xref: /linux/drivers/gpu/drm/xe/xe_svm.c (revision 82f78acd5a9270370ef4aa3f032ede25f3dc91ee)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2024 Intel Corporation
4  */
5 
6 #include <drm/drm_drv.h>
7 
8 #include "xe_bo.h"
9 #include "xe_exec_queue_types.h"
10 #include "xe_gt_stats.h"
11 #include "xe_migrate.h"
12 #include "xe_module.h"
13 #include "xe_pm.h"
14 #include "xe_pt.h"
15 #include "xe_svm.h"
16 #include "xe_tile.h"
17 #include "xe_ttm_vram_mgr.h"
18 #include "xe_vm.h"
19 #include "xe_vm_types.h"
20 #include "xe_vram_types.h"
21 
xe_svm_range_in_vram(struct xe_svm_range * range)22 static bool xe_svm_range_in_vram(struct xe_svm_range *range)
23 {
24 	/*
25 	 * Advisory only check whether the range is currently backed by VRAM
26 	 * memory.
27 	 */
28 
29 	struct drm_gpusvm_pages_flags flags = {
30 		/* Pairs with WRITE_ONCE in drm_gpusvm.c */
31 		.__flags = READ_ONCE(range->base.pages.flags.__flags),
32 	};
33 
34 	return flags.has_devmem_pages;
35 }
36 
xe_svm_range_has_vram_binding(struct xe_svm_range * range)37 static bool xe_svm_range_has_vram_binding(struct xe_svm_range *range)
38 {
39 	/* Not reliable without notifier lock */
40 	return xe_svm_range_in_vram(range) && range->tile_present;
41 }
42 
gpusvm_to_vm(struct drm_gpusvm * gpusvm)43 static struct xe_vm *gpusvm_to_vm(struct drm_gpusvm *gpusvm)
44 {
45 	return container_of(gpusvm, struct xe_vm, svm.gpusvm);
46 }
47 
range_to_vm(struct drm_gpusvm_range * r)48 static struct xe_vm *range_to_vm(struct drm_gpusvm_range *r)
49 {
50 	return gpusvm_to_vm(r->gpusvm);
51 }
52 
53 #define range_debug(r__, operation__)					\
54 	vm_dbg(&range_to_vm(&(r__)->base)->xe->drm,			\
55 	       "%s: asid=%u, gpusvm=%p, vram=%d,%d, seqno=%lu, " \
56 	       "start=0x%014lx, end=0x%014lx, size=%lu",		\
57 	       (operation__), range_to_vm(&(r__)->base)->usm.asid,	\
58 	       (r__)->base.gpusvm,					\
59 	       xe_svm_range_in_vram((r__)) ? 1 : 0,			\
60 	       xe_svm_range_has_vram_binding((r__)) ? 1 : 0,		\
61 	       (r__)->base.pages.notifier_seq,				\
62 	       xe_svm_range_start((r__)), xe_svm_range_end((r__)),	\
63 	       xe_svm_range_size((r__)))
64 
xe_svm_range_debug(struct xe_svm_range * range,const char * operation)65 void xe_svm_range_debug(struct xe_svm_range *range, const char *operation)
66 {
67 	range_debug(range, operation);
68 }
69 
70 static struct drm_gpusvm_range *
xe_svm_range_alloc(struct drm_gpusvm * gpusvm)71 xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
72 {
73 	struct xe_svm_range *range;
74 
75 	range = kzalloc(sizeof(*range), GFP_KERNEL);
76 	if (!range)
77 		return NULL;
78 
79 	INIT_LIST_HEAD(&range->garbage_collector_link);
80 	xe_vm_get(gpusvm_to_vm(gpusvm));
81 
82 	return &range->base;
83 }
84 
xe_svm_range_free(struct drm_gpusvm_range * range)85 static void xe_svm_range_free(struct drm_gpusvm_range *range)
86 {
87 	xe_vm_put(range_to_vm(range));
88 	kfree(range);
89 }
90 
91 static void
xe_svm_garbage_collector_add_range(struct xe_vm * vm,struct xe_svm_range * range,const struct mmu_notifier_range * mmu_range)92 xe_svm_garbage_collector_add_range(struct xe_vm *vm, struct xe_svm_range *range,
93 				   const struct mmu_notifier_range *mmu_range)
94 {
95 	struct xe_device *xe = vm->xe;
96 
97 	range_debug(range, "GARBAGE COLLECTOR ADD");
98 
99 	drm_gpusvm_range_set_unmapped(&range->base, mmu_range);
100 
101 	spin_lock(&vm->svm.garbage_collector.lock);
102 	if (list_empty(&range->garbage_collector_link))
103 		list_add_tail(&range->garbage_collector_link,
104 			      &vm->svm.garbage_collector.range_list);
105 	spin_unlock(&vm->svm.garbage_collector.lock);
106 
107 	queue_work(xe->usm.pf_wq, &vm->svm.garbage_collector.work);
108 }
109 
xe_svm_tlb_inval_count_stats_incr(struct xe_gt * gt)110 static void xe_svm_tlb_inval_count_stats_incr(struct xe_gt *gt)
111 {
112 	xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_TLB_INVAL_COUNT, 1);
113 }
114 
115 static u8
xe_svm_range_notifier_event_begin(struct xe_vm * vm,struct drm_gpusvm_range * r,const struct mmu_notifier_range * mmu_range,u64 * adj_start,u64 * adj_end)116 xe_svm_range_notifier_event_begin(struct xe_vm *vm, struct drm_gpusvm_range *r,
117 				  const struct mmu_notifier_range *mmu_range,
118 				  u64 *adj_start, u64 *adj_end)
119 {
120 	struct xe_svm_range *range = to_xe_range(r);
121 	struct xe_device *xe = vm->xe;
122 	struct xe_tile *tile;
123 	u8 tile_mask = 0;
124 	u8 id;
125 
126 	xe_svm_assert_in_notifier(vm);
127 
128 	range_debug(range, "NOTIFIER");
129 
130 	/* Skip if already unmapped or if no binding exist */
131 	if (range->base.pages.flags.unmapped || !range->tile_present)
132 		return 0;
133 
134 	range_debug(range, "NOTIFIER - EXECUTE");
135 
136 	/* Adjust invalidation to range boundaries */
137 	*adj_start = min(xe_svm_range_start(range), mmu_range->start);
138 	*adj_end = max(xe_svm_range_end(range), mmu_range->end);
139 
140 	/*
141 	 * XXX: Ideally would zap PTEs in one shot in xe_svm_invalidate but the
142 	 * invalidation code can't correctly cope with sparse ranges or
143 	 * invalidations spanning multiple ranges.
144 	 */
145 	for_each_tile(tile, xe, id)
146 		if (xe_pt_zap_ptes_range(tile, vm, range)) {
147 			/*
148 			 * WRITE_ONCE pairs with READ_ONCE in
149 			 * xe_vm_has_valid_gpu_mapping()
150 			 */
151 			WRITE_ONCE(range->tile_invalidated,
152 				   range->tile_invalidated | BIT(id));
153 
154 			if (!(tile_mask & BIT(id))) {
155 				xe_svm_tlb_inval_count_stats_incr(tile->primary_gt);
156 				if (tile->media_gt)
157 					xe_svm_tlb_inval_count_stats_incr(tile->media_gt);
158 				tile_mask |= BIT(id);
159 			}
160 		}
161 
162 	return tile_mask;
163 }
164 
165 static void
xe_svm_range_notifier_event_end(struct xe_vm * vm,struct drm_gpusvm_range * r,const struct mmu_notifier_range * mmu_range)166 xe_svm_range_notifier_event_end(struct xe_vm *vm, struct drm_gpusvm_range *r,
167 				const struct mmu_notifier_range *mmu_range)
168 {
169 	struct drm_gpusvm_ctx ctx = { .in_notifier = true, };
170 
171 	xe_svm_assert_in_notifier(vm);
172 
173 	drm_gpusvm_range_unmap_pages(&vm->svm.gpusvm, r, &ctx);
174 	if (!xe_vm_is_closed(vm) && mmu_range->event == MMU_NOTIFY_UNMAP)
175 		xe_svm_garbage_collector_add_range(vm, to_xe_range(r),
176 						   mmu_range);
177 }
178 
xe_svm_stats_ktime_us_delta(ktime_t start)179 static s64 xe_svm_stats_ktime_us_delta(ktime_t start)
180 {
181 	return IS_ENABLED(CONFIG_DEBUG_FS) ?
182 		ktime_us_delta(ktime_get(), start) : 0;
183 }
184 
xe_svm_tlb_inval_us_stats_incr(struct xe_gt * gt,ktime_t start)185 static void xe_svm_tlb_inval_us_stats_incr(struct xe_gt *gt, ktime_t start)
186 {
187 	s64 us_delta = xe_svm_stats_ktime_us_delta(start);
188 
189 	xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_TLB_INVAL_US, us_delta);
190 }
191 
xe_svm_stats_ktime_get(void)192 static ktime_t xe_svm_stats_ktime_get(void)
193 {
194 	return IS_ENABLED(CONFIG_DEBUG_FS) ? ktime_get() : 0;
195 }
196 
xe_svm_invalidate(struct drm_gpusvm * gpusvm,struct drm_gpusvm_notifier * notifier,const struct mmu_notifier_range * mmu_range)197 static void xe_svm_invalidate(struct drm_gpusvm *gpusvm,
198 			      struct drm_gpusvm_notifier *notifier,
199 			      const struct mmu_notifier_range *mmu_range)
200 {
201 	struct xe_vm *vm = gpusvm_to_vm(gpusvm);
202 	struct xe_device *xe = vm->xe;
203 	struct drm_gpusvm_range *r, *first;
204 	struct xe_tile *tile;
205 	ktime_t start = xe_svm_stats_ktime_get();
206 	u64 adj_start = mmu_range->start, adj_end = mmu_range->end;
207 	u8 tile_mask = 0, id;
208 	long err;
209 
210 	xe_svm_assert_in_notifier(vm);
211 
212 	vm_dbg(&gpusvm_to_vm(gpusvm)->xe->drm,
213 	       "INVALIDATE: asid=%u, gpusvm=%p, seqno=%lu, start=0x%016lx, end=0x%016lx, event=%d",
214 	       vm->usm.asid, gpusvm, notifier->notifier.invalidate_seq,
215 	       mmu_range->start, mmu_range->end, mmu_range->event);
216 
217 	/* Adjust invalidation to notifier boundaries */
218 	adj_start = max(drm_gpusvm_notifier_start(notifier), adj_start);
219 	adj_end = min(drm_gpusvm_notifier_end(notifier), adj_end);
220 
221 	first = drm_gpusvm_range_find(notifier, adj_start, adj_end);
222 	if (!first)
223 		return;
224 
225 	/*
226 	 * PTs may be getting destroyed so not safe to touch these but PT should
227 	 * be invalidated at this point in time. Regardless we still need to
228 	 * ensure any dma mappings are unmapped in the here.
229 	 */
230 	if (xe_vm_is_closed(vm))
231 		goto range_notifier_event_end;
232 
233 	/*
234 	 * XXX: Less than ideal to always wait on VM's resv slots if an
235 	 * invalidation is not required. Could walk range list twice to figure
236 	 * out if an invalidations is need, but also not ideal.
237 	 */
238 	err = dma_resv_wait_timeout(xe_vm_resv(vm),
239 				    DMA_RESV_USAGE_BOOKKEEP,
240 				    false, MAX_SCHEDULE_TIMEOUT);
241 	XE_WARN_ON(err <= 0);
242 
243 	r = first;
244 	drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end)
245 		tile_mask |= xe_svm_range_notifier_event_begin(vm, r, mmu_range,
246 							       &adj_start,
247 							       &adj_end);
248 	if (!tile_mask)
249 		goto range_notifier_event_end;
250 
251 	xe_device_wmb(xe);
252 
253 	err = xe_vm_range_tilemask_tlb_inval(vm, adj_start, adj_end, tile_mask);
254 	WARN_ON_ONCE(err);
255 
256 range_notifier_event_end:
257 	r = first;
258 	drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end)
259 		xe_svm_range_notifier_event_end(vm, r, mmu_range);
260 	for_each_tile(tile, xe, id) {
261 		if (tile_mask & BIT(id)) {
262 			xe_svm_tlb_inval_us_stats_incr(tile->primary_gt, start);
263 			if (tile->media_gt)
264 				xe_svm_tlb_inval_us_stats_incr(tile->media_gt, start);
265 		}
266 	}
267 }
268 
__xe_svm_garbage_collector(struct xe_vm * vm,struct xe_svm_range * range)269 static int __xe_svm_garbage_collector(struct xe_vm *vm,
270 				      struct xe_svm_range *range)
271 {
272 	struct dma_fence *fence;
273 
274 	range_debug(range, "GARBAGE COLLECTOR");
275 
276 	xe_vm_lock(vm, false);
277 	fence = xe_vm_range_unbind(vm, range);
278 	xe_vm_unlock(vm);
279 	if (IS_ERR(fence))
280 		return PTR_ERR(fence);
281 	dma_fence_put(fence);
282 
283 	drm_gpusvm_range_remove(&vm->svm.gpusvm, &range->base);
284 
285 	return 0;
286 }
287 
xe_svm_range_set_default_attr(struct xe_vm * vm,u64 range_start,u64 range_end)288 static int xe_svm_range_set_default_attr(struct xe_vm *vm, u64 range_start, u64 range_end)
289 {
290 	struct xe_vma *vma;
291 	struct xe_vma_mem_attr default_attr = {
292 		.preferred_loc = {
293 			.devmem_fd = DRM_XE_PREFERRED_LOC_DEFAULT_DEVICE,
294 			.migration_policy = DRM_XE_MIGRATE_ALL_PAGES,
295 		},
296 		.atomic_access = DRM_XE_ATOMIC_UNDEFINED,
297 	};
298 	int err = 0;
299 
300 	vma = xe_vm_find_vma_by_addr(vm, range_start);
301 	if (!vma)
302 		return -EINVAL;
303 
304 	if (!(vma->gpuva.flags & XE_VMA_MADV_AUTORESET)) {
305 		drm_dbg(&vm->xe->drm, "Skipping madvise reset for vma.\n");
306 		return 0;
307 	}
308 
309 	if (xe_vma_has_default_mem_attrs(vma))
310 		return 0;
311 
312 	vm_dbg(&vm->xe->drm, "Existing VMA start=0x%016llx, vma_end=0x%016llx",
313 	       xe_vma_start(vma), xe_vma_end(vma));
314 
315 	if (xe_vma_start(vma) == range_start && xe_vma_end(vma) == range_end) {
316 		default_attr.pat_index = vma->attr.default_pat_index;
317 		default_attr.default_pat_index  = vma->attr.default_pat_index;
318 		vma->attr = default_attr;
319 	} else {
320 		vm_dbg(&vm->xe->drm, "Split VMA start=0x%016llx, vma_end=0x%016llx",
321 		       range_start, range_end);
322 		err = xe_vm_alloc_cpu_addr_mirror_vma(vm, range_start, range_end - range_start);
323 		if (err) {
324 			drm_warn(&vm->xe->drm, "VMA SPLIT failed: %pe\n", ERR_PTR(err));
325 			xe_vm_kill(vm, true);
326 			return err;
327 		}
328 	}
329 
330 	/*
331 	 * On call from xe_svm_handle_pagefault original VMA might be changed
332 	 * signal this to lookup for VMA again.
333 	 */
334 	return -EAGAIN;
335 }
336 
xe_svm_garbage_collector(struct xe_vm * vm)337 static int xe_svm_garbage_collector(struct xe_vm *vm)
338 {
339 	struct xe_svm_range *range;
340 	u64 range_start;
341 	u64 range_end;
342 	int err, ret = 0;
343 
344 	lockdep_assert_held_write(&vm->lock);
345 
346 	if (xe_vm_is_closed_or_banned(vm))
347 		return -ENOENT;
348 
349 	for (;;) {
350 		spin_lock(&vm->svm.garbage_collector.lock);
351 		range = list_first_entry_or_null(&vm->svm.garbage_collector.range_list,
352 						 typeof(*range),
353 						 garbage_collector_link);
354 		if (!range)
355 			break;
356 
357 		range_start = xe_svm_range_start(range);
358 		range_end = xe_svm_range_end(range);
359 
360 		list_del(&range->garbage_collector_link);
361 		spin_unlock(&vm->svm.garbage_collector.lock);
362 
363 		err = __xe_svm_garbage_collector(vm, range);
364 		if (err) {
365 			drm_warn(&vm->xe->drm,
366 				 "Garbage collection failed: %pe\n",
367 				 ERR_PTR(err));
368 			xe_vm_kill(vm, true);
369 			return err;
370 		}
371 
372 		err = xe_svm_range_set_default_attr(vm, range_start, range_end);
373 		if (err) {
374 			if (err == -EAGAIN)
375 				ret = -EAGAIN;
376 			else
377 				return err;
378 		}
379 	}
380 	spin_unlock(&vm->svm.garbage_collector.lock);
381 
382 	return ret;
383 }
384 
xe_svm_garbage_collector_work_func(struct work_struct * w)385 static void xe_svm_garbage_collector_work_func(struct work_struct *w)
386 {
387 	struct xe_vm *vm = container_of(w, struct xe_vm,
388 					svm.garbage_collector.work);
389 
390 	down_write(&vm->lock);
391 	xe_svm_garbage_collector(vm);
392 	up_write(&vm->lock);
393 }
394 
395 #if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
396 
page_to_vr(struct page * page)397 static struct xe_vram_region *page_to_vr(struct page *page)
398 {
399 	return container_of(page_pgmap(page), struct xe_vram_region, pagemap);
400 }
401 
xe_vram_region_page_to_dpa(struct xe_vram_region * vr,struct page * page)402 static u64 xe_vram_region_page_to_dpa(struct xe_vram_region *vr,
403 				      struct page *page)
404 {
405 	u64 dpa;
406 	u64 pfn = page_to_pfn(page);
407 	u64 offset;
408 
409 	xe_assert(vr->xe, is_device_private_page(page));
410 	xe_assert(vr->xe, (pfn << PAGE_SHIFT) >= vr->hpa_base);
411 
412 	offset = (pfn << PAGE_SHIFT) - vr->hpa_base;
413 	dpa = vr->dpa_base + offset;
414 
415 	return dpa;
416 }
417 
418 enum xe_svm_copy_dir {
419 	XE_SVM_COPY_TO_VRAM,
420 	XE_SVM_COPY_TO_SRAM,
421 };
422 
xe_svm_copy_kb_stats_incr(struct xe_gt * gt,const enum xe_svm_copy_dir dir,int kb)423 static void xe_svm_copy_kb_stats_incr(struct xe_gt *gt,
424 				      const enum xe_svm_copy_dir dir,
425 				      int kb)
426 {
427 	if (dir == XE_SVM_COPY_TO_VRAM)
428 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_DEVICE_COPY_KB, kb);
429 	else
430 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_CPU_COPY_KB, kb);
431 }
432 
xe_svm_copy_us_stats_incr(struct xe_gt * gt,const enum xe_svm_copy_dir dir,unsigned long npages,ktime_t start)433 static void xe_svm_copy_us_stats_incr(struct xe_gt *gt,
434 				      const enum xe_svm_copy_dir dir,
435 				      unsigned long npages,
436 				      ktime_t start)
437 {
438 	s64 us_delta = xe_svm_stats_ktime_us_delta(start);
439 
440 	if (dir == XE_SVM_COPY_TO_VRAM) {
441 		switch (npages) {
442 		case 1:
443 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_4K_DEVICE_COPY_US,
444 					 us_delta);
445 			break;
446 		case 16:
447 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_64K_DEVICE_COPY_US,
448 					 us_delta);
449 			break;
450 		case 512:
451 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_2M_DEVICE_COPY_US,
452 					 us_delta);
453 			break;
454 		}
455 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_DEVICE_COPY_US,
456 				 us_delta);
457 	} else {
458 		switch (npages) {
459 		case 1:
460 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_4K_CPU_COPY_US,
461 					 us_delta);
462 			break;
463 		case 16:
464 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_64K_CPU_COPY_US,
465 					 us_delta);
466 			break;
467 		case 512:
468 			xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_2M_CPU_COPY_US,
469 					 us_delta);
470 			break;
471 		}
472 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_CPU_COPY_US,
473 				 us_delta);
474 	}
475 }
476 
xe_svm_copy(struct page ** pages,struct drm_pagemap_addr * pagemap_addr,unsigned long npages,const enum xe_svm_copy_dir dir)477 static int xe_svm_copy(struct page **pages,
478 		       struct drm_pagemap_addr *pagemap_addr,
479 		       unsigned long npages, const enum xe_svm_copy_dir dir)
480 {
481 	struct xe_vram_region *vr = NULL;
482 	struct xe_gt *gt = NULL;
483 	struct xe_device *xe;
484 	struct dma_fence *fence = NULL;
485 	unsigned long i;
486 #define XE_VRAM_ADDR_INVALID	~0x0ull
487 	u64 vram_addr = XE_VRAM_ADDR_INVALID;
488 	int err = 0, pos = 0;
489 	bool sram = dir == XE_SVM_COPY_TO_SRAM;
490 	ktime_t start = xe_svm_stats_ktime_get();
491 
492 	/*
493 	 * This flow is complex: it locates physically contiguous device pages,
494 	 * derives the starting physical address, and performs a single GPU copy
495 	 * to for every 8M chunk in a DMA address array. Both device pages and
496 	 * DMA addresses may be sparsely populated. If either is NULL, a copy is
497 	 * triggered based on the current search state. The last GPU copy is
498 	 * waited on to ensure all copies are complete.
499 	 */
500 
501 	for (i = 0; i < npages; ++i) {
502 		struct page *spage = pages[i];
503 		struct dma_fence *__fence;
504 		u64 __vram_addr;
505 		bool match = false, chunk, last;
506 
507 #define XE_MIGRATE_CHUNK_SIZE	SZ_8M
508 		chunk = (i - pos) == (XE_MIGRATE_CHUNK_SIZE / PAGE_SIZE);
509 		last = (i + 1) == npages;
510 
511 		/* No CPU page and no device pages queue'd to copy */
512 		if (!pagemap_addr[i].addr && vram_addr == XE_VRAM_ADDR_INVALID)
513 			continue;
514 
515 		if (!vr && spage) {
516 			vr = page_to_vr(spage);
517 			gt = xe_migrate_exec_queue(vr->migrate)->gt;
518 			xe = vr->xe;
519 		}
520 		XE_WARN_ON(spage && page_to_vr(spage) != vr);
521 
522 		/*
523 		 * CPU page and device page valid, capture physical address on
524 		 * first device page, check if physical contiguous on subsequent
525 		 * device pages.
526 		 */
527 		if (pagemap_addr[i].addr && spage) {
528 			__vram_addr = xe_vram_region_page_to_dpa(vr, spage);
529 			if (vram_addr == XE_VRAM_ADDR_INVALID) {
530 				vram_addr = __vram_addr;
531 				pos = i;
532 			}
533 
534 			match = vram_addr + PAGE_SIZE * (i - pos) == __vram_addr;
535 			/* Expected with contiguous memory */
536 			xe_assert(vr->xe, match);
537 
538 			if (pagemap_addr[i].order) {
539 				i += NR_PAGES(pagemap_addr[i].order) - 1;
540 				chunk = (i - pos) == (XE_MIGRATE_CHUNK_SIZE / PAGE_SIZE);
541 				last = (i + 1) == npages;
542 			}
543 		}
544 
545 		/*
546 		 * Mismatched physical address, 8M copy chunk, or last page -
547 		 * trigger a copy.
548 		 */
549 		if (!match || chunk || last) {
550 			/*
551 			 * Extra page for first copy if last page and matching
552 			 * physical address.
553 			 */
554 			int incr = (match && last) ? 1 : 0;
555 
556 			if (vram_addr != XE_VRAM_ADDR_INVALID) {
557 				xe_svm_copy_kb_stats_incr(gt, dir,
558 							  (i - pos + incr) *
559 							  (PAGE_SIZE / SZ_1K));
560 				if (sram) {
561 					vm_dbg(&xe->drm,
562 					       "COPY TO SRAM - 0x%016llx -> 0x%016llx, NPAGES=%ld",
563 					       vram_addr,
564 					       (u64)pagemap_addr[pos].addr, i - pos + incr);
565 					__fence = xe_migrate_from_vram(vr->migrate,
566 								       i - pos + incr,
567 								       vram_addr,
568 								       &pagemap_addr[pos]);
569 				} else {
570 					vm_dbg(&xe->drm,
571 					       "COPY TO VRAM - 0x%016llx -> 0x%016llx, NPAGES=%ld",
572 					       (u64)pagemap_addr[pos].addr, vram_addr,
573 					       i - pos + incr);
574 					__fence = xe_migrate_to_vram(vr->migrate,
575 								     i - pos + incr,
576 								     &pagemap_addr[pos],
577 								     vram_addr);
578 				}
579 				if (IS_ERR(__fence)) {
580 					err = PTR_ERR(__fence);
581 					goto err_out;
582 				}
583 
584 				dma_fence_put(fence);
585 				fence = __fence;
586 			}
587 
588 			/* Setup physical address of next device page */
589 			if (pagemap_addr[i].addr && spage) {
590 				vram_addr = __vram_addr;
591 				pos = i;
592 			} else {
593 				vram_addr = XE_VRAM_ADDR_INVALID;
594 			}
595 
596 			/* Extra mismatched device page, copy it */
597 			if (!match && last && vram_addr != XE_VRAM_ADDR_INVALID) {
598 				xe_svm_copy_kb_stats_incr(gt, dir,
599 							  (PAGE_SIZE / SZ_1K));
600 				if (sram) {
601 					vm_dbg(&xe->drm,
602 					       "COPY TO SRAM - 0x%016llx -> 0x%016llx, NPAGES=%d",
603 					       vram_addr, (u64)pagemap_addr[pos].addr, 1);
604 					__fence = xe_migrate_from_vram(vr->migrate, 1,
605 								       vram_addr,
606 								       &pagemap_addr[pos]);
607 				} else {
608 					vm_dbg(&xe->drm,
609 					       "COPY TO VRAM - 0x%016llx -> 0x%016llx, NPAGES=%d",
610 					       (u64)pagemap_addr[pos].addr, vram_addr, 1);
611 					__fence = xe_migrate_to_vram(vr->migrate, 1,
612 								     &pagemap_addr[pos],
613 								     vram_addr);
614 				}
615 				if (IS_ERR(__fence)) {
616 					err = PTR_ERR(__fence);
617 					goto err_out;
618 				}
619 
620 				dma_fence_put(fence);
621 				fence = __fence;
622 			}
623 		}
624 	}
625 
626 err_out:
627 	/* Wait for all copies to complete */
628 	if (fence) {
629 		dma_fence_wait(fence, false);
630 		dma_fence_put(fence);
631 	}
632 
633 	/*
634 	 * XXX: We can't derive the GT here (or anywhere in this functions, but
635 	 * compute always uses the primary GT so accumulate stats on the likely
636 	 * GT of the fault.
637 	 */
638 	if (gt)
639 		xe_svm_copy_us_stats_incr(gt, dir, npages, start);
640 
641 	return err;
642 #undef XE_MIGRATE_CHUNK_SIZE
643 #undef XE_VRAM_ADDR_INVALID
644 }
645 
xe_svm_copy_to_devmem(struct page ** pages,struct drm_pagemap_addr * pagemap_addr,unsigned long npages)646 static int xe_svm_copy_to_devmem(struct page **pages,
647 				 struct drm_pagemap_addr *pagemap_addr,
648 				 unsigned long npages)
649 {
650 	return xe_svm_copy(pages, pagemap_addr, npages, XE_SVM_COPY_TO_VRAM);
651 }
652 
xe_svm_copy_to_ram(struct page ** pages,struct drm_pagemap_addr * pagemap_addr,unsigned long npages)653 static int xe_svm_copy_to_ram(struct page **pages,
654 			      struct drm_pagemap_addr *pagemap_addr,
655 			      unsigned long npages)
656 {
657 	return xe_svm_copy(pages, pagemap_addr, npages, XE_SVM_COPY_TO_SRAM);
658 }
659 
to_xe_bo(struct drm_pagemap_devmem * devmem_allocation)660 static struct xe_bo *to_xe_bo(struct drm_pagemap_devmem *devmem_allocation)
661 {
662 	return container_of(devmem_allocation, struct xe_bo, devmem_allocation);
663 }
664 
xe_svm_devmem_release(struct drm_pagemap_devmem * devmem_allocation)665 static void xe_svm_devmem_release(struct drm_pagemap_devmem *devmem_allocation)
666 {
667 	struct xe_bo *bo = to_xe_bo(devmem_allocation);
668 	struct xe_device *xe = xe_bo_device(bo);
669 
670 	xe_bo_put_async(bo);
671 	xe_pm_runtime_put(xe);
672 }
673 
block_offset_to_pfn(struct xe_vram_region * vr,u64 offset)674 static u64 block_offset_to_pfn(struct xe_vram_region *vr, u64 offset)
675 {
676 	return PHYS_PFN(offset + vr->hpa_base);
677 }
678 
vram_to_buddy(struct xe_vram_region * vram)679 static struct drm_buddy *vram_to_buddy(struct xe_vram_region *vram)
680 {
681 	return &vram->ttm.mm;
682 }
683 
xe_svm_populate_devmem_pfn(struct drm_pagemap_devmem * devmem_allocation,unsigned long npages,unsigned long * pfn)684 static int xe_svm_populate_devmem_pfn(struct drm_pagemap_devmem *devmem_allocation,
685 				      unsigned long npages, unsigned long *pfn)
686 {
687 	struct xe_bo *bo = to_xe_bo(devmem_allocation);
688 	struct ttm_resource *res = bo->ttm.resource;
689 	struct list_head *blocks = &to_xe_ttm_vram_mgr_resource(res)->blocks;
690 	struct drm_buddy_block *block;
691 	int j = 0;
692 
693 	list_for_each_entry(block, blocks, link) {
694 		struct xe_vram_region *vr = block->private;
695 		struct drm_buddy *buddy = vram_to_buddy(vr);
696 		u64 block_pfn = block_offset_to_pfn(vr, drm_buddy_block_offset(block));
697 		int i;
698 
699 		for (i = 0; i < drm_buddy_block_size(buddy, block) >> PAGE_SHIFT; ++i)
700 			pfn[j++] = block_pfn + i;
701 	}
702 
703 	return 0;
704 }
705 
706 static const struct drm_pagemap_devmem_ops dpagemap_devmem_ops = {
707 	.devmem_release = xe_svm_devmem_release,
708 	.populate_devmem_pfn = xe_svm_populate_devmem_pfn,
709 	.copy_to_devmem = xe_svm_copy_to_devmem,
710 	.copy_to_ram = xe_svm_copy_to_ram,
711 };
712 
713 #endif
714 
715 static const struct drm_gpusvm_ops gpusvm_ops = {
716 	.range_alloc = xe_svm_range_alloc,
717 	.range_free = xe_svm_range_free,
718 	.invalidate = xe_svm_invalidate,
719 };
720 
721 static const unsigned long fault_chunk_sizes[] = {
722 	SZ_2M,
723 	SZ_64K,
724 	SZ_4K,
725 };
726 
727 /**
728  * xe_svm_init() - SVM initialize
729  * @vm: The VM.
730  *
731  * Initialize SVM state which is embedded within the VM.
732  *
733  * Return: 0 on success, negative error code on error.
734  */
xe_svm_init(struct xe_vm * vm)735 int xe_svm_init(struct xe_vm *vm)
736 {
737 	int err;
738 
739 	if (vm->flags & XE_VM_FLAG_FAULT_MODE) {
740 		spin_lock_init(&vm->svm.garbage_collector.lock);
741 		INIT_LIST_HEAD(&vm->svm.garbage_collector.range_list);
742 		INIT_WORK(&vm->svm.garbage_collector.work,
743 			  xe_svm_garbage_collector_work_func);
744 
745 		err = drm_gpusvm_init(&vm->svm.gpusvm, "Xe SVM", &vm->xe->drm,
746 				      current->mm, 0, vm->size,
747 				      xe_modparam.svm_notifier_size * SZ_1M,
748 				      &gpusvm_ops, fault_chunk_sizes,
749 				      ARRAY_SIZE(fault_chunk_sizes));
750 		drm_gpusvm_driver_set_lock(&vm->svm.gpusvm, &vm->lock);
751 	} else {
752 		err = drm_gpusvm_init(&vm->svm.gpusvm, "Xe SVM (simple)",
753 				      &vm->xe->drm, NULL, 0, 0, 0, NULL,
754 				      NULL, 0);
755 	}
756 
757 	return err;
758 }
759 
760 /**
761  * xe_svm_close() - SVM close
762  * @vm: The VM.
763  *
764  * Close SVM state (i.e., stop and flush all SVM actions).
765  */
xe_svm_close(struct xe_vm * vm)766 void xe_svm_close(struct xe_vm *vm)
767 {
768 	xe_assert(vm->xe, xe_vm_is_closed(vm));
769 	flush_work(&vm->svm.garbage_collector.work);
770 }
771 
772 /**
773  * xe_svm_fini() - SVM finalize
774  * @vm: The VM.
775  *
776  * Finalize SVM state which is embedded within the VM.
777  */
xe_svm_fini(struct xe_vm * vm)778 void xe_svm_fini(struct xe_vm *vm)
779 {
780 	xe_assert(vm->xe, xe_vm_is_closed(vm));
781 
782 	drm_gpusvm_fini(&vm->svm.gpusvm);
783 }
784 
xe_svm_range_is_valid(struct xe_svm_range * range,struct xe_tile * tile,bool devmem_only)785 static bool xe_svm_range_is_valid(struct xe_svm_range *range,
786 				  struct xe_tile *tile,
787 				  bool devmem_only)
788 {
789 	return (xe_vm_has_valid_gpu_mapping(tile, range->tile_present,
790 					    range->tile_invalidated) &&
791 		(!devmem_only || xe_svm_range_in_vram(range)));
792 }
793 
794 /** xe_svm_range_migrate_to_smem() - Move range pages from VRAM to SMEM
795  * @vm: xe_vm pointer
796  * @range: Pointer to the SVM range structure
797  *
798  * The xe_svm_range_migrate_to_smem() checks range has pages in VRAM
799  * and migrates them to SMEM
800  */
xe_svm_range_migrate_to_smem(struct xe_vm * vm,struct xe_svm_range * range)801 void xe_svm_range_migrate_to_smem(struct xe_vm *vm, struct xe_svm_range *range)
802 {
803 	if (xe_svm_range_in_vram(range))
804 		drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
805 }
806 
807 /**
808  * xe_svm_range_validate() - Check if the SVM range is valid
809  * @vm: xe_vm pointer
810  * @range: Pointer to the SVM range structure
811  * @tile_mask: Mask representing the tiles to be checked
812  * @devmem_preferred : if true range needs to be in devmem
813  *
814  * The xe_svm_range_validate() function checks if a range is
815  * valid and located in the desired memory region.
816  *
817  * Return: true if the range is valid, false otherwise
818  */
xe_svm_range_validate(struct xe_vm * vm,struct xe_svm_range * range,u8 tile_mask,bool devmem_preferred)819 bool xe_svm_range_validate(struct xe_vm *vm,
820 			   struct xe_svm_range *range,
821 			   u8 tile_mask, bool devmem_preferred)
822 {
823 	bool ret;
824 
825 	xe_svm_notifier_lock(vm);
826 
827 	ret = (range->tile_present & ~range->tile_invalidated & tile_mask) == tile_mask &&
828 	       (devmem_preferred == range->base.pages.flags.has_devmem_pages);
829 
830 	xe_svm_notifier_unlock(vm);
831 
832 	return ret;
833 }
834 
835 /**
836  * xe_svm_find_vma_start - Find start of CPU VMA
837  * @vm: xe_vm pointer
838  * @start: start address
839  * @end: end address
840  * @vma: Pointer to struct xe_vma
841  *
842  *
843  * This function searches for a cpu vma, within the specified
844  * range [start, end] in the given VM. It adjusts the range based on the
845  * xe_vma start and end addresses. If no cpu VMA is found, it returns ULONG_MAX.
846  *
847  * Return: The starting address of the VMA within the range,
848  * or ULONG_MAX if no VMA is found
849  */
xe_svm_find_vma_start(struct xe_vm * vm,u64 start,u64 end,struct xe_vma * vma)850 u64 xe_svm_find_vma_start(struct xe_vm *vm, u64 start, u64 end, struct xe_vma *vma)
851 {
852 	return drm_gpusvm_find_vma_start(&vm->svm.gpusvm,
853 					 max(start, xe_vma_start(vma)),
854 					 min(end, xe_vma_end(vma)));
855 }
856 
857 #if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
xe_drm_pagemap_populate_mm(struct drm_pagemap * dpagemap,unsigned long start,unsigned long end,struct mm_struct * mm,unsigned long timeslice_ms)858 static int xe_drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
859 				      unsigned long start, unsigned long end,
860 				      struct mm_struct *mm,
861 				      unsigned long timeslice_ms)
862 {
863 	struct xe_vram_region *vr = container_of(dpagemap, typeof(*vr), dpagemap);
864 	struct xe_device *xe = vr->xe;
865 	struct device *dev = xe->drm.dev;
866 	struct drm_buddy_block *block;
867 	struct xe_validation_ctx vctx;
868 	struct list_head *blocks;
869 	struct drm_exec exec;
870 	struct xe_bo *bo;
871 	int err = 0, idx;
872 
873 	if (!drm_dev_enter(&xe->drm, &idx))
874 		return -ENODEV;
875 
876 	xe_pm_runtime_get(xe);
877 
878 	xe_validation_guard(&vctx, &xe->val, &exec, (struct xe_val_flags) {}, err) {
879 		bo = xe_bo_create_locked(xe, NULL, NULL, end - start,
880 					 ttm_bo_type_device,
881 					 (IS_DGFX(xe) ? XE_BO_FLAG_VRAM(vr) : XE_BO_FLAG_SYSTEM) |
882 					 XE_BO_FLAG_CPU_ADDR_MIRROR, &exec);
883 		drm_exec_retry_on_contention(&exec);
884 		if (IS_ERR(bo)) {
885 			err = PTR_ERR(bo);
886 			xe_validation_retry_on_oom(&vctx, &err);
887 			break;
888 		}
889 
890 		drm_pagemap_devmem_init(&bo->devmem_allocation, dev, mm,
891 					&dpagemap_devmem_ops, dpagemap, end - start);
892 
893 		blocks = &to_xe_ttm_vram_mgr_resource(bo->ttm.resource)->blocks;
894 		list_for_each_entry(block, blocks, link)
895 			block->private = vr;
896 
897 		xe_bo_get(bo);
898 
899 		/* Ensure the device has a pm ref while there are device pages active. */
900 		xe_pm_runtime_get_noresume(xe);
901 		err = drm_pagemap_migrate_to_devmem(&bo->devmem_allocation, mm,
902 						    start, end, timeslice_ms,
903 						    xe_svm_devm_owner(xe));
904 		if (err)
905 			xe_svm_devmem_release(&bo->devmem_allocation);
906 		xe_bo_unlock(bo);
907 		xe_bo_put(bo);
908 	}
909 	xe_pm_runtime_put(xe);
910 	drm_dev_exit(idx);
911 
912 	return err;
913 }
914 #endif
915 
supports_4K_migration(struct xe_device * xe)916 static bool supports_4K_migration(struct xe_device *xe)
917 {
918 	if (xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K)
919 		return false;
920 
921 	return true;
922 }
923 
924 /**
925  * xe_svm_range_needs_migrate_to_vram() - SVM range needs migrate to VRAM or not
926  * @range: SVM range for which migration needs to be decided
927  * @vma: vma which has range
928  * @preferred_region_is_vram: preferred region for range is vram
929  *
930  * Return: True for range needing migration and migration is supported else false
931  */
xe_svm_range_needs_migrate_to_vram(struct xe_svm_range * range,struct xe_vma * vma,bool preferred_region_is_vram)932 bool xe_svm_range_needs_migrate_to_vram(struct xe_svm_range *range, struct xe_vma *vma,
933 					bool preferred_region_is_vram)
934 {
935 	struct xe_vm *vm = range_to_vm(&range->base);
936 	u64 range_size = xe_svm_range_size(range);
937 
938 	if (!range->base.pages.flags.migrate_devmem || !preferred_region_is_vram)
939 		return false;
940 
941 	xe_assert(vm->xe, IS_DGFX(vm->xe));
942 
943 	if (xe_svm_range_in_vram(range)) {
944 		drm_info(&vm->xe->drm, "Range is already in VRAM\n");
945 		return false;
946 	}
947 
948 	if (range_size < SZ_64K && !supports_4K_migration(vm->xe)) {
949 		drm_dbg(&vm->xe->drm, "Platform doesn't support SZ_4K range migration\n");
950 		return false;
951 	}
952 
953 	return true;
954 }
955 
956 #define DECL_SVM_RANGE_COUNT_STATS(elem, stat) \
957 static void xe_svm_range_##elem##_count_stats_incr(struct xe_gt *gt, \
958 						   struct xe_svm_range *range) \
959 { \
960 	switch (xe_svm_range_size(range)) { \
961 	case SZ_4K: \
962 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_4K_##stat##_COUNT, 1); \
963 		break; \
964 	case SZ_64K: \
965 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_64K_##stat##_COUNT, 1); \
966 		break; \
967 	case SZ_2M: \
968 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_2M_##stat##_COUNT, 1); \
969 		break; \
970 	} \
971 } \
972 
DECL_SVM_RANGE_COUNT_STATS(fault,PAGEFAULT)973 DECL_SVM_RANGE_COUNT_STATS(fault, PAGEFAULT)
974 DECL_SVM_RANGE_COUNT_STATS(valid_fault, VALID_PAGEFAULT)
975 DECL_SVM_RANGE_COUNT_STATS(migrate, MIGRATE)
976 
977 #define DECL_SVM_RANGE_US_STATS(elem, stat) \
978 static void xe_svm_range_##elem##_us_stats_incr(struct xe_gt *gt, \
979 						struct xe_svm_range *range, \
980 						ktime_t start) \
981 { \
982 	s64 us_delta = xe_svm_stats_ktime_us_delta(start); \
983 \
984 	switch (xe_svm_range_size(range)) { \
985 	case SZ_4K: \
986 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_4K_##stat##_US, \
987 				 us_delta); \
988 		break; \
989 	case SZ_64K: \
990 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_64K_##stat##_US, \
991 				 us_delta); \
992 		break; \
993 	case SZ_2M: \
994 		xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_2M_##stat##_US, \
995 				 us_delta); \
996 		break; \
997 	} \
998 } \
999 
1000 DECL_SVM_RANGE_US_STATS(migrate, MIGRATE)
1001 DECL_SVM_RANGE_US_STATS(get_pages, GET_PAGES)
1002 DECL_SVM_RANGE_US_STATS(bind, BIND)
1003 DECL_SVM_RANGE_US_STATS(fault, PAGEFAULT)
1004 
1005 static int __xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
1006 				     struct xe_gt *gt, u64 fault_addr,
1007 				     bool need_vram)
1008 {
1009 	int devmem_possible = IS_DGFX(vm->xe) &&
1010 		IS_ENABLED(CONFIG_DRM_XE_PAGEMAP);
1011 	struct drm_gpusvm_ctx ctx = {
1012 		.read_only = xe_vma_read_only(vma),
1013 		.devmem_possible = devmem_possible,
1014 		.check_pages_threshold = devmem_possible ? SZ_64K : 0,
1015 		.devmem_only = need_vram && devmem_possible,
1016 		.timeslice_ms = need_vram && devmem_possible ?
1017 			vm->xe->atomic_svm_timeslice_ms : 0,
1018 		.device_private_page_owner = xe_svm_devm_owner(vm->xe),
1019 	};
1020 	struct xe_validation_ctx vctx;
1021 	struct drm_exec exec;
1022 	struct xe_svm_range *range;
1023 	struct dma_fence *fence;
1024 	struct drm_pagemap *dpagemap;
1025 	struct xe_tile *tile = gt_to_tile(gt);
1026 	int migrate_try_count = ctx.devmem_only ? 3 : 1;
1027 	ktime_t start = xe_svm_stats_ktime_get(), bind_start, get_pages_start;
1028 	int err;
1029 
1030 	lockdep_assert_held_write(&vm->lock);
1031 	xe_assert(vm->xe, xe_vma_is_cpu_addr_mirror(vma));
1032 
1033 	xe_gt_stats_incr(gt, XE_GT_STATS_ID_SVM_PAGEFAULT_COUNT, 1);
1034 
1035 retry:
1036 	/* Always process UNMAPs first so view SVM ranges is current */
1037 	err = xe_svm_garbage_collector(vm);
1038 	if (err)
1039 		return err;
1040 
1041 	dpagemap = xe_vma_resolve_pagemap(vma, tile);
1042 	if (!dpagemap && !ctx.devmem_only)
1043 		ctx.device_private_page_owner = NULL;
1044 	range = xe_svm_range_find_or_insert(vm, fault_addr, vma, &ctx);
1045 
1046 	if (IS_ERR(range))
1047 		return PTR_ERR(range);
1048 
1049 	xe_svm_range_fault_count_stats_incr(gt, range);
1050 
1051 	if (ctx.devmem_only && !range->base.pages.flags.migrate_devmem) {
1052 		err = -EACCES;
1053 		goto out;
1054 	}
1055 
1056 	if (xe_svm_range_is_valid(range, tile, ctx.devmem_only)) {
1057 		xe_svm_range_valid_fault_count_stats_incr(gt, range);
1058 		range_debug(range, "PAGE FAULT - VALID");
1059 		goto out;
1060 	}
1061 
1062 	range_debug(range, "PAGE FAULT");
1063 
1064 	if (--migrate_try_count >= 0 &&
1065 	    xe_svm_range_needs_migrate_to_vram(range, vma, !!dpagemap || ctx.devmem_only)) {
1066 		ktime_t migrate_start = xe_svm_stats_ktime_get();
1067 
1068 		/* TODO : For multi-device dpagemap will be used to find the
1069 		 * remote tile and remote device. Will need to modify
1070 		 * xe_svm_alloc_vram to use dpagemap for future multi-device
1071 		 * support.
1072 		 */
1073 		xe_svm_range_migrate_count_stats_incr(gt, range);
1074 		err = xe_svm_alloc_vram(tile, range, &ctx);
1075 		xe_svm_range_migrate_us_stats_incr(gt, range, migrate_start);
1076 		ctx.timeslice_ms <<= 1;	/* Double timeslice if we have to retry */
1077 		if (err) {
1078 			if (migrate_try_count || !ctx.devmem_only) {
1079 				drm_dbg(&vm->xe->drm,
1080 					"VRAM allocation failed, falling back to retrying fault, asid=%u, errno=%pe\n",
1081 					vm->usm.asid, ERR_PTR(err));
1082 
1083 				/*
1084 				 * In the devmem-only case, mixed mappings may
1085 				 * be found. The get_pages function will fix
1086 				 * these up to a single location, allowing the
1087 				 * page fault handler to make forward progress.
1088 				 */
1089 				if (ctx.devmem_only)
1090 					goto get_pages;
1091 				else
1092 					goto retry;
1093 			} else {
1094 				drm_err(&vm->xe->drm,
1095 					"VRAM allocation failed, retry count exceeded, asid=%u, errno=%pe\n",
1096 					vm->usm.asid, ERR_PTR(err));
1097 				return err;
1098 			}
1099 		}
1100 	}
1101 
1102 get_pages:
1103 	get_pages_start = xe_svm_stats_ktime_get();
1104 
1105 	range_debug(range, "GET PAGES");
1106 	err = xe_svm_range_get_pages(vm, range, &ctx);
1107 	/* Corner where CPU mappings have changed */
1108 	if (err == -EOPNOTSUPP || err == -EFAULT || err == -EPERM) {
1109 		ctx.timeslice_ms <<= 1;	/* Double timeslice if we have to retry */
1110 		if (migrate_try_count > 0 || !ctx.devmem_only) {
1111 			drm_dbg(&vm->xe->drm,
1112 				"Get pages failed, falling back to retrying, asid=%u, gpusvm=%p, errno=%pe\n",
1113 				vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
1114 			range_debug(range, "PAGE FAULT - RETRY PAGES");
1115 			goto retry;
1116 		} else {
1117 			drm_err(&vm->xe->drm,
1118 				"Get pages failed, retry count exceeded, asid=%u, gpusvm=%p, errno=%pe\n",
1119 				vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
1120 		}
1121 	}
1122 	if (err) {
1123 		range_debug(range, "PAGE FAULT - FAIL PAGE COLLECT");
1124 		goto out;
1125 	}
1126 
1127 	xe_svm_range_get_pages_us_stats_incr(gt, range, get_pages_start);
1128 	range_debug(range, "PAGE FAULT - BIND");
1129 
1130 	bind_start = xe_svm_stats_ktime_get();
1131 	xe_validation_guard(&vctx, &vm->xe->val, &exec, (struct xe_val_flags) {}, err) {
1132 		err = xe_vm_drm_exec_lock(vm, &exec);
1133 		drm_exec_retry_on_contention(&exec);
1134 
1135 		xe_vm_set_validation_exec(vm, &exec);
1136 		fence = xe_vm_range_rebind(vm, vma, range, BIT(tile->id));
1137 		xe_vm_set_validation_exec(vm, NULL);
1138 		if (IS_ERR(fence)) {
1139 			drm_exec_retry_on_contention(&exec);
1140 			err = PTR_ERR(fence);
1141 			xe_validation_retry_on_oom(&vctx, &err);
1142 			xe_svm_range_bind_us_stats_incr(gt, range, bind_start);
1143 			break;
1144 		}
1145 	}
1146 	if (err)
1147 		goto err_out;
1148 
1149 	dma_fence_wait(fence, false);
1150 	dma_fence_put(fence);
1151 	xe_svm_range_bind_us_stats_incr(gt, range, bind_start);
1152 
1153 out:
1154 	xe_svm_range_fault_us_stats_incr(gt, range, start);
1155 	return 0;
1156 
1157 err_out:
1158 	if (err == -EAGAIN) {
1159 		ctx.timeslice_ms <<= 1;	/* Double timeslice if we have to retry */
1160 		range_debug(range, "PAGE FAULT - RETRY BIND");
1161 		goto retry;
1162 	}
1163 
1164 	return err;
1165 }
1166 
1167 /**
1168  * xe_svm_handle_pagefault() - SVM handle page fault
1169  * @vm: The VM.
1170  * @vma: The CPU address mirror VMA.
1171  * @gt: The gt upon the fault occurred.
1172  * @fault_addr: The GPU fault address.
1173  * @atomic: The fault atomic access bit.
1174  *
1175  * Create GPU bindings for a SVM page fault. Optionally migrate to device
1176  * memory.
1177  *
1178  * Return: 0 on success, negative error code on error.
1179  */
xe_svm_handle_pagefault(struct xe_vm * vm,struct xe_vma * vma,struct xe_gt * gt,u64 fault_addr,bool atomic)1180 int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
1181 			    struct xe_gt *gt, u64 fault_addr,
1182 			    bool atomic)
1183 {
1184 	int need_vram, ret;
1185 retry:
1186 	need_vram = xe_vma_need_vram_for_atomic(vm->xe, vma, atomic);
1187 	if (need_vram < 0)
1188 		return need_vram;
1189 
1190 	ret =  __xe_svm_handle_pagefault(vm, vma, gt, fault_addr,
1191 					 need_vram ? true : false);
1192 	if (ret == -EAGAIN) {
1193 		/*
1194 		 * Retry once on -EAGAIN to re-lookup the VMA, as the original VMA
1195 		 * may have been split by xe_svm_range_set_default_attr.
1196 		 */
1197 		vma = xe_vm_find_vma_by_addr(vm, fault_addr);
1198 		if (!vma)
1199 			return -EINVAL;
1200 
1201 		goto retry;
1202 	}
1203 	return ret;
1204 }
1205 
1206 /**
1207  * xe_svm_has_mapping() - SVM has mappings
1208  * @vm: The VM.
1209  * @start: Start address.
1210  * @end: End address.
1211  *
1212  * Check if an address range has SVM mappings.
1213  *
1214  * Return: True if address range has a SVM mapping, False otherwise
1215  */
xe_svm_has_mapping(struct xe_vm * vm,u64 start,u64 end)1216 bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end)
1217 {
1218 	return drm_gpusvm_has_mapping(&vm->svm.gpusvm, start, end);
1219 }
1220 
1221 /**
1222  * xe_svm_unmap_address_range - UNMAP SVM mappings and ranges
1223  * @vm: The VM
1224  * @start: start addr
1225  * @end: end addr
1226  *
1227  * This function UNMAPS svm ranges if start or end address are inside them.
1228  */
xe_svm_unmap_address_range(struct xe_vm * vm,u64 start,u64 end)1229 void xe_svm_unmap_address_range(struct xe_vm *vm, u64 start, u64 end)
1230 {
1231 	struct drm_gpusvm_notifier *notifier, *next;
1232 
1233 	lockdep_assert_held_write(&vm->lock);
1234 
1235 	drm_gpusvm_for_each_notifier_safe(notifier, next, &vm->svm.gpusvm, start, end) {
1236 		struct drm_gpusvm_range *range, *__next;
1237 
1238 		drm_gpusvm_for_each_range_safe(range, __next, notifier, start, end) {
1239 			if (start > drm_gpusvm_range_start(range) ||
1240 			    end < drm_gpusvm_range_end(range)) {
1241 				if (IS_DGFX(vm->xe) && xe_svm_range_in_vram(to_xe_range(range)))
1242 					drm_gpusvm_range_evict(&vm->svm.gpusvm, range);
1243 				drm_gpusvm_range_get(range);
1244 				__xe_svm_garbage_collector(vm, to_xe_range(range));
1245 				if (!list_empty(&to_xe_range(range)->garbage_collector_link)) {
1246 					spin_lock(&vm->svm.garbage_collector.lock);
1247 					list_del(&to_xe_range(range)->garbage_collector_link);
1248 					spin_unlock(&vm->svm.garbage_collector.lock);
1249 				}
1250 				drm_gpusvm_range_put(range);
1251 			}
1252 		}
1253 	}
1254 }
1255 
1256 /**
1257  * xe_svm_bo_evict() - SVM evict BO to system memory
1258  * @bo: BO to evict
1259  *
1260  * SVM evict BO to system memory. GPU SVM layer ensures all device pages
1261  * are evicted before returning.
1262  *
1263  * Return: 0 on success standard error code otherwise
1264  */
xe_svm_bo_evict(struct xe_bo * bo)1265 int xe_svm_bo_evict(struct xe_bo *bo)
1266 {
1267 	return drm_pagemap_evict_to_ram(&bo->devmem_allocation);
1268 }
1269 
1270 /**
1271  * xe_svm_range_find_or_insert- Find or insert GPU SVM range
1272  * @vm: xe_vm pointer
1273  * @addr: address for which range needs to be found/inserted
1274  * @vma:  Pointer to struct xe_vma which mirrors CPU
1275  * @ctx: GPU SVM context
1276  *
1277  * This function finds or inserts a newly allocated a SVM range based on the
1278  * address.
1279  *
1280  * Return: Pointer to the SVM range on success, ERR_PTR() on failure.
1281  */
xe_svm_range_find_or_insert(struct xe_vm * vm,u64 addr,struct xe_vma * vma,struct drm_gpusvm_ctx * ctx)1282 struct xe_svm_range *xe_svm_range_find_or_insert(struct xe_vm *vm, u64 addr,
1283 						 struct xe_vma *vma, struct drm_gpusvm_ctx *ctx)
1284 {
1285 	struct drm_gpusvm_range *r;
1286 
1287 	r = drm_gpusvm_range_find_or_insert(&vm->svm.gpusvm, max(addr, xe_vma_start(vma)),
1288 					    xe_vma_start(vma), xe_vma_end(vma), ctx);
1289 	if (IS_ERR(r))
1290 		return ERR_CAST(r);
1291 
1292 	return to_xe_range(r);
1293 }
1294 
1295 /**
1296  * xe_svm_range_get_pages() - Get pages for a SVM range
1297  * @vm: Pointer to the struct xe_vm
1298  * @range: Pointer to the xe SVM range structure
1299  * @ctx: GPU SVM context
1300  *
1301  * This function gets pages for a SVM range and ensures they are mapped for
1302  * DMA access. In case of failure with -EOPNOTSUPP, it evicts the range.
1303  *
1304  * Return: 0 on success, negative error code on failure.
1305  */
xe_svm_range_get_pages(struct xe_vm * vm,struct xe_svm_range * range,struct drm_gpusvm_ctx * ctx)1306 int xe_svm_range_get_pages(struct xe_vm *vm, struct xe_svm_range *range,
1307 			   struct drm_gpusvm_ctx *ctx)
1308 {
1309 	int err = 0;
1310 
1311 	err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, &range->base, ctx);
1312 	if (err == -EOPNOTSUPP) {
1313 		range_debug(range, "PAGE FAULT - EVICT PAGES");
1314 		drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
1315 	}
1316 
1317 	return err;
1318 }
1319 
1320 /**
1321  * xe_svm_ranges_zap_ptes_in_range - clear ptes of svm ranges in input range
1322  * @vm: Pointer to the xe_vm structure
1323  * @start: Start of the input range
1324  * @end: End of the input range
1325  *
1326  * This function removes the page table entries (PTEs) associated
1327  * with the svm ranges within the given input start and end
1328  *
1329  * Return: tile_mask for which gt's need to be tlb invalidated.
1330  */
xe_svm_ranges_zap_ptes_in_range(struct xe_vm * vm,u64 start,u64 end)1331 u8 xe_svm_ranges_zap_ptes_in_range(struct xe_vm *vm, u64 start, u64 end)
1332 {
1333 	struct drm_gpusvm_notifier *notifier;
1334 	struct xe_svm_range *range;
1335 	u64 adj_start, adj_end;
1336 	struct xe_tile *tile;
1337 	u8 tile_mask = 0;
1338 	u8 id;
1339 
1340 	lockdep_assert(lockdep_is_held_type(&vm->svm.gpusvm.notifier_lock, 1) &&
1341 		       lockdep_is_held_type(&vm->lock, 0));
1342 
1343 	drm_gpusvm_for_each_notifier(notifier, &vm->svm.gpusvm, start, end) {
1344 		struct drm_gpusvm_range *r = NULL;
1345 
1346 		adj_start = max(start, drm_gpusvm_notifier_start(notifier));
1347 		adj_end = min(end, drm_gpusvm_notifier_end(notifier));
1348 		drm_gpusvm_for_each_range(r, notifier, adj_start, adj_end) {
1349 			range = to_xe_range(r);
1350 			for_each_tile(tile, vm->xe, id) {
1351 				if (xe_pt_zap_ptes_range(tile, vm, range)) {
1352 					tile_mask |= BIT(id);
1353 					/*
1354 					 * WRITE_ONCE pairs with READ_ONCE in
1355 					 * xe_vm_has_valid_gpu_mapping().
1356 					 * Must not fail after setting
1357 					 * tile_invalidated and before
1358 					 * TLB invalidation.
1359 					 */
1360 					WRITE_ONCE(range->tile_invalidated,
1361 						   range->tile_invalidated | BIT(id));
1362 				}
1363 			}
1364 		}
1365 	}
1366 
1367 	return tile_mask;
1368 }
1369 
1370 #if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
1371 
tile_local_pagemap(struct xe_tile * tile)1372 static struct drm_pagemap *tile_local_pagemap(struct xe_tile *tile)
1373 {
1374 	return &tile->mem.vram->dpagemap;
1375 }
1376 
1377 /**
1378  * xe_vma_resolve_pagemap - Resolve the appropriate DRM pagemap for a VMA
1379  * @vma: Pointer to the xe_vma structure containing memory attributes
1380  * @tile: Pointer to the xe_tile structure used as fallback for VRAM mapping
1381  *
1382  * This function determines the correct DRM pagemap to use for a given VMA.
1383  * It first checks if a valid devmem_fd is provided in the VMA's preferred
1384  * location. If the devmem_fd is negative, it returns NULL, indicating no
1385  * pagemap is available and smem to be used as preferred location.
1386  * If the devmem_fd is equal to the default faulting
1387  * GT identifier, it returns the VRAM pagemap associated with the tile.
1388  *
1389  * Future support for multi-device configurations may use drm_pagemap_from_fd()
1390  * to resolve pagemaps from arbitrary file descriptors.
1391  *
1392  * Return: A pointer to the resolved drm_pagemap, or NULL if none is applicable.
1393  */
xe_vma_resolve_pagemap(struct xe_vma * vma,struct xe_tile * tile)1394 struct drm_pagemap *xe_vma_resolve_pagemap(struct xe_vma *vma, struct xe_tile *tile)
1395 {
1396 	s32 fd = (s32)vma->attr.preferred_loc.devmem_fd;
1397 
1398 	if (fd == DRM_XE_PREFERRED_LOC_DEFAULT_SYSTEM)
1399 		return NULL;
1400 
1401 	if (fd == DRM_XE_PREFERRED_LOC_DEFAULT_DEVICE)
1402 		return IS_DGFX(tile_to_xe(tile)) ? tile_local_pagemap(tile) : NULL;
1403 
1404 	/* TODO: Support multi-device with drm_pagemap_from_fd(fd) */
1405 	return NULL;
1406 }
1407 
1408 /**
1409  * xe_svm_alloc_vram()- Allocate device memory pages for range,
1410  * migrating existing data.
1411  * @tile: tile to allocate vram from
1412  * @range: SVM range
1413  * @ctx: DRM GPU SVM context
1414  *
1415  * Return: 0 on success, error code on failure.
1416  */
xe_svm_alloc_vram(struct xe_tile * tile,struct xe_svm_range * range,const struct drm_gpusvm_ctx * ctx)1417 int xe_svm_alloc_vram(struct xe_tile *tile, struct xe_svm_range *range,
1418 		      const struct drm_gpusvm_ctx *ctx)
1419 {
1420 	struct drm_pagemap *dpagemap;
1421 
1422 	xe_assert(tile_to_xe(tile), range->base.pages.flags.migrate_devmem);
1423 	range_debug(range, "ALLOCATE VRAM");
1424 
1425 	dpagemap = tile_local_pagemap(tile);
1426 	return drm_pagemap_populate_mm(dpagemap, xe_svm_range_start(range),
1427 				       xe_svm_range_end(range),
1428 				       range->base.gpusvm->mm,
1429 				       ctx->timeslice_ms);
1430 }
1431 
1432 static struct drm_pagemap_addr
xe_drm_pagemap_device_map(struct drm_pagemap * dpagemap,struct device * dev,struct page * page,unsigned int order,enum dma_data_direction dir)1433 xe_drm_pagemap_device_map(struct drm_pagemap *dpagemap,
1434 			  struct device *dev,
1435 			  struct page *page,
1436 			  unsigned int order,
1437 			  enum dma_data_direction dir)
1438 {
1439 	struct device *pgmap_dev = dpagemap->dev;
1440 	enum drm_interconnect_protocol prot;
1441 	dma_addr_t addr;
1442 
1443 	if (pgmap_dev == dev) {
1444 		addr = xe_vram_region_page_to_dpa(page_to_vr(page), page);
1445 		prot = XE_INTERCONNECT_VRAM;
1446 	} else {
1447 		addr = DMA_MAPPING_ERROR;
1448 		prot = 0;
1449 	}
1450 
1451 	return drm_pagemap_addr_encode(addr, prot, order, dir);
1452 }
1453 
1454 static const struct drm_pagemap_ops xe_drm_pagemap_ops = {
1455 	.device_map = xe_drm_pagemap_device_map,
1456 	.populate_mm = xe_drm_pagemap_populate_mm,
1457 };
1458 
1459 /**
1460  * xe_devm_add: Remap and provide memmap backing for device memory
1461  * @tile: tile that the memory region belongs to
1462  * @vr: vram memory region to remap
1463  *
1464  * This remap device memory to host physical address space and create
1465  * struct page to back device memory
1466  *
1467  * Return: 0 on success standard error code otherwise
1468  */
xe_devm_add(struct xe_tile * tile,struct xe_vram_region * vr)1469 int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr)
1470 {
1471 	struct xe_device *xe = tile_to_xe(tile);
1472 	struct device *dev = &to_pci_dev(xe->drm.dev)->dev;
1473 	struct resource *res;
1474 	void *addr;
1475 	int ret;
1476 
1477 	res = devm_request_free_mem_region(dev, &iomem_resource,
1478 					   vr->usable_size);
1479 	if (IS_ERR(res)) {
1480 		ret = PTR_ERR(res);
1481 		return ret;
1482 	}
1483 
1484 	vr->pagemap.type = MEMORY_DEVICE_PRIVATE;
1485 	vr->pagemap.range.start = res->start;
1486 	vr->pagemap.range.end = res->end;
1487 	vr->pagemap.nr_range = 1;
1488 	vr->pagemap.ops = drm_pagemap_pagemap_ops_get();
1489 	vr->pagemap.owner = xe_svm_devm_owner(xe);
1490 	addr = devm_memremap_pages(dev, &vr->pagemap);
1491 
1492 	vr->dpagemap.dev = dev;
1493 	vr->dpagemap.ops = &xe_drm_pagemap_ops;
1494 
1495 	if (IS_ERR(addr)) {
1496 		devm_release_mem_region(dev, res->start, resource_size(res));
1497 		ret = PTR_ERR(addr);
1498 		drm_err(&xe->drm, "Failed to remap tile %d memory, errno %pe\n",
1499 			tile->id, ERR_PTR(ret));
1500 		return ret;
1501 	}
1502 	vr->hpa_base = res->start;
1503 
1504 	drm_dbg(&xe->drm, "Added tile %d memory [%llx-%llx] to devm, remapped to %pr\n",
1505 		tile->id, vr->io_start, vr->io_start + vr->usable_size, res);
1506 	return 0;
1507 }
1508 #else
xe_svm_alloc_vram(struct xe_tile * tile,struct xe_svm_range * range,const struct drm_gpusvm_ctx * ctx)1509 int xe_svm_alloc_vram(struct xe_tile *tile,
1510 		      struct xe_svm_range *range,
1511 		      const struct drm_gpusvm_ctx *ctx)
1512 {
1513 	return -EOPNOTSUPP;
1514 }
1515 
xe_devm_add(struct xe_tile * tile,struct xe_vram_region * vr)1516 int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr)
1517 {
1518 	return 0;
1519 }
1520 
xe_vma_resolve_pagemap(struct xe_vma * vma,struct xe_tile * tile)1521 struct drm_pagemap *xe_vma_resolve_pagemap(struct xe_vma *vma, struct xe_tile *tile)
1522 {
1523 	return NULL;
1524 }
1525 #endif
1526 
1527 /**
1528  * xe_svm_flush() - SVM flush
1529  * @vm: The VM.
1530  *
1531  * Flush all SVM actions.
1532  */
xe_svm_flush(struct xe_vm * vm)1533 void xe_svm_flush(struct xe_vm *vm)
1534 {
1535 	if (xe_vm_in_fault_mode(vm))
1536 		flush_work(&vm->svm.garbage_collector.work);
1537 }
1538