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
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.
26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
32 #ifndef _TTM_BO_DRIVER_H_
33 #define _TTM_BO_DRIVER_H_
35 #include <dev/drm2/drmP.h>
36 #include <dev/drm2/ttm/ttm_bo_api.h>
37 #include <dev/drm2/ttm/ttm_memory.h>
38 #include <dev/drm2/ttm/ttm_module.h>
39 #include <dev/drm2/drm_global.h>
40 #include <sys/rwlock.h>
43 struct ttm_backend_func {
45 * struct ttm_backend_func member bind
47 * @ttm: Pointer to a struct ttm_tt.
48 * @bo_mem: Pointer to a struct ttm_mem_reg describing the
49 * memory type and location for binding.
51 * Bind the backend pages into the aperture in the location
52 * indicated by @bo_mem. This function should be able to handle
53 * differences between aperture and system page sizes.
55 int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
58 * struct ttm_backend_func member unbind
60 * @ttm: Pointer to a struct ttm_tt.
62 * Unbind previously bound backend pages. This function should be
63 * able to handle differences between aperture and system page sizes.
65 int (*unbind) (struct ttm_tt *ttm);
68 * struct ttm_backend_func member destroy
70 * @ttm: Pointer to a struct ttm_tt.
72 * Destroy the backend. This will be call back from ttm_tt_destroy so
73 * don't call ttm_tt_destroy from the callback or infinite loop.
75 void (*destroy) (struct ttm_tt *ttm);
78 #define TTM_PAGE_FLAG_WRITE (1 << 3)
79 #define TTM_PAGE_FLAG_SWAPPED (1 << 4)
80 #define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
81 #define TTM_PAGE_FLAG_ZERO_ALLOC (1 << 6)
82 #define TTM_PAGE_FLAG_DMA32 (1 << 7)
83 #define TTM_PAGE_FLAG_SG (1 << 8)
85 enum ttm_caching_state {
94 * @bdev: Pointer to a struct ttm_bo_device.
95 * @func: Pointer to a struct ttm_backend_func that describes
96 * the backend methods.
97 * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL
99 * @pages: Array of pages backing the data.
100 * @num_pages: Number of pages in the page array.
101 * @bdev: Pointer to the current struct ttm_bo_device.
102 * @be: Pointer to the ttm backend.
103 * @swap_storage: Pointer to shmem struct file for swap storage.
104 * @caching_state: The current caching state of the pages.
105 * @state: The current binding state of the pages.
107 * This is a structure holding the pages, caching- and aperture binding
108 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
113 struct ttm_bo_device *bdev;
114 struct ttm_backend_func *func;
115 struct vm_page *dummy_read_page;
116 struct vm_page **pages;
118 unsigned long num_pages;
119 struct sg_table *sg; /* for SG objects via dma-buf */
120 struct ttm_bo_global *glob;
121 struct vm_object *swap_storage;
122 enum ttm_caching_state caching_state;
133 * @ttm: Base ttm_tt struct.
134 * @dma_address: The DMA (bus) addresses of the pages
135 * @pages_list: used by some page allocation backend
137 * This is a structure holding the pages, caching- and aperture binding
138 * status for a buffer object that isn't backed by fixed (VRAM / AGP)
143 dma_addr_t *dma_address;
144 struct list_head pages_list;
147 #define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */
148 #define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */
149 #define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */
151 struct ttm_mem_type_manager;
153 struct ttm_mem_type_manager_func {
155 * struct ttm_mem_type_manager member init
157 * @man: Pointer to a memory type manager.
158 * @p_size: Implementation dependent, but typically the size of the
159 * range to be managed in pages.
161 * Called to initialize a private range manager. The function is
162 * expected to initialize the man::priv member.
163 * Returns 0 on success, negative error code on failure.
165 int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size);
168 * struct ttm_mem_type_manager member takedown
170 * @man: Pointer to a memory type manager.
172 * Called to undo the setup done in init. All allocated resources
175 int (*takedown)(struct ttm_mem_type_manager *man);
178 * struct ttm_mem_type_manager member get_node
180 * @man: Pointer to a memory type manager.
181 * @bo: Pointer to the buffer object we're allocating space for.
182 * @placement: Placement details.
183 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
185 * This function should allocate space in the memory type managed
186 * by @man. Placement details if
187 * applicable are given by @placement. If successful,
188 * @mem::mm_node should be set to a non-null value, and
189 * @mem::start should be set to a value identifying the beginning
190 * of the range allocated, and the function should return zero.
191 * If the memory region accommodate the buffer object, @mem::mm_node
192 * should be set to NULL, and the function should return 0.
193 * If a system error occurred, preventing the request to be fulfilled,
194 * the function should return a negative error code.
196 * Note that @mem::mm_node will only be dereferenced by
197 * struct ttm_mem_type_manager functions and optionally by the driver,
198 * which has knowledge of the underlying type.
200 * This function may not be called from within atomic context, so
201 * an implementation can and must use either a mutex or a spinlock to
202 * protect any data structures managing the space.
204 int (*get_node)(struct ttm_mem_type_manager *man,
205 struct ttm_buffer_object *bo,
206 struct ttm_placement *placement,
207 struct ttm_mem_reg *mem);
210 * struct ttm_mem_type_manager member put_node
212 * @man: Pointer to a memory type manager.
213 * @mem: Pointer to a struct ttm_mem_reg to be filled in.
215 * This function frees memory type resources previously allocated
216 * and that are identified by @mem::mm_node and @mem::start. May not
217 * be called from within atomic context.
219 void (*put_node)(struct ttm_mem_type_manager *man,
220 struct ttm_mem_reg *mem);
223 * struct ttm_mem_type_manager member debug
225 * @man: Pointer to a memory type manager.
226 * @prefix: Prefix to be used in printout to identify the caller.
228 * This function is called to print out the state of the memory
229 * type manager to aid debugging of out-of-memory conditions.
230 * It may not be called from within atomic context.
232 void (*debug)(struct ttm_mem_type_manager *man, const char *prefix);
236 * struct ttm_mem_type_manager
238 * @has_type: The memory type has been initialized.
239 * @use_type: The memory type is enabled.
240 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
241 * managed by this memory type.
242 * @gpu_offset: If used, the GPU offset of the first managed page of
243 * fixed memory or the first managed location in an aperture.
244 * @size: Size of the managed region.
245 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
246 * as defined in ttm_placement_common.h
247 * @default_caching: The default caching policy used for a buffer object
248 * placed in this memory type if the user doesn't provide one.
249 * @func: structure pointer implementing the range manager. See above
250 * @priv: Driver private closure for @func.
251 * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures
252 * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions
253 * reserved by the TTM vm system.
254 * @io_reserve_lru: Optional lru list for unreserving io mem regions.
255 * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain
256 * static information. bdev::driver::io_mem_free is never used.
257 * @lru: The lru list for this memory type.
259 * This structure is used to identify and manage memory types for a device.
260 * It's set up by the ttm_bo_driver::init_mem_type method.
265 struct ttm_mem_type_manager {
266 struct ttm_bo_device *bdev;
269 * No protection. Constant from start.
275 unsigned long gpu_offset;
277 uint32_t available_caching;
278 uint32_t default_caching;
279 const struct ttm_mem_type_manager_func *func;
281 struct sx io_reserve_mutex;
282 bool use_io_reserve_lru;
283 bool io_reserve_fastpath;
286 * Protected by @io_reserve_mutex:
289 struct list_head io_reserve_lru;
292 * Protected by the global->lru_lock.
295 struct list_head lru;
299 * struct ttm_bo_driver
301 * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
302 * @invalidate_caches: Callback to invalidate read caches when a buffer object
304 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
306 * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
307 * @move: Callback for a driver to hook in accelerated functions to
309 * If set to NULL, a potentially slow memcpy() move is used.
310 * @sync_obj_signaled: See ttm_fence_api.h
311 * @sync_obj_wait: See ttm_fence_api.h
312 * @sync_obj_flush: See ttm_fence_api.h
313 * @sync_obj_unref: See ttm_fence_api.h
314 * @sync_obj_ref: See ttm_fence_api.h
317 struct ttm_bo_driver {
321 * @bdev: pointer to a struct ttm_bo_device:
322 * @size: Size of the data needed backing.
323 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
324 * @dummy_read_page: See struct ttm_bo_device.
326 * Create a struct ttm_tt to back data with system memory pages.
327 * No pages are actually allocated.
329 * NULL: Out of memory.
331 struct ttm_tt *(*ttm_tt_create)(struct ttm_bo_device *bdev,
334 struct vm_page *dummy_read_page);
339 * @ttm: The struct ttm_tt to contain the backing pages.
341 * Allocate all backing pages
343 * -ENOMEM: Out of memory.
345 int (*ttm_tt_populate)(struct ttm_tt *ttm);
350 * @ttm: The struct ttm_tt to contain the backing pages.
352 * Free all backing page
354 void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);
357 * struct ttm_bo_driver member invalidate_caches
359 * @bdev: the buffer object device.
360 * @flags: new placement of the rebound buffer object.
362 * A previosly evicted buffer has been rebound in a
363 * potentially new location. Tell the driver that it might
364 * consider invalidating read (texture) caches on the next command
365 * submission as a consequence.
368 int (*invalidate_caches) (struct ttm_bo_device *bdev, uint32_t flags);
369 int (*init_mem_type) (struct ttm_bo_device *bdev, uint32_t type,
370 struct ttm_mem_type_manager *man);
372 * struct ttm_bo_driver member evict_flags:
374 * @bo: the buffer object to be evicted
376 * Return the bo flags for a buffer which is not mapped to the hardware.
377 * These will be placed in proposed_flags so that when the move is
378 * finished, they'll end up in bo->mem.flags
381 void(*evict_flags) (struct ttm_buffer_object *bo,
382 struct ttm_placement *placement);
384 * struct ttm_bo_driver member move:
386 * @bo: the buffer to move
387 * @evict: whether this motion is evicting the buffer from
388 * the graphics address space
389 * @interruptible: Use interruptible sleeps if possible when sleeping.
390 * @no_wait: whether this should give up and return -EBUSY
391 * if this move would require sleeping
392 * @new_mem: the new memory region receiving the buffer
394 * Move a buffer between two memory regions.
396 int (*move) (struct ttm_buffer_object *bo,
397 bool evict, bool interruptible,
399 struct ttm_mem_reg *new_mem);
402 * struct ttm_bo_driver_member verify_access
404 * @bo: Pointer to a buffer object.
405 * @filp: Pointer to a struct file trying to access the object.
406 * FreeBSD: use devfs_get_cdevpriv etc.
408 * Called from the map / write / read methods to verify that the
409 * caller is permitted to access the buffer object.
410 * This member may be set to NULL, which will refuse this kind of
411 * access for all buffer objects.
412 * This function should return 0 if access is granted, -EPERM otherwise.
414 int (*verify_access) (struct ttm_buffer_object *bo);
417 * In case a driver writer dislikes the TTM fence objects,
418 * the driver writer can replace those with sync objects of
419 * his / her own. If it turns out that no driver writer is
420 * using these. I suggest we remove these hooks and plug in
421 * fences directly. The bo driver needs the following functionality:
422 * See the corresponding functions in the fence object API
426 bool (*sync_obj_signaled) (void *sync_obj);
427 int (*sync_obj_wait) (void *sync_obj,
428 bool lazy, bool interruptible);
429 int (*sync_obj_flush) (void *sync_obj);
430 void (*sync_obj_unref) (void **sync_obj);
431 void *(*sync_obj_ref) (void *sync_obj);
433 /* hook to notify driver about a driver move so it
434 * can do tiling things */
435 void (*move_notify)(struct ttm_buffer_object *bo,
436 struct ttm_mem_reg *new_mem);
437 /* notify the driver we are taking a fault on this BO
438 * and have reserved it */
439 int (*fault_reserve_notify)(struct ttm_buffer_object *bo);
442 * notify the driver that we're about to swap out this bo
444 void (*swap_notify) (struct ttm_buffer_object *bo);
447 * Driver callback on when mapping io memory (for bo_move_memcpy
448 * for instance). TTM will take care to call io_mem_free whenever
449 * the mapping is not use anymore. io_mem_reserve & io_mem_free
452 int (*io_mem_reserve)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
453 void (*io_mem_free)(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem);
457 * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
460 struct ttm_bo_global_ref {
461 struct drm_global_reference ref;
462 struct ttm_mem_global *mem_glob;
466 * struct ttm_bo_global - Buffer object driver global data.
468 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
469 * @dummy_read_page: Pointer to a dummy page used for mapping requests
470 * of unpopulated pages.
471 * @shrink: A shrink callback object used for buffer object swap.
472 * @device_list_mutex: Mutex protecting the device list.
473 * This mutex is held while traversing the device list for pm options.
474 * @lru_lock: Spinlock protecting the bo subsystem lru lists.
475 * @device_list: List of buffer object devices.
476 * @swap_lru: Lru list of buffer objects used for swapping.
479 struct ttm_bo_global {
483 * Constant after init.
486 struct ttm_mem_global *mem_glob;
487 struct vm_page *dummy_read_page;
488 struct ttm_mem_shrink shrink;
489 struct sx device_list_mutex;
493 * Protected by device_list_mutex.
495 struct list_head device_list;
498 * Protected by the lru_lock.
500 struct list_head swap_lru;
503 * Internal protection.
509 #define TTM_NUM_MEM_TYPES 8
511 #define TTM_BO_PRIV_FLAG_MOVING 0 /* Buffer object is moving and needs
512 idling before CPU mapping */
513 #define TTM_BO_PRIV_FLAG_MAX 1
515 * struct ttm_bo_device - Buffer object driver device-specific data.
517 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
518 * @man: An array of mem_type_managers.
519 * @fence_lock: Protects the synchronizing members on *all* bos belonging
521 * @addr_space_mm: Range manager for the device address space.
522 * lru_lock: Spinlock that protects the buffer+device lru lists and
524 * @val_seq: Current validation sequence.
525 * @dev_mapping: A pointer to the struct address_space representing the
526 * device address space.
527 * @wq: Work queue structure for the delayed delete workqueue.
531 struct ttm_bo_device {
534 * Constant after bo device init / atomic.
536 struct list_head device_list;
537 struct ttm_bo_global *glob;
538 struct ttm_bo_driver *driver;
539 struct rwlock vm_lock;
540 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
541 struct mtx fence_lock;
543 * Protected by the vm lock.
545 RB_HEAD(ttm_bo_device_buffer_objects, ttm_buffer_object) addr_space_rb;
546 struct drm_mm addr_space_mm;
549 * Protected by the global:lru lock.
551 struct list_head ddestroy;
555 * Protected by load / firstopen / lastclose /unload sync.
558 struct address_space *dev_mapping;
561 * Internal protection.
564 struct timeout_task wq;
572 * @old: Pointer to the result and original value.
573 * @new: New value of bits.
574 * @mask: Mask of bits to change.
576 * Convenience function to change a number of bits identified by a mask.
579 static inline uint32_t
580 ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
582 *old ^= (*old ^ new) & mask;
589 * @ttm: The struct ttm_tt.
590 * @bdev: pointer to a struct ttm_bo_device:
591 * @size: Size of the data needed backing.
592 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
593 * @dummy_read_page: See struct ttm_bo_device.
595 * Create a struct ttm_tt to back data with system memory pages.
596 * No pages are actually allocated.
598 * NULL: Out of memory.
600 extern int ttm_tt_init(struct ttm_tt *ttm, struct ttm_bo_device *bdev,
601 unsigned long size, uint32_t page_flags,
602 struct vm_page *dummy_read_page);
603 extern int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_bo_device *bdev,
604 unsigned long size, uint32_t page_flags,
605 struct vm_page *dummy_read_page);
610 * @ttm: the ttm_tt structure.
612 * Free memory of ttm_tt structure
614 extern void ttm_tt_fini(struct ttm_tt *ttm);
615 extern void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma);
620 * @ttm: The struct ttm_tt containing backing pages.
621 * @bo_mem: The struct ttm_mem_reg identifying the binding location.
623 * Bind the pages of @ttm to an aperture location identified by @bo_mem
625 extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
630 * @ttm: The struct ttm_tt.
632 * Unbind, unpopulate and destroy common struct ttm_tt.
634 extern void ttm_tt_destroy(struct ttm_tt *ttm);
639 * @ttm: The struct ttm_tt.
641 * Unbind a struct ttm_tt.
643 extern void ttm_tt_unbind(struct ttm_tt *ttm);
648 * @ttm: The struct ttm_tt.
650 * Swap in a previously swap out ttm_tt.
652 extern int ttm_tt_swapin(struct ttm_tt *ttm);
655 * ttm_tt_cache_flush:
657 * @pages: An array of pointers to struct page:s to flush.
658 * @num_pages: Number of pages to flush.
660 * Flush the data of the indicated pages from the cpu caches.
661 * This is used when changing caching attributes of the pages from
664 extern void ttm_tt_cache_flush(struct vm_page *pages[], unsigned long num_pages);
667 * ttm_tt_set_placement_caching:
669 * @ttm A struct ttm_tt the backing pages of which will change caching policy.
670 * @placement: Flag indicating the desired caching policy.
672 * This function will change caching policy of any default kernel mappings of
673 * the pages backing @ttm. If changing from cached to uncached or
675 * all CPU caches will first be flushed to make sure the data of the pages
676 * hit RAM. This function may be very costly as it involves global TLB
677 * and cache flushes and potential page splitting / combining.
679 extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
680 extern int ttm_tt_swapout(struct ttm_tt *ttm,
681 struct vm_object *persistent_swap_storage);
690 * @bdev: Pointer to a struct ttm_bo_device.
691 * @mem: A valid struct ttm_mem_reg.
693 * Returns true if the memory described by @mem is PCI memory,
696 extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
697 struct ttm_mem_reg *mem);
702 * @bo: Pointer to a struct ttm_buffer_object. the data of which
703 * we want to allocate space for.
704 * @proposed_placement: Proposed new placement for the buffer object.
705 * @mem: A struct ttm_mem_reg.
706 * @interruptible: Sleep interruptible when sliping.
707 * @no_wait_gpu: Return immediately if the GPU is busy.
709 * Allocate memory space for the buffer object pointed to by @bo, using
710 * the placement flags in @mem, potentially evicting other idle buffer objects.
711 * This function may sleep while waiting for space to become available.
713 * -EBUSY: No space available (only if no_wait == 1).
714 * -ENOMEM: Could not allocate memory for the buffer object, either due to
715 * fragmentation or concurrent allocators.
716 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
718 extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
719 struct ttm_placement *placement,
720 struct ttm_mem_reg *mem,
724 extern void ttm_bo_mem_put(struct ttm_buffer_object *bo,
725 struct ttm_mem_reg *mem);
726 extern void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo,
727 struct ttm_mem_reg *mem);
729 extern void ttm_bo_global_release(struct drm_global_reference *ref);
730 extern int ttm_bo_global_init(struct drm_global_reference *ref);
732 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
737 * @bdev: A pointer to a struct ttm_bo_device to initialize.
738 * @glob: A pointer to an initialized struct ttm_bo_global.
739 * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
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 uint64_t file_page_offset, bool need_dma32);
754 * ttm_bo_unmap_virtual
756 * @bo: tear down the virtual mappings for this BO
758 extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
761 * ttm_bo_unmap_virtual
763 * @bo: tear down the virtual mappings for this BO
765 * The caller must take ttm_mem_io_lock before calling this function.
767 extern void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo);
769 extern int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo);
770 extern void ttm_mem_io_free_vm(struct ttm_buffer_object *bo);
771 extern int ttm_mem_io_lock(struct ttm_mem_type_manager *man,
773 extern void ttm_mem_io_unlock(struct ttm_mem_type_manager *man);
779 * @bo: A pointer to a struct ttm_buffer_object.
780 * @interruptible: Sleep interruptible if waiting.
781 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
782 * @use_sequence: If @bo is already reserved, Only sleep waiting for
783 * it to become unreserved if @sequence < (@bo)->sequence.
785 * Locks a buffer object for validation. (Or prevents other processes from
786 * locking it for validation) and removes it from lru lists, while taking
787 * a number of measures to prevent deadlocks.
789 * Deadlocks may occur when two processes try to reserve multiple buffers in
790 * different order, either by will or as a result of a buffer being evicted
791 * to make room for a buffer already reserved. (Buffers are reserved before
792 * they are evicted). The following algorithm prevents such deadlocks from
794 * Processes attempting to reserve multiple buffers other than for eviction,
795 * (typically execbuf), should first obtain a unique 32-bit
796 * validation sequence number,
797 * and call this function with @use_sequence == 1 and @sequence == the unique
798 * sequence number. If upon call of this function, the buffer object is already
799 * reserved, the validation sequence is checked against the validation
800 * sequence of the process currently reserving the buffer,
801 * and if the current validation sequence is greater than that of the process
802 * holding the reservation, the function returns -EAGAIN. Otherwise it sleeps
803 * waiting for the buffer to become unreserved, after which it retries
805 * The caller should, when receiving an -EAGAIN error
806 * release all its buffer reservations, wait for @bo to become unreserved, and
807 * then rerun the validation with the same validation sequence. This procedure
808 * will always guarantee that the process with the lowest validation sequence
809 * will eventually succeed, preventing both deadlocks and starvation.
812 * -EAGAIN: The reservation may cause a deadlock.
813 * Release all buffer reservations, wait for @bo to become unreserved and
814 * try again. (only if use_sequence == 1).
815 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
816 * a signal. Release all buffer reservations and return to user-space.
817 * -EBUSY: The function needed to sleep, but @no_wait was true
818 * -EDEADLK: Bo already reserved using @sequence. This error code will only
819 * be returned if @use_sequence is set to true.
821 extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
823 bool no_wait, bool use_sequence, uint32_t sequence);
826 * ttm_bo_reserve_slowpath_nolru:
827 * @bo: A pointer to a struct ttm_buffer_object.
828 * @interruptible: Sleep interruptible if waiting.
829 * @sequence: Set (@bo)->sequence to this value after lock
831 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
832 * from all our other reservations. Because there are no other reservations
833 * held by us, this function cannot deadlock any more.
835 * Will not remove reserved buffers from the lru lists.
836 * Otherwise identical to ttm_bo_reserve_slowpath.
838 extern int ttm_bo_reserve_slowpath_nolru(struct ttm_buffer_object *bo,
844 * ttm_bo_reserve_slowpath:
845 * @bo: A pointer to a struct ttm_buffer_object.
846 * @interruptible: Sleep interruptible if waiting.
847 * @sequence: Set (@bo)->sequence to this value after lock
849 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off
850 * from all our other reservations. Because there are no other reservations
851 * held by us, this function cannot deadlock any more.
853 extern int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
854 bool interruptible, uint32_t sequence);
857 * ttm_bo_reserve_nolru:
859 * @bo: A pointer to a struct ttm_buffer_object.
860 * @interruptible: Sleep interruptible if waiting.
861 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
862 * @use_sequence: If @bo is already reserved, Only sleep waiting for
863 * it to become unreserved if @sequence < (@bo)->sequence.
865 * Will not remove reserved buffers from the lru lists.
866 * Otherwise identical to ttm_bo_reserve.
869 * -EAGAIN: The reservation may cause a deadlock.
870 * Release all buffer reservations, wait for @bo to become unreserved and
871 * try again. (only if use_sequence == 1).
872 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
873 * a signal. Release all buffer reservations and return to user-space.
874 * -EBUSY: The function needed to sleep, but @no_wait was true
875 * -EDEADLK: Bo already reserved using @sequence. This error code will only
876 * be returned if @use_sequence is set to true.
878 extern int ttm_bo_reserve_nolru(struct ttm_buffer_object *bo,
880 bool no_wait, bool use_sequence,
886 * @bo: A pointer to a struct ttm_buffer_object.
888 * Unreserve a previous reservation of @bo.
890 extern void ttm_bo_unreserve(struct ttm_buffer_object *bo);
893 * ttm_bo_unreserve_locked
895 * @bo: A pointer to a struct ttm_buffer_object.
897 * Unreserve a previous reservation of @bo.
898 * Needs to be called with struct ttm_bo_global::lru_lock held.
900 extern void ttm_bo_unreserve_locked(struct ttm_buffer_object *bo);
909 * @bo: A pointer to a struct ttm_buffer_object.
910 * @evict: 1: This is an eviction. Don't try to pipeline.
911 * @no_wait_gpu: Return immediately if the GPU is busy.
912 * @new_mem: struct ttm_mem_reg indicating where to move.
914 * Optimized move function for a buffer object with both old and
915 * new placement backed by a TTM. The function will, if successful,
916 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
917 * and update the (@bo)->mem placement flags. If unsuccessful, the old
918 * data remains untouched, and it's up to the caller to free the
919 * memory space indicated by @new_mem.
924 extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
925 bool evict, bool no_wait_gpu,
926 struct ttm_mem_reg *new_mem);
931 * @bo: A pointer to a struct ttm_buffer_object.
932 * @evict: 1: This is an eviction. Don't try to pipeline.
933 * @no_wait_gpu: Return immediately if the GPU is busy.
934 * @new_mem: struct ttm_mem_reg indicating where to move.
936 * Fallback move function for a mappable buffer object in mappable memory.
937 * The function will, if successful,
938 * free any old aperture space, and set (@new_mem)->mm_node to NULL,
939 * and update the (@bo)->mem placement flags. If unsuccessful, the old
940 * data remains untouched, and it's up to the caller to free the
941 * memory space indicated by @new_mem.
946 extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
947 bool evict, bool no_wait_gpu,
948 struct ttm_mem_reg *new_mem);
951 * ttm_bo_free_old_node
953 * @bo: A pointer to a struct ttm_buffer_object.
955 * Utility function to free an old placement after a successful move.
957 extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
960 * ttm_bo_move_accel_cleanup.
962 * @bo: A pointer to a struct ttm_buffer_object.
963 * @sync_obj: A sync object that signals when moving is complete.
964 * @evict: This is an evict move. Don't return until the buffer is idle.
965 * @no_wait_gpu: Return immediately if the GPU is busy.
966 * @new_mem: struct ttm_mem_reg indicating where to move.
968 * Accelerated move function to be called when an accelerated move
969 * has been scheduled. The function will create a new temporary buffer object
970 * representing the old placement, and put the sync object on both buffer
971 * objects. After that the newly created buffer object is unref'd to be
972 * destroyed when the move is complete. This will help pipeline
976 extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
978 bool evict, bool no_wait_gpu,
979 struct ttm_mem_reg *new_mem);
983 * @c_state: Caching state.
984 * @tmp: Page protection flag for a normal, cached mapping.
986 * Utility function that returns the pgprot_t that should be used for
987 * setting up a PTE with the caching model indicated by @c_state.
989 extern vm_memattr_t ttm_io_prot(uint32_t caching_flags);
991 extern const struct ttm_mem_type_manager_func ttm_bo_manager_func;
999 * @bdev: Pointer to a struct ttm_bo_device.
1000 * @bridge: The agp bridge this device is sitting on.
1001 * @size: Size of the data needed backing.
1002 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
1003 * @dummy_read_page: See struct ttm_bo_device.
1006 * Create a TTM backend that uses the indicated AGP bridge as an aperture
1007 * for TT memory. This function uses the linux agpgart interface to
1008 * bind and unbind memory backing a ttm_tt.
1010 extern struct ttm_tt *ttm_agp_tt_create(struct ttm_bo_device *bdev,
1012 unsigned long size, uint32_t page_flags,
1013 struct vm_page *dummy_read_page);
1014 int ttm_agp_tt_populate(struct ttm_tt *ttm);
1015 void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);
1018 int ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a,
1019 struct ttm_buffer_object *b);
1021 RB_PROTOTYPE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb,
1022 ttm_bo_cmp_rb_tree_items);