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
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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
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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
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26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 #ifndef _TTM_BO_DRIVER_H_
31 #define _TTM_BO_DRIVER_H_
33 #include <ttm/ttm_bo_api.h>
34 #include <ttm/ttm_memory.h>
35 #include <ttm/ttm_module.h>
36 #include <ttm/ttm_placement.h>
37 #include <drm/drm_mm.h>
38 #include <drm/drm_global.h>
39 #include <drm/drm_vma_manager.h>
40 #include <linux/workqueue.h>
42 #include <linux/spinlock.h>
43 #include <linux/reservation.h>
45 #define TTM_MAX_BO_PRIORITY 16U
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 page *dummy_read_page;
122 unsigned long num_pages;
123 struct sg_table *sg; /* for SG objects via dma-buf */
124 struct ttm_bo_global *glob;
125 struct file *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 * @move_lock: lock for move fence
262 * static information. bdev::driver::io_mem_free is never used.
263 * @lru: The lru list for this memory type.
264 * @move: The fence of the last pipelined move operation.
266 * This structure is used to identify and manage memory types for a device.
267 * It's set up by the ttm_bo_driver::init_mem_type method.
272 struct ttm_mem_type_manager {
273 struct ttm_bo_device *bdev;
276 * No protection. Constant from start.
282 uint64_t gpu_offset; /* GPU address space is independent of CPU word size */
284 uint32_t available_caching;
285 uint32_t default_caching;
286 const struct ttm_mem_type_manager_func *func;
288 struct mutex io_reserve_mutex;
289 bool use_io_reserve_lru;
290 bool io_reserve_fastpath;
291 spinlock_t move_lock;
294 * Protected by @io_reserve_mutex:
297 struct list_head io_reserve_lru;
300 * Protected by the global->lru_lock.
303 struct list_head lru[TTM_MAX_BO_PRIORITY];
306 * Protected by @move_lock.
308 struct dma_fence *move;
312 * struct ttm_bo_driver
314 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
315 * @invalidate_caches: Callback to invalidate read caches when a buffer object
317 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
319 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
320 * @move: Callback for a driver to hook in accelerated functions to
322 * If set to NULL, a potentially slow memcpy() move is used.
325 struct ttm_bo_driver {
329 * @bdev: pointer to a struct ttm_bo_device:
330 * @size: Size of the data needed backing.
331 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
332 * @dummy_read_page: See struct ttm_bo_device.
334 * Create a struct ttm_tt to back data with system memory pages.
335 * No pages are actually allocated.
337 * NULL: Out of memory.
339 struct ttm_tt *(*ttm_tt_create)(struct ttm_bo_device *bdev,
342 struct page *dummy_read_page);
347 * @ttm: The struct ttm_tt to contain the backing pages.
349 * Allocate all backing pages
351 * -ENOMEM: Out of memory.
353 int (*ttm_tt_populate)(struct ttm_tt *ttm);
358 * @ttm: The struct ttm_tt to contain the backing pages.
360 * Free all backing page
362 void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);
365 * struct ttm_bo_driver member invalidate_caches
367 * @bdev: the buffer object device.
368 * @flags: new placement of the rebound buffer object.
370 * A previosly evicted buffer has been rebound in a
371 * potentially new location. Tell the driver that it might
372 * consider invalidating read (texture) caches on the next command
373 * submission as a consequence.
376 int (*invalidate_caches)(struct ttm_bo_device *bdev, uint32_t flags);
377 int (*init_mem_type)(struct ttm_bo_device *bdev, uint32_t type,
378 struct ttm_mem_type_manager *man);
381 * struct ttm_bo_driver member eviction_valuable
383 * @bo: the buffer object to be evicted
384 * @place: placement we need room for
386 * Check with the driver if it is valuable to evict a BO to make room
387 * for a certain placement.
389 bool (*eviction_valuable)(struct ttm_buffer_object *bo,
390 const struct ttm_place *place);
392 * struct ttm_bo_driver member evict_flags:
394 * @bo: the buffer object to be evicted
396 * Return the bo flags for a buffer which is not mapped to the hardware.
397 * These will be placed in proposed_flags so that when the move is
398 * finished, they'll end up in bo->mem.flags
401 void (*evict_flags)(struct ttm_buffer_object *bo,
402 struct ttm_placement *placement);
405 * struct ttm_bo_driver member move:
407 * @bo: the buffer to move
408 * @evict: whether this motion is evicting the buffer from
409 * the graphics address space
410 * @interruptible: Use interruptible sleeps if possible when sleeping.
411 * @no_wait: whether this should give up and return -EBUSY
412 * if this move would require sleeping
413 * @new_mem: the new memory region receiving the buffer
415 * Move a buffer between two memory regions.
417 int (*move)(struct ttm_buffer_object *bo, bool evict,
418 bool interruptible, bool no_wait_gpu,
419 struct ttm_mem_reg *new_mem);
422 * struct ttm_bo_driver_member verify_access
424 * @bo: Pointer to a buffer object.
425 * @filp: Pointer to a struct file trying to access the object.
427 * Called from the map / write / read methods to verify that the
428 * caller is permitted to access the buffer object.
429 * This member may be set to NULL, which will refuse this kind of
430 * access for all buffer objects.
431 * This function should return 0 if access is granted, -EPERM otherwise.
433 int (*verify_access)(struct ttm_buffer_object *bo,
437 * Hook to notify driver about a driver move so it
438 * can do tiling things and book-keeping.
440 * @evict: whether this move is evicting the buffer from the graphics
443 void (*move_notify)(struct ttm_buffer_object *bo,
445 struct ttm_mem_reg *new_mem);
446 /* notify the driver we are taking a fault on this BO
447 * and have reserved it */
448 int (*fault_reserve_notify)(struct ttm_buffer_object *bo);
451 * notify the driver that we're about to swap out this bo
453 void (*swap_notify)(struct ttm_buffer_object *bo);
456 * Driver callback on when mapping io memory (for bo_move_memcpy
457 * for instance). TTM will take care to call io_mem_free whenever
458 * the mapping is not use anymore. io_mem_reserve & io_mem_free
461 int (*io_mem_reserve)(struct ttm_bo_device *bdev,
462 struct ttm_mem_reg *mem);
463 void (*io_mem_free)(struct ttm_bo_device *bdev,
464 struct ttm_mem_reg *mem);
468 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
471 struct ttm_bo_global_ref {
472 struct drm_global_reference ref;
473 struct ttm_mem_global *mem_glob;
477 * struct ttm_bo_global - Buffer object driver global data.
479 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
480 * @dummy_read_page: Pointer to a dummy page used for mapping requests
481 * of unpopulated pages.
482 * @shrink: A shrink callback object used for buffer object swap.
483 * @device_list_mutex: Mutex protecting the device list.
484 * This mutex is held while traversing the device list for pm options.
485 * @lru_lock: Spinlock protecting the bo subsystem lru lists.
486 * @device_list: List of buffer object devices.
487 * @swap_lru: Lru list of buffer objects used for swapping.
490 struct ttm_bo_global {
493 * Constant after init.
497 struct ttm_mem_global *mem_glob;
498 struct page *dummy_read_page;
499 struct ttm_mem_shrink shrink;
500 struct mutex device_list_mutex;
504 * Protected by device_list_mutex.
506 struct list_head device_list;
509 * Protected by the lru_lock.
511 struct list_head swap_lru[TTM_MAX_BO_PRIORITY];
514 * Internal protection.
520 #define TTM_NUM_MEM_TYPES 8
523 * struct ttm_bo_device - Buffer object driver device-specific data.
525 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
526 * @man: An array of mem_type_managers.
527 * @vma_manager: Address space manager
528 * lru_lock: Spinlock that protects the buffer+device lru lists and
530 * @dev_mapping: A pointer to the struct address_space representing the
531 * device address space.
532 * @wq: Work queue structure for the delayed delete workqueue.
536 struct ttm_bo_device {
539 * Constant after bo device init / atomic.
541 struct list_head device_list;
542 struct ttm_bo_global *glob;
543 struct ttm_bo_driver *driver;
544 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
547 * Protected by internal locks.
549 struct drm_vma_offset_manager vma_manager;
552 * Protected by the global:lru lock.
554 struct list_head ddestroy;
557 * Protected by load / firstopen / lastclose /unload sync.
560 struct address_space *dev_mapping;
563 * Internal protection.
566 struct delayed_work wq;
574 * @old: Pointer to the result and original value.
575 * @new: New value of bits.
576 * @mask: Mask of bits to change.
578 * Convenience function to change a number of bits identified by a mask.
581 static inline uint32_t
582 ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
584 *old ^= (*old ^ new) & mask;
591 * @ttm: The struct ttm_tt.
592 * @bdev: pointer to a struct ttm_bo_device:
593 * @size: Size of the data needed backing.
594 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
595 * @dummy_read_page: See struct ttm_bo_device.
597 * Create a struct ttm_tt to back data with system memory pages.
598 * No pages are actually allocated.
600 * NULL: Out of memory.
602 extern int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
603 unsigned long size, uint32_t page_flags,
604 struct page *dummy_read_page);
605 extern int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
606 unsigned long size, uint32_t page_flags,
607 struct page *dummy_read_page);
612 * @ttm: the ttm_tt structure.
614 * Free memory of ttm_tt structure
616 extern void ttm_tt_fini(struct ttm_tt *ttm);
617 extern void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma);
622 * @ttm: The struct ttm_tt containing backing pages.
623 * @bo_mem: The struct ttm_mem_reg identifying the binding location.
625 * Bind the pages of @ttm to an aperture location identified by @bo_mem
627 extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
632 * @ttm: The struct ttm_tt.
634 * Unbind, unpopulate and destroy common struct ttm_tt.
636 extern void ttm_tt_destroy(struct ttm_tt *ttm);
641 * @ttm: The struct ttm_tt.
643 * Unbind a struct ttm_tt.
645 extern void ttm_tt_unbind(struct ttm_tt *ttm);
650 * @ttm: The struct ttm_tt.
652 * Swap in a previously swap out ttm_tt.
654 extern int ttm_tt_swapin(struct ttm_tt *ttm);
657 * ttm_tt_set_placement_caching:
659 * @ttm A struct ttm_tt the backing pages of which will change caching policy.
660 * @placement: Flag indicating the desired caching policy.
662 * This function will change caching policy of any default kernel mappings of
663 * the pages backing @ttm. If changing from cached to uncached or
665 * all CPU caches will first be flushed to make sure the data of the pages
666 * hit RAM. This function may be very costly as it involves global TLB
667 * and cache flushes and potential page splitting / combining.
669 extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
670 extern int ttm_tt_swapout(struct ttm_tt *ttm,
671 struct file *persistent_swap_storage);
674 * ttm_tt_unpopulate - free pages from a ttm
676 * @ttm: Pointer to the ttm_tt structure
678 * Calls the driver method to free all pages from a ttm
680 extern void ttm_tt_unpopulate(struct ttm_tt *ttm);
689 * @bdev: Pointer to a struct ttm_bo_device.
690 * @mem: A valid struct ttm_mem_reg.
692 * Returns true if the memory described by @mem is PCI memory,
695 extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
696 struct ttm_mem_reg *mem);
701 * @bo: Pointer to a struct ttm_buffer_object. the data of which
702 * we want to allocate space for.
703 * @proposed_placement: Proposed new placement for the buffer object.
704 * @mem: A struct ttm_mem_reg.
705 * @interruptible: Sleep interruptible when sliping.
706 * @no_wait_gpu: Return immediately if the GPU is busy.
708 * Allocate memory space for the buffer object pointed to by @bo, using
709 * the placement flags in @mem, potentially evicting other idle buffer objects.
710 * This function may sleep while waiting for space to become available.
712 * -EBUSY: No space available (only if no_wait == 1).
713 * -ENOMEM: Could not allocate memory for the buffer object, either due to
714 * fragmentation or concurrent allocators.
715 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
717 extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
718 struct ttm_placement *placement,
719 struct ttm_mem_reg *mem,
723 extern void ttm_bo_mem_put(struct ttm_buffer_object *bo,
724 struct ttm_mem_reg *mem);
725 extern void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo,
726 struct ttm_mem_reg *mem);
728 extern void ttm_bo_global_release(struct drm_global_reference *ref);
729 extern int ttm_bo_global_init(struct drm_global_reference *ref);
731 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
736 * @bdev: A pointer to a struct ttm_bo_device to initialize.
737 * @glob: A pointer to an initialized struct ttm_bo_global.
738 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
739 * @mapping: The address space to use for this bo.
740 * @file_page_offset: Offset into the device address space that is available
741 * for buffer data. This ensures compatibility with other users of the
744 * Initializes a struct ttm_bo_device:
748 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
749 struct ttm_bo_global *glob,
750 struct ttm_bo_driver *driver,
751 struct address_space *mapping,
752 uint64_t file_page_offset, bool need_dma32);
755 * ttm_bo_unmap_virtual
757 * @bo: tear down the virtual mappings for this BO
759 extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
762 * ttm_bo_unmap_virtual
764 * @bo: tear down the virtual mappings for this BO
766 * The caller must take ttm_mem_io_lock before calling this function.
768 extern void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);
770 extern int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
771 extern void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
772 extern int ttm_mem_io_lock(struct ttm_mem_type_manager *man,
774 extern void ttm_mem_io_unlock(struct ttm_mem_type_manager *man);
776 extern void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo);
777 extern void ttm_bo_add_to_lru(struct ttm_buffer_object *bo);
782 * @bo: A pointer to a struct ttm_buffer_object.
783 * @interruptible: Sleep interruptible if waiting.
784 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
785 * @ticket: ticket used to acquire the ww_mutex.
787 * Will not remove reserved buffers from the lru lists.
788 * Otherwise identical to ttm_bo_reserve.
791 * -EDEADLK: The reservation may cause a deadlock.
792 * Release all buffer reservations, wait for @bo to become unreserved and
793 * try again. (only if use_sequence == 1).
794 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
795 * a signal. Release all buffer reservations and return to user-space.
796 * -EBUSY: The function needed to sleep, but @no_wait was true
797 * -EALREADY: Bo already reserved using @ticket. This error code will only
798 * be returned if @use_ticket is set to true.
800 static inline int __ttm_bo_reserve(struct ttm_buffer_object *bo,
801 bool interruptible, bool no_wait,
802 struct ww_acquire_ctx *ticket)
811 success = ww_mutex_trylock(&bo->resv->lock);
812 return success ? 0 : -EBUSY;
816 ret = ww_mutex_lock_interruptible(&bo->resv->lock, ticket);
818 ret = ww_mutex_lock(&bo->resv->lock, ticket);
827 * @bo: A pointer to a struct ttm_buffer_object.
828 * @interruptible: Sleep interruptible if waiting.
829 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
830 * @ticket: ticket used to acquire the ww_mutex.
832 * Locks a buffer object for validation. (Or prevents other processes from
833 * locking it for validation) and removes it from lru lists, while taking
834 * a number of measures to prevent deadlocks.
836 * Deadlocks may occur when two processes try to reserve multiple buffers in
837 * different order, either by will or as a result of a buffer being evicted
838 * to make room for a buffer already reserved. (Buffers are reserved before
839 * they are evicted). The following algorithm prevents such deadlocks from
841 * Processes attempting to reserve multiple buffers other than for eviction,
842 * (typically execbuf), should first obtain a unique 32-bit
843 * validation sequence number,
844 * and call this function with @use_ticket == 1 and @ticket->stamp == the unique
845 * sequence number. If upon call of this function, the buffer object is already
846 * reserved, the validation sequence is checked against the validation
847 * sequence of the process currently reserving the buffer,
848 * and if the current validation sequence is greater than that of the process
849 * holding the reservation, the function returns -EDEADLK. Otherwise it sleeps
850 * waiting for the buffer to become unreserved, after which it retries
852 * The caller should, when receiving an -EDEADLK error
853 * release all its buffer reservations, wait for @bo to become unreserved, and
854 * then rerun the validation with the same validation sequence. This procedure
855 * will always guarantee that the process with the lowest validation sequence
856 * will eventually succeed, preventing both deadlocks and starvation.
859 * -EDEADLK: The reservation may cause a deadlock.
860 * Release all buffer reservations, wait for @bo to become unreserved and
861 * try again. (only if use_sequence == 1).
862 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
863 * a signal. Release all buffer reservations and return to user-space.
864 * -EBUSY: The function needed to sleep, but @no_wait was true
865 * -EALREADY: Bo already reserved using @ticket. This error code will only
866 * be returned if @use_ticket is set to true.
868 static inline int ttm_bo_reserve(struct ttm_buffer_object *bo,
869 bool interruptible, bool no_wait,
870 struct ww_acquire_ctx *ticket)
874 WARN_ON(!kref_read(&bo->kref));
876 ret = __ttm_bo_reserve(bo, interruptible, no_wait, ticket);
877 if (likely(ret == 0))
878 ttm_bo_del_sub_from_lru(bo);
884 * ttm_bo_reserve_slowpath:
885 * @bo: A pointer to a struct ttm_buffer_object.
886 * @interruptible: Sleep interruptible if waiting.
887 * @sequence: Set (@bo)->sequence to this value after lock
889 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
890 * from all our other reservations. Because there are no other reservations
891 * held by us, this function cannot deadlock any more.
893 static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
895 struct ww_acquire_ctx *ticket)
899 WARN_ON(!kref_read(&bo->kref));
902 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
905 ww_mutex_lock_slow(&bo->resv->lock, ticket);
907 if (likely(ret == 0))
908 ttm_bo_del_sub_from_lru(bo);
909 else if (ret == -EINTR)
917 * @bo: A pointer to a struct ttm_buffer_object.
919 * Unreserve a previous reservation of @bo where the buffer object is
920 * already on lru lists.
922 static inline void __ttm_bo_unreserve(struct ttm_buffer_object *bo)
924 ww_mutex_unlock(&bo->resv->lock);
930 * @bo: A pointer to a struct ttm_buffer_object.
932 * Unreserve a previous reservation of @bo.
934 static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo)
936 if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
937 spin_lock(&bo->glob->lru_lock);
938 ttm_bo_add_to_lru(bo);
939 spin_unlock(&bo->glob->lru_lock);
941 __ttm_bo_unreserve(bo);
945 * ttm_bo_unreserve_ticket
946 * @bo: A pointer to a struct ttm_buffer_object.
947 * @ticket: ww_acquire_ctx used for reserving
949 * Unreserve a previous reservation of @bo made with @ticket.
951 static inline void ttm_bo_unreserve_ticket(struct ttm_buffer_object *bo,
952 struct ww_acquire_ctx *t)
954 ttm_bo_unreserve(bo);
961 int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
962 struct ttm_mem_reg *mem);
963 void ttm_mem_io_free(struct ttm_bo_device *bdev,
964 struct ttm_mem_reg *mem);
968 * @bo: A pointer to a struct ttm_buffer_object.
969 * @interruptible: Sleep interruptible if waiting.
970 * @no_wait_gpu: Return immediately if the GPU is busy.
971 * @new_mem: struct ttm_mem_reg indicating where to move.
973 * Optimized move function for a buffer object with both old and
974 * new placement backed by a TTM. The function will, if successful,
975 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
976 * and update the (@bo)->mem placement flags. If unsuccessful, the old
977 * data remains untouched, and it's up to the caller to free the
978 * memory space indicated by @new_mem.
983 extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
984 bool interruptible, bool no_wait_gpu,
985 struct ttm_mem_reg *new_mem);
990 * @bo: A pointer to a struct ttm_buffer_object.
991 * @interruptible: Sleep interruptible if waiting.
992 * @no_wait_gpu: Return immediately if the GPU is busy.
993 * @new_mem: struct ttm_mem_reg indicating where to move.
995 * Fallback move function for a mappable buffer object in mappable memory.
996 * The function will, if successful,
997 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
998 * and update the (@bo)->mem placement flags. If unsuccessful, the old
999 * data remains untouched, and it's up to the caller to free the
1000 * memory space indicated by @new_mem.
1005 extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
1006 bool interruptible, bool no_wait_gpu,
1007 struct ttm_mem_reg *new_mem);
1010 * ttm_bo_free_old_node
1012 * @bo: A pointer to a struct ttm_buffer_object.
1014 * Utility function to free an old placement after a successful move.
1016 extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
1019 * ttm_bo_move_accel_cleanup.
1021 * @bo: A pointer to a struct ttm_buffer_object.
1022 * @fence: A fence object that signals when moving is complete.
1023 * @evict: This is an evict move. Don't return until the buffer is idle.
1024 * @new_mem: struct ttm_mem_reg indicating where to move.
1026 * Accelerated move function to be called when an accelerated move
1027 * has been scheduled. The function will create a new temporary buffer object
1028 * representing the old placement, and put the sync object on both buffer
1029 * objects. After that the newly created buffer object is unref'd to be
1030 * destroyed when the move is complete. This will help pipeline
1034 extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
1035 struct dma_fence *fence, bool evict,
1036 struct ttm_mem_reg *new_mem);
1039 * ttm_bo_pipeline_move.
1041 * @bo: A pointer to a struct ttm_buffer_object.
1042 * @fence: A fence object that signals when moving is complete.
1043 * @evict: This is an evict move. Don't return until the buffer is idle.
1044 * @new_mem: struct ttm_mem_reg indicating where to move.
1046 * Function for pipelining accelerated moves. Either free the memory
1047 * immediately or hang it on a temporary buffer object.
1049 int ttm_bo_pipeline_move(struct ttm_buffer_object *bo,
1050 struct dma_fence *fence, bool evict,
1051 struct ttm_mem_reg *new_mem);
1056 * @c_state: Caching state.
1057 * @tmp: Page protection flag for a normal, cached mapping.
1059 * Utility function that returns the pgprot_t that should be used for
1060 * setting up a PTE with the caching model indicated by @c_state.
1062 extern pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp);
1064 extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
1066 #if IS_ENABLED(CONFIG_AGP)
1067 #include <linux/agp_backend.h>
1072 * @bdev: Pointer to a struct ttm_bo_device.
1073 * @bridge: The agp bridge this device is sitting on.
1074 * @size: Size of the data needed backing.
1075 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
1076 * @dummy_read_page: See struct ttm_bo_device.
1079 * Create a TTM backend that uses the indicated AGP bridge as an aperture
1080 * for TT memory. This function uses the linux agpgart interface to
1081 * bind and unbind memory backing a ttm_tt.
1083 extern struct ttm_tt *ttm_agp_tt_create(struct ttm_bo_device *bdev,
1084 struct agp_bridge_data *bridge,
1085 unsigned long size, uint32_t page_flags,
1086 struct page *dummy_read_page);
1087 int ttm_agp_tt_populate(struct ttm_tt *ttm);
1088 void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);