xref: /openbsd/sys/dev/pci/drm/amd/amdkfd/kfd_svm.c (revision 510d2225)
1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright 2020-2021 Advanced Micro Devices, Inc.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9  * and/or sell copies of the Software, and to permit persons to whom the
10  * Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be included in
13  * all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21  * OTHER DEALINGS IN THE SOFTWARE.
22  */
23 
24 #include <linux/types.h>
25 #include <linux/sched/task.h>
26 #include "amdgpu_sync.h"
27 #include "amdgpu_object.h"
28 #include "amdgpu_vm.h"
29 #include "amdgpu_mn.h"
30 #include "amdgpu.h"
31 #include "amdgpu_xgmi.h"
32 #include "kfd_priv.h"
33 #include "kfd_svm.h"
34 #include "kfd_migrate.h"
35 #include "kfd_smi_events.h"
36 
37 #ifdef dev_fmt
38 #undef dev_fmt
39 #endif
40 #define dev_fmt(fmt) "kfd_svm: %s: " fmt, __func__
41 
42 #define AMDGPU_SVM_RANGE_RESTORE_DELAY_MS 1
43 
44 /* Long enough to ensure no retry fault comes after svm range is restored and
45  * page table is updated.
46  */
47 #define AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING	(2UL * NSEC_PER_MSEC)
48 
49 /* Giant svm range split into smaller ranges based on this, it is decided using
50  * minimum of all dGPU/APU 1/32 VRAM size, between 2MB to 1GB and alignment to
51  * power of 2MB.
52  */
53 static uint64_t max_svm_range_pages;
54 
55 struct criu_svm_metadata {
56 	struct list_head list;
57 	struct kfd_criu_svm_range_priv_data data;
58 };
59 
60 static void svm_range_evict_svm_bo_worker(struct work_struct *work);
61 static bool
62 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
63 				    const struct mmu_notifier_range *range,
64 				    unsigned long cur_seq);
65 static int
66 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
67 		   uint64_t *bo_s, uint64_t *bo_l);
68 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
69 	.invalidate = svm_range_cpu_invalidate_pagetables,
70 };
71 
72 /**
73  * svm_range_unlink - unlink svm_range from lists and interval tree
74  * @prange: svm range structure to be removed
75  *
76  * Remove the svm_range from the svms and svm_bo lists and the svms
77  * interval tree.
78  *
79  * Context: The caller must hold svms->lock
80  */
81 static void svm_range_unlink(struct svm_range *prange)
82 {
83 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
84 		 prange, prange->start, prange->last);
85 
86 	if (prange->svm_bo) {
87 		spin_lock(&prange->svm_bo->list_lock);
88 		list_del(&prange->svm_bo_list);
89 		spin_unlock(&prange->svm_bo->list_lock);
90 	}
91 
92 	list_del(&prange->list);
93 	if (prange->it_node.start != 0 && prange->it_node.last != 0)
94 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
95 }
96 
97 static void
98 svm_range_add_notifier_locked(struct mm_struct *mm, struct svm_range *prange)
99 {
100 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
101 		 prange, prange->start, prange->last);
102 
103 	mmu_interval_notifier_insert_locked(&prange->notifier, mm,
104 				     prange->start << PAGE_SHIFT,
105 				     prange->npages << PAGE_SHIFT,
106 				     &svm_range_mn_ops);
107 }
108 
109 /**
110  * svm_range_add_to_svms - add svm range to svms
111  * @prange: svm range structure to be added
112  *
113  * Add the svm range to svms interval tree and link list
114  *
115  * Context: The caller must hold svms->lock
116  */
117 static void svm_range_add_to_svms(struct svm_range *prange)
118 {
119 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms,
120 		 prange, prange->start, prange->last);
121 
122 	list_move_tail(&prange->list, &prange->svms->list);
123 	prange->it_node.start = prange->start;
124 	prange->it_node.last = prange->last;
125 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
126 }
127 
128 static void svm_range_remove_notifier(struct svm_range *prange)
129 {
130 	pr_debug("remove notifier svms 0x%p prange 0x%p [0x%lx 0x%lx]\n",
131 		 prange->svms, prange,
132 		 prange->notifier.interval_tree.start >> PAGE_SHIFT,
133 		 prange->notifier.interval_tree.last >> PAGE_SHIFT);
134 
135 	if (prange->notifier.interval_tree.start != 0 &&
136 	    prange->notifier.interval_tree.last != 0)
137 		mmu_interval_notifier_remove(&prange->notifier);
138 }
139 
140 static bool
141 svm_is_valid_dma_mapping_addr(struct device *dev, dma_addr_t dma_addr)
142 {
143 	return dma_addr && !dma_mapping_error(dev, dma_addr) &&
144 	       !(dma_addr & SVM_RANGE_VRAM_DOMAIN);
145 }
146 
147 static int
148 svm_range_dma_map_dev(struct amdgpu_device *adev, struct svm_range *prange,
149 		      unsigned long offset, unsigned long npages,
150 		      unsigned long *hmm_pfns, uint32_t gpuidx)
151 {
152 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
153 	dma_addr_t *addr = prange->dma_addr[gpuidx];
154 	struct device *dev = adev->dev;
155 	struct page *page;
156 	int i, r;
157 
158 	if (!addr) {
159 		addr = kvcalloc(prange->npages, sizeof(*addr), GFP_KERNEL);
160 		if (!addr)
161 			return -ENOMEM;
162 		prange->dma_addr[gpuidx] = addr;
163 	}
164 
165 	addr += offset;
166 	for (i = 0; i < npages; i++) {
167 		if (svm_is_valid_dma_mapping_addr(dev, addr[i]))
168 			dma_unmap_page(dev, addr[i], PAGE_SIZE, dir);
169 
170 		page = hmm_pfn_to_page(hmm_pfns[i]);
171 		if (is_zone_device_page(page)) {
172 			struct amdgpu_device *bo_adev =
173 					amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
174 
175 			addr[i] = (hmm_pfns[i] << PAGE_SHIFT) +
176 				   bo_adev->vm_manager.vram_base_offset -
177 				   bo_adev->kfd.dev->pgmap.range.start;
178 			addr[i] |= SVM_RANGE_VRAM_DOMAIN;
179 			pr_debug_ratelimited("vram address: 0x%llx\n", addr[i]);
180 			continue;
181 		}
182 		addr[i] = dma_map_page(dev, page, 0, PAGE_SIZE, dir);
183 		r = dma_mapping_error(dev, addr[i]);
184 		if (r) {
185 			dev_err(dev, "failed %d dma_map_page\n", r);
186 			return r;
187 		}
188 		pr_debug_ratelimited("dma mapping 0x%llx for page addr 0x%lx\n",
189 				     addr[i] >> PAGE_SHIFT, page_to_pfn(page));
190 	}
191 	return 0;
192 }
193 
194 static int
195 svm_range_dma_map(struct svm_range *prange, unsigned long *bitmap,
196 		  unsigned long offset, unsigned long npages,
197 		  unsigned long *hmm_pfns)
198 {
199 	struct kfd_process *p;
200 	uint32_t gpuidx;
201 	int r;
202 
203 	p = container_of(prange->svms, struct kfd_process, svms);
204 
205 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
206 		struct kfd_process_device *pdd;
207 
208 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
209 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
210 		if (!pdd) {
211 			pr_debug("failed to find device idx %d\n", gpuidx);
212 			return -EINVAL;
213 		}
214 
215 		r = svm_range_dma_map_dev(pdd->dev->adev, prange, offset, npages,
216 					  hmm_pfns, gpuidx);
217 		if (r)
218 			break;
219 	}
220 
221 	return r;
222 }
223 
224 void svm_range_dma_unmap(struct device *dev, dma_addr_t *dma_addr,
225 			 unsigned long offset, unsigned long npages)
226 {
227 	enum dma_data_direction dir = DMA_BIDIRECTIONAL;
228 	int i;
229 
230 	if (!dma_addr)
231 		return;
232 
233 	for (i = offset; i < offset + npages; i++) {
234 		if (!svm_is_valid_dma_mapping_addr(dev, dma_addr[i]))
235 			continue;
236 		pr_debug_ratelimited("unmap 0x%llx\n", dma_addr[i] >> PAGE_SHIFT);
237 		dma_unmap_page(dev, dma_addr[i], PAGE_SIZE, dir);
238 		dma_addr[i] = 0;
239 	}
240 }
241 
242 void svm_range_free_dma_mappings(struct svm_range *prange)
243 {
244 	struct kfd_process_device *pdd;
245 	dma_addr_t *dma_addr;
246 	struct device *dev;
247 	struct kfd_process *p;
248 	uint32_t gpuidx;
249 
250 	p = container_of(prange->svms, struct kfd_process, svms);
251 
252 	for (gpuidx = 0; gpuidx < MAX_GPU_INSTANCE; gpuidx++) {
253 		dma_addr = prange->dma_addr[gpuidx];
254 		if (!dma_addr)
255 			continue;
256 
257 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
258 		if (!pdd) {
259 			pr_debug("failed to find device idx %d\n", gpuidx);
260 			continue;
261 		}
262 		dev = &pdd->dev->pdev->dev;
263 		svm_range_dma_unmap(dev, dma_addr, 0, prange->npages);
264 		kvfree(dma_addr);
265 		prange->dma_addr[gpuidx] = NULL;
266 	}
267 }
268 
269 static void svm_range_free(struct svm_range *prange, bool update_mem_usage)
270 {
271 	uint64_t size = (prange->last - prange->start + 1) << PAGE_SHIFT;
272 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
273 
274 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx]\n", prange->svms, prange,
275 		 prange->start, prange->last);
276 
277 	svm_range_vram_node_free(prange);
278 	svm_range_free_dma_mappings(prange);
279 
280 	if (update_mem_usage && !p->xnack_enabled) {
281 		pr_debug("unreserve prange 0x%p size: 0x%llx\n", prange, size);
282 		amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
283 					KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
284 	}
285 	mutex_destroy(&prange->lock);
286 	mutex_destroy(&prange->migrate_mutex);
287 	kfree(prange);
288 }
289 
290 static void
291 svm_range_set_default_attributes(int32_t *location, int32_t *prefetch_loc,
292 				 uint8_t *granularity, uint32_t *flags)
293 {
294 	*location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
295 	*prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
296 	*granularity = 9;
297 	*flags =
298 		KFD_IOCTL_SVM_FLAG_HOST_ACCESS | KFD_IOCTL_SVM_FLAG_COHERENT;
299 }
300 
301 static struct
302 svm_range *svm_range_new(struct svm_range_list *svms, uint64_t start,
303 			 uint64_t last, bool update_mem_usage)
304 {
305 	uint64_t size = last - start + 1;
306 	struct svm_range *prange;
307 	struct kfd_process *p;
308 
309 	prange = kzalloc(sizeof(*prange), GFP_KERNEL);
310 	if (!prange)
311 		return NULL;
312 
313 	p = container_of(svms, struct kfd_process, svms);
314 	if (!p->xnack_enabled && update_mem_usage &&
315 	    amdgpu_amdkfd_reserve_mem_limit(NULL, size << PAGE_SHIFT,
316 					    KFD_IOC_ALLOC_MEM_FLAGS_USERPTR)) {
317 		pr_info("SVM mapping failed, exceeds resident system memory limit\n");
318 		kfree(prange);
319 		return NULL;
320 	}
321 	prange->npages = size;
322 	prange->svms = svms;
323 	prange->start = start;
324 	prange->last = last;
325 	INIT_LIST_HEAD(&prange->list);
326 	INIT_LIST_HEAD(&prange->update_list);
327 	INIT_LIST_HEAD(&prange->svm_bo_list);
328 	INIT_LIST_HEAD(&prange->deferred_list);
329 	INIT_LIST_HEAD(&prange->child_list);
330 	atomic_set(&prange->invalid, 0);
331 	prange->validate_timestamp = 0;
332 	mutex_init(&prange->migrate_mutex);
333 	mutex_init(&prange->lock);
334 
335 	if (p->xnack_enabled)
336 		bitmap_copy(prange->bitmap_access, svms->bitmap_supported,
337 			    MAX_GPU_INSTANCE);
338 
339 	svm_range_set_default_attributes(&prange->preferred_loc,
340 					 &prange->prefetch_loc,
341 					 &prange->granularity, &prange->flags);
342 
343 	pr_debug("svms 0x%p [0x%llx 0x%llx]\n", svms, start, last);
344 
345 	return prange;
346 }
347 
348 static bool svm_bo_ref_unless_zero(struct svm_range_bo *svm_bo)
349 {
350 	if (!svm_bo || !kref_get_unless_zero(&svm_bo->kref))
351 		return false;
352 
353 	return true;
354 }
355 
356 static void svm_range_bo_release(struct kref *kref)
357 {
358 	struct svm_range_bo *svm_bo;
359 
360 	svm_bo = container_of(kref, struct svm_range_bo, kref);
361 	pr_debug("svm_bo 0x%p\n", svm_bo);
362 
363 	spin_lock(&svm_bo->list_lock);
364 	while (!list_empty(&svm_bo->range_list)) {
365 		struct svm_range *prange =
366 				list_first_entry(&svm_bo->range_list,
367 						struct svm_range, svm_bo_list);
368 		/* list_del_init tells a concurrent svm_range_vram_node_new when
369 		 * it's safe to reuse the svm_bo pointer and svm_bo_list head.
370 		 */
371 		list_del_init(&prange->svm_bo_list);
372 		spin_unlock(&svm_bo->list_lock);
373 
374 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
375 			 prange->start, prange->last);
376 		mutex_lock(&prange->lock);
377 		prange->svm_bo = NULL;
378 		mutex_unlock(&prange->lock);
379 
380 		spin_lock(&svm_bo->list_lock);
381 	}
382 	spin_unlock(&svm_bo->list_lock);
383 	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
384 		/* We're not in the eviction worker.
385 		 * Signal the fence and synchronize with any
386 		 * pending eviction work.
387 		 */
388 		dma_fence_signal(&svm_bo->eviction_fence->base);
389 		cancel_work_sync(&svm_bo->eviction_work);
390 	}
391 	dma_fence_put(&svm_bo->eviction_fence->base);
392 	amdgpu_bo_unref(&svm_bo->bo);
393 	kfree(svm_bo);
394 }
395 
396 static void svm_range_bo_wq_release(struct work_struct *work)
397 {
398 	struct svm_range_bo *svm_bo;
399 
400 	svm_bo = container_of(work, struct svm_range_bo, release_work);
401 	svm_range_bo_release(&svm_bo->kref);
402 }
403 
404 static void svm_range_bo_release_async(struct kref *kref)
405 {
406 	struct svm_range_bo *svm_bo;
407 
408 	svm_bo = container_of(kref, struct svm_range_bo, kref);
409 	pr_debug("svm_bo 0x%p\n", svm_bo);
410 	INIT_WORK(&svm_bo->release_work, svm_range_bo_wq_release);
411 	schedule_work(&svm_bo->release_work);
412 }
413 
414 void svm_range_bo_unref_async(struct svm_range_bo *svm_bo)
415 {
416 	kref_put(&svm_bo->kref, svm_range_bo_release_async);
417 }
418 
419 static void svm_range_bo_unref(struct svm_range_bo *svm_bo)
420 {
421 	if (svm_bo)
422 		kref_put(&svm_bo->kref, svm_range_bo_release);
423 }
424 
425 static bool
426 svm_range_validate_svm_bo(struct amdgpu_device *adev, struct svm_range *prange)
427 {
428 	struct amdgpu_device *bo_adev;
429 
430 	mutex_lock(&prange->lock);
431 	if (!prange->svm_bo) {
432 		mutex_unlock(&prange->lock);
433 		return false;
434 	}
435 	if (prange->ttm_res) {
436 		/* We still have a reference, all is well */
437 		mutex_unlock(&prange->lock);
438 		return true;
439 	}
440 	if (svm_bo_ref_unless_zero(prange->svm_bo)) {
441 		/*
442 		 * Migrate from GPU to GPU, remove range from source bo_adev
443 		 * svm_bo range list, and return false to allocate svm_bo from
444 		 * destination adev.
445 		 */
446 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
447 		if (bo_adev != adev) {
448 			mutex_unlock(&prange->lock);
449 
450 			spin_lock(&prange->svm_bo->list_lock);
451 			list_del_init(&prange->svm_bo_list);
452 			spin_unlock(&prange->svm_bo->list_lock);
453 
454 			svm_range_bo_unref(prange->svm_bo);
455 			return false;
456 		}
457 		if (READ_ONCE(prange->svm_bo->evicting)) {
458 			struct dma_fence *f;
459 			struct svm_range_bo *svm_bo;
460 			/* The BO is getting evicted,
461 			 * we need to get a new one
462 			 */
463 			mutex_unlock(&prange->lock);
464 			svm_bo = prange->svm_bo;
465 			f = dma_fence_get(&svm_bo->eviction_fence->base);
466 			svm_range_bo_unref(prange->svm_bo);
467 			/* wait for the fence to avoid long spin-loop
468 			 * at list_empty_careful
469 			 */
470 			dma_fence_wait(f, false);
471 			dma_fence_put(f);
472 		} else {
473 			/* The BO was still around and we got
474 			 * a new reference to it
475 			 */
476 			mutex_unlock(&prange->lock);
477 			pr_debug("reuse old bo svms 0x%p [0x%lx 0x%lx]\n",
478 				 prange->svms, prange->start, prange->last);
479 
480 			prange->ttm_res = prange->svm_bo->bo->tbo.resource;
481 			return true;
482 		}
483 
484 	} else {
485 		mutex_unlock(&prange->lock);
486 	}
487 
488 	/* We need a new svm_bo. Spin-loop to wait for concurrent
489 	 * svm_range_bo_release to finish removing this range from
490 	 * its range list and set prange->svm_bo to null. After this,
491 	 * it is safe to reuse the svm_bo pointer and svm_bo_list head.
492 	 */
493 	while (!list_empty_careful(&prange->svm_bo_list) || prange->svm_bo)
494 		cond_resched();
495 
496 	return false;
497 }
498 
499 static struct svm_range_bo *svm_range_bo_new(void)
500 {
501 	struct svm_range_bo *svm_bo;
502 
503 	svm_bo = kzalloc(sizeof(*svm_bo), GFP_KERNEL);
504 	if (!svm_bo)
505 		return NULL;
506 
507 	kref_init(&svm_bo->kref);
508 	INIT_LIST_HEAD(&svm_bo->range_list);
509 	spin_lock_init(&svm_bo->list_lock);
510 
511 	return svm_bo;
512 }
513 
514 int
515 svm_range_vram_node_new(struct amdgpu_device *adev, struct svm_range *prange,
516 			bool clear)
517 {
518 	struct amdgpu_bo_param bp;
519 	struct svm_range_bo *svm_bo;
520 	struct amdgpu_bo_user *ubo;
521 	struct amdgpu_bo *bo;
522 	struct kfd_process *p;
523 	struct mm_struct *mm;
524 	int r;
525 
526 	p = container_of(prange->svms, struct kfd_process, svms);
527 	pr_debug("pasid: %x svms 0x%p [0x%lx 0x%lx]\n", p->pasid, prange->svms,
528 		 prange->start, prange->last);
529 
530 	if (svm_range_validate_svm_bo(adev, prange))
531 		return 0;
532 
533 	svm_bo = svm_range_bo_new();
534 	if (!svm_bo) {
535 		pr_debug("failed to alloc svm bo\n");
536 		return -ENOMEM;
537 	}
538 	mm = get_task_mm(p->lead_thread);
539 	if (!mm) {
540 		pr_debug("failed to get mm\n");
541 		kfree(svm_bo);
542 		return -ESRCH;
543 	}
544 	svm_bo->eviction_fence =
545 		amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1),
546 					   mm,
547 					   svm_bo);
548 	mmput(mm);
549 	INIT_WORK(&svm_bo->eviction_work, svm_range_evict_svm_bo_worker);
550 	svm_bo->evicting = 0;
551 	memset(&bp, 0, sizeof(bp));
552 	bp.size = prange->npages * PAGE_SIZE;
553 	bp.byte_align = PAGE_SIZE;
554 	bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
555 	bp.flags = AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
556 	bp.flags |= clear ? AMDGPU_GEM_CREATE_VRAM_CLEARED : 0;
557 	bp.flags |= AMDGPU_GEM_CREATE_DISCARDABLE;
558 	bp.type = ttm_bo_type_device;
559 	bp.resv = NULL;
560 
561 	r = amdgpu_bo_create_user(adev, &bp, &ubo);
562 	if (r) {
563 		pr_debug("failed %d to create bo\n", r);
564 		goto create_bo_failed;
565 	}
566 	bo = &ubo->bo;
567 	r = amdgpu_bo_reserve(bo, true);
568 	if (r) {
569 		pr_debug("failed %d to reserve bo\n", r);
570 		goto reserve_bo_failed;
571 	}
572 
573 	if (clear) {
574 		r = amdgpu_bo_sync_wait(bo, AMDGPU_FENCE_OWNER_KFD, false);
575 		if (r) {
576 			pr_debug("failed %d to sync bo\n", r);
577 			amdgpu_bo_unreserve(bo);
578 			goto reserve_bo_failed;
579 		}
580 	}
581 
582 	r = dma_resv_reserve_fences(bo->tbo.base.resv, 1);
583 	if (r) {
584 		pr_debug("failed %d to reserve bo\n", r);
585 		amdgpu_bo_unreserve(bo);
586 		goto reserve_bo_failed;
587 	}
588 	amdgpu_bo_fence(bo, &svm_bo->eviction_fence->base, true);
589 
590 	amdgpu_bo_unreserve(bo);
591 
592 	svm_bo->bo = bo;
593 	prange->svm_bo = svm_bo;
594 	prange->ttm_res = bo->tbo.resource;
595 	prange->offset = 0;
596 
597 	spin_lock(&svm_bo->list_lock);
598 	list_add(&prange->svm_bo_list, &svm_bo->range_list);
599 	spin_unlock(&svm_bo->list_lock);
600 
601 	return 0;
602 
603 reserve_bo_failed:
604 	amdgpu_bo_unref(&bo);
605 create_bo_failed:
606 	dma_fence_put(&svm_bo->eviction_fence->base);
607 	kfree(svm_bo);
608 	prange->ttm_res = NULL;
609 
610 	return r;
611 }
612 
613 void svm_range_vram_node_free(struct svm_range *prange)
614 {
615 	/* serialize prange->svm_bo unref */
616 	mutex_lock(&prange->lock);
617 	/* prange->svm_bo has not been unref */
618 	if (prange->ttm_res) {
619 		prange->ttm_res = NULL;
620 		mutex_unlock(&prange->lock);
621 		svm_range_bo_unref(prange->svm_bo);
622 	} else
623 		mutex_unlock(&prange->lock);
624 }
625 
626 struct amdgpu_device *
627 svm_range_get_adev_by_id(struct svm_range *prange, uint32_t gpu_id)
628 {
629 	struct kfd_process_device *pdd;
630 	struct kfd_process *p;
631 	int32_t gpu_idx;
632 
633 	p = container_of(prange->svms, struct kfd_process, svms);
634 
635 	gpu_idx = kfd_process_gpuidx_from_gpuid(p, gpu_id);
636 	if (gpu_idx < 0) {
637 		pr_debug("failed to get device by id 0x%x\n", gpu_id);
638 		return NULL;
639 	}
640 	pdd = kfd_process_device_from_gpuidx(p, gpu_idx);
641 	if (!pdd) {
642 		pr_debug("failed to get device by idx 0x%x\n", gpu_idx);
643 		return NULL;
644 	}
645 
646 	return pdd->dev->adev;
647 }
648 
649 struct kfd_process_device *
650 svm_range_get_pdd_by_adev(struct svm_range *prange, struct amdgpu_device *adev)
651 {
652 	struct kfd_process *p;
653 	int32_t gpu_idx, gpuid;
654 	int r;
655 
656 	p = container_of(prange->svms, struct kfd_process, svms);
657 
658 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpu_idx);
659 	if (r) {
660 		pr_debug("failed to get device id by adev %p\n", adev);
661 		return NULL;
662 	}
663 
664 	return kfd_process_device_from_gpuidx(p, gpu_idx);
665 }
666 
667 static int svm_range_bo_validate(void *param, struct amdgpu_bo *bo)
668 {
669 	struct ttm_operation_ctx ctx = { false, false };
670 
671 	amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_VRAM);
672 
673 	return ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
674 }
675 
676 static int
677 svm_range_check_attr(struct kfd_process *p,
678 		     uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
679 {
680 	uint32_t i;
681 
682 	for (i = 0; i < nattr; i++) {
683 		uint32_t val = attrs[i].value;
684 		int gpuidx = MAX_GPU_INSTANCE;
685 
686 		switch (attrs[i].type) {
687 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
688 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM &&
689 			    val != KFD_IOCTL_SVM_LOCATION_UNDEFINED)
690 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
691 			break;
692 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
693 			if (val != KFD_IOCTL_SVM_LOCATION_SYSMEM)
694 				gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
695 			break;
696 		case KFD_IOCTL_SVM_ATTR_ACCESS:
697 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
698 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
699 			gpuidx = kfd_process_gpuidx_from_gpuid(p, val);
700 			break;
701 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
702 			break;
703 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
704 			break;
705 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
706 			break;
707 		default:
708 			pr_debug("unknown attr type 0x%x\n", attrs[i].type);
709 			return -EINVAL;
710 		}
711 
712 		if (gpuidx < 0) {
713 			pr_debug("no GPU 0x%x found\n", val);
714 			return -EINVAL;
715 		} else if (gpuidx < MAX_GPU_INSTANCE &&
716 			   !test_bit(gpuidx, p->svms.bitmap_supported)) {
717 			pr_debug("GPU 0x%x not supported\n", val);
718 			return -EINVAL;
719 		}
720 	}
721 
722 	return 0;
723 }
724 
725 static void
726 svm_range_apply_attrs(struct kfd_process *p, struct svm_range *prange,
727 		      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
728 		      bool *update_mapping)
729 {
730 	uint32_t i;
731 	int gpuidx;
732 
733 	for (i = 0; i < nattr; i++) {
734 		switch (attrs[i].type) {
735 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
736 			prange->preferred_loc = attrs[i].value;
737 			break;
738 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
739 			prange->prefetch_loc = attrs[i].value;
740 			break;
741 		case KFD_IOCTL_SVM_ATTR_ACCESS:
742 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
743 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
744 			*update_mapping = true;
745 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
746 							       attrs[i].value);
747 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
748 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
749 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
750 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
751 				bitmap_set(prange->bitmap_access, gpuidx, 1);
752 				bitmap_clear(prange->bitmap_aip, gpuidx, 1);
753 			} else {
754 				bitmap_clear(prange->bitmap_access, gpuidx, 1);
755 				bitmap_set(prange->bitmap_aip, gpuidx, 1);
756 			}
757 			break;
758 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
759 			*update_mapping = true;
760 			prange->flags |= attrs[i].value;
761 			break;
762 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
763 			*update_mapping = true;
764 			prange->flags &= ~attrs[i].value;
765 			break;
766 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
767 			prange->granularity = min_t(uint32_t, attrs[i].value, 0x3F);
768 			break;
769 		default:
770 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
771 		}
772 	}
773 }
774 
775 static bool
776 svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
777 			uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs)
778 {
779 	uint32_t i;
780 	int gpuidx;
781 
782 	for (i = 0; i < nattr; i++) {
783 		switch (attrs[i].type) {
784 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
785 			if (prange->preferred_loc != attrs[i].value)
786 				return false;
787 			break;
788 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
789 			/* Prefetch should always trigger a migration even
790 			 * if the value of the attribute didn't change.
791 			 */
792 			return false;
793 		case KFD_IOCTL_SVM_ATTR_ACCESS:
794 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
795 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
796 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
797 							       attrs[i].value);
798 			if (attrs[i].type == KFD_IOCTL_SVM_ATTR_NO_ACCESS) {
799 				if (test_bit(gpuidx, prange->bitmap_access) ||
800 				    test_bit(gpuidx, prange->bitmap_aip))
801 					return false;
802 			} else if (attrs[i].type == KFD_IOCTL_SVM_ATTR_ACCESS) {
803 				if (!test_bit(gpuidx, prange->bitmap_access))
804 					return false;
805 			} else {
806 				if (!test_bit(gpuidx, prange->bitmap_aip))
807 					return false;
808 			}
809 			break;
810 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
811 			if ((prange->flags & attrs[i].value) != attrs[i].value)
812 				return false;
813 			break;
814 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
815 			if ((prange->flags & attrs[i].value) != 0)
816 				return false;
817 			break;
818 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
819 			if (prange->granularity != attrs[i].value)
820 				return false;
821 			break;
822 		default:
823 			WARN_ONCE(1, "svm_range_check_attrs wasn't called?");
824 		}
825 	}
826 
827 	return true;
828 }
829 
830 /**
831  * svm_range_debug_dump - print all range information from svms
832  * @svms: svm range list header
833  *
834  * debug output svm range start, end, prefetch location from svms
835  * interval tree and link list
836  *
837  * Context: The caller must hold svms->lock
838  */
839 static void svm_range_debug_dump(struct svm_range_list *svms)
840 {
841 	struct interval_tree_node *node;
842 	struct svm_range *prange;
843 
844 	pr_debug("dump svms 0x%p list\n", svms);
845 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
846 
847 	list_for_each_entry(prange, &svms->list, list) {
848 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
849 			 prange, prange->start, prange->npages,
850 			 prange->start + prange->npages - 1,
851 			 prange->actual_loc);
852 	}
853 
854 	pr_debug("dump svms 0x%p interval tree\n", svms);
855 	pr_debug("range\tstart\tpage\tend\t\tlocation\n");
856 	node = interval_tree_iter_first(&svms->objects, 0, ~0ULL);
857 	while (node) {
858 		prange = container_of(node, struct svm_range, it_node);
859 		pr_debug("0x%p 0x%lx\t0x%llx\t0x%llx\t0x%x\n",
860 			 prange, prange->start, prange->npages,
861 			 prange->start + prange->npages - 1,
862 			 prange->actual_loc);
863 		node = interval_tree_iter_next(node, 0, ~0ULL);
864 	}
865 }
866 
867 static int
868 svm_range_split_array(void *ppnew, void *ppold, size_t size,
869 		      uint64_t old_start, uint64_t old_n,
870 		      uint64_t new_start, uint64_t new_n)
871 {
872 	unsigned char *new, *old, *pold;
873 	uint64_t d;
874 
875 	if (!ppold)
876 		return 0;
877 	pold = *(unsigned char **)ppold;
878 	if (!pold)
879 		return 0;
880 
881 	new = kvmalloc_array(new_n, size, GFP_KERNEL);
882 	if (!new)
883 		return -ENOMEM;
884 
885 	d = (new_start - old_start) * size;
886 	memcpy(new, pold + d, new_n * size);
887 
888 	old = kvmalloc_array(old_n, size, GFP_KERNEL);
889 	if (!old) {
890 		kvfree(new);
891 		return -ENOMEM;
892 	}
893 
894 	d = (new_start == old_start) ? new_n * size : 0;
895 	memcpy(old, pold + d, old_n * size);
896 
897 	kvfree(pold);
898 	*(void **)ppold = old;
899 	*(void **)ppnew = new;
900 
901 	return 0;
902 }
903 
904 static int
905 svm_range_split_pages(struct svm_range *new, struct svm_range *old,
906 		      uint64_t start, uint64_t last)
907 {
908 	uint64_t npages = last - start + 1;
909 	int i, r;
910 
911 	for (i = 0; i < MAX_GPU_INSTANCE; i++) {
912 		r = svm_range_split_array(&new->dma_addr[i], &old->dma_addr[i],
913 					  sizeof(*old->dma_addr[i]), old->start,
914 					  npages, new->start, new->npages);
915 		if (r)
916 			return r;
917 	}
918 
919 	return 0;
920 }
921 
922 static int
923 svm_range_split_nodes(struct svm_range *new, struct svm_range *old,
924 		      uint64_t start, uint64_t last)
925 {
926 	uint64_t npages = last - start + 1;
927 
928 	pr_debug("svms 0x%p new prange 0x%p start 0x%lx [0x%llx 0x%llx]\n",
929 		 new->svms, new, new->start, start, last);
930 
931 	if (new->start == old->start) {
932 		new->offset = old->offset;
933 		old->offset += new->npages;
934 	} else {
935 		new->offset = old->offset + npages;
936 	}
937 
938 	new->svm_bo = svm_range_bo_ref(old->svm_bo);
939 	new->ttm_res = old->ttm_res;
940 
941 	spin_lock(&new->svm_bo->list_lock);
942 	list_add(&new->svm_bo_list, &new->svm_bo->range_list);
943 	spin_unlock(&new->svm_bo->list_lock);
944 
945 	return 0;
946 }
947 
948 /**
949  * svm_range_split_adjust - split range and adjust
950  *
951  * @new: new range
952  * @old: the old range
953  * @start: the old range adjust to start address in pages
954  * @last: the old range adjust to last address in pages
955  *
956  * Copy system memory dma_addr or vram ttm_res in old range to new
957  * range from new_start up to size new->npages, the remaining old range is from
958  * start to last
959  *
960  * Return:
961  * 0 - OK, -ENOMEM - out of memory
962  */
963 static int
964 svm_range_split_adjust(struct svm_range *new, struct svm_range *old,
965 		      uint64_t start, uint64_t last)
966 {
967 	int r;
968 
969 	pr_debug("svms 0x%p new 0x%lx old [0x%lx 0x%lx] => [0x%llx 0x%llx]\n",
970 		 new->svms, new->start, old->start, old->last, start, last);
971 
972 	if (new->start < old->start ||
973 	    new->last > old->last) {
974 		WARN_ONCE(1, "invalid new range start or last\n");
975 		return -EINVAL;
976 	}
977 
978 	r = svm_range_split_pages(new, old, start, last);
979 	if (r)
980 		return r;
981 
982 	if (old->actual_loc && old->ttm_res) {
983 		r = svm_range_split_nodes(new, old, start, last);
984 		if (r)
985 			return r;
986 	}
987 
988 	old->npages = last - start + 1;
989 	old->start = start;
990 	old->last = last;
991 	new->flags = old->flags;
992 	new->preferred_loc = old->preferred_loc;
993 	new->prefetch_loc = old->prefetch_loc;
994 	new->actual_loc = old->actual_loc;
995 	new->granularity = old->granularity;
996 	new->mapped_to_gpu = old->mapped_to_gpu;
997 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
998 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
999 
1000 	return 0;
1001 }
1002 
1003 /**
1004  * svm_range_split - split a range in 2 ranges
1005  *
1006  * @prange: the svm range to split
1007  * @start: the remaining range start address in pages
1008  * @last: the remaining range last address in pages
1009  * @new: the result new range generated
1010  *
1011  * Two cases only:
1012  * case 1: if start == prange->start
1013  *         prange ==> prange[start, last]
1014  *         new range [last + 1, prange->last]
1015  *
1016  * case 2: if last == prange->last
1017  *         prange ==> prange[start, last]
1018  *         new range [prange->start, start - 1]
1019  *
1020  * Return:
1021  * 0 - OK, -ENOMEM - out of memory, -EINVAL - invalid start, last
1022  */
1023 static int
1024 svm_range_split(struct svm_range *prange, uint64_t start, uint64_t last,
1025 		struct svm_range **new)
1026 {
1027 	uint64_t old_start = prange->start;
1028 	uint64_t old_last = prange->last;
1029 	struct svm_range_list *svms;
1030 	int r = 0;
1031 
1032 	pr_debug("svms 0x%p [0x%llx 0x%llx] to [0x%llx 0x%llx]\n", prange->svms,
1033 		 old_start, old_last, start, last);
1034 
1035 	if (old_start != start && old_last != last)
1036 		return -EINVAL;
1037 	if (start < old_start || last > old_last)
1038 		return -EINVAL;
1039 
1040 	svms = prange->svms;
1041 	if (old_start == start)
1042 		*new = svm_range_new(svms, last + 1, old_last, false);
1043 	else
1044 		*new = svm_range_new(svms, old_start, start - 1, false);
1045 	if (!*new)
1046 		return -ENOMEM;
1047 
1048 	r = svm_range_split_adjust(*new, prange, start, last);
1049 	if (r) {
1050 		pr_debug("failed %d split [0x%llx 0x%llx] to [0x%llx 0x%llx]\n",
1051 			 r, old_start, old_last, start, last);
1052 		svm_range_free(*new, false);
1053 		*new = NULL;
1054 	}
1055 
1056 	return r;
1057 }
1058 
1059 static int
1060 svm_range_split_tail(struct svm_range *prange,
1061 		     uint64_t new_last, struct list_head *insert_list)
1062 {
1063 	struct svm_range *tail;
1064 	int r = svm_range_split(prange, prange->start, new_last, &tail);
1065 
1066 	if (!r)
1067 		list_add(&tail->list, insert_list);
1068 	return r;
1069 }
1070 
1071 static int
1072 svm_range_split_head(struct svm_range *prange,
1073 		     uint64_t new_start, struct list_head *insert_list)
1074 {
1075 	struct svm_range *head;
1076 	int r = svm_range_split(prange, new_start, prange->last, &head);
1077 
1078 	if (!r)
1079 		list_add(&head->list, insert_list);
1080 	return r;
1081 }
1082 
1083 static void
1084 svm_range_add_child(struct svm_range *prange, struct mm_struct *mm,
1085 		    struct svm_range *pchild, enum svm_work_list_ops op)
1086 {
1087 	pr_debug("add child 0x%p [0x%lx 0x%lx] to prange 0x%p child list %d\n",
1088 		 pchild, pchild->start, pchild->last, prange, op);
1089 
1090 	pchild->work_item.mm = mm;
1091 	pchild->work_item.op = op;
1092 	list_add_tail(&pchild->child_list, &prange->child_list);
1093 }
1094 
1095 /**
1096  * svm_range_split_by_granularity - collect ranges within granularity boundary
1097  *
1098  * @p: the process with svms list
1099  * @mm: mm structure
1100  * @addr: the vm fault address in pages, to split the prange
1101  * @parent: parent range if prange is from child list
1102  * @prange: prange to split
1103  *
1104  * Trims @prange to be a single aligned block of prange->granularity if
1105  * possible. The head and tail are added to the child_list in @parent.
1106  *
1107  * Context: caller must hold mmap_read_lock and prange->lock
1108  *
1109  * Return:
1110  * 0 - OK, otherwise error code
1111  */
1112 int
1113 svm_range_split_by_granularity(struct kfd_process *p, struct mm_struct *mm,
1114 			       unsigned long addr, struct svm_range *parent,
1115 			       struct svm_range *prange)
1116 {
1117 	struct svm_range *head, *tail;
1118 	unsigned long start, last, size;
1119 	int r;
1120 
1121 	/* Align splited range start and size to granularity size, then a single
1122 	 * PTE will be used for whole range, this reduces the number of PTE
1123 	 * updated and the L1 TLB space used for translation.
1124 	 */
1125 	size = 1UL << prange->granularity;
1126 	start = ALIGN_DOWN(addr, size);
1127 	last = ALIGN(addr + 1, size) - 1;
1128 
1129 	pr_debug("svms 0x%p split [0x%lx 0x%lx] to [0x%lx 0x%lx] size 0x%lx\n",
1130 		 prange->svms, prange->start, prange->last, start, last, size);
1131 
1132 	if (start > prange->start) {
1133 		r = svm_range_split(prange, start, prange->last, &head);
1134 		if (r)
1135 			return r;
1136 		svm_range_add_child(parent, mm, head, SVM_OP_ADD_RANGE);
1137 	}
1138 
1139 	if (last < prange->last) {
1140 		r = svm_range_split(prange, prange->start, last, &tail);
1141 		if (r)
1142 			return r;
1143 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
1144 	}
1145 
1146 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
1147 	if (p->xnack_enabled && prange->work_item.op == SVM_OP_ADD_RANGE) {
1148 		prange->work_item.op = SVM_OP_ADD_RANGE_AND_MAP;
1149 		pr_debug("change prange 0x%p [0x%lx 0x%lx] op %d\n",
1150 			 prange, prange->start, prange->last,
1151 			 SVM_OP_ADD_RANGE_AND_MAP);
1152 	}
1153 	return 0;
1154 }
1155 
1156 static uint64_t
1157 svm_range_get_pte_flags(struct amdgpu_device *adev, struct svm_range *prange,
1158 			int domain)
1159 {
1160 	struct amdgpu_device *bo_adev;
1161 	uint32_t flags = prange->flags;
1162 	uint32_t mapping_flags = 0;
1163 	uint64_t pte_flags;
1164 	bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
1165 	bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
1166 
1167 	if (domain == SVM_RANGE_VRAM_DOMAIN)
1168 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1169 
1170 	switch (KFD_GC_VERSION(adev->kfd.dev)) {
1171 	case IP_VERSION(9, 4, 1):
1172 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1173 			if (bo_adev == adev) {
1174 				mapping_flags |= coherent ?
1175 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1176 			} else {
1177 				mapping_flags |= coherent ?
1178 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1179 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1180 					snoop = true;
1181 			}
1182 		} else {
1183 			mapping_flags |= coherent ?
1184 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1185 		}
1186 		break;
1187 	case IP_VERSION(9, 4, 2):
1188 		if (domain == SVM_RANGE_VRAM_DOMAIN) {
1189 			if (bo_adev == adev) {
1190 				mapping_flags |= coherent ?
1191 					AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
1192 				if (adev->gmc.xgmi.connected_to_cpu)
1193 					snoop = true;
1194 			} else {
1195 				mapping_flags |= coherent ?
1196 					AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1197 				if (amdgpu_xgmi_same_hive(adev, bo_adev))
1198 					snoop = true;
1199 			}
1200 		} else {
1201 			mapping_flags |= coherent ?
1202 				AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1203 		}
1204 		break;
1205 	default:
1206 		mapping_flags |= coherent ?
1207 			AMDGPU_VM_MTYPE_UC : AMDGPU_VM_MTYPE_NC;
1208 	}
1209 
1210 	mapping_flags |= AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE;
1211 
1212 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_RO)
1213 		mapping_flags &= ~AMDGPU_VM_PAGE_WRITEABLE;
1214 	if (flags & KFD_IOCTL_SVM_FLAG_GPU_EXEC)
1215 		mapping_flags |= AMDGPU_VM_PAGE_EXECUTABLE;
1216 
1217 	pte_flags = AMDGPU_PTE_VALID;
1218 	pte_flags |= (domain == SVM_RANGE_VRAM_DOMAIN) ? 0 : AMDGPU_PTE_SYSTEM;
1219 	pte_flags |= snoop ? AMDGPU_PTE_SNOOPED : 0;
1220 
1221 	pte_flags |= amdgpu_gem_va_map_flags(adev, mapping_flags);
1222 	return pte_flags;
1223 }
1224 
1225 static int
1226 svm_range_unmap_from_gpu(struct amdgpu_device *adev, struct amdgpu_vm *vm,
1227 			 uint64_t start, uint64_t last,
1228 			 struct dma_fence **fence)
1229 {
1230 	uint64_t init_pte_value = 0;
1231 
1232 	pr_debug("[0x%llx 0x%llx]\n", start, last);
1233 
1234 	return amdgpu_vm_update_range(adev, vm, false, true, true, NULL, start,
1235 				      last, init_pte_value, 0, 0, NULL, NULL,
1236 				      fence);
1237 }
1238 
1239 static int
1240 svm_range_unmap_from_gpus(struct svm_range *prange, unsigned long start,
1241 			  unsigned long last, uint32_t trigger)
1242 {
1243 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1244 	struct kfd_process_device *pdd;
1245 	struct dma_fence *fence = NULL;
1246 	struct kfd_process *p;
1247 	uint32_t gpuidx;
1248 	int r = 0;
1249 
1250 	if (!prange->mapped_to_gpu) {
1251 		pr_debug("prange 0x%p [0x%lx 0x%lx] not mapped to GPU\n",
1252 			 prange, prange->start, prange->last);
1253 		return 0;
1254 	}
1255 
1256 	if (prange->start == start && prange->last == last) {
1257 		pr_debug("unmap svms 0x%p prange 0x%p\n", prange->svms, prange);
1258 		prange->mapped_to_gpu = false;
1259 	}
1260 
1261 	bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
1262 		  MAX_GPU_INSTANCE);
1263 	p = container_of(prange->svms, struct kfd_process, svms);
1264 
1265 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1266 		pr_debug("unmap from gpu idx 0x%x\n", gpuidx);
1267 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1268 		if (!pdd) {
1269 			pr_debug("failed to find device idx %d\n", gpuidx);
1270 			return -EINVAL;
1271 		}
1272 
1273 		kfd_smi_event_unmap_from_gpu(pdd->dev, p->lead_thread->pid,
1274 					     start, last, trigger);
1275 
1276 		r = svm_range_unmap_from_gpu(pdd->dev->adev,
1277 					     drm_priv_to_vm(pdd->drm_priv),
1278 					     start, last, &fence);
1279 		if (r)
1280 			break;
1281 
1282 		if (fence) {
1283 			r = dma_fence_wait(fence, false);
1284 			dma_fence_put(fence);
1285 			fence = NULL;
1286 			if (r)
1287 				break;
1288 		}
1289 		kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
1290 	}
1291 
1292 	return r;
1293 }
1294 
1295 static int
1296 svm_range_map_to_gpu(struct kfd_process_device *pdd, struct svm_range *prange,
1297 		     unsigned long offset, unsigned long npages, bool readonly,
1298 		     dma_addr_t *dma_addr, struct amdgpu_device *bo_adev,
1299 		     struct dma_fence **fence, bool flush_tlb)
1300 {
1301 	struct amdgpu_device *adev = pdd->dev->adev;
1302 	struct amdgpu_vm *vm = drm_priv_to_vm(pdd->drm_priv);
1303 	uint64_t pte_flags;
1304 	unsigned long last_start;
1305 	int last_domain;
1306 	int r = 0;
1307 	int64_t i, j;
1308 
1309 	last_start = prange->start + offset;
1310 
1311 	pr_debug("svms 0x%p [0x%lx 0x%lx] readonly %d\n", prange->svms,
1312 		 last_start, last_start + npages - 1, readonly);
1313 
1314 	for (i = offset; i < offset + npages; i++) {
1315 		last_domain = dma_addr[i] & SVM_RANGE_VRAM_DOMAIN;
1316 		dma_addr[i] &= ~SVM_RANGE_VRAM_DOMAIN;
1317 
1318 		/* Collect all pages in the same address range and memory domain
1319 		 * that can be mapped with a single call to update mapping.
1320 		 */
1321 		if (i < offset + npages - 1 &&
1322 		    last_domain == (dma_addr[i + 1] & SVM_RANGE_VRAM_DOMAIN))
1323 			continue;
1324 
1325 		pr_debug("Mapping range [0x%lx 0x%llx] on domain: %s\n",
1326 			 last_start, prange->start + i, last_domain ? "GPU" : "CPU");
1327 
1328 		pte_flags = svm_range_get_pte_flags(adev, prange, last_domain);
1329 		if (readonly)
1330 			pte_flags &= ~AMDGPU_PTE_WRITEABLE;
1331 
1332 		pr_debug("svms 0x%p map [0x%lx 0x%llx] vram %d PTE 0x%llx\n",
1333 			 prange->svms, last_start, prange->start + i,
1334 			 (last_domain == SVM_RANGE_VRAM_DOMAIN) ? 1 : 0,
1335 			 pte_flags);
1336 
1337 		r = amdgpu_vm_update_range(adev, vm, false, false, flush_tlb, NULL,
1338 					   last_start, prange->start + i,
1339 					   pte_flags,
1340 					   (last_start - prange->start) << PAGE_SHIFT,
1341 					   bo_adev ? bo_adev->vm_manager.vram_base_offset : 0,
1342 					   NULL, dma_addr, &vm->last_update);
1343 
1344 		for (j = last_start - prange->start; j <= i; j++)
1345 			dma_addr[j] |= last_domain;
1346 
1347 		if (r) {
1348 			pr_debug("failed %d to map to gpu 0x%lx\n", r, prange->start);
1349 			goto out;
1350 		}
1351 		last_start = prange->start + i + 1;
1352 	}
1353 
1354 	r = amdgpu_vm_update_pdes(adev, vm, false);
1355 	if (r) {
1356 		pr_debug("failed %d to update directories 0x%lx\n", r,
1357 			 prange->start);
1358 		goto out;
1359 	}
1360 
1361 	if (fence)
1362 		*fence = dma_fence_get(vm->last_update);
1363 
1364 out:
1365 	return r;
1366 }
1367 
1368 static int
1369 svm_range_map_to_gpus(struct svm_range *prange, unsigned long offset,
1370 		      unsigned long npages, bool readonly,
1371 		      unsigned long *bitmap, bool wait, bool flush_tlb)
1372 {
1373 	struct kfd_process_device *pdd;
1374 	struct amdgpu_device *bo_adev;
1375 	struct kfd_process *p;
1376 	struct dma_fence *fence = NULL;
1377 	uint32_t gpuidx;
1378 	int r = 0;
1379 
1380 	if (prange->svm_bo && prange->ttm_res)
1381 		bo_adev = amdgpu_ttm_adev(prange->svm_bo->bo->tbo.bdev);
1382 	else
1383 		bo_adev = NULL;
1384 
1385 	p = container_of(prange->svms, struct kfd_process, svms);
1386 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
1387 		pr_debug("mapping to gpu idx 0x%x\n", gpuidx);
1388 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1389 		if (!pdd) {
1390 			pr_debug("failed to find device idx %d\n", gpuidx);
1391 			return -EINVAL;
1392 		}
1393 
1394 		pdd = kfd_bind_process_to_device(pdd->dev, p);
1395 		if (IS_ERR(pdd))
1396 			return -EINVAL;
1397 
1398 		if (bo_adev && pdd->dev->adev != bo_adev &&
1399 		    !amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
1400 			pr_debug("cannot map to device idx %d\n", gpuidx);
1401 			continue;
1402 		}
1403 
1404 		r = svm_range_map_to_gpu(pdd, prange, offset, npages, readonly,
1405 					 prange->dma_addr[gpuidx],
1406 					 bo_adev, wait ? &fence : NULL,
1407 					 flush_tlb);
1408 		if (r)
1409 			break;
1410 
1411 		if (fence) {
1412 			r = dma_fence_wait(fence, false);
1413 			dma_fence_put(fence);
1414 			fence = NULL;
1415 			if (r) {
1416 				pr_debug("failed %d to dma fence wait\n", r);
1417 				break;
1418 			}
1419 		}
1420 
1421 		kfd_flush_tlb(pdd, TLB_FLUSH_LEGACY);
1422 	}
1423 
1424 	return r;
1425 }
1426 
1427 struct svm_validate_context {
1428 	struct kfd_process *process;
1429 	struct svm_range *prange;
1430 	bool intr;
1431 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
1432 	struct ttm_validate_buffer tv[MAX_GPU_INSTANCE];
1433 	struct list_head validate_list;
1434 	struct ww_acquire_ctx ticket;
1435 };
1436 
1437 static int svm_range_reserve_bos(struct svm_validate_context *ctx)
1438 {
1439 	struct kfd_process_device *pdd;
1440 	struct amdgpu_vm *vm;
1441 	uint32_t gpuidx;
1442 	int r;
1443 
1444 	INIT_LIST_HEAD(&ctx->validate_list);
1445 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1446 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1447 		if (!pdd) {
1448 			pr_debug("failed to find device idx %d\n", gpuidx);
1449 			return -EINVAL;
1450 		}
1451 		vm = drm_priv_to_vm(pdd->drm_priv);
1452 
1453 		ctx->tv[gpuidx].bo = &vm->root.bo->tbo;
1454 		ctx->tv[gpuidx].num_shared = 4;
1455 		list_add(&ctx->tv[gpuidx].head, &ctx->validate_list);
1456 	}
1457 
1458 	r = ttm_eu_reserve_buffers(&ctx->ticket, &ctx->validate_list,
1459 				   ctx->intr, NULL);
1460 	if (r) {
1461 		pr_debug("failed %d to reserve bo\n", r);
1462 		return r;
1463 	}
1464 
1465 	for_each_set_bit(gpuidx, ctx->bitmap, MAX_GPU_INSTANCE) {
1466 		pdd = kfd_process_device_from_gpuidx(ctx->process, gpuidx);
1467 		if (!pdd) {
1468 			pr_debug("failed to find device idx %d\n", gpuidx);
1469 			r = -EINVAL;
1470 			goto unreserve_out;
1471 		}
1472 
1473 		r = amdgpu_vm_validate_pt_bos(pdd->dev->adev,
1474 					      drm_priv_to_vm(pdd->drm_priv),
1475 					      svm_range_bo_validate, NULL);
1476 		if (r) {
1477 			pr_debug("failed %d validate pt bos\n", r);
1478 			goto unreserve_out;
1479 		}
1480 	}
1481 
1482 	return 0;
1483 
1484 unreserve_out:
1485 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1486 	return r;
1487 }
1488 
1489 static void svm_range_unreserve_bos(struct svm_validate_context *ctx)
1490 {
1491 	ttm_eu_backoff_reservation(&ctx->ticket, &ctx->validate_list);
1492 }
1493 
1494 static void *kfd_svm_page_owner(struct kfd_process *p, int32_t gpuidx)
1495 {
1496 	struct kfd_process_device *pdd;
1497 
1498 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
1499 
1500 	return SVM_ADEV_PGMAP_OWNER(pdd->dev->adev);
1501 }
1502 
1503 /*
1504  * Validation+GPU mapping with concurrent invalidation (MMU notifiers)
1505  *
1506  * To prevent concurrent destruction or change of range attributes, the
1507  * svm_read_lock must be held. The caller must not hold the svm_write_lock
1508  * because that would block concurrent evictions and lead to deadlocks. To
1509  * serialize concurrent migrations or validations of the same range, the
1510  * prange->migrate_mutex must be held.
1511  *
1512  * For VRAM ranges, the SVM BO must be allocated and valid (protected by its
1513  * eviction fence.
1514  *
1515  * The following sequence ensures race-free validation and GPU mapping:
1516  *
1517  * 1. Reserve page table (and SVM BO if range is in VRAM)
1518  * 2. hmm_range_fault to get page addresses (if system memory)
1519  * 3. DMA-map pages (if system memory)
1520  * 4-a. Take notifier lock
1521  * 4-b. Check that pages still valid (mmu_interval_read_retry)
1522  * 4-c. Check that the range was not split or otherwise invalidated
1523  * 4-d. Update GPU page table
1524  * 4.e. Release notifier lock
1525  * 5. Release page table (and SVM BO) reservation
1526  */
1527 static int svm_range_validate_and_map(struct mm_struct *mm,
1528 				      struct svm_range *prange, int32_t gpuidx,
1529 				      bool intr, bool wait, bool flush_tlb)
1530 {
1531 	struct svm_validate_context ctx;
1532 	unsigned long start, end, addr;
1533 	struct kfd_process *p;
1534 	void *owner;
1535 	int32_t idx;
1536 	int r = 0;
1537 
1538 	ctx.process = container_of(prange->svms, struct kfd_process, svms);
1539 	ctx.prange = prange;
1540 	ctx.intr = intr;
1541 
1542 	if (gpuidx < MAX_GPU_INSTANCE) {
1543 		bitmap_zero(ctx.bitmap, MAX_GPU_INSTANCE);
1544 		bitmap_set(ctx.bitmap, gpuidx, 1);
1545 	} else if (ctx.process->xnack_enabled) {
1546 		bitmap_copy(ctx.bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
1547 
1548 		/* If prefetch range to GPU, or GPU retry fault migrate range to
1549 		 * GPU, which has ACCESS attribute to the range, create mapping
1550 		 * on that GPU.
1551 		 */
1552 		if (prange->actual_loc) {
1553 			gpuidx = kfd_process_gpuidx_from_gpuid(ctx.process,
1554 							prange->actual_loc);
1555 			if (gpuidx < 0) {
1556 				WARN_ONCE(1, "failed get device by id 0x%x\n",
1557 					 prange->actual_loc);
1558 				return -EINVAL;
1559 			}
1560 			if (test_bit(gpuidx, prange->bitmap_access))
1561 				bitmap_set(ctx.bitmap, gpuidx, 1);
1562 		}
1563 	} else {
1564 		bitmap_or(ctx.bitmap, prange->bitmap_access,
1565 			  prange->bitmap_aip, MAX_GPU_INSTANCE);
1566 	}
1567 
1568 	if (bitmap_empty(ctx.bitmap, MAX_GPU_INSTANCE)) {
1569 		if (!prange->mapped_to_gpu)
1570 			return 0;
1571 
1572 		bitmap_copy(ctx.bitmap, prange->bitmap_access, MAX_GPU_INSTANCE);
1573 	}
1574 
1575 	if (prange->actual_loc && !prange->ttm_res) {
1576 		/* This should never happen. actual_loc gets set by
1577 		 * svm_migrate_ram_to_vram after allocating a BO.
1578 		 */
1579 		WARN_ONCE(1, "VRAM BO missing during validation\n");
1580 		return -EINVAL;
1581 	}
1582 
1583 	svm_range_reserve_bos(&ctx);
1584 
1585 	p = container_of(prange->svms, struct kfd_process, svms);
1586 	owner = kfd_svm_page_owner(p, find_first_bit(ctx.bitmap,
1587 						MAX_GPU_INSTANCE));
1588 	for_each_set_bit(idx, ctx.bitmap, MAX_GPU_INSTANCE) {
1589 		if (kfd_svm_page_owner(p, idx) != owner) {
1590 			owner = NULL;
1591 			break;
1592 		}
1593 	}
1594 
1595 	start = prange->start << PAGE_SHIFT;
1596 	end = (prange->last + 1) << PAGE_SHIFT;
1597 	for (addr = start; addr < end && !r; ) {
1598 		struct hmm_range *hmm_range;
1599 		struct vm_area_struct *vma;
1600 		unsigned long next;
1601 		unsigned long offset;
1602 		unsigned long npages;
1603 		bool readonly;
1604 
1605 		vma = find_vma(mm, addr);
1606 		if (!vma || addr < vma->vm_start) {
1607 			r = -EFAULT;
1608 			goto unreserve_out;
1609 		}
1610 		readonly = !(vma->vm_flags & VM_WRITE);
1611 
1612 		next = min(vma->vm_end, end);
1613 		npages = (next - addr) >> PAGE_SHIFT;
1614 		WRITE_ONCE(p->svms.faulting_task, current);
1615 		r = amdgpu_hmm_range_get_pages(&prange->notifier, mm, NULL,
1616 					       addr, npages, &hmm_range,
1617 					       readonly, true, owner);
1618 		WRITE_ONCE(p->svms.faulting_task, NULL);
1619 		if (r) {
1620 			pr_debug("failed %d to get svm range pages\n", r);
1621 			goto unreserve_out;
1622 		}
1623 
1624 		offset = (addr - start) >> PAGE_SHIFT;
1625 		r = svm_range_dma_map(prange, ctx.bitmap, offset, npages,
1626 				      hmm_range->hmm_pfns);
1627 		if (r) {
1628 			pr_debug("failed %d to dma map range\n", r);
1629 			goto unreserve_out;
1630 		}
1631 
1632 		svm_range_lock(prange);
1633 		if (amdgpu_hmm_range_get_pages_done(hmm_range)) {
1634 			pr_debug("hmm update the range, need validate again\n");
1635 			r = -EAGAIN;
1636 			goto unlock_out;
1637 		}
1638 		if (!list_empty(&prange->child_list)) {
1639 			pr_debug("range split by unmap in parallel, validate again\n");
1640 			r = -EAGAIN;
1641 			goto unlock_out;
1642 		}
1643 
1644 		r = svm_range_map_to_gpus(prange, offset, npages, readonly,
1645 					  ctx.bitmap, wait, flush_tlb);
1646 
1647 unlock_out:
1648 		svm_range_unlock(prange);
1649 
1650 		addr = next;
1651 	}
1652 
1653 	if (addr == end) {
1654 		prange->validated_once = true;
1655 		prange->mapped_to_gpu = true;
1656 	}
1657 
1658 unreserve_out:
1659 	svm_range_unreserve_bos(&ctx);
1660 
1661 	if (!r)
1662 		prange->validate_timestamp = ktime_get_boottime();
1663 
1664 	return r;
1665 }
1666 
1667 /**
1668  * svm_range_list_lock_and_flush_work - flush pending deferred work
1669  *
1670  * @svms: the svm range list
1671  * @mm: the mm structure
1672  *
1673  * Context: Returns with mmap write lock held, pending deferred work flushed
1674  *
1675  */
1676 void
1677 svm_range_list_lock_and_flush_work(struct svm_range_list *svms,
1678 				   struct mm_struct *mm)
1679 {
1680 retry_flush_work:
1681 	flush_work(&svms->deferred_list_work);
1682 	mmap_write_lock(mm);
1683 
1684 	if (list_empty(&svms->deferred_range_list))
1685 		return;
1686 	mmap_write_unlock(mm);
1687 	pr_debug("retry flush\n");
1688 	goto retry_flush_work;
1689 }
1690 
1691 static void svm_range_restore_work(struct work_struct *work)
1692 {
1693 	struct delayed_work *dwork = to_delayed_work(work);
1694 	struct amdkfd_process_info *process_info;
1695 	struct svm_range_list *svms;
1696 	struct svm_range *prange;
1697 	struct kfd_process *p;
1698 	struct mm_struct *mm;
1699 	int evicted_ranges;
1700 	int invalid;
1701 	int r;
1702 
1703 	svms = container_of(dwork, struct svm_range_list, restore_work);
1704 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1705 	if (!evicted_ranges)
1706 		return;
1707 
1708 	pr_debug("restore svm ranges\n");
1709 
1710 	p = container_of(svms, struct kfd_process, svms);
1711 	process_info = p->kgd_process_info;
1712 
1713 	/* Keep mm reference when svm_range_validate_and_map ranges */
1714 	mm = get_task_mm(p->lead_thread);
1715 	if (!mm) {
1716 		pr_debug("svms 0x%p process mm gone\n", svms);
1717 		return;
1718 	}
1719 
1720 	mutex_lock(&process_info->lock);
1721 	svm_range_list_lock_and_flush_work(svms, mm);
1722 	mutex_lock(&svms->lock);
1723 
1724 	evicted_ranges = atomic_read(&svms->evicted_ranges);
1725 
1726 	list_for_each_entry(prange, &svms->list, list) {
1727 		invalid = atomic_read(&prange->invalid);
1728 		if (!invalid)
1729 			continue;
1730 
1731 		pr_debug("restoring svms 0x%p prange 0x%p [0x%lx %lx] inv %d\n",
1732 			 prange->svms, prange, prange->start, prange->last,
1733 			 invalid);
1734 
1735 		/*
1736 		 * If range is migrating, wait for migration is done.
1737 		 */
1738 		mutex_lock(&prange->migrate_mutex);
1739 
1740 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
1741 					       false, true, false);
1742 		if (r)
1743 			pr_debug("failed %d to map 0x%lx to gpus\n", r,
1744 				 prange->start);
1745 
1746 		mutex_unlock(&prange->migrate_mutex);
1747 		if (r)
1748 			goto out_reschedule;
1749 
1750 		if (atomic_cmpxchg(&prange->invalid, invalid, 0) != invalid)
1751 			goto out_reschedule;
1752 	}
1753 
1754 	if (atomic_cmpxchg(&svms->evicted_ranges, evicted_ranges, 0) !=
1755 	    evicted_ranges)
1756 		goto out_reschedule;
1757 
1758 	evicted_ranges = 0;
1759 
1760 	r = kgd2kfd_resume_mm(mm);
1761 	if (r) {
1762 		/* No recovery from this failure. Probably the CP is
1763 		 * hanging. No point trying again.
1764 		 */
1765 		pr_debug("failed %d to resume KFD\n", r);
1766 	}
1767 
1768 	pr_debug("restore svm ranges successfully\n");
1769 
1770 out_reschedule:
1771 	mutex_unlock(&svms->lock);
1772 	mmap_write_unlock(mm);
1773 	mutex_unlock(&process_info->lock);
1774 
1775 	/* If validation failed, reschedule another attempt */
1776 	if (evicted_ranges) {
1777 		pr_debug("reschedule to restore svm range\n");
1778 		schedule_delayed_work(&svms->restore_work,
1779 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1780 
1781 		kfd_smi_event_queue_restore_rescheduled(mm);
1782 	}
1783 	mmput(mm);
1784 }
1785 
1786 /**
1787  * svm_range_evict - evict svm range
1788  * @prange: svm range structure
1789  * @mm: current process mm_struct
1790  * @start: starting process queue number
1791  * @last: last process queue number
1792  *
1793  * Stop all queues of the process to ensure GPU doesn't access the memory, then
1794  * return to let CPU evict the buffer and proceed CPU pagetable update.
1795  *
1796  * Don't need use lock to sync cpu pagetable invalidation with GPU execution.
1797  * If invalidation happens while restore work is running, restore work will
1798  * restart to ensure to get the latest CPU pages mapping to GPU, then start
1799  * the queues.
1800  */
1801 static int
1802 svm_range_evict(struct svm_range *prange, struct mm_struct *mm,
1803 		unsigned long start, unsigned long last,
1804 		enum mmu_notifier_event event)
1805 {
1806 	struct svm_range_list *svms = prange->svms;
1807 	struct svm_range *pchild;
1808 	struct kfd_process *p;
1809 	int r = 0;
1810 
1811 	p = container_of(svms, struct kfd_process, svms);
1812 
1813 	pr_debug("invalidate svms 0x%p prange [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
1814 		 svms, prange->start, prange->last, start, last);
1815 
1816 	if (!p->xnack_enabled ||
1817 	    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) {
1818 		int evicted_ranges;
1819 		bool mapped = prange->mapped_to_gpu;
1820 
1821 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1822 			if (!pchild->mapped_to_gpu)
1823 				continue;
1824 			mapped = true;
1825 			mutex_lock_nested(&pchild->lock, 1);
1826 			if (pchild->start <= last && pchild->last >= start) {
1827 				pr_debug("increment pchild invalid [0x%lx 0x%lx]\n",
1828 					 pchild->start, pchild->last);
1829 				atomic_inc(&pchild->invalid);
1830 			}
1831 			mutex_unlock(&pchild->lock);
1832 		}
1833 
1834 		if (!mapped)
1835 			return r;
1836 
1837 		if (prange->start <= last && prange->last >= start)
1838 			atomic_inc(&prange->invalid);
1839 
1840 		evicted_ranges = atomic_inc_return(&svms->evicted_ranges);
1841 		if (evicted_ranges != 1)
1842 			return r;
1843 
1844 		pr_debug("evicting svms 0x%p range [0x%lx 0x%lx]\n",
1845 			 prange->svms, prange->start, prange->last);
1846 
1847 		/* First eviction, stop the queues */
1848 		r = kgd2kfd_quiesce_mm(mm, KFD_QUEUE_EVICTION_TRIGGER_SVM);
1849 		if (r)
1850 			pr_debug("failed to quiesce KFD\n");
1851 
1852 		pr_debug("schedule to restore svm %p ranges\n", svms);
1853 		schedule_delayed_work(&svms->restore_work,
1854 			msecs_to_jiffies(AMDGPU_SVM_RANGE_RESTORE_DELAY_MS));
1855 	} else {
1856 		unsigned long s, l;
1857 		uint32_t trigger;
1858 
1859 		if (event == MMU_NOTIFY_MIGRATE)
1860 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY_MIGRATE;
1861 		else
1862 			trigger = KFD_SVM_UNMAP_TRIGGER_MMU_NOTIFY;
1863 
1864 		pr_debug("invalidate unmap svms 0x%p [0x%lx 0x%lx] from GPUs\n",
1865 			 prange->svms, start, last);
1866 		list_for_each_entry(pchild, &prange->child_list, child_list) {
1867 			mutex_lock_nested(&pchild->lock, 1);
1868 			s = max(start, pchild->start);
1869 			l = min(last, pchild->last);
1870 			if (l >= s)
1871 				svm_range_unmap_from_gpus(pchild, s, l, trigger);
1872 			mutex_unlock(&pchild->lock);
1873 		}
1874 		s = max(start, prange->start);
1875 		l = min(last, prange->last);
1876 		if (l >= s)
1877 			svm_range_unmap_from_gpus(prange, s, l, trigger);
1878 	}
1879 
1880 	return r;
1881 }
1882 
1883 static struct svm_range *svm_range_clone(struct svm_range *old)
1884 {
1885 	struct svm_range *new;
1886 
1887 	new = svm_range_new(old->svms, old->start, old->last, false);
1888 	if (!new)
1889 		return NULL;
1890 
1891 	if (old->svm_bo) {
1892 		new->ttm_res = old->ttm_res;
1893 		new->offset = old->offset;
1894 		new->svm_bo = svm_range_bo_ref(old->svm_bo);
1895 		spin_lock(&new->svm_bo->list_lock);
1896 		list_add(&new->svm_bo_list, &new->svm_bo->range_list);
1897 		spin_unlock(&new->svm_bo->list_lock);
1898 	}
1899 	new->flags = old->flags;
1900 	new->preferred_loc = old->preferred_loc;
1901 	new->prefetch_loc = old->prefetch_loc;
1902 	new->actual_loc = old->actual_loc;
1903 	new->granularity = old->granularity;
1904 	new->mapped_to_gpu = old->mapped_to_gpu;
1905 	bitmap_copy(new->bitmap_access, old->bitmap_access, MAX_GPU_INSTANCE);
1906 	bitmap_copy(new->bitmap_aip, old->bitmap_aip, MAX_GPU_INSTANCE);
1907 
1908 	return new;
1909 }
1910 
1911 void svm_range_set_max_pages(struct amdgpu_device *adev)
1912 {
1913 	uint64_t max_pages;
1914 	uint64_t pages, _pages;
1915 
1916 	/* 1/32 VRAM size in pages */
1917 	pages = adev->gmc.real_vram_size >> 17;
1918 	pages = clamp(pages, 1ULL << 9, 1ULL << 18);
1919 	pages = rounddown_pow_of_two(pages);
1920 	do {
1921 		max_pages = READ_ONCE(max_svm_range_pages);
1922 		_pages = min_not_zero(max_pages, pages);
1923 	} while (cmpxchg(&max_svm_range_pages, max_pages, _pages) != max_pages);
1924 }
1925 
1926 static int
1927 svm_range_split_new(struct svm_range_list *svms, uint64_t start, uint64_t last,
1928 		    uint64_t max_pages, struct list_head *insert_list,
1929 		    struct list_head *update_list)
1930 {
1931 	struct svm_range *prange;
1932 	uint64_t l;
1933 
1934 	pr_debug("max_svm_range_pages 0x%llx adding [0x%llx 0x%llx]\n",
1935 		 max_pages, start, last);
1936 
1937 	while (last >= start) {
1938 		l = min(last, ALIGN_DOWN(start + max_pages, max_pages) - 1);
1939 
1940 		prange = svm_range_new(svms, start, l, true);
1941 		if (!prange)
1942 			return -ENOMEM;
1943 		list_add(&prange->list, insert_list);
1944 		list_add(&prange->update_list, update_list);
1945 
1946 		start = l + 1;
1947 	}
1948 	return 0;
1949 }
1950 
1951 /**
1952  * svm_range_add - add svm range and handle overlap
1953  * @p: the range add to this process svms
1954  * @start: page size aligned
1955  * @size: page size aligned
1956  * @nattr: number of attributes
1957  * @attrs: array of attributes
1958  * @update_list: output, the ranges need validate and update GPU mapping
1959  * @insert_list: output, the ranges need insert to svms
1960  * @remove_list: output, the ranges are replaced and need remove from svms
1961  *
1962  * Check if the virtual address range has overlap with any existing ranges,
1963  * split partly overlapping ranges and add new ranges in the gaps. All changes
1964  * should be applied to the range_list and interval tree transactionally. If
1965  * any range split or allocation fails, the entire update fails. Therefore any
1966  * existing overlapping svm_ranges are cloned and the original svm_ranges left
1967  * unchanged.
1968  *
1969  * If the transaction succeeds, the caller can update and insert clones and
1970  * new ranges, then free the originals.
1971  *
1972  * Otherwise the caller can free the clones and new ranges, while the old
1973  * svm_ranges remain unchanged.
1974  *
1975  * Context: Process context, caller must hold svms->lock
1976  *
1977  * Return:
1978  * 0 - OK, otherwise error code
1979  */
1980 static int
1981 svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
1982 	      uint32_t nattr, struct kfd_ioctl_svm_attribute *attrs,
1983 	      struct list_head *update_list, struct list_head *insert_list,
1984 	      struct list_head *remove_list)
1985 {
1986 	unsigned long last = start + size - 1UL;
1987 	struct svm_range_list *svms = &p->svms;
1988 	struct interval_tree_node *node;
1989 	struct svm_range *prange;
1990 	struct svm_range *tmp;
1991 	struct list_head new_list;
1992 	int r = 0;
1993 
1994 	pr_debug("svms 0x%p [0x%llx 0x%lx]\n", &p->svms, start, last);
1995 
1996 	INIT_LIST_HEAD(update_list);
1997 	INIT_LIST_HEAD(insert_list);
1998 	INIT_LIST_HEAD(remove_list);
1999 	INIT_LIST_HEAD(&new_list);
2000 
2001 	node = interval_tree_iter_first(&svms->objects, start, last);
2002 	while (node) {
2003 		struct interval_tree_node *next;
2004 		unsigned long next_start;
2005 
2006 		pr_debug("found overlap node [0x%lx 0x%lx]\n", node->start,
2007 			 node->last);
2008 
2009 		prange = container_of(node, struct svm_range, it_node);
2010 		next = interval_tree_iter_next(node, start, last);
2011 		next_start = min(node->last, last) + 1;
2012 
2013 		if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
2014 			/* nothing to do */
2015 		} else if (node->start < start || node->last > last) {
2016 			/* node intersects the update range and its attributes
2017 			 * will change. Clone and split it, apply updates only
2018 			 * to the overlapping part
2019 			 */
2020 			struct svm_range *old = prange;
2021 
2022 			prange = svm_range_clone(old);
2023 			if (!prange) {
2024 				r = -ENOMEM;
2025 				goto out;
2026 			}
2027 
2028 			list_add(&old->update_list, remove_list);
2029 			list_add(&prange->list, insert_list);
2030 			list_add(&prange->update_list, update_list);
2031 
2032 			if (node->start < start) {
2033 				pr_debug("change old range start\n");
2034 				r = svm_range_split_head(prange, start,
2035 							 insert_list);
2036 				if (r)
2037 					goto out;
2038 			}
2039 			if (node->last > last) {
2040 				pr_debug("change old range last\n");
2041 				r = svm_range_split_tail(prange, last,
2042 							 insert_list);
2043 				if (r)
2044 					goto out;
2045 			}
2046 		} else {
2047 			/* The node is contained within start..last,
2048 			 * just update it
2049 			 */
2050 			list_add(&prange->update_list, update_list);
2051 		}
2052 
2053 		/* insert a new node if needed */
2054 		if (node->start > start) {
2055 			r = svm_range_split_new(svms, start, node->start - 1,
2056 						READ_ONCE(max_svm_range_pages),
2057 						&new_list, update_list);
2058 			if (r)
2059 				goto out;
2060 		}
2061 
2062 		node = next;
2063 		start = next_start;
2064 	}
2065 
2066 	/* add a final range at the end if needed */
2067 	if (start <= last)
2068 		r = svm_range_split_new(svms, start, last,
2069 					READ_ONCE(max_svm_range_pages),
2070 					&new_list, update_list);
2071 
2072 out:
2073 	if (r) {
2074 		list_for_each_entry_safe(prange, tmp, insert_list, list)
2075 			svm_range_free(prange, false);
2076 		list_for_each_entry_safe(prange, tmp, &new_list, list)
2077 			svm_range_free(prange, true);
2078 	} else {
2079 		list_splice(&new_list, insert_list);
2080 	}
2081 
2082 	return r;
2083 }
2084 
2085 static void
2086 svm_range_update_notifier_and_interval_tree(struct mm_struct *mm,
2087 					    struct svm_range *prange)
2088 {
2089 	unsigned long start;
2090 	unsigned long last;
2091 
2092 	start = prange->notifier.interval_tree.start >> PAGE_SHIFT;
2093 	last = prange->notifier.interval_tree.last >> PAGE_SHIFT;
2094 
2095 	if (prange->start == start && prange->last == last)
2096 		return;
2097 
2098 	pr_debug("up notifier 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n",
2099 		  prange->svms, prange, start, last, prange->start,
2100 		  prange->last);
2101 
2102 	if (start != 0 && last != 0) {
2103 		interval_tree_remove(&prange->it_node, &prange->svms->objects);
2104 		svm_range_remove_notifier(prange);
2105 	}
2106 	prange->it_node.start = prange->start;
2107 	prange->it_node.last = prange->last;
2108 
2109 	interval_tree_insert(&prange->it_node, &prange->svms->objects);
2110 	svm_range_add_notifier_locked(mm, prange);
2111 }
2112 
2113 static void
2114 svm_range_handle_list_op(struct svm_range_list *svms, struct svm_range *prange,
2115 			 struct mm_struct *mm)
2116 {
2117 	switch (prange->work_item.op) {
2118 	case SVM_OP_NULL:
2119 		pr_debug("NULL OP 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2120 			 svms, prange, prange->start, prange->last);
2121 		break;
2122 	case SVM_OP_UNMAP_RANGE:
2123 		pr_debug("remove 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2124 			 svms, prange, prange->start, prange->last);
2125 		svm_range_unlink(prange);
2126 		svm_range_remove_notifier(prange);
2127 		svm_range_free(prange, true);
2128 		break;
2129 	case SVM_OP_UPDATE_RANGE_NOTIFIER:
2130 		pr_debug("update notifier 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2131 			 svms, prange, prange->start, prange->last);
2132 		svm_range_update_notifier_and_interval_tree(mm, prange);
2133 		break;
2134 	case SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP:
2135 		pr_debug("update and map 0x%p prange 0x%p [0x%lx 0x%lx]\n",
2136 			 svms, prange, prange->start, prange->last);
2137 		svm_range_update_notifier_and_interval_tree(mm, prange);
2138 		/* TODO: implement deferred validation and mapping */
2139 		break;
2140 	case SVM_OP_ADD_RANGE:
2141 		pr_debug("add 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms, prange,
2142 			 prange->start, prange->last);
2143 		svm_range_add_to_svms(prange);
2144 		svm_range_add_notifier_locked(mm, prange);
2145 		break;
2146 	case SVM_OP_ADD_RANGE_AND_MAP:
2147 		pr_debug("add and map 0x%p prange 0x%p [0x%lx 0x%lx]\n", svms,
2148 			 prange, prange->start, prange->last);
2149 		svm_range_add_to_svms(prange);
2150 		svm_range_add_notifier_locked(mm, prange);
2151 		/* TODO: implement deferred validation and mapping */
2152 		break;
2153 	default:
2154 		WARN_ONCE(1, "Unknown prange 0x%p work op %d\n", prange,
2155 			 prange->work_item.op);
2156 	}
2157 }
2158 
2159 static void svm_range_drain_retry_fault(struct svm_range_list *svms)
2160 {
2161 	struct kfd_process_device *pdd;
2162 	struct kfd_process *p;
2163 	int drain;
2164 	uint32_t i;
2165 
2166 	p = container_of(svms, struct kfd_process, svms);
2167 
2168 restart:
2169 	drain = atomic_read(&svms->drain_pagefaults);
2170 	if (!drain)
2171 		return;
2172 
2173 	for_each_set_bit(i, svms->bitmap_supported, p->n_pdds) {
2174 		pdd = p->pdds[i];
2175 		if (!pdd)
2176 			continue;
2177 
2178 		pr_debug("drain retry fault gpu %d svms %p\n", i, svms);
2179 
2180 		amdgpu_ih_wait_on_checkpoint_process_ts(pdd->dev->adev,
2181 						     &pdd->dev->adev->irq.ih1);
2182 		pr_debug("drain retry fault gpu %d svms 0x%p done\n", i, svms);
2183 	}
2184 	if (atomic_cmpxchg(&svms->drain_pagefaults, drain, 0) != drain)
2185 		goto restart;
2186 }
2187 
2188 static void svm_range_deferred_list_work(struct work_struct *work)
2189 {
2190 	struct svm_range_list *svms;
2191 	struct svm_range *prange;
2192 	struct mm_struct *mm;
2193 
2194 	svms = container_of(work, struct svm_range_list, deferred_list_work);
2195 	pr_debug("enter svms 0x%p\n", svms);
2196 
2197 	spin_lock(&svms->deferred_list_lock);
2198 	while (!list_empty(&svms->deferred_range_list)) {
2199 		prange = list_first_entry(&svms->deferred_range_list,
2200 					  struct svm_range, deferred_list);
2201 		spin_unlock(&svms->deferred_list_lock);
2202 
2203 		pr_debug("prange 0x%p [0x%lx 0x%lx] op %d\n", prange,
2204 			 prange->start, prange->last, prange->work_item.op);
2205 
2206 		mm = prange->work_item.mm;
2207 retry:
2208 		mmap_write_lock(mm);
2209 
2210 		/* Checking for the need to drain retry faults must be inside
2211 		 * mmap write lock to serialize with munmap notifiers.
2212 		 */
2213 		if (unlikely(atomic_read(&svms->drain_pagefaults))) {
2214 			mmap_write_unlock(mm);
2215 			svm_range_drain_retry_fault(svms);
2216 			goto retry;
2217 		}
2218 
2219 		/* Remove from deferred_list must be inside mmap write lock, for
2220 		 * two race cases:
2221 		 * 1. unmap_from_cpu may change work_item.op and add the range
2222 		 *    to deferred_list again, cause use after free bug.
2223 		 * 2. svm_range_list_lock_and_flush_work may hold mmap write
2224 		 *    lock and continue because deferred_list is empty, but
2225 		 *    deferred_list work is actually waiting for mmap lock.
2226 		 */
2227 		spin_lock(&svms->deferred_list_lock);
2228 		list_del_init(&prange->deferred_list);
2229 		spin_unlock(&svms->deferred_list_lock);
2230 
2231 		mutex_lock(&svms->lock);
2232 		mutex_lock(&prange->migrate_mutex);
2233 		while (!list_empty(&prange->child_list)) {
2234 			struct svm_range *pchild;
2235 
2236 			pchild = list_first_entry(&prange->child_list,
2237 						struct svm_range, child_list);
2238 			pr_debug("child prange 0x%p op %d\n", pchild,
2239 				 pchild->work_item.op);
2240 			list_del_init(&pchild->child_list);
2241 			svm_range_handle_list_op(svms, pchild, mm);
2242 		}
2243 		mutex_unlock(&prange->migrate_mutex);
2244 
2245 		svm_range_handle_list_op(svms, prange, mm);
2246 		mutex_unlock(&svms->lock);
2247 		mmap_write_unlock(mm);
2248 
2249 		/* Pairs with mmget in svm_range_add_list_work */
2250 		mmput(mm);
2251 
2252 		spin_lock(&svms->deferred_list_lock);
2253 	}
2254 	spin_unlock(&svms->deferred_list_lock);
2255 	pr_debug("exit svms 0x%p\n", svms);
2256 }
2257 
2258 void
2259 svm_range_add_list_work(struct svm_range_list *svms, struct svm_range *prange,
2260 			struct mm_struct *mm, enum svm_work_list_ops op)
2261 {
2262 	spin_lock(&svms->deferred_list_lock);
2263 	/* if prange is on the deferred list */
2264 	if (!list_empty(&prange->deferred_list)) {
2265 		pr_debug("update exist prange 0x%p work op %d\n", prange, op);
2266 		WARN_ONCE(prange->work_item.mm != mm, "unmatch mm\n");
2267 		if (op != SVM_OP_NULL &&
2268 		    prange->work_item.op != SVM_OP_UNMAP_RANGE)
2269 			prange->work_item.op = op;
2270 	} else {
2271 		prange->work_item.op = op;
2272 
2273 		/* Pairs with mmput in deferred_list_work */
2274 		mmget(mm);
2275 		prange->work_item.mm = mm;
2276 		list_add_tail(&prange->deferred_list,
2277 			      &prange->svms->deferred_range_list);
2278 		pr_debug("add prange 0x%p [0x%lx 0x%lx] to work list op %d\n",
2279 			 prange, prange->start, prange->last, op);
2280 	}
2281 	spin_unlock(&svms->deferred_list_lock);
2282 }
2283 
2284 void schedule_deferred_list_work(struct svm_range_list *svms)
2285 {
2286 	spin_lock(&svms->deferred_list_lock);
2287 	if (!list_empty(&svms->deferred_range_list))
2288 		schedule_work(&svms->deferred_list_work);
2289 	spin_unlock(&svms->deferred_list_lock);
2290 }
2291 
2292 static void
2293 svm_range_unmap_split(struct mm_struct *mm, struct svm_range *parent,
2294 		      struct svm_range *prange, unsigned long start,
2295 		      unsigned long last)
2296 {
2297 	struct svm_range *head;
2298 	struct svm_range *tail;
2299 
2300 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2301 		pr_debug("prange 0x%p [0x%lx 0x%lx] is already freed\n", prange,
2302 			 prange->start, prange->last);
2303 		return;
2304 	}
2305 	if (start > prange->last || last < prange->start)
2306 		return;
2307 
2308 	head = tail = prange;
2309 	if (start > prange->start)
2310 		svm_range_split(prange, prange->start, start - 1, &tail);
2311 	if (last < tail->last)
2312 		svm_range_split(tail, last + 1, tail->last, &head);
2313 
2314 	if (head != prange && tail != prange) {
2315 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2316 		svm_range_add_child(parent, mm, tail, SVM_OP_ADD_RANGE);
2317 	} else if (tail != prange) {
2318 		svm_range_add_child(parent, mm, tail, SVM_OP_UNMAP_RANGE);
2319 	} else if (head != prange) {
2320 		svm_range_add_child(parent, mm, head, SVM_OP_UNMAP_RANGE);
2321 	} else if (parent != prange) {
2322 		prange->work_item.op = SVM_OP_UNMAP_RANGE;
2323 	}
2324 }
2325 
2326 static void
2327 svm_range_unmap_from_cpu(struct mm_struct *mm, struct svm_range *prange,
2328 			 unsigned long start, unsigned long last)
2329 {
2330 	uint32_t trigger = KFD_SVM_UNMAP_TRIGGER_UNMAP_FROM_CPU;
2331 	struct svm_range_list *svms;
2332 	struct svm_range *pchild;
2333 	struct kfd_process *p;
2334 	unsigned long s, l;
2335 	bool unmap_parent;
2336 
2337 	p = kfd_lookup_process_by_mm(mm);
2338 	if (!p)
2339 		return;
2340 	svms = &p->svms;
2341 
2342 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] [0x%lx 0x%lx]\n", svms,
2343 		 prange, prange->start, prange->last, start, last);
2344 
2345 	/* Make sure pending page faults are drained in the deferred worker
2346 	 * before the range is freed to avoid straggler interrupts on
2347 	 * unmapped memory causing "phantom faults".
2348 	 */
2349 	atomic_inc(&svms->drain_pagefaults);
2350 
2351 	unmap_parent = start <= prange->start && last >= prange->last;
2352 
2353 	list_for_each_entry(pchild, &prange->child_list, child_list) {
2354 		mutex_lock_nested(&pchild->lock, 1);
2355 		s = max(start, pchild->start);
2356 		l = min(last, pchild->last);
2357 		if (l >= s)
2358 			svm_range_unmap_from_gpus(pchild, s, l, trigger);
2359 		svm_range_unmap_split(mm, prange, pchild, start, last);
2360 		mutex_unlock(&pchild->lock);
2361 	}
2362 	s = max(start, prange->start);
2363 	l = min(last, prange->last);
2364 	if (l >= s)
2365 		svm_range_unmap_from_gpus(prange, s, l, trigger);
2366 	svm_range_unmap_split(mm, prange, prange, start, last);
2367 
2368 	if (unmap_parent)
2369 		svm_range_add_list_work(svms, prange, mm, SVM_OP_UNMAP_RANGE);
2370 	else
2371 		svm_range_add_list_work(svms, prange, mm,
2372 					SVM_OP_UPDATE_RANGE_NOTIFIER);
2373 	schedule_deferred_list_work(svms);
2374 
2375 	kfd_unref_process(p);
2376 }
2377 
2378 /**
2379  * svm_range_cpu_invalidate_pagetables - interval notifier callback
2380  * @mni: mmu_interval_notifier struct
2381  * @range: mmu_notifier_range struct
2382  * @cur_seq: value to pass to mmu_interval_set_seq()
2383  *
2384  * If event is MMU_NOTIFY_UNMAP, this is from CPU unmap range, otherwise, it
2385  * is from migration, or CPU page invalidation callback.
2386  *
2387  * For unmap event, unmap range from GPUs, remove prange from svms in a delayed
2388  * work thread, and split prange if only part of prange is unmapped.
2389  *
2390  * For invalidation event, if GPU retry fault is not enabled, evict the queues,
2391  * then schedule svm_range_restore_work to update GPU mapping and resume queues.
2392  * If GPU retry fault is enabled, unmap the svm range from GPU, retry fault will
2393  * update GPU mapping to recover.
2394  *
2395  * Context: mmap lock, notifier_invalidate_start lock are held
2396  *          for invalidate event, prange lock is held if this is from migration
2397  */
2398 static bool
2399 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
2400 				    const struct mmu_notifier_range *range,
2401 				    unsigned long cur_seq)
2402 {
2403 	struct svm_range *prange;
2404 	unsigned long start;
2405 	unsigned long last;
2406 
2407 	if (range->event == MMU_NOTIFY_RELEASE)
2408 		return true;
2409 	if (!mmget_not_zero(mni->mm))
2410 		return true;
2411 
2412 	start = mni->interval_tree.start;
2413 	last = mni->interval_tree.last;
2414 	start = max(start, range->start) >> PAGE_SHIFT;
2415 	last = min(last, range->end - 1) >> PAGE_SHIFT;
2416 	pr_debug("[0x%lx 0x%lx] range[0x%lx 0x%lx] notifier[0x%lx 0x%lx] %d\n",
2417 		 start, last, range->start >> PAGE_SHIFT,
2418 		 (range->end - 1) >> PAGE_SHIFT,
2419 		 mni->interval_tree.start >> PAGE_SHIFT,
2420 		 mni->interval_tree.last >> PAGE_SHIFT, range->event);
2421 
2422 	prange = container_of(mni, struct svm_range, notifier);
2423 
2424 	svm_range_lock(prange);
2425 	mmu_interval_set_seq(mni, cur_seq);
2426 
2427 	switch (range->event) {
2428 	case MMU_NOTIFY_UNMAP:
2429 		svm_range_unmap_from_cpu(mni->mm, prange, start, last);
2430 		break;
2431 	default:
2432 		svm_range_evict(prange, mni->mm, start, last, range->event);
2433 		break;
2434 	}
2435 
2436 	svm_range_unlock(prange);
2437 	mmput(mni->mm);
2438 
2439 	return true;
2440 }
2441 
2442 /**
2443  * svm_range_from_addr - find svm range from fault address
2444  * @svms: svm range list header
2445  * @addr: address to search range interval tree, in pages
2446  * @parent: parent range if range is on child list
2447  *
2448  * Context: The caller must hold svms->lock
2449  *
2450  * Return: the svm_range found or NULL
2451  */
2452 struct svm_range *
2453 svm_range_from_addr(struct svm_range_list *svms, unsigned long addr,
2454 		    struct svm_range **parent)
2455 {
2456 	struct interval_tree_node *node;
2457 	struct svm_range *prange;
2458 	struct svm_range *pchild;
2459 
2460 	node = interval_tree_iter_first(&svms->objects, addr, addr);
2461 	if (!node)
2462 		return NULL;
2463 
2464 	prange = container_of(node, struct svm_range, it_node);
2465 	pr_debug("address 0x%lx prange [0x%lx 0x%lx] node [0x%lx 0x%lx]\n",
2466 		 addr, prange->start, prange->last, node->start, node->last);
2467 
2468 	if (addr >= prange->start && addr <= prange->last) {
2469 		if (parent)
2470 			*parent = prange;
2471 		return prange;
2472 	}
2473 	list_for_each_entry(pchild, &prange->child_list, child_list)
2474 		if (addr >= pchild->start && addr <= pchild->last) {
2475 			pr_debug("found address 0x%lx pchild [0x%lx 0x%lx]\n",
2476 				 addr, pchild->start, pchild->last);
2477 			if (parent)
2478 				*parent = prange;
2479 			return pchild;
2480 		}
2481 
2482 	return NULL;
2483 }
2484 
2485 /* svm_range_best_restore_location - decide the best fault restore location
2486  * @prange: svm range structure
2487  * @adev: the GPU on which vm fault happened
2488  *
2489  * This is only called when xnack is on, to decide the best location to restore
2490  * the range mapping after GPU vm fault. Caller uses the best location to do
2491  * migration if actual loc is not best location, then update GPU page table
2492  * mapping to the best location.
2493  *
2494  * If the preferred loc is accessible by faulting GPU, use preferred loc.
2495  * If vm fault gpu idx is on range ACCESSIBLE bitmap, best_loc is vm fault gpu
2496  * If vm fault gpu idx is on range ACCESSIBLE_IN_PLACE bitmap, then
2497  *    if range actual loc is cpu, best_loc is cpu
2498  *    if vm fault gpu is on xgmi same hive of range actual loc gpu, best_loc is
2499  *    range actual loc.
2500  * Otherwise, GPU no access, best_loc is -1.
2501  *
2502  * Return:
2503  * -1 means vm fault GPU no access
2504  * 0 for CPU or GPU id
2505  */
2506 static int32_t
2507 svm_range_best_restore_location(struct svm_range *prange,
2508 				struct amdgpu_device *adev,
2509 				int32_t *gpuidx)
2510 {
2511 	struct amdgpu_device *bo_adev, *preferred_adev;
2512 	struct kfd_process *p;
2513 	uint32_t gpuid;
2514 	int r;
2515 
2516 	p = container_of(prange->svms, struct kfd_process, svms);
2517 
2518 	r = kfd_process_gpuid_from_adev(p, adev, &gpuid, gpuidx);
2519 	if (r < 0) {
2520 		pr_debug("failed to get gpuid from kgd\n");
2521 		return -1;
2522 	}
2523 
2524 	if (prange->preferred_loc == gpuid ||
2525 	    prange->preferred_loc == KFD_IOCTL_SVM_LOCATION_SYSMEM) {
2526 		return prange->preferred_loc;
2527 	} else if (prange->preferred_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
2528 		preferred_adev = svm_range_get_adev_by_id(prange,
2529 							prange->preferred_loc);
2530 		if (amdgpu_xgmi_same_hive(adev, preferred_adev))
2531 			return prange->preferred_loc;
2532 		/* fall through */
2533 	}
2534 
2535 	if (test_bit(*gpuidx, prange->bitmap_access))
2536 		return gpuid;
2537 
2538 	if (test_bit(*gpuidx, prange->bitmap_aip)) {
2539 		if (!prange->actual_loc)
2540 			return 0;
2541 
2542 		bo_adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
2543 		if (amdgpu_xgmi_same_hive(adev, bo_adev))
2544 			return prange->actual_loc;
2545 		else
2546 			return 0;
2547 	}
2548 
2549 	return -1;
2550 }
2551 
2552 static int
2553 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
2554 			       unsigned long *start, unsigned long *last,
2555 			       bool *is_heap_stack)
2556 {
2557 	struct vm_area_struct *vma;
2558 	struct interval_tree_node *node;
2559 	unsigned long start_limit, end_limit;
2560 
2561 	vma = find_vma(p->mm, addr << PAGE_SHIFT);
2562 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2563 		pr_debug("VMA does not exist in address [0x%llx]\n", addr);
2564 		return -EFAULT;
2565 	}
2566 
2567 	*is_heap_stack = (vma->vm_start <= vma->vm_mm->brk &&
2568 			  vma->vm_end >= vma->vm_mm->start_brk) ||
2569 			 (vma->vm_start <= vma->vm_mm->start_stack &&
2570 			  vma->vm_end >= vma->vm_mm->start_stack);
2571 
2572 	start_limit = max(vma->vm_start >> PAGE_SHIFT,
2573 		      (unsigned long)ALIGN_DOWN(addr, 2UL << 8));
2574 	end_limit = min(vma->vm_end >> PAGE_SHIFT,
2575 		    (unsigned long)ALIGN(addr + 1, 2UL << 8));
2576 	/* First range that starts after the fault address */
2577 	node = interval_tree_iter_first(&p->svms.objects, addr + 1, ULONG_MAX);
2578 	if (node) {
2579 		end_limit = min(end_limit, node->start);
2580 		/* Last range that ends before the fault address */
2581 		node = container_of(rb_prev(&node->rb),
2582 				    struct interval_tree_node, rb);
2583 	} else {
2584 		/* Last range must end before addr because
2585 		 * there was no range after addr
2586 		 */
2587 		node = container_of(rb_last(&p->svms.objects.rb_root),
2588 				    struct interval_tree_node, rb);
2589 	}
2590 	if (node) {
2591 		if (node->last >= addr) {
2592 			WARN(1, "Overlap with prev node and page fault addr\n");
2593 			return -EFAULT;
2594 		}
2595 		start_limit = max(start_limit, node->last + 1);
2596 	}
2597 
2598 	*start = start_limit;
2599 	*last = end_limit - 1;
2600 
2601 	pr_debug("vma [0x%lx 0x%lx] range [0x%lx 0x%lx] is_heap_stack %d\n",
2602 		 vma->vm_start >> PAGE_SHIFT, vma->vm_end >> PAGE_SHIFT,
2603 		 *start, *last, *is_heap_stack);
2604 
2605 	return 0;
2606 }
2607 
2608 static int
2609 svm_range_check_vm_userptr(struct kfd_process *p, uint64_t start, uint64_t last,
2610 			   uint64_t *bo_s, uint64_t *bo_l)
2611 {
2612 	struct amdgpu_bo_va_mapping *mapping;
2613 	struct interval_tree_node *node;
2614 	struct amdgpu_bo *bo = NULL;
2615 	unsigned long userptr;
2616 	uint32_t i;
2617 	int r;
2618 
2619 	for (i = 0; i < p->n_pdds; i++) {
2620 		struct amdgpu_vm *vm;
2621 
2622 		if (!p->pdds[i]->drm_priv)
2623 			continue;
2624 
2625 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
2626 		r = amdgpu_bo_reserve(vm->root.bo, false);
2627 		if (r)
2628 			return r;
2629 
2630 		/* Check userptr by searching entire vm->va interval tree */
2631 		node = interval_tree_iter_first(&vm->va, 0, ~0ULL);
2632 		while (node) {
2633 			mapping = container_of((struct rb_node *)node,
2634 					       struct amdgpu_bo_va_mapping, rb);
2635 			bo = mapping->bo_va->base.bo;
2636 
2637 			if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm,
2638 							 start << PAGE_SHIFT,
2639 							 last << PAGE_SHIFT,
2640 							 &userptr)) {
2641 				node = interval_tree_iter_next(node, 0, ~0ULL);
2642 				continue;
2643 			}
2644 
2645 			pr_debug("[0x%llx 0x%llx] already userptr mapped\n",
2646 				 start, last);
2647 			if (bo_s && bo_l) {
2648 				*bo_s = userptr >> PAGE_SHIFT;
2649 				*bo_l = *bo_s + bo->tbo.ttm->num_pages - 1;
2650 			}
2651 			amdgpu_bo_unreserve(vm->root.bo);
2652 			return -EADDRINUSE;
2653 		}
2654 		amdgpu_bo_unreserve(vm->root.bo);
2655 	}
2656 	return 0;
2657 }
2658 
2659 static struct
2660 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
2661 						struct kfd_process *p,
2662 						struct mm_struct *mm,
2663 						int64_t addr)
2664 {
2665 	struct svm_range *prange = NULL;
2666 	unsigned long start, last;
2667 	uint32_t gpuid, gpuidx;
2668 	bool is_heap_stack;
2669 	uint64_t bo_s = 0;
2670 	uint64_t bo_l = 0;
2671 	int r;
2672 
2673 	if (svm_range_get_range_boundaries(p, addr, &start, &last,
2674 					   &is_heap_stack))
2675 		return NULL;
2676 
2677 	r = svm_range_check_vm(p, start, last, &bo_s, &bo_l);
2678 	if (r != -EADDRINUSE)
2679 		r = svm_range_check_vm_userptr(p, start, last, &bo_s, &bo_l);
2680 
2681 	if (r == -EADDRINUSE) {
2682 		if (addr >= bo_s && addr <= bo_l)
2683 			return NULL;
2684 
2685 		/* Create one page svm range if 2MB range overlapping */
2686 		start = addr;
2687 		last = addr;
2688 	}
2689 
2690 	prange = svm_range_new(&p->svms, start, last, true);
2691 	if (!prange) {
2692 		pr_debug("Failed to create prange in address [0x%llx]\n", addr);
2693 		return NULL;
2694 	}
2695 	if (kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx)) {
2696 		pr_debug("failed to get gpuid from kgd\n");
2697 		svm_range_free(prange, true);
2698 		return NULL;
2699 	}
2700 
2701 	if (is_heap_stack)
2702 		prange->preferred_loc = KFD_IOCTL_SVM_LOCATION_SYSMEM;
2703 
2704 	svm_range_add_to_svms(prange);
2705 	svm_range_add_notifier_locked(mm, prange);
2706 
2707 	return prange;
2708 }
2709 
2710 /* svm_range_skip_recover - decide if prange can be recovered
2711  * @prange: svm range structure
2712  *
2713  * GPU vm retry fault handle skip recover the range for cases:
2714  * 1. prange is on deferred list to be removed after unmap, it is stale fault,
2715  *    deferred list work will drain the stale fault before free the prange.
2716  * 2. prange is on deferred list to add interval notifier after split, or
2717  * 3. prange is child range, it is split from parent prange, recover later
2718  *    after interval notifier is added.
2719  *
2720  * Return: true to skip recover, false to recover
2721  */
2722 static bool svm_range_skip_recover(struct svm_range *prange)
2723 {
2724 	struct svm_range_list *svms = prange->svms;
2725 
2726 	spin_lock(&svms->deferred_list_lock);
2727 	if (list_empty(&prange->deferred_list) &&
2728 	    list_empty(&prange->child_list)) {
2729 		spin_unlock(&svms->deferred_list_lock);
2730 		return false;
2731 	}
2732 	spin_unlock(&svms->deferred_list_lock);
2733 
2734 	if (prange->work_item.op == SVM_OP_UNMAP_RANGE) {
2735 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] unmapped\n",
2736 			 svms, prange, prange->start, prange->last);
2737 		return true;
2738 	}
2739 	if (prange->work_item.op == SVM_OP_ADD_RANGE_AND_MAP ||
2740 	    prange->work_item.op == SVM_OP_ADD_RANGE) {
2741 		pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] not added yet\n",
2742 			 svms, prange, prange->start, prange->last);
2743 		return true;
2744 	}
2745 	return false;
2746 }
2747 
2748 static void
2749 svm_range_count_fault(struct amdgpu_device *adev, struct kfd_process *p,
2750 		      int32_t gpuidx)
2751 {
2752 	struct kfd_process_device *pdd;
2753 
2754 	/* fault is on different page of same range
2755 	 * or fault is skipped to recover later
2756 	 * or fault is on invalid virtual address
2757 	 */
2758 	if (gpuidx == MAX_GPU_INSTANCE) {
2759 		uint32_t gpuid;
2760 		int r;
2761 
2762 		r = kfd_process_gpuid_from_adev(p, adev, &gpuid, &gpuidx);
2763 		if (r < 0)
2764 			return;
2765 	}
2766 
2767 	/* fault is recovered
2768 	 * or fault cannot recover because GPU no access on the range
2769 	 */
2770 	pdd = kfd_process_device_from_gpuidx(p, gpuidx);
2771 	if (pdd)
2772 		WRITE_ONCE(pdd->faults, pdd->faults + 1);
2773 }
2774 
2775 static bool
2776 svm_fault_allowed(struct vm_area_struct *vma, bool write_fault)
2777 {
2778 	unsigned long requested = VM_READ;
2779 
2780 	if (write_fault)
2781 		requested |= VM_WRITE;
2782 
2783 	pr_debug("requested 0x%lx, vma permission flags 0x%lx\n", requested,
2784 		vma->vm_flags);
2785 	return (vma->vm_flags & requested) == requested;
2786 }
2787 
2788 int
2789 svm_range_restore_pages(struct amdgpu_device *adev, unsigned int pasid,
2790 			uint64_t addr, bool write_fault)
2791 {
2792 	struct mm_struct *mm = NULL;
2793 	struct svm_range_list *svms;
2794 	struct svm_range *prange;
2795 	struct kfd_process *p;
2796 	ktime_t timestamp = ktime_get_boottime();
2797 	int32_t best_loc;
2798 	int32_t gpuidx = MAX_GPU_INSTANCE;
2799 	bool write_locked = false;
2800 	struct vm_area_struct *vma;
2801 	bool migration = false;
2802 	int r = 0;
2803 
2804 	if (!KFD_IS_SVM_API_SUPPORTED(adev->kfd.dev)) {
2805 		pr_debug("device does not support SVM\n");
2806 		return -EFAULT;
2807 	}
2808 
2809 	p = kfd_lookup_process_by_pasid(pasid);
2810 	if (!p) {
2811 		pr_debug("kfd process not founded pasid 0x%x\n", pasid);
2812 		return 0;
2813 	}
2814 	svms = &p->svms;
2815 
2816 	pr_debug("restoring svms 0x%p fault address 0x%llx\n", svms, addr);
2817 
2818 	if (atomic_read(&svms->drain_pagefaults)) {
2819 		pr_debug("draining retry fault, drop fault 0x%llx\n", addr);
2820 		r = 0;
2821 		goto out;
2822 	}
2823 
2824 	if (!p->xnack_enabled) {
2825 		pr_debug("XNACK not enabled for pasid 0x%x\n", pasid);
2826 		r = -EFAULT;
2827 		goto out;
2828 	}
2829 
2830 	/* p->lead_thread is available as kfd_process_wq_release flush the work
2831 	 * before releasing task ref.
2832 	 */
2833 	mm = get_task_mm(p->lead_thread);
2834 	if (!mm) {
2835 		pr_debug("svms 0x%p failed to get mm\n", svms);
2836 		r = 0;
2837 		goto out;
2838 	}
2839 
2840 	mmap_read_lock(mm);
2841 retry_write_locked:
2842 	mutex_lock(&svms->lock);
2843 	prange = svm_range_from_addr(svms, addr, NULL);
2844 	if (!prange) {
2845 		pr_debug("failed to find prange svms 0x%p address [0x%llx]\n",
2846 			 svms, addr);
2847 		if (!write_locked) {
2848 			/* Need the write lock to create new range with MMU notifier.
2849 			 * Also flush pending deferred work to make sure the interval
2850 			 * tree is up to date before we add a new range
2851 			 */
2852 			mutex_unlock(&svms->lock);
2853 			mmap_read_unlock(mm);
2854 			mmap_write_lock(mm);
2855 			write_locked = true;
2856 			goto retry_write_locked;
2857 		}
2858 		prange = svm_range_create_unregistered_range(adev, p, mm, addr);
2859 		if (!prange) {
2860 			pr_debug("failed to create unregistered range svms 0x%p address [0x%llx]\n",
2861 				 svms, addr);
2862 			mmap_write_downgrade(mm);
2863 			r = -EFAULT;
2864 			goto out_unlock_svms;
2865 		}
2866 	}
2867 	if (write_locked)
2868 		mmap_write_downgrade(mm);
2869 
2870 	mutex_lock(&prange->migrate_mutex);
2871 
2872 	if (svm_range_skip_recover(prange)) {
2873 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2874 		r = 0;
2875 		goto out_unlock_range;
2876 	}
2877 
2878 	/* skip duplicate vm fault on different pages of same range */
2879 	if (ktime_before(timestamp, ktime_add_ns(prange->validate_timestamp,
2880 				AMDGPU_SVM_RANGE_RETRY_FAULT_PENDING))) {
2881 		pr_debug("svms 0x%p [0x%lx %lx] already restored\n",
2882 			 svms, prange->start, prange->last);
2883 		r = 0;
2884 		goto out_unlock_range;
2885 	}
2886 
2887 	/* __do_munmap removed VMA, return success as we are handling stale
2888 	 * retry fault.
2889 	 */
2890 	vma = find_vma(mm, addr << PAGE_SHIFT);
2891 	if (!vma || (addr << PAGE_SHIFT) < vma->vm_start) {
2892 		pr_debug("address 0x%llx VMA is removed\n", addr);
2893 		r = 0;
2894 		goto out_unlock_range;
2895 	}
2896 
2897 	if (!svm_fault_allowed(vma, write_fault)) {
2898 		pr_debug("fault addr 0x%llx no %s permission\n", addr,
2899 			write_fault ? "write" : "read");
2900 		r = -EPERM;
2901 		goto out_unlock_range;
2902 	}
2903 
2904 	best_loc = svm_range_best_restore_location(prange, adev, &gpuidx);
2905 	if (best_loc == -1) {
2906 		pr_debug("svms %p failed get best restore loc [0x%lx 0x%lx]\n",
2907 			 svms, prange->start, prange->last);
2908 		r = -EACCES;
2909 		goto out_unlock_range;
2910 	}
2911 
2912 	pr_debug("svms %p [0x%lx 0x%lx] best restore 0x%x, actual loc 0x%x\n",
2913 		 svms, prange->start, prange->last, best_loc,
2914 		 prange->actual_loc);
2915 
2916 	kfd_smi_event_page_fault_start(adev->kfd.dev, p->lead_thread->pid, addr,
2917 				       write_fault, timestamp);
2918 
2919 	if (prange->actual_loc != best_loc) {
2920 		migration = true;
2921 		if (best_loc) {
2922 			r = svm_migrate_to_vram(prange, best_loc, mm,
2923 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU);
2924 			if (r) {
2925 				pr_debug("svm_migrate_to_vram failed (%d) at %llx, falling back to system memory\n",
2926 					 r, addr);
2927 				/* Fallback to system memory if migration to
2928 				 * VRAM failed
2929 				 */
2930 				if (prange->actual_loc)
2931 					r = svm_migrate_vram_to_ram(prange, mm,
2932 					   KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU,
2933 					   NULL);
2934 				else
2935 					r = 0;
2936 			}
2937 		} else {
2938 			r = svm_migrate_vram_to_ram(prange, mm,
2939 					KFD_MIGRATE_TRIGGER_PAGEFAULT_GPU,
2940 					NULL);
2941 		}
2942 		if (r) {
2943 			pr_debug("failed %d to migrate svms %p [0x%lx 0x%lx]\n",
2944 				 r, svms, prange->start, prange->last);
2945 			goto out_unlock_range;
2946 		}
2947 	}
2948 
2949 	r = svm_range_validate_and_map(mm, prange, gpuidx, false, false, false);
2950 	if (r)
2951 		pr_debug("failed %d to map svms 0x%p [0x%lx 0x%lx] to gpus\n",
2952 			 r, svms, prange->start, prange->last);
2953 
2954 	kfd_smi_event_page_fault_end(adev->kfd.dev, p->lead_thread->pid, addr,
2955 				     migration);
2956 
2957 out_unlock_range:
2958 	mutex_unlock(&prange->migrate_mutex);
2959 out_unlock_svms:
2960 	mutex_unlock(&svms->lock);
2961 	mmap_read_unlock(mm);
2962 
2963 	svm_range_count_fault(adev, p, gpuidx);
2964 
2965 	mmput(mm);
2966 out:
2967 	kfd_unref_process(p);
2968 
2969 	if (r == -EAGAIN) {
2970 		pr_debug("recover vm fault later\n");
2971 		amdgpu_gmc_filter_faults_remove(adev, addr, pasid);
2972 		r = 0;
2973 	}
2974 	return r;
2975 }
2976 
2977 int
2978 svm_range_switch_xnack_reserve_mem(struct kfd_process *p, bool xnack_enabled)
2979 {
2980 	struct svm_range *prange, *pchild;
2981 	uint64_t reserved_size = 0;
2982 	uint64_t size;
2983 	int r = 0;
2984 
2985 	pr_debug("switching xnack from %d to %d\n", p->xnack_enabled, xnack_enabled);
2986 
2987 	mutex_lock(&p->svms.lock);
2988 
2989 	list_for_each_entry(prange, &p->svms.list, list) {
2990 		svm_range_lock(prange);
2991 		list_for_each_entry(pchild, &prange->child_list, child_list) {
2992 			size = (pchild->last - pchild->start + 1) << PAGE_SHIFT;
2993 			if (xnack_enabled) {
2994 				amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
2995 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2996 			} else {
2997 				r = amdgpu_amdkfd_reserve_mem_limit(NULL, size,
2998 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
2999 				if (r)
3000 					goto out_unlock;
3001 				reserved_size += size;
3002 			}
3003 		}
3004 
3005 		size = (prange->last - prange->start + 1) << PAGE_SHIFT;
3006 		if (xnack_enabled) {
3007 			amdgpu_amdkfd_unreserve_mem_limit(NULL, size,
3008 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
3009 		} else {
3010 			r = amdgpu_amdkfd_reserve_mem_limit(NULL, size,
3011 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
3012 			if (r)
3013 				goto out_unlock;
3014 			reserved_size += size;
3015 		}
3016 out_unlock:
3017 		svm_range_unlock(prange);
3018 		if (r)
3019 			break;
3020 	}
3021 
3022 	if (r)
3023 		amdgpu_amdkfd_unreserve_mem_limit(NULL, reserved_size,
3024 						KFD_IOC_ALLOC_MEM_FLAGS_USERPTR);
3025 	else
3026 		/* Change xnack mode must be inside svms lock, to avoid race with
3027 		 * svm_range_deferred_list_work unreserve memory in parallel.
3028 		 */
3029 		p->xnack_enabled = xnack_enabled;
3030 
3031 	mutex_unlock(&p->svms.lock);
3032 	return r;
3033 }
3034 
3035 void svm_range_list_fini(struct kfd_process *p)
3036 {
3037 	struct svm_range *prange;
3038 	struct svm_range *next;
3039 
3040 	pr_debug("pasid 0x%x svms 0x%p\n", p->pasid, &p->svms);
3041 
3042 	cancel_delayed_work_sync(&p->svms.restore_work);
3043 
3044 	/* Ensure list work is finished before process is destroyed */
3045 	flush_work(&p->svms.deferred_list_work);
3046 
3047 	/*
3048 	 * Ensure no retry fault comes in afterwards, as page fault handler will
3049 	 * not find kfd process and take mm lock to recover fault.
3050 	 */
3051 	atomic_inc(&p->svms.drain_pagefaults);
3052 	svm_range_drain_retry_fault(&p->svms);
3053 
3054 	list_for_each_entry_safe(prange, next, &p->svms.list, list) {
3055 		svm_range_unlink(prange);
3056 		svm_range_remove_notifier(prange);
3057 		svm_range_free(prange, true);
3058 	}
3059 
3060 	mutex_destroy(&p->svms.lock);
3061 
3062 	pr_debug("pasid 0x%x svms 0x%p done\n", p->pasid, &p->svms);
3063 }
3064 
3065 int svm_range_list_init(struct kfd_process *p)
3066 {
3067 	struct svm_range_list *svms = &p->svms;
3068 	int i;
3069 
3070 	svms->objects = RB_ROOT_CACHED;
3071 	mutex_init(&svms->lock);
3072 	INIT_LIST_HEAD(&svms->list);
3073 	atomic_set(&svms->evicted_ranges, 0);
3074 	atomic_set(&svms->drain_pagefaults, 0);
3075 	INIT_DELAYED_WORK(&svms->restore_work, svm_range_restore_work);
3076 	INIT_WORK(&svms->deferred_list_work, svm_range_deferred_list_work);
3077 	INIT_LIST_HEAD(&svms->deferred_range_list);
3078 	INIT_LIST_HEAD(&svms->criu_svm_metadata_list);
3079 	spin_lock_init(&svms->deferred_list_lock);
3080 
3081 	for (i = 0; i < p->n_pdds; i++)
3082 		if (KFD_IS_SVM_API_SUPPORTED(p->pdds[i]->dev))
3083 			bitmap_set(svms->bitmap_supported, i, 1);
3084 
3085 	return 0;
3086 }
3087 
3088 /**
3089  * svm_range_check_vm - check if virtual address range mapped already
3090  * @p: current kfd_process
3091  * @start: range start address, in pages
3092  * @last: range last address, in pages
3093  * @bo_s: mapping start address in pages if address range already mapped
3094  * @bo_l: mapping last address in pages if address range already mapped
3095  *
3096  * The purpose is to avoid virtual address ranges already allocated by
3097  * kfd_ioctl_alloc_memory_of_gpu ioctl.
3098  * It looks for each pdd in the kfd_process.
3099  *
3100  * Context: Process context
3101  *
3102  * Return 0 - OK, if the range is not mapped.
3103  * Otherwise error code:
3104  * -EADDRINUSE - if address is mapped already by kfd_ioctl_alloc_memory_of_gpu
3105  * -ERESTARTSYS - A wait for the buffer to become unreserved was interrupted by
3106  * a signal. Release all buffer reservations and return to user-space.
3107  */
3108 static int
3109 svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last,
3110 		   uint64_t *bo_s, uint64_t *bo_l)
3111 {
3112 	struct amdgpu_bo_va_mapping *mapping;
3113 	struct interval_tree_node *node;
3114 	uint32_t i;
3115 	int r;
3116 
3117 	for (i = 0; i < p->n_pdds; i++) {
3118 		struct amdgpu_vm *vm;
3119 
3120 		if (!p->pdds[i]->drm_priv)
3121 			continue;
3122 
3123 		vm = drm_priv_to_vm(p->pdds[i]->drm_priv);
3124 		r = amdgpu_bo_reserve(vm->root.bo, false);
3125 		if (r)
3126 			return r;
3127 
3128 		node = interval_tree_iter_first(&vm->va, start, last);
3129 		if (node) {
3130 			pr_debug("range [0x%llx 0x%llx] already TTM mapped\n",
3131 				 start, last);
3132 			mapping = container_of((struct rb_node *)node,
3133 					       struct amdgpu_bo_va_mapping, rb);
3134 			if (bo_s && bo_l) {
3135 				*bo_s = mapping->start;
3136 				*bo_l = mapping->last;
3137 			}
3138 			amdgpu_bo_unreserve(vm->root.bo);
3139 			return -EADDRINUSE;
3140 		}
3141 		amdgpu_bo_unreserve(vm->root.bo);
3142 	}
3143 
3144 	return 0;
3145 }
3146 
3147 /**
3148  * svm_range_is_valid - check if virtual address range is valid
3149  * @p: current kfd_process
3150  * @start: range start address, in pages
3151  * @size: range size, in pages
3152  *
3153  * Valid virtual address range means it belongs to one or more VMAs
3154  *
3155  * Context: Process context
3156  *
3157  * Return:
3158  *  0 - OK, otherwise error code
3159  */
3160 static int
3161 svm_range_is_valid(struct kfd_process *p, uint64_t start, uint64_t size)
3162 {
3163 	const unsigned long device_vma = VM_IO | VM_PFNMAP | VM_MIXEDMAP;
3164 	struct vm_area_struct *vma;
3165 	unsigned long end;
3166 	unsigned long start_unchg = start;
3167 
3168 	start <<= PAGE_SHIFT;
3169 	end = start + (size << PAGE_SHIFT);
3170 	do {
3171 		vma = find_vma(p->mm, start);
3172 		if (!vma || start < vma->vm_start ||
3173 		    (vma->vm_flags & device_vma))
3174 			return -EFAULT;
3175 		start = min(end, vma->vm_end);
3176 	} while (start < end);
3177 
3178 	return svm_range_check_vm(p, start_unchg, (end - 1) >> PAGE_SHIFT, NULL,
3179 				  NULL);
3180 }
3181 
3182 /**
3183  * svm_range_best_prefetch_location - decide the best prefetch location
3184  * @prange: svm range structure
3185  *
3186  * For xnack off:
3187  * If range map to single GPU, the best prefetch location is prefetch_loc, which
3188  * can be CPU or GPU.
3189  *
3190  * If range is ACCESS or ACCESS_IN_PLACE by mGPUs, only if mGPU connection on
3191  * XGMI same hive, the best prefetch location is prefetch_loc GPU, othervise
3192  * the best prefetch location is always CPU, because GPU can not have coherent
3193  * mapping VRAM of other GPUs even with large-BAR PCIe connection.
3194  *
3195  * For xnack on:
3196  * If range is not ACCESS_IN_PLACE by mGPUs, the best prefetch location is
3197  * prefetch_loc, other GPU access will generate vm fault and trigger migration.
3198  *
3199  * If range is ACCESS_IN_PLACE by mGPUs, only if mGPU connection on XGMI same
3200  * hive, the best prefetch location is prefetch_loc GPU, otherwise the best
3201  * prefetch location is always CPU.
3202  *
3203  * Context: Process context
3204  *
3205  * Return:
3206  * 0 for CPU or GPU id
3207  */
3208 static uint32_t
3209 svm_range_best_prefetch_location(struct svm_range *prange)
3210 {
3211 	DECLARE_BITMAP(bitmap, MAX_GPU_INSTANCE);
3212 	uint32_t best_loc = prange->prefetch_loc;
3213 	struct kfd_process_device *pdd;
3214 	struct amdgpu_device *bo_adev;
3215 	struct kfd_process *p;
3216 	uint32_t gpuidx;
3217 
3218 	p = container_of(prange->svms, struct kfd_process, svms);
3219 
3220 	if (!best_loc || best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED)
3221 		goto out;
3222 
3223 	bo_adev = svm_range_get_adev_by_id(prange, best_loc);
3224 	if (!bo_adev) {
3225 		WARN_ONCE(1, "failed to get device by id 0x%x\n", best_loc);
3226 		best_loc = 0;
3227 		goto out;
3228 	}
3229 
3230 	if (p->xnack_enabled)
3231 		bitmap_copy(bitmap, prange->bitmap_aip, MAX_GPU_INSTANCE);
3232 	else
3233 		bitmap_or(bitmap, prange->bitmap_access, prange->bitmap_aip,
3234 			  MAX_GPU_INSTANCE);
3235 
3236 	for_each_set_bit(gpuidx, bitmap, MAX_GPU_INSTANCE) {
3237 		pdd = kfd_process_device_from_gpuidx(p, gpuidx);
3238 		if (!pdd) {
3239 			pr_debug("failed to get device by idx 0x%x\n", gpuidx);
3240 			continue;
3241 		}
3242 
3243 		if (pdd->dev->adev == bo_adev)
3244 			continue;
3245 
3246 		if (!amdgpu_xgmi_same_hive(pdd->dev->adev, bo_adev)) {
3247 			best_loc = 0;
3248 			break;
3249 		}
3250 	}
3251 
3252 out:
3253 	pr_debug("xnack %d svms 0x%p [0x%lx 0x%lx] best loc 0x%x\n",
3254 		 p->xnack_enabled, &p->svms, prange->start, prange->last,
3255 		 best_loc);
3256 
3257 	return best_loc;
3258 }
3259 
3260 /* svm_range_trigger_migration - start page migration if prefetch loc changed
3261  * @mm: current process mm_struct
3262  * @prange: svm range structure
3263  * @migrated: output, true if migration is triggered
3264  *
3265  * If range perfetch_loc is GPU, actual loc is cpu 0, then migrate the range
3266  * from ram to vram.
3267  * If range prefetch_loc is cpu 0, actual loc is GPU, then migrate the range
3268  * from vram to ram.
3269  *
3270  * If GPU vm fault retry is not enabled, migration interact with MMU notifier
3271  * and restore work:
3272  * 1. migrate_vma_setup invalidate pages, MMU notifier callback svm_range_evict
3273  *    stops all queues, schedule restore work
3274  * 2. svm_range_restore_work wait for migration is done by
3275  *    a. svm_range_validate_vram takes prange->migrate_mutex
3276  *    b. svm_range_validate_ram HMM get pages wait for CPU fault handle returns
3277  * 3. restore work update mappings of GPU, resume all queues.
3278  *
3279  * Context: Process context
3280  *
3281  * Return:
3282  * 0 - OK, otherwise - error code of migration
3283  */
3284 static int
3285 svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
3286 			    bool *migrated)
3287 {
3288 	uint32_t best_loc;
3289 	int r = 0;
3290 
3291 	*migrated = false;
3292 	best_loc = svm_range_best_prefetch_location(prange);
3293 
3294 	if (best_loc == KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3295 	    best_loc == prange->actual_loc)
3296 		return 0;
3297 
3298 	if (!best_loc) {
3299 		r = svm_migrate_vram_to_ram(prange, mm,
3300 					KFD_MIGRATE_TRIGGER_PREFETCH, NULL);
3301 		*migrated = !r;
3302 		return r;
3303 	}
3304 
3305 	r = svm_migrate_to_vram(prange, best_loc, mm, KFD_MIGRATE_TRIGGER_PREFETCH);
3306 	*migrated = !r;
3307 
3308 	return r;
3309 }
3310 
3311 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
3312 {
3313 	if (!fence)
3314 		return -EINVAL;
3315 
3316 	if (dma_fence_is_signaled(&fence->base))
3317 		return 0;
3318 
3319 	if (fence->svm_bo) {
3320 		WRITE_ONCE(fence->svm_bo->evicting, 1);
3321 		schedule_work(&fence->svm_bo->eviction_work);
3322 	}
3323 
3324 	return 0;
3325 }
3326 
3327 static void svm_range_evict_svm_bo_worker(struct work_struct *work)
3328 {
3329 	struct svm_range_bo *svm_bo;
3330 	struct mm_struct *mm;
3331 	int r = 0;
3332 
3333 	svm_bo = container_of(work, struct svm_range_bo, eviction_work);
3334 	if (!svm_bo_ref_unless_zero(svm_bo))
3335 		return; /* svm_bo was freed while eviction was pending */
3336 
3337 	if (mmget_not_zero(svm_bo->eviction_fence->mm)) {
3338 		mm = svm_bo->eviction_fence->mm;
3339 	} else {
3340 		svm_range_bo_unref(svm_bo);
3341 		return;
3342 	}
3343 
3344 	mmap_read_lock(mm);
3345 	spin_lock(&svm_bo->list_lock);
3346 	while (!list_empty(&svm_bo->range_list) && !r) {
3347 		struct svm_range *prange =
3348 				list_first_entry(&svm_bo->range_list,
3349 						struct svm_range, svm_bo_list);
3350 		int retries = 3;
3351 
3352 		list_del_init(&prange->svm_bo_list);
3353 		spin_unlock(&svm_bo->list_lock);
3354 
3355 		pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms,
3356 			 prange->start, prange->last);
3357 
3358 		mutex_lock(&prange->migrate_mutex);
3359 		do {
3360 			r = svm_migrate_vram_to_ram(prange, mm,
3361 					KFD_MIGRATE_TRIGGER_TTM_EVICTION, NULL);
3362 		} while (!r && prange->actual_loc && --retries);
3363 
3364 		if (!r && prange->actual_loc)
3365 			pr_info_once("Migration failed during eviction");
3366 
3367 		if (!prange->actual_loc) {
3368 			mutex_lock(&prange->lock);
3369 			prange->svm_bo = NULL;
3370 			mutex_unlock(&prange->lock);
3371 		}
3372 		mutex_unlock(&prange->migrate_mutex);
3373 
3374 		spin_lock(&svm_bo->list_lock);
3375 	}
3376 	spin_unlock(&svm_bo->list_lock);
3377 	mmap_read_unlock(mm);
3378 	mmput(mm);
3379 
3380 	dma_fence_signal(&svm_bo->eviction_fence->base);
3381 
3382 	/* This is the last reference to svm_bo, after svm_range_vram_node_free
3383 	 * has been called in svm_migrate_vram_to_ram
3384 	 */
3385 	WARN_ONCE(!r && kref_read(&svm_bo->kref) != 1, "This was not the last reference\n");
3386 	svm_range_bo_unref(svm_bo);
3387 }
3388 
3389 static int
3390 svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
3391 		   uint64_t start, uint64_t size, uint32_t nattr,
3392 		   struct kfd_ioctl_svm_attribute *attrs)
3393 {
3394 	struct amdkfd_process_info *process_info = p->kgd_process_info;
3395 	struct list_head update_list;
3396 	struct list_head insert_list;
3397 	struct list_head remove_list;
3398 	struct svm_range_list *svms;
3399 	struct svm_range *prange;
3400 	struct svm_range *next;
3401 	bool update_mapping = false;
3402 	bool flush_tlb;
3403 	int r = 0;
3404 
3405 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
3406 		 p->pasid, &p->svms, start, start + size - 1, size);
3407 
3408 	r = svm_range_check_attr(p, nattr, attrs);
3409 	if (r)
3410 		return r;
3411 
3412 	svms = &p->svms;
3413 
3414 	mutex_lock(&process_info->lock);
3415 
3416 	svm_range_list_lock_and_flush_work(svms, mm);
3417 
3418 	r = svm_range_is_valid(p, start, size);
3419 	if (r) {
3420 		pr_debug("invalid range r=%d\n", r);
3421 		mmap_write_unlock(mm);
3422 		goto out;
3423 	}
3424 
3425 	mutex_lock(&svms->lock);
3426 
3427 	/* Add new range and split existing ranges as needed */
3428 	r = svm_range_add(p, start, size, nattr, attrs, &update_list,
3429 			  &insert_list, &remove_list);
3430 	if (r) {
3431 		mutex_unlock(&svms->lock);
3432 		mmap_write_unlock(mm);
3433 		goto out;
3434 	}
3435 	/* Apply changes as a transaction */
3436 	list_for_each_entry_safe(prange, next, &insert_list, list) {
3437 		svm_range_add_to_svms(prange);
3438 		svm_range_add_notifier_locked(mm, prange);
3439 	}
3440 	list_for_each_entry(prange, &update_list, update_list) {
3441 		svm_range_apply_attrs(p, prange, nattr, attrs, &update_mapping);
3442 		/* TODO: unmap ranges from GPU that lost access */
3443 	}
3444 	list_for_each_entry_safe(prange, next, &remove_list, update_list) {
3445 		pr_debug("unlink old 0x%p prange 0x%p [0x%lx 0x%lx]\n",
3446 			 prange->svms, prange, prange->start,
3447 			 prange->last);
3448 		svm_range_unlink(prange);
3449 		svm_range_remove_notifier(prange);
3450 		svm_range_free(prange, false);
3451 	}
3452 
3453 	mmap_write_downgrade(mm);
3454 	/* Trigger migrations and revalidate and map to GPUs as needed. If
3455 	 * this fails we may be left with partially completed actions. There
3456 	 * is no clean way of rolling back to the previous state in such a
3457 	 * case because the rollback wouldn't be guaranteed to work either.
3458 	 */
3459 	list_for_each_entry(prange, &update_list, update_list) {
3460 		bool migrated;
3461 
3462 		mutex_lock(&prange->migrate_mutex);
3463 
3464 		r = svm_range_trigger_migration(mm, prange, &migrated);
3465 		if (r)
3466 			goto out_unlock_range;
3467 
3468 		if (migrated && (!p->xnack_enabled ||
3469 		    (prange->flags & KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED)) &&
3470 		    prange->mapped_to_gpu) {
3471 			pr_debug("restore_work will update mappings of GPUs\n");
3472 			mutex_unlock(&prange->migrate_mutex);
3473 			continue;
3474 		}
3475 
3476 		if (!migrated && !update_mapping) {
3477 			mutex_unlock(&prange->migrate_mutex);
3478 			continue;
3479 		}
3480 
3481 		flush_tlb = !migrated && update_mapping && prange->mapped_to_gpu;
3482 
3483 		r = svm_range_validate_and_map(mm, prange, MAX_GPU_INSTANCE,
3484 					       true, true, flush_tlb);
3485 		if (r)
3486 			pr_debug("failed %d to map svm range\n", r);
3487 
3488 out_unlock_range:
3489 		mutex_unlock(&prange->migrate_mutex);
3490 		if (r)
3491 			break;
3492 	}
3493 
3494 	svm_range_debug_dump(svms);
3495 
3496 	mutex_unlock(&svms->lock);
3497 	mmap_read_unlock(mm);
3498 out:
3499 	mutex_unlock(&process_info->lock);
3500 
3501 	pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
3502 		 &p->svms, start, start + size - 1, r);
3503 
3504 	return r;
3505 }
3506 
3507 static int
3508 svm_range_get_attr(struct kfd_process *p, struct mm_struct *mm,
3509 		   uint64_t start, uint64_t size, uint32_t nattr,
3510 		   struct kfd_ioctl_svm_attribute *attrs)
3511 {
3512 	DECLARE_BITMAP(bitmap_access, MAX_GPU_INSTANCE);
3513 	DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
3514 	bool get_preferred_loc = false;
3515 	bool get_prefetch_loc = false;
3516 	bool get_granularity = false;
3517 	bool get_accessible = false;
3518 	bool get_flags = false;
3519 	uint64_t last = start + size - 1UL;
3520 	uint8_t granularity = 0xff;
3521 	struct interval_tree_node *node;
3522 	struct svm_range_list *svms;
3523 	struct svm_range *prange;
3524 	uint32_t prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3525 	uint32_t location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3526 	uint32_t flags_and = 0xffffffff;
3527 	uint32_t flags_or = 0;
3528 	int gpuidx;
3529 	uint32_t i;
3530 	int r = 0;
3531 
3532 	pr_debug("svms 0x%p [0x%llx 0x%llx] nattr 0x%x\n", &p->svms, start,
3533 		 start + size - 1, nattr);
3534 
3535 	/* Flush pending deferred work to avoid racing with deferred actions from
3536 	 * previous memory map changes (e.g. munmap). Concurrent memory map changes
3537 	 * can still race with get_attr because we don't hold the mmap lock. But that
3538 	 * would be a race condition in the application anyway, and undefined
3539 	 * behaviour is acceptable in that case.
3540 	 */
3541 	flush_work(&p->svms.deferred_list_work);
3542 
3543 	mmap_read_lock(mm);
3544 	r = svm_range_is_valid(p, start, size);
3545 	mmap_read_unlock(mm);
3546 	if (r) {
3547 		pr_debug("invalid range r=%d\n", r);
3548 		return r;
3549 	}
3550 
3551 	for (i = 0; i < nattr; i++) {
3552 		switch (attrs[i].type) {
3553 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3554 			get_preferred_loc = true;
3555 			break;
3556 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3557 			get_prefetch_loc = true;
3558 			break;
3559 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3560 			get_accessible = true;
3561 			break;
3562 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3563 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3564 			get_flags = true;
3565 			break;
3566 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3567 			get_granularity = true;
3568 			break;
3569 		case KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE:
3570 		case KFD_IOCTL_SVM_ATTR_NO_ACCESS:
3571 			fallthrough;
3572 		default:
3573 			pr_debug("get invalid attr type 0x%x\n", attrs[i].type);
3574 			return -EINVAL;
3575 		}
3576 	}
3577 
3578 	svms = &p->svms;
3579 
3580 	mutex_lock(&svms->lock);
3581 
3582 	node = interval_tree_iter_first(&svms->objects, start, last);
3583 	if (!node) {
3584 		pr_debug("range attrs not found return default values\n");
3585 		svm_range_set_default_attributes(&location, &prefetch_loc,
3586 						 &granularity, &flags_and);
3587 		flags_or = flags_and;
3588 		if (p->xnack_enabled)
3589 			bitmap_copy(bitmap_access, svms->bitmap_supported,
3590 				    MAX_GPU_INSTANCE);
3591 		else
3592 			bitmap_zero(bitmap_access, MAX_GPU_INSTANCE);
3593 		bitmap_zero(bitmap_aip, MAX_GPU_INSTANCE);
3594 		goto fill_values;
3595 	}
3596 	bitmap_copy(bitmap_access, svms->bitmap_supported, MAX_GPU_INSTANCE);
3597 	bitmap_copy(bitmap_aip, svms->bitmap_supported, MAX_GPU_INSTANCE);
3598 
3599 	while (node) {
3600 		struct interval_tree_node *next;
3601 
3602 		prange = container_of(node, struct svm_range, it_node);
3603 		next = interval_tree_iter_next(node, start, last);
3604 
3605 		if (get_preferred_loc) {
3606 			if (prange->preferred_loc ==
3607 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3608 			    (location != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3609 			     location != prange->preferred_loc)) {
3610 				location = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3611 				get_preferred_loc = false;
3612 			} else {
3613 				location = prange->preferred_loc;
3614 			}
3615 		}
3616 		if (get_prefetch_loc) {
3617 			if (prange->prefetch_loc ==
3618 					KFD_IOCTL_SVM_LOCATION_UNDEFINED ||
3619 			    (prefetch_loc != KFD_IOCTL_SVM_LOCATION_UNDEFINED &&
3620 			     prefetch_loc != prange->prefetch_loc)) {
3621 				prefetch_loc = KFD_IOCTL_SVM_LOCATION_UNDEFINED;
3622 				get_prefetch_loc = false;
3623 			} else {
3624 				prefetch_loc = prange->prefetch_loc;
3625 			}
3626 		}
3627 		if (get_accessible) {
3628 			bitmap_and(bitmap_access, bitmap_access,
3629 				   prange->bitmap_access, MAX_GPU_INSTANCE);
3630 			bitmap_and(bitmap_aip, bitmap_aip,
3631 				   prange->bitmap_aip, MAX_GPU_INSTANCE);
3632 		}
3633 		if (get_flags) {
3634 			flags_and &= prange->flags;
3635 			flags_or |= prange->flags;
3636 		}
3637 
3638 		if (get_granularity && prange->granularity < granularity)
3639 			granularity = prange->granularity;
3640 
3641 		node = next;
3642 	}
3643 fill_values:
3644 	mutex_unlock(&svms->lock);
3645 
3646 	for (i = 0; i < nattr; i++) {
3647 		switch (attrs[i].type) {
3648 		case KFD_IOCTL_SVM_ATTR_PREFERRED_LOC:
3649 			attrs[i].value = location;
3650 			break;
3651 		case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3652 			attrs[i].value = prefetch_loc;
3653 			break;
3654 		case KFD_IOCTL_SVM_ATTR_ACCESS:
3655 			gpuidx = kfd_process_gpuidx_from_gpuid(p,
3656 							       attrs[i].value);
3657 			if (gpuidx < 0) {
3658 				pr_debug("invalid gpuid %x\n", attrs[i].value);
3659 				return -EINVAL;
3660 			}
3661 			if (test_bit(gpuidx, bitmap_access))
3662 				attrs[i].type = KFD_IOCTL_SVM_ATTR_ACCESS;
3663 			else if (test_bit(gpuidx, bitmap_aip))
3664 				attrs[i].type =
3665 					KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE;
3666 			else
3667 				attrs[i].type = KFD_IOCTL_SVM_ATTR_NO_ACCESS;
3668 			break;
3669 		case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3670 			attrs[i].value = flags_and;
3671 			break;
3672 		case KFD_IOCTL_SVM_ATTR_CLR_FLAGS:
3673 			attrs[i].value = ~flags_or;
3674 			break;
3675 		case KFD_IOCTL_SVM_ATTR_GRANULARITY:
3676 			attrs[i].value = (uint32_t)granularity;
3677 			break;
3678 		}
3679 	}
3680 
3681 	return 0;
3682 }
3683 
3684 int kfd_criu_resume_svm(struct kfd_process *p)
3685 {
3686 	struct kfd_ioctl_svm_attribute *set_attr_new, *set_attr = NULL;
3687 	int nattr_common = 4, nattr_accessibility = 1;
3688 	struct criu_svm_metadata *criu_svm_md = NULL;
3689 	struct svm_range_list *svms = &p->svms;
3690 	struct criu_svm_metadata *next = NULL;
3691 	uint32_t set_flags = 0xffffffff;
3692 	int i, j, num_attrs, ret = 0;
3693 	uint64_t set_attr_size;
3694 	struct mm_struct *mm;
3695 
3696 	if (list_empty(&svms->criu_svm_metadata_list)) {
3697 		pr_debug("No SVM data from CRIU restore stage 2\n");
3698 		return ret;
3699 	}
3700 
3701 	mm = get_task_mm(p->lead_thread);
3702 	if (!mm) {
3703 		pr_err("failed to get mm for the target process\n");
3704 		return -ESRCH;
3705 	}
3706 
3707 	num_attrs = nattr_common + (nattr_accessibility * p->n_pdds);
3708 
3709 	i = j = 0;
3710 	list_for_each_entry(criu_svm_md, &svms->criu_svm_metadata_list, list) {
3711 		pr_debug("criu_svm_md[%d]\n\tstart: 0x%llx size: 0x%llx (npages)\n",
3712 			 i, criu_svm_md->data.start_addr, criu_svm_md->data.size);
3713 
3714 		for (j = 0; j < num_attrs; j++) {
3715 			pr_debug("\ncriu_svm_md[%d]->attrs[%d].type : 0x%x\ncriu_svm_md[%d]->attrs[%d].value : 0x%x\n",
3716 				 i, j, criu_svm_md->data.attrs[j].type,
3717 				 i, j, criu_svm_md->data.attrs[j].value);
3718 			switch (criu_svm_md->data.attrs[j].type) {
3719 			/* During Checkpoint operation, the query for
3720 			 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC attribute might
3721 			 * return KFD_IOCTL_SVM_LOCATION_UNDEFINED if they were
3722 			 * not used by the range which was checkpointed. Care
3723 			 * must be taken to not restore with an invalid value
3724 			 * otherwise the gpuidx value will be invalid and
3725 			 * set_attr would eventually fail so just replace those
3726 			 * with another dummy attribute such as
3727 			 * KFD_IOCTL_SVM_ATTR_SET_FLAGS.
3728 			 */
3729 			case KFD_IOCTL_SVM_ATTR_PREFETCH_LOC:
3730 				if (criu_svm_md->data.attrs[j].value ==
3731 				    KFD_IOCTL_SVM_LOCATION_UNDEFINED) {
3732 					criu_svm_md->data.attrs[j].type =
3733 						KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3734 					criu_svm_md->data.attrs[j].value = 0;
3735 				}
3736 				break;
3737 			case KFD_IOCTL_SVM_ATTR_SET_FLAGS:
3738 				set_flags = criu_svm_md->data.attrs[j].value;
3739 				break;
3740 			default:
3741 				break;
3742 			}
3743 		}
3744 
3745 		/* CLR_FLAGS is not available via get_attr during checkpoint but
3746 		 * it needs to be inserted before restoring the ranges so
3747 		 * allocate extra space for it before calling set_attr
3748 		 */
3749 		set_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3750 						(num_attrs + 1);
3751 		set_attr_new = krealloc(set_attr, set_attr_size,
3752 					    GFP_KERNEL);
3753 		if (!set_attr_new) {
3754 			ret = -ENOMEM;
3755 			goto exit;
3756 		}
3757 		set_attr = set_attr_new;
3758 
3759 		memcpy(set_attr, criu_svm_md->data.attrs, num_attrs *
3760 					sizeof(struct kfd_ioctl_svm_attribute));
3761 		set_attr[num_attrs].type = KFD_IOCTL_SVM_ATTR_CLR_FLAGS;
3762 		set_attr[num_attrs].value = ~set_flags;
3763 
3764 		ret = svm_range_set_attr(p, mm, criu_svm_md->data.start_addr,
3765 					 criu_svm_md->data.size, num_attrs + 1,
3766 					 set_attr);
3767 		if (ret) {
3768 			pr_err("CRIU: failed to set range attributes\n");
3769 			goto exit;
3770 		}
3771 
3772 		i++;
3773 	}
3774 exit:
3775 	kfree(set_attr);
3776 	list_for_each_entry_safe(criu_svm_md, next, &svms->criu_svm_metadata_list, list) {
3777 		pr_debug("freeing criu_svm_md[]\n\tstart: 0x%llx\n",
3778 						criu_svm_md->data.start_addr);
3779 		kfree(criu_svm_md);
3780 	}
3781 
3782 	mmput(mm);
3783 	return ret;
3784 
3785 }
3786 
3787 int kfd_criu_restore_svm(struct kfd_process *p,
3788 			 uint8_t __user *user_priv_ptr,
3789 			 uint64_t *priv_data_offset,
3790 			 uint64_t max_priv_data_size)
3791 {
3792 	uint64_t svm_priv_data_size, svm_object_md_size, svm_attrs_size;
3793 	int nattr_common = 4, nattr_accessibility = 1;
3794 	struct criu_svm_metadata *criu_svm_md = NULL;
3795 	struct svm_range_list *svms = &p->svms;
3796 	uint32_t num_devices;
3797 	int ret = 0;
3798 
3799 	num_devices = p->n_pdds;
3800 	/* Handle one SVM range object at a time, also the number of gpus are
3801 	 * assumed to be same on the restore node, checking must be done while
3802 	 * evaluating the topology earlier
3803 	 */
3804 
3805 	svm_attrs_size = sizeof(struct kfd_ioctl_svm_attribute) *
3806 		(nattr_common + nattr_accessibility * num_devices);
3807 	svm_object_md_size = sizeof(struct criu_svm_metadata) + svm_attrs_size;
3808 
3809 	svm_priv_data_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3810 								svm_attrs_size;
3811 
3812 	criu_svm_md = kzalloc(svm_object_md_size, GFP_KERNEL);
3813 	if (!criu_svm_md) {
3814 		pr_err("failed to allocate memory to store svm metadata\n");
3815 		return -ENOMEM;
3816 	}
3817 	if (*priv_data_offset + svm_priv_data_size > max_priv_data_size) {
3818 		ret = -EINVAL;
3819 		goto exit;
3820 	}
3821 
3822 	ret = copy_from_user(&criu_svm_md->data, user_priv_ptr + *priv_data_offset,
3823 			     svm_priv_data_size);
3824 	if (ret) {
3825 		ret = -EFAULT;
3826 		goto exit;
3827 	}
3828 	*priv_data_offset += svm_priv_data_size;
3829 
3830 	list_add_tail(&criu_svm_md->list, &svms->criu_svm_metadata_list);
3831 
3832 	return 0;
3833 
3834 
3835 exit:
3836 	kfree(criu_svm_md);
3837 	return ret;
3838 }
3839 
3840 int svm_range_get_info(struct kfd_process *p, uint32_t *num_svm_ranges,
3841 		       uint64_t *svm_priv_data_size)
3842 {
3843 	uint64_t total_size, accessibility_size, common_attr_size;
3844 	int nattr_common = 4, nattr_accessibility = 1;
3845 	int num_devices = p->n_pdds;
3846 	struct svm_range_list *svms;
3847 	struct svm_range *prange;
3848 	uint32_t count = 0;
3849 
3850 	*svm_priv_data_size = 0;
3851 
3852 	svms = &p->svms;
3853 	if (!svms)
3854 		return -EINVAL;
3855 
3856 	mutex_lock(&svms->lock);
3857 	list_for_each_entry(prange, &svms->list, list) {
3858 		pr_debug("prange: 0x%p start: 0x%lx\t npages: 0x%llx\t end: 0x%llx\n",
3859 			 prange, prange->start, prange->npages,
3860 			 prange->start + prange->npages - 1);
3861 		count++;
3862 	}
3863 	mutex_unlock(&svms->lock);
3864 
3865 	*num_svm_ranges = count;
3866 	/* Only the accessbility attributes need to be queried for all the gpus
3867 	 * individually, remaining ones are spanned across the entire process
3868 	 * regardless of the various gpu nodes. Of the remaining attributes,
3869 	 * KFD_IOCTL_SVM_ATTR_CLR_FLAGS need not be saved.
3870 	 *
3871 	 * KFD_IOCTL_SVM_ATTR_PREFERRED_LOC
3872 	 * KFD_IOCTL_SVM_ATTR_PREFETCH_LOC
3873 	 * KFD_IOCTL_SVM_ATTR_SET_FLAGS
3874 	 * KFD_IOCTL_SVM_ATTR_GRANULARITY
3875 	 *
3876 	 * ** ACCESSBILITY ATTRIBUTES **
3877 	 * (Considered as one, type is altered during query, value is gpuid)
3878 	 * KFD_IOCTL_SVM_ATTR_ACCESS
3879 	 * KFD_IOCTL_SVM_ATTR_ACCESS_IN_PLACE
3880 	 * KFD_IOCTL_SVM_ATTR_NO_ACCESS
3881 	 */
3882 	if (*num_svm_ranges > 0) {
3883 		common_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3884 			nattr_common;
3885 		accessibility_size = sizeof(struct kfd_ioctl_svm_attribute) *
3886 			nattr_accessibility * num_devices;
3887 
3888 		total_size = sizeof(struct kfd_criu_svm_range_priv_data) +
3889 			common_attr_size + accessibility_size;
3890 
3891 		*svm_priv_data_size = *num_svm_ranges * total_size;
3892 	}
3893 
3894 	pr_debug("num_svm_ranges %u total_priv_size %llu\n", *num_svm_ranges,
3895 		 *svm_priv_data_size);
3896 	return 0;
3897 }
3898 
3899 int kfd_criu_checkpoint_svm(struct kfd_process *p,
3900 			    uint8_t __user *user_priv_data,
3901 			    uint64_t *priv_data_offset)
3902 {
3903 	struct kfd_criu_svm_range_priv_data *svm_priv = NULL;
3904 	struct kfd_ioctl_svm_attribute *query_attr = NULL;
3905 	uint64_t svm_priv_data_size, query_attr_size = 0;
3906 	int index, nattr_common = 4, ret = 0;
3907 	struct svm_range_list *svms;
3908 	int num_devices = p->n_pdds;
3909 	struct svm_range *prange;
3910 	struct mm_struct *mm;
3911 
3912 	svms = &p->svms;
3913 	if (!svms)
3914 		return -EINVAL;
3915 
3916 	mm = get_task_mm(p->lead_thread);
3917 	if (!mm) {
3918 		pr_err("failed to get mm for the target process\n");
3919 		return -ESRCH;
3920 	}
3921 
3922 	query_attr_size = sizeof(struct kfd_ioctl_svm_attribute) *
3923 				(nattr_common + num_devices);
3924 
3925 	query_attr = kzalloc(query_attr_size, GFP_KERNEL);
3926 	if (!query_attr) {
3927 		ret = -ENOMEM;
3928 		goto exit;
3929 	}
3930 
3931 	query_attr[0].type = KFD_IOCTL_SVM_ATTR_PREFERRED_LOC;
3932 	query_attr[1].type = KFD_IOCTL_SVM_ATTR_PREFETCH_LOC;
3933 	query_attr[2].type = KFD_IOCTL_SVM_ATTR_SET_FLAGS;
3934 	query_attr[3].type = KFD_IOCTL_SVM_ATTR_GRANULARITY;
3935 
3936 	for (index = 0; index < num_devices; index++) {
3937 		struct kfd_process_device *pdd = p->pdds[index];
3938 
3939 		query_attr[index + nattr_common].type =
3940 			KFD_IOCTL_SVM_ATTR_ACCESS;
3941 		query_attr[index + nattr_common].value = pdd->user_gpu_id;
3942 	}
3943 
3944 	svm_priv_data_size = sizeof(*svm_priv) + query_attr_size;
3945 
3946 	svm_priv = kzalloc(svm_priv_data_size, GFP_KERNEL);
3947 	if (!svm_priv) {
3948 		ret = -ENOMEM;
3949 		goto exit_query;
3950 	}
3951 
3952 	index = 0;
3953 	list_for_each_entry(prange, &svms->list, list) {
3954 
3955 		svm_priv->object_type = KFD_CRIU_OBJECT_TYPE_SVM_RANGE;
3956 		svm_priv->start_addr = prange->start;
3957 		svm_priv->size = prange->npages;
3958 		memcpy(&svm_priv->attrs, query_attr, query_attr_size);
3959 		pr_debug("CRIU: prange: 0x%p start: 0x%lx\t npages: 0x%llx end: 0x%llx\t size: 0x%llx\n",
3960 			 prange, prange->start, prange->npages,
3961 			 prange->start + prange->npages - 1,
3962 			 prange->npages * PAGE_SIZE);
3963 
3964 		ret = svm_range_get_attr(p, mm, svm_priv->start_addr,
3965 					 svm_priv->size,
3966 					 (nattr_common + num_devices),
3967 					 svm_priv->attrs);
3968 		if (ret) {
3969 			pr_err("CRIU: failed to obtain range attributes\n");
3970 			goto exit_priv;
3971 		}
3972 
3973 		if (copy_to_user(user_priv_data + *priv_data_offset, svm_priv,
3974 				 svm_priv_data_size)) {
3975 			pr_err("Failed to copy svm priv to user\n");
3976 			ret = -EFAULT;
3977 			goto exit_priv;
3978 		}
3979 
3980 		*priv_data_offset += svm_priv_data_size;
3981 
3982 	}
3983 
3984 
3985 exit_priv:
3986 	kfree(svm_priv);
3987 exit_query:
3988 	kfree(query_attr);
3989 exit:
3990 	mmput(mm);
3991 	return ret;
3992 }
3993 
3994 int
3995 svm_ioctl(struct kfd_process *p, enum kfd_ioctl_svm_op op, uint64_t start,
3996 	  uint64_t size, uint32_t nattrs, struct kfd_ioctl_svm_attribute *attrs)
3997 {
3998 	struct mm_struct *mm = current->mm;
3999 	int r;
4000 
4001 	start >>= PAGE_SHIFT;
4002 	size >>= PAGE_SHIFT;
4003 
4004 	switch (op) {
4005 	case KFD_IOCTL_SVM_OP_SET_ATTR:
4006 		r = svm_range_set_attr(p, mm, start, size, nattrs, attrs);
4007 		break;
4008 	case KFD_IOCTL_SVM_OP_GET_ATTR:
4009 		r = svm_range_get_attr(p, mm, start, size, nattrs, attrs);
4010 		break;
4011 	default:
4012 		r = EINVAL;
4013 		break;
4014 	}
4015 
4016 	return r;
4017 }
4018