xref: /linux/drivers/gpu/drm/xe/xe_bo.h (revision 5b0764a53235d3c77e1ed674e836e1b3fe1a4b1f)
1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 
6 #ifndef _XE_BO_H_
7 #define _XE_BO_H_
8 
9 #include <drm/drm_prime.h>
10 #include <drm/ttm/ttm_tt.h>
11 
12 #include <xen/xen.h>
13 
14 #include "xe_bo_types.h"
15 #include "xe_ggtt.h"
16 #include "xe_macros.h"
17 #include "xe_validation.h"
18 #include "xe_vm_types.h"
19 #include "xe_vm.h"
20 #include "xe_vram_types.h"
21 
22 #define XE_DEFAULT_GTT_SIZE_MB          3072ULL /* 3GB by default */
23 
24 #define XE_BO_FLAG_USER		BIT(0)
25 /* The bits below need to be contiguous, or things break */
26 #define XE_BO_FLAG_SYSTEM		BIT(1)
27 #define XE_BO_FLAG_VRAM0		BIT(2)
28 #define XE_BO_FLAG_VRAM1		BIT(3)
29 #define XE_BO_FLAG_VRAM_MASK		(XE_BO_FLAG_VRAM0 | XE_BO_FLAG_VRAM1)
30 /* -- */
31 #define XE_BO_FLAG_STOLEN		BIT(4)
32 #define XE_BO_FLAG_VRAM(vram)		(XE_BO_FLAG_VRAM0 << ((vram)->id))
33 #define XE_BO_FLAG_VRAM_IF_DGFX(tile)	(IS_DGFX(tile_to_xe(tile)) ? \
34 					 XE_BO_FLAG_VRAM((tile)->mem.vram) : \
35 					 XE_BO_FLAG_SYSTEM)
36 #define XE_BO_FLAG_GGTT			BIT(5)
37 #define XE_BO_FLAG_IGNORE_MIN_PAGE_SIZE BIT(6)
38 #define XE_BO_FLAG_PINNED		BIT(7)
39 #define XE_BO_FLAG_NO_RESV_EVICT	BIT(8)
40 #define XE_BO_FLAG_DEFER_BACKING	BIT(9)
41 #define XE_BO_FLAG_FORCE_WC		BIT(10)
42 #define XE_BO_FLAG_FIXED_PLACEMENT	BIT(11)
43 #define XE_BO_FLAG_PAGETABLE		BIT(12)
44 #define XE_BO_FLAG_NEEDS_CPU_ACCESS	BIT(13)
45 #define XE_BO_FLAG_NEEDS_UC		BIT(14)
46 #define XE_BO_FLAG_NEEDS_64K		BIT(15)
47 #define XE_BO_FLAG_NEEDS_2M		BIT(16)
48 #define XE_BO_FLAG_GGTT_INVALIDATE	BIT(17)
49 #define XE_BO_FLAG_PINNED_NORESTORE	BIT(18)
50 #define XE_BO_FLAG_PINNED_LATE_RESTORE	BIT(19)
51 #define XE_BO_FLAG_GGTT0		BIT(20)
52 #define XE_BO_FLAG_GGTT1		BIT(21)
53 #define XE_BO_FLAG_GGTT2		BIT(22)
54 #define XE_BO_FLAG_GGTT3		BIT(23)
55 #define XE_BO_FLAG_CPU_ADDR_MIRROR	BIT(24)
56 #define XE_BO_FLAG_FORCE_USER_VRAM	BIT(25)
57 #define XE_BO_FLAG_NO_COMPRESSION	BIT(26)
58 #define XE_BO_FLAG_NEEDS_1G		BIT(27)
59 
60 /* this one is trigger internally only */
61 #define XE_BO_FLAG_INTERNAL_TEST	BIT(30)
62 #define XE_BO_FLAG_INTERNAL_64K		BIT(31)
63 
64 #define XE_BO_FLAG_GGTT_ALL		(XE_BO_FLAG_GGTT0 | \
65 					 XE_BO_FLAG_GGTT1 | \
66 					 XE_BO_FLAG_GGTT2 | \
67 					 XE_BO_FLAG_GGTT3)
68 
69 #define XE_BO_FLAG_GGTTx(tile) \
70 	(XE_BO_FLAG_GGTT0 << (tile)->id)
71 
72 #define XE_PTE_SHIFT			12
73 #define XE_PAGE_SIZE			(1 << XE_PTE_SHIFT)
74 #define XE_PTE_MASK			(XE_PAGE_SIZE - 1)
75 #define XE_PDE_SHIFT			(XE_PTE_SHIFT - 3)
76 #define XE_PDES				(1 << XE_PDE_SHIFT)
77 #define XE_PDE_MASK			(XE_PDES - 1)
78 
79 #define XE_64K_PTE_SHIFT		16
80 #define XE_64K_PAGE_SIZE		(1 << XE_64K_PTE_SHIFT)
81 #define XE_64K_PTE_MASK			(XE_64K_PAGE_SIZE - 1)
82 #define XE_64K_PDE_MASK			(XE_PDE_MASK >> 4)
83 
84 #define XE_PL_SYSTEM		TTM_PL_SYSTEM
85 #define XE_PL_TT		TTM_PL_TT
86 #define XE_PL_VRAM0		TTM_PL_VRAM
87 #define XE_PL_VRAM1		(XE_PL_VRAM0 + 1)
88 #define XE_PL_STOLEN		(TTM_NUM_MEM_TYPES - 1)
89 
90 #define XE_BO_PROPS_INVALID	(-1)
91 
92 
93 /**
94  * enum xe_madv_purgeable_state - Buffer object purgeable state enumeration
95  *
96  * This enum defines the possible purgeable states for a buffer object,
97  * allowing userspace to provide memory usage hints to the kernel for
98  * better memory management under pressure.
99  *
100  * @XE_MADV_PURGEABLE_WILLNEED: The buffer object is needed and should not be purged.
101  * This is the default state.
102  * @XE_MADV_PURGEABLE_DONTNEED: The buffer object is not currently needed and can be
103  * purged by the kernel under memory pressure.
104  * @XE_MADV_PURGEABLE_PURGED: The buffer object has been purged by the kernel.
105  *
106  * Accessing a purged buffer will result in an error. Per i915 semantics,
107  * once purged, a BO remains permanently invalid and must be destroyed and recreated.
108  */
109 enum xe_madv_purgeable_state {
110 	XE_MADV_PURGEABLE_WILLNEED,
111 	XE_MADV_PURGEABLE_DONTNEED,
112 	XE_MADV_PURGEABLE_PURGED,
113 };
114 
115 struct sg_table;
116 
117 struct xe_bo *xe_bo_alloc(void);
118 void xe_bo_free(struct xe_bo *bo);
119 
120 struct xe_bo *xe_bo_init_locked(struct xe_device *xe, struct xe_bo *bo,
121 				struct xe_tile *tile, struct dma_resv *resv,
122 				struct ttm_lru_bulk_move *bulk, size_t size,
123 				u16 cpu_caching, enum ttm_bo_type type,
124 				u32 flags, struct dma_buf *dma_buf,
125 				struct drm_exec *exec);
126 struct xe_bo *xe_bo_create_locked(struct xe_device *xe, struct xe_tile *tile,
127 				  struct xe_vm *vm, size_t size,
128 				  enum ttm_bo_type type, u32 flags,
129 				  struct drm_exec *exec);
130 struct xe_bo *xe_bo_create_user(struct xe_device *xe, struct xe_vm *vm, size_t size,
131 				u16 cpu_caching, u32 flags, struct drm_exec *exec);
132 struct xe_bo *xe_bo_create_pin_map(struct xe_device *xe, struct xe_tile *tile,
133 				   struct xe_vm *vm, size_t size,
134 				   enum ttm_bo_type type, u32 flags,
135 				   struct drm_exec *exec);
136 struct xe_bo *xe_bo_create_pin_map_novm(struct xe_device *xe, struct xe_tile *tile,
137 					size_t size, enum ttm_bo_type type, u32 flags,
138 					bool intr);
139 struct xe_bo *xe_bo_create_pin_range_novm(struct xe_device *xe, struct xe_tile *tile,
140 					  size_t size, u64 start, u64 end,
141 					  enum ttm_bo_type type, u32 flags);
142 struct xe_bo *
143 xe_bo_create_pin_map_at_novm(struct xe_device *xe, struct xe_tile *tile,
144 			     size_t size, u64 offset, enum ttm_bo_type type,
145 			     u32 flags, u64 alignment, bool intr);
146 struct xe_bo *xe_managed_bo_create_pin_map(struct xe_device *xe, struct xe_tile *tile,
147 					   size_t size, u32 flags);
148 void xe_managed_bo_unpin_map_no_vm(struct xe_bo *bo);
149 struct xe_bo *xe_managed_bo_create_from_data(struct xe_device *xe, struct xe_tile *tile,
150 					     const void *data, size_t size, u32 flags);
151 int xe_managed_bo_reinit_in_vram(struct xe_device *xe, struct xe_tile *tile, struct xe_bo **src);
152 
153 int xe_bo_placement_for_flags(struct xe_device *xe, struct xe_bo *bo,
154 			      u32 bo_flags, enum ttm_bo_type type);
155 
156 static inline struct xe_bo *ttm_to_xe_bo(const struct ttm_buffer_object *bo)
157 {
158 	return container_of(bo, struct xe_bo, ttm);
159 }
160 
161 static inline struct xe_bo *gem_to_xe_bo(const struct drm_gem_object *obj)
162 {
163 	return container_of(obj, struct xe_bo, ttm.base);
164 }
165 
166 #define xe_bo_device(bo) ttm_to_xe_device((bo)->ttm.bdev)
167 
168 static inline struct xe_bo *xe_bo_get(struct xe_bo *bo)
169 {
170 	if (bo)
171 		drm_gem_object_get(&bo->ttm.base);
172 
173 	return bo;
174 }
175 
176 void xe_bo_put(struct xe_bo *bo);
177 
178 /*
179  * xe_bo_get_unless_zero() - Conditionally obtain a GEM object refcount on an
180  * xe bo
181  * @bo: The bo for which we want to obtain a refcount.
182  *
183  * There is a short window between where the bo's GEM object refcount reaches
184  * zero and where we put the final ttm_bo reference. Code in the eviction- and
185  * shrinking path should therefore attempt to grab a gem object reference before
186  * trying to use members outside of the base class ttm object. This function is
187  * intended for that purpose. On successful return, this function must be paired
188  * with an xe_bo_put().
189  *
190  * Return: @bo on success, NULL on failure.
191  */
192 static inline __must_check struct xe_bo *xe_bo_get_unless_zero(struct xe_bo *bo)
193 {
194 	if (!bo || !kref_get_unless_zero(&bo->ttm.base.refcount))
195 		return NULL;
196 
197 	return bo;
198 }
199 
200 static inline void __xe_bo_unset_bulk_move(struct xe_bo *bo)
201 {
202 	if (bo)
203 		ttm_bo_set_bulk_move(&bo->ttm, NULL);
204 }
205 
206 static inline void xe_bo_assert_held(struct xe_bo *bo)
207 {
208 	if (bo)
209 		dma_resv_assert_held((bo)->ttm.base.resv);
210 }
211 
212 int xe_bo_lock(struct xe_bo *bo, bool intr);
213 
214 void xe_bo_unlock(struct xe_bo *bo);
215 
216 static inline void xe_bo_unlock_vm_held(struct xe_bo *bo)
217 {
218 	if (bo) {
219 		XE_WARN_ON(bo->vm && bo->ttm.base.resv != xe_vm_resv(bo->vm));
220 		if (bo->vm)
221 			xe_vm_assert_held(bo->vm);
222 		else
223 			dma_resv_unlock(bo->ttm.base.resv);
224 	}
225 }
226 
227 int xe_bo_pin_external(struct xe_bo *bo, bool in_place, struct drm_exec *exec);
228 int xe_bo_pin(struct xe_bo *bo, struct drm_exec *exec);
229 void xe_bo_unpin_external(struct xe_bo *bo);
230 void xe_bo_unpin(struct xe_bo *bo);
231 void xe_bo_pin_account(struct xe_bo *bo);
232 void xe_bo_unpin_account(struct xe_bo *bo);
233 int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict,
234 		   struct drm_exec *exec);
235 
236 static inline bool xe_bo_is_pinned(struct xe_bo *bo)
237 {
238 	return bo->ttm.pin_count;
239 }
240 
241 static inline bool xe_bo_is_protected(const struct xe_bo *bo)
242 {
243 	return bo->pxp_key_instance;
244 }
245 
246 /**
247  * xe_bo_is_purged() - Check if buffer object has been purged
248  * @bo: The buffer object to check
249  *
250  * Checks if the buffer object's backing store has been discarded by the
251  * kernel due to memory pressure after being marked as purgeable (DONTNEED).
252  * Once purged, the BO cannot be restored and any attempt to use it will fail.
253  *
254  * Context: Caller must hold the BO's dma-resv lock
255  * Return: true if the BO has been purged, false otherwise
256  */
257 static inline bool xe_bo_is_purged(struct xe_bo *bo)
258 {
259 	xe_bo_assert_held(bo);
260 	return bo->purgeable.state == XE_MADV_PURGEABLE_PURGED;
261 }
262 
263 /**
264  * xe_bo_madv_is_dontneed() - Check if BO is marked as DONTNEED
265  * @bo: The buffer object to check
266  *
267  * Checks if userspace has marked this BO as DONTNEED (i.e., its contents
268  * are not currently needed and can be discarded under memory pressure).
269  * This is used internally to decide whether a BO is eligible for purging.
270  *
271  * Context: Caller must hold the BO's dma-resv lock
272  * Return: true if the BO is marked DONTNEED, false otherwise
273  */
274 static inline bool xe_bo_madv_is_dontneed(struct xe_bo *bo)
275 {
276 	xe_bo_assert_held(bo);
277 	return bo->purgeable.state == XE_MADV_PURGEABLE_DONTNEED;
278 }
279 
280 void xe_bo_set_purgeable_state(struct xe_bo *bo, enum xe_madv_purgeable_state new_state);
281 
282 /**
283  * xe_bo_willneed_get_locked() - Acquire a WILLNEED holder on a BO
284  * @bo: Buffer object
285  *
286  * Increments willneed_count and, on a 0->1 transition, promotes the BO
287  * from DONTNEED to WILLNEED. PURGED is terminal and is never modified.
288  *
289  * Caller must hold the BO's dma-resv lock.
290  */
291 static inline void xe_bo_willneed_get_locked(struct xe_bo *bo)
292 {
293 	xe_bo_assert_held(bo);
294 
295 	/* Imported BOs are owned externally; do not track purgeability. */
296 	if (drm_gem_is_imported(&bo->ttm.base))
297 		return;
298 
299 	if (bo->purgeable.willneed_count++ == 0 && xe_bo_madv_is_dontneed(bo))
300 		xe_bo_set_purgeable_state(bo, XE_MADV_PURGEABLE_WILLNEED);
301 }
302 
303 /**
304  * xe_bo_willneed_put_locked() - Release a WILLNEED holder on a BO
305  * @bo: Buffer object
306  *
307  * Decrements willneed_count and, on a 1->0 transition, marks the BO
308  * DONTNEED only if it still has VMAs (implying all active VMAs are
309  * DONTNEED). If the last VMA is being removed, preserve the current BO
310  * state to match the previous VMA-walk semantics.
311  *
312  * PURGED is terminal and the BO state is never modified.
313  *
314  * Caller must hold the BO's dma-resv lock.
315  */
316 static inline void xe_bo_willneed_put_locked(struct xe_bo *bo)
317 {
318 	xe_bo_assert_held(bo);
319 
320 	if (drm_gem_is_imported(&bo->ttm.base))
321 		return;
322 
323 	xe_assert(xe_bo_device(bo), bo->purgeable.willneed_count > 0);
324 	if (--bo->purgeable.willneed_count == 0 && bo->purgeable.vma_count > 0 &&
325 	    !xe_bo_is_purged(bo))
326 		xe_bo_set_purgeable_state(bo, XE_MADV_PURGEABLE_DONTNEED);
327 }
328 
329 /**
330  * xe_bo_vma_count_inc_locked() - Account a new VMA on a BO
331  * @bo: Buffer object
332  *
333  * Increments vma_count.
334  *
335  * Caller must hold the BO's dma-resv lock.
336  */
337 static inline void xe_bo_vma_count_inc_locked(struct xe_bo *bo)
338 {
339 	xe_bo_assert_held(bo);
340 
341 	if (drm_gem_is_imported(&bo->ttm.base))
342 		return;
343 
344 	bo->purgeable.vma_count++;
345 }
346 
347 /**
348  * xe_bo_vma_count_dec_locked() - Account a VMA removal on a BO
349  * @bo: Buffer object
350  *
351  * Decrements vma_count.
352  *
353  * Caller must hold the BO's dma-resv lock.
354  */
355 static inline void xe_bo_vma_count_dec_locked(struct xe_bo *bo)
356 {
357 	xe_bo_assert_held(bo);
358 
359 	if (drm_gem_is_imported(&bo->ttm.base))
360 		return;
361 
362 	xe_assert(xe_bo_device(bo), bo->purgeable.vma_count > 0);
363 	bo->purgeable.vma_count--;
364 }
365 
366 static inline void xe_bo_unpin_map_no_vm(struct xe_bo *bo)
367 {
368 	if (likely(bo)) {
369 		xe_bo_lock(bo, false);
370 		xe_bo_unpin(bo);
371 		xe_bo_unlock(bo);
372 
373 		xe_bo_put(bo);
374 	}
375 }
376 
377 bool xe_bo_is_xe_bo(struct ttm_buffer_object *bo);
378 dma_addr_t __xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
379 dma_addr_t xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
380 
381 static inline dma_addr_t
382 xe_bo_main_addr(struct xe_bo *bo, size_t page_size)
383 {
384 	return xe_bo_addr(bo, 0, page_size);
385 }
386 
387 /**
388  * xe_bo_size() - Xe BO size
389  * @bo: The bo object.
390  *
391  * Simple helper to return Xe BO's size.
392  *
393  * Return: Xe BO's size
394  */
395 static inline size_t xe_bo_size(struct xe_bo *bo)
396 {
397 	return bo->ttm.base.size;
398 }
399 
400 static inline u32
401 __xe_bo_ggtt_addr(struct xe_bo *bo, u8 tile_id)
402 {
403 	struct xe_ggtt_node *ggtt_node = bo->ggtt_node[tile_id];
404 	u64 offset;
405 
406 	if (XE_WARN_ON(!ggtt_node))
407 		return 0;
408 
409 	offset = xe_ggtt_node_addr(ggtt_node);
410 	XE_WARN_ON(offset + xe_bo_size(bo) > (1ull << 32));
411 	return offset;
412 }
413 
414 static inline u32
415 xe_bo_ggtt_addr(struct xe_bo *bo)
416 {
417 	xe_assert(xe_bo_device(bo), bo->tile);
418 
419 	return __xe_bo_ggtt_addr(bo, bo->tile->id);
420 }
421 
422 int xe_bo_vmap(struct xe_bo *bo);
423 void xe_bo_vunmap(struct xe_bo *bo);
424 int xe_bo_read(struct xe_bo *bo, u64 offset, void *dst, int size);
425 
426 bool mem_type_is_vram(u32 mem_type);
427 bool xe_bo_is_vram(struct xe_bo *bo);
428 bool xe_bo_is_visible_vram(struct xe_bo *bo);
429 bool xe_bo_is_stolen(struct xe_bo *bo);
430 bool xe_bo_is_stolen_devmem(struct xe_bo *bo);
431 bool xe_bo_is_vm_bound(struct xe_bo *bo);
432 bool xe_bo_has_single_placement(struct xe_bo *bo);
433 uint64_t vram_region_gpu_offset(struct ttm_resource *res);
434 
435 bool xe_bo_can_migrate(struct xe_bo *bo, u32 mem_type);
436 
437 int xe_bo_migrate(struct xe_bo *bo, u32 mem_type, struct ttm_operation_ctx *ctc,
438 		  struct drm_exec *exec);
439 int xe_bo_evict(struct xe_bo *bo, struct drm_exec *exec);
440 
441 int xe_bo_evict_pinned(struct xe_bo *bo);
442 int xe_bo_notifier_prepare_pinned(struct xe_bo *bo);
443 int xe_bo_notifier_unprepare_pinned(struct xe_bo *bo);
444 int xe_bo_restore_pinned(struct xe_bo *bo);
445 
446 int xe_bo_dma_unmap_pinned(struct xe_bo *bo);
447 
448 extern const struct ttm_device_funcs xe_ttm_funcs;
449 extern const char *const xe_mem_type_to_name[];
450 
451 int xe_gem_create_ioctl(struct drm_device *dev, void *data,
452 			struct drm_file *file);
453 int xe_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
454 			     struct drm_file *file);
455 void xe_bo_runtime_pm_release_mmap_offset(struct xe_bo *bo);
456 
457 int xe_bo_dumb_create(struct drm_file *file_priv,
458 		      struct drm_device *dev,
459 		      struct drm_mode_create_dumb *args);
460 
461 bool xe_bo_needs_ccs_pages(struct xe_bo *bo);
462 
463 int xe_bo_decompress(struct xe_bo *bo);
464 
465 static inline size_t xe_bo_ccs_pages_start(struct xe_bo *bo)
466 {
467 	return PAGE_ALIGN(xe_bo_size(bo));
468 }
469 
470 /**
471  * xe_bo_has_valid_ccs_bb - Check if CCS's BBs were setup for the BO.
472  * @bo: the &xe_bo to check
473  *
474  * The CCS's BBs should only be setup by the driver VF, but it is safe
475  * to call this function also by non-VF driver.
476  *
477  * Return: true iff the CCS's BBs are setup, false otherwise.
478  */
479 static inline bool xe_bo_has_valid_ccs_bb(struct xe_bo *bo)
480 {
481 	return bo->bb_ccs[XE_SRIOV_VF_CCS_READ_CTX] &&
482 	       bo->bb_ccs[XE_SRIOV_VF_CCS_WRITE_CTX];
483 }
484 
485 static inline bool xe_bo_has_pages(struct xe_bo *bo)
486 {
487 	if ((bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm)) ||
488 	    xe_bo_is_vram(bo))
489 		return true;
490 
491 	return false;
492 }
493 
494 void __xe_bo_release_dummy(struct kref *kref);
495 
496 /**
497  * xe_bo_put_deferred() - Put a buffer object with delayed final freeing
498  * @bo: The bo to put.
499  * @deferred: List to which to add the buffer object if we cannot put, or
500  * NULL if the function is to put unconditionally.
501  * @added: BO was added to deferred list, written back to caller, can be NULL if
502  * writeback is not needed. Only set to true when added, never set to false.
503  *
504  * Since the final freeing of an object includes both sleeping and (!)
505  * memory allocation in the dma_resv individualization, it's not ok
506  * to put an object from atomic context nor from within a held lock
507  * tainted by reclaim. In such situations we want to defer the final
508  * freeing until we've exited the restricting context, or in the worst
509  * case to a workqueue.
510  * This function either puts the object if possible without the refcount
511  * reaching zero, or adds it to the @deferred list if that was not possible.
512  * The caller needs to follow up with a call to xe_bo_put_commit() to actually
513  * put the bo iff this function returns true. It's safe to always
514  * follow up with a call to xe_bo_put_commit().
515  * TODO: It's TTM that is the villain here. Perhaps TTM should add an
516  * interface like this.
517  *
518  * Return: true if @bo was the first object put on the @freed list,
519  * false otherwise.
520  */
521 static inline bool
522 xe_bo_put_deferred(struct xe_bo *bo, struct llist_head *deferred,
523 		   bool *added)
524 {
525 	if (!deferred) {
526 		xe_bo_put(bo);
527 		return false;
528 	}
529 
530 	if (!kref_put(&bo->ttm.base.refcount, __xe_bo_release_dummy))
531 		return false;
532 
533 	if (added)
534 		*added = true;
535 
536 	return llist_add(&bo->freed, deferred);
537 }
538 
539 void xe_bo_put_commit(struct llist_head *deferred);
540 
541 /**
542  * xe_bo_put_async() - Put BO async
543  * @bo: The bo to put.
544  *
545  * Put BO async, the final put is deferred to a worker to exit an IRQ context.
546  */
547 static inline void
548 xe_bo_put_async(struct xe_bo *bo)
549 {
550 	struct xe_bo_dev *bo_device = &xe_bo_device(bo)->bo_device;
551 
552 	if (xe_bo_put_deferred(bo, &bo_device->async_list, NULL))
553 		schedule_work(&bo_device->async_free);
554 }
555 
556 void xe_bo_dev_init(struct xe_bo_dev *bo_device);
557 
558 void xe_bo_dev_fini(struct xe_bo_dev *bo_device);
559 
560 struct sg_table *xe_bo_sg(struct xe_bo *bo);
561 
562 /**
563  * xe_bo_sg_is_contiguous() - Check if a BO's DMA address space is contiguous.
564  * @bo: the BO to check (must have a valid sg table, i.e. !xe_bo_is_vram())
565  * @len: required contiguous length in bytes
566  *
567  * Returns true if the first @len bytes of the BO are mapped to a contiguous
568  * DMA address range.
569  */
570 static inline bool xe_bo_sg_is_contiguous(struct xe_bo *bo, size_t len)
571 {
572 	return drm_prime_get_contiguous_size(xe_bo_sg(bo)) >= len;
573 }
574 
575 /*
576  * xe_sg_segment_size() - Provides upper limit for sg segment size.
577  * @dev: device pointer
578  *
579  * Returns the maximum segment size for the 'struct scatterlist'
580  * elements.
581  */
582 static inline unsigned int xe_sg_segment_size(struct device *dev)
583 {
584 	struct scatterlist __maybe_unused sg;
585 	size_t max = BIT_ULL(sizeof(sg.length) * 8) - 1;
586 
587 	/*
588 	 * For Xen PV guests pages aren't contiguous in DMA (machine) address
589 	 * space.  The DMA API takes care of that both in dma_alloc_* (by
590 	 * calling into the hypervisor to make the pages contiguous) and in
591 	 * dma_map_* (by bounce buffering).  But xe (like i915, see commit
592 	 * 78a07fe777c4) ignores the coherency aspects of the DMA API and thus
593 	 * can't cope with bounce buffering actually happening, so add a hack
594 	 * here to force small allocations and mappings when running in PV
595 	 * mode on Xen.
596 	 *
597 	 * Note this will still break if bounce buffering is required for other
598 	 * reasons, like confidential computing hypervisors or PCIe root ports
599 	 * with addressing limitations.
600 	 */
601 	if (xen_pv_domain())
602 		return PAGE_SIZE;
603 
604 	max = min_t(size_t, max, dma_max_mapping_size(dev));
605 
606 	/*
607 	 * The iommu_dma_map_sg() function ensures iova allocation doesn't
608 	 * cross dma segment boundary. It does so by padding some sg elements.
609 	 * This can cause overflow, ending up with sg->length being set to 0.
610 	 * Avoid this by ensuring maximum segment size is half of 'max'
611 	 * rounded down to PAGE_SIZE.
612 	 */
613 	return round_down(max / 2, PAGE_SIZE);
614 }
615 
616 /**
617  * struct xe_bo_shrink_flags - flags governing the shrink behaviour.
618  * @purge: Only purging allowed. Don't shrink if bo not purgeable.
619  * @writeback: Attempt to immediately move content to swap.
620  */
621 struct xe_bo_shrink_flags {
622 	u32 purge : 1;
623 	u32 writeback : 1;
624 };
625 
626 long xe_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo,
627 		  const struct xe_bo_shrink_flags flags,
628 		  unsigned long *scanned);
629 int xe_ttm_bo_purge(struct ttm_buffer_object *ttm_bo, struct ttm_operation_ctx *ctx);
630 bool xe_bo_is_user(struct xe_bo *bo);
631 
632 /**
633  * xe_bo_is_mem_type - Whether the bo currently resides in the given
634  * TTM memory type
635  * @bo: The bo to check.
636  * @mem_type: The TTM memory type.
637  *
638  * Return: true iff the bo resides in @mem_type, false otherwise.
639  */
640 static inline bool xe_bo_is_mem_type(struct xe_bo *bo, u32 mem_type)
641 {
642 	xe_bo_assert_held(bo);
643 	return bo->ttm.resource->mem_type == mem_type;
644 }
645 #endif
646