xref: /openbmc/linux/include/drm/drm_file.h (revision 236bdb88)
1 /*
2  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
3  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
4  * Copyright (c) 2009-2010, Code Aurora Forum.
5  * All rights reserved.
6  *
7  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
8  * Author: Gareth Hughes <gareth@valinux.com>
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a
11  * copy of this software and associated documentation files (the "Software"),
12  * to deal in the Software without restriction, including without limitation
13  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
14  * and/or sell copies of the Software, and to permit persons to whom the
15  * Software is furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice (including the next
18  * paragraph) shall be included in all copies or substantial portions of the
19  * Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
24  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
25  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
26  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
27  * OTHER DEALINGS IN THE SOFTWARE.
28  */
29 
30 #ifndef _DRM_FILE_H_
31 #define _DRM_FILE_H_
32 
33 #include <linux/types.h>
34 #include <linux/completion.h>
35 #include <linux/idr.h>
36 
37 #include <uapi/drm/drm.h>
38 
39 #include <drm/drm_prime.h>
40 
41 struct dma_fence;
42 struct drm_file;
43 struct drm_device;
44 struct device;
45 struct file;
46 
47 /*
48  * FIXME: Not sure we want to have drm_minor here in the end, but to avoid
49  * header include loops we need it here for now.
50  */
51 
52 /* Note that the order of this enum is ABI (it determines
53  * /dev/dri/renderD* numbers).
54  *
55  * Setting DRM_MINOR_ACCEL to 32 gives enough space for more drm minors to
56  * be implemented before we hit any future
57  */
58 enum drm_minor_type {
59 	DRM_MINOR_PRIMARY,
60 	DRM_MINOR_CONTROL,
61 	DRM_MINOR_RENDER,
62 	DRM_MINOR_ACCEL = 32,
63 };
64 
65 /**
66  * struct drm_minor - DRM device minor structure
67  *
68  * This structure represents a DRM minor number for device nodes in /dev.
69  * Entirely opaque to drivers and should never be inspected directly by drivers.
70  * Drivers instead should only interact with &struct drm_file and of course
71  * &struct drm_device, which is also where driver-private data and resources can
72  * be attached to.
73  */
74 struct drm_minor {
75 	/* private: */
76 	int index;			/* Minor device number */
77 	int type;                       /* Control or render or accel */
78 	struct device *kdev;		/* Linux device */
79 	struct drm_device *dev;
80 
81 	struct dentry *debugfs_root;
82 
83 	struct list_head debugfs_list;
84 	struct mutex debugfs_lock; /* Protects debugfs_list. */
85 };
86 
87 /**
88  * struct drm_pending_event - Event queued up for userspace to read
89  *
90  * This represents a DRM event. Drivers can use this as a generic completion
91  * mechanism, which supports kernel-internal &struct completion, &struct dma_fence
92  * and also the DRM-specific &struct drm_event delivery mechanism.
93  */
94 struct drm_pending_event {
95 	/**
96 	 * @completion:
97 	 *
98 	 * Optional pointer to a kernel internal completion signalled when
99 	 * drm_send_event() is called, useful to internally synchronize with
100 	 * nonblocking operations.
101 	 */
102 	struct completion *completion;
103 
104 	/**
105 	 * @completion_release:
106 	 *
107 	 * Optional callback currently only used by the atomic modeset helpers
108 	 * to clean up the reference count for the structure @completion is
109 	 * stored in.
110 	 */
111 	void (*completion_release)(struct completion *completion);
112 
113 	/**
114 	 * @event:
115 	 *
116 	 * Pointer to the actual event that should be sent to userspace to be
117 	 * read using drm_read(). Can be optional, since nowadays events are
118 	 * also used to signal kernel internal threads with @completion or DMA
119 	 * transactions using @fence.
120 	 */
121 	struct drm_event *event;
122 
123 	/**
124 	 * @fence:
125 	 *
126 	 * Optional DMA fence to unblock other hardware transactions which
127 	 * depend upon the nonblocking DRM operation this event represents.
128 	 */
129 	struct dma_fence *fence;
130 
131 	/**
132 	 * @file_priv:
133 	 *
134 	 * &struct drm_file where @event should be delivered to. Only set when
135 	 * @event is set.
136 	 */
137 	struct drm_file *file_priv;
138 
139 	/**
140 	 * @link:
141 	 *
142 	 * Double-linked list to keep track of this event. Can be used by the
143 	 * driver up to the point when it calls drm_send_event(), after that
144 	 * this list entry is owned by the core for its own book-keeping.
145 	 */
146 	struct list_head link;
147 
148 	/**
149 	 * @pending_link:
150 	 *
151 	 * Entry on &drm_file.pending_event_list, to keep track of all pending
152 	 * events for @file_priv, to allow correct unwinding of them when
153 	 * userspace closes the file before the event is delivered.
154 	 */
155 	struct list_head pending_link;
156 };
157 
158 /**
159  * struct drm_file - DRM file private data
160  *
161  * This structure tracks DRM state per open file descriptor.
162  */
163 struct drm_file {
164 	/**
165 	 * @authenticated:
166 	 *
167 	 * Whether the client is allowed to submit rendering, which for legacy
168 	 * nodes means it must be authenticated.
169 	 *
170 	 * See also the :ref:`section on primary nodes and authentication
171 	 * <drm_primary_node>`.
172 	 */
173 	bool authenticated;
174 
175 	/**
176 	 * @stereo_allowed:
177 	 *
178 	 * True when the client has asked us to expose stereo 3D mode flags.
179 	 */
180 	bool stereo_allowed;
181 
182 	/**
183 	 * @universal_planes:
184 	 *
185 	 * True if client understands CRTC primary planes and cursor planes
186 	 * in the plane list. Automatically set when @atomic is set.
187 	 */
188 	bool universal_planes;
189 
190 	/** @atomic: True if client understands atomic properties. */
191 	bool atomic;
192 
193 	/**
194 	 * @aspect_ratio_allowed:
195 	 *
196 	 * True, if client can handle picture aspect ratios, and has requested
197 	 * to pass this information along with the mode.
198 	 */
199 	bool aspect_ratio_allowed;
200 
201 	/**
202 	 * @writeback_connectors:
203 	 *
204 	 * True if client understands writeback connectors
205 	 */
206 	bool writeback_connectors;
207 
208 	/**
209 	 * @was_master:
210 	 *
211 	 * This client has or had, master capability. Protected by struct
212 	 * &drm_device.master_mutex.
213 	 *
214 	 * This is used to ensure that CAP_SYS_ADMIN is not enforced, if the
215 	 * client is or was master in the past.
216 	 */
217 	bool was_master;
218 
219 	/**
220 	 * @is_master:
221 	 *
222 	 * This client is the creator of @master. Protected by struct
223 	 * &drm_device.master_mutex.
224 	 *
225 	 * See also the :ref:`section on primary nodes and authentication
226 	 * <drm_primary_node>`.
227 	 */
228 	bool is_master;
229 
230 	/**
231 	 * @master:
232 	 *
233 	 * Master this node is currently associated with. Protected by struct
234 	 * &drm_device.master_mutex, and serialized by @master_lookup_lock.
235 	 *
236 	 * Only relevant if drm_is_primary_client() returns true. Note that
237 	 * this only matches &drm_device.master if the master is the currently
238 	 * active one.
239 	 *
240 	 * To update @master, both &drm_device.master_mutex and
241 	 * @master_lookup_lock need to be held, therefore holding either of
242 	 * them is safe and enough for the read side.
243 	 *
244 	 * When dereferencing this pointer, either hold struct
245 	 * &drm_device.master_mutex for the duration of the pointer's use, or
246 	 * use drm_file_get_master() if struct &drm_device.master_mutex is not
247 	 * currently held and there is no other need to hold it. This prevents
248 	 * @master from being freed during use.
249 	 *
250 	 * See also @authentication and @is_master and the :ref:`section on
251 	 * primary nodes and authentication <drm_primary_node>`.
252 	 */
253 	struct drm_master *master;
254 
255 	/** @master_lookup_lock: Serializes @master. */
256 	spinlock_t master_lookup_lock;
257 
258 	/** @pid: Process that opened this file. */
259 	struct pid *pid;
260 
261 	/** @magic: Authentication magic, see @authenticated. */
262 	drm_magic_t magic;
263 
264 	/**
265 	 * @lhead:
266 	 *
267 	 * List of all open files of a DRM device, linked into
268 	 * &drm_device.filelist. Protected by &drm_device.filelist_mutex.
269 	 */
270 	struct list_head lhead;
271 
272 	/** @minor: &struct drm_minor for this file. */
273 	struct drm_minor *minor;
274 
275 	/**
276 	 * @object_idr:
277 	 *
278 	 * Mapping of mm object handles to object pointers. Used by the GEM
279 	 * subsystem. Protected by @table_lock.
280 	 */
281 	struct idr object_idr;
282 
283 	/** @table_lock: Protects @object_idr. */
284 	spinlock_t table_lock;
285 
286 	/** @syncobj_idr: Mapping of sync object handles to object pointers. */
287 	struct idr syncobj_idr;
288 	/** @syncobj_table_lock: Protects @syncobj_idr. */
289 	spinlock_t syncobj_table_lock;
290 
291 	/** @filp: Pointer to the core file structure. */
292 	struct file *filp;
293 
294 	/**
295 	 * @driver_priv:
296 	 *
297 	 * Optional pointer for driver private data. Can be allocated in
298 	 * &drm_driver.open and should be freed in &drm_driver.postclose.
299 	 */
300 	void *driver_priv;
301 
302 	/**
303 	 * @fbs:
304 	 *
305 	 * List of &struct drm_framebuffer associated with this file, using the
306 	 * &drm_framebuffer.filp_head entry.
307 	 *
308 	 * Protected by @fbs_lock. Note that the @fbs list holds a reference on
309 	 * the framebuffer object to prevent it from untimely disappearing.
310 	 */
311 	struct list_head fbs;
312 
313 	/** @fbs_lock: Protects @fbs. */
314 	struct mutex fbs_lock;
315 
316 	/**
317 	 * @blobs:
318 	 *
319 	 * User-created blob properties; this retains a reference on the
320 	 * property.
321 	 *
322 	 * Protected by @drm_mode_config.blob_lock;
323 	 */
324 	struct list_head blobs;
325 
326 	/** @event_wait: Waitqueue for new events added to @event_list. */
327 	wait_queue_head_t event_wait;
328 
329 	/**
330 	 * @pending_event_list:
331 	 *
332 	 * List of pending &struct drm_pending_event, used to clean up pending
333 	 * events in case this file gets closed before the event is signalled.
334 	 * Uses the &drm_pending_event.pending_link entry.
335 	 *
336 	 * Protect by &drm_device.event_lock.
337 	 */
338 	struct list_head pending_event_list;
339 
340 	/**
341 	 * @event_list:
342 	 *
343 	 * List of &struct drm_pending_event, ready for delivery to userspace
344 	 * through drm_read(). Uses the &drm_pending_event.link entry.
345 	 *
346 	 * Protect by &drm_device.event_lock.
347 	 */
348 	struct list_head event_list;
349 
350 	/**
351 	 * @event_space:
352 	 *
353 	 * Available event space to prevent userspace from
354 	 * exhausting kernel memory. Currently limited to the fairly arbitrary
355 	 * value of 4KB.
356 	 */
357 	int event_space;
358 
359 	/** @event_read_lock: Serializes drm_read(). */
360 	struct mutex event_read_lock;
361 
362 	/**
363 	 * @prime:
364 	 *
365 	 * Per-file buffer caches used by the PRIME buffer sharing code.
366 	 */
367 	struct drm_prime_file_private prime;
368 
369 	/* private: */
370 #if IS_ENABLED(CONFIG_DRM_LEGACY)
371 	unsigned long lock_count; /* DRI1 legacy lock count */
372 #endif
373 };
374 
375 /**
376  * drm_is_primary_client - is this an open file of the primary node
377  * @file_priv: DRM file
378  *
379  * Returns true if this is an open file of the primary node, i.e.
380  * &drm_file.minor of @file_priv is a primary minor.
381  *
382  * See also the :ref:`section on primary nodes and authentication
383  * <drm_primary_node>`.
384  */
385 static inline bool drm_is_primary_client(const struct drm_file *file_priv)
386 {
387 	return file_priv->minor->type == DRM_MINOR_PRIMARY;
388 }
389 
390 /**
391  * drm_is_render_client - is this an open file of the render node
392  * @file_priv: DRM file
393  *
394  * Returns true if this is an open file of the render node, i.e.
395  * &drm_file.minor of @file_priv is a render minor.
396  *
397  * See also the :ref:`section on render nodes <drm_render_node>`.
398  */
399 static inline bool drm_is_render_client(const struct drm_file *file_priv)
400 {
401 	return file_priv->minor->type == DRM_MINOR_RENDER;
402 }
403 
404 /**
405  * drm_is_accel_client - is this an open file of the compute acceleration node
406  * @file_priv: DRM file
407  *
408  * Returns true if this is an open file of the compute acceleration node, i.e.
409  * &drm_file.minor of @file_priv is a accel minor.
410  *
411  * See also the :ref:`section on accel nodes <drm_accel_node>`.
412  */
413 static inline bool drm_is_accel_client(const struct drm_file *file_priv)
414 {
415 	return file_priv->minor->type == DRM_MINOR_ACCEL;
416 }
417 
418 int drm_open(struct inode *inode, struct file *filp);
419 int drm_open_helper(struct file *filp, struct drm_minor *minor);
420 ssize_t drm_read(struct file *filp, char __user *buffer,
421 		 size_t count, loff_t *offset);
422 int drm_release(struct inode *inode, struct file *filp);
423 int drm_release_noglobal(struct inode *inode, struct file *filp);
424 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait);
425 int drm_event_reserve_init_locked(struct drm_device *dev,
426 				  struct drm_file *file_priv,
427 				  struct drm_pending_event *p,
428 				  struct drm_event *e);
429 int drm_event_reserve_init(struct drm_device *dev,
430 			   struct drm_file *file_priv,
431 			   struct drm_pending_event *p,
432 			   struct drm_event *e);
433 void drm_event_cancel_free(struct drm_device *dev,
434 			   struct drm_pending_event *p);
435 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e);
436 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e);
437 void drm_send_event_timestamp_locked(struct drm_device *dev,
438 				     struct drm_pending_event *e,
439 				     ktime_t timestamp);
440 
441 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);
442 
443 #endif /* _DRM_FILE_H_ */
444