1 /**************************************************************************
3 * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA
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
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11 * permit persons to whom the Software is furnished to do so, subject to
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14 * The above copyright notice and this permission notice (including the
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18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 /* $FreeBSD: head/sys/dev/drm2/ttm/ttm_bo_driver.h 247835 2013-03-05 09:49:34Z kib $ */
31 #ifndef _TTM_BO_DRIVER_H_
32 #define _TTM_BO_DRIVER_H_
34 #include <drm/ttm/ttm_bo_api.h>
35 #include <drm/ttm/ttm_memory.h>
36 #include <drm/ttm/ttm_module.h>
37 #include <drm/drm_mm.h>
38 #include <drm/drm_global.h>
40 #include <linux/workqueue.h>
41 #include <linux/reservation.h>
43 /* XXX nasty hack, but does the job */
45 #define RB_ROOT(head) (head)->rbh_root
47 struct ttm_backend_func {
49 * struct ttm_backend_func member bind
51 * @ttm: Pointer to a struct ttm_tt.
52 * @bo_mem: Pointer to a struct ttm_mem_reg describing the
53 * memory type and location for binding.
55 * Bind the backend pages into the aperture in the location
56 * indicated by @bo_mem. This function should be able to handle
57 * differences between aperture and system page sizes.
59 int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
62 * struct ttm_backend_func member unbind
64 * @ttm: Pointer to a struct ttm_tt.
66 * Unbind previously bound backend pages. This function should be
67 * able to handle differences between aperture and system page sizes.
69 int (*unbind) (struct ttm_tt *ttm);
72 * struct ttm_backend_func member destroy
74 * @ttm: Pointer to a struct ttm_tt.
76 * Destroy the backend. This will be call back from ttm_tt_destroy so
77 * don't call ttm_tt_destroy from the callback or infinite loop.
79 void (*destroy) (struct ttm_tt *ttm);
82 #define TTM_PAGE_FLAG_WRITE (1 << 3)
83 #define TTM_PAGE_FLAG_SWAPPED (1 << 4)
84 #define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
85 #define TTM_PAGE_FLAG_ZERO_ALLOC (1 << 6)
86 #define TTM_PAGE_FLAG_DMA32 (1 << 7)
87 #define TTM_PAGE_FLAG_SG (1 << 8)
89 enum ttm_caching_state {
98 * @bdev: Pointer to a struct ttm_bo_device.
99 * @func: Pointer to a struct ttm_backend_func that describes
100 * the backend methods.
101 * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL
103 * @pages: Array of pages backing the data.
104 * @num_pages: Number of pages in the page array.
105 * @bdev: Pointer to the current struct ttm_bo_device.
106 * @be: Pointer to the ttm backend.
107 * @swap_storage: Pointer to shmem struct file for swap storage.
108 * @caching_state: The current caching state of the pages.
109 * @state: The current binding state of the pages.
111 * This is a structure holding the pages, caching- and aperture binding
112 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
117 struct ttm_bo_device *bdev;
118 struct ttm_backend_func *func;
119 struct vm_page *dummy_read_page;
120 struct vm_page **pages;
122 unsigned long num_pages;
123 struct sg_table *sg; /* for SG objects via dma-buf */
124 struct ttm_bo_global *glob;
125 struct vm_object *swap_storage;
126 enum ttm_caching_state caching_state;
137 * @ttm: Base ttm_tt struct.
138 * @dma_address: The DMA (bus) addresses of the pages
139 * @pages_list: used by some page allocation backend
141 * This is a structure holding the pages, caching- and aperture binding
142 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
147 dma_addr_t *dma_address;
148 struct list_head pages_list;
151 #define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */
152 #define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */
153 #define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */
155 struct ttm_mem_type_manager;
157 struct ttm_mem_type_manager_func {
159 * struct ttm_mem_type_manager member init
161 * @man: Pointer to a memory type manager.
162 * @p_size: Implementation dependent, but typically the size of the
163 * range to be managed in pages.
165 * Called to initialize a private range manager. The function is
166 * expected to initialize the man::priv member.
167 * Returns 0 on success, negative error code on failure.
169 int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size);
172 * struct ttm_mem_type_manager member takedown
174 * @man: Pointer to a memory type manager.
176 * Called to undo the setup done in init. All allocated resources
179 int (*takedown)(struct ttm_mem_type_manager *man);
182 * struct ttm_mem_type_manager member get_node
184 * @man: Pointer to a memory type manager.
185 * @bo: Pointer to the buffer object we're allocating space for.
186 * @placement: Placement details.
187 * @flags: Additional placement flags.
188 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
190 * This function should allocate space in the memory type managed
191 * by @man. Placement details if
192 * applicable are given by @placement. If successful,
193 * @mem::mm_node should be set to a non-null value, and
194 * @mem::start should be set to a value identifying the beginning
195 * of the range allocated, and the function should return zero.
196 * If the memory region accommodate the buffer object, @mem::mm_node
197 * should be set to NULL, and the function should return 0.
198 * If a system error occurred, preventing the request to be fulfilled,
199 * the function should return a negative error code.
201 * Note that @mem::mm_node will only be dereferenced by
202 * struct ttm_mem_type_manager functions and optionally by the driver,
203 * which has knowledge of the underlying type.
205 * This function may not be called from within atomic context, so
206 * an implementation can and must use either a mutex or a spinlock to
207 * protect any data structures managing the space.
209 int (*get_node)(struct ttm_mem_type_manager *man,
210 struct ttm_buffer_object *bo,
211 const struct ttm_place *place,
212 struct ttm_mem_reg *mem);
215 * struct ttm_mem_type_manager member put_node
217 * @man: Pointer to a memory type manager.
218 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
220 * This function frees memory type resources previously allocated
221 * and that are identified by @mem::mm_node and @mem::start. May not
222 * be called from within atomic context.
224 void (*put_node)(struct ttm_mem_type_manager *man,
225 struct ttm_mem_reg *mem);
228 * struct ttm_mem_type_manager member debug
230 * @man: Pointer to a memory type manager.
231 * @prefix: Prefix to be used in printout to identify the caller.
233 * This function is called to print out the state of the memory
234 * type manager to aid debugging of out-of-memory conditions.
235 * It may not be called from within atomic context.
237 void (*debug)(struct ttm_mem_type_manager *man, const char *prefix);
241 * struct ttm_mem_type_manager
243 * @has_type: The memory type has been initialized.
244 * @use_type: The memory type is enabled.
245 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
246 * managed by this memory type.
247 * @gpu_offset: If used, the GPU offset of the first managed page of
248 * fixed memory or the first managed location in an aperture.
249 * @size: Size of the managed region.
250 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
251 * as defined in ttm_placement_common.h
252 * @default_caching: The default caching policy used for a buffer object
253 * placed in this memory type if the user doesn't provide one.
254 * @func: structure pointer implementing the range manager. See above
255 * @priv: Driver private closure for @func.
256 * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures
257 * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions
258 * reserved by the TTM vm system.
259 * @io_reserve_lru: Optional lru list for unreserving io mem regions.
260 * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain
261 * static information. bdev::driver::io_mem_free is never used.
262 * @lru: The lru list for this memory type.
264 * This structure is used to identify and manage memory types for a device.
265 * It's set up by the ttm_bo_driver::init_mem_type method.
270 struct ttm_mem_type_manager {
271 struct ttm_bo_device *bdev;
274 * No protection. Constant from start.
280 unsigned long gpu_offset;
282 uint32_t available_caching;
283 uint32_t default_caching;
284 const struct ttm_mem_type_manager_func *func;
286 struct lock io_reserve_mutex;
287 bool use_io_reserve_lru;
288 bool io_reserve_fastpath;
291 * Protected by @io_reserve_mutex:
294 struct list_head io_reserve_lru;
297 * Protected by the global->lru_lock.
300 struct list_head lru;
304 * struct ttm_bo_driver
306 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
307 * @invalidate_caches: Callback to invalidate read caches when a buffer object
309 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
311 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
312 * @move: Callback for a driver to hook in accelerated functions to
314 * If set to NULL, a potentially slow memcpy() move is used.
315 * @sync_obj_signaled: See ttm_fence_api.h
316 * @sync_obj_wait: See ttm_fence_api.h
317 * @sync_obj_flush: See ttm_fence_api.h
318 * @sync_obj_unref: See ttm_fence_api.h
319 * @sync_obj_ref: See ttm_fence_api.h
322 struct ttm_bo_driver {
326 * @bdev: pointer to a struct ttm_bo_device:
327 * @size: Size of the data needed backing.
328 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
329 * @dummy_read_page: See struct ttm_bo_device.
331 * Create a struct ttm_tt to back data with system memory pages.
332 * No pages are actually allocated.
334 * NULL: Out of memory.
336 struct ttm_tt *(*ttm_tt_create)(struct ttm_bo_device *bdev,
339 struct vm_page *dummy_read_page);
344 * @ttm: The struct ttm_tt to contain the backing pages.
346 * Allocate all backing pages
348 * -ENOMEM: Out of memory.
350 int (*ttm_tt_populate)(struct ttm_tt *ttm);
355 * @ttm: The struct ttm_tt to contain the backing pages.
357 * Free all backing page
359 void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);
362 * struct ttm_bo_driver member invalidate_caches
364 * @bdev: the buffer object device.
365 * @flags: new placement of the rebound buffer object.
367 * A previosly evicted buffer has been rebound in a
368 * potentially new location. Tell the driver that it might
369 * consider invalidating read (texture) caches on the next command
370 * submission as a consequence.
373 int (*invalidate_caches) (struct ttm_bo_device *bdev, uint32_t flags);
374 int (*init_mem_type) (struct ttm_bo_device *bdev, uint32_t type,
375 struct ttm_mem_type_manager *man);
377 * struct ttm_bo_driver member evict_flags:
379 * @bo: the buffer object to be evicted
381 * Return the bo flags for a buffer which is not mapped to the hardware.
382 * These will be placed in proposed_flags so that when the move is
383 * finished, they'll end up in bo->mem.flags
386 void(*evict_flags) (struct ttm_buffer_object *bo,
387 struct ttm_placement *placement);
389 * struct ttm_bo_driver member move:
391 * @bo: the buffer to move
392 * @evict: whether this motion is evicting the buffer from
393 * the graphics address space
394 * @interruptible: Use interruptible sleeps if possible when sleeping.
395 * @no_wait: whether this should give up and return -EBUSY
396 * if this move would require sleeping
397 * @new_mem: the new memory region receiving the buffer
399 * Move a buffer between two memory regions.
401 int (*move) (struct ttm_buffer_object *bo,
402 bool evict, bool interruptible,
404 struct ttm_mem_reg *new_mem);
407 * struct ttm_bo_driver_member verify_access
409 * @bo: Pointer to a buffer object.
410 * @filp: Pointer to a struct file trying to access the object.
411 * FreeBSD: use devfs_get_cdevpriv etc.
413 * Called from the map / write / read methods to verify that the
414 * caller is permitted to access the buffer object.
415 * This member may be set to NULL, which will refuse this kind of
416 * access for all buffer objects.
417 * This function should return 0 if access is granted, -EPERM otherwise.
419 int (*verify_access) (struct ttm_buffer_object *bo);
422 * In case a driver writer dislikes the TTM fence objects,
423 * the driver writer can replace those with sync objects of
424 * his / her own. If it turns out that no driver writer is
425 * using these. I suggest we remove these hooks and plug in
426 * fences directly. The bo driver needs the following functionality:
427 * See the corresponding functions in the fence object API
431 bool (*sync_obj_signaled) (void *sync_obj);
432 int (*sync_obj_wait) (void *sync_obj,
433 bool lazy, bool interruptible);
434 int (*sync_obj_flush) (void *sync_obj);
435 void (*sync_obj_unref) (void **sync_obj);
436 void *(*sync_obj_ref) (void *sync_obj);
438 /* hook to notify driver about a driver move so it
439 * can do tiling things */
440 void (*move_notify)(struct ttm_buffer_object *bo,
441 struct ttm_mem_reg *new_mem);
442 /* notify the driver we are taking a fault on this BO
443 * and have reserved it */
444 int (*fault_reserve_notify)(struct ttm_buffer_object *bo);
447 * notify the driver that we're about to swap out this bo
449 void (*swap_notify) (struct ttm_buffer_object *bo);
452 * Driver callback on when mapping io memory (for bo_move_memcpy
453 * for instance). TTM will take care to call io_mem_free whenever
454 * the mapping is not use anymore. io_mem_reserve & io_mem_free
457 int (*io_mem_reserve)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
458 void (*io_mem_free)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
462 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
465 struct ttm_bo_global_ref {
466 struct drm_global_reference ref;
467 struct ttm_mem_global *mem_glob;
471 * struct ttm_bo_global - Buffer object driver global data.
473 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
474 * @dummy_read_page: Pointer to a dummy page used for mapping requests
475 * of unpopulated pages.
476 * @shrink: A shrink callback object used for buffer object swap.
477 * @device_list_mutex: Mutex protecting the device list.
478 * This mutex is held while traversing the device list for pm options.
479 * @lru_lock: Spinlock protecting the bo subsystem lru lists.
480 * @device_list: List of buffer object devices.
481 * @swap_lru: Lru list of buffer objects used for swapping.
484 struct ttm_bo_global {
488 * Constant after init.
491 struct ttm_mem_global *mem_glob;
492 struct vm_page *dummy_read_page;
493 struct ttm_mem_shrink shrink;
494 struct lock device_list_mutex;
495 struct lock lru_lock;
498 * Protected by device_list_mutex.
500 struct list_head device_list;
503 * Protected by the lru_lock.
505 struct list_head swap_lru;
508 * Internal protection.
514 #define TTM_NUM_MEM_TYPES 8
516 #define TTM_BO_PRIV_FLAG_MOVING 0 /* Buffer object is moving and needs
517 idling before CPU mapping */
518 #define TTM_BO_PRIV_FLAG_MAX 1
519 #define TTM_BO_PRIV_FLAG_ACTIVE 2 /* Used for release sequencing */
521 * struct ttm_bo_device - Buffer object driver device-specific data.
523 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
524 * @man: An array of mem_type_managers.
525 * @fence_lock: Protects the synchronizing members on *all* bos belonging
527 * @addr_space_mm: Range manager for the device address space.
528 * lru_lock: Spinlock that protects the buffer+device lru lists and
530 * @val_seq: Current validation sequence.
531 * @dev_mapping: A pointer to the struct address_space representing the
532 * device address space.
533 * @wq: Work queue structure for the delayed delete workqueue.
537 struct ttm_bo_device {
540 * Constant after bo device init / atomic.
542 struct list_head device_list;
543 struct ttm_bo_global *glob;
544 struct ttm_bo_driver *driver;
546 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
547 struct lock fence_lock;
549 * Protected by the vm lock.
552 RB_HEAD(ttm_bo_device_buffer_objects, ttm_buffer_object) addr_space_rb;
553 struct drm_mm addr_space_mm;
556 * Protected by the global:lru lock.
558 struct list_head ddestroy;
562 * Protected by load / firstopen / lastclose /unload sync.
565 struct address_space *dev_mapping;
568 * Internal protection.
571 struct delayed_work wq;
579 * @old: Pointer to the result and original value.
580 * @new: New value of bits.
581 * @mask: Mask of bits to change.
583 * Convenience function to change a number of bits identified by a mask.
586 static inline uint32_t
587 ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
589 *old ^= (*old ^ new) & mask;
596 * @ttm: The struct ttm_tt.
597 * @bdev: pointer to a struct ttm_bo_device:
598 * @size: Size of the data needed backing.
599 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
600 * @dummy_read_page: See struct ttm_bo_device.
602 * Create a struct ttm_tt to back data with system memory pages.
603 * No pages are actually allocated.
605 * NULL: Out of memory.
607 extern int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
608 unsigned long size, uint32_t page_flags,
609 struct vm_page *dummy_read_page);
610 extern int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
611 unsigned long size, uint32_t page_flags,
612 struct vm_page *dummy_read_page);
617 * @ttm: the ttm_tt structure.
619 * Free memory of ttm_tt structure
621 extern void ttm_tt_fini(struct ttm_tt *ttm);
622 extern void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma);
627 * @ttm: The struct ttm_tt containing backing pages.
628 * @bo_mem: The struct ttm_mem_reg identifying the binding location.
630 * Bind the pages of @ttm to an aperture location identified by @bo_mem
632 extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
637 * @ttm: The struct ttm_tt.
639 * Unbind, unpopulate and destroy common struct ttm_tt.
641 extern void ttm_tt_destroy(struct ttm_tt *ttm);
646 * @ttm: The struct ttm_tt.
648 * Unbind a struct ttm_tt.
650 extern void ttm_tt_unbind(struct ttm_tt *ttm);
655 * @ttm: The struct ttm_tt.
657 * Swap in a previously swap out ttm_tt.
659 extern int ttm_tt_swapin(struct ttm_tt *ttm);
662 * ttm_tt_set_placement_caching:
664 * @ttm A struct ttm_tt the backing pages of which will change caching policy.
665 * @placement: Flag indicating the desired caching policy.
667 * This function will change caching policy of any default kernel mappings of
668 * the pages backing @ttm. If changing from cached to uncached or
670 * all CPU caches will first be flushed to make sure the data of the pages
671 * hit RAM. This function may be very costly as it involves global TLB
672 * and cache flushes and potential page splitting / combining.
674 extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
675 extern int ttm_tt_swapout(struct ttm_tt *ttm,
676 struct vm_object *persistent_swap_storage);
685 * @bdev: Pointer to a struct ttm_bo_device.
686 * @mem: A valid struct ttm_mem_reg.
688 * Returns true if the memory described by @mem is PCI memory,
691 extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
692 struct ttm_mem_reg *mem);
697 * @bo: Pointer to a struct ttm_buffer_object. the data of which
698 * we want to allocate space for.
699 * @proposed_placement: Proposed new placement for the buffer object.
700 * @mem: A struct ttm_mem_reg.
701 * @interruptible: Sleep interruptible when sliping.
702 * @no_wait_gpu: Return immediately if the GPU is busy.
704 * Allocate memory space for the buffer object pointed to by @bo, using
705 * the placement flags in @mem, potentially evicting other idle buffer objects.
706 * This function may sleep while waiting for space to become available.
708 * -EBUSY: No space available (only if no_wait == 1).
709 * -ENOMEM: Could not allocate memory for the buffer object, either due to
710 * fragmentation or concurrent allocators.
711 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
713 extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
714 struct ttm_placement *placement,
715 struct ttm_mem_reg *mem,
719 extern void ttm_bo_mem_put(struct ttm_buffer_object *bo,
720 struct ttm_mem_reg *mem);
721 extern void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo,
722 struct ttm_mem_reg *mem);
724 extern void ttm_bo_global_release(struct drm_global_reference *ref);
725 extern int ttm_bo_global_init(struct drm_global_reference *ref);
727 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
732 * @bdev: A pointer to a struct ttm_bo_device to initialize.
733 * @glob: A pointer to an initialized struct ttm_bo_global.
734 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
735 * @file_page_offset: Offset into the device address space that is available
736 * for buffer data. This ensures compatibility with other users of the
739 * Initializes a struct ttm_bo_device:
743 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
744 struct ttm_bo_global *glob,
745 struct ttm_bo_driver *driver,
746 uint64_t file_page_offset, bool need_dma32);
749 * ttm_bo_unmap_virtual
751 * @bo: tear down the virtual mappings for this BO
753 extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
756 * ttm_bo_unmap_virtual
758 * @bo: tear down the virtual mappings for this BO
760 * The caller must take ttm_mem_io_lock before calling this function.
762 extern void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);
764 extern int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
765 extern void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
766 extern int ttm_mem_io_lock(struct ttm_mem_type_manager *man,
768 extern void ttm_mem_io_unlock(struct ttm_mem_type_manager *man);
774 * @bo: A pointer to a struct ttm_buffer_object.
775 * @interruptible: Sleep interruptible if waiting.
776 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
777 * @use_ticket: If @bo is already reserved, Only sleep waiting for
778 * it to become unreserved if @sequence < (@bo)->sequence.
780 * Locks a buffer object for validation. (Or prevents other processes from
781 * locking it for validation) and removes it from lru lists, while taking
782 * a number of measures to prevent deadlocks.
784 * Deadlocks may occur when two processes try to reserve multiple buffers in
785 * different order, either by will or as a result of a buffer being evicted
786 * to make room for a buffer already reserved. (Buffers are reserved before
787 * they are evicted). The following algorithm prevents such deadlocks from
789 * Processes attempting to reserve multiple buffers other than for eviction,
790 * (typically execbuf), should first obtain a unique 32-bit
791 * validation sequence number,
792 * and call this function with @use_sequence == 1 and @sequence == the unique
793 * sequence number. If upon call of this function, the buffer object is already
794 * reserved, the validation sequence is checked against the validation
795 * sequence of the process currently reserving the buffer,
796 * and if the current validation sequence is greater than that of the process
797 * holding the reservation, the function returns -EAGAIN. Otherwise it sleeps
798 * waiting for the buffer to become unreserved, after which it retries
800 * The caller should, when receiving an -EAGAIN error
801 * release all its buffer reservations, wait for @bo to become unreserved, and
802 * then rerun the validation with the same validation sequence. This procedure
803 * will always guarantee that the process with the lowest validation sequence
804 * will eventually succeed, preventing both deadlocks and starvation.
807 * -EAGAIN: The reservation may cause a deadlock.
808 * Release all buffer reservations, wait for @bo to become unreserved and
809 * try again. (only if use_sequence == 1).
810 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
811 * a signal. Release all buffer reservations and return to user-space.
812 * -EBUSY: The function needed to sleep, but @no_wait was true
813 * -EDEADLK: Bo already reserved using @sequence. This error code will only
814 * be returned if @use_sequence is set to true.
816 extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
818 bool no_wait, bool use_ticket,
819 struct ww_acquire_ctx *ticket);
822 * ttm_bo_reserve_slowpath_nolru:
823 * @bo: A pointer to a struct ttm_buffer_object.
824 * @interruptible: Sleep interruptible if waiting.
825 * @sequence: Set (@bo)->sequence to this value after lock
827 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
828 * from all our other reservations. Because there are no other reservations
829 * held by us, this function cannot deadlock any more.
831 * Will not remove reserved buffers from the lru lists.
832 * Otherwise identical to ttm_bo_reserve_slowpath.
834 extern int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
836 struct ww_acquire_ctx *ticket);
840 * ttm_bo_reserve_slowpath:
841 * @bo: A pointer to a struct ttm_buffer_object.
842 * @interruptible: Sleep interruptible if waiting.
843 * @sequence: Set (@bo)->sequence to this value after lock
845 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
846 * from all our other reservations. Because there are no other reservations
847 * held by us, this function cannot deadlock any more.
849 extern int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
851 struct ww_acquire_ctx *ticket);
854 * ttm_bo_reserve_nolru:
856 * @bo: A pointer to a struct ttm_buffer_object.
857 * @interruptible: Sleep interruptible if waiting.
858 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
859 * @use_sequence: If @bo is already reserved, Only sleep waiting for
860 * it to become unreserved if @sequence < (@bo)->sequence.
862 * Will not remove reserved buffers from the lru lists.
863 * Otherwise identical to ttm_bo_reserve.
866 * -EAGAIN: The reservation may cause a deadlock.
867 * Release all buffer reservations, wait for @bo to become unreserved and
868 * try again. (only if use_sequence == 1).
869 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
870 * a signal. Release all buffer reservations and return to user-space.
871 * -EBUSY: The function needed to sleep, but @no_wait was true
872 * -EDEADLK: Bo already reserved using @sequence. This error code will only
873 * be returned if @use_sequence is set to true.
875 extern int ttm_bo_reserve_nolru(struct ttm_buffer_object *bo,
877 bool no_wait, bool use_ticket,
878 struct ww_acquire_ctx *ticket);
883 * @bo: A pointer to a struct ttm_buffer_object.
885 * Unreserve a previous reservation of @bo.
887 extern void ttm_bo_unreserve(struct ttm_buffer_object *bo);
890 * ttm_bo_unreserve_ticket
891 * @bo: A pointer to a struct ttm_buffer_object.
892 * @ticket: ww_acquire_ctx used for reserving
894 * Unreserve a previous reservation of @bo made with @ticket.
896 extern void ttm_bo_unreserve_ticket(struct ttm_buffer_object *bo,
897 struct ww_acquire_ctx *ticket);
900 * ttm_bo_unreserve_locked
901 * @bo: A pointer to a struct ttm_buffer_object.
902 * @ticket: ww_acquire_ctx used for reserving, or NULL
904 * Unreserve a previous reservation of @bo made with @ticket.
905 * Needs to be called with struct ttm_bo_global::lru_lock held.
907 extern void ttm_bo_unreserve_ticket_locked(struct ttm_buffer_object *bo,
908 struct ww_acquire_ctx *ticket);
914 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
915 struct ttm_mem_reg *mem);
916 void ttm_mem_io_free(struct ttm_bo_device *bdev,
917 struct ttm_mem_reg *mem);
921 * @bo: A pointer to a struct ttm_buffer_object.
922 * @evict: 1: This is an eviction. Don't try to pipeline.
923 * @no_wait_gpu: Return immediately if the GPU is busy.
924 * @new_mem: struct ttm_mem_reg indicating where to move.
926 * Optimized move function for a buffer object with both old and
927 * new placement backed by a TTM. The function will, if successful,
928 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
929 * and update the (@bo)->mem placement flags. If unsuccessful, the old
930 * data remains untouched, and it's up to the caller to free the
931 * memory space indicated by @new_mem.
936 extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
937 bool evict, bool no_wait_gpu,
938 struct ttm_mem_reg *new_mem);
943 * @bo: A pointer to a struct ttm_buffer_object.
944 * @evict: 1: This is an eviction. Don't try to pipeline.
945 * @no_wait_gpu: Return immediately if the GPU is busy.
946 * @new_mem: struct ttm_mem_reg indicating where to move.
948 * Fallback move function for a mappable buffer object in mappable memory.
949 * The function will, if successful,
950 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
951 * and update the (@bo)->mem placement flags. If unsuccessful, the old
952 * data remains untouched, and it's up to the caller to free the
953 * memory space indicated by @new_mem.
958 extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
959 bool evict, bool no_wait_gpu,
960 struct ttm_mem_reg *new_mem);
963 * ttm_bo_free_old_node
965 * @bo: A pointer to a struct ttm_buffer_object.
967 * Utility function to free an old placement after a successful move.
969 extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
972 * ttm_bo_move_accel_cleanup.
974 * @bo: A pointer to a struct ttm_buffer_object.
975 * @sync_obj: A sync object that signals when moving is complete.
976 * @evict: This is an evict move. Don't return until the buffer is idle.
977 * @no_wait_gpu: Return immediately if the GPU is busy.
978 * @new_mem: struct ttm_mem_reg indicating where to move.
980 * Accelerated move function to be called when an accelerated move
981 * has been scheduled. The function will create a new temporary buffer object
982 * representing the old placement, and put the sync object on both buffer
983 * objects. After that the newly created buffer object is unref'd to be
984 * destroyed when the move is complete. This will help pipeline
988 extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
990 bool evict, bool no_wait_gpu,
991 struct ttm_mem_reg *new_mem);
995 * @c_state: Caching state.
996 * @tmp: Page protection flag for a normal, cached mapping.
998 * Utility function that returns the pgprot_t that should be used for
999 * setting up a PTE with the caching model indicated by @c_state.
1001 extern vm_memattr_t ttm_io_prot(uint32_t caching_flags);
1003 extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
1005 #if (defined(CONFIG_AGP) || (defined(CONFIG_AGP_MODULE) && defined(MODULE)))
1007 #include <linux/agp_backend.h>
1012 * @bdev: Pointer to a struct ttm_bo_device.
1013 * @bridge: The agp bridge this device is sitting on.
1014 * @size: Size of the data needed backing.
1015 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
1016 * @dummy_read_page: See struct ttm_bo_device.
1019 * Create a TTM backend that uses the indicated AGP bridge as an aperture
1020 * for TT memory. This function uses the linux agpgart interface to
1021 * bind and unbind memory backing a ttm_tt.
1023 extern struct ttm_tt *ttm_agp_tt_create(struct ttm_bo_device *bdev,
1024 struct agp_bridge_data *bridge,
1025 unsigned long size, uint32_t page_flags,
1026 struct vm_page *dummy_read_page);
1027 int ttm_agp_tt_populate(struct ttm_tt *ttm);
1028 void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);
1032 int ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a,
1033 struct ttm_buffer_object *b);
1034 RB_PROTOTYPE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb,
1035 ttm_bo_cmp_rb_tree_items);