xref: /linux/include/drm/drm_drv.h (revision bf070bb0e6c62ba3075db0a666763ba52c677102)
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  * Copyright 2016 Intel Corp.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the next
15  * paragraph) shall be included in all copies or substantial portions of the
16  * Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
21  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24  * OTHER DEALINGS IN THE SOFTWARE.
25  */
26 
27 #ifndef _DRM_DRV_H_
28 #define _DRM_DRV_H_
29 
30 #include <linux/list.h>
31 #include <linux/irqreturn.h>
32 
33 #include <drm/drm_device.h>
34 
35 struct drm_file;
36 struct drm_gem_object;
37 struct drm_master;
38 struct drm_minor;
39 struct dma_buf_attachment;
40 struct drm_display_mode;
41 struct drm_mode_create_dumb;
42 
43 /* driver capabilities and requirements mask */
44 #define DRIVER_USE_AGP			0x1
45 #define DRIVER_LEGACY			0x2
46 #define DRIVER_PCI_DMA			0x8
47 #define DRIVER_SG			0x10
48 #define DRIVER_HAVE_DMA			0x20
49 #define DRIVER_HAVE_IRQ			0x40
50 #define DRIVER_IRQ_SHARED		0x80
51 #define DRIVER_GEM			0x1000
52 #define DRIVER_MODESET			0x2000
53 #define DRIVER_PRIME			0x4000
54 #define DRIVER_RENDER			0x8000
55 #define DRIVER_ATOMIC			0x10000
56 #define DRIVER_KMS_LEGACY_CONTEXT	0x20000
57 #define DRIVER_SYNCOBJ                  0x40000
58 
59 /**
60  * struct drm_driver - DRM driver structure
61  *
62  * This structure represent the common code for a family of cards. There will
63  * one drm_device for each card present in this family. It contains lots of
64  * vfunc entries, and a pile of those probably should be moved to more
65  * appropriate places like &drm_mode_config_funcs or into a new operations
66  * structure for GEM drivers.
67  */
68 struct drm_driver {
69 	/**
70 	 * @load:
71 	 *
72 	 * Backward-compatible driver callback to complete
73 	 * initialization steps after the driver is registered.  For
74 	 * this reason, may suffer from race conditions and its use is
75 	 * deprecated for new drivers.  It is therefore only supported
76 	 * for existing drivers not yet converted to the new scheme.
77 	 * See drm_dev_init() and drm_dev_register() for proper and
78 	 * race-free way to set up a &struct drm_device.
79 	 *
80 	 * This is deprecated, do not use!
81 	 *
82 	 * Returns:
83 	 *
84 	 * Zero on success, non-zero value on failure.
85 	 */
86 	int (*load) (struct drm_device *, unsigned long flags);
87 
88 	/**
89 	 * @open:
90 	 *
91 	 * Driver callback when a new &struct drm_file is opened. Useful for
92 	 * setting up driver-private data structures like buffer allocators,
93 	 * execution contexts or similar things. Such driver-private resources
94 	 * must be released again in @postclose.
95 	 *
96 	 * Since the display/modeset side of DRM can only be owned by exactly
97 	 * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
98 	 * there should never be a need to set up any modeset related resources
99 	 * in this callback. Doing so would be a driver design bug.
100 	 *
101 	 * Returns:
102 	 *
103 	 * 0 on success, a negative error code on failure, which will be
104 	 * promoted to userspace as the result of the open() system call.
105 	 */
106 	int (*open) (struct drm_device *, struct drm_file *);
107 
108 	/**
109 	 * @postclose:
110 	 *
111 	 * One of the driver callbacks when a new &struct drm_file is closed.
112 	 * Useful for tearing down driver-private data structures allocated in
113 	 * @open like buffer allocators, execution contexts or similar things.
114 	 *
115 	 * Since the display/modeset side of DRM can only be owned by exactly
116 	 * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
117 	 * there should never be a need to tear down any modeset related
118 	 * resources in this callback. Doing so would be a driver design bug.
119 	 */
120 	void (*postclose) (struct drm_device *, struct drm_file *);
121 
122 	/**
123 	 * @lastclose:
124 	 *
125 	 * Called when the last &struct drm_file has been closed and there's
126 	 * currently no userspace client for the &struct drm_device.
127 	 *
128 	 * Modern drivers should only use this to force-restore the fbdev
129 	 * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
130 	 * Anything else would indicate there's something seriously wrong.
131 	 * Modern drivers can also use this to execute delayed power switching
132 	 * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
133 	 * infrastructure.
134 	 *
135 	 * This is called after @postclose hook has been called.
136 	 *
137 	 * NOTE:
138 	 *
139 	 * All legacy drivers use this callback to de-initialize the hardware.
140 	 * This is purely because of the shadow-attach model, where the DRM
141 	 * kernel driver does not really own the hardware. Instead ownershipe is
142 	 * handled with the help of userspace through an inheritedly racy dance
143 	 * to set/unset the VT into raw mode.
144 	 *
145 	 * Legacy drivers initialize the hardware in the @firstopen callback,
146 	 * which isn't even called for modern drivers.
147 	 */
148 	void (*lastclose) (struct drm_device *);
149 
150 	/**
151 	 * @unload:
152 	 *
153 	 * Reverse the effects of the driver load callback.  Ideally,
154 	 * the clean up performed by the driver should happen in the
155 	 * reverse order of the initialization.  Similarly to the load
156 	 * hook, this handler is deprecated and its usage should be
157 	 * dropped in favor of an open-coded teardown function at the
158 	 * driver layer.  See drm_dev_unregister() and drm_dev_put()
159 	 * for the proper way to remove a &struct drm_device.
160 	 *
161 	 * The unload() hook is called right after unregistering
162 	 * the device.
163 	 *
164 	 */
165 	void (*unload) (struct drm_device *);
166 
167 	/**
168 	 * @release:
169 	 *
170 	 * Optional callback for destroying device data after the final
171 	 * reference is released, i.e. the device is being destroyed. Drivers
172 	 * using this callback are responsible for calling drm_dev_fini()
173 	 * to finalize the device and then freeing the struct themselves.
174 	 */
175 	void (*release) (struct drm_device *);
176 
177 	/**
178 	 * @get_vblank_counter:
179 	 *
180 	 * Driver callback for fetching a raw hardware vblank counter for the
181 	 * CRTC specified with the pipe argument.  If a device doesn't have a
182 	 * hardware counter, the driver can simply leave the hook as NULL.
183 	 * The DRM core will account for missed vblank events while interrupts
184 	 * where disabled based on system timestamps.
185 	 *
186 	 * Wraparound handling and loss of events due to modesetting is dealt
187 	 * with in the DRM core code, as long as drivers call
188 	 * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
189 	 * enabling a CRTC.
190 	 *
191 	 * This is deprecated and should not be used by new drivers.
192 	 * Use &drm_crtc_funcs.get_vblank_counter instead.
193 	 *
194 	 * Returns:
195 	 *
196 	 * Raw vblank counter value.
197 	 */
198 	u32 (*get_vblank_counter) (struct drm_device *dev, unsigned int pipe);
199 
200 	/**
201 	 * @enable_vblank:
202 	 *
203 	 * Enable vblank interrupts for the CRTC specified with the pipe
204 	 * argument.
205 	 *
206 	 * This is deprecated and should not be used by new drivers.
207 	 * Use &drm_crtc_funcs.enable_vblank instead.
208 	 *
209 	 * Returns:
210 	 *
211 	 * Zero on success, appropriate errno if the given @crtc's vblank
212 	 * interrupt cannot be enabled.
213 	 */
214 	int (*enable_vblank) (struct drm_device *dev, unsigned int pipe);
215 
216 	/**
217 	 * @disable_vblank:
218 	 *
219 	 * Disable vblank interrupts for the CRTC specified with the pipe
220 	 * argument.
221 	 *
222 	 * This is deprecated and should not be used by new drivers.
223 	 * Use &drm_crtc_funcs.disable_vblank instead.
224 	 */
225 	void (*disable_vblank) (struct drm_device *dev, unsigned int pipe);
226 
227 	/**
228 	 * @get_scanout_position:
229 	 *
230 	 * Called by vblank timestamping code.
231 	 *
232 	 * Returns the current display scanout position from a crtc, and an
233 	 * optional accurate ktime_get() timestamp of when position was
234 	 * measured. Note that this is a helper callback which is only used if a
235 	 * driver uses drm_calc_vbltimestamp_from_scanoutpos() for the
236 	 * @get_vblank_timestamp callback.
237 	 *
238 	 * Parameters:
239 	 *
240 	 * dev:
241 	 *     DRM device.
242 	 * pipe:
243 	 *     Id of the crtc to query.
244 	 * in_vblank_irq:
245 	 *     True when called from drm_crtc_handle_vblank().  Some drivers
246 	 *     need to apply some workarounds for gpu-specific vblank irq quirks
247 	 *     if flag is set.
248 	 * vpos:
249 	 *     Target location for current vertical scanout position.
250 	 * hpos:
251 	 *     Target location for current horizontal scanout position.
252 	 * stime:
253 	 *     Target location for timestamp taken immediately before
254 	 *     scanout position query. Can be NULL to skip timestamp.
255 	 * etime:
256 	 *     Target location for timestamp taken immediately after
257 	 *     scanout position query. Can be NULL to skip timestamp.
258 	 * mode:
259 	 *     Current display timings.
260 	 *
261 	 * Returns vpos as a positive number while in active scanout area.
262 	 * Returns vpos as a negative number inside vblank, counting the number
263 	 * of scanlines to go until end of vblank, e.g., -1 means "one scanline
264 	 * until start of active scanout / end of vblank."
265 	 *
266 	 * Returns:
267 	 *
268 	 * True on success, false if a reliable scanout position counter could
269 	 * not be read out.
270 	 *
271 	 * FIXME:
272 	 *
273 	 * Since this is a helper to implement @get_vblank_timestamp, we should
274 	 * move it to &struct drm_crtc_helper_funcs, like all the other
275 	 * helper-internal hooks.
276 	 */
277 	bool (*get_scanout_position) (struct drm_device *dev, unsigned int pipe,
278 				      bool in_vblank_irq, int *vpos, int *hpos,
279 				      ktime_t *stime, ktime_t *etime,
280 				      const struct drm_display_mode *mode);
281 
282 	/**
283 	 * @get_vblank_timestamp:
284 	 *
285 	 * Called by drm_get_last_vbltimestamp(). Should return a precise
286 	 * timestamp when the most recent VBLANK interval ended or will end.
287 	 *
288 	 * Specifically, the timestamp in @vblank_time should correspond as
289 	 * closely as possible to the time when the first video scanline of
290 	 * the video frame after the end of VBLANK will start scanning out,
291 	 * the time immediately after end of the VBLANK interval. If the
292 	 * @crtc is currently inside VBLANK, this will be a time in the future.
293 	 * If the @crtc is currently scanning out a frame, this will be the
294 	 * past start time of the current scanout. This is meant to adhere
295 	 * to the OpenML OML_sync_control extension specification.
296 	 *
297 	 * Paramters:
298 	 *
299 	 * dev:
300 	 *     dev DRM device handle.
301 	 * pipe:
302 	 *     crtc for which timestamp should be returned.
303 	 * max_error:
304 	 *     Maximum allowable timestamp error in nanoseconds.
305 	 *     Implementation should strive to provide timestamp
306 	 *     with an error of at most max_error nanoseconds.
307 	 *     Returns true upper bound on error for timestamp.
308 	 * vblank_time:
309 	 *     Target location for returned vblank timestamp.
310 	 * in_vblank_irq:
311 	 *     True when called from drm_crtc_handle_vblank().  Some drivers
312 	 *     need to apply some workarounds for gpu-specific vblank irq quirks
313 	 *     if flag is set.
314 	 *
315 	 * Returns:
316 	 *
317 	 * True on success, false on failure, which means the core should
318 	 * fallback to a simple timestamp taken in drm_crtc_handle_vblank().
319 	 *
320 	 * FIXME:
321 	 *
322 	 * We should move this hook to &struct drm_crtc_funcs like all the other
323 	 * vblank hooks.
324 	 */
325 	bool (*get_vblank_timestamp) (struct drm_device *dev, unsigned int pipe,
326 				     int *max_error,
327 				     ktime_t *vblank_time,
328 				     bool in_vblank_irq);
329 
330 	/**
331 	 * @irq_handler:
332 	 *
333 	 * Interrupt handler called when using drm_irq_install(). Not used by
334 	 * drivers which implement their own interrupt handling.
335 	 */
336 	irqreturn_t(*irq_handler) (int irq, void *arg);
337 
338 	/**
339 	 * @irq_preinstall:
340 	 *
341 	 * Optional callback used by drm_irq_install() which is called before
342 	 * the interrupt handler is registered. This should be used to clear out
343 	 * any pending interrupts (from e.g. firmware based drives) and reset
344 	 * the interrupt handling registers.
345 	 */
346 	void (*irq_preinstall) (struct drm_device *dev);
347 
348 	/**
349 	 * @irq_postinstall:
350 	 *
351 	 * Optional callback used by drm_irq_install() which is called after
352 	 * the interrupt handler is registered. This should be used to enable
353 	 * interrupt generation in the hardware.
354 	 */
355 	int (*irq_postinstall) (struct drm_device *dev);
356 
357 	/**
358 	 * @irq_uninstall:
359 	 *
360 	 * Optional callback used by drm_irq_uninstall() which is called before
361 	 * the interrupt handler is unregistered. This should be used to disable
362 	 * interrupt generation in the hardware.
363 	 */
364 	void (*irq_uninstall) (struct drm_device *dev);
365 
366 	/**
367 	 * @master_create:
368 	 *
369 	 * Called whenever a new master is created. Only used by vmwgfx.
370 	 */
371 	int (*master_create)(struct drm_device *dev, struct drm_master *master);
372 
373 	/**
374 	 * @master_destroy:
375 	 *
376 	 * Called whenever a master is destroyed. Only used by vmwgfx.
377 	 */
378 	void (*master_destroy)(struct drm_device *dev, struct drm_master *master);
379 
380 	/**
381 	 * @master_set:
382 	 *
383 	 * Called whenever the minor master is set. Only used by vmwgfx.
384 	 */
385 	int (*master_set)(struct drm_device *dev, struct drm_file *file_priv,
386 			  bool from_open);
387 	/**
388 	 * @master_drop:
389 	 *
390 	 * Called whenever the minor master is dropped. Only used by vmwgfx.
391 	 */
392 	void (*master_drop)(struct drm_device *dev, struct drm_file *file_priv);
393 
394 	/**
395 	 * @debugfs_init:
396 	 *
397 	 * Allows drivers to create driver-specific debugfs files.
398 	 */
399 	int (*debugfs_init)(struct drm_minor *minor);
400 
401 	/**
402 	 * @gem_free_object: deconstructor for drm_gem_objects
403 	 *
404 	 * This is deprecated and should not be used by new drivers. Use
405 	 * @gem_free_object_unlocked instead.
406 	 */
407 	void (*gem_free_object) (struct drm_gem_object *obj);
408 
409 	/**
410 	 * @gem_free_object_unlocked: deconstructor for drm_gem_objects
411 	 *
412 	 * This is for drivers which are not encumbered with &drm_device.struct_mutex
413 	 * legacy locking schemes. Use this hook instead of @gem_free_object.
414 	 */
415 	void (*gem_free_object_unlocked) (struct drm_gem_object *obj);
416 
417 	/**
418 	 * @gem_open_object:
419 	 *
420 	 * Driver hook called upon gem handle creation
421 	 */
422 	int (*gem_open_object) (struct drm_gem_object *, struct drm_file *);
423 
424 	/**
425 	 * @gem_close_object:
426 	 *
427 	 * Driver hook called upon gem handle release
428 	 */
429 	void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);
430 
431 	/**
432 	 * @gem_create_object: constructor for gem objects
433 	 *
434 	 * Hook for allocating the GEM object struct, for use by core
435 	 * helpers.
436 	 */
437 	struct drm_gem_object *(*gem_create_object)(struct drm_device *dev,
438 						    size_t size);
439 
440 	/* prime: */
441 	/**
442 	 * @prime_handle_to_fd:
443 	 *
444 	 * export handle -> fd (see drm_gem_prime_handle_to_fd() helper)
445 	 */
446 	int (*prime_handle_to_fd)(struct drm_device *dev, struct drm_file *file_priv,
447 				uint32_t handle, uint32_t flags, int *prime_fd);
448 	/**
449 	 * @prime_fd_to_handle:
450 	 *
451 	 * import fd -> handle (see drm_gem_prime_fd_to_handle() helper)
452 	 */
453 	int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv,
454 				int prime_fd, uint32_t *handle);
455 	/**
456 	 * @gem_prime_export:
457 	 *
458 	 * export GEM -> dmabuf
459 	 */
460 	struct dma_buf * (*gem_prime_export)(struct drm_device *dev,
461 				struct drm_gem_object *obj, int flags);
462 	/**
463 	 * @gem_prime_import:
464 	 *
465 	 * import dmabuf -> GEM
466 	 */
467 	struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
468 				struct dma_buf *dma_buf);
469 	int (*gem_prime_pin)(struct drm_gem_object *obj);
470 	void (*gem_prime_unpin)(struct drm_gem_object *obj);
471 	struct reservation_object * (*gem_prime_res_obj)(
472 				struct drm_gem_object *obj);
473 	struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);
474 	struct drm_gem_object *(*gem_prime_import_sg_table)(
475 				struct drm_device *dev,
476 				struct dma_buf_attachment *attach,
477 				struct sg_table *sgt);
478 	void *(*gem_prime_vmap)(struct drm_gem_object *obj);
479 	void (*gem_prime_vunmap)(struct drm_gem_object *obj, void *vaddr);
480 	int (*gem_prime_mmap)(struct drm_gem_object *obj,
481 				struct vm_area_struct *vma);
482 
483 	/**
484 	 * @dumb_create:
485 	 *
486 	 * This creates a new dumb buffer in the driver's backing storage manager (GEM,
487 	 * TTM or something else entirely) and returns the resulting buffer handle. This
488 	 * handle can then be wrapped up into a framebuffer modeset object.
489 	 *
490 	 * Note that userspace is not allowed to use such objects for render
491 	 * acceleration - drivers must create their own private ioctls for such a use
492 	 * case.
493 	 *
494 	 * Width, height and depth are specified in the &drm_mode_create_dumb
495 	 * argument. The callback needs to fill the handle, pitch and size for
496 	 * the created buffer.
497 	 *
498 	 * Called by the user via ioctl.
499 	 *
500 	 * Returns:
501 	 *
502 	 * Zero on success, negative errno on failure.
503 	 */
504 	int (*dumb_create)(struct drm_file *file_priv,
505 			   struct drm_device *dev,
506 			   struct drm_mode_create_dumb *args);
507 	/**
508 	 * @dumb_map_offset:
509 	 *
510 	 * Allocate an offset in the drm device node's address space to be able to
511 	 * memory map a dumb buffer. GEM-based drivers must use
512 	 * drm_gem_create_mmap_offset() to implement this.
513 	 *
514 	 * Called by the user via ioctl.
515 	 *
516 	 * Returns:
517 	 *
518 	 * Zero on success, negative errno on failure.
519 	 */
520 	int (*dumb_map_offset)(struct drm_file *file_priv,
521 			       struct drm_device *dev, uint32_t handle,
522 			       uint64_t *offset);
523 	/**
524 	 * @dumb_destroy:
525 	 *
526 	 * This destroys the userspace handle for the given dumb backing storage buffer.
527 	 * Since buffer objects must be reference counted in the kernel a buffer object
528 	 * won't be immediately freed if a framebuffer modeset object still uses it.
529 	 *
530 	 * Called by the user via ioctl.
531 	 *
532 	 * Returns:
533 	 *
534 	 * Zero on success, negative errno on failure.
535 	 */
536 	int (*dumb_destroy)(struct drm_file *file_priv,
537 			    struct drm_device *dev,
538 			    uint32_t handle);
539 
540 	/**
541 	 * @gem_vm_ops: Driver private ops for this object
542 	 */
543 	const struct vm_operations_struct *gem_vm_ops;
544 
545 	/** @major: driver major number */
546 	int major;
547 	/** @minor: driver minor number */
548 	int minor;
549 	/** @patchlevel: driver patch level */
550 	int patchlevel;
551 	/** @name: driver name */
552 	char *name;
553 	/** @desc: driver description */
554 	char *desc;
555 	/** @date: driver date */
556 	char *date;
557 
558 	/** @driver_features: driver features */
559 	u32 driver_features;
560 
561 	/**
562 	 * @ioctls:
563 	 *
564 	 * Array of driver-private IOCTL description entries. See the chapter on
565 	 * :ref:`IOCTL support in the userland interfaces
566 	 * chapter<drm_driver_ioctl>` for the full details.
567 	 */
568 
569 	const struct drm_ioctl_desc *ioctls;
570 	/** @num_ioctls: Number of entries in @ioctls. */
571 	int num_ioctls;
572 
573 	/**
574 	 * @fops:
575 	 *
576 	 * File operations for the DRM device node. See the discussion in
577 	 * :ref:`file operations<drm_driver_fops>` for in-depth coverage and
578 	 * some examples.
579 	 */
580 	const struct file_operations *fops;
581 
582 	/* Everything below here is for legacy driver, never use! */
583 	/* private: */
584 
585 	/* List of devices hanging off this driver with stealth attach. */
586 	struct list_head legacy_dev_list;
587 	int (*firstopen) (struct drm_device *);
588 	void (*preclose) (struct drm_device *, struct drm_file *file_priv);
589 	int (*dma_ioctl) (struct drm_device *dev, void *data, struct drm_file *file_priv);
590 	int (*dma_quiescent) (struct drm_device *);
591 	int (*context_dtor) (struct drm_device *dev, int context);
592 	int dev_priv_size;
593 };
594 
595 __printf(6, 7)
596 void drm_dev_printk(const struct device *dev, const char *level,
597 		    unsigned int category, const char *function_name,
598 		    const char *prefix, const char *format, ...);
599 __printf(3, 4)
600 void drm_printk(const char *level, unsigned int category,
601 		const char *format, ...);
602 extern unsigned int drm_debug;
603 
604 int drm_dev_init(struct drm_device *dev,
605 		 struct drm_driver *driver,
606 		 struct device *parent);
607 void drm_dev_fini(struct drm_device *dev);
608 
609 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
610 				 struct device *parent);
611 int drm_dev_register(struct drm_device *dev, unsigned long flags);
612 void drm_dev_unregister(struct drm_device *dev);
613 
614 void drm_dev_get(struct drm_device *dev);
615 void drm_dev_put(struct drm_device *dev);
616 void drm_dev_unref(struct drm_device *dev);
617 void drm_put_dev(struct drm_device *dev);
618 void drm_dev_unplug(struct drm_device *dev);
619 
620 /**
621  * drm_dev_is_unplugged - is a DRM device unplugged
622  * @dev: DRM device
623  *
624  * This function can be called to check whether a hotpluggable is unplugged.
625  * Unplugging itself is singalled through drm_dev_unplug(). If a device is
626  * unplugged, these two functions guarantee that any store before calling
627  * drm_dev_unplug() is visible to callers of this function after it completes
628  */
629 static inline int drm_dev_is_unplugged(struct drm_device *dev)
630 {
631 	int ret = atomic_read(&dev->unplugged);
632 	smp_rmb();
633 	return ret;
634 }
635 
636 
637 int drm_dev_set_unique(struct drm_device *dev, const char *name);
638 
639 
640 #endif
641