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 "amdgpu_sync.h"
28 #include "amdgpu_object.h"
29 #include "amdgpu_vm.h"
30 #include "amdgpu_mn.h"
31 #include "amdgpu_res_cursor.h"
32 #include "kfd_priv.h"
33 #include "kfd_svm.h"
34 #include "kfd_migrate.h"
35 
36 #ifdef dev_fmt
37 #undef dev_fmt
38 #endif
39 #define dev_fmt(fmt) "kfd_migrate: %s: " fmt, __func__
40 
41 static uint64_t
42 svm_migrate_direct_mapping_addr(struct amdgpu_device *adev, uint64_t addr)
43 {
44 	return addr + amdgpu_ttm_domain_start(adev, TTM_PL_VRAM);
45 }
46 
47 static int
48 svm_migrate_gart_map(struct amdgpu_ring *ring, uint64_t npages,
49 		     dma_addr_t *addr, uint64_t *gart_addr, uint64_t flags)
50 {
51 	struct amdgpu_device *adev = ring->adev;
52 	struct amdgpu_job *job;
53 	unsigned int num_dw, num_bytes;
54 	struct dma_fence *fence;
55 	uint64_t src_addr, dst_addr;
56 	uint64_t pte_flags;
57 	void *cpu_addr;
58 	int r;
59 
60 	/* use gart window 0 */
61 	*gart_addr = adev->gmc.gart_start;
62 
63 	num_dw = ALIGN(adev->mman.buffer_funcs->copy_num_dw, 8);
64 	num_bytes = npages * 8;
65 
66 	r = amdgpu_job_alloc_with_ib(adev, num_dw * 4 + num_bytes,
67 				     AMDGPU_IB_POOL_DELAYED, &job);
68 	if (r)
69 		return r;
70 
71 	src_addr = num_dw * 4;
72 	src_addr += job->ibs[0].gpu_addr;
73 
74 	dst_addr = amdgpu_bo_gpu_offset(adev->gart.bo);
75 	amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr,
76 				dst_addr, num_bytes, false);
77 
78 	amdgpu_ring_pad_ib(ring, &job->ibs[0]);
79 	WARN_ON(job->ibs[0].length_dw > num_dw);
80 
81 	pte_flags = AMDGPU_PTE_VALID | AMDGPU_PTE_READABLE;
82 	pte_flags |= AMDGPU_PTE_SYSTEM | AMDGPU_PTE_SNOOPED;
83 	if (!(flags & KFD_IOCTL_SVM_FLAG_GPU_RO))
84 		pte_flags |= AMDGPU_PTE_WRITEABLE;
85 	pte_flags |= adev->gart.gart_pte_flags;
86 
87 	cpu_addr = &job->ibs[0].ptr[num_dw];
88 
89 	amdgpu_gart_map(adev, 0, npages, addr, pte_flags, cpu_addr);
90 	r = amdgpu_job_submit(job, &adev->mman.entity,
91 			      AMDGPU_FENCE_OWNER_UNDEFINED, &fence);
92 	if (r)
93 		goto error_free;
94 
95 	dma_fence_put(fence);
96 
97 	return r;
98 
99 error_free:
100 	amdgpu_job_free(job);
101 	return r;
102 }
103 
104 /**
105  * svm_migrate_copy_memory_gart - sdma copy data between ram and vram
106  *
107  * @adev: amdgpu device the sdma ring running
108  * @sys: system DMA pointer to be copied
109  * @vram: vram destination DMA pointer
110  * @npages: number of pages to copy
111  * @direction: enum MIGRATION_COPY_DIR
112  * @mfence: output, sdma fence to signal after sdma is done
113  *
114  * ram address uses GART table continuous entries mapping to ram pages,
115  * vram address uses direct mapping of vram pages, which must have npages
116  * number of continuous pages.
117  * GART update and sdma uses same buf copy function ring, sdma is splited to
118  * multiple GTT_MAX_PAGES transfer, all sdma operations are serialized, wait for
119  * the last sdma finish fence which is returned to check copy memory is done.
120  *
121  * Context: Process context, takes and releases gtt_window_lock
122  *
123  * Return:
124  * 0 - OK, otherwise error code
125  */
126 
127 static int
128 svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys,
129 			     uint64_t *vram, uint64_t npages,
130 			     enum MIGRATION_COPY_DIR direction,
131 			     struct dma_fence **mfence)
132 {
133 	const uint64_t GTT_MAX_PAGES = AMDGPU_GTT_MAX_TRANSFER_SIZE;
134 	struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
135 	uint64_t gart_s, gart_d;
136 	struct dma_fence *next;
137 	uint64_t size;
138 	int r;
139 
140 	mutex_lock(&adev->mman.gtt_window_lock);
141 
142 	while (npages) {
143 		size = min(GTT_MAX_PAGES, npages);
144 
145 		if (direction == FROM_VRAM_TO_RAM) {
146 			gart_s = svm_migrate_direct_mapping_addr(adev, *vram);
147 			r = svm_migrate_gart_map(ring, size, sys, &gart_d, 0);
148 
149 		} else if (direction == FROM_RAM_TO_VRAM) {
150 			r = svm_migrate_gart_map(ring, size, sys, &gart_s,
151 						 KFD_IOCTL_SVM_FLAG_GPU_RO);
152 			gart_d = svm_migrate_direct_mapping_addr(adev, *vram);
153 		}
154 		if (r) {
155 			dev_err(adev->dev, "fail %d create gart mapping\n", r);
156 			goto out_unlock;
157 		}
158 
159 		r = amdgpu_copy_buffer(ring, gart_s, gart_d, size * PAGE_SIZE,
160 				       NULL, &next, false, true, false);
161 		if (r) {
162 			dev_err(adev->dev, "fail %d to copy memory\n", r);
163 			goto out_unlock;
164 		}
165 
166 		dma_fence_put(*mfence);
167 		*mfence = next;
168 		npages -= size;
169 		if (npages) {
170 			sys += size;
171 			vram += size;
172 		}
173 	}
174 
175 out_unlock:
176 	mutex_unlock(&adev->mman.gtt_window_lock);
177 
178 	return r;
179 }
180 
181 /**
182  * svm_migrate_copy_done - wait for memory copy sdma is done
183  *
184  * @adev: amdgpu device the sdma memory copy is executing on
185  * @mfence: migrate fence
186  *
187  * Wait for dma fence is signaled, if the copy ssplit into multiple sdma
188  * operations, this is the last sdma operation fence.
189  *
190  * Context: called after svm_migrate_copy_memory
191  *
192  * Return:
193  * 0		- success
194  * otherwise	- error code from dma fence signal
195  */
196 static int
197 svm_migrate_copy_done(struct amdgpu_device *adev, struct dma_fence *mfence)
198 {
199 	int r = 0;
200 
201 	if (mfence) {
202 		r = dma_fence_wait(mfence, false);
203 		dma_fence_put(mfence);
204 		pr_debug("sdma copy memory fence done\n");
205 	}
206 
207 	return r;
208 }
209 
210 unsigned long
211 svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr)
212 {
213 	return (addr + adev->kfd.dev->pgmap.range.start) >> PAGE_SHIFT;
214 }
215 
216 static void
217 svm_migrate_get_vram_page(struct svm_range *prange, unsigned long pfn)
218 {
219 	struct page *page;
220 
221 	page = pfn_to_page(pfn);
222 	svm_range_bo_ref(prange->svm_bo);
223 	page->zone_device_data = prange->svm_bo;
224 	get_page(page);
225 	lock_page(page);
226 }
227 
228 static void
229 svm_migrate_put_vram_page(struct amdgpu_device *adev, unsigned long addr)
230 {
231 	struct page *page;
232 
233 	page = pfn_to_page(svm_migrate_addr_to_pfn(adev, addr));
234 	unlock_page(page);
235 	put_page(page);
236 }
237 
238 static unsigned long
239 svm_migrate_addr(struct amdgpu_device *adev, struct page *page)
240 {
241 	unsigned long addr;
242 
243 	addr = page_to_pfn(page) << PAGE_SHIFT;
244 	return (addr - adev->kfd.dev->pgmap.range.start);
245 }
246 
247 static struct page *
248 svm_migrate_get_sys_page(struct vm_area_struct *vma, unsigned long addr)
249 {
250 	struct page *page;
251 
252 	page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
253 	if (page)
254 		lock_page(page);
255 
256 	return page;
257 }
258 
259 static void svm_migrate_put_sys_page(unsigned long addr)
260 {
261 	struct page *page;
262 
263 	page = pfn_to_page(addr >> PAGE_SHIFT);
264 	unlock_page(page);
265 	put_page(page);
266 }
267 
268 static unsigned long svm_migrate_successful_pages(struct migrate_vma *migrate)
269 {
270 	unsigned long cpages = 0;
271 	unsigned long i;
272 
273 	for (i = 0; i < migrate->npages; i++) {
274 		if (migrate->src[i] & MIGRATE_PFN_VALID &&
275 		    migrate->src[i] & MIGRATE_PFN_MIGRATE)
276 			cpages++;
277 	}
278 	return cpages;
279 }
280 
281 static unsigned long svm_migrate_unsuccessful_pages(struct migrate_vma *migrate)
282 {
283 	unsigned long upages = 0;
284 	unsigned long i;
285 
286 	for (i = 0; i < migrate->npages; i++) {
287 		if (migrate->src[i] & MIGRATE_PFN_VALID &&
288 		    !(migrate->src[i] & MIGRATE_PFN_MIGRATE))
289 			upages++;
290 	}
291 	return upages;
292 }
293 
294 static int
295 svm_migrate_copy_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
296 			 struct migrate_vma *migrate, struct dma_fence **mfence,
297 			 dma_addr_t *scratch)
298 {
299 	uint64_t npages = migrate->cpages;
300 	struct device *dev = adev->dev;
301 	struct amdgpu_res_cursor cursor;
302 	dma_addr_t *src;
303 	uint64_t *dst;
304 	uint64_t i, j;
305 	int r;
306 
307 	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
308 		 prange->last);
309 
310 	src = scratch;
311 	dst = (uint64_t *)(scratch + npages);
312 
313 	r = svm_range_vram_node_new(adev, prange, true);
314 	if (r) {
315 		dev_err(adev->dev, "fail %d to alloc vram\n", r);
316 		goto out;
317 	}
318 
319 	amdgpu_res_first(prange->ttm_res, prange->offset << PAGE_SHIFT,
320 			 npages << PAGE_SHIFT, &cursor);
321 	for (i = j = 0; i < npages; i++) {
322 		struct page *spage;
323 
324 		spage = migrate_pfn_to_page(migrate->src[i]);
325 		if (spage && !is_zone_device_page(spage)) {
326 			dst[i] = cursor.start + (j << PAGE_SHIFT);
327 			migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
328 			svm_migrate_get_vram_page(prange, migrate->dst[i]);
329 			migrate->dst[i] = migrate_pfn(migrate->dst[i]);
330 			src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
331 					      DMA_TO_DEVICE);
332 			r = dma_mapping_error(dev, src[i]);
333 			if (r) {
334 				dev_err(adev->dev, "fail %d dma_map_page\n", r);
335 				goto out_free_vram_pages;
336 			}
337 		} else {
338 			if (j) {
339 				r = svm_migrate_copy_memory_gart(
340 						adev, src + i - j,
341 						dst + i - j, j,
342 						FROM_RAM_TO_VRAM,
343 						mfence);
344 				if (r)
345 					goto out_free_vram_pages;
346 				amdgpu_res_next(&cursor, j << PAGE_SHIFT);
347 				j = 0;
348 			} else {
349 				amdgpu_res_next(&cursor, PAGE_SIZE);
350 			}
351 			continue;
352 		}
353 
354 		pr_debug_ratelimited("dma mapping src to 0x%llx, pfn 0x%lx\n",
355 				     src[i] >> PAGE_SHIFT, page_to_pfn(spage));
356 
357 		if (j >= (cursor.size >> PAGE_SHIFT) - 1 && i < npages - 1) {
358 			r = svm_migrate_copy_memory_gart(adev, src + i - j,
359 							 dst + i - j, j + 1,
360 							 FROM_RAM_TO_VRAM,
361 							 mfence);
362 			if (r)
363 				goto out_free_vram_pages;
364 			amdgpu_res_next(&cursor, (j + 1) * PAGE_SIZE);
365 			j= 0;
366 		} else {
367 			j++;
368 		}
369 	}
370 
371 	r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,
372 					 FROM_RAM_TO_VRAM, mfence);
373 
374 out_free_vram_pages:
375 	if (r) {
376 		pr_debug("failed %d to copy memory to vram\n", r);
377 		while (i--) {
378 			svm_migrate_put_vram_page(adev, dst[i]);
379 			migrate->dst[i] = 0;
380 		}
381 	}
382 
383 #ifdef DEBUG_FORCE_MIXED_DOMAINS
384 	for (i = 0, j = 0; i < npages; i += 4, j++) {
385 		if (j & 1)
386 			continue;
387 		svm_migrate_put_vram_page(adev, dst[i]);
388 		migrate->dst[i] = 0;
389 		svm_migrate_put_vram_page(adev, dst[i + 1]);
390 		migrate->dst[i + 1] = 0;
391 		svm_migrate_put_vram_page(adev, dst[i + 2]);
392 		migrate->dst[i + 2] = 0;
393 		svm_migrate_put_vram_page(adev, dst[i + 3]);
394 		migrate->dst[i + 3] = 0;
395 	}
396 #endif
397 out:
398 	return r;
399 }
400 
401 static long
402 svm_migrate_vma_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
403 			struct vm_area_struct *vma, uint64_t start,
404 			uint64_t end)
405 {
406 	uint64_t npages = (end - start) >> PAGE_SHIFT;
407 	struct kfd_process_device *pdd;
408 	struct dma_fence *mfence = NULL;
409 	struct migrate_vma migrate;
410 	unsigned long cpages = 0;
411 	dma_addr_t *scratch;
412 	size_t size;
413 	void *buf;
414 	int r = -ENOMEM;
415 
416 	memset(&migrate, 0, sizeof(migrate));
417 	migrate.vma = vma;
418 	migrate.start = start;
419 	migrate.end = end;
420 	migrate.flags = MIGRATE_VMA_SELECT_SYSTEM;
421 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
422 
423 	size = 2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t);
424 	size *= npages;
425 	buf = kvmalloc(size, GFP_KERNEL | __GFP_ZERO);
426 	if (!buf)
427 		goto out;
428 
429 	migrate.src = buf;
430 	migrate.dst = migrate.src + npages;
431 	scratch = (dma_addr_t *)(migrate.dst + npages);
432 
433 	r = migrate_vma_setup(&migrate);
434 	if (r) {
435 		dev_err(adev->dev, "vma setup fail %d range [0x%lx 0x%lx]\n", r,
436 			prange->start, prange->last);
437 		goto out_free;
438 	}
439 
440 	cpages = migrate.cpages;
441 	if (!cpages) {
442 		pr_debug("failed collect migrate sys pages [0x%lx 0x%lx]\n",
443 			 prange->start, prange->last);
444 		goto out_free;
445 	}
446 	if (cpages != npages)
447 		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
448 			 cpages, npages);
449 	else
450 		pr_debug("0x%lx pages migrated\n", cpages);
451 
452 	r = svm_migrate_copy_to_vram(adev, prange, &migrate, &mfence, scratch);
453 	migrate_vma_pages(&migrate);
454 
455 	pr_debug("successful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
456 		svm_migrate_successful_pages(&migrate), cpages, migrate.npages);
457 
458 	svm_migrate_copy_done(adev, mfence);
459 	migrate_vma_finalize(&migrate);
460 
461 	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
462 	svm_range_free_dma_mappings(prange);
463 
464 out_free:
465 	kvfree(buf);
466 out:
467 	if (!r && cpages) {
468 		pdd = svm_range_get_pdd_by_adev(prange, adev);
469 		if (pdd)
470 			WRITE_ONCE(pdd->page_in, pdd->page_in + cpages);
471 
472 		return cpages;
473 	}
474 	return r;
475 }
476 
477 /**
478  * svm_migrate_ram_to_vram - migrate svm range from system to device
479  * @prange: range structure
480  * @best_loc: the device to migrate to
481  * @mm: the process mm structure
482  *
483  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
484  *
485  * Return:
486  * 0 - OK, otherwise error code
487  */
488 static int
489 svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
490 			struct mm_struct *mm)
491 {
492 	unsigned long addr, start, end;
493 	struct vm_area_struct *vma;
494 	struct amdgpu_device *adev;
495 	unsigned long cpages = 0;
496 	long r = 0;
497 
498 	if (prange->actual_loc == best_loc) {
499 		pr_debug("svms 0x%p [0x%lx 0x%lx] already on best_loc 0x%x\n",
500 			 prange->svms, prange->start, prange->last, best_loc);
501 		return 0;
502 	}
503 
504 	adev = svm_range_get_adev_by_id(prange, best_loc);
505 	if (!adev) {
506 		pr_debug("failed to get device by id 0x%x\n", best_loc);
507 		return -ENODEV;
508 	}
509 
510 	pr_debug("svms 0x%p [0x%lx 0x%lx] to gpu 0x%x\n", prange->svms,
511 		 prange->start, prange->last, best_loc);
512 
513 	/* FIXME: workaround for page locking bug with invalid pages */
514 	svm_range_prefault(prange, mm, SVM_ADEV_PGMAP_OWNER(adev));
515 
516 	start = prange->start << PAGE_SHIFT;
517 	end = (prange->last + 1) << PAGE_SHIFT;
518 
519 	for (addr = start; addr < end;) {
520 		unsigned long next;
521 
522 		vma = find_vma(mm, addr);
523 		if (!vma || addr < vma->vm_start)
524 			break;
525 
526 		next = min(vma->vm_end, end);
527 		r = svm_migrate_vma_to_vram(adev, prange, vma, addr, next);
528 		if (r < 0) {
529 			pr_debug("failed %ld to migrate\n", r);
530 			break;
531 		} else {
532 			cpages += r;
533 		}
534 		addr = next;
535 	}
536 
537 	if (cpages)
538 		prange->actual_loc = best_loc;
539 
540 	return r < 0 ? r : 0;
541 }
542 
543 static void svm_migrate_page_free(struct page *page)
544 {
545 	struct svm_range_bo *svm_bo = page->zone_device_data;
546 
547 	if (svm_bo) {
548 		pr_debug_ratelimited("ref: %d\n", kref_read(&svm_bo->kref));
549 		svm_range_bo_unref_async(svm_bo);
550 	}
551 }
552 
553 static int
554 svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
555 			struct migrate_vma *migrate, struct dma_fence **mfence,
556 			dma_addr_t *scratch, uint64_t npages)
557 {
558 	struct device *dev = adev->dev;
559 	uint64_t *src;
560 	dma_addr_t *dst;
561 	struct page *dpage;
562 	uint64_t i = 0, j;
563 	uint64_t addr;
564 	int r = 0;
565 
566 	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
567 		 prange->last);
568 
569 	addr = prange->start << PAGE_SHIFT;
570 
571 	src = (uint64_t *)(scratch + npages);
572 	dst = scratch;
573 
574 	for (i = 0, j = 0; i < npages; i++, addr += PAGE_SIZE) {
575 		struct page *spage;
576 
577 		spage = migrate_pfn_to_page(migrate->src[i]);
578 		if (!spage || !is_zone_device_page(spage)) {
579 			pr_debug("invalid page. Could be in CPU already svms 0x%p [0x%lx 0x%lx]\n",
580 				 prange->svms, prange->start, prange->last);
581 			if (j) {
582 				r = svm_migrate_copy_memory_gart(adev, dst + i - j,
583 								 src + i - j, j,
584 								 FROM_VRAM_TO_RAM,
585 								 mfence);
586 				if (r)
587 					goto out_oom;
588 				j = 0;
589 			}
590 			continue;
591 		}
592 		src[i] = svm_migrate_addr(adev, spage);
593 		if (i > 0 && src[i] != src[i - 1] + PAGE_SIZE) {
594 			r = svm_migrate_copy_memory_gart(adev, dst + i - j,
595 							 src + i - j, j,
596 							 FROM_VRAM_TO_RAM,
597 							 mfence);
598 			if (r)
599 				goto out_oom;
600 			j = 0;
601 		}
602 
603 		dpage = svm_migrate_get_sys_page(migrate->vma, addr);
604 		if (!dpage) {
605 			pr_debug("failed get page svms 0x%p [0x%lx 0x%lx]\n",
606 				 prange->svms, prange->start, prange->last);
607 			r = -ENOMEM;
608 			goto out_oom;
609 		}
610 
611 		dst[i] = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_FROM_DEVICE);
612 		r = dma_mapping_error(dev, dst[i]);
613 		if (r) {
614 			dev_err(adev->dev, "fail %d dma_map_page\n", r);
615 			goto out_oom;
616 		}
617 
618 		pr_debug_ratelimited("dma mapping dst to 0x%llx, pfn 0x%lx\n",
619 				     dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
620 
621 		migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
622 		j++;
623 	}
624 
625 	r = svm_migrate_copy_memory_gart(adev, dst + i - j, src + i - j, j,
626 					 FROM_VRAM_TO_RAM, mfence);
627 
628 out_oom:
629 	if (r) {
630 		pr_debug("failed %d copy to ram\n", r);
631 		while (i--) {
632 			svm_migrate_put_sys_page(dst[i]);
633 			migrate->dst[i] = 0;
634 		}
635 	}
636 
637 	return r;
638 }
639 
640 static long
641 svm_migrate_vma_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
642 		       struct vm_area_struct *vma, uint64_t start, uint64_t end)
643 {
644 	uint64_t npages = (end - start) >> PAGE_SHIFT;
645 	unsigned long upages = npages;
646 	unsigned long cpages = 0;
647 	struct kfd_process_device *pdd;
648 	struct dma_fence *mfence = NULL;
649 	struct migrate_vma migrate;
650 	dma_addr_t *scratch;
651 	size_t size;
652 	void *buf;
653 	int r = -ENOMEM;
654 
655 	memset(&migrate, 0, sizeof(migrate));
656 	migrate.vma = vma;
657 	migrate.start = start;
658 	migrate.end = end;
659 	migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
660 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
661 
662 	size = 2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t);
663 	size *= npages;
664 	buf = kvmalloc(size, GFP_KERNEL | __GFP_ZERO);
665 	if (!buf)
666 		goto out;
667 
668 	migrate.src = buf;
669 	migrate.dst = migrate.src + npages;
670 	scratch = (dma_addr_t *)(migrate.dst + npages);
671 
672 	r = migrate_vma_setup(&migrate);
673 	if (r) {
674 		dev_err(adev->dev, "vma setup fail %d range [0x%lx 0x%lx]\n", r,
675 			prange->start, prange->last);
676 		goto out_free;
677 	}
678 
679 	cpages = migrate.cpages;
680 	if (!cpages) {
681 		pr_debug("failed collect migrate device pages [0x%lx 0x%lx]\n",
682 			 prange->start, prange->last);
683 		upages = svm_migrate_unsuccessful_pages(&migrate);
684 		goto out_free;
685 	}
686 	if (cpages != npages)
687 		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
688 			 cpages, npages);
689 	else
690 		pr_debug("0x%lx pages migrated\n", cpages);
691 
692 	r = svm_migrate_copy_to_ram(adev, prange, &migrate, &mfence,
693 				    scratch, npages);
694 	migrate_vma_pages(&migrate);
695 
696 	upages = svm_migrate_unsuccessful_pages(&migrate);
697 	pr_debug("unsuccessful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
698 		 upages, cpages, migrate.npages);
699 
700 	svm_migrate_copy_done(adev, mfence);
701 	migrate_vma_finalize(&migrate);
702 	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
703 
704 out_free:
705 	kvfree(buf);
706 out:
707 	if (!r && cpages) {
708 		pdd = svm_range_get_pdd_by_adev(prange, adev);
709 		if (pdd)
710 			WRITE_ONCE(pdd->page_out, pdd->page_out + cpages);
711 
712 		return upages;
713 	}
714 	return r ? r : upages;
715 }
716 
717 /**
718  * svm_migrate_vram_to_ram - migrate svm range from device to system
719  * @prange: range structure
720  * @mm: process mm, use current->mm if NULL
721  *
722  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
723  *
724  * Return:
725  * 0 - OK, otherwise error code
726  */
727 int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm)
728 {
729 	struct amdgpu_device *adev;
730 	struct vm_area_struct *vma;
731 	unsigned long addr;
732 	unsigned long start;
733 	unsigned long end;
734 	unsigned long upages = 0;
735 	long r = 0;
736 
737 	if (!prange->actual_loc) {
738 		pr_debug("[0x%lx 0x%lx] already migrated to ram\n",
739 			 prange->start, prange->last);
740 		return 0;
741 	}
742 
743 	adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
744 	if (!adev) {
745 		pr_debug("failed to get device by id 0x%x\n",
746 			 prange->actual_loc);
747 		return -ENODEV;
748 	}
749 
750 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] from gpu 0x%x to ram\n",
751 		 prange->svms, prange, prange->start, prange->last,
752 		 prange->actual_loc);
753 
754 	start = prange->start << PAGE_SHIFT;
755 	end = (prange->last + 1) << PAGE_SHIFT;
756 
757 	for (addr = start; addr < end;) {
758 		unsigned long next;
759 
760 		vma = find_vma(mm, addr);
761 		if (!vma || addr < vma->vm_start)
762 			break;
763 
764 		next = min(vma->vm_end, end);
765 		r = svm_migrate_vma_to_ram(adev, prange, vma, addr, next);
766 		if (r < 0) {
767 			pr_debug("failed %ld to migrate\n", r);
768 			break;
769 		} else {
770 			upages += r;
771 		}
772 		addr = next;
773 	}
774 
775 	if (!upages) {
776 		svm_range_vram_node_free(prange);
777 		prange->actual_loc = 0;
778 	}
779 
780 	return r < 0 ? r : 0;
781 }
782 
783 /**
784  * svm_migrate_vram_to_vram - migrate svm range from device to device
785  * @prange: range structure
786  * @best_loc: the device to migrate to
787  * @mm: process mm, use current->mm if NULL
788  *
789  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
790  *
791  * Return:
792  * 0 - OK, otherwise error code
793  */
794 static int
795 svm_migrate_vram_to_vram(struct svm_range *prange, uint32_t best_loc,
796 			 struct mm_struct *mm)
797 {
798 	int r, retries = 3;
799 
800 	/*
801 	 * TODO: for both devices with PCIe large bar or on same xgmi hive, skip
802 	 * system memory as migration bridge
803 	 */
804 
805 	pr_debug("from gpu 0x%x to gpu 0x%x\n", prange->actual_loc, best_loc);
806 
807 	do {
808 		r = svm_migrate_vram_to_ram(prange, mm);
809 		if (r)
810 			return r;
811 	} while (prange->actual_loc && --retries);
812 
813 	if (prange->actual_loc)
814 		return -EDEADLK;
815 
816 	return svm_migrate_ram_to_vram(prange, best_loc, mm);
817 }
818 
819 int
820 svm_migrate_to_vram(struct svm_range *prange, uint32_t best_loc,
821 		    struct mm_struct *mm)
822 {
823 	if  (!prange->actual_loc)
824 		return svm_migrate_ram_to_vram(prange, best_loc, mm);
825 	else
826 		return svm_migrate_vram_to_vram(prange, best_loc, mm);
827 
828 }
829 
830 /**
831  * svm_migrate_to_ram - CPU page fault handler
832  * @vmf: CPU vm fault vma, address
833  *
834  * Context: vm fault handler, caller holds the mmap read lock
835  *
836  * Return:
837  * 0 - OK
838  * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
839  */
840 static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
841 {
842 	unsigned long addr = vmf->address;
843 	struct vm_area_struct *vma;
844 	enum svm_work_list_ops op;
845 	struct svm_range *parent;
846 	struct svm_range *prange;
847 	struct kfd_process *p;
848 	struct mm_struct *mm;
849 	int r = 0;
850 
851 	vma = vmf->vma;
852 	mm = vma->vm_mm;
853 
854 	p = kfd_lookup_process_by_mm(vma->vm_mm);
855 	if (!p) {
856 		pr_debug("failed find process at fault address 0x%lx\n", addr);
857 		return VM_FAULT_SIGBUS;
858 	}
859 	if (READ_ONCE(p->svms.faulting_task) == current) {
860 		pr_debug("skipping ram migration\n");
861 		kfd_unref_process(p);
862 		return 0;
863 	}
864 	addr >>= PAGE_SHIFT;
865 	pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr);
866 
867 	mutex_lock(&p->svms.lock);
868 
869 	prange = svm_range_from_addr(&p->svms, addr, &parent);
870 	if (!prange) {
871 		pr_debug("cannot find svm range at 0x%lx\n", addr);
872 		r = -EFAULT;
873 		goto out;
874 	}
875 
876 	mutex_lock(&parent->migrate_mutex);
877 	if (prange != parent)
878 		mutex_lock_nested(&prange->migrate_mutex, 1);
879 
880 	if (!prange->actual_loc)
881 		goto out_unlock_prange;
882 
883 	svm_range_lock(parent);
884 	if (prange != parent)
885 		mutex_lock_nested(&prange->lock, 1);
886 	r = svm_range_split_by_granularity(p, mm, addr, parent, prange);
887 	if (prange != parent)
888 		mutex_unlock(&prange->lock);
889 	svm_range_unlock(parent);
890 	if (r) {
891 		pr_debug("failed %d to split range by granularity\n", r);
892 		goto out_unlock_prange;
893 	}
894 
895 	r = svm_migrate_vram_to_ram(prange, mm);
896 	if (r)
897 		pr_debug("failed %d migrate 0x%p [0x%lx 0x%lx] to ram\n", r,
898 			 prange, prange->start, prange->last);
899 
900 	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
901 	if (p->xnack_enabled && parent == prange)
902 		op = SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP;
903 	else
904 		op = SVM_OP_UPDATE_RANGE_NOTIFIER;
905 	svm_range_add_list_work(&p->svms, parent, mm, op);
906 	schedule_deferred_list_work(&p->svms);
907 
908 out_unlock_prange:
909 	if (prange != parent)
910 		mutex_unlock(&prange->migrate_mutex);
911 	mutex_unlock(&parent->migrate_mutex);
912 out:
913 	mutex_unlock(&p->svms.lock);
914 	kfd_unref_process(p);
915 
916 	pr_debug("CPU fault svms 0x%p address 0x%lx done\n", &p->svms, addr);
917 
918 	return r ? VM_FAULT_SIGBUS : 0;
919 }
920 
921 static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
922 	.page_free		= svm_migrate_page_free,
923 	.migrate_to_ram		= svm_migrate_to_ram,
924 };
925 
926 /* Each VRAM page uses sizeof(struct page) on system memory */
927 #define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
928 
929 int svm_migrate_init(struct amdgpu_device *adev)
930 {
931 	struct kfd_dev *kfddev = adev->kfd.dev;
932 	struct dev_pagemap *pgmap;
933 	struct resource *res;
934 	unsigned long size;
935 	void *r;
936 
937 	/* Page migration works on Vega10 or newer */
938 	if (!KFD_IS_SOC15(kfddev))
939 		return -EINVAL;
940 
941 	pgmap = &kfddev->pgmap;
942 	memset(pgmap, 0, sizeof(*pgmap));
943 
944 	/* TODO: register all vram to HMM for now.
945 	 * should remove reserved size
946 	 */
947 	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
948 	res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
949 	if (IS_ERR(res))
950 		return -ENOMEM;
951 
952 	pgmap->type = MEMORY_DEVICE_PRIVATE;
953 	pgmap->nr_range = 1;
954 	pgmap->range.start = res->start;
955 	pgmap->range.end = res->end;
956 	pgmap->ops = &svm_migrate_pgmap_ops;
957 	pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
958 	pgmap->flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
959 
960 	/* Device manager releases device-specific resources, memory region and
961 	 * pgmap when driver disconnects from device.
962 	 */
963 	r = devm_memremap_pages(adev->dev, pgmap);
964 	if (IS_ERR(r)) {
965 		pr_err("failed to register HMM device memory\n");
966 
967 		/* Disable SVM support capability */
968 		pgmap->type = 0;
969 		devm_release_mem_region(adev->dev, res->start, resource_size(res));
970 		return PTR_ERR(r);
971 	}
972 
973 	pr_debug("reserve %ldMB system memory for VRAM pages struct\n",
974 		 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);
975 
976 	amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));
977 
978 	pr_info("HMM registered %ldMB device memory\n", size >> 20);
979 
980 	return 0;
981 }
982