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 #ifndef _TTM_BO_DRIVER_H_
31 #define _TTM_BO_DRIVER_H_
32
33 #include <drm/drm_mm.h>
34 #include <drm/drm_global.h>
35 #include <drm/drm_vma_manager.h>
36 #include <linux/workqueue.h>
37 #include <linux/fs.h>
38 #include <linux/spinlock.h>
39 #include <linux/reservation.h>
40
41 #include "ttm_bo_api.h"
42 #include "ttm_memory.h"
43 #include "ttm_module.h"
44 #include "ttm_placement.h"
45 #include "ttm_tt.h"
46
47 #define TTM_MAX_BO_PRIORITY 4U
48
49 #define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */
50 #define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */
51 #define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */
52
53 struct ttm_mem_type_manager;
54
55 struct ttm_mem_type_manager_func {
56 /**
57 * struct ttm_mem_type_manager member init
58 *
59 * @man: Pointer to a memory type manager.
60 * @p_size: Implementation dependent, but typically the size of the
61 * range to be managed in pages.
62 *
63 * Called to initialize a private range manager. The function is
64 * expected to initialize the man::priv member.
65 * Returns 0 on success, negative error code on failure.
66 */
67 int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size);
68
69 /**
70 * struct ttm_mem_type_manager member takedown
71 *
72 * @man: Pointer to a memory type manager.
73 *
74 * Called to undo the setup done in init. All allocated resources
75 * should be freed.
76 */
77 int (*takedown)(struct ttm_mem_type_manager *man);
78
79 /**
80 * struct ttm_mem_type_manager member get_node
81 *
82 * @man: Pointer to a memory type manager.
83 * @bo: Pointer to the buffer object we're allocating space for.
84 * @placement: Placement details.
85 * @flags: Additional placement flags.
86 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
87 *
88 * This function should allocate space in the memory type managed
89 * by @man. Placement details if
90 * applicable are given by @placement. If successful,
91 * @mem::mm_node should be set to a non-null value, and
92 * @mem::start should be set to a value identifying the beginning
93 * of the range allocated, and the function should return zero.
94 * If the memory region accommodate the buffer object, @mem::mm_node
95 * should be set to NULL, and the function should return 0.
96 * If a system error occurred, preventing the request to be fulfilled,
97 * the function should return a negative error code.
98 *
99 * Note that @mem::mm_node will only be dereferenced by
100 * struct ttm_mem_type_manager functions and optionally by the driver,
101 * which has knowledge of the underlying type.
102 *
103 * This function may not be called from within atomic context, so
104 * an implementation can and must use either a mutex or a spinlock to
105 * protect any data structures managing the space.
106 */
107 int (*get_node)(struct ttm_mem_type_manager *man,
108 struct ttm_buffer_object *bo,
109 const struct ttm_place *place,
110 struct ttm_mem_reg *mem);
111
112 /**
113 * struct ttm_mem_type_manager member put_node
114 *
115 * @man: Pointer to a memory type manager.
116 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
117 *
118 * This function frees memory type resources previously allocated
119 * and that are identified by @mem::mm_node and @mem::start. May not
120 * be called from within atomic context.
121 */
122 void (*put_node)(struct ttm_mem_type_manager *man,
123 struct ttm_mem_reg *mem);
124
125 /**
126 * struct ttm_mem_type_manager member debug
127 *
128 * @man: Pointer to a memory type manager.
129 * @printer: Prefix to be used in printout to identify the caller.
130 *
131 * This function is called to print out the state of the memory
132 * type manager to aid debugging of out-of-memory conditions.
133 * It may not be called from within atomic context.
134 */
135 void (*debug)(struct ttm_mem_type_manager *man,
136 struct drm_printer *printer);
137 };
138
139 /**
140 * struct ttm_mem_type_manager
141 *
142 * @has_type: The memory type has been initialized.
143 * @use_type: The memory type is enabled.
144 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
145 * managed by this memory type.
146 * @gpu_offset: If used, the GPU offset of the first managed page of
147 * fixed memory or the first managed location in an aperture.
148 * @size: Size of the managed region.
149 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
150 * as defined in ttm_placement_common.h
151 * @default_caching: The default caching policy used for a buffer object
152 * placed in this memory type if the user doesn't provide one.
153 * @func: structure pointer implementing the range manager. See above
154 * @priv: Driver private closure for @func.
155 * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures
156 * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions
157 * reserved by the TTM vm system.
158 * @io_reserve_lru: Optional lru list for unreserving io mem regions.
159 * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain
160 * @move_lock: lock for move fence
161 * static information. bdev::driver::io_mem_free is never used.
162 * @lru: The lru list for this memory type.
163 * @move: The fence of the last pipelined move operation.
164 *
165 * This structure is used to identify and manage memory types for a device.
166 * It's set up by the ttm_bo_driver::init_mem_type method.
167 */
168
169
170
171 struct ttm_mem_type_manager {
172 struct ttm_bo_device *bdev;
173
174 /*
175 * No protection. Constant from start.
176 */
177
178 bool has_type;
179 bool use_type;
180 uint32_t flags;
181 uint64_t gpu_offset; /* GPU address space is independent of CPU word size */
182 uint64_t size;
183 uint32_t available_caching;
184 uint32_t default_caching;
185 const struct ttm_mem_type_manager_func *func;
186 void *priv;
187 struct mutex io_reserve_mutex;
188 bool use_io_reserve_lru;
189 bool io_reserve_fastpath;
190 spinlock_t move_lock;
191
192 /*
193 * Protected by @io_reserve_mutex:
194 */
195
196 struct list_head io_reserve_lru;
197
198 /*
199 * Protected by the global->lru_lock.
200 */
201
202 struct list_head lru[TTM_MAX_BO_PRIORITY];
203
204 /*
205 * Protected by @move_lock.
206 */
207 struct dma_fence *move;
208 };
209
210 /**
211 * struct ttm_bo_driver
212 *
213 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
214 * @invalidate_caches: Callback to invalidate read caches when a buffer object
215 * has been evicted.
216 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
217 * structure.
218 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
219 * @move: Callback for a driver to hook in accelerated functions to
220 * move a buffer.
221 * If set to NULL, a potentially slow memcpy() move is used.
222 */
223
224 struct ttm_bo_driver {
225 /**
226 * ttm_tt_create
227 *
228 * @bo: The buffer object to create the ttm for.
229 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
230 *
231 * Create a struct ttm_tt to back data with system memory pages.
232 * No pages are actually allocated.
233 * Returns:
234 * NULL: Out of memory.
235 */
236 struct ttm_tt *(*ttm_tt_create)(struct ttm_buffer_object *bo,
237 uint32_t page_flags);
238
239 /**
240 * ttm_tt_populate
241 *
242 * @ttm: The struct ttm_tt to contain the backing pages.
243 *
244 * Allocate all backing pages
245 * Returns:
246 * -ENOMEM: Out of memory.
247 */
248 int (*ttm_tt_populate)(struct ttm_tt *ttm,
249 struct ttm_operation_ctx *ctx);
250
251 /**
252 * ttm_tt_unpopulate
253 *
254 * @ttm: The struct ttm_tt to contain the backing pages.
255 *
256 * Free all backing page
257 */
258 void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);
259
260 /**
261 * struct ttm_bo_driver member invalidate_caches
262 *
263 * @bdev: the buffer object device.
264 * @flags: new placement of the rebound buffer object.
265 *
266 * A previosly evicted buffer has been rebound in a
267 * potentially new location. Tell the driver that it might
268 * consider invalidating read (texture) caches on the next command
269 * submission as a consequence.
270 */
271
272 int (*invalidate_caches)(struct ttm_bo_device *bdev, uint32_t flags);
273 int (*init_mem_type)(struct ttm_bo_device *bdev, uint32_t type,
274 struct ttm_mem_type_manager *man);
275
276 /**
277 * struct ttm_bo_driver member eviction_valuable
278 *
279 * @bo: the buffer object to be evicted
280 * @place: placement we need room for
281 *
282 * Check with the driver if it is valuable to evict a BO to make room
283 * for a certain placement.
284 */
285 bool (*eviction_valuable)(struct ttm_buffer_object *bo,
286 const struct ttm_place *place);
287 /**
288 * struct ttm_bo_driver member evict_flags:
289 *
290 * @bo: the buffer object to be evicted
291 *
292 * Return the bo flags for a buffer which is not mapped to the hardware.
293 * These will be placed in proposed_flags so that when the move is
294 * finished, they'll end up in bo->mem.flags
295 */
296
297 void (*evict_flags)(struct ttm_buffer_object *bo,
298 struct ttm_placement *placement);
299
300 /**
301 * struct ttm_bo_driver member move:
302 *
303 * @bo: the buffer to move
304 * @evict: whether this motion is evicting the buffer from
305 * the graphics address space
306 * @ctx: context for this move with parameters
307 * @new_mem: the new memory region receiving the buffer
308 *
309 * Move a buffer between two memory regions.
310 */
311 int (*move)(struct ttm_buffer_object *bo, bool evict,
312 struct ttm_operation_ctx *ctx,
313 struct ttm_mem_reg *new_mem);
314
315 /**
316 * struct ttm_bo_driver_member verify_access
317 *
318 * @bo: Pointer to a buffer object.
319 * @filp: Pointer to a struct file trying to access the object.
320 *
321 * Called from the map / write / read methods to verify that the
322 * caller is permitted to access the buffer object.
323 * This member may be set to NULL, which will refuse this kind of
324 * access for all buffer objects.
325 * This function should return 0 if access is granted, -EPERM otherwise.
326 */
327 int (*verify_access)(struct ttm_buffer_object *bo,
328 struct file *filp);
329
330 /**
331 * Hook to notify driver about a driver move so it
332 * can do tiling things and book-keeping.
333 *
334 * @evict: whether this move is evicting the buffer from the graphics
335 * address space
336 */
337 void (*move_notify)(struct ttm_buffer_object *bo,
338 bool evict,
339 struct ttm_mem_reg *new_mem);
340 /* notify the driver we are taking a fault on this BO
341 * and have reserved it */
342 int (*fault_reserve_notify)(struct ttm_buffer_object *bo);
343
344 /**
345 * notify the driver that we're about to swap out this bo
346 */
347 void (*swap_notify)(struct ttm_buffer_object *bo);
348
349 /**
350 * Driver callback on when mapping io memory (for bo_move_memcpy
351 * for instance). TTM will take care to call io_mem_free whenever
352 * the mapping is not use anymore. io_mem_reserve & io_mem_free
353 * are balanced.
354 */
355 int (*io_mem_reserve)(struct ttm_bo_device *bdev,
356 struct ttm_mem_reg *mem);
357 void (*io_mem_free)(struct ttm_bo_device *bdev,
358 struct ttm_mem_reg *mem);
359
360 /**
361 * Return the pfn for a given page_offset inside the BO.
362 *
363 * @bo: the BO to look up the pfn for
364 * @page_offset: the offset to look up
365 */
366 unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo,
367 unsigned long page_offset);
368
369 /**
370 * Read/write memory buffers for ptrace access
371 *
372 * @bo: the BO to access
373 * @offset: the offset from the start of the BO
374 * @buf: pointer to source/destination buffer
375 * @len: number of bytes to copy
376 * @write: whether to read (0) from or write (non-0) to BO
377 *
378 * If successful, this function should return the number of
379 * bytes copied, -EIO otherwise. If the number of bytes
380 * returned is < len, the function may be called again with
381 * the remainder of the buffer to copy.
382 */
383 int (*access_memory)(struct ttm_buffer_object *bo, unsigned long offset,
384 void *buf, int len, int write);
385 };
386
387 /**
388 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
389 */
390
391 struct ttm_bo_global_ref {
392 struct drm_global_reference ref;
393 struct ttm_mem_global *mem_glob;
394 };
395
396 /**
397 * struct ttm_bo_global - Buffer object driver global data.
398 *
399 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
400 * @dummy_read_page: Pointer to a dummy page used for mapping requests
401 * of unpopulated pages.
402 * @shrink: A shrink callback object used for buffer object swap.
403 * @device_list_mutex: Mutex protecting the device list.
404 * This mutex is held while traversing the device list for pm options.
405 * @lru_lock: Spinlock protecting the bo subsystem lru lists.
406 * @device_list: List of buffer object devices.
407 * @swap_lru: Lru list of buffer objects used for swapping.
408 */
409
410 struct ttm_bo_global {
411
412 /**
413 * Constant after init.
414 */
415
416 struct kobject kobj;
417 struct ttm_mem_global *mem_glob;
418 struct page *dummy_read_page;
419 struct mutex device_list_mutex;
420 spinlock_t lru_lock;
421
422 /**
423 * Protected by device_list_mutex.
424 */
425 struct list_head device_list;
426
427 /**
428 * Protected by the lru_lock.
429 */
430 struct list_head swap_lru[TTM_MAX_BO_PRIORITY];
431
432 /**
433 * Internal protection.
434 */
435 atomic_t bo_count;
436 };
437
438
439 #define TTM_NUM_MEM_TYPES 8
440
441 /**
442 * struct ttm_bo_device - Buffer object driver device-specific data.
443 *
444 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
445 * @man: An array of mem_type_managers.
446 * @vma_manager: Address space manager
447 * lru_lock: Spinlock that protects the buffer+device lru lists and
448 * ddestroy lists.
449 * @dev_mapping: A pointer to the struct address_space representing the
450 * device address space.
451 * @wq: Work queue structure for the delayed delete workqueue.
452 * @no_retry: Don't retry allocation if it fails
453 *
454 */
455
456 struct ttm_bo_device {
457
458 /*
459 * Constant after bo device init / atomic.
460 */
461 struct list_head device_list;
462 struct ttm_bo_global *glob;
463 struct ttm_bo_driver *driver;
464 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
465
466 /*
467 * Protected by internal locks.
468 */
469 struct drm_vma_offset_manager vma_manager;
470
471 /*
472 * Protected by the global:lru lock.
473 */
474 struct list_head ddestroy;
475
476 /*
477 * Protected by load / firstopen / lastclose /unload sync.
478 */
479
480 struct address_space *dev_mapping;
481
482 /*
483 * Internal protection.
484 */
485
486 struct delayed_work wq;
487
488 bool need_dma32;
489
490 bool no_retry;
491 };
492
493 /**
494 * ttm_flag_masked
495 *
496 * @old: Pointer to the result and original value.
497 * @new: New value of bits.
498 * @mask: Mask of bits to change.
499 *
500 * Convenience function to change a number of bits identified by a mask.
501 */
502
503 static inline uint32_t
ttm_flag_masked(uint32_t * old,uint32_t new,uint32_t mask)504 ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
505 {
506 *old ^= (*old ^ new) & mask;
507 return *old;
508 }
509
510 /*
511 * ttm_bo.c
512 */
513
514 /**
515 * ttm_mem_reg_is_pci
516 *
517 * @bdev: Pointer to a struct ttm_bo_device.
518 * @mem: A valid struct ttm_mem_reg.
519 *
520 * Returns true if the memory described by @mem is PCI memory,
521 * false otherwise.
522 */
523 bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
524
525 /**
526 * ttm_bo_mem_space
527 *
528 * @bo: Pointer to a struct ttm_buffer_object. the data of which
529 * we want to allocate space for.
530 * @proposed_placement: Proposed new placement for the buffer object.
531 * @mem: A struct ttm_mem_reg.
532 * @interruptible: Sleep interruptible when sliping.
533 * @no_wait_gpu: Return immediately if the GPU is busy.
534 *
535 * Allocate memory space for the buffer object pointed to by @bo, using
536 * the placement flags in @mem, potentially evicting other idle buffer objects.
537 * This function may sleep while waiting for space to become available.
538 * Returns:
539 * -EBUSY: No space available (only if no_wait == 1).
540 * -ENOMEM: Could not allocate memory for the buffer object, either due to
541 * fragmentation or concurrent allocators.
542 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
543 */
544 int ttm_bo_mem_space(struct ttm_buffer_object *bo,
545 struct ttm_placement *placement,
546 struct ttm_mem_reg *mem,
547 struct ttm_operation_ctx *ctx);
548
549 void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem);
550 void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo,
551 struct ttm_mem_reg *mem);
552
553 void ttm_bo_global_release(struct drm_global_reference *ref);
554 int ttm_bo_global_init(struct drm_global_reference *ref);
555
556 int ttm_bo_device_release(struct ttm_bo_device *bdev);
557
558 /**
559 * ttm_bo_device_init
560 *
561 * @bdev: A pointer to a struct ttm_bo_device to initialize.
562 * @glob: A pointer to an initialized struct ttm_bo_global.
563 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
564 * @mapping: The address space to use for this bo.
565 * @file_page_offset: Offset into the device address space that is available
566 * for buffer data. This ensures compatibility with other users of the
567 * address space.
568 *
569 * Initializes a struct ttm_bo_device:
570 * Returns:
571 * !0: Failure.
572 */
573 int ttm_bo_device_init(struct ttm_bo_device *bdev, struct ttm_bo_global *glob,
574 struct ttm_bo_driver *driver,
575 struct address_space *mapping,
576 uint64_t file_page_offset, bool need_dma32);
577
578 /**
579 * ttm_bo_unmap_virtual
580 *
581 * @bo: tear down the virtual mappings for this BO
582 */
583 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
584
585 /**
586 * ttm_bo_unmap_virtual
587 *
588 * @bo: tear down the virtual mappings for this BO
589 *
590 * The caller must take ttm_mem_io_lock before calling this function.
591 */
592 void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);
593
594 int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
595 void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
596 int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible);
597 void ttm_mem_io_unlock(struct ttm_mem_type_manager *man);
598
599 void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo);
600 void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
601
602 /**
603 * __ttm_bo_reserve:
604 *
605 * @bo: A pointer to a struct ttm_buffer_object.
606 * @interruptible: Sleep interruptible if waiting.
607 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
608 * @ticket: ticket used to acquire the ww_mutex.
609 *
610 * Will not remove reserved buffers from the lru lists.
611 * Otherwise identical to ttm_bo_reserve.
612 *
613 * Returns:
614 * -EDEADLK: The reservation may cause a deadlock.
615 * Release all buffer reservations, wait for @bo to become unreserved and
616 * try again. (only if use_sequence == 1).
617 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
618 * a signal. Release all buffer reservations and return to user-space.
619 * -EBUSY: The function needed to sleep, but @no_wait was true
620 * -EALREADY: Bo already reserved using @ticket. This error code will only
621 * be returned if @use_ticket is set to true.
622 */
__ttm_bo_reserve(struct ttm_buffer_object * bo,bool interruptible,bool no_wait,struct ww_acquire_ctx * ticket)623 static inline int __ttm_bo_reserve(struct ttm_buffer_object *bo,
624 bool interruptible, bool no_wait,
625 struct ww_acquire_ctx *ticket)
626 {
627 int ret = 0;
628
629 if (no_wait) {
630 bool success;
631 if (WARN_ON(ticket))
632 return -EBUSY;
633
634 success = reservation_object_trylock(bo->resv);
635 return success ? 0 : -EBUSY;
636 }
637
638 if (interruptible)
639 ret = reservation_object_lock_interruptible(bo->resv, ticket);
640 else
641 ret = reservation_object_lock(bo->resv, ticket);
642 if (ret == -EINTR)
643 return -ERESTARTSYS;
644 return ret;
645 }
646
647 /**
648 * ttm_bo_reserve:
649 *
650 * @bo: A pointer to a struct ttm_buffer_object.
651 * @interruptible: Sleep interruptible if waiting.
652 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
653 * @ticket: ticket used to acquire the ww_mutex.
654 *
655 * Locks a buffer object for validation. (Or prevents other processes from
656 * locking it for validation) and removes it from lru lists, while taking
657 * a number of measures to prevent deadlocks.
658 *
659 * Deadlocks may occur when two processes try to reserve multiple buffers in
660 * different order, either by will or as a result of a buffer being evicted
661 * to make room for a buffer already reserved. (Buffers are reserved before
662 * they are evicted). The following algorithm prevents such deadlocks from
663 * occurring:
664 * Processes attempting to reserve multiple buffers other than for eviction,
665 * (typically execbuf), should first obtain a unique 32-bit
666 * validation sequence number,
667 * and call this function with @use_ticket == 1 and @ticket->stamp == the unique
668 * sequence number. If upon call of this function, the buffer object is already
669 * reserved, the validation sequence is checked against the validation
670 * sequence of the process currently reserving the buffer,
671 * and if the current validation sequence is greater than that of the process
672 * holding the reservation, the function returns -EDEADLK. Otherwise it sleeps
673 * waiting for the buffer to become unreserved, after which it retries
674 * reserving.
675 * The caller should, when receiving an -EDEADLK error
676 * release all its buffer reservations, wait for @bo to become unreserved, and
677 * then rerun the validation with the same validation sequence. This procedure
678 * will always guarantee that the process with the lowest validation sequence
679 * will eventually succeed, preventing both deadlocks and starvation.
680 *
681 * Returns:
682 * -EDEADLK: The reservation may cause a deadlock.
683 * Release all buffer reservations, wait for @bo to become unreserved and
684 * try again. (only if use_sequence == 1).
685 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
686 * a signal. Release all buffer reservations and return to user-space.
687 * -EBUSY: The function needed to sleep, but @no_wait was true
688 * -EALREADY: Bo already reserved using @ticket. This error code will only
689 * be returned if @use_ticket is set to true.
690 */
ttm_bo_reserve(struct ttm_buffer_object * bo,bool interruptible,bool no_wait,struct ww_acquire_ctx * ticket)691 static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
692 bool interruptible, bool no_wait,
693 struct ww_acquire_ctx *ticket)
694 {
695 int ret;
696
697 WARN_ON(!kref_read(&bo->kref));
698
699 ret = __ttm_bo_reserve(bo, interruptible, no_wait, ticket);
700 if (likely(ret == 0))
701 ttm_bo_del_sub_from_lru(bo);
702
703 return ret;
704 }
705
706 /**
707 * ttm_bo_reserve_slowpath:
708 * @bo: A pointer to a struct ttm_buffer_object.
709 * @interruptible: Sleep interruptible if waiting.
710 * @sequence: Set (@bo)->sequence to this value after lock
711 *
712 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
713 * from all our other reservations. Because there are no other reservations
714 * held by us, this function cannot deadlock any more.
715 */
ttm_bo_reserve_slowpath(struct ttm_buffer_object * bo,bool interruptible,struct ww_acquire_ctx * ticket)716 static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
717 bool interruptible,
718 struct ww_acquire_ctx *ticket)
719 {
720 int ret = 0;
721
722 WARN_ON(!kref_read(&bo->kref));
723
724 if (interruptible)
725 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
726 ticket);
727 else
728 ww_mutex_lock_slow(&bo->resv->lock, ticket);
729
730 if (likely(ret == 0))
731 ttm_bo_del_sub_from_lru(bo);
732 else if (ret == -EINTR)
733 ret = -ERESTARTSYS;
734
735 return ret;
736 }
737
738 /**
739 * ttm_bo_unreserve
740 *
741 * @bo: A pointer to a struct ttm_buffer_object.
742 *
743 * Unreserve a previous reservation of @bo.
744 */
ttm_bo_unreserve(struct ttm_buffer_object * bo)745 static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
746 {
747 if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
748 spin_lock(&bo->bdev->glob->lru_lock);
749 ttm_bo_add_to_lru(bo);
750 spin_unlock(&bo->bdev->glob->lru_lock);
751 }
752 reservation_object_unlock(bo->resv);
753 }
754
755 /*
756 * ttm_bo_util.c
757 */
758
759 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
760 struct ttm_mem_reg *mem);
761 void ttm_mem_io_free(struct ttm_bo_device *bdev,
762 struct ttm_mem_reg *mem);
763 /**
764 * ttm_bo_move_ttm
765 *
766 * @bo: A pointer to a struct ttm_buffer_object.
767 * @interruptible: Sleep interruptible if waiting.
768 * @no_wait_gpu: Return immediately if the GPU is busy.
769 * @new_mem: struct ttm_mem_reg indicating where to move.
770 *
771 * Optimized move function for a buffer object with both old and
772 * new placement backed by a TTM. The function will, if successful,
773 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
774 * and update the (@bo)->mem placement flags. If unsuccessful, the old
775 * data remains untouched, and it's up to the caller to free the
776 * memory space indicated by @new_mem.
777 * Returns:
778 * !0: Failure.
779 */
780
781 int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
782 struct ttm_operation_ctx *ctx,
783 struct ttm_mem_reg *new_mem);
784
785 /**
786 * ttm_bo_move_memcpy
787 *
788 * @bo: A pointer to a struct ttm_buffer_object.
789 * @interruptible: Sleep interruptible if waiting.
790 * @no_wait_gpu: Return immediately if the GPU is busy.
791 * @new_mem: struct ttm_mem_reg indicating where to move.
792 *
793 * Fallback move function for a mappable buffer object in mappable memory.
794 * The function will, if successful,
795 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
796 * and update the (@bo)->mem placement flags. If unsuccessful, the old
797 * data remains untouched, and it's up to the caller to free the
798 * memory space indicated by @new_mem.
799 * Returns:
800 * !0: Failure.
801 */
802
803 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
804 struct ttm_operation_ctx *ctx,
805 struct ttm_mem_reg *new_mem);
806
807 /**
808 * ttm_bo_free_old_node
809 *
810 * @bo: A pointer to a struct ttm_buffer_object.
811 *
812 * Utility function to free an old placement after a successful move.
813 */
814 void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
815
816 /**
817 * ttm_bo_move_accel_cleanup.
818 *
819 * @bo: A pointer to a struct ttm_buffer_object.
820 * @fence: A fence object that signals when moving is complete.
821 * @evict: This is an evict move. Don't return until the buffer is idle.
822 * @new_mem: struct ttm_mem_reg indicating where to move.
823 *
824 * Accelerated move function to be called when an accelerated move
825 * has been scheduled. The function will create a new temporary buffer object
826 * representing the old placement, and put the sync object on both buffer
827 * objects. After that the newly created buffer object is unref'd to be
828 * destroyed when the move is complete. This will help pipeline
829 * buffer moves.
830 */
831 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
832 struct dma_fence *fence, bool evict,
833 struct ttm_mem_reg *new_mem);
834
835 /**
836 * ttm_bo_pipeline_move.
837 *
838 * @bo: A pointer to a struct ttm_buffer_object.
839 * @fence: A fence object that signals when moving is complete.
840 * @evict: This is an evict move. Don't return until the buffer is idle.
841 * @new_mem: struct ttm_mem_reg indicating where to move.
842 *
843 * Function for pipelining accelerated moves. Either free the memory
844 * immediately or hang it on a temporary buffer object.
845 */
846 int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
847 struct dma_fence *fence, bool evict,
848 struct ttm_mem_reg *new_mem);
849
850 /**
851 * ttm_bo_pipeline_gutting.
852 *
853 * @bo: A pointer to a struct ttm_buffer_object.
854 *
855 * Pipelined gutting a BO of it's backing store.
856 */
857 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo);
858
859 /**
860 * ttm_io_prot
861 *
862 * @c_state: Caching state.
863 * @tmp: Page protection flag for a normal, cached mapping.
864 *
865 * Utility function that returns the pgprot_t that should be used for
866 * setting up a PTE with the caching model indicated by @c_state.
867 */
868 pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp);
869
870 extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
871
872 #endif
873