include/drm/ttm/ttm_bo_api.h

   1 /**************************************************************************
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   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
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  15  * next paragraph) shall be included in all copies or substantial portions
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  26  **************************************************************************/
  27 /*
  28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29  */
  30
  31 #ifndef _TTM_BO_API_H_
  32 #define _TTM_BO_API_H_
  33
  34 #include <drm/drm_hashtab.h>
  35 #include <drm/drm_vma_manager.h>
  36 #include <linux/kref.h>
  37 #include <linux/list.h>
  38 #include <linux/wait.h>
  39 #include <linux/mutex.h>
  40 #include <linux/mm.h>
  41 #include <linux/bitmap.h>
  42 #include <linux/reservation.h>
  43
  44 struct ttm_bo_device;
  45
  46 struct drm_mm_node;
  47
  48
  49 /**
  50  * struct ttm_placement
  51  *
  52  * @fpfn:               first valid page frame number to put the object
  53  * @lpfn:               last valid page frame number to put the object
  54  * @num_placement:      number of preferred placements
  55  * @placement:          preferred placements
  56  * @num_busy_placement: number of preferred placements when need to evict buffer
  57  * @busy_placement:     preferred placements when need to evict buffer
  58  *
  59  * Structure indicating the placement you request for an object.
  60  */
  61 struct ttm_placement {
  62         unsigned        fpfn;
  63         unsigned        lpfn;
  64         unsigned        num_placement;
  65         const uint32_t  *placement;
  66         unsigned        num_busy_placement;
  67         const uint32_t  *busy_placement;
  68 };
  69
  70 /**
  71  * struct ttm_bus_placement
  72  *
  73  * @addr:               mapped virtual address
  74  * @base:               bus base address
  75  * @is_iomem:           is this io memory ?
  76  * @size:               size in byte
  77  * @offset:             offset from the base address
  78  * @io_reserved_vm:     The VM system has a refcount in @io_reserved_count
  79  * @io_reserved_count:  Refcounting the numbers of callers to ttm_mem_io_reserve
  80  *
  81  * Structure indicating the bus placement of an object.
  82  */
  83 struct ttm_bus_placement {
  84         void            *addr;
  85         unsigned long   base;
  86         unsigned long   size;
  87         unsigned long   offset;
  88         bool            is_iomem;
  89         bool            io_reserved_vm;
  90         uint64_t        io_reserved_count;
  91 };
  92
  93
  94 /**
  95  * struct ttm_mem_reg
  96  *
  97  * @mm_node: Memory manager node.
  98  * @size: Requested size of memory region.
  99  * @num_pages: Actual size of memory region in pages.
 100  * @page_alignment: Page alignment.
 101  * @placement: Placement flags.
 102  * @bus: Placement on io bus accessible to the CPU
 103  *
 104  * Structure indicating the placement and space resources used by a
 105  * buffer object.
 106  */
 107
 108 struct ttm_mem_reg {
 109         void *mm_node;
 110         unsigned long start;
 111         unsigned long size;
 112         unsigned long num_pages;
 113         uint32_t page_alignment;
 114         uint32_t mem_type;
 115         uint32_t placement;
 116         struct ttm_bus_placement bus;
 117 };
 118
 119 /**
 120  * enum ttm_bo_type
 121  *
 122  * @ttm_bo_type_device: These are 'normal' buffers that can
 123  * be mmapped by user space. Each of these bos occupy a slot in the
 124  * device address space, that can be used for normal vm operations.
 125  *
 126  * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
 127  * but they cannot be accessed from user-space. For kernel-only use.
 128  *
 129  * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
 130  * driver.
 131  */
 132
 133 enum ttm_bo_type {
 134         ttm_bo_type_device,
 135         ttm_bo_type_kernel,
 136         ttm_bo_type_sg
 137 };
 138
 139 struct ttm_tt;
 140
 141 /**
 142  * struct ttm_buffer_object
 143  *
 144  * @bdev: Pointer to the buffer object device structure.
 145  * @type: The bo type.
 146  * @destroy: Destruction function. If NULL, kfree is used.
 147  * @num_pages: Actual number of pages.
 148  * @acc_size: Accounted size for this object.
 149  * @kref: Reference count of this buffer object. When this refcount reaches
 150  * zero, the object is put on the delayed delete list.
 151  * @list_kref: List reference count of this buffer object. This member is
 152  * used to avoid destruction while the buffer object is still on a list.
 153  * Lru lists may keep one refcount, the delayed delete list, and kref != 0
 154  * keeps one refcount. When this refcount reaches zero,
 155  * the object is destroyed.
 156  * @mem: structure describing current placement.
 157  * @persistent_swap_storage: Usually the swap storage is deleted for buffers
 158  * pinned in physical memory. If this behaviour is not desired, this member
 159  * holds a pointer to a persistent shmem object.
 160  * @ttm: TTM structure holding system pages.
 161  * @evicted: Whether the object was evicted without user-space knowing.
 162  * @cpu_writes: For synchronization. Number of cpu writers.
 163  * @lru: List head for the lru list.
 164  * @ddestroy: List head for the delayed destroy list.
 165  * @swap: List head for swap LRU list.
 166  * @sync_obj: Pointer to a synchronization object.
 167  * @priv_flags: Flags describing buffer object internal state.
 168  * @vma_node: Address space manager node.
 169  * @offset: The current GPU offset, which can have different meanings
 170  * depending on the memory type. For SYSTEM type memory, it should be 0.
 171  * @cur_placement: Hint of current placement.
 172  * @wu_mutex: Wait unreserved mutex.
 173  *
 174  * Base class for TTM buffer object, that deals with data placement and CPU
 175  * mappings. GPU mappings are really up to the driver, but for simpler GPUs
 176  * the driver can usually use the placement offset @offset directly as the
 177  * GPU virtual address. For drivers implementing multiple
 178  * GPU memory manager contexts, the driver should manage the address space
 179  * in these contexts separately and use these objects to get the correct
 180  * placement and caching for these GPU maps. This makes it possible to use
 181  * these objects for even quite elaborate memory management schemes.
 182  * The destroy member, the API visibility of this object makes it possible
 183  * to derive driver specific types.
 184  */
 185
 186 struct ttm_buffer_object {
 187         /**
 188          * Members constant at init.
 189          */
 190
 191         struct ttm_bo_global *glob;
 192         struct ttm_bo_device *bdev;
 193         enum ttm_bo_type type;
 194         void (*destroy) (struct ttm_buffer_object *);
 195         unsigned long num_pages;
 196         size_t acc_size;
 197
 198         /**
 199         * Members not needing protection.
 200         */
 201
 202         struct kref kref;
 203         struct kref list_kref;
 204
 205         /**
 206          * Members protected by the bo::resv::reserved lock.
 207          */
 208
 209         struct ttm_mem_reg mem;
 210         struct file *persistent_swap_storage;
 211         struct ttm_tt *ttm;
 212         bool evicted;
 213
 214         /**
 215          * Members protected by the bo::reserved lock only when written to.
 216          */
 217
 218         atomic_t cpu_writers;
 219
 220         /**
 221          * Members protected by the bdev::lru_lock.
 222          */
 223
 224         struct list_head lru;
 225         struct list_head ddestroy;
 226         struct list_head swap;
 227         struct list_head io_reserve_lru;
 228
 229         /**
 230          * Members protected by struct buffer_object_device::fence_lock
 231          * In addition, setting sync_obj to anything else
 232          * than NULL requires bo::reserved to be held. This allows for
 233          * checking NULL while reserved but not holding the mentioned lock.
 234          */
 235
 236         void *sync_obj;
 237         unsigned long priv_flags;
 238
 239         struct drm_vma_offset_node vma_node;
 240
 241         /**
 242          * Special members that are protected by the reserve lock
 243          * and the bo::lock when written to. Can be read with
 244          * either of these locks held.
 245          */
 246
 247         unsigned long offset;
 248         uint32_t cur_placement;
 249
 250         struct sg_table *sg;
 251
 252         struct reservation_object *resv;
 253         struct reservation_object ttm_resv;
 254         struct mutex wu_mutex;
 255 };
 256
 257 /**
 258  * struct ttm_bo_kmap_obj
 259  *
 260  * @virtual: The current kernel virtual address.
 261  * @page: The page when kmap'ing a single page.
 262  * @bo_kmap_type: Type of bo_kmap.
 263  *
 264  * Object describing a kernel mapping. Since a TTM bo may be located
 265  * in various memory types with various caching policies, the
 266  * mapping can either be an ioremap, a vmap, a kmap or part of a
 267  * premapped region.
 268  */
 269
 270 #define TTM_BO_MAP_IOMEM_MASK 0x80
 271 struct ttm_bo_kmap_obj {
 272         void *virtual;
 273         struct page *page;
 274         enum {
 275                 ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
 276                 ttm_bo_map_vmap         = 2,
 277                 ttm_bo_map_kmap         = 3,
 278                 ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
 279         } bo_kmap_type;
 280         struct ttm_buffer_object *bo;
 281 };
 282
 283 /**
 284  * ttm_bo_reference - reference a struct ttm_buffer_object
 285  *
 286  * @bo: The buffer object.
 287  *
 288  * Returns a refcounted pointer to a buffer object.
 289  */
 290
 291 static inline struct ttm_buffer_object *
 292 ttm_bo_reference(struct ttm_buffer_object *bo)
 293 {
 294         kref_get(&bo->kref);
 295         return bo;
 296 }
 297
 298 /**
 299  * ttm_bo_wait - wait for buffer idle.
 300  *
 301  * @bo:  The buffer object.
 302  * @interruptible:  Use interruptible wait.
 303  * @no_wait:  Return immediately if buffer is busy.
 304  *
 305  * This function must be called with the bo::mutex held, and makes
 306  * sure any previous rendering to the buffer is completed.
 307  * Note: It might be necessary to block validations before the
 308  * wait by reserving the buffer.
 309  * Returns -EBUSY if no_wait is true and the buffer is busy.
 310  * Returns -ERESTARTSYS if interrupted by a signal.
 311  */
 312 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
 313                        bool interruptible, bool no_wait);
 314 /**
 315  * ttm_bo_validate
 316  *
 317  * @bo: The buffer object.
 318  * @placement: Proposed placement for the buffer object.
 319  * @interruptible: Sleep interruptible if sleeping.
 320  * @no_wait_gpu: Return immediately if the GPU is busy.
 321  *
 322  * Changes placement and caching policy of the buffer object
 323  * according proposed placement.
 324  * Returns
 325  * -EINVAL on invalid proposed placement.
 326  * -ENOMEM on out-of-memory condition.
 327  * -EBUSY if no_wait is true and buffer busy.
 328  * -ERESTARTSYS if interrupted by a signal.
 329  */
 330 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
 331                                 struct ttm_placement *placement,
 332                                 bool interruptible,
 333                                 bool no_wait_gpu);
 334
 335 /**
 336  * ttm_bo_unref
 337  *
 338  * @bo: The buffer object.
 339  *
 340  * Unreference and clear a pointer to a buffer object.
 341  */
 342 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
 343
 344
 345 /**
 346  * ttm_bo_list_ref_sub
 347  *
 348  * @bo: The buffer object.
 349  * @count: The number of references with which to decrease @bo::list_kref;
 350  * @never_free: The refcount should not reach zero with this operation.
 351  *
 352  * Release @count lru list references to this buffer object.
 353  */
 354 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
 355                                 bool never_free);
 356
 357 /**
 358  * ttm_bo_add_to_lru
 359  *
 360  * @bo: The buffer object.
 361  *
 362  * Add this bo to the relevant mem type lru and, if it's backed by
 363  * system pages (ttms) to the swap list.
 364  * This function must be called with struct ttm_bo_global::lru_lock held, and
 365  * is typically called immediately prior to unreserving a bo.
 366  */
 367 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
 368
 369 /**
 370  * ttm_bo_del_from_lru
 371  *
 372  * @bo: The buffer object.
 373  *
 374  * Remove this bo from all lru lists used to lookup and reserve an object.
 375  * This function must be called with struct ttm_bo_global::lru_lock held,
 376  * and is usually called just immediately after the bo has been reserved to
 377  * avoid recursive reservation from lru lists.
 378  */
 379 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
 380
 381
 382 /**
 383  * ttm_bo_lock_delayed_workqueue
 384  *
 385  * Prevent the delayed workqueue from running.
 386  * Returns
 387  * True if the workqueue was queued at the time
 388  */
 389 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
 390
 391 /**
 392  * ttm_bo_unlock_delayed_workqueue
 393  *
 394  * Allows the delayed workqueue to run.
 395  */
 396 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
 397                                             int resched);
 398
 399 /**
 400  * ttm_bo_synccpu_write_grab
 401  *
 402  * @bo: The buffer object:
 403  * @no_wait: Return immediately if buffer is busy.
 404  *
 405  * Synchronizes a buffer object for CPU RW access. This means
 406  * command submission that affects the buffer will return -EBUSY
 407  * until ttm_bo_synccpu_write_release is called.
 408  *
 409  * Returns
 410  * -EBUSY if the buffer is busy and no_wait is true.
 411  * -ERESTARTSYS if interrupted by a signal.
 412  */
 413 extern int
 414 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
 415
 416 /**
 417  * ttm_bo_synccpu_write_release:
 418  *
 419  * @bo : The buffer object.
 420  *
 421  * Releases a synccpu lock.
 422  */
 423 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
 424
 425 /**
 426  * ttm_bo_acc_size
 427  *
 428  * @bdev: Pointer to a ttm_bo_device struct.
 429  * @bo_size: size of the buffer object in byte.
 430  * @struct_size: size of the structure holding buffer object datas
 431  *
 432  * Returns size to account for a buffer object
 433  */
 434 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
 435                        unsigned long bo_size,
 436                        unsigned struct_size);
 437 size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
 438                            unsigned long bo_size,
 439                            unsigned struct_size);
 440
 441 /**
 442  * ttm_bo_init
 443  *
 444  * @bdev: Pointer to a ttm_bo_device struct.
 445  * @bo: Pointer to a ttm_buffer_object to be initialized.
 446  * @size: Requested size of buffer object.
 447  * @type: Requested type of buffer object.
 448  * @flags: Initial placement flags.
 449  * @page_alignment: Data alignment in pages.
 450  * @interruptible: If needing to sleep to wait for GPU resources,
 451  * sleep interruptible.
 452  * @persistent_swap_storage: Usually the swap storage is deleted for buffers
 453  * pinned in physical memory. If this behaviour is not desired, this member
 454  * holds a pointer to a persistent shmem object. Typically, this would
 455  * point to the shmem object backing a GEM object if TTM is used to back a
 456  * GEM user interface.
 457  * @acc_size: Accounted size for this object.
 458  * @destroy: Destroy function. Use NULL for kfree().
 459  *
 460  * This function initializes a pre-allocated struct ttm_buffer_object.
 461  * As this object may be part of a larger structure, this function,
 462  * together with the @destroy function,
 463  * enables driver-specific objects derived from a ttm_buffer_object.
 464  * On successful return, the object kref and list_kref are set to 1.
 465  * If a failure occurs, the function will call the @destroy function, or
 466  * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
 467  * illegal and will likely cause memory corruption.
 468  *
 469  * Returns
 470  * -ENOMEM: Out of memory.
 471  * -EINVAL: Invalid placement flags.
 472  * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 473  */
 474
 475 extern int ttm_bo_init(struct ttm_bo_device *bdev,
 476                         struct ttm_buffer_object *bo,
 477                         unsigned long size,
 478                         enum ttm_bo_type type,
 479                         struct ttm_placement *placement,
 480                         uint32_t page_alignment,
 481                         bool interrubtible,
 482                         struct file *persistent_swap_storage,
 483                         size_t acc_size,
 484                         struct sg_table *sg,
 485                         void (*destroy) (struct ttm_buffer_object *));
 486
 487 /**
 488  * ttm_bo_create
 489  *
 490  * @bdev: Pointer to a ttm_bo_device struct.
 491  * @size: Requested size of buffer object.
 492  * @type: Requested type of buffer object.
 493  * @placement: Initial placement.
 494  * @page_alignment: Data alignment in pages.
 495  * @interruptible: If needing to sleep while waiting for GPU resources,
 496  * sleep interruptible.
 497  * @persistent_swap_storage: Usually the swap storage is deleted for buffers
 498  * pinned in physical memory. If this behaviour is not desired, this member
 499  * holds a pointer to a persistent shmem object. Typically, this would
 500  * point to the shmem object backing a GEM object if TTM is used to back a
 501  * GEM user interface.
 502  * @p_bo: On successful completion *p_bo points to the created object.
 503  *
 504  * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
 505  * on that object. The destroy function is set to kfree().
 506  * Returns
 507  * -ENOMEM: Out of memory.
 508  * -EINVAL: Invalid placement flags.
 509  * -ERESTARTSYS: Interrupted by signal while waiting for resources.
 510  */
 511
 512 extern int ttm_bo_create(struct ttm_bo_device *bdev,
 513                                 unsigned long size,
 514                                 enum ttm_bo_type type,
 515                                 struct ttm_placement *placement,
 516                                 uint32_t page_alignment,
 517                                 bool interruptible,
 518                                 struct file *persistent_swap_storage,
 519                                 struct ttm_buffer_object **p_bo);
 520
 521 /**
 522  * ttm_bo_check_placement
 523  *
 524  * @bo:         the buffer object.
 525  * @placement:  placements
 526  *
 527  * Performs minimal validity checking on an intended change of
 528  * placement flags.
 529  * Returns
 530  * -EINVAL: Intended change is invalid or not allowed.
 531  */
 532 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
 533                                         struct ttm_placement *placement);
 534
 535 /**
 536  * ttm_bo_init_mm
 537  *
 538  * @bdev: Pointer to a ttm_bo_device struct.
 539  * @mem_type: The memory type.
 540  * @p_size: size managed area in pages.
 541  *
 542  * Initialize a manager for a given memory type.
 543  * Note: if part of driver firstopen, it must be protected from a
 544  * potentially racing lastclose.
 545  * Returns:
 546  * -EINVAL: invalid size or memory type.
 547  * -ENOMEM: Not enough memory.
 548  * May also return driver-specified errors.
 549  */
 550
 551 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
 552                                 unsigned long p_size);
 553 /**
 554  * ttm_bo_clean_mm
 555  *
 556  * @bdev: Pointer to a ttm_bo_device struct.
 557  * @mem_type: The memory type.
 558  *
 559  * Take down a manager for a given memory type after first walking
 560  * the LRU list to evict any buffers left alive.
 561  *
 562  * Normally, this function is part of lastclose() or unload(), and at that
 563  * point there shouldn't be any buffers left created by user-space, since
 564  * there should've been removed by the file descriptor release() method.
 565  * However, before this function is run, make sure to signal all sync objects,
 566  * and verify that the delayed delete queue is empty. The driver must also
 567  * make sure that there are no NO_EVICT buffers present in this memory type
 568  * when the call is made.
 569  *
 570  * If this function is part of a VT switch, the caller must make sure that
 571  * there are no appications currently validating buffers before this
 572  * function is called. The caller can do that by first taking the
 573  * struct ttm_bo_device::ttm_lock in write mode.
 574  *
 575  * Returns:
 576  * -EINVAL: invalid or uninitialized memory type.
 577  * -EBUSY: There are still buffers left in this memory type.
 578  */
 579
 580 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 581
 582 /**
 583  * ttm_bo_evict_mm
 584  *
 585  * @bdev: Pointer to a ttm_bo_device struct.
 586  * @mem_type: The memory type.
 587  *
 588  * Evicts all buffers on the lru list of the memory type.
 589  * This is normally part of a VT switch or an
 590  * out-of-memory-space-due-to-fragmentation handler.
 591  * The caller must make sure that there are no other processes
 592  * currently validating buffers, and can do that by taking the
 593  * struct ttm_bo_device::ttm_lock in write mode.
 594  *
 595  * Returns:
 596  * -EINVAL: Invalid or uninitialized memory type.
 597  * -ERESTARTSYS: The call was interrupted by a signal while waiting to
 598  * evict a buffer.
 599  */
 600
 601 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 602
 603 /**
 604  * ttm_kmap_obj_virtual
 605  *
 606  * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
 607  * @is_iomem: Pointer to an integer that on return indicates 1 if the
 608  * virtual map is io memory, 0 if normal memory.
 609  *
 610  * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
 611  * If *is_iomem is 1 on return, the virtual address points to an io memory area,
 612  * that should strictly be accessed by the iowriteXX() and similar functions.
 613  */
 614
 615 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
 616                                          bool *is_iomem)
 617 {
 618         *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
 619         return map->virtual;
 620 }
 621
 622 /**
 623  * ttm_bo_kmap
 624  *
 625  * @bo: The buffer object.
 626  * @start_page: The first page to map.
 627  * @num_pages: Number of pages to map.
 628  * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
 629  *
 630  * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
 631  * data in the buffer object. The ttm_kmap_obj_virtual function can then be
 632  * used to obtain a virtual address to the data.
 633  *
 634  * Returns
 635  * -ENOMEM: Out of memory.
 636  * -EINVAL: Invalid range.
 637  */
 638
 639 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
 640                        unsigned long num_pages, struct ttm_bo_kmap_obj *map);
 641
 642 /**
 643  * ttm_bo_kunmap
 644  *
 645  * @map: Object describing the map to unmap.
 646  *
 647  * Unmaps a kernel map set up by ttm_bo_kmap.
 648  */
 649
 650 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 651
 652 /**
 653  * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
 654  *
 655  * @vma:       vma as input from the fbdev mmap method.
 656  * @bo:        The bo backing the address space. The address space will
 657  * have the same size as the bo, and start at offset 0.
 658  *
 659  * This function is intended to be called by the fbdev mmap method
 660  * if the fbdev address space is to be backed by a bo.
 661  */
 662
 663 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
 664                           struct ttm_buffer_object *bo);
 665
 666 /**
 667  * ttm_bo_mmap - mmap out of the ttm device address space.
 668  *
 669  * @filp:      filp as input from the mmap method.
 670  * @vma:       vma as input from the mmap method.
 671  * @bdev:      Pointer to the ttm_bo_device with the address space manager.
 672  *
 673  * This function is intended to be called by the device mmap method.
 674  * if the device address space is to be backed by the bo manager.
 675  */
 676
 677 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 678                        struct ttm_bo_device *bdev);
 679
 680 /**
 681  * ttm_bo_io
 682  *
 683  * @bdev:      Pointer to the struct ttm_bo_device.
 684  * @filp:      Pointer to the struct file attempting to read / write.
 685  * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
 686  * @rbuf:      User-space pointer to address of buffer to read into.
 687  * Null on write.
 688  * @count:     Number of bytes to read / write.
 689  * @f_pos:     Pointer to current file position.
 690  * @write:     1 for read, 0 for write.
 691  *
 692  * This function implements read / write into ttm buffer objects, and is
 693  * intended to
 694  * be called from the fops::read and fops::write method.
 695  * Returns:
 696  * See man (2) write, man(2) read. In particular,
 697  * the function may return -ERESTARTSYS if
 698  * interrupted by a signal.
 699  */
 700
 701 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 702                          const char __user *wbuf, char __user *rbuf,
 703                          size_t count, loff_t *f_pos, bool write);
 704
 705 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
 706 extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
 707 #endif