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 enum drm_minor_type {
56 	DRM_MINOR_PRIMARY,
57 	DRM_MINOR_CONTROL,
58 	DRM_MINOR_RENDER,
59 };
60 
61 /**
62  * struct drm_minor - DRM device minor structure
63  *
64  * This structure represents a DRM minor number for device nodes in /dev.
65  * Entirely opaque to drivers and should never be inspected directly by drivers.
66  * Drivers instead should only interact with &struct drm_file and of course
67  * &struct drm_device, which is also where driver-private data and resources can
68  * be attached to.
69  */
70 struct drm_minor {
71 	/* private: */
72 	int index;			/* Minor device number */
73 	int type;                       /* Control or render */
74 	struct device *kdev;		/* Linux device */
75 	struct drm_device *dev;
76 
77 	struct dentry *debugfs_root;
78 
79 	struct list_head debugfs_list;
80 	struct mutex debugfs_lock; /* Protects debugfs_list. */
81 };
82 
83 /**
84  * struct drm_pending_event - Event queued up for userspace to read
85  *
86  * This represents a DRM event. Drivers can use this as a generic completion
87  * mechanism, which supports kernel-internal &struct completion, &struct dma_fence
88  * and also the DRM-specific &struct drm_event delivery mechanism.
89  */
90 struct drm_pending_event {
91 	/**
92 	 * @completion:
93 	 *
94 	 * Optional pointer to a kernel internal completion signalled when
95 	 * drm_send_event() is called, useful to internally synchronize with
96 	 * nonblocking operations.
97 	 */
98 	struct completion *completion;
99 
100 	/**
101 	 * @completion_release:
102 	 *
103 	 * Optional callback currently only used by the atomic modeset helpers
104 	 * to clean up the reference count for the structure @completion is
105 	 * stored in.
106 	 */
107 	void (*completion_release)(struct completion *completion);
108 
109 	/**
110 	 * @event:
111 	 *
112 	 * Pointer to the actual event that should be sent to userspace to be
113 	 * read using drm_read(). Can be optional, since nowadays events are
114 	 * also used to signal kernel internal threads with @completion or DMA
115 	 * transactions using @fence.
116 	 */
117 	struct drm_event *event;
118 
119 	/**
120 	 * @fence:
121 	 *
122 	 * Optional DMA fence to unblock other hardware transactions which
123 	 * depend upon the nonblocking DRM operation this event represents.
124 	 */
125 	struct dma_fence *fence;
126 
127 	/**
128 	 * @file_priv:
129 	 *
130 	 * &struct drm_file where @event should be delivered to. Only set when
131 	 * @event is set.
132 	 */
133 	struct drm_file *file_priv;
134 
135 	/**
136 	 * @link:
137 	 *
138 	 * Double-linked list to keep track of this event. Can be used by the
139 	 * driver up to the point when it calls drm_send_event(), after that
140 	 * this list entry is owned by the core for its own book-keeping.
141 	 */
142 	struct list_head link;
143 
144 	/**
145 	 * @pending_link:
146 	 *
147 	 * Entry on &drm_file.pending_event_list, to keep track of all pending
148 	 * events for @file_priv, to allow correct unwinding of them when
149 	 * userspace closes the file before the event is delivered.
150 	 */
151 	struct list_head pending_link;
152 };
153 
154 /**
155  * struct drm_file - DRM file private data
156  *
157  * This structure tracks DRM state per open file descriptor.
158  */
159 struct drm_file {
160 	/**
161 	 * @authenticated:
162 	 *
163 	 * Whether the client is allowed to submit rendering, which for legacy
164 	 * nodes means it must be authenticated.
165 	 *
166 	 * See also the :ref:`section on primary nodes and authentication
167 	 * <drm_primary_node>`.
168 	 */
169 	bool authenticated;
170 
171 	/**
172 	 * @stereo_allowed:
173 	 *
174 	 * True when the client has asked us to expose stereo 3D mode flags.
175 	 */
176 	bool stereo_allowed;
177 
178 	/**
179 	 * @universal_planes:
180 	 *
181 	 * True if client understands CRTC primary planes and cursor planes
182 	 * in the plane list. Automatically set when @atomic is set.
183 	 */
184 	bool universal_planes;
185 
186 	/** @atomic: True if client understands atomic properties. */
187 	bool atomic;
188 
189 	/**
190 	 * @aspect_ratio_allowed:
191 	 *
192 	 * True, if client can handle picture aspect ratios, and has requested
193 	 * to pass this information along with the mode.
194 	 */
195 	bool aspect_ratio_allowed;
196 
197 	/**
198 	 * @writeback_connectors:
199 	 *
200 	 * True if client understands writeback connectors
201 	 */
202 	bool writeback_connectors;
203 
204 	/**
205 	 * @was_master:
206 	 *
207 	 * This client has or had, master capability. Protected by struct
208 	 * &drm_device.master_mutex.
209 	 *
210 	 * This is used to ensure that CAP_SYS_ADMIN is not enforced, if the
211 	 * client is or was master in the past.
212 	 */
213 	bool was_master;
214 
215 	/**
216 	 * @is_master:
217 	 *
218 	 * This client is the creator of @master. Protected by struct
219 	 * &drm_device.master_mutex.
220 	 *
221 	 * See also the :ref:`section on primary nodes and authentication
222 	 * <drm_primary_node>`.
223 	 */
224 	bool is_master;
225 
226 	/**
227 	 * @master:
228 	 *
229 	 * Master this node is currently associated with. Protected by struct
230 	 * &drm_device.master_mutex, and serialized by @master_lookup_lock.
231 	 *
232 	 * Only relevant if drm_is_primary_client() returns true. Note that
233 	 * this only matches &drm_device.master if the master is the currently
234 	 * active one.
235 	 *
236 	 * To update @master, both &drm_device.master_mutex and
237 	 * @master_lookup_lock need to be held, therefore holding either of
238 	 * them is safe and enough for the read side.
239 	 *
240 	 * When dereferencing this pointer, either hold struct
241 	 * &drm_device.master_mutex for the duration of the pointer's use, or
242 	 * use drm_file_get_master() if struct &drm_device.master_mutex is not
243 	 * currently held and there is no other need to hold it. This prevents
244 	 * @master from being freed during use.
245 	 *
246 	 * See also @authentication and @is_master and the :ref:`section on
247 	 * primary nodes and authentication <drm_primary_node>`.
248 	 */
249 	struct drm_master *master;
250 
251 	/** @master_lookup_lock: Serializes @master. */
252 	spinlock_t master_lookup_lock;
253 
254 	/** @pid: Process that opened this file. */
255 	struct pid *pid;
256 
257 	/** @magic: Authentication magic, see @authenticated. */
258 	drm_magic_t magic;
259 
260 	/**
261 	 * @lhead:
262 	 *
263 	 * List of all open files of a DRM device, linked into
264 	 * &drm_device.filelist. Protected by &drm_device.filelist_mutex.
265 	 */
266 	struct list_head lhead;
267 
268 	/** @minor: &struct drm_minor for this file. */
269 	struct drm_minor *minor;
270 
271 	/**
272 	 * @object_idr:
273 	 *
274 	 * Mapping of mm object handles to object pointers. Used by the GEM
275 	 * subsystem. Protected by @table_lock.
276 	 */
277 	struct idr object_idr;
278 
279 	/** @table_lock: Protects @object_idr. */
280 	spinlock_t table_lock;
281 
282 	/** @syncobj_idr: Mapping of sync object handles to object pointers. */
283 	struct idr syncobj_idr;
284 	/** @syncobj_table_lock: Protects @syncobj_idr. */
285 	spinlock_t syncobj_table_lock;
286 
287 	/** @filp: Pointer to the core file structure. */
288 	struct file *filp;
289 
290 	/**
291 	 * @driver_priv:
292 	 *
293 	 * Optional pointer for driver private data. Can be allocated in
294 	 * &drm_driver.open and should be freed in &drm_driver.postclose.
295 	 */
296 	void *driver_priv;
297 
298 	/**
299 	 * @fbs:
300 	 *
301 	 * List of &struct drm_framebuffer associated with this file, using the
302 	 * &drm_framebuffer.filp_head entry.
303 	 *
304 	 * Protected by @fbs_lock. Note that the @fbs list holds a reference on
305 	 * the framebuffer object to prevent it from untimely disappearing.
306 	 */
307 	struct list_head fbs;
308 
309 	/** @fbs_lock: Protects @fbs. */
310 	struct mutex fbs_lock;
311 
312 	/**
313 	 * @blobs:
314 	 *
315 	 * User-created blob properties; this retains a reference on the
316 	 * property.
317 	 *
318 	 * Protected by @drm_mode_config.blob_lock;
319 	 */
320 	struct list_head blobs;
321 
322 	/** @event_wait: Waitqueue for new events added to @event_list. */
323 	wait_queue_head_t event_wait;
324 
325 	/**
326 	 * @pending_event_list:
327 	 *
328 	 * List of pending &struct drm_pending_event, used to clean up pending
329 	 * events in case this file gets closed before the event is signalled.
330 	 * Uses the &drm_pending_event.pending_link entry.
331 	 *
332 	 * Protect by &drm_device.event_lock.
333 	 */
334 	struct list_head pending_event_list;
335 
336 	/**
337 	 * @event_list:
338 	 *
339 	 * List of &struct drm_pending_event, ready for delivery to userspace
340 	 * through drm_read(). Uses the &drm_pending_event.link entry.
341 	 *
342 	 * Protect by &drm_device.event_lock.
343 	 */
344 	struct list_head event_list;
345 
346 	/**
347 	 * @event_space:
348 	 *
349 	 * Available event space to prevent userspace from
350 	 * exhausting kernel memory. Currently limited to the fairly arbitrary
351 	 * value of 4KB.
352 	 */
353 	int event_space;
354 
355 	/** @event_read_lock: Serializes drm_read(). */
356 	struct mutex event_read_lock;
357 
358 	/**
359 	 * @prime:
360 	 *
361 	 * Per-file buffer caches used by the PRIME buffer sharing code.
362 	 */
363 	struct drm_prime_file_private prime;
364 
365 	/* private: */
366 #if IS_ENABLED(CONFIG_DRM_LEGACY)
367 	unsigned long lock_count; /* DRI1 legacy lock count */
368 #endif
369 };
370 
371 /**
372  * drm_is_primary_client - is this an open file of the primary node
373  * @file_priv: DRM file
374  *
375  * Returns true if this is an open file of the primary node, i.e.
376  * &drm_file.minor of @file_priv is a primary minor.
377  *
378  * See also the :ref:`section on primary nodes and authentication
379  * <drm_primary_node>`.
380  */
drm_is_primary_client(const struct drm_file * file_priv)381 static inline bool drm_is_primary_client(const struct drm_file *file_priv)
382 {
383 	return file_priv->minor->type == DRM_MINOR_PRIMARY;
384 }
385 
386 /**
387  * drm_is_render_client - is this an open file of the render node
388  * @file_priv: DRM file
389  *
390  * Returns true if this is an open file of the render node, i.e.
391  * &drm_file.minor of @file_priv is a render minor.
392  *
393  * See also the :ref:`section on render nodes <drm_render_node>`.
394  */
drm_is_render_client(const struct drm_file * file_priv)395 static inline bool drm_is_render_client(const struct drm_file *file_priv)
396 {
397 	return file_priv->minor->type == DRM_MINOR_RENDER;
398 }
399 
400 int drm_open(struct inode *inode, struct file *filp);
401 ssize_t drm_read(struct file *filp, char __user *buffer,
402 		 size_t count, loff_t *offset);
403 int drm_release(struct inode *inode, struct file *filp);
404 int drm_release_noglobal(struct inode *inode, struct file *filp);
405 __poll_t drm_poll(struct file *filp, struct poll_table_struct *wait);
406 int drm_event_reserve_init_locked(struct drm_device *dev,
407 				  struct drm_file *file_priv,
408 				  struct drm_pending_event *p,
409 				  struct drm_event *e);
410 int drm_event_reserve_init(struct drm_device *dev,
411 			   struct drm_file *file_priv,
412 			   struct drm_pending_event *p,
413 			   struct drm_event *e);
414 void drm_event_cancel_free(struct drm_device *dev,
415 			   struct drm_pending_event *p);
416 void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e);
417 void drm_send_event(struct drm_device *dev, struct drm_pending_event *e);
418 void drm_send_event_timestamp_locked(struct drm_device *dev,
419 				     struct drm_pending_event *e,
420 				     ktime_t timestamp);
421 
422 struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);
423 
424 #endif /* _DRM_FILE_H_ */
425