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_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
 43struct ttm_bo_device;
 44
 45struct 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 */
 60struct 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 */
 82struct 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
107struct 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_kernel: These buffers are like ttm_bo_type_device buffers,
126 * but they cannot be accessed from user-space. For kernel-only use.
127 *
128 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
129 * driver.
130 */
131
132enum ttm_bo_type {
133	ttm_bo_type_device,
134	ttm_bo_type_kernel,
135	ttm_bo_type_sg
136};
137
138struct ttm_tt;
139
140/**
141 * struct ttm_buffer_object
142 *
143 * @bdev: Pointer to the buffer object device structure.
144 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
145 * buffers.
146 * @type: The bo type.
147 * @destroy: Destruction function. If NULL, kfree is used.
148 * @num_pages: Actual number of pages.
149 * @addr_space_offset: Address space offset.
150 * @acc_size: Accounted size for this object.
151 * @kref: Reference count of this buffer object. When this refcount reaches
152 * zero, the object is put on the delayed delete list.
153 * @list_kref: List reference count of this buffer object. This member is
154 * used to avoid destruction while the buffer object is still on a list.
155 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
156 * keeps one refcount. When this refcount reaches zero,
157 * the object is destroyed.
158 * @event_queue: Queue for processes waiting on buffer object status change.
159 * @mem: structure describing current placement.
160 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
161 * pinned in physical memory. If this behaviour is not desired, this member
162 * holds a pointer to a persistent shmem object.
163 * @ttm: TTM structure holding system pages.
164 * @evicted: Whether the object was evicted without user-space knowing.
165 * @cpu_writes: For synchronization. Number of cpu writers.
166 * @lru: List head for the lru list.
167 * @ddestroy: List head for the delayed destroy list.
168 * @swap: List head for swap LRU list.
169 * @val_seq: Sequence of the validation holding the @reserved lock.
170 * Used to avoid starvation when many processes compete to validate the
171 * buffer. This member is protected by the bo_device::lru_lock.
172 * @seq_valid: The value of @val_seq is valid. This value is protected by
173 * the bo_device::lru_lock.
174 * @reserved: Deadlock-free lock used for synchronization state transitions.
175 * @sync_obj_arg: Opaque argument to synchronization object function.
176 * @sync_obj: Pointer to a synchronization object.
177 * @priv_flags: Flags describing buffer object internal state.
178 * @vm_rb: Rb node for the vm rb tree.
179 * @vm_node: Address space manager node.
180 * @offset: The current GPU offset, which can have different meanings
181 * depending on the memory type. For SYSTEM type memory, it should be 0.
182 * @cur_placement: Hint of current placement.
183 *
184 * Base class for TTM buffer object, that deals with data placement and CPU
185 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
186 * the driver can usually use the placement offset @offset directly as the
187 * GPU virtual address. For drivers implementing multiple
188 * GPU memory manager contexts, the driver should manage the address space
189 * in these contexts separately and use these objects to get the correct
190 * placement and caching for these GPU maps. This makes it possible to use
191 * these objects for even quite elaborate memory management schemes.
192 * The destroy member, the API visibility of this object makes it possible
193 * to derive driver specific types.
194 */
195
196struct ttm_buffer_object {
197	/**
198	 * Members constant at init.
199	 */
200
201	struct ttm_bo_global *glob;
202	struct ttm_bo_device *bdev;
203	unsigned long buffer_start;
204	enum ttm_bo_type type;
205	void (*destroy) (struct ttm_buffer_object *);
206	unsigned long num_pages;
207	uint64_t addr_space_offset;
208	size_t acc_size;
209
210	/**
211	* Members not needing protection.
212	*/
213
214	struct kref kref;
215	struct kref list_kref;
216	wait_queue_head_t event_queue;
217
218	/**
219	 * Members protected by the bo::reserved lock.
220	 */
221
222	struct ttm_mem_reg mem;
223	struct file *persistent_swap_storage;
224	struct ttm_tt *ttm;
225	bool evicted;
226
227	/**
228	 * Members protected by the bo::reserved lock only when written to.
229	 */
230
231	atomic_t cpu_writers;
232
233	/**
234	 * Members protected by the bdev::lru_lock.
235	 */
236
237	struct list_head lru;
238	struct list_head ddestroy;
239	struct list_head swap;
240	struct list_head io_reserve_lru;
241	uint32_t val_seq;
242	bool seq_valid;
243
244	/**
245	 * Members protected by the bdev::lru_lock
246	 * only when written to.
247	 */
248
249	atomic_t reserved;
250
251	/**
252	 * Members protected by struct buffer_object_device::fence_lock
253	 * In addition, setting sync_obj to anything else
254	 * than NULL requires bo::reserved to be held. This allows for
255	 * checking NULL while reserved but not holding the mentioned lock.
256	 */
257
258	void *sync_obj_arg;
259	void *sync_obj;
260	unsigned long priv_flags;
261
262	/**
263	 * Members protected by the bdev::vm_lock
264	 */
265
266	struct rb_node vm_rb;
267	struct drm_mm_node *vm_node;
268
269
270	/**
271	 * Special members that are protected by the reserve lock
272	 * and the bo::lock when written to. Can be read with
273	 * either of these locks held.
274	 */
275
276	unsigned long offset;
277	uint32_t cur_placement;
278
279	struct sg_table *sg;
280};
281
282/**
283 * struct ttm_bo_kmap_obj
284 *
285 * @virtual: The current kernel virtual address.
286 * @page: The page when kmap'ing a single page.
287 * @bo_kmap_type: Type of bo_kmap.
288 *
289 * Object describing a kernel mapping. Since a TTM bo may be located
290 * in various memory types with various caching policies, the
291 * mapping can either be an ioremap, a vmap, a kmap or part of a
292 * premapped region.
293 */
294
295#define TTM_BO_MAP_IOMEM_MASK 0x80
296struct ttm_bo_kmap_obj {
297	void *virtual;
298	struct page *page;
299	enum {
300		ttm_bo_map_iomap        = 1 | TTM_BO_MAP_IOMEM_MASK,
301		ttm_bo_map_vmap         = 2,
302		ttm_bo_map_kmap         = 3,
303		ttm_bo_map_premapped    = 4 | TTM_BO_MAP_IOMEM_MASK,
304	} bo_kmap_type;
305	struct ttm_buffer_object *bo;
306};
307
308/**
309 * ttm_bo_reference - reference a struct ttm_buffer_object
310 *
311 * @bo: The buffer object.
312 *
313 * Returns a refcounted pointer to a buffer object.
314 */
315
316static inline struct ttm_buffer_object *
317ttm_bo_reference(struct ttm_buffer_object *bo)
318{
319	kref_get(&bo->kref);
320	return bo;
321}
322
323/**
324 * ttm_bo_wait - wait for buffer idle.
325 *
326 * @bo:  The buffer object.
327 * @interruptible:  Use interruptible wait.
328 * @no_wait:  Return immediately if buffer is busy.
329 *
330 * This function must be called with the bo::mutex held, and makes
331 * sure any previous rendering to the buffer is completed.
332 * Note: It might be necessary to block validations before the
333 * wait by reserving the buffer.
334 * Returns -EBUSY if no_wait is true and the buffer is busy.
335 * Returns -ERESTARTSYS if interrupted by a signal.
336 */
337extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
338		       bool interruptible, bool no_wait);
339/**
340 * ttm_bo_validate
341 *
342 * @bo: The buffer object.
343 * @placement: Proposed placement for the buffer object.
344 * @interruptible: Sleep interruptible if sleeping.
345 * @no_wait_reserve: Return immediately if other buffers are busy.
346 * @no_wait_gpu: Return immediately if the GPU is busy.
347 *
348 * Changes placement and caching policy of the buffer object
349 * according proposed placement.
350 * Returns
351 * -EINVAL on invalid proposed placement.
352 * -ENOMEM on out-of-memory condition.
353 * -EBUSY if no_wait is true and buffer busy.
354 * -ERESTARTSYS if interrupted by a signal.
355 */
356extern int ttm_bo_validate(struct ttm_buffer_object *bo,
357				struct ttm_placement *placement,
358				bool interruptible, bool no_wait_reserve,
359				bool no_wait_gpu);
360
361/**
362 * ttm_bo_unref
363 *
364 * @bo: The buffer object.
365 *
366 * Unreference and clear a pointer to a buffer object.
367 */
368extern void ttm_bo_unref(struct ttm_buffer_object **bo);
369
370
371/**
372 * ttm_bo_list_ref_sub
373 *
374 * @bo: The buffer object.
375 * @count: The number of references with which to decrease @bo::list_kref;
376 * @never_free: The refcount should not reach zero with this operation.
377 *
378 * Release @count lru list references to this buffer object.
379 */
380extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
381				bool never_free);
382
383/**
384 * ttm_bo_add_to_lru
385 *
386 * @bo: The buffer object.
387 *
388 * Add this bo to the relevant mem type lru and, if it's backed by
389 * system pages (ttms) to the swap list.
390 * This function must be called with struct ttm_bo_global::lru_lock held, and
391 * is typically called immediately prior to unreserving a bo.
392 */
393extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
394
395/**
396 * ttm_bo_del_from_lru
397 *
398 * @bo: The buffer object.
399 *
400 * Remove this bo from all lru lists used to lookup and reserve an object.
401 * This function must be called with struct ttm_bo_global::lru_lock held,
402 * and is usually called just immediately after the bo has been reserved to
403 * avoid recursive reservation from lru lists.
404 */
405extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
406
407
408/**
409 * ttm_bo_lock_delayed_workqueue
410 *
411 * Prevent the delayed workqueue from running.
412 * Returns
413 * True if the workqueue was queued at the time
414 */
415extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
416
417/**
418 * ttm_bo_unlock_delayed_workqueue
419 *
420 * Allows the delayed workqueue to run.
421 */
422extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
423					    int resched);
424
425/**
426 * ttm_bo_synccpu_write_grab
427 *
428 * @bo: The buffer object:
429 * @no_wait: Return immediately if buffer is busy.
430 *
431 * Synchronizes a buffer object for CPU RW access. This means
432 * blocking command submission that affects the buffer and
433 * waiting for buffer idle. This lock is recursive.
434 * Returns
435 * -EBUSY if the buffer is busy and no_wait is true.
436 * -ERESTARTSYS if interrupted by a signal.
437 */
438extern int
439ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
440
441/**
442 * ttm_bo_synccpu_write_release:
443 *
444 * @bo : The buffer object.
445 *
446 * Releases a synccpu lock.
447 */
448extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
449
450/**
451 * ttm_bo_acc_size
452 *
453 * @bdev: Pointer to a ttm_bo_device struct.
454 * @bo_size: size of the buffer object in byte.
455 * @struct_size: size of the structure holding buffer object datas
456 *
457 * Returns size to account for a buffer object
458 */
459size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
460		       unsigned long bo_size,
461		       unsigned struct_size);
462size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
463			   unsigned long bo_size,
464			   unsigned struct_size);
465
466/**
467 * ttm_bo_init
468 *
469 * @bdev: Pointer to a ttm_bo_device struct.
470 * @bo: Pointer to a ttm_buffer_object to be initialized.
471 * @size: Requested size of buffer object.
472 * @type: Requested type of buffer object.
473 * @flags: Initial placement flags.
474 * @page_alignment: Data alignment in pages.
475 * @buffer_start: Virtual address of user space data backing a
476 * user buffer object.
477 * @interruptible: If needing to sleep to wait for GPU resources,
478 * sleep interruptible.
479 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
480 * pinned in physical memory. If this behaviour is not desired, this member
481 * holds a pointer to a persistent shmem object. Typically, this would
482 * point to the shmem object backing a GEM object if TTM is used to back a
483 * GEM user interface.
484 * @acc_size: Accounted size for this object.
485 * @destroy: Destroy function. Use NULL for kfree().
486 *
487 * This function initializes a pre-allocated struct ttm_buffer_object.
488 * As this object may be part of a larger structure, this function,
489 * together with the @destroy function,
490 * enables driver-specific objects derived from a ttm_buffer_object.
491 * On successful return, the object kref and list_kref are set to 1.
492 * If a failure occurs, the function will call the @destroy function, or
493 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
494 * illegal and will likely cause memory corruption.
495 *
496 * Returns
497 * -ENOMEM: Out of memory.
498 * -EINVAL: Invalid placement flags.
499 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
500 */
501
502extern int ttm_bo_init(struct ttm_bo_device *bdev,
503			struct ttm_buffer_object *bo,
504			unsigned long size,
505			enum ttm_bo_type type,
506			struct ttm_placement *placement,
507			uint32_t page_alignment,
508			unsigned long buffer_start,
509			bool interrubtible,
510			struct file *persistent_swap_storage,
511			size_t acc_size,
512			struct sg_table *sg,
513			void (*destroy) (struct ttm_buffer_object *));
514
515/**
516 * ttm_bo_synccpu_object_init
517 *
518 * @bdev: Pointer to a ttm_bo_device struct.
519 * @bo: Pointer to a ttm_buffer_object to be initialized.
520 * @size: Requested size of buffer object.
521 * @type: Requested type of buffer object.
522 * @flags: Initial placement flags.
523 * @page_alignment: Data alignment in pages.
524 * @buffer_start: Virtual address of user space data backing a
525 * user buffer object.
526 * @interruptible: If needing to sleep while waiting for GPU resources,
527 * sleep interruptible.
528 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
529 * pinned in physical memory. If this behaviour is not desired, this member
530 * holds a pointer to a persistent shmem object. Typically, this would
531 * point to the shmem object backing a GEM object if TTM is used to back a
532 * GEM user interface.
533 * @p_bo: On successful completion *p_bo points to the created object.
534 *
535 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
536 * on that object. The destroy function is set to kfree().
537 * Returns
538 * -ENOMEM: Out of memory.
539 * -EINVAL: Invalid placement flags.
540 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
541 */
542
543extern int ttm_bo_create(struct ttm_bo_device *bdev,
544				unsigned long size,
545				enum ttm_bo_type type,
546				struct ttm_placement *placement,
547				uint32_t page_alignment,
548				unsigned long buffer_start,
549				bool interruptible,
550				struct file *persistent_swap_storage,
551				struct ttm_buffer_object **p_bo);
552
553/**
554 * ttm_bo_check_placement
555 *
556 * @bo:		the buffer object.
557 * @placement:	placements
558 *
559 * Performs minimal validity checking on an intended change of
560 * placement flags.
561 * Returns
562 * -EINVAL: Intended change is invalid or not allowed.
563 */
564extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
565					struct ttm_placement *placement);
566
567/**
568 * ttm_bo_init_mm
569 *
570 * @bdev: Pointer to a ttm_bo_device struct.
571 * @mem_type: The memory type.
572 * @p_size: size managed area in pages.
573 *
574 * Initialize a manager for a given memory type.
575 * Note: if part of driver firstopen, it must be protected from a
576 * potentially racing lastclose.
577 * Returns:
578 * -EINVAL: invalid size or memory type.
579 * -ENOMEM: Not enough memory.
580 * May also return driver-specified errors.
581 */
582
583extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
584				unsigned long p_size);
585/**
586 * ttm_bo_clean_mm
587 *
588 * @bdev: Pointer to a ttm_bo_device struct.
589 * @mem_type: The memory type.
590 *
591 * Take down a manager for a given memory type after first walking
592 * the LRU list to evict any buffers left alive.
593 *
594 * Normally, this function is part of lastclose() or unload(), and at that
595 * point there shouldn't be any buffers left created by user-space, since
596 * there should've been removed by the file descriptor release() method.
597 * However, before this function is run, make sure to signal all sync objects,
598 * and verify that the delayed delete queue is empty. The driver must also
599 * make sure that there are no NO_EVICT buffers present in this memory type
600 * when the call is made.
601 *
602 * If this function is part of a VT switch, the caller must make sure that
603 * there are no appications currently validating buffers before this
604 * function is called. The caller can do that by first taking the
605 * struct ttm_bo_device::ttm_lock in write mode.
606 *
607 * Returns:
608 * -EINVAL: invalid or uninitialized memory type.
609 * -EBUSY: There are still buffers left in this memory type.
610 */
611
612extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
613
614/**
615 * ttm_bo_evict_mm
616 *
617 * @bdev: Pointer to a ttm_bo_device struct.
618 * @mem_type: The memory type.
619 *
620 * Evicts all buffers on the lru list of the memory type.
621 * This is normally part of a VT switch or an
622 * out-of-memory-space-due-to-fragmentation handler.
623 * The caller must make sure that there are no other processes
624 * currently validating buffers, and can do that by taking the
625 * struct ttm_bo_device::ttm_lock in write mode.
626 *
627 * Returns:
628 * -EINVAL: Invalid or uninitialized memory type.
629 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
630 * evict a buffer.
631 */
632
633extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
634
635/**
636 * ttm_kmap_obj_virtual
637 *
638 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
639 * @is_iomem: Pointer to an integer that on return indicates 1 if the
640 * virtual map is io memory, 0 if normal memory.
641 *
642 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
643 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
644 * that should strictly be accessed by the iowriteXX() and similar functions.
645 */
646
647static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
648					 bool *is_iomem)
649{
650	*is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
651	return map->virtual;
652}
653
654/**
655 * ttm_bo_kmap
656 *
657 * @bo: The buffer object.
658 * @start_page: The first page to map.
659 * @num_pages: Number of pages to map.
660 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
661 *
662 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
663 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
664 * used to obtain a virtual address to the data.
665 *
666 * Returns
667 * -ENOMEM: Out of memory.
668 * -EINVAL: Invalid range.
669 */
670
671extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
672		       unsigned long num_pages, struct ttm_bo_kmap_obj *map);
673
674/**
675 * ttm_bo_kunmap
676 *
677 * @map: Object describing the map to unmap.
678 *
679 * Unmaps a kernel map set up by ttm_bo_kmap.
680 */
681
682extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
683
684/**
685 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
686 *
687 * @vma:       vma as input from the fbdev mmap method.
688 * @bo:        The bo backing the address space. The address space will
689 * have the same size as the bo, and start at offset 0.
690 *
691 * This function is intended to be called by the fbdev mmap method
692 * if the fbdev address space is to be backed by a bo.
693 */
694
695extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
696			  struct ttm_buffer_object *bo);
697
698/**
699 * ttm_bo_mmap - mmap out of the ttm device address space.
700 *
701 * @filp:      filp as input from the mmap method.
702 * @vma:       vma as input from the mmap method.
703 * @bdev:      Pointer to the ttm_bo_device with the address space manager.
704 *
705 * This function is intended to be called by the device mmap method.
706 * if the device address space is to be backed by the bo manager.
707 */
708
709extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
710		       struct ttm_bo_device *bdev);
711
712/**
713 * ttm_bo_io
714 *
715 * @bdev:      Pointer to the struct ttm_bo_device.
716 * @filp:      Pointer to the struct file attempting to read / write.
717 * @wbuf:      User-space pointer to address of buffer to write. NULL on read.
718 * @rbuf:      User-space pointer to address of buffer to read into.
719 * Null on write.
720 * @count:     Number of bytes to read / write.
721 * @f_pos:     Pointer to current file position.
722 * @write:     1 for read, 0 for write.
723 *
724 * This function implements read / write into ttm buffer objects, and is
725 * intended to
726 * be called from the fops::read and fops::write method.
727 * Returns:
728 * See man (2) write, man(2) read. In particular,
729 * the function may return -ERESTARTSYS if
730 * interrupted by a signal.
731 */
732
733extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
734			 const char __user *wbuf, char __user *rbuf,
735			 size_t count, loff_t *f_pos, bool write);
736
737extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
738
739#endif