out_err1;
593 	}
594 
595 	flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
596 
597 	/* If userspace annotates copy, clips must come in pairs */
598 	if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
599 		ret = -EINVAL;
600 		goto out_err1;
601 	}
602 
603 	if (num_clips && clips_ptr) {
604 		if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
605 			ret = -EINVAL;
606 			goto out_err1;
607 		}
608 		clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
609 		if (!clips) {
610 			ret = -ENOMEM;
611 			goto out_err1;
612 		}
613 
614 		ret = copy_from_user(clips, clips_ptr,
615 				     num_clips * sizeof(*clips));
616 		if (ret) {
617 			ret = -EFAULT;
618 			goto out_err2;
619 		}
620 	}
621 
622 	if (fb->funcs->dirty) {
623 		ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
624 				       clips, num_clips);
625 	} else {
626 		ret = -ENOSYS;
627 	}
628 
629 out_err2:
630 	kfree(clips);
631 out_err1:
632 	drm_framebuffer_put(fb);
633 
634 	return ret;
635 }
636 
637 /**
638  * drm_fb_release - remove and free the FBs on this file
639  * @priv: drm file for the ioctl
640  *
641  * Destroy all the FBs associated with @filp.
642  *
643  * Called by the user via ioctl.
644  *
645  * Returns:
646  * Zero on success, negative errno on failure.
647  */
648 void drm_fb_release(struct drm_file *priv)
649 {
650 	struct drm_framebuffer *fb, *tfb;
651 	struct drm_mode_rmfb_work arg;
652 
653 	INIT_LIST_HEAD(&arg.fbs);
654 
655 	/*
656 	 * When the file gets released that means no one else can access the fb
657 	 * list any more, so no need to grab fpriv->fbs_lock. And we need to
658 	 * avoid upsetting lockdep since the universal cursor code adds a
659 	 * framebuffer while holding mutex locks.
660 	 *
661 	 * Note that a real deadlock between fpriv->fbs_lock and the modeset
662 	 * locks is impossible here since no one else but this function can get
663 	 * at it any more.
664 	 */
665 	list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
666 		if (drm_framebuffer_read_refcount(fb) > 1) {
667 			list_move_tail(&fb->filp_head, &arg.fbs);
668 		} else {
669 			list_del_init(&fb->filp_head);
670 
671 			/* This drops the fpriv->fbs reference. */
672 			drm_framebuffer_put(fb);
673 		}
674 	}
675 
676 	if (!list_empty(&arg.fbs)) {
677 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
678 
679 		schedule_work(&arg.work);
680 		flush_work(&arg.work);
681 		destroy_work_on_stack(&arg.work);
682 	}
683 }
684 
685 void drm_framebuffer_free(struct kref *kref)
686 {
687 	struct drm_framebuffer *fb =
688 			container_of(kref, struct drm_framebuffer, base.refcount);
689 	struct drm_device *dev = fb->dev;
690 
691 	/*
692 	 * The lookup idr holds a weak reference, which has not necessarily been
693 	 * removed at this point. Check for that.
694 	 */
695 	drm_mode_object_unregister(dev, &fb->base);
696 
697 	fb->funcs->destroy(fb);
698 }
699 
700 /**
701  * drm_framebuffer_init - initialize a framebuffer
702  * @dev: DRM device
703  * @fb: framebuffer to be initialized
704  * @funcs: ... with these functions
705  *
706  * Allocates an ID for the framebuffer's parent mode object, sets its mode
707  * functions & device file and adds it to the master fd list.
708  *
709  * IMPORTANT:
710  * This functions publishes the fb and makes it available for concurrent access
711  * by other users. Which means by this point the fb _must_ be fully set up -
712  * since all the fb attributes are invariant over its lifetime, no further
713  * locking but only correct reference counting is required.
714  *
715  * Returns:
716  * Zero on success, error code on failure.
717  */
718 int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
719 			 const struct drm_framebuffer_funcs *funcs)
720 {
721 	int ret;
722 
723 	if (WARN_ON_ONCE(fb->dev != dev || !fb->format))
724 		return -EINVAL;
725 
726 	INIT_LIST_HEAD(&fb->filp_head);
727 
728 	fb->funcs = funcs;
729 	strcpy(fb->comm, current->comm);
730 
731 	ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB,
732 				    false, drm_framebuffer_free);
733 	if (ret)
734 		goto out;
735 
736 	mutex_lock(&dev->mode_config.fb_lock);
737 	dev->mode_config.num_fb++;
738 	list_add(&fb->head, &dev->mode_config.fb_list);
739 	mutex_unlock(&dev->mode_config.fb_lock);
740 
741 	drm_mode_object_register(dev, &fb->base);
742 out:
743 	return ret;
744 }
745 EXPORT_SYMBOL(drm_framebuffer_init);
746 
747 /**
748  * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
749  * @dev: drm device
750  * @file_priv: drm file to check for lease against.
751  * @id: id of the fb object
752  *
753  * If successful, this grabs an additional reference to the framebuffer -
754  * callers need to make sure to eventually unreference the returned framebuffer
755  * again, using drm_framebuffer_put().
756  */
757 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
758 					       struct drm_file *file_priv,
759 					       uint32_t id)
760 {
761 	struct drm_mode_object *obj;
762 	struct drm_framebuffer *fb = NULL;
763 
764 	obj = __drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_FB);
765 	if (obj)
766 		fb = obj_to_fb(obj);
767 	return fb;
768 }
769 EXPORT_SYMBOL(drm_framebuffer_lookup);
770 
771 /**
772  * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
773  * @fb: fb to unregister
774  *
775  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
776  * those used for fbdev. Note that the caller must hold a reference of its own,
777  * i.e. the object may not be destroyed through this call (since it'll lead to a
778  * locking inversion).
779  *
780  * NOTE: This function is deprecated. For driver-private framebuffers it is not
781  * recommended to embed a framebuffer struct info fbdev struct, instead, a
782  * framebuffer pointer is preferred and drm_framebuffer_put() should be called
783  * when the framebuffer is to be cleaned up.
784  */
785 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
786 {
787 	struct drm_device *dev;
788 
789 	if (!fb)
790 		return;
791 
792 	dev = fb->dev;
793 
794 	/* Mark fb as reaped and drop idr ref. */
795 	drm_mode_object_unregister(dev, &fb->base);
796 }
797 EXPORT_SYMBOL(drm_framebuffer_unregister_private);
798 
799 /**
800  * drm_framebuffer_cleanup - remove a framebuffer object
801  * @fb: framebuffer to remove
802  *
803  * Cleanup framebuffer. This function is intended to be used from the drivers
804  * &drm_framebuffer_funcs.destroy callback. It can also be used to clean up
805  * driver private framebuffers embedded into a larger structure.
806  *
807  * Note that this function does not remove the fb from active usage - if it is
808  * still used anywhere, hilarity can ensue since userspace could call getfb on
809  * the id and get back -EINVAL. Obviously no concern at driver unload time.
810  *
811  * Also, the framebuffer will not be removed from the lookup idr - for
812  * user-created framebuffers this will happen in in the rmfb ioctl. For
813  * driver-private objects (e.g. for fbdev) drivers need to explicitly call
814  * drm_framebuffer_unregister_private.
815  */
816 void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
817 {
818 	struct drm_device *dev = fb->dev;
819 
820 	mutex_lock(&dev->mode_config.fb_lock);
821 	list_del(&fb->head);
822 	dev->mode_config.num_fb--;
823 	mutex_unlock(&dev->mode_config.fb_lock);
824 }
825 EXPORT_SYMBOL(drm_framebuffer_cleanup);
826 
827 static int atomic_remove_fb(struct drm_framebuffer *fb)
828 {
829 	struct drm_modeset_acquire_ctx ctx;
830 	struct drm_device *dev = fb->dev;
831 	struct drm_atomic_state *state;
832 	struct drm_plane *plane;
833 	struct drm_connector *conn;
834 	struct drm_connector_state *conn_state;
835 	int i, ret;
836 	unsigned plane_mask;
837 	bool disable_crtcs = false;
838 
839 retry_disable:
840 	drm_modeset_acquire_init(&ctx, 0);
841 
842 	state = drm_atomic_state_alloc(dev);
843 	if (!state) {
844 		ret = -ENOMEM;
845 		goto out;
846 	}
847 	state->acquire_ctx = &ctx;
848 
849 retry:
850 	plane_mask = 0;
851 	ret = drm_modeset_lock_all_ctx(dev, &ctx);
852 	if (ret)
853 		goto unlock;
854 
855 	drm_for_each_plane(plane, dev) {
856 		struct drm_plane_state *plane_state;
857 
858 		if (plane->state->fb != fb)
859 			continue;
860 
861 		plane_state = drm_atomic_get_plane_state(state, plane);
862 		if (IS_ERR(plane_state)) {
863 			ret = PTR_ERR(plane_state);
864 			goto unlock;
865 		}
866 
867 		if (disable_crtcs && plane_state->crtc->primary == plane) {
868 			struct drm_crtc_state *crtc_state;
869 
870 			crtc_state = drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
871 
872 			ret = drm_atomic_add_affected_connectors(state, plane_state->crtc);
873 			if (ret)
874 				goto unlock;
875 
876 			crtc_state->active = false;
877 			ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
878 			if (ret)
879 				goto unlock;
880 		}
881 
882 		drm_atomic_set_fb_for_plane(plane_state, NULL);
883 		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
884 		if (ret)
885 			goto unlock;
886 
887 		plane_mask |= drm_plane_mask(plane);
888 	}
889 
890 	/* This list is only filled when disable_crtcs is set. */
891 	for_each_new_connector_in_state(state, conn, conn_state, i) {
892 		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
893 
894 		if (ret)
895 			goto unlock;
896 	}
897 
898 	if (plane_mask)
899 		ret = drm_atomic_commit(state);
900 
901 unlock:
902 	if (ret == -EDEADLK) {
903 		drm_atomic_state_clear(state);
904 		drm_modeset_backoff(&ctx);
905 		goto retry;
906 	}
907 
908 	drm_atomic_state_put(state);
909 
910 out:
911 	drm_modeset_drop_locks(&ctx);
912 	drm_modeset_acquire_fini(&ctx);
913 
914 	if (ret == -EINVAL && !disable_crtcs) {
915 		disable_crtcs = true;
916 		goto retry_disable;
917 	}
918 
919 	return ret;
920 }
921 
922 static void legacy_remove_fb(struct drm_framebuffer *fb)
923 {
924 	struct drm_device *dev = fb->dev;
925 	struct drm_crtc *crtc;
926 	struct drm_plane *plane;
927 
928 	drm_modeset_lock_all(dev);
929 	/* remove from any CRTC */
930 	drm_for_each_crtc(crtc, dev) {
931 		if (crtc->primary->fb == fb) {
932 			/* should turn off the crtc */
933 			if (drm_crtc_force_disable(crtc))
934 				DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
935 		}
936 	}
937 
938 	drm_for_each_plane(plane, dev) {
939 		if (plane->fb == fb)
940 			drm_plane_force_disable(plane);
941 	}
942 	drm_modeset_unlock_all(dev);
943 }
944 
945 /**
946  * drm_framebuffer_remove - remove and unreference a framebuffer object
947  * @fb: framebuffer to remove
948  *
949  * Scans all the CRTCs and planes in @dev's mode_config.  If they're
950  * using @fb, removes it, setting it to NULL. Then drops the reference to the
951  * passed-in framebuffer. Might take the modeset locks.
952  *
953  * Note that this function optimizes the cleanup away if the caller holds the
954  * last reference to the framebuffer. It is also guaranteed to not take the
955  * modeset locks in this case.
956  */
957 void drm_framebuffer_remove(struct drm_framebuffer *fb)
958 {
959 	struct drm_device *dev;
960 
961 	if (!fb)
962 		return;
963 
964 	dev = fb->dev;
965 
966 	WARN_ON(!list_empty(&fb->filp_head));
967 
968 	/*
969 	 * drm ABI mandates that we remove any deleted framebuffers from active
970 	 * useage. But since most sane clients only remove framebuffers they no
971 	 * longer need, try to optimize this away.
972 	 *
973 	 * Since we're holding a reference ourselves, observing a refcount of 1
974 	 * means that we're the last holder and can skip it. Also, the refcount
975 	 * can never increase from 1 again, so we don't need any barriers or
976 	 * locks.
977 	 *
978 	 * Note that userspace could try to race with use and instate a new
979 	 * usage _after_ we've cleared all current ones. End result will be an
980 	 * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
981 	 * in this manner.
982 	 */
983 	if (drm_framebuffer_read_refcount(fb) > 1) {
984 		if (drm_drv_uses_atomic_modeset(dev)) {
985 			int ret = atomic_remove_fb(fb);
986 			WARN(ret, "atomic remove_fb failed with %i\n", ret);
987 		} else
988 			legacy_remove_fb(fb);
989 	}
990 
991 	drm_framebuffer_put(fb);
992 }
993 EXPORT_SYMBOL(drm_framebuffer_remove);
994 
995 /**
996  * drm_framebuffer_plane_width - width of the plane given the first plane
997  * @width: width of the first plane
998  * @fb: the framebuffer
999  * @plane: plane index
1000  *
1001  * Returns:
1002  * The width of @plane, given that the width of the first plane is @width.
1003  */
1004 int drm_framebuffer_plane_width(int width,
1005 				const struct drm_framebuffer *fb, int plane)
1006 {
1007 	if (plane >= fb->format->num_planes)
1008 		return 0;
1009 
1010 	return fb_plane_width(width, fb->format, plane);
1011 }
1012 EXPORT_SYMBOL(drm_framebuffer_plane_width);
1013 
1014 /**
1015  * drm_framebuffer_plane_height - height of the plane given the first plane
1016  * @height: height of the first plane
1017  * @fb: the framebuffer
1018  * @plane: plane index
1019  *
1020  * Returns:
1021  * The height of @plane, given that the height of the first plane is @height.
1022  */
1023 int drm_framebuffer_plane_height(int height,
1024 				 const struct drm_framebuffer *fb, int plane)
1025 {
1026 	if (plane >= fb->format->num_planes)
1027 		return 0;
1028 
1029 	return fb_plane_height(height, fb->format, plane);
1030 }
1031 EXPORT_SYMBOL(drm_framebuffer_plane_height);
1032 
1033 void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
1034 				const struct drm_framebuffer *fb)
1035 {
1036 	struct drm_format_name_buf format_name;
1037 	unsigned int i;
1038 
1039 	drm_printf_indent(p, indent, "allocated by = %s\n", fb->comm);
1040 	drm_printf_indent(p, indent, "refcount=%u\n",
1041 			  drm_framebuffer_read_refcount(fb));
1042 	drm_printf_indent(p, indent, "format=%s\n",
1043 			  drm_get_format_name(fb->format->format, &format_name));
1044 	drm_printf_indent(p, indent, "modifier=0x%llx\n", fb->modifier);
1045 	drm_printf_indent(p, indent, "size=%ux%u\n", fb->width, fb->height);
1046 	drm_printf_indent(p, indent, "layers:\n");
1047 
1048 	for (i = 0; i < fb->format->num_planes; i++) {
1049 		drm_printf_indent(p, indent + 1, "size[%u]=%dx%d\n", i,
1050 				  drm_framebuffer_plane_width(fb->width, fb, i),
1051 				  drm_framebuffer_plane_height(fb->height, fb, i));
1052 		drm_printf_indent(p, indent + 1, "pitch[%u]=%u\n", i, fb->pitches[i]);
1053 		drm_printf_indent(p, indent + 1, "offset[%u]=%u\n", i, fb->offsets[i]);
1054 		drm_printf_indent(p, indent + 1, "obj[%u]:%s\n", i,
1055 				  fb->obj[i] ? "" : "(null)");
1056 		if (fb->obj[i])
1057 			drm_gem_print_info(p, indent + 2, fb->obj[i]);
1058 	}
1059 }
1060 
1061 #ifdef CONFIG_DEBUG_FS
1062 static int drm_framebuffer_info(struct seq_file *m, void *data)
1063 {
1064 	struct drm_info_node *node = m->private;
1065 	struct drm_device *dev = node->minor->dev;
1066 	struct drm_printer p = drm_seq_file_printer(m);
1067 	struct drm_framebuffer *fb;
1068 
1069 	mutex_lock(&dev->mode_config.fb_lock);
1070 	drm_for_each_fb(fb, dev) {
1071 		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
1072 		drm_framebuffer_print_info(&p, 1, fb);
1073 	}
1074 	mutex_unlock(&dev->mode_config.fb_lock);
1075 
1076 	return 0;
1077 }
1078 
1079 static const struct drm_info_list drm_framebuffer_debugfs_list[] = {
1080 	{ "framebuffer", drm_framebuffer_info, 0 },
1081 };
1082 
1083 int drm_framebuffer_debugfs_init(struct drm_minor *minor)
1084 {
1085 	return drm_debugfs_create_files(drm_framebuffer_debugfs_list,
1086 				ARRAY_SIZE(drm_framebuffer_debugfs_list),
1087 				minor->debugfs_root, minor);
1088 }
1089 #endif
1090