linux/include/drm/ttm/ttm_bo_api.h
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   1/**************************************************************************
   2 *
   3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4 * All Rights Reserved.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a
   7 * copy of this software and associated documentation files (the
   8 * "Software"), to deal in the Software without restriction, including
   9 * without limitation the rights to use, copy, modify, merge, publish,
  10 * distribute, sub license, and/or sell copies of the Software, and to
  11 * permit persons to whom the Software is furnished to do so, subject to
  12 * the following conditions:
  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,
  22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25 *
  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_gem.h>
  35#include <drm/drm_hashtab.h>
  36#include <drm/drm_vma_manager.h>
  37#include <linux/kref.h>
  38#include <linux/list.h>
  39#include <linux/wait.h>
  40#include <linux/mutex.h>
  41#include <linux/mm.h>
  42#include <linux/bitmap.h>
  43#include <linux/dma-resv.h>
  44
  45struct ttm_bo_global;
  46
  47struct ttm_bo_device;
  48
  49struct drm_mm_node;
  50
  51struct ttm_placement;
  52
  53struct ttm_place;
  54
  55struct ttm_lru_bulk_move;
  56
  57/**
  58 * struct ttm_bus_placement
  59 *
  60 * @addr:               mapped virtual address
  61 * @base:               bus base address
  62 * @is_iomem:           is this io memory ?
  63 * @size:               size in byte
  64 * @offset:             offset from the base address
  65 * @io_reserved_vm:     The VM system has a refcount in @io_reserved_count
  66 * @io_reserved_count:  Refcounting the numbers of callers to ttm_mem_io_reserve
  67 *
  68 * Structure indicating the bus placement of an object.
  69 */
  70struct ttm_bus_placement {
  71        void            *addr;
  72        phys_addr_t     base;
  73        unsigned long   size;
  74        unsigned long   offset;
  75        bool            is_iomem;
  76        bool            io_reserved_vm;
  77        uint64_t        io_reserved_count;
  78};
  79
  80
  81/**
  82 * struct ttm_mem_reg
  83 *
  84 * @mm_node: Memory manager node.
  85 * @size: Requested size of memory region.
  86 * @num_pages: Actual size of memory region in pages.
  87 * @page_alignment: Page alignment.
  88 * @placement: Placement flags.
  89 * @bus: Placement on io bus accessible to the CPU
  90 *
  91 * Structure indicating the placement and space resources used by a
  92 * buffer object.
  93 */
  94
  95struct ttm_mem_reg {
  96        void *mm_node;
  97        unsigned long start;
  98        unsigned long size;
  99        unsigned long num_pages;
 100        uint32_t page_alignment;
 101        uint32_t mem_type;
 102        uint32_t placement;
 103        struct ttm_bus_placement bus;
 104};
 105
 106/**
 107 * enum ttm_bo_type
 108 *
 109 * @ttm_bo_type_device: These are 'normal' buffers that can
 110 * be mmapped by user space. Each of these bos occupy a slot in the
 111 * device address space, that can be used for normal vm operations.
 112 *
 113 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
 114 * but they cannot be accessed from user-space. For kernel-only use.
 115 *
 116 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
 117 * driver.
 118 */
 119
 120enum ttm_bo_type {
 121        ttm_bo_type_device,
 122        ttm_bo_type_kernel,
 123        ttm_bo_type_sg
 124};
 125
 126struct ttm_tt;
 127
 128/**
 129 * struct ttm_buffer_object
 130 *
 131 * @base: drm_gem_object superclass data.
 132 * @bdev: Pointer to the buffer object device structure.
 133 * @type: The bo type.
 134 * @destroy: Destruction function. If NULL, kfree is used.
 135 * @num_pages: Actual number of pages.
 136 * @acc_size: Accounted size for this object.
 137 * @kref: Reference count of this buffer object. When this refcount reaches
 138 * zero, the object is put on the delayed delete list.
 139 * @list_kref: List reference count of this buffer object. This member is
 140 * used to avoid destruction while the buffer object is still on a list.
 141 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
 142 * keeps one refcount. When this refcount reaches zero,
 143 * the object is destroyed.
 144 * @mem: structure describing current placement.
 145 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
 146 * pinned in physical memory. If this behaviour is not desired, this member
 147 * holds a pointer to a persistent shmem object.
 148 * @ttm: TTM structure holding system pages.
 149 * @evicted: Whether the object was evicted without user-space knowing.
 150 * @lru: List head for the lru list.
 151 * @ddestroy: List head for the delayed destroy list.
 152 * @swap: List head for swap LRU list.
 153 * @moving: Fence set when BO is moving
 154 * @offset: The current GPU offset, which can have different meanings
 155 * depending on the memory type. For SYSTEM type memory, it should be 0.
 156 * @cur_placement: Hint of current placement.
 157 * @wu_mutex: Wait unreserved mutex.
 158 *
 159 * Base class for TTM buffer object, that deals with data placement and CPU
 160 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
 161 * the driver can usually use the placement offset @offset directly as the
 162 * GPU virtual address. For drivers implementing multiple
 163 * GPU memory manager contexts, the driver should manage the address space
 164 * in these contexts separately and use these objects to get the correct
 165 * placement and caching for these GPU maps. This makes it possible to use
 166 * these objects for even quite elaborate memory management schemes.
 167 * The destroy member, the API visibility of this object makes it possible
 168 * to derive driver specific types.
 169 */
 170
 171struct ttm_buffer_object {
 172        struct drm_gem_object base;
 173
 174        /**
 175         * Members constant at init.
 176         */
 177
 178        struct ttm_bo_device *bdev;
 179        enum ttm_bo_type type;
 180        void (*destroy) (struct ttm_buffer_object *);
 181        unsigned long num_pages;
 182        size_t acc_size;
 183
 184        /**
 185        * Members not needing protection.
 186        */
 187
 188        struct kref kref;
 189        struct kref list_kref;
 190
 191        /**
 192         * Members protected by the bo::resv::reserved lock.
 193         */
 194
 195        struct ttm_mem_reg mem;
 196        struct file *persistent_swap_storage;
 197        struct ttm_tt *ttm;
 198        bool evicted;
 199
 200        /**
 201         * Members protected by the bdev::lru_lock.
 202         */
 203
 204        struct list_head lru;
 205        struct list_head ddestroy;
 206        struct list_head swap;
 207        struct list_head io_reserve_lru;
 208
 209        /**
 210         * Members protected by a bo reservation.
 211         */
 212
 213        struct dma_fence *moving;
 214        unsigned priority;
 215
 216        /**
 217         * Special members that are protected by the reserve lock
 218         * and the bo::lock when written to. Can be read with
 219         * either of these locks held.
 220         */
 221
 222        uint64_t offset; /* GPU address space is independent of CPU word size */
 223
 224        struct sg_table *sg;
 225
 226        struct mutex wu_mutex;
 227};
 228
 229/**
 230 * struct ttm_bo_kmap_obj
 231 *
 232 * @virtual: The current kernel virtual address.
 233 * @page: The page when kmap'ing a single page.
 234 * @bo_kmap_type: Type of bo_kmap.
 235 *
 236 * Object describing a kernel mapping. Since a TTM bo may be located
 237 * in various memory types with various caching policies, the
 238 * mapping can either be an ioremap, a vmap, a kmap or part of a
 239 * premapped region.
 240 */
 241
 242#define TTM_BO_MAP_IOMEM_MASK 0x80
 243struct ttm_bo_kmap_obj {
 244        void *virtual;
 245        struct page *page;
 246        enum {
 247                ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
 248                ttm_bo_map_vmap         = 2,
 249                ttm_bo_map_kmap         = 3,
 250                ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
 251        } bo_kmap_type;
 252        struct ttm_buffer_object *bo;
 253};
 254
 255/**
 256 * struct ttm_operation_ctx
 257 *
 258 * @interruptible: Sleep interruptible if sleeping.
 259 * @no_wait_gpu: Return immediately if the GPU is busy.
 260 * @resv: Reservation object to allow reserved evictions with.
 261 * @flags: Including the following flags
 262 *
 263 * Context for TTM operations like changing buffer placement or general memory
 264 * allocation.
 265 */
 266struct ttm_operation_ctx {
 267        bool interruptible;
 268        bool no_wait_gpu;
 269        struct dma_resv *resv;
 270        uint64_t bytes_moved;
 271        uint32_t flags;
 272};
 273
 274/* Allow eviction of reserved BOs */
 275#define TTM_OPT_FLAG_ALLOW_RES_EVICT            0x1
 276/* when serving page fault or suspend, allow alloc anyway */
 277#define TTM_OPT_FLAG_FORCE_ALLOC                0x2
 278
 279/**
 280 * ttm_bo_get - reference a struct ttm_buffer_object
 281 *
 282 * @bo: The buffer object.
 283 */
 284static inline void ttm_bo_get(struct ttm_buffer_object *bo)
 285{
 286        kref_get(&bo->kref);
 287}
 288
 289/**
 290 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
 291 * its refcount has already reached zero.
 292 * @bo: The buffer object.
 293 *
 294 * Used to reference a TTM buffer object in lookups where the object is removed
 295 * from the lookup structure during the destructor and for RCU lookups.
 296 *
 297 * Returns: @bo if the referencing was successful, NULL otherwise.
 298 */
 299static inline __must_check struct ttm_buffer_object *
 300ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
 301{
 302        if (!kref_get_unless_zero(&bo->kref))
 303                return NULL;
 304        return bo;
 305}
 306
 307/**
 308 * ttm_bo_wait - wait for buffer idle.
 309 *
 310 * @bo:  The buffer object.
 311 * @interruptible:  Use interruptible wait.
 312 * @no_wait:  Return immediately if buffer is busy.
 313 *
 314 * This function must be called with the bo::mutex held, and makes
 315 * sure any previous rendering to the buffer is completed.
 316 * Note: It might be necessary to block validations before the
 317 * wait by reserving the buffer.
 318 * Returns -EBUSY if no_wait is true and the buffer is busy.
 319 * Returns -ERESTARTSYS if interrupted by a signal.
 320 */
 321int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
 322
 323/**
 324 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
 325 *
 326 * @placement:  Return immediately if buffer is busy.
 327 * @mem:  The struct ttm_mem_reg indicating the region where the bo resides
 328 * @new_flags: Describes compatible placement found
 329 *
 330 * Returns true if the placement is compatible
 331 */
 332bool ttm_bo_mem_compat(struct ttm_placement *placement, struct ttm_mem_reg *mem,
 333                       uint32_t *new_flags);
 334
 335/**
 336 * ttm_bo_validate
 337 *
 338 * @bo: The buffer object.
 339 * @placement: Proposed placement for the buffer object.
 340 * @ctx: validation parameters.
 341 *
 342 * Changes placement and caching policy of the buffer object
 343 * according proposed placement.
 344 * Returns
 345 * -EINVAL on invalid proposed placement.
 346 * -ENOMEM on out-of-memory condition.
 347 * -EBUSY if no_wait is true and buffer busy.
 348 * -ERESTARTSYS if interrupted by a signal.
 349 */
 350int ttm_bo_validate(struct ttm_buffer_object *bo,
 351                    struct ttm_placement *placement,
 352                    struct ttm_operation_ctx *ctx);
 353
 354/**
 355 * ttm_bo_put
 356 *
 357 * @bo: The buffer object.
 358 *
 359 * Unreference a buffer object.
 360 */
 361void ttm_bo_put(struct ttm_buffer_object *bo);
 362
 363/**
 364 * ttm_bo_move_to_lru_tail
 365 *
 366 * @bo: The buffer object.
 367 * @bulk: optional bulk move structure to remember BO positions
 368 *
 369 * Move this BO to the tail of all lru lists used to lookup and reserve an
 370 * object. This function must be called with struct ttm_bo_global::lru_lock
 371 * held, and is used to make a BO less likely to be considered for eviction.
 372 */
 373void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
 374                             struct ttm_lru_bulk_move *bulk);
 375
 376/**
 377 * ttm_bo_bulk_move_lru_tail
 378 *
 379 * @bulk: bulk move structure
 380 *
 381 * Bulk move BOs to the LRU tail, only valid to use when driver makes sure that
 382 * BO order never changes. Should be called with ttm_bo_global::lru_lock held.
 383 */
 384void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk);
 385
 386/**
 387 * ttm_bo_lock_delayed_workqueue
 388 *
 389 * Prevent the delayed workqueue from running.
 390 * Returns
 391 * True if the workqueue was queued at the time
 392 */
 393int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
 394
 395/**
 396 * ttm_bo_unlock_delayed_workqueue
 397 *
 398 * Allows the delayed workqueue to run.
 399 */
 400void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched);
 401
 402/**
 403 * ttm_bo_eviction_valuable
 404 *
 405 * @bo: The buffer object to evict
 406 * @place: the placement we need to make room for
 407 *
 408 * Check if it is valuable to evict the BO to make room for the given placement.
 409 */
 410bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 411                              const struct ttm_place *place);
 412
 413/**
 414 * ttm_bo_acc_size
 415 *
 416 * @bdev: Pointer to a ttm_bo_device struct.
 417 * @bo_size: size of the buffer object in byte.
 418 * @struct_size: size of the structure holding buffer object datas
 419 *
 420 * Returns size to account for a buffer object
 421 */
 422size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
 423                       unsigned long bo_size,
 424                       unsigned struct_size);
 425size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
 426                           unsigned long bo_size,
 427                           unsigned struct_size);
 428
 429/**
 430 * ttm_bo_init_reserved
 431 *
 432 * @bdev: Pointer to a ttm_bo_device struct.
 433 * @bo: Pointer to a ttm_buffer_object to be initialized.
 434 * @size: Requested size of buffer object.
 435 * @type: Requested type of buffer object.
 436 * @flags: Initial placement flags.
 437 * @page_alignment: Data alignment in pages.
 438 * @ctx: TTM operation context for memory allocation.
 439 * @acc_size: Accounted size for this object.
 440 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
 441 * @destroy: Destroy function. Use NULL for kfree().
 442 *
 443 * This function initializes a pre-allocated struct ttm_buffer_object.
 444 * As this object may be part of a larger structure, this function,
 445 * together with the @destroy function,
 446 * enables driver-specific objects derived from a ttm_buffer_object.
 447 *
 448 * On successful return, the caller owns an object kref to @bo. The kref and
 449 * list_kref are usually set to 1, but note that in some situations, other
 450 * tasks may already be holding references to @bo as well.
 451 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
 452 * and it is the caller's responsibility to call ttm_bo_unreserve.
 453 *
 454 * If a failure occurs, the function will call the @destroy function, or
 455 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
 456 * illegal and will likely cause memory corruption.
 457 *
 458 * Returns
 459 * -ENOMEM: Out of memory.
 460 * -EINVAL: Invalid placement flags.
 461 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 462 */
 463
 464int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
 465                         struct ttm_buffer_object *bo,
 466                         unsigned long size,
 467                         enum ttm_bo_type type,
 468                         struct ttm_placement *placement,
 469                         uint32_t page_alignment,
 470                         struct ttm_operation_ctx *ctx,
 471                         size_t acc_size,
 472                         struct sg_table *sg,
 473                         struct dma_resv *resv,
 474                         void (*destroy) (struct ttm_buffer_object *));
 475
 476/**
 477 * ttm_bo_init
 478 *
 479 * @bdev: Pointer to a ttm_bo_device struct.
 480 * @bo: Pointer to a ttm_buffer_object to be initialized.
 481 * @size: Requested size of buffer object.
 482 * @type: Requested type of buffer object.
 483 * @flags: Initial placement flags.
 484 * @page_alignment: Data alignment in pages.
 485 * @interruptible: If needing to sleep to wait for GPU resources,
 486 * sleep interruptible.
 487 * pinned in physical memory. If this behaviour is not desired, this member
 488 * holds a pointer to a persistent shmem object. Typically, this would
 489 * point to the shmem object backing a GEM object if TTM is used to back a
 490 * GEM user interface.
 491 * @acc_size: Accounted size for this object.
 492 * @resv: Pointer to a dma_resv, or NULL to let ttm allocate one.
 493 * @destroy: Destroy function. Use NULL for kfree().
 494 *
 495 * This function initializes a pre-allocated struct ttm_buffer_object.
 496 * As this object may be part of a larger structure, this function,
 497 * together with the @destroy function,
 498 * enables driver-specific objects derived from a ttm_buffer_object.
 499 *
 500 * On successful return, the caller owns an object kref to @bo. The kref and
 501 * list_kref are usually set to 1, but note that in some situations, other
 502 * tasks may already be holding references to @bo as well.
 503 *
 504 * If a failure occurs, the function will call the @destroy function, or
 505 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
 506 * illegal and will likely cause memory corruption.
 507 *
 508 * Returns
 509 * -ENOMEM: Out of memory.
 510 * -EINVAL: Invalid placement flags.
 511 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
 512 */
 513int ttm_bo_init(struct ttm_bo_device *bdev, struct ttm_buffer_object *bo,
 514                unsigned long size, enum ttm_bo_type type,
 515                struct ttm_placement *placement,
 516                uint32_t page_alignment, bool interrubtible, size_t acc_size,
 517                struct sg_table *sg, struct dma_resv *resv,
 518                void (*destroy) (struct ttm_buffer_object *));
 519
 520/**
 521 * ttm_bo_create
 522 *
 523 * @bdev: Pointer to a ttm_bo_device struct.
 524 * @size: Requested size of buffer object.
 525 * @type: Requested type of buffer object.
 526 * @placement: Initial placement.
 527 * @page_alignment: Data alignment in pages.
 528 * @interruptible: If needing to sleep while waiting for GPU resources,
 529 * sleep interruptible.
 530 * @p_bo: On successful completion *p_bo points to the created object.
 531 *
 532 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
 533 * on that object. The destroy function is set to kfree().
 534 * Returns
 535 * -ENOMEM: Out of memory.
 536 * -EINVAL: Invalid placement flags.
 537 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
 538 */
 539int ttm_bo_create(struct ttm_bo_device *bdev, unsigned long size,
 540                  enum ttm_bo_type type, struct ttm_placement *placement,
 541                  uint32_t page_alignment, bool interruptible,
 542                  struct ttm_buffer_object **p_bo);
 543
 544/**
 545 * ttm_bo_init_mm
 546 *
 547 * @bdev: Pointer to a ttm_bo_device struct.
 548 * @mem_type: The memory type.
 549 * @p_size: size managed area in pages.
 550 *
 551 * Initialize a manager for a given memory type.
 552 * Note: if part of driver firstopen, it must be protected from a
 553 * potentially racing lastclose.
 554 * Returns:
 555 * -EINVAL: invalid size or memory type.
 556 * -ENOMEM: Not enough memory.
 557 * May also return driver-specified errors.
 558 */
 559int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
 560                   unsigned long p_size);
 561
 562/**
 563 * ttm_bo_clean_mm
 564 *
 565 * @bdev: Pointer to a ttm_bo_device struct.
 566 * @mem_type: The memory type.
 567 *
 568 * Take down a manager for a given memory type after first walking
 569 * the LRU list to evict any buffers left alive.
 570 *
 571 * Normally, this function is part of lastclose() or unload(), and at that
 572 * point there shouldn't be any buffers left created by user-space, since
 573 * there should've been removed by the file descriptor release() method.
 574 * However, before this function is run, make sure to signal all sync objects,
 575 * and verify that the delayed delete queue is empty. The driver must also
 576 * make sure that there are no NO_EVICT buffers present in this memory type
 577 * when the call is made.
 578 *
 579 * If this function is part of a VT switch, the caller must make sure that
 580 * there are no appications currently validating buffers before this
 581 * function is called. The caller can do that by first taking the
 582 * struct ttm_bo_device::ttm_lock in write mode.
 583 *
 584 * Returns:
 585 * -EINVAL: invalid or uninitialized memory type.
 586 * -EBUSY: There are still buffers left in this memory type.
 587 */
 588int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 589
 590/**
 591 * ttm_bo_evict_mm
 592 *
 593 * @bdev: Pointer to a ttm_bo_device struct.
 594 * @mem_type: The memory type.
 595 *
 596 * Evicts all buffers on the lru list of the memory type.
 597 * This is normally part of a VT switch or an
 598 * out-of-memory-space-due-to-fragmentation handler.
 599 * The caller must make sure that there are no other processes
 600 * currently validating buffers, and can do that by taking the
 601 * struct ttm_bo_device::ttm_lock in write mode.
 602 *
 603 * Returns:
 604 * -EINVAL: Invalid or uninitialized memory type.
 605 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
 606 * evict a buffer.
 607 */
 608int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
 609
 610/**
 611 * ttm_kmap_obj_virtual
 612 *
 613 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
 614 * @is_iomem: Pointer to an integer that on return indicates 1 if the
 615 * virtual map is io memory, 0 if normal memory.
 616 *
 617 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
 618 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
 619 * that should strictly be accessed by the iowriteXX() and similar functions.
 620 */
 621static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
 622                                         bool *is_iomem)
 623{
 624        *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
 625        return map->virtual;
 626}
 627
 628/**
 629 * ttm_bo_kmap
 630 *
 631 * @bo: The buffer object.
 632 * @start_page: The first page to map.
 633 * @num_pages: Number of pages to map.
 634 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
 635 *
 636 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
 637 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
 638 * used to obtain a virtual address to the data.
 639 *
 640 * Returns
 641 * -ENOMEM: Out of memory.
 642 * -EINVAL: Invalid range.
 643 */
 644int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
 645                unsigned long num_pages, struct ttm_bo_kmap_obj *map);
 646
 647/**
 648 * ttm_bo_kunmap
 649 *
 650 * @map: Object describing the map to unmap.
 651 *
 652 * Unmaps a kernel map set up by ttm_bo_kmap.
 653 */
 654void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 655
 656/**
 657 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
 658 *
 659 * @vma:       vma as input from the fbdev mmap method.
 660 * @bo:        The bo backing the address space.
 661 *
 662 * Maps a buffer object.
 663 */
 664int ttm_bo_mmap_obj(struct vm_area_struct *vma, 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 */
 676int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 677                struct ttm_bo_device *bdev);
 678
 679void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
 680
 681void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
 682
 683/**
 684 * ttm_bo_io
 685 *
 686 * @bdev:      Pointer to the struct ttm_bo_device.
 687 * @filp:      Pointer to the struct file attempting to read / write.
 688 * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
 689 * @rbuf:      User-space pointer to address of buffer to read into.
 690 * Null on write.
 691 * @count:     Number of bytes to read / write.
 692 * @f_pos:     Pointer to current file position.
 693 * @write:     1 for read, 0 for write.
 694 *
 695 * This function implements read / write into ttm buffer objects, and is
 696 * intended to
 697 * be called from the fops::read and fops::write method.
 698 * Returns:
 699 * See man (2) write, man(2) read. In particular,
 700 * the function may return -ERESTARTSYS if
 701 * interrupted by a signal.
 702 */
 703ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
 704                  const char __user *wbuf, char __user *rbuf,
 705                  size_t count, loff_t *f_pos, bool write);
 706
 707int ttm_bo_swapout(struct ttm_bo_global *glob,
 708                        struct ttm_operation_ctx *ctx);
 709void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
 710int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
 711
 712/**
 713 * ttm_bo_uses_embedded_gem_object - check if the given bo uses the
 714 * embedded drm_gem_object.
 715 *
 716 * Most ttm drivers are using gem too, so the embedded
 717 * ttm_buffer_object.base will be initialized by the driver (before
 718 * calling ttm_bo_init).  It is also possible to use ttm without gem
 719 * though (vmwgfx does that).
 720 *
 721 * This helper will figure whenever a given ttm bo is a gem object too
 722 * or not.
 723 *
 724 * @bo: The bo to check.
 725 */
 726static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object *bo)
 727{
 728        return bo->base.dev != NULL;
 729}
 730
 731/* Default number of pre-faulted pages in the TTM fault handler */
 732#define TTM_BO_VM_NUM_PREFAULT 16
 733
 734vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
 735                             struct vm_fault *vmf);
 736
 737vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
 738                                    pgprot_t prot,
 739                                    pgoff_t num_prefault);
 740
 741void ttm_bo_vm_open(struct vm_area_struct *vma);
 742
 743void ttm_bo_vm_close(struct vm_area_struct *vma);
 744#endif
 745