1/************************************************************************** 2 * 3 * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 24 * USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 **************************************************************************/ 27/* 28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> 29 */ 30#ifndef _TTM_BO_DRIVER_H_ 31#define _TTM_BO_DRIVER_H_ 32 33#include <drm/drm_mm.h> 34#include <drm/drm_vma_manager.h> 35#include <linux/workqueue.h> 36#include <linux/fs.h> 37#include <linux/spinlock.h> 38#include <linux/reservation.h> 39 40#include "ttm_bo_api.h" 41#include "ttm_memory.h" 42#include "ttm_module.h" 43#include "ttm_placement.h" 44#include "ttm_tt.h" 45 46#define TTM_MAX_BO_PRIORITY 4U 47 48#define TTM_MEMTYPE_FLAG_FIXED (1 << 0) /* Fixed (on-card) PCI memory */ 49#define TTM_MEMTYPE_FLAG_MAPPABLE (1 << 1) /* Memory mappable */ 50#define TTM_MEMTYPE_FLAG_CMA (1 << 3) /* Can't map aperture */ 51 52struct ttm_mem_type_manager; 53 54struct ttm_mem_type_manager_func { 55 /** 56 * struct ttm_mem_type_manager member init 57 * 58 * @man: Pointer to a memory type manager. 59 * @p_size: Implementation dependent, but typically the size of the 60 * range to be managed in pages. 61 * 62 * Called to initialize a private range manager. The function is 63 * expected to initialize the man::priv member. 64 * Returns 0 on success, negative error code on failure. 65 */ 66 int (*init)(struct ttm_mem_type_manager *man, unsigned long p_size); 67 68 /** 69 * struct ttm_mem_type_manager member takedown 70 * 71 * @man: Pointer to a memory type manager. 72 * 73 * Called to undo the setup done in init. All allocated resources 74 * should be freed. 75 */ 76 int (*takedown)(struct ttm_mem_type_manager *man); 77 78 /** 79 * struct ttm_mem_type_manager member get_node 80 * 81 * @man: Pointer to a memory type manager. 82 * @bo: Pointer to the buffer object we're allocating space for. 83 * @placement: Placement details. 84 * @flags: Additional placement flags. 85 * @mem: Pointer to a struct ttm_mem_reg to be filled in. 86 * 87 * This function should allocate space in the memory type managed 88 * by @man. Placement details if 89 * applicable are given by @placement. If successful, 90 * @mem::mm_node should be set to a non-null value, and 91 * @mem::start should be set to a value identifying the beginning 92 * of the range allocated, and the function should return zero. 93 * If the memory region accommodate the buffer object, @mem::mm_node 94 * should be set to NULL, and the function should return 0. 95 * If a system error occurred, preventing the request to be fulfilled, 96 * the function should return a negative error code. 97 * 98 * Note that @mem::mm_node will only be dereferenced by 99 * struct ttm_mem_type_manager functions and optionally by the driver, 100 * which has knowledge of the underlying type. 101 * 102 * This function may not be called from within atomic context, so 103 * an implementation can and must use either a mutex or a spinlock to 104 * protect any data structures managing the space. 105 */ 106 int (*get_node)(struct ttm_mem_type_manager *man, 107 struct ttm_buffer_object *bo, 108 const struct ttm_place *place, 109 struct ttm_mem_reg *mem); 110 111 /** 112 * struct ttm_mem_type_manager member put_node 113 * 114 * @man: Pointer to a memory type manager. 115 * @mem: Pointer to a struct ttm_mem_reg to be filled in. 116 * 117 * This function frees memory type resources previously allocated 118 * and that are identified by @mem::mm_node and @mem::start. May not 119 * be called from within atomic context. 120 */ 121 void (*put_node)(struct ttm_mem_type_manager *man, 122 struct ttm_mem_reg *mem); 123 124 /** 125 * struct ttm_mem_type_manager member debug 126 * 127 * @man: Pointer to a memory type manager. 128 * @printer: Prefix to be used in printout to identify the caller. 129 * 130 * This function is called to print out the state of the memory 131 * type manager to aid debugging of out-of-memory conditions. 132 * It may not be called from within atomic context. 133 */ 134 void (*debug)(struct ttm_mem_type_manager *man, 135 struct drm_printer *printer); 136}; 137 138/** 139 * struct ttm_mem_type_manager 140 * 141 * @has_type: The memory type has been initialized. 142 * @use_type: The memory type is enabled. 143 * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory 144 * managed by this memory type. 145 * @gpu_offset: If used, the GPU offset of the first managed page of 146 * fixed memory or the first managed location in an aperture. 147 * @size: Size of the managed region. 148 * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX, 149 * as defined in ttm_placement_common.h 150 * @default_caching: The default caching policy used for a buffer object 151 * placed in this memory type if the user doesn't provide one. 152 * @func: structure pointer implementing the range manager. See above 153 * @priv: Driver private closure for @func. 154 * @io_reserve_mutex: Mutex optionally protecting shared io_reserve structures 155 * @use_io_reserve_lru: Use an lru list to try to unreserve io_mem_regions 156 * reserved by the TTM vm system. 157 * @io_reserve_lru: Optional lru list for unreserving io mem regions. 158 * @io_reserve_fastpath: Only use bdev::driver::io_mem_reserve to obtain 159 * @move_lock: lock for move fence 160 * static information. bdev::driver::io_mem_free is never used. 161 * @lru: The lru list for this memory type. 162 * @move: The fence of the last pipelined move operation. 163 * 164 * This structure is used to identify and manage memory types for a device. 165 * It's set up by the ttm_bo_driver::init_mem_type method. 166 */ 167 168 169 170struct ttm_mem_type_manager { 171 struct ttm_bo_device *bdev; 172 173 /* 174 * No protection. Constant from start. 175 */ 176 177 bool has_type; 178 bool use_type; 179 uint32_t flags; 180 uint64_t gpu_offset; /* GPU address space is independent of CPU word size */ 181 uint64_t size; 182 uint32_t available_caching; 183 uint32_t default_caching; 184 const struct ttm_mem_type_manager_func *func; 185 void *priv; 186 struct mutex io_reserve_mutex; 187 bool use_io_reserve_lru; 188 bool io_reserve_fastpath; 189 spinlock_t move_lock; 190 191 /* 192 * Protected by @io_reserve_mutex: 193 */ 194 195 struct list_head io_reserve_lru; 196 197 /* 198 * Protected by the global->lru_lock. 199 */ 200 201 struct list_head lru[TTM_MAX_BO_PRIORITY]; 202 203 /* 204 * Protected by @move_lock. 205 */ 206 struct dma_fence *move; 207}; 208 209/** 210 * struct ttm_bo_driver 211 * 212 * @create_ttm_backend_entry: Callback to create a struct ttm_backend. 213 * @invalidate_caches: Callback to invalidate read caches when a buffer object 214 * has been evicted. 215 * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager 216 * structure. 217 * @evict_flags: Callback to obtain placement flags when a buffer is evicted. 218 * @move: Callback for a driver to hook in accelerated functions to 219 * move a buffer. 220 * If set to NULL, a potentially slow memcpy() move is used. 221 */ 222 223struct ttm_bo_driver { 224 /** 225 * ttm_tt_create 226 * 227 * @bo: The buffer object to create the ttm for. 228 * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags. 229 * 230 * Create a struct ttm_tt to back data with system memory pages. 231 * No pages are actually allocated. 232 * Returns: 233 * NULL: Out of memory. 234 */ 235 struct ttm_tt *(*ttm_tt_create)(struct ttm_buffer_object *bo, 236 uint32_t page_flags); 237 238 /** 239 * ttm_tt_populate 240 * 241 * @ttm: The struct ttm_tt to contain the backing pages. 242 * 243 * Allocate all backing pages 244 * Returns: 245 * -ENOMEM: Out of memory. 246 */ 247 int (*ttm_tt_populate)(struct ttm_tt *ttm, 248 struct ttm_operation_ctx *ctx); 249 250 /** 251 * ttm_tt_unpopulate 252 * 253 * @ttm: The struct ttm_tt to contain the backing pages. 254 * 255 * Free all backing page 256 */ 257 void (*ttm_tt_unpopulate)(struct ttm_tt *ttm); 258 259 /** 260 * struct ttm_bo_driver member invalidate_caches 261 * 262 * @bdev: the buffer object device. 263 * @flags: new placement of the rebound buffer object. 264 * 265 * A previosly evicted buffer has been rebound in a 266 * potentially new location. Tell the driver that it might 267 * consider invalidating read (texture) caches on the next command 268 * submission as a consequence. 269 */ 270 271 int (*invalidate_caches)(struct ttm_bo_device *bdev, uint32_t flags); 272 int (*init_mem_type)(struct ttm_bo_device *bdev, uint32_t type, 273 struct ttm_mem_type_manager *man); 274 275 /** 276 * struct ttm_bo_driver member eviction_valuable 277 * 278 * @bo: the buffer object to be evicted 279 * @place: placement we need room for 280 * 281 * Check with the driver if it is valuable to evict a BO to make room 282 * for a certain placement. 283 */ 284 bool (*eviction_valuable)(struct ttm_buffer_object *bo, 285 const struct ttm_place *place); 286 /** 287 * struct ttm_bo_driver member evict_flags: 288 * 289 * @bo: the buffer object to be evicted 290 * 291 * Return the bo flags for a buffer which is not mapped to the hardware. 292 * These will be placed in proposed_flags so that when the move is 293 * finished, they'll end up in bo->mem.flags 294 */ 295 296 void (*evict_flags)(struct ttm_buffer_object *bo, 297 struct ttm_placement *placement); 298 299 /** 300 * struct ttm_bo_driver member move: 301 * 302 * @bo: the buffer to move 303 * @evict: whether this motion is evicting the buffer from 304 * the graphics address space 305 * @ctx: context for this move with parameters 306 * @new_mem: the new memory region receiving the buffer 307 * 308 * Move a buffer between two memory regions. 309 */ 310 int (*move)(struct ttm_buffer_object *bo, bool evict, 311 struct ttm_operation_ctx *ctx, 312 struct ttm_mem_reg *new_mem); 313 314 /** 315 * struct ttm_bo_driver_member verify_access 316 * 317 * @bo: Pointer to a buffer object. 318 * @filp: Pointer to a struct file trying to access the object. 319 * 320 * Called from the map / write / read methods to verify that the 321 * caller is permitted to access the buffer object. 322 * This member may be set to NULL, which will refuse this kind of 323 * access for all buffer objects. 324 * This function should return 0 if access is granted, -EPERM otherwise. 325 */ 326 int (*verify_access)(struct ttm_buffer_object *bo, 327 struct file *filp); 328 329 /** 330 * Hook to notify driver about a driver move so it 331 * can do tiling things and book-keeping. 332 * 333 * @evict: whether this move is evicting the buffer from the graphics 334 * address space 335 */ 336 void (*move_notify)(struct ttm_buffer_object *bo, 337 bool evict, 338 struct ttm_mem_reg *new_mem); 339 /* notify the driver we are taking a fault on this BO 340 * and have reserved it */ 341 int (*fault_reserve_notify)(struct ttm_buffer_object *bo); 342 343 /** 344 * notify the driver that we're about to swap out this bo 345 */ 346 void (*swap_notify)(struct ttm_buffer_object *bo); 347 348 /** 349 * Driver callback on when mapping io memory (for bo_move_memcpy 350 * for instance). TTM will take care to call io_mem_free whenever 351 * the mapping is not use anymore. io_mem_reserve & io_mem_free 352 * are balanced. 353 */ 354 int (*io_mem_reserve)(struct ttm_bo_device *bdev, 355 struct ttm_mem_reg *mem); 356 void (*io_mem_free)(struct ttm_bo_device *bdev, 357 struct ttm_mem_reg *mem); 358 359 /** 360 * Return the pfn for a given page_offset inside the BO. 361 * 362 * @bo: the BO to look up the pfn for 363 * @page_offset: the offset to look up 364 */ 365 unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo, 366 unsigned long page_offset); 367 368 /** 369 * Read/write memory buffers for ptrace access 370 * 371 * @bo: the BO to access 372 * @offset: the offset from the start of the BO 373 * @buf: pointer to source/destination buffer 374 * @len: number of bytes to copy 375 * @write: whether to read (0) from or write (non-0) to BO 376 * 377 * If successful, this function should return the number of 378 * bytes copied, -EIO otherwise. If the number of bytes 379 * returned is < len, the function may be called again with 380 * the remainder of the buffer to copy. 381 */ 382 int (*access_memory)(struct ttm_buffer_object *bo, unsigned long offset, 383 void *buf, int len, int write); 384 385 /** 386 * struct ttm_bo_driver member del_from_lru_notify 387 * 388 * @bo: the buffer object deleted from lru 389 * 390 * notify driver that a BO was deleted from LRU. 391 */ 392 void (*del_from_lru_notify)(struct ttm_buffer_object *bo); 393}; 394 395/** 396 * struct ttm_bo_global - Buffer object driver global data. 397 * 398 * @mem_glob: Pointer to a struct ttm_mem_global object for accounting. 399 * @dummy_read_page: Pointer to a dummy page used for mapping requests 400 * of unpopulated pages. 401 * @shrink: A shrink callback object used for buffer object swap. 402 * @device_list_mutex: Mutex protecting the device list. 403 * This mutex is held while traversing the device list for pm options. 404 * @lru_lock: Spinlock protecting the bo subsystem lru lists. 405 * @device_list: List of buffer object devices. 406 * @swap_lru: Lru list of buffer objects used for swapping. 407 */ 408 409extern struct ttm_bo_global { 410 411 /** 412 * Constant after init. 413 */ 414 415 struct kobject kobj; 416 struct ttm_mem_global *mem_glob; 417 struct page *dummy_read_page; 418 spinlock_t lru_lock; 419 420 /** 421 * Protected by ttm_global_mutex. 422 */ 423 struct list_head device_list; 424 425 /** 426 * Protected by the lru_lock. 427 */ 428 struct list_head swap_lru[TTM_MAX_BO_PRIORITY]; 429 430 /** 431 * Internal protection. 432 */ 433 atomic_t bo_count; 434} ttm_bo_glob; 435 436 437#define TTM_NUM_MEM_TYPES 8 438 439/** 440 * struct ttm_bo_device - Buffer object driver device-specific data. 441 * 442 * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver. 443 * @man: An array of mem_type_managers. 444 * @vma_manager: Address space manager 445 * lru_lock: Spinlock that protects the buffer+device lru lists and 446 * ddestroy lists. 447 * @dev_mapping: A pointer to the struct address_space representing the 448 * device address space. 449 * @wq: Work queue structure for the delayed delete workqueue. 450 * @no_retry: Don't retry allocation if it fails 451 * 452 */ 453 454struct ttm_bo_device { 455 456 /* 457 * Constant after bo device init / atomic. 458 */ 459 struct list_head device_list; 460 struct ttm_bo_global *glob; 461 struct ttm_bo_driver *driver; 462 struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES]; 463 464 /* 465 * Protected by internal locks. 466 */ 467 struct drm_vma_offset_manager vma_manager; 468 469 /* 470 * Protected by the global:lru lock. 471 */ 472 struct list_head ddestroy; 473 474 /* 475 * Protected by load / firstopen / lastclose /unload sync. 476 */ 477 478 struct address_space *dev_mapping; 479 480 /* 481 * Internal protection. 482 */ 483 484 struct delayed_work wq; 485 486 bool need_dma32; 487 488 bool no_retry; 489}; 490 491/** 492 * struct ttm_lru_bulk_move_pos 493 * 494 * @first: first BO in the bulk move range 495 * @last: last BO in the bulk move range 496 * 497 * Positions for a lru bulk move. 498 */ 499struct ttm_lru_bulk_move_pos { 500 struct ttm_buffer_object *first; 501 struct ttm_buffer_object *last; 502}; 503 504/** 505 * struct ttm_lru_bulk_move 506 * 507 * @tt: first/last lru entry for BOs in the TT domain 508 * @vram: first/last lru entry for BOs in the VRAM domain 509 * @swap: first/last lru entry for BOs on the swap list 510 * 511 * Helper structure for bulk moves on the LRU list. 512 */ 513struct ttm_lru_bulk_move { 514 struct ttm_lru_bulk_move_pos tt[TTM_MAX_BO_PRIORITY]; 515 struct ttm_lru_bulk_move_pos vram[TTM_MAX_BO_PRIORITY]; 516 struct ttm_lru_bulk_move_pos swap[TTM_MAX_BO_PRIORITY]; 517}; 518 519/** 520 * ttm_flag_masked 521 * 522 * @old: Pointer to the result and original value. 523 * @new: New value of bits. 524 * @mask: Mask of bits to change. 525 * 526 * Convenience function to change a number of bits identified by a mask. 527 */ 528 529static inline uint32_t 530ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask) 531{ 532 *old ^= (*old ^ new) & mask; 533 return *old; 534} 535 536/* 537 * ttm_bo.c 538 */ 539 540/** 541 * ttm_mem_reg_is_pci 542 * 543 * @bdev: Pointer to a struct ttm_bo_device. 544 * @mem: A valid struct ttm_mem_reg. 545 * 546 * Returns true if the memory described by @mem is PCI memory, 547 * false otherwise. 548 */ 549bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem); 550 551/** 552 * ttm_bo_mem_space 553 * 554 * @bo: Pointer to a struct ttm_buffer_object. the data of which 555 * we want to allocate space for. 556 * @proposed_placement: Proposed new placement for the buffer object. 557 * @mem: A struct ttm_mem_reg. 558 * @interruptible: Sleep interruptible when sliping. 559 * @no_wait_gpu: Return immediately if the GPU is busy. 560 * 561 * Allocate memory space for the buffer object pointed to by @bo, using 562 * the placement flags in @mem, potentially evicting other idle buffer objects. 563 * This function may sleep while waiting for space to become available. 564 * Returns: 565 * -EBUSY: No space available (only if no_wait == 1). 566 * -ENOMEM: Could not allocate memory for the buffer object, either due to 567 * fragmentation or concurrent allocators. 568 * -ERESTARTSYS: An interruptible sleep was interrupted by a signal. 569 */ 570int ttm_bo_mem_space(struct ttm_buffer_object *bo, 571 struct ttm_placement *placement, 572 struct ttm_mem_reg *mem, 573 struct ttm_operation_ctx *ctx); 574 575void ttm_bo_mem_put(struct ttm_buffer_object *bo, struct ttm_mem_reg *mem); 576void ttm_bo_mem_put_locked(struct ttm_buffer_object *bo, 577 struct ttm_mem_reg *mem); 578 579int ttm_bo_device_release(struct ttm_bo_device *bdev); 580 581/** 582 * ttm_bo_device_init 583 * 584 * @bdev: A pointer to a struct ttm_bo_device to initialize. 585 * @glob: A pointer to an initialized struct ttm_bo_global. 586 * @driver: A pointer to a struct ttm_bo_driver set up by the caller. 587 * @mapping: The address space to use for this bo. 588 * @file_page_offset: Offset into the device address space that is available 589 * for buffer data. This ensures compatibility with other users of the 590 * address space. 591 * 592 * Initializes a struct ttm_bo_device: 593 * Returns: 594 * !0: Failure. 595 */ 596int ttm_bo_device_init(struct ttm_bo_device *bdev, 597 struct ttm_bo_driver *driver, 598 struct address_space *mapping, 599 uint64_t file_page_offset, bool need_dma32); 600 601/** 602 * ttm_bo_unmap_virtual 603 * 604 * @bo: tear down the virtual mappings for this BO 605 */ 606void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo); 607 608/** 609 * ttm_bo_unmap_virtual 610 * 611 * @bo: tear down the virtual mappings for this BO 612 * 613 * The caller must take ttm_mem_io_lock before calling this function. 614 */ 615void ttm_bo_unmap_virtual_locked(struct ttm_buffer_object *bo); 616 617int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo); 618void ttm_mem_io_free_vm(struct ttm_buffer_object *bo); 619int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible); 620void ttm_mem_io_unlock(struct ttm_mem_type_manager *man); 621 622void ttm_bo_del_sub_from_lru(struct ttm_buffer_object *bo); 623void ttm_bo_add_to_lru(struct ttm_buffer_object *bo); 624 625/** 626 * __ttm_bo_reserve: 627 * 628 * @bo: A pointer to a struct ttm_buffer_object. 629 * @interruptible: Sleep interruptible if waiting. 630 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY. 631 * @ticket: ticket used to acquire the ww_mutex. 632 * 633 * Will not remove reserved buffers from the lru lists. 634 * Otherwise identical to ttm_bo_reserve. 635 * 636 * Returns: 637 * -EDEADLK: The reservation may cause a deadlock. 638 * Release all buffer reservations, wait for @bo to become unreserved and 639 * try again. (only if use_sequence == 1). 640 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by 641 * a signal. Release all buffer reservations and return to user-space. 642 * -EBUSY: The function needed to sleep, but @no_wait was true 643 * -EALREADY: Bo already reserved using @ticket. This error code will only 644 * be returned if @use_ticket is set to true. 645 */ 646static inline int __ttm_bo_reserve(struct ttm_buffer_object *bo, 647 bool interruptible, bool no_wait, 648 struct ww_acquire_ctx *ticket) 649{ 650 int ret = 0; 651 652 if (no_wait) { 653 bool success; 654 if (WARN_ON(ticket)) 655 return -EBUSY; 656 657 success = reservation_object_trylock(bo->resv); 658 return success ? 0 : -EBUSY; 659 } 660 661 if (interruptible) 662 ret = reservation_object_lock_interruptible(bo->resv, ticket); 663 else 664 ret = reservation_object_lock(bo->resv, ticket); 665 if (ret == -EINTR) 666 return -ERESTARTSYS; 667 return ret; 668} 669 670/** 671 * ttm_bo_reserve: 672 * 673 * @bo: A pointer to a struct ttm_buffer_object. 674 * @interruptible: Sleep interruptible if waiting. 675 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY. 676 * @ticket: ticket used to acquire the ww_mutex. 677 * 678 * Locks a buffer object for validation. (Or prevents other processes from 679 * locking it for validation) and removes it from lru lists, while taking 680 * a number of measures to prevent deadlocks. 681 * 682 * Deadlocks may occur when two processes try to reserve multiple buffers in 683 * different order, either by will or as a result of a buffer being evicted 684 * to make room for a buffer already reserved. (Buffers are reserved before 685 * they are evicted). The following algorithm prevents such deadlocks from 686 * occurring: 687 * Processes attempting to reserve multiple buffers other than for eviction, 688 * (typically execbuf), should first obtain a unique 32-bit 689 * validation sequence number, 690 * and call this function with @use_ticket == 1 and @ticket->stamp == the unique 691 * sequence number. If upon call of this function, the buffer object is already 692 * reserved, the validation sequence is checked against the validation 693 * sequence of the process currently reserving the buffer, 694 * and if the current validation sequence is greater than that of the process 695 * holding the reservation, the function returns -EDEADLK. Otherwise it sleeps 696 * waiting for the buffer to become unreserved, after which it retries 697 * reserving. 698 * The caller should, when receiving an -EDEADLK error 699 * release all its buffer reservations, wait for @bo to become unreserved, and 700 * then rerun the validation with the same validation sequence. This procedure 701 * will always guarantee that the process with the lowest validation sequence 702 * will eventually succeed, preventing both deadlocks and starvation. 703 * 704 * Returns: 705 * -EDEADLK: The reservation may cause a deadlock. 706 * Release all buffer reservations, wait for @bo to become unreserved and 707 * try again. (only if use_sequence == 1). 708 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by 709 * a signal. Release all buffer reservations and return to user-space. 710 * -EBUSY: The function needed to sleep, but @no_wait was true 711 * -EALREADY: Bo already reserved using @ticket. This error code will only 712 * be returned if @use_ticket is set to true. 713 */ 714static inline int ttm_bo_reserve(struct ttm_buffer_object *bo, 715 bool interruptible, bool no_wait, 716 struct ww_acquire_ctx *ticket) 717{ 718 int ret; 719 720 WARN_ON(!kref_read(&bo->kref)); 721 722 ret = __ttm_bo_reserve(bo, interruptible, no_wait, ticket); 723 if (likely(ret == 0)) 724 ttm_bo_del_sub_from_lru(bo); 725 726 return ret; 727} 728 729/** 730 * ttm_bo_reserve_slowpath: 731 * @bo: A pointer to a struct ttm_buffer_object. 732 * @interruptible: Sleep interruptible if waiting. 733 * @sequence: Set (@bo)->sequence to this value after lock 734 * 735 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off 736 * from all our other reservations. Because there are no other reservations 737 * held by us, this function cannot deadlock any more. 738 */ 739static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo, 740 bool interruptible, 741 struct ww_acquire_ctx *ticket) 742{ 743 int ret = 0; 744 745 WARN_ON(!kref_read(&bo->kref)); 746 747 if (interruptible) 748 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 749 ticket); 750 else 751 ww_mutex_lock_slow(&bo->resv->lock, ticket); 752 753 if (likely(ret == 0)) 754 ttm_bo_del_sub_from_lru(bo); 755 else if (ret == -EINTR) 756 ret = -ERESTARTSYS; 757 758 return ret; 759} 760 761/** 762 * ttm_bo_unreserve 763 * 764 * @bo: A pointer to a struct ttm_buffer_object. 765 * 766 * Unreserve a previous reservation of @bo. 767 */ 768static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo) 769{ 770 if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) { 771 spin_lock(&bo->bdev->glob->lru_lock); 772 ttm_bo_add_to_lru(bo); 773 spin_unlock(&bo->bdev->glob->lru_lock); 774 } 775 reservation_object_unlock(bo->resv); 776} 777 778/* 779 * ttm_bo_util.c 780 */ 781 782int ttm_mem_io_reserve(struct ttm_bo_device *bdev, 783 struct ttm_mem_reg *mem); 784void ttm_mem_io_free(struct ttm_bo_device *bdev, 785 struct ttm_mem_reg *mem); 786/** 787 * ttm_bo_move_ttm 788 * 789 * @bo: A pointer to a struct ttm_buffer_object. 790 * @interruptible: Sleep interruptible if waiting. 791 * @no_wait_gpu: Return immediately if the GPU is busy. 792 * @new_mem: struct ttm_mem_reg indicating where to move. 793 * 794 * Optimized move function for a buffer object with both old and 795 * new placement backed by a TTM. The function will, if successful, 796 * free any old aperture space, and set (@new_mem)->mm_node to NULL, 797 * and update the (@bo)->mem placement flags. If unsuccessful, the old 798 * data remains untouched, and it's up to the caller to free the 799 * memory space indicated by @new_mem. 800 * Returns: 801 * !0: Failure. 802 */ 803 804int ttm_bo_move_ttm(struct ttm_buffer_object *bo, 805 struct ttm_operation_ctx *ctx, 806 struct ttm_mem_reg *new_mem); 807 808/** 809 * ttm_bo_move_memcpy 810 * 811 * @bo: A pointer to a struct ttm_buffer_object. 812 * @interruptible: Sleep interruptible if waiting. 813 * @no_wait_gpu: Return immediately if the GPU is busy. 814 * @new_mem: struct ttm_mem_reg indicating where to move. 815 * 816 * Fallback move function for a mappable buffer object in mappable memory. 817 * The function will, if successful, 818 * free any old aperture space, and set (@new_mem)->mm_node to NULL, 819 * and update the (@bo)->mem placement flags. If unsuccessful, the old 820 * data remains untouched, and it's up to the caller to free the 821 * memory space indicated by @new_mem. 822 * Returns: 823 * !0: Failure. 824 */ 825 826int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, 827 struct ttm_operation_ctx *ctx, 828 struct ttm_mem_reg *new_mem); 829 830/** 831 * ttm_bo_free_old_node 832 * 833 * @bo: A pointer to a struct ttm_buffer_object. 834 * 835 * Utility function to free an old placement after a successful move. 836 */ 837void ttm_bo_free_old_node(struct ttm_buffer_object *bo); 838 839/** 840 * ttm_bo_move_accel_cleanup. 841 * 842 * @bo: A pointer to a struct ttm_buffer_object. 843 * @fence: A fence object that signals when moving is complete. 844 * @evict: This is an evict move. Don't return until the buffer is idle. 845 * @new_mem: struct ttm_mem_reg indicating where to move. 846 * 847 * Accelerated move function to be called when an accelerated move 848 * has been scheduled. The function will create a new temporary buffer object 849 * representing the old placement, and put the sync object on both buffer 850 * objects. After that the newly created buffer object is unref'd to be 851 * destroyed when the move is complete. This will help pipeline 852 * buffer moves. 853 */ 854int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo, 855 struct dma_fence *fence, bool evict, 856 struct ttm_mem_reg *new_mem); 857 858/** 859 * ttm_bo_pipeline_move. 860 * 861 * @bo: A pointer to a struct ttm_buffer_object. 862 * @fence: A fence object that signals when moving is complete. 863 * @evict: This is an evict move. Don't return until the buffer is idle. 864 * @new_mem: struct ttm_mem_reg indicating where to move. 865 * 866 * Function for pipelining accelerated moves. Either free the memory 867 * immediately or hang it on a temporary buffer object. 868 */ 869int ttm_bo_pipeline_move(struct ttm_buffer_object *bo, 870 struct dma_fence *fence, bool evict, 871 struct ttm_mem_reg *new_mem); 872 873/** 874 * ttm_bo_pipeline_gutting. 875 * 876 * @bo: A pointer to a struct ttm_buffer_object. 877 * 878 * Pipelined gutting a BO of its backing store. 879 */ 880int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo); 881 882/** 883 * ttm_io_prot 884 * 885 * @c_state: Caching state. 886 * @tmp: Page protection flag for a normal, cached mapping. 887 * 888 * Utility function that returns the pgprot_t that should be used for 889 * setting up a PTE with the caching model indicated by @c_state. 890 */ 891pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp); 892 893extern const struct ttm_mem_type_manager_func ttm_bo_manager_func; 894 895#endif 896