include/drm/ttm/ttm_bo_api.h

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
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   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the 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 NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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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_hashtab.h"
  35 #include <linux/kref.h>
  36 #include <linux/list.h>
  37 #include <linux/wait.h>
  38 #include <linux/mutex.h>
  39 #include <linux/mm.h>
  40 #include <linux/rbtree.h>
  41 #include <linux/bitmap.h>
  42
  43 struct ttm_bo_device;
  44
  45 struct drm_mm_node;
  46
  47
  48 /**
  49  * struct ttm_placement
  50  *
  51  * @fpfn:               first valid page frame number to put the object
  52  * @lpfn:               last valid page frame number to put the object
  53  * @num_placement:      number of preferred placements
  54  * @placement:          preferred placements
  55  * @num_busy_placement: number of preferred placements when need to evict buffer
  56  * @busy_placement:     preferred placements when need to evict buffer
  57  *
  58  * Structure indicating the placement you request for an object.
  59  */
  60 struct ttm_placement {
  61         unsigned        fpfn;
  62         unsigned        lpfn;
  63         unsigned        num_placement;
  64         const uint32_t  *placement;
  65         unsigned        num_busy_placement;
  66         const uint32_t  *busy_placement;
  67 };
  68
  69 /**
  70  * struct ttm_bus_placement
  71  *
  72  * @addr:               mapped virtual address
  73  * @base:               bus base address
  74  * @is_iomem:           is this io memory ?
  75  * @size:               size in byte
  76  * @offset:             offset from the base address
  77  * @io_reserved_vm:     The VM system has a refcount in @io_reserved_count
  78  * @io_reserved_count:  Refcounting the numbers of callers to ttm_mem_io_reserve
  79  *
  80  * Structure indicating the bus placement of an object.
  81  */
  82 struct ttm_bus_placement {
  83         void            *addr;
  84         unsigned long   base;
  85         unsigned long   size;
  86         unsigned long   offset;
  87         bool            is_iomem;
  88         bool            io_reserved_vm;
  89         uint64_t        io_reserved_count;
  90 };
  91
  92
  93 /**
  94  * struct ttm_mem_reg
  95  *
  96  * @mm_node: Memory manager node.
  97  * @size: Requested size of memory region.
  98  * @num_pages: Actual size of memory region in pages.
  99  * @page_alignment: Page alignment.
 100  * @placement: Placement flags.
 101  * @bus: Placement on io bus accessible to the CPU
 102  *
 103  * Structure indicating the placement and space resources used by a
 104  * buffer object.
 105  */
 106
 107 struct ttm_mem_reg {
 108         void *mm_node;
 109         unsigned long start;
 110         unsigned long size;
 111         unsigned long num_pages;
 112         uint32_t page_alignment;
 113         uint32_t mem_type;
 114         uint32_t placement;
 115         struct ttm_bus_placement bus;
 116 };
 117
 118 /**
 119  * enum ttm_bo_type
 120  *
 121  * @ttm_bo_type_device: These are 'normal' buffers that can
 122  * be mmapped by user space. Each of these bos occupy a slot in the
 123  * device address space, that can be used for normal vm operations.
 124  *
 125  * @ttm_bo_type_user: These are user-space memory areas that are made
 126  * available to the GPU by mapping the buffer pages into the GPU aperture
 127  * space. These buffers cannot be mmaped from the device address space.
 128  *
 129  * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
 130  * but they cannot be accessed from user-space. For kernel-only use.
 131  */
 132
 133 enum ttm_bo_type {
 134         ttm_bo_type_device,
 135         ttm_bo_type_user,
 136         ttm_bo_type_kernel
 137 };
 138
 139 struct ttm_tt;
 140
 141 /**
 142  * struct ttm_buffer_object
 143  *
 144  * @bdev: Pointer to the buffer object device structure.
 145  * @buffer_start: The virtual user-space start address of ttm_bo_type_user
 146  * buffers.
 147  * @type: The bo type.
 148  * @destroy: Destruction function. If NULL, kfree is used.
 149  * @num_pages: Actual number of pages.
 150  * @addr_space_offset: Address space offset.
 151  * @acc_size: Accounted size for this object.
 152  * @kref: Reference count of this buffer object. When this refcount reaches
 153  * zero, the object is put on the delayed delete list.
 154  * @list_kref: List reference count of this buffer object. This member is
 155  * used to avoid destruction while the buffer object is still on a list.
 156  * Lru lists may keep one refcount, the delayed delete list, and kref != 0
 157  * keeps one refcount. When this refcount reaches zero,
 158  * the object is destroyed.
 159  * @event_queue: Queue for processes waiting on buffer object status change.
 160  * @mem: structure describing current placement.
 161  * @persistant_swap_storage: Usually the swap storage is deleted for buffers
 162  * pinned in physical memory. If this behaviour is not desired, this member
 163  * holds a pointer to a persistent shmem object.
 164  * @ttm: TTM structure holding system pages.
 165  * @evicted: Whether the object was evicted without user-space knowing.
 166  * @cpu_writes: For synchronization. Number of cpu writers.
 167  * @lru: List head for the lru list.
 168  * @ddestroy: List head for the delayed destroy list.
 169  * @swap: List head for swap LRU list.
 170  * @val_seq: Sequence of the validation holding the @reserved lock.
 171  * Used to avoid starvation when many processes compete to validate the
 172  * buffer. This member is protected by the bo_device::lru_lock.
 173  * @seq_valid: The value of @val_seq is valid. This value is protected by
 174  * the bo_device::lru_lock.
 175  * @reserved: Deadlock-free lock used for synchronization state transitions.
 176  * @sync_obj_arg: Opaque argument to synchronization object function.
 177  * @sync_obj: Pointer to a synchronization object.
 178  * @priv_flags: Flags describing buffer object internal state.
 179  * @vm_rb: Rb node for the vm rb tree.
 180  * @vm_node: Address space manager node.
 181  * @offset: The current GPU offset, which can have different meanings
 182  * depending on the memory type. For SYSTEM type memory, it should be 0.
 183  * @cur_placement: Hint of current placement.
 184  *
 185  * Base class for TTM buffer object, that deals with data placement and CPU
 186  * mappings. GPU mappings are really up to the driver, but for simpler GPUs
 187  * the driver can usually use the placement offset @offset directly as the
 188  * GPU virtual address. For drivers implementing multiple
 189  * GPU memory manager contexts, the driver should manage the address space
 190  * in these contexts separately and use these objects to get the correct
 191  * placement and caching for these GPU maps. This makes it possible to use
 192  * these objects for even quite elaborate memory management schemes.
 193  * The destroy member, the API visibility of this object makes it possible
 194  * to derive driver specific types.
 195  */
 196
 197 struct ttm_buffer_object {
 198         /**
 199          * Members constant at init.
 200          */
 201
 202         struct ttm_bo_global *glob;
 203         struct ttm_bo_device *bdev;
 204         unsigned long buffer_start;
 205         enum ttm_bo_type type;
 206         void (*destroy) (struct ttm_buffer_object *);
 207         unsigned long num_pages;
 208         uint64_t addr_space_offset;
 209         size_t acc_size;
 210
 211         /**
 212         * Members not needing protection.
 213         */
 214
 215         struct kref kref;
 216         struct kref list_kref;
 217         wait_queue_head_t event_queue;
 218
 219         /**
 220          * Members protected by the bo::reserved lock.
 221          */
 222
 223         struct ttm_mem_reg mem;
 224         struct file *persistant_swap_storage;
 225         struct ttm_tt *ttm;
 226         bool evicted;
 227
 228         /**
 229          * Members protected by the bo::reserved lock only when written to.
 230          */
 231
 232         atomic_t cpu_writers;
 233
 234         /**
 235          * Members protected by the bdev::lru_lock.
 236          */
 237
 238         struct list_head lru;
 239         struct list_head ddestroy;
 240         struct list_head swap;
 241         struct list_head io_reserve_lru;
 242         uint32_t val_seq;
 243         bool seq_valid;
 244
 245         /**
 246          * Members protected by the bdev::lru_lock
 247          * only when written to.
 248          */
 249
 250         atomic_t reserved;
 251
 252         /**
 253          * Members protected by struct buffer_object_device::fence_lock
 254          * In addition, setting sync_obj to anything else
 255          * than NULL requires bo::reserved to be held. This allows for
 256          * checking NULL while reserved but not holding the mentioned lock.
 257          */
 258
 259         void *sync_obj_arg;
 260         void *sync_obj;
 261         unsigned long priv_flags;
 262
 263         /**
 264          * Members protected by the bdev::vm_lock
 265          */
 266
 267         struct rb_node vm_rb;
 268         struct drm_mm_node *vm_node;
 269
 270
 271         /**
 272          * Special members that are protected by the reserve lock
 273          * and the bo::lock when written to. Can be read with
 274          * either of these locks held.
 275          */
 276
 277         unsigned long offset;
 278         uint32_t cur_placement;
 279 };
 280
 281 /**
 282  * struct ttm_bo_kmap_obj
 283  *
 284  * @virtual: The current kernel virtual address.
 285  * @page: The page when kmap'ing a single page.
 286  * @bo_kmap_type: Type of bo_kmap.
 287  *
 288  * Object describing a kernel mapping. Since a TTM bo may be located
 289  * in various memory types with various caching policies, the
 290  * mapping can either be an ioremap, a vmap, a kmap or part of a
 291  * premapped region.
 292  */
 293
 294 #define TTM_BO_MAP_IOMEM_MASK 0x80
 295 struct ttm_bo_kmap_obj {
 296         void *virtual;
 297         struct page *page;
 298         enum {
 299                 ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
 300                 ttm_bo_map_vmap         = 2,
 301                 ttm_bo_map_kmap         = 3,
 302                 ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
 303         } bo_kmap_type;
 304         struct ttm_buffer_object *bo;
 305 };
 306
 307 /**
 308  * ttm_bo_reference - reference a struct ttm_buffer_object
 309  *
 310  * @bo: The buffer object.
 311  *
 312  * Returns a refcounted pointer to a buffer object.
 313  */
 314
 315 static inline struct ttm_buffer_object *
 316 ttm_bo_reference(struct ttm_buffer_object *bo)
 317 {
 318         kref_get(&bo->kref);
 319         return bo;
 320 }
 321
 322 /**
 323  * ttm_bo_wait - wait for buffer idle.
 324  *
 325  * @bo:  The buffer object.
 326  * @interruptible:  Use interruptible wait.
 327  * @no_wait:  Return immediately if buffer is busy.
 328  *
 329  * This function must be called with the bo::mutex held, and makes
 330  * sure any previous rendering to the buffer is completed.
 331  * Note: It might be necessary to block validations before the
 332  * wait by reserving the buffer.
 333  * Returns -EBUSY if no_wait is true and the buffer is busy.
 334  * Returns -ERESTARTSYS if interrupted by a signal.
 335  */
 336 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
 337                        bool interruptible, bool no_wait);
 338 /**
 339  * ttm_bo_validate
 340  *
 341  * @bo: The buffer object.
 342  * @placement: Proposed placement for the buffer object.
 343  * @interruptible: Sleep interruptible if sleeping.
 344  * @no_wait_reserve: Return immediately if other buffers are busy.
 345  * @no_wait_gpu: Return immediately if the GPU is busy.
 346  *
 347  * Changes placement and caching policy of the buffer object
 348  * according proposed placement.
 349  * Returns
 350  * -EINVAL on invalid proposed placement.
 351  * -ENOMEM on out-of-memory condition.
 352  * -EBUSY if no_wait is true and buffer busy.
 353  * -ERESTARTSYS if interrupted by a signal.
 354  */
 355 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
 356                                 struct ttm_placement *placement,
 357                                 bool interruptible, bool no_wait_reserve,
 358                                 bool no_wait_gpu);
 359
 360 /**
 361  * ttm_bo_unref
 362  *
 363  * @bo: The buffer object.
 364  *
 365  * Unreference and clear a pointer to a buffer object.
 366  */
 367 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
 368
 369
 370 /**
 371  * ttm_bo_list_ref_sub
 372  *
 373  * @bo: The buffer object.
 374  * @count: The number of references with which to decrease @bo::list_kref;
 375  * @never_free: The refcount should not reach zero with this operation.
 376  *
 377  * Release @count lru list references to this buffer object.
 378  */
 379 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
 380                                 bool never_free);
 381
 382 /**
 383  * ttm_bo_add_to_lru
 384  *
 385  * @bo: The buffer object.
 386  *
 387  * Add this bo to the relevant mem type lru and, if it's backed by
 388  * system pages (ttms) to the swap list.
 389  * This function must be called with struct ttm_bo_global::lru_lock held, and
 390  * is typically called immediately prior to unreserving a bo.
 391  */
 392 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
 393
 394 /**
 395  * ttm_bo_del_from_lru
 396  *
 397  * @bo: The buffer object.
 398  *
 399  * Remove this bo from all lru lists used to lookup and reserve an object.
 400  * This function must be called with struct ttm_bo_global::lru_lock held,
 401  * and is usually called just immediately after the bo has been reserved to
 402  * avoid recursive reservation from lru lists.
 403  */
 404 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
 405
 406
 407 /**
 408  * ttm_bo_lock_delayed_workqueue
 409  *
 410  * Prevent the delayed workqueue from running.
 411  * Returns
 412  * True if the workqueue was queued at the time
 413  */
 414 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
 415
 416 /**
 417  * ttm_bo_unlock_delayed_workqueue
 418  *
 419  * Allows the delayed workqueue to run.
 420  */
 421 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
 422                                             int resched);
 423
 424 /**
 425  * ttm_bo_synccpu_write_grab
 426  *
 427  * @bo: The buffer object:
 428  * @no_wait: Return immediately if buffer is busy.
 429  *
 430  * Synchronizes a buffer object for CPU RW access. This means
 431  * blocking command submission that affects the buffer and
 432  * waiting for buffer idle. This lock is recursive.
 433  * Returns
 434  * -EBUSY if the buffer is busy and no_wait is true.
 435  * -ERESTARTSYS if interrupted by a signal.
 436  */
 437
 438 extern int
 439 ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
 440 /**
 441  * ttm_bo_synccpu_write_release:
 442  *
 443  * @bo : The buffer object.
 444  *
 445  * Releases a synccpu lock.
 446  */
 447 extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
 448
 449 /**
 450  * ttm_bo_init
 451  *
 452  * @bdev: Pointer to a ttm_bo_device struct.
 453  * @bo: Pointer to a ttm_buffer_object to be initialized.
 454  * @size: Requested size of buffer object.
 455  * @type: Requested type of buffer object.
 456  * @flags: Initial placement flags.
 457  * @page_alignment: Data alignment in pages.
 458  * @buffer_start: Virtual address of user space data backing a
 459  * user buffer object.
 460  * @interruptible: If needing to sleep to wait for GPU resources,
 461  * sleep interruptible.
 462  * @persistant_swap_storage: Usually the swap storage is deleted for buffers
 463  * pinned in physical memory. If this behaviour is not desired, this member
 464  * holds a pointer to a persistent shmem object. Typically, this would
 465  * point to the shmem object backing a GEM object if TTM is used to back a
 466  * GEM user interface.
 467  * @acc_size: Accounted size for this object.
 468  * @destroy: Destroy function. Use NULL for kfree().
 469  *
 470  * This function initializes a pre-allocated struct ttm_buffer_object.
 471  * As this object may be part of a larger structure, this function,
 472  * together with the @destroy function,
 473  * enables driver-specific objects derived from a ttm_buffer_object.
 474  * On successful return, the object kref and list_kref are set to 1.
 475  * If a failure occurs, the function will call the @destroy function, or
 476  * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
 477  * illegal and will likely cause memory corruption.
 478  *
 479  * Returns
 480  * -ENOMEM: Out of memory.
 481  * -EINVAL: Invalid placement flags.
 482  * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 483  */
 484
 485 extern int ttm_bo_init(struct ttm_bo_device *bdev,
 486                         struct ttm_buffer_object *bo,
 487                         unsigned long size,
 488                         enum ttm_bo_type type,
 489                         struct ttm_placement *placement,
 490                         uint32_t page_alignment,
 491                         unsigned long buffer_start,
 492                         bool interrubtible,
 493                         struct file *persistant_swap_storage,
 494                         size_t acc_size,
 495                         void (*destroy) (struct ttm_buffer_object *));
 496 /**
 497  * ttm_bo_synccpu_object_init
 498  *
 499  * @bdev: Pointer to a ttm_bo_device struct.
 500  * @bo: Pointer to a ttm_buffer_object to be initialized.
 501  * @size: Requested size of buffer object.
 502  * @type: Requested type of buffer object.
 503  * @flags: Initial placement flags.
 504  * @page_alignment: Data alignment in pages.
 505  * @buffer_start: Virtual address of user space data backing a
 506  * user buffer object.
 507  * @interruptible: If needing to sleep while waiting for GPU resources,
 508  * sleep interruptible.
 509  * @persistant_swap_storage: Usually the swap storage is deleted for buffers
 510  * pinned in physical memory. If this behaviour is not desired, this member
 511  * holds a pointer to a persistent shmem object. Typically, this would
 512  * point to the shmem object backing a GEM object if TTM is used to back a
 513  * GEM user interface.
 514  * @p_bo: On successful completion *p_bo points to the created object.
 515  *
 516  * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
 517  * on that object. The destroy function is set to kfree().
 518  * Returns
 519  * -ENOMEM: Out of memory.
 520  * -EINVAL: Invalid placement flags.
 521  * -ERESTARTSYS: Interrupted by signal while waiting for resources.
 522  */
 523
 524 extern int ttm_bo_create(struct ttm_bo_device *bdev,
 525                                 unsigned long size,
 526                                 enum ttm_bo_type type,
 527                                 struct ttm_placement *placement,
 528                                 uint32_t page_alignment,
 529                                 unsigned long buffer_start,
 530                                 bool interruptible,
 531                                 struct file *persistant_swap_storage,
 532                                 struct ttm_buffer_object **p_bo);
 533
 534 /**
 535  * ttm_bo_check_placement
 536  *
 537  * @bo:         the buffer object.
 538  * @placement:  placements
 539  *
 540  * Performs minimal validity checking on an intended change of
 541  * placement flags.
 542  * Returns
 543  * -EINVAL: Intended change is invalid or not allowed.
 544  */
 545 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
 546                                         struct ttm_placement *placement);
 547
 548 /**
 549  * ttm_bo_init_mm
 550  *
 551  * @bdev: Pointer to a ttm_bo_device struct.
 552  * @mem_type: The memory type.
 553  * @p_size: size managed area in pages.
 554  *
 555  * Initialize a manager for a given memory type.
 556  * Note: if part of driver firstopen, it must be protected from a
 557  * potentially racing lastclose.
 558  * Returns:
 559  * -EINVAL: invalid size or memory type.
 560  * -ENOMEM: Not enough memory.
 561  * May also return driver-specified errors.
 562  */
 563
 564 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
 565                                 unsigned long p_size);
 566 /**
 567  * ttm_bo_clean_mm
 568  *
 569  * @bdev: Pointer to a ttm_bo_device struct.
 570  * @mem_type: The memory type.
 571  *
 572  * Take down a manager for a given memory type after first walking
 573  * the LRU list to evict any buffers left alive.
 574  *
 575  * Normally, this function is part of lastclose() or unload(), and at that
 576  * point there shouldn't be any buffers left created by user-space, since
 577  * there should've been removed by the file descriptor release() method.
 578  * However, before this function is run, make sure to signal all sync objects,
 579  * and verify that the delayed delete queue is empty. The driver must also
 580  * make sure that there are no NO_EVICT buffers present in this memory type
 581  * when the call is made.
 582  *
 583  * If this function is part of a VT switch, the caller must make sure that
 584  * there are no appications currently validating buffers before this
 585  * function is called. The caller can do that by first taking the
 586  * struct ttm_bo_device::ttm_lock in write mode.
 587  *
 588  * Returns:
 589  * -EINVAL: invalid or uninitialized memory type.
 590  * -EBUSY: There are still buffers left in this memory type.
 591  */
 592
 593 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 594
 595 /**
 596  * ttm_bo_evict_mm
 597  *
 598  * @bdev: Pointer to a ttm_bo_device struct.
 599  * @mem_type: The memory type.
 600  *
 601  * Evicts all buffers on the lru list of the memory type.
 602  * This is normally part of a VT switch or an
 603  * out-of-memory-space-due-to-fragmentation handler.
 604  * The caller must make sure that there are no other processes
 605  * currently validating buffers, and can do that by taking the
 606  * struct ttm_bo_device::ttm_lock in write mode.
 607  *
 608  * Returns:
 609  * -EINVAL: Invalid or uninitialized memory type.
 610  * -ERESTARTSYS: The call was interrupted by a signal while waiting to
 611  * evict a buffer.
 612  */
 613
 614 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 615
 616 /**
 617  * ttm_kmap_obj_virtual
 618  *
 619  * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
 620  * @is_iomem: Pointer to an integer that on return indicates 1 if the
 621  * virtual map is io memory, 0 if normal memory.
 622  *
 623  * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
 624  * If *is_iomem is 1 on return, the virtual address points to an io memory area,
 625  * that should strictly be accessed by the iowriteXX() and similar functions.
 626  */
 627
 628 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
 629                                          bool *is_iomem)
 630 {
 631         *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
 632         return map->virtual;
 633 }
 634
 635 /**
 636  * ttm_bo_kmap
 637  *
 638  * @bo: The buffer object.
 639  * @start_page: The first page to map.
 640  * @num_pages: Number of pages to map.
 641  * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
 642  *
 643  * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
 644  * data in the buffer object. The ttm_kmap_obj_virtual function can then be
 645  * used to obtain a virtual address to the data.
 646  *
 647  * Returns
 648  * -ENOMEM: Out of memory.
 649  * -EINVAL: Invalid range.
 650  */
 651
 652 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
 653                        unsigned long num_pages, struct ttm_bo_kmap_obj *map);
 654
 655 /**
 656  * ttm_bo_kunmap
 657  *
 658  * @map: Object describing the map to unmap.
 659  *
 660  * Unmaps a kernel map set up by ttm_bo_kmap.
 661  */
 662
 663 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 664
 665 #if 0
 666 #endif
 667
 668 /**
 669  * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
 670  *
 671  * @vma:       vma as input from the fbdev mmap method.
 672  * @bo:        The bo backing the address space. The address space will
 673  * have the same size as the bo, and start at offset 0.
 674  *
 675  * This function is intended to be called by the fbdev mmap method
 676  * if the fbdev address space is to be backed by a bo.
 677  */
 678
 679 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
 680                           struct ttm_buffer_object *bo);
 681
 682 /**
 683  * ttm_bo_mmap - mmap out of the ttm device address space.
 684  *
 685  * @filp:      filp as input from the mmap method.
 686  * @vma:       vma as input from the mmap method.
 687  * @bdev:      Pointer to the ttm_bo_device with the address space manager.
 688  *
 689  * This function is intended to be called by the device mmap method.
 690  * if the device address space is to be backed by the bo manager.
 691  */
 692
 693 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 694                        struct ttm_bo_device *bdev);
 695
 696 /**
 697  * ttm_bo_io
 698  *
 699  * @bdev:      Pointer to the struct ttm_bo_device.
 700  * @filp:      Pointer to the struct file attempting to read / write.
 701  * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
 702  * @rbuf:      User-space pointer to address of buffer to read into.
 703  * Null on write.
 704  * @count:     Number of bytes to read / write.
 705  * @f_pos:     Pointer to current file position.
 706  * @write:     1 for read, 0 for write.
 707  *
 708  * This function implements read / write into ttm buffer objects, and is
 709  * intended to
 710  * be called from the fops::read and fops::write method.
 711  * Returns:
 712  * See man (2) write, man(2) read. In particular,
 713  * the function may return -ERESTARTSYS if
 714  * interrupted by a signal.
 715  */
 716
 717 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 718                          const char __user *wbuf, char __user *rbuf,
 719                          size_t count, loff_t *f_pos, bool write);
 720
 721 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
 722
 723 #endif