Linux Audio

Check our new training course

Loading...
Note: File does not exist in v6.13.7.
  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_global;
 45
 46struct ttm_bo_device;
 47
 48struct drm_mm_node;
 49
 50struct ttm_placement;
 51
 52struct ttm_place;
 53
 54/**
 55 * struct ttm_bus_placement
 56 *
 57 * @addr:		mapped virtual address
 58 * @base:		bus base address
 59 * @is_iomem:		is this io memory ?
 60 * @size:		size in byte
 61 * @offset:		offset from the base address
 62 * @io_reserved_vm:     The VM system has a refcount in @io_reserved_count
 63 * @io_reserved_count:  Refcounting the numbers of callers to ttm_mem_io_reserve
 64 *
 65 * Structure indicating the bus placement of an object.
 66 */
 67struct ttm_bus_placement {
 68	void		*addr;
 69	phys_addr_t	base;
 70	unsigned long	size;
 71	unsigned long	offset;
 72	bool		is_iomem;
 73	bool		io_reserved_vm;
 74	uint64_t        io_reserved_count;
 75};
 76
 77
 78/**
 79 * struct ttm_mem_reg
 80 *
 81 * @mm_node: Memory manager node.
 82 * @size: Requested size of memory region.
 83 * @num_pages: Actual size of memory region in pages.
 84 * @page_alignment: Page alignment.
 85 * @placement: Placement flags.
 86 * @bus: Placement on io bus accessible to the CPU
 87 *
 88 * Structure indicating the placement and space resources used by a
 89 * buffer object.
 90 */
 91
 92struct ttm_mem_reg {
 93	void *mm_node;
 94	unsigned long start;
 95	unsigned long size;
 96	unsigned long num_pages;
 97	uint32_t page_alignment;
 98	uint32_t mem_type;
 99	uint32_t placement;
100	struct ttm_bus_placement bus;
101};
102
103/**
104 * enum ttm_bo_type
105 *
106 * @ttm_bo_type_device:	These are 'normal' buffers that can
107 * be mmapped by user space. Each of these bos occupy a slot in the
108 * device address space, that can be used for normal vm operations.
109 *
110 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
111 * but they cannot be accessed from user-space. For kernel-only use.
112 *
113 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
114 * driver.
115 */
116
117enum ttm_bo_type {
118	ttm_bo_type_device,
119	ttm_bo_type_kernel,
120	ttm_bo_type_sg
121};
122
123struct ttm_tt;
124
125/**
126 * struct ttm_buffer_object
127 *
128 * @bdev: Pointer to the buffer object device structure.
129 * @type: The bo type.
130 * @destroy: Destruction function. If NULL, kfree is used.
131 * @num_pages: Actual number of pages.
132 * @acc_size: Accounted size for this object.
133 * @kref: Reference count of this buffer object. When this refcount reaches
134 * zero, the object is put on the delayed delete list.
135 * @list_kref: List reference count of this buffer object. This member is
136 * used to avoid destruction while the buffer object is still on a list.
137 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
138 * keeps one refcount. When this refcount reaches zero,
139 * the object is destroyed.
140 * @mem: structure describing current placement.
141 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
142 * pinned in physical memory. If this behaviour is not desired, this member
143 * holds a pointer to a persistent shmem object.
144 * @ttm: TTM structure holding system pages.
145 * @evicted: Whether the object was evicted without user-space knowing.
146 * @cpu_writes: For synchronization. Number of cpu writers.
147 * @lru: List head for the lru list.
148 * @ddestroy: List head for the delayed destroy list.
149 * @swap: List head for swap LRU list.
150 * @moving: Fence set when BO is moving
151 * @vma_node: Address space manager node.
152 * @offset: The current GPU offset, which can have different meanings
153 * depending on the memory type. For SYSTEM type memory, it should be 0.
154 * @cur_placement: Hint of current placement.
155 * @wu_mutex: Wait unreserved mutex.
156 *
157 * Base class for TTM buffer object, that deals with data placement and CPU
158 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
159 * the driver can usually use the placement offset @offset directly as the
160 * GPU virtual address. For drivers implementing multiple
161 * GPU memory manager contexts, the driver should manage the address space
162 * in these contexts separately and use these objects to get the correct
163 * placement and caching for these GPU maps. This makes it possible to use
164 * these objects for even quite elaborate memory management schemes.
165 * The destroy member, the API visibility of this object makes it possible
166 * to derive driver specific types.
167 */
168
169struct ttm_buffer_object {
170	/**
171	 * Members constant at init.
172	 */
173
174	struct ttm_bo_device *bdev;
175	enum ttm_bo_type type;
176	void (*destroy) (struct ttm_buffer_object *);
177	unsigned long num_pages;
178	size_t acc_size;
179
180	/**
181	* Members not needing protection.
182	*/
183
184	struct kref kref;
185	struct kref list_kref;
186
187	/**
188	 * Members protected by the bo::resv::reserved lock.
189	 */
190
191	struct ttm_mem_reg mem;
192	struct file *persistent_swap_storage;
193	struct ttm_tt *ttm;
194	bool evicted;
195
196	/**
197	 * Members protected by the bo::reserved lock only when written to.
198	 */
199
200	atomic_t cpu_writers;
201
202	/**
203	 * Members protected by the bdev::lru_lock.
204	 */
205
206	struct list_head lru;
207	struct list_head ddestroy;
208	struct list_head swap;
209	struct list_head io_reserve_lru;
210
211	/**
212	 * Members protected by a bo reservation.
213	 */
214
215	struct dma_fence *moving;
216
217	struct drm_vma_offset_node vma_node;
218
219	unsigned priority;
220
221	/**
222	 * Special members that are protected by the reserve lock
223	 * and the bo::lock when written to. Can be read with
224	 * either of these locks held.
225	 */
226
227	uint64_t offset; /* GPU address space is independent of CPU word size */
228
229	struct sg_table *sg;
230
231	struct reservation_object *resv;
232	struct reservation_object ttm_resv;
233	struct mutex wu_mutex;
234};
235
236/**
237 * struct ttm_bo_kmap_obj
238 *
239 * @virtual: The current kernel virtual address.
240 * @page: The page when kmap'ing a single page.
241 * @bo_kmap_type: Type of bo_kmap.
242 *
243 * Object describing a kernel mapping. Since a TTM bo may be located
244 * in various memory types with various caching policies, the
245 * mapping can either be an ioremap, a vmap, a kmap or part of a
246 * premapped region.
247 */
248
249#define TTM_BO_MAP_IOMEM_MASK 0x80
250struct ttm_bo_kmap_obj {
251	void *virtual;
252	struct page *page;
253	enum {
254		ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
255		ttm_bo_map_vmap         = 2,
256		ttm_bo_map_kmap         = 3,
257		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
258	} bo_kmap_type;
259	struct ttm_buffer_object *bo;
260};
261
262/**
263 * struct ttm_operation_ctx
264 *
265 * @interruptible: Sleep interruptible if sleeping.
266 * @no_wait_gpu: Return immediately if the GPU is busy.
267 * @resv: Reservation object to allow reserved evictions with.
268 * @flags: Including the following flags
269 *
270 * Context for TTM operations like changing buffer placement or general memory
271 * allocation.
272 */
273struct ttm_operation_ctx {
274	bool interruptible;
275	bool no_wait_gpu;
276	struct reservation_object *resv;
277	uint64_t bytes_moved;
278	uint32_t flags;
279};
280
281/* Allow eviction of reserved BOs */
282#define TTM_OPT_FLAG_ALLOW_RES_EVICT		0x1
283/* when serving page fault or suspend, allow alloc anyway */
284#define TTM_OPT_FLAG_FORCE_ALLOC		0x2
285
286/**
287 * ttm_bo_reference - reference a struct ttm_buffer_object
288 *
289 * @bo: The buffer object.
290 *
291 * Returns a refcounted pointer to a buffer object.
292 */
293
294static inline struct ttm_buffer_object *
295ttm_bo_reference(struct ttm_buffer_object *bo)
296{
297	kref_get(&bo->kref);
298	return bo;
299}
300
301/**
302 * ttm_bo_wait - wait for buffer idle.
303 *
304 * @bo:  The buffer object.
305 * @interruptible:  Use interruptible wait.
306 * @no_wait:  Return immediately if buffer is busy.
307 *
308 * This function must be called with the bo::mutex held, and makes
309 * sure any previous rendering to the buffer is completed.
310 * Note: It might be necessary to block validations before the
311 * wait by reserving the buffer.
312 * Returns -EBUSY if no_wait is true and the buffer is busy.
313 * Returns -ERESTARTSYS if interrupted by a signal.
314 */
315int ttm_bo_wait(struct ttm_buffer_object *bo, bool interruptible, bool no_wait);
316
317/**
318 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
319 *
320 * @placement:  Return immediately if buffer is busy.
321 * @mem:  The struct ttm_mem_reg indicating the region where the bo resides
322 * @new_flags: Describes compatible placement found
323 *
324 * Returns true if the placement is compatible
325 */
326bool ttm_bo_mem_compat(struct ttm_placement *placement, struct ttm_mem_reg *mem,
327		       uint32_t *new_flags);
328
329/**
330 * ttm_bo_validate
331 *
332 * @bo: The buffer object.
333 * @placement: Proposed placement for the buffer object.
334 * @ctx: validation parameters.
335 *
336 * Changes placement and caching policy of the buffer object
337 * according proposed placement.
338 * Returns
339 * -EINVAL on invalid proposed placement.
340 * -ENOMEM on out-of-memory condition.
341 * -EBUSY if no_wait is true and buffer busy.
342 * -ERESTARTSYS if interrupted by a signal.
343 */
344int ttm_bo_validate(struct ttm_buffer_object *bo,
345		    struct ttm_placement *placement,
346		    struct ttm_operation_ctx *ctx);
347
348/**
349 * ttm_bo_unref
350 *
351 * @bo: The buffer object.
352 *
353 * Unreference and clear a pointer to a buffer object.
354 */
355void ttm_bo_unref(struct ttm_buffer_object **bo);
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 */
367void 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 */
379void ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
380
381/**
382 * ttm_bo_move_to_lru_tail
383 *
384 * @bo: The buffer object.
385 *
386 * Move this BO to the tail of all lru lists used to lookup and reserve an
387 * object. This function must be called with struct ttm_bo_global::lru_lock
388 * held, and is used to make a BO less likely to be considered for eviction.
389 */
390void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
391
392/**
393 * ttm_bo_lock_delayed_workqueue
394 *
395 * Prevent the delayed workqueue from running.
396 * Returns
397 * True if the workqueue was queued at the time
398 */
399int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
400
401/**
402 * ttm_bo_unlock_delayed_workqueue
403 *
404 * Allows the delayed workqueue to run.
405 */
406void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev, int resched);
407
408/**
409 * ttm_bo_eviction_valuable
410 *
411 * @bo: The buffer object to evict
412 * @place: the placement we need to make room for
413 *
414 * Check if it is valuable to evict the BO to make room for the given placement.
415 */
416bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
417			      const struct ttm_place *place);
418
419/**
420 * ttm_bo_synccpu_write_grab
421 *
422 * @bo: The buffer object:
423 * @no_wait: Return immediately if buffer is busy.
424 *
425 * Synchronizes a buffer object for CPU RW access. This means
426 * command submission that affects the buffer will return -EBUSY
427 * until ttm_bo_synccpu_write_release is called.
428 *
429 * Returns
430 * -EBUSY if the buffer is busy and no_wait is true.
431 * -ERESTARTSYS if interrupted by a signal.
432 */
433int ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
434
435/**
436 * ttm_bo_synccpu_write_release:
437 *
438 * @bo : The buffer object.
439 *
440 * Releases a synccpu lock.
441 */
442void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
443
444/**
445 * ttm_bo_acc_size
446 *
447 * @bdev: Pointer to a ttm_bo_device struct.
448 * @bo_size: size of the buffer object in byte.
449 * @struct_size: size of the structure holding buffer object datas
450 *
451 * Returns size to account for a buffer object
452 */
453size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
454		       unsigned long bo_size,
455		       unsigned struct_size);
456size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
457			   unsigned long bo_size,
458			   unsigned struct_size);
459
460/**
461 * ttm_bo_init_reserved
462 *
463 * @bdev: Pointer to a ttm_bo_device struct.
464 * @bo: Pointer to a ttm_buffer_object to be initialized.
465 * @size: Requested size of buffer object.
466 * @type: Requested type of buffer object.
467 * @flags: Initial placement flags.
468 * @page_alignment: Data alignment in pages.
469 * @ctx: TTM operation context for memory allocation.
470 * @acc_size: Accounted size for this object.
471 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
472 * @destroy: Destroy function. Use NULL for kfree().
473 *
474 * This function initializes a pre-allocated struct ttm_buffer_object.
475 * As this object may be part of a larger structure, this function,
476 * together with the @destroy function,
477 * enables driver-specific objects derived from a ttm_buffer_object.
478 *
479 * On successful return, the caller owns an object kref to @bo. The kref and
480 * list_kref are usually set to 1, but note that in some situations, other
481 * tasks may already be holding references to @bo as well.
482 * Furthermore, if resv == NULL, the buffer's reservation lock will be held,
483 * and it is the caller's responsibility to call ttm_bo_unreserve.
484 *
485 * If a failure occurs, the function will call the @destroy function, or
486 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
487 * illegal and will likely cause memory corruption.
488 *
489 * Returns
490 * -ENOMEM: Out of memory.
491 * -EINVAL: Invalid placement flags.
492 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
493 */
494
495int ttm_bo_init_reserved(struct ttm_bo_device *bdev,
496			 struct ttm_buffer_object *bo,
497			 unsigned long size,
498			 enum ttm_bo_type type,
499			 struct ttm_placement *placement,
500			 uint32_t page_alignment,
501			 struct ttm_operation_ctx *ctx,
502			 size_t acc_size,
503			 struct sg_table *sg,
504			 struct reservation_object *resv,
505			 void (*destroy) (struct ttm_buffer_object *));
506
507/**
508 * ttm_bo_init
509 *
510 * @bdev: Pointer to a ttm_bo_device struct.
511 * @bo: Pointer to a ttm_buffer_object to be initialized.
512 * @size: Requested size of buffer object.
513 * @type: Requested type of buffer object.
514 * @flags: Initial placement flags.
515 * @page_alignment: Data alignment in pages.
516 * @interruptible: If needing to sleep to wait for GPU resources,
517 * sleep interruptible.
518 * pinned in physical memory. If this behaviour is not desired, this member
519 * holds a pointer to a persistent shmem object. Typically, this would
520 * point to the shmem object backing a GEM object if TTM is used to back a
521 * GEM user interface.
522 * @acc_size: Accounted size for this object.
523 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
524 * @destroy: Destroy function. Use NULL for kfree().
525 *
526 * This function initializes a pre-allocated struct ttm_buffer_object.
527 * As this object may be part of a larger structure, this function,
528 * together with the @destroy function,
529 * enables driver-specific objects derived from a ttm_buffer_object.
530 *
531 * On successful return, the caller owns an object kref to @bo. The kref and
532 * list_kref are usually set to 1, but note that in some situations, other
533 * tasks may already be holding references to @bo as well.
534 *
535 * If a failure occurs, the function will call the @destroy function, or
536 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
537 * illegal and will likely cause memory corruption.
538 *
539 * Returns
540 * -ENOMEM: Out of memory.
541 * -EINVAL: Invalid placement flags.
542 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
543 */
544int ttm_bo_init(struct ttm_bo_device *bdev, struct ttm_buffer_object *bo,
545		unsigned long size, enum ttm_bo_type type,
546		struct ttm_placement *placement,
547		uint32_t page_alignment, bool interrubtible, size_t acc_size,
548		struct sg_table *sg, struct reservation_object *resv,
549		void (*destroy) (struct ttm_buffer_object *));
550
551/**
552 * ttm_bo_create
553 *
554 * @bdev: Pointer to a ttm_bo_device struct.
555 * @size: Requested size of buffer object.
556 * @type: Requested type of buffer object.
557 * @placement: Initial placement.
558 * @page_alignment: Data alignment in pages.
559 * @interruptible: If needing to sleep while waiting for GPU resources,
560 * sleep interruptible.
561 * @p_bo: On successful completion *p_bo points to the created object.
562 *
563 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
564 * on that object. The destroy function is set to kfree().
565 * Returns
566 * -ENOMEM: Out of memory.
567 * -EINVAL: Invalid placement flags.
568 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
569 */
570int ttm_bo_create(struct ttm_bo_device *bdev, unsigned long size,
571		  enum ttm_bo_type type, struct ttm_placement *placement,
572		  uint32_t page_alignment, bool interruptible,
573		  struct ttm_buffer_object **p_bo);
574
575/**
576 * ttm_bo_init_mm
577 *
578 * @bdev: Pointer to a ttm_bo_device struct.
579 * @mem_type: The memory type.
580 * @p_size: size managed area in pages.
581 *
582 * Initialize a manager for a given memory type.
583 * Note: if part of driver firstopen, it must be protected from a
584 * potentially racing lastclose.
585 * Returns:
586 * -EINVAL: invalid size or memory type.
587 * -ENOMEM: Not enough memory.
588 * May also return driver-specified errors.
589 */
590int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
591		   unsigned long p_size);
592
593/**
594 * ttm_bo_clean_mm
595 *
596 * @bdev: Pointer to a ttm_bo_device struct.
597 * @mem_type: The memory type.
598 *
599 * Take down a manager for a given memory type after first walking
600 * the LRU list to evict any buffers left alive.
601 *
602 * Normally, this function is part of lastclose() or unload(), and at that
603 * point there shouldn't be any buffers left created by user-space, since
604 * there should've been removed by the file descriptor release() method.
605 * However, before this function is run, make sure to signal all sync objects,
606 * and verify that the delayed delete queue is empty. The driver must also
607 * make sure that there are no NO_EVICT buffers present in this memory type
608 * when the call is made.
609 *
610 * If this function is part of a VT switch, the caller must make sure that
611 * there are no appications currently validating buffers before this
612 * function is called. The caller can do that by first taking the
613 * struct ttm_bo_device::ttm_lock in write mode.
614 *
615 * Returns:
616 * -EINVAL: invalid or uninitialized memory type.
617 * -EBUSY: There are still buffers left in this memory type.
618 */
619int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
620
621/**
622 * ttm_bo_evict_mm
623 *
624 * @bdev: Pointer to a ttm_bo_device struct.
625 * @mem_type: The memory type.
626 *
627 * Evicts all buffers on the lru list of the memory type.
628 * This is normally part of a VT switch or an
629 * out-of-memory-space-due-to-fragmentation handler.
630 * The caller must make sure that there are no other processes
631 * currently validating buffers, and can do that by taking the
632 * struct ttm_bo_device::ttm_lock in write mode.
633 *
634 * Returns:
635 * -EINVAL: Invalid or uninitialized memory type.
636 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
637 * evict a buffer.
638 */
639int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
640
641/**
642 * ttm_kmap_obj_virtual
643 *
644 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
645 * @is_iomem: Pointer to an integer that on return indicates 1 if the
646 * virtual map is io memory, 0 if normal memory.
647 *
648 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
649 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
650 * that should strictly be accessed by the iowriteXX() and similar functions.
651 */
652static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
653					 bool *is_iomem)
654{
655	*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
656	return map->virtual;
657}
658
659/**
660 * ttm_bo_kmap
661 *
662 * @bo: The buffer object.
663 * @start_page: The first page to map.
664 * @num_pages: Number of pages to map.
665 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
666 *
667 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
668 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
669 * used to obtain a virtual address to the data.
670 *
671 * Returns
672 * -ENOMEM: Out of memory.
673 * -EINVAL: Invalid range.
674 */
675int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
676		unsigned long num_pages, struct ttm_bo_kmap_obj *map);
677
678/**
679 * ttm_bo_kunmap
680 *
681 * @map: Object describing the map to unmap.
682 *
683 * Unmaps a kernel map set up by ttm_bo_kmap.
684 */
685void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
686
687/**
688 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
689 *
690 * @vma:       vma as input from the fbdev mmap method.
691 * @bo:        The bo backing the address space. The address space will
692 * have the same size as the bo, and start at offset 0.
693 *
694 * This function is intended to be called by the fbdev mmap method
695 * if the fbdev address space is to be backed by a bo.
696 */
697int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
698
699/**
700 * ttm_bo_mmap - mmap out of the ttm device address space.
701 *
702 * @filp:      filp as input from the mmap method.
703 * @vma:       vma as input from the mmap method.
704 * @bdev:      Pointer to the ttm_bo_device with the address space manager.
705 *
706 * This function is intended to be called by the device mmap method.
707 * if the device address space is to be backed by the bo manager.
708 */
709int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
710		struct ttm_bo_device *bdev);
711
712void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
713
714void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
715
716/**
717 * ttm_bo_io
718 *
719 * @bdev:      Pointer to the struct ttm_bo_device.
720 * @filp:      Pointer to the struct file attempting to read / write.
721 * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
722 * @rbuf:      User-space pointer to address of buffer to read into.
723 * Null on write.
724 * @count:     Number of bytes to read / write.
725 * @f_pos:     Pointer to current file position.
726 * @write:     1 for read, 0 for write.
727 *
728 * This function implements read / write into ttm buffer objects, and is
729 * intended to
730 * be called from the fops::read and fops::write method.
731 * Returns:
732 * See man (2) write, man(2) read. In particular,
733 * the function may return -ERESTARTSYS if
734 * interrupted by a signal.
735 */
736ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
737		  const char __user *wbuf, char __user *rbuf,
738		  size_t count, loff_t *f_pos, bool write);
739
740int ttm_bo_swapout(struct ttm_bo_global *glob,
741			struct ttm_operation_ctx *ctx);
742void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
743int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
744#endif