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 <linux/uaccess.h>
25 
26 #include <drm/drm_atomic.h>
27 #include <drm/drm_atomic_uapi.h>
28 #include <drm/drm_auth.h>
29 #include <drm/drm_debugfs.h>
30 #include <drm/drm_drv.h>
31 #include <drm/drm_file.h>
32 #include <drm/drm_fourcc.h>
33 #include <drm/drm_framebuffer.h>
34 #include <drm/drm_print.h>
35 #include <drm/drm_util.h>
36 
37 #include "drm_crtc_internal.h"
38 #include "drm_internal.h"
39 
40 /**
41  * DOC: overview
42  *
43  * Frame buffers are abstract memory objects that provide a source of pixels to
44  * scanout to a CRTC. Applications explicitly request the creation of frame
45  * buffers through the DRM_IOCTL_MODE_ADDFB(2) ioctls and receive an opaque
46  * handle that can be passed to the KMS CRTC control, plane configuration and
47  * page flip functions.
48  *
49  * Frame buffers rely on the underlying memory manager for allocating backing
50  * storage. When creating a frame buffer applications pass a memory handle
51  * (or a list of memory handles for multi-planar formats) through the
52  * &struct drm_mode_fb_cmd2 argument. For drivers using GEM as their userspace
53  * buffer management interface this would be a GEM handle.  Drivers are however
54  * free to use their own backing storage object handles, e.g. vmwgfx directly
55  * exposes special TTM handles to userspace and so expects TTM handles in the
56  * create ioctl and not GEM handles.
57  *
58  * Framebuffers are tracked with &struct drm_framebuffer. They are published
59  * using drm_framebuffer_init() - after calling that function userspace can use
60  * and access the framebuffer object. The helper function
61  * drm_helper_mode_fill_fb_struct() can be used to pre-fill the required
62  * metadata fields.
63  *
64  * The lifetime of a drm framebuffer is controlled with a reference count,
65  * drivers can grab additional references with drm_framebuffer_get() and drop
66  * them again with drm_framebuffer_put(). For driver-private framebuffers for
67  * which the last reference is never dropped (e.g. for the fbdev framebuffer
68  * when the struct &struct drm_framebuffer is embedded into the fbdev helper
69  * struct) drivers can manually clean up a framebuffer at module unload time
70  * with drm_framebuffer_unregister_private(). But doing this is not
71  * recommended, and it's better to have a normal free-standing &struct
72  * drm_framebuffer.
73  */
74 
75 int drm_framebuffer_check_src_coords(uint32_t src_x, uint32_t src_y,
76 				     uint32_t src_w, uint32_t src_h,
77 				     const struct drm_framebuffer *fb)
78 {
79 	unsigned int fb_width, fb_height;
80 
81 	fb_width = fb->width << 16;
82 	fb_height = fb->height << 16;
83 
84 	/* Make sure source coordinates are inside the fb. */
85 	if (src_w > fb_width ||
86 	    src_x > fb_width - src_w ||
87 	    src_h > fb_height ||
88 	    src_y > fb_height - src_h) {
89 		DRM_DEBUG_KMS("Invalid source coordinates "
90 			      "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
91 			      src_w >> 16, ((src_w & 0xffff) * 15625) >> 10,
92 			      src_h >> 16, ((src_h & 0xffff) * 15625) >> 10,
93 			      src_x >> 16, ((src_x & 0xffff) * 15625) >> 10,
94 			      src_y >> 16, ((src_y & 0xffff) * 15625) >> 10,
95 			      fb->width, fb->height);
96 		return -ENOSPC;
97 	}
98 
99 	return 0;
100 }
101 
102 /**
103  * drm_mode_addfb - add an FB to the graphics configuration
104  * @dev: drm device for the ioctl
105  * @or: pointer to request structure
106  * @file_priv: drm file
107  *
108  * Add a new FB to the specified CRTC, given a user request. This is the
109  * original addfb ioctl which only supported RGB formats.
110  *
111  * Called by the user via ioctl, or by an in-kernel client.
112  *
113  * Returns:
114  * Zero on success, negative errno on failure.
115  */
116 int drm_mode_addfb(struct drm_device *dev, struct drm_mode_fb_cmd *or,
117 		   struct drm_file *file_priv)
118 {
119 	struct drm_mode_fb_cmd2 r = {};
120 	int ret;
121 
122 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
123 		return -EOPNOTSUPP;
124 
125 	r.pixel_format = drm_driver_legacy_fb_format(dev, or->bpp, or->depth);
126 	if (r.pixel_format == DRM_FORMAT_INVALID) {
127 		DRM_DEBUG("bad {bpp:%d, depth:%d}\n", or->bpp, or->depth);
128 		return -EINVAL;
129 	}
130 
131 	/* convert to new format and call new ioctl */
132 	r.fb_id = or->fb_id;
133 	r.width = or->width;
134 	r.height = or->height;
135 	r.pitches[0] = or->pitch;
136 	r.handles[0] = or->handle;
137 
138 	ret = drm_mode_addfb2(dev, &r, file_priv);
139 	if (ret)
140 		return ret;
141 
142 	or->fb_id = r.fb_id;
143 
144 	return 0;
145 }
146 
147 int drm_mode_addfb_ioctl(struct drm_device *dev,
148 			 void *data, struct drm_file *file_priv)
149 {
150 	return drm_mode_addfb(dev, data, file_priv);
151 }
152 
153 static int fb_plane_width(int width,
154 			  const struct drm_format_info *format, int plane)
155 {
156 	if (plane == 0)
157 		return width;
158 
159 	return DIV_ROUND_UP(width, format->hsub);
160 }
161 
162 static int fb_plane_height(int height,
163 			   const struct drm_format_info *format, int plane)
164 {
165 	if (plane == 0)
166 		return height;
167 
168 	return DIV_ROUND_UP(height, format->vsub);
169 }
170 
171 static int framebuffer_check(struct drm_device *dev,
172 			     const struct drm_mode_fb_cmd2 *r)
173 {
174 	const struct drm_format_info *info;
175 	int i;
176 
177 	/* check if the format is supported at all */
178 	info = __drm_format_info(r->pixel_format);
179 	if (!info) {
180 		struct drm_format_name_buf format_name;
181 
182 		DRM_DEBUG_KMS("bad framebuffer format %s\n",
183 			      drm_get_format_name(r->pixel_format,
184 						  &format_name));
185 		return -EINVAL;
186 	}
187 
188 	/* now let the driver pick its own format info */
189 	info = drm_get_format_info(dev, r);
190 
191 	if (r->width == 0) {
192 		DRM_DEBUG_KMS("bad framebuffer width %u\n", r->width);
193 		return -EINVAL;
194 	}
195 
196 	if (r->height == 0) {
197 		DRM_DEBUG_KMS("bad framebuffer height %u\n", r->height);
198 		return -EINVAL;
199 	}
200 
201 	for (i = 0; i < info->num_planes; i++) {
202 		unsigned int width = fb_plane_width(r->width, info, i);
203 		unsigned int height = fb_plane_height(r->height, info, i);
204 		unsigned int block_size = info->char_per_block[i];
205 		u64 min_pitch = drm_format_info_min_pitch(info, i, width);
206 
207 		if (!block_size && (r->modifier[i] == DRM_FORMAT_MOD_LINEAR)) {
208 			DRM_DEBUG_KMS("Format requires non-linear modifier for plane %d\n", i);
209 			return -EINVAL;
210 		}
211 
212 		if (!r->handles[i]) {
213 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
214 			return -EINVAL;
215 		}
216 
217 		if (min_pitch > UINT_MAX)
218 			return -ERANGE;
219 
220 		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
221 			return -ERANGE;
222 
223 		if (block_size && r->pitches[i] < min_pitch) {
224 			DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
225 			return -EINVAL;
226 		}
227 
228 		if (r->modifier[i] && !(r->flags & DRM_MODE_FB_MODIFIERS)) {
229 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
230 				      r->modifier[i], i);
231 			return -EINVAL;
232 		}
233 
234 		if (r->flags & DRM_MODE_FB_MODIFIERS &&
235 		    r->modifier[i] != r->modifier[0]) {
236 			DRM_DEBUG_KMS("bad fb modifier %llu for plane %d\n",
237 				      r->modifier[i], i);
238 			return -EINVAL;
239 		}
240 
241 		/* modifier specific checks: */
242 		switch (r->modifier[i]) {
243 		case DRM_FORMAT_MOD_SAMSUNG_64_32_TILE:
244 			/* NOTE: the pitch restriction may be lifted later if it turns
245 			 * out that no hw has this restriction:
246 			 */
247 			if (r->pixel_format != DRM_FORMAT_NV12 ||
248 					width % 128 || height % 32 ||
249 					r->pitches[i] % 128) {
250 				DRM_DEBUG_KMS("bad modifier data for plane %d\n", i);
251 				return -EINVAL;
252 			}
253 			break;
254 
255 		default:
256 			break;
257 		}
258 	}
259 
260 	for (i = info->num_planes; i < 4; i++) {
261 		if (r->modifier[i]) {
262 			DRM_DEBUG_KMS("non-zero modifier for unused plane %d\n", i);
263 			return -EINVAL;
264 		}
265 
266 		/* Pre-FB_MODIFIERS userspace didn't clear the structs properly. */
267 		if (!(r->flags & DRM_MODE_FB_MODIFIERS))
268 			continue;
269 
270 		if (r->handles[i]) {
271 			DRM_DEBUG_KMS("buffer object handle for unused plane %d\n", i);
272 			return -EINVAL;
273 		}
274 
275 		if (r->pitches[i]) {
276 			DRM_DEBUG_KMS("non-zero pitch for unused plane %d\n", i);
277 			return -EINVAL;
278 		}
279 
280 		if (r->offsets[i]) {
281 			DRM_DEBUG_KMS("non-zero offset for unused plane %d\n", i);
282 			return -EINVAL;
283 		}
284 	}
285 
286 	return 0;
287 }
288 
289 struct drm_framebuffer *
290 drm_internal_framebuffer_create(struct drm_device *dev,
291 				const struct drm_mode_fb_cmd2 *r,
292 				struct drm_file *file_priv)
293 {
294 	struct drm_mode_config *config = &dev->mode_config;
295 	struct drm_framebuffer *fb;
296 	int ret;
297 
298 	if (r->flags & ~(DRM_MODE_FB_INTERLACED | DRM_MODE_FB_MODIFIERS)) {
299 		DRM_DEBUG_KMS("bad framebuffer flags 0x%08x\n", r->flags);
300 		return ERR_PTR(-EINVAL);
301 	}
302 
303 	if ((config->min_width > r->width) || (r->width > config->max_width)) {
304 		DRM_DEBUG_KMS("bad framebuffer width %d, should be >= %d && <= %d\n",
305 			  r->width, config->min_width, config->max_width);
306 		return ERR_PTR(-EINVAL);
307 	}
308 	if ((config->min_height > r->height) || (r->height > config->max_height)) {
309 		DRM_DEBUG_KMS("bad framebuffer height %d, should be >= %d && <= %d\n",
310 			  r->height, config->min_height, config->max_height);
311 		return ERR_PTR(-EINVAL);
312 	}
313 
314 	if (r->flags & DRM_MODE_FB_MODIFIERS &&
315 	    !dev->mode_config.allow_fb_modifiers) {
316 		DRM_DEBUG_KMS("driver does not support fb modifiers\n");
317 		return ERR_PTR(-EINVAL);
318 	}
319 
320 	ret = framebuffer_check(dev, r);
321 	if (ret)
322 		return ERR_PTR(ret);
323 
324 	fb = dev->mode_config.funcs->fb_create(dev, file_priv, r);
325 	if (IS_ERR(fb)) {
326 		DRM_DEBUG_KMS("could not create framebuffer\n");
327 		return fb;
328 	}
329 
330 	return fb;
331 }
332 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_internal_framebuffer_create);
333 
334 /**
335  * drm_mode_addfb2 - add an FB to the graphics configuration
336  * @dev: drm device for the ioctl
337  * @data: data pointer for the ioctl
338  * @file_priv: drm file for the ioctl call
339  *
340  * Add a new FB to the specified CRTC, given a user request with format. This is
341  * the 2nd version of the addfb ioctl, which supports multi-planar framebuffers
342  * and uses fourcc codes as pixel format specifiers.
343  *
344  * Called by the user via ioctl.
345  *
346  * Returns:
347  * Zero on success, negative errno on failure.
348  */
349 int drm_mode_addfb2(struct drm_device *dev,
350 		    void *data, struct drm_file *file_priv)
351 {
352 	struct drm_mode_fb_cmd2 *r = data;
353 	struct drm_framebuffer *fb;
354 
355 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
356 		return -EOPNOTSUPP;
357 
358 	fb = drm_internal_framebuffer_create(dev, r, file_priv);
359 	if (IS_ERR(fb))
360 		return PTR_ERR(fb);
361 
362 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
363 	r->fb_id = fb->base.id;
364 
365 	/* Transfer ownership to the filp for reaping on close */
366 	mutex_lock(&file_priv->fbs_lock);
367 	list_add(&fb->filp_head, &file_priv->fbs);
368 	mutex_unlock(&file_priv->fbs_lock);
369 
370 	return 0;
371 }
372 
373 int drm_mode_addfb2_ioctl(struct drm_device *dev,
374 			  void *data, struct drm_file *file_priv)
375 {
376 #ifdef __BIG_ENDIAN
377 	if (!dev->mode_config.quirk_addfb_prefer_host_byte_order) {
378 		/*
379 		 * Drivers must set the
380 		 * quirk_addfb_prefer_host_byte_order quirk to make
381 		 * the drm_mode_addfb() compat code work correctly on
382 		 * bigendian machines.
383 		 *
384 		 * If they don't they interpret pixel_format values
385 		 * incorrectly for bug compatibility, which in turn
386 		 * implies the ADDFB2 ioctl does not work correctly
387 		 * then.  So block it to make userspace fallback to
388 		 * ADDFB.
389 		 */
390 		DRM_DEBUG_KMS("addfb2 broken on bigendian");
391 		return -EOPNOTSUPP;
392 	}
393 #endif
394 	return drm_mode_addfb2(dev, data, file_priv);
395 }
396 
397 struct drm_mode_rmfb_work {
398 	struct work_struct work;
399 	struct list_head fbs;
400 };
401 
402 static void drm_mode_rmfb_work_fn(struct work_struct *w)
403 {
404 	struct drm_mode_rmfb_work *arg = container_of(w, typeof(*arg), work);
405 
406 	while (!list_empty(&arg->fbs)) {
407 		struct drm_framebuffer *fb =
408 			list_first_entry(&arg->fbs, typeof(*fb), filp_head);
409 
410 		list_del_init(&fb->filp_head);
411 		drm_framebuffer_remove(fb);
412 	}
413 }
414 
415 /**
416  * drm_mode_rmfb - remove an FB from the configuration
417  * @dev: drm device
418  * @fb_id: id of framebuffer to remove
419  * @file_priv: drm file
420  *
421  * Remove the specified FB.
422  *
423  * Called by the user via ioctl, or by an in-kernel client.
424  *
425  * Returns:
426  * Zero on success, negative errno on failure.
427  */
428 int drm_mode_rmfb(struct drm_device *dev, u32 fb_id,
429 		  struct drm_file *file_priv)
430 {
431 	struct drm_framebuffer *fb = NULL;
432 	struct drm_framebuffer *fbl = NULL;
433 	int found = 0;
434 
435 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
436 		return -EOPNOTSUPP;
437 
438 	fb = drm_framebuffer_lookup(dev, file_priv, fb_id);
439 	if (!fb)
440 		return -ENOENT;
441 
442 	mutex_lock(&file_priv->fbs_lock);
443 	list_for_each_entry(fbl, &file_priv->fbs, filp_head)
444 		if (fb == fbl)
445 			found = 1;
446 	if (!found) {
447 		mutex_unlock(&file_priv->fbs_lock);
448 		goto fail_unref;
449 	}
450 
451 	list_del_init(&fb->filp_head);
452 	mutex_unlock(&file_priv->fbs_lock);
453 
454 	/* drop the reference we picked up in framebuffer lookup */
455 	drm_framebuffer_put(fb);
456 
457 	/*
458 	 * we now own the reference that was stored in the fbs list
459 	 *
460 	 * drm_framebuffer_remove may fail with -EINTR on pending signals,
461 	 * so run this in a separate stack as there's no way to correctly
462 	 * handle this after the fb is already removed from the lookup table.
463 	 */
464 	if (drm_framebuffer_read_refcount(fb) > 1) {
465 		struct drm_mode_rmfb_work arg;
466 
467 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
468 		INIT_LIST_HEAD(&arg.fbs);
469 		list_add_tail(&fb->filp_head, &arg.fbs);
470 
471 		schedule_work(&arg.work);
472 		flush_work(&arg.work);
473 		destroy_work_on_stack(&arg.work);
474 	} else
475 		drm_framebuffer_put(fb);
476 
477 	return 0;
478 
479 fail_unref:
480 	drm_framebuffer_put(fb);
481 	return -ENOENT;
482 }
483 
484 int drm_mode_rmfb_ioctl(struct drm_device *dev,
485 			void *data, struct drm_file *file_priv)
486 {
487 	uint32_t *fb_id = data;
488 
489 	return drm_mode_rmfb(dev, *fb_id, file_priv);
490 }
491 
492 /**
493  * drm_mode_getfb - get FB info
494  * @dev: drm device for the ioctl
495  * @data: data pointer for the ioctl
496  * @file_priv: drm file for the ioctl call
497  *
498  * Lookup the FB given its ID and return info about it.
499  *
500  * Called by the user via ioctl.
501  *
502  * Returns:
503  * Zero on success, negative errno on failure.
504  */
505 int drm_mode_getfb(struct drm_device *dev,
506 		   void *data, struct drm_file *file_priv)
507 {
508 	struct drm_mode_fb_cmd *r = data;
509 	struct drm_framebuffer *fb;
510 	int ret;
511 
512 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
513 		return -EOPNOTSUPP;
514 
515 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
516 	if (!fb)
517 		return -ENOENT;
518 
519 	/* Multi-planar framebuffers need getfb2. */
520 	if (fb->format->num_planes > 1) {
521 		ret = -EINVAL;
522 		goto out;
523 	}
524 
525 	if (!fb->funcs->create_handle) {
526 		ret = -ENODEV;
527 		goto out;
528 	}
529 
530 	r->height = fb->height;
531 	r->width = fb->width;
532 	r->depth = fb->format->depth;
533 	r->bpp = fb->format->cpp[0] * 8;
534 	r->pitch = fb->pitches[0];
535 
536 	/* GET_FB() is an unprivileged ioctl so we must not return a
537 	 * buffer-handle to non-master processes! For
538 	 * backwards-compatibility reasons, we cannot make GET_FB() privileged,
539 	 * so just return an invalid handle for non-masters.
540 	 */
541 	if (!drm_is_current_master(file_priv) && !capable(CAP_SYS_ADMIN)) {
542 		r->handle = 0;
543 		ret = 0;
544 		goto out;
545 	}
546 
547 	ret = fb->funcs->create_handle(fb, file_priv, &r->handle);
548 
549 out:
550 	drm_framebuffer_put(fb);
551 
552 	return ret;
553 }
554 
555 /**
556  * drm_mode_dirtyfb_ioctl - flush frontbuffer rendering on an FB
557  * @dev: drm device for the ioctl
558  * @data: data pointer for the ioctl
559  * @file_priv: drm file for the ioctl call
560  *
561  * Lookup the FB and flush out the damaged area supplied by userspace as a clip
562  * rectangle list. Generic userspace which does frontbuffer rendering must call
563  * this ioctl to flush out the changes on manual-update display outputs, e.g.
564  * usb display-link, mipi manual update panels or edp panel self refresh modes.
565  *
566  * Modesetting drivers which always update the frontbuffer do not need to
567  * implement the corresponding &drm_framebuffer_funcs.dirty callback.
568  *
569  * Called by the user via ioctl.
570  *
571  * Returns:
572  * Zero on success, negative errno on failure.
573  */
574 int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
575 			   void *data, struct drm_file *file_priv)
576 {
577 	struct drm_clip_rect __user *clips_ptr;
578 	struct drm_clip_rect *clips = NULL;
579 	struct drm_mode_fb_dirty_cmd *r = data;
580 	struct drm_framebuffer *fb;
581 	unsigned flags;
582 	int num_clips;
583 	int ret;
584 
585 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
586 		return -EOPNOTSUPP;
587 
588 	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
589 	if (!fb)
590 		return -ENOENT;
591 
592 	num_clips = r->num_clips;
593 	clips_ptr = (struct drm_clip_rect __user *)(unsigned long)r->clips_ptr;
594 
595 	if (!num_clips != !clips_ptr) {
596 		ret = -EINVAL;
597 		goto out_err1;
598 	}
599 
600 	flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;
601 
602 	/* If userspace annotates copy, clips must come in pairs */
603 	if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
604 		ret = -EINVAL;
605 		goto out_err1;
606 	}
607 
608 	if (num_clips && clips_ptr) {
609 		if (num_clips < 0 || num_clips > DRM_MODE_FB_DIRTY_MAX_CLIPS) {
610 			ret = -EINVAL;
611 			goto out_err1;
612 		}
613 		clips = kcalloc(num_clips, sizeof(*clips), GFP_KERNEL);
614 		if (!clips) {
615 			ret = -ENOMEM;
616 			goto out_err1;
617 		}
618 
619 		ret = copy_from_user(clips, clips_ptr,
620 				     num_clips * sizeof(*clips));
621 		if (ret) {
622 			ret = -EFAULT;
623 			goto out_err2;
624 		}
625 	}
626 
627 	if (fb->funcs->dirty) {
628 		ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
629 				       clips, num_clips);
630 	} else {
631 		ret = -ENOSYS;
632 	}
633 
634 out_err2:
635 	kfree(clips);
636 out_err1:
637 	drm_framebuffer_put(fb);
638 
639 	return ret;
640 }
641 
642 /**
643  * drm_fb_release - remove and free the FBs on this file
644  * @priv: drm file for the ioctl
645  *
646  * Destroy all the FBs associated with @filp.
647  *
648  * Called by the user via ioctl.
649  *
650  * Returns:
651  * Zero on success, negative errno on failure.
652  */
653 void drm_fb_release(struct drm_file *priv)
654 {
655 	struct drm_framebuffer *fb, *tfb;
656 	struct drm_mode_rmfb_work arg;
657 
658 	INIT_LIST_HEAD(&arg.fbs);
659 
660 	/*
661 	 * When the file gets released that means no one else can access the fb
662 	 * list any more, so no need to grab fpriv->fbs_lock. And we need to
663 	 * avoid upsetting lockdep since the universal cursor code adds a
664 	 * framebuffer while holding mutex locks.
665 	 *
666 	 * Note that a real deadlock between fpriv->fbs_lock and the modeset
667 	 * locks is impossible here since no one else but this function can get
668 	 * at it any more.
669 	 */
670 	list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
671 		if (drm_framebuffer_read_refcount(fb) > 1) {
672 			list_move_tail(&fb->filp_head, &arg.fbs);
673 		} else {
674 			list_del_init(&fb->filp_head);
675 
676 			/* This drops the fpriv->fbs reference. */
677 			drm_framebuffer_put(fb);
678 		}
679 	}
680 
681 	if (!list_empty(&arg.fbs)) {
682 		INIT_WORK_ONSTACK(&arg.work, drm_mode_rmfb_work_fn);
683 
684 		schedule_work(&arg.work);
685 		flush_work(&arg.work);
686 		destroy_work_on_stack(&arg.work);
687 	}
688 }
689 
690 void drm_framebuffer_free(struct kref *kref)
691 {
692 	struct drm_framebuffer *fb =
693 			container_of(kref, struct drm_framebuffer, base.refcount);
694 	struct drm_device *dev = fb->dev;
695 
696 	/*
697 	 * The lookup idr holds a weak reference, which has not necessarily been
698 	 * removed at this point. Check for that.
699 	 */
700 	drm_mode_object_unregister(dev, &fb->base);
701 
702 	fb->funcs->destroy(fb);
703 }
704 
705 /**
706  * drm_framebuffer_init - initialize a framebuffer
707  * @dev: DRM device
708  * @fb: framebuffer to be initialized
709  * @funcs: ... with these functions
710  *
711  * Allocates an ID for the framebuffer's parent mode object, sets its mode
712  * functions & device file and adds it to the master fd list.
713  *
714  * IMPORTANT:
715  * This functions publishes the fb and makes it available for concurrent access
716  * by other users. Which means by this point the fb _must_ be fully set up -
717  * since all the fb attributes are invariant over its lifetime, no further
718  * locking but only correct reference counting is required.
719  *
720  * Returns:
721  * Zero on success, error code on failure.
722  */
723 int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
724 			 const struct drm_framebuffer_funcs *funcs)
725 {
726 	int ret;
727 
728 	if (WARN_ON_ONCE(fb->dev != dev || !fb->format))
729 		return -EINVAL;
730 
731 	INIT_LIST_HEAD(&fb->filp_head);
732 
733 	fb->funcs = funcs;
734 	strcpy(fb->comm, current->comm);
735 
736 	ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB,
737 				    false, drm_framebuffer_free);
738 	if (ret)
739 		goto out;
740 
741 	mutex_lock(&dev->mode_config.fb_lock);
742 	dev->mode_config.num_fb++;
743 	list_add(&fb->head, &dev->mode_config.fb_list);
744 	mutex_unlock(&dev->mode_config.fb_lock);
745 
746 	drm_mode_object_register(dev, &fb->base);
747 out:
748 	return ret;
749 }
750 EXPORT_SYMBOL(drm_framebuffer_init);
751 
752 /**
753  * drm_framebuffer_lookup - look up a drm framebuffer and grab a reference
754  * @dev: drm device
755  * @file_priv: drm file to check for lease against.
756  * @id: id of the fb object
757  *
758  * If successful, this grabs an additional reference to the framebuffer -
759  * callers need to make sure to eventually unreference the returned framebuffer
760  * again, using drm_framebuffer_put().
761  */
762 struct drm_framebuffer *drm_framebuffer_lookup(struct drm_device *dev,
763 					       struct drm_file *file_priv,
764 					       uint32_t id)
765 {
766 	struct drm_mode_object *obj;
767 	struct drm_framebuffer *fb = NULL;
768 
769 	obj = __drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_FB);
770 	if (obj)
771 		fb = obj_to_fb(obj);
772 	return fb;
773 }
774 EXPORT_SYMBOL(drm_framebuffer_lookup);
775 
776 /**
777  * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr
778  * @fb: fb to unregister
779  *
780  * Drivers need to call this when cleaning up driver-private framebuffers, e.g.
781  * those used for fbdev. Note that the caller must hold a reference of its own,
782  * i.e. the object may not be destroyed through this call (since it'll lead to a
783  * locking inversion).
784  *
785  * NOTE: This function is deprecated. For driver-private framebuffers it is not
786  * recommended to embed a framebuffer struct info fbdev struct, instead, a
787  * framebuffer pointer is preferred and drm_framebuffer_put() should be called
788  * when the framebuffer is to be cleaned up.
789  */
790 void drm_framebuffer_unregister_private(struct drm_framebuffer *fb)
791 {
792 	struct drm_device *dev;
793 
794 	if (!fb)
795 		return;
796 
797 	dev = fb->dev;
798 
799 	/* Mark fb as reaped and drop idr ref. */
800 	drm_mode_object_unregister(dev, &fb->base);
801 }
802 EXPORT_SYMBOL(drm_framebuffer_unregister_private);
803 
804 /**
805  * drm_framebuffer_cleanup - remove a framebuffer object
806  * @fb: framebuffer to remove
807  *
808  * Cleanup framebuffer. This function is intended to be used from the drivers
809  * &drm_framebuffer_funcs.destroy callback. It can also be used to clean up
810  * driver private framebuffers embedded into a larger structure.
811  *
812  * Note that this function does not remove the fb from active usage - if it is
813  * still used anywhere, hilarity can ensue since userspace could call getfb on
814  * the id and get back -EINVAL. Obviously no concern at driver unload time.
815  *
816  * Also, the framebuffer will not be removed from the lookup idr - for
817  * user-created framebuffers this will happen in in the rmfb ioctl. For
818  * driver-private objects (e.g. for fbdev) drivers need to explicitly call
819  * drm_framebuffer_unregister_private.
820  */
821 void drm_framebuffer_cleanup(struct drm_framebuffer *fb)
822 {
823 	struct drm_device *dev = fb->dev;
824 
825 	mutex_lock(&dev->mode_config.fb_lock);
826 	list_del(&fb->head);
827 	dev->mode_config.num_fb--;
828 	mutex_unlock(&dev->mode_config.fb_lock);
829 }
830 EXPORT_SYMBOL(drm_framebuffer_cleanup);
831 
832 static int atomic_remove_fb(struct drm_framebuffer *fb)
833 {
834 	struct drm_modeset_acquire_ctx ctx;
835 	struct drm_device *dev = fb->dev;
836 	struct drm_atomic_state *state;
837 	struct drm_plane *plane;
838 	struct drm_connector *conn;
839 	struct drm_connector_state *conn_state;
840 	int i, ret;
841 	unsigned plane_mask;
842 	bool disable_crtcs = false;
843 
844 retry_disable:
845 	drm_modeset_acquire_init(&ctx, 0);
846 
847 	state = drm_atomic_state_alloc(dev);
848 	if (!state) {
849 		ret = -ENOMEM;
850 		goto out;
851 	}
852 	state->acquire_ctx = &ctx;
853 
854 retry:
855 	plane_mask = 0;
856 	ret = drm_modeset_lock_all_ctx(dev, &ctx);
857 	if (ret)
858 		goto unlock;
859 
860 	drm_for_each_plane(plane, dev) {
861 		struct drm_plane_state *plane_state;
862 
863 		if (plane->state->fb != fb)
864 			continue;
865 
866 		plane_state = drm_atomic_get_plane_state(state, plane);
867 		if (IS_ERR(plane_state)) {
868 			ret = PTR_ERR(plane_state);
869 			goto unlock;
870 		}
871 
872 		if (disable_crtcs && plane_state->crtc->primary == plane) {
873 			struct drm_crtc_state *crtc_state;
874 
875 			crtc_state = drm_atomic_get_existing_crtc_state(state, plane_state->crtc);
876 
877 			ret = drm_atomic_add_affected_connectors(state, plane_state->crtc);
878 			if (ret)
879 				goto unlock;
880 
881 			crtc_state->active = false;
882 			ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
883 			if (ret)
884 				goto unlock;
885 		}
886 
887 		drm_atomic_set_fb_for_plane(plane_state, NULL);
888 		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
889 		if (ret)
890 			goto unlock;
891 
892 		plane_mask |= drm_plane_mask(plane);
893 	}
894 
895 	/* This list is only filled when disable_crtcs is set. */
896 	for_each_new_connector_in_state(state, conn, conn_state, i) {
897 		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
898 
899 		if (ret)
900 			goto unlock;
901 	}
902 
903 	if (plane_mask)
904 		ret = drm_atomic_commit(state);
905 
906 unlock:
907 	if (ret == -EDEADLK) {
908 		drm_atomic_state_clear(state);
909 		drm_modeset_backoff(&ctx);
910 		goto retry;
911 	}
912 
913 	drm_atomic_state_put(state);
914 
915 out:
916 	drm_modeset_drop_locks(&ctx);
917 	drm_modeset_acquire_fini(&ctx);
918 
919 	if (ret == -EINVAL && !disable_crtcs) {
920 		disable_crtcs = true;
921 		goto retry_disable;
922 	}
923 
924 	return ret;
925 }
926 
927 static void legacy_remove_fb(struct drm_framebuffer *fb)
928 {
929 	struct drm_device *dev = fb->dev;
930 	struct drm_crtc *crtc;
931 	struct drm_plane *plane;
932 
933 	drm_modeset_lock_all(dev);
934 	/* remove from any CRTC */
935 	drm_for_each_crtc(crtc, dev) {
936 		if (crtc->primary->fb == fb) {
937 			/* should turn off the crtc */
938 			if (drm_crtc_force_disable(crtc))
939 				DRM_ERROR("failed to reset crtc %p when fb was deleted\n", crtc);
940 		}
941 	}
942 
943 	drm_for_each_plane(plane, dev) {
944 		if (plane->fb == fb)
945 			drm_plane_force_disable(plane);
946 	}
947 	drm_modeset_unlock_all(dev);
948 }
949 
950 /**
951  * drm_framebuffer_remove - remove and unreference a framebuffer object
952  * @fb: framebuffer to remove
953  *
954  * Scans all the CRTCs and planes in @dev's mode_config.  If they're
955  * using @fb, removes it, setting it to NULL. Then drops the reference to the
956  * passed-in framebuffer. Might take the modeset locks.
957  *
958  * Note that this function optimizes the cleanup away if the caller holds the
959  * last reference to the framebuffer. It is also guaranteed to not take the
960  * modeset locks in this case.
961  */
962 void drm_framebuffer_remove(struct drm_framebuffer *fb)
963 {
964 	struct drm_device *dev;
965 
966 	if (!fb)
967 		return;
968 
969 	dev = fb->dev;
970 
971 	WARN_ON(!list_empty(&fb->filp_head));
972 
973 	/*
974 	 * drm ABI mandates that we remove any deleted framebuffers from active
975 	 * useage. But since most sane clients only remove framebuffers they no
976 	 * longer need, try to optimize this away.
977 	 *
978 	 * Since we're holding a reference ourselves, observing a refcount of 1
979 	 * means that we're the last holder and can skip it. Also, the refcount
980 	 * can never increase from 1 again, so we don't need any barriers or
981 	 * locks.
982 	 *
983 	 * Note that userspace could try to race with use and instate a new
984 	 * usage _after_ we've cleared all current ones. End result will be an
985 	 * in-use fb with fb-id == 0. Userspace is allowed to shoot its own foot
986 	 * in this manner.
987 	 */
988 	if (drm_framebuffer_read_refcount(fb) > 1) {
989 		if (drm_drv_uses_atomic_modeset(dev)) {
990 			int ret = atomic_remove_fb(fb);
991 			WARN(ret, "atomic remove_fb failed with %i\n", ret);
992 		} else
993 			legacy_remove_fb(fb);
994 	}
995 
996 	drm_framebuffer_put(fb);
997 }
998 EXPORT_SYMBOL(drm_framebuffer_remove);
999 
1000 /**
1001  * drm_framebuffer_plane_width - width of the plane given the first plane
1002  * @width: width of the first plane
1003  * @fb: the framebuffer
1004  * @plane: plane index
1005  *
1006  * Returns:
1007  * The width of @plane, given that the width of the first plane is @width.
1008  */
1009 int drm_framebuffer_plane_width(int width,
1010 				const struct drm_framebuffer *fb, int plane)
1011 {
1012 	if (plane >= fb->format->num_planes)
1013 		return 0;
1014 
1015 	return fb_plane_width(width, fb->format, plane);
1016 }
1017 EXPORT_SYMBOL(drm_framebuffer_plane_width);
1018 
1019 /**
1020  * drm_framebuffer_plane_height - height of the plane given the first plane
1021  * @height: height of the first plane
1022  * @fb: the framebuffer
1023  * @plane: plane index
1024  *
1025  * Returns:
1026  * The height of @plane, given that the height of the first plane is @height.
1027  */
1028 int drm_framebuffer_plane_height(int height,
1029 				 const struct drm_framebuffer *fb, int plane)
1030 {
1031 	if (plane >= fb->format->num_planes)
1032 		return 0;
1033 
1034 	return fb_plane_height(height, fb->format, plane);
1035 }
1036 EXPORT_SYMBOL(drm_framebuffer_plane_height);
1037 
1038 void drm_framebuffer_print_info(struct drm_printer *p, unsigned int indent,
1039 				const struct drm_framebuffer *fb)
1040 {
1041 	struct drm_format_name_buf format_name;
1042 	unsigned int i;
1043 
1044 	drm_printf_indent(p, indent, "allocated by = %s\n", fb->comm);
1045 	drm_printf_indent(p, indent, "refcount=%u\n",
1046 			  drm_framebuffer_read_refcount(fb));
1047 	drm_printf_indent(p, indent, "format=%s\n",
1048 			  drm_get_format_name(fb->format->format, &format_name));
1049 	drm_printf_indent(p, indent, "modifier=0x%llx\n", fb->modifier);
1050 	drm_printf_indent(p, indent, "size=%ux%u\n", fb->width, fb->height);
1051 	drm_printf_indent(p, indent, "layers:\n");
1052 
1053 	for (i = 0; i < fb->format->num_planes; i++) {
1054 		drm_printf_indent(p, indent + 1, "size[%u]=%dx%d\n", i,
1055 				  drm_framebuffer_plane_width(fb->width, fb, i),
1056 				  drm_framebuffer_plane_height(fb->height, fb, i));
1057 		drm_printf_indent(p, indent + 1, "pitch[%u]=%u\n", i, fb->pitches[i]);
1058 		drm_printf_indent(p, indent + 1, "offset[%u]=%u\n", i, fb->offsets[i]);
1059 		drm_printf_indent(p, indent + 1, "obj[%u]:%s\n", i,
1060 				  fb->obj[i] ? "" : "(null)");
1061 		if (fb->obj[i])
1062 			drm_gem_print_info(p, indent + 2, fb->obj[i]);
1063 	}
1064 }
1065 
1066 #ifdef CONFIG_DEBUG_FS
1067 static int drm_framebuffer_info(struct seq_file *m, void *data)
1068 {
1069 	struct drm_info_node *node = m->private;
1070 	struct drm_device *dev = node->minor->dev;
1071 	struct drm_printer p = drm_seq_file_printer(m);
1072 	struct drm_framebuffer *fb;
1073 
1074 	mutex_lock(&dev->mode_config.fb_lock);
1075 	drm_for_each_fb(fb, dev) {
1076 		drm_printf(&p, "framebuffer[%u]:\n", fb->base.id);
1077 		drm_framebuffer_print_info(&p, 1, fb);
1078 	}
1079 	mutex_unlock(&dev->mode_config.fb_lock);
1080 
1081 	return 0;
1082 }
1083 
1084 static const struct drm_info_list drm_framebuffer_debugfs_list[] = {
1085 	{ "framebuffer", drm_framebuffer_info, 0 },
1086 };
1087 
1088 int drm_framebuffer_debugfs_init(struct drm_minor *minor)
1089 {
1090 	return drm_debugfs_create_files(drm_framebuffer_debugfs_list,
1091 				ARRAY_SIZE(drm_framebuffer_debugfs_list),
1092 				minor->debugfs_root, minor);
1093 }
1094 #endif
1095