include/drm/drm_drv.h

   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 struct drm_printer;
  43
  44 /**
  45  * enum drm_driver_feature - feature flags
  46  *
  47  * See &drm_driver.driver_features, drm_device.driver_features and
  48  * drm_core_check_feature().
  49  */
  50 enum drm_driver_feature {
  51         /**
  52          * @DRIVER_GEM:
  53          *
  54          * Driver use the GEM memory manager. This should be set for all modern
  55          * drivers.
  56          */
  57         DRIVER_GEM                      = BIT(0),
  58         /**
  59          * @DRIVER_MODESET:
  60          *
  61          * Driver supports mode setting interfaces (KMS).
  62          */
  63         DRIVER_MODESET                  = BIT(1),
  64         /**
  65          * @DRIVER_RENDER:
  66          *
  67          * Driver supports dedicated render nodes. See also the :ref:`section on
  68          * render nodes <drm_render_node>` for details.
  69          */
  70         DRIVER_RENDER                   = BIT(3),
  71         /**
  72          * @DRIVER_ATOMIC:
  73          *
  74          * Driver supports the full atomic modesetting userspace API. Drivers
  75          * which only use atomic internally, but do not the support the full
  76          * userspace API (e.g. not all properties converted to atomic, or
  77          * multi-plane updates are not guaranteed to be tear-free) should not
  78          * set this flag.
  79          */
  80         DRIVER_ATOMIC                   = BIT(4),
  81         /**
  82          * @DRIVER_SYNCOBJ:
  83          *
  84          * Driver supports &drm_syncobj for explicit synchronization of command
  85          * submission.
  86          */
  87         DRIVER_SYNCOBJ                  = BIT(5),
  88         /**
  89          * @DRIVER_SYNCOBJ_TIMELINE:
  90          *
  91          * Driver supports the timeline flavor of &drm_syncobj for explicit
  92          * synchronization of command submission.
  93          */
  94         DRIVER_SYNCOBJ_TIMELINE         = BIT(6),
  95
  96         /* IMPORTANT: Below are all the legacy flags, add new ones above. */
  97
  98         /**
  99          * @DRIVER_USE_AGP:
 100          *
 101          * Set up DRM AGP support, see drm_agp_init(), the DRM core will manage
 102          * AGP resources. New drivers don't need this.
 103          */
 104         DRIVER_USE_AGP                  = BIT(25),
 105         /**
 106          * @DRIVER_LEGACY:
 107          *
 108          * Denote a legacy driver using shadow attach. Do not use.
 109          */
 110         DRIVER_LEGACY                   = BIT(26),
 111         /**
 112          * @DRIVER_PCI_DMA:
 113          *
 114          * Driver is capable of PCI DMA, mapping of PCI DMA buffers to userspace
 115          * will be enabled. Only for legacy drivers. Do not use.
 116          */
 117         DRIVER_PCI_DMA                  = BIT(27),
 118         /**
 119          * @DRIVER_SG:
 120          *
 121          * Driver can perform scatter/gather DMA, allocation and mapping of
 122          * scatter/gather buffers will be enabled. Only for legacy drivers. Do
 123          * not use.
 124          */
 125         DRIVER_SG                       = BIT(28),
 126
 127         /**
 128          * @DRIVER_HAVE_DMA:
 129          *
 130          * Driver supports DMA, the userspace DMA API will be supported. Only
 131          * for legacy drivers. Do not use.
 132          */
 133         DRIVER_HAVE_DMA                 = BIT(29),
 134         /**
 135          * @DRIVER_HAVE_IRQ:
 136          *
 137          * Legacy irq support. Only for legacy drivers. Do not use.
 138          *
 139          * New drivers can either use the drm_irq_install() and
 140          * drm_irq_uninstall() helper functions, or roll their own irq support
 141          * code by calling request_irq() directly.
 142          */
 143         DRIVER_HAVE_IRQ                 = BIT(30),
 144         /**
 145          * @DRIVER_KMS_LEGACY_CONTEXT:
 146          *
 147          * Used only by nouveau for backwards compatibility with existing
 148          * userspace.  Do not use.
 149          */
 150         DRIVER_KMS_LEGACY_CONTEXT       = BIT(31),
 151 };
 152
 153 /**
 154  * struct drm_driver - DRM driver structure
 155  *
 156  * This structure represent the common code for a family of cards. There will be
 157  * one &struct drm_device for each card present in this family. It contains lots
 158  * of vfunc entries, and a pile of those probably should be moved to more
 159  * appropriate places like &drm_mode_config_funcs or into a new operations
 160  * structure for GEM drivers.
 161  */
 162 struct drm_driver {
 163         /**
 164          * @load:
 165          *
 166          * Backward-compatible driver callback to complete
 167          * initialization steps after the driver is registered.  For
 168          * this reason, may suffer from race conditions and its use is
 169          * deprecated for new drivers.  It is therefore only supported
 170          * for existing drivers not yet converted to the new scheme.
 171          * See drm_dev_init() and drm_dev_register() for proper and
 172          * race-free way to set up a &struct drm_device.
 173          *
 174          * This is deprecated, do not use!
 175          *
 176          * Returns:
 177          *
 178          * Zero on success, non-zero value on failure.
 179          */
 180         int (*load) (struct drm_device *, unsigned long flags);
 181
 182         /**
 183          * @open:
 184          *
 185          * Driver callback when a new &struct drm_file is opened. Useful for
 186          * setting up driver-private data structures like buffer allocators,
 187          * execution contexts or similar things. Such driver-private resources
 188          * must be released again in @postclose.
 189          *
 190          * Since the display/modeset side of DRM can only be owned by exactly
 191          * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
 192          * there should never be a need to set up any modeset related resources
 193          * in this callback. Doing so would be a driver design bug.
 194          *
 195          * Returns:
 196          *
 197          * 0 on success, a negative error code on failure, which will be
 198          * promoted to userspace as the result of the open() system call.
 199          */
 200         int (*open) (struct drm_device *, struct drm_file *);
 201
 202         /**
 203          * @postclose:
 204          *
 205          * One of the driver callbacks when a new &struct drm_file is closed.
 206          * Useful for tearing down driver-private data structures allocated in
 207          * @open like buffer allocators, execution contexts or similar things.
 208          *
 209          * Since the display/modeset side of DRM can only be owned by exactly
 210          * one &struct drm_file (see &drm_file.is_master and &drm_device.master)
 211          * there should never be a need to tear down any modeset related
 212          * resources in this callback. Doing so would be a driver design bug.
 213          */
 214         void (*postclose) (struct drm_device *, struct drm_file *);
 215
 216         /**
 217          * @lastclose:
 218          *
 219          * Called when the last &struct drm_file has been closed and there's
 220          * currently no userspace client for the &struct drm_device.
 221          *
 222          * Modern drivers should only use this to force-restore the fbdev
 223          * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
 224          * Anything else would indicate there's something seriously wrong.
 225          * Modern drivers can also use this to execute delayed power switching
 226          * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
 227          * infrastructure.
 228          *
 229          * This is called after @postclose hook has been called.
 230          *
 231          * NOTE:
 232          *
 233          * All legacy drivers use this callback to de-initialize the hardware.
 234          * This is purely because of the shadow-attach model, where the DRM
 235          * kernel driver does not really own the hardware. Instead ownershipe is
 236          * handled with the help of userspace through an inheritedly racy dance
 237          * to set/unset the VT into raw mode.
 238          *
 239          * Legacy drivers initialize the hardware in the @firstopen callback,
 240          * which isn't even called for modern drivers.
 241          */
 242         void (*lastclose) (struct drm_device *);
 243
 244         /**
 245          * @unload:
 246          *
 247          * Reverse the effects of the driver load callback.  Ideally,
 248          * the clean up performed by the driver should happen in the
 249          * reverse order of the initialization.  Similarly to the load
 250          * hook, this handler is deprecated and its usage should be
 251          * dropped in favor of an open-coded teardown function at the
 252          * driver layer.  See drm_dev_unregister() and drm_dev_put()
 253          * for the proper way to remove a &struct drm_device.
 254          *
 255          * The unload() hook is called right after unregistering
 256          * the device.
 257          *
 258          */
 259         void (*unload) (struct drm_device *);
 260
 261         /**
 262          * @release:
 263          *
 264          * Optional callback for destroying device data after the final
 265          * reference is released, i.e. the device is being destroyed.
 266          *
 267          * This is deprecated, clean up all memory allocations associated with a
 268          * &drm_device using drmm_add_action(), drmm_kmalloc() and related
 269          * managed resources functions.
 270          */
 271         void (*release) (struct drm_device *);
 272
 273         /**
 274          * @irq_handler:
 275          *
 276          * Interrupt handler called when using drm_irq_install(). Not used by
 277          * drivers which implement their own interrupt handling.
 278          */
 279         irqreturn_t(*irq_handler) (int irq, void *arg);
 280
 281         /**
 282          * @irq_preinstall:
 283          *
 284          * Optional callback used by drm_irq_install() which is called before
 285          * the interrupt handler is registered. This should be used to clear out
 286          * any pending interrupts (from e.g. firmware based drives) and reset
 287          * the interrupt handling registers.
 288          */
 289         void (*irq_preinstall) (struct drm_device *dev);
 290
 291         /**
 292          * @irq_postinstall:
 293          *
 294          * Optional callback used by drm_irq_install() which is called after
 295          * the interrupt handler is registered. This should be used to enable
 296          * interrupt generation in the hardware.
 297          */
 298         int (*irq_postinstall) (struct drm_device *dev);
 299
 300         /**
 301          * @irq_uninstall:
 302          *
 303          * Optional callback used by drm_irq_uninstall() which is called before
 304          * the interrupt handler is unregistered. This should be used to disable
 305          * interrupt generation in the hardware.
 306          */
 307         void (*irq_uninstall) (struct drm_device *dev);
 308
 309         /**
 310          * @master_set:
 311          *
 312          * Called whenever the minor master is set. Only used by vmwgfx.
 313          */
 314         void (*master_set)(struct drm_device *dev, struct drm_file *file_priv,
 315                            bool from_open);
 316         /**
 317          * @master_drop:
 318          *
 319          * Called whenever the minor master is dropped. Only used by vmwgfx.
 320          */
 321         void (*master_drop)(struct drm_device *dev, struct drm_file *file_priv);
 322
 323         /**
 324          * @debugfs_init:
 325          *
 326          * Allows drivers to create driver-specific debugfs files.
 327          */
 328         void (*debugfs_init)(struct drm_minor *minor);
 329
 330         /**
 331          * @gem_free_object_unlocked: deconstructor for drm_gem_objects
 332          *
 333          * This is deprecated and should not be used by new drivers. Use
 334          * &drm_gem_object_funcs.free instead.
 335          */
 336         void (*gem_free_object_unlocked) (struct drm_gem_object *obj);
 337
 338         /**
 339          * @gem_open_object:
 340          *
 341          * This callback is deprecated in favour of &drm_gem_object_funcs.open.
 342          *
 343          * Driver hook called upon gem handle creation
 344          */
 345         int (*gem_open_object) (struct drm_gem_object *, struct drm_file *);
 346
 347         /**
 348          * @gem_close_object:
 349          *
 350          * This callback is deprecated in favour of &drm_gem_object_funcs.close.
 351          *
 352          * Driver hook called upon gem handle release
 353          */
 354         void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);
 355
 356         /**
 357          * @gem_create_object: constructor for gem objects
 358          *
 359          * Hook for allocating the GEM object struct, for use by the CMA and
 360          * SHMEM GEM helpers.
 361          */
 362         struct drm_gem_object *(*gem_create_object)(struct drm_device *dev,
 363                                                     size_t size);
 364         /**
 365          * @prime_handle_to_fd:
 366          *
 367          * Main PRIME export function. Should be implemented with
 368          * drm_gem_prime_handle_to_fd() for GEM based drivers.
 369          *
 370          * For an in-depth discussion see :ref:`PRIME buffer sharing
 371          * documentation <prime_buffer_sharing>`.
 372          */
 373         int (*prime_handle_to_fd)(struct drm_device *dev, struct drm_file *file_priv,
 374                                 uint32_t handle, uint32_t flags, int *prime_fd);
 375         /**
 376          * @prime_fd_to_handle:
 377          *
 378          * Main PRIME import function. Should be implemented with
 379          * drm_gem_prime_fd_to_handle() for GEM based drivers.
 380          *
 381          * For an in-depth discussion see :ref:`PRIME buffer sharing
 382          * documentation <prime_buffer_sharing>`.
 383          */
 384         int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv,
 385                                 int prime_fd, uint32_t *handle);
 386         /**
 387          * @gem_prime_export:
 388          *
 389          * Export hook for GEM drivers. Deprecated in favour of
 390          * &drm_gem_object_funcs.export.
 391          */
 392         struct dma_buf * (*gem_prime_export)(struct drm_gem_object *obj,
 393                                              int flags);
 394         /**
 395          * @gem_prime_import:
 396          *
 397          * Import hook for GEM drivers.
 398          *
 399          * This defaults to drm_gem_prime_import() if not set.
 400          */
 401         struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
 402                                 struct dma_buf *dma_buf);
 403
 404         /**
 405          * @gem_prime_pin:
 406          *
 407          * Deprecated hook in favour of &drm_gem_object_funcs.pin.
 408          */
 409         int (*gem_prime_pin)(struct drm_gem_object *obj);
 410
 411         /**
 412          * @gem_prime_unpin:
 413          *
 414          * Deprecated hook in favour of &drm_gem_object_funcs.unpin.
 415          */
 416         void (*gem_prime_unpin)(struct drm_gem_object *obj);
 417
 418
 419         /**
 420          * @gem_prime_get_sg_table:
 421          *
 422          * Deprecated hook in favour of &drm_gem_object_funcs.get_sg_table.
 423          */
 424         struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);
 425
 426         /**
 427          * @gem_prime_import_sg_table:
 428          *
 429          * Optional hook used by the PRIME helper functions
 430          * drm_gem_prime_import() respectively drm_gem_prime_import_dev().
 431          */
 432         struct drm_gem_object *(*gem_prime_import_sg_table)(
 433                                 struct drm_device *dev,
 434                                 struct dma_buf_attachment *attach,
 435                                 struct sg_table *sgt);
 436         /**
 437          * @gem_prime_vmap:
 438          *
 439          * Deprecated vmap hook for GEM drivers. Please use
 440          * &drm_gem_object_funcs.vmap instead.
 441          */
 442         void *(*gem_prime_vmap)(struct drm_gem_object *obj);
 443
 444         /**
 445          * @gem_prime_vunmap:
 446          *
 447          * Deprecated vunmap hook for GEM drivers. Please use
 448          * &drm_gem_object_funcs.vunmap instead.
 449          */
 450         void (*gem_prime_vunmap)(struct drm_gem_object *obj, void *vaddr);
 451
 452         /**
 453          * @gem_prime_mmap:
 454          *
 455          * mmap hook for GEM drivers, used to implement dma-buf mmap in the
 456          * PRIME helpers.
 457          *
 458          * FIXME: There's way too much duplication going on here, and also moved
 459          * to &drm_gem_object_funcs.
 460          */
 461         int (*gem_prime_mmap)(struct drm_gem_object *obj,
 462                                 struct vm_area_struct *vma);
 463
 464         /**
 465          * @dumb_create:
 466          *
 467          * This creates a new dumb buffer in the driver's backing storage manager (GEM,
 468          * TTM or something else entirely) and returns the resulting buffer handle. This
 469          * handle can then be wrapped up into a framebuffer modeset object.
 470          *
 471          * Note that userspace is not allowed to use such objects for render
 472          * acceleration - drivers must create their own private ioctls for such a use
 473          * case.
 474          *
 475          * Width, height and depth are specified in the &drm_mode_create_dumb
 476          * argument. The callback needs to fill the handle, pitch and size for
 477          * the created buffer.
 478          *
 479          * Called by the user via ioctl.
 480          *
 481          * Returns:
 482          *
 483          * Zero on success, negative errno on failure.
 484          */
 485         int (*dumb_create)(struct drm_file *file_priv,
 486                            struct drm_device *dev,
 487                            struct drm_mode_create_dumb *args);
 488         /**
 489          * @dumb_map_offset:
 490          *
 491          * Allocate an offset in the drm device node's address space to be able to
 492          * memory map a dumb buffer.
 493          *
 494          * The default implementation is drm_gem_create_mmap_offset(). GEM based
 495          * drivers must not overwrite this.
 496          *
 497          * Called by the user via ioctl.
 498          *
 499          * Returns:
 500          *
 501          * Zero on success, negative errno on failure.
 502          */
 503         int (*dumb_map_offset)(struct drm_file *file_priv,
 504                                struct drm_device *dev, uint32_t handle,
 505                                uint64_t *offset);
 506         /**
 507          * @dumb_destroy:
 508          *
 509          * This destroys the userspace handle for the given dumb backing storage buffer.
 510          * Since buffer objects must be reference counted in the kernel a buffer object
 511          * won't be immediately freed if a framebuffer modeset object still uses it.
 512          *
 513          * Called by the user via ioctl.
 514          *
 515          * The default implementation is drm_gem_dumb_destroy(). GEM based drivers
 516          * must not overwrite this.
 517          *
 518          * Returns:
 519          *
 520          * Zero on success, negative errno on failure.
 521          */
 522         int (*dumb_destroy)(struct drm_file *file_priv,
 523                             struct drm_device *dev,
 524                             uint32_t handle);
 525
 526         /**
 527          * @gem_vm_ops: Driver private ops for this object
 528          *
 529          * For GEM drivers this is deprecated in favour of
 530          * &drm_gem_object_funcs.vm_ops.
 531          */
 532         const struct vm_operations_struct *gem_vm_ops;
 533
 534         /** @major: driver major number */
 535         int major;
 536         /** @minor: driver minor number */
 537         int minor;
 538         /** @patchlevel: driver patch level */
 539         int patchlevel;
 540         /** @name: driver name */
 541         char *name;
 542         /** @desc: driver description */
 543         char *desc;
 544         /** @date: driver date */
 545         char *date;
 546
 547         /**
 548          * @driver_features:
 549          * Driver features, see &enum drm_driver_feature. Drivers can disable
 550          * some features on a per-instance basis using
 551          * &drm_device.driver_features.
 552          */
 553         u32 driver_features;
 554
 555         /**
 556          * @ioctls:
 557          *
 558          * Array of driver-private IOCTL description entries. See the chapter on
 559          * :ref:`IOCTL support in the userland interfaces
 560          * chapter<drm_driver_ioctl>` for the full details.
 561          */
 562
 563         const struct drm_ioctl_desc *ioctls;
 564         /** @num_ioctls: Number of entries in @ioctls. */
 565         int num_ioctls;
 566
 567         /**
 568          * @fops:
 569          *
 570          * File operations for the DRM device node. See the discussion in
 571          * :ref:`file operations<drm_driver_fops>` for in-depth coverage and
 572          * some examples.
 573          */
 574         const struct file_operations *fops;
 575
 576         /* Everything below here is for legacy driver, never use! */
 577         /* private: */
 578
 579         /* List of devices hanging off this driver with stealth attach. */
 580         struct list_head legacy_dev_list;
 581         int (*firstopen) (struct drm_device *);
 582         void (*preclose) (struct drm_device *, struct drm_file *file_priv);
 583         int (*dma_ioctl) (struct drm_device *dev, void *data, struct drm_file *file_priv);
 584         int (*dma_quiescent) (struct drm_device *);
 585         int (*context_dtor) (struct drm_device *dev, int context);
 586         u32 (*get_vblank_counter)(struct drm_device *dev, unsigned int pipe);
 587         int (*enable_vblank)(struct drm_device *dev, unsigned int pipe);
 588         void (*disable_vblank)(struct drm_device *dev, unsigned int pipe);
 589         int dev_priv_size;
 590 };
 591
 592 int drm_dev_init(struct drm_device *dev,
 593                  struct drm_driver *driver,
 594                  struct device *parent);
 595 int devm_drm_dev_init(struct device *parent,
 596                       struct drm_device *dev,
 597                       struct drm_driver *driver);
 598
 599 void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
 600                            size_t size, size_t offset);
 601
 602 /**
 603  * devm_drm_dev_alloc - Resource managed allocation of a &drm_device instance
 604  * @parent: Parent device object
 605  * @driver: DRM driver
 606  * @type: the type of the struct which contains struct &drm_device
 607  * @member: the name of the &drm_device within @type.
 608  *
 609  * This allocates and initialize a new DRM device. No device registration is done.
 610  * Call drm_dev_register() to advertice the device to user space and register it
 611  * with other core subsystems. This should be done last in the device
 612  * initialization sequence to make sure userspace can't access an inconsistent
 613  * state.
 614  *
 615  * The initial ref-count of the object is 1. Use drm_dev_get() and
 616  * drm_dev_put() to take and drop further ref-counts.
 617  *
 618  * It is recommended that drivers embed &struct drm_device into their own device
 619  * structure.
 620  *
 621  * Note that this manages the lifetime of the resulting &drm_device
 622  * automatically using devres. The DRM device initialized with this function is
 623  * automatically put on driver detach using drm_dev_put().
 624  *
 625  * RETURNS:
 626  * Pointer to new DRM device, or ERR_PTR on failure.
 627  */
 628 #define devm_drm_dev_alloc(parent, driver, type, member) \
 629         ((type *) __devm_drm_dev_alloc(parent, driver, sizeof(type), \
 630                                        offsetof(type, member)))
 631
 632 struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 633                                  struct device *parent);
 634 int drm_dev_register(struct drm_device *dev, unsigned long flags);
 635 void drm_dev_unregister(struct drm_device *dev);
 636
 637 void drm_dev_get(struct drm_device *dev);
 638 void drm_dev_put(struct drm_device *dev);
 639 void drm_put_dev(struct drm_device *dev);
 640 bool drm_dev_enter(struct drm_device *dev, int *idx);
 641 void drm_dev_exit(int idx);
 642 void drm_dev_unplug(struct drm_device *dev);
 643
 644 /**
 645  * drm_dev_is_unplugged - is a DRM device unplugged
 646  * @dev: DRM device
 647  *
 648  * This function can be called to check whether a hotpluggable is unplugged.
 649  * Unplugging itself is singalled through drm_dev_unplug(). If a device is
 650  * unplugged, these two functions guarantee that any store before calling
 651  * drm_dev_unplug() is visible to callers of this function after it completes
 652  *
 653  * WARNING: This function fundamentally races against drm_dev_unplug(). It is
 654  * recommended that drivers instead use the underlying drm_dev_enter() and
 655  * drm_dev_exit() function pairs.
 656  */
 657 static inline bool drm_dev_is_unplugged(struct drm_device *dev)
 658 {
 659         int idx;
 660
 661         if (drm_dev_enter(dev, &idx)) {
 662                 drm_dev_exit(idx);
 663                 return false;
 664         }
 665
 666         return true;
 667 }
 668
 669 /**
 670  * drm_core_check_all_features - check driver feature flags mask
 671  * @dev: DRM device to check
 672  * @features: feature flag(s) mask
 673  *
 674  * This checks @dev for driver features, see &drm_driver.driver_features,
 675  * &drm_device.driver_features, and the various &enum drm_driver_feature flags.
 676  *
 677  * Returns true if all features in the @features mask are supported, false
 678  * otherwise.
 679  */
 680 static inline bool drm_core_check_all_features(const struct drm_device *dev,
 681                                                u32 features)
 682 {
 683         u32 supported = dev->driver->driver_features & dev->driver_features;
 684
 685         return features && (supported & features) == features;
 686 }
 687
 688 /**
 689  * drm_core_check_feature - check driver feature flags
 690  * @dev: DRM device to check
 691  * @feature: feature flag
 692  *
 693  * This checks @dev for driver features, see &drm_driver.driver_features,
 694  * &drm_device.driver_features, and the various &enum drm_driver_feature flags.
 695  *
 696  * Returns true if the @feature is supported, false otherwise.
 697  */
 698 static inline bool drm_core_check_feature(const struct drm_device *dev,
 699                                           enum drm_driver_feature feature)
 700 {
 701         return drm_core_check_all_features(dev, feature);
 702 }
 703
 704 /**
 705  * drm_drv_uses_atomic_modeset - check if the driver implements
 706  * atomic_commit()
 707  * @dev: DRM device
 708  *
 709  * This check is useful if drivers do not have DRIVER_ATOMIC set but
 710  * have atomic modesetting internally implemented.
 711  */
 712 static inline bool drm_drv_uses_atomic_modeset(struct drm_device *dev)
 713 {
 714         return drm_core_check_feature(dev, DRIVER_ATOMIC) ||
 715                 (dev->mode_config.funcs && dev->mode_config.funcs->atomic_commit != NULL);
 716 }
 717
 718
 719 int drm_dev_set_unique(struct drm_device *dev, const char *name);
 720
 721
 722 #endif