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 #include <linux/types.h>
24 #include <linux/hmm.h>
25 #include <linux/dma-direction.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/migrate.h>
28 #include "amdgpu_sync.h"
29 #include "amdgpu_object.h"
30 #include "amdgpu_vm.h"
31 #include "amdgpu_res_cursor.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_migrate: " fmt
41 
42 static uint64_t
43 svm_migrate_direct_mapping_addr(struct amdgpu_device *adev, uint64_t addr)
44 {
45 	return addr + amdgpu_ttm_domain_start(adev, TTM_PL_VRAM);
46 }
47 
48 static int
49 svm_migrate_gart_map(struct amdgpu_ring *ring, uint64_t npages,
50 		     dma_addr_t *addr, uint64_t *gart_addr, uint64_t flags)
51 {
52 	struct amdgpu_device *adev = ring->adev;
53 	struct amdgpu_job *job;
54 	unsigned int num_dw, num_bytes;
55 	struct dma_fence *fence;
56 	uint64_t src_addr, dst_addr;
57 	uint64_t pte_flags;
58 	void *cpu_addr;
59 	int r;
60 
61 	/* use gart window 0 */
62 	*gart_addr = adev->gmc.gart_start;
63 
64 	num_dw = ALIGN(adev->mman.buffer_funcs->copy_num_dw, 8);
65 	num_bytes = npages * 8;
66 
67 	r = amdgpu_job_alloc_with_ib(adev, &adev->mman.high_pr,
68 				     AMDGPU_FENCE_OWNER_UNDEFINED,
69 				     num_dw * 4 + num_bytes,
70 				     AMDGPU_IB_POOL_DELAYED,
71 				     &job);
72 	if (r)
73 		return r;
74 
75 	src_addr = num_dw * 4;
76 	src_addr += job->ibs[0].gpu_addr;
77 
78 	dst_addr = amdgpu_bo_gpu_offset(adev->gart.bo);
79 	amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr,
80 				dst_addr, num_bytes, false);
81 
82 	amdgpu_ring_pad_ib(ring, &job->ibs[0]);
83 	WARN_ON(job->ibs[0].length_dw > num_dw);
84 
85 	pte_flags = AMDGPU_PTE_VALID | AMDGPU_PTE_READABLE;
86 	pte_flags |= AMDGPU_PTE_SYSTEM | AMDGPU_PTE_SNOOPED;
87 	if (!(flags & KFD_IOCTL_SVM_FLAG_GPU_RO))
88 		pte_flags |= AMDGPU_PTE_WRITEABLE;
89 	pte_flags |= adev->gart.gart_pte_flags;
90 
91 	cpu_addr = &job->ibs[0].ptr[num_dw];
92 
93 	amdgpu_gart_map(adev, 0, npages, addr, pte_flags, cpu_addr);
94 	fence = amdgpu_job_submit(job);
95 	dma_fence_put(fence);
96 
97 	return r;
98 }
99 
100 /**
101  * svm_migrate_copy_memory_gart - sdma copy data between ram and vram
102  *
103  * @adev: amdgpu device the sdma ring running
104  * @sys: system DMA pointer to be copied
105  * @vram: vram destination DMA pointer
106  * @npages: number of pages to copy
107  * @direction: enum MIGRATION_COPY_DIR
108  * @mfence: output, sdma fence to signal after sdma is done
109  *
110  * ram address uses GART table continuous entries mapping to ram pages,
111  * vram address uses direct mapping of vram pages, which must have npages
112  * number of continuous pages.
113  * GART update and sdma uses same buf copy function ring, sdma is splited to
114  * multiple GTT_MAX_PAGES transfer, all sdma operations are serialized, wait for
115  * the last sdma finish fence which is returned to check copy memory is done.
116  *
117  * Context: Process context, takes and releases gtt_window_lock
118  *
119  * Return:
120  * 0 - OK, otherwise error code
121  */
122 
123 static int
124 svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys,
125 			     uint64_t *vram, uint64_t npages,
126 			     enum MIGRATION_COPY_DIR direction,
127 			     struct dma_fence **mfence)
128 {
129 	const uint64_t GTT_MAX_PAGES = AMDGPU_GTT_MAX_TRANSFER_SIZE;
130 	struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
131 	uint64_t gart_s, gart_d;
132 	struct dma_fence *next;
133 	uint64_t size;
134 	int r;
135 
136 	mutex_lock(&adev->mman.gtt_window_lock);
137 
138 	while (npages) {
139 		size = min(GTT_MAX_PAGES, npages);
140 
141 		if (direction == FROM_VRAM_TO_RAM) {
142 			gart_s = svm_migrate_direct_mapping_addr(adev, *vram);
143 			r = svm_migrate_gart_map(ring, size, sys, &gart_d, 0);
144 
145 		} else if (direction == FROM_RAM_TO_VRAM) {
146 			r = svm_migrate_gart_map(ring, size, sys, &gart_s,
147 						 KFD_IOCTL_SVM_FLAG_GPU_RO);
148 			gart_d = svm_migrate_direct_mapping_addr(adev, *vram);
149 		}
150 		if (r) {
151 			dev_err(adev->dev, "fail %d create gart mapping\n", r);
152 			goto out_unlock;
153 		}
154 
155 		r = amdgpu_copy_buffer(ring, gart_s, gart_d, size * PAGE_SIZE,
156 				       NULL, &next, false, true, false);
157 		if (r) {
158 			dev_err(adev->dev, "fail %d to copy memory\n", r);
159 			goto out_unlock;
160 		}
161 
162 		dma_fence_put(*mfence);
163 		*mfence = next;
164 		npages -= size;
165 		if (npages) {
166 			sys += size;
167 			vram += size;
168 		}
169 	}
170 
171 out_unlock:
172 	mutex_unlock(&adev->mman.gtt_window_lock);
173 
174 	return r;
175 }
176 
177 /**
178  * svm_migrate_copy_done - wait for memory copy sdma is done
179  *
180  * @adev: amdgpu device the sdma memory copy is executing on
181  * @mfence: migrate fence
182  *
183  * Wait for dma fence is signaled, if the copy ssplit into multiple sdma
184  * operations, this is the last sdma operation fence.
185  *
186  * Context: called after svm_migrate_copy_memory
187  *
188  * Return:
189  * 0		- success
190  * otherwise	- error code from dma fence signal
191  */
192 static int
193 svm_migrate_copy_done(struct amdgpu_device *adev, struct dma_fence *mfence)
194 {
195 	int r = 0;
196 
197 	if (mfence) {
198 		r = dma_fence_wait(mfence, false);
199 		dma_fence_put(mfence);
200 		pr_debug("sdma copy memory fence done\n");
201 	}
202 
203 	return r;
204 }
205 
206 unsigned long
207 svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr)
208 {
209 	return (addr + adev->kfd.pgmap.range.start) >> PAGE_SHIFT;
210 }
211 
212 static void
213 svm_migrate_get_vram_page(struct svm_range *prange, unsigned long pfn)
214 {
215 	struct page *page;
216 
217 	page = pfn_to_page(pfn);
218 	svm_range_bo_ref(prange->svm_bo);
219 	page->zone_device_data = prange->svm_bo;
220 	zone_device_page_init(page);
221 }
222 
223 static void
224 svm_migrate_put_vram_page(struct amdgpu_device *adev, unsigned long addr)
225 {
226 	struct page *page;
227 
228 	page = pfn_to_page(svm_migrate_addr_to_pfn(adev, addr));
229 	unlock_page(page);
230 	put_page(page);
231 }
232 
233 static unsigned long
234 svm_migrate_addr(struct amdgpu_device *adev, struct page *page)
235 {
236 	unsigned long addr;
237 
238 	addr = page_to_pfn(page) << PAGE_SHIFT;
239 	return (addr - adev->kfd.pgmap.range.start);
240 }
241 
242 static struct page *
243 svm_migrate_get_sys_page(struct vm_area_struct *vma, unsigned long addr)
244 {
245 	struct page *page;
246 
247 	page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
248 	if (page)
249 		lock_page(page);
250 
251 	return page;
252 }
253 
254 static void svm_migrate_put_sys_page(unsigned long addr)
255 {
256 	struct page *page;
257 
258 	page = pfn_to_page(addr >> PAGE_SHIFT);
259 	unlock_page(page);
260 	put_page(page);
261 }
262 
263 static unsigned long svm_migrate_successful_pages(struct migrate_vma *migrate)
264 {
265 	unsigned long cpages = 0;
266 	unsigned long i;
267 
268 	for (i = 0; i < migrate->npages; i++) {
269 		if (migrate->src[i] & MIGRATE_PFN_VALID &&
270 		    migrate->src[i] & MIGRATE_PFN_MIGRATE)
271 			cpages++;
272 	}
273 	return cpages;
274 }
275 
276 static unsigned long svm_migrate_unsuccessful_pages(struct migrate_vma *migrate)
277 {
278 	unsigned long upages = 0;
279 	unsigned long i;
280 
281 	for (i = 0; i < migrate->npages; i++) {
282 		if (migrate->src[i] & MIGRATE_PFN_VALID &&
283 		    !(migrate->src[i] & MIGRATE_PFN_MIGRATE))
284 			upages++;
285 	}
286 	return upages;
287 }
288 
289 static int
290 svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,
291 			 struct migrate_vma *migrate, struct dma_fence **mfence,
292 			 dma_addr_t *scratch, uint64_t ttm_res_offset)
293 {
294 	uint64_t npages = migrate->cpages;
295 	struct amdgpu_device *adev = node->adev;
296 	struct device *dev = adev->dev;
297 	struct amdgpu_res_cursor cursor;
298 	dma_addr_t *src;
299 	uint64_t *dst;
300 	uint64_t i, j;
301 	int r;
302 
303 	pr_debug("svms 0x%p [0x%lx 0x%lx 0x%llx]\n", prange->svms, prange->start,
304 		 prange->last, ttm_res_offset);
305 
306 	src = scratch;
307 	dst = (uint64_t *)(scratch + npages);
308 
309 	amdgpu_res_first(prange->ttm_res, ttm_res_offset,
310 			 npages << PAGE_SHIFT, &cursor);
311 	for (i = j = 0; i < npages; i++) {
312 		struct page *spage;
313 
314 		dst[i] = cursor.start + (j << PAGE_SHIFT);
315 		migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
316 		svm_migrate_get_vram_page(prange, migrate->dst[i]);
317 		migrate->dst[i] = migrate_pfn(migrate->dst[i]);
318 
319 		spage = migrate_pfn_to_page(migrate->src[i]);
320 		if (spage && !is_zone_device_page(spage)) {
321 			src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
322 					      DMA_TO_DEVICE);
323 			r = dma_mapping_error(dev, src[i]);
324 			if (r) {
325 				dev_err(dev, "%s: fail %d dma_map_page\n",
326 					__func__, r);
327 				goto out_free_vram_pages;
328 			}
329 		} else {
330 			if (j) {
331 				r = svm_migrate_copy_memory_gart(
332 						adev, src + i - j,
333 						dst + i - j, j,
334 						FROM_RAM_TO_VRAM,
335 						mfence);
336 				if (r)
337 					goto out_free_vram_pages;
338 				amdgpu_res_next(&cursor, (j + 1) << PAGE_SHIFT);
339 				j = 0;
340 			} else {
341 				amdgpu_res_next(&cursor, PAGE_SIZE);
342 			}
343 			continue;
344 		}
345 
346 		pr_debug_ratelimited("dma mapping src to 0x%llx, pfn 0x%lx\n",
347 				     src[i] >> PAGE_SHIFT, page_to_pfn(spage));
348 
349 		if (j >= (cursor.size >> PAGE_SHIFT) - 1 && i < npages - 1) {
350 			r = svm_migrate_copy_memory_gart(adev, src + i - j,
351 							 dst + i - j, j + 1,
352 							 FROM_RAM_TO_VRAM,
353 							 mfence);
354 			if (r)
355 				goto out_free_vram_pages;
356 			amdgpu_res_next(&cursor, (j + 1) * PAGE_SIZE);
357 			j = 0;
358 		} else {
359 			j++;
360 		}
361 	}
362 
363 	r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,
364 					 FROM_RAM_TO_VRAM, mfence);
365 
366 out_free_vram_pages:
367 	if (r) {
368 		pr_debug("failed %d to copy memory to vram\n", r);
369 		while (i--) {
370 			svm_migrate_put_vram_page(adev, dst[i]);
371 			migrate->dst[i] = 0;
372 		}
373 	}
374 
375 #ifdef DEBUG_FORCE_MIXED_DOMAINS
376 	for (i = 0, j = 0; i < npages; i += 4, j++) {
377 		if (j & 1)
378 			continue;
379 		svm_migrate_put_vram_page(adev, dst[i]);
380 		migrate->dst[i] = 0;
381 		svm_migrate_put_vram_page(adev, dst[i + 1]);
382 		migrate->dst[i + 1] = 0;
383 		svm_migrate_put_vram_page(adev, dst[i + 2]);
384 		migrate->dst[i + 2] = 0;
385 		svm_migrate_put_vram_page(adev, dst[i + 3]);
386 		migrate->dst[i + 3] = 0;
387 	}
388 #endif
389 
390 	return r;
391 }
392 
393 static long
394 svm_migrate_vma_to_vram(struct kfd_node *node, struct svm_range *prange,
395 			struct vm_area_struct *vma, uint64_t start,
396 			uint64_t end, uint32_t trigger, uint64_t ttm_res_offset)
397 {
398 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
399 	uint64_t npages = (end - start) >> PAGE_SHIFT;
400 	struct amdgpu_device *adev = node->adev;
401 	struct kfd_process_device *pdd;
402 	struct dma_fence *mfence = NULL;
403 	struct migrate_vma migrate = { 0 };
404 	unsigned long cpages = 0;
405 	dma_addr_t *scratch;
406 	void *buf;
407 	int r = -ENOMEM;
408 
409 	memset(&migrate, 0, sizeof(migrate));
410 	migrate.vma = vma;
411 	migrate.start = start;
412 	migrate.end = end;
413 	migrate.flags = MIGRATE_VMA_SELECT_SYSTEM;
414 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
415 
416 	buf = kvcalloc(npages,
417 		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
418 		       GFP_KERNEL);
419 	if (!buf)
420 		goto out;
421 
422 	migrate.src = buf;
423 	migrate.dst = migrate.src + npages;
424 	scratch = (dma_addr_t *)(migrate.dst + npages);
425 
426 	kfd_smi_event_migration_start(node, p->lead_thread->pid,
427 				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
428 				      0, node->id, prange->prefetch_loc,
429 				      prange->preferred_loc, trigger);
430 
431 	r = migrate_vma_setup(&migrate);
432 	if (r) {
433 		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
434 			__func__, r, prange->start, prange->last);
435 		goto out_free;
436 	}
437 
438 	cpages = migrate.cpages;
439 	if (!cpages) {
440 		pr_debug("failed collect migrate sys pages [0x%lx 0x%lx]\n",
441 			 prange->start, prange->last);
442 		goto out_free;
443 	}
444 	if (cpages != npages)
445 		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
446 			 cpages, npages);
447 	else
448 		pr_debug("0x%lx pages migrated\n", cpages);
449 
450 	r = svm_migrate_copy_to_vram(node, prange, &migrate, &mfence, scratch, ttm_res_offset);
451 	migrate_vma_pages(&migrate);
452 
453 	pr_debug("successful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
454 		svm_migrate_successful_pages(&migrate), cpages, migrate.npages);
455 
456 	svm_migrate_copy_done(adev, mfence);
457 	migrate_vma_finalize(&migrate);
458 
459 	kfd_smi_event_migration_end(node, p->lead_thread->pid,
460 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
461 				    0, node->id, trigger);
462 
463 	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
464 	svm_range_free_dma_mappings(prange);
465 
466 out_free:
467 	kvfree(buf);
468 out:
469 	if (!r && cpages) {
470 		pdd = svm_range_get_pdd_by_node(prange, node);
471 		if (pdd)
472 			WRITE_ONCE(pdd->page_in, pdd->page_in + cpages);
473 
474 		return cpages;
475 	}
476 	return r;
477 }
478 
479 /**
480  * svm_migrate_ram_to_vram - migrate svm range from system to device
481  * @prange: range structure
482  * @best_loc: the device to migrate to
483  * @mm: the process mm structure
484  * @trigger: reason of migration
485  *
486  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
487  *
488  * Return:
489  * 0 - OK, otherwise error code
490  */
491 static int
492 svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
493 			struct mm_struct *mm, uint32_t trigger)
494 {
495 	unsigned long addr, start, end;
496 	struct vm_area_struct *vma;
497 	uint64_t ttm_res_offset;
498 	struct kfd_node *node;
499 	unsigned long cpages = 0;
500 	long r = 0;
501 
502 	if (prange->actual_loc == best_loc) {
503 		pr_debug("svms 0x%p [0x%lx 0x%lx] already on best_loc 0x%x\n",
504 			 prange->svms, prange->start, prange->last, best_loc);
505 		return 0;
506 	}
507 
508 	node = svm_range_get_node_by_id(prange, best_loc);
509 	if (!node) {
510 		pr_debug("failed to get kfd node by id 0x%x\n", best_loc);
511 		return -ENODEV;
512 	}
513 
514 	pr_debug("svms 0x%p [0x%lx 0x%lx] to gpu 0x%x\n", prange->svms,
515 		 prange->start, prange->last, best_loc);
516 
517 	start = prange->start << PAGE_SHIFT;
518 	end = (prange->last + 1) << PAGE_SHIFT;
519 
520 	r = svm_range_vram_node_new(node, prange, true);
521 	if (r) {
522 		dev_dbg(node->adev->dev, "fail %ld to alloc vram\n", r);
523 		return r;
524 	}
525 	ttm_res_offset = prange->offset << PAGE_SHIFT;
526 
527 	for (addr = start; addr < end;) {
528 		unsigned long next;
529 
530 		vma = vma_lookup(mm, addr);
531 		if (!vma)
532 			break;
533 
534 		next = min(vma->vm_end, end);
535 		r = svm_migrate_vma_to_vram(node, prange, vma, addr, next, trigger, ttm_res_offset);
536 		if (r < 0) {
537 			pr_debug("failed %ld to migrate\n", r);
538 			break;
539 		} else {
540 			cpages += r;
541 		}
542 		ttm_res_offset += next - addr;
543 		addr = next;
544 	}
545 
546 	if (cpages)
547 		prange->actual_loc = best_loc;
548 	else
549 		svm_range_vram_node_free(prange);
550 
551 	return r < 0 ? r : 0;
552 }
553 
554 static void svm_migrate_page_free(struct page *page)
555 {
556 	struct svm_range_bo *svm_bo = page->zone_device_data;
557 
558 	if (svm_bo) {
559 		pr_debug_ratelimited("ref: %d\n", kref_read(&svm_bo->kref));
560 		svm_range_bo_unref_async(svm_bo);
561 	}
562 }
563 
564 static int
565 svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
566 			struct migrate_vma *migrate, struct dma_fence **mfence,
567 			dma_addr_t *scratch, uint64_t npages)
568 {
569 	struct device *dev = adev->dev;
570 	uint64_t *src;
571 	dma_addr_t *dst;
572 	struct page *dpage;
573 	uint64_t i = 0, j;
574 	uint64_t addr;
575 	int r = 0;
576 
577 	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
578 		 prange->last);
579 
580 	addr = prange->start << PAGE_SHIFT;
581 
582 	src = (uint64_t *)(scratch + npages);
583 	dst = scratch;
584 
585 	for (i = 0, j = 0; i < npages; i++, addr += PAGE_SIZE) {
586 		struct page *spage;
587 
588 		spage = migrate_pfn_to_page(migrate->src[i]);
589 		if (!spage || !is_zone_device_page(spage)) {
590 			pr_debug("invalid page. Could be in CPU already svms 0x%p [0x%lx 0x%lx]\n",
591 				 prange->svms, prange->start, prange->last);
592 			if (j) {
593 				r = svm_migrate_copy_memory_gart(adev, dst + i - j,
594 								 src + i - j, j,
595 								 FROM_VRAM_TO_RAM,
596 								 mfence);
597 				if (r)
598 					goto out_oom;
599 				j = 0;
600 			}
601 			continue;
602 		}
603 		src[i] = svm_migrate_addr(adev, spage);
604 		if (j > 0 && src[i] != src[i - 1] + PAGE_SIZE) {
605 			r = svm_migrate_copy_memory_gart(adev, dst + i - j,
606 							 src + i - j, j,
607 							 FROM_VRAM_TO_RAM,
608 							 mfence);
609 			if (r)
610 				goto out_oom;
611 			j = 0;
612 		}
613 
614 		dpage = svm_migrate_get_sys_page(migrate->vma, addr);
615 		if (!dpage) {
616 			pr_debug("failed get page svms 0x%p [0x%lx 0x%lx]\n",
617 				 prange->svms, prange->start, prange->last);
618 			r = -ENOMEM;
619 			goto out_oom;
620 		}
621 
622 		dst[i] = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_FROM_DEVICE);
623 		r = dma_mapping_error(dev, dst[i]);
624 		if (r) {
625 			dev_err(adev->dev, "%s: fail %d dma_map_page\n", __func__, r);
626 			goto out_oom;
627 		}
628 
629 		pr_debug_ratelimited("dma mapping dst to 0x%llx, pfn 0x%lx\n",
630 				     dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
631 
632 		migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
633 		j++;
634 	}
635 
636 	r = svm_migrate_copy_memory_gart(adev, dst + i - j, src + i - j, j,
637 					 FROM_VRAM_TO_RAM, mfence);
638 
639 out_oom:
640 	if (r) {
641 		pr_debug("failed %d copy to ram\n", r);
642 		while (i--) {
643 			svm_migrate_put_sys_page(dst[i]);
644 			migrate->dst[i] = 0;
645 		}
646 	}
647 
648 	return r;
649 }
650 
651 /**
652  * svm_migrate_vma_to_ram - migrate range inside one vma from device to system
653  *
654  * @prange: svm range structure
655  * @vma: vm_area_struct that range [start, end] belongs to
656  * @start: range start virtual address in pages
657  * @end: range end virtual address in pages
658  * @node: kfd node device to migrate from
659  * @trigger: reason of migration
660  * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
661  *
662  * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
663  *
664  * Return:
665  *   0 - success with all pages migrated
666  *   negative values - indicate error
667  *   positive values - partial migration, number of pages not migrated
668  */
669 static long
670 svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
671 		       struct vm_area_struct *vma, uint64_t start, uint64_t end,
672 		       uint32_t trigger, struct page *fault_page)
673 {
674 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
675 	uint64_t npages = (end - start) >> PAGE_SHIFT;
676 	unsigned long upages = npages;
677 	unsigned long cpages = 0;
678 	struct amdgpu_device *adev = node->adev;
679 	struct kfd_process_device *pdd;
680 	struct dma_fence *mfence = NULL;
681 	struct migrate_vma migrate = { 0 };
682 	dma_addr_t *scratch;
683 	void *buf;
684 	int r = -ENOMEM;
685 
686 	memset(&migrate, 0, sizeof(migrate));
687 	migrate.vma = vma;
688 	migrate.start = start;
689 	migrate.end = end;
690 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
691 	if (adev->gmc.xgmi.connected_to_cpu)
692 		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_COHERENT;
693 	else
694 		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
695 
696 	buf = kvcalloc(npages,
697 		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
698 		       GFP_KERNEL);
699 	if (!buf)
700 		goto out;
701 
702 	migrate.src = buf;
703 	migrate.dst = migrate.src + npages;
704 	migrate.fault_page = fault_page;
705 	scratch = (dma_addr_t *)(migrate.dst + npages);
706 
707 	kfd_smi_event_migration_start(node, p->lead_thread->pid,
708 				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
709 				      node->id, 0, prange->prefetch_loc,
710 				      prange->preferred_loc, trigger);
711 
712 	r = migrate_vma_setup(&migrate);
713 	if (r) {
714 		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
715 			__func__, r, prange->start, prange->last);
716 		goto out_free;
717 	}
718 
719 	cpages = migrate.cpages;
720 	if (!cpages) {
721 		pr_debug("failed collect migrate device pages [0x%lx 0x%lx]\n",
722 			 prange->start, prange->last);
723 		upages = svm_migrate_unsuccessful_pages(&migrate);
724 		goto out_free;
725 	}
726 	if (cpages != npages)
727 		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
728 			 cpages, npages);
729 	else
730 		pr_debug("0x%lx pages migrated\n", cpages);
731 
732 	r = svm_migrate_copy_to_ram(adev, prange, &migrate, &mfence,
733 				    scratch, npages);
734 	migrate_vma_pages(&migrate);
735 
736 	upages = svm_migrate_unsuccessful_pages(&migrate);
737 	pr_debug("unsuccessful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
738 		 upages, cpages, migrate.npages);
739 
740 	svm_migrate_copy_done(adev, mfence);
741 	migrate_vma_finalize(&migrate);
742 
743 	kfd_smi_event_migration_end(node, p->lead_thread->pid,
744 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
745 				    node->id, 0, trigger);
746 
747 	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
748 
749 out_free:
750 	kvfree(buf);
751 out:
752 	if (!r && cpages) {
753 		pdd = svm_range_get_pdd_by_node(prange, node);
754 		if (pdd)
755 			WRITE_ONCE(pdd->page_out, pdd->page_out + cpages);
756 	}
757 	return r ? r : upages;
758 }
759 
760 /**
761  * svm_migrate_vram_to_ram - migrate svm range from device to system
762  * @prange: range structure
763  * @mm: process mm, use current->mm if NULL
764  * @trigger: reason of migration
765  * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
766  *
767  * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
768  *
769  * Return:
770  * 0 - OK, otherwise error code
771  */
772 int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm,
773 			    uint32_t trigger, struct page *fault_page)
774 {
775 	struct kfd_node *node;
776 	struct vm_area_struct *vma;
777 	unsigned long addr;
778 	unsigned long start;
779 	unsigned long end;
780 	unsigned long upages = 0;
781 	long r = 0;
782 
783 	if (!prange->actual_loc) {
784 		pr_debug("[0x%lx 0x%lx] already migrated to ram\n",
785 			 prange->start, prange->last);
786 		return 0;
787 	}
788 
789 	node = svm_range_get_node_by_id(prange, prange->actual_loc);
790 	if (!node) {
791 		pr_debug("failed to get kfd node by id 0x%x\n", prange->actual_loc);
792 		return -ENODEV;
793 	}
794 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] from gpu 0x%x to ram\n",
795 		 prange->svms, prange, prange->start, prange->last,
796 		 prange->actual_loc);
797 
798 	start = prange->start << PAGE_SHIFT;
799 	end = (prange->last + 1) << PAGE_SHIFT;
800 
801 	for (addr = start; addr < end;) {
802 		unsigned long next;
803 
804 		vma = vma_lookup(mm, addr);
805 		if (!vma) {
806 			pr_debug("failed to find vma for prange %p\n", prange);
807 			r = -EFAULT;
808 			break;
809 		}
810 
811 		next = min(vma->vm_end, end);
812 		r = svm_migrate_vma_to_ram(node, prange, vma, addr, next, trigger,
813 			fault_page);
814 		if (r < 0) {
815 			pr_debug("failed %ld to migrate prange %p\n", r, prange);
816 			break;
817 		} else {
818 			upages += r;
819 		}
820 		addr = next;
821 	}
822 
823 	if (r >= 0 && !upages) {
824 		svm_range_vram_node_free(prange);
825 		prange->actual_loc = 0;
826 	}
827 
828 	return r < 0 ? r : 0;
829 }
830 
831 /**
832  * svm_migrate_vram_to_vram - migrate svm range from device to device
833  * @prange: range structure
834  * @best_loc: the device to migrate to
835  * @mm: process mm, use current->mm if NULL
836  * @trigger: reason of migration
837  *
838  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
839  *
840  * Return:
841  * 0 - OK, otherwise error code
842  */
843 static int
844 svm_migrate_vram_to_vram(struct svm_range *prange, uint32_t best_loc,
845 			 struct mm_struct *mm, uint32_t trigger)
846 {
847 	int r, retries = 3;
848 
849 	/*
850 	 * TODO: for both devices with PCIe large bar or on same xgmi hive, skip
851 	 * system memory as migration bridge
852 	 */
853 
854 	pr_debug("from gpu 0x%x to gpu 0x%x\n", prange->actual_loc, best_loc);
855 
856 	do {
857 		r = svm_migrate_vram_to_ram(prange, mm, trigger, NULL);
858 		if (r)
859 			return r;
860 	} while (prange->actual_loc && --retries);
861 
862 	if (prange->actual_loc)
863 		return -EDEADLK;
864 
865 	return svm_migrate_ram_to_vram(prange, best_loc, mm, trigger);
866 }
867 
868 int
869 svm_migrate_to_vram(struct svm_range *prange, uint32_t best_loc,
870 		    struct mm_struct *mm, uint32_t trigger)
871 {
872 	if  (!prange->actual_loc)
873 		return svm_migrate_ram_to_vram(prange, best_loc, mm, trigger);
874 	else
875 		return svm_migrate_vram_to_vram(prange, best_loc, mm, trigger);
876 
877 }
878 
879 /**
880  * svm_migrate_to_ram - CPU page fault handler
881  * @vmf: CPU vm fault vma, address
882  *
883  * Context: vm fault handler, caller holds the mmap read lock
884  *
885  * Return:
886  * 0 - OK
887  * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
888  */
889 static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
890 {
891 	unsigned long addr = vmf->address;
892 	struct svm_range_bo *svm_bo;
893 	enum svm_work_list_ops op;
894 	struct svm_range *parent;
895 	struct svm_range *prange;
896 	struct kfd_process *p;
897 	struct mm_struct *mm;
898 	int r = 0;
899 
900 	svm_bo = vmf->page->zone_device_data;
901 	if (!svm_bo) {
902 		pr_debug("failed get device page at addr 0x%lx\n", addr);
903 		return VM_FAULT_SIGBUS;
904 	}
905 	if (!mmget_not_zero(svm_bo->eviction_fence->mm)) {
906 		pr_debug("addr 0x%lx of process mm is destroyed\n", addr);
907 		return VM_FAULT_SIGBUS;
908 	}
909 
910 	mm = svm_bo->eviction_fence->mm;
911 	if (mm != vmf->vma->vm_mm)
912 		pr_debug("addr 0x%lx is COW mapping in child process\n", addr);
913 
914 	p = kfd_lookup_process_by_mm(mm);
915 	if (!p) {
916 		pr_debug("failed find process at fault address 0x%lx\n", addr);
917 		r = VM_FAULT_SIGBUS;
918 		goto out_mmput;
919 	}
920 	if (READ_ONCE(p->svms.faulting_task) == current) {
921 		pr_debug("skipping ram migration\n");
922 		r = 0;
923 		goto out_unref_process;
924 	}
925 
926 	pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr);
927 	addr >>= PAGE_SHIFT;
928 
929 	mutex_lock(&p->svms.lock);
930 
931 	prange = svm_range_from_addr(&p->svms, addr, &parent);
932 	if (!prange) {
933 		pr_debug("failed get range svms 0x%p addr 0x%lx\n", &p->svms, addr);
934 		r = -EFAULT;
935 		goto out_unlock_svms;
936 	}
937 
938 	mutex_lock(&parent->migrate_mutex);
939 	if (prange != parent)
940 		mutex_lock_nested(&prange->migrate_mutex, 1);
941 
942 	if (!prange->actual_loc)
943 		goto out_unlock_prange;
944 
945 	svm_range_lock(parent);
946 	if (prange != parent)
947 		mutex_lock_nested(&prange->lock, 1);
948 	r = svm_range_split_by_granularity(p, mm, addr, parent, prange);
949 	if (prange != parent)
950 		mutex_unlock(&prange->lock);
951 	svm_range_unlock(parent);
952 	if (r) {
953 		pr_debug("failed %d to split range by granularity\n", r);
954 		goto out_unlock_prange;
955 	}
956 
957 	r = svm_migrate_vram_to_ram(prange, vmf->vma->vm_mm,
958 				    KFD_MIGRATE_TRIGGER_PAGEFAULT_CPU,
959 				    vmf->page);
960 	if (r)
961 		pr_debug("failed %d migrate svms 0x%p range 0x%p [0x%lx 0x%lx]\n",
962 			 r, prange->svms, prange, prange->start, prange->last);
963 
964 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
965 	if (p->xnack_enabled && parent == prange)
966 		op = SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP;
967 	else
968 		op = SVM_OP_UPDATE_RANGE_NOTIFIER;
969 	svm_range_add_list_work(&p->svms, parent, mm, op);
970 	schedule_deferred_list_work(&p->svms);
971 
972 out_unlock_prange:
973 	if (prange != parent)
974 		mutex_unlock(&prange->migrate_mutex);
975 	mutex_unlock(&parent->migrate_mutex);
976 out_unlock_svms:
977 	mutex_unlock(&p->svms.lock);
978 out_unref_process:
979 	pr_debug("CPU fault svms 0x%p address 0x%lx done\n", &p->svms, addr);
980 	kfd_unref_process(p);
981 out_mmput:
982 	mmput(mm);
983 	return r ? VM_FAULT_SIGBUS : 0;
984 }
985 
986 static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
987 	.page_free		= svm_migrate_page_free,
988 	.migrate_to_ram		= svm_migrate_to_ram,
989 };
990 
991 /* Each VRAM page uses sizeof(struct page) on system memory */
992 #define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
993 
994 int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
995 {
996 	struct amdgpu_kfd_dev *kfddev = &adev->kfd;
997 	struct dev_pagemap *pgmap;
998 	struct resource *res = NULL;
999 	unsigned long size;
1000 	void *r;
1001 
1002 	/* Page migration works on gfx9 or newer */
1003 	if (adev->ip_versions[GC_HWIP][0] < IP_VERSION(9, 0, 1))
1004 		return -EINVAL;
1005 
1006 	if (adev->gmc.is_app_apu)
1007 		return 0;
1008 
1009 	pgmap = &kfddev->pgmap;
1010 	memset(pgmap, 0, sizeof(*pgmap));
1011 
1012 	/* TODO: register all vram to HMM for now.
1013 	 * should remove reserved size
1014 	 */
1015 	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
1016 	if (adev->gmc.xgmi.connected_to_cpu) {
1017 		pgmap->range.start = adev->gmc.aper_base;
1018 		pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
1019 		pgmap->type = MEMORY_DEVICE_COHERENT;
1020 	} else {
1021 		res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
1022 		if (IS_ERR(res))
1023 			return -ENOMEM;
1024 		pgmap->range.start = res->start;
1025 		pgmap->range.end = res->end;
1026 		pgmap->type = MEMORY_DEVICE_PRIVATE;
1027 	}
1028 
1029 	pgmap->nr_range = 1;
1030 	pgmap->ops = &svm_migrate_pgmap_ops;
1031 	pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
1032 	pgmap->flags = 0;
1033 	/* Device manager releases device-specific resources, memory region and
1034 	 * pgmap when driver disconnects from device.
1035 	 */
1036 	r = devm_memremap_pages(adev->dev, pgmap);
1037 	if (IS_ERR(r)) {
1038 		pr_err("failed to register HMM device memory\n");
1039 		/* Disable SVM support capability */
1040 		pgmap->type = 0;
1041 		if (pgmap->type == MEMORY_DEVICE_PRIVATE)
1042 			devm_release_mem_region(adev->dev, res->start, resource_size(res));
1043 		return PTR_ERR(r);
1044 	}
1045 
1046 	pr_debug("reserve %ldMB system memory for VRAM pages struct\n",
1047 		 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);
1048 
1049 	amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));
1050 
1051 	pr_info("HMM registered %ldMB device memory\n", size >> 20);
1052 
1053 	return 0;
1054 }
1055