xref: /openbmc/linux/drivers/gpu/drm/amd/amdkfd/kfd_svm.c (revision 149f6d1a)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright 2020-2021 Advanced Micro Devices, Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  */
23 
24 #include <linux/types.h>
25 #include <linux/sched/task.h>
26 #include "amdgpu_sync.h"
27 #include "amdgpu_object.h"
28 #include "amdgpu_vm.h"
29 #include "amdgpu_mn.h"
30 #include "amdgpu.h"
31 #include "amdgpu_xgmi.h"
32 #include "kfd_priv.h"
33 #include "kfd_svm.h"
34 #include "kfd_migrate.h"
35 #include "kfd_smi_events.h"
36 
37 #ifdef dev_fmt
38 #undef dev_fmt
39 #endif
40 #define dev_fmt(fmt) "kfd_svm: %s: " fmt, __func__
41 
42 #define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
43 
44 /* Long enough to ensure no retry fault comes after svm range is restored and
45  * page table is updated.
46  */
47 #define AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING	(2UL * NSEC_PER_MSEC)
48 
49 struct criu_svm_metadata {
50 	struct list_head list;
51 	struct kfd_criu_svm_range_priv_data data;
52 };
53 
54 static void svm_range_evict_svm_bo_worker(struct work_struct *work);
55 static bool
56 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
57 				    const struct mmu_notifier_range *range,
58 				    unsigned long cur_seq);
59 static int
60 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
61 		   uint64_t *bo_s, uint64_t *bo_l);
62 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
63 	.invalidate = svm_range_cpu_invalidate_pagetables,
64 };
65 
66 /**
67  * svm_range_unlink - unlink svm_range from lists and interval tree
68  * @prange: svm range structure to be removed
69  *
70  * Remove the svm_range from the svms and svm_bo lists and the svms
71  * interval tree.
72  *
73  * Context: The caller must hold svms->lock
74  */
75 static void svm_range_unlink(struct svm_range *prange)
76 {
77 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
78 		 prange, prange->start, prange->last);
79 
80 	if (prange->svm_bo) {
81 		spin_lock(&prange->svm_bo->list_lock);
82 		list_del(&prange->svm_bo_list);
83 		spin_unlock(&prange->svm_bo->list_lock);
84 	}
85 
86 	list_del(&prange->list);
87 	if (prange->it_node.start != 0 && prange->it_node.last != 0)
88 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
89 }
90 
91 static void
92 svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
93 {
94 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
95 		 prange, prange->start, prange->last);
96 
97 	mmu_interval_notifier_insert_locked(&prange->notifier, mm,
98 				     prange->start << PAGE_SHIFT,
99 				     prange->npages << PAGE_SHIFT,
100 				     &svm_range_mn_ops);
101 }
102 
103 /**
104  * svm_range_add_to_svms - add svm range to svms
105  * @prange: svm range structure to be added
106  *
107  * Add the svm range to svms interval tree and link list
108  *
109  * Context: The caller must hold svms->lock
110  */
111 static void svm_range_add_to_svms(struct svm_range *prange)
112 {
113 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
114 		 prange, prange->start, prange->last);
115 
116 	list_move_tail(&prange->list, &prange->svms->list);
117 	prange->it_node.start = prange->start;
118 	prange->it_node.last = prange->last;
119 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
120 }
121 
122 static void svm_range_remove_notifier(struct svm_range *prange)
123 {
124 	pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
125 		 prange->svms, prange,
126 		 prange->notifier.interval_tree.start >> PAGE_SHIFT,
127 		 prange->notifier.interval_tree.last >> PAGE_SHIFT);
128 
129 	if (prange->notifier.interval_tree.start != 0 &&
130 	    prange->notifier.interval_tree.last != 0)
131 		mmu_interval_notifier_remove(&prange->notifier);
132 }
133 
134 static bool
135 svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
136 {
137 	return dma_addr && !dma_mapping_error(dev, dma_addr) &&
138 	       !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
139 }
140 
141 static int
142 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
143 		      unsigned long offset, unsigned long npages,
144 		      unsigned long *hmm_pfns, uint32_t gpuidx)
145 {
146 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
147 	dma_addr_t *addr = prange->dma_addr[gpuidx];
148 	struct device *dev = adev->dev;
149 	struct page *page;
150 	int i, r;
151 
152 	if (!addr) {
153 		addr = kvcalloc(prange->npages, sizeof(*addr), GFP_KERNEL);
154 		if (!addr)
155 			return -ENOMEM;
156 		prange->dma_addr[gpuidx] = addr;
157 	}
158 
159 	addr += offset;
160 	for (i = 0; i < npages; i++) {
161 		if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
162 			dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
163 
164 		page = hmm_pfn_to_page(hmm_pfns[i]);
165 		if (is_zone_device_page(page)) {
166 			struct amdgpu_device *bo_adev =
167 					amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
168 
169 			addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
170 				   bo_adev->vm_manager.vram_base_offset -
171 				   bo_adev->kfd.dev->pgmap.range.start;
172 			addr[i] |= SVM_RANGE_VRAM_DOMAIN;
173 			pr_debug_ratelimited("vram address: 0x%llx\n", addr[i]);
174 			continue;
175 		}
176 		addr[i] = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
177 		r = dma_mapping_error(dev, addr[i]);
178 		if (r) {
179 			dev_err(dev, "failed %d dma_map_page\n", r);
180 			return r;
181 		}
182 		pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
183 				     addr[i] >> PAGE_SHIFT, page_to_pfn(page));
184 	}
185 	return 0;
186 }
187 
188 static int
189 svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
190 		  unsigned long offset, unsigned long npages,
191 		  unsigned long *hmm_pfns)
192 {
193 	struct kfd_process *p;
194 	uint32_t gpuidx;
195 	int r;
196 
197 	p = container_of(prange->svms, struct kfd_process, svms);
198 
199 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
200 		struct kfd_process_device *pdd;
201 
202 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
203 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
204 		if (!pdd) {
205 			pr_debug("failed to find device idx %d\n", gpuidx);
206 			return -EINVAL;
207 		}
208 
209 		r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
210 					  hmm_pfns, gpuidx);
211 		if (r)
212 			break;
213 	}
214 
215 	return r;
216 }
217 
218 void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
219 			 unsigned long offset, unsigned long npages)
220 {
221 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
222 	int i;
223 
224 	if (!dma_addr)
225 		return;
226 
227 	for (i = offset; i < offset + npages; i++) {
228 		if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
229 			continue;
230 		pr_debug_ratelimited("unmap 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
231 		dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
232 		dma_addr[i] = 0;
233 	}
234 }
235 
236 void svm_range_free_dma_mappings(struct svm_range *prange)
237 {
238 	struct kfd_process_device *pdd;
239 	dma_addr_t *dma_addr;
240 	struct device *dev;
241 	struct kfd_process *p;
242 	uint32_t gpuidx;
243 
244 	p = container_of(prange->svms, struct kfd_process, svms);
245 
246 	for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
247 		dma_addr = prange->dma_addr[gpuidx];
248 		if (!dma_addr)
249 			continue;
250 
251 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
252 		if (!pdd) {
253 			pr_debug("failed to find device idx %d\n", gpuidx);
254 			continue;
255 		}
256 		dev = &pdd->dev->pdev->dev;
257 		svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
258 		kvfree(dma_addr);
259 		prange->dma_addr[gpuidx] = NULL;
260 	}
261 }
262 
263 static void svm_range_free(struct svm_range *prange)
264 {
265 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
266 		 prange->start, prange->last);
267 
268 	svm_range_vram_node_free(prange);
269 	svm_range_free_dma_mappings(prange);
270 	mutex_destroy(&prange->lock);
271 	mutex_destroy(&prange->migrate_mutex);
272 	kfree(prange);
273 }
274 
275 static void
276 svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,
277 				 uint8_t *granularity, uint32_t *flags)
278 {
279 	*location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
280 	*prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
281 	*granularity = 9;
282 	*flags =
283 		KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;
284 }
285 
286 static struct
287 svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
288 			 uint64_t last)
289 {
290 	uint64_t size = last - start + 1;
291 	struct svm_range *prange;
292 	struct kfd_process *p;
293 
294 	prange = kzalloc(sizeof(*prange), GFP_KERNEL);
295 	if (!prange)
296 		return NULL;
297 	prange->npages = size;
298 	prange->svms = svms;
299 	prange->start = start;
300 	prange->last = last;
301 	INIT_LIST_HEAD(&prange->list);
302 	INIT_LIST_HEAD(&prange->update_list);
303 	INIT_LIST_HEAD(&prange->svm_bo_list);
304 	INIT_LIST_HEAD(&prange->deferred_list);
305 	INIT_LIST_HEAD(&prange->child_list);
306 	atomic_set(&prange->invalid, 0);
307 	prange->validate_timestamp = 0;
308 	mutex_init(&prange->migrate_mutex);
309 	mutex_init(&prange->lock);
310 
311 	p = container_of(svms, struct kfd_process, svms);
312 	if (p->xnack_enabled)
313 		bitmap_copy(prange->bitmap_access, svms->bitmap_supported,
314 			    MAX_GPU_INSTANCE);
315 
316 	svm_range_set_default_attributes(&prange->preferred_loc,
317 					 &prange->prefetch_loc,
318 					 &prange->granularity, &prange->flags);
319 
320 	pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last);
321 
322 	return prange;
323 }
324 
325 static bool svm_bo_ref_unless_zero(struct svm_range_bo *svm_bo)
326 {
327 	if (!svm_bo || !kref_get_unless_zero(&svm_bo->kref))
328 		return false;
329 
330 	return true;
331 }
332 
333 static void svm_range_bo_release(struct kref *kref)
334 {
335 	struct svm_range_bo *svm_bo;
336 
337 	svm_bo = container_of(kref, struct svm_range_bo, kref);
338 	pr_debug("svm_bo 0x%p\n", svm_bo);
339 
340 	spin_lock(&svm_bo->list_lock);
341 	while (!list_empty(&svm_bo->range_list)) {
342 		struct svm_range *prange =
343 				list_first_entry(&svm_bo->range_list,
344 						struct svm_range, svm_bo_list);
345 		/* list_del_init tells a concurrent svm_range_vram_node_new when
346 		 * it's safe to reuse the svm_bo pointer and svm_bo_list head.
347 		 */
348 		list_del_init(&prange->svm_bo_list);
349 		spin_unlock(&svm_bo->list_lock);
350 
351 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
352 			 prange->start, prange->last);
353 		mutex_lock(&prange->lock);
354 		prange->svm_bo = NULL;
355 		mutex_unlock(&prange->lock);
356 
357 		spin_lock(&svm_bo->list_lock);
358 	}
359 	spin_unlock(&svm_bo->list_lock);
360 	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
361 		/* We're not in the eviction worker.
362 		 * Signal the fence and synchronize with any
363 		 * pending eviction work.
364 		 */
365 		dma_fence_signal(&svm_bo->eviction_fence->base);
366 		cancel_work_sync(&svm_bo->eviction_work);
367 	}
368 	dma_fence_put(&svm_bo->eviction_fence->base);
369 	amdgpu_bo_unref(&svm_bo->bo);
370 	kfree(svm_bo);
371 }
372 
373 static void svm_range_bo_wq_release(struct work_struct *work)
374 {
375 	struct svm_range_bo *svm_bo;
376 
377 	svm_bo = container_of(work, struct svm_range_bo, release_work);
378 	svm_range_bo_release(&svm_bo->kref);
379 }
380 
381 static void svm_range_bo_release_async(struct kref *kref)
382 {
383 	struct svm_range_bo *svm_bo;
384 
385 	svm_bo = container_of(kref, struct svm_range_bo, kref);
386 	pr_debug("svm_bo 0x%p\n", svm_bo);
387 	INIT_WORK(&svm_bo->release_work, svm_range_bo_wq_release);
388 	schedule_work(&svm_bo->release_work);
389 }
390 
391 void svm_range_bo_unref_async(struct svm_range_bo *svm_bo)
392 {
393 	kref_put(&svm_bo->kref, svm_range_bo_release_async);
394 }
395 
396 static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
397 {
398 	if (svm_bo)
399 		kref_put(&svm_bo->kref, svm_range_bo_release);
400 }
401 
402 static bool
403 svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
404 {
405 	struct amdgpu_device *bo_adev;
406 
407 	mutex_lock(&prange->lock);
408 	if (!prange->svm_bo) {
409 		mutex_unlock(&prange->lock);
410 		return false;
411 	}
412 	if (prange->ttm_res) {
413 		/* We still have a reference, all is well */
414 		mutex_unlock(&prange->lock);
415 		return true;
416 	}
417 	if (svm_bo_ref_unless_zero(prange->svm_bo)) {
418 		/*
419 		 * Migrate from GPU to GPU, remove range from source bo_adev
420 		 * svm_bo range list, and return false to allocate svm_bo from
421 		 * destination adev.
422 		 */
423 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
424 		if (bo_adev != adev) {
425 			mutex_unlock(&prange->lock);
426 
427 			spin_lock(&prange->svm_bo->list_lock);
428 			list_del_init(&prange->svm_bo_list);
429 			spin_unlock(&prange->svm_bo->list_lock);
430 
431 			svm_range_bo_unref(prange->svm_bo);
432 			return false;
433 		}
434 		if (READ_ONCE(prange->svm_bo->evicting)) {
435 			struct dma_fence *f;
436 			struct svm_range_bo *svm_bo;
437 			/* The BO is getting evicted,
438 			 * we need to get a new one
439 			 */
440 			mutex_unlock(&prange->lock);
441 			svm_bo = prange->svm_bo;
442 			f = dma_fence_get(&svm_bo->eviction_fence->base);
443 			svm_range_bo_unref(prange->svm_bo);
444 			/* wait for the fence to avoid long spin-loop
445 			 * at list_empty_careful
446 			 */
447 			dma_fence_wait(f, false);
448 			dma_fence_put(f);
449 		} else {
450 			/* The BO was still around and we got
451 			 * a new reference to it
452 			 */
453 			mutex_unlock(&prange->lock);
454 			pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
455 				 prange->svms, prange->start, prange->last);
456 
457 			prange->ttm_res = prange->svm_bo->bo->tbo.resource;
458 			return true;
459 		}
460 
461 	} else {
462 		mutex_unlock(&prange->lock);
463 	}
464 
465 	/* We need a new svm_bo. Spin-loop to wait for concurrent
466 	 * svm_range_bo_release to finish removing this range from
467 	 * its range list. After this, it is safe to reuse the
468 	 * svm_bo pointer and svm_bo_list head.
469 	 */
470 	while (!list_empty_careful(&prange->svm_bo_list))
471 		;
472 
473 	return false;
474 }
475 
476 static struct svm_range_bo *svm_range_bo_new(void)
477 {
478 	struct svm_range_bo *svm_bo;
479 
480 	svm_bo = kzalloc(sizeof(*svm_bo), GFP_KERNEL);
481 	if (!svm_bo)
482 		return NULL;
483 
484 	kref_init(&svm_bo->kref);
485 	INIT_LIST_HEAD(&svm_bo->range_list);
486 	spin_lock_init(&svm_bo->list_lock);
487 
488 	return svm_bo;
489 }
490 
491 int
492 svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
493 			bool clear)
494 {
495 	struct amdgpu_bo_param bp;
496 	struct svm_range_bo *svm_bo;
497 	struct amdgpu_bo_user *ubo;
498 	struct amdgpu_bo *bo;
499 	struct kfd_process *p;
500 	struct mm_struct *mm;
501 	int r;
502 
503 	p = container_of(prange->svms, struct kfd_process, svms);
504 	pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
505 		 prange->start, prange->last);
506 
507 	if (svm_range_validate_svm_bo(adev, prange))
508 		return 0;
509 
510 	svm_bo = svm_range_bo_new();
511 	if (!svm_bo) {
512 		pr_debug("failed to alloc svm bo\n");
513 		return -ENOMEM;
514 	}
515 	mm = get_task_mm(p->lead_thread);
516 	if (!mm) {
517 		pr_debug("failed to get mm\n");
518 		kfree(svm_bo);
519 		return -ESRCH;
520 	}
521 	svm_bo->svms = prange->svms;
522 	svm_bo->eviction_fence =
523 		amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
524 					   mm,
525 					   svm_bo);
526 	mmput(mm);
527 	INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
528 	svm_bo->evicting = 0;
529 	memset(&bp, 0, sizeof(bp));
530 	bp.size = prange->npages * PAGE_SIZE;
531 	bp.byte_align = PAGE_SIZE;
532 	bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
533 	bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
534 	bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
535 	bp.flags |= AMDGPU_GEM_CREATE_DISCARDABLE;
536 	bp.type = ttm_bo_type_device;
537 	bp.resv = NULL;
538 
539 	r = amdgpu_bo_create_user(adev, &bp, &ubo);
540 	if (r) {
541 		pr_debug("failed %d to create bo\n", r);
542 		goto create_bo_failed;
543 	}
544 	bo = &ubo->bo;
545 	r = amdgpu_bo_reserve(bo, true);
546 	if (r) {
547 		pr_debug("failed %d to reserve bo\n", r);
548 		goto reserve_bo_failed;
549 	}
550 
551 	r = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
552 	if (r) {
553 		pr_debug("failed %d to reserve bo\n", r);
554 		amdgpu_bo_unreserve(bo);
555 		goto reserve_bo_failed;
556 	}
557 	amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
558 
559 	amdgpu_bo_unreserve(bo);
560 
561 	svm_bo->bo = bo;
562 	prange->svm_bo = svm_bo;
563 	prange->ttm_res = bo->tbo.resource;
564 	prange->offset = 0;
565 
566 	spin_lock(&svm_bo->list_lock);
567 	list_add(&prange->svm_bo_list, &svm_bo->range_list);
568 	spin_unlock(&svm_bo->list_lock);
569 
570 	return 0;
571 
572 reserve_bo_failed:
573 	amdgpu_bo_unref(&bo);
574 create_bo_failed:
575 	dma_fence_put(&svm_bo->eviction_fence->base);
576 	kfree(svm_bo);
577 	prange->ttm_res = NULL;
578 
579 	return r;
580 }
581 
582 void svm_range_vram_node_free(struct svm_range *prange)
583 {
584 	svm_range_bo_unref(prange->svm_bo);
585 	prange->ttm_res = NULL;
586 }
587 
588 struct amdgpu_device *
589 svm_range_get_adev_by_id(struct svm_range *prange, uint32_t gpu_id)
590 {
591 	struct kfd_process_device *pdd;
592 	struct kfd_process *p;
593 	int32_t gpu_idx;
594 
595 	p = container_of(prange->svms, struct kfd_process, svms);
596 
597 	gpu_idx = kfd_process_gpuidx_from_gpuid(p, gpu_id);
598 	if (gpu_idx < 0) {
599 		pr_debug("failed to get device by id 0x%x\n", gpu_id);
600 		return NULL;
601 	}
602 	pdd = kfd_process_device_from_gpuidx(p, gpu_idx);
603 	if (!pdd) {
604 		pr_debug("failed to get device by idx 0x%x\n", gpu_idx);
605 		return NULL;
606 	}
607 
608 	return pdd->dev->adev;
609 }
610 
611 struct kfd_process_device *
612 svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev)
613 {
614 	struct kfd_process *p;
615 	int32_t gpu_idx, gpuid;
616 	int r;
617 
618 	p = container_of(prange->svms, struct kfd_process, svms);
619 
620 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpu_idx);
621 	if (r) {
622 		pr_debug("failed to get device id by adev %p\n", adev);
623 		return NULL;
624 	}
625 
626 	return kfd_process_device_from_gpuidx(p, gpu_idx);
627 }
628 
629 static int svm_range_bo_validate(void *param, struct amdgpu_bo *bo)
630 {
631 	struct ttm_operation_ctx ctx = { false, false };
632 
633 	amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_VRAM);
634 
635 	return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
636 }
637 
638 static int
639 svm_range_check_attr(struct kfd_process *p,
640 		     uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
641 {
642 	uint32_t i;
643 
644 	for (i = 0; i < nattr; i++) {
645 		uint32_t val = attrs[i].value;
646 		int gpuidx = MAX_GPU_INSTANCE;
647 
648 		switch (attrs[i].type) {
649 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
650 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM &&
651 			    val != KFD_IOCTL_SVM_LOCATION_UNDEFINED)
652 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
653 			break;
654 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
655 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM)
656 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
657 			break;
658 		case KFD_IOCTL_SVM_ATTR_ACCESS:
659 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
660 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
661 			gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
662 			break;
663 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
664 			break;
665 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
666 			break;
667 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
668 			break;
669 		default:
670 			pr_debug("unknown attr type 0x%x\n", attrs[i].type);
671 			return -EINVAL;
672 		}
673 
674 		if (gpuidx < 0) {
675 			pr_debug("no GPU 0x%x found\n", val);
676 			return -EINVAL;
677 		} else if (gpuidx < MAX_GPU_INSTANCE &&
678 			   !test_bit(gpuidx, p->svms.bitmap_supported)) {
679 			pr_debug("GPU 0x%x not supported\n", val);
680 			return -EINVAL;
681 		}
682 	}
683 
684 	return 0;
685 }
686 
687 static void
688 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
689 		      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
690 		      bool *update_mapping)
691 {
692 	uint32_t i;
693 	int gpuidx;
694 
695 	for (i = 0; i < nattr; i++) {
696 		switch (attrs[i].type) {
697 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
698 			prange->preferred_loc = attrs[i].value;
699 			break;
700 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
701 			prange->prefetch_loc = attrs[i].value;
702 			break;
703 		case KFD_IOCTL_SVM_ATTR_ACCESS:
704 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
705 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
706 			*update_mapping = true;
707 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
708 							       attrs[i].value);
709 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
710 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
711 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
712 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
713 				bitmap_set(prange->bitmap_access, gpuidx, 1);
714 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
715 			} else {
716 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
717 				bitmap_set(prange->bitmap_aip, gpuidx, 1);
718 			}
719 			break;
720 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
721 			*update_mapping = true;
722 			prange->flags |= attrs[i].value;
723 			break;
724 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
725 			*update_mapping = true;
726 			prange->flags &= ~attrs[i].value;
727 			break;
728 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
729 			prange->granularity = attrs[i].value;
730 			break;
731 		default:
732 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
733 		}
734 	}
735 }
736 
737 static bool
738 svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
739 			uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
740 {
741 	uint32_t i;
742 	int gpuidx;
743 
744 	for (i = 0; i < nattr; i++) {
745 		switch (attrs[i].type) {
746 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
747 			if (prange->preferred_loc != attrs[i].value)
748 				return false;
749 			break;
750 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
751 			/* Prefetch should always trigger a migration even
752 			 * if the value of the attribute didn't change.
753 			 */
754 			return false;
755 		case KFD_IOCTL_SVM_ATTR_ACCESS:
756 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
757 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
758 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
759 							       attrs[i].value);
760 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
761 				if (test_bit(gpuidx, prange->bitmap_access) ||
762 				    test_bit(gpuidx, prange->bitmap_aip))
763 					return false;
764 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
765 				if (!test_bit(gpuidx, prange->bitmap_access))
766 					return false;
767 			} else {
768 				if (!test_bit(gpuidx, prange->bitmap_aip))
769 					return false;
770 			}
771 			break;
772 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
773 			if ((prange->flags & attrs[i].value) != attrs[i].value)
774 				return false;
775 			break;
776 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
777 			if ((prange->flags & attrs[i].value) != 0)
778 				return false;
779 			break;
780 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
781 			if (prange->granularity != attrs[i].value)
782 				return false;
783 			break;
784 		default:
785 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
786 		}
787 	}
788 
789 	return true;
790 }
791 
792 /**
793  * svm_range_debug_dump - print all range information from svms
794  * @svms: svm range list header
795  *
796  * debug output svm range start, end, prefetch location from svms
797  * interval tree and link list
798  *
799  * Context: The caller must hold svms->lock
800  */
801 static void svm_range_debug_dump(struct svm_range_list *svms)
802 {
803 	struct interval_tree_node *node;
804 	struct svm_range *prange;
805 
806 	pr_debug("dump svms 0x%p list\n", svms);
807 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
808 
809 	list_for_each_entry(prange, &svms->list, list) {
810 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
811 			 prange, prange->start, prange->npages,
812 			 prange->start + prange->npages - 1,
813 			 prange->actual_loc);
814 	}
815 
816 	pr_debug("dump svms 0x%p interval tree\n", svms);
817 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
818 	node = interval_tree_iter_first(&svms->objects, 0, ~0ULL);
819 	while (node) {
820 		prange = container_of(node, struct svm_range, it_node);
821 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
822 			 prange, prange->start, prange->npages,
823 			 prange->start + prange->npages - 1,
824 			 prange->actual_loc);
825 		node = interval_tree_iter_next(node, 0, ~0ULL);
826 	}
827 }
828 
829 static int
830 svm_range_split_array(void *ppnew, void *ppold, size_t size,
831 		      uint64_t old_start, uint64_t old_n,
832 		      uint64_t new_start, uint64_t new_n)
833 {
834 	unsigned char *new, *old, *pold;
835 	uint64_t d;
836 
837 	if (!ppold)
838 		return 0;
839 	pold = *(unsigned char **)ppold;
840 	if (!pold)
841 		return 0;
842 
843 	new = kvmalloc_array(new_n, size, GFP_KERNEL);
844 	if (!new)
845 		return -ENOMEM;
846 
847 	d = (new_start - old_start) * size;
848 	memcpy(new, pold + d, new_n * size);
849 
850 	old = kvmalloc_array(old_n, size, GFP_KERNEL);
851 	if (!old) {
852 		kvfree(new);
853 		return -ENOMEM;
854 	}
855 
856 	d = (new_start == old_start) ? new_n * size : 0;
857 	memcpy(old, pold + d, old_n * size);
858 
859 	kvfree(pold);
860 	*(void **)ppold = old;
861 	*(void **)ppnew = new;
862 
863 	return 0;
864 }
865 
866 static int
867 svm_range_split_pages(struct svm_range *new, struct svm_range *old,
868 		      uint64_t start, uint64_t last)
869 {
870 	uint64_t npages = last - start + 1;
871 	int i, r;
872 
873 	for (i = 0; i < MAX_GPU_INSTANCE; i++) {
874 		r = svm_range_split_array(&new->dma_addr[i], &old->dma_addr[i],
875 					  sizeof(*old->dma_addr[i]), old->start,
876 					  npages, new->start, new->npages);
877 		if (r)
878 			return r;
879 	}
880 
881 	return 0;
882 }
883 
884 static int
885 svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
886 		      uint64_t start, uint64_t last)
887 {
888 	uint64_t npages = last - start + 1;
889 
890 	pr_debug("svms 0x%p new prange 0x%p start 0x%lx [0x%llx 0x%llx]\n",
891 		 new->svms, new, new->start, start, last);
892 
893 	if (new->start == old->start) {
894 		new->offset = old->offset;
895 		old->offset += new->npages;
896 	} else {
897 		new->offset = old->offset + npages;
898 	}
899 
900 	new->svm_bo = svm_range_bo_ref(old->svm_bo);
901 	new->ttm_res = old->ttm_res;
902 
903 	spin_lock(&new->svm_bo->list_lock);
904 	list_add(&new->svm_bo_list, &new->svm_bo->range_list);
905 	spin_unlock(&new->svm_bo->list_lock);
906 
907 	return 0;
908 }
909 
910 /**
911  * svm_range_split_adjust - split range and adjust
912  *
913  * @new: new range
914  * @old: the old range
915  * @start: the old range adjust to start address in pages
916  * @last: the old range adjust to last address in pages
917  *
918  * Copy system memory dma_addr or vram ttm_res in old range to new
919  * range from new_start up to size new->npages, the remaining old range is from
920  * start to last
921  *
922  * Return:
923  * 0 - OK, -ENOMEM - out of memory
924  */
925 static int
926 svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
927 		      uint64_t start, uint64_t last)
928 {
929 	int r;
930 
931 	pr_debug("svms 0x%p new 0x%lx old [0x%lx 0x%lx] => [0x%llx 0x%llx]\n",
932 		 new->svms, new->start, old->start, old->last, start, last);
933 
934 	if (new->start < old->start ||
935 	    new->last > old->last) {
936 		WARN_ONCE(1, "invalid new range start or last\n");
937 		return -EINVAL;
938 	}
939 
940 	r = svm_range_split_pages(new, old, start, last);
941 	if (r)
942 		return r;
943 
944 	if (old->actual_loc && old->ttm_res) {
945 		r = svm_range_split_nodes(new, old, start, last);
946 		if (r)
947 			return r;
948 	}
949 
950 	old->npages = last - start + 1;
951 	old->start = start;
952 	old->last = last;
953 	new->flags = old->flags;
954 	new->preferred_loc = old->preferred_loc;
955 	new->prefetch_loc = old->prefetch_loc;
956 	new->actual_loc = old->actual_loc;
957 	new->granularity = old->granularity;
958 	new->mapped_to_gpu = old->mapped_to_gpu;
959 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
960 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
961 
962 	return 0;
963 }
964 
965 /**
966  * svm_range_split - split a range in 2 ranges
967  *
968  * @prange: the svm range to split
969  * @start: the remaining range start address in pages
970  * @last: the remaining range last address in pages
971  * @new: the result new range generated
972  *
973  * Two cases only:
974  * case 1: if start == prange->start
975  *         prange ==> prange[start, last]
976  *         new range [last + 1, prange->last]
977  *
978  * case 2: if last == prange->last
979  *         prange ==> prange[start, last]
980  *         new range [prange->start, start - 1]
981  *
982  * Return:
983  * 0 - OK, -ENOMEM - out of memory, -EINVAL - invalid start, last
984  */
985 static int
986 svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
987 		struct svm_range **new)
988 {
989 	uint64_t old_start = prange->start;
990 	uint64_t old_last = prange->last;
991 	struct svm_range_list *svms;
992 	int r = 0;
993 
994 	pr_debug("svms 0x%p [0x%llx 0x%llx] to [0x%llx 0x%llx]\n", prange->svms,
995 		 old_start, old_last, start, last);
996 
997 	if (old_start != start && old_last != last)
998 		return -EINVAL;
999 	if (start < old_start || last > old_last)
1000 		return -EINVAL;
1001 
1002 	svms = prange->svms;
1003 	if (old_start == start)
1004 		*new = svm_range_new(svms, last + 1, old_last);
1005 	else
1006 		*new = svm_range_new(svms, old_start, start - 1);
1007 	if (!*new)
1008 		return -ENOMEM;
1009 
1010 	r = svm_range_split_adjust(*new, prange, start, last);
1011 	if (r) {
1012 		pr_debug("failed %d split [0x%llx 0x%llx] to [0x%llx 0x%llx]\n",
1013 			 r, old_start, old_last, start, last);
1014 		svm_range_free(*new);
1015 		*new = NULL;
1016 	}
1017 
1018 	return r;
1019 }
1020 
1021 static int
1022 svm_range_split_tail(struct svm_range *prange,
1023 		     uint64_t new_last, struct list_head *insert_list)
1024 {
1025 	struct svm_range *tail;
1026 	int r = svm_range_split(prange, prange->start, new_last, &tail);
1027 
1028 	if (!r)
1029 		list_add(&tail->list, insert_list);
1030 	return r;
1031 }
1032 
1033 static int
1034 svm_range_split_head(struct svm_range *prange,
1035 		     uint64_t new_start, struct list_head *insert_list)
1036 {
1037 	struct svm_range *head;
1038 	int r = svm_range_split(prange, new_start, prange->last, &head);
1039 
1040 	if (!r)
1041 		list_add(&head->list, insert_list);
1042 	return r;
1043 }
1044 
1045 static void
1046 svm_range_add_child(struct svm_range *prange, struct mm_struct *mm,
1047 		    struct svm_range *pchild, enum svm_work_list_ops op)
1048 {
1049 	pr_debug("add child 0x%p [0x%lx 0x%lx] to prange 0x%p child list %d\n",
1050 		 pchild, pchild->start, pchild->last, prange, op);
1051 
1052 	pchild->work_item.mm = mm;
1053 	pchild->work_item.op = op;
1054 	list_add_tail(&pchild->child_list, &prange->child_list);
1055 }
1056 
1057 /**
1058  * svm_range_split_by_granularity - collect ranges within granularity boundary
1059  *
1060  * @p: the process with svms list
1061  * @mm: mm structure
1062  * @addr: the vm fault address in pages, to split the prange
1063  * @parent: parent range if prange is from child list
1064  * @prange: prange to split
1065  *
1066  * Trims @prange to be a single aligned block of prange->granularity if
1067  * possible. The head and tail are added to the child_list in @parent.
1068  *
1069  * Context: caller must hold mmap_read_lock and prange->lock
1070  *
1071  * Return:
1072  * 0 - OK, otherwise error code
1073  */
1074 int
1075 svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
1076 			       unsigned long addr, struct svm_range *parent,
1077 			       struct svm_range *prange)
1078 {
1079 	struct svm_range *head, *tail;
1080 	unsigned long start, last, size;
1081 	int r;
1082 
1083 	/* Align splited range start and size to granularity size, then a single
1084 	 * PTE will be used for whole range, this reduces the number of PTE
1085 	 * updated and the L1 TLB space used for translation.
1086 	 */
1087 	size = 1UL << prange->granularity;
1088 	start = ALIGN_DOWN(addr, size);
1089 	last = ALIGN(addr + 1, size) - 1;
1090 
1091 	pr_debug("svms 0x%p split [0x%lx 0x%lx] to [0x%lx 0x%lx] size 0x%lx\n",
1092 		 prange->svms, prange->start, prange->last, start, last, size);
1093 
1094 	if (start > prange->start) {
1095 		r = svm_range_split(prange, start, prange->last, &head);
1096 		if (r)
1097 			return r;
1098 		svm_range_add_child(parent, mm, head, SVM_OP_ADD_RANGE);
1099 	}
1100 
1101 	if (last < prange->last) {
1102 		r = svm_range_split(prange, prange->start, last, &tail);
1103 		if (r)
1104 			return r;
1105 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
1106 	}
1107 
1108 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
1109 	if (p->xnack_enabled && prange->work_item.op == SVM_OP_ADD_RANGE) {
1110 		prange->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
1111 		pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
1112 			 prange, prange->start, prange->last,
1113 			 SVM_OP_ADD_RANGE_AND_MAP);
1114 	}
1115 	return 0;
1116 }
1117 
1118 static uint64_t
1119 svm_range_get_pte_flags(struct amdgpu_device *adev, struct svm_range *prange,
1120 			int domain)
1121 {
1122 	struct amdgpu_device *bo_adev;
1123 	uint32_t flags = prange->flags;
1124 	uint32_t mapping_flags = 0;
1125 	uint64_t pte_flags;
1126 	bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
1127 	bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
1128 
1129 	if (domain == SVM_RANGE_VRAM_DOMAIN)
1130 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1131 
1132 	switch (KFD_GC_VERSION(adev->kfd.dev)) {
1133 	case IP_VERSION(9, 4, 1):
1134 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1135 			if (bo_adev == adev) {
1136 				mapping_flags |= coherent ?
1137 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1138 			} else {
1139 				mapping_flags |= coherent ?
1140 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1141 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1142 					snoop = true;
1143 			}
1144 		} else {
1145 			mapping_flags |= coherent ?
1146 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1147 		}
1148 		break;
1149 	case IP_VERSION(9, 4, 2):
1150 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1151 			if (bo_adev == adev) {
1152 				mapping_flags |= coherent ?
1153 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1154 				if (adev->gmc.xgmi.connected_to_cpu)
1155 					snoop = true;
1156 			} else {
1157 				mapping_flags |= coherent ?
1158 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1159 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1160 					snoop = true;
1161 			}
1162 		} else {
1163 			mapping_flags |= coherent ?
1164 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1165 		}
1166 		break;
1167 	default:
1168 		mapping_flags |= coherent ?
1169 			AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1170 	}
1171 
1172 	mapping_flags |= AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE;
1173 
1174 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_RO)
1175 		mapping_flags &= ~AMDGPU_VM_PAGE_WRITEABLE;
1176 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_EXEC)
1177 		mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;
1178 
1179 	pte_flags = AMDGPU_PTE_VALID;
1180 	pte_flags |= (domain == SVM_RANGE_VRAM_DOMAIN) ? 0 : AMDGPU_PTE_SYSTEM;
1181 	pte_flags |= snoop ? AMDGPU_PTE_SNOOPED : 0;
1182 
1183 	pte_flags |= amdgpu_gem_va_map_flags(adev, mapping_flags);
1184 	return pte_flags;
1185 }
1186 
1187 static int
1188 svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
1189 			 uint64_t start, uint64_t last,
1190 			 struct dma_fence **fence)
1191 {
1192 	uint64_t init_pte_value = 0;
1193 
1194 	pr_debug("[0x%llx 0x%llx]\n", start, last);
1195 
1196 	return amdgpu_vm_update_range(adev, vm, false, true, true, NULL, start,
1197 				      last, init_pte_value, 0, 0, NULL, NULL,
1198 				      fence);
1199 }
1200 
1201 static int
1202 svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
1203 			  unsigned long last, uint32_t trigger)
1204 {
1205 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1206 	struct kfd_process_device *pdd;
1207 	struct dma_fence *fence = NULL;
1208 	struct kfd_process *p;
1209 	uint32_t gpuidx;
1210 	int r = 0;
1211 
1212 	if (!prange->mapped_to_gpu) {
1213 		pr_debug("prange 0x%p [0x%lx 0x%lx] not mapped to GPU\n",
1214 			 prange, prange->start, prange->last);
1215 		return 0;
1216 	}
1217 
1218 	if (prange->start == start && prange->last == last) {
1219 		pr_debug("unmap svms 0x%p prange 0x%p\n", prange->svms, prange);
1220 		prange->mapped_to_gpu = false;
1221 	}
1222 
1223 	bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
1224 		  MAX_GPU_INSTANCE);
1225 	p = container_of(prange->svms, struct kfd_process, svms);
1226 
1227 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1228 		pr_debug("unmap from gpu idx 0x%x\n", gpuidx);
1229 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1230 		if (!pdd) {
1231 			pr_debug("failed to find device idx %d\n", gpuidx);
1232 			return -EINVAL;
1233 		}
1234 
1235 		kfd_smi_event_unmap_from_gpu(pdd->dev, p->lead_thread->pid,
1236 					     start, last, trigger);
1237 
1238 		r = svm_range_unmap_from_gpu(pdd->dev->adev,
1239 					     drm_priv_to_vm(pdd->drm_priv),
1240 					     start, last, &fence);
1241 		if (r)
1242 			break;
1243 
1244 		if (fence) {
1245 			r = dma_fence_wait(fence, false);
1246 			dma_fence_put(fence);
1247 			fence = NULL;
1248 			if (r)
1249 				break;
1250 		}
1251 		kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
1252 	}
1253 
1254 	return r;
1255 }
1256 
1257 static int
1258 svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
1259 		     unsigned long offset, unsigned long npages, bool readonly,
1260 		     dma_addr_t *dma_addr, struct amdgpu_device *bo_adev,
1261 		     struct dma_fence **fence, bool flush_tlb)
1262 {
1263 	struct amdgpu_device *adev = pdd->dev->adev;
1264 	struct amdgpu_vm *vm = drm_priv_to_vm(pdd->drm_priv);
1265 	uint64_t pte_flags;
1266 	unsigned long last_start;
1267 	int last_domain;
1268 	int r = 0;
1269 	int64_t i, j;
1270 
1271 	last_start = prange->start + offset;
1272 
1273 	pr_debug("svms 0x%p [0x%lx 0x%lx] readonly %d\n", prange->svms,
1274 		 last_start, last_start + npages - 1, readonly);
1275 
1276 	for (i = offset; i < offset + npages; i++) {
1277 		last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
1278 		dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
1279 
1280 		/* Collect all pages in the same address range and memory domain
1281 		 * that can be mapped with a single call to update mapping.
1282 		 */
1283 		if (i < offset + npages - 1 &&
1284 		    last_domain == (dma_addr[i + 1] & SVM_RANGE_VRAM_DOMAIN))
1285 			continue;
1286 
1287 		pr_debug("Mapping range [0x%lx 0x%llx] on domain: %s\n",
1288 			 last_start, prange->start + i, last_domain ? "GPU" : "CPU");
1289 
1290 		pte_flags = svm_range_get_pte_flags(adev, prange, last_domain);
1291 		if (readonly)
1292 			pte_flags &= ~AMDGPU_PTE_WRITEABLE;
1293 
1294 		pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n",
1295 			 prange->svms, last_start, prange->start + i,
1296 			 (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
1297 			 pte_flags);
1298 
1299 		r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, NULL,
1300 					   last_start, prange->start + i,
1301 					   pte_flags,
1302 					   (last_start - prange->start) << PAGE_SHIFT,
1303 					   bo_adev ? bo_adev->vm_manager.vram_base_offset : 0,
1304 					   NULL, dma_addr, &vm->last_update);
1305 
1306 		for (j = last_start - prange->start; j <= i; j++)
1307 			dma_addr[j] |= last_domain;
1308 
1309 		if (r) {
1310 			pr_debug("failed %d to map to gpu 0x%lx\n", r, prange->start);
1311 			goto out;
1312 		}
1313 		last_start = prange->start + i + 1;
1314 	}
1315 
1316 	r = amdgpu_vm_update_pdes(adev, vm, false);
1317 	if (r) {
1318 		pr_debug("failed %d to update directories 0x%lx\n", r,
1319 			 prange->start);
1320 		goto out;
1321 	}
1322 
1323 	if (fence)
1324 		*fence = dma_fence_get(vm->last_update);
1325 
1326 out:
1327 	return r;
1328 }
1329 
1330 static int
1331 svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
1332 		      unsigned long npages, bool readonly,
1333 		      unsigned long *bitmap, bool wait, bool flush_tlb)
1334 {
1335 	struct kfd_process_device *pdd;
1336 	struct amdgpu_device *bo_adev;
1337 	struct kfd_process *p;
1338 	struct dma_fence *fence = NULL;
1339 	uint32_t gpuidx;
1340 	int r = 0;
1341 
1342 	if (prange->svm_bo && prange->ttm_res)
1343 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1344 	else
1345 		bo_adev = NULL;
1346 
1347 	p = container_of(prange->svms, struct kfd_process, svms);
1348 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1349 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
1350 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1351 		if (!pdd) {
1352 			pr_debug("failed to find device idx %d\n", gpuidx);
1353 			return -EINVAL;
1354 		}
1355 
1356 		pdd = kfd_bind_process_to_device(pdd->dev, p);
1357 		if (IS_ERR(pdd))
1358 			return -EINVAL;
1359 
1360 		if (bo_adev && pdd->dev->adev != bo_adev &&
1361 		    !amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
1362 			pr_debug("cannot map to device idx %d\n", gpuidx);
1363 			continue;
1364 		}
1365 
1366 		r = svm_range_map_to_gpu(pdd, prange, offset, npages, readonly,
1367 					 prange->dma_addr[gpuidx],
1368 					 bo_adev, wait ? &fence : NULL,
1369 					 flush_tlb);
1370 		if (r)
1371 			break;
1372 
1373 		if (fence) {
1374 			r = dma_fence_wait(fence, false);
1375 			dma_fence_put(fence);
1376 			fence = NULL;
1377 			if (r) {
1378 				pr_debug("failed %d to dma fence wait\n", r);
1379 				break;
1380 			}
1381 		}
1382 
1383 		kfd_flush_tlb(pdd, TLB_FLUSH_LEGACY);
1384 	}
1385 
1386 	return r;
1387 }
1388 
1389 struct svm_validate_context {
1390 	struct kfd_process *process;
1391 	struct svm_range *prange;
1392 	bool intr;
1393 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1394 	struct ttm_validate_buffer tv[MAX_GPU_INSTANCE];
1395 	struct list_head validate_list;
1396 	struct ww_acquire_ctx ticket;
1397 };
1398 
1399 static int svm_range_reserve_bos(struct svm_validate_context *ctx)
1400 {
1401 	struct kfd_process_device *pdd;
1402 	struct amdgpu_vm *vm;
1403 	uint32_t gpuidx;
1404 	int r;
1405 
1406 	INIT_LIST_HEAD(&ctx->validate_list);
1407 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1408 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1409 		if (!pdd) {
1410 			pr_debug("failed to find device idx %d\n", gpuidx);
1411 			return -EINVAL;
1412 		}
1413 		vm = drm_priv_to_vm(pdd->drm_priv);
1414 
1415 		ctx->tv[gpuidx].bo = &vm->root.bo->tbo;
1416 		ctx->tv[gpuidx].num_shared = 4;
1417 		list_add(&ctx->tv[gpuidx].head, &ctx->validate_list);
1418 	}
1419 
1420 	r = ttm_eu_reserve_buffers(&ctx->ticket, &ctx->validate_list,
1421 				   ctx->intr, NULL);
1422 	if (r) {
1423 		pr_debug("failed %d to reserve bo\n", r);
1424 		return r;
1425 	}
1426 
1427 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1428 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1429 		if (!pdd) {
1430 			pr_debug("failed to find device idx %d\n", gpuidx);
1431 			r = -EINVAL;
1432 			goto unreserve_out;
1433 		}
1434 
1435 		r = amdgpu_vm_validate_pt_bos(pdd->dev->adev,
1436 					      drm_priv_to_vm(pdd->drm_priv),
1437 					      svm_range_bo_validate, NULL);
1438 		if (r) {
1439 			pr_debug("failed %d validate pt bos\n", r);
1440 			goto unreserve_out;
1441 		}
1442 	}
1443 
1444 	return 0;
1445 
1446 unreserve_out:
1447 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1448 	return r;
1449 }
1450 
1451 static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
1452 {
1453 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1454 }
1455 
1456 static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
1457 {
1458 	struct kfd_process_device *pdd;
1459 
1460 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1461 
1462 	return SVM_ADEV_PGMAP_OWNER(pdd->dev->adev);
1463 }
1464 
1465 /*
1466  * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
1467  *
1468  * To prevent concurrent destruction or change of range attributes, the
1469  * svm_read_lock must be held. The caller must not hold the svm_write_lock
1470  * because that would block concurrent evictions and lead to deadlocks. To
1471  * serialize concurrent migrations or validations of the same range, the
1472  * prange->migrate_mutex must be held.
1473  *
1474  * For VRAM ranges, the SVM BO must be allocated and valid (protected by its
1475  * eviction fence.
1476  *
1477  * The following sequence ensures race-free validation and GPU mapping:
1478  *
1479  * 1. Reserve page table (and SVM BO if range is in VRAM)
1480  * 2. hmm_range_fault to get page addresses (if system memory)
1481  * 3. DMA-map pages (if system memory)
1482  * 4-a. Take notifier lock
1483  * 4-b. Check that pages still valid (mmu_interval_read_retry)
1484  * 4-c. Check that the range was not split or otherwise invalidated
1485  * 4-d. Update GPU page table
1486  * 4.e. Release notifier lock
1487  * 5. Release page table (and SVM BO) reservation
1488  */
1489 static int svm_range_validate_and_map(struct mm_struct *mm,
1490 				      struct svm_range *prange, int32_t gpuidx,
1491 				      bool intr, bool wait, bool flush_tlb)
1492 {
1493 	struct svm_validate_context ctx;
1494 	unsigned long start, end, addr;
1495 	struct kfd_process *p;
1496 	void *owner;
1497 	int32_t idx;
1498 	int r = 0;
1499 
1500 	ctx.process = container_of(prange->svms, struct kfd_process, svms);
1501 	ctx.prange = prange;
1502 	ctx.intr = intr;
1503 
1504 	if (gpuidx < MAX_GPU_INSTANCE) {
1505 		bitmap_zero(ctx.bitmap, MAX_GPU_INSTANCE);
1506 		bitmap_set(ctx.bitmap, gpuidx, 1);
1507 	} else if (ctx.process->xnack_enabled) {
1508 		bitmap_copy(ctx.bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
1509 
1510 		/* If prefetch range to GPU, or GPU retry fault migrate range to
1511 		 * GPU, which has ACCESS attribute to the range, create mapping
1512 		 * on that GPU.
1513 		 */
1514 		if (prange->actual_loc) {
1515 			gpuidx = kfd_process_gpuidx_from_gpuid(ctx.process,
1516 							prange->actual_loc);
1517 			if (gpuidx < 0) {
1518 				WARN_ONCE(1, "failed get device by id 0x%x\n",
1519 					 prange->actual_loc);
1520 				return -EINVAL;
1521 			}
1522 			if (test_bit(gpuidx, prange->bitmap_access))
1523 				bitmap_set(ctx.bitmap, gpuidx, 1);
1524 		}
1525 	} else {
1526 		bitmap_or(ctx.bitmap, prange->bitmap_access,
1527 			  prange->bitmap_aip, MAX_GPU_INSTANCE);
1528 	}
1529 
1530 	if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE)) {
1531 		if (!prange->mapped_to_gpu)
1532 			return 0;
1533 
1534 		bitmap_copy(ctx.bitmap, prange->bitmap_access, MAX_GPU_INSTANCE);
1535 	}
1536 
1537 	if (prange->actual_loc && !prange->ttm_res) {
1538 		/* This should never happen. actual_loc gets set by
1539 		 * svm_migrate_ram_to_vram after allocating a BO.
1540 		 */
1541 		WARN_ONCE(1, "VRAM BO missing during validation\n");
1542 		return -EINVAL;
1543 	}
1544 
1545 	svm_range_reserve_bos(&ctx);
1546 
1547 	p = container_of(prange->svms, struct kfd_process, svms);
1548 	owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
1549 						MAX_GPU_INSTANCE));
1550 	for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
1551 		if (kfd_svm_page_owner(p, idx) != owner) {
1552 			owner = NULL;
1553 			break;
1554 		}
1555 	}
1556 
1557 	start = prange->start << PAGE_SHIFT;
1558 	end = (prange->last + 1) << PAGE_SHIFT;
1559 	for (addr = start; addr < end && !r; ) {
1560 		struct hmm_range *hmm_range;
1561 		struct vm_area_struct *vma;
1562 		unsigned long next;
1563 		unsigned long offset;
1564 		unsigned long npages;
1565 		bool readonly;
1566 
1567 		vma = find_vma(mm, addr);
1568 		if (!vma || addr < vma->vm_start) {
1569 			r = -EFAULT;
1570 			goto unreserve_out;
1571 		}
1572 		readonly = !(vma->vm_flags & VM_WRITE);
1573 
1574 		next = min(vma->vm_end, end);
1575 		npages = (next - addr) >> PAGE_SHIFT;
1576 		WRITE_ONCE(p->svms.faulting_task, current);
1577 		r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
1578 					       addr, npages, &hmm_range,
1579 					       readonly, true, owner);
1580 		WRITE_ONCE(p->svms.faulting_task, NULL);
1581 		if (r) {
1582 			pr_debug("failed %d to get svm range pages\n", r);
1583 			goto unreserve_out;
1584 		}
1585 
1586 		offset = (addr - start) >> PAGE_SHIFT;
1587 		r = svm_range_dma_map(prange, ctx.bitmap, offset, npages,
1588 				      hmm_range->hmm_pfns);
1589 		if (r) {
1590 			pr_debug("failed %d to dma map range\n", r);
1591 			goto unreserve_out;
1592 		}
1593 
1594 		svm_range_lock(prange);
1595 		if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
1596 			pr_debug("hmm update the range, need validate again\n");
1597 			r = -EAGAIN;
1598 			goto unlock_out;
1599 		}
1600 		if (!list_empty(&prange->child_list)) {
1601 			pr_debug("range split by unmap in parallel, validate again\n");
1602 			r = -EAGAIN;
1603 			goto unlock_out;
1604 		}
1605 
1606 		r = svm_range_map_to_gpus(prange, offset, npages, readonly,
1607 					  ctx.bitmap, wait, flush_tlb);
1608 
1609 unlock_out:
1610 		svm_range_unlock(prange);
1611 
1612 		addr = next;
1613 	}
1614 
1615 	if (addr == end) {
1616 		prange->validated_once = true;
1617 		prange->mapped_to_gpu = true;
1618 	}
1619 
1620 unreserve_out:
1621 	svm_range_unreserve_bos(&ctx);
1622 
1623 	if (!r)
1624 		prange->validate_timestamp = ktime_get_boottime();
1625 
1626 	return r;
1627 }
1628 
1629 /**
1630  * svm_range_list_lock_and_flush_work - flush pending deferred work
1631  *
1632  * @svms: the svm range list
1633  * @mm: the mm structure
1634  *
1635  * Context: Returns with mmap write lock held, pending deferred work flushed
1636  *
1637  */
1638 void
1639 svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
1640 				   struct mm_struct *mm)
1641 {
1642 retry_flush_work:
1643 	flush_work(&svms->deferred_list_work);
1644 	mmap_write_lock(mm);
1645 
1646 	if (list_empty(&svms->deferred_range_list))
1647 		return;
1648 	mmap_write_unlock(mm);
1649 	pr_debug("retry flush\n");
1650 	goto retry_flush_work;
1651 }
1652 
1653 static void svm_range_restore_work(struct work_struct *work)
1654 {
1655 	struct delayed_work *dwork = to_delayed_work(work);
1656 	struct amdkfd_process_info *process_info;
1657 	struct svm_range_list *svms;
1658 	struct svm_range *prange;
1659 	struct kfd_process *p;
1660 	struct mm_struct *mm;
1661 	int evicted_ranges;
1662 	int invalid;
1663 	int r;
1664 
1665 	svms = container_of(dwork, struct svm_range_list, restore_work);
1666 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1667 	if (!evicted_ranges)
1668 		return;
1669 
1670 	pr_debug("restore svm ranges\n");
1671 
1672 	p = container_of(svms, struct kfd_process, svms);
1673 	process_info = p->kgd_process_info;
1674 
1675 	/* Keep mm reference when svm_range_validate_and_map ranges */
1676 	mm = get_task_mm(p->lead_thread);
1677 	if (!mm) {
1678 		pr_debug("svms 0x%p process mm gone\n", svms);
1679 		return;
1680 	}
1681 
1682 	mutex_lock(&process_info->lock);
1683 	svm_range_list_lock_and_flush_work(svms, mm);
1684 	mutex_lock(&svms->lock);
1685 
1686 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1687 
1688 	list_for_each_entry(prange, &svms->list, list) {
1689 		invalid = atomic_read(&prange->invalid);
1690 		if (!invalid)
1691 			continue;
1692 
1693 		pr_debug("restoring svms 0x%p prange 0x%p [0x%lx %lx] inv %d\n",
1694 			 prange->svms, prange, prange->start, prange->last,
1695 			 invalid);
1696 
1697 		/*
1698 		 * If range is migrating, wait for migration is done.
1699 		 */
1700 		mutex_lock(&prange->migrate_mutex);
1701 
1702 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
1703 					       false, true, false);
1704 		if (r)
1705 			pr_debug("failed %d to map 0x%lx to gpus\n", r,
1706 				 prange->start);
1707 
1708 		mutex_unlock(&prange->migrate_mutex);
1709 		if (r)
1710 			goto out_reschedule;
1711 
1712 		if (atomic_cmpxchg(&prange->invalid, invalid, 0) != invalid)
1713 			goto out_reschedule;
1714 	}
1715 
1716 	if (atomic_cmpxchg(&svms->evicted_ranges, evicted_ranges, 0) !=
1717 	    evicted_ranges)
1718 		goto out_reschedule;
1719 
1720 	evicted_ranges = 0;
1721 
1722 	r = kgd2kfd_resume_mm(mm);
1723 	if (r) {
1724 		/* No recovery from this failure. Probably the CP is
1725 		 * hanging. No point trying again.
1726 		 */
1727 		pr_debug("failed %d to resume KFD\n", r);
1728 	}
1729 
1730 	pr_debug("restore svm ranges successfully\n");
1731 
1732 out_reschedule:
1733 	mutex_unlock(&svms->lock);
1734 	mmap_write_unlock(mm);
1735 	mutex_unlock(&process_info->lock);
1736 
1737 	/* If validation failed, reschedule another attempt */
1738 	if (evicted_ranges) {
1739 		pr_debug("reschedule to restore svm range\n");
1740 		schedule_delayed_work(&svms->restore_work,
1741 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1742 
1743 		kfd_smi_event_queue_restore_rescheduled(mm);
1744 	}
1745 	mmput(mm);
1746 }
1747 
1748 /**
1749  * svm_range_evict - evict svm range
1750  * @prange: svm range structure
1751  * @mm: current process mm_struct
1752  * @start: starting process queue number
1753  * @last: last process queue number
1754  *
1755  * Stop all queues of the process to ensure GPU doesn't access the memory, then
1756  * return to let CPU evict the buffer and proceed CPU pagetable update.
1757  *
1758  * Don't need use lock to sync cpu pagetable invalidation with GPU execution.
1759  * If invalidation happens while restore work is running, restore work will
1760  * restart to ensure to get the latest CPU pages mapping to GPU, then start
1761  * the queues.
1762  */
1763 static int
1764 svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
1765 		unsigned long start, unsigned long last,
1766 		enum mmu_notifier_event event)
1767 {
1768 	struct svm_range_list *svms = prange->svms;
1769 	struct svm_range *pchild;
1770 	struct kfd_process *p;
1771 	int r = 0;
1772 
1773 	p = container_of(svms, struct kfd_process, svms);
1774 
1775 	pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
1776 		 svms, prange->start, prange->last, start, last);
1777 
1778 	if (!p->xnack_enabled ||
1779 	    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) {
1780 		int evicted_ranges;
1781 		bool mapped = prange->mapped_to_gpu;
1782 
1783 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1784 			if (!pchild->mapped_to_gpu)
1785 				continue;
1786 			mapped = true;
1787 			mutex_lock_nested(&pchild->lock, 1);
1788 			if (pchild->start <= last && pchild->last >= start) {
1789 				pr_debug("increment pchild invalid [0x%lx 0x%lx]\n",
1790 					 pchild->start, pchild->last);
1791 				atomic_inc(&pchild->invalid);
1792 			}
1793 			mutex_unlock(&pchild->lock);
1794 		}
1795 
1796 		if (!mapped)
1797 			return r;
1798 
1799 		if (prange->start <= last && prange->last >= start)
1800 			atomic_inc(&prange->invalid);
1801 
1802 		evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
1803 		if (evicted_ranges != 1)
1804 			return r;
1805 
1806 		pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
1807 			 prange->svms, prange->start, prange->last);
1808 
1809 		/* First eviction, stop the queues */
1810 		r = kgd2kfd_quiesce_mm(mm, KFD_QUEUE_EVICTION_TRIGGER_SVM);
1811 		if (r)
1812 			pr_debug("failed to quiesce KFD\n");
1813 
1814 		pr_debug("schedule to restore svm %p ranges\n", svms);
1815 		schedule_delayed_work(&svms->restore_work,
1816 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1817 	} else {
1818 		unsigned long s, l;
1819 		uint32_t trigger;
1820 
1821 		if (event == MMU_NOTIFY_MIGRATE)
1822 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY_MIGRATE;
1823 		else
1824 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY;
1825 
1826 		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
1827 			 prange->svms, start, last);
1828 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1829 			mutex_lock_nested(&pchild->lock, 1);
1830 			s = max(start, pchild->start);
1831 			l = min(last, pchild->last);
1832 			if (l >= s)
1833 				svm_range_unmap_from_gpus(pchild, s, l, trigger);
1834 			mutex_unlock(&pchild->lock);
1835 		}
1836 		s = max(start, prange->start);
1837 		l = min(last, prange->last);
1838 		if (l >= s)
1839 			svm_range_unmap_from_gpus(prange, s, l, trigger);
1840 	}
1841 
1842 	return r;
1843 }
1844 
1845 static struct svm_range *svm_range_clone(struct svm_range *old)
1846 {
1847 	struct svm_range *new;
1848 
1849 	new = svm_range_new(old->svms, old->start, old->last);
1850 	if (!new)
1851 		return NULL;
1852 
1853 	if (old->svm_bo) {
1854 		new->ttm_res = old->ttm_res;
1855 		new->offset = old->offset;
1856 		new->svm_bo = svm_range_bo_ref(old->svm_bo);
1857 		spin_lock(&new->svm_bo->list_lock);
1858 		list_add(&new->svm_bo_list, &new->svm_bo->range_list);
1859 		spin_unlock(&new->svm_bo->list_lock);
1860 	}
1861 	new->flags = old->flags;
1862 	new->preferred_loc = old->preferred_loc;
1863 	new->prefetch_loc = old->prefetch_loc;
1864 	new->actual_loc = old->actual_loc;
1865 	new->granularity = old->granularity;
1866 	new->mapped_to_gpu = old->mapped_to_gpu;
1867 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
1868 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
1869 
1870 	return new;
1871 }
1872 
1873 /**
1874  * svm_range_add - add svm range and handle overlap
1875  * @p: the range add to this process svms
1876  * @start: page size aligned
1877  * @size: page size aligned
1878  * @nattr: number of attributes
1879  * @attrs: array of attributes
1880  * @update_list: output, the ranges need validate and update GPU mapping
1881  * @insert_list: output, the ranges need insert to svms
1882  * @remove_list: output, the ranges are replaced and need remove from svms
1883  *
1884  * Check if the virtual address range has overlap with any existing ranges,
1885  * split partly overlapping ranges and add new ranges in the gaps. All changes
1886  * should be applied to the range_list and interval tree transactionally. If
1887  * any range split or allocation fails, the entire update fails. Therefore any
1888  * existing overlapping svm_ranges are cloned and the original svm_ranges left
1889  * unchanged.
1890  *
1891  * If the transaction succeeds, the caller can update and insert clones and
1892  * new ranges, then free the originals.
1893  *
1894  * Otherwise the caller can free the clones and new ranges, while the old
1895  * svm_ranges remain unchanged.
1896  *
1897  * Context: Process context, caller must hold svms->lock
1898  *
1899  * Return:
1900  * 0 - OK, otherwise error code
1901  */
1902 static int
1903 svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
1904 	      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
1905 	      struct list_head *update_list, struct list_head *insert_list,
1906 	      struct list_head *remove_list)
1907 {
1908 	unsigned long last = start + size - 1UL;
1909 	struct svm_range_list *svms = &p->svms;
1910 	struct interval_tree_node *node;
1911 	struct svm_range *prange;
1912 	struct svm_range *tmp;
1913 	int r = 0;
1914 
1915 	pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
1916 
1917 	INIT_LIST_HEAD(update_list);
1918 	INIT_LIST_HEAD(insert_list);
1919 	INIT_LIST_HEAD(remove_list);
1920 
1921 	node = interval_tree_iter_first(&svms->objects, start, last);
1922 	while (node) {
1923 		struct interval_tree_node *next;
1924 		unsigned long next_start;
1925 
1926 		pr_debug("found overlap node [0x%lx 0x%lx]\n", node->start,
1927 			 node->last);
1928 
1929 		prange = container_of(node, struct svm_range, it_node);
1930 		next = interval_tree_iter_next(node, start, last);
1931 		next_start = min(node->last, last) + 1;
1932 
1933 		if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
1934 			/* nothing to do */
1935 		} else if (node->start < start || node->last > last) {
1936 			/* node intersects the update range and its attributes
1937 			 * will change. Clone and split it, apply updates only
1938 			 * to the overlapping part
1939 			 */
1940 			struct svm_range *old = prange;
1941 
1942 			prange = svm_range_clone(old);
1943 			if (!prange) {
1944 				r = -ENOMEM;
1945 				goto out;
1946 			}
1947 
1948 			list_add(&old->update_list, remove_list);
1949 			list_add(&prange->list, insert_list);
1950 			list_add(&prange->update_list, update_list);
1951 
1952 			if (node->start < start) {
1953 				pr_debug("change old range start\n");
1954 				r = svm_range_split_head(prange, start,
1955 							 insert_list);
1956 				if (r)
1957 					goto out;
1958 			}
1959 			if (node->last > last) {
1960 				pr_debug("change old range last\n");
1961 				r = svm_range_split_tail(prange, last,
1962 							 insert_list);
1963 				if (r)
1964 					goto out;
1965 			}
1966 		} else {
1967 			/* The node is contained within start..last,
1968 			 * just update it
1969 			 */
1970 			list_add(&prange->update_list, update_list);
1971 		}
1972 
1973 		/* insert a new node if needed */
1974 		if (node->start > start) {
1975 			prange = svm_range_new(svms, start, node->start - 1);
1976 			if (!prange) {
1977 				r = -ENOMEM;
1978 				goto out;
1979 			}
1980 
1981 			list_add(&prange->list, insert_list);
1982 			list_add(&prange->update_list, update_list);
1983 		}
1984 
1985 		node = next;
1986 		start = next_start;
1987 	}
1988 
1989 	/* add a final range at the end if needed */
1990 	if (start <= last) {
1991 		prange = svm_range_new(svms, start, last);
1992 		if (!prange) {
1993 			r = -ENOMEM;
1994 			goto out;
1995 		}
1996 		list_add(&prange->list, insert_list);
1997 		list_add(&prange->update_list, update_list);
1998 	}
1999 
2000 out:
2001 	if (r)
2002 		list_for_each_entry_safe(prange, tmp, insert_list, list)
2003 			svm_range_free(prange);
2004 
2005 	return r;
2006 }
2007 
2008 static void
2009 svm_range_update_notifier_and_interval_tree(struct mm_struct *mm,
2010 					    struct svm_range *prange)
2011 {
2012 	unsigned long start;
2013 	unsigned long last;
2014 
2015 	start = prange->notifier.interval_tree.start >> PAGE_SHIFT;
2016 	last = prange->notifier.interval_tree.last >> PAGE_SHIFT;
2017 
2018 	if (prange->start == start && prange->last == last)
2019 		return;
2020 
2021 	pr_debug("up notifier 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
2022 		  prange->svms, prange, start, last, prange->start,
2023 		  prange->last);
2024 
2025 	if (start != 0 && last != 0) {
2026 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
2027 		svm_range_remove_notifier(prange);
2028 	}
2029 	prange->it_node.start = prange->start;
2030 	prange->it_node.last = prange->last;
2031 
2032 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
2033 	svm_range_add_notifier_locked(mm, prange);
2034 }
2035 
2036 static void
2037 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange,
2038 			 struct mm_struct *mm)
2039 {
2040 	switch (prange->work_item.op) {
2041 	case SVM_OP_NULL:
2042 		pr_debug("NULL OP 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2043 			 svms, prange, prange->start, prange->last);
2044 		break;
2045 	case SVM_OP_UNMAP_RANGE:
2046 		pr_debug("remove 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2047 			 svms, prange, prange->start, prange->last);
2048 		svm_range_unlink(prange);
2049 		svm_range_remove_notifier(prange);
2050 		svm_range_free(prange);
2051 		break;
2052 	case SVM_OP_UPDATE_RANGE_NOTIFIER:
2053 		pr_debug("update notifier 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2054 			 svms, prange, prange->start, prange->last);
2055 		svm_range_update_notifier_and_interval_tree(mm, prange);
2056 		break;
2057 	case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
2058 		pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2059 			 svms, prange, prange->start, prange->last);
2060 		svm_range_update_notifier_and_interval_tree(mm, prange);
2061 		/* TODO: implement deferred validation and mapping */
2062 		break;
2063 	case SVM_OP_ADD_RANGE:
2064 		pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
2065 			 prange->start, prange->last);
2066 		svm_range_add_to_svms(prange);
2067 		svm_range_add_notifier_locked(mm, prange);
2068 		break;
2069 	case SVM_OP_ADD_RANGE_AND_MAP:
2070 		pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
2071 			 prange, prange->start, prange->last);
2072 		svm_range_add_to_svms(prange);
2073 		svm_range_add_notifier_locked(mm, prange);
2074 		/* TODO: implement deferred validation and mapping */
2075 		break;
2076 	default:
2077 		WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
2078 			 prange->work_item.op);
2079 	}
2080 }
2081 
2082 static void svm_range_drain_retry_fault(struct svm_range_list *svms)
2083 {
2084 	struct kfd_process_device *pdd;
2085 	struct kfd_process *p;
2086 	int drain;
2087 	uint32_t i;
2088 
2089 	p = container_of(svms, struct kfd_process, svms);
2090 
2091 restart:
2092 	drain = atomic_read(&svms->drain_pagefaults);
2093 	if (!drain)
2094 		return;
2095 
2096 	for_each_set_bit(i, svms->bitmap_supported, p->n_pdds) {
2097 		pdd = p->pdds[i];
2098 		if (!pdd)
2099 			continue;
2100 
2101 		pr_debug("drain retry fault gpu %d svms %p\n", i, svms);
2102 
2103 		amdgpu_ih_wait_on_checkpoint_process_ts(pdd->dev->adev,
2104 						     &pdd->dev->adev->irq.ih1);
2105 		pr_debug("drain retry fault gpu %d svms 0x%p done\n", i, svms);
2106 	}
2107 	if (atomic_cmpxchg(&svms->drain_pagefaults, drain, 0) != drain)
2108 		goto restart;
2109 }
2110 
2111 static void svm_range_deferred_list_work(struct work_struct *work)
2112 {
2113 	struct svm_range_list *svms;
2114 	struct svm_range *prange;
2115 	struct mm_struct *mm;
2116 
2117 	svms = container_of(work, struct svm_range_list, deferred_list_work);
2118 	pr_debug("enter svms 0x%p\n", svms);
2119 
2120 	spin_lock(&svms->deferred_list_lock);
2121 	while (!list_empty(&svms->deferred_range_list)) {
2122 		prange = list_first_entry(&svms->deferred_range_list,
2123 					  struct svm_range, deferred_list);
2124 		spin_unlock(&svms->deferred_list_lock);
2125 
2126 		pr_debug("prange 0x%p [0x%lx 0x%lx] op %d\n", prange,
2127 			 prange->start, prange->last, prange->work_item.op);
2128 
2129 		mm = prange->work_item.mm;
2130 retry:
2131 		mmap_write_lock(mm);
2132 
2133 		/* Checking for the need to drain retry faults must be inside
2134 		 * mmap write lock to serialize with munmap notifiers.
2135 		 */
2136 		if (unlikely(atomic_read(&svms->drain_pagefaults))) {
2137 			mmap_write_unlock(mm);
2138 			svm_range_drain_retry_fault(svms);
2139 			goto retry;
2140 		}
2141 
2142 		/* Remove from deferred_list must be inside mmap write lock, for
2143 		 * two race cases:
2144 		 * 1. unmap_from_cpu may change work_item.op and add the range
2145 		 *    to deferred_list again, cause use after free bug.
2146 		 * 2. svm_range_list_lock_and_flush_work may hold mmap write
2147 		 *    lock and continue because deferred_list is empty, but
2148 		 *    deferred_list work is actually waiting for mmap lock.
2149 		 */
2150 		spin_lock(&svms->deferred_list_lock);
2151 		list_del_init(&prange->deferred_list);
2152 		spin_unlock(&svms->deferred_list_lock);
2153 
2154 		mutex_lock(&svms->lock);
2155 		mutex_lock(&prange->migrate_mutex);
2156 		while (!list_empty(&prange->child_list)) {
2157 			struct svm_range *pchild;
2158 
2159 			pchild = list_first_entry(&prange->child_list,
2160 						struct svm_range, child_list);
2161 			pr_debug("child prange 0x%p op %d\n", pchild,
2162 				 pchild->work_item.op);
2163 			list_del_init(&pchild->child_list);
2164 			svm_range_handle_list_op(svms, pchild, mm);
2165 		}
2166 		mutex_unlock(&prange->migrate_mutex);
2167 
2168 		svm_range_handle_list_op(svms, prange, mm);
2169 		mutex_unlock(&svms->lock);
2170 		mmap_write_unlock(mm);
2171 
2172 		/* Pairs with mmget in svm_range_add_list_work */
2173 		mmput(mm);
2174 
2175 		spin_lock(&svms->deferred_list_lock);
2176 	}
2177 	spin_unlock(&svms->deferred_list_lock);
2178 	pr_debug("exit svms 0x%p\n", svms);
2179 }
2180 
2181 void
2182 svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
2183 			struct mm_struct *mm, enum svm_work_list_ops op)
2184 {
2185 	spin_lock(&svms->deferred_list_lock);
2186 	/* if prange is on the deferred list */
2187 	if (!list_empty(&prange->deferred_list)) {
2188 		pr_debug("update exist prange 0x%p work op %d\n", prange, op);
2189 		WARN_ONCE(prange->work_item.mm != mm, "unmatch mm\n");
2190 		if (op != SVM_OP_NULL &&
2191 		    prange->work_item.op != SVM_OP_UNMAP_RANGE)
2192 			prange->work_item.op = op;
2193 	} else {
2194 		prange->work_item.op = op;
2195 
2196 		/* Pairs with mmput in deferred_list_work */
2197 		mmget(mm);
2198 		prange->work_item.mm = mm;
2199 		list_add_tail(&prange->deferred_list,
2200 			      &prange->svms->deferred_range_list);
2201 		pr_debug("add prange 0x%p [0x%lx 0x%lx] to work list op %d\n",
2202 			 prange, prange->start, prange->last, op);
2203 	}
2204 	spin_unlock(&svms->deferred_list_lock);
2205 }
2206 
2207 void schedule_deferred_list_work(struct svm_range_list *svms)
2208 {
2209 	spin_lock(&svms->deferred_list_lock);
2210 	if (!list_empty(&svms->deferred_range_list))
2211 		schedule_work(&svms->deferred_list_work);
2212 	spin_unlock(&svms->deferred_list_lock);
2213 }
2214 
2215 static void
2216 svm_range_unmap_split(struct mm_struct *mm, struct svm_range *parent,
2217 		      struct svm_range *prange, unsigned long start,
2218 		      unsigned long last)
2219 {
2220 	struct svm_range *head;
2221 	struct svm_range *tail;
2222 
2223 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2224 		pr_debug("prange 0x%p [0x%lx 0x%lx] is already freed\n", prange,
2225 			 prange->start, prange->last);
2226 		return;
2227 	}
2228 	if (start > prange->last || last < prange->start)
2229 		return;
2230 
2231 	head = tail = prange;
2232 	if (start > prange->start)
2233 		svm_range_split(prange, prange->start, start - 1, &tail);
2234 	if (last < tail->last)
2235 		svm_range_split(tail, last + 1, tail->last, &head);
2236 
2237 	if (head != prange && tail != prange) {
2238 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2239 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
2240 	} else if (tail != prange) {
2241 		svm_range_add_child(parent, mm, tail, SVM_OP_UNMAP_RANGE);
2242 	} else if (head != prange) {
2243 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2244 	} else if (parent != prange) {
2245 		prange->work_item.op = SVM_OP_UNMAP_RANGE;
2246 	}
2247 }
2248 
2249 static void
2250 svm_range_unmap_from_cpu(struct mm_struct *mm, struct svm_range *prange,
2251 			 unsigned long start, unsigned long last)
2252 {
2253 	uint32_t trigger = KFD_SVM_UNMAP_TRIGGER_UNMAP_FROM_CPU;
2254 	struct svm_range_list *svms;
2255 	struct svm_range *pchild;
2256 	struct kfd_process *p;
2257 	unsigned long s, l;
2258 	bool unmap_parent;
2259 
2260 	p = kfd_lookup_process_by_mm(mm);
2261 	if (!p)
2262 		return;
2263 	svms = &p->svms;
2264 
2265 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n", svms,
2266 		 prange, prange->start, prange->last, start, last);
2267 
2268 	/* Make sure pending page faults are drained in the deferred worker
2269 	 * before the range is freed to avoid straggler interrupts on
2270 	 * unmapped memory causing "phantom faults".
2271 	 */
2272 	atomic_inc(&svms->drain_pagefaults);
2273 
2274 	unmap_parent = start <= prange->start && last >= prange->last;
2275 
2276 	list_for_each_entry(pchild, &prange->child_list, child_list) {
2277 		mutex_lock_nested(&pchild->lock, 1);
2278 		s = max(start, pchild->start);
2279 		l = min(last, pchild->last);
2280 		if (l >= s)
2281 			svm_range_unmap_from_gpus(pchild, s, l, trigger);
2282 		svm_range_unmap_split(mm, prange, pchild, start, last);
2283 		mutex_unlock(&pchild->lock);
2284 	}
2285 	s = max(start, prange->start);
2286 	l = min(last, prange->last);
2287 	if (l >= s)
2288 		svm_range_unmap_from_gpus(prange, s, l, trigger);
2289 	svm_range_unmap_split(mm, prange, prange, start, last);
2290 
2291 	if (unmap_parent)
2292 		svm_range_add_list_work(svms, prange, mm, SVM_OP_UNMAP_RANGE);
2293 	else
2294 		svm_range_add_list_work(svms, prange, mm,
2295 					SVM_OP_UPDATE_RANGE_NOTIFIER);
2296 	schedule_deferred_list_work(svms);
2297 
2298 	kfd_unref_process(p);
2299 }
2300 
2301 /**
2302  * svm_range_cpu_invalidate_pagetables - interval notifier callback
2303  * @mni: mmu_interval_notifier struct
2304  * @range: mmu_notifier_range struct
2305  * @cur_seq: value to pass to mmu_interval_set_seq()
2306  *
2307  * If event is MMU_NOTIFY_UNMAP, this is from CPU unmap range, otherwise, it
2308  * is from migration, or CPU page invalidation callback.
2309  *
2310  * For unmap event, unmap range from GPUs, remove prange from svms in a delayed
2311  * work thread, and split prange if only part of prange is unmapped.
2312  *
2313  * For invalidation event, if GPU retry fault is not enabled, evict the queues,
2314  * then schedule svm_range_restore_work to update GPU mapping and resume queues.
2315  * If GPU retry fault is enabled, unmap the svm range from GPU, retry fault will
2316  * update GPU mapping to recover.
2317  *
2318  * Context: mmap lock, notifier_invalidate_start lock are held
2319  *          for invalidate event, prange lock is held if this is from migration
2320  */
2321 static bool
2322 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
2323 				    const struct mmu_notifier_range *range,
2324 				    unsigned long cur_seq)
2325 {
2326 	struct svm_range *prange;
2327 	unsigned long start;
2328 	unsigned long last;
2329 
2330 	if (range->event == MMU_NOTIFY_RELEASE)
2331 		return true;
2332 	if (!mmget_not_zero(mni->mm))
2333 		return true;
2334 
2335 	start = mni->interval_tree.start;
2336 	last = mni->interval_tree.last;
2337 	start = max(start, range->start) >> PAGE_SHIFT;
2338 	last = min(last, range->end - 1) >> PAGE_SHIFT;
2339 	pr_debug("[0x%lx 0x%lx] range[0x%lx 0x%lx] notifier[0x%lx 0x%lx] %d\n",
2340 		 start, last, range->start >> PAGE_SHIFT,
2341 		 (range->end - 1) >> PAGE_SHIFT,
2342 		 mni->interval_tree.start >> PAGE_SHIFT,
2343 		 mni->interval_tree.last >> PAGE_SHIFT, range->event);
2344 
2345 	prange = container_of(mni, struct svm_range, notifier);
2346 
2347 	svm_range_lock(prange);
2348 	mmu_interval_set_seq(mni, cur_seq);
2349 
2350 	switch (range->event) {
2351 	case MMU_NOTIFY_UNMAP:
2352 		svm_range_unmap_from_cpu(mni->mm, prange, start, last);
2353 		break;
2354 	default:
2355 		svm_range_evict(prange, mni->mm, start, last, range->event);
2356 		break;
2357 	}
2358 
2359 	svm_range_unlock(prange);
2360 	mmput(mni->mm);
2361 
2362 	return true;
2363 }
2364 
2365 /**
2366  * svm_range_from_addr - find svm range from fault address
2367  * @svms: svm range list header
2368  * @addr: address to search range interval tree, in pages
2369  * @parent: parent range if range is on child list
2370  *
2371  * Context: The caller must hold svms->lock
2372  *
2373  * Return: the svm_range found or NULL
2374  */
2375 struct svm_range *
2376 svm_range_from_addr(struct svm_range_list *svms, unsigned long addr,
2377 		    struct svm_range **parent)
2378 {
2379 	struct interval_tree_node *node;
2380 	struct svm_range *prange;
2381 	struct svm_range *pchild;
2382 
2383 	node = interval_tree_iter_first(&svms->objects, addr, addr);
2384 	if (!node)
2385 		return NULL;
2386 
2387 	prange = container_of(node, struct svm_range, it_node);
2388 	pr_debug("address 0x%lx prange [0x%lx 0x%lx] node [0x%lx 0x%lx]\n",
2389 		 addr, prange->start, prange->last, node->start, node->last);
2390 
2391 	if (addr >= prange->start && addr <= prange->last) {
2392 		if (parent)
2393 			*parent = prange;
2394 		return prange;
2395 	}
2396 	list_for_each_entry(pchild, &prange->child_list, child_list)
2397 		if (addr >= pchild->start && addr <= pchild->last) {
2398 			pr_debug("found address 0x%lx pchild [0x%lx 0x%lx]\n",
2399 				 addr, pchild->start, pchild->last);
2400 			if (parent)
2401 				*parent = prange;
2402 			return pchild;
2403 		}
2404 
2405 	return NULL;
2406 }
2407 
2408 /* svm_range_best_restore_location - decide the best fault restore location
2409  * @prange: svm range structure
2410  * @adev: the GPU on which vm fault happened
2411  *
2412  * This is only called when xnack is on, to decide the best location to restore
2413  * the range mapping after GPU vm fault. Caller uses the best location to do
2414  * migration if actual loc is not best location, then update GPU page table
2415  * mapping to the best location.
2416  *
2417  * If the preferred loc is accessible by faulting GPU, use preferred loc.
2418  * If vm fault gpu idx is on range ACCESSIBLE bitmap, best_loc is vm fault gpu
2419  * If vm fault gpu idx is on range ACCESSIBLE_IN_PLACE bitmap, then
2420  *    if range actual loc is cpu, best_loc is cpu
2421  *    if vm fault gpu is on xgmi same hive of range actual loc gpu, best_loc is
2422  *    range actual loc.
2423  * Otherwise, GPU no access, best_loc is -1.
2424  *
2425  * Return:
2426  * -1 means vm fault GPU no access
2427  * 0 for CPU or GPU id
2428  */
2429 static int32_t
2430 svm_range_best_restore_location(struct svm_range *prange,
2431 				struct amdgpu_device *adev,
2432 				int32_t *gpuidx)
2433 {
2434 	struct amdgpu_device *bo_adev, *preferred_adev;
2435 	struct kfd_process *p;
2436 	uint32_t gpuid;
2437 	int r;
2438 
2439 	p = container_of(prange->svms, struct kfd_process, svms);
2440 
2441 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, gpuidx);
2442 	if (r < 0) {
2443 		pr_debug("failed to get gpuid from kgd\n");
2444 		return -1;
2445 	}
2446 
2447 	if (prange->preferred_loc == gpuid ||
2448 	    prange->preferred_loc == KFD_IOCTL_SVM_LOCATION_SYSMEM) {
2449 		return prange->preferred_loc;
2450 	} else if (prange->preferred_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
2451 		preferred_adev = svm_range_get_adev_by_id(prange,
2452 							prange->preferred_loc);
2453 		if (amdgpu_xgmi_same_hive(adev, preferred_adev))
2454 			return prange->preferred_loc;
2455 		/* fall through */
2456 	}
2457 
2458 	if (test_bit(*gpuidx, prange->bitmap_access))
2459 		return gpuid;
2460 
2461 	if (test_bit(*gpuidx, prange->bitmap_aip)) {
2462 		if (!prange->actual_loc)
2463 			return 0;
2464 
2465 		bo_adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
2466 		if (amdgpu_xgmi_same_hive(adev, bo_adev))
2467 			return prange->actual_loc;
2468 		else
2469 			return 0;
2470 	}
2471 
2472 	return -1;
2473 }
2474 
2475 static int
2476 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
2477 			       unsigned long *start, unsigned long *last,
2478 			       bool *is_heap_stack)
2479 {
2480 	struct vm_area_struct *vma;
2481 	struct interval_tree_node *node;
2482 	unsigned long start_limit, end_limit;
2483 
2484 	vma = find_vma(p->mm, addr << PAGE_SHIFT);
2485 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2486 		pr_debug("VMA does not exist in address [0x%llx]\n", addr);
2487 		return -EFAULT;
2488 	}
2489 
2490 	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
2491 			  vma->vm_end >= vma->vm_mm->start_brk) ||
2492 			 (vma->vm_start <= vma->vm_mm->start_stack &&
2493 			  vma->vm_end >= vma->vm_mm->start_stack);
2494 
2495 	start_limit = max(vma->vm_start >> PAGE_SHIFT,
2496 		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
2497 	end_limit = min(vma->vm_end >> PAGE_SHIFT,
2498 		    (unsigned long)ALIGN(addr + 1, 2UL << 8));
2499 	/* First range that starts after the fault address */
2500 	node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);
2501 	if (node) {
2502 		end_limit = min(end_limit, node->start);
2503 		/* Last range that ends before the fault address */
2504 		node = container_of(rb_prev(&node->rb),
2505 				    struct interval_tree_node, rb);
2506 	} else {
2507 		/* Last range must end before addr because
2508 		 * there was no range after addr
2509 		 */
2510 		node = container_of(rb_last(&p->svms.objects.rb_root),
2511 				    struct interval_tree_node, rb);
2512 	}
2513 	if (node) {
2514 		if (node->last >= addr) {
2515 			WARN(1, "Overlap with prev node and page fault addr\n");
2516 			return -EFAULT;
2517 		}
2518 		start_limit = max(start_limit, node->last + 1);
2519 	}
2520 
2521 	*start = start_limit;
2522 	*last = end_limit - 1;
2523 
2524 	pr_debug("vma [0x%lx 0x%lx] range [0x%lx 0x%lx] is_heap_stack %d\n",
2525 		 vma->vm_start >> PAGE_SHIFT, vma->vm_end >> PAGE_SHIFT,
2526 		 *start, *last, *is_heap_stack);
2527 
2528 	return 0;
2529 }
2530 
2531 static int
2532 svm_range_check_vm_userptr(struct kfd_process *p, uint64_t start, uint64_t last,
2533 			   uint64_t *bo_s, uint64_t *bo_l)
2534 {
2535 	struct amdgpu_bo_va_mapping *mapping;
2536 	struct interval_tree_node *node;
2537 	struct amdgpu_bo *bo = NULL;
2538 	unsigned long userptr;
2539 	uint32_t i;
2540 	int r;
2541 
2542 	for (i = 0; i < p->n_pdds; i++) {
2543 		struct amdgpu_vm *vm;
2544 
2545 		if (!p->pdds[i]->drm_priv)
2546 			continue;
2547 
2548 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2549 		r = amdgpu_bo_reserve(vm->root.bo, false);
2550 		if (r)
2551 			return r;
2552 
2553 		/* Check userptr by searching entire vm->va interval tree */
2554 		node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
2555 		while (node) {
2556 			mapping = container_of((struct rb_node *)node,
2557 					       struct amdgpu_bo_va_mapping, rb);
2558 			bo = mapping->bo_va->base.bo;
2559 
2560 			if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
2561 							 start << PAGE_SHIFT,
2562 							 last << PAGE_SHIFT,
2563 							 &userptr)) {
2564 				node = interval_tree_iter_next(node, 0, ~0ULL);
2565 				continue;
2566 			}
2567 
2568 			pr_debug("[0x%llx 0x%llx] already userptr mapped\n",
2569 				 start, last);
2570 			if (bo_s && bo_l) {
2571 				*bo_s = userptr >> PAGE_SHIFT;
2572 				*bo_l = *bo_s + bo->tbo.ttm->num_pages - 1;
2573 			}
2574 			amdgpu_bo_unreserve(vm->root.bo);
2575 			return -EADDRINUSE;
2576 		}
2577 		amdgpu_bo_unreserve(vm->root.bo);
2578 	}
2579 	return 0;
2580 }
2581 
2582 static struct
2583 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
2584 						struct kfd_process *p,
2585 						struct mm_struct *mm,
2586 						int64_t addr)
2587 {
2588 	struct svm_range *prange = NULL;
2589 	unsigned long start, last;
2590 	uint32_t gpuid, gpuidx;
2591 	bool is_heap_stack;
2592 	uint64_t bo_s = 0;
2593 	uint64_t bo_l = 0;
2594 	int r;
2595 
2596 	if (svm_range_get_range_boundaries(p, addr, &start, &last,
2597 					   &is_heap_stack))
2598 		return NULL;
2599 
2600 	r = svm_range_check_vm(p, start, last, &bo_s, &bo_l);
2601 	if (r != -EADDRINUSE)
2602 		r = svm_range_check_vm_userptr(p, start, last, &bo_s, &bo_l);
2603 
2604 	if (r == -EADDRINUSE) {
2605 		if (addr >= bo_s && addr <= bo_l)
2606 			return NULL;
2607 
2608 		/* Create one page svm range if 2MB range overlapping */
2609 		start = addr;
2610 		last = addr;
2611 	}
2612 
2613 	prange = svm_range_new(&p->svms, start, last);
2614 	if (!prange) {
2615 		pr_debug("Failed to create prange in address [0x%llx]\n", addr);
2616 		return NULL;
2617 	}
2618 	if (kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx)) {
2619 		pr_debug("failed to get gpuid from kgd\n");
2620 		svm_range_free(prange);
2621 		return NULL;
2622 	}
2623 
2624 	if (is_heap_stack)
2625 		prange->preferred_loc = KFD_IOCTL_SVM_LOCATION_SYSMEM;
2626 
2627 	svm_range_add_to_svms(prange);
2628 	svm_range_add_notifier_locked(mm, prange);
2629 
2630 	return prange;
2631 }
2632 
2633 /* svm_range_skip_recover - decide if prange can be recovered
2634  * @prange: svm range structure
2635  *
2636  * GPU vm retry fault handle skip recover the range for cases:
2637  * 1. prange is on deferred list to be removed after unmap, it is stale fault,
2638  *    deferred list work will drain the stale fault before free the prange.
2639  * 2. prange is on deferred list to add interval notifier after split, or
2640  * 3. prange is child range, it is split from parent prange, recover later
2641  *    after interval notifier is added.
2642  *
2643  * Return: true to skip recover, false to recover
2644  */
2645 static bool svm_range_skip_recover(struct svm_range *prange)
2646 {
2647 	struct svm_range_list *svms = prange->svms;
2648 
2649 	spin_lock(&svms->deferred_list_lock);
2650 	if (list_empty(&prange->deferred_list) &&
2651 	    list_empty(&prange->child_list)) {
2652 		spin_unlock(&svms->deferred_list_lock);
2653 		return false;
2654 	}
2655 	spin_unlock(&svms->deferred_list_lock);
2656 
2657 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2658 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] unmapped\n",
2659 			 svms, prange, prange->start, prange->last);
2660 		return true;
2661 	}
2662 	if (prange->work_item.op == SVM_OP_ADD_RANGE_AND_MAP ||
2663 	    prange->work_item.op == SVM_OP_ADD_RANGE) {
2664 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] not added yet\n",
2665 			 svms, prange, prange->start, prange->last);
2666 		return true;
2667 	}
2668 	return false;
2669 }
2670 
2671 static void
2672 svm_range_count_fault(struct amdgpu_device *adev, struct kfd_process *p,
2673 		      int32_t gpuidx)
2674 {
2675 	struct kfd_process_device *pdd;
2676 
2677 	/* fault is on different page of same range
2678 	 * or fault is skipped to recover later
2679 	 * or fault is on invalid virtual address
2680 	 */
2681 	if (gpuidx == MAX_GPU_INSTANCE) {
2682 		uint32_t gpuid;
2683 		int r;
2684 
2685 		r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx);
2686 		if (r < 0)
2687 			return;
2688 	}
2689 
2690 	/* fault is recovered
2691 	 * or fault cannot recover because GPU no access on the range
2692 	 */
2693 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
2694 	if (pdd)
2695 		WRITE_ONCE(pdd->faults, pdd->faults + 1);
2696 }
2697 
2698 static bool
2699 svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
2700 {
2701 	unsigned long requested = VM_READ;
2702 
2703 	if (write_fault)
2704 		requested |= VM_WRITE;
2705 
2706 	pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
2707 		vma->vm_flags);
2708 	return (vma->vm_flags & requested) == requested;
2709 }
2710 
2711 int
2712 svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
2713 			uint64_t addr, bool write_fault)
2714 {
2715 	struct mm_struct *mm = NULL;
2716 	struct svm_range_list *svms;
2717 	struct svm_range *prange;
2718 	struct kfd_process *p;
2719 	ktime_t timestamp = ktime_get_boottime();
2720 	int32_t best_loc;
2721 	int32_t gpuidx = MAX_GPU_INSTANCE;
2722 	bool write_locked = false;
2723 	struct vm_area_struct *vma;
2724 	bool migration = false;
2725 	int r = 0;
2726 
2727 	if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
2728 		pr_debug("device does not support SVM\n");
2729 		return -EFAULT;
2730 	}
2731 
2732 	p = kfd_lookup_process_by_pasid(pasid);
2733 	if (!p) {
2734 		pr_debug("kfd process not founded pasid 0x%x\n", pasid);
2735 		return 0;
2736 	}
2737 	svms = &p->svms;
2738 
2739 	pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
2740 
2741 	if (atomic_read(&svms->drain_pagefaults)) {
2742 		pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
2743 		r = 0;
2744 		goto out;
2745 	}
2746 
2747 	if (!p->xnack_enabled) {
2748 		pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
2749 		r = -EFAULT;
2750 		goto out;
2751 	}
2752 
2753 	/* p->lead_thread is available as kfd_process_wq_release flush the work
2754 	 * before releasing task ref.
2755 	 */
2756 	mm = get_task_mm(p->lead_thread);
2757 	if (!mm) {
2758 		pr_debug("svms 0x%p failed to get mm\n", svms);
2759 		r = 0;
2760 		goto out;
2761 	}
2762 
2763 	mmap_read_lock(mm);
2764 retry_write_locked:
2765 	mutex_lock(&svms->lock);
2766 	prange = svm_range_from_addr(svms, addr, NULL);
2767 	if (!prange) {
2768 		pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
2769 			 svms, addr);
2770 		if (!write_locked) {
2771 			/* Need the write lock to create new range with MMU notifier.
2772 			 * Also flush pending deferred work to make sure the interval
2773 			 * tree is up to date before we add a new range
2774 			 */
2775 			mutex_unlock(&svms->lock);
2776 			mmap_read_unlock(mm);
2777 			mmap_write_lock(mm);
2778 			write_locked = true;
2779 			goto retry_write_locked;
2780 		}
2781 		prange = svm_range_create_unregistered_range(adev, p, mm, addr);
2782 		if (!prange) {
2783 			pr_debug("failed to create unregistered range svms 0x%p address [0x%llx]\n",
2784 				 svms, addr);
2785 			mmap_write_downgrade(mm);
2786 			r = -EFAULT;
2787 			goto out_unlock_svms;
2788 		}
2789 	}
2790 	if (write_locked)
2791 		mmap_write_downgrade(mm);
2792 
2793 	mutex_lock(&prange->migrate_mutex);
2794 
2795 	if (svm_range_skip_recover(prange)) {
2796 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2797 		r = 0;
2798 		goto out_unlock_range;
2799 	}
2800 
2801 	/* skip duplicate vm fault on different pages of same range */
2802 	if (ktime_before(timestamp, ktime_add_ns(prange->validate_timestamp,
2803 				AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING))) {
2804 		pr_debug("svms 0x%p [0x%lx %lx] already restored\n",
2805 			 svms, prange->start, prange->last);
2806 		r = 0;
2807 		goto out_unlock_range;
2808 	}
2809 
2810 	/* __do_munmap removed VMA, return success as we are handling stale
2811 	 * retry fault.
2812 	 */
2813 	vma = find_vma(mm, addr << PAGE_SHIFT);
2814 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2815 		pr_debug("address 0x%llx VMA is removed\n", addr);
2816 		r = 0;
2817 		goto out_unlock_range;
2818 	}
2819 
2820 	if (!svm_fault_allowed(vma, write_fault)) {
2821 		pr_debug("fault addr 0x%llx no %s permission\n", addr,
2822 			write_fault ? "write" : "read");
2823 		r = -EPERM;
2824 		goto out_unlock_range;
2825 	}
2826 
2827 	best_loc = svm_range_best_restore_location(prange, adev, &gpuidx);
2828 	if (best_loc == -1) {
2829 		pr_debug("svms %p failed get best restore loc [0x%lx 0x%lx]\n",
2830 			 svms, prange->start, prange->last);
2831 		r = -EACCES;
2832 		goto out_unlock_range;
2833 	}
2834 
2835 	pr_debug("svms %p [0x%lx 0x%lx] best restore 0x%x, actual loc 0x%x\n",
2836 		 svms, prange->start, prange->last, best_loc,
2837 		 prange->actual_loc);
2838 
2839 	kfd_smi_event_page_fault_start(adev->kfd.dev, p->lead_thread->pid, addr,
2840 				       write_fault, timestamp);
2841 
2842 	if (prange->actual_loc != best_loc) {
2843 		migration = true;
2844 		if (best_loc) {
2845 			r = svm_migrate_to_vram(prange, best_loc, mm,
2846 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
2847 			if (r) {
2848 				pr_debug("svm_migrate_to_vram failed (%d) at %llx, falling back to system memory\n",
2849 					 r, addr);
2850 				/* Fallback to system memory if migration to
2851 				 * VRAM failed
2852 				 */
2853 				if (prange->actual_loc)
2854 					r = svm_migrate_vram_to_ram(prange, mm,
2855 					   KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
2856 				else
2857 					r = 0;
2858 			}
2859 		} else {
2860 			r = svm_migrate_vram_to_ram(prange, mm,
2861 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
2862 		}
2863 		if (r) {
2864 			pr_debug("failed %d to migrate svms %p [0x%lx 0x%lx]\n",
2865 				 r, svms, prange->start, prange->last);
2866 			goto out_unlock_range;
2867 		}
2868 	}
2869 
2870 	r = svm_range_validate_and_map(mm, prange, gpuidx, false, false, false);
2871 	if (r)
2872 		pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
2873 			 r, svms, prange->start, prange->last);
2874 
2875 	kfd_smi_event_page_fault_end(adev->kfd.dev, p->lead_thread->pid, addr,
2876 				     migration);
2877 
2878 out_unlock_range:
2879 	mutex_unlock(&prange->migrate_mutex);
2880 out_unlock_svms:
2881 	mutex_unlock(&svms->lock);
2882 	mmap_read_unlock(mm);
2883 
2884 	svm_range_count_fault(adev, p, gpuidx);
2885 
2886 	mmput(mm);
2887 out:
2888 	kfd_unref_process(p);
2889 
2890 	if (r == -EAGAIN) {
2891 		pr_debug("recover vm fault later\n");
2892 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2893 		r = 0;
2894 	}
2895 	return r;
2896 }
2897 
2898 void svm_range_list_fini(struct kfd_process *p)
2899 {
2900 	struct svm_range *prange;
2901 	struct svm_range *next;
2902 
2903 	pr_debug("pasid 0x%x svms 0x%p\n", p->pasid, &p->svms);
2904 
2905 	cancel_delayed_work_sync(&p->svms.restore_work);
2906 
2907 	/* Ensure list work is finished before process is destroyed */
2908 	flush_work(&p->svms.deferred_list_work);
2909 
2910 	/*
2911 	 * Ensure no retry fault comes in afterwards, as page fault handler will
2912 	 * not find kfd process and take mm lock to recover fault.
2913 	 */
2914 	atomic_inc(&p->svms.drain_pagefaults);
2915 	svm_range_drain_retry_fault(&p->svms);
2916 
2917 	list_for_each_entry_safe(prange, next, &p->svms.list, list) {
2918 		svm_range_unlink(prange);
2919 		svm_range_remove_notifier(prange);
2920 		svm_range_free(prange);
2921 	}
2922 
2923 	mutex_destroy(&p->svms.lock);
2924 
2925 	pr_debug("pasid 0x%x svms 0x%p done\n", p->pasid, &p->svms);
2926 }
2927 
2928 int svm_range_list_init(struct kfd_process *p)
2929 {
2930 	struct svm_range_list *svms = &p->svms;
2931 	int i;
2932 
2933 	svms->objects = RB_ROOT_CACHED;
2934 	mutex_init(&svms->lock);
2935 	INIT_LIST_HEAD(&svms->list);
2936 	atomic_set(&svms->evicted_ranges, 0);
2937 	atomic_set(&svms->drain_pagefaults, 0);
2938 	INIT_DELAYED_WORK(&svms->restore_work, svm_range_restore_work);
2939 	INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work);
2940 	INIT_LIST_HEAD(&svms->deferred_range_list);
2941 	INIT_LIST_HEAD(&svms->criu_svm_metadata_list);
2942 	spin_lock_init(&svms->deferred_list_lock);
2943 
2944 	for (i = 0; i < p->n_pdds; i++)
2945 		if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev))
2946 			bitmap_set(svms->bitmap_supported, i, 1);
2947 
2948 	return 0;
2949 }
2950 
2951 /**
2952  * svm_range_check_vm - check if virtual address range mapped already
2953  * @p: current kfd_process
2954  * @start: range start address, in pages
2955  * @last: range last address, in pages
2956  * @bo_s: mapping start address in pages if address range already mapped
2957  * @bo_l: mapping last address in pages if address range already mapped
2958  *
2959  * The purpose is to avoid virtual address ranges already allocated by
2960  * kfd_ioctl_alloc_memory_of_gpu ioctl.
2961  * It looks for each pdd in the kfd_process.
2962  *
2963  * Context: Process context
2964  *
2965  * Return 0 - OK, if the range is not mapped.
2966  * Otherwise error code:
2967  * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
2968  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
2969  * a signal. Release all buffer reservations and return to user-space.
2970  */
2971 static int
2972 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
2973 		   uint64_t *bo_s, uint64_t *bo_l)
2974 {
2975 	struct amdgpu_bo_va_mapping *mapping;
2976 	struct interval_tree_node *node;
2977 	uint32_t i;
2978 	int r;
2979 
2980 	for (i = 0; i < p->n_pdds; i++) {
2981 		struct amdgpu_vm *vm;
2982 
2983 		if (!p->pdds[i]->drm_priv)
2984 			continue;
2985 
2986 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2987 		r = amdgpu_bo_reserve(vm->root.bo, false);
2988 		if (r)
2989 			return r;
2990 
2991 		node = interval_tree_iter_first(&vm->va, start, last);
2992 		if (node) {
2993 			pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
2994 				 start, last);
2995 			mapping = container_of((struct rb_node *)node,
2996 					       struct amdgpu_bo_va_mapping, rb);
2997 			if (bo_s && bo_l) {
2998 				*bo_s = mapping->start;
2999 				*bo_l = mapping->last;
3000 			}
3001 			amdgpu_bo_unreserve(vm->root.bo);
3002 			return -EADDRINUSE;
3003 		}
3004 		amdgpu_bo_unreserve(vm->root.bo);
3005 	}
3006 
3007 	return 0;
3008 }
3009 
3010 /**
3011  * svm_range_is_valid - check if virtual address range is valid
3012  * @p: current kfd_process
3013  * @start: range start address, in pages
3014  * @size: range size, in pages
3015  *
3016  * Valid virtual address range means it belongs to one or more VMAs
3017  *
3018  * Context: Process context
3019  *
3020  * Return:
3021  *  0 - OK, otherwise error code
3022  */
3023 static int
3024 svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
3025 {
3026 	const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
3027 	struct vm_area_struct *vma;
3028 	unsigned long end;
3029 	unsigned long start_unchg = start;
3030 
3031 	start <<= PAGE_SHIFT;
3032 	end = start + (size << PAGE_SHIFT);
3033 	do {
3034 		vma = find_vma(p->mm, start);
3035 		if (!vma || start < vma->vm_start ||
3036 		    (vma->vm_flags & device_vma))
3037 			return -EFAULT;
3038 		start = min(end, vma->vm_end);
3039 	} while (start < end);
3040 
3041 	return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT, NULL,
3042 				  NULL);
3043 }
3044 
3045 /**
3046  * svm_range_best_prefetch_location - decide the best prefetch location
3047  * @prange: svm range structure
3048  *
3049  * For xnack off:
3050  * If range map to single GPU, the best prefetch location is prefetch_loc, which
3051  * can be CPU or GPU.
3052  *
3053  * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on
3054  * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise
3055  * the best prefetch location is always CPU, because GPU can not have coherent
3056  * mapping VRAM of other GPUs even with large-BAR PCIe connection.
3057  *
3058  * For xnack on:
3059  * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is
3060  * prefetch_loc, other GPU access will generate vm fault and trigger migration.
3061  *
3062  * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same
3063  * hive, the best prefetch location is prefetch_loc GPU, otherwise the best
3064  * prefetch location is always CPU.
3065  *
3066  * Context: Process context
3067  *
3068  * Return:
3069  * 0 for CPU or GPU id
3070  */
3071 static uint32_t
3072 svm_range_best_prefetch_location(struct svm_range *prange)
3073 {
3074 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
3075 	uint32_t best_loc = prange->prefetch_loc;
3076 	struct kfd_process_device *pdd;
3077 	struct amdgpu_device *bo_adev;
3078 	struct kfd_process *p;
3079 	uint32_t gpuidx;
3080 
3081 	p = container_of(prange->svms, struct kfd_process, svms);
3082 
3083 	if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED)
3084 		goto out;
3085 
3086 	bo_adev = svm_range_get_adev_by_id(prange, best_loc);
3087 	if (!bo_adev) {
3088 		WARN_ONCE(1, "failed to get device by id 0x%x\n", best_loc);
3089 		best_loc = 0;
3090 		goto out;
3091 	}
3092 
3093 	if (p->xnack_enabled)
3094 		bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
3095 	else
3096 		bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
3097 			  MAX_GPU_INSTANCE);
3098 
3099 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
3100 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
3101 		if (!pdd) {
3102 			pr_debug("failed to get device by idx 0x%x\n", gpuidx);
3103 			continue;
3104 		}
3105 
3106 		if (pdd->dev->adev == bo_adev)
3107 			continue;
3108 
3109 		if (!amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
3110 			best_loc = 0;
3111 			break;
3112 		}
3113 	}
3114 
3115 out:
3116 	pr_debug("xnack %d svms 0x%p [0x%lx 0x%lx] best loc 0x%x\n",
3117 		 p->xnack_enabled, &p->svms, prange->start, prange->last,
3118 		 best_loc);
3119 
3120 	return best_loc;
3121 }
3122 
3123 /* FIXME: This is a workaround for page locking bug when some pages are
3124  * invalid during migration to VRAM
3125  */
3126 void svm_range_prefault(struct svm_range *prange, struct mm_struct *mm,
3127 			void *owner)
3128 {
3129 	struct hmm_range *hmm_range;
3130 	int r;
3131 
3132 	if (prange->validated_once)
3133 		return;
3134 
3135 	r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
3136 				       prange->start << PAGE_SHIFT,
3137 				       prange->npages, &hmm_range,
3138 				       false, true, owner);
3139 	if (!r) {
3140 		amdgpu_hmm_range_get_pages_done(hmm_range);
3141 		prange->validated_once = true;
3142 	}
3143 }
3144 
3145 /* svm_range_trigger_migration - start page migration if prefetch loc changed
3146  * @mm: current process mm_struct
3147  * @prange: svm range structure
3148  * @migrated: output, true if migration is triggered
3149  *
3150  * If range perfetch_loc is GPU, actual loc is cpu 0, then migrate the range
3151  * from ram to vram.
3152  * If range prefetch_loc is cpu 0, actual loc is GPU, then migrate the range
3153  * from vram to ram.
3154  *
3155  * If GPU vm fault retry is not enabled, migration interact with MMU notifier
3156  * and restore work:
3157  * 1. migrate_vma_setup invalidate pages, MMU notifier callback svm_range_evict
3158  *    stops all queues, schedule restore work
3159  * 2. svm_range_restore_work wait for migration is done by
3160  *    a. svm_range_validate_vram takes prange->migrate_mutex
3161  *    b. svm_range_validate_ram HMM get pages wait for CPU fault handle returns
3162  * 3. restore work update mappings of GPU, resume all queues.
3163  *
3164  * Context: Process context
3165  *
3166  * Return:
3167  * 0 - OK, otherwise - error code of migration
3168  */
3169 static int
3170 svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
3171 			    bool *migrated)
3172 {
3173 	uint32_t best_loc;
3174 	int r = 0;
3175 
3176 	*migrated = false;
3177 	best_loc = svm_range_best_prefetch_location(prange);
3178 
3179 	if (best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3180 	    best_loc == prange->actual_loc)
3181 		return 0;
3182 
3183 	if (!best_loc) {
3184 		r = svm_migrate_vram_to_ram(prange, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
3185 		*migrated = !r;
3186 		return r;
3187 	}
3188 
3189 	r = svm_migrate_to_vram(prange, best_loc, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
3190 	*migrated = !r;
3191 
3192 	return r;
3193 }
3194 
3195 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
3196 {
3197 	if (!fence)
3198 		return -EINVAL;
3199 
3200 	if (dma_fence_is_signaled(&fence->base))
3201 		return 0;
3202 
3203 	if (fence->svm_bo) {
3204 		WRITE_ONCE(fence->svm_bo->evicting, 1);
3205 		schedule_work(&fence->svm_bo->eviction_work);
3206 	}
3207 
3208 	return 0;
3209 }
3210 
3211 static void svm_range_evict_svm_bo_worker(struct work_struct *work)
3212 {
3213 	struct svm_range_bo *svm_bo;
3214 	struct kfd_process *p;
3215 	struct mm_struct *mm;
3216 	int r = 0;
3217 
3218 	svm_bo = container_of(work, struct svm_range_bo, eviction_work);
3219 	if (!svm_bo_ref_unless_zero(svm_bo))
3220 		return; /* svm_bo was freed while eviction was pending */
3221 
3222 	/* svm_range_bo_release destroys this worker thread. So during
3223 	 * the lifetime of this thread, kfd_process and mm will be valid.
3224 	 */
3225 	p = container_of(svm_bo->svms, struct kfd_process, svms);
3226 	mm = p->mm;
3227 	if (!mm)
3228 		return;
3229 
3230 	mmap_read_lock(mm);
3231 	spin_lock(&svm_bo->list_lock);
3232 	while (!list_empty(&svm_bo->range_list) && !r) {
3233 		struct svm_range *prange =
3234 				list_first_entry(&svm_bo->range_list,
3235 						struct svm_range, svm_bo_list);
3236 		int retries = 3;
3237 
3238 		list_del_init(&prange->svm_bo_list);
3239 		spin_unlock(&svm_bo->list_lock);
3240 
3241 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
3242 			 prange->start, prange->last);
3243 
3244 		mutex_lock(&prange->migrate_mutex);
3245 		do {
3246 			r = svm_migrate_vram_to_ram(prange,
3247 						svm_bo->eviction_fence->mm,
3248 						KFD_MIGRATE_TRIGGER_TTM_EVICTION);
3249 		} while (!r && prange->actual_loc && --retries);
3250 
3251 		if (!r && prange->actual_loc)
3252 			pr_info_once("Migration failed during eviction");
3253 
3254 		if (!prange->actual_loc) {
3255 			mutex_lock(&prange->lock);
3256 			prange->svm_bo = NULL;
3257 			mutex_unlock(&prange->lock);
3258 		}
3259 		mutex_unlock(&prange->migrate_mutex);
3260 
3261 		spin_lock(&svm_bo->list_lock);
3262 	}
3263 	spin_unlock(&svm_bo->list_lock);
3264 	mmap_read_unlock(mm);
3265 
3266 	dma_fence_signal(&svm_bo->eviction_fence->base);
3267 
3268 	/* This is the last reference to svm_bo, after svm_range_vram_node_free
3269 	 * has been called in svm_migrate_vram_to_ram
3270 	 */
3271 	WARN_ONCE(!r && kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
3272 	svm_range_bo_unref(svm_bo);
3273 }
3274 
3275 static int
3276 svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
3277 		   uint64_t start, uint64_t size, uint32_t nattr,
3278 		   struct kfd_ioctl_svm_attribute *attrs)
3279 {
3280 	struct amdkfd_process_info *process_info = p->kgd_process_info;
3281 	struct list_head update_list;
3282 	struct list_head insert_list;
3283 	struct list_head remove_list;
3284 	struct svm_range_list *svms;
3285 	struct svm_range *prange;
3286 	struct svm_range *next;
3287 	bool update_mapping = false;
3288 	bool flush_tlb;
3289 	int r = 0;
3290 
3291 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
3292 		 p->pasid, &p->svms, start, start + size - 1, size);
3293 
3294 	r = svm_range_check_attr(p, nattr, attrs);
3295 	if (r)
3296 		return r;
3297 
3298 	svms = &p->svms;
3299 
3300 	mutex_lock(&process_info->lock);
3301 
3302 	svm_range_list_lock_and_flush_work(svms, mm);
3303 
3304 	r = svm_range_is_valid(p, start, size);
3305 	if (r) {
3306 		pr_debug("invalid range r=%d\n", r);
3307 		mmap_write_unlock(mm);
3308 		goto out;
3309 	}
3310 
3311 	mutex_lock(&svms->lock);
3312 
3313 	/* Add new range and split existing ranges as needed */
3314 	r = svm_range_add(p, start, size, nattr, attrs, &update_list,
3315 			  &insert_list, &remove_list);
3316 	if (r) {
3317 		mutex_unlock(&svms->lock);
3318 		mmap_write_unlock(mm);
3319 		goto out;
3320 	}
3321 	/* Apply changes as a transaction */
3322 	list_for_each_entry_safe(prange, next, &insert_list, list) {
3323 		svm_range_add_to_svms(prange);
3324 		svm_range_add_notifier_locked(mm, prange);
3325 	}
3326 	list_for_each_entry(prange, &update_list, update_list) {
3327 		svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
3328 		/* TODO: unmap ranges from GPU that lost access */
3329 	}
3330 	list_for_each_entry_safe(prange, next, &remove_list, update_list) {
3331 		pr_debug("unlink old 0x%p prange 0x%p [0x%lx 0x%lx]\n",
3332 			 prange->svms, prange, prange->start,
3333 			 prange->last);
3334 		svm_range_unlink(prange);
3335 		svm_range_remove_notifier(prange);
3336 		svm_range_free(prange);
3337 	}
3338 
3339 	mmap_write_downgrade(mm);
3340 	/* Trigger migrations and revalidate and map to GPUs as needed. If
3341 	 * this fails we may be left with partially completed actions. There
3342 	 * is no clean way of rolling back to the previous state in such a
3343 	 * case because the rollback wouldn't be guaranteed to work either.
3344 	 */
3345 	list_for_each_entry(prange, &update_list, update_list) {
3346 		bool migrated;
3347 
3348 		mutex_lock(&prange->migrate_mutex);
3349 
3350 		r = svm_range_trigger_migration(mm, prange, &migrated);
3351 		if (r)
3352 			goto out_unlock_range;
3353 
3354 		if (migrated && (!p->xnack_enabled ||
3355 		    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) &&
3356 		    prange->mapped_to_gpu) {
3357 			pr_debug("restore_work will update mappings of GPUs\n");
3358 			mutex_unlock(&prange->migrate_mutex);
3359 			continue;
3360 		}
3361 
3362 		if (!migrated && !update_mapping) {
3363 			mutex_unlock(&prange->migrate_mutex);
3364 			continue;
3365 		}
3366 
3367 		flush_tlb = !migrated && update_mapping && prange->mapped_to_gpu;
3368 
3369 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
3370 					       true, true, flush_tlb);
3371 		if (r)
3372 			pr_debug("failed %d to map svm range\n", r);
3373 
3374 out_unlock_range:
3375 		mutex_unlock(&prange->migrate_mutex);
3376 		if (r)
3377 			break;
3378 	}
3379 
3380 	svm_range_debug_dump(svms);
3381 
3382 	mutex_unlock(&svms->lock);
3383 	mmap_read_unlock(mm);
3384 out:
3385 	mutex_unlock(&process_info->lock);
3386 
3387 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
3388 		 &p->svms, start, start + size - 1, r);
3389 
3390 	return r;
3391 }
3392 
3393 static int
3394 svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm,
3395 		   uint64_t start, uint64_t size, uint32_t nattr,
3396 		   struct kfd_ioctl_svm_attribute *attrs)
3397 {
3398 	DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
3399 	DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
3400 	bool get_preferred_loc = false;
3401 	bool get_prefetch_loc = false;
3402 	bool get_granularity = false;
3403 	bool get_accessible = false;
3404 	bool get_flags = false;
3405 	uint64_t last = start + size - 1UL;
3406 	uint8_t granularity = 0xff;
3407 	struct interval_tree_node *node;
3408 	struct svm_range_list *svms;
3409 	struct svm_range *prange;
3410 	uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3411 	uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3412 	uint32_t flags_and = 0xffffffff;
3413 	uint32_t flags_or = 0;
3414 	int gpuidx;
3415 	uint32_t i;
3416 	int r = 0;
3417 
3418 	pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
3419 		 start + size - 1, nattr);
3420 
3421 	/* Flush pending deferred work to avoid racing with deferred actions from
3422 	 * previous memory map changes (e.g. munmap). Concurrent memory map changes
3423 	 * can still race with get_attr because we don't hold the mmap lock. But that
3424 	 * would be a race condition in the application anyway, and undefined
3425 	 * behaviour is acceptable in that case.
3426 	 */
3427 	flush_work(&p->svms.deferred_list_work);
3428 
3429 	mmap_read_lock(mm);
3430 	r = svm_range_is_valid(p, start, size);
3431 	mmap_read_unlock(mm);
3432 	if (r) {
3433 		pr_debug("invalid range r=%d\n", r);
3434 		return r;
3435 	}
3436 
3437 	for (i = 0; i < nattr; i++) {
3438 		switch (attrs[i].type) {
3439 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3440 			get_preferred_loc = true;
3441 			break;
3442 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3443 			get_prefetch_loc = true;
3444 			break;
3445 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3446 			get_accessible = true;
3447 			break;
3448 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3449 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3450 			get_flags = true;
3451 			break;
3452 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3453 			get_granularity = true;
3454 			break;
3455 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
3456 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
3457 			fallthrough;
3458 		default:
3459 			pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
3460 			return -EINVAL;
3461 		}
3462 	}
3463 
3464 	svms = &p->svms;
3465 
3466 	mutex_lock(&svms->lock);
3467 
3468 	node = interval_tree_iter_first(&svms->objects, start, last);
3469 	if (!node) {
3470 		pr_debug("range attrs not found return default values\n");
3471 		svm_range_set_default_attributes(&location, &prefetch_loc,
3472 						 &granularity, &flags_and);
3473 		flags_or = flags_and;
3474 		if (p->xnack_enabled)
3475 			bitmap_copy(bitmap_access, svms->bitmap_supported,
3476 				    MAX_GPU_INSTANCE);
3477 		else
3478 			bitmap_zero(bitmap_access, MAX_GPU_INSTANCE);
3479 		bitmap_zero(bitmap_aip, MAX_GPU_INSTANCE);
3480 		goto fill_values;
3481 	}
3482 	bitmap_copy(bitmap_access, svms->bitmap_supported, MAX_GPU_INSTANCE);
3483 	bitmap_copy(bitmap_aip, svms->bitmap_supported, MAX_GPU_INSTANCE);
3484 
3485 	while (node) {
3486 		struct interval_tree_node *next;
3487 
3488 		prange = container_of(node, struct svm_range, it_node);
3489 		next = interval_tree_iter_next(node, start, last);
3490 
3491 		if (get_preferred_loc) {
3492 			if (prange->preferred_loc ==
3493 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3494 			    (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3495 			     location != prange->preferred_loc)) {
3496 				location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3497 				get_preferred_loc = false;
3498 			} else {
3499 				location = prange->preferred_loc;
3500 			}
3501 		}
3502 		if (get_prefetch_loc) {
3503 			if (prange->prefetch_loc ==
3504 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3505 			    (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3506 			     prefetch_loc != prange->prefetch_loc)) {
3507 				prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3508 				get_prefetch_loc = false;
3509 			} else {
3510 				prefetch_loc = prange->prefetch_loc;
3511 			}
3512 		}
3513 		if (get_accessible) {
3514 			bitmap_and(bitmap_access, bitmap_access,
3515 				   prange->bitmap_access, MAX_GPU_INSTANCE);
3516 			bitmap_and(bitmap_aip, bitmap_aip,
3517 				   prange->bitmap_aip, MAX_GPU_INSTANCE);
3518 		}
3519 		if (get_flags) {
3520 			flags_and &= prange->flags;
3521 			flags_or |= prange->flags;
3522 		}
3523 
3524 		if (get_granularity && prange->granularity < granularity)
3525 			granularity = prange->granularity;
3526 
3527 		node = next;
3528 	}
3529 fill_values:
3530 	mutex_unlock(&svms->lock);
3531 
3532 	for (i = 0; i < nattr; i++) {
3533 		switch (attrs[i].type) {
3534 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3535 			attrs[i].value = location;
3536 			break;
3537 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3538 			attrs[i].value = prefetch_loc;
3539 			break;
3540 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3541 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
3542 							       attrs[i].value);
3543 			if (gpuidx < 0) {
3544 				pr_debug("invalid gpuid %x\n", attrs[i].value);
3545 				return -EINVAL;
3546 			}
3547 			if (test_bit(gpuidx, bitmap_access))
3548 				attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
3549 			else if (test_bit(gpuidx, bitmap_aip))
3550 				attrs[i].type =
3551 					KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
3552 			else
3553 				attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
3554 			break;
3555 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3556 			attrs[i].value = flags_and;
3557 			break;
3558 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3559 			attrs[i].value = ~flags_or;
3560 			break;
3561 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3562 			attrs[i].value = (uint32_t)granularity;
3563 			break;
3564 		}
3565 	}
3566 
3567 	return 0;
3568 }
3569 
3570 int kfd_criu_resume_svm(struct kfd_process *p)
3571 {
3572 	struct kfd_ioctl_svm_attribute *set_attr_new, *set_attr = NULL;
3573 	int nattr_common = 4, nattr_accessibility = 1;
3574 	struct criu_svm_metadata *criu_svm_md = NULL;
3575 	struct svm_range_list *svms = &p->svms;
3576 	struct criu_svm_metadata *next = NULL;
3577 	uint32_t set_flags = 0xffffffff;
3578 	int i, j, num_attrs, ret = 0;
3579 	uint64_t set_attr_size;
3580 	struct mm_struct *mm;
3581 
3582 	if (list_empty(&svms->criu_svm_metadata_list)) {
3583 		pr_debug("No SVM data from CRIU restore stage 2\n");
3584 		return ret;
3585 	}
3586 
3587 	mm = get_task_mm(p->lead_thread);
3588 	if (!mm) {
3589 		pr_err("failed to get mm for the target process\n");
3590 		return -ESRCH;
3591 	}
3592 
3593 	num_attrs = nattr_common + (nattr_accessibility * p->n_pdds);
3594 
3595 	i = j = 0;
3596 	list_for_each_entry(criu_svm_md, &svms->criu_svm_metadata_list, list) {
3597 		pr_debug("criu_svm_md[%d]\n\tstart: 0x%llx size: 0x%llx (npages)\n",
3598 			 i, criu_svm_md->data.start_addr, criu_svm_md->data.size);
3599 
3600 		for (j = 0; j < num_attrs; j++) {
3601 			pr_debug("\ncriu_svm_md[%d]->attrs[%d].type : 0x%x\ncriu_svm_md[%d]->attrs[%d].value : 0x%x\n",
3602 				 i, j, criu_svm_md->data.attrs[j].type,
3603 				 i, j, criu_svm_md->data.attrs[j].value);
3604 			switch (criu_svm_md->data.attrs[j].type) {
3605 			/* During Checkpoint operation, the query for
3606 			 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC attribute might
3607 			 * return KFD_IOCTL_SVM_LOCATION_UNDEFINED if they were
3608 			 * not used by the range which was checkpointed. Care
3609 			 * must be taken to not restore with an invalid value
3610 			 * otherwise the gpuidx value will be invalid and
3611 			 * set_attr would eventually fail so just replace those
3612 			 * with another dummy attribute such as
3613 			 * KFD_IOCTL_SVM_ATTR_SET_FLAGS.
3614 			 */
3615 			case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3616 				if (criu_svm_md->data.attrs[j].value ==
3617 				    KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
3618 					criu_svm_md->data.attrs[j].type =
3619 						KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3620 					criu_svm_md->data.attrs[j].value = 0;
3621 				}
3622 				break;
3623 			case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3624 				set_flags = criu_svm_md->data.attrs[j].value;
3625 				break;
3626 			default:
3627 				break;
3628 			}
3629 		}
3630 
3631 		/* CLR_FLAGS is not available via get_attr during checkpoint but
3632 		 * it needs to be inserted before restoring the ranges so
3633 		 * allocate extra space for it before calling set_attr
3634 		 */
3635 		set_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3636 						(num_attrs + 1);
3637 		set_attr_new = krealloc(set_attr, set_attr_size,
3638 					    GFP_KERNEL);
3639 		if (!set_attr_new) {
3640 			ret = -ENOMEM;
3641 			goto exit;
3642 		}
3643 		set_attr = set_attr_new;
3644 
3645 		memcpy(set_attr, criu_svm_md->data.attrs, num_attrs *
3646 					sizeof(struct kfd_ioctl_svm_attribute));
3647 		set_attr[num_attrs].type = KFD_IOCTL_SVM_ATTR_CLR_FLAGS;
3648 		set_attr[num_attrs].value = ~set_flags;
3649 
3650 		ret = svm_range_set_attr(p, mm, criu_svm_md->data.start_addr,
3651 					 criu_svm_md->data.size, num_attrs + 1,
3652 					 set_attr);
3653 		if (ret) {
3654 			pr_err("CRIU: failed to set range attributes\n");
3655 			goto exit;
3656 		}
3657 
3658 		i++;
3659 	}
3660 exit:
3661 	kfree(set_attr);
3662 	list_for_each_entry_safe(criu_svm_md, next, &svms->criu_svm_metadata_list, list) {
3663 		pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
3664 						criu_svm_md->data.start_addr);
3665 		kfree(criu_svm_md);
3666 	}
3667 
3668 	mmput(mm);
3669 	return ret;
3670 
3671 }
3672 
3673 int kfd_criu_restore_svm(struct kfd_process *p,
3674 			 uint8_t __user *user_priv_ptr,
3675 			 uint64_t *priv_data_offset,
3676 			 uint64_t max_priv_data_size)
3677 {
3678 	uint64_t svm_priv_data_size, svm_object_md_size, svm_attrs_size;
3679 	int nattr_common = 4, nattr_accessibility = 1;
3680 	struct criu_svm_metadata *criu_svm_md = NULL;
3681 	struct svm_range_list *svms = &p->svms;
3682 	uint32_t num_devices;
3683 	int ret = 0;
3684 
3685 	num_devices = p->n_pdds;
3686 	/* Handle one SVM range object at a time, also the number of gpus are
3687 	 * assumed to be same on the restore node, checking must be done while
3688 	 * evaluating the topology earlier
3689 	 */
3690 
3691 	svm_attrs_size = sizeof(struct kfd_ioctl_svm_attribute) *
3692 		(nattr_common + nattr_accessibility * num_devices);
3693 	svm_object_md_size = sizeof(struct criu_svm_metadata) + svm_attrs_size;
3694 
3695 	svm_priv_data_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3696 								svm_attrs_size;
3697 
3698 	criu_svm_md = kzalloc(svm_object_md_size, GFP_KERNEL);
3699 	if (!criu_svm_md) {
3700 		pr_err("failed to allocate memory to store svm metadata\n");
3701 		return -ENOMEM;
3702 	}
3703 	if (*priv_data_offset + svm_priv_data_size > max_priv_data_size) {
3704 		ret = -EINVAL;
3705 		goto exit;
3706 	}
3707 
3708 	ret = copy_from_user(&criu_svm_md->data, user_priv_ptr + *priv_data_offset,
3709 			     svm_priv_data_size);
3710 	if (ret) {
3711 		ret = -EFAULT;
3712 		goto exit;
3713 	}
3714 	*priv_data_offset += svm_priv_data_size;
3715 
3716 	list_add_tail(&criu_svm_md->list, &svms->criu_svm_metadata_list);
3717 
3718 	return 0;
3719 
3720 
3721 exit:
3722 	kfree(criu_svm_md);
3723 	return ret;
3724 }
3725 
3726 int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
3727 		       uint64_t *svm_priv_data_size)
3728 {
3729 	uint64_t total_size, accessibility_size, common_attr_size;
3730 	int nattr_common = 4, nattr_accessibility = 1;
3731 	int num_devices = p->n_pdds;
3732 	struct svm_range_list *svms;
3733 	struct svm_range *prange;
3734 	uint32_t count = 0;
3735 
3736 	*svm_priv_data_size = 0;
3737 
3738 	svms = &p->svms;
3739 	if (!svms)
3740 		return -EINVAL;
3741 
3742 	mutex_lock(&svms->lock);
3743 	list_for_each_entry(prange, &svms->list, list) {
3744 		pr_debug("prange: 0x%p start: 0x%lx\t npages: 0x%llx\t end: 0x%llx\n",
3745 			 prange, prange->start, prange->npages,
3746 			 prange->start + prange->npages - 1);
3747 		count++;
3748 	}
3749 	mutex_unlock(&svms->lock);
3750 
3751 	*num_svm_ranges = count;
3752 	/* Only the accessbility attributes need to be queried for all the gpus
3753 	 * individually, remaining ones are spanned across the entire process
3754 	 * regardless of the various gpu nodes. Of the remaining attributes,
3755 	 * KFD_IOCTL_SVM_ATTR_CLR_FLAGS need not be saved.
3756 	 *
3757 	 * KFD_IOCTL_SVM_ATTR_PREFERRED_LOC
3758 	 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC
3759 	 * KFD_IOCTL_SVM_ATTR_SET_FLAGS
3760 	 * KFD_IOCTL_SVM_ATTR_GRANULARITY
3761 	 *
3762 	 * ** ACCESSBILITY ATTRIBUTES **
3763 	 * (Considered as one, type is altered during query, value is gpuid)
3764 	 * KFD_IOCTL_SVM_ATTR_ACCESS
3765 	 * KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE
3766 	 * KFD_IOCTL_SVM_ATTR_NO_ACCESS
3767 	 */
3768 	if (*num_svm_ranges > 0) {
3769 		common_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3770 			nattr_common;
3771 		accessibility_size = sizeof(struct kfd_ioctl_svm_attribute) *
3772 			nattr_accessibility * num_devices;
3773 
3774 		total_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3775 			common_attr_size + accessibility_size;
3776 
3777 		*svm_priv_data_size = *num_svm_ranges * total_size;
3778 	}
3779 
3780 	pr_debug("num_svm_ranges %u total_priv_size %llu\n", *num_svm_ranges,
3781 		 *svm_priv_data_size);
3782 	return 0;
3783 }
3784 
3785 int kfd_criu_checkpoint_svm(struct kfd_process *p,
3786 			    uint8_t __user *user_priv_data,
3787 			    uint64_t *priv_data_offset)
3788 {
3789 	struct kfd_criu_svm_range_priv_data *svm_priv = NULL;
3790 	struct kfd_ioctl_svm_attribute *query_attr = NULL;
3791 	uint64_t svm_priv_data_size, query_attr_size = 0;
3792 	int index, nattr_common = 4, ret = 0;
3793 	struct svm_range_list *svms;
3794 	int num_devices = p->n_pdds;
3795 	struct svm_range *prange;
3796 	struct mm_struct *mm;
3797 
3798 	svms = &p->svms;
3799 	if (!svms)
3800 		return -EINVAL;
3801 
3802 	mm = get_task_mm(p->lead_thread);
3803 	if (!mm) {
3804 		pr_err("failed to get mm for the target process\n");
3805 		return -ESRCH;
3806 	}
3807 
3808 	query_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3809 				(nattr_common + num_devices);
3810 
3811 	query_attr = kzalloc(query_attr_size, GFP_KERNEL);
3812 	if (!query_attr) {
3813 		ret = -ENOMEM;
3814 		goto exit;
3815 	}
3816 
3817 	query_attr[0].type = KFD_IOCTL_SVM_ATTR_PREFERRED_LOC;
3818 	query_attr[1].type = KFD_IOCTL_SVM_ATTR_PREFETCH_LOC;
3819 	query_attr[2].type = KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3820 	query_attr[3].type = KFD_IOCTL_SVM_ATTR_GRANULARITY;
3821 
3822 	for (index = 0; index < num_devices; index++) {
3823 		struct kfd_process_device *pdd = p->pdds[index];
3824 
3825 		query_attr[index + nattr_common].type =
3826 			KFD_IOCTL_SVM_ATTR_ACCESS;
3827 		query_attr[index + nattr_common].value = pdd->user_gpu_id;
3828 	}
3829 
3830 	svm_priv_data_size = sizeof(*svm_priv) + query_attr_size;
3831 
3832 	svm_priv = kzalloc(svm_priv_data_size, GFP_KERNEL);
3833 	if (!svm_priv) {
3834 		ret = -ENOMEM;
3835 		goto exit_query;
3836 	}
3837 
3838 	index = 0;
3839 	list_for_each_entry(prange, &svms->list, list) {
3840 
3841 		svm_priv->object_type = KFD_CRIU_OBJECT_TYPE_SVM_RANGE;
3842 		svm_priv->start_addr = prange->start;
3843 		svm_priv->size = prange->npages;
3844 		memcpy(&svm_priv->attrs, query_attr, query_attr_size);
3845 		pr_debug("CRIU: prange: 0x%p start: 0x%lx\t npages: 0x%llx end: 0x%llx\t size: 0x%llx\n",
3846 			 prange, prange->start, prange->npages,
3847 			 prange->start + prange->npages - 1,
3848 			 prange->npages * PAGE_SIZE);
3849 
3850 		ret = svm_range_get_attr(p, mm, svm_priv->start_addr,
3851 					 svm_priv->size,
3852 					 (nattr_common + num_devices),
3853 					 svm_priv->attrs);
3854 		if (ret) {
3855 			pr_err("CRIU: failed to obtain range attributes\n");
3856 			goto exit_priv;
3857 		}
3858 
3859 		if (copy_to_user(user_priv_data + *priv_data_offset, svm_priv,
3860 				 svm_priv_data_size)) {
3861 			pr_err("Failed to copy svm priv to user\n");
3862 			ret = -EFAULT;
3863 			goto exit_priv;
3864 		}
3865 
3866 		*priv_data_offset += svm_priv_data_size;
3867 
3868 	}
3869 
3870 
3871 exit_priv:
3872 	kfree(svm_priv);
3873 exit_query:
3874 	kfree(query_attr);
3875 exit:
3876 	mmput(mm);
3877 	return ret;
3878 }
3879 
3880 int
3881 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
3882 	  uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
3883 {
3884 	struct mm_struct *mm = current->mm;
3885 	int r;
3886 
3887 	start >>= PAGE_SHIFT;
3888 	size >>= PAGE_SHIFT;
3889 
3890 	switch (op) {
3891 	case KFD_IOCTL_SVM_OP_SET_ATTR:
3892 		r = svm_range_set_attr(p, mm, start, size, nattrs, attrs);
3893 		break;
3894 	case KFD_IOCTL_SVM_OP_GET_ATTR:
3895 		r = svm_range_get_attr(p, mm, start, size, nattrs, attrs);
3896 		break;
3897 	default:
3898 		r = EINVAL;
3899 		break;
3900 	}
3901 
3902 	return r;
3903 }
3904