1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright © 2016 Intel Corporation 5 */ 6 7 #ifndef __I915_GEM_OBJECT_H__ 8 #define __I915_GEM_OBJECT_H__ 9 10 #include <drm/drm_gem.h> 11 #include <drm/drm_file.h> 12 #include <drm/drm_device.h> 13 14 #include "display/intel_frontbuffer.h" 15 #include "intel_memory_region.h" 16 #include "i915_gem_object_types.h" 17 #include "i915_gem_gtt.h" 18 #include "i915_gem_ww.h" 19 #include "i915_vma_types.h" 20 21 enum intel_region_id; 22 23 /* 24 * XXX: There is a prevalence of the assumption that we fit the 25 * object's page count inside a 32bit _signed_ variable. Let's document 26 * this and catch if we ever need to fix it. In the meantime, if you do 27 * spot such a local variable, please consider fixing! 28 * 29 * Aside from our own locals (for which we have no excuse!): 30 * - sg_table embeds unsigned int for num_pages 31 * - get_user_pages*() mixed ints with longs 32 */ 33 #define GEM_CHECK_SIZE_OVERFLOW(sz) \ 34 GEM_WARN_ON((sz) >> PAGE_SHIFT > INT_MAX) 35 36 static inline bool i915_gem_object_size_2big(u64 size) 37 { 38 struct drm_i915_gem_object *obj; 39 40 if (GEM_CHECK_SIZE_OVERFLOW(size)) 41 return true; 42 43 if (overflows_type(size, obj->base.size)) 44 return true; 45 46 return false; 47 } 48 49 void i915_gem_init__objects(struct drm_i915_private *i915); 50 51 void i915_objects_module_exit(void); 52 int i915_objects_module_init(void); 53 54 struct drm_i915_gem_object *i915_gem_object_alloc(void); 55 void i915_gem_object_free(struct drm_i915_gem_object *obj); 56 57 void i915_gem_object_init(struct drm_i915_gem_object *obj, 58 const struct drm_i915_gem_object_ops *ops, 59 struct lock_class_key *key, 60 unsigned alloc_flags); 61 62 void __i915_gem_object_fini(struct drm_i915_gem_object *obj); 63 64 struct drm_i915_gem_object * 65 i915_gem_object_create_shmem(struct drm_i915_private *i915, 66 resource_size_t size); 67 struct drm_i915_gem_object * 68 i915_gem_object_create_shmem_from_data(struct drm_i915_private *i915, 69 const void *data, resource_size_t size); 70 struct drm_i915_gem_object * 71 __i915_gem_object_create_user(struct drm_i915_private *i915, u64 size, 72 struct intel_memory_region **placements, 73 unsigned int n_placements); 74 75 extern const struct drm_i915_gem_object_ops i915_gem_shmem_ops; 76 77 void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj, 78 struct sg_table *pages, 79 bool needs_clflush); 80 81 int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj, 82 const struct drm_i915_gem_pwrite *args); 83 int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj, 84 const struct drm_i915_gem_pread *args); 85 86 int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align); 87 void i915_gem_object_put_pages_shmem(struct drm_i915_gem_object *obj, 88 struct sg_table *pages); 89 void i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, 90 struct sg_table *pages); 91 92 void i915_gem_flush_free_objects(struct drm_i915_private *i915); 93 94 struct sg_table * 95 __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj); 96 97 /** 98 * i915_gem_object_lookup_rcu - look up a temporary GEM object from its handle 99 * @filp: DRM file private date 100 * @handle: userspace handle 101 * 102 * Returns: 103 * 104 * A pointer to the object named by the handle if such exists on @filp, NULL 105 * otherwise. This object is only valid whilst under the RCU read lock, and 106 * note carefully the object may be in the process of being destroyed. 107 */ 108 static inline struct drm_i915_gem_object * 109 i915_gem_object_lookup_rcu(struct drm_file *file, u32 handle) 110 { 111 #ifdef CONFIG_LOCKDEP 112 WARN_ON(debug_locks && !lock_is_held(&rcu_lock_map)); 113 #endif 114 return idr_find(&file->object_idr, handle); 115 } 116 117 static inline struct drm_i915_gem_object * 118 i915_gem_object_get_rcu(struct drm_i915_gem_object *obj) 119 { 120 if (obj && !kref_get_unless_zero(&obj->base.refcount)) 121 obj = NULL; 122 123 return obj; 124 } 125 126 static inline struct drm_i915_gem_object * 127 i915_gem_object_lookup(struct drm_file *file, u32 handle) 128 { 129 struct drm_i915_gem_object *obj; 130 131 rcu_read_lock(); 132 obj = i915_gem_object_lookup_rcu(file, handle); 133 obj = i915_gem_object_get_rcu(obj); 134 rcu_read_unlock(); 135 136 return obj; 137 } 138 139 __deprecated 140 struct drm_gem_object * 141 drm_gem_object_lookup(struct drm_file *file, u32 handle); 142 143 __attribute__((nonnull)) 144 static inline struct drm_i915_gem_object * 145 i915_gem_object_get(struct drm_i915_gem_object *obj) 146 { 147 drm_gem_object_get(&obj->base); 148 return obj; 149 } 150 151 __attribute__((nonnull)) 152 static inline void 153 i915_gem_object_put(struct drm_i915_gem_object *obj) 154 { 155 __drm_gem_object_put(&obj->base); 156 } 157 158 #define assert_object_held(obj) dma_resv_assert_held((obj)->base.resv) 159 160 /* 161 * If more than one potential simultaneous locker, assert held. 162 */ 163 static inline void assert_object_held_shared(const struct drm_i915_gem_object *obj) 164 { 165 /* 166 * Note mm list lookup is protected by 167 * kref_get_unless_zero(). 168 */ 169 if (IS_ENABLED(CONFIG_LOCKDEP) && 170 kref_read(&obj->base.refcount) > 0) 171 assert_object_held(obj); 172 } 173 174 static inline int __i915_gem_object_lock(struct drm_i915_gem_object *obj, 175 struct i915_gem_ww_ctx *ww, 176 bool intr) 177 { 178 int ret; 179 180 if (intr) 181 ret = dma_resv_lock_interruptible(obj->base.resv, ww ? &ww->ctx : NULL); 182 else 183 ret = dma_resv_lock(obj->base.resv, ww ? &ww->ctx : NULL); 184 185 if (!ret && ww) { 186 i915_gem_object_get(obj); 187 list_add_tail(&obj->obj_link, &ww->obj_list); 188 } 189 if (ret == -EALREADY) 190 ret = 0; 191 192 if (ret == -EDEADLK) { 193 i915_gem_object_get(obj); 194 ww->contended = obj; 195 } 196 197 return ret; 198 } 199 200 static inline int i915_gem_object_lock(struct drm_i915_gem_object *obj, 201 struct i915_gem_ww_ctx *ww) 202 { 203 return __i915_gem_object_lock(obj, ww, ww && ww->intr); 204 } 205 206 static inline int i915_gem_object_lock_interruptible(struct drm_i915_gem_object *obj, 207 struct i915_gem_ww_ctx *ww) 208 { 209 WARN_ON(ww && !ww->intr); 210 return __i915_gem_object_lock(obj, ww, true); 211 } 212 213 static inline bool i915_gem_object_trylock(struct drm_i915_gem_object *obj, 214 struct i915_gem_ww_ctx *ww) 215 { 216 if (!ww) 217 return dma_resv_trylock(obj->base.resv); 218 else 219 return ww_mutex_trylock(&obj->base.resv->lock, &ww->ctx); 220 } 221 222 static inline void i915_gem_object_unlock(struct drm_i915_gem_object *obj) 223 { 224 if (obj->ops->adjust_lru) 225 obj->ops->adjust_lru(obj); 226 227 dma_resv_unlock(obj->base.resv); 228 } 229 230 static inline void 231 i915_gem_object_set_readonly(struct drm_i915_gem_object *obj) 232 { 233 obj->flags |= I915_BO_READONLY; 234 } 235 236 static inline bool 237 i915_gem_object_is_readonly(const struct drm_i915_gem_object *obj) 238 { 239 return obj->flags & I915_BO_READONLY; 240 } 241 242 static inline bool 243 i915_gem_object_is_contiguous(const struct drm_i915_gem_object *obj) 244 { 245 return obj->flags & I915_BO_ALLOC_CONTIGUOUS; 246 } 247 248 static inline bool 249 i915_gem_object_is_volatile(const struct drm_i915_gem_object *obj) 250 { 251 return obj->flags & I915_BO_ALLOC_VOLATILE; 252 } 253 254 static inline void 255 i915_gem_object_set_volatile(struct drm_i915_gem_object *obj) 256 { 257 obj->flags |= I915_BO_ALLOC_VOLATILE; 258 } 259 260 static inline bool 261 i915_gem_object_has_tiling_quirk(struct drm_i915_gem_object *obj) 262 { 263 return test_bit(I915_TILING_QUIRK_BIT, &obj->flags); 264 } 265 266 static inline void 267 i915_gem_object_set_tiling_quirk(struct drm_i915_gem_object *obj) 268 { 269 set_bit(I915_TILING_QUIRK_BIT, &obj->flags); 270 } 271 272 static inline void 273 i915_gem_object_clear_tiling_quirk(struct drm_i915_gem_object *obj) 274 { 275 clear_bit(I915_TILING_QUIRK_BIT, &obj->flags); 276 } 277 278 static inline bool 279 i915_gem_object_is_protected(const struct drm_i915_gem_object *obj) 280 { 281 return obj->flags & I915_BO_PROTECTED; 282 } 283 284 static inline bool 285 i915_gem_object_type_has(const struct drm_i915_gem_object *obj, 286 unsigned long flags) 287 { 288 return obj->ops->flags & flags; 289 } 290 291 bool i915_gem_object_has_struct_page(const struct drm_i915_gem_object *obj); 292 293 bool i915_gem_object_has_iomem(const struct drm_i915_gem_object *obj); 294 295 static inline bool 296 i915_gem_object_is_shrinkable(const struct drm_i915_gem_object *obj) 297 { 298 return i915_gem_object_type_has(obj, I915_GEM_OBJECT_IS_SHRINKABLE); 299 } 300 301 static inline bool 302 i915_gem_object_has_self_managed_shrink_list(const struct drm_i915_gem_object *obj) 303 { 304 return i915_gem_object_type_has(obj, I915_GEM_OBJECT_SELF_MANAGED_SHRINK_LIST); 305 } 306 307 static inline bool 308 i915_gem_object_is_proxy(const struct drm_i915_gem_object *obj) 309 { 310 return i915_gem_object_type_has(obj, I915_GEM_OBJECT_IS_PROXY); 311 } 312 313 static inline bool 314 i915_gem_object_never_mmap(const struct drm_i915_gem_object *obj) 315 { 316 return i915_gem_object_type_has(obj, I915_GEM_OBJECT_NO_MMAP); 317 } 318 319 static inline bool 320 i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj) 321 { 322 return READ_ONCE(obj->frontbuffer); 323 } 324 325 static inline unsigned int 326 i915_gem_object_get_tiling(const struct drm_i915_gem_object *obj) 327 { 328 return obj->tiling_and_stride & TILING_MASK; 329 } 330 331 static inline bool 332 i915_gem_object_is_tiled(const struct drm_i915_gem_object *obj) 333 { 334 return i915_gem_object_get_tiling(obj) != I915_TILING_NONE; 335 } 336 337 static inline unsigned int 338 i915_gem_object_get_stride(const struct drm_i915_gem_object *obj) 339 { 340 return obj->tiling_and_stride & STRIDE_MASK; 341 } 342 343 static inline unsigned int 344 i915_gem_tile_height(unsigned int tiling) 345 { 346 GEM_BUG_ON(!tiling); 347 return tiling == I915_TILING_Y ? 32 : 8; 348 } 349 350 static inline unsigned int 351 i915_gem_object_get_tile_height(const struct drm_i915_gem_object *obj) 352 { 353 return i915_gem_tile_height(i915_gem_object_get_tiling(obj)); 354 } 355 356 static inline unsigned int 357 i915_gem_object_get_tile_row_size(const struct drm_i915_gem_object *obj) 358 { 359 return (i915_gem_object_get_stride(obj) * 360 i915_gem_object_get_tile_height(obj)); 361 } 362 363 int i915_gem_object_set_tiling(struct drm_i915_gem_object *obj, 364 unsigned int tiling, unsigned int stride); 365 366 struct scatterlist * 367 __i915_gem_object_get_sg(struct drm_i915_gem_object *obj, 368 struct i915_gem_object_page_iter *iter, 369 unsigned int n, 370 unsigned int *offset, bool dma); 371 372 static inline struct scatterlist * 373 i915_gem_object_get_sg(struct drm_i915_gem_object *obj, 374 unsigned int n, 375 unsigned int *offset) 376 { 377 return __i915_gem_object_get_sg(obj, &obj->mm.get_page, n, offset, false); 378 } 379 380 static inline struct scatterlist * 381 i915_gem_object_get_sg_dma(struct drm_i915_gem_object *obj, 382 unsigned int n, 383 unsigned int *offset) 384 { 385 return __i915_gem_object_get_sg(obj, &obj->mm.get_dma_page, n, offset, true); 386 } 387 388 struct page * 389 i915_gem_object_get_page(struct drm_i915_gem_object *obj, 390 unsigned int n); 391 392 struct page * 393 i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, 394 unsigned int n); 395 396 dma_addr_t 397 i915_gem_object_get_dma_address_len(struct drm_i915_gem_object *obj, 398 unsigned long n, 399 unsigned int *len); 400 401 dma_addr_t 402 i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj, 403 unsigned long n); 404 405 void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, 406 struct sg_table *pages, 407 unsigned int sg_page_sizes); 408 409 int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj); 410 int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj); 411 412 static inline int __must_check 413 i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) 414 { 415 assert_object_held(obj); 416 417 if (atomic_inc_not_zero(&obj->mm.pages_pin_count)) 418 return 0; 419 420 return __i915_gem_object_get_pages(obj); 421 } 422 423 int i915_gem_object_pin_pages_unlocked(struct drm_i915_gem_object *obj); 424 425 static inline bool 426 i915_gem_object_has_pages(struct drm_i915_gem_object *obj) 427 { 428 return !IS_ERR_OR_NULL(READ_ONCE(obj->mm.pages)); 429 } 430 431 static inline void 432 __i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) 433 { 434 GEM_BUG_ON(!i915_gem_object_has_pages(obj)); 435 436 atomic_inc(&obj->mm.pages_pin_count); 437 } 438 439 static inline bool 440 i915_gem_object_has_pinned_pages(struct drm_i915_gem_object *obj) 441 { 442 return atomic_read(&obj->mm.pages_pin_count); 443 } 444 445 static inline void 446 __i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) 447 { 448 GEM_BUG_ON(!i915_gem_object_has_pages(obj)); 449 GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj)); 450 451 atomic_dec(&obj->mm.pages_pin_count); 452 } 453 454 static inline void 455 i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) 456 { 457 __i915_gem_object_unpin_pages(obj); 458 } 459 460 int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj); 461 int i915_gem_object_truncate(struct drm_i915_gem_object *obj); 462 463 /** 464 * i915_gem_object_pin_map - return a contiguous mapping of the entire object 465 * @obj: the object to map into kernel address space 466 * @type: the type of mapping, used to select pgprot_t 467 * 468 * Calls i915_gem_object_pin_pages() to prevent reaping of the object's 469 * pages and then returns a contiguous mapping of the backing storage into 470 * the kernel address space. Based on the @type of mapping, the PTE will be 471 * set to either WriteBack or WriteCombine (via pgprot_t). 472 * 473 * The caller is responsible for calling i915_gem_object_unpin_map() when the 474 * mapping is no longer required. 475 * 476 * Returns the pointer through which to access the mapped object, or an 477 * ERR_PTR() on error. 478 */ 479 void *__must_check i915_gem_object_pin_map(struct drm_i915_gem_object *obj, 480 enum i915_map_type type); 481 482 void *__must_check i915_gem_object_pin_map_unlocked(struct drm_i915_gem_object *obj, 483 enum i915_map_type type); 484 485 void __i915_gem_object_flush_map(struct drm_i915_gem_object *obj, 486 unsigned long offset, 487 unsigned long size); 488 static inline void i915_gem_object_flush_map(struct drm_i915_gem_object *obj) 489 { 490 __i915_gem_object_flush_map(obj, 0, obj->base.size); 491 } 492 493 /** 494 * i915_gem_object_unpin_map - releases an earlier mapping 495 * @obj: the object to unmap 496 * 497 * After pinning the object and mapping its pages, once you are finished 498 * with your access, call i915_gem_object_unpin_map() to release the pin 499 * upon the mapping. Once the pin count reaches zero, that mapping may be 500 * removed. 501 */ 502 static inline void i915_gem_object_unpin_map(struct drm_i915_gem_object *obj) 503 { 504 i915_gem_object_unpin_pages(obj); 505 } 506 507 void __i915_gem_object_release_map(struct drm_i915_gem_object *obj); 508 509 int i915_gem_object_prepare_read(struct drm_i915_gem_object *obj, 510 unsigned int *needs_clflush); 511 int i915_gem_object_prepare_write(struct drm_i915_gem_object *obj, 512 unsigned int *needs_clflush); 513 #define CLFLUSH_BEFORE BIT(0) 514 #define CLFLUSH_AFTER BIT(1) 515 #define CLFLUSH_FLAGS (CLFLUSH_BEFORE | CLFLUSH_AFTER) 516 517 static inline void 518 i915_gem_object_finish_access(struct drm_i915_gem_object *obj) 519 { 520 i915_gem_object_unpin_pages(obj); 521 } 522 523 int i915_gem_object_get_moving_fence(struct drm_i915_gem_object *obj, 524 struct dma_fence **fence); 525 int i915_gem_object_wait_moving_fence(struct drm_i915_gem_object *obj, 526 bool intr); 527 528 void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj, 529 unsigned int cache_level); 530 bool i915_gem_object_can_bypass_llc(struct drm_i915_gem_object *obj); 531 void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj); 532 void i915_gem_object_flush_if_display_locked(struct drm_i915_gem_object *obj); 533 bool i915_gem_cpu_write_needs_clflush(struct drm_i915_gem_object *obj); 534 535 int __must_check 536 i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write); 537 int __must_check 538 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write); 539 int __must_check 540 i915_gem_object_set_to_cpu_domain(struct drm_i915_gem_object *obj, bool write); 541 struct i915_vma * __must_check 542 i915_gem_object_pin_to_display_plane(struct drm_i915_gem_object *obj, 543 struct i915_gem_ww_ctx *ww, 544 u32 alignment, 545 const struct i915_ggtt_view *view, 546 unsigned int flags); 547 548 void i915_gem_object_make_unshrinkable(struct drm_i915_gem_object *obj); 549 void i915_gem_object_make_shrinkable(struct drm_i915_gem_object *obj); 550 void __i915_gem_object_make_shrinkable(struct drm_i915_gem_object *obj); 551 void __i915_gem_object_make_purgeable(struct drm_i915_gem_object *obj); 552 void i915_gem_object_make_purgeable(struct drm_i915_gem_object *obj); 553 554 static inline void __start_cpu_write(struct drm_i915_gem_object *obj) 555 { 556 obj->read_domains = I915_GEM_DOMAIN_CPU; 557 obj->write_domain = I915_GEM_DOMAIN_CPU; 558 if (i915_gem_cpu_write_needs_clflush(obj)) 559 obj->cache_dirty = true; 560 } 561 562 void i915_gem_fence_wait_priority(struct dma_fence *fence, 563 const struct i915_sched_attr *attr); 564 565 int i915_gem_object_wait(struct drm_i915_gem_object *obj, 566 unsigned int flags, 567 long timeout); 568 int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj, 569 unsigned int flags, 570 const struct i915_sched_attr *attr); 571 572 void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj, 573 enum fb_op_origin origin); 574 void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj, 575 enum fb_op_origin origin); 576 577 static inline void 578 i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj, 579 enum fb_op_origin origin) 580 { 581 if (unlikely(rcu_access_pointer(obj->frontbuffer))) 582 __i915_gem_object_flush_frontbuffer(obj, origin); 583 } 584 585 static inline void 586 i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj, 587 enum fb_op_origin origin) 588 { 589 if (unlikely(rcu_access_pointer(obj->frontbuffer))) 590 __i915_gem_object_invalidate_frontbuffer(obj, origin); 591 } 592 593 int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size); 594 595 bool i915_gem_object_is_shmem(const struct drm_i915_gem_object *obj); 596 597 void __i915_gem_free_object_rcu(struct rcu_head *head); 598 599 void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj); 600 601 void __i915_gem_free_object(struct drm_i915_gem_object *obj); 602 603 bool i915_gem_object_evictable(struct drm_i915_gem_object *obj); 604 605 bool i915_gem_object_migratable(struct drm_i915_gem_object *obj); 606 607 int i915_gem_object_migrate(struct drm_i915_gem_object *obj, 608 struct i915_gem_ww_ctx *ww, 609 enum intel_region_id id); 610 611 bool i915_gem_object_can_migrate(struct drm_i915_gem_object *obj, 612 enum intel_region_id id); 613 614 int i915_gem_object_wait_migration(struct drm_i915_gem_object *obj, 615 unsigned int flags); 616 617 bool i915_gem_object_placement_possible(struct drm_i915_gem_object *obj, 618 enum intel_memory_type type); 619 620 int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, 621 size_t size, struct intel_memory_region *mr, 622 struct address_space *mapping, 623 unsigned int max_segment); 624 void shmem_sg_free_table(struct sg_table *st, struct address_space *mapping, 625 bool dirty, bool backup); 626 void __shmem_writeback(size_t size, struct address_space *mapping); 627 628 #ifdef CONFIG_MMU_NOTIFIER 629 static inline bool 630 i915_gem_object_is_userptr(struct drm_i915_gem_object *obj) 631 { 632 return obj->userptr.notifier.mm; 633 } 634 635 int i915_gem_object_userptr_submit_init(struct drm_i915_gem_object *obj); 636 int i915_gem_object_userptr_submit_done(struct drm_i915_gem_object *obj); 637 int i915_gem_object_userptr_validate(struct drm_i915_gem_object *obj); 638 #else 639 static inline bool i915_gem_object_is_userptr(struct drm_i915_gem_object *obj) { return false; } 640 641 static inline int i915_gem_object_userptr_submit_init(struct drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; } 642 static inline int i915_gem_object_userptr_submit_done(struct drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; } 643 static inline int i915_gem_object_userptr_validate(struct drm_i915_gem_object *obj) { GEM_BUG_ON(1); return -ENODEV; } 644 645 #endif 646 647 #endif 648