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1/**************************************************************************
2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27/*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30
31#ifndef _TTM_BO_API_H_
32#define _TTM_BO_API_H_
33
34#include <drm/drm_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
48struct ttm_placement;
49
50struct ttm_place;
51
52/**
53 * struct ttm_bus_placement
54 *
55 * @addr: mapped virtual address
56 * @base: bus base address
57 * @is_iomem: is this io memory ?
58 * @size: size in byte
59 * @offset: offset from the base address
60 * @io_reserved_vm: The VM system has a refcount in @io_reserved_count
61 * @io_reserved_count: Refcounting the numbers of callers to ttm_mem_io_reserve
62 *
63 * Structure indicating the bus placement of an object.
64 */
65struct ttm_bus_placement {
66 void *addr;
67 phys_addr_t base;
68 unsigned long size;
69 unsigned long offset;
70 bool is_iomem;
71 bool io_reserved_vm;
72 uint64_t io_reserved_count;
73};
74
75
76/**
77 * struct ttm_mem_reg
78 *
79 * @mm_node: Memory manager node.
80 * @size: Requested size of memory region.
81 * @num_pages: Actual size of memory region in pages.
82 * @page_alignment: Page alignment.
83 * @placement: Placement flags.
84 * @bus: Placement on io bus accessible to the CPU
85 *
86 * Structure indicating the placement and space resources used by a
87 * buffer object.
88 */
89
90struct ttm_mem_reg {
91 void *mm_node;
92 unsigned long start;
93 unsigned long size;
94 unsigned long num_pages;
95 uint32_t page_alignment;
96 uint32_t mem_type;
97 uint32_t placement;
98 struct ttm_bus_placement bus;
99};
100
101/**
102 * enum ttm_bo_type
103 *
104 * @ttm_bo_type_device: These are 'normal' buffers that can
105 * be mmapped by user space. Each of these bos occupy a slot in the
106 * device address space, that can be used for normal vm operations.
107 *
108 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers,
109 * but they cannot be accessed from user-space. For kernel-only use.
110 *
111 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another
112 * driver.
113 */
114
115enum ttm_bo_type {
116 ttm_bo_type_device,
117 ttm_bo_type_kernel,
118 ttm_bo_type_sg
119};
120
121struct ttm_tt;
122
123/**
124 * struct ttm_buffer_object
125 *
126 * @bdev: Pointer to the buffer object device structure.
127 * @type: The bo type.
128 * @destroy: Destruction function. If NULL, kfree is used.
129 * @num_pages: Actual number of pages.
130 * @acc_size: Accounted size for this object.
131 * @kref: Reference count of this buffer object. When this refcount reaches
132 * zero, the object is put on the delayed delete list.
133 * @list_kref: List reference count of this buffer object. This member is
134 * used to avoid destruction while the buffer object is still on a list.
135 * Lru lists may keep one refcount, the delayed delete list, and kref != 0
136 * keeps one refcount. When this refcount reaches zero,
137 * the object is destroyed.
138 * @mem: structure describing current placement.
139 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
140 * pinned in physical memory. If this behaviour is not desired, this member
141 * holds a pointer to a persistent shmem object.
142 * @ttm: TTM structure holding system pages.
143 * @evicted: Whether the object was evicted without user-space knowing.
144 * @cpu_writes: For synchronization. Number of cpu writers.
145 * @lru: List head for the lru list.
146 * @ddestroy: List head for the delayed destroy list.
147 * @swap: List head for swap LRU list.
148 * @moving: Fence set when BO is moving
149 * @vma_node: Address space manager node.
150 * @offset: The current GPU offset, which can have different meanings
151 * depending on the memory type. For SYSTEM type memory, it should be 0.
152 * @cur_placement: Hint of current placement.
153 * @wu_mutex: Wait unreserved mutex.
154 *
155 * Base class for TTM buffer object, that deals with data placement and CPU
156 * mappings. GPU mappings are really up to the driver, but for simpler GPUs
157 * the driver can usually use the placement offset @offset directly as the
158 * GPU virtual address. For drivers implementing multiple
159 * GPU memory manager contexts, the driver should manage the address space
160 * in these contexts separately and use these objects to get the correct
161 * placement and caching for these GPU maps. This makes it possible to use
162 * these objects for even quite elaborate memory management schemes.
163 * The destroy member, the API visibility of this object makes it possible
164 * to derive driver specific types.
165 */
166
167struct ttm_buffer_object {
168 /**
169 * Members constant at init.
170 */
171
172 struct ttm_bo_global *glob;
173 struct ttm_bo_device *bdev;
174 enum ttm_bo_type type;
175 void (*destroy) (struct ttm_buffer_object *);
176 unsigned long num_pages;
177 size_t acc_size;
178
179 /**
180 * Members not needing protection.
181 */
182
183 struct kref kref;
184 struct kref list_kref;
185
186 /**
187 * Members protected by the bo::resv::reserved lock.
188 */
189
190 struct ttm_mem_reg mem;
191 struct file *persistent_swap_storage;
192 struct ttm_tt *ttm;
193 bool evicted;
194
195 /**
196 * Members protected by the bo::reserved lock only when written to.
197 */
198
199 atomic_t cpu_writers;
200
201 /**
202 * Members protected by the bdev::lru_lock.
203 */
204
205 struct list_head lru;
206 struct list_head ddestroy;
207 struct list_head swap;
208 struct list_head io_reserve_lru;
209
210 /**
211 * Members protected by a bo reservation.
212 */
213
214 struct dma_fence *moving;
215
216 struct drm_vma_offset_node vma_node;
217
218 /**
219 * Special members that are protected by the reserve lock
220 * and the bo::lock when written to. Can be read with
221 * either of these locks held.
222 */
223
224 uint64_t offset; /* GPU address space is independent of CPU word size */
225 uint32_t cur_placement;
226
227 struct sg_table *sg;
228
229 struct reservation_object *resv;
230 struct reservation_object ttm_resv;
231 struct mutex wu_mutex;
232};
233
234/**
235 * struct ttm_bo_kmap_obj
236 *
237 * @virtual: The current kernel virtual address.
238 * @page: The page when kmap'ing a single page.
239 * @bo_kmap_type: Type of bo_kmap.
240 *
241 * Object describing a kernel mapping. Since a TTM bo may be located
242 * in various memory types with various caching policies, the
243 * mapping can either be an ioremap, a vmap, a kmap or part of a
244 * premapped region.
245 */
246
247#define TTM_BO_MAP_IOMEM_MASK 0x80
248struct ttm_bo_kmap_obj {
249 void *virtual;
250 struct page *page;
251 enum {
252 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK,
253 ttm_bo_map_vmap = 2,
254 ttm_bo_map_kmap = 3,
255 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK,
256 } bo_kmap_type;
257 struct ttm_buffer_object *bo;
258};
259
260/**
261 * ttm_bo_reference - reference a struct ttm_buffer_object
262 *
263 * @bo: The buffer object.
264 *
265 * Returns a refcounted pointer to a buffer object.
266 */
267
268static inline struct ttm_buffer_object *
269ttm_bo_reference(struct ttm_buffer_object *bo)
270{
271 kref_get(&bo->kref);
272 return bo;
273}
274
275/**
276 * ttm_bo_wait - wait for buffer idle.
277 *
278 * @bo: The buffer object.
279 * @interruptible: Use interruptible wait.
280 * @no_wait: Return immediately if buffer is busy.
281 *
282 * This function must be called with the bo::mutex held, and makes
283 * sure any previous rendering to the buffer is completed.
284 * Note: It might be necessary to block validations before the
285 * wait by reserving the buffer.
286 * Returns -EBUSY if no_wait is true and the buffer is busy.
287 * Returns -ERESTARTSYS if interrupted by a signal.
288 */
289extern int ttm_bo_wait(struct ttm_buffer_object *bo,
290 bool interruptible, bool no_wait);
291
292/**
293 * ttm_bo_mem_compat - Check if proposed placement is compatible with a bo
294 *
295 * @placement: Return immediately if buffer is busy.
296 * @mem: The struct ttm_mem_reg indicating the region where the bo resides
297 * @new_flags: Describes compatible placement found
298 *
299 * Returns true if the placement is compatible
300 */
301extern bool ttm_bo_mem_compat(struct ttm_placement *placement,
302 struct ttm_mem_reg *mem,
303 uint32_t *new_flags);
304
305/**
306 * ttm_bo_validate
307 *
308 * @bo: The buffer object.
309 * @placement: Proposed placement for the buffer object.
310 * @interruptible: Sleep interruptible if sleeping.
311 * @no_wait_gpu: Return immediately if the GPU is busy.
312 *
313 * Changes placement and caching policy of the buffer object
314 * according proposed placement.
315 * Returns
316 * -EINVAL on invalid proposed placement.
317 * -ENOMEM on out-of-memory condition.
318 * -EBUSY if no_wait is true and buffer busy.
319 * -ERESTARTSYS if interrupted by a signal.
320 */
321extern int ttm_bo_validate(struct ttm_buffer_object *bo,
322 struct ttm_placement *placement,
323 bool interruptible,
324 bool no_wait_gpu);
325
326/**
327 * ttm_bo_unref
328 *
329 * @bo: The buffer object.
330 *
331 * Unreference and clear a pointer to a buffer object.
332 */
333extern void ttm_bo_unref(struct ttm_buffer_object **bo);
334
335
336/**
337 * ttm_bo_list_ref_sub
338 *
339 * @bo: The buffer object.
340 * @count: The number of references with which to decrease @bo::list_kref;
341 * @never_free: The refcount should not reach zero with this operation.
342 *
343 * Release @count lru list references to this buffer object.
344 */
345extern void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count,
346 bool never_free);
347
348/**
349 * ttm_bo_add_to_lru
350 *
351 * @bo: The buffer object.
352 *
353 * Add this bo to the relevant mem type lru and, if it's backed by
354 * system pages (ttms) to the swap list.
355 * This function must be called with struct ttm_bo_global::lru_lock held, and
356 * is typically called immediately prior to unreserving a bo.
357 */
358extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
359
360/**
361 * ttm_bo_del_from_lru
362 *
363 * @bo: The buffer object.
364 *
365 * Remove this bo from all lru lists used to lookup and reserve an object.
366 * This function must be called with struct ttm_bo_global::lru_lock held,
367 * and is usually called just immediately after the bo has been reserved to
368 * avoid recursive reservation from lru lists.
369 */
370extern int ttm_bo_del_from_lru(struct ttm_buffer_object *bo);
371
372/**
373 * ttm_bo_move_to_lru_tail
374 *
375 * @bo: The buffer object.
376 *
377 * Move this BO to the tail of all lru lists used to lookup and reserve an
378 * object. This function must be called with struct ttm_bo_global::lru_lock
379 * held, and is used to make a BO less likely to be considered for eviction.
380 */
381extern void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo);
382
383/**
384 * ttm_bo_lock_delayed_workqueue
385 *
386 * Prevent the delayed workqueue from running.
387 * Returns
388 * True if the workqueue was queued at the time
389 */
390extern int ttm_bo_lock_delayed_workqueue(struct ttm_bo_device *bdev);
391
392/**
393 * ttm_bo_unlock_delayed_workqueue
394 *
395 * Allows the delayed workqueue to run.
396 */
397extern void ttm_bo_unlock_delayed_workqueue(struct ttm_bo_device *bdev,
398 int resched);
399
400/**
401 * ttm_bo_eviction_valuable
402 *
403 * @bo: The buffer object to evict
404 * @place: the placement we need to make room for
405 *
406 * Check if it is valuable to evict the BO to make room for the given placement.
407 */
408bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
409 const struct ttm_place *place);
410
411/**
412 * ttm_bo_synccpu_write_grab
413 *
414 * @bo: The buffer object:
415 * @no_wait: Return immediately if buffer is busy.
416 *
417 * Synchronizes a buffer object for CPU RW access. This means
418 * command submission that affects the buffer will return -EBUSY
419 * until ttm_bo_synccpu_write_release is called.
420 *
421 * Returns
422 * -EBUSY if the buffer is busy and no_wait is true.
423 * -ERESTARTSYS if interrupted by a signal.
424 */
425extern int
426ttm_bo_synccpu_write_grab(struct ttm_buffer_object *bo, bool no_wait);
427
428/**
429 * ttm_bo_synccpu_write_release:
430 *
431 * @bo : The buffer object.
432 *
433 * Releases a synccpu lock.
434 */
435extern void ttm_bo_synccpu_write_release(struct ttm_buffer_object *bo);
436
437/**
438 * ttm_bo_acc_size
439 *
440 * @bdev: Pointer to a ttm_bo_device struct.
441 * @bo_size: size of the buffer object in byte.
442 * @struct_size: size of the structure holding buffer object datas
443 *
444 * Returns size to account for a buffer object
445 */
446size_t ttm_bo_acc_size(struct ttm_bo_device *bdev,
447 unsigned long bo_size,
448 unsigned struct_size);
449size_t ttm_bo_dma_acc_size(struct ttm_bo_device *bdev,
450 unsigned long bo_size,
451 unsigned struct_size);
452
453/**
454 * ttm_bo_init
455 *
456 * @bdev: Pointer to a ttm_bo_device struct.
457 * @bo: Pointer to a ttm_buffer_object to be initialized.
458 * @size: Requested size of buffer object.
459 * @type: Requested type of buffer object.
460 * @flags: Initial placement flags.
461 * @page_alignment: Data alignment in pages.
462 * @interruptible: If needing to sleep to wait for GPU resources,
463 * sleep interruptible.
464 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
465 * pinned in physical memory. If this behaviour is not desired, this member
466 * holds a pointer to a persistent shmem object. Typically, this would
467 * point to the shmem object backing a GEM object if TTM is used to back a
468 * GEM user interface.
469 * @acc_size: Accounted size for this object.
470 * @resv: Pointer to a reservation_object, or NULL to let ttm allocate one.
471 * @destroy: Destroy function. Use NULL for kfree().
472 *
473 * This function initializes a pre-allocated struct ttm_buffer_object.
474 * As this object may be part of a larger structure, this function,
475 * together with the @destroy function,
476 * enables driver-specific objects derived from a ttm_buffer_object.
477 * On successful return, the object kref and list_kref are set to 1.
478 * If a failure occurs, the function will call the @destroy function, or
479 * kfree() if @destroy is NULL. Thus, after a failure, dereferencing @bo is
480 * illegal and will likely cause memory corruption.
481 *
482 * Returns
483 * -ENOMEM: Out of memory.
484 * -EINVAL: Invalid placement flags.
485 * -ERESTARTSYS: Interrupted by signal while sleeping waiting for resources.
486 */
487
488extern int ttm_bo_init(struct ttm_bo_device *bdev,
489 struct ttm_buffer_object *bo,
490 unsigned long size,
491 enum ttm_bo_type type,
492 struct ttm_placement *placement,
493 uint32_t page_alignment,
494 bool interrubtible,
495 struct file *persistent_swap_storage,
496 size_t acc_size,
497 struct sg_table *sg,
498 struct reservation_object *resv,
499 void (*destroy) (struct ttm_buffer_object *));
500
501/**
502 * ttm_bo_create
503 *
504 * @bdev: Pointer to a ttm_bo_device struct.
505 * @size: Requested size of buffer object.
506 * @type: Requested type of buffer object.
507 * @placement: Initial placement.
508 * @page_alignment: Data alignment in pages.
509 * @interruptible: If needing to sleep while waiting for GPU resources,
510 * sleep interruptible.
511 * @persistent_swap_storage: Usually the swap storage is deleted for buffers
512 * pinned in physical memory. If this behaviour is not desired, this member
513 * holds a pointer to a persistent shmem object. Typically, this would
514 * point to the shmem object backing a GEM object if TTM is used to back a
515 * GEM user interface.
516 * @p_bo: On successful completion *p_bo points to the created object.
517 *
518 * This function allocates a ttm_buffer_object, and then calls ttm_bo_init
519 * on that object. The destroy function is set to kfree().
520 * Returns
521 * -ENOMEM: Out of memory.
522 * -EINVAL: Invalid placement flags.
523 * -ERESTARTSYS: Interrupted by signal while waiting for resources.
524 */
525
526extern int ttm_bo_create(struct ttm_bo_device *bdev,
527 unsigned long size,
528 enum ttm_bo_type type,
529 struct ttm_placement *placement,
530 uint32_t page_alignment,
531 bool interruptible,
532 struct file *persistent_swap_storage,
533 struct ttm_buffer_object **p_bo);
534
535/**
536 * ttm_bo_init_mm
537 *
538 * @bdev: Pointer to a ttm_bo_device struct.
539 * @mem_type: The memory type.
540 * @p_size: size managed area in pages.
541 *
542 * Initialize a manager for a given memory type.
543 * Note: if part of driver firstopen, it must be protected from a
544 * potentially racing lastclose.
545 * Returns:
546 * -EINVAL: invalid size or memory type.
547 * -ENOMEM: Not enough memory.
548 * May also return driver-specified errors.
549 */
550
551extern int ttm_bo_init_mm(struct ttm_bo_device *bdev, unsigned type,
552 unsigned long p_size);
553/**
554 * ttm_bo_clean_mm
555 *
556 * @bdev: Pointer to a ttm_bo_device struct.
557 * @mem_type: The memory type.
558 *
559 * Take down a manager for a given memory type after first walking
560 * the LRU list to evict any buffers left alive.
561 *
562 * Normally, this function is part of lastclose() or unload(), and at that
563 * point there shouldn't be any buffers left created by user-space, since
564 * there should've been removed by the file descriptor release() method.
565 * However, before this function is run, make sure to signal all sync objects,
566 * and verify that the delayed delete queue is empty. The driver must also
567 * make sure that there are no NO_EVICT buffers present in this memory type
568 * when the call is made.
569 *
570 * If this function is part of a VT switch, the caller must make sure that
571 * there are no appications currently validating buffers before this
572 * function is called. The caller can do that by first taking the
573 * struct ttm_bo_device::ttm_lock in write mode.
574 *
575 * Returns:
576 * -EINVAL: invalid or uninitialized memory type.
577 * -EBUSY: There are still buffers left in this memory type.
578 */
579
580extern int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type);
581
582/**
583 * ttm_bo_evict_mm
584 *
585 * @bdev: Pointer to a ttm_bo_device struct.
586 * @mem_type: The memory type.
587 *
588 * Evicts all buffers on the lru list of the memory type.
589 * This is normally part of a VT switch or an
590 * out-of-memory-space-due-to-fragmentation handler.
591 * The caller must make sure that there are no other processes
592 * currently validating buffers, and can do that by taking the
593 * struct ttm_bo_device::ttm_lock in write mode.
594 *
595 * Returns:
596 * -EINVAL: Invalid or uninitialized memory type.
597 * -ERESTARTSYS: The call was interrupted by a signal while waiting to
598 * evict a buffer.
599 */
600
601extern int ttm_bo_evict_mm(struct ttm_bo_device *bdev, unsigned mem_type);
602
603/**
604 * ttm_kmap_obj_virtual
605 *
606 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap.
607 * @is_iomem: Pointer to an integer that on return indicates 1 if the
608 * virtual map is io memory, 0 if normal memory.
609 *
610 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap.
611 * If *is_iomem is 1 on return, the virtual address points to an io memory area,
612 * that should strictly be accessed by the iowriteXX() and similar functions.
613 */
614
615static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map,
616 bool *is_iomem)
617{
618 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK);
619 return map->virtual;
620}
621
622/**
623 * ttm_bo_kmap
624 *
625 * @bo: The buffer object.
626 * @start_page: The first page to map.
627 * @num_pages: Number of pages to map.
628 * @map: pointer to a struct ttm_bo_kmap_obj representing the map.
629 *
630 * Sets up a kernel virtual mapping, using ioremap, vmap or kmap to the
631 * data in the buffer object. The ttm_kmap_obj_virtual function can then be
632 * used to obtain a virtual address to the data.
633 *
634 * Returns
635 * -ENOMEM: Out of memory.
636 * -EINVAL: Invalid range.
637 */
638
639extern int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
640 unsigned long num_pages, struct ttm_bo_kmap_obj *map);
641
642/**
643 * ttm_bo_kunmap
644 *
645 * @map: Object describing the map to unmap.
646 *
647 * Unmaps a kernel map set up by ttm_bo_kmap.
648 */
649
650extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
651
652/**
653 * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
654 *
655 * @vma: vma as input from the fbdev mmap method.
656 * @bo: The bo backing the address space. The address space will
657 * have the same size as the bo, and start at offset 0.
658 *
659 * This function is intended to be called by the fbdev mmap method
660 * if the fbdev address space is to be backed by a bo.
661 */
662
663extern int ttm_fbdev_mmap(struct vm_area_struct *vma,
664 struct ttm_buffer_object *bo);
665
666/**
667 * ttm_bo_mmap - mmap out of the ttm device address space.
668 *
669 * @filp: filp as input from the mmap method.
670 * @vma: vma as input from the mmap method.
671 * @bdev: Pointer to the ttm_bo_device with the address space manager.
672 *
673 * This function is intended to be called by the device mmap method.
674 * if the device address space is to be backed by the bo manager.
675 */
676
677extern int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
678 struct ttm_bo_device *bdev);
679
680/**
681 * ttm_bo_io
682 *
683 * @bdev: Pointer to the struct ttm_bo_device.
684 * @filp: Pointer to the struct file attempting to read / write.
685 * @wbuf: User-space pointer to address of buffer to write. NULL on read.
686 * @rbuf: User-space pointer to address of buffer to read into.
687 * Null on write.
688 * @count: Number of bytes to read / write.
689 * @f_pos: Pointer to current file position.
690 * @write: 1 for read, 0 for write.
691 *
692 * This function implements read / write into ttm buffer objects, and is
693 * intended to
694 * be called from the fops::read and fops::write method.
695 * Returns:
696 * See man (2) write, man(2) read. In particular,
697 * the function may return -ERESTARTSYS if
698 * interrupted by a signal.
699 */
700
701extern ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
702 const char __user *wbuf, char __user *rbuf,
703 size_t count, loff_t *f_pos, bool write);
704
705extern void ttm_bo_swapout_all(struct ttm_bo_device *bdev);
706extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo);
707#endif
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