xref: /openbmc/linux/drivers/gpu/drm/amd/amdkfd/kfd_svm.c (revision 67ff4a72)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright 2020-2021 Advanced Micro Devices, Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  */
23 
24 #include <linux/types.h>
25 #include <linux/sched/task.h>
26 #include "amdgpu_sync.h"
27 #include "amdgpu_object.h"
28 #include "amdgpu_vm.h"
29 #include "amdgpu_mn.h"
30 #include "amdgpu.h"
31 #include "amdgpu_xgmi.h"
32 #include "kfd_priv.h"
33 #include "kfd_svm.h"
34 #include "kfd_migrate.h"
35 
36 #ifdef dev_fmt
37 #undef dev_fmt
38 #endif
39 #define dev_fmt(fmt) "kfd_svm: %s: " fmt, __func__
40 
41 #define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
42 
43 /* Long enough to ensure no retry fault comes after svm range is restored and
44  * page table is updated.
45  */
46 #define AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING	2000
47 
48 static void svm_range_evict_svm_bo_worker(struct work_struct *work);
49 static bool
50 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
51 				    const struct mmu_notifier_range *range,
52 				    unsigned long cur_seq);
53 static int
54 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
55 		   uint64_t *bo_s, uint64_t *bo_l);
56 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
57 	.invalidate = svm_range_cpu_invalidate_pagetables,
58 };
59 
60 /**
61  * svm_range_unlink - unlink svm_range from lists and interval tree
62  * @prange: svm range structure to be removed
63  *
64  * Remove the svm_range from the svms and svm_bo lists and the svms
65  * interval tree.
66  *
67  * Context: The caller must hold svms->lock
68  */
69 static void svm_range_unlink(struct svm_range *prange)
70 {
71 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
72 		 prange, prange->start, prange->last);
73 
74 	if (prange->svm_bo) {
75 		spin_lock(&prange->svm_bo->list_lock);
76 		list_del(&prange->svm_bo_list);
77 		spin_unlock(&prange->svm_bo->list_lock);
78 	}
79 
80 	list_del(&prange->list);
81 	if (prange->it_node.start != 0 && prange->it_node.last != 0)
82 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
83 }
84 
85 static void
86 svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
87 {
88 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
89 		 prange, prange->start, prange->last);
90 
91 	mmu_interval_notifier_insert_locked(&prange->notifier, mm,
92 				     prange->start << PAGE_SHIFT,
93 				     prange->npages << PAGE_SHIFT,
94 				     &svm_range_mn_ops);
95 }
96 
97 /**
98  * svm_range_add_to_svms - add svm range to svms
99  * @prange: svm range structure to be added
100  *
101  * Add the svm range to svms interval tree and link list
102  *
103  * Context: The caller must hold svms->lock
104  */
105 static void svm_range_add_to_svms(struct svm_range *prange)
106 {
107 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
108 		 prange, prange->start, prange->last);
109 
110 	list_move_tail(&prange->list, &prange->svms->list);
111 	prange->it_node.start = prange->start;
112 	prange->it_node.last = prange->last;
113 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
114 }
115 
116 static void svm_range_remove_notifier(struct svm_range *prange)
117 {
118 	pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
119 		 prange->svms, prange,
120 		 prange->notifier.interval_tree.start >> PAGE_SHIFT,
121 		 prange->notifier.interval_tree.last >> PAGE_SHIFT);
122 
123 	if (prange->notifier.interval_tree.start != 0 &&
124 	    prange->notifier.interval_tree.last != 0)
125 		mmu_interval_notifier_remove(&prange->notifier);
126 }
127 
128 static bool
129 svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
130 {
131 	return dma_addr && !dma_mapping_error(dev, dma_addr) &&
132 	       !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
133 }
134 
135 static int
136 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
137 		      unsigned long offset, unsigned long npages,
138 		      unsigned long *hmm_pfns, uint32_t gpuidx)
139 {
140 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
141 	dma_addr_t *addr = prange->dma_addr[gpuidx];
142 	struct device *dev = adev->dev;
143 	struct page *page;
144 	int i, r;
145 
146 	if (!addr) {
147 		addr = kvmalloc_array(prange->npages, sizeof(*addr),
148 				      GFP_KERNEL | __GFP_ZERO);
149 		if (!addr)
150 			return -ENOMEM;
151 		prange->dma_addr[gpuidx] = addr;
152 	}
153 
154 	addr += offset;
155 	for (i = 0; i < npages; i++) {
156 		if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
157 			dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
158 
159 		page = hmm_pfn_to_page(hmm_pfns[i]);
160 		if (is_zone_device_page(page)) {
161 			struct amdgpu_device *bo_adev =
162 					amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
163 
164 			addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
165 				   bo_adev->vm_manager.vram_base_offset -
166 				   bo_adev->kfd.dev->pgmap.range.start;
167 			addr[i] |= SVM_RANGE_VRAM_DOMAIN;
168 			pr_debug_ratelimited("vram address: 0x%llx\n", addr[i]);
169 			continue;
170 		}
171 		addr[i] = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
172 		r = dma_mapping_error(dev, addr[i]);
173 		if (r) {
174 			dev_err(dev, "failed %d dma_map_page\n", r);
175 			return r;
176 		}
177 		pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
178 				     addr[i] >> PAGE_SHIFT, page_to_pfn(page));
179 	}
180 	return 0;
181 }
182 
183 static int
184 svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
185 		  unsigned long offset, unsigned long npages,
186 		  unsigned long *hmm_pfns)
187 {
188 	struct kfd_process *p;
189 	uint32_t gpuidx;
190 	int r;
191 
192 	p = container_of(prange->svms, struct kfd_process, svms);
193 
194 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
195 		struct kfd_process_device *pdd;
196 
197 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
198 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
199 		if (!pdd) {
200 			pr_debug("failed to find device idx %d\n", gpuidx);
201 			return -EINVAL;
202 		}
203 
204 		r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
205 					  hmm_pfns, gpuidx);
206 		if (r)
207 			break;
208 	}
209 
210 	return r;
211 }
212 
213 void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
214 			 unsigned long offset, unsigned long npages)
215 {
216 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
217 	int i;
218 
219 	if (!dma_addr)
220 		return;
221 
222 	for (i = offset; i < offset + npages; i++) {
223 		if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
224 			continue;
225 		pr_debug_ratelimited("unmap 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
226 		dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
227 		dma_addr[i] = 0;
228 	}
229 }
230 
231 void svm_range_free_dma_mappings(struct svm_range *prange)
232 {
233 	struct kfd_process_device *pdd;
234 	dma_addr_t *dma_addr;
235 	struct device *dev;
236 	struct kfd_process *p;
237 	uint32_t gpuidx;
238 
239 	p = container_of(prange->svms, struct kfd_process, svms);
240 
241 	for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
242 		dma_addr = prange->dma_addr[gpuidx];
243 		if (!dma_addr)
244 			continue;
245 
246 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
247 		if (!pdd) {
248 			pr_debug("failed to find device idx %d\n", gpuidx);
249 			continue;
250 		}
251 		dev = &pdd->dev->pdev->dev;
252 		svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
253 		kvfree(dma_addr);
254 		prange->dma_addr[gpuidx] = NULL;
255 	}
256 }
257 
258 static void svm_range_free(struct svm_range *prange)
259 {
260 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
261 		 prange->start, prange->last);
262 
263 	svm_range_vram_node_free(prange);
264 	svm_range_free_dma_mappings(prange);
265 	mutex_destroy(&prange->lock);
266 	mutex_destroy(&prange->migrate_mutex);
267 	kfree(prange);
268 }
269 
270 static void
271 svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,
272 				 uint8_t *granularity, uint32_t *flags)
273 {
274 	*location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
275 	*prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
276 	*granularity = 9;
277 	*flags =
278 		KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;
279 }
280 
281 static struct
282 svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
283 			 uint64_t last)
284 {
285 	uint64_t size = last - start + 1;
286 	struct svm_range *prange;
287 	struct kfd_process *p;
288 
289 	prange = kzalloc(sizeof(*prange), GFP_KERNEL);
290 	if (!prange)
291 		return NULL;
292 	prange->npages = size;
293 	prange->svms = svms;
294 	prange->start = start;
295 	prange->last = last;
296 	INIT_LIST_HEAD(&prange->list);
297 	INIT_LIST_HEAD(&prange->update_list);
298 	INIT_LIST_HEAD(&prange->svm_bo_list);
299 	INIT_LIST_HEAD(&prange->deferred_list);
300 	INIT_LIST_HEAD(&prange->child_list);
301 	atomic_set(&prange->invalid, 0);
302 	prange->validate_timestamp = 0;
303 	mutex_init(&prange->migrate_mutex);
304 	mutex_init(&prange->lock);
305 
306 	p = container_of(svms, struct kfd_process, svms);
307 	if (p->xnack_enabled)
308 		bitmap_copy(prange->bitmap_access, svms->bitmap_supported,
309 			    MAX_GPU_INSTANCE);
310 
311 	svm_range_set_default_attributes(&prange->preferred_loc,
312 					 &prange->prefetch_loc,
313 					 &prange->granularity, &prange->flags);
314 
315 	pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last);
316 
317 	return prange;
318 }
319 
320 static bool svm_bo_ref_unless_zero(struct svm_range_bo *svm_bo)
321 {
322 	if (!svm_bo || !kref_get_unless_zero(&svm_bo->kref))
323 		return false;
324 
325 	return true;
326 }
327 
328 static void svm_range_bo_release(struct kref *kref)
329 {
330 	struct svm_range_bo *svm_bo;
331 
332 	svm_bo = container_of(kref, struct svm_range_bo, kref);
333 	pr_debug("svm_bo 0x%p\n", svm_bo);
334 
335 	spin_lock(&svm_bo->list_lock);
336 	while (!list_empty(&svm_bo->range_list)) {
337 		struct svm_range *prange =
338 				list_first_entry(&svm_bo->range_list,
339 						struct svm_range, svm_bo_list);
340 		/* list_del_init tells a concurrent svm_range_vram_node_new when
341 		 * it's safe to reuse the svm_bo pointer and svm_bo_list head.
342 		 */
343 		list_del_init(&prange->svm_bo_list);
344 		spin_unlock(&svm_bo->list_lock);
345 
346 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
347 			 prange->start, prange->last);
348 		mutex_lock(&prange->lock);
349 		prange->svm_bo = NULL;
350 		mutex_unlock(&prange->lock);
351 
352 		spin_lock(&svm_bo->list_lock);
353 	}
354 	spin_unlock(&svm_bo->list_lock);
355 	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
356 		/* We're not in the eviction worker.
357 		 * Signal the fence and synchronize with any
358 		 * pending eviction work.
359 		 */
360 		dma_fence_signal(&svm_bo->eviction_fence->base);
361 		cancel_work_sync(&svm_bo->eviction_work);
362 	}
363 	dma_fence_put(&svm_bo->eviction_fence->base);
364 	amdgpu_bo_unref(&svm_bo->bo);
365 	kfree(svm_bo);
366 }
367 
368 static void svm_range_bo_wq_release(struct work_struct *work)
369 {
370 	struct svm_range_bo *svm_bo;
371 
372 	svm_bo = container_of(work, struct svm_range_bo, release_work);
373 	svm_range_bo_release(&svm_bo->kref);
374 }
375 
376 static void svm_range_bo_release_async(struct kref *kref)
377 {
378 	struct svm_range_bo *svm_bo;
379 
380 	svm_bo = container_of(kref, struct svm_range_bo, kref);
381 	pr_debug("svm_bo 0x%p\n", svm_bo);
382 	INIT_WORK(&svm_bo->release_work, svm_range_bo_wq_release);
383 	schedule_work(&svm_bo->release_work);
384 }
385 
386 void svm_range_bo_unref_async(struct svm_range_bo *svm_bo)
387 {
388 	kref_put(&svm_bo->kref, svm_range_bo_release_async);
389 }
390 
391 static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
392 {
393 	if (svm_bo)
394 		kref_put(&svm_bo->kref, svm_range_bo_release);
395 }
396 
397 static bool
398 svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
399 {
400 	struct amdgpu_device *bo_adev;
401 
402 	mutex_lock(&prange->lock);
403 	if (!prange->svm_bo) {
404 		mutex_unlock(&prange->lock);
405 		return false;
406 	}
407 	if (prange->ttm_res) {
408 		/* We still have a reference, all is well */
409 		mutex_unlock(&prange->lock);
410 		return true;
411 	}
412 	if (svm_bo_ref_unless_zero(prange->svm_bo)) {
413 		/*
414 		 * Migrate from GPU to GPU, remove range from source bo_adev
415 		 * svm_bo range list, and return false to allocate svm_bo from
416 		 * destination adev.
417 		 */
418 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
419 		if (bo_adev != adev) {
420 			mutex_unlock(&prange->lock);
421 
422 			spin_lock(&prange->svm_bo->list_lock);
423 			list_del_init(&prange->svm_bo_list);
424 			spin_unlock(&prange->svm_bo->list_lock);
425 
426 			svm_range_bo_unref(prange->svm_bo);
427 			return false;
428 		}
429 		if (READ_ONCE(prange->svm_bo->evicting)) {
430 			struct dma_fence *f;
431 			struct svm_range_bo *svm_bo;
432 			/* The BO is getting evicted,
433 			 * we need to get a new one
434 			 */
435 			mutex_unlock(&prange->lock);
436 			svm_bo = prange->svm_bo;
437 			f = dma_fence_get(&svm_bo->eviction_fence->base);
438 			svm_range_bo_unref(prange->svm_bo);
439 			/* wait for the fence to avoid long spin-loop
440 			 * at list_empty_careful
441 			 */
442 			dma_fence_wait(f, false);
443 			dma_fence_put(f);
444 		} else {
445 			/* The BO was still around and we got
446 			 * a new reference to it
447 			 */
448 			mutex_unlock(&prange->lock);
449 			pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
450 				 prange->svms, prange->start, prange->last);
451 
452 			prange->ttm_res = prange->svm_bo->bo->tbo.resource;
453 			return true;
454 		}
455 
456 	} else {
457 		mutex_unlock(&prange->lock);
458 	}
459 
460 	/* We need a new svm_bo. Spin-loop to wait for concurrent
461 	 * svm_range_bo_release to finish removing this range from
462 	 * its range list. After this, it is safe to reuse the
463 	 * svm_bo pointer and svm_bo_list head.
464 	 */
465 	while (!list_empty_careful(&prange->svm_bo_list))
466 		;
467 
468 	return false;
469 }
470 
471 static struct svm_range_bo *svm_range_bo_new(void)
472 {
473 	struct svm_range_bo *svm_bo;
474 
475 	svm_bo = kzalloc(sizeof(*svm_bo), GFP_KERNEL);
476 	if (!svm_bo)
477 		return NULL;
478 
479 	kref_init(&svm_bo->kref);
480 	INIT_LIST_HEAD(&svm_bo->range_list);
481 	spin_lock_init(&svm_bo->list_lock);
482 
483 	return svm_bo;
484 }
485 
486 int
487 svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
488 			bool clear)
489 {
490 	struct amdgpu_bo_param bp;
491 	struct svm_range_bo *svm_bo;
492 	struct amdgpu_bo_user *ubo;
493 	struct amdgpu_bo *bo;
494 	struct kfd_process *p;
495 	struct mm_struct *mm;
496 	int r;
497 
498 	p = container_of(prange->svms, struct kfd_process, svms);
499 	pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
500 		 prange->start, prange->last);
501 
502 	if (svm_range_validate_svm_bo(adev, prange))
503 		return 0;
504 
505 	svm_bo = svm_range_bo_new();
506 	if (!svm_bo) {
507 		pr_debug("failed to alloc svm bo\n");
508 		return -ENOMEM;
509 	}
510 	mm = get_task_mm(p->lead_thread);
511 	if (!mm) {
512 		pr_debug("failed to get mm\n");
513 		kfree(svm_bo);
514 		return -ESRCH;
515 	}
516 	svm_bo->svms = prange->svms;
517 	svm_bo->eviction_fence =
518 		amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
519 					   mm,
520 					   svm_bo);
521 	mmput(mm);
522 	INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
523 	svm_bo->evicting = 0;
524 	memset(&bp, 0, sizeof(bp));
525 	bp.size = prange->npages * PAGE_SIZE;
526 	bp.byte_align = PAGE_SIZE;
527 	bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
528 	bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
529 	bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
530 	bp.flags |= AMDGPU_AMDKFD_CREATE_SVM_BO;
531 	bp.type = ttm_bo_type_device;
532 	bp.resv = NULL;
533 
534 	r = amdgpu_bo_create_user(adev, &bp, &ubo);
535 	if (r) {
536 		pr_debug("failed %d to create bo\n", r);
537 		goto create_bo_failed;
538 	}
539 	bo = &ubo->bo;
540 	r = amdgpu_bo_reserve(bo, true);
541 	if (r) {
542 		pr_debug("failed %d to reserve bo\n", r);
543 		goto reserve_bo_failed;
544 	}
545 
546 	r = dma_resv_reserve_shared(bo->tbo.base.resv, 1);
547 	if (r) {
548 		pr_debug("failed %d to reserve bo\n", r);
549 		amdgpu_bo_unreserve(bo);
550 		goto reserve_bo_failed;
551 	}
552 	amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
553 
554 	amdgpu_bo_unreserve(bo);
555 
556 	svm_bo->bo = bo;
557 	prange->svm_bo = svm_bo;
558 	prange->ttm_res = bo->tbo.resource;
559 	prange->offset = 0;
560 
561 	spin_lock(&svm_bo->list_lock);
562 	list_add(&prange->svm_bo_list, &svm_bo->range_list);
563 	spin_unlock(&svm_bo->list_lock);
564 
565 	return 0;
566 
567 reserve_bo_failed:
568 	amdgpu_bo_unref(&bo);
569 create_bo_failed:
570 	dma_fence_put(&svm_bo->eviction_fence->base);
571 	kfree(svm_bo);
572 	prange->ttm_res = NULL;
573 
574 	return r;
575 }
576 
577 void svm_range_vram_node_free(struct svm_range *prange)
578 {
579 	svm_range_bo_unref(prange->svm_bo);
580 	prange->ttm_res = NULL;
581 }
582 
583 struct amdgpu_device *
584 svm_range_get_adev_by_id(struct svm_range *prange, uint32_t gpu_id)
585 {
586 	struct kfd_process_device *pdd;
587 	struct kfd_process *p;
588 	int32_t gpu_idx;
589 
590 	p = container_of(prange->svms, struct kfd_process, svms);
591 
592 	gpu_idx = kfd_process_gpuidx_from_gpuid(p, gpu_id);
593 	if (gpu_idx < 0) {
594 		pr_debug("failed to get device by id 0x%x\n", gpu_id);
595 		return NULL;
596 	}
597 	pdd = kfd_process_device_from_gpuidx(p, gpu_idx);
598 	if (!pdd) {
599 		pr_debug("failed to get device by idx 0x%x\n", gpu_idx);
600 		return NULL;
601 	}
602 
603 	return pdd->dev->adev;
604 }
605 
606 struct kfd_process_device *
607 svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev)
608 {
609 	struct kfd_process *p;
610 	int32_t gpu_idx, gpuid;
611 	int r;
612 
613 	p = container_of(prange->svms, struct kfd_process, svms);
614 
615 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpu_idx);
616 	if (r) {
617 		pr_debug("failed to get device id by adev %p\n", adev);
618 		return NULL;
619 	}
620 
621 	return kfd_process_device_from_gpuidx(p, gpu_idx);
622 }
623 
624 static int svm_range_bo_validate(void *param, struct amdgpu_bo *bo)
625 {
626 	struct ttm_operation_ctx ctx = { false, false };
627 
628 	amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_VRAM);
629 
630 	return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
631 }
632 
633 static int
634 svm_range_check_attr(struct kfd_process *p,
635 		     uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
636 {
637 	uint32_t i;
638 
639 	for (i = 0; i < nattr; i++) {
640 		uint32_t val = attrs[i].value;
641 		int gpuidx = MAX_GPU_INSTANCE;
642 
643 		switch (attrs[i].type) {
644 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
645 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM &&
646 			    val != KFD_IOCTL_SVM_LOCATION_UNDEFINED)
647 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
648 			break;
649 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
650 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM)
651 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
652 			break;
653 		case KFD_IOCTL_SVM_ATTR_ACCESS:
654 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
655 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
656 			gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
657 			break;
658 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
659 			break;
660 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
661 			break;
662 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
663 			break;
664 		default:
665 			pr_debug("unknown attr type 0x%x\n", attrs[i].type);
666 			return -EINVAL;
667 		}
668 
669 		if (gpuidx < 0) {
670 			pr_debug("no GPU 0x%x found\n", val);
671 			return -EINVAL;
672 		} else if (gpuidx < MAX_GPU_INSTANCE &&
673 			   !test_bit(gpuidx, p->svms.bitmap_supported)) {
674 			pr_debug("GPU 0x%x not supported\n", val);
675 			return -EINVAL;
676 		}
677 	}
678 
679 	return 0;
680 }
681 
682 static void
683 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
684 		      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
685 {
686 	uint32_t i;
687 	int gpuidx;
688 
689 	for (i = 0; i < nattr; i++) {
690 		switch (attrs[i].type) {
691 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
692 			prange->preferred_loc = attrs[i].value;
693 			break;
694 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
695 			prange->prefetch_loc = attrs[i].value;
696 			break;
697 		case KFD_IOCTL_SVM_ATTR_ACCESS:
698 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
699 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
700 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
701 							       attrs[i].value);
702 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
703 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
704 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
705 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
706 				bitmap_set(prange->bitmap_access, gpuidx, 1);
707 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
708 			} else {
709 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
710 				bitmap_set(prange->bitmap_aip, gpuidx, 1);
711 			}
712 			break;
713 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
714 			prange->flags |= attrs[i].value;
715 			break;
716 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
717 			prange->flags &= ~attrs[i].value;
718 			break;
719 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
720 			prange->granularity = attrs[i].value;
721 			break;
722 		default:
723 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
724 		}
725 	}
726 }
727 
728 static bool
729 svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
730 			uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
731 {
732 	uint32_t i;
733 	int gpuidx;
734 
735 	for (i = 0; i < nattr; i++) {
736 		switch (attrs[i].type) {
737 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
738 			if (prange->preferred_loc != attrs[i].value)
739 				return false;
740 			break;
741 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
742 			/* Prefetch should always trigger a migration even
743 			 * if the value of the attribute didn't change.
744 			 */
745 			return false;
746 		case KFD_IOCTL_SVM_ATTR_ACCESS:
747 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
748 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
749 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
750 							       attrs[i].value);
751 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
752 				if (test_bit(gpuidx, prange->bitmap_access) ||
753 				    test_bit(gpuidx, prange->bitmap_aip))
754 					return false;
755 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
756 				if (!test_bit(gpuidx, prange->bitmap_access))
757 					return false;
758 			} else {
759 				if (!test_bit(gpuidx, prange->bitmap_aip))
760 					return false;
761 			}
762 			break;
763 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
764 			if ((prange->flags & attrs[i].value) != attrs[i].value)
765 				return false;
766 			break;
767 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
768 			if ((prange->flags & attrs[i].value) != 0)
769 				return false;
770 			break;
771 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
772 			if (prange->granularity != attrs[i].value)
773 				return false;
774 			break;
775 		default:
776 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
777 		}
778 	}
779 
780 	return true;
781 }
782 
783 /**
784  * svm_range_debug_dump - print all range information from svms
785  * @svms: svm range list header
786  *
787  * debug output svm range start, end, prefetch location from svms
788  * interval tree and link list
789  *
790  * Context: The caller must hold svms->lock
791  */
792 static void svm_range_debug_dump(struct svm_range_list *svms)
793 {
794 	struct interval_tree_node *node;
795 	struct svm_range *prange;
796 
797 	pr_debug("dump svms 0x%p list\n", svms);
798 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
799 
800 	list_for_each_entry(prange, &svms->list, list) {
801 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
802 			 prange, prange->start, prange->npages,
803 			 prange->start + prange->npages - 1,
804 			 prange->actual_loc);
805 	}
806 
807 	pr_debug("dump svms 0x%p interval tree\n", svms);
808 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
809 	node = interval_tree_iter_first(&svms->objects, 0, ~0ULL);
810 	while (node) {
811 		prange = container_of(node, struct svm_range, it_node);
812 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
813 			 prange, prange->start, prange->npages,
814 			 prange->start + prange->npages - 1,
815 			 prange->actual_loc);
816 		node = interval_tree_iter_next(node, 0, ~0ULL);
817 	}
818 }
819 
820 static int
821 svm_range_split_array(void *ppnew, void *ppold, size_t size,
822 		      uint64_t old_start, uint64_t old_n,
823 		      uint64_t new_start, uint64_t new_n)
824 {
825 	unsigned char *new, *old, *pold;
826 	uint64_t d;
827 
828 	if (!ppold)
829 		return 0;
830 	pold = *(unsigned char **)ppold;
831 	if (!pold)
832 		return 0;
833 
834 	new = kvmalloc_array(new_n, size, GFP_KERNEL);
835 	if (!new)
836 		return -ENOMEM;
837 
838 	d = (new_start - old_start) * size;
839 	memcpy(new, pold + d, new_n * size);
840 
841 	old = kvmalloc_array(old_n, size, GFP_KERNEL);
842 	if (!old) {
843 		kvfree(new);
844 		return -ENOMEM;
845 	}
846 
847 	d = (new_start == old_start) ? new_n * size : 0;
848 	memcpy(old, pold + d, old_n * size);
849 
850 	kvfree(pold);
851 	*(void **)ppold = old;
852 	*(void **)ppnew = new;
853 
854 	return 0;
855 }
856 
857 static int
858 svm_range_split_pages(struct svm_range *new, struct svm_range *old,
859 		      uint64_t start, uint64_t last)
860 {
861 	uint64_t npages = last - start + 1;
862 	int i, r;
863 
864 	for (i = 0; i < MAX_GPU_INSTANCE; i++) {
865 		r = svm_range_split_array(&new->dma_addr[i], &old->dma_addr[i],
866 					  sizeof(*old->dma_addr[i]), old->start,
867 					  npages, new->start, new->npages);
868 		if (r)
869 			return r;
870 	}
871 
872 	return 0;
873 }
874 
875 static int
876 svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
877 		      uint64_t start, uint64_t last)
878 {
879 	uint64_t npages = last - start + 1;
880 
881 	pr_debug("svms 0x%p new prange 0x%p start 0x%lx [0x%llx 0x%llx]\n",
882 		 new->svms, new, new->start, start, last);
883 
884 	if (new->start == old->start) {
885 		new->offset = old->offset;
886 		old->offset += new->npages;
887 	} else {
888 		new->offset = old->offset + npages;
889 	}
890 
891 	new->svm_bo = svm_range_bo_ref(old->svm_bo);
892 	new->ttm_res = old->ttm_res;
893 
894 	spin_lock(&new->svm_bo->list_lock);
895 	list_add(&new->svm_bo_list, &new->svm_bo->range_list);
896 	spin_unlock(&new->svm_bo->list_lock);
897 
898 	return 0;
899 }
900 
901 /**
902  * svm_range_split_adjust - split range and adjust
903  *
904  * @new: new range
905  * @old: the old range
906  * @start: the old range adjust to start address in pages
907  * @last: the old range adjust to last address in pages
908  *
909  * Copy system memory dma_addr or vram ttm_res in old range to new
910  * range from new_start up to size new->npages, the remaining old range is from
911  * start to last
912  *
913  * Return:
914  * 0 - OK, -ENOMEM - out of memory
915  */
916 static int
917 svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
918 		      uint64_t start, uint64_t last)
919 {
920 	int r;
921 
922 	pr_debug("svms 0x%p new 0x%lx old [0x%lx 0x%lx] => [0x%llx 0x%llx]\n",
923 		 new->svms, new->start, old->start, old->last, start, last);
924 
925 	if (new->start < old->start ||
926 	    new->last > old->last) {
927 		WARN_ONCE(1, "invalid new range start or last\n");
928 		return -EINVAL;
929 	}
930 
931 	r = svm_range_split_pages(new, old, start, last);
932 	if (r)
933 		return r;
934 
935 	if (old->actual_loc && old->ttm_res) {
936 		r = svm_range_split_nodes(new, old, start, last);
937 		if (r)
938 			return r;
939 	}
940 
941 	old->npages = last - start + 1;
942 	old->start = start;
943 	old->last = last;
944 	new->flags = old->flags;
945 	new->preferred_loc = old->preferred_loc;
946 	new->prefetch_loc = old->prefetch_loc;
947 	new->actual_loc = old->actual_loc;
948 	new->granularity = old->granularity;
949 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
950 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
951 
952 	return 0;
953 }
954 
955 /**
956  * svm_range_split - split a range in 2 ranges
957  *
958  * @prange: the svm range to split
959  * @start: the remaining range start address in pages
960  * @last: the remaining range last address in pages
961  * @new: the result new range generated
962  *
963  * Two cases only:
964  * case 1: if start == prange->start
965  *         prange ==> prange[start, last]
966  *         new range [last + 1, prange->last]
967  *
968  * case 2: if last == prange->last
969  *         prange ==> prange[start, last]
970  *         new range [prange->start, start - 1]
971  *
972  * Return:
973  * 0 - OK, -ENOMEM - out of memory, -EINVAL - invalid start, last
974  */
975 static int
976 svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
977 		struct svm_range **new)
978 {
979 	uint64_t old_start = prange->start;
980 	uint64_t old_last = prange->last;
981 	struct svm_range_list *svms;
982 	int r = 0;
983 
984 	pr_debug("svms 0x%p [0x%llx 0x%llx] to [0x%llx 0x%llx]\n", prange->svms,
985 		 old_start, old_last, start, last);
986 
987 	if (old_start != start && old_last != last)
988 		return -EINVAL;
989 	if (start < old_start || last > old_last)
990 		return -EINVAL;
991 
992 	svms = prange->svms;
993 	if (old_start == start)
994 		*new = svm_range_new(svms, last + 1, old_last);
995 	else
996 		*new = svm_range_new(svms, old_start, start - 1);
997 	if (!*new)
998 		return -ENOMEM;
999 
1000 	r = svm_range_split_adjust(*new, prange, start, last);
1001 	if (r) {
1002 		pr_debug("failed %d split [0x%llx 0x%llx] to [0x%llx 0x%llx]\n",
1003 			 r, old_start, old_last, start, last);
1004 		svm_range_free(*new);
1005 		*new = NULL;
1006 	}
1007 
1008 	return r;
1009 }
1010 
1011 static int
1012 svm_range_split_tail(struct svm_range *prange,
1013 		     uint64_t new_last, struct list_head *insert_list)
1014 {
1015 	struct svm_range *tail;
1016 	int r = svm_range_split(prange, prange->start, new_last, &tail);
1017 
1018 	if (!r)
1019 		list_add(&tail->list, insert_list);
1020 	return r;
1021 }
1022 
1023 static int
1024 svm_range_split_head(struct svm_range *prange,
1025 		     uint64_t new_start, struct list_head *insert_list)
1026 {
1027 	struct svm_range *head;
1028 	int r = svm_range_split(prange, new_start, prange->last, &head);
1029 
1030 	if (!r)
1031 		list_add(&head->list, insert_list);
1032 	return r;
1033 }
1034 
1035 static void
1036 svm_range_add_child(struct svm_range *prange, struct mm_struct *mm,
1037 		    struct svm_range *pchild, enum svm_work_list_ops op)
1038 {
1039 	pr_debug("add child 0x%p [0x%lx 0x%lx] to prange 0x%p child list %d\n",
1040 		 pchild, pchild->start, pchild->last, prange, op);
1041 
1042 	pchild->work_item.mm = mm;
1043 	pchild->work_item.op = op;
1044 	list_add_tail(&pchild->child_list, &prange->child_list);
1045 }
1046 
1047 /**
1048  * svm_range_split_by_granularity - collect ranges within granularity boundary
1049  *
1050  * @p: the process with svms list
1051  * @mm: mm structure
1052  * @addr: the vm fault address in pages, to split the prange
1053  * @parent: parent range if prange is from child list
1054  * @prange: prange to split
1055  *
1056  * Trims @prange to be a single aligned block of prange->granularity if
1057  * possible. The head and tail are added to the child_list in @parent.
1058  *
1059  * Context: caller must hold mmap_read_lock and prange->lock
1060  *
1061  * Return:
1062  * 0 - OK, otherwise error code
1063  */
1064 int
1065 svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
1066 			       unsigned long addr, struct svm_range *parent,
1067 			       struct svm_range *prange)
1068 {
1069 	struct svm_range *head, *tail;
1070 	unsigned long start, last, size;
1071 	int r;
1072 
1073 	/* Align splited range start and size to granularity size, then a single
1074 	 * PTE will be used for whole range, this reduces the number of PTE
1075 	 * updated and the L1 TLB space used for translation.
1076 	 */
1077 	size = 1UL << prange->granularity;
1078 	start = ALIGN_DOWN(addr, size);
1079 	last = ALIGN(addr + 1, size) - 1;
1080 
1081 	pr_debug("svms 0x%p split [0x%lx 0x%lx] to [0x%lx 0x%lx] size 0x%lx\n",
1082 		 prange->svms, prange->start, prange->last, start, last, size);
1083 
1084 	if (start > prange->start) {
1085 		r = svm_range_split(prange, start, prange->last, &head);
1086 		if (r)
1087 			return r;
1088 		svm_range_add_child(parent, mm, head, SVM_OP_ADD_RANGE);
1089 	}
1090 
1091 	if (last < prange->last) {
1092 		r = svm_range_split(prange, prange->start, last, &tail);
1093 		if (r)
1094 			return r;
1095 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
1096 	}
1097 
1098 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
1099 	if (p->xnack_enabled && prange->work_item.op == SVM_OP_ADD_RANGE) {
1100 		prange->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
1101 		pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
1102 			 prange, prange->start, prange->last,
1103 			 SVM_OP_ADD_RANGE_AND_MAP);
1104 	}
1105 	return 0;
1106 }
1107 
1108 static uint64_t
1109 svm_range_get_pte_flags(struct amdgpu_device *adev, struct svm_range *prange,
1110 			int domain)
1111 {
1112 	struct amdgpu_device *bo_adev;
1113 	uint32_t flags = prange->flags;
1114 	uint32_t mapping_flags = 0;
1115 	uint64_t pte_flags;
1116 	bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
1117 	bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
1118 
1119 	if (domain == SVM_RANGE_VRAM_DOMAIN)
1120 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1121 
1122 	switch (KFD_GC_VERSION(adev->kfd.dev)) {
1123 	case IP_VERSION(9, 4, 1):
1124 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1125 			if (bo_adev == adev) {
1126 				mapping_flags |= coherent ?
1127 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1128 			} else {
1129 				mapping_flags |= coherent ?
1130 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1131 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1132 					snoop = true;
1133 			}
1134 		} else {
1135 			mapping_flags |= coherent ?
1136 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1137 		}
1138 		break;
1139 	case IP_VERSION(9, 4, 2):
1140 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1141 			if (bo_adev == adev) {
1142 				mapping_flags |= coherent ?
1143 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1144 				if (adev->gmc.xgmi.connected_to_cpu)
1145 					snoop = true;
1146 			} else {
1147 				mapping_flags |= coherent ?
1148 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1149 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1150 					snoop = true;
1151 			}
1152 		} else {
1153 			mapping_flags |= coherent ?
1154 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1155 		}
1156 		break;
1157 	default:
1158 		mapping_flags |= coherent ?
1159 			AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1160 	}
1161 
1162 	mapping_flags |= AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE;
1163 
1164 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_RO)
1165 		mapping_flags &= ~AMDGPU_VM_PAGE_WRITEABLE;
1166 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_EXEC)
1167 		mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;
1168 
1169 	pte_flags = AMDGPU_PTE_VALID;
1170 	pte_flags |= (domain == SVM_RANGE_VRAM_DOMAIN) ? 0 : AMDGPU_PTE_SYSTEM;
1171 	pte_flags |= snoop ? AMDGPU_PTE_SNOOPED : 0;
1172 
1173 	pte_flags |= amdgpu_gem_va_map_flags(adev, mapping_flags);
1174 	return pte_flags;
1175 }
1176 
1177 static int
1178 svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
1179 			 uint64_t start, uint64_t last,
1180 			 struct dma_fence **fence)
1181 {
1182 	uint64_t init_pte_value = 0;
1183 
1184 	pr_debug("[0x%llx 0x%llx]\n", start, last);
1185 
1186 	return amdgpu_vm_bo_update_mapping(adev, adev, vm, false, true, NULL,
1187 					   start, last, init_pte_value, 0,
1188 					   NULL, NULL, fence, NULL);
1189 }
1190 
1191 static int
1192 svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
1193 			  unsigned long last)
1194 {
1195 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1196 	struct kfd_process_device *pdd;
1197 	struct dma_fence *fence = NULL;
1198 	struct kfd_process *p;
1199 	uint32_t gpuidx;
1200 	int r = 0;
1201 
1202 	bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
1203 		  MAX_GPU_INSTANCE);
1204 	p = container_of(prange->svms, struct kfd_process, svms);
1205 
1206 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1207 		pr_debug("unmap from gpu idx 0x%x\n", gpuidx);
1208 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1209 		if (!pdd) {
1210 			pr_debug("failed to find device idx %d\n", gpuidx);
1211 			return -EINVAL;
1212 		}
1213 
1214 		r = svm_range_unmap_from_gpu(pdd->dev->adev,
1215 					     drm_priv_to_vm(pdd->drm_priv),
1216 					     start, last, &fence);
1217 		if (r)
1218 			break;
1219 
1220 		if (fence) {
1221 			r = dma_fence_wait(fence, false);
1222 			dma_fence_put(fence);
1223 			fence = NULL;
1224 			if (r)
1225 				break;
1226 		}
1227 		amdgpu_amdkfd_flush_gpu_tlb_pasid(pdd->dev->adev,
1228 					p->pasid, TLB_FLUSH_HEAVYWEIGHT);
1229 	}
1230 
1231 	return r;
1232 }
1233 
1234 static int
1235 svm_range_map_to_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
1236 		     struct svm_range *prange, unsigned long offset,
1237 		     unsigned long npages, bool readonly, dma_addr_t *dma_addr,
1238 		     struct amdgpu_device *bo_adev, struct dma_fence **fence)
1239 {
1240 	bool table_freed = false;
1241 	uint64_t pte_flags;
1242 	unsigned long last_start;
1243 	int last_domain;
1244 	int r = 0;
1245 	int64_t i, j;
1246 
1247 	last_start = prange->start + offset;
1248 
1249 	pr_debug("svms 0x%p [0x%lx 0x%lx] readonly %d\n", prange->svms,
1250 		 last_start, last_start + npages - 1, readonly);
1251 
1252 	for (i = offset; i < offset + npages; i++) {
1253 		last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
1254 		dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
1255 
1256 		/* Collect all pages in the same address range and memory domain
1257 		 * that can be mapped with a single call to update mapping.
1258 		 */
1259 		if (i < offset + npages - 1 &&
1260 		    last_domain == (dma_addr[i + 1] & SVM_RANGE_VRAM_DOMAIN))
1261 			continue;
1262 
1263 		pr_debug("Mapping range [0x%lx 0x%llx] on domain: %s\n",
1264 			 last_start, prange->start + i, last_domain ? "GPU" : "CPU");
1265 
1266 		pte_flags = svm_range_get_pte_flags(adev, prange, last_domain);
1267 		if (readonly)
1268 			pte_flags &= ~AMDGPU_PTE_WRITEABLE;
1269 
1270 		pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n",
1271 			 prange->svms, last_start, prange->start + i,
1272 			 (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
1273 			 pte_flags);
1274 
1275 		r = amdgpu_vm_bo_update_mapping(adev, bo_adev, vm, false, false,
1276 						NULL, last_start,
1277 						prange->start + i, pte_flags,
1278 						last_start - prange->start,
1279 						NULL, dma_addr,
1280 						&vm->last_update,
1281 						&table_freed);
1282 
1283 		for (j = last_start - prange->start; j <= i; j++)
1284 			dma_addr[j] |= last_domain;
1285 
1286 		if (r) {
1287 			pr_debug("failed %d to map to gpu 0x%lx\n", r, prange->start);
1288 			goto out;
1289 		}
1290 		last_start = prange->start + i + 1;
1291 	}
1292 
1293 	r = amdgpu_vm_update_pdes(adev, vm, false);
1294 	if (r) {
1295 		pr_debug("failed %d to update directories 0x%lx\n", r,
1296 			 prange->start);
1297 		goto out;
1298 	}
1299 
1300 	if (fence)
1301 		*fence = dma_fence_get(vm->last_update);
1302 
1303 	if (table_freed) {
1304 		struct kfd_process *p;
1305 
1306 		p = container_of(prange->svms, struct kfd_process, svms);
1307 		amdgpu_amdkfd_flush_gpu_tlb_pasid(adev, p->pasid, TLB_FLUSH_LEGACY);
1308 	}
1309 out:
1310 	return r;
1311 }
1312 
1313 static int
1314 svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
1315 		      unsigned long npages, bool readonly,
1316 		      unsigned long *bitmap, bool wait)
1317 {
1318 	struct kfd_process_device *pdd;
1319 	struct amdgpu_device *bo_adev;
1320 	struct kfd_process *p;
1321 	struct dma_fence *fence = NULL;
1322 	uint32_t gpuidx;
1323 	int r = 0;
1324 
1325 	if (prange->svm_bo && prange->ttm_res)
1326 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1327 	else
1328 		bo_adev = NULL;
1329 
1330 	p = container_of(prange->svms, struct kfd_process, svms);
1331 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1332 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
1333 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1334 		if (!pdd) {
1335 			pr_debug("failed to find device idx %d\n", gpuidx);
1336 			return -EINVAL;
1337 		}
1338 
1339 		pdd = kfd_bind_process_to_device(pdd->dev, p);
1340 		if (IS_ERR(pdd))
1341 			return -EINVAL;
1342 
1343 		if (bo_adev && pdd->dev->adev != bo_adev &&
1344 		    !amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
1345 			pr_debug("cannot map to device idx %d\n", gpuidx);
1346 			continue;
1347 		}
1348 
1349 		r = svm_range_map_to_gpu(pdd->dev->adev, drm_priv_to_vm(pdd->drm_priv),
1350 					 prange, offset, npages, readonly,
1351 					 prange->dma_addr[gpuidx],
1352 					 bo_adev, wait ? &fence : NULL);
1353 		if (r)
1354 			break;
1355 
1356 		if (fence) {
1357 			r = dma_fence_wait(fence, false);
1358 			dma_fence_put(fence);
1359 			fence = NULL;
1360 			if (r) {
1361 				pr_debug("failed %d to dma fence wait\n", r);
1362 				break;
1363 			}
1364 		}
1365 	}
1366 
1367 	return r;
1368 }
1369 
1370 struct svm_validate_context {
1371 	struct kfd_process *process;
1372 	struct svm_range *prange;
1373 	bool intr;
1374 	unsigned long bitmap[MAX_GPU_INSTANCE];
1375 	struct ttm_validate_buffer tv[MAX_GPU_INSTANCE];
1376 	struct list_head validate_list;
1377 	struct ww_acquire_ctx ticket;
1378 };
1379 
1380 static int svm_range_reserve_bos(struct svm_validate_context *ctx)
1381 {
1382 	struct kfd_process_device *pdd;
1383 	struct amdgpu_vm *vm;
1384 	uint32_t gpuidx;
1385 	int r;
1386 
1387 	INIT_LIST_HEAD(&ctx->validate_list);
1388 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1389 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1390 		if (!pdd) {
1391 			pr_debug("failed to find device idx %d\n", gpuidx);
1392 			return -EINVAL;
1393 		}
1394 		vm = drm_priv_to_vm(pdd->drm_priv);
1395 
1396 		ctx->tv[gpuidx].bo = &vm->root.bo->tbo;
1397 		ctx->tv[gpuidx].num_shared = 4;
1398 		list_add(&ctx->tv[gpuidx].head, &ctx->validate_list);
1399 	}
1400 
1401 	r = ttm_eu_reserve_buffers(&ctx->ticket, &ctx->validate_list,
1402 				   ctx->intr, NULL);
1403 	if (r) {
1404 		pr_debug("failed %d to reserve bo\n", r);
1405 		return r;
1406 	}
1407 
1408 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1409 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1410 		if (!pdd) {
1411 			pr_debug("failed to find device idx %d\n", gpuidx);
1412 			r = -EINVAL;
1413 			goto unreserve_out;
1414 		}
1415 
1416 		r = amdgpu_vm_validate_pt_bos(pdd->dev->adev,
1417 					      drm_priv_to_vm(pdd->drm_priv),
1418 					      svm_range_bo_validate, NULL);
1419 		if (r) {
1420 			pr_debug("failed %d validate pt bos\n", r);
1421 			goto unreserve_out;
1422 		}
1423 	}
1424 
1425 	return 0;
1426 
1427 unreserve_out:
1428 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1429 	return r;
1430 }
1431 
1432 static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
1433 {
1434 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1435 }
1436 
1437 static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
1438 {
1439 	struct kfd_process_device *pdd;
1440 
1441 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1442 
1443 	return SVM_ADEV_PGMAP_OWNER(pdd->dev->adev);
1444 }
1445 
1446 /*
1447  * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
1448  *
1449  * To prevent concurrent destruction or change of range attributes, the
1450  * svm_read_lock must be held. The caller must not hold the svm_write_lock
1451  * because that would block concurrent evictions and lead to deadlocks. To
1452  * serialize concurrent migrations or validations of the same range, the
1453  * prange->migrate_mutex must be held.
1454  *
1455  * For VRAM ranges, the SVM BO must be allocated and valid (protected by its
1456  * eviction fence.
1457  *
1458  * The following sequence ensures race-free validation and GPU mapping:
1459  *
1460  * 1. Reserve page table (and SVM BO if range is in VRAM)
1461  * 2. hmm_range_fault to get page addresses (if system memory)
1462  * 3. DMA-map pages (if system memory)
1463  * 4-a. Take notifier lock
1464  * 4-b. Check that pages still valid (mmu_interval_read_retry)
1465  * 4-c. Check that the range was not split or otherwise invalidated
1466  * 4-d. Update GPU page table
1467  * 4.e. Release notifier lock
1468  * 5. Release page table (and SVM BO) reservation
1469  */
1470 static int svm_range_validate_and_map(struct mm_struct *mm,
1471 				      struct svm_range *prange,
1472 				      int32_t gpuidx, bool intr, bool wait)
1473 {
1474 	struct svm_validate_context ctx;
1475 	unsigned long start, end, addr;
1476 	struct kfd_process *p;
1477 	void *owner;
1478 	int32_t idx;
1479 	int r = 0;
1480 
1481 	ctx.process = container_of(prange->svms, struct kfd_process, svms);
1482 	ctx.prange = prange;
1483 	ctx.intr = intr;
1484 
1485 	if (gpuidx < MAX_GPU_INSTANCE) {
1486 		bitmap_zero(ctx.bitmap, MAX_GPU_INSTANCE);
1487 		bitmap_set(ctx.bitmap, gpuidx, 1);
1488 	} else if (ctx.process->xnack_enabled) {
1489 		bitmap_copy(ctx.bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
1490 
1491 		/* If prefetch range to GPU, or GPU retry fault migrate range to
1492 		 * GPU, which has ACCESS attribute to the range, create mapping
1493 		 * on that GPU.
1494 		 */
1495 		if (prange->actual_loc) {
1496 			gpuidx = kfd_process_gpuidx_from_gpuid(ctx.process,
1497 							prange->actual_loc);
1498 			if (gpuidx < 0) {
1499 				WARN_ONCE(1, "failed get device by id 0x%x\n",
1500 					 prange->actual_loc);
1501 				return -EINVAL;
1502 			}
1503 			if (test_bit(gpuidx, prange->bitmap_access))
1504 				bitmap_set(ctx.bitmap, gpuidx, 1);
1505 		}
1506 	} else {
1507 		bitmap_or(ctx.bitmap, prange->bitmap_access,
1508 			  prange->bitmap_aip, MAX_GPU_INSTANCE);
1509 	}
1510 
1511 	if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE))
1512 		return 0;
1513 
1514 	if (prange->actual_loc && !prange->ttm_res) {
1515 		/* This should never happen. actual_loc gets set by
1516 		 * svm_migrate_ram_to_vram after allocating a BO.
1517 		 */
1518 		WARN_ONCE(1, "VRAM BO missing during validation\n");
1519 		return -EINVAL;
1520 	}
1521 
1522 	svm_range_reserve_bos(&ctx);
1523 
1524 	p = container_of(prange->svms, struct kfd_process, svms);
1525 	owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
1526 						MAX_GPU_INSTANCE));
1527 	for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
1528 		if (kfd_svm_page_owner(p, idx) != owner) {
1529 			owner = NULL;
1530 			break;
1531 		}
1532 	}
1533 
1534 	start = prange->start << PAGE_SHIFT;
1535 	end = (prange->last + 1) << PAGE_SHIFT;
1536 	for (addr = start; addr < end && !r; ) {
1537 		struct hmm_range *hmm_range;
1538 		struct vm_area_struct *vma;
1539 		unsigned long next;
1540 		unsigned long offset;
1541 		unsigned long npages;
1542 		bool readonly;
1543 
1544 		vma = find_vma(mm, addr);
1545 		if (!vma || addr < vma->vm_start) {
1546 			r = -EFAULT;
1547 			goto unreserve_out;
1548 		}
1549 		readonly = !(vma->vm_flags & VM_WRITE);
1550 
1551 		next = min(vma->vm_end, end);
1552 		npages = (next - addr) >> PAGE_SHIFT;
1553 		WRITE_ONCE(p->svms.faulting_task, current);
1554 		r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
1555 					       addr, npages, &hmm_range,
1556 					       readonly, true, owner);
1557 		WRITE_ONCE(p->svms.faulting_task, NULL);
1558 		if (r) {
1559 			pr_debug("failed %d to get svm range pages\n", r);
1560 			goto unreserve_out;
1561 		}
1562 
1563 		offset = (addr - start) >> PAGE_SHIFT;
1564 		r = svm_range_dma_map(prange, ctx.bitmap, offset, npages,
1565 				      hmm_range->hmm_pfns);
1566 		if (r) {
1567 			pr_debug("failed %d to dma map range\n", r);
1568 			goto unreserve_out;
1569 		}
1570 
1571 		svm_range_lock(prange);
1572 		if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
1573 			pr_debug("hmm update the range, need validate again\n");
1574 			r = -EAGAIN;
1575 			goto unlock_out;
1576 		}
1577 		if (!list_empty(&prange->child_list)) {
1578 			pr_debug("range split by unmap in parallel, validate again\n");
1579 			r = -EAGAIN;
1580 			goto unlock_out;
1581 		}
1582 
1583 		r = svm_range_map_to_gpus(prange, offset, npages, readonly,
1584 					  ctx.bitmap, wait);
1585 
1586 unlock_out:
1587 		svm_range_unlock(prange);
1588 
1589 		addr = next;
1590 	}
1591 
1592 	if (addr == end)
1593 		prange->validated_once = true;
1594 
1595 unreserve_out:
1596 	svm_range_unreserve_bos(&ctx);
1597 
1598 	if (!r)
1599 		prange->validate_timestamp = ktime_to_us(ktime_get());
1600 
1601 	return r;
1602 }
1603 
1604 /**
1605  * svm_range_list_lock_and_flush_work - flush pending deferred work
1606  *
1607  * @svms: the svm range list
1608  * @mm: the mm structure
1609  *
1610  * Context: Returns with mmap write lock held, pending deferred work flushed
1611  *
1612  */
1613 void
1614 svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
1615 				   struct mm_struct *mm)
1616 {
1617 retry_flush_work:
1618 	flush_work(&svms->deferred_list_work);
1619 	mmap_write_lock(mm);
1620 
1621 	if (list_empty(&svms->deferred_range_list))
1622 		return;
1623 	mmap_write_unlock(mm);
1624 	pr_debug("retry flush\n");
1625 	goto retry_flush_work;
1626 }
1627 
1628 static void svm_range_restore_work(struct work_struct *work)
1629 {
1630 	struct delayed_work *dwork = to_delayed_work(work);
1631 	struct svm_range_list *svms;
1632 	struct svm_range *prange;
1633 	struct kfd_process *p;
1634 	struct mm_struct *mm;
1635 	int evicted_ranges;
1636 	int invalid;
1637 	int r;
1638 
1639 	svms = container_of(dwork, struct svm_range_list, restore_work);
1640 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1641 	if (!evicted_ranges)
1642 		return;
1643 
1644 	pr_debug("restore svm ranges\n");
1645 
1646 	p = container_of(svms, struct kfd_process, svms);
1647 
1648 	/* Keep mm reference when svm_range_validate_and_map ranges */
1649 	mm = get_task_mm(p->lead_thread);
1650 	if (!mm) {
1651 		pr_debug("svms 0x%p process mm gone\n", svms);
1652 		return;
1653 	}
1654 
1655 	svm_range_list_lock_and_flush_work(svms, mm);
1656 	mutex_lock(&svms->lock);
1657 
1658 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1659 
1660 	list_for_each_entry(prange, &svms->list, list) {
1661 		invalid = atomic_read(&prange->invalid);
1662 		if (!invalid)
1663 			continue;
1664 
1665 		pr_debug("restoring svms 0x%p prange 0x%p [0x%lx %lx] inv %d\n",
1666 			 prange->svms, prange, prange->start, prange->last,
1667 			 invalid);
1668 
1669 		/*
1670 		 * If range is migrating, wait for migration is done.
1671 		 */
1672 		mutex_lock(&prange->migrate_mutex);
1673 
1674 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
1675 					       false, true);
1676 		if (r)
1677 			pr_debug("failed %d to map 0x%lx to gpus\n", r,
1678 				 prange->start);
1679 
1680 		mutex_unlock(&prange->migrate_mutex);
1681 		if (r)
1682 			goto out_reschedule;
1683 
1684 		if (atomic_cmpxchg(&prange->invalid, invalid, 0) != invalid)
1685 			goto out_reschedule;
1686 	}
1687 
1688 	if (atomic_cmpxchg(&svms->evicted_ranges, evicted_ranges, 0) !=
1689 	    evicted_ranges)
1690 		goto out_reschedule;
1691 
1692 	evicted_ranges = 0;
1693 
1694 	r = kgd2kfd_resume_mm(mm);
1695 	if (r) {
1696 		/* No recovery from this failure. Probably the CP is
1697 		 * hanging. No point trying again.
1698 		 */
1699 		pr_debug("failed %d to resume KFD\n", r);
1700 	}
1701 
1702 	pr_debug("restore svm ranges successfully\n");
1703 
1704 out_reschedule:
1705 	mutex_unlock(&svms->lock);
1706 	mmap_write_unlock(mm);
1707 	mmput(mm);
1708 
1709 	/* If validation failed, reschedule another attempt */
1710 	if (evicted_ranges) {
1711 		pr_debug("reschedule to restore svm range\n");
1712 		schedule_delayed_work(&svms->restore_work,
1713 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1714 	}
1715 }
1716 
1717 /**
1718  * svm_range_evict - evict svm range
1719  * @prange: svm range structure
1720  * @mm: current process mm_struct
1721  * @start: starting process queue number
1722  * @last: last process queue number
1723  *
1724  * Stop all queues of the process to ensure GPU doesn't access the memory, then
1725  * return to let CPU evict the buffer and proceed CPU pagetable update.
1726  *
1727  * Don't need use lock to sync cpu pagetable invalidation with GPU execution.
1728  * If invalidation happens while restore work is running, restore work will
1729  * restart to ensure to get the latest CPU pages mapping to GPU, then start
1730  * the queues.
1731  */
1732 static int
1733 svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
1734 		unsigned long start, unsigned long last)
1735 {
1736 	struct svm_range_list *svms = prange->svms;
1737 	struct svm_range *pchild;
1738 	struct kfd_process *p;
1739 	int r = 0;
1740 
1741 	p = container_of(svms, struct kfd_process, svms);
1742 
1743 	pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
1744 		 svms, prange->start, prange->last, start, last);
1745 
1746 	if (!p->xnack_enabled) {
1747 		int evicted_ranges;
1748 
1749 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1750 			mutex_lock_nested(&pchild->lock, 1);
1751 			if (pchild->start <= last && pchild->last >= start) {
1752 				pr_debug("increment pchild invalid [0x%lx 0x%lx]\n",
1753 					 pchild->start, pchild->last);
1754 				atomic_inc(&pchild->invalid);
1755 			}
1756 			mutex_unlock(&pchild->lock);
1757 		}
1758 
1759 		if (prange->start <= last && prange->last >= start)
1760 			atomic_inc(&prange->invalid);
1761 
1762 		evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
1763 		if (evicted_ranges != 1)
1764 			return r;
1765 
1766 		pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
1767 			 prange->svms, prange->start, prange->last);
1768 
1769 		/* First eviction, stop the queues */
1770 		r = kgd2kfd_quiesce_mm(mm);
1771 		if (r)
1772 			pr_debug("failed to quiesce KFD\n");
1773 
1774 		pr_debug("schedule to restore svm %p ranges\n", svms);
1775 		schedule_delayed_work(&svms->restore_work,
1776 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1777 	} else {
1778 		unsigned long s, l;
1779 
1780 		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
1781 			 prange->svms, start, last);
1782 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1783 			mutex_lock_nested(&pchild->lock, 1);
1784 			s = max(start, pchild->start);
1785 			l = min(last, pchild->last);
1786 			if (l >= s)
1787 				svm_range_unmap_from_gpus(pchild, s, l);
1788 			mutex_unlock(&pchild->lock);
1789 		}
1790 		s = max(start, prange->start);
1791 		l = min(last, prange->last);
1792 		if (l >= s)
1793 			svm_range_unmap_from_gpus(prange, s, l);
1794 	}
1795 
1796 	return r;
1797 }
1798 
1799 static struct svm_range *svm_range_clone(struct svm_range *old)
1800 {
1801 	struct svm_range *new;
1802 
1803 	new = svm_range_new(old->svms, old->start, old->last);
1804 	if (!new)
1805 		return NULL;
1806 
1807 	if (old->svm_bo) {
1808 		new->ttm_res = old->ttm_res;
1809 		new->offset = old->offset;
1810 		new->svm_bo = svm_range_bo_ref(old->svm_bo);
1811 		spin_lock(&new->svm_bo->list_lock);
1812 		list_add(&new->svm_bo_list, &new->svm_bo->range_list);
1813 		spin_unlock(&new->svm_bo->list_lock);
1814 	}
1815 	new->flags = old->flags;
1816 	new->preferred_loc = old->preferred_loc;
1817 	new->prefetch_loc = old->prefetch_loc;
1818 	new->actual_loc = old->actual_loc;
1819 	new->granularity = old->granularity;
1820 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
1821 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
1822 
1823 	return new;
1824 }
1825 
1826 /**
1827  * svm_range_add - add svm range and handle overlap
1828  * @p: the range add to this process svms
1829  * @start: page size aligned
1830  * @size: page size aligned
1831  * @nattr: number of attributes
1832  * @attrs: array of attributes
1833  * @update_list: output, the ranges need validate and update GPU mapping
1834  * @insert_list: output, the ranges need insert to svms
1835  * @remove_list: output, the ranges are replaced and need remove from svms
1836  *
1837  * Check if the virtual address range has overlap with any existing ranges,
1838  * split partly overlapping ranges and add new ranges in the gaps. All changes
1839  * should be applied to the range_list and interval tree transactionally. If
1840  * any range split or allocation fails, the entire update fails. Therefore any
1841  * existing overlapping svm_ranges are cloned and the original svm_ranges left
1842  * unchanged.
1843  *
1844  * If the transaction succeeds, the caller can update and insert clones and
1845  * new ranges, then free the originals.
1846  *
1847  * Otherwise the caller can free the clones and new ranges, while the old
1848  * svm_ranges remain unchanged.
1849  *
1850  * Context: Process context, caller must hold svms->lock
1851  *
1852  * Return:
1853  * 0 - OK, otherwise error code
1854  */
1855 static int
1856 svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
1857 	      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
1858 	      struct list_head *update_list, struct list_head *insert_list,
1859 	      struct list_head *remove_list)
1860 {
1861 	unsigned long last = start + size - 1UL;
1862 	struct svm_range_list *svms = &p->svms;
1863 	struct interval_tree_node *node;
1864 	struct svm_range *prange;
1865 	struct svm_range *tmp;
1866 	int r = 0;
1867 
1868 	pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
1869 
1870 	INIT_LIST_HEAD(update_list);
1871 	INIT_LIST_HEAD(insert_list);
1872 	INIT_LIST_HEAD(remove_list);
1873 
1874 	node = interval_tree_iter_first(&svms->objects, start, last);
1875 	while (node) {
1876 		struct interval_tree_node *next;
1877 		unsigned long next_start;
1878 
1879 		pr_debug("found overlap node [0x%lx 0x%lx]\n", node->start,
1880 			 node->last);
1881 
1882 		prange = container_of(node, struct svm_range, it_node);
1883 		next = interval_tree_iter_next(node, start, last);
1884 		next_start = min(node->last, last) + 1;
1885 
1886 		if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
1887 			/* nothing to do */
1888 		} else if (node->start < start || node->last > last) {
1889 			/* node intersects the update range and its attributes
1890 			 * will change. Clone and split it, apply updates only
1891 			 * to the overlapping part
1892 			 */
1893 			struct svm_range *old = prange;
1894 
1895 			prange = svm_range_clone(old);
1896 			if (!prange) {
1897 				r = -ENOMEM;
1898 				goto out;
1899 			}
1900 
1901 			list_add(&old->update_list, remove_list);
1902 			list_add(&prange->list, insert_list);
1903 			list_add(&prange->update_list, update_list);
1904 
1905 			if (node->start < start) {
1906 				pr_debug("change old range start\n");
1907 				r = svm_range_split_head(prange, start,
1908 							 insert_list);
1909 				if (r)
1910 					goto out;
1911 			}
1912 			if (node->last > last) {
1913 				pr_debug("change old range last\n");
1914 				r = svm_range_split_tail(prange, last,
1915 							 insert_list);
1916 				if (r)
1917 					goto out;
1918 			}
1919 		} else {
1920 			/* The node is contained within start..last,
1921 			 * just update it
1922 			 */
1923 			list_add(&prange->update_list, update_list);
1924 		}
1925 
1926 		/* insert a new node if needed */
1927 		if (node->start > start) {
1928 			prange = svm_range_new(svms, start, node->start - 1);
1929 			if (!prange) {
1930 				r = -ENOMEM;
1931 				goto out;
1932 			}
1933 
1934 			list_add(&prange->list, insert_list);
1935 			list_add(&prange->update_list, update_list);
1936 		}
1937 
1938 		node = next;
1939 		start = next_start;
1940 	}
1941 
1942 	/* add a final range at the end if needed */
1943 	if (start <= last) {
1944 		prange = svm_range_new(svms, start, last);
1945 		if (!prange) {
1946 			r = -ENOMEM;
1947 			goto out;
1948 		}
1949 		list_add(&prange->list, insert_list);
1950 		list_add(&prange->update_list, update_list);
1951 	}
1952 
1953 out:
1954 	if (r)
1955 		list_for_each_entry_safe(prange, tmp, insert_list, list)
1956 			svm_range_free(prange);
1957 
1958 	return r;
1959 }
1960 
1961 static void
1962 svm_range_update_notifier_and_interval_tree(struct mm_struct *mm,
1963 					    struct svm_range *prange)
1964 {
1965 	unsigned long start;
1966 	unsigned long last;
1967 
1968 	start = prange->notifier.interval_tree.start >> PAGE_SHIFT;
1969 	last = prange->notifier.interval_tree.last >> PAGE_SHIFT;
1970 
1971 	if (prange->start == start && prange->last == last)
1972 		return;
1973 
1974 	pr_debug("up notifier 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
1975 		  prange->svms, prange, start, last, prange->start,
1976 		  prange->last);
1977 
1978 	if (start != 0 && last != 0) {
1979 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
1980 		svm_range_remove_notifier(prange);
1981 	}
1982 	prange->it_node.start = prange->start;
1983 	prange->it_node.last = prange->last;
1984 
1985 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
1986 	svm_range_add_notifier_locked(mm, prange);
1987 }
1988 
1989 static void
1990 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange,
1991 			 struct mm_struct *mm)
1992 {
1993 	switch (prange->work_item.op) {
1994 	case SVM_OP_NULL:
1995 		pr_debug("NULL OP 0x%p prange 0x%p [0x%lx 0x%lx]\n",
1996 			 svms, prange, prange->start, prange->last);
1997 		break;
1998 	case SVM_OP_UNMAP_RANGE:
1999 		pr_debug("remove 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2000 			 svms, prange, prange->start, prange->last);
2001 		svm_range_unlink(prange);
2002 		svm_range_remove_notifier(prange);
2003 		svm_range_free(prange);
2004 		break;
2005 	case SVM_OP_UPDATE_RANGE_NOTIFIER:
2006 		pr_debug("update notifier 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2007 			 svms, prange, prange->start, prange->last);
2008 		svm_range_update_notifier_and_interval_tree(mm, prange);
2009 		break;
2010 	case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
2011 		pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2012 			 svms, prange, prange->start, prange->last);
2013 		svm_range_update_notifier_and_interval_tree(mm, prange);
2014 		/* TODO: implement deferred validation and mapping */
2015 		break;
2016 	case SVM_OP_ADD_RANGE:
2017 		pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
2018 			 prange->start, prange->last);
2019 		svm_range_add_to_svms(prange);
2020 		svm_range_add_notifier_locked(mm, prange);
2021 		break;
2022 	case SVM_OP_ADD_RANGE_AND_MAP:
2023 		pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
2024 			 prange, prange->start, prange->last);
2025 		svm_range_add_to_svms(prange);
2026 		svm_range_add_notifier_locked(mm, prange);
2027 		/* TODO: implement deferred validation and mapping */
2028 		break;
2029 	default:
2030 		WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
2031 			 prange->work_item.op);
2032 	}
2033 }
2034 
2035 static void svm_range_drain_retry_fault(struct svm_range_list *svms)
2036 {
2037 	struct kfd_process_device *pdd;
2038 	struct kfd_process *p;
2039 	int drain;
2040 	uint32_t i;
2041 
2042 	p = container_of(svms, struct kfd_process, svms);
2043 
2044 restart:
2045 	drain = atomic_read(&svms->drain_pagefaults);
2046 	if (!drain)
2047 		return;
2048 
2049 	for_each_set_bit(i, svms->bitmap_supported, p->n_pdds) {
2050 		pdd = p->pdds[i];
2051 		if (!pdd)
2052 			continue;
2053 
2054 		pr_debug("drain retry fault gpu %d svms %p\n", i, svms);
2055 
2056 		amdgpu_ih_wait_on_checkpoint_process_ts(pdd->dev->adev,
2057 						     &pdd->dev->adev->irq.ih1);
2058 		pr_debug("drain retry fault gpu %d svms 0x%p done\n", i, svms);
2059 	}
2060 	if (atomic_cmpxchg(&svms->drain_pagefaults, drain, 0) != drain)
2061 		goto restart;
2062 }
2063 
2064 static void svm_range_deferred_list_work(struct work_struct *work)
2065 {
2066 	struct svm_range_list *svms;
2067 	struct svm_range *prange;
2068 	struct mm_struct *mm;
2069 
2070 	svms = container_of(work, struct svm_range_list, deferred_list_work);
2071 	pr_debug("enter svms 0x%p\n", svms);
2072 
2073 	spin_lock(&svms->deferred_list_lock);
2074 	while (!list_empty(&svms->deferred_range_list)) {
2075 		prange = list_first_entry(&svms->deferred_range_list,
2076 					  struct svm_range, deferred_list);
2077 		spin_unlock(&svms->deferred_list_lock);
2078 
2079 		pr_debug("prange 0x%p [0x%lx 0x%lx] op %d\n", prange,
2080 			 prange->start, prange->last, prange->work_item.op);
2081 
2082 		mm = prange->work_item.mm;
2083 retry:
2084 		mmap_write_lock(mm);
2085 
2086 		/* Checking for the need to drain retry faults must be inside
2087 		 * mmap write lock to serialize with munmap notifiers.
2088 		 */
2089 		if (unlikely(atomic_read(&svms->drain_pagefaults))) {
2090 			mmap_write_unlock(mm);
2091 			svm_range_drain_retry_fault(svms);
2092 			goto retry;
2093 		}
2094 
2095 		/* Remove from deferred_list must be inside mmap write lock, for
2096 		 * two race cases:
2097 		 * 1. unmap_from_cpu may change work_item.op and add the range
2098 		 *    to deferred_list again, cause use after free bug.
2099 		 * 2. svm_range_list_lock_and_flush_work may hold mmap write
2100 		 *    lock and continue because deferred_list is empty, but
2101 		 *    deferred_list work is actually waiting for mmap lock.
2102 		 */
2103 		spin_lock(&svms->deferred_list_lock);
2104 		list_del_init(&prange->deferred_list);
2105 		spin_unlock(&svms->deferred_list_lock);
2106 
2107 		mutex_lock(&svms->lock);
2108 		mutex_lock(&prange->migrate_mutex);
2109 		while (!list_empty(&prange->child_list)) {
2110 			struct svm_range *pchild;
2111 
2112 			pchild = list_first_entry(&prange->child_list,
2113 						struct svm_range, child_list);
2114 			pr_debug("child prange 0x%p op %d\n", pchild,
2115 				 pchild->work_item.op);
2116 			list_del_init(&pchild->child_list);
2117 			svm_range_handle_list_op(svms, pchild, mm);
2118 		}
2119 		mutex_unlock(&prange->migrate_mutex);
2120 
2121 		svm_range_handle_list_op(svms, prange, mm);
2122 		mutex_unlock(&svms->lock);
2123 		mmap_write_unlock(mm);
2124 
2125 		/* Pairs with mmget in svm_range_add_list_work */
2126 		mmput(mm);
2127 
2128 		spin_lock(&svms->deferred_list_lock);
2129 	}
2130 	spin_unlock(&svms->deferred_list_lock);
2131 	pr_debug("exit svms 0x%p\n", svms);
2132 }
2133 
2134 void
2135 svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
2136 			struct mm_struct *mm, enum svm_work_list_ops op)
2137 {
2138 	spin_lock(&svms->deferred_list_lock);
2139 	/* if prange is on the deferred list */
2140 	if (!list_empty(&prange->deferred_list)) {
2141 		pr_debug("update exist prange 0x%p work op %d\n", prange, op);
2142 		WARN_ONCE(prange->work_item.mm != mm, "unmatch mm\n");
2143 		if (op != SVM_OP_NULL &&
2144 		    prange->work_item.op != SVM_OP_UNMAP_RANGE)
2145 			prange->work_item.op = op;
2146 	} else {
2147 		prange->work_item.op = op;
2148 
2149 		/* Pairs with mmput in deferred_list_work */
2150 		mmget(mm);
2151 		prange->work_item.mm = mm;
2152 		list_add_tail(&prange->deferred_list,
2153 			      &prange->svms->deferred_range_list);
2154 		pr_debug("add prange 0x%p [0x%lx 0x%lx] to work list op %d\n",
2155 			 prange, prange->start, prange->last, op);
2156 	}
2157 	spin_unlock(&svms->deferred_list_lock);
2158 }
2159 
2160 void schedule_deferred_list_work(struct svm_range_list *svms)
2161 {
2162 	spin_lock(&svms->deferred_list_lock);
2163 	if (!list_empty(&svms->deferred_range_list))
2164 		schedule_work(&svms->deferred_list_work);
2165 	spin_unlock(&svms->deferred_list_lock);
2166 }
2167 
2168 static void
2169 svm_range_unmap_split(struct mm_struct *mm, struct svm_range *parent,
2170 		      struct svm_range *prange, unsigned long start,
2171 		      unsigned long last)
2172 {
2173 	struct svm_range *head;
2174 	struct svm_range *tail;
2175 
2176 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2177 		pr_debug("prange 0x%p [0x%lx 0x%lx] is already freed\n", prange,
2178 			 prange->start, prange->last);
2179 		return;
2180 	}
2181 	if (start > prange->last || last < prange->start)
2182 		return;
2183 
2184 	head = tail = prange;
2185 	if (start > prange->start)
2186 		svm_range_split(prange, prange->start, start - 1, &tail);
2187 	if (last < tail->last)
2188 		svm_range_split(tail, last + 1, tail->last, &head);
2189 
2190 	if (head != prange && tail != prange) {
2191 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2192 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
2193 	} else if (tail != prange) {
2194 		svm_range_add_child(parent, mm, tail, SVM_OP_UNMAP_RANGE);
2195 	} else if (head != prange) {
2196 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2197 	} else if (parent != prange) {
2198 		prange->work_item.op = SVM_OP_UNMAP_RANGE;
2199 	}
2200 }
2201 
2202 static void
2203 svm_range_unmap_from_cpu(struct mm_struct *mm, struct svm_range *prange,
2204 			 unsigned long start, unsigned long last)
2205 {
2206 	struct svm_range_list *svms;
2207 	struct svm_range *pchild;
2208 	struct kfd_process *p;
2209 	unsigned long s, l;
2210 	bool unmap_parent;
2211 
2212 	p = kfd_lookup_process_by_mm(mm);
2213 	if (!p)
2214 		return;
2215 	svms = &p->svms;
2216 
2217 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n", svms,
2218 		 prange, prange->start, prange->last, start, last);
2219 
2220 	/* Make sure pending page faults are drained in the deferred worker
2221 	 * before the range is freed to avoid straggler interrupts on
2222 	 * unmapped memory causing "phantom faults".
2223 	 */
2224 	atomic_inc(&svms->drain_pagefaults);
2225 
2226 	unmap_parent = start <= prange->start && last >= prange->last;
2227 
2228 	list_for_each_entry(pchild, &prange->child_list, child_list) {
2229 		mutex_lock_nested(&pchild->lock, 1);
2230 		s = max(start, pchild->start);
2231 		l = min(last, pchild->last);
2232 		if (l >= s)
2233 			svm_range_unmap_from_gpus(pchild, s, l);
2234 		svm_range_unmap_split(mm, prange, pchild, start, last);
2235 		mutex_unlock(&pchild->lock);
2236 	}
2237 	s = max(start, prange->start);
2238 	l = min(last, prange->last);
2239 	if (l >= s)
2240 		svm_range_unmap_from_gpus(prange, s, l);
2241 	svm_range_unmap_split(mm, prange, prange, start, last);
2242 
2243 	if (unmap_parent)
2244 		svm_range_add_list_work(svms, prange, mm, SVM_OP_UNMAP_RANGE);
2245 	else
2246 		svm_range_add_list_work(svms, prange, mm,
2247 					SVM_OP_UPDATE_RANGE_NOTIFIER);
2248 	schedule_deferred_list_work(svms);
2249 
2250 	kfd_unref_process(p);
2251 }
2252 
2253 /**
2254  * svm_range_cpu_invalidate_pagetables - interval notifier callback
2255  * @mni: mmu_interval_notifier struct
2256  * @range: mmu_notifier_range struct
2257  * @cur_seq: value to pass to mmu_interval_set_seq()
2258  *
2259  * If event is MMU_NOTIFY_UNMAP, this is from CPU unmap range, otherwise, it
2260  * is from migration, or CPU page invalidation callback.
2261  *
2262  * For unmap event, unmap range from GPUs, remove prange from svms in a delayed
2263  * work thread, and split prange if only part of prange is unmapped.
2264  *
2265  * For invalidation event, if GPU retry fault is not enabled, evict the queues,
2266  * then schedule svm_range_restore_work to update GPU mapping and resume queues.
2267  * If GPU retry fault is enabled, unmap the svm range from GPU, retry fault will
2268  * update GPU mapping to recover.
2269  *
2270  * Context: mmap lock, notifier_invalidate_start lock are held
2271  *          for invalidate event, prange lock is held if this is from migration
2272  */
2273 static bool
2274 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
2275 				    const struct mmu_notifier_range *range,
2276 				    unsigned long cur_seq)
2277 {
2278 	struct svm_range *prange;
2279 	unsigned long start;
2280 	unsigned long last;
2281 
2282 	if (range->event == MMU_NOTIFY_RELEASE)
2283 		return true;
2284 
2285 	start = mni->interval_tree.start;
2286 	last = mni->interval_tree.last;
2287 	start = max(start, range->start) >> PAGE_SHIFT;
2288 	last = min(last, range->end - 1) >> PAGE_SHIFT;
2289 	pr_debug("[0x%lx 0x%lx] range[0x%lx 0x%lx] notifier[0x%lx 0x%lx] %d\n",
2290 		 start, last, range->start >> PAGE_SHIFT,
2291 		 (range->end - 1) >> PAGE_SHIFT,
2292 		 mni->interval_tree.start >> PAGE_SHIFT,
2293 		 mni->interval_tree.last >> PAGE_SHIFT, range->event);
2294 
2295 	prange = container_of(mni, struct svm_range, notifier);
2296 
2297 	svm_range_lock(prange);
2298 	mmu_interval_set_seq(mni, cur_seq);
2299 
2300 	switch (range->event) {
2301 	case MMU_NOTIFY_UNMAP:
2302 		svm_range_unmap_from_cpu(mni->mm, prange, start, last);
2303 		break;
2304 	default:
2305 		svm_range_evict(prange, mni->mm, start, last);
2306 		break;
2307 	}
2308 
2309 	svm_range_unlock(prange);
2310 
2311 	return true;
2312 }
2313 
2314 /**
2315  * svm_range_from_addr - find svm range from fault address
2316  * @svms: svm range list header
2317  * @addr: address to search range interval tree, in pages
2318  * @parent: parent range if range is on child list
2319  *
2320  * Context: The caller must hold svms->lock
2321  *
2322  * Return: the svm_range found or NULL
2323  */
2324 struct svm_range *
2325 svm_range_from_addr(struct svm_range_list *svms, unsigned long addr,
2326 		    struct svm_range **parent)
2327 {
2328 	struct interval_tree_node *node;
2329 	struct svm_range *prange;
2330 	struct svm_range *pchild;
2331 
2332 	node = interval_tree_iter_first(&svms->objects, addr, addr);
2333 	if (!node)
2334 		return NULL;
2335 
2336 	prange = container_of(node, struct svm_range, it_node);
2337 	pr_debug("address 0x%lx prange [0x%lx 0x%lx] node [0x%lx 0x%lx]\n",
2338 		 addr, prange->start, prange->last, node->start, node->last);
2339 
2340 	if (addr >= prange->start && addr <= prange->last) {
2341 		if (parent)
2342 			*parent = prange;
2343 		return prange;
2344 	}
2345 	list_for_each_entry(pchild, &prange->child_list, child_list)
2346 		if (addr >= pchild->start && addr <= pchild->last) {
2347 			pr_debug("found address 0x%lx pchild [0x%lx 0x%lx]\n",
2348 				 addr, pchild->start, pchild->last);
2349 			if (parent)
2350 				*parent = prange;
2351 			return pchild;
2352 		}
2353 
2354 	return NULL;
2355 }
2356 
2357 /* svm_range_best_restore_location - decide the best fault restore location
2358  * @prange: svm range structure
2359  * @adev: the GPU on which vm fault happened
2360  *
2361  * This is only called when xnack is on, to decide the best location to restore
2362  * the range mapping after GPU vm fault. Caller uses the best location to do
2363  * migration if actual loc is not best location, then update GPU page table
2364  * mapping to the best location.
2365  *
2366  * If the preferred loc is accessible by faulting GPU, use preferred loc.
2367  * If vm fault gpu idx is on range ACCESSIBLE bitmap, best_loc is vm fault gpu
2368  * If vm fault gpu idx is on range ACCESSIBLE_IN_PLACE bitmap, then
2369  *    if range actual loc is cpu, best_loc is cpu
2370  *    if vm fault gpu is on xgmi same hive of range actual loc gpu, best_loc is
2371  *    range actual loc.
2372  * Otherwise, GPU no access, best_loc is -1.
2373  *
2374  * Return:
2375  * -1 means vm fault GPU no access
2376  * 0 for CPU or GPU id
2377  */
2378 static int32_t
2379 svm_range_best_restore_location(struct svm_range *prange,
2380 				struct amdgpu_device *adev,
2381 				int32_t *gpuidx)
2382 {
2383 	struct amdgpu_device *bo_adev, *preferred_adev;
2384 	struct kfd_process *p;
2385 	uint32_t gpuid;
2386 	int r;
2387 
2388 	p = container_of(prange->svms, struct kfd_process, svms);
2389 
2390 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, gpuidx);
2391 	if (r < 0) {
2392 		pr_debug("failed to get gpuid from kgd\n");
2393 		return -1;
2394 	}
2395 
2396 	if (prange->preferred_loc == gpuid ||
2397 	    prange->preferred_loc == KFD_IOCTL_SVM_LOCATION_SYSMEM) {
2398 		return prange->preferred_loc;
2399 	} else if (prange->preferred_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
2400 		preferred_adev = svm_range_get_adev_by_id(prange,
2401 							prange->preferred_loc);
2402 		if (amdgpu_xgmi_same_hive(adev, preferred_adev))
2403 			return prange->preferred_loc;
2404 		/* fall through */
2405 	}
2406 
2407 	if (test_bit(*gpuidx, prange->bitmap_access))
2408 		return gpuid;
2409 
2410 	if (test_bit(*gpuidx, prange->bitmap_aip)) {
2411 		if (!prange->actual_loc)
2412 			return 0;
2413 
2414 		bo_adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
2415 		if (amdgpu_xgmi_same_hive(adev, bo_adev))
2416 			return prange->actual_loc;
2417 		else
2418 			return 0;
2419 	}
2420 
2421 	return -1;
2422 }
2423 
2424 static int
2425 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
2426 			       unsigned long *start, unsigned long *last,
2427 			       bool *is_heap_stack)
2428 {
2429 	struct vm_area_struct *vma;
2430 	struct interval_tree_node *node;
2431 	unsigned long start_limit, end_limit;
2432 
2433 	vma = find_vma(p->mm, addr << PAGE_SHIFT);
2434 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2435 		pr_debug("VMA does not exist in address [0x%llx]\n", addr);
2436 		return -EFAULT;
2437 	}
2438 
2439 	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
2440 			  vma->vm_end >= vma->vm_mm->start_brk) ||
2441 			 (vma->vm_start <= vma->vm_mm->start_stack &&
2442 			  vma->vm_end >= vma->vm_mm->start_stack);
2443 
2444 	start_limit = max(vma->vm_start >> PAGE_SHIFT,
2445 		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
2446 	end_limit = min(vma->vm_end >> PAGE_SHIFT,
2447 		    (unsigned long)ALIGN(addr + 1, 2UL << 8));
2448 	/* First range that starts after the fault address */
2449 	node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);
2450 	if (node) {
2451 		end_limit = min(end_limit, node->start);
2452 		/* Last range that ends before the fault address */
2453 		node = container_of(rb_prev(&node->rb),
2454 				    struct interval_tree_node, rb);
2455 	} else {
2456 		/* Last range must end before addr because
2457 		 * there was no range after addr
2458 		 */
2459 		node = container_of(rb_last(&p->svms.objects.rb_root),
2460 				    struct interval_tree_node, rb);
2461 	}
2462 	if (node) {
2463 		if (node->last >= addr) {
2464 			WARN(1, "Overlap with prev node and page fault addr\n");
2465 			return -EFAULT;
2466 		}
2467 		start_limit = max(start_limit, node->last + 1);
2468 	}
2469 
2470 	*start = start_limit;
2471 	*last = end_limit - 1;
2472 
2473 	pr_debug("vma [0x%lx 0x%lx] range [0x%lx 0x%lx] is_heap_stack %d\n",
2474 		 vma->vm_start >> PAGE_SHIFT, vma->vm_end >> PAGE_SHIFT,
2475 		 *start, *last, *is_heap_stack);
2476 
2477 	return 0;
2478 }
2479 
2480 static int
2481 svm_range_check_vm_userptr(struct kfd_process *p, uint64_t start, uint64_t last,
2482 			   uint64_t *bo_s, uint64_t *bo_l)
2483 {
2484 	struct amdgpu_bo_va_mapping *mapping;
2485 	struct interval_tree_node *node;
2486 	struct amdgpu_bo *bo = NULL;
2487 	unsigned long userptr;
2488 	uint32_t i;
2489 	int r;
2490 
2491 	for (i = 0; i < p->n_pdds; i++) {
2492 		struct amdgpu_vm *vm;
2493 
2494 		if (!p->pdds[i]->drm_priv)
2495 			continue;
2496 
2497 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2498 		r = amdgpu_bo_reserve(vm->root.bo, false);
2499 		if (r)
2500 			return r;
2501 
2502 		/* Check userptr by searching entire vm->va interval tree */
2503 		node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
2504 		while (node) {
2505 			mapping = container_of((struct rb_node *)node,
2506 					       struct amdgpu_bo_va_mapping, rb);
2507 			bo = mapping->bo_va->base.bo;
2508 
2509 			if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
2510 							 start << PAGE_SHIFT,
2511 							 last << PAGE_SHIFT,
2512 							 &userptr)) {
2513 				node = interval_tree_iter_next(node, 0, ~0ULL);
2514 				continue;
2515 			}
2516 
2517 			pr_debug("[0x%llx 0x%llx] already userptr mapped\n",
2518 				 start, last);
2519 			if (bo_s && bo_l) {
2520 				*bo_s = userptr >> PAGE_SHIFT;
2521 				*bo_l = *bo_s + bo->tbo.ttm->num_pages - 1;
2522 			}
2523 			amdgpu_bo_unreserve(vm->root.bo);
2524 			return -EADDRINUSE;
2525 		}
2526 		amdgpu_bo_unreserve(vm->root.bo);
2527 	}
2528 	return 0;
2529 }
2530 
2531 static struct
2532 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
2533 						struct kfd_process *p,
2534 						struct mm_struct *mm,
2535 						int64_t addr)
2536 {
2537 	struct svm_range *prange = NULL;
2538 	unsigned long start, last;
2539 	uint32_t gpuid, gpuidx;
2540 	bool is_heap_stack;
2541 	uint64_t bo_s = 0;
2542 	uint64_t bo_l = 0;
2543 	int r;
2544 
2545 	if (svm_range_get_range_boundaries(p, addr, &start, &last,
2546 					   &is_heap_stack))
2547 		return NULL;
2548 
2549 	r = svm_range_check_vm(p, start, last, &bo_s, &bo_l);
2550 	if (r != -EADDRINUSE)
2551 		r = svm_range_check_vm_userptr(p, start, last, &bo_s, &bo_l);
2552 
2553 	if (r == -EADDRINUSE) {
2554 		if (addr >= bo_s && addr <= bo_l)
2555 			return NULL;
2556 
2557 		/* Create one page svm range if 2MB range overlapping */
2558 		start = addr;
2559 		last = addr;
2560 	}
2561 
2562 	prange = svm_range_new(&p->svms, start, last);
2563 	if (!prange) {
2564 		pr_debug("Failed to create prange in address [0x%llx]\n", addr);
2565 		return NULL;
2566 	}
2567 	if (kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx)) {
2568 		pr_debug("failed to get gpuid from kgd\n");
2569 		svm_range_free(prange);
2570 		return NULL;
2571 	}
2572 
2573 	if (is_heap_stack)
2574 		prange->preferred_loc = KFD_IOCTL_SVM_LOCATION_SYSMEM;
2575 
2576 	svm_range_add_to_svms(prange);
2577 	svm_range_add_notifier_locked(mm, prange);
2578 
2579 	return prange;
2580 }
2581 
2582 /* svm_range_skip_recover - decide if prange can be recovered
2583  * @prange: svm range structure
2584  *
2585  * GPU vm retry fault handle skip recover the range for cases:
2586  * 1. prange is on deferred list to be removed after unmap, it is stale fault,
2587  *    deferred list work will drain the stale fault before free the prange.
2588  * 2. prange is on deferred list to add interval notifier after split, or
2589  * 3. prange is child range, it is split from parent prange, recover later
2590  *    after interval notifier is added.
2591  *
2592  * Return: true to skip recover, false to recover
2593  */
2594 static bool svm_range_skip_recover(struct svm_range *prange)
2595 {
2596 	struct svm_range_list *svms = prange->svms;
2597 
2598 	spin_lock(&svms->deferred_list_lock);
2599 	if (list_empty(&prange->deferred_list) &&
2600 	    list_empty(&prange->child_list)) {
2601 		spin_unlock(&svms->deferred_list_lock);
2602 		return false;
2603 	}
2604 	spin_unlock(&svms->deferred_list_lock);
2605 
2606 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2607 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] unmapped\n",
2608 			 svms, prange, prange->start, prange->last);
2609 		return true;
2610 	}
2611 	if (prange->work_item.op == SVM_OP_ADD_RANGE_AND_MAP ||
2612 	    prange->work_item.op == SVM_OP_ADD_RANGE) {
2613 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] not added yet\n",
2614 			 svms, prange, prange->start, prange->last);
2615 		return true;
2616 	}
2617 	return false;
2618 }
2619 
2620 static void
2621 svm_range_count_fault(struct amdgpu_device *adev, struct kfd_process *p,
2622 		      int32_t gpuidx)
2623 {
2624 	struct kfd_process_device *pdd;
2625 
2626 	/* fault is on different page of same range
2627 	 * or fault is skipped to recover later
2628 	 * or fault is on invalid virtual address
2629 	 */
2630 	if (gpuidx == MAX_GPU_INSTANCE) {
2631 		uint32_t gpuid;
2632 		int r;
2633 
2634 		r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx);
2635 		if (r < 0)
2636 			return;
2637 	}
2638 
2639 	/* fault is recovered
2640 	 * or fault cannot recover because GPU no access on the range
2641 	 */
2642 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
2643 	if (pdd)
2644 		WRITE_ONCE(pdd->faults, pdd->faults + 1);
2645 }
2646 
2647 static bool
2648 svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
2649 {
2650 	unsigned long requested = VM_READ;
2651 
2652 	if (write_fault)
2653 		requested |= VM_WRITE;
2654 
2655 	pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
2656 		vma->vm_flags);
2657 	return (vma->vm_flags & requested) == requested;
2658 }
2659 
2660 int
2661 svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
2662 			uint64_t addr, bool write_fault)
2663 {
2664 	struct mm_struct *mm = NULL;
2665 	struct svm_range_list *svms;
2666 	struct svm_range *prange;
2667 	struct kfd_process *p;
2668 	uint64_t timestamp;
2669 	int32_t best_loc;
2670 	int32_t gpuidx = MAX_GPU_INSTANCE;
2671 	bool write_locked = false;
2672 	struct vm_area_struct *vma;
2673 	int r = 0;
2674 
2675 	if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
2676 		pr_debug("device does not support SVM\n");
2677 		return -EFAULT;
2678 	}
2679 
2680 	p = kfd_lookup_process_by_pasid(pasid);
2681 	if (!p) {
2682 		pr_debug("kfd process not founded pasid 0x%x\n", pasid);
2683 		return 0;
2684 	}
2685 	if (!p->xnack_enabled) {
2686 		pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
2687 		r = -EFAULT;
2688 		goto out;
2689 	}
2690 	svms = &p->svms;
2691 
2692 	pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
2693 
2694 	if (atomic_read(&svms->drain_pagefaults)) {
2695 		pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
2696 		r = 0;
2697 		goto out;
2698 	}
2699 
2700 	/* p->lead_thread is available as kfd_process_wq_release flush the work
2701 	 * before releasing task ref.
2702 	 */
2703 	mm = get_task_mm(p->lead_thread);
2704 	if (!mm) {
2705 		pr_debug("svms 0x%p failed to get mm\n", svms);
2706 		r = 0;
2707 		goto out;
2708 	}
2709 
2710 	mmap_read_lock(mm);
2711 retry_write_locked:
2712 	mutex_lock(&svms->lock);
2713 	prange = svm_range_from_addr(svms, addr, NULL);
2714 	if (!prange) {
2715 		pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
2716 			 svms, addr);
2717 		if (!write_locked) {
2718 			/* Need the write lock to create new range with MMU notifier.
2719 			 * Also flush pending deferred work to make sure the interval
2720 			 * tree is up to date before we add a new range
2721 			 */
2722 			mutex_unlock(&svms->lock);
2723 			mmap_read_unlock(mm);
2724 			mmap_write_lock(mm);
2725 			write_locked = true;
2726 			goto retry_write_locked;
2727 		}
2728 		prange = svm_range_create_unregistered_range(adev, p, mm, addr);
2729 		if (!prange) {
2730 			pr_debug("failed to create unregistered range svms 0x%p address [0x%llx]\n",
2731 				 svms, addr);
2732 			mmap_write_downgrade(mm);
2733 			r = -EFAULT;
2734 			goto out_unlock_svms;
2735 		}
2736 	}
2737 	if (write_locked)
2738 		mmap_write_downgrade(mm);
2739 
2740 	mutex_lock(&prange->migrate_mutex);
2741 
2742 	if (svm_range_skip_recover(prange)) {
2743 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2744 		r = 0;
2745 		goto out_unlock_range;
2746 	}
2747 
2748 	timestamp = ktime_to_us(ktime_get()) - prange->validate_timestamp;
2749 	/* skip duplicate vm fault on different pages of same range */
2750 	if (timestamp < AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING) {
2751 		pr_debug("svms 0x%p [0x%lx %lx] already restored\n",
2752 			 svms, prange->start, prange->last);
2753 		r = 0;
2754 		goto out_unlock_range;
2755 	}
2756 
2757 	/* __do_munmap removed VMA, return success as we are handling stale
2758 	 * retry fault.
2759 	 */
2760 	vma = find_vma(mm, addr << PAGE_SHIFT);
2761 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2762 		pr_debug("address 0x%llx VMA is removed\n", addr);
2763 		r = 0;
2764 		goto out_unlock_range;
2765 	}
2766 
2767 	if (!svm_fault_allowed(vma, write_fault)) {
2768 		pr_debug("fault addr 0x%llx no %s permission\n", addr,
2769 			write_fault ? "write" : "read");
2770 		r = -EPERM;
2771 		goto out_unlock_range;
2772 	}
2773 
2774 	best_loc = svm_range_best_restore_location(prange, adev, &gpuidx);
2775 	if (best_loc == -1) {
2776 		pr_debug("svms %p failed get best restore loc [0x%lx 0x%lx]\n",
2777 			 svms, prange->start, prange->last);
2778 		r = -EACCES;
2779 		goto out_unlock_range;
2780 	}
2781 
2782 	pr_debug("svms %p [0x%lx 0x%lx] best restore 0x%x, actual loc 0x%x\n",
2783 		 svms, prange->start, prange->last, best_loc,
2784 		 prange->actual_loc);
2785 
2786 	if (prange->actual_loc != best_loc) {
2787 		if (best_loc) {
2788 			r = svm_migrate_to_vram(prange, best_loc, mm);
2789 			if (r) {
2790 				pr_debug("svm_migrate_to_vram failed (%d) at %llx, falling back to system memory\n",
2791 					 r, addr);
2792 				/* Fallback to system memory if migration to
2793 				 * VRAM failed
2794 				 */
2795 				if (prange->actual_loc)
2796 					r = svm_migrate_vram_to_ram(prange, mm);
2797 				else
2798 					r = 0;
2799 			}
2800 		} else {
2801 			r = svm_migrate_vram_to_ram(prange, mm);
2802 		}
2803 		if (r) {
2804 			pr_debug("failed %d to migrate svms %p [0x%lx 0x%lx]\n",
2805 				 r, svms, prange->start, prange->last);
2806 			goto out_unlock_range;
2807 		}
2808 	}
2809 
2810 	r = svm_range_validate_and_map(mm, prange, gpuidx, false, false);
2811 	if (r)
2812 		pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
2813 			 r, svms, prange->start, prange->last);
2814 
2815 out_unlock_range:
2816 	mutex_unlock(&prange->migrate_mutex);
2817 out_unlock_svms:
2818 	mutex_unlock(&svms->lock);
2819 	mmap_read_unlock(mm);
2820 
2821 	svm_range_count_fault(adev, p, gpuidx);
2822 
2823 	mmput(mm);
2824 out:
2825 	kfd_unref_process(p);
2826 
2827 	if (r == -EAGAIN) {
2828 		pr_debug("recover vm fault later\n");
2829 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2830 		r = 0;
2831 	}
2832 	return r;
2833 }
2834 
2835 void svm_range_list_fini(struct kfd_process *p)
2836 {
2837 	struct svm_range *prange;
2838 	struct svm_range *next;
2839 
2840 	pr_debug("pasid 0x%x svms 0x%p\n", p->pasid, &p->svms);
2841 
2842 	cancel_delayed_work_sync(&p->svms.restore_work);
2843 
2844 	/* Ensure list work is finished before process is destroyed */
2845 	flush_work(&p->svms.deferred_list_work);
2846 
2847 	/*
2848 	 * Ensure no retry fault comes in afterwards, as page fault handler will
2849 	 * not find kfd process and take mm lock to recover fault.
2850 	 */
2851 	atomic_inc(&p->svms.drain_pagefaults);
2852 	svm_range_drain_retry_fault(&p->svms);
2853 
2854 	list_for_each_entry_safe(prange, next, &p->svms.list, list) {
2855 		svm_range_unlink(prange);
2856 		svm_range_remove_notifier(prange);
2857 		svm_range_free(prange);
2858 	}
2859 
2860 	mutex_destroy(&p->svms.lock);
2861 
2862 	pr_debug("pasid 0x%x svms 0x%p done\n", p->pasid, &p->svms);
2863 }
2864 
2865 int svm_range_list_init(struct kfd_process *p)
2866 {
2867 	struct svm_range_list *svms = &p->svms;
2868 	int i;
2869 
2870 	svms->objects = RB_ROOT_CACHED;
2871 	mutex_init(&svms->lock);
2872 	INIT_LIST_HEAD(&svms->list);
2873 	atomic_set(&svms->evicted_ranges, 0);
2874 	atomic_set(&svms->drain_pagefaults, 0);
2875 	INIT_DELAYED_WORK(&svms->restore_work, svm_range_restore_work);
2876 	INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work);
2877 	INIT_LIST_HEAD(&svms->deferred_range_list);
2878 	spin_lock_init(&svms->deferred_list_lock);
2879 
2880 	for (i = 0; i < p->n_pdds; i++)
2881 		if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev))
2882 			bitmap_set(svms->bitmap_supported, i, 1);
2883 
2884 	return 0;
2885 }
2886 
2887 /**
2888  * svm_range_check_vm - check if virtual address range mapped already
2889  * @p: current kfd_process
2890  * @start: range start address, in pages
2891  * @last: range last address, in pages
2892  * @bo_s: mapping start address in pages if address range already mapped
2893  * @bo_l: mapping last address in pages if address range already mapped
2894  *
2895  * The purpose is to avoid virtual address ranges already allocated by
2896  * kfd_ioctl_alloc_memory_of_gpu ioctl.
2897  * It looks for each pdd in the kfd_process.
2898  *
2899  * Context: Process context
2900  *
2901  * Return 0 - OK, if the range is not mapped.
2902  * Otherwise error code:
2903  * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
2904  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
2905  * a signal. Release all buffer reservations and return to user-space.
2906  */
2907 static int
2908 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
2909 		   uint64_t *bo_s, uint64_t *bo_l)
2910 {
2911 	struct amdgpu_bo_va_mapping *mapping;
2912 	struct interval_tree_node *node;
2913 	uint32_t i;
2914 	int r;
2915 
2916 	for (i = 0; i < p->n_pdds; i++) {
2917 		struct amdgpu_vm *vm;
2918 
2919 		if (!p->pdds[i]->drm_priv)
2920 			continue;
2921 
2922 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2923 		r = amdgpu_bo_reserve(vm->root.bo, false);
2924 		if (r)
2925 			return r;
2926 
2927 		node = interval_tree_iter_first(&vm->va, start, last);
2928 		if (node) {
2929 			pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
2930 				 start, last);
2931 			mapping = container_of((struct rb_node *)node,
2932 					       struct amdgpu_bo_va_mapping, rb);
2933 			if (bo_s && bo_l) {
2934 				*bo_s = mapping->start;
2935 				*bo_l = mapping->last;
2936 			}
2937 			amdgpu_bo_unreserve(vm->root.bo);
2938 			return -EADDRINUSE;
2939 		}
2940 		amdgpu_bo_unreserve(vm->root.bo);
2941 	}
2942 
2943 	return 0;
2944 }
2945 
2946 /**
2947  * svm_range_is_valid - check if virtual address range is valid
2948  * @p: current kfd_process
2949  * @start: range start address, in pages
2950  * @size: range size, in pages
2951  *
2952  * Valid virtual address range means it belongs to one or more VMAs
2953  *
2954  * Context: Process context
2955  *
2956  * Return:
2957  *  0 - OK, otherwise error code
2958  */
2959 static int
2960 svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
2961 {
2962 	const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
2963 	struct vm_area_struct *vma;
2964 	unsigned long end;
2965 	unsigned long start_unchg = start;
2966 
2967 	start <<= PAGE_SHIFT;
2968 	end = start + (size << PAGE_SHIFT);
2969 	do {
2970 		vma = find_vma(p->mm, start);
2971 		if (!vma || start < vma->vm_start ||
2972 		    (vma->vm_flags & device_vma))
2973 			return -EFAULT;
2974 		start = min(end, vma->vm_end);
2975 	} while (start < end);
2976 
2977 	return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT, NULL,
2978 				  NULL);
2979 }
2980 
2981 /**
2982  * svm_range_best_prefetch_location - decide the best prefetch location
2983  * @prange: svm range structure
2984  *
2985  * For xnack off:
2986  * If range map to single GPU, the best prefetch location is prefetch_loc, which
2987  * can be CPU or GPU.
2988  *
2989  * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on
2990  * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise
2991  * the best prefetch location is always CPU, because GPU can not have coherent
2992  * mapping VRAM of other GPUs even with large-BAR PCIe connection.
2993  *
2994  * For xnack on:
2995  * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is
2996  * prefetch_loc, other GPU access will generate vm fault and trigger migration.
2997  *
2998  * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same
2999  * hive, the best prefetch location is prefetch_loc GPU, otherwise the best
3000  * prefetch location is always CPU.
3001  *
3002  * Context: Process context
3003  *
3004  * Return:
3005  * 0 for CPU or GPU id
3006  */
3007 static uint32_t
3008 svm_range_best_prefetch_location(struct svm_range *prange)
3009 {
3010 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
3011 	uint32_t best_loc = prange->prefetch_loc;
3012 	struct kfd_process_device *pdd;
3013 	struct amdgpu_device *bo_adev;
3014 	struct kfd_process *p;
3015 	uint32_t gpuidx;
3016 
3017 	p = container_of(prange->svms, struct kfd_process, svms);
3018 
3019 	if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED)
3020 		goto out;
3021 
3022 	bo_adev = svm_range_get_adev_by_id(prange, best_loc);
3023 	if (!bo_adev) {
3024 		WARN_ONCE(1, "failed to get device by id 0x%x\n", best_loc);
3025 		best_loc = 0;
3026 		goto out;
3027 	}
3028 
3029 	if (p->xnack_enabled)
3030 		bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
3031 	else
3032 		bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
3033 			  MAX_GPU_INSTANCE);
3034 
3035 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
3036 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
3037 		if (!pdd) {
3038 			pr_debug("failed to get device by idx 0x%x\n", gpuidx);
3039 			continue;
3040 		}
3041 
3042 		if (pdd->dev->adev == bo_adev)
3043 			continue;
3044 
3045 		if (!amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
3046 			best_loc = 0;
3047 			break;
3048 		}
3049 	}
3050 
3051 out:
3052 	pr_debug("xnack %d svms 0x%p [0x%lx 0x%lx] best loc 0x%x\n",
3053 		 p->xnack_enabled, &p->svms, prange->start, prange->last,
3054 		 best_loc);
3055 
3056 	return best_loc;
3057 }
3058 
3059 /* FIXME: This is a workaround for page locking bug when some pages are
3060  * invalid during migration to VRAM
3061  */
3062 void svm_range_prefault(struct svm_range *prange, struct mm_struct *mm,
3063 			void *owner)
3064 {
3065 	struct hmm_range *hmm_range;
3066 	int r;
3067 
3068 	if (prange->validated_once)
3069 		return;
3070 
3071 	r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
3072 				       prange->start << PAGE_SHIFT,
3073 				       prange->npages, &hmm_range,
3074 				       false, true, owner);
3075 	if (!r) {
3076 		amdgpu_hmm_range_get_pages_done(hmm_range);
3077 		prange->validated_once = true;
3078 	}
3079 }
3080 
3081 /* svm_range_trigger_migration - start page migration if prefetch loc changed
3082  * @mm: current process mm_struct
3083  * @prange: svm range structure
3084  * @migrated: output, true if migration is triggered
3085  *
3086  * If range perfetch_loc is GPU, actual loc is cpu 0, then migrate the range
3087  * from ram to vram.
3088  * If range prefetch_loc is cpu 0, actual loc is GPU, then migrate the range
3089  * from vram to ram.
3090  *
3091  * If GPU vm fault retry is not enabled, migration interact with MMU notifier
3092  * and restore work:
3093  * 1. migrate_vma_setup invalidate pages, MMU notifier callback svm_range_evict
3094  *    stops all queues, schedule restore work
3095  * 2. svm_range_restore_work wait for migration is done by
3096  *    a. svm_range_validate_vram takes prange->migrate_mutex
3097  *    b. svm_range_validate_ram HMM get pages wait for CPU fault handle returns
3098  * 3. restore work update mappings of GPU, resume all queues.
3099  *
3100  * Context: Process context
3101  *
3102  * Return:
3103  * 0 - OK, otherwise - error code of migration
3104  */
3105 static int
3106 svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
3107 			    bool *migrated)
3108 {
3109 	uint32_t best_loc;
3110 	int r = 0;
3111 
3112 	*migrated = false;
3113 	best_loc = svm_range_best_prefetch_location(prange);
3114 
3115 	if (best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3116 	    best_loc == prange->actual_loc)
3117 		return 0;
3118 
3119 	if (!best_loc) {
3120 		r = svm_migrate_vram_to_ram(prange, mm);
3121 		*migrated = !r;
3122 		return r;
3123 	}
3124 
3125 	r = svm_migrate_to_vram(prange, best_loc, mm);
3126 	*migrated = !r;
3127 
3128 	return r;
3129 }
3130 
3131 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
3132 {
3133 	if (!fence)
3134 		return -EINVAL;
3135 
3136 	if (dma_fence_is_signaled(&fence->base))
3137 		return 0;
3138 
3139 	if (fence->svm_bo) {
3140 		WRITE_ONCE(fence->svm_bo->evicting, 1);
3141 		schedule_work(&fence->svm_bo->eviction_work);
3142 	}
3143 
3144 	return 0;
3145 }
3146 
3147 static void svm_range_evict_svm_bo_worker(struct work_struct *work)
3148 {
3149 	struct svm_range_bo *svm_bo;
3150 	struct kfd_process *p;
3151 	struct mm_struct *mm;
3152 
3153 	svm_bo = container_of(work, struct svm_range_bo, eviction_work);
3154 	if (!svm_bo_ref_unless_zero(svm_bo))
3155 		return; /* svm_bo was freed while eviction was pending */
3156 
3157 	/* svm_range_bo_release destroys this worker thread. So during
3158 	 * the lifetime of this thread, kfd_process and mm will be valid.
3159 	 */
3160 	p = container_of(svm_bo->svms, struct kfd_process, svms);
3161 	mm = p->mm;
3162 	if (!mm)
3163 		return;
3164 
3165 	mmap_read_lock(mm);
3166 	spin_lock(&svm_bo->list_lock);
3167 	while (!list_empty(&svm_bo->range_list)) {
3168 		struct svm_range *prange =
3169 				list_first_entry(&svm_bo->range_list,
3170 						struct svm_range, svm_bo_list);
3171 		int retries = 3;
3172 
3173 		list_del_init(&prange->svm_bo_list);
3174 		spin_unlock(&svm_bo->list_lock);
3175 
3176 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
3177 			 prange->start, prange->last);
3178 
3179 		mutex_lock(&prange->migrate_mutex);
3180 		do {
3181 			svm_migrate_vram_to_ram(prange,
3182 						svm_bo->eviction_fence->mm);
3183 		} while (prange->actual_loc && --retries);
3184 		WARN(prange->actual_loc, "Migration failed during eviction");
3185 
3186 		mutex_lock(&prange->lock);
3187 		prange->svm_bo = NULL;
3188 		mutex_unlock(&prange->lock);
3189 
3190 		mutex_unlock(&prange->migrate_mutex);
3191 
3192 		spin_lock(&svm_bo->list_lock);
3193 	}
3194 	spin_unlock(&svm_bo->list_lock);
3195 	mmap_read_unlock(mm);
3196 
3197 	dma_fence_signal(&svm_bo->eviction_fence->base);
3198 	/* This is the last reference to svm_bo, after svm_range_vram_node_free
3199 	 * has been called in svm_migrate_vram_to_ram
3200 	 */
3201 	WARN_ONCE(kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
3202 	svm_range_bo_unref(svm_bo);
3203 }
3204 
3205 static int
3206 svm_range_set_attr(struct kfd_process *p, uint64_t start, uint64_t size,
3207 		   uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
3208 {
3209 	struct mm_struct *mm = current->mm;
3210 	struct list_head update_list;
3211 	struct list_head insert_list;
3212 	struct list_head remove_list;
3213 	struct svm_range_list *svms;
3214 	struct svm_range *prange;
3215 	struct svm_range *next;
3216 	int r = 0;
3217 
3218 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
3219 		 p->pasid, &p->svms, start, start + size - 1, size);
3220 
3221 	r = svm_range_check_attr(p, nattr, attrs);
3222 	if (r)
3223 		return r;
3224 
3225 	svms = &p->svms;
3226 
3227 	svm_range_list_lock_and_flush_work(svms, mm);
3228 
3229 	r = svm_range_is_valid(p, start, size);
3230 	if (r) {
3231 		pr_debug("invalid range r=%d\n", r);
3232 		mmap_write_unlock(mm);
3233 		goto out;
3234 	}
3235 
3236 	mutex_lock(&svms->lock);
3237 
3238 	/* Add new range and split existing ranges as needed */
3239 	r = svm_range_add(p, start, size, nattr, attrs, &update_list,
3240 			  &insert_list, &remove_list);
3241 	if (r) {
3242 		mutex_unlock(&svms->lock);
3243 		mmap_write_unlock(mm);
3244 		goto out;
3245 	}
3246 	/* Apply changes as a transaction */
3247 	list_for_each_entry_safe(prange, next, &insert_list, list) {
3248 		svm_range_add_to_svms(prange);
3249 		svm_range_add_notifier_locked(mm, prange);
3250 	}
3251 	list_for_each_entry(prange, &update_list, update_list) {
3252 		svm_range_apply_attrs(p, prange, nattr, attrs);
3253 		/* TODO: unmap ranges from GPU that lost access */
3254 	}
3255 	list_for_each_entry_safe(prange, next, &remove_list, update_list) {
3256 		pr_debug("unlink old 0x%p prange 0x%p [0x%lx 0x%lx]\n",
3257 			 prange->svms, prange, prange->start,
3258 			 prange->last);
3259 		svm_range_unlink(prange);
3260 		svm_range_remove_notifier(prange);
3261 		svm_range_free(prange);
3262 	}
3263 
3264 	mmap_write_downgrade(mm);
3265 	/* Trigger migrations and revalidate and map to GPUs as needed. If
3266 	 * this fails we may be left with partially completed actions. There
3267 	 * is no clean way of rolling back to the previous state in such a
3268 	 * case because the rollback wouldn't be guaranteed to work either.
3269 	 */
3270 	list_for_each_entry(prange, &update_list, update_list) {
3271 		bool migrated;
3272 
3273 		mutex_lock(&prange->migrate_mutex);
3274 
3275 		r = svm_range_trigger_migration(mm, prange, &migrated);
3276 		if (r)
3277 			goto out_unlock_range;
3278 
3279 		if (migrated && !p->xnack_enabled) {
3280 			pr_debug("restore_work will update mappings of GPUs\n");
3281 			mutex_unlock(&prange->migrate_mutex);
3282 			continue;
3283 		}
3284 
3285 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
3286 					       true, true);
3287 		if (r)
3288 			pr_debug("failed %d to map svm range\n", r);
3289 
3290 out_unlock_range:
3291 		mutex_unlock(&prange->migrate_mutex);
3292 		if (r)
3293 			break;
3294 	}
3295 
3296 	svm_range_debug_dump(svms);
3297 
3298 	mutex_unlock(&svms->lock);
3299 	mmap_read_unlock(mm);
3300 out:
3301 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
3302 		 &p->svms, start, start + size - 1, r);
3303 
3304 	return r;
3305 }
3306 
3307 static int
3308 svm_range_get_attr(struct kfd_process *p, uint64_t start, uint64_t size,
3309 		   uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
3310 {
3311 	DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
3312 	DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
3313 	bool get_preferred_loc = false;
3314 	bool get_prefetch_loc = false;
3315 	bool get_granularity = false;
3316 	bool get_accessible = false;
3317 	bool get_flags = false;
3318 	uint64_t last = start + size - 1UL;
3319 	struct mm_struct *mm = current->mm;
3320 	uint8_t granularity = 0xff;
3321 	struct interval_tree_node *node;
3322 	struct svm_range_list *svms;
3323 	struct svm_range *prange;
3324 	uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3325 	uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3326 	uint32_t flags_and = 0xffffffff;
3327 	uint32_t flags_or = 0;
3328 	int gpuidx;
3329 	uint32_t i;
3330 	int r = 0;
3331 
3332 	pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
3333 		 start + size - 1, nattr);
3334 
3335 	/* Flush pending deferred work to avoid racing with deferred actions from
3336 	 * previous memory map changes (e.g. munmap). Concurrent memory map changes
3337 	 * can still race with get_attr because we don't hold the mmap lock. But that
3338 	 * would be a race condition in the application anyway, and undefined
3339 	 * behaviour is acceptable in that case.
3340 	 */
3341 	flush_work(&p->svms.deferred_list_work);
3342 
3343 	mmap_read_lock(mm);
3344 	r = svm_range_is_valid(p, start, size);
3345 	mmap_read_unlock(mm);
3346 	if (r) {
3347 		pr_debug("invalid range r=%d\n", r);
3348 		return r;
3349 	}
3350 
3351 	for (i = 0; i < nattr; i++) {
3352 		switch (attrs[i].type) {
3353 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3354 			get_preferred_loc = true;
3355 			break;
3356 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3357 			get_prefetch_loc = true;
3358 			break;
3359 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3360 			get_accessible = true;
3361 			break;
3362 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3363 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3364 			get_flags = true;
3365 			break;
3366 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3367 			get_granularity = true;
3368 			break;
3369 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
3370 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
3371 			fallthrough;
3372 		default:
3373 			pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
3374 			return -EINVAL;
3375 		}
3376 	}
3377 
3378 	svms = &p->svms;
3379 
3380 	mutex_lock(&svms->lock);
3381 
3382 	node = interval_tree_iter_first(&svms->objects, start, last);
3383 	if (!node) {
3384 		pr_debug("range attrs not found return default values\n");
3385 		svm_range_set_default_attributes(&location, &prefetch_loc,
3386 						 &granularity, &flags_and);
3387 		flags_or = flags_and;
3388 		if (p->xnack_enabled)
3389 			bitmap_copy(bitmap_access, svms->bitmap_supported,
3390 				    MAX_GPU_INSTANCE);
3391 		else
3392 			bitmap_zero(bitmap_access, MAX_GPU_INSTANCE);
3393 		bitmap_zero(bitmap_aip, MAX_GPU_INSTANCE);
3394 		goto fill_values;
3395 	}
3396 	bitmap_copy(bitmap_access, svms->bitmap_supported, MAX_GPU_INSTANCE);
3397 	bitmap_copy(bitmap_aip, svms->bitmap_supported, MAX_GPU_INSTANCE);
3398 
3399 	while (node) {
3400 		struct interval_tree_node *next;
3401 
3402 		prange = container_of(node, struct svm_range, it_node);
3403 		next = interval_tree_iter_next(node, start, last);
3404 
3405 		if (get_preferred_loc) {
3406 			if (prange->preferred_loc ==
3407 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3408 			    (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3409 			     location != prange->preferred_loc)) {
3410 				location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3411 				get_preferred_loc = false;
3412 			} else {
3413 				location = prange->preferred_loc;
3414 			}
3415 		}
3416 		if (get_prefetch_loc) {
3417 			if (prange->prefetch_loc ==
3418 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3419 			    (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3420 			     prefetch_loc != prange->prefetch_loc)) {
3421 				prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3422 				get_prefetch_loc = false;
3423 			} else {
3424 				prefetch_loc = prange->prefetch_loc;
3425 			}
3426 		}
3427 		if (get_accessible) {
3428 			bitmap_and(bitmap_access, bitmap_access,
3429 				   prange->bitmap_access, MAX_GPU_INSTANCE);
3430 			bitmap_and(bitmap_aip, bitmap_aip,
3431 				   prange->bitmap_aip, MAX_GPU_INSTANCE);
3432 		}
3433 		if (get_flags) {
3434 			flags_and &= prange->flags;
3435 			flags_or |= prange->flags;
3436 		}
3437 
3438 		if (get_granularity && prange->granularity < granularity)
3439 			granularity = prange->granularity;
3440 
3441 		node = next;
3442 	}
3443 fill_values:
3444 	mutex_unlock(&svms->lock);
3445 
3446 	for (i = 0; i < nattr; i++) {
3447 		switch (attrs[i].type) {
3448 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3449 			attrs[i].value = location;
3450 			break;
3451 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3452 			attrs[i].value = prefetch_loc;
3453 			break;
3454 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3455 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
3456 							       attrs[i].value);
3457 			if (gpuidx < 0) {
3458 				pr_debug("invalid gpuid %x\n", attrs[i].value);
3459 				return -EINVAL;
3460 			}
3461 			if (test_bit(gpuidx, bitmap_access))
3462 				attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
3463 			else if (test_bit(gpuidx, bitmap_aip))
3464 				attrs[i].type =
3465 					KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
3466 			else
3467 				attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
3468 			break;
3469 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3470 			attrs[i].value = flags_and;
3471 			break;
3472 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3473 			attrs[i].value = ~flags_or;
3474 			break;
3475 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3476 			attrs[i].value = (uint32_t)granularity;
3477 			break;
3478 		}
3479 	}
3480 
3481 	return 0;
3482 }
3483 
3484 int
3485 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
3486 	  uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
3487 {
3488 	int r;
3489 
3490 	start >>= PAGE_SHIFT;
3491 	size >>= PAGE_SHIFT;
3492 
3493 	switch (op) {
3494 	case KFD_IOCTL_SVM_OP_SET_ATTR:
3495 		r = svm_range_set_attr(p, start, size, nattrs, attrs);
3496 		break;
3497 	case KFD_IOCTL_SVM_OP_GET_ATTR:
3498 		r = svm_range_get_attr(p, start, size, nattrs, attrs);
3499 		break;
3500 	default:
3501 		r = EINVAL;
3502 		break;
3503 	}
3504 
3505 	return r;
3506 }
3507