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