xref: /linux/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c (revision 6f17ab9a63e670bd62a287f95e3982f99eafd77e)
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 				     AMDGPU_KERNEL_JOB_ID_KFD_GART_MAP);
73 	if (r)
74 		return r;
75 
76 	src_addr = num_dw * 4;
77 	src_addr += job->ibs[0].gpu_addr;
78 
79 	dst_addr = amdgpu_bo_gpu_offset(adev->gart.bo);
80 	amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr,
81 				dst_addr, num_bytes, 0);
82 
83 	amdgpu_ring_pad_ib(ring, &job->ibs[0]);
84 	WARN_ON(job->ibs[0].length_dw > num_dw);
85 
86 	pte_flags = AMDGPU_PTE_VALID | AMDGPU_PTE_READABLE;
87 	pte_flags |= AMDGPU_PTE_SYSTEM | AMDGPU_PTE_SNOOPED;
88 	if (!(flags & KFD_IOCTL_SVM_FLAG_GPU_RO))
89 		pte_flags |= AMDGPU_PTE_WRITEABLE;
90 	pte_flags |= adev->gart.gart_pte_flags;
91 
92 	cpu_addr = &job->ibs[0].ptr[num_dw];
93 
94 	amdgpu_gart_map(adev, 0, npages, addr, pte_flags, cpu_addr);
95 	fence = amdgpu_job_submit(job);
96 	dma_fence_put(fence);
97 
98 	return r;
99 }
100 
101 /**
102  * svm_migrate_copy_memory_gart - sdma copy data between ram and vram
103  *
104  * @adev: amdgpu device the sdma ring running
105  * @sys: system DMA pointer to be copied
106  * @vram: vram destination DMA pointer
107  * @npages: number of pages to copy
108  * @direction: enum MIGRATION_COPY_DIR
109  * @mfence: output, sdma fence to signal after sdma is done
110  *
111  * ram address uses GART table continuous entries mapping to ram pages,
112  * vram address uses direct mapping of vram pages, which must have npages
113  * number of continuous pages.
114  * GART update and sdma uses same buf copy function ring, sdma is splited to
115  * multiple GTT_MAX_PAGES transfer, all sdma operations are serialized, wait for
116  * the last sdma finish fence which is returned to check copy memory is done.
117  *
118  * Context: Process context, takes and releases gtt_window_lock
119  *
120  * Return:
121  * 0 - OK, otherwise error code
122  */
123 
124 static int
125 svm_migrate_copy_memory_gart(struct amdgpu_device *adev, dma_addr_t *sys,
126 			     uint64_t *vram, uint64_t npages,
127 			     enum MIGRATION_COPY_DIR direction,
128 			     struct dma_fence **mfence)
129 {
130 	const uint64_t GTT_MAX_PAGES = AMDGPU_GTT_MAX_TRANSFER_SIZE;
131 	struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
132 	uint64_t gart_s, gart_d;
133 	struct dma_fence *next;
134 	uint64_t size;
135 	int r;
136 
137 	mutex_lock(&adev->mman.gtt_window_lock);
138 
139 	while (npages) {
140 		size = min(GTT_MAX_PAGES, npages);
141 
142 		if (direction == FROM_VRAM_TO_RAM) {
143 			gart_s = svm_migrate_direct_mapping_addr(adev, *vram);
144 			r = svm_migrate_gart_map(ring, size, sys, &gart_d, 0);
145 
146 		} else if (direction == FROM_RAM_TO_VRAM) {
147 			r = svm_migrate_gart_map(ring, size, sys, &gart_s,
148 						 KFD_IOCTL_SVM_FLAG_GPU_RO);
149 			gart_d = svm_migrate_direct_mapping_addr(adev, *vram);
150 		}
151 		if (r) {
152 			dev_err(adev->dev, "fail %d create gart mapping\n", r);
153 			goto out_unlock;
154 		}
155 
156 		r = amdgpu_copy_buffer(ring, gart_s, gart_d, size * PAGE_SIZE,
157 				       NULL, &next, false, true, 0);
158 		if (r) {
159 			dev_err(adev->dev, "fail %d to copy memory\n", r);
160 			goto out_unlock;
161 		}
162 
163 		dma_fence_put(*mfence);
164 		*mfence = next;
165 		npages -= size;
166 		if (npages) {
167 			sys += size;
168 			vram += size;
169 		}
170 	}
171 
172 out_unlock:
173 	mutex_unlock(&adev->mman.gtt_window_lock);
174 
175 	return r;
176 }
177 
178 /**
179  * svm_migrate_copy_done - wait for memory copy sdma is done
180  *
181  * @adev: amdgpu device the sdma memory copy is executing on
182  * @mfence: migrate fence
183  *
184  * Wait for dma fence is signaled, if the copy ssplit into multiple sdma
185  * operations, this is the last sdma operation fence.
186  *
187  * Context: called after svm_migrate_copy_memory
188  *
189  * Return:
190  * 0		- success
191  * otherwise	- error code from dma fence signal
192  */
193 static int
194 svm_migrate_copy_done(struct amdgpu_device *adev, struct dma_fence *mfence)
195 {
196 	int r = 0;
197 
198 	if (mfence) {
199 		r = dma_fence_wait(mfence, false);
200 		dma_fence_put(mfence);
201 		pr_debug("sdma copy memory fence done\n");
202 	}
203 
204 	return r;
205 }
206 
207 unsigned long
208 svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr)
209 {
210 	return (addr + adev->kfd.pgmap.range.start) >> PAGE_SHIFT;
211 }
212 
213 static void
214 svm_migrate_get_vram_page(struct svm_range *prange, unsigned long pfn)
215 {
216 	struct page *page;
217 
218 	page = pfn_to_page(pfn);
219 	svm_range_bo_ref(prange->svm_bo);
220 	page->zone_device_data = prange->svm_bo;
221 	zone_device_page_init(page);
222 }
223 
224 static void
225 svm_migrate_put_vram_page(struct amdgpu_device *adev, unsigned long addr)
226 {
227 	struct page *page;
228 
229 	page = pfn_to_page(svm_migrate_addr_to_pfn(adev, addr));
230 	unlock_page(page);
231 	put_page(page);
232 }
233 
234 static unsigned long
235 svm_migrate_addr(struct amdgpu_device *adev, struct page *page)
236 {
237 	unsigned long addr;
238 
239 	addr = page_to_pfn(page) << PAGE_SHIFT;
240 	return (addr - adev->kfd.pgmap.range.start);
241 }
242 
243 static struct page *
244 svm_migrate_get_sys_page(struct vm_area_struct *vma, unsigned long addr)
245 {
246 	struct page *page;
247 
248 	page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
249 	if (page)
250 		lock_page(page);
251 
252 	return page;
253 }
254 
255 static void svm_migrate_put_sys_page(unsigned long addr)
256 {
257 	struct page *page;
258 
259 	page = pfn_to_page(addr >> PAGE_SHIFT);
260 	unlock_page(page);
261 	put_page(page);
262 }
263 
264 static long
265 svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,
266 			 struct migrate_vma *migrate, struct dma_fence **mfence,
267 			 dma_addr_t *scratch, uint64_t ttm_res_offset)
268 {
269 	uint64_t npages = migrate->npages;
270 	struct amdgpu_device *adev = node->adev;
271 	struct device *dev = adev->dev;
272 	struct amdgpu_res_cursor cursor;
273 	long mpages;
274 	dma_addr_t *src;
275 	uint64_t *dst;
276 	uint64_t i, j;
277 	int r;
278 
279 	pr_debug("svms 0x%p [0x%lx 0x%lx 0x%llx]\n", prange->svms, prange->start,
280 		 prange->last, ttm_res_offset);
281 
282 	src = scratch;
283 	dst = (uint64_t *)(scratch + npages);
284 
285 	amdgpu_res_first(prange->ttm_res, ttm_res_offset,
286 			 npages << PAGE_SHIFT, &cursor);
287 	mpages = 0;
288 	for (i = j = 0; (i < npages) && (mpages < migrate->cpages); i++) {
289 		struct page *spage;
290 
291 		if (migrate->src[i] & MIGRATE_PFN_MIGRATE) {
292 			dst[i] = cursor.start + (j << PAGE_SHIFT);
293 			migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
294 			svm_migrate_get_vram_page(prange, migrate->dst[i]);
295 			migrate->dst[i] = migrate_pfn(migrate->dst[i]);
296 			mpages++;
297 		}
298 		spage = migrate_pfn_to_page(migrate->src[i]);
299 		if (spage && !is_zone_device_page(spage)) {
300 			src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
301 					      DMA_BIDIRECTIONAL);
302 			r = dma_mapping_error(dev, src[i]);
303 			if (r) {
304 				dev_err(dev, "%s: fail %d dma_map_page\n",
305 					__func__, r);
306 				goto out_free_vram_pages;
307 			}
308 		} else {
309 			if (j) {
310 				r = svm_migrate_copy_memory_gart(
311 						adev, src + i - j,
312 						dst + i - j, j,
313 						FROM_RAM_TO_VRAM,
314 						mfence);
315 				if (r)
316 					goto out_free_vram_pages;
317 				amdgpu_res_next(&cursor, (j + 1) << PAGE_SHIFT);
318 				j = 0;
319 			} else {
320 				amdgpu_res_next(&cursor, PAGE_SIZE);
321 			}
322 			continue;
323 		}
324 
325 		pr_debug_ratelimited("dma mapping src to 0x%llx, pfn 0x%lx\n",
326 				     src[i] >> PAGE_SHIFT, page_to_pfn(spage));
327 
328 		if (j >= (cursor.size >> PAGE_SHIFT) - 1 && i < npages - 1) {
329 			r = svm_migrate_copy_memory_gart(adev, src + i - j,
330 							 dst + i - j, j + 1,
331 							 FROM_RAM_TO_VRAM,
332 							 mfence);
333 			if (r)
334 				goto out_free_vram_pages;
335 			amdgpu_res_next(&cursor, (j + 1) * PAGE_SIZE);
336 			j = 0;
337 		} else {
338 			j++;
339 		}
340 	}
341 
342 	r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,
343 					 FROM_RAM_TO_VRAM, mfence);
344 
345 out_free_vram_pages:
346 	if (r) {
347 		pr_debug("failed %d to copy memory to vram\n", r);
348 		while (i-- && mpages) {
349 			if (!dst[i])
350 				continue;
351 			svm_migrate_put_vram_page(adev, dst[i]);
352 			migrate->dst[i] = 0;
353 			mpages--;
354 		}
355 		mpages = r;
356 	}
357 
358 #ifdef DEBUG_FORCE_MIXED_DOMAINS
359 	for (i = 0, j = 0; i < npages; i += 4, j++) {
360 		if (j & 1)
361 			continue;
362 		svm_migrate_put_vram_page(adev, dst[i]);
363 		migrate->dst[i] = 0;
364 		svm_migrate_put_vram_page(adev, dst[i + 1]);
365 		migrate->dst[i + 1] = 0;
366 		svm_migrate_put_vram_page(adev, dst[i + 2]);
367 		migrate->dst[i + 2] = 0;
368 		svm_migrate_put_vram_page(adev, dst[i + 3]);
369 		migrate->dst[i + 3] = 0;
370 	}
371 #endif
372 
373 	return mpages;
374 }
375 
376 static long
377 svm_migrate_vma_to_vram(struct kfd_node *node, struct svm_range *prange,
378 			struct vm_area_struct *vma, uint64_t start,
379 			uint64_t end, uint32_t trigger, uint64_t ttm_res_offset)
380 {
381 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
382 	uint64_t npages = (end - start) >> PAGE_SHIFT;
383 	struct amdgpu_device *adev = node->adev;
384 	struct kfd_process_device *pdd;
385 	struct dma_fence *mfence = NULL;
386 	struct migrate_vma migrate = { 0 };
387 	unsigned long cpages = 0;
388 	long mpages = 0;
389 	dma_addr_t *scratch;
390 	void *buf;
391 	int r = -ENOMEM;
392 
393 	memset(&migrate, 0, sizeof(migrate));
394 	migrate.vma = vma;
395 	migrate.start = start;
396 	migrate.end = end;
397 	migrate.flags = MIGRATE_VMA_SELECT_SYSTEM;
398 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
399 
400 	buf = kvcalloc(npages,
401 		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
402 		       GFP_KERNEL);
403 	if (!buf)
404 		goto out;
405 
406 	migrate.src = buf;
407 	migrate.dst = migrate.src + npages;
408 	scratch = (dma_addr_t *)(migrate.dst + npages);
409 
410 	kfd_smi_event_migration_start(node, p->lead_thread->pid,
411 				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
412 				      0, node->id, prange->prefetch_loc,
413 				      prange->preferred_loc, trigger);
414 
415 	r = migrate_vma_setup(&migrate);
416 	if (r) {
417 		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
418 			__func__, r, prange->start, prange->last);
419 		goto out_free;
420 	}
421 
422 	cpages = migrate.cpages;
423 	if (!cpages) {
424 		pr_debug("failed collect migrate sys pages [0x%lx 0x%lx]\n",
425 			 prange->start, prange->last);
426 		goto out_free;
427 	}
428 	if (cpages != npages)
429 		pr_debug("partial migration, 0x%lx/0x%llx pages collected\n",
430 			 cpages, npages);
431 	else
432 		pr_debug("0x%lx pages collected\n", cpages);
433 
434 	mpages = svm_migrate_copy_to_vram(node, prange, &migrate, &mfence, scratch, ttm_res_offset);
435 	migrate_vma_pages(&migrate);
436 
437 	svm_migrate_copy_done(adev, mfence);
438 	migrate_vma_finalize(&migrate);
439 
440 	if (mpages >= 0)
441 		pr_debug("migrated/collected/requested 0x%lx/0x%lx/0x%lx\n",
442 			 mpages, cpages, migrate.npages);
443 	else
444 		r = mpages;
445 
446 	svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
447 
448 out_free:
449 	kvfree(buf);
450 	kfd_smi_event_migration_end(node, p->lead_thread->pid,
451 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
452 				    0, node->id, trigger, r);
453 out:
454 	if (!r && mpages > 0) {
455 		pdd = svm_range_get_pdd_by_node(prange, node);
456 		if (pdd)
457 			WRITE_ONCE(pdd->page_in, pdd->page_in + mpages);
458 	}
459 
460 	return r ? r : mpages;
461 }
462 
463 /**
464  * svm_migrate_ram_to_vram - migrate svm range from system to device
465  * @prange: range structure
466  * @best_loc: the device to migrate to
467  * @start_mgr: start page to migrate
468  * @last_mgr: last page to migrate
469  * @mm: the process mm structure
470  * @trigger: reason of migration
471  *
472  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
473  *
474  * Return:
475  * 0 - OK, otherwise error code
476  */
477 static int
478 svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
479 			unsigned long start_mgr, unsigned long last_mgr,
480 			struct mm_struct *mm, uint32_t trigger)
481 {
482 	unsigned long addr, start, end;
483 	struct vm_area_struct *vma;
484 	uint64_t ttm_res_offset;
485 	struct kfd_node *node;
486 	unsigned long mpages = 0;
487 	long r = 0;
488 
489 	if (start_mgr < prange->start || last_mgr > prange->last) {
490 		pr_debug("range [0x%lx 0x%lx] out prange [0x%lx 0x%lx]\n",
491 			 start_mgr, last_mgr, prange->start, prange->last);
492 		return -EFAULT;
493 	}
494 
495 	node = svm_range_get_node_by_id(prange, best_loc);
496 	if (!node) {
497 		pr_debug("failed to get kfd node by id 0x%x\n", best_loc);
498 		return -ENODEV;
499 	}
500 
501 	pr_debug("svms 0x%p [0x%lx 0x%lx] in [0x%lx 0x%lx] to gpu 0x%x\n",
502 		prange->svms, start_mgr, last_mgr, prange->start, prange->last,
503 		best_loc);
504 
505 	start = start_mgr << PAGE_SHIFT;
506 	end = (last_mgr + 1) << PAGE_SHIFT;
507 
508 	r = amdgpu_amdkfd_reserve_mem_limit(node->adev,
509 					prange->npages * PAGE_SIZE,
510 					KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
511 					node->xcp ? node->xcp->id : 0);
512 	if (r) {
513 		dev_dbg(node->adev->dev, "failed to reserve VRAM, r: %ld\n", r);
514 		return -ENOSPC;
515 	}
516 
517 	r = svm_range_vram_node_new(node, prange, true);
518 	if (r) {
519 		dev_dbg(node->adev->dev, "fail %ld to alloc vram\n", r);
520 		goto out;
521 	}
522 	ttm_res_offset = (start_mgr - prange->start + prange->offset) << PAGE_SHIFT;
523 
524 	for (addr = start; addr < end;) {
525 		unsigned long next;
526 
527 		vma = vma_lookup(mm, addr);
528 		if (!vma)
529 			break;
530 
531 		next = min(vma->vm_end, end);
532 		r = svm_migrate_vma_to_vram(node, prange, vma, addr, next, trigger, ttm_res_offset);
533 		if (r < 0) {
534 			pr_debug("failed %ld to migrate\n", r);
535 			break;
536 		} else {
537 			mpages += r;
538 		}
539 		ttm_res_offset += next - addr;
540 		addr = next;
541 	}
542 
543 	if (mpages) {
544 		prange->actual_loc = best_loc;
545 		prange->vram_pages += mpages;
546 	} else if (!prange->actual_loc) {
547 		/* if no page migrated and all pages from prange are at
548 		 * sys ram drop svm_bo got from svm_range_vram_node_new
549 		 */
550 		svm_range_vram_node_free(prange);
551 	}
552 
553 out:
554 	amdgpu_amdkfd_unreserve_mem_limit(node->adev,
555 					prange->npages * PAGE_SIZE,
556 					KFD_IOC_ALLOC_MEM_FLAGS_VRAM,
557 					node->xcp ? node->xcp->id : 0);
558 	return r < 0 ? r : 0;
559 }
560 
561 static void svm_migrate_page_free(struct page *page)
562 {
563 	struct svm_range_bo *svm_bo = page->zone_device_data;
564 
565 	if (svm_bo) {
566 		pr_debug_ratelimited("ref: %d\n", kref_read(&svm_bo->kref));
567 		svm_range_bo_unref_async(svm_bo);
568 	}
569 }
570 
571 static long
572 svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
573 			struct migrate_vma *migrate, struct dma_fence **mfence,
574 			dma_addr_t *scratch, uint64_t npages)
575 {
576 	struct device *dev = adev->dev;
577 	uint64_t *src;
578 	dma_addr_t *dst;
579 	struct page *dpage;
580 	long mpages;
581 	uint64_t i = 0, j;
582 	uint64_t addr;
583 	int r = 0;
584 
585 	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
586 		 prange->last);
587 
588 	addr = migrate->start;
589 
590 	src = (uint64_t *)(scratch + npages);
591 	dst = scratch;
592 
593 	mpages = 0;
594 	for (i = 0, j = 0; i < npages; i++, addr += PAGE_SIZE) {
595 		struct page *spage;
596 
597 		spage = migrate_pfn_to_page(migrate->src[i]);
598 		if (!spage || !is_zone_device_page(spage)) {
599 			pr_debug("invalid page. Could be in CPU already svms 0x%p [0x%lx 0x%lx]\n",
600 				 prange->svms, prange->start, prange->last);
601 			if (j) {
602 				r = svm_migrate_copy_memory_gart(adev, dst + i - j,
603 								 src + i - j, j,
604 								 FROM_VRAM_TO_RAM,
605 								 mfence);
606 				if (r)
607 					goto out_oom;
608 				j = 0;
609 			}
610 			continue;
611 		}
612 		src[i] = svm_migrate_addr(adev, spage);
613 		if (j > 0 && src[i] != src[i - 1] + PAGE_SIZE) {
614 			r = svm_migrate_copy_memory_gart(adev, dst + i - j,
615 							 src + i - j, j,
616 							 FROM_VRAM_TO_RAM,
617 							 mfence);
618 			if (r)
619 				goto out_oom;
620 			j = 0;
621 		}
622 
623 		dpage = svm_migrate_get_sys_page(migrate->vma, addr);
624 		if (!dpage) {
625 			pr_debug("failed get page svms 0x%p [0x%lx 0x%lx]\n",
626 				 prange->svms, prange->start, prange->last);
627 			r = -ENOMEM;
628 			goto out_oom;
629 		}
630 
631 		dst[i] = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
632 		r = dma_mapping_error(dev, dst[i]);
633 		if (r) {
634 			dev_err(adev->dev, "%s: fail %d dma_map_page\n", __func__, r);
635 			goto out_oom;
636 		}
637 
638 		pr_debug_ratelimited("dma mapping dst to 0x%llx, pfn 0x%lx\n",
639 				     dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
640 
641 		migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
642 		mpages++;
643 		j++;
644 	}
645 
646 	r = svm_migrate_copy_memory_gart(adev, dst + i - j, src + i - j, j,
647 					 FROM_VRAM_TO_RAM, mfence);
648 
649 out_oom:
650 	if (r) {
651 		pr_debug("failed %d copy to ram\n", r);
652 		while (i-- && mpages) {
653 			if (!migrate->dst[i])
654 				continue;
655 			svm_migrate_put_sys_page(dst[i]);
656 			migrate->dst[i] = 0;
657 			mpages--;
658 		}
659 		mpages = r;
660 	}
661 
662 	return mpages;
663 }
664 
665 /**
666  * svm_migrate_vma_to_ram - migrate range inside one vma from device to system
667  *
668  * @prange: svm range structure
669  * @vma: vm_area_struct that range [start, end] belongs to
670  * @start: range start virtual address in pages
671  * @end: range end virtual address in pages
672  * @node: kfd node device to migrate from
673  * @trigger: reason of migration
674  * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
675  *
676  * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
677  *
678  * Return:
679  *   negative values - indicate error
680  *   positive values or zero - number of pages got migrated
681  */
682 static long
683 svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
684 		       struct vm_area_struct *vma, uint64_t start, uint64_t end,
685 		       uint32_t trigger, struct page *fault_page)
686 {
687 	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
688 	uint64_t npages = (end - start) >> PAGE_SHIFT;
689 	unsigned long cpages = 0;
690 	long mpages = 0;
691 	struct amdgpu_device *adev = node->adev;
692 	struct kfd_process_device *pdd;
693 	struct dma_fence *mfence = NULL;
694 	struct migrate_vma migrate = { 0 };
695 	dma_addr_t *scratch;
696 	void *buf;
697 	int r = -ENOMEM;
698 
699 	memset(&migrate, 0, sizeof(migrate));
700 	migrate.vma = vma;
701 	migrate.start = start;
702 	migrate.end = end;
703 	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
704 	if (adev->gmc.xgmi.connected_to_cpu)
705 		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_COHERENT;
706 	else
707 		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
708 
709 	buf = kvcalloc(npages,
710 		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
711 		       GFP_KERNEL);
712 	if (!buf)
713 		goto out;
714 
715 	migrate.src = buf;
716 	migrate.dst = migrate.src + npages;
717 	migrate.fault_page = fault_page;
718 	scratch = (dma_addr_t *)(migrate.dst + npages);
719 
720 	kfd_smi_event_migration_start(node, p->lead_thread->pid,
721 				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
722 				      node->id, 0, prange->prefetch_loc,
723 				      prange->preferred_loc, trigger);
724 
725 	r = migrate_vma_setup(&migrate);
726 	if (r) {
727 		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
728 			__func__, r, prange->start, prange->last);
729 		goto out_free;
730 	}
731 
732 	cpages = migrate.cpages;
733 	if (!cpages) {
734 		pr_debug("failed collect migrate device pages [0x%lx 0x%lx]\n",
735 			 prange->start, prange->last);
736 		goto out_free;
737 	}
738 	if (cpages != npages)
739 		pr_debug("partial migration, 0x%lx/0x%llx pages collected\n",
740 			 cpages, npages);
741 	else
742 		pr_debug("0x%lx pages collected\n", cpages);
743 
744 	mpages = svm_migrate_copy_to_ram(adev, prange, &migrate, &mfence,
745 				    scratch, npages);
746 	migrate_vma_pages(&migrate);
747 
748 	if (mpages >= 0)
749 		pr_debug("migrated/collected/requested 0x%lx/0x%lx/0x%lx\n",
750 		 mpages, cpages, migrate.npages);
751 	else
752 		r = mpages;
753 
754 	svm_migrate_copy_done(adev, mfence);
755 	migrate_vma_finalize(&migrate);
756 
757 	svm_range_dma_unmap_dev(adev->dev, scratch, 0, npages);
758 
759 out_free:
760 	kvfree(buf);
761 	kfd_smi_event_migration_end(node, p->lead_thread->pid,
762 				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
763 				    node->id, 0, trigger, r);
764 out:
765 	if (!r && mpages > 0) {
766 		pdd = svm_range_get_pdd_by_node(prange, node);
767 		if (pdd)
768 			WRITE_ONCE(pdd->page_out, pdd->page_out + mpages);
769 	}
770 
771 	return r ? r : mpages;
772 }
773 
774 /**
775  * svm_migrate_vram_to_ram - migrate svm range from device to system
776  * @prange: range structure
777  * @mm: process mm, use current->mm if NULL
778  * @start_mgr: start page need be migrated to sys ram
779  * @last_mgr: last page need be migrated to sys ram
780  * @trigger: reason of migration
781  * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
782  *
783  * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
784  *
785  * Return:
786  * 0 - OK, otherwise error code
787  */
788 int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm,
789 			    unsigned long start_mgr, unsigned long last_mgr,
790 			    uint32_t trigger, struct page *fault_page)
791 {
792 	struct kfd_node *node;
793 	struct vm_area_struct *vma;
794 	unsigned long addr;
795 	unsigned long start;
796 	unsigned long end;
797 	unsigned long mpages = 0;
798 	long r = 0;
799 
800 	/* this pragne has no any vram page to migrate to sys ram */
801 	if (!prange->actual_loc) {
802 		pr_debug("[0x%lx 0x%lx] already migrated to ram\n",
803 			 prange->start, prange->last);
804 		return 0;
805 	}
806 
807 	if (start_mgr < prange->start || last_mgr > prange->last) {
808 		pr_debug("range [0x%lx 0x%lx] out prange [0x%lx 0x%lx]\n",
809 			 start_mgr, last_mgr, prange->start, prange->last);
810 		return -EFAULT;
811 	}
812 
813 	node = svm_range_get_node_by_id(prange, prange->actual_loc);
814 	if (!node) {
815 		pr_debug("failed to get kfd node by id 0x%x\n", prange->actual_loc);
816 		return -ENODEV;
817 	}
818 	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] from gpu 0x%x to ram\n",
819 		 prange->svms, prange, start_mgr, last_mgr,
820 		 prange->actual_loc);
821 
822 	start = start_mgr << PAGE_SHIFT;
823 	end = (last_mgr + 1) << PAGE_SHIFT;
824 
825 	for (addr = start; addr < end;) {
826 		unsigned long next;
827 
828 		vma = vma_lookup(mm, addr);
829 		if (!vma) {
830 			pr_debug("failed to find vma for prange %p\n", prange);
831 			r = -EFAULT;
832 			break;
833 		}
834 
835 		next = min(vma->vm_end, end);
836 		r = svm_migrate_vma_to_ram(node, prange, vma, addr, next, trigger,
837 			fault_page);
838 		if (r < 0) {
839 			pr_debug("failed %ld to migrate prange %p\n", r, prange);
840 			break;
841 		} else {
842 			mpages += r;
843 		}
844 		addr = next;
845 	}
846 
847 	if (r >= 0) {
848 		WARN_ONCE(prange->vram_pages < mpages,
849 			"Recorded vram pages(0x%llx) should not be less than migration pages(0x%lx).",
850 			prange->vram_pages, mpages);
851 		prange->vram_pages -= mpages;
852 
853 		/* prange does not have vram page set its actual_loc to system
854 		 * and drop its svm_bo ref
855 		 */
856 		if (prange->vram_pages == 0 && prange->ttm_res) {
857 			prange->actual_loc = 0;
858 			svm_range_vram_node_free(prange);
859 		}
860 	}
861 
862 	return r < 0 ? r : 0;
863 }
864 
865 /**
866  * svm_migrate_vram_to_vram - migrate svm range from device to device
867  * @prange: range structure
868  * @best_loc: the device to migrate to
869  * @start: start page need be migrated to sys ram
870  * @last: last page need be migrated to sys ram
871  * @mm: process mm, use current->mm if NULL
872  * @trigger: reason of migration
873  *
874  * Context: Process context, caller hold mmap read lock, svms lock, prange lock
875  *
876  * migrate all vram pages in prange to sys ram, then migrate
877  * [start, last] pages from sys ram to gpu node best_loc.
878  *
879  * Return:
880  * 0 - OK, otherwise error code
881  */
882 static int
883 svm_migrate_vram_to_vram(struct svm_range *prange, uint32_t best_loc,
884 			unsigned long start, unsigned long last,
885 			struct mm_struct *mm, uint32_t trigger)
886 {
887 	int r, retries = 3;
888 
889 	/*
890 	 * TODO: for both devices with PCIe large bar or on same xgmi hive, skip
891 	 * system memory as migration bridge
892 	 */
893 
894 	pr_debug("from gpu 0x%x to gpu 0x%x\n", prange->actual_loc, best_loc);
895 
896 	do {
897 		r = svm_migrate_vram_to_ram(prange, mm, prange->start, prange->last,
898 					    trigger, NULL);
899 		if (r)
900 			return r;
901 	} while (prange->actual_loc && --retries);
902 
903 	if (prange->actual_loc)
904 		return -EDEADLK;
905 
906 	return svm_migrate_ram_to_vram(prange, best_loc, start, last, mm, trigger);
907 }
908 
909 int
910 svm_migrate_to_vram(struct svm_range *prange, uint32_t best_loc,
911 		    unsigned long start, unsigned long last,
912 		    struct mm_struct *mm, uint32_t trigger)
913 {
914 	if  (!prange->actual_loc || prange->actual_loc == best_loc)
915 		return svm_migrate_ram_to_vram(prange, best_loc, start, last,
916 					       mm, trigger);
917 
918 	else
919 		return svm_migrate_vram_to_vram(prange, best_loc, start, last,
920 						mm, trigger);
921 
922 }
923 
924 /**
925  * svm_migrate_to_ram - CPU page fault handler
926  * @vmf: CPU vm fault vma, address
927  *
928  * Context: vm fault handler, caller holds the mmap read lock
929  *
930  * Return:
931  * 0 - OK
932  * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
933  */
934 static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
935 {
936 	unsigned long start, last, size;
937 	unsigned long addr = vmf->address;
938 	struct svm_range_bo *svm_bo;
939 	struct svm_range *prange;
940 	struct kfd_process *p;
941 	struct mm_struct *mm;
942 	int r = 0;
943 
944 	svm_bo = vmf->page->zone_device_data;
945 	if (!svm_bo) {
946 		pr_debug("failed get device page at addr 0x%lx\n", addr);
947 		return VM_FAULT_SIGBUS;
948 	}
949 	if (!mmget_not_zero(svm_bo->eviction_fence->mm)) {
950 		pr_debug("addr 0x%lx of process mm is destroyed\n", addr);
951 		return VM_FAULT_SIGBUS;
952 	}
953 
954 	mm = svm_bo->eviction_fence->mm;
955 	if (mm != vmf->vma->vm_mm)
956 		pr_debug("addr 0x%lx is COW mapping in child process\n", addr);
957 
958 	p = kfd_lookup_process_by_mm(mm);
959 	if (!p) {
960 		pr_debug("failed find process at fault address 0x%lx\n", addr);
961 		r = VM_FAULT_SIGBUS;
962 		goto out_mmput;
963 	}
964 	if (READ_ONCE(p->svms.faulting_task) == current) {
965 		pr_debug("skipping ram migration\n");
966 		r = 0;
967 		goto out_unref_process;
968 	}
969 
970 	pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr);
971 	addr >>= PAGE_SHIFT;
972 
973 	mutex_lock(&p->svms.lock);
974 
975 	prange = svm_range_from_addr(&p->svms, addr, NULL);
976 	if (!prange) {
977 		pr_debug("failed get range svms 0x%p addr 0x%lx\n", &p->svms, addr);
978 		r = -EFAULT;
979 		goto out_unlock_svms;
980 	}
981 
982 	mutex_lock(&prange->migrate_mutex);
983 
984 	if (!prange->actual_loc)
985 		goto out_unlock_prange;
986 
987 	/* Align migration range start and size to granularity size */
988 	size = 1UL << prange->granularity;
989 	start = max(ALIGN_DOWN(addr, size), prange->start);
990 	last = min(ALIGN(addr + 1, size) - 1, prange->last);
991 
992 	r = svm_migrate_vram_to_ram(prange, vmf->vma->vm_mm, start, last,
993 				    KFD_MIGRATE_TRIGGER_PAGEFAULT_CPU, vmf->page);
994 	if (r)
995 		pr_debug("failed %d migrate svms 0x%p range 0x%p [0x%lx 0x%lx]\n",
996 			r, prange->svms, prange, start, last);
997 
998 out_unlock_prange:
999 	mutex_unlock(&prange->migrate_mutex);
1000 out_unlock_svms:
1001 	mutex_unlock(&p->svms.lock);
1002 out_unref_process:
1003 	pr_debug("CPU fault svms 0x%p address 0x%lx done\n", &p->svms, addr);
1004 	kfd_unref_process(p);
1005 out_mmput:
1006 	mmput(mm);
1007 	return r ? VM_FAULT_SIGBUS : 0;
1008 }
1009 
1010 static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
1011 	.page_free		= svm_migrate_page_free,
1012 	.migrate_to_ram		= svm_migrate_to_ram,
1013 };
1014 
1015 /* Each VRAM page uses sizeof(struct page) on system memory */
1016 #define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
1017 
1018 int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
1019 {
1020 	struct amdgpu_kfd_dev *kfddev = &adev->kfd;
1021 	struct dev_pagemap *pgmap;
1022 	struct resource *res = NULL;
1023 	unsigned long size;
1024 	void *r;
1025 
1026 	/* Page migration works on gfx9 or newer */
1027 	if (amdgpu_ip_version(adev, GC_HWIP, 0) < IP_VERSION(9, 0, 1))
1028 		return -EINVAL;
1029 
1030 	if (adev->apu_prefer_gtt)
1031 		return 0;
1032 
1033 	pgmap = &kfddev->pgmap;
1034 	memset(pgmap, 0, sizeof(*pgmap));
1035 
1036 	/* TODO: register all vram to HMM for now.
1037 	 * should remove reserved size
1038 	 */
1039 	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
1040 	if (adev->gmc.xgmi.connected_to_cpu) {
1041 		pgmap->range.start = adev->gmc.aper_base;
1042 		pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
1043 		pgmap->type = MEMORY_DEVICE_COHERENT;
1044 	} else {
1045 		res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
1046 		if (IS_ERR(res))
1047 			return PTR_ERR(res);
1048 		pgmap->range.start = res->start;
1049 		pgmap->range.end = res->end;
1050 		pgmap->type = MEMORY_DEVICE_PRIVATE;
1051 	}
1052 
1053 	pgmap->nr_range = 1;
1054 	pgmap->ops = &svm_migrate_pgmap_ops;
1055 	pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
1056 	pgmap->flags = 0;
1057 	/* Device manager releases device-specific resources, memory region and
1058 	 * pgmap when driver disconnects from device.
1059 	 */
1060 	r = devm_memremap_pages(adev->dev, pgmap);
1061 	if (IS_ERR(r)) {
1062 		pr_err("failed to register HMM device memory\n");
1063 		if (pgmap->type == MEMORY_DEVICE_PRIVATE)
1064 			devm_release_mem_region(adev->dev, res->start, resource_size(res));
1065 		/* Disable SVM support capability */
1066 		pgmap->type = 0;
1067 		return PTR_ERR(r);
1068 	}
1069 
1070 	pr_debug("reserve %ldMB system memory for VRAM pages struct\n",
1071 		 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);
1072 
1073 	amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));
1074 
1075 	pr_info("HMM registered %ldMB device memory\n", size >> 20);
1076 
1077 	return 0;
1078 }
1079