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
43 struct ttm_bo_device;
44
45 struct drm_mm_node;
46
47
48 /**
49 * struct ttm_placement
50 *
51 * @fpfn: first valid page frame number to put the object
52 * @lpfn: last valid page frame number to put the object
53 * @num_placement: number of preferred placements
54 * @placement: preferred placements
55 * @num_busy_placement: number of preferred placements when need to evict buffer
56 * @busy_placement: preferred placements when need to evict buffer
57 *
58 * Structure indicating the placement you request for an object.
59 */
60 struct ttm_placement {
61 unsigned fpfn;
62 unsigned lpfn;
63 unsigned num_placement;
64 const uint32_t *placement;
65 unsigned num_busy_placement;
66 const uint32_t *busy_placement;
67 };
68
69 /**
70 * struct ttm_bus_placement
71 *
72 * @addr: mapped virtual address
73 * @base: bus base address
74 * @is_iomem: is this io memory ?
75 * @size: size in byte
76 * @offset: offset from the base address
77 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
78 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
79 *
80 * Structure indicating the bus placement of an object.
81 */
82 struct ttm_bus_placement {
83 void *addr;
84 unsigned long base;
85 unsigned long size;
86 unsigned long offset;
87 bool is_iomem;
88 bool io_reserved_vm;
89 uint64_t io_reserved_count;
90 };
91
92
93 /**
94 * struct ttm_mem_reg
95 *
96 * @mm_node: Memory manager node.
97 * @size: Requested size of memory region.
98 * @num_pages: Actual size of memory region in pages.
99 * @page_alignment: Page alignment.
100 * @placement: Placement flags.
101 * @bus: Placement on io bus accessible to the CPU
102 *
103 * Structure indicating the placement and space resources used by a
104 * buffer object.
105 */
106
107 struct ttm_mem_reg {
108 void *mm_node;
109 unsigned long start;
110 unsigned long size;
111 unsigned long num_pages;
112 uint32_t page_alignment;
113 uint32_t mem_type;
114 uint32_t placement;
115 struct ttm_bus_placement bus;
116 };
117
118 /**
119 * enum ttm_bo_type
120 *
121 * @ttm_bo_type_device: These are 'normal' buffers that can
122 * be mmapped by user space. Each of these bos occupy a slot in the
123 * device address space, that can be used for normal vm operations.
124 *
125 * @ttm_bo_type_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
129 enum ttm_bo_type {
130 ttm_bo_type_device,
131 ttm_bo_type_kernel
132 };
133
134 struct ttm_tt;
135
136 /**
137 * struct ttm_buffer_object
138 *
139 * @bdev: Pointer to the buffer object device structure.
140 * @buffer_start: The virtual user-space start address of ttm_bo_type_user
141 * buffers.
142 * @type: The bo type.
143 * @destroy: Destruction function. If NULL, kfree is used.
144 * @num_pages: Actual number of pages.
145 * @addr_space_offset: Address space offset.
146 * @acc_size: Accounted size for this object.
147 * @kref: Reference count of this buffer object. When this refcount reaches
148 * zero, the object is put on the delayed delete list.
149 * @list_kref: List reference count of this buffer object. This member is
150 * used to avoid destruction while the buffer object is still on a list.
151 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
152 * keeps one refcount. When this refcount reaches zero,
153 * the object is destroyed.
154 * @event_queue: Queue for processes waiting on buffer object status change.
155 * @mem: structure describing current placement.
156 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
157 * pinned in physical memory. If this behaviour is not desired, this member
158 * holds a pointer to a persistent shmem object.
159 * @ttm: TTM structure holding system pages.
160 * @evicted: Whether the object was evicted without user-space knowing.
161 * @cpu_writes: For synchronization. Number of cpu writers.
162 * @lru: List head for the lru list.
163 * @ddestroy: List head for the delayed destroy list.
164 * @swap: List head for swap LRU list.
165 * @val_seq: Sequence of the validation holding the @reserved lock.
166 * Used to avoid starvation when many processes compete to validate the
167 * buffer. This member is protected by the bo_device::lru_lock.
168 * @seq_valid: The value of @val_seq is valid. This value is protected by
169 * the bo_device::lru_lock.
170 * @reserved: Deadlock-free lock used for synchronization state transitions.
171 * @sync_obj_arg: Opaque argument to synchronization object function.
172 * @sync_obj: Pointer to a synchronization object.
173 * @priv_flags: Flags describing buffer object internal state.
174 * @vm_rb: Rb node for the vm rb tree.
175 * @vm_node: Address space manager node.
176 * @offset: The current GPU offset, which can have different meanings
177 * depending on the memory type. For SYSTEM type memory, it should be 0.
178 * @cur_placement: Hint of current placement.
179 *
180 * Base class for TTM buffer object, that deals with data placement and CPU
181 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
182 * the driver can usually use the placement offset @offset directly as the
183 * GPU virtual address. For drivers implementing multiple
184 * GPU memory manager contexts, the driver should manage the address space
185 * in these contexts separately and use these objects to get the correct
186 * placement and caching for these GPU maps. This makes it possible to use
187 * these objects for even quite elaborate memory management schemes.
188 * The destroy member, the API visibility of this object makes it possible
189 * to derive driver specific types.
190 */
191
192 struct ttm_buffer_object {
193 /**
194 * Members constant at init.
195 */
196
197 struct ttm_bo_global *glob;
198 struct ttm_bo_device *bdev;
199 unsigned long buffer_start;
200 enum ttm_bo_type type;
201 void (*destroy) (struct ttm_buffer_object *);
202 unsigned long num_pages;
203 uint64_t addr_space_offset;
204 size_t acc_size;
205
206 /**
207 * Members not needing protection.
208 */
209
210 struct kref kref;
211 struct kref list_kref;
212 wait_queue_head_t event_queue;
213
214 /**
215 * Members protected by the bo::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 uint32_t val_seq;
238 bool seq_valid;
239
240 /**
241 * Members protected by the bdev::lru_lock
242 * only when written to.
243 */
244
245 atomic_t reserved;
246
247 /**
248 * Members protected by struct buffer_object_device::fence_lock
249 * In addition, setting sync_obj to anything else
250 * than NULL requires bo::reserved to be held. This allows for
251 * checking NULL while reserved but not holding the mentioned lock.
252 */
253
254 void *sync_obj_arg;
255 void *sync_obj;
256 unsigned long priv_flags;
257
258 /**
259 * Members protected by the bdev::vm_lock
260 */
261
262 struct rb_node vm_rb;
263 struct drm_mm_node *vm_node;
264
265
266 /**
267 * Special members that are protected by the reserve lock
268 * and the bo::lock when written to. Can be read with
269 * either of these locks held.
270 */
271
272 unsigned long offset;
273 uint32_t cur_placement;
274 };
275
276 /**
277 * struct ttm_bo_kmap_obj
278 *
279 * @virtual: The current kernel virtual address.
280 * @page: The page when kmap'ing a single page.
281 * @bo_kmap_type: Type of bo_kmap.
282 *
283 * Object describing a kernel mapping. Since a TTM bo may be located
284 * in various memory types with various caching policies, the
285 * mapping can either be an ioremap, a vmap, a kmap or part of a
286 * premapped region.
287 */
288
289 #define TTM_BO_MAP_IOMEM_MASK 0x80
290 struct ttm_bo_kmap_obj {
291 void *virtual;
292 struct page *page;
293 enum {
294 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
295 ttm_bo_map_vmap = 2,
296 ttm_bo_map_kmap = 3,
297 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
298 } bo_kmap_type;
299 struct ttm_buffer_object *bo;
300 };
301
302 /**
303 * ttm_bo_reference - reference a struct ttm_buffer_object
304 *
305 * @bo: The buffer object.
306 *
307 * Returns a refcounted pointer to a buffer object.
308 */
309
310 static inline struct ttm_buffer_object *
ttm_bo_reference(struct ttm_buffer_object * bo)311 ttm_bo_reference(struct ttm_buffer_object *bo)
312 {
313 kref_get(&bo->kref);
314 return bo;
315 }
316
317 /**
318 * ttm_bo_wait - wait for buffer idle.
319 *
320 * @bo: The buffer object.
321 * @interruptible: Use interruptible wait.
322 * @no_wait: Return immediately if buffer is busy.
323 *
324 * This function must be called with the bo::mutex held, and makes
325 * sure any previous rendering to the buffer is completed.
326 * Note: It might be necessary to block validations before the
327 * wait by reserving the buffer.
328 * Returns -EBUSY if no_wait is true and the buffer is busy.
329 * Returns -ERESTARTSYS if interrupted by a signal.
330 */
331 extern int ttm_bo_wait(struct ttm_buffer_object *bo, bool lazy,
332 bool interruptible, bool no_wait);
333 /**
334 * ttm_bo_validate
335 *
336 * @bo: The buffer object.
337 * @placement: Proposed placement for the buffer object.
338 * @interruptible: Sleep interruptible if sleeping.
339 * @no_wait_reserve: Return immediately if other buffers are busy.
340 * @no_wait_gpu: Return immediately if the GPU is busy.
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 */
350 extern int ttm_bo_validate(struct ttm_buffer_object *bo,
351 struct ttm_placement *placement,
352 bool interruptible, bool no_wait_reserve,
353 bool no_wait_gpu);
354
355 /**
356 * ttm_bo_unref
357 *
358 * @bo: The buffer object.
359 *
360 * Unreference and clear a pointer to a buffer object.
361 */
362 extern void ttm_bo_unref(struct ttm_buffer_object **bo);
363
364
365 /**
366 * ttm_bo_list_ref_sub
367 *
368 * @bo: The buffer object.
369 * @count: The number of references with which to decrease @bo::list_kref;
370 * @never_free: The refcount should not reach zero with this operation.
371 *
372 * Release @count lru list references to this buffer object.
373 */
374 extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
375 bool never_free);
376
377 /**
378 * ttm_bo_add_to_lru
379 *
380 * @bo: The buffer object.
381 *
382 * Add this bo to the relevant mem type lru and, if it's backed by
383 * system pages (ttms) to the swap list.
384 * This function must be called with struct ttm_bo_global::lru_lock held, and
385 * is typically called immediately prior to unreserving a bo.
386 */
387 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
388
389 /**
390 * ttm_bo_del_from_lru
391 *
392 * @bo: The buffer object.
393 *
394 * Remove this bo from all lru lists used to lookup and reserve an object.
395 * This function must be called with struct ttm_bo_global::lru_lock held,
396 * and is usually called just immediately after the bo has been reserved to
397 * avoid recursive reservation from lru lists.
398 */
399 extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
400
401
402 /**
403 * ttm_bo_lock_delayed_workqueue
404 *
405 * Prevent the delayed workqueue from running.
406 * Returns
407 * True if the workqueue was queued at the time
408 */
409 extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
410
411 /**
412 * ttm_bo_unlock_delayed_workqueue
413 *
414 * Allows the delayed workqueue to run.
415 */
416 extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
417 int resched);
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 * blocking command submission that affects the buffer and
427 * waiting for buffer idle. This lock is recursive.
428 * Returns
429 * -EBUSY if the buffer is busy and no_wait is true.
430 * -ERESTARTSYS if interrupted by a signal.
431 */
432 extern int
433 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 */
442 extern void 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 */
453 size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
454 unsigned long bo_size,
455 unsigned struct_size);
456 size_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
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 * @buffer_start: Virtual address of user space data backing a
470 * user buffer object.
471 * @interruptible: If needing to sleep to wait for GPU resources,
472 * sleep interruptible.
473 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
474 * pinned in physical memory. If this behaviour is not desired, this member
475 * holds a pointer to a persistent shmem object. Typically, this would
476 * point to the shmem object backing a GEM object if TTM is used to back a
477 * GEM user interface.
478 * @acc_size: Accounted size for this object.
479 * @destroy: Destroy function. Use NULL for kfree().
480 *
481 * This function initializes a pre-allocated struct ttm_buffer_object.
482 * As this object may be part of a larger structure, this function,
483 * together with the @destroy function,
484 * enables driver-specific objects derived from a ttm_buffer_object.
485 * On successful return, the object kref and list_kref are set to 1.
486 * If a failure occurs, the function will call the @destroy function, or
487 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
488 * illegal and will likely cause memory corruption.
489 *
490 * Returns
491 * -ENOMEM: Out of memory.
492 * -EINVAL: Invalid placement flags.
493 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
494 */
495
496 extern int ttm_bo_init(struct ttm_bo_device *bdev,
497 struct ttm_buffer_object *bo,
498 unsigned long size,
499 enum ttm_bo_type type,
500 struct ttm_placement *placement,
501 uint32_t page_alignment,
502 unsigned long buffer_start,
503 bool interrubtible,
504 struct file *persistent_swap_storage,
505 size_t acc_size,
506 void (*destroy) (struct ttm_buffer_object *));
507
508 /**
509 * ttm_bo_synccpu_object_init
510 *
511 * @bdev: Pointer to a ttm_bo_device struct.
512 * @bo: Pointer to a ttm_buffer_object to be initialized.
513 * @size: Requested size of buffer object.
514 * @type: Requested type of buffer object.
515 * @flags: Initial placement flags.
516 * @page_alignment: Data alignment in pages.
517 * @buffer_start: Virtual address of user space data backing a
518 * user buffer object.
519 * @interruptible: If needing to sleep while waiting for GPU resources,
520 * sleep interruptible.
521 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
522 * pinned in physical memory. If this behaviour is not desired, this member
523 * holds a pointer to a persistent shmem object. Typically, this would
524 * point to the shmem object backing a GEM object if TTM is used to back a
525 * GEM user interface.
526 * @p_bo: On successful completion *p_bo points to the created object.
527 *
528 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
529 * on that object. The destroy function is set to kfree().
530 * Returns
531 * -ENOMEM: Out of memory.
532 * -EINVAL: Invalid placement flags.
533 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
534 */
535
536 extern int ttm_bo_create(struct ttm_bo_device *bdev,
537 unsigned long size,
538 enum ttm_bo_type type,
539 struct ttm_placement *placement,
540 uint32_t page_alignment,
541 unsigned long buffer_start,
542 bool interruptible,
543 struct file *persistent_swap_storage,
544 struct ttm_buffer_object **p_bo);
545
546 /**
547 * ttm_bo_check_placement
548 *
549 * @bo: the buffer object.
550 * @placement: placements
551 *
552 * Performs minimal validity checking on an intended change of
553 * placement flags.
554 * Returns
555 * -EINVAL: Intended change is invalid or not allowed.
556 */
557 extern int ttm_bo_check_placement(struct ttm_buffer_object *bo,
558 struct ttm_placement *placement);
559
560 /**
561 * ttm_bo_init_mm
562 *
563 * @bdev: Pointer to a ttm_bo_device struct.
564 * @mem_type: The memory type.
565 * @p_size: size managed area in pages.
566 *
567 * Initialize a manager for a given memory type.
568 * Note: if part of driver firstopen, it must be protected from a
569 * potentially racing lastclose.
570 * Returns:
571 * -EINVAL: invalid size or memory type.
572 * -ENOMEM: Not enough memory.
573 * May also return driver-specified errors.
574 */
575
576 extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
577 unsigned long p_size);
578 /**
579 * ttm_bo_clean_mm
580 *
581 * @bdev: Pointer to a ttm_bo_device struct.
582 * @mem_type: The memory type.
583 *
584 * Take down a manager for a given memory type after first walking
585 * the LRU list to evict any buffers left alive.
586 *
587 * Normally, this function is part of lastclose() or unload(), and at that
588 * point there shouldn't be any buffers left created by user-space, since
589 * there should've been removed by the file descriptor release() method.
590 * However, before this function is run, make sure to signal all sync objects,
591 * and verify that the delayed delete queue is empty. The driver must also
592 * make sure that there are no NO_EVICT buffers present in this memory type
593 * when the call is made.
594 *
595 * If this function is part of a VT switch, the caller must make sure that
596 * there are no appications currently validating buffers before this
597 * function is called. The caller can do that by first taking the
598 * struct ttm_bo_device::ttm_lock in write mode.
599 *
600 * Returns:
601 * -EINVAL: invalid or uninitialized memory type.
602 * -EBUSY: There are still buffers left in this memory type.
603 */
604
605 extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
606
607 /**
608 * ttm_bo_evict_mm
609 *
610 * @bdev: Pointer to a ttm_bo_device struct.
611 * @mem_type: The memory type.
612 *
613 * Evicts all buffers on the lru list of the memory type.
614 * This is normally part of a VT switch or an
615 * out-of-memory-space-due-to-fragmentation handler.
616 * The caller must make sure that there are no other processes
617 * currently validating buffers, and can do that by taking the
618 * struct ttm_bo_device::ttm_lock in write mode.
619 *
620 * Returns:
621 * -EINVAL: Invalid or uninitialized memory type.
622 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
623 * evict a buffer.
624 */
625
626 extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
627
628 /**
629 * ttm_kmap_obj_virtual
630 *
631 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
632 * @is_iomem: Pointer to an integer that on return indicates 1 if the
633 * virtual map is io memory, 0 if normal memory.
634 *
635 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
636 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
637 * that should strictly be accessed by the iowriteXX() and similar functions.
638 */
639
ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj * map,bool * is_iomem)640 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
641 bool *is_iomem)
642 {
643 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
644 return map->virtual;
645 }
646
647 /**
648 * ttm_bo_kmap
649 *
650 * @bo: The buffer object.
651 * @start_page: The first page to map.
652 * @num_pages: Number of pages to map.
653 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
654 *
655 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
656 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
657 * used to obtain a virtual address to the data.
658 *
659 * Returns
660 * -ENOMEM: Out of memory.
661 * -EINVAL: Invalid range.
662 */
663
664 extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
665 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
666
667 /**
668 * ttm_bo_kunmap
669 *
670 * @map: Object describing the map to unmap.
671 *
672 * Unmaps a kernel map set up by ttm_bo_kmap.
673 */
674
675 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
676
677 /**
678 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
679 *
680 * @vma: vma as input from the fbdev mmap method.
681 * @bo: The bo backing the address space. The address space will
682 * have the same size as the bo, and start at offset 0.
683 *
684 * This function is intended to be called by the fbdev mmap method
685 * if the fbdev address space is to be backed by a bo.
686 */
687
688 extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
689 struct ttm_buffer_object *bo);
690
691 /**
692 * ttm_bo_mmap - mmap out of the ttm device address space.
693 *
694 * @filp: filp as input from the mmap method.
695 * @vma: vma as input from the mmap method.
696 * @bdev: Pointer to the ttm_bo_device with the address space manager.
697 *
698 * This function is intended to be called by the device mmap method.
699 * if the device address space is to be backed by the bo manager.
700 */
701
702 extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
703 struct ttm_bo_device *bdev);
704
705 /**
706 * ttm_bo_io
707 *
708 * @bdev: Pointer to the struct ttm_bo_device.
709 * @filp: Pointer to the struct file attempting to read / write.
710 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
711 * @rbuf: User-space pointer to address of buffer to read into.
712 * Null on write.
713 * @count: Number of bytes to read / write.
714 * @f_pos: Pointer to current file position.
715 * @write: 1 for read, 0 for write.
716 *
717 * This function implements read / write into ttm buffer objects, and is
718 * intended to
719 * be called from the fops::read and fops::write method.
720 * Returns:
721 * See man (2) write, man(2) read. In particular,
722 * the function may return -ERESTARTSYS if
723 * interrupted by a signal.
724 */
725
726 extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
727 const char __user *wbuf, char __user *rbuf,
728 size_t count, loff_t *f_pos, bool write);
729
730 extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
731
732 #endif
733