xref: /linux/drivers/gpu/drm/xe/xe_bo.h (revision 6812ce4e4379ffc99c52401ec28f0d7ffbc36206)
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 #define XE_PCI_BARRIER_MMAP_OFFSET	(0x50 << XE_PTE_SHIFT)
93 
94 /**
95  * enum xe_madv_purgeable_state - Buffer object purgeable state enumeration
96  *
97  * This enum defines the possible purgeable states for a buffer object,
98  * allowing userspace to provide memory usage hints to the kernel for
99  * better memory management under pressure.
100  *
101  * @XE_MADV_PURGEABLE_WILLNEED: The buffer object is needed and should not be purged.
102  * This is the default state.
103  * @XE_MADV_PURGEABLE_DONTNEED: The buffer object is not currently needed and can be
104  * purged by the kernel under memory pressure.
105  * @XE_MADV_PURGEABLE_PURGED: The buffer object has been purged by the kernel.
106  *
107  * Accessing a purged buffer will result in an error. Per i915 semantics,
108  * once purged, a BO remains permanently invalid and must be destroyed and recreated.
109  */
110 enum xe_madv_purgeable_state {
111 	XE_MADV_PURGEABLE_WILLNEED,
112 	XE_MADV_PURGEABLE_DONTNEED,
113 	XE_MADV_PURGEABLE_PURGED,
114 };
115 
116 struct sg_table;
117 
118 struct xe_bo *xe_bo_alloc(void);
119 void xe_bo_free(struct xe_bo *bo);
120 
121 struct xe_bo *xe_bo_init_locked(struct xe_device *xe, struct xe_bo *bo,
122 				struct xe_tile *tile, struct dma_resv *resv,
123 				struct ttm_lru_bulk_move *bulk, size_t size,
124 				u16 cpu_caching, enum ttm_bo_type type,
125 				u32 flags, struct dma_buf *dma_buf,
126 				struct drm_exec *exec);
127 struct xe_bo *xe_bo_create_locked(struct xe_device *xe, struct xe_tile *tile,
128 				  struct xe_vm *vm, size_t size,
129 				  enum ttm_bo_type type, u32 flags,
130 				  struct drm_exec *exec);
131 struct xe_bo *xe_bo_create_user(struct xe_device *xe, struct xe_vm *vm, size_t size,
132 				u16 cpu_caching, u32 flags, struct drm_exec *exec);
133 struct xe_bo *xe_bo_create_pin_map(struct xe_device *xe, struct xe_tile *tile,
134 				   struct xe_vm *vm, size_t size,
135 				   enum ttm_bo_type type, u32 flags,
136 				   struct drm_exec *exec);
137 struct xe_bo *xe_bo_create_pin_map_novm(struct xe_device *xe, struct xe_tile *tile,
138 					size_t size, enum ttm_bo_type type, u32 flags,
139 					bool intr);
140 struct xe_bo *xe_bo_create_pin_range_novm(struct xe_device *xe, struct xe_tile *tile,
141 					  size_t size, u64 start, u64 end,
142 					  enum ttm_bo_type type, u32 flags);
143 struct xe_bo *
144 xe_bo_create_pin_map_at_novm(struct xe_device *xe, struct xe_tile *tile,
145 			     size_t size, u64 offset, enum ttm_bo_type type,
146 			     u32 flags, u64 alignment, bool intr);
147 struct xe_bo *xe_managed_bo_create_pin_map(struct xe_device *xe, struct xe_tile *tile,
148 					   size_t size, u32 flags);
149 void xe_managed_bo_unpin_map_no_vm(struct xe_bo *bo);
150 struct xe_bo *xe_managed_bo_create_from_data(struct xe_device *xe, struct xe_tile *tile,
151 					     const void *data, size_t size, u32 flags);
152 int xe_managed_bo_reinit_in_vram(struct xe_device *xe, struct xe_tile *tile, struct xe_bo **src);
153 
154 int xe_bo_placement_for_flags(struct xe_device *xe, struct xe_bo *bo,
155 			      u32 bo_flags, enum ttm_bo_type type);
156 
ttm_to_xe_bo(const struct ttm_buffer_object * bo)157 static inline struct xe_bo *ttm_to_xe_bo(const struct ttm_buffer_object *bo)
158 {
159 	return container_of(bo, struct xe_bo, ttm);
160 }
161 
gem_to_xe_bo(const struct drm_gem_object * obj)162 static inline struct xe_bo *gem_to_xe_bo(const struct drm_gem_object *obj)
163 {
164 	return container_of(obj, struct xe_bo, ttm.base);
165 }
166 
167 #define xe_bo_device(bo) ttm_to_xe_device((bo)->ttm.bdev)
168 
xe_bo_get(struct xe_bo * bo)169 static inline struct xe_bo *xe_bo_get(struct xe_bo *bo)
170 {
171 	if (bo)
172 		drm_gem_object_get(&bo->ttm.base);
173 
174 	return bo;
175 }
176 
177 void xe_bo_put(struct xe_bo *bo);
178 
179 /*
180  * xe_bo_get_unless_zero() - Conditionally obtain a GEM object refcount on an
181  * xe bo
182  * @bo: The bo for which we want to obtain a refcount.
183  *
184  * There is a short window between where the bo's GEM object refcount reaches
185  * zero and where we put the final ttm_bo reference. Code in the eviction- and
186  * shrinking path should therefore attempt to grab a gem object reference before
187  * trying to use members outside of the base class ttm object. This function is
188  * intended for that purpose. On successful return, this function must be paired
189  * with an xe_bo_put().
190  *
191  * Return: @bo on success, NULL on failure.
192  */
xe_bo_get_unless_zero(struct xe_bo * bo)193 static inline __must_check struct xe_bo *xe_bo_get_unless_zero(struct xe_bo *bo)
194 {
195 	if (!bo || !kref_get_unless_zero(&bo->ttm.base.refcount))
196 		return NULL;
197 
198 	return bo;
199 }
200 
__xe_bo_unset_bulk_move(struct xe_bo * bo)201 static inline void __xe_bo_unset_bulk_move(struct xe_bo *bo)
202 {
203 	if (bo)
204 		ttm_bo_set_bulk_move(&bo->ttm, NULL);
205 }
206 
xe_bo_assert_held(struct xe_bo * bo)207 static inline void xe_bo_assert_held(struct xe_bo *bo)
208 {
209 	if (bo)
210 		dma_resv_assert_held((bo)->ttm.base.resv);
211 }
212 
213 int xe_bo_lock(struct xe_bo *bo, bool intr);
214 
215 void xe_bo_unlock(struct xe_bo *bo);
216 
xe_bo_unlock_vm_held(struct xe_bo * bo)217 static inline void xe_bo_unlock_vm_held(struct xe_bo *bo)
218 {
219 	if (bo) {
220 		XE_WARN_ON(bo->vm && bo->ttm.base.resv != xe_vm_resv(bo->vm));
221 		if (bo->vm)
222 			xe_vm_assert_held(bo->vm);
223 		else
224 			dma_resv_unlock(bo->ttm.base.resv);
225 	}
226 }
227 
228 int xe_bo_pin_external(struct xe_bo *bo, bool in_place, struct drm_exec *exec);
229 int xe_bo_pin(struct xe_bo *bo, struct drm_exec *exec);
230 void xe_bo_unpin_external(struct xe_bo *bo);
231 void xe_bo_unpin(struct xe_bo *bo);
232 int xe_bo_validate(struct xe_bo *bo, struct xe_vm *vm, bool allow_res_evict,
233 		   struct drm_exec *exec);
234 
xe_bo_is_pinned(struct xe_bo * bo)235 static inline bool xe_bo_is_pinned(struct xe_bo *bo)
236 {
237 	return bo->ttm.pin_count;
238 }
239 
xe_bo_is_protected(const struct xe_bo * bo)240 static inline bool xe_bo_is_protected(const struct xe_bo *bo)
241 {
242 	return bo->pxp_key_instance;
243 }
244 
245 /**
246  * xe_bo_is_purged() - Check if buffer object has been purged
247  * @bo: The buffer object to check
248  *
249  * Checks if the buffer object's backing store has been discarded by the
250  * kernel due to memory pressure after being marked as purgeable (DONTNEED).
251  * Once purged, the BO cannot be restored and any attempt to use it will fail.
252  *
253  * Context: Caller must hold the BO's dma-resv lock
254  * Return: true if the BO has been purged, false otherwise
255  */
xe_bo_is_purged(struct xe_bo * bo)256 static inline bool xe_bo_is_purged(struct xe_bo *bo)
257 {
258 	xe_bo_assert_held(bo);
259 	return bo->purgeable.state == XE_MADV_PURGEABLE_PURGED;
260 }
261 
262 /**
263  * xe_bo_madv_is_dontneed() - Check if BO is marked as DONTNEED
264  * @bo: The buffer object to check
265  *
266  * Checks if userspace has marked this BO as DONTNEED (i.e., its contents
267  * are not currently needed and can be discarded under memory pressure).
268  * This is used internally to decide whether a BO is eligible for purging.
269  *
270  * Context: Caller must hold the BO's dma-resv lock
271  * Return: true if the BO is marked DONTNEED, false otherwise
272  */
xe_bo_madv_is_dontneed(struct xe_bo * bo)273 static inline bool xe_bo_madv_is_dontneed(struct xe_bo *bo)
274 {
275 	xe_bo_assert_held(bo);
276 	return bo->purgeable.state == XE_MADV_PURGEABLE_DONTNEED;
277 }
278 
279 void xe_bo_set_purgeable_state(struct xe_bo *bo, enum xe_madv_purgeable_state new_state);
280 
281 /**
282  * xe_bo_willneed_get_locked() - Acquire a WILLNEED holder on a BO
283  * @bo: Buffer object
284  *
285  * Increments willneed_count and, on a 0->1 transition, promotes the BO
286  * from DONTNEED to WILLNEED. PURGED is terminal and is never modified.
287  *
288  * Caller must hold the BO's dma-resv lock.
289  */
xe_bo_willneed_get_locked(struct xe_bo * bo)290 static inline void xe_bo_willneed_get_locked(struct xe_bo *bo)
291 {
292 	xe_bo_assert_held(bo);
293 
294 	/* Imported BOs are owned externally; do not track purgeability. */
295 	if (drm_gem_is_imported(&bo->ttm.base))
296 		return;
297 
298 	if (bo->purgeable.willneed_count++ == 0 && xe_bo_madv_is_dontneed(bo))
299 		xe_bo_set_purgeable_state(bo, XE_MADV_PURGEABLE_WILLNEED);
300 }
301 
302 /**
303  * xe_bo_willneed_put_locked() - Release a WILLNEED holder on a BO
304  * @bo: Buffer object
305  *
306  * Decrements willneed_count and, on a 1->0 transition, marks the BO
307  * DONTNEED only if it still has VMAs (implying all active VMAs are
308  * DONTNEED). If the last VMA is being removed, preserve the current BO
309  * state to match the previous VMA-walk semantics.
310  *
311  * PURGED is terminal and the BO state is never modified.
312  *
313  * Caller must hold the BO's dma-resv lock.
314  */
xe_bo_willneed_put_locked(struct xe_bo * bo)315 static inline void xe_bo_willneed_put_locked(struct xe_bo *bo)
316 {
317 	xe_bo_assert_held(bo);
318 
319 	if (drm_gem_is_imported(&bo->ttm.base))
320 		return;
321 
322 	xe_assert(xe_bo_device(bo), bo->purgeable.willneed_count > 0);
323 	if (--bo->purgeable.willneed_count == 0 && bo->purgeable.vma_count > 0 &&
324 	    !xe_bo_is_purged(bo))
325 		xe_bo_set_purgeable_state(bo, XE_MADV_PURGEABLE_DONTNEED);
326 }
327 
328 /**
329  * xe_bo_vma_count_inc_locked() - Account a new VMA on a BO
330  * @bo: Buffer object
331  *
332  * Increments vma_count.
333  *
334  * Caller must hold the BO's dma-resv lock.
335  */
xe_bo_vma_count_inc_locked(struct xe_bo * bo)336 static inline void xe_bo_vma_count_inc_locked(struct xe_bo *bo)
337 {
338 	xe_bo_assert_held(bo);
339 
340 	if (drm_gem_is_imported(&bo->ttm.base))
341 		return;
342 
343 	bo->purgeable.vma_count++;
344 }
345 
346 /**
347  * xe_bo_vma_count_dec_locked() - Account a VMA removal on a BO
348  * @bo: Buffer object
349  *
350  * Decrements vma_count.
351  *
352  * Caller must hold the BO's dma-resv lock.
353  */
xe_bo_vma_count_dec_locked(struct xe_bo * bo)354 static inline void xe_bo_vma_count_dec_locked(struct xe_bo *bo)
355 {
356 	xe_bo_assert_held(bo);
357 
358 	if (drm_gem_is_imported(&bo->ttm.base))
359 		return;
360 
361 	xe_assert(xe_bo_device(bo), bo->purgeable.vma_count > 0);
362 	bo->purgeable.vma_count--;
363 }
364 
xe_bo_unpin_map_no_vm(struct xe_bo * bo)365 static inline void xe_bo_unpin_map_no_vm(struct xe_bo *bo)
366 {
367 	if (likely(bo)) {
368 		xe_bo_lock(bo, false);
369 		xe_bo_unpin(bo);
370 		xe_bo_unlock(bo);
371 
372 		xe_bo_put(bo);
373 	}
374 }
375 
376 bool xe_bo_is_xe_bo(struct ttm_buffer_object *bo);
377 dma_addr_t __xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
378 dma_addr_t xe_bo_addr(struct xe_bo *bo, u64 offset, size_t page_size);
379 
380 static inline dma_addr_t
xe_bo_main_addr(struct xe_bo * bo,size_t page_size)381 xe_bo_main_addr(struct xe_bo *bo, size_t page_size)
382 {
383 	return xe_bo_addr(bo, 0, page_size);
384 }
385 
386 /**
387  * xe_bo_size() - Xe BO size
388  * @bo: The bo object.
389  *
390  * Simple helper to return Xe BO's size.
391  *
392  * Return: Xe BO's size
393  */
xe_bo_size(struct xe_bo * bo)394 static inline size_t xe_bo_size(struct xe_bo *bo)
395 {
396 	return bo->ttm.base.size;
397 }
398 
399 static inline u32
__xe_bo_ggtt_addr(struct xe_bo * bo,u8 tile_id)400 __xe_bo_ggtt_addr(struct xe_bo *bo, u8 tile_id)
401 {
402 	struct xe_ggtt_node *ggtt_node = bo->ggtt_node[tile_id];
403 	u64 offset;
404 
405 	if (XE_WARN_ON(!ggtt_node))
406 		return 0;
407 
408 	offset = xe_ggtt_node_addr(ggtt_node);
409 	XE_WARN_ON(offset + xe_bo_size(bo) > (1ull << 32));
410 	return offset;
411 }
412 
413 static inline u32
xe_bo_ggtt_addr(struct xe_bo * bo)414 xe_bo_ggtt_addr(struct xe_bo *bo)
415 {
416 	xe_assert(xe_bo_device(bo), bo->tile);
417 
418 	return __xe_bo_ggtt_addr(bo, bo->tile->id);
419 }
420 
421 int xe_bo_vmap(struct xe_bo *bo);
422 void xe_bo_vunmap(struct xe_bo *bo);
423 int xe_bo_read(struct xe_bo *bo, u64 offset, void *dst, int size);
424 
425 bool mem_type_is_vram(u32 mem_type);
426 bool xe_bo_is_vram(struct xe_bo *bo);
427 bool xe_bo_is_visible_vram(struct xe_bo *bo);
428 bool xe_bo_is_stolen(struct xe_bo *bo);
429 bool xe_bo_is_stolen_devmem(struct xe_bo *bo);
430 bool xe_bo_is_vm_bound(struct xe_bo *bo);
431 bool xe_bo_has_single_placement(struct xe_bo *bo);
432 uint64_t vram_region_gpu_offset(struct ttm_resource *res);
433 
434 bool xe_bo_can_migrate(struct xe_bo *bo, u32 mem_type);
435 
436 int xe_bo_migrate(struct xe_bo *bo, u32 mem_type, struct ttm_operation_ctx *ctc,
437 		  struct drm_exec *exec);
438 int xe_bo_evict(struct xe_bo *bo, struct drm_exec *exec);
439 
440 int xe_bo_evict_pinned(struct xe_bo *bo);
441 int xe_bo_notifier_prepare_pinned(struct xe_bo *bo);
442 int xe_bo_notifier_unprepare_pinned(struct xe_bo *bo);
443 int xe_bo_restore_pinned(struct xe_bo *bo);
444 
445 int xe_bo_dma_unmap_pinned(struct xe_bo *bo);
446 
447 extern const struct ttm_device_funcs xe_ttm_funcs;
448 extern const char *const xe_mem_type_to_name[];
449 
450 int xe_gem_create_ioctl(struct drm_device *dev, void *data,
451 			struct drm_file *file);
452 int xe_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
453 			     struct drm_file *file);
454 void xe_bo_runtime_pm_release_mmap_offset(struct xe_bo *bo);
455 
456 int xe_bo_dumb_create(struct drm_file *file_priv,
457 		      struct drm_device *dev,
458 		      struct drm_mode_create_dumb *args);
459 
460 bool xe_bo_needs_ccs_pages(struct xe_bo *bo);
461 
462 int xe_bo_decompress(struct xe_bo *bo);
463 
xe_bo_ccs_pages_start(struct xe_bo * bo)464 static inline size_t xe_bo_ccs_pages_start(struct xe_bo *bo)
465 {
466 	return PAGE_ALIGN(xe_bo_size(bo));
467 }
468 
469 /**
470  * xe_bo_has_valid_ccs_bb - Check if CCS's BBs were setup for the BO.
471  * @bo: the &xe_bo to check
472  *
473  * The CCS's BBs should only be setup by the driver VF, but it is safe
474  * to call this function also by non-VF driver.
475  *
476  * Return: true iff the CCS's BBs are setup, false otherwise.
477  */
xe_bo_has_valid_ccs_bb(struct xe_bo * bo)478 static inline bool xe_bo_has_valid_ccs_bb(struct xe_bo *bo)
479 {
480 	return bo->bb_ccs[XE_SRIOV_VF_CCS_READ_CTX] &&
481 	       bo->bb_ccs[XE_SRIOV_VF_CCS_WRITE_CTX];
482 }
483 
xe_bo_has_pages(struct xe_bo * bo)484 static inline bool xe_bo_has_pages(struct xe_bo *bo)
485 {
486 	if ((bo->ttm.ttm && ttm_tt_is_populated(bo->ttm.ttm)) ||
487 	    xe_bo_is_vram(bo))
488 		return true;
489 
490 	return false;
491 }
492 
493 void __xe_bo_release_dummy(struct kref *kref);
494 
495 /**
496  * xe_bo_put_deferred() - Put a buffer object with delayed final freeing
497  * @bo: The bo to put.
498  * @deferred: List to which to add the buffer object if we cannot put, or
499  * NULL if the function is to put unconditionally.
500  *
501  * Since the final freeing of an object includes both sleeping and (!)
502  * memory allocation in the dma_resv individualization, it's not ok
503  * to put an object from atomic context nor from within a held lock
504  * tainted by reclaim. In such situations we want to defer the final
505  * freeing until we've exited the restricting context, or in the worst
506  * case to a workqueue.
507  * This function either puts the object if possible without the refcount
508  * reaching zero, or adds it to the @deferred list if that was not possible.
509  * The caller needs to follow up with a call to xe_bo_put_commit() to actually
510  * put the bo iff this function returns true. It's safe to always
511  * follow up with a call to xe_bo_put_commit().
512  * TODO: It's TTM that is the villain here. Perhaps TTM should add an
513  * interface like this.
514  *
515  * Return: true if @bo was the first object put on the @freed list,
516  * false otherwise.
517  */
518 static inline bool
xe_bo_put_deferred(struct xe_bo * bo,struct llist_head * deferred)519 xe_bo_put_deferred(struct xe_bo *bo, struct llist_head *deferred)
520 {
521 	if (!deferred) {
522 		xe_bo_put(bo);
523 		return false;
524 	}
525 
526 	if (!kref_put(&bo->ttm.base.refcount, __xe_bo_release_dummy))
527 		return false;
528 
529 	return llist_add(&bo->freed, deferred);
530 }
531 
532 void xe_bo_put_commit(struct llist_head *deferred);
533 
534 /**
535  * xe_bo_put_async() - Put BO async
536  * @bo: The bo to put.
537  *
538  * Put BO async, the final put is deferred to a worker to exit an IRQ context.
539  */
540 static inline void
xe_bo_put_async(struct xe_bo * bo)541 xe_bo_put_async(struct xe_bo *bo)
542 {
543 	struct xe_bo_dev *bo_device = &xe_bo_device(bo)->bo_device;
544 
545 	if (xe_bo_put_deferred(bo, &bo_device->async_list))
546 		schedule_work(&bo_device->async_free);
547 }
548 
549 void xe_bo_dev_init(struct xe_bo_dev *bo_device);
550 
551 void xe_bo_dev_fini(struct xe_bo_dev *bo_device);
552 
553 struct sg_table *xe_bo_sg(struct xe_bo *bo);
554 
555 /**
556  * xe_bo_sg_is_contiguous() - Check if a BO's DMA address space is contiguous.
557  * @bo: the BO to check (must have a valid sg table, i.e. !xe_bo_is_vram())
558  * @len: required contiguous length in bytes
559  *
560  * Returns true if the first @len bytes of the BO are mapped to a contiguous
561  * DMA address range.
562  */
xe_bo_sg_is_contiguous(struct xe_bo * bo,size_t len)563 static inline bool xe_bo_sg_is_contiguous(struct xe_bo *bo, size_t len)
564 {
565 	return drm_prime_get_contiguous_size(xe_bo_sg(bo)) >= len;
566 }
567 
568 /*
569  * xe_sg_segment_size() - Provides upper limit for sg segment size.
570  * @dev: device pointer
571  *
572  * Returns the maximum segment size for the 'struct scatterlist'
573  * elements.
574  */
xe_sg_segment_size(struct device * dev)575 static inline unsigned int xe_sg_segment_size(struct device *dev)
576 {
577 	struct scatterlist __maybe_unused sg;
578 	size_t max = BIT_ULL(sizeof(sg.length) * 8) - 1;
579 
580 	/*
581 	 * For Xen PV guests pages aren't contiguous in DMA (machine) address
582 	 * space.  The DMA API takes care of that both in dma_alloc_* (by
583 	 * calling into the hypervisor to make the pages contiguous) and in
584 	 * dma_map_* (by bounce buffering).  But xe (like i915, see commit
585 	 * 78a07fe777c4) ignores the coherency aspects of the DMA API and thus
586 	 * can't cope with bounce buffering actually happening, so add a hack
587 	 * here to force small allocations and mappings when running in PV
588 	 * mode on Xen.
589 	 *
590 	 * Note this will still break if bounce buffering is required for other
591 	 * reasons, like confidential computing hypervisors or PCIe root ports
592 	 * with addressing limitations.
593 	 */
594 	if (xen_pv_domain())
595 		return PAGE_SIZE;
596 
597 	max = min_t(size_t, max, dma_max_mapping_size(dev));
598 
599 	/*
600 	 * The iommu_dma_map_sg() function ensures iova allocation doesn't
601 	 * cross dma segment boundary. It does so by padding some sg elements.
602 	 * This can cause overflow, ending up with sg->length being set to 0.
603 	 * Avoid this by ensuring maximum segment size is half of 'max'
604 	 * rounded down to PAGE_SIZE.
605 	 */
606 	return round_down(max / 2, PAGE_SIZE);
607 }
608 
609 /**
610  * struct xe_bo_shrink_flags - flags governing the shrink behaviour.
611  * @purge: Only purging allowed. Don't shrink if bo not purgeable.
612  * @writeback: Attempt to immediately move content to swap.
613  */
614 struct xe_bo_shrink_flags {
615 	u32 purge : 1;
616 	u32 writeback : 1;
617 };
618 
619 long xe_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo,
620 		  const struct xe_bo_shrink_flags flags,
621 		  unsigned long *scanned);
622 
623 /**
624  * xe_bo_is_mem_type - Whether the bo currently resides in the given
625  * TTM memory type
626  * @bo: The bo to check.
627  * @mem_type: The TTM memory type.
628  *
629  * Return: true iff the bo resides in @mem_type, false otherwise.
630  */
xe_bo_is_mem_type(struct xe_bo * bo,u32 mem_type)631 static inline bool xe_bo_is_mem_type(struct xe_bo *bo, u32 mem_type)
632 {
633 	xe_bo_assert_held(bo);
634 	return bo->ttm.resource->mem_type == mem_type;
635 }
636 #endif
637