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 31 #ifndef _TTM_BO_API_H_ 32 #define _TTM_BO_API_H_ 33 34 #include <drm/drm_gem.h> 35 36 #include <linux/kref.h> 37 #include <linux/list.h> 38 39 #include "ttm_device.h" 40 41 /* Default number of pre-faulted pages in the TTM fault handler */ 42 #define TTM_BO_VM_NUM_PREFAULT 16 43 44 struct iosys_map; 45 46 struct ttm_global; 47 struct ttm_device; 48 struct ttm_placement; 49 struct ttm_place; 50 struct ttm_resource; 51 struct ttm_resource_manager; 52 struct ttm_tt; 53 54 /** 55 * enum ttm_bo_type 56 * 57 * @ttm_bo_type_device: These are 'normal' buffers that can 58 * be mmapped by user space. Each of these bos occupy a slot in the 59 * device address space, that can be used for normal vm operations. 60 * 61 * @ttm_bo_type_kernel: These buffers are like ttm_bo_type_device buffers, 62 * but they cannot be accessed from user-space. For kernel-only use. 63 * 64 * @ttm_bo_type_sg: Buffer made from dmabuf sg table shared with another 65 * driver. 66 */ 67 enum ttm_bo_type { 68 ttm_bo_type_device, 69 ttm_bo_type_kernel, 70 ttm_bo_type_sg 71 }; 72 73 /** 74 * struct ttm_buffer_object 75 * 76 * @base: drm_gem_object superclass data. 77 * @bdev: Pointer to the buffer object device structure. 78 * @type: The bo type. 79 * @page_alignment: Page alignment. 80 * @destroy: Destruction function. If NULL, kfree is used. 81 * @kref: Reference count of this buffer object. When this refcount reaches 82 * zero, the object is destroyed or put on the delayed delete list. 83 * @resource: structure describing current placement. 84 * @ttm: TTM structure holding system pages. 85 * @deleted: True if the object is only a zombie and already deleted. 86 * @bulk_move: The bulk move object. 87 * @priority: Priority for LRU, BOs with lower priority are evicted first. 88 * @pin_count: Pin count. 89 * 90 * Base class for TTM buffer object, that deals with data placement and CPU 91 * mappings. GPU mappings are really up to the driver, but for simpler GPUs 92 * the driver can usually use the placement offset @offset directly as the 93 * GPU virtual address. For drivers implementing multiple 94 * GPU memory manager contexts, the driver should manage the address space 95 * in these contexts separately and use these objects to get the correct 96 * placement and caching for these GPU maps. This makes it possible to use 97 * these objects for even quite elaborate memory management schemes. 98 * The destroy member, the API visibility of this object makes it possible 99 * to derive driver specific types. 100 */ 101 struct ttm_buffer_object { 102 struct drm_gem_object base; 103 104 /* 105 * Members constant at init. 106 */ 107 struct ttm_device *bdev; 108 enum ttm_bo_type type; 109 uint32_t page_alignment; 110 void (*destroy) (struct ttm_buffer_object *); 111 112 /* 113 * Members not needing protection. 114 */ 115 struct kref kref; 116 117 /* 118 * Members protected by the bo::resv::reserved lock. 119 */ 120 struct ttm_resource *resource; 121 struct ttm_tt *ttm; 122 bool deleted; 123 struct ttm_lru_bulk_move *bulk_move; 124 unsigned priority; 125 unsigned pin_count; 126 127 /** 128 * @delayed_delete: Work item used when we can't delete the BO 129 * immediately 130 */ 131 struct work_struct delayed_delete; 132 133 /** 134 * @sg: external source of pages and DMA addresses, protected by the 135 * reservation lock. 136 */ 137 struct sg_table *sg; 138 }; 139 140 #define TTM_BO_MAP_IOMEM_MASK 0x80 141 142 /** 143 * struct ttm_bo_kmap_obj 144 * 145 * @virtual: The current kernel virtual address. 146 * @page: The page when kmap'ing a single page. 147 * @bo_kmap_type: Type of bo_kmap. 148 * @bo: The TTM BO. 149 * 150 * Object describing a kernel mapping. Since a TTM bo may be located 151 * in various memory types with various caching policies, the 152 * mapping can either be an ioremap, a vmap, a kmap or part of a 153 * premapped region. 154 */ 155 struct ttm_bo_kmap_obj { 156 void *virtual; 157 struct page *page; 158 enum { 159 ttm_bo_map_iomap = 1 | TTM_BO_MAP_IOMEM_MASK, 160 ttm_bo_map_vmap = 2, 161 ttm_bo_map_kmap = 3, 162 ttm_bo_map_premapped = 4 | TTM_BO_MAP_IOMEM_MASK, 163 } bo_kmap_type; 164 struct ttm_buffer_object *bo; 165 }; 166 167 /** 168 * struct ttm_operation_ctx 169 * 170 * @interruptible: Sleep interruptible if sleeping. 171 * @no_wait_gpu: Return immediately if the GPU is busy. 172 * @gfp_retry_mayfail: Set the __GFP_RETRY_MAYFAIL when allocation pages. 173 * @allow_res_evict: Allow eviction of reserved BOs. Can be used when multiple 174 * BOs share the same reservation object. 175 * faults. Should only be used by TTM internally. 176 * @resv: Reservation object to allow reserved evictions with. 177 * @bytes_moved: Statistics on how many bytes have been moved. 178 * 179 * Context for TTM operations like changing buffer placement or general memory 180 * allocation. 181 */ 182 struct ttm_operation_ctx { 183 bool interruptible; 184 bool no_wait_gpu; 185 bool gfp_retry_mayfail; 186 bool allow_res_evict; 187 struct dma_resv *resv; 188 uint64_t bytes_moved; 189 }; 190 191 struct ttm_lru_walk; 192 193 /** struct ttm_lru_walk_ops - Operations for a LRU walk. */ 194 struct ttm_lru_walk_ops { 195 /** 196 * process_bo - Process this bo. 197 * @walk: struct ttm_lru_walk describing the walk. 198 * @bo: A locked and referenced buffer object. 199 * 200 * Return: Negative error code on error, User-defined positive value 201 * (typically, but not always, size of the processed bo) on success. 202 * On success, the returned values are summed by the walk and the 203 * walk exits when its target is met. 204 * 0 also indicates success, -EBUSY means this bo was skipped. 205 */ 206 s64 (*process_bo)(struct ttm_lru_walk *walk, struct ttm_buffer_object *bo); 207 }; 208 209 /** 210 * struct ttm_lru_walk - Structure describing a LRU walk. 211 */ 212 struct ttm_lru_walk { 213 /** @ops: Pointer to the ops structure. */ 214 const struct ttm_lru_walk_ops *ops; 215 /** @ctx: Pointer to the struct ttm_operation_ctx. */ 216 struct ttm_operation_ctx *ctx; 217 /** @ticket: The struct ww_acquire_ctx if any. */ 218 struct ww_acquire_ctx *ticket; 219 /** @trylock_only: Only use trylock for locking. */ 220 bool trylock_only; 221 }; 222 223 s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev, 224 struct ttm_resource_manager *man, s64 target); 225 226 /** 227 * struct ttm_bo_shrink_flags - flags to govern the bo shrinking behaviour 228 * @purge: Purge the content rather than backing it up. 229 * @writeback: Attempt to immediately write content to swap space. 230 * @allow_move: Allow moving to system before shrinking. This is typically 231 * not desired for zombie- or ghost objects (with zombie object meaning 232 * objects with a zero gem object refcount) 233 */ 234 struct ttm_bo_shrink_flags { 235 u32 purge : 1; 236 u32 writeback : 1; 237 u32 allow_move : 1; 238 }; 239 240 long ttm_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo, 241 const struct ttm_bo_shrink_flags flags); 242 243 bool ttm_bo_shrink_suitable(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx); 244 245 bool ttm_bo_shrink_avoid_wait(void); 246 247 /** 248 * ttm_bo_reserve: 249 * 250 * @bo: A pointer to a struct ttm_buffer_object. 251 * @interruptible: Sleep interruptible if waiting. 252 * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY. 253 * @ticket: ticket used to acquire the ww_mutex. 254 * 255 * Locks a buffer object for validation. (Or prevents other processes from 256 * locking it for validation), while taking a number of measures to prevent 257 * deadlocks. 258 * 259 * Returns: 260 * -EDEADLK: The reservation may cause a deadlock. 261 * Release all buffer reservations, wait for @bo to become unreserved and 262 * try again. 263 * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by 264 * a signal. Release all buffer reservations and return to user-space. 265 * -EBUSY: The function needed to sleep, but @no_wait was true 266 * -EALREADY: Bo already reserved using @ticket. This error code will only 267 * be returned if @use_ticket is set to true. 268 */ 269 static inline int ttm_bo_reserve(struct ttm_buffer_object *bo, 270 bool interruptible, bool no_wait, 271 struct ww_acquire_ctx *ticket) 272 { 273 int ret = 0; 274 275 if (no_wait) { 276 bool success; 277 278 if (WARN_ON(ticket)) 279 return -EBUSY; 280 281 success = dma_resv_trylock(bo->base.resv); 282 return success ? 0 : -EBUSY; 283 } 284 285 if (interruptible) 286 ret = dma_resv_lock_interruptible(bo->base.resv, ticket); 287 else 288 ret = dma_resv_lock(bo->base.resv, ticket); 289 if (ret == -EINTR) 290 return -ERESTARTSYS; 291 return ret; 292 } 293 294 /** 295 * ttm_bo_reserve_slowpath: 296 * @bo: A pointer to a struct ttm_buffer_object. 297 * @interruptible: Sleep interruptible if waiting. 298 * @ticket: Ticket used to acquire the ww_mutex. 299 * 300 * This is called after ttm_bo_reserve returns -EAGAIN and we backed off 301 * from all our other reservations. Because there are no other reservations 302 * held by us, this function cannot deadlock any more. 303 */ 304 static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo, 305 bool interruptible, 306 struct ww_acquire_ctx *ticket) 307 { 308 if (interruptible) { 309 int ret = dma_resv_lock_slow_interruptible(bo->base.resv, 310 ticket); 311 if (ret == -EINTR) 312 ret = -ERESTARTSYS; 313 return ret; 314 } 315 dma_resv_lock_slow(bo->base.resv, ticket); 316 return 0; 317 } 318 319 void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo); 320 321 static inline void 322 ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo) 323 { 324 spin_lock(&bo->bdev->lru_lock); 325 ttm_bo_move_to_lru_tail(bo); 326 spin_unlock(&bo->bdev->lru_lock); 327 } 328 329 static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo, 330 struct ttm_resource *new_mem) 331 { 332 WARN_ON(bo->resource); 333 bo->resource = new_mem; 334 } 335 336 /** 337 * ttm_bo_move_null - assign memory for a buffer object. 338 * @bo: The bo to assign the memory to 339 * @new_mem: The memory to be assigned. 340 * 341 * Assign the memory from new_mem to the memory of the buffer object bo. 342 */ 343 static inline void ttm_bo_move_null(struct ttm_buffer_object *bo, 344 struct ttm_resource *new_mem) 345 { 346 ttm_resource_free(bo, &bo->resource); 347 ttm_bo_assign_mem(bo, new_mem); 348 } 349 350 /** 351 * ttm_bo_unreserve 352 * 353 * @bo: A pointer to a struct ttm_buffer_object. 354 * 355 * Unreserve a previous reservation of @bo. 356 */ 357 static inline void ttm_bo_unreserve(struct ttm_buffer_object *bo) 358 { 359 ttm_bo_move_to_lru_tail_unlocked(bo); 360 dma_resv_unlock(bo->base.resv); 361 } 362 363 /** 364 * ttm_kmap_obj_virtual 365 * 366 * @map: A struct ttm_bo_kmap_obj returned from ttm_bo_kmap. 367 * @is_iomem: Pointer to an integer that on return indicates 1 if the 368 * virtual map is io memory, 0 if normal memory. 369 * 370 * Returns the virtual address of a buffer object area mapped by ttm_bo_kmap. 371 * If *is_iomem is 1 on return, the virtual address points to an io memory area, 372 * that should strictly be accessed by the iowriteXX() and similar functions. 373 */ 374 static inline void *ttm_kmap_obj_virtual(struct ttm_bo_kmap_obj *map, 375 bool *is_iomem) 376 { 377 *is_iomem = !!(map->bo_kmap_type & TTM_BO_MAP_IOMEM_MASK); 378 return map->virtual; 379 } 380 381 int ttm_bo_wait_ctx(struct ttm_buffer_object *bo, 382 struct ttm_operation_ctx *ctx); 383 int ttm_bo_validate(struct ttm_buffer_object *bo, 384 struct ttm_placement *placement, 385 struct ttm_operation_ctx *ctx); 386 void ttm_bo_put(struct ttm_buffer_object *bo); 387 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo, 388 struct ttm_lru_bulk_move *bulk); 389 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo, 390 const struct ttm_place *place); 391 int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo, 392 enum ttm_bo_type type, struct ttm_placement *placement, 393 uint32_t alignment, struct ttm_operation_ctx *ctx, 394 struct sg_table *sg, struct dma_resv *resv, 395 void (*destroy)(struct ttm_buffer_object *)); 396 int ttm_bo_init_validate(struct ttm_device *bdev, struct ttm_buffer_object *bo, 397 enum ttm_bo_type type, struct ttm_placement *placement, 398 uint32_t alignment, bool interruptible, 399 struct sg_table *sg, struct dma_resv *resv, 400 void (*destroy)(struct ttm_buffer_object *)); 401 int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page, 402 unsigned long num_pages, struct ttm_bo_kmap_obj *map); 403 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map); 404 int ttm_bo_vmap(struct ttm_buffer_object *bo, struct iosys_map *map); 405 void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct iosys_map *map); 406 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo); 407 s64 ttm_bo_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx, 408 struct ttm_resource_manager *man, gfp_t gfp_flags, 409 s64 target); 410 void ttm_bo_pin(struct ttm_buffer_object *bo); 411 void ttm_bo_unpin(struct ttm_buffer_object *bo); 412 int ttm_bo_evict_first(struct ttm_device *bdev, 413 struct ttm_resource_manager *man, 414 struct ttm_operation_ctx *ctx); 415 int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset, 416 void *buf, int len, int write); 417 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, 418 struct vm_fault *vmf); 419 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, 420 pgprot_t prot, 421 pgoff_t num_prefault); 422 vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf); 423 void ttm_bo_vm_open(struct vm_area_struct *vma); 424 void ttm_bo_vm_close(struct vm_area_struct *vma); 425 int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, 426 void *buf, int len, int write); 427 vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot); 428 429 int ttm_bo_mem_space(struct ttm_buffer_object *bo, 430 struct ttm_placement *placement, 431 struct ttm_resource **mem, 432 struct ttm_operation_ctx *ctx); 433 434 void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo); 435 /* 436 * ttm_bo_util.c 437 */ 438 int ttm_mem_io_reserve(struct ttm_device *bdev, 439 struct ttm_resource *mem); 440 void ttm_mem_io_free(struct ttm_device *bdev, 441 struct ttm_resource *mem); 442 void ttm_move_memcpy(bool clear, u32 num_pages, 443 struct ttm_kmap_iter *dst_iter, 444 struct ttm_kmap_iter *src_iter); 445 int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, 446 struct ttm_operation_ctx *ctx, 447 struct ttm_resource *new_mem); 448 int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo, 449 struct dma_fence *fence, bool evict, 450 bool pipeline, 451 struct ttm_resource *new_mem); 452 void ttm_bo_move_sync_cleanup(struct ttm_buffer_object *bo, 453 struct ttm_resource *new_mem); 454 int ttm_bo_pipeline_gutting(struct ttm_buffer_object *bo); 455 pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res, 456 pgprot_t tmp); 457 void ttm_bo_tt_destroy(struct ttm_buffer_object *bo); 458 int ttm_bo_populate(struct ttm_buffer_object *bo, 459 struct ttm_operation_ctx *ctx); 460 461 /* Driver LRU walk helpers initially targeted for shrinking. */ 462 463 /** 464 * struct ttm_bo_lru_cursor - Iterator cursor for TTM LRU list looping 465 */ 466 struct ttm_bo_lru_cursor { 467 /** @res_curs: Embedded struct ttm_resource_cursor. */ 468 struct ttm_resource_cursor res_curs; 469 /** 470 * @ctx: The struct ttm_operation_ctx used while looping. 471 * governs the locking mode. 472 */ 473 struct ttm_operation_ctx *ctx; 474 /** 475 * @bo: Buffer object pointer if a buffer object is refcounted, 476 * NULL otherwise. 477 */ 478 struct ttm_buffer_object *bo; 479 /** 480 * @needs_unlock: Valid iff @bo != NULL. The bo resv needs 481 * unlock before the next iteration or after loop exit. 482 */ 483 bool needs_unlock; 484 }; 485 486 void ttm_bo_lru_cursor_fini(struct ttm_bo_lru_cursor *curs); 487 488 struct ttm_bo_lru_cursor * 489 ttm_bo_lru_cursor_init(struct ttm_bo_lru_cursor *curs, 490 struct ttm_resource_manager *man, 491 struct ttm_operation_ctx *ctx); 492 493 struct ttm_buffer_object *ttm_bo_lru_cursor_first(struct ttm_bo_lru_cursor *curs); 494 495 struct ttm_buffer_object *ttm_bo_lru_cursor_next(struct ttm_bo_lru_cursor *curs); 496 497 /* 498 * Defines needed to use autocleanup (linux/cleanup.h) with struct ttm_bo_lru_cursor. 499 */ 500 DEFINE_CLASS(ttm_bo_lru_cursor, struct ttm_bo_lru_cursor *, 501 if (_T) {ttm_bo_lru_cursor_fini(_T); }, 502 ttm_bo_lru_cursor_init(curs, man, ctx), 503 struct ttm_bo_lru_cursor *curs, struct ttm_resource_manager *man, 504 struct ttm_operation_ctx *ctx); 505 static inline void * 506 class_ttm_bo_lru_cursor_lock_ptr(class_ttm_bo_lru_cursor_t *_T) 507 { return *_T; } 508 #define class_ttm_bo_lru_cursor_is_conditional false 509 510 /** 511 * ttm_bo_lru_for_each_reserved_guarded() - Iterate over buffer objects owning 512 * resources on LRU lists. 513 * @_cursor: struct ttm_bo_lru_cursor to use for the iteration. 514 * @_man: The resource manager whose LRU lists to iterate over. 515 * @_ctx: The struct ttm_operation_context to govern the @_bo locking. 516 * @_bo: The struct ttm_buffer_object pointer pointing to the buffer object 517 * for the current iteration. 518 * 519 * Iterate over all resources of @_man and for each resource, attempt to 520 * reference and lock (using the locking mode detailed in @_ctx) the buffer 521 * object it points to. If successful, assign @_bo to the address of the 522 * buffer object and update @_cursor. The iteration is guarded in the 523 * sense that @_cursor will be initialized before looping start and cleaned 524 * up at looping termination, even if terminated prematurely by, for 525 * example a return or break statement. Exiting the loop will also unlock 526 * (if needed) and unreference @_bo. 527 */ 528 #define ttm_bo_lru_for_each_reserved_guarded(_cursor, _man, _ctx, _bo) \ 529 scoped_guard(ttm_bo_lru_cursor, _cursor, _man, _ctx) \ 530 for ((_bo) = ttm_bo_lru_cursor_first(_cursor); (_bo); \ 531 (_bo) = ttm_bo_lru_cursor_next(_cursor)) 532 533 #endif 534