xref: /linux/drivers/gpu/drm/amd/amdkfd/kfd_svm.c (revision bc50cf64e9c7cd048a4b14d111b6a7f94783d6f8)
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 <drm/ttm/ttm_tt.h>
27 #include "amdgpu_sync.h"
28 #include "amdgpu_object.h"
29 #include "amdgpu_vm.h"
30 #include "amdgpu_hmm.h"
31 #include "amdgpu.h"
32 #include "amdgpu_xgmi.h"
33 #include "kfd_priv.h"
34 #include "kfd_svm.h"
35 #include "kfd_migrate.h"
36 #include "kfd_smi_events.h"
37 
38 #ifdef dev_fmt
39 #undef dev_fmt
40 #endif
41 #define dev_fmt(fmt) "kfd_svm: %s: " fmt, __func__
42 
43 #define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
44 
45 /* Long enough to ensure no retry fault comes after svm range is restored and
46  * page table is updated.
47  */
48 #define AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING	(2UL * NSEC_PER_MSEC)
49 
50 /* Giant svm range split into smaller ranges based on this, it is decided using
51  * minimum of all dGPU/APU 1/32 VRAM size, between 2MB to 1GB and alignment to
52  * power of 2MB.
53  */
54 static uint64_t max_svm_range_pages;
55 
56 struct criu_svm_metadata {
57 	struct list_head list;
58 	struct kfd_criu_svm_range_priv_data data;
59 };
60 
61 static void svm_range_evict_svm_bo_worker(struct work_struct *work);
62 static bool
63 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
64 				    const struct mmu_notifier_range *range,
65 				    unsigned long cur_seq);
66 static int
67 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
68 		   uint64_t *bo_s, uint64_t *bo_l);
69 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
70 	.invalidate = svm_range_cpu_invalidate_pagetables,
71 };
72 
73 /**
74  * svm_range_unlink - unlink svm_range from lists and interval tree
75  * @prange: svm range structure to be removed
76  *
77  * Remove the svm_range from the svms and svm_bo lists and the svms
78  * interval tree.
79  *
80  * Context: The caller must hold svms->lock
81  */
82 static void svm_range_unlink(struct svm_range *prange)
83 {
84 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
85 		 prange, prange->start, prange->last);
86 
87 	if (prange->svm_bo) {
88 		spin_lock(&prange->svm_bo->list_lock);
89 		list_del(&prange->svm_bo_list);
90 		spin_unlock(&prange->svm_bo->list_lock);
91 	}
92 
93 	list_del(&prange->list);
94 	if (prange->it_node.start != 0 && prange->it_node.last != 0)
95 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
96 }
97 
98 static void
99 svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
100 {
101 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
102 		 prange, prange->start, prange->last);
103 
104 	mmu_interval_notifier_insert_locked(&prange->notifier, mm,
105 				     prange->start << PAGE_SHIFT,
106 				     prange->npages << PAGE_SHIFT,
107 				     &svm_range_mn_ops);
108 }
109 
110 /**
111  * svm_range_add_to_svms - add svm range to svms
112  * @prange: svm range structure to be added
113  *
114  * Add the svm range to svms interval tree and link list
115  *
116  * Context: The caller must hold svms->lock
117  */
118 static void svm_range_add_to_svms(struct svm_range *prange)
119 {
120 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
121 		 prange, prange->start, prange->last);
122 
123 	list_move_tail(&prange->list, &prange->svms->list);
124 	prange->it_node.start = prange->start;
125 	prange->it_node.last = prange->last;
126 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
127 }
128 
129 static void svm_range_remove_notifier(struct svm_range *prange)
130 {
131 	pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
132 		 prange->svms, prange,
133 		 prange->notifier.interval_tree.start >> PAGE_SHIFT,
134 		 prange->notifier.interval_tree.last >> PAGE_SHIFT);
135 
136 	if (prange->notifier.interval_tree.start != 0 &&
137 	    prange->notifier.interval_tree.last != 0)
138 		mmu_interval_notifier_remove(&prange->notifier);
139 }
140 
141 static bool
142 svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
143 {
144 	return dma_addr && !dma_mapping_error(dev, dma_addr) &&
145 	       !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
146 }
147 
148 static int
149 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
150 		      unsigned long offset, unsigned long npages,
151 		      unsigned long *hmm_pfns, uint32_t gpuidx)
152 {
153 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
154 	dma_addr_t *addr = prange->dma_addr[gpuidx];
155 	struct device *dev = adev->dev;
156 	struct page *page;
157 	int i, r;
158 
159 	if (!addr) {
160 		addr = kvcalloc(prange->npages, sizeof(*addr), GFP_KERNEL);
161 		if (!addr)
162 			return -ENOMEM;
163 		prange->dma_addr[gpuidx] = addr;
164 	}
165 
166 	addr += offset;
167 	for (i = 0; i < npages; i++) {
168 		if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
169 			dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
170 
171 		page = hmm_pfn_to_page(hmm_pfns[i]);
172 		if (is_zone_device_page(page)) {
173 			struct amdgpu_device *bo_adev =
174 					amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
175 
176 			addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
177 				   bo_adev->vm_manager.vram_base_offset -
178 				   bo_adev->kfd.dev->pgmap.range.start;
179 			addr[i] |= SVM_RANGE_VRAM_DOMAIN;
180 			pr_debug_ratelimited("vram address: 0x%llx\n", addr[i]);
181 			continue;
182 		}
183 		addr[i] = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
184 		r = dma_mapping_error(dev, addr[i]);
185 		if (r) {
186 			dev_err(dev, "failed %d dma_map_page\n", r);
187 			return r;
188 		}
189 		pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
190 				     addr[i] >> PAGE_SHIFT, page_to_pfn(page));
191 	}
192 	return 0;
193 }
194 
195 static int
196 svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
197 		  unsigned long offset, unsigned long npages,
198 		  unsigned long *hmm_pfns)
199 {
200 	struct kfd_process *p;
201 	uint32_t gpuidx;
202 	int r;
203 
204 	p = container_of(prange->svms, struct kfd_process, svms);
205 
206 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
207 		struct kfd_process_device *pdd;
208 
209 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
210 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
211 		if (!pdd) {
212 			pr_debug("failed to find device idx %d\n", gpuidx);
213 			return -EINVAL;
214 		}
215 
216 		r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
217 					  hmm_pfns, gpuidx);
218 		if (r)
219 			break;
220 	}
221 
222 	return r;
223 }
224 
225 void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
226 			 unsigned long offset, unsigned long npages)
227 {
228 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
229 	int i;
230 
231 	if (!dma_addr)
232 		return;
233 
234 	for (i = offset; i < offset + npages; i++) {
235 		if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
236 			continue;
237 		pr_debug_ratelimited("unmap 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
238 		dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
239 		dma_addr[i] = 0;
240 	}
241 }
242 
243 void svm_range_free_dma_mappings(struct svm_range *prange)
244 {
245 	struct kfd_process_device *pdd;
246 	dma_addr_t *dma_addr;
247 	struct device *dev;
248 	struct kfd_process *p;
249 	uint32_t gpuidx;
250 
251 	p = container_of(prange->svms, struct kfd_process, svms);
252 
253 	for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
254 		dma_addr = prange->dma_addr[gpuidx];
255 		if (!dma_addr)
256 			continue;
257 
258 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
259 		if (!pdd) {
260 			pr_debug("failed to find device idx %d\n", gpuidx);
261 			continue;
262 		}
263 		dev = &pdd->dev->adev->pdev->dev;
264 		svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
265 		kvfree(dma_addr);
266 		prange->dma_addr[gpuidx] = NULL;
267 	}
268 }
269 
270 static void svm_range_free(struct svm_range *prange, bool update_mem_usage)
271 {
272 	uint64_t size = (prange->last - prange->start + 1) << PAGE_SHIFT;
273 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
274 
275 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
276 		 prange->start, prange->last);
277 
278 	svm_range_vram_node_free(prange);
279 	svm_range_free_dma_mappings(prange);
280 
281 	if (update_mem_usage && !p->xnack_enabled) {
282 		pr_debug("unreserve prange 0x%p size: 0x%llx\n", prange, size);
283 		amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
284 					KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
285 	}
286 	mutex_destroy(&prange->lock);
287 	mutex_destroy(&prange->migrate_mutex);
288 	kfree(prange);
289 }
290 
291 static void
292 svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,
293 				 uint8_t *granularity, uint32_t *flags)
294 {
295 	*location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
296 	*prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
297 	*granularity = 9;
298 	*flags =
299 		KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;
300 }
301 
302 static struct
303 svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
304 			 uint64_t last, bool update_mem_usage)
305 {
306 	uint64_t size = last - start + 1;
307 	struct svm_range *prange;
308 	struct kfd_process *p;
309 
310 	prange = kzalloc(sizeof(*prange), GFP_KERNEL);
311 	if (!prange)
312 		return NULL;
313 
314 	p = container_of(svms, struct kfd_process, svms);
315 	if (!p->xnack_enabled && update_mem_usage &&
316 	    amdgpu_amdkfd_reserve_mem_limit(NULL, size << PAGE_SHIFT,
317 					    KFD_IOC_ALLOC_MEM_FLAGS_USERPTR)) {
318 		pr_info("SVM mapping failed, exceeds resident system memory limit\n");
319 		kfree(prange);
320 		return NULL;
321 	}
322 	prange->npages = size;
323 	prange->svms = svms;
324 	prange->start = start;
325 	prange->last = last;
326 	INIT_LIST_HEAD(&prange->list);
327 	INIT_LIST_HEAD(&prange->update_list);
328 	INIT_LIST_HEAD(&prange->svm_bo_list);
329 	INIT_LIST_HEAD(&prange->deferred_list);
330 	INIT_LIST_HEAD(&prange->child_list);
331 	atomic_set(&prange->invalid, 0);
332 	prange->validate_timestamp = 0;
333 	mutex_init(&prange->migrate_mutex);
334 	mutex_init(&prange->lock);
335 
336 	if (p->xnack_enabled)
337 		bitmap_copy(prange->bitmap_access, svms->bitmap_supported,
338 			    MAX_GPU_INSTANCE);
339 
340 	svm_range_set_default_attributes(&prange->preferred_loc,
341 					 &prange->prefetch_loc,
342 					 &prange->granularity, &prange->flags);
343 
344 	pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last);
345 
346 	return prange;
347 }
348 
349 static bool svm_bo_ref_unless_zero(struct svm_range_bo *svm_bo)
350 {
351 	if (!svm_bo || !kref_get_unless_zero(&svm_bo->kref))
352 		return false;
353 
354 	return true;
355 }
356 
357 static void svm_range_bo_release(struct kref *kref)
358 {
359 	struct svm_range_bo *svm_bo;
360 
361 	svm_bo = container_of(kref, struct svm_range_bo, kref);
362 	pr_debug("svm_bo 0x%p\n", svm_bo);
363 
364 	spin_lock(&svm_bo->list_lock);
365 	while (!list_empty(&svm_bo->range_list)) {
366 		struct svm_range *prange =
367 				list_first_entry(&svm_bo->range_list,
368 						struct svm_range, svm_bo_list);
369 		/* list_del_init tells a concurrent svm_range_vram_node_new when
370 		 * it's safe to reuse the svm_bo pointer and svm_bo_list head.
371 		 */
372 		list_del_init(&prange->svm_bo_list);
373 		spin_unlock(&svm_bo->list_lock);
374 
375 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
376 			 prange->start, prange->last);
377 		mutex_lock(&prange->lock);
378 		prange->svm_bo = NULL;
379 		mutex_unlock(&prange->lock);
380 
381 		spin_lock(&svm_bo->list_lock);
382 	}
383 	spin_unlock(&svm_bo->list_lock);
384 	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
385 		/* We're not in the eviction worker.
386 		 * Signal the fence and synchronize with any
387 		 * pending eviction work.
388 		 */
389 		dma_fence_signal(&svm_bo->eviction_fence->base);
390 		cancel_work_sync(&svm_bo->eviction_work);
391 	}
392 	dma_fence_put(&svm_bo->eviction_fence->base);
393 	amdgpu_bo_unref(&svm_bo->bo);
394 	kfree(svm_bo);
395 }
396 
397 static void svm_range_bo_wq_release(struct work_struct *work)
398 {
399 	struct svm_range_bo *svm_bo;
400 
401 	svm_bo = container_of(work, struct svm_range_bo, release_work);
402 	svm_range_bo_release(&svm_bo->kref);
403 }
404 
405 static void svm_range_bo_release_async(struct kref *kref)
406 {
407 	struct svm_range_bo *svm_bo;
408 
409 	svm_bo = container_of(kref, struct svm_range_bo, kref);
410 	pr_debug("svm_bo 0x%p\n", svm_bo);
411 	INIT_WORK(&svm_bo->release_work, svm_range_bo_wq_release);
412 	schedule_work(&svm_bo->release_work);
413 }
414 
415 void svm_range_bo_unref_async(struct svm_range_bo *svm_bo)
416 {
417 	kref_put(&svm_bo->kref, svm_range_bo_release_async);
418 }
419 
420 static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
421 {
422 	if (svm_bo)
423 		kref_put(&svm_bo->kref, svm_range_bo_release);
424 }
425 
426 static bool
427 svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
428 {
429 	struct amdgpu_device *bo_adev;
430 
431 	mutex_lock(&prange->lock);
432 	if (!prange->svm_bo) {
433 		mutex_unlock(&prange->lock);
434 		return false;
435 	}
436 	if (prange->ttm_res) {
437 		/* We still have a reference, all is well */
438 		mutex_unlock(&prange->lock);
439 		return true;
440 	}
441 	if (svm_bo_ref_unless_zero(prange->svm_bo)) {
442 		/*
443 		 * Migrate from GPU to GPU, remove range from source bo_adev
444 		 * svm_bo range list, and return false to allocate svm_bo from
445 		 * destination adev.
446 		 */
447 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
448 		if (bo_adev != adev) {
449 			mutex_unlock(&prange->lock);
450 
451 			spin_lock(&prange->svm_bo->list_lock);
452 			list_del_init(&prange->svm_bo_list);
453 			spin_unlock(&prange->svm_bo->list_lock);
454 
455 			svm_range_bo_unref(prange->svm_bo);
456 			return false;
457 		}
458 		if (READ_ONCE(prange->svm_bo->evicting)) {
459 			struct dma_fence *f;
460 			struct svm_range_bo *svm_bo;
461 			/* The BO is getting evicted,
462 			 * we need to get a new one
463 			 */
464 			mutex_unlock(&prange->lock);
465 			svm_bo = prange->svm_bo;
466 			f = dma_fence_get(&svm_bo->eviction_fence->base);
467 			svm_range_bo_unref(prange->svm_bo);
468 			/* wait for the fence to avoid long spin-loop
469 			 * at list_empty_careful
470 			 */
471 			dma_fence_wait(f, false);
472 			dma_fence_put(f);
473 		} else {
474 			/* The BO was still around and we got
475 			 * a new reference to it
476 			 */
477 			mutex_unlock(&prange->lock);
478 			pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
479 				 prange->svms, prange->start, prange->last);
480 
481 			prange->ttm_res = prange->svm_bo->bo->tbo.resource;
482 			return true;
483 		}
484 
485 	} else {
486 		mutex_unlock(&prange->lock);
487 	}
488 
489 	/* We need a new svm_bo. Spin-loop to wait for concurrent
490 	 * svm_range_bo_release to finish removing this range from
491 	 * its range list. After this, it is safe to reuse the
492 	 * svm_bo pointer and svm_bo_list head.
493 	 */
494 	while (!list_empty_careful(&prange->svm_bo_list))
495 		;
496 
497 	return false;
498 }
499 
500 static struct svm_range_bo *svm_range_bo_new(void)
501 {
502 	struct svm_range_bo *svm_bo;
503 
504 	svm_bo = kzalloc(sizeof(*svm_bo), GFP_KERNEL);
505 	if (!svm_bo)
506 		return NULL;
507 
508 	kref_init(&svm_bo->kref);
509 	INIT_LIST_HEAD(&svm_bo->range_list);
510 	spin_lock_init(&svm_bo->list_lock);
511 
512 	return svm_bo;
513 }
514 
515 int
516 svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
517 			bool clear)
518 {
519 	struct amdgpu_bo_param bp;
520 	struct svm_range_bo *svm_bo;
521 	struct amdgpu_bo_user *ubo;
522 	struct amdgpu_bo *bo;
523 	struct kfd_process *p;
524 	struct mm_struct *mm;
525 	int r;
526 
527 	p = container_of(prange->svms, struct kfd_process, svms);
528 	pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
529 		 prange->start, prange->last);
530 
531 	if (svm_range_validate_svm_bo(adev, prange))
532 		return 0;
533 
534 	svm_bo = svm_range_bo_new();
535 	if (!svm_bo) {
536 		pr_debug("failed to alloc svm bo\n");
537 		return -ENOMEM;
538 	}
539 	mm = get_task_mm(p->lead_thread);
540 	if (!mm) {
541 		pr_debug("failed to get mm\n");
542 		kfree(svm_bo);
543 		return -ESRCH;
544 	}
545 	svm_bo->eviction_fence =
546 		amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
547 					   mm,
548 					   svm_bo);
549 	mmput(mm);
550 	INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
551 	svm_bo->evicting = 0;
552 	memset(&bp, 0, sizeof(bp));
553 	bp.size = prange->npages * PAGE_SIZE;
554 	bp.byte_align = PAGE_SIZE;
555 	bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
556 	bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
557 	bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
558 	bp.flags |= AMDGPU_GEM_CREATE_DISCARDABLE;
559 	bp.type = ttm_bo_type_device;
560 	bp.resv = NULL;
561 
562 	r = amdgpu_bo_create_user(adev, &bp, &ubo);
563 	if (r) {
564 		pr_debug("failed %d to create bo\n", r);
565 		goto create_bo_failed;
566 	}
567 	bo = &ubo->bo;
568 	r = amdgpu_bo_reserve(bo, true);
569 	if (r) {
570 		pr_debug("failed %d to reserve bo\n", r);
571 		goto reserve_bo_failed;
572 	}
573 
574 	r = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
575 	if (r) {
576 		pr_debug("failed %d to reserve bo\n", r);
577 		amdgpu_bo_unreserve(bo);
578 		goto reserve_bo_failed;
579 	}
580 	amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
581 
582 	amdgpu_bo_unreserve(bo);
583 
584 	svm_bo->bo = bo;
585 	prange->svm_bo = svm_bo;
586 	prange->ttm_res = bo->tbo.resource;
587 	prange->offset = 0;
588 
589 	spin_lock(&svm_bo->list_lock);
590 	list_add(&prange->svm_bo_list, &svm_bo->range_list);
591 	spin_unlock(&svm_bo->list_lock);
592 
593 	return 0;
594 
595 reserve_bo_failed:
596 	amdgpu_bo_unref(&bo);
597 create_bo_failed:
598 	dma_fence_put(&svm_bo->eviction_fence->base);
599 	kfree(svm_bo);
600 	prange->ttm_res = NULL;
601 
602 	return r;
603 }
604 
605 void svm_range_vram_node_free(struct svm_range *prange)
606 {
607 	svm_range_bo_unref(prange->svm_bo);
608 	prange->ttm_res = NULL;
609 }
610 
611 struct amdgpu_device *
612 svm_range_get_adev_by_id(struct svm_range *prange, uint32_t gpu_id)
613 {
614 	struct kfd_process_device *pdd;
615 	struct kfd_process *p;
616 	int32_t gpu_idx;
617 
618 	p = container_of(prange->svms, struct kfd_process, svms);
619 
620 	gpu_idx = kfd_process_gpuidx_from_gpuid(p, gpu_id);
621 	if (gpu_idx < 0) {
622 		pr_debug("failed to get device by id 0x%x\n", gpu_id);
623 		return NULL;
624 	}
625 	pdd = kfd_process_device_from_gpuidx(p, gpu_idx);
626 	if (!pdd) {
627 		pr_debug("failed to get device by idx 0x%x\n", gpu_idx);
628 		return NULL;
629 	}
630 
631 	return pdd->dev->adev;
632 }
633 
634 struct kfd_process_device *
635 svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev)
636 {
637 	struct kfd_process *p;
638 	int32_t gpu_idx, gpuid;
639 	int r;
640 
641 	p = container_of(prange->svms, struct kfd_process, svms);
642 
643 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpu_idx);
644 	if (r) {
645 		pr_debug("failed to get device id by adev %p\n", adev);
646 		return NULL;
647 	}
648 
649 	return kfd_process_device_from_gpuidx(p, gpu_idx);
650 }
651 
652 static int svm_range_bo_validate(void *param, struct amdgpu_bo *bo)
653 {
654 	struct ttm_operation_ctx ctx = { false, false };
655 
656 	amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_VRAM);
657 
658 	return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
659 }
660 
661 static int
662 svm_range_check_attr(struct kfd_process *p,
663 		     uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
664 {
665 	uint32_t i;
666 
667 	for (i = 0; i < nattr; i++) {
668 		uint32_t val = attrs[i].value;
669 		int gpuidx = MAX_GPU_INSTANCE;
670 
671 		switch (attrs[i].type) {
672 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
673 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM &&
674 			    val != KFD_IOCTL_SVM_LOCATION_UNDEFINED)
675 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
676 			break;
677 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
678 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM)
679 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
680 			break;
681 		case KFD_IOCTL_SVM_ATTR_ACCESS:
682 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
683 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
684 			gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
685 			break;
686 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
687 			break;
688 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
689 			break;
690 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
691 			break;
692 		default:
693 			pr_debug("unknown attr type 0x%x\n", attrs[i].type);
694 			return -EINVAL;
695 		}
696 
697 		if (gpuidx < 0) {
698 			pr_debug("no GPU 0x%x found\n", val);
699 			return -EINVAL;
700 		} else if (gpuidx < MAX_GPU_INSTANCE &&
701 			   !test_bit(gpuidx, p->svms.bitmap_supported)) {
702 			pr_debug("GPU 0x%x not supported\n", val);
703 			return -EINVAL;
704 		}
705 	}
706 
707 	return 0;
708 }
709 
710 static void
711 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
712 		      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
713 		      bool *update_mapping)
714 {
715 	uint32_t i;
716 	int gpuidx;
717 
718 	for (i = 0; i < nattr; i++) {
719 		switch (attrs[i].type) {
720 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
721 			prange->preferred_loc = attrs[i].value;
722 			break;
723 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
724 			prange->prefetch_loc = attrs[i].value;
725 			break;
726 		case KFD_IOCTL_SVM_ATTR_ACCESS:
727 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
728 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
729 			*update_mapping = true;
730 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
731 							       attrs[i].value);
732 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
733 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
734 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
735 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
736 				bitmap_set(prange->bitmap_access, gpuidx, 1);
737 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
738 			} else {
739 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
740 				bitmap_set(prange->bitmap_aip, gpuidx, 1);
741 			}
742 			break;
743 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
744 			*update_mapping = true;
745 			prange->flags |= attrs[i].value;
746 			break;
747 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
748 			*update_mapping = true;
749 			prange->flags &= ~attrs[i].value;
750 			break;
751 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
752 			prange->granularity = attrs[i].value;
753 			break;
754 		default:
755 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
756 		}
757 	}
758 }
759 
760 static bool
761 svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
762 			uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
763 {
764 	uint32_t i;
765 	int gpuidx;
766 
767 	for (i = 0; i < nattr; i++) {
768 		switch (attrs[i].type) {
769 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
770 			if (prange->preferred_loc != attrs[i].value)
771 				return false;
772 			break;
773 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
774 			/* Prefetch should always trigger a migration even
775 			 * if the value of the attribute didn't change.
776 			 */
777 			return false;
778 		case KFD_IOCTL_SVM_ATTR_ACCESS:
779 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
780 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
781 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
782 							       attrs[i].value);
783 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
784 				if (test_bit(gpuidx, prange->bitmap_access) ||
785 				    test_bit(gpuidx, prange->bitmap_aip))
786 					return false;
787 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
788 				if (!test_bit(gpuidx, prange->bitmap_access))
789 					return false;
790 			} else {
791 				if (!test_bit(gpuidx, prange->bitmap_aip))
792 					return false;
793 			}
794 			break;
795 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
796 			if ((prange->flags & attrs[i].value) != attrs[i].value)
797 				return false;
798 			break;
799 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
800 			if ((prange->flags & attrs[i].value) != 0)
801 				return false;
802 			break;
803 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
804 			if (prange->granularity != attrs[i].value)
805 				return false;
806 			break;
807 		default:
808 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
809 		}
810 	}
811 
812 	return true;
813 }
814 
815 /**
816  * svm_range_debug_dump - print all range information from svms
817  * @svms: svm range list header
818  *
819  * debug output svm range start, end, prefetch location from svms
820  * interval tree and link list
821  *
822  * Context: The caller must hold svms->lock
823  */
824 static void svm_range_debug_dump(struct svm_range_list *svms)
825 {
826 	struct interval_tree_node *node;
827 	struct svm_range *prange;
828 
829 	pr_debug("dump svms 0x%p list\n", svms);
830 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
831 
832 	list_for_each_entry(prange, &svms->list, list) {
833 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
834 			 prange, prange->start, prange->npages,
835 			 prange->start + prange->npages - 1,
836 			 prange->actual_loc);
837 	}
838 
839 	pr_debug("dump svms 0x%p interval tree\n", svms);
840 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
841 	node = interval_tree_iter_first(&svms->objects, 0, ~0ULL);
842 	while (node) {
843 		prange = container_of(node, struct svm_range, it_node);
844 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
845 			 prange, prange->start, prange->npages,
846 			 prange->start + prange->npages - 1,
847 			 prange->actual_loc);
848 		node = interval_tree_iter_next(node, 0, ~0ULL);
849 	}
850 }
851 
852 static int
853 svm_range_split_array(void *ppnew, void *ppold, size_t size,
854 		      uint64_t old_start, uint64_t old_n,
855 		      uint64_t new_start, uint64_t new_n)
856 {
857 	unsigned char *new, *old, *pold;
858 	uint64_t d;
859 
860 	if (!ppold)
861 		return 0;
862 	pold = *(unsigned char **)ppold;
863 	if (!pold)
864 		return 0;
865 
866 	new = kvmalloc_array(new_n, size, GFP_KERNEL);
867 	if (!new)
868 		return -ENOMEM;
869 
870 	d = (new_start - old_start) * size;
871 	memcpy(new, pold + d, new_n * size);
872 
873 	old = kvmalloc_array(old_n, size, GFP_KERNEL);
874 	if (!old) {
875 		kvfree(new);
876 		return -ENOMEM;
877 	}
878 
879 	d = (new_start == old_start) ? new_n * size : 0;
880 	memcpy(old, pold + d, old_n * size);
881 
882 	kvfree(pold);
883 	*(void **)ppold = old;
884 	*(void **)ppnew = new;
885 
886 	return 0;
887 }
888 
889 static int
890 svm_range_split_pages(struct svm_range *new, struct svm_range *old,
891 		      uint64_t start, uint64_t last)
892 {
893 	uint64_t npages = last - start + 1;
894 	int i, r;
895 
896 	for (i = 0; i < MAX_GPU_INSTANCE; i++) {
897 		r = svm_range_split_array(&new->dma_addr[i], &old->dma_addr[i],
898 					  sizeof(*old->dma_addr[i]), old->start,
899 					  npages, new->start, new->npages);
900 		if (r)
901 			return r;
902 	}
903 
904 	return 0;
905 }
906 
907 static int
908 svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
909 		      uint64_t start, uint64_t last)
910 {
911 	uint64_t npages = last - start + 1;
912 
913 	pr_debug("svms 0x%p new prange 0x%p start 0x%lx [0x%llx 0x%llx]\n",
914 		 new->svms, new, new->start, start, last);
915 
916 	if (new->start == old->start) {
917 		new->offset = old->offset;
918 		old->offset += new->npages;
919 	} else {
920 		new->offset = old->offset + npages;
921 	}
922 
923 	new->svm_bo = svm_range_bo_ref(old->svm_bo);
924 	new->ttm_res = old->ttm_res;
925 
926 	spin_lock(&new->svm_bo->list_lock);
927 	list_add(&new->svm_bo_list, &new->svm_bo->range_list);
928 	spin_unlock(&new->svm_bo->list_lock);
929 
930 	return 0;
931 }
932 
933 /**
934  * svm_range_split_adjust - split range and adjust
935  *
936  * @new: new range
937  * @old: the old range
938  * @start: the old range adjust to start address in pages
939  * @last: the old range adjust to last address in pages
940  *
941  * Copy system memory dma_addr or vram ttm_res in old range to new
942  * range from new_start up to size new->npages, the remaining old range is from
943  * start to last
944  *
945  * Return:
946  * 0 - OK, -ENOMEM - out of memory
947  */
948 static int
949 svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
950 		      uint64_t start, uint64_t last)
951 {
952 	int r;
953 
954 	pr_debug("svms 0x%p new 0x%lx old [0x%lx 0x%lx] => [0x%llx 0x%llx]\n",
955 		 new->svms, new->start, old->start, old->last, start, last);
956 
957 	if (new->start < old->start ||
958 	    new->last > old->last) {
959 		WARN_ONCE(1, "invalid new range start or last\n");
960 		return -EINVAL;
961 	}
962 
963 	r = svm_range_split_pages(new, old, start, last);
964 	if (r)
965 		return r;
966 
967 	if (old->actual_loc && old->ttm_res) {
968 		r = svm_range_split_nodes(new, old, start, last);
969 		if (r)
970 			return r;
971 	}
972 
973 	old->npages = last - start + 1;
974 	old->start = start;
975 	old->last = last;
976 	new->flags = old->flags;
977 	new->preferred_loc = old->preferred_loc;
978 	new->prefetch_loc = old->prefetch_loc;
979 	new->actual_loc = old->actual_loc;
980 	new->granularity = old->granularity;
981 	new->mapped_to_gpu = old->mapped_to_gpu;
982 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
983 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
984 
985 	return 0;
986 }
987 
988 /**
989  * svm_range_split - split a range in 2 ranges
990  *
991  * @prange: the svm range to split
992  * @start: the remaining range start address in pages
993  * @last: the remaining range last address in pages
994  * @new: the result new range generated
995  *
996  * Two cases only:
997  * case 1: if start == prange->start
998  *         prange ==> prange[start, last]
999  *         new range [last + 1, prange->last]
1000  *
1001  * case 2: if last == prange->last
1002  *         prange ==> prange[start, last]
1003  *         new range [prange->start, start - 1]
1004  *
1005  * Return:
1006  * 0 - OK, -ENOMEM - out of memory, -EINVAL - invalid start, last
1007  */
1008 static int
1009 svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
1010 		struct svm_range **new)
1011 {
1012 	uint64_t old_start = prange->start;
1013 	uint64_t old_last = prange->last;
1014 	struct svm_range_list *svms;
1015 	int r = 0;
1016 
1017 	pr_debug("svms 0x%p [0x%llx 0x%llx] to [0x%llx 0x%llx]\n", prange->svms,
1018 		 old_start, old_last, start, last);
1019 
1020 	if (old_start != start && old_last != last)
1021 		return -EINVAL;
1022 	if (start < old_start || last > old_last)
1023 		return -EINVAL;
1024 
1025 	svms = prange->svms;
1026 	if (old_start == start)
1027 		*new = svm_range_new(svms, last + 1, old_last, false);
1028 	else
1029 		*new = svm_range_new(svms, old_start, start - 1, false);
1030 	if (!*new)
1031 		return -ENOMEM;
1032 
1033 	r = svm_range_split_adjust(*new, prange, start, last);
1034 	if (r) {
1035 		pr_debug("failed %d split [0x%llx 0x%llx] to [0x%llx 0x%llx]\n",
1036 			 r, old_start, old_last, start, last);
1037 		svm_range_free(*new, false);
1038 		*new = NULL;
1039 	}
1040 
1041 	return r;
1042 }
1043 
1044 static int
1045 svm_range_split_tail(struct svm_range *prange,
1046 		     uint64_t new_last, struct list_head *insert_list)
1047 {
1048 	struct svm_range *tail;
1049 	int r = svm_range_split(prange, prange->start, new_last, &tail);
1050 
1051 	if (!r)
1052 		list_add(&tail->list, insert_list);
1053 	return r;
1054 }
1055 
1056 static int
1057 svm_range_split_head(struct svm_range *prange,
1058 		     uint64_t new_start, struct list_head *insert_list)
1059 {
1060 	struct svm_range *head;
1061 	int r = svm_range_split(prange, new_start, prange->last, &head);
1062 
1063 	if (!r)
1064 		list_add(&head->list, insert_list);
1065 	return r;
1066 }
1067 
1068 static void
1069 svm_range_add_child(struct svm_range *prange, struct mm_struct *mm,
1070 		    struct svm_range *pchild, enum svm_work_list_ops op)
1071 {
1072 	pr_debug("add child 0x%p [0x%lx 0x%lx] to prange 0x%p child list %d\n",
1073 		 pchild, pchild->start, pchild->last, prange, op);
1074 
1075 	pchild->work_item.mm = mm;
1076 	pchild->work_item.op = op;
1077 	list_add_tail(&pchild->child_list, &prange->child_list);
1078 }
1079 
1080 /**
1081  * svm_range_split_by_granularity - collect ranges within granularity boundary
1082  *
1083  * @p: the process with svms list
1084  * @mm: mm structure
1085  * @addr: the vm fault address in pages, to split the prange
1086  * @parent: parent range if prange is from child list
1087  * @prange: prange to split
1088  *
1089  * Trims @prange to be a single aligned block of prange->granularity if
1090  * possible. The head and tail are added to the child_list in @parent.
1091  *
1092  * Context: caller must hold mmap_read_lock and prange->lock
1093  *
1094  * Return:
1095  * 0 - OK, otherwise error code
1096  */
1097 int
1098 svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
1099 			       unsigned long addr, struct svm_range *parent,
1100 			       struct svm_range *prange)
1101 {
1102 	struct svm_range *head, *tail;
1103 	unsigned long start, last, size;
1104 	int r;
1105 
1106 	/* Align splited range start and size to granularity size, then a single
1107 	 * PTE will be used for whole range, this reduces the number of PTE
1108 	 * updated and the L1 TLB space used for translation.
1109 	 */
1110 	size = 1UL << prange->granularity;
1111 	start = ALIGN_DOWN(addr, size);
1112 	last = ALIGN(addr + 1, size) - 1;
1113 
1114 	pr_debug("svms 0x%p split [0x%lx 0x%lx] to [0x%lx 0x%lx] size 0x%lx\n",
1115 		 prange->svms, prange->start, prange->last, start, last, size);
1116 
1117 	if (start > prange->start) {
1118 		r = svm_range_split(prange, start, prange->last, &head);
1119 		if (r)
1120 			return r;
1121 		svm_range_add_child(parent, mm, head, SVM_OP_ADD_RANGE);
1122 	}
1123 
1124 	if (last < prange->last) {
1125 		r = svm_range_split(prange, prange->start, last, &tail);
1126 		if (r)
1127 			return r;
1128 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
1129 	}
1130 
1131 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
1132 	if (p->xnack_enabled && prange->work_item.op == SVM_OP_ADD_RANGE) {
1133 		prange->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
1134 		pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
1135 			 prange, prange->start, prange->last,
1136 			 SVM_OP_ADD_RANGE_AND_MAP);
1137 	}
1138 	return 0;
1139 }
1140 
1141 static uint64_t
1142 svm_range_get_pte_flags(struct amdgpu_device *adev, struct svm_range *prange,
1143 			int domain)
1144 {
1145 	struct amdgpu_device *bo_adev;
1146 	uint32_t flags = prange->flags;
1147 	uint32_t mapping_flags = 0;
1148 	uint64_t pte_flags;
1149 	bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
1150 	bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
1151 
1152 	if (domain == SVM_RANGE_VRAM_DOMAIN)
1153 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1154 
1155 	switch (KFD_GC_VERSION(adev->kfd.dev)) {
1156 	case IP_VERSION(9, 4, 1):
1157 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1158 			if (bo_adev == adev) {
1159 				mapping_flags |= coherent ?
1160 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1161 			} else {
1162 				mapping_flags |= coherent ?
1163 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1164 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1165 					snoop = true;
1166 			}
1167 		} else {
1168 			mapping_flags |= coherent ?
1169 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1170 		}
1171 		break;
1172 	case IP_VERSION(9, 4, 2):
1173 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1174 			if (bo_adev == adev) {
1175 				mapping_flags |= coherent ?
1176 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1177 				if (adev->gmc.xgmi.connected_to_cpu)
1178 					snoop = true;
1179 			} else {
1180 				mapping_flags |= coherent ?
1181 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1182 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1183 					snoop = true;
1184 			}
1185 		} else {
1186 			mapping_flags |= coherent ?
1187 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1188 		}
1189 		break;
1190 	default:
1191 		mapping_flags |= coherent ?
1192 			AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1193 	}
1194 
1195 	mapping_flags |= AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE;
1196 
1197 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_RO)
1198 		mapping_flags &= ~AMDGPU_VM_PAGE_WRITEABLE;
1199 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_EXEC)
1200 		mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;
1201 
1202 	pte_flags = AMDGPU_PTE_VALID;
1203 	pte_flags |= (domain == SVM_RANGE_VRAM_DOMAIN) ? 0 : AMDGPU_PTE_SYSTEM;
1204 	pte_flags |= snoop ? AMDGPU_PTE_SNOOPED : 0;
1205 
1206 	pte_flags |= amdgpu_gem_va_map_flags(adev, mapping_flags);
1207 	return pte_flags;
1208 }
1209 
1210 static int
1211 svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
1212 			 uint64_t start, uint64_t last,
1213 			 struct dma_fence **fence)
1214 {
1215 	uint64_t init_pte_value = 0;
1216 
1217 	pr_debug("[0x%llx 0x%llx]\n", start, last);
1218 
1219 	return amdgpu_vm_update_range(adev, vm, false, true, true, NULL, start,
1220 				      last, init_pte_value, 0, 0, NULL, NULL,
1221 				      fence);
1222 }
1223 
1224 static int
1225 svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
1226 			  unsigned long last, uint32_t trigger)
1227 {
1228 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1229 	struct kfd_process_device *pdd;
1230 	struct dma_fence *fence = NULL;
1231 	struct kfd_process *p;
1232 	uint32_t gpuidx;
1233 	int r = 0;
1234 
1235 	if (!prange->mapped_to_gpu) {
1236 		pr_debug("prange 0x%p [0x%lx 0x%lx] not mapped to GPU\n",
1237 			 prange, prange->start, prange->last);
1238 		return 0;
1239 	}
1240 
1241 	if (prange->start == start && prange->last == last) {
1242 		pr_debug("unmap svms 0x%p prange 0x%p\n", prange->svms, prange);
1243 		prange->mapped_to_gpu = false;
1244 	}
1245 
1246 	bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
1247 		  MAX_GPU_INSTANCE);
1248 	p = container_of(prange->svms, struct kfd_process, svms);
1249 
1250 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1251 		pr_debug("unmap from gpu idx 0x%x\n", gpuidx);
1252 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1253 		if (!pdd) {
1254 			pr_debug("failed to find device idx %d\n", gpuidx);
1255 			return -EINVAL;
1256 		}
1257 
1258 		kfd_smi_event_unmap_from_gpu(pdd->dev, p->lead_thread->pid,
1259 					     start, last, trigger);
1260 
1261 		r = svm_range_unmap_from_gpu(pdd->dev->adev,
1262 					     drm_priv_to_vm(pdd->drm_priv),
1263 					     start, last, &fence);
1264 		if (r)
1265 			break;
1266 
1267 		if (fence) {
1268 			r = dma_fence_wait(fence, false);
1269 			dma_fence_put(fence);
1270 			fence = NULL;
1271 			if (r)
1272 				break;
1273 		}
1274 		kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
1275 	}
1276 
1277 	return r;
1278 }
1279 
1280 static int
1281 svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
1282 		     unsigned long offset, unsigned long npages, bool readonly,
1283 		     dma_addr_t *dma_addr, struct amdgpu_device *bo_adev,
1284 		     struct dma_fence **fence, bool flush_tlb)
1285 {
1286 	struct amdgpu_device *adev = pdd->dev->adev;
1287 	struct amdgpu_vm *vm = drm_priv_to_vm(pdd->drm_priv);
1288 	uint64_t pte_flags;
1289 	unsigned long last_start;
1290 	int last_domain;
1291 	int r = 0;
1292 	int64_t i, j;
1293 
1294 	last_start = prange->start + offset;
1295 
1296 	pr_debug("svms 0x%p [0x%lx 0x%lx] readonly %d\n", prange->svms,
1297 		 last_start, last_start + npages - 1, readonly);
1298 
1299 	for (i = offset; i < offset + npages; i++) {
1300 		last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
1301 		dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
1302 
1303 		/* Collect all pages in the same address range and memory domain
1304 		 * that can be mapped with a single call to update mapping.
1305 		 */
1306 		if (i < offset + npages - 1 &&
1307 		    last_domain == (dma_addr[i + 1] & SVM_RANGE_VRAM_DOMAIN))
1308 			continue;
1309 
1310 		pr_debug("Mapping range [0x%lx 0x%llx] on domain: %s\n",
1311 			 last_start, prange->start + i, last_domain ? "GPU" : "CPU");
1312 
1313 		pte_flags = svm_range_get_pte_flags(adev, prange, last_domain);
1314 		if (readonly)
1315 			pte_flags &= ~AMDGPU_PTE_WRITEABLE;
1316 
1317 		pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n",
1318 			 prange->svms, last_start, prange->start + i,
1319 			 (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
1320 			 pte_flags);
1321 
1322 		r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, NULL,
1323 					   last_start, prange->start + i,
1324 					   pte_flags,
1325 					   (last_start - prange->start) << PAGE_SHIFT,
1326 					   bo_adev ? bo_adev->vm_manager.vram_base_offset : 0,
1327 					   NULL, dma_addr, &vm->last_update);
1328 
1329 		for (j = last_start - prange->start; j <= i; j++)
1330 			dma_addr[j] |= last_domain;
1331 
1332 		if (r) {
1333 			pr_debug("failed %d to map to gpu 0x%lx\n", r, prange->start);
1334 			goto out;
1335 		}
1336 		last_start = prange->start + i + 1;
1337 	}
1338 
1339 	r = amdgpu_vm_update_pdes(adev, vm, false);
1340 	if (r) {
1341 		pr_debug("failed %d to update directories 0x%lx\n", r,
1342 			 prange->start);
1343 		goto out;
1344 	}
1345 
1346 	if (fence)
1347 		*fence = dma_fence_get(vm->last_update);
1348 
1349 out:
1350 	return r;
1351 }
1352 
1353 static int
1354 svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
1355 		      unsigned long npages, bool readonly,
1356 		      unsigned long *bitmap, bool wait, bool flush_tlb)
1357 {
1358 	struct kfd_process_device *pdd;
1359 	struct amdgpu_device *bo_adev;
1360 	struct kfd_process *p;
1361 	struct dma_fence *fence = NULL;
1362 	uint32_t gpuidx;
1363 	int r = 0;
1364 
1365 	if (prange->svm_bo && prange->ttm_res)
1366 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1367 	else
1368 		bo_adev = NULL;
1369 
1370 	p = container_of(prange->svms, struct kfd_process, svms);
1371 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1372 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
1373 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1374 		if (!pdd) {
1375 			pr_debug("failed to find device idx %d\n", gpuidx);
1376 			return -EINVAL;
1377 		}
1378 
1379 		pdd = kfd_bind_process_to_device(pdd->dev, p);
1380 		if (IS_ERR(pdd))
1381 			return -EINVAL;
1382 
1383 		if (bo_adev && pdd->dev->adev != bo_adev &&
1384 		    !amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
1385 			pr_debug("cannot map to device idx %d\n", gpuidx);
1386 			continue;
1387 		}
1388 
1389 		r = svm_range_map_to_gpu(pdd, prange, offset, npages, readonly,
1390 					 prange->dma_addr[gpuidx],
1391 					 bo_adev, wait ? &fence : NULL,
1392 					 flush_tlb);
1393 		if (r)
1394 			break;
1395 
1396 		if (fence) {
1397 			r = dma_fence_wait(fence, false);
1398 			dma_fence_put(fence);
1399 			fence = NULL;
1400 			if (r) {
1401 				pr_debug("failed %d to dma fence wait\n", r);
1402 				break;
1403 			}
1404 		}
1405 
1406 		kfd_flush_tlb(pdd, TLB_FLUSH_LEGACY);
1407 	}
1408 
1409 	return r;
1410 }
1411 
1412 struct svm_validate_context {
1413 	struct kfd_process *process;
1414 	struct svm_range *prange;
1415 	bool intr;
1416 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1417 	struct ttm_validate_buffer tv[MAX_GPU_INSTANCE];
1418 	struct list_head validate_list;
1419 	struct ww_acquire_ctx ticket;
1420 };
1421 
1422 static int svm_range_reserve_bos(struct svm_validate_context *ctx)
1423 {
1424 	struct kfd_process_device *pdd;
1425 	struct amdgpu_vm *vm;
1426 	uint32_t gpuidx;
1427 	int r;
1428 
1429 	INIT_LIST_HEAD(&ctx->validate_list);
1430 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1431 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1432 		if (!pdd) {
1433 			pr_debug("failed to find device idx %d\n", gpuidx);
1434 			return -EINVAL;
1435 		}
1436 		vm = drm_priv_to_vm(pdd->drm_priv);
1437 
1438 		ctx->tv[gpuidx].bo = &vm->root.bo->tbo;
1439 		ctx->tv[gpuidx].num_shared = 4;
1440 		list_add(&ctx->tv[gpuidx].head, &ctx->validate_list);
1441 	}
1442 
1443 	r = ttm_eu_reserve_buffers(&ctx->ticket, &ctx->validate_list,
1444 				   ctx->intr, NULL);
1445 	if (r) {
1446 		pr_debug("failed %d to reserve bo\n", r);
1447 		return r;
1448 	}
1449 
1450 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1451 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1452 		if (!pdd) {
1453 			pr_debug("failed to find device idx %d\n", gpuidx);
1454 			r = -EINVAL;
1455 			goto unreserve_out;
1456 		}
1457 
1458 		r = amdgpu_vm_validate_pt_bos(pdd->dev->adev,
1459 					      drm_priv_to_vm(pdd->drm_priv),
1460 					      svm_range_bo_validate, NULL);
1461 		if (r) {
1462 			pr_debug("failed %d validate pt bos\n", r);
1463 			goto unreserve_out;
1464 		}
1465 	}
1466 
1467 	return 0;
1468 
1469 unreserve_out:
1470 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1471 	return r;
1472 }
1473 
1474 static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
1475 {
1476 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1477 }
1478 
1479 static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
1480 {
1481 	struct kfd_process_device *pdd;
1482 
1483 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1484 
1485 	return SVM_ADEV_PGMAP_OWNER(pdd->dev->adev);
1486 }
1487 
1488 /*
1489  * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
1490  *
1491  * To prevent concurrent destruction or change of range attributes, the
1492  * svm_read_lock must be held. The caller must not hold the svm_write_lock
1493  * because that would block concurrent evictions and lead to deadlocks. To
1494  * serialize concurrent migrations or validations of the same range, the
1495  * prange->migrate_mutex must be held.
1496  *
1497  * For VRAM ranges, the SVM BO must be allocated and valid (protected by its
1498  * eviction fence.
1499  *
1500  * The following sequence ensures race-free validation and GPU mapping:
1501  *
1502  * 1. Reserve page table (and SVM BO if range is in VRAM)
1503  * 2. hmm_range_fault to get page addresses (if system memory)
1504  * 3. DMA-map pages (if system memory)
1505  * 4-a. Take notifier lock
1506  * 4-b. Check that pages still valid (mmu_interval_read_retry)
1507  * 4-c. Check that the range was not split or otherwise invalidated
1508  * 4-d. Update GPU page table
1509  * 4.e. Release notifier lock
1510  * 5. Release page table (and SVM BO) reservation
1511  */
1512 static int svm_range_validate_and_map(struct mm_struct *mm,
1513 				      struct svm_range *prange, int32_t gpuidx,
1514 				      bool intr, bool wait, bool flush_tlb)
1515 {
1516 	struct svm_validate_context ctx;
1517 	unsigned long start, end, addr;
1518 	struct kfd_process *p;
1519 	void *owner;
1520 	int32_t idx;
1521 	int r = 0;
1522 
1523 	ctx.process = container_of(prange->svms, struct kfd_process, svms);
1524 	ctx.prange = prange;
1525 	ctx.intr = intr;
1526 
1527 	if (gpuidx < MAX_GPU_INSTANCE) {
1528 		bitmap_zero(ctx.bitmap, MAX_GPU_INSTANCE);
1529 		bitmap_set(ctx.bitmap, gpuidx, 1);
1530 	} else if (ctx.process->xnack_enabled) {
1531 		bitmap_copy(ctx.bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
1532 
1533 		/* If prefetch range to GPU, or GPU retry fault migrate range to
1534 		 * GPU, which has ACCESS attribute to the range, create mapping
1535 		 * on that GPU.
1536 		 */
1537 		if (prange->actual_loc) {
1538 			gpuidx = kfd_process_gpuidx_from_gpuid(ctx.process,
1539 							prange->actual_loc);
1540 			if (gpuidx < 0) {
1541 				WARN_ONCE(1, "failed get device by id 0x%x\n",
1542 					 prange->actual_loc);
1543 				return -EINVAL;
1544 			}
1545 			if (test_bit(gpuidx, prange->bitmap_access))
1546 				bitmap_set(ctx.bitmap, gpuidx, 1);
1547 		}
1548 	} else {
1549 		bitmap_or(ctx.bitmap, prange->bitmap_access,
1550 			  prange->bitmap_aip, MAX_GPU_INSTANCE);
1551 	}
1552 
1553 	if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE)) {
1554 		if (!prange->mapped_to_gpu)
1555 			return 0;
1556 
1557 		bitmap_copy(ctx.bitmap, prange->bitmap_access, MAX_GPU_INSTANCE);
1558 	}
1559 
1560 	if (prange->actual_loc && !prange->ttm_res) {
1561 		/* This should never happen. actual_loc gets set by
1562 		 * svm_migrate_ram_to_vram after allocating a BO.
1563 		 */
1564 		WARN_ONCE(1, "VRAM BO missing during validation\n");
1565 		return -EINVAL;
1566 	}
1567 
1568 	svm_range_reserve_bos(&ctx);
1569 
1570 	p = container_of(prange->svms, struct kfd_process, svms);
1571 	owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
1572 						MAX_GPU_INSTANCE));
1573 	for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
1574 		if (kfd_svm_page_owner(p, idx) != owner) {
1575 			owner = NULL;
1576 			break;
1577 		}
1578 	}
1579 
1580 	start = prange->start << PAGE_SHIFT;
1581 	end = (prange->last + 1) << PAGE_SHIFT;
1582 	for (addr = start; addr < end && !r; ) {
1583 		struct hmm_range *hmm_range;
1584 		struct vm_area_struct *vma;
1585 		unsigned long next;
1586 		unsigned long offset;
1587 		unsigned long npages;
1588 		bool readonly;
1589 
1590 		vma = vma_lookup(mm, addr);
1591 		if (!vma) {
1592 			r = -EFAULT;
1593 			goto unreserve_out;
1594 		}
1595 		readonly = !(vma->vm_flags & VM_WRITE);
1596 
1597 		next = min(vma->vm_end, end);
1598 		npages = (next - addr) >> PAGE_SHIFT;
1599 		WRITE_ONCE(p->svms.faulting_task, current);
1600 		r = amdgpu_hmm_range_get_pages(&prange->notifier, addr, npages,
1601 					       readonly, owner, NULL,
1602 					       &hmm_range);
1603 		WRITE_ONCE(p->svms.faulting_task, NULL);
1604 		if (r) {
1605 			pr_debug("failed %d to get svm range pages\n", r);
1606 			goto unreserve_out;
1607 		}
1608 
1609 		offset = (addr - start) >> PAGE_SHIFT;
1610 		r = svm_range_dma_map(prange, ctx.bitmap, offset, npages,
1611 				      hmm_range->hmm_pfns);
1612 		if (r) {
1613 			pr_debug("failed %d to dma map range\n", r);
1614 			goto unreserve_out;
1615 		}
1616 
1617 		svm_range_lock(prange);
1618 		if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
1619 			pr_debug("hmm update the range, need validate again\n");
1620 			r = -EAGAIN;
1621 			goto unlock_out;
1622 		}
1623 		if (!list_empty(&prange->child_list)) {
1624 			pr_debug("range split by unmap in parallel, validate again\n");
1625 			r = -EAGAIN;
1626 			goto unlock_out;
1627 		}
1628 
1629 		r = svm_range_map_to_gpus(prange, offset, npages, readonly,
1630 					  ctx.bitmap, wait, flush_tlb);
1631 
1632 unlock_out:
1633 		svm_range_unlock(prange);
1634 
1635 		addr = next;
1636 	}
1637 
1638 	if (addr == end) {
1639 		prange->validated_once = true;
1640 		prange->mapped_to_gpu = true;
1641 	}
1642 
1643 unreserve_out:
1644 	svm_range_unreserve_bos(&ctx);
1645 
1646 	if (!r)
1647 		prange->validate_timestamp = ktime_get_boottime();
1648 
1649 	return r;
1650 }
1651 
1652 /**
1653  * svm_range_list_lock_and_flush_work - flush pending deferred work
1654  *
1655  * @svms: the svm range list
1656  * @mm: the mm structure
1657  *
1658  * Context: Returns with mmap write lock held, pending deferred work flushed
1659  *
1660  */
1661 void
1662 svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
1663 				   struct mm_struct *mm)
1664 {
1665 retry_flush_work:
1666 	flush_work(&svms->deferred_list_work);
1667 	mmap_write_lock(mm);
1668 
1669 	if (list_empty(&svms->deferred_range_list))
1670 		return;
1671 	mmap_write_unlock(mm);
1672 	pr_debug("retry flush\n");
1673 	goto retry_flush_work;
1674 }
1675 
1676 static void svm_range_restore_work(struct work_struct *work)
1677 {
1678 	struct delayed_work *dwork = to_delayed_work(work);
1679 	struct amdkfd_process_info *process_info;
1680 	struct svm_range_list *svms;
1681 	struct svm_range *prange;
1682 	struct kfd_process *p;
1683 	struct mm_struct *mm;
1684 	int evicted_ranges;
1685 	int invalid;
1686 	int r;
1687 
1688 	svms = container_of(dwork, struct svm_range_list, restore_work);
1689 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1690 	if (!evicted_ranges)
1691 		return;
1692 
1693 	pr_debug("restore svm ranges\n");
1694 
1695 	p = container_of(svms, struct kfd_process, svms);
1696 	process_info = p->kgd_process_info;
1697 
1698 	/* Keep mm reference when svm_range_validate_and_map ranges */
1699 	mm = get_task_mm(p->lead_thread);
1700 	if (!mm) {
1701 		pr_debug("svms 0x%p process mm gone\n", svms);
1702 		return;
1703 	}
1704 
1705 	mutex_lock(&process_info->lock);
1706 	svm_range_list_lock_and_flush_work(svms, mm);
1707 	mutex_lock(&svms->lock);
1708 
1709 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1710 
1711 	list_for_each_entry(prange, &svms->list, list) {
1712 		invalid = atomic_read(&prange->invalid);
1713 		if (!invalid)
1714 			continue;
1715 
1716 		pr_debug("restoring svms 0x%p prange 0x%p [0x%lx %lx] inv %d\n",
1717 			 prange->svms, prange, prange->start, prange->last,
1718 			 invalid);
1719 
1720 		/*
1721 		 * If range is migrating, wait for migration is done.
1722 		 */
1723 		mutex_lock(&prange->migrate_mutex);
1724 
1725 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
1726 					       false, true, false);
1727 		if (r)
1728 			pr_debug("failed %d to map 0x%lx to gpus\n", r,
1729 				 prange->start);
1730 
1731 		mutex_unlock(&prange->migrate_mutex);
1732 		if (r)
1733 			goto out_reschedule;
1734 
1735 		if (atomic_cmpxchg(&prange->invalid, invalid, 0) != invalid)
1736 			goto out_reschedule;
1737 	}
1738 
1739 	if (atomic_cmpxchg(&svms->evicted_ranges, evicted_ranges, 0) !=
1740 	    evicted_ranges)
1741 		goto out_reschedule;
1742 
1743 	evicted_ranges = 0;
1744 
1745 	r = kgd2kfd_resume_mm(mm);
1746 	if (r) {
1747 		/* No recovery from this failure. Probably the CP is
1748 		 * hanging. No point trying again.
1749 		 */
1750 		pr_debug("failed %d to resume KFD\n", r);
1751 	}
1752 
1753 	pr_debug("restore svm ranges successfully\n");
1754 
1755 out_reschedule:
1756 	mutex_unlock(&svms->lock);
1757 	mmap_write_unlock(mm);
1758 	mutex_unlock(&process_info->lock);
1759 
1760 	/* If validation failed, reschedule another attempt */
1761 	if (evicted_ranges) {
1762 		pr_debug("reschedule to restore svm range\n");
1763 		schedule_delayed_work(&svms->restore_work,
1764 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1765 
1766 		kfd_smi_event_queue_restore_rescheduled(mm);
1767 	}
1768 	mmput(mm);
1769 }
1770 
1771 /**
1772  * svm_range_evict - evict svm range
1773  * @prange: svm range structure
1774  * @mm: current process mm_struct
1775  * @start: starting process queue number
1776  * @last: last process queue number
1777  *
1778  * Stop all queues of the process to ensure GPU doesn't access the memory, then
1779  * return to let CPU evict the buffer and proceed CPU pagetable update.
1780  *
1781  * Don't need use lock to sync cpu pagetable invalidation with GPU execution.
1782  * If invalidation happens while restore work is running, restore work will
1783  * restart to ensure to get the latest CPU pages mapping to GPU, then start
1784  * the queues.
1785  */
1786 static int
1787 svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
1788 		unsigned long start, unsigned long last,
1789 		enum mmu_notifier_event event)
1790 {
1791 	struct svm_range_list *svms = prange->svms;
1792 	struct svm_range *pchild;
1793 	struct kfd_process *p;
1794 	int r = 0;
1795 
1796 	p = container_of(svms, struct kfd_process, svms);
1797 
1798 	pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
1799 		 svms, prange->start, prange->last, start, last);
1800 
1801 	if (!p->xnack_enabled ||
1802 	    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) {
1803 		int evicted_ranges;
1804 		bool mapped = prange->mapped_to_gpu;
1805 
1806 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1807 			if (!pchild->mapped_to_gpu)
1808 				continue;
1809 			mapped = true;
1810 			mutex_lock_nested(&pchild->lock, 1);
1811 			if (pchild->start <= last && pchild->last >= start) {
1812 				pr_debug("increment pchild invalid [0x%lx 0x%lx]\n",
1813 					 pchild->start, pchild->last);
1814 				atomic_inc(&pchild->invalid);
1815 			}
1816 			mutex_unlock(&pchild->lock);
1817 		}
1818 
1819 		if (!mapped)
1820 			return r;
1821 
1822 		if (prange->start <= last && prange->last >= start)
1823 			atomic_inc(&prange->invalid);
1824 
1825 		evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
1826 		if (evicted_ranges != 1)
1827 			return r;
1828 
1829 		pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
1830 			 prange->svms, prange->start, prange->last);
1831 
1832 		/* First eviction, stop the queues */
1833 		r = kgd2kfd_quiesce_mm(mm, KFD_QUEUE_EVICTION_TRIGGER_SVM);
1834 		if (r)
1835 			pr_debug("failed to quiesce KFD\n");
1836 
1837 		pr_debug("schedule to restore svm %p ranges\n", svms);
1838 		schedule_delayed_work(&svms->restore_work,
1839 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1840 	} else {
1841 		unsigned long s, l;
1842 		uint32_t trigger;
1843 
1844 		if (event == MMU_NOTIFY_MIGRATE)
1845 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY_MIGRATE;
1846 		else
1847 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY;
1848 
1849 		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
1850 			 prange->svms, start, last);
1851 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1852 			mutex_lock_nested(&pchild->lock, 1);
1853 			s = max(start, pchild->start);
1854 			l = min(last, pchild->last);
1855 			if (l >= s)
1856 				svm_range_unmap_from_gpus(pchild, s, l, trigger);
1857 			mutex_unlock(&pchild->lock);
1858 		}
1859 		s = max(start, prange->start);
1860 		l = min(last, prange->last);
1861 		if (l >= s)
1862 			svm_range_unmap_from_gpus(prange, s, l, trigger);
1863 	}
1864 
1865 	return r;
1866 }
1867 
1868 static struct svm_range *svm_range_clone(struct svm_range *old)
1869 {
1870 	struct svm_range *new;
1871 
1872 	new = svm_range_new(old->svms, old->start, old->last, false);
1873 	if (!new)
1874 		return NULL;
1875 
1876 	if (old->svm_bo) {
1877 		new->ttm_res = old->ttm_res;
1878 		new->offset = old->offset;
1879 		new->svm_bo = svm_range_bo_ref(old->svm_bo);
1880 		spin_lock(&new->svm_bo->list_lock);
1881 		list_add(&new->svm_bo_list, &new->svm_bo->range_list);
1882 		spin_unlock(&new->svm_bo->list_lock);
1883 	}
1884 	new->flags = old->flags;
1885 	new->preferred_loc = old->preferred_loc;
1886 	new->prefetch_loc = old->prefetch_loc;
1887 	new->actual_loc = old->actual_loc;
1888 	new->granularity = old->granularity;
1889 	new->mapped_to_gpu = old->mapped_to_gpu;
1890 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
1891 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
1892 
1893 	return new;
1894 }
1895 
1896 void svm_range_set_max_pages(struct amdgpu_device *adev)
1897 {
1898 	uint64_t max_pages;
1899 	uint64_t pages, _pages;
1900 
1901 	/* 1/32 VRAM size in pages */
1902 	pages = adev->gmc.real_vram_size >> 17;
1903 	pages = clamp(pages, 1ULL << 9, 1ULL << 18);
1904 	pages = rounddown_pow_of_two(pages);
1905 	do {
1906 		max_pages = READ_ONCE(max_svm_range_pages);
1907 		_pages = min_not_zero(max_pages, pages);
1908 	} while (cmpxchg(&max_svm_range_pages, max_pages, _pages) != max_pages);
1909 }
1910 
1911 static int
1912 svm_range_split_new(struct svm_range_list *svms, uint64_t start, uint64_t last,
1913 		    uint64_t max_pages, struct list_head *insert_list,
1914 		    struct list_head *update_list)
1915 {
1916 	struct svm_range *prange;
1917 	uint64_t l;
1918 
1919 	pr_debug("max_svm_range_pages 0x%llx adding [0x%llx 0x%llx]\n",
1920 		 max_pages, start, last);
1921 
1922 	while (last >= start) {
1923 		l = min(last, ALIGN_DOWN(start + max_pages, max_pages) - 1);
1924 
1925 		prange = svm_range_new(svms, start, l, true);
1926 		if (!prange)
1927 			return -ENOMEM;
1928 		list_add(&prange->list, insert_list);
1929 		list_add(&prange->update_list, update_list);
1930 
1931 		start = l + 1;
1932 	}
1933 	return 0;
1934 }
1935 
1936 /**
1937  * svm_range_add - add svm range and handle overlap
1938  * @p: the range add to this process svms
1939  * @start: page size aligned
1940  * @size: page size aligned
1941  * @nattr: number of attributes
1942  * @attrs: array of attributes
1943  * @update_list: output, the ranges need validate and update GPU mapping
1944  * @insert_list: output, the ranges need insert to svms
1945  * @remove_list: output, the ranges are replaced and need remove from svms
1946  *
1947  * Check if the virtual address range has overlap with any existing ranges,
1948  * split partly overlapping ranges and add new ranges in the gaps. All changes
1949  * should be applied to the range_list and interval tree transactionally. If
1950  * any range split or allocation fails, the entire update fails. Therefore any
1951  * existing overlapping svm_ranges are cloned and the original svm_ranges left
1952  * unchanged.
1953  *
1954  * If the transaction succeeds, the caller can update and insert clones and
1955  * new ranges, then free the originals.
1956  *
1957  * Otherwise the caller can free the clones and new ranges, while the old
1958  * svm_ranges remain unchanged.
1959  *
1960  * Context: Process context, caller must hold svms->lock
1961  *
1962  * Return:
1963  * 0 - OK, otherwise error code
1964  */
1965 static int
1966 svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
1967 	      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
1968 	      struct list_head *update_list, struct list_head *insert_list,
1969 	      struct list_head *remove_list)
1970 {
1971 	unsigned long last = start + size - 1UL;
1972 	struct svm_range_list *svms = &p->svms;
1973 	struct interval_tree_node *node;
1974 	struct svm_range *prange;
1975 	struct svm_range *tmp;
1976 	struct list_head new_list;
1977 	int r = 0;
1978 
1979 	pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
1980 
1981 	INIT_LIST_HEAD(update_list);
1982 	INIT_LIST_HEAD(insert_list);
1983 	INIT_LIST_HEAD(remove_list);
1984 	INIT_LIST_HEAD(&new_list);
1985 
1986 	node = interval_tree_iter_first(&svms->objects, start, last);
1987 	while (node) {
1988 		struct interval_tree_node *next;
1989 		unsigned long next_start;
1990 
1991 		pr_debug("found overlap node [0x%lx 0x%lx]\n", node->start,
1992 			 node->last);
1993 
1994 		prange = container_of(node, struct svm_range, it_node);
1995 		next = interval_tree_iter_next(node, start, last);
1996 		next_start = min(node->last, last) + 1;
1997 
1998 		if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
1999 			/* nothing to do */
2000 		} else if (node->start < start || node->last > last) {
2001 			/* node intersects the update range and its attributes
2002 			 * will change. Clone and split it, apply updates only
2003 			 * to the overlapping part
2004 			 */
2005 			struct svm_range *old = prange;
2006 
2007 			prange = svm_range_clone(old);
2008 			if (!prange) {
2009 				r = -ENOMEM;
2010 				goto out;
2011 			}
2012 
2013 			list_add(&old->update_list, remove_list);
2014 			list_add(&prange->list, insert_list);
2015 			list_add(&prange->update_list, update_list);
2016 
2017 			if (node->start < start) {
2018 				pr_debug("change old range start\n");
2019 				r = svm_range_split_head(prange, start,
2020 							 insert_list);
2021 				if (r)
2022 					goto out;
2023 			}
2024 			if (node->last > last) {
2025 				pr_debug("change old range last\n");
2026 				r = svm_range_split_tail(prange, last,
2027 							 insert_list);
2028 				if (r)
2029 					goto out;
2030 			}
2031 		} else {
2032 			/* The node is contained within start..last,
2033 			 * just update it
2034 			 */
2035 			list_add(&prange->update_list, update_list);
2036 		}
2037 
2038 		/* insert a new node if needed */
2039 		if (node->start > start) {
2040 			r = svm_range_split_new(svms, start, node->start - 1,
2041 						READ_ONCE(max_svm_range_pages),
2042 						&new_list, update_list);
2043 			if (r)
2044 				goto out;
2045 		}
2046 
2047 		node = next;
2048 		start = next_start;
2049 	}
2050 
2051 	/* add a final range at the end if needed */
2052 	if (start <= last)
2053 		r = svm_range_split_new(svms, start, last,
2054 					READ_ONCE(max_svm_range_pages),
2055 					&new_list, update_list);
2056 
2057 out:
2058 	if (r) {
2059 		list_for_each_entry_safe(prange, tmp, insert_list, list)
2060 			svm_range_free(prange, false);
2061 		list_for_each_entry_safe(prange, tmp, &new_list, list)
2062 			svm_range_free(prange, true);
2063 	} else {
2064 		list_splice(&new_list, insert_list);
2065 	}
2066 
2067 	return r;
2068 }
2069 
2070 static void
2071 svm_range_update_notifier_and_interval_tree(struct mm_struct *mm,
2072 					    struct svm_range *prange)
2073 {
2074 	unsigned long start;
2075 	unsigned long last;
2076 
2077 	start = prange->notifier.interval_tree.start >> PAGE_SHIFT;
2078 	last = prange->notifier.interval_tree.last >> PAGE_SHIFT;
2079 
2080 	if (prange->start == start && prange->last == last)
2081 		return;
2082 
2083 	pr_debug("up notifier 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
2084 		  prange->svms, prange, start, last, prange->start,
2085 		  prange->last);
2086 
2087 	if (start != 0 && last != 0) {
2088 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
2089 		svm_range_remove_notifier(prange);
2090 	}
2091 	prange->it_node.start = prange->start;
2092 	prange->it_node.last = prange->last;
2093 
2094 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
2095 	svm_range_add_notifier_locked(mm, prange);
2096 }
2097 
2098 static void
2099 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange,
2100 			 struct mm_struct *mm)
2101 {
2102 	switch (prange->work_item.op) {
2103 	case SVM_OP_NULL:
2104 		pr_debug("NULL OP 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2105 			 svms, prange, prange->start, prange->last);
2106 		break;
2107 	case SVM_OP_UNMAP_RANGE:
2108 		pr_debug("remove 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2109 			 svms, prange, prange->start, prange->last);
2110 		svm_range_unlink(prange);
2111 		svm_range_remove_notifier(prange);
2112 		svm_range_free(prange, true);
2113 		break;
2114 	case SVM_OP_UPDATE_RANGE_NOTIFIER:
2115 		pr_debug("update notifier 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2116 			 svms, prange, prange->start, prange->last);
2117 		svm_range_update_notifier_and_interval_tree(mm, prange);
2118 		break;
2119 	case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
2120 		pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2121 			 svms, prange, prange->start, prange->last);
2122 		svm_range_update_notifier_and_interval_tree(mm, prange);
2123 		/* TODO: implement deferred validation and mapping */
2124 		break;
2125 	case SVM_OP_ADD_RANGE:
2126 		pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
2127 			 prange->start, prange->last);
2128 		svm_range_add_to_svms(prange);
2129 		svm_range_add_notifier_locked(mm, prange);
2130 		break;
2131 	case SVM_OP_ADD_RANGE_AND_MAP:
2132 		pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
2133 			 prange, prange->start, prange->last);
2134 		svm_range_add_to_svms(prange);
2135 		svm_range_add_notifier_locked(mm, prange);
2136 		/* TODO: implement deferred validation and mapping */
2137 		break;
2138 	default:
2139 		WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
2140 			 prange->work_item.op);
2141 	}
2142 }
2143 
2144 static void svm_range_drain_retry_fault(struct svm_range_list *svms)
2145 {
2146 	struct kfd_process_device *pdd;
2147 	struct kfd_process *p;
2148 	int drain;
2149 	uint32_t i;
2150 
2151 	p = container_of(svms, struct kfd_process, svms);
2152 
2153 restart:
2154 	drain = atomic_read(&svms->drain_pagefaults);
2155 	if (!drain)
2156 		return;
2157 
2158 	for_each_set_bit(i, svms->bitmap_supported, p->n_pdds) {
2159 		pdd = p->pdds[i];
2160 		if (!pdd)
2161 			continue;
2162 
2163 		pr_debug("drain retry fault gpu %d svms %p\n", i, svms);
2164 
2165 		amdgpu_ih_wait_on_checkpoint_process_ts(pdd->dev->adev,
2166 						     &pdd->dev->adev->irq.ih1);
2167 		pr_debug("drain retry fault gpu %d svms 0x%p done\n", i, svms);
2168 	}
2169 	if (atomic_cmpxchg(&svms->drain_pagefaults, drain, 0) != drain)
2170 		goto restart;
2171 }
2172 
2173 static void svm_range_deferred_list_work(struct work_struct *work)
2174 {
2175 	struct svm_range_list *svms;
2176 	struct svm_range *prange;
2177 	struct mm_struct *mm;
2178 
2179 	svms = container_of(work, struct svm_range_list, deferred_list_work);
2180 	pr_debug("enter svms 0x%p\n", svms);
2181 
2182 	spin_lock(&svms->deferred_list_lock);
2183 	while (!list_empty(&svms->deferred_range_list)) {
2184 		prange = list_first_entry(&svms->deferred_range_list,
2185 					  struct svm_range, deferred_list);
2186 		spin_unlock(&svms->deferred_list_lock);
2187 
2188 		pr_debug("prange 0x%p [0x%lx 0x%lx] op %d\n", prange,
2189 			 prange->start, prange->last, prange->work_item.op);
2190 
2191 		mm = prange->work_item.mm;
2192 retry:
2193 		mmap_write_lock(mm);
2194 
2195 		/* Checking for the need to drain retry faults must be inside
2196 		 * mmap write lock to serialize with munmap notifiers.
2197 		 */
2198 		if (unlikely(atomic_read(&svms->drain_pagefaults))) {
2199 			mmap_write_unlock(mm);
2200 			svm_range_drain_retry_fault(svms);
2201 			goto retry;
2202 		}
2203 
2204 		/* Remove from deferred_list must be inside mmap write lock, for
2205 		 * two race cases:
2206 		 * 1. unmap_from_cpu may change work_item.op and add the range
2207 		 *    to deferred_list again, cause use after free bug.
2208 		 * 2. svm_range_list_lock_and_flush_work may hold mmap write
2209 		 *    lock and continue because deferred_list is empty, but
2210 		 *    deferred_list work is actually waiting for mmap lock.
2211 		 */
2212 		spin_lock(&svms->deferred_list_lock);
2213 		list_del_init(&prange->deferred_list);
2214 		spin_unlock(&svms->deferred_list_lock);
2215 
2216 		mutex_lock(&svms->lock);
2217 		mutex_lock(&prange->migrate_mutex);
2218 		while (!list_empty(&prange->child_list)) {
2219 			struct svm_range *pchild;
2220 
2221 			pchild = list_first_entry(&prange->child_list,
2222 						struct svm_range, child_list);
2223 			pr_debug("child prange 0x%p op %d\n", pchild,
2224 				 pchild->work_item.op);
2225 			list_del_init(&pchild->child_list);
2226 			svm_range_handle_list_op(svms, pchild, mm);
2227 		}
2228 		mutex_unlock(&prange->migrate_mutex);
2229 
2230 		svm_range_handle_list_op(svms, prange, mm);
2231 		mutex_unlock(&svms->lock);
2232 		mmap_write_unlock(mm);
2233 
2234 		/* Pairs with mmget in svm_range_add_list_work */
2235 		mmput(mm);
2236 
2237 		spin_lock(&svms->deferred_list_lock);
2238 	}
2239 	spin_unlock(&svms->deferred_list_lock);
2240 	pr_debug("exit svms 0x%p\n", svms);
2241 }
2242 
2243 void
2244 svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
2245 			struct mm_struct *mm, enum svm_work_list_ops op)
2246 {
2247 	spin_lock(&svms->deferred_list_lock);
2248 	/* if prange is on the deferred list */
2249 	if (!list_empty(&prange->deferred_list)) {
2250 		pr_debug("update exist prange 0x%p work op %d\n", prange, op);
2251 		WARN_ONCE(prange->work_item.mm != mm, "unmatch mm\n");
2252 		if (op != SVM_OP_NULL &&
2253 		    prange->work_item.op != SVM_OP_UNMAP_RANGE)
2254 			prange->work_item.op = op;
2255 	} else {
2256 		prange->work_item.op = op;
2257 
2258 		/* Pairs with mmput in deferred_list_work */
2259 		mmget(mm);
2260 		prange->work_item.mm = mm;
2261 		list_add_tail(&prange->deferred_list,
2262 			      &prange->svms->deferred_range_list);
2263 		pr_debug("add prange 0x%p [0x%lx 0x%lx] to work list op %d\n",
2264 			 prange, prange->start, prange->last, op);
2265 	}
2266 	spin_unlock(&svms->deferred_list_lock);
2267 }
2268 
2269 void schedule_deferred_list_work(struct svm_range_list *svms)
2270 {
2271 	spin_lock(&svms->deferred_list_lock);
2272 	if (!list_empty(&svms->deferred_range_list))
2273 		schedule_work(&svms->deferred_list_work);
2274 	spin_unlock(&svms->deferred_list_lock);
2275 }
2276 
2277 static void
2278 svm_range_unmap_split(struct mm_struct *mm, struct svm_range *parent,
2279 		      struct svm_range *prange, unsigned long start,
2280 		      unsigned long last)
2281 {
2282 	struct svm_range *head;
2283 	struct svm_range *tail;
2284 
2285 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2286 		pr_debug("prange 0x%p [0x%lx 0x%lx] is already freed\n", prange,
2287 			 prange->start, prange->last);
2288 		return;
2289 	}
2290 	if (start > prange->last || last < prange->start)
2291 		return;
2292 
2293 	head = tail = prange;
2294 	if (start > prange->start)
2295 		svm_range_split(prange, prange->start, start - 1, &tail);
2296 	if (last < tail->last)
2297 		svm_range_split(tail, last + 1, tail->last, &head);
2298 
2299 	if (head != prange && tail != prange) {
2300 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2301 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
2302 	} else if (tail != prange) {
2303 		svm_range_add_child(parent, mm, tail, SVM_OP_UNMAP_RANGE);
2304 	} else if (head != prange) {
2305 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2306 	} else if (parent != prange) {
2307 		prange->work_item.op = SVM_OP_UNMAP_RANGE;
2308 	}
2309 }
2310 
2311 static void
2312 svm_range_unmap_from_cpu(struct mm_struct *mm, struct svm_range *prange,
2313 			 unsigned long start, unsigned long last)
2314 {
2315 	uint32_t trigger = KFD_SVM_UNMAP_TRIGGER_UNMAP_FROM_CPU;
2316 	struct svm_range_list *svms;
2317 	struct svm_range *pchild;
2318 	struct kfd_process *p;
2319 	unsigned long s, l;
2320 	bool unmap_parent;
2321 
2322 	p = kfd_lookup_process_by_mm(mm);
2323 	if (!p)
2324 		return;
2325 	svms = &p->svms;
2326 
2327 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n", svms,
2328 		 prange, prange->start, prange->last, start, last);
2329 
2330 	/* Make sure pending page faults are drained in the deferred worker
2331 	 * before the range is freed to avoid straggler interrupts on
2332 	 * unmapped memory causing "phantom faults".
2333 	 */
2334 	atomic_inc(&svms->drain_pagefaults);
2335 
2336 	unmap_parent = start <= prange->start && last >= prange->last;
2337 
2338 	list_for_each_entry(pchild, &prange->child_list, child_list) {
2339 		mutex_lock_nested(&pchild->lock, 1);
2340 		s = max(start, pchild->start);
2341 		l = min(last, pchild->last);
2342 		if (l >= s)
2343 			svm_range_unmap_from_gpus(pchild, s, l, trigger);
2344 		svm_range_unmap_split(mm, prange, pchild, start, last);
2345 		mutex_unlock(&pchild->lock);
2346 	}
2347 	s = max(start, prange->start);
2348 	l = min(last, prange->last);
2349 	if (l >= s)
2350 		svm_range_unmap_from_gpus(prange, s, l, trigger);
2351 	svm_range_unmap_split(mm, prange, prange, start, last);
2352 
2353 	if (unmap_parent)
2354 		svm_range_add_list_work(svms, prange, mm, SVM_OP_UNMAP_RANGE);
2355 	else
2356 		svm_range_add_list_work(svms, prange, mm,
2357 					SVM_OP_UPDATE_RANGE_NOTIFIER);
2358 	schedule_deferred_list_work(svms);
2359 
2360 	kfd_unref_process(p);
2361 }
2362 
2363 /**
2364  * svm_range_cpu_invalidate_pagetables - interval notifier callback
2365  * @mni: mmu_interval_notifier struct
2366  * @range: mmu_notifier_range struct
2367  * @cur_seq: value to pass to mmu_interval_set_seq()
2368  *
2369  * If event is MMU_NOTIFY_UNMAP, this is from CPU unmap range, otherwise, it
2370  * is from migration, or CPU page invalidation callback.
2371  *
2372  * For unmap event, unmap range from GPUs, remove prange from svms in a delayed
2373  * work thread, and split prange if only part of prange is unmapped.
2374  *
2375  * For invalidation event, if GPU retry fault is not enabled, evict the queues,
2376  * then schedule svm_range_restore_work to update GPU mapping and resume queues.
2377  * If GPU retry fault is enabled, unmap the svm range from GPU, retry fault will
2378  * update GPU mapping to recover.
2379  *
2380  * Context: mmap lock, notifier_invalidate_start lock are held
2381  *          for invalidate event, prange lock is held if this is from migration
2382  */
2383 static bool
2384 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
2385 				    const struct mmu_notifier_range *range,
2386 				    unsigned long cur_seq)
2387 {
2388 	struct svm_range *prange;
2389 	unsigned long start;
2390 	unsigned long last;
2391 
2392 	if (range->event == MMU_NOTIFY_RELEASE)
2393 		return true;
2394 	if (!mmget_not_zero(mni->mm))
2395 		return true;
2396 
2397 	start = mni->interval_tree.start;
2398 	last = mni->interval_tree.last;
2399 	start = max(start, range->start) >> PAGE_SHIFT;
2400 	last = min(last, range->end - 1) >> PAGE_SHIFT;
2401 	pr_debug("[0x%lx 0x%lx] range[0x%lx 0x%lx] notifier[0x%lx 0x%lx] %d\n",
2402 		 start, last, range->start >> PAGE_SHIFT,
2403 		 (range->end - 1) >> PAGE_SHIFT,
2404 		 mni->interval_tree.start >> PAGE_SHIFT,
2405 		 mni->interval_tree.last >> PAGE_SHIFT, range->event);
2406 
2407 	prange = container_of(mni, struct svm_range, notifier);
2408 
2409 	svm_range_lock(prange);
2410 	mmu_interval_set_seq(mni, cur_seq);
2411 
2412 	switch (range->event) {
2413 	case MMU_NOTIFY_UNMAP:
2414 		svm_range_unmap_from_cpu(mni->mm, prange, start, last);
2415 		break;
2416 	default:
2417 		svm_range_evict(prange, mni->mm, start, last, range->event);
2418 		break;
2419 	}
2420 
2421 	svm_range_unlock(prange);
2422 	mmput(mni->mm);
2423 
2424 	return true;
2425 }
2426 
2427 /**
2428  * svm_range_from_addr - find svm range from fault address
2429  * @svms: svm range list header
2430  * @addr: address to search range interval tree, in pages
2431  * @parent: parent range if range is on child list
2432  *
2433  * Context: The caller must hold svms->lock
2434  *
2435  * Return: the svm_range found or NULL
2436  */
2437 struct svm_range *
2438 svm_range_from_addr(struct svm_range_list *svms, unsigned long addr,
2439 		    struct svm_range **parent)
2440 {
2441 	struct interval_tree_node *node;
2442 	struct svm_range *prange;
2443 	struct svm_range *pchild;
2444 
2445 	node = interval_tree_iter_first(&svms->objects, addr, addr);
2446 	if (!node)
2447 		return NULL;
2448 
2449 	prange = container_of(node, struct svm_range, it_node);
2450 	pr_debug("address 0x%lx prange [0x%lx 0x%lx] node [0x%lx 0x%lx]\n",
2451 		 addr, prange->start, prange->last, node->start, node->last);
2452 
2453 	if (addr >= prange->start && addr <= prange->last) {
2454 		if (parent)
2455 			*parent = prange;
2456 		return prange;
2457 	}
2458 	list_for_each_entry(pchild, &prange->child_list, child_list)
2459 		if (addr >= pchild->start && addr <= pchild->last) {
2460 			pr_debug("found address 0x%lx pchild [0x%lx 0x%lx]\n",
2461 				 addr, pchild->start, pchild->last);
2462 			if (parent)
2463 				*parent = prange;
2464 			return pchild;
2465 		}
2466 
2467 	return NULL;
2468 }
2469 
2470 /* svm_range_best_restore_location - decide the best fault restore location
2471  * @prange: svm range structure
2472  * @adev: the GPU on which vm fault happened
2473  *
2474  * This is only called when xnack is on, to decide the best location to restore
2475  * the range mapping after GPU vm fault. Caller uses the best location to do
2476  * migration if actual loc is not best location, then update GPU page table
2477  * mapping to the best location.
2478  *
2479  * If the preferred loc is accessible by faulting GPU, use preferred loc.
2480  * If vm fault gpu idx is on range ACCESSIBLE bitmap, best_loc is vm fault gpu
2481  * If vm fault gpu idx is on range ACCESSIBLE_IN_PLACE bitmap, then
2482  *    if range actual loc is cpu, best_loc is cpu
2483  *    if vm fault gpu is on xgmi same hive of range actual loc gpu, best_loc is
2484  *    range actual loc.
2485  * Otherwise, GPU no access, best_loc is -1.
2486  *
2487  * Return:
2488  * -1 means vm fault GPU no access
2489  * 0 for CPU or GPU id
2490  */
2491 static int32_t
2492 svm_range_best_restore_location(struct svm_range *prange,
2493 				struct amdgpu_device *adev,
2494 				int32_t *gpuidx)
2495 {
2496 	struct amdgpu_device *bo_adev, *preferred_adev;
2497 	struct kfd_process *p;
2498 	uint32_t gpuid;
2499 	int r;
2500 
2501 	p = container_of(prange->svms, struct kfd_process, svms);
2502 
2503 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, gpuidx);
2504 	if (r < 0) {
2505 		pr_debug("failed to get gpuid from kgd\n");
2506 		return -1;
2507 	}
2508 
2509 	if (prange->preferred_loc == gpuid ||
2510 	    prange->preferred_loc == KFD_IOCTL_SVM_LOCATION_SYSMEM) {
2511 		return prange->preferred_loc;
2512 	} else if (prange->preferred_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
2513 		preferred_adev = svm_range_get_adev_by_id(prange,
2514 							prange->preferred_loc);
2515 		if (amdgpu_xgmi_same_hive(adev, preferred_adev))
2516 			return prange->preferred_loc;
2517 		/* fall through */
2518 	}
2519 
2520 	if (test_bit(*gpuidx, prange->bitmap_access))
2521 		return gpuid;
2522 
2523 	if (test_bit(*gpuidx, prange->bitmap_aip)) {
2524 		if (!prange->actual_loc)
2525 			return 0;
2526 
2527 		bo_adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
2528 		if (amdgpu_xgmi_same_hive(adev, bo_adev))
2529 			return prange->actual_loc;
2530 		else
2531 			return 0;
2532 	}
2533 
2534 	return -1;
2535 }
2536 
2537 static int
2538 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
2539 			       unsigned long *start, unsigned long *last,
2540 			       bool *is_heap_stack)
2541 {
2542 	struct vm_area_struct *vma;
2543 	struct interval_tree_node *node;
2544 	unsigned long start_limit, end_limit;
2545 
2546 	vma = vma_lookup(p->mm, addr << PAGE_SHIFT);
2547 	if (!vma) {
2548 		pr_debug("VMA does not exist in address [0x%llx]\n", addr);
2549 		return -EFAULT;
2550 	}
2551 
2552 	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
2553 			  vma->vm_end >= vma->vm_mm->start_brk) ||
2554 			 (vma->vm_start <= vma->vm_mm->start_stack &&
2555 			  vma->vm_end >= vma->vm_mm->start_stack);
2556 
2557 	start_limit = max(vma->vm_start >> PAGE_SHIFT,
2558 		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
2559 	end_limit = min(vma->vm_end >> PAGE_SHIFT,
2560 		    (unsigned long)ALIGN(addr + 1, 2UL << 8));
2561 	/* First range that starts after the fault address */
2562 	node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);
2563 	if (node) {
2564 		end_limit = min(end_limit, node->start);
2565 		/* Last range that ends before the fault address */
2566 		node = container_of(rb_prev(&node->rb),
2567 				    struct interval_tree_node, rb);
2568 	} else {
2569 		/* Last range must end before addr because
2570 		 * there was no range after addr
2571 		 */
2572 		node = container_of(rb_last(&p->svms.objects.rb_root),
2573 				    struct interval_tree_node, rb);
2574 	}
2575 	if (node) {
2576 		if (node->last >= addr) {
2577 			WARN(1, "Overlap with prev node and page fault addr\n");
2578 			return -EFAULT;
2579 		}
2580 		start_limit = max(start_limit, node->last + 1);
2581 	}
2582 
2583 	*start = start_limit;
2584 	*last = end_limit - 1;
2585 
2586 	pr_debug("vma [0x%lx 0x%lx] range [0x%lx 0x%lx] is_heap_stack %d\n",
2587 		 vma->vm_start >> PAGE_SHIFT, vma->vm_end >> PAGE_SHIFT,
2588 		 *start, *last, *is_heap_stack);
2589 
2590 	return 0;
2591 }
2592 
2593 static int
2594 svm_range_check_vm_userptr(struct kfd_process *p, uint64_t start, uint64_t last,
2595 			   uint64_t *bo_s, uint64_t *bo_l)
2596 {
2597 	struct amdgpu_bo_va_mapping *mapping;
2598 	struct interval_tree_node *node;
2599 	struct amdgpu_bo *bo = NULL;
2600 	unsigned long userptr;
2601 	uint32_t i;
2602 	int r;
2603 
2604 	for (i = 0; i < p->n_pdds; i++) {
2605 		struct amdgpu_vm *vm;
2606 
2607 		if (!p->pdds[i]->drm_priv)
2608 			continue;
2609 
2610 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2611 		r = amdgpu_bo_reserve(vm->root.bo, false);
2612 		if (r)
2613 			return r;
2614 
2615 		/* Check userptr by searching entire vm->va interval tree */
2616 		node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
2617 		while (node) {
2618 			mapping = container_of((struct rb_node *)node,
2619 					       struct amdgpu_bo_va_mapping, rb);
2620 			bo = mapping->bo_va->base.bo;
2621 
2622 			if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
2623 							 start << PAGE_SHIFT,
2624 							 last << PAGE_SHIFT,
2625 							 &userptr)) {
2626 				node = interval_tree_iter_next(node, 0, ~0ULL);
2627 				continue;
2628 			}
2629 
2630 			pr_debug("[0x%llx 0x%llx] already userptr mapped\n",
2631 				 start, last);
2632 			if (bo_s && bo_l) {
2633 				*bo_s = userptr >> PAGE_SHIFT;
2634 				*bo_l = *bo_s + bo->tbo.ttm->num_pages - 1;
2635 			}
2636 			amdgpu_bo_unreserve(vm->root.bo);
2637 			return -EADDRINUSE;
2638 		}
2639 		amdgpu_bo_unreserve(vm->root.bo);
2640 	}
2641 	return 0;
2642 }
2643 
2644 static struct
2645 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
2646 						struct kfd_process *p,
2647 						struct mm_struct *mm,
2648 						int64_t addr)
2649 {
2650 	struct svm_range *prange = NULL;
2651 	unsigned long start, last;
2652 	uint32_t gpuid, gpuidx;
2653 	bool is_heap_stack;
2654 	uint64_t bo_s = 0;
2655 	uint64_t bo_l = 0;
2656 	int r;
2657 
2658 	if (svm_range_get_range_boundaries(p, addr, &start, &last,
2659 					   &is_heap_stack))
2660 		return NULL;
2661 
2662 	r = svm_range_check_vm(p, start, last, &bo_s, &bo_l);
2663 	if (r != -EADDRINUSE)
2664 		r = svm_range_check_vm_userptr(p, start, last, &bo_s, &bo_l);
2665 
2666 	if (r == -EADDRINUSE) {
2667 		if (addr >= bo_s && addr <= bo_l)
2668 			return NULL;
2669 
2670 		/* Create one page svm range if 2MB range overlapping */
2671 		start = addr;
2672 		last = addr;
2673 	}
2674 
2675 	prange = svm_range_new(&p->svms, start, last, true);
2676 	if (!prange) {
2677 		pr_debug("Failed to create prange in address [0x%llx]\n", addr);
2678 		return NULL;
2679 	}
2680 	if (kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx)) {
2681 		pr_debug("failed to get gpuid from kgd\n");
2682 		svm_range_free(prange, true);
2683 		return NULL;
2684 	}
2685 
2686 	if (is_heap_stack)
2687 		prange->preferred_loc = KFD_IOCTL_SVM_LOCATION_SYSMEM;
2688 
2689 	svm_range_add_to_svms(prange);
2690 	svm_range_add_notifier_locked(mm, prange);
2691 
2692 	return prange;
2693 }
2694 
2695 /* svm_range_skip_recover - decide if prange can be recovered
2696  * @prange: svm range structure
2697  *
2698  * GPU vm retry fault handle skip recover the range for cases:
2699  * 1. prange is on deferred list to be removed after unmap, it is stale fault,
2700  *    deferred list work will drain the stale fault before free the prange.
2701  * 2. prange is on deferred list to add interval notifier after split, or
2702  * 3. prange is child range, it is split from parent prange, recover later
2703  *    after interval notifier is added.
2704  *
2705  * Return: true to skip recover, false to recover
2706  */
2707 static bool svm_range_skip_recover(struct svm_range *prange)
2708 {
2709 	struct svm_range_list *svms = prange->svms;
2710 
2711 	spin_lock(&svms->deferred_list_lock);
2712 	if (list_empty(&prange->deferred_list) &&
2713 	    list_empty(&prange->child_list)) {
2714 		spin_unlock(&svms->deferred_list_lock);
2715 		return false;
2716 	}
2717 	spin_unlock(&svms->deferred_list_lock);
2718 
2719 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2720 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] unmapped\n",
2721 			 svms, prange, prange->start, prange->last);
2722 		return true;
2723 	}
2724 	if (prange->work_item.op == SVM_OP_ADD_RANGE_AND_MAP ||
2725 	    prange->work_item.op == SVM_OP_ADD_RANGE) {
2726 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] not added yet\n",
2727 			 svms, prange, prange->start, prange->last);
2728 		return true;
2729 	}
2730 	return false;
2731 }
2732 
2733 static void
2734 svm_range_count_fault(struct amdgpu_device *adev, struct kfd_process *p,
2735 		      int32_t gpuidx)
2736 {
2737 	struct kfd_process_device *pdd;
2738 
2739 	/* fault is on different page of same range
2740 	 * or fault is skipped to recover later
2741 	 * or fault is on invalid virtual address
2742 	 */
2743 	if (gpuidx == MAX_GPU_INSTANCE) {
2744 		uint32_t gpuid;
2745 		int r;
2746 
2747 		r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx);
2748 		if (r < 0)
2749 			return;
2750 	}
2751 
2752 	/* fault is recovered
2753 	 * or fault cannot recover because GPU no access on the range
2754 	 */
2755 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
2756 	if (pdd)
2757 		WRITE_ONCE(pdd->faults, pdd->faults + 1);
2758 }
2759 
2760 static bool
2761 svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
2762 {
2763 	unsigned long requested = VM_READ;
2764 
2765 	if (write_fault)
2766 		requested |= VM_WRITE;
2767 
2768 	pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
2769 		vma->vm_flags);
2770 	return (vma->vm_flags & requested) == requested;
2771 }
2772 
2773 int
2774 svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
2775 			uint64_t addr, bool write_fault)
2776 {
2777 	struct mm_struct *mm = NULL;
2778 	struct svm_range_list *svms;
2779 	struct svm_range *prange;
2780 	struct kfd_process *p;
2781 	ktime_t timestamp = ktime_get_boottime();
2782 	int32_t best_loc;
2783 	int32_t gpuidx = MAX_GPU_INSTANCE;
2784 	bool write_locked = false;
2785 	struct vm_area_struct *vma;
2786 	bool migration = false;
2787 	int r = 0;
2788 
2789 	if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
2790 		pr_debug("device does not support SVM\n");
2791 		return -EFAULT;
2792 	}
2793 
2794 	p = kfd_lookup_process_by_pasid(pasid);
2795 	if (!p) {
2796 		pr_debug("kfd process not founded pasid 0x%x\n", pasid);
2797 		return 0;
2798 	}
2799 	svms = &p->svms;
2800 
2801 	pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
2802 
2803 	if (atomic_read(&svms->drain_pagefaults)) {
2804 		pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
2805 		r = 0;
2806 		goto out;
2807 	}
2808 
2809 	if (!p->xnack_enabled) {
2810 		pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
2811 		r = -EFAULT;
2812 		goto out;
2813 	}
2814 
2815 	/* p->lead_thread is available as kfd_process_wq_release flush the work
2816 	 * before releasing task ref.
2817 	 */
2818 	mm = get_task_mm(p->lead_thread);
2819 	if (!mm) {
2820 		pr_debug("svms 0x%p failed to get mm\n", svms);
2821 		r = 0;
2822 		goto out;
2823 	}
2824 
2825 	mmap_read_lock(mm);
2826 retry_write_locked:
2827 	mutex_lock(&svms->lock);
2828 	prange = svm_range_from_addr(svms, addr, NULL);
2829 	if (!prange) {
2830 		pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
2831 			 svms, addr);
2832 		if (!write_locked) {
2833 			/* Need the write lock to create new range with MMU notifier.
2834 			 * Also flush pending deferred work to make sure the interval
2835 			 * tree is up to date before we add a new range
2836 			 */
2837 			mutex_unlock(&svms->lock);
2838 			mmap_read_unlock(mm);
2839 			mmap_write_lock(mm);
2840 			write_locked = true;
2841 			goto retry_write_locked;
2842 		}
2843 		prange = svm_range_create_unregistered_range(adev, p, mm, addr);
2844 		if (!prange) {
2845 			pr_debug("failed to create unregistered range svms 0x%p address [0x%llx]\n",
2846 				 svms, addr);
2847 			mmap_write_downgrade(mm);
2848 			r = -EFAULT;
2849 			goto out_unlock_svms;
2850 		}
2851 	}
2852 	if (write_locked)
2853 		mmap_write_downgrade(mm);
2854 
2855 	mutex_lock(&prange->migrate_mutex);
2856 
2857 	if (svm_range_skip_recover(prange)) {
2858 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2859 		r = 0;
2860 		goto out_unlock_range;
2861 	}
2862 
2863 	/* skip duplicate vm fault on different pages of same range */
2864 	if (ktime_before(timestamp, ktime_add_ns(prange->validate_timestamp,
2865 				AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING))) {
2866 		pr_debug("svms 0x%p [0x%lx %lx] already restored\n",
2867 			 svms, prange->start, prange->last);
2868 		r = 0;
2869 		goto out_unlock_range;
2870 	}
2871 
2872 	/* __do_munmap removed VMA, return success as we are handling stale
2873 	 * retry fault.
2874 	 */
2875 	vma = vma_lookup(mm, addr << PAGE_SHIFT);
2876 	if (!vma) {
2877 		pr_debug("address 0x%llx VMA is removed\n", addr);
2878 		r = 0;
2879 		goto out_unlock_range;
2880 	}
2881 
2882 	if (!svm_fault_allowed(vma, write_fault)) {
2883 		pr_debug("fault addr 0x%llx no %s permission\n", addr,
2884 			write_fault ? "write" : "read");
2885 		r = -EPERM;
2886 		goto out_unlock_range;
2887 	}
2888 
2889 	best_loc = svm_range_best_restore_location(prange, adev, &gpuidx);
2890 	if (best_loc == -1) {
2891 		pr_debug("svms %p failed get best restore loc [0x%lx 0x%lx]\n",
2892 			 svms, prange->start, prange->last);
2893 		r = -EACCES;
2894 		goto out_unlock_range;
2895 	}
2896 
2897 	pr_debug("svms %p [0x%lx 0x%lx] best restore 0x%x, actual loc 0x%x\n",
2898 		 svms, prange->start, prange->last, best_loc,
2899 		 prange->actual_loc);
2900 
2901 	kfd_smi_event_page_fault_start(adev->kfd.dev, p->lead_thread->pid, addr,
2902 				       write_fault, timestamp);
2903 
2904 	if (prange->actual_loc != best_loc) {
2905 		migration = true;
2906 		if (best_loc) {
2907 			r = svm_migrate_to_vram(prange, best_loc, mm,
2908 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
2909 			if (r) {
2910 				pr_debug("svm_migrate_to_vram failed (%d) at %llx, falling back to system memory\n",
2911 					 r, addr);
2912 				/* Fallback to system memory if migration to
2913 				 * VRAM failed
2914 				 */
2915 				if (prange->actual_loc)
2916 					r = svm_migrate_vram_to_ram(prange, mm,
2917 					   KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU,
2918 					   NULL);
2919 				else
2920 					r = 0;
2921 			}
2922 		} else {
2923 			r = svm_migrate_vram_to_ram(prange, mm,
2924 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU,
2925 					NULL);
2926 		}
2927 		if (r) {
2928 			pr_debug("failed %d to migrate svms %p [0x%lx 0x%lx]\n",
2929 				 r, svms, prange->start, prange->last);
2930 			goto out_unlock_range;
2931 		}
2932 	}
2933 
2934 	r = svm_range_validate_and_map(mm, prange, gpuidx, false, false, false);
2935 	if (r)
2936 		pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
2937 			 r, svms, prange->start, prange->last);
2938 
2939 	kfd_smi_event_page_fault_end(adev->kfd.dev, p->lead_thread->pid, addr,
2940 				     migration);
2941 
2942 out_unlock_range:
2943 	mutex_unlock(&prange->migrate_mutex);
2944 out_unlock_svms:
2945 	mutex_unlock(&svms->lock);
2946 	mmap_read_unlock(mm);
2947 
2948 	svm_range_count_fault(adev, p, gpuidx);
2949 
2950 	mmput(mm);
2951 out:
2952 	kfd_unref_process(p);
2953 
2954 	if (r == -EAGAIN) {
2955 		pr_debug("recover vm fault later\n");
2956 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2957 		r = 0;
2958 	}
2959 	return r;
2960 }
2961 
2962 int
2963 svm_range_switch_xnack_reserve_mem(struct kfd_process *p, bool xnack_enabled)
2964 {
2965 	struct svm_range *prange, *pchild;
2966 	uint64_t reserved_size = 0;
2967 	uint64_t size;
2968 	int r = 0;
2969 
2970 	pr_debug("switching xnack from %d to %d\n", p->xnack_enabled, xnack_enabled);
2971 
2972 	mutex_lock(&p->svms.lock);
2973 
2974 	list_for_each_entry(prange, &p->svms.list, list) {
2975 		svm_range_lock(prange);
2976 		list_for_each_entry(pchild, &prange->child_list, child_list) {
2977 			size = (pchild->last - pchild->start + 1) << PAGE_SHIFT;
2978 			if (xnack_enabled) {
2979 				amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
2980 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2981 			} else {
2982 				r = amdgpu_amdkfd_reserve_mem_limit(NULL, size,
2983 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2984 				if (r)
2985 					goto out_unlock;
2986 				reserved_size += size;
2987 			}
2988 		}
2989 
2990 		size = (prange->last - prange->start + 1) << PAGE_SHIFT;
2991 		if (xnack_enabled) {
2992 			amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
2993 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2994 		} else {
2995 			r = amdgpu_amdkfd_reserve_mem_limit(NULL, size,
2996 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2997 			if (r)
2998 				goto out_unlock;
2999 			reserved_size += size;
3000 		}
3001 out_unlock:
3002 		svm_range_unlock(prange);
3003 		if (r)
3004 			break;
3005 	}
3006 
3007 	if (r)
3008 		amdgpu_amdkfd_unreserve_mem_limit(NULL, reserved_size,
3009 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
3010 	else
3011 		/* Change xnack mode must be inside svms lock, to avoid race with
3012 		 * svm_range_deferred_list_work unreserve memory in parallel.
3013 		 */
3014 		p->xnack_enabled = xnack_enabled;
3015 
3016 	mutex_unlock(&p->svms.lock);
3017 	return r;
3018 }
3019 
3020 void svm_range_list_fini(struct kfd_process *p)
3021 {
3022 	struct svm_range *prange;
3023 	struct svm_range *next;
3024 
3025 	pr_debug("pasid 0x%x svms 0x%p\n", p->pasid, &p->svms);
3026 
3027 	cancel_delayed_work_sync(&p->svms.restore_work);
3028 
3029 	/* Ensure list work is finished before process is destroyed */
3030 	flush_work(&p->svms.deferred_list_work);
3031 
3032 	/*
3033 	 * Ensure no retry fault comes in afterwards, as page fault handler will
3034 	 * not find kfd process and take mm lock to recover fault.
3035 	 */
3036 	atomic_inc(&p->svms.drain_pagefaults);
3037 	svm_range_drain_retry_fault(&p->svms);
3038 
3039 	list_for_each_entry_safe(prange, next, &p->svms.list, list) {
3040 		svm_range_unlink(prange);
3041 		svm_range_remove_notifier(prange);
3042 		svm_range_free(prange, true);
3043 	}
3044 
3045 	mutex_destroy(&p->svms.lock);
3046 
3047 	pr_debug("pasid 0x%x svms 0x%p done\n", p->pasid, &p->svms);
3048 }
3049 
3050 int svm_range_list_init(struct kfd_process *p)
3051 {
3052 	struct svm_range_list *svms = &p->svms;
3053 	int i;
3054 
3055 	svms->objects = RB_ROOT_CACHED;
3056 	mutex_init(&svms->lock);
3057 	INIT_LIST_HEAD(&svms->list);
3058 	atomic_set(&svms->evicted_ranges, 0);
3059 	atomic_set(&svms->drain_pagefaults, 0);
3060 	INIT_DELAYED_WORK(&svms->restore_work, svm_range_restore_work);
3061 	INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work);
3062 	INIT_LIST_HEAD(&svms->deferred_range_list);
3063 	INIT_LIST_HEAD(&svms->criu_svm_metadata_list);
3064 	spin_lock_init(&svms->deferred_list_lock);
3065 
3066 	for (i = 0; i < p->n_pdds; i++)
3067 		if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev))
3068 			bitmap_set(svms->bitmap_supported, i, 1);
3069 
3070 	return 0;
3071 }
3072 
3073 /**
3074  * svm_range_check_vm - check if virtual address range mapped already
3075  * @p: current kfd_process
3076  * @start: range start address, in pages
3077  * @last: range last address, in pages
3078  * @bo_s: mapping start address in pages if address range already mapped
3079  * @bo_l: mapping last address in pages if address range already mapped
3080  *
3081  * The purpose is to avoid virtual address ranges already allocated by
3082  * kfd_ioctl_alloc_memory_of_gpu ioctl.
3083  * It looks for each pdd in the kfd_process.
3084  *
3085  * Context: Process context
3086  *
3087  * Return 0 - OK, if the range is not mapped.
3088  * Otherwise error code:
3089  * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
3090  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
3091  * a signal. Release all buffer reservations and return to user-space.
3092  */
3093 static int
3094 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
3095 		   uint64_t *bo_s, uint64_t *bo_l)
3096 {
3097 	struct amdgpu_bo_va_mapping *mapping;
3098 	struct interval_tree_node *node;
3099 	uint32_t i;
3100 	int r;
3101 
3102 	for (i = 0; i < p->n_pdds; i++) {
3103 		struct amdgpu_vm *vm;
3104 
3105 		if (!p->pdds[i]->drm_priv)
3106 			continue;
3107 
3108 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
3109 		r = amdgpu_bo_reserve(vm->root.bo, false);
3110 		if (r)
3111 			return r;
3112 
3113 		node = interval_tree_iter_first(&vm->va, start, last);
3114 		if (node) {
3115 			pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
3116 				 start, last);
3117 			mapping = container_of((struct rb_node *)node,
3118 					       struct amdgpu_bo_va_mapping, rb);
3119 			if (bo_s && bo_l) {
3120 				*bo_s = mapping->start;
3121 				*bo_l = mapping->last;
3122 			}
3123 			amdgpu_bo_unreserve(vm->root.bo);
3124 			return -EADDRINUSE;
3125 		}
3126 		amdgpu_bo_unreserve(vm->root.bo);
3127 	}
3128 
3129 	return 0;
3130 }
3131 
3132 /**
3133  * svm_range_is_valid - check if virtual address range is valid
3134  * @p: current kfd_process
3135  * @start: range start address, in pages
3136  * @size: range size, in pages
3137  *
3138  * Valid virtual address range means it belongs to one or more VMAs
3139  *
3140  * Context: Process context
3141  *
3142  * Return:
3143  *  0 - OK, otherwise error code
3144  */
3145 static int
3146 svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
3147 {
3148 	const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
3149 	struct vm_area_struct *vma;
3150 	unsigned long end;
3151 	unsigned long start_unchg = start;
3152 
3153 	start <<= PAGE_SHIFT;
3154 	end = start + (size << PAGE_SHIFT);
3155 	do {
3156 		vma = vma_lookup(p->mm, start);
3157 		if (!vma || (vma->vm_flags & device_vma))
3158 			return -EFAULT;
3159 		start = min(end, vma->vm_end);
3160 	} while (start < end);
3161 
3162 	return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT, NULL,
3163 				  NULL);
3164 }
3165 
3166 /**
3167  * svm_range_best_prefetch_location - decide the best prefetch location
3168  * @prange: svm range structure
3169  *
3170  * For xnack off:
3171  * If range map to single GPU, the best prefetch location is prefetch_loc, which
3172  * can be CPU or GPU.
3173  *
3174  * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on
3175  * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise
3176  * the best prefetch location is always CPU, because GPU can not have coherent
3177  * mapping VRAM of other GPUs even with large-BAR PCIe connection.
3178  *
3179  * For xnack on:
3180  * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is
3181  * prefetch_loc, other GPU access will generate vm fault and trigger migration.
3182  *
3183  * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same
3184  * hive, the best prefetch location is prefetch_loc GPU, otherwise the best
3185  * prefetch location is always CPU.
3186  *
3187  * Context: Process context
3188  *
3189  * Return:
3190  * 0 for CPU or GPU id
3191  */
3192 static uint32_t
3193 svm_range_best_prefetch_location(struct svm_range *prange)
3194 {
3195 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
3196 	uint32_t best_loc = prange->prefetch_loc;
3197 	struct kfd_process_device *pdd;
3198 	struct amdgpu_device *bo_adev;
3199 	struct kfd_process *p;
3200 	uint32_t gpuidx;
3201 
3202 	p = container_of(prange->svms, struct kfd_process, svms);
3203 
3204 	if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED)
3205 		goto out;
3206 
3207 	bo_adev = svm_range_get_adev_by_id(prange, best_loc);
3208 	if (!bo_adev) {
3209 		WARN_ONCE(1, "failed to get device by id 0x%x\n", best_loc);
3210 		best_loc = 0;
3211 		goto out;
3212 	}
3213 
3214 	if (p->xnack_enabled)
3215 		bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
3216 	else
3217 		bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
3218 			  MAX_GPU_INSTANCE);
3219 
3220 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
3221 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
3222 		if (!pdd) {
3223 			pr_debug("failed to get device by idx 0x%x\n", gpuidx);
3224 			continue;
3225 		}
3226 
3227 		if (pdd->dev->adev == bo_adev)
3228 			continue;
3229 
3230 		if (!amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
3231 			best_loc = 0;
3232 			break;
3233 		}
3234 	}
3235 
3236 out:
3237 	pr_debug("xnack %d svms 0x%p [0x%lx 0x%lx] best loc 0x%x\n",
3238 		 p->xnack_enabled, &p->svms, prange->start, prange->last,
3239 		 best_loc);
3240 
3241 	return best_loc;
3242 }
3243 
3244 /* svm_range_trigger_migration - start page migration if prefetch loc changed
3245  * @mm: current process mm_struct
3246  * @prange: svm range structure
3247  * @migrated: output, true if migration is triggered
3248  *
3249  * If range perfetch_loc is GPU, actual loc is cpu 0, then migrate the range
3250  * from ram to vram.
3251  * If range prefetch_loc is cpu 0, actual loc is GPU, then migrate the range
3252  * from vram to ram.
3253  *
3254  * If GPU vm fault retry is not enabled, migration interact with MMU notifier
3255  * and restore work:
3256  * 1. migrate_vma_setup invalidate pages, MMU notifier callback svm_range_evict
3257  *    stops all queues, schedule restore work
3258  * 2. svm_range_restore_work wait for migration is done by
3259  *    a. svm_range_validate_vram takes prange->migrate_mutex
3260  *    b. svm_range_validate_ram HMM get pages wait for CPU fault handle returns
3261  * 3. restore work update mappings of GPU, resume all queues.
3262  *
3263  * Context: Process context
3264  *
3265  * Return:
3266  * 0 - OK, otherwise - error code of migration
3267  */
3268 static int
3269 svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
3270 			    bool *migrated)
3271 {
3272 	uint32_t best_loc;
3273 	int r = 0;
3274 
3275 	*migrated = false;
3276 	best_loc = svm_range_best_prefetch_location(prange);
3277 
3278 	if (best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3279 	    best_loc == prange->actual_loc)
3280 		return 0;
3281 
3282 	if (!best_loc) {
3283 		r = svm_migrate_vram_to_ram(prange, mm,
3284 					KFD_MIGRATE_TRIGGER_PREFETCH, NULL);
3285 		*migrated = !r;
3286 		return r;
3287 	}
3288 
3289 	r = svm_migrate_to_vram(prange, best_loc, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
3290 	*migrated = !r;
3291 
3292 	return r;
3293 }
3294 
3295 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
3296 {
3297 	if (!fence)
3298 		return -EINVAL;
3299 
3300 	if (dma_fence_is_signaled(&fence->base))
3301 		return 0;
3302 
3303 	if (fence->svm_bo) {
3304 		WRITE_ONCE(fence->svm_bo->evicting, 1);
3305 		schedule_work(&fence->svm_bo->eviction_work);
3306 	}
3307 
3308 	return 0;
3309 }
3310 
3311 static void svm_range_evict_svm_bo_worker(struct work_struct *work)
3312 {
3313 	struct svm_range_bo *svm_bo;
3314 	struct mm_struct *mm;
3315 	int r = 0;
3316 
3317 	svm_bo = container_of(work, struct svm_range_bo, eviction_work);
3318 	if (!svm_bo_ref_unless_zero(svm_bo))
3319 		return; /* svm_bo was freed while eviction was pending */
3320 
3321 	if (mmget_not_zero(svm_bo->eviction_fence->mm)) {
3322 		mm = svm_bo->eviction_fence->mm;
3323 	} else {
3324 		svm_range_bo_unref(svm_bo);
3325 		return;
3326 	}
3327 
3328 	mmap_read_lock(mm);
3329 	spin_lock(&svm_bo->list_lock);
3330 	while (!list_empty(&svm_bo->range_list) && !r) {
3331 		struct svm_range *prange =
3332 				list_first_entry(&svm_bo->range_list,
3333 						struct svm_range, svm_bo_list);
3334 		int retries = 3;
3335 
3336 		list_del_init(&prange->svm_bo_list);
3337 		spin_unlock(&svm_bo->list_lock);
3338 
3339 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
3340 			 prange->start, prange->last);
3341 
3342 		mutex_lock(&prange->migrate_mutex);
3343 		do {
3344 			r = svm_migrate_vram_to_ram(prange, mm,
3345 					KFD_MIGRATE_TRIGGER_TTM_EVICTION, NULL);
3346 		} while (!r && prange->actual_loc && --retries);
3347 
3348 		if (!r && prange->actual_loc)
3349 			pr_info_once("Migration failed during eviction");
3350 
3351 		if (!prange->actual_loc) {
3352 			mutex_lock(&prange->lock);
3353 			prange->svm_bo = NULL;
3354 			mutex_unlock(&prange->lock);
3355 		}
3356 		mutex_unlock(&prange->migrate_mutex);
3357 
3358 		spin_lock(&svm_bo->list_lock);
3359 	}
3360 	spin_unlock(&svm_bo->list_lock);
3361 	mmap_read_unlock(mm);
3362 	mmput(mm);
3363 
3364 	dma_fence_signal(&svm_bo->eviction_fence->base);
3365 
3366 	/* This is the last reference to svm_bo, after svm_range_vram_node_free
3367 	 * has been called in svm_migrate_vram_to_ram
3368 	 */
3369 	WARN_ONCE(!r && kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
3370 	svm_range_bo_unref(svm_bo);
3371 }
3372 
3373 static int
3374 svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
3375 		   uint64_t start, uint64_t size, uint32_t nattr,
3376 		   struct kfd_ioctl_svm_attribute *attrs)
3377 {
3378 	struct amdkfd_process_info *process_info = p->kgd_process_info;
3379 	struct list_head update_list;
3380 	struct list_head insert_list;
3381 	struct list_head remove_list;
3382 	struct svm_range_list *svms;
3383 	struct svm_range *prange;
3384 	struct svm_range *next;
3385 	bool update_mapping = false;
3386 	bool flush_tlb;
3387 	int r = 0;
3388 
3389 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
3390 		 p->pasid, &p->svms, start, start + size - 1, size);
3391 
3392 	r = svm_range_check_attr(p, nattr, attrs);
3393 	if (r)
3394 		return r;
3395 
3396 	svms = &p->svms;
3397 
3398 	mutex_lock(&process_info->lock);
3399 
3400 	svm_range_list_lock_and_flush_work(svms, mm);
3401 
3402 	r = svm_range_is_valid(p, start, size);
3403 	if (r) {
3404 		pr_debug("invalid range r=%d\n", r);
3405 		mmap_write_unlock(mm);
3406 		goto out;
3407 	}
3408 
3409 	mutex_lock(&svms->lock);
3410 
3411 	/* Add new range and split existing ranges as needed */
3412 	r = svm_range_add(p, start, size, nattr, attrs, &update_list,
3413 			  &insert_list, &remove_list);
3414 	if (r) {
3415 		mutex_unlock(&svms->lock);
3416 		mmap_write_unlock(mm);
3417 		goto out;
3418 	}
3419 	/* Apply changes as a transaction */
3420 	list_for_each_entry_safe(prange, next, &insert_list, list) {
3421 		svm_range_add_to_svms(prange);
3422 		svm_range_add_notifier_locked(mm, prange);
3423 	}
3424 	list_for_each_entry(prange, &update_list, update_list) {
3425 		svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
3426 		/* TODO: unmap ranges from GPU that lost access */
3427 	}
3428 	list_for_each_entry_safe(prange, next, &remove_list, update_list) {
3429 		pr_debug("unlink old 0x%p prange 0x%p [0x%lx 0x%lx]\n",
3430 			 prange->svms, prange, prange->start,
3431 			 prange->last);
3432 		svm_range_unlink(prange);
3433 		svm_range_remove_notifier(prange);
3434 		svm_range_free(prange, false);
3435 	}
3436 
3437 	mmap_write_downgrade(mm);
3438 	/* Trigger migrations and revalidate and map to GPUs as needed. If
3439 	 * this fails we may be left with partially completed actions. There
3440 	 * is no clean way of rolling back to the previous state in such a
3441 	 * case because the rollback wouldn't be guaranteed to work either.
3442 	 */
3443 	list_for_each_entry(prange, &update_list, update_list) {
3444 		bool migrated;
3445 
3446 		mutex_lock(&prange->migrate_mutex);
3447 
3448 		r = svm_range_trigger_migration(mm, prange, &migrated);
3449 		if (r)
3450 			goto out_unlock_range;
3451 
3452 		if (migrated && (!p->xnack_enabled ||
3453 		    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) &&
3454 		    prange->mapped_to_gpu) {
3455 			pr_debug("restore_work will update mappings of GPUs\n");
3456 			mutex_unlock(&prange->migrate_mutex);
3457 			continue;
3458 		}
3459 
3460 		if (!migrated && !update_mapping) {
3461 			mutex_unlock(&prange->migrate_mutex);
3462 			continue;
3463 		}
3464 
3465 		flush_tlb = !migrated && update_mapping && prange->mapped_to_gpu;
3466 
3467 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
3468 					       true, true, flush_tlb);
3469 		if (r)
3470 			pr_debug("failed %d to map svm range\n", r);
3471 
3472 out_unlock_range:
3473 		mutex_unlock(&prange->migrate_mutex);
3474 		if (r)
3475 			break;
3476 	}
3477 
3478 	svm_range_debug_dump(svms);
3479 
3480 	mutex_unlock(&svms->lock);
3481 	mmap_read_unlock(mm);
3482 out:
3483 	mutex_unlock(&process_info->lock);
3484 
3485 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
3486 		 &p->svms, start, start + size - 1, r);
3487 
3488 	return r;
3489 }
3490 
3491 static int
3492 svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm,
3493 		   uint64_t start, uint64_t size, uint32_t nattr,
3494 		   struct kfd_ioctl_svm_attribute *attrs)
3495 {
3496 	DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
3497 	DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
3498 	bool get_preferred_loc = false;
3499 	bool get_prefetch_loc = false;
3500 	bool get_granularity = false;
3501 	bool get_accessible = false;
3502 	bool get_flags = false;
3503 	uint64_t last = start + size - 1UL;
3504 	uint8_t granularity = 0xff;
3505 	struct interval_tree_node *node;
3506 	struct svm_range_list *svms;
3507 	struct svm_range *prange;
3508 	uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3509 	uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3510 	uint32_t flags_and = 0xffffffff;
3511 	uint32_t flags_or = 0;
3512 	int gpuidx;
3513 	uint32_t i;
3514 	int r = 0;
3515 
3516 	pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
3517 		 start + size - 1, nattr);
3518 
3519 	/* Flush pending deferred work to avoid racing with deferred actions from
3520 	 * previous memory map changes (e.g. munmap). Concurrent memory map changes
3521 	 * can still race with get_attr because we don't hold the mmap lock. But that
3522 	 * would be a race condition in the application anyway, and undefined
3523 	 * behaviour is acceptable in that case.
3524 	 */
3525 	flush_work(&p->svms.deferred_list_work);
3526 
3527 	mmap_read_lock(mm);
3528 	r = svm_range_is_valid(p, start, size);
3529 	mmap_read_unlock(mm);
3530 	if (r) {
3531 		pr_debug("invalid range r=%d\n", r);
3532 		return r;
3533 	}
3534 
3535 	for (i = 0; i < nattr; i++) {
3536 		switch (attrs[i].type) {
3537 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3538 			get_preferred_loc = true;
3539 			break;
3540 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3541 			get_prefetch_loc = true;
3542 			break;
3543 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3544 			get_accessible = true;
3545 			break;
3546 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3547 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3548 			get_flags = true;
3549 			break;
3550 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3551 			get_granularity = true;
3552 			break;
3553 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
3554 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
3555 			fallthrough;
3556 		default:
3557 			pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
3558 			return -EINVAL;
3559 		}
3560 	}
3561 
3562 	svms = &p->svms;
3563 
3564 	mutex_lock(&svms->lock);
3565 
3566 	node = interval_tree_iter_first(&svms->objects, start, last);
3567 	if (!node) {
3568 		pr_debug("range attrs not found return default values\n");
3569 		svm_range_set_default_attributes(&location, &prefetch_loc,
3570 						 &granularity, &flags_and);
3571 		flags_or = flags_and;
3572 		if (p->xnack_enabled)
3573 			bitmap_copy(bitmap_access, svms->bitmap_supported,
3574 				    MAX_GPU_INSTANCE);
3575 		else
3576 			bitmap_zero(bitmap_access, MAX_GPU_INSTANCE);
3577 		bitmap_zero(bitmap_aip, MAX_GPU_INSTANCE);
3578 		goto fill_values;
3579 	}
3580 	bitmap_copy(bitmap_access, svms->bitmap_supported, MAX_GPU_INSTANCE);
3581 	bitmap_copy(bitmap_aip, svms->bitmap_supported, MAX_GPU_INSTANCE);
3582 
3583 	while (node) {
3584 		struct interval_tree_node *next;
3585 
3586 		prange = container_of(node, struct svm_range, it_node);
3587 		next = interval_tree_iter_next(node, start, last);
3588 
3589 		if (get_preferred_loc) {
3590 			if (prange->preferred_loc ==
3591 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3592 			    (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3593 			     location != prange->preferred_loc)) {
3594 				location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3595 				get_preferred_loc = false;
3596 			} else {
3597 				location = prange->preferred_loc;
3598 			}
3599 		}
3600 		if (get_prefetch_loc) {
3601 			if (prange->prefetch_loc ==
3602 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3603 			    (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3604 			     prefetch_loc != prange->prefetch_loc)) {
3605 				prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3606 				get_prefetch_loc = false;
3607 			} else {
3608 				prefetch_loc = prange->prefetch_loc;
3609 			}
3610 		}
3611 		if (get_accessible) {
3612 			bitmap_and(bitmap_access, bitmap_access,
3613 				   prange->bitmap_access, MAX_GPU_INSTANCE);
3614 			bitmap_and(bitmap_aip, bitmap_aip,
3615 				   prange->bitmap_aip, MAX_GPU_INSTANCE);
3616 		}
3617 		if (get_flags) {
3618 			flags_and &= prange->flags;
3619 			flags_or |= prange->flags;
3620 		}
3621 
3622 		if (get_granularity && prange->granularity < granularity)
3623 			granularity = prange->granularity;
3624 
3625 		node = next;
3626 	}
3627 fill_values:
3628 	mutex_unlock(&svms->lock);
3629 
3630 	for (i = 0; i < nattr; i++) {
3631 		switch (attrs[i].type) {
3632 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3633 			attrs[i].value = location;
3634 			break;
3635 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3636 			attrs[i].value = prefetch_loc;
3637 			break;
3638 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3639 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
3640 							       attrs[i].value);
3641 			if (gpuidx < 0) {
3642 				pr_debug("invalid gpuid %x\n", attrs[i].value);
3643 				return -EINVAL;
3644 			}
3645 			if (test_bit(gpuidx, bitmap_access))
3646 				attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
3647 			else if (test_bit(gpuidx, bitmap_aip))
3648 				attrs[i].type =
3649 					KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
3650 			else
3651 				attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
3652 			break;
3653 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3654 			attrs[i].value = flags_and;
3655 			break;
3656 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3657 			attrs[i].value = ~flags_or;
3658 			break;
3659 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3660 			attrs[i].value = (uint32_t)granularity;
3661 			break;
3662 		}
3663 	}
3664 
3665 	return 0;
3666 }
3667 
3668 int kfd_criu_resume_svm(struct kfd_process *p)
3669 {
3670 	struct kfd_ioctl_svm_attribute *set_attr_new, *set_attr = NULL;
3671 	int nattr_common = 4, nattr_accessibility = 1;
3672 	struct criu_svm_metadata *criu_svm_md = NULL;
3673 	struct svm_range_list *svms = &p->svms;
3674 	struct criu_svm_metadata *next = NULL;
3675 	uint32_t set_flags = 0xffffffff;
3676 	int i, j, num_attrs, ret = 0;
3677 	uint64_t set_attr_size;
3678 	struct mm_struct *mm;
3679 
3680 	if (list_empty(&svms->criu_svm_metadata_list)) {
3681 		pr_debug("No SVM data from CRIU restore stage 2\n");
3682 		return ret;
3683 	}
3684 
3685 	mm = get_task_mm(p->lead_thread);
3686 	if (!mm) {
3687 		pr_err("failed to get mm for the target process\n");
3688 		return -ESRCH;
3689 	}
3690 
3691 	num_attrs = nattr_common + (nattr_accessibility * p->n_pdds);
3692 
3693 	i = j = 0;
3694 	list_for_each_entry(criu_svm_md, &svms->criu_svm_metadata_list, list) {
3695 		pr_debug("criu_svm_md[%d]\n\tstart: 0x%llx size: 0x%llx (npages)\n",
3696 			 i, criu_svm_md->data.start_addr, criu_svm_md->data.size);
3697 
3698 		for (j = 0; j < num_attrs; j++) {
3699 			pr_debug("\ncriu_svm_md[%d]->attrs[%d].type : 0x%x\ncriu_svm_md[%d]->attrs[%d].value : 0x%x\n",
3700 				 i, j, criu_svm_md->data.attrs[j].type,
3701 				 i, j, criu_svm_md->data.attrs[j].value);
3702 			switch (criu_svm_md->data.attrs[j].type) {
3703 			/* During Checkpoint operation, the query for
3704 			 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC attribute might
3705 			 * return KFD_IOCTL_SVM_LOCATION_UNDEFINED if they were
3706 			 * not used by the range which was checkpointed. Care
3707 			 * must be taken to not restore with an invalid value
3708 			 * otherwise the gpuidx value will be invalid and
3709 			 * set_attr would eventually fail so just replace those
3710 			 * with another dummy attribute such as
3711 			 * KFD_IOCTL_SVM_ATTR_SET_FLAGS.
3712 			 */
3713 			case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3714 				if (criu_svm_md->data.attrs[j].value ==
3715 				    KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
3716 					criu_svm_md->data.attrs[j].type =
3717 						KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3718 					criu_svm_md->data.attrs[j].value = 0;
3719 				}
3720 				break;
3721 			case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3722 				set_flags = criu_svm_md->data.attrs[j].value;
3723 				break;
3724 			default:
3725 				break;
3726 			}
3727 		}
3728 
3729 		/* CLR_FLAGS is not available via get_attr during checkpoint but
3730 		 * it needs to be inserted before restoring the ranges so
3731 		 * allocate extra space for it before calling set_attr
3732 		 */
3733 		set_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3734 						(num_attrs + 1);
3735 		set_attr_new = krealloc(set_attr, set_attr_size,
3736 					    GFP_KERNEL);
3737 		if (!set_attr_new) {
3738 			ret = -ENOMEM;
3739 			goto exit;
3740 		}
3741 		set_attr = set_attr_new;
3742 
3743 		memcpy(set_attr, criu_svm_md->data.attrs, num_attrs *
3744 					sizeof(struct kfd_ioctl_svm_attribute));
3745 		set_attr[num_attrs].type = KFD_IOCTL_SVM_ATTR_CLR_FLAGS;
3746 		set_attr[num_attrs].value = ~set_flags;
3747 
3748 		ret = svm_range_set_attr(p, mm, criu_svm_md->data.start_addr,
3749 					 criu_svm_md->data.size, num_attrs + 1,
3750 					 set_attr);
3751 		if (ret) {
3752 			pr_err("CRIU: failed to set range attributes\n");
3753 			goto exit;
3754 		}
3755 
3756 		i++;
3757 	}
3758 exit:
3759 	kfree(set_attr);
3760 	list_for_each_entry_safe(criu_svm_md, next, &svms->criu_svm_metadata_list, list) {
3761 		pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
3762 						criu_svm_md->data.start_addr);
3763 		kfree(criu_svm_md);
3764 	}
3765 
3766 	mmput(mm);
3767 	return ret;
3768 
3769 }
3770 
3771 int kfd_criu_restore_svm(struct kfd_process *p,
3772 			 uint8_t __user *user_priv_ptr,
3773 			 uint64_t *priv_data_offset,
3774 			 uint64_t max_priv_data_size)
3775 {
3776 	uint64_t svm_priv_data_size, svm_object_md_size, svm_attrs_size;
3777 	int nattr_common = 4, nattr_accessibility = 1;
3778 	struct criu_svm_metadata *criu_svm_md = NULL;
3779 	struct svm_range_list *svms = &p->svms;
3780 	uint32_t num_devices;
3781 	int ret = 0;
3782 
3783 	num_devices = p->n_pdds;
3784 	/* Handle one SVM range object at a time, also the number of gpus are
3785 	 * assumed to be same on the restore node, checking must be done while
3786 	 * evaluating the topology earlier
3787 	 */
3788 
3789 	svm_attrs_size = sizeof(struct kfd_ioctl_svm_attribute) *
3790 		(nattr_common + nattr_accessibility * num_devices);
3791 	svm_object_md_size = sizeof(struct criu_svm_metadata) + svm_attrs_size;
3792 
3793 	svm_priv_data_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3794 								svm_attrs_size;
3795 
3796 	criu_svm_md = kzalloc(svm_object_md_size, GFP_KERNEL);
3797 	if (!criu_svm_md) {
3798 		pr_err("failed to allocate memory to store svm metadata\n");
3799 		return -ENOMEM;
3800 	}
3801 	if (*priv_data_offset + svm_priv_data_size > max_priv_data_size) {
3802 		ret = -EINVAL;
3803 		goto exit;
3804 	}
3805 
3806 	ret = copy_from_user(&criu_svm_md->data, user_priv_ptr + *priv_data_offset,
3807 			     svm_priv_data_size);
3808 	if (ret) {
3809 		ret = -EFAULT;
3810 		goto exit;
3811 	}
3812 	*priv_data_offset += svm_priv_data_size;
3813 
3814 	list_add_tail(&criu_svm_md->list, &svms->criu_svm_metadata_list);
3815 
3816 	return 0;
3817 
3818 
3819 exit:
3820 	kfree(criu_svm_md);
3821 	return ret;
3822 }
3823 
3824 int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
3825 		       uint64_t *svm_priv_data_size)
3826 {
3827 	uint64_t total_size, accessibility_size, common_attr_size;
3828 	int nattr_common = 4, nattr_accessibility = 1;
3829 	int num_devices = p->n_pdds;
3830 	struct svm_range_list *svms;
3831 	struct svm_range *prange;
3832 	uint32_t count = 0;
3833 
3834 	*svm_priv_data_size = 0;
3835 
3836 	svms = &p->svms;
3837 	if (!svms)
3838 		return -EINVAL;
3839 
3840 	mutex_lock(&svms->lock);
3841 	list_for_each_entry(prange, &svms->list, list) {
3842 		pr_debug("prange: 0x%p start: 0x%lx\t npages: 0x%llx\t end: 0x%llx\n",
3843 			 prange, prange->start, prange->npages,
3844 			 prange->start + prange->npages - 1);
3845 		count++;
3846 	}
3847 	mutex_unlock(&svms->lock);
3848 
3849 	*num_svm_ranges = count;
3850 	/* Only the accessbility attributes need to be queried for all the gpus
3851 	 * individually, remaining ones are spanned across the entire process
3852 	 * regardless of the various gpu nodes. Of the remaining attributes,
3853 	 * KFD_IOCTL_SVM_ATTR_CLR_FLAGS need not be saved.
3854 	 *
3855 	 * KFD_IOCTL_SVM_ATTR_PREFERRED_LOC
3856 	 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC
3857 	 * KFD_IOCTL_SVM_ATTR_SET_FLAGS
3858 	 * KFD_IOCTL_SVM_ATTR_GRANULARITY
3859 	 *
3860 	 * ** ACCESSBILITY ATTRIBUTES **
3861 	 * (Considered as one, type is altered during query, value is gpuid)
3862 	 * KFD_IOCTL_SVM_ATTR_ACCESS
3863 	 * KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE
3864 	 * KFD_IOCTL_SVM_ATTR_NO_ACCESS
3865 	 */
3866 	if (*num_svm_ranges > 0) {
3867 		common_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3868 			nattr_common;
3869 		accessibility_size = sizeof(struct kfd_ioctl_svm_attribute) *
3870 			nattr_accessibility * num_devices;
3871 
3872 		total_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3873 			common_attr_size + accessibility_size;
3874 
3875 		*svm_priv_data_size = *num_svm_ranges * total_size;
3876 	}
3877 
3878 	pr_debug("num_svm_ranges %u total_priv_size %llu\n", *num_svm_ranges,
3879 		 *svm_priv_data_size);
3880 	return 0;
3881 }
3882 
3883 int kfd_criu_checkpoint_svm(struct kfd_process *p,
3884 			    uint8_t __user *user_priv_data,
3885 			    uint64_t *priv_data_offset)
3886 {
3887 	struct kfd_criu_svm_range_priv_data *svm_priv = NULL;
3888 	struct kfd_ioctl_svm_attribute *query_attr = NULL;
3889 	uint64_t svm_priv_data_size, query_attr_size = 0;
3890 	int index, nattr_common = 4, ret = 0;
3891 	struct svm_range_list *svms;
3892 	int num_devices = p->n_pdds;
3893 	struct svm_range *prange;
3894 	struct mm_struct *mm;
3895 
3896 	svms = &p->svms;
3897 	if (!svms)
3898 		return -EINVAL;
3899 
3900 	mm = get_task_mm(p->lead_thread);
3901 	if (!mm) {
3902 		pr_err("failed to get mm for the target process\n");
3903 		return -ESRCH;
3904 	}
3905 
3906 	query_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3907 				(nattr_common + num_devices);
3908 
3909 	query_attr = kzalloc(query_attr_size, GFP_KERNEL);
3910 	if (!query_attr) {
3911 		ret = -ENOMEM;
3912 		goto exit;
3913 	}
3914 
3915 	query_attr[0].type = KFD_IOCTL_SVM_ATTR_PREFERRED_LOC;
3916 	query_attr[1].type = KFD_IOCTL_SVM_ATTR_PREFETCH_LOC;
3917 	query_attr[2].type = KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3918 	query_attr[3].type = KFD_IOCTL_SVM_ATTR_GRANULARITY;
3919 
3920 	for (index = 0; index < num_devices; index++) {
3921 		struct kfd_process_device *pdd = p->pdds[index];
3922 
3923 		query_attr[index + nattr_common].type =
3924 			KFD_IOCTL_SVM_ATTR_ACCESS;
3925 		query_attr[index + nattr_common].value = pdd->user_gpu_id;
3926 	}
3927 
3928 	svm_priv_data_size = sizeof(*svm_priv) + query_attr_size;
3929 
3930 	svm_priv = kzalloc(svm_priv_data_size, GFP_KERNEL);
3931 	if (!svm_priv) {
3932 		ret = -ENOMEM;
3933 		goto exit_query;
3934 	}
3935 
3936 	index = 0;
3937 	list_for_each_entry(prange, &svms->list, list) {
3938 
3939 		svm_priv->object_type = KFD_CRIU_OBJECT_TYPE_SVM_RANGE;
3940 		svm_priv->start_addr = prange->start;
3941 		svm_priv->size = prange->npages;
3942 		memcpy(&svm_priv->attrs, query_attr, query_attr_size);
3943 		pr_debug("CRIU: prange: 0x%p start: 0x%lx\t npages: 0x%llx end: 0x%llx\t size: 0x%llx\n",
3944 			 prange, prange->start, prange->npages,
3945 			 prange->start + prange->npages - 1,
3946 			 prange->npages * PAGE_SIZE);
3947 
3948 		ret = svm_range_get_attr(p, mm, svm_priv->start_addr,
3949 					 svm_priv->size,
3950 					 (nattr_common + num_devices),
3951 					 svm_priv->attrs);
3952 		if (ret) {
3953 			pr_err("CRIU: failed to obtain range attributes\n");
3954 			goto exit_priv;
3955 		}
3956 
3957 		if (copy_to_user(user_priv_data + *priv_data_offset, svm_priv,
3958 				 svm_priv_data_size)) {
3959 			pr_err("Failed to copy svm priv to user\n");
3960 			ret = -EFAULT;
3961 			goto exit_priv;
3962 		}
3963 
3964 		*priv_data_offset += svm_priv_data_size;
3965 
3966 	}
3967 
3968 
3969 exit_priv:
3970 	kfree(svm_priv);
3971 exit_query:
3972 	kfree(query_attr);
3973 exit:
3974 	mmput(mm);
3975 	return ret;
3976 }
3977 
3978 int
3979 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
3980 	  uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
3981 {
3982 	struct mm_struct *mm = current->mm;
3983 	int r;
3984 
3985 	start >>= PAGE_SHIFT;
3986 	size >>= PAGE_SHIFT;
3987 
3988 	switch (op) {
3989 	case KFD_IOCTL_SVM_OP_SET_ATTR:
3990 		r = svm_range_set_attr(p, mm, start, size, nattrs, attrs);
3991 		break;
3992 	case KFD_IOCTL_SVM_OP_GET_ATTR:
3993 		r = svm_range_get_attr(p, mm, start, size, nattrs, attrs);
3994 		break;
3995 	default:
3996 		r = EINVAL;
3997 		break;
3998 	}
3999 
4000 	return r;
4001 }
4002