blob: 62ed733c52a23898a893c51bf05eb80e17995bf4 [file] [log] [blame]
Thomas Hellstromba4e7d92009-06-10 15:20:19 +02001/**************************************************************************
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 "ttm/ttm_bo_api.h"
34#include "ttm/ttm_memory.h"
35#include "drm_mm.h"
36#include "linux/workqueue.h"
37#include "linux/fs.h"
38#include "linux/spinlock.h"
39
40struct ttm_backend;
41
42struct ttm_backend_func {
43 /**
44 * struct ttm_backend_func member populate
45 *
46 * @backend: Pointer to a struct ttm_backend.
47 * @num_pages: Number of pages to populate.
48 * @pages: Array of pointers to ttm pages.
49 * @dummy_read_page: Page to be used instead of NULL pages in the
50 * array @pages.
51 *
52 * Populate the backend with ttm pages. Depending on the backend,
53 * it may or may not copy the @pages array.
54 */
55 int (*populate) (struct ttm_backend *backend,
56 unsigned long num_pages, struct page **pages,
57 struct page *dummy_read_page);
58 /**
59 * struct ttm_backend_func member clear
60 *
61 * @backend: Pointer to a struct ttm_backend.
62 *
63 * This is an "unpopulate" function. Release all resources
64 * allocated with populate.
65 */
66 void (*clear) (struct ttm_backend *backend);
67
68 /**
69 * struct ttm_backend_func member bind
70 *
71 * @backend: Pointer to a struct ttm_backend.
72 * @bo_mem: Pointer to a struct ttm_mem_reg describing the
73 * memory type and location for binding.
74 *
75 * Bind the backend pages into the aperture in the location
76 * indicated by @bo_mem. This function should be able to handle
77 * differences between aperture- and system page sizes.
78 */
79 int (*bind) (struct ttm_backend *backend, struct ttm_mem_reg *bo_mem);
80
81 /**
82 * struct ttm_backend_func member unbind
83 *
84 * @backend: Pointer to a struct ttm_backend.
85 *
86 * Unbind previously bound backend pages. This function should be
87 * able to handle differences between aperture- and system page sizes.
88 */
89 int (*unbind) (struct ttm_backend *backend);
90
91 /**
92 * struct ttm_backend_func member destroy
93 *
94 * @backend: Pointer to a struct ttm_backend.
95 *
96 * Destroy the backend.
97 */
98 void (*destroy) (struct ttm_backend *backend);
99};
100
101/**
102 * struct ttm_backend
103 *
104 * @bdev: Pointer to a struct ttm_bo_device.
105 * @flags: For driver use.
106 * @func: Pointer to a struct ttm_backend_func that describes
107 * the backend methods.
108 *
109 */
110
111struct ttm_backend {
112 struct ttm_bo_device *bdev;
113 uint32_t flags;
114 struct ttm_backend_func *func;
115};
116
117#define TTM_PAGE_FLAG_VMALLOC (1 << 0)
118#define TTM_PAGE_FLAG_USER (1 << 1)
119#define TTM_PAGE_FLAG_USER_DIRTY (1 << 2)
120#define TTM_PAGE_FLAG_WRITE (1 << 3)
121#define TTM_PAGE_FLAG_SWAPPED (1 << 4)
122#define TTM_PAGE_FLAG_PERSISTANT_SWAP (1 << 5)
123#define TTM_PAGE_FLAG_ZERO_ALLOC (1 << 6)
124
125enum ttm_caching_state {
126 tt_uncached,
127 tt_wc,
128 tt_cached
129};
130
131/**
132 * struct ttm_tt
133 *
134 * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL
135 * pointer.
136 * @pages: Array of pages backing the data.
137 * @first_himem_page: Himem pages are put last in the page array, which
138 * enables us to run caching attribute changes on only the first part
139 * of the page array containing lomem pages. This is the index of the
140 * first himem page.
141 * @last_lomem_page: Index of the last lomem page in the page array.
142 * @num_pages: Number of pages in the page array.
143 * @bdev: Pointer to the current struct ttm_bo_device.
144 * @be: Pointer to the ttm backend.
145 * @tsk: The task for user ttm.
146 * @start: virtual address for user ttm.
147 * @swap_storage: Pointer to shmem struct file for swap storage.
148 * @caching_state: The current caching state of the pages.
149 * @state: The current binding state of the pages.
150 *
151 * This is a structure holding the pages, caching- and aperture binding
152 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
153 * memory.
154 */
155
156struct ttm_tt {
157 struct page *dummy_read_page;
158 struct page **pages;
159 long first_himem_page;
160 long last_lomem_page;
161 uint32_t page_flags;
162 unsigned long num_pages;
163 struct ttm_bo_device *bdev;
164 struct ttm_backend *be;
165 struct task_struct *tsk;
166 unsigned long start;
167 struct file *swap_storage;
168 enum ttm_caching_state caching_state;
169 enum {
170 tt_bound,
171 tt_unbound,
172 tt_unpopulated,
173 } state;
174};
175
176#define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */
177#define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */
178#define TTM_MEMTYPE_FLAG_NEEDS_IOREMAP (1 << 2) /* Fixed memory needs ioremap
179 before kernel access. */
180#define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */
181
182/**
183 * struct ttm_mem_type_manager
184 *
185 * @has_type: The memory type has been initialized.
186 * @use_type: The memory type is enabled.
187 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
188 * managed by this memory type.
189 * @gpu_offset: If used, the GPU offset of the first managed page of
190 * fixed memory or the first managed location in an aperture.
191 * @io_offset: The io_offset of the first managed page of IO memory or
192 * the first managed location in an aperture. For TTM_MEMTYPE_FLAG_CMA
193 * memory, this should be set to NULL.
194 * @io_size: The size of a managed IO region (fixed memory or aperture).
195 * @io_addr: Virtual kernel address if the io region is pre-mapped. For
196 * TTM_MEMTYPE_FLAG_NEEDS_IOREMAP there is no pre-mapped io map and
197 * @io_addr should be set to NULL.
198 * @size: Size of the managed region.
199 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
200 * as defined in ttm_placement_common.h
201 * @default_caching: The default caching policy used for a buffer object
202 * placed in this memory type if the user doesn't provide one.
203 * @manager: The range manager used for this memory type. FIXME: If the aperture
204 * has a page size different from the underlying system, the granularity
205 * of this manager should take care of this. But the range allocating code
206 * in ttm_bo.c needs to be modified for this.
207 * @lru: The lru list for this memory type.
208 *
209 * This structure is used to identify and manage memory types for a device.
210 * It's set up by the ttm_bo_driver::init_mem_type method.
211 */
212
213struct ttm_mem_type_manager {
214
215 /*
216 * No protection. Constant from start.
217 */
218
219 bool has_type;
220 bool use_type;
221 uint32_t flags;
222 unsigned long gpu_offset;
223 unsigned long io_offset;
224 unsigned long io_size;
225 void *io_addr;
226 uint64_t size;
227 uint32_t available_caching;
228 uint32_t default_caching;
229
230 /*
231 * Protected by the bdev->lru_lock.
232 * TODO: Consider one lru_lock per ttm_mem_type_manager.
233 * Plays ill with list removal, though.
234 */
235
236 struct drm_mm manager;
237 struct list_head lru;
238};
239
240/**
241 * struct ttm_bo_driver
242 *
243 * @mem_type_prio: Priority array of memory types to place a buffer object in
244 * if it fits without evicting buffers from any of these memory types.
245 * @mem_busy_prio: Priority array of memory types to place a buffer object in
246 * if it needs to evict buffers to make room.
247 * @num_mem_type_prio: Number of elements in the @mem_type_prio array.
248 * @num_mem_busy_prio: Number of elements in the @num_mem_busy_prio array.
249 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
250 * @invalidate_caches: Callback to invalidate read caches when a buffer object
251 * has been evicted.
252 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
253 * structure.
254 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
255 * @move: Callback for a driver to hook in accelerated functions to
256 * move a buffer.
257 * If set to NULL, a potentially slow memcpy() move is used.
258 * @sync_obj_signaled: See ttm_fence_api.h
259 * @sync_obj_wait: See ttm_fence_api.h
260 * @sync_obj_flush: See ttm_fence_api.h
261 * @sync_obj_unref: See ttm_fence_api.h
262 * @sync_obj_ref: See ttm_fence_api.h
263 */
264
265struct ttm_bo_driver {
266 const uint32_t *mem_type_prio;
267 const uint32_t *mem_busy_prio;
268 uint32_t num_mem_type_prio;
269 uint32_t num_mem_busy_prio;
270
271 /**
272 * struct ttm_bo_driver member create_ttm_backend_entry
273 *
274 * @bdev: The buffer object device.
275 *
276 * Create a driver specific struct ttm_backend.
277 */
278
279 struct ttm_backend *(*create_ttm_backend_entry)
280 (struct ttm_bo_device *bdev);
281
282 /**
283 * struct ttm_bo_driver member invalidate_caches
284 *
285 * @bdev: the buffer object device.
286 * @flags: new placement of the rebound buffer object.
287 *
288 * A previosly evicted buffer has been rebound in a
289 * potentially new location. Tell the driver that it might
290 * consider invalidating read (texture) caches on the next command
291 * submission as a consequence.
292 */
293
294 int (*invalidate_caches) (struct ttm_bo_device *bdev, uint32_t flags);
295 int (*init_mem_type) (struct ttm_bo_device *bdev, uint32_t type,
296 struct ttm_mem_type_manager *man);
297 /**
298 * struct ttm_bo_driver member evict_flags:
299 *
300 * @bo: the buffer object to be evicted
301 *
302 * Return the bo flags for a buffer which is not mapped to the hardware.
303 * These will be placed in proposed_flags so that when the move is
304 * finished, they'll end up in bo->mem.flags
305 */
306
307 uint32_t(*evict_flags) (struct ttm_buffer_object *bo);
308 /**
309 * struct ttm_bo_driver member move:
310 *
311 * @bo: the buffer to move
312 * @evict: whether this motion is evicting the buffer from
313 * the graphics address space
314 * @interruptible: Use interruptible sleeps if possible when sleeping.
315 * @no_wait: whether this should give up and return -EBUSY
316 * if this move would require sleeping
317 * @new_mem: the new memory region receiving the buffer
318 *
319 * Move a buffer between two memory regions.
320 */
321 int (*move) (struct ttm_buffer_object *bo,
322 bool evict, bool interruptible,
323 bool no_wait, struct ttm_mem_reg *new_mem);
324
325 /**
326 * struct ttm_bo_driver_member verify_access
327 *
328 * @bo: Pointer to a buffer object.
329 * @filp: Pointer to a struct file trying to access the object.
330 *
331 * Called from the map / write / read methods to verify that the
332 * caller is permitted to access the buffer object.
333 * This member may be set to NULL, which will refuse this kind of
334 * access for all buffer objects.
335 * This function should return 0 if access is granted, -EPERM otherwise.
336 */
337 int (*verify_access) (struct ttm_buffer_object *bo,
338 struct file *filp);
339
340 /**
341 * In case a driver writer dislikes the TTM fence objects,
342 * the driver writer can replace those with sync objects of
343 * his / her own. If it turns out that no driver writer is
344 * using these. I suggest we remove these hooks and plug in
345 * fences directly. The bo driver needs the following functionality:
346 * See the corresponding functions in the fence object API
347 * documentation.
348 */
349
350 bool (*sync_obj_signaled) (void *sync_obj, void *sync_arg);
351 int (*sync_obj_wait) (void *sync_obj, void *sync_arg,
352 bool lazy, bool interruptible);
353 int (*sync_obj_flush) (void *sync_obj, void *sync_arg);
354 void (*sync_obj_unref) (void **sync_obj);
355 void *(*sync_obj_ref) (void *sync_obj);
356};
357
358#define TTM_NUM_MEM_TYPES 8
359
360#define TTM_BO_PRIV_FLAG_MOVING 0 /* Buffer object is moving and needs
361 idling before CPU mapping */
362#define TTM_BO_PRIV_FLAG_MAX 1
363/**
364 * struct ttm_bo_device - Buffer object driver device-specific data.
365 *
366 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
367 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
368 * @count: Current number of buffer object.
369 * @pages: Current number of pinned pages.
370 * @dummy_read_page: Pointer to a dummy page used for mapping requests
371 * of unpopulated pages.
372 * @shrink: A shrink callback object used for buffre object swap.
373 * @ttm_bo_extra_size: Extra size (sizeof(struct ttm_buffer_object) excluded)
374 * used by a buffer object. This is excluding page arrays and backing pages.
375 * @ttm_bo_size: This is @ttm_bo_extra_size + sizeof(struct ttm_buffer_object).
376 * @man: An array of mem_type_managers.
377 * @addr_space_mm: Range manager for the device address space.
378 * lru_lock: Spinlock that protects the buffer+device lru lists and
379 * ddestroy lists.
380 * @nice_mode: Try nicely to wait for buffer idle when cleaning a manager.
381 * If a GPU lockup has been detected, this is forced to 0.
382 * @dev_mapping: A pointer to the struct address_space representing the
383 * device address space.
384 * @wq: Work queue structure for the delayed delete workqueue.
385 *
386 */
387
388struct ttm_bo_device {
389
390 /*
391 * Constant after bo device init / atomic.
392 */
393
394 struct ttm_mem_global *mem_glob;
395 struct ttm_bo_driver *driver;
396 struct page *dummy_read_page;
397 struct ttm_mem_shrink shrink;
398
399 size_t ttm_bo_extra_size;
400 size_t ttm_bo_size;
401
402 rwlock_t vm_lock;
403 /*
404 * Protected by the vm lock.
405 */
406 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
407 struct rb_root addr_space_rb;
408 struct drm_mm addr_space_mm;
409
410 /*
411 * Might want to change this to one lock per manager.
412 */
413 spinlock_t lru_lock;
414 /*
415 * Protected by the lru lock.
416 */
417 struct list_head ddestroy;
418 struct list_head swap_lru;
419
420 /*
421 * Protected by load / firstopen / lastclose /unload sync.
422 */
423
424 bool nice_mode;
425 struct address_space *dev_mapping;
426
427 /*
428 * Internal protection.
429 */
430
431 struct delayed_work wq;
432};
433
434/**
435 * ttm_flag_masked
436 *
437 * @old: Pointer to the result and original value.
438 * @new: New value of bits.
439 * @mask: Mask of bits to change.
440 *
441 * Convenience function to change a number of bits identified by a mask.
442 */
443
444static inline uint32_t
445ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
446{
447 *old ^= (*old ^ new) & mask;
448 return *old;
449}
450
451/**
452 * ttm_tt_create
453 *
454 * @bdev: pointer to a struct ttm_bo_device:
455 * @size: Size of the data needed backing.
456 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
457 * @dummy_read_page: See struct ttm_bo_device.
458 *
459 * Create a struct ttm_tt to back data with system memory pages.
460 * No pages are actually allocated.
461 * Returns:
462 * NULL: Out of memory.
463 */
464extern struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev,
465 unsigned long size,
466 uint32_t page_flags,
467 struct page *dummy_read_page);
468
469/**
470 * ttm_tt_set_user:
471 *
472 * @ttm: The struct ttm_tt to populate.
473 * @tsk: A struct task_struct for which @start is a valid user-space address.
474 * @start: A valid user-space address.
475 * @num_pages: Size in pages of the user memory area.
476 *
477 * Populate a struct ttm_tt with a user-space memory area after first pinning
478 * the pages backing it.
479 * Returns:
480 * !0: Error.
481 */
482
483extern int ttm_tt_set_user(struct ttm_tt *ttm,
484 struct task_struct *tsk,
485 unsigned long start, unsigned long num_pages);
486
487/**
488 * ttm_ttm_bind:
489 *
490 * @ttm: The struct ttm_tt containing backing pages.
491 * @bo_mem: The struct ttm_mem_reg identifying the binding location.
492 *
493 * Bind the pages of @ttm to an aperture location identified by @bo_mem
494 */
495extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
496
497/**
498 * ttm_ttm_destroy:
499 *
500 * @ttm: The struct ttm_tt.
501 *
502 * Unbind, unpopulate and destroy a struct ttm_tt.
503 */
504extern void ttm_tt_destroy(struct ttm_tt *ttm);
505
506/**
507 * ttm_ttm_unbind:
508 *
509 * @ttm: The struct ttm_tt.
510 *
511 * Unbind a struct ttm_tt.
512 */
513extern void ttm_tt_unbind(struct ttm_tt *ttm);
514
515/**
516 * ttm_ttm_destroy:
517 *
518 * @ttm: The struct ttm_tt.
519 * @index: Index of the desired page.
520 *
521 * Return a pointer to the struct page backing @ttm at page
522 * index @index. If the page is unpopulated, one will be allocated to
523 * populate that index.
524 *
525 * Returns:
526 * NULL on OOM.
527 */
528extern struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index);
529
530/**
531 * ttm_tt_cache_flush:
532 *
533 * @pages: An array of pointers to struct page:s to flush.
534 * @num_pages: Number of pages to flush.
535 *
536 * Flush the data of the indicated pages from the cpu caches.
537 * This is used when changing caching attributes of the pages from
538 * cache-coherent.
539 */
540extern void ttm_tt_cache_flush(struct page *pages[], unsigned long num_pages);
541
542/**
543 * ttm_tt_set_placement_caching:
544 *
545 * @ttm A struct ttm_tt the backing pages of which will change caching policy.
546 * @placement: Flag indicating the desired caching policy.
547 *
548 * This function will change caching policy of any default kernel mappings of
549 * the pages backing @ttm. If changing from cached to uncached or
550 * write-combined,
551 * all CPU caches will first be flushed to make sure the data of the pages
552 * hit RAM. This function may be very costly as it involves global TLB
553 * and cache flushes and potential page splitting / combining.
554 */
555extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
556extern int ttm_tt_swapout(struct ttm_tt *ttm,
557 struct file *persistant_swap_storage);
558
559/*
560 * ttm_bo.c
561 */
562
563/**
564 * ttm_mem_reg_is_pci
565 *
566 * @bdev: Pointer to a struct ttm_bo_device.
567 * @mem: A valid struct ttm_mem_reg.
568 *
569 * Returns true if the memory described by @mem is PCI memory,
570 * false otherwise.
571 */
572extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
573 struct ttm_mem_reg *mem);
574
575/**
576 * ttm_bo_mem_space
577 *
578 * @bo: Pointer to a struct ttm_buffer_object. the data of which
579 * we want to allocate space for.
580 * @proposed_placement: Proposed new placement for the buffer object.
581 * @mem: A struct ttm_mem_reg.
582 * @interruptible: Sleep interruptible when sliping.
583 * @no_wait: Don't sleep waiting for space to become available.
584 *
585 * Allocate memory space for the buffer object pointed to by @bo, using
586 * the placement flags in @mem, potentially evicting other idle buffer objects.
587 * This function may sleep while waiting for space to become available.
588 * Returns:
589 * -EBUSY: No space available (only if no_wait == 1).
590 * -ENOMEM: Could not allocate memory for the buffer object, either due to
591 * fragmentation or concurrent allocators.
592 * -ERESTART: An interruptible sleep was interrupted by a signal.
593 */
594extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
595 uint32_t proposed_placement,
596 struct ttm_mem_reg *mem,
597 bool interruptible, bool no_wait);
598/**
599 * ttm_bo_wait_for_cpu
600 *
601 * @bo: Pointer to a struct ttm_buffer_object.
602 * @no_wait: Don't sleep while waiting.
603 *
604 * Wait until a buffer object is no longer sync'ed for CPU access.
605 * Returns:
606 * -EBUSY: Buffer object was sync'ed for CPU access. (only if no_wait == 1).
607 * -ERESTART: An interruptible sleep was interrupted by a signal.
608 */
609
610extern int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait);
611
612/**
613 * ttm_bo_pci_offset - Get the PCI offset for the buffer object memory.
614 *
615 * @bo Pointer to a struct ttm_buffer_object.
616 * @bus_base On return the base of the PCI region
617 * @bus_offset On return the byte offset into the PCI region
618 * @bus_size On return the byte size of the buffer object or zero if
619 * the buffer object memory is not accessible through a PCI region.
620 *
621 * Returns:
622 * -EINVAL if the buffer object is currently not mappable.
623 * 0 otherwise.
624 */
625
626extern int ttm_bo_pci_offset(struct ttm_bo_device *bdev,
627 struct ttm_mem_reg *mem,
628 unsigned long *bus_base,
629 unsigned long *bus_offset,
630 unsigned long *bus_size);
631
632extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
633
634/**
635 * ttm_bo_device_init
636 *
637 * @bdev: A pointer to a struct ttm_bo_device to initialize.
638 * @mem_global: A pointer to an initialized struct ttm_mem_global.
639 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
640 * @file_page_offset: Offset into the device address space that is available
641 * for buffer data. This ensures compatibility with other users of the
642 * address space.
643 *
644 * Initializes a struct ttm_bo_device:
645 * Returns:
646 * !0: Failure.
647 */
648extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
649 struct ttm_mem_global *mem_glob,
650 struct ttm_bo_driver *driver,
651 uint64_t file_page_offset);
652
653/**
654 * ttm_bo_reserve:
655 *
656 * @bo: A pointer to a struct ttm_buffer_object.
657 * @interruptible: Sleep interruptible if waiting.
658 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
659 * @use_sequence: If @bo is already reserved, Only sleep waiting for
660 * it to become unreserved if @sequence < (@bo)->sequence.
661 *
662 * Locks a buffer object for validation. (Or prevents other processes from
663 * locking it for validation) and removes it from lru lists, while taking
664 * a number of measures to prevent deadlocks.
665 *
666 * Deadlocks may occur when two processes try to reserve multiple buffers in
667 * different order, either by will or as a result of a buffer being evicted
668 * to make room for a buffer already reserved. (Buffers are reserved before
669 * they are evicted). The following algorithm prevents such deadlocks from
670 * occuring:
671 * 1) Buffers are reserved with the lru spinlock held. Upon successful
672 * reservation they are removed from the lru list. This stops a reserved buffer
673 * from being evicted. However the lru spinlock is released between the time
674 * a buffer is selected for eviction and the time it is reserved.
675 * Therefore a check is made when a buffer is reserved for eviction, that it
676 * is still the first buffer in the lru list, before it is removed from the
677 * list. @check_lru == 1 forces this check. If it fails, the function returns
678 * -EINVAL, and the caller should then choose a new buffer to evict and repeat
679 * the procedure.
680 * 2) Processes attempting to reserve multiple buffers other than for eviction,
681 * (typically execbuf), should first obtain a unique 32-bit
682 * validation sequence number,
683 * and call this function with @use_sequence == 1 and @sequence == the unique
684 * sequence number. If upon call of this function, the buffer object is already
685 * reserved, the validation sequence is checked against the validation
686 * sequence of the process currently reserving the buffer,
687 * and if the current validation sequence is greater than that of the process
688 * holding the reservation, the function returns -EAGAIN. Otherwise it sleeps
689 * waiting for the buffer to become unreserved, after which it retries
690 * reserving.
691 * The caller should, when receiving an -EAGAIN error
692 * release all its buffer reservations, wait for @bo to become unreserved, and
693 * then rerun the validation with the same validation sequence. This procedure
694 * will always guarantee that the process with the lowest validation sequence
695 * will eventually succeed, preventing both deadlocks and starvation.
696 *
697 * Returns:
698 * -EAGAIN: The reservation may cause a deadlock.
699 * Release all buffer reservations, wait for @bo to become unreserved and
700 * try again. (only if use_sequence == 1).
701 * -ERESTART: A wait for the buffer to become unreserved was interrupted by
702 * a signal. Release all buffer reservations and return to user-space.
703 */
704extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
705 bool interruptible,
706 bool no_wait, bool use_sequence, uint32_t sequence);
707
708/**
709 * ttm_bo_unreserve
710 *
711 * @bo: A pointer to a struct ttm_buffer_object.
712 *
713 * Unreserve a previous reservation of @bo.
714 */
715extern void ttm_bo_unreserve(struct ttm_buffer_object *bo);
716
717/**
718 * ttm_bo_wait_unreserved
719 *
720 * @bo: A pointer to a struct ttm_buffer_object.
721 *
722 * Wait for a struct ttm_buffer_object to become unreserved.
723 * This is typically used in the execbuf code to relax cpu-usage when
724 * a potential deadlock condition backoff.
725 */
726extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo,
727 bool interruptible);
728
729/**
730 * ttm_bo_block_reservation
731 *
732 * @bo: A pointer to a struct ttm_buffer_object.
733 * @interruptible: Use interruptible sleep when waiting.
734 * @no_wait: Don't sleep, but rather return -EBUSY.
735 *
736 * Block reservation for validation by simply reserving the buffer.
737 * This is intended for single buffer use only without eviction,
738 * and thus needs no deadlock protection.
739 *
740 * Returns:
741 * -EBUSY: If no_wait == 1 and the buffer is already reserved.
742 * -ERESTART: If interruptible == 1 and the process received a signal
743 * while sleeping.
744 */
745extern int ttm_bo_block_reservation(struct ttm_buffer_object *bo,
746 bool interruptible, bool no_wait);
747
748/**
749 * ttm_bo_unblock_reservation
750 *
751 * @bo: A pointer to a struct ttm_buffer_object.
752 *
753 * Unblocks reservation leaving lru lists untouched.
754 */
755extern void ttm_bo_unblock_reservation(struct ttm_buffer_object *bo);
756
757/*
758 * ttm_bo_util.c
759 */
760
761/**
762 * ttm_bo_move_ttm
763 *
764 * @bo: A pointer to a struct ttm_buffer_object.
765 * @evict: 1: This is an eviction. Don't try to pipeline.
766 * @no_wait: Never sleep, but rather return with -EBUSY.
767 * @new_mem: struct ttm_mem_reg indicating where to move.
768 *
769 * Optimized move function for a buffer object with both old and
770 * new placement backed by a TTM. The function will, if successful,
771 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
772 * and update the (@bo)->mem placement flags. If unsuccessful, the old
773 * data remains untouched, and it's up to the caller to free the
774 * memory space indicated by @new_mem.
775 * Returns:
776 * !0: Failure.
777 */
778
779extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
780 bool evict, bool no_wait,
781 struct ttm_mem_reg *new_mem);
782
783/**
784 * ttm_bo_move_memcpy
785 *
786 * @bo: A pointer to a struct ttm_buffer_object.
787 * @evict: 1: This is an eviction. Don't try to pipeline.
788 * @no_wait: Never sleep, but rather return with -EBUSY.
789 * @new_mem: struct ttm_mem_reg indicating where to move.
790 *
791 * Fallback move function for a mappable buffer object in mappable memory.
792 * The function will, if successful,
793 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
794 * and update the (@bo)->mem placement flags. If unsuccessful, the old
795 * data remains untouched, and it's up to the caller to free the
796 * memory space indicated by @new_mem.
797 * Returns:
798 * !0: Failure.
799 */
800
801extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
802 bool evict,
803 bool no_wait, struct ttm_mem_reg *new_mem);
804
805/**
806 * ttm_bo_free_old_node
807 *
808 * @bo: A pointer to a struct ttm_buffer_object.
809 *
810 * Utility function to free an old placement after a successful move.
811 */
812extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
813
814/**
815 * ttm_bo_move_accel_cleanup.
816 *
817 * @bo: A pointer to a struct ttm_buffer_object.
818 * @sync_obj: A sync object that signals when moving is complete.
819 * @sync_obj_arg: An argument to pass to the sync object idle / wait
820 * functions.
821 * @evict: This is an evict move. Don't return until the buffer is idle.
822 * @no_wait: Never sleep, but rather return with -EBUSY.
823 * @new_mem: struct ttm_mem_reg indicating where to move.
824 *
825 * Accelerated move function to be called when an accelerated move
826 * has been scheduled. The function will create a new temporary buffer object
827 * representing the old placement, and put the sync object on both buffer
828 * objects. After that the newly created buffer object is unref'd to be
829 * destroyed when the move is complete. This will help pipeline
830 * buffer moves.
831 */
832
833extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
834 void *sync_obj,
835 void *sync_obj_arg,
836 bool evict, bool no_wait,
837 struct ttm_mem_reg *new_mem);
838/**
839 * ttm_io_prot
840 *
841 * @c_state: Caching state.
842 * @tmp: Page protection flag for a normal, cached mapping.
843 *
844 * Utility function that returns the pgprot_t that should be used for
845 * setting up a PTE with the caching model indicated by @c_state.
846 */
847extern pgprot_t ttm_io_prot(enum ttm_caching_state c_state, pgprot_t tmp);
848
849#if (defined(CONFIG_AGP) || (defined(CONFIG_AGP_MODULE) && defined(MODULE)))
850#define TTM_HAS_AGP
851#include <linux/agp_backend.h>
852
853/**
854 * ttm_agp_backend_init
855 *
856 * @bdev: Pointer to a struct ttm_bo_device.
857 * @bridge: The agp bridge this device is sitting on.
858 *
859 * Create a TTM backend that uses the indicated AGP bridge as an aperture
860 * for TT memory. This function uses the linux agpgart interface to
861 * bind and unbind memory backing a ttm_tt.
862 */
863extern struct ttm_backend *ttm_agp_backend_init(struct ttm_bo_device *bdev,
864 struct agp_bridge_data *bridge);
865#endif
866
867#endif