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   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
  42static uint64_t
  43svm_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
  48static int
  49svm_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.entity,
  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
 123static int
 124svm_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
 171out_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 */
 192static int
 193svm_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
 206unsigned long
 207svm_migrate_addr_to_pfn(struct amdgpu_device *adev, unsigned long addr)
 208{
 209	return (addr + adev->kfd.dev->pgmap.range.start) >> PAGE_SHIFT;
 210}
 211
 212static void
 213svm_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
 223static void
 224svm_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
 233static unsigned long
 234svm_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.dev->pgmap.range.start);
 240}
 241
 242static struct page *
 243svm_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
 254static 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
 263static 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
 276static 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
 289static int
 290svm_migrate_copy_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
 291			 struct migrate_vma *migrate, struct dma_fence **mfence,
 292			 dma_addr_t *scratch)
 293{
 294	uint64_t npages = migrate->npages;
 295	struct device *dev = adev->dev;
 296	struct amdgpu_res_cursor cursor;
 297	dma_addr_t *src;
 298	uint64_t *dst;
 299	uint64_t i, j;
 300	int r;
 301
 302	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
 303		 prange->last);
 304
 305	src = scratch;
 306	dst = (uint64_t *)(scratch + npages);
 307
 308	r = svm_range_vram_node_new(adev, prange, true);
 309	if (r) {
 310		dev_dbg(adev->dev, "fail %d to alloc vram\n", r);
 311		goto out;
 312	}
 313
 314	amdgpu_res_first(prange->ttm_res, prange->offset << PAGE_SHIFT,
 315			 npages << PAGE_SHIFT, &cursor);
 316	for (i = j = 0; i < npages; i++) {
 317		struct page *spage;
 318
 319		dst[i] = cursor.start + (j << PAGE_SHIFT);
 320		migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
 321		svm_migrate_get_vram_page(prange, migrate->dst[i]);
 322		migrate->dst[i] = migrate_pfn(migrate->dst[i]);
 323
 324		spage = migrate_pfn_to_page(migrate->src[i]);
 325		if (spage && !is_zone_device_page(spage)) {
 326			src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
 327					      DMA_TO_DEVICE);
 328			r = dma_mapping_error(dev, src[i]);
 329			if (r) {
 330				dev_err(adev->dev, "%s: fail %d dma_map_page\n",
 331					__func__, r);
 332				goto out_free_vram_pages;
 333			}
 334		} else {
 335			if (j) {
 336				r = svm_migrate_copy_memory_gart(
 337						adev, src + i - j,
 338						dst + i - j, j,
 339						FROM_RAM_TO_VRAM,
 340						mfence);
 341				if (r)
 342					goto out_free_vram_pages;
 343				amdgpu_res_next(&cursor, (j + 1) << PAGE_SHIFT);
 344				j = 0;
 345			} else {
 346				amdgpu_res_next(&cursor, PAGE_SIZE);
 347			}
 348			continue;
 349		}
 350
 351		pr_debug_ratelimited("dma mapping src to 0x%llx, pfn 0x%lx\n",
 352				     src[i] >> PAGE_SHIFT, page_to_pfn(spage));
 353
 354		if (j >= (cursor.size >> PAGE_SHIFT) - 1 && i < npages - 1) {
 355			r = svm_migrate_copy_memory_gart(adev, src + i - j,
 356							 dst + i - j, j + 1,
 357							 FROM_RAM_TO_VRAM,
 358							 mfence);
 359			if (r)
 360				goto out_free_vram_pages;
 361			amdgpu_res_next(&cursor, (j + 1) * PAGE_SIZE);
 362			j = 0;
 363		} else {
 364			j++;
 365		}
 366	}
 367
 368	r = svm_migrate_copy_memory_gart(adev, src + i - j, dst + i - j, j,
 369					 FROM_RAM_TO_VRAM, mfence);
 370
 371out_free_vram_pages:
 372	if (r) {
 373		pr_debug("failed %d to copy memory to vram\n", r);
 374		while (i--) {
 375			svm_migrate_put_vram_page(adev, dst[i]);
 376			migrate->dst[i] = 0;
 377		}
 378	}
 379
 380#ifdef DEBUG_FORCE_MIXED_DOMAINS
 381	for (i = 0, j = 0; i < npages; i += 4, j++) {
 382		if (j & 1)
 383			continue;
 384		svm_migrate_put_vram_page(adev, dst[i]);
 385		migrate->dst[i] = 0;
 386		svm_migrate_put_vram_page(adev, dst[i + 1]);
 387		migrate->dst[i + 1] = 0;
 388		svm_migrate_put_vram_page(adev, dst[i + 2]);
 389		migrate->dst[i + 2] = 0;
 390		svm_migrate_put_vram_page(adev, dst[i + 3]);
 391		migrate->dst[i + 3] = 0;
 392	}
 393#endif
 394out:
 395	return r;
 396}
 397
 398static long
 399svm_migrate_vma_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
 400			struct vm_area_struct *vma, uint64_t start,
 401			uint64_t end, uint32_t trigger)
 402{
 403	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
 404	uint64_t npages = (end - start) >> PAGE_SHIFT;
 405	struct kfd_process_device *pdd;
 406	struct dma_fence *mfence = NULL;
 407	struct migrate_vma migrate = { 0 };
 408	unsigned long cpages = 0;
 409	dma_addr_t *scratch;
 410	void *buf;
 411	int r = -ENOMEM;
 412
 413	memset(&migrate, 0, sizeof(migrate));
 414	migrate.vma = vma;
 415	migrate.start = start;
 416	migrate.end = end;
 417	migrate.flags = MIGRATE_VMA_SELECT_SYSTEM;
 418	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
 419
 420	buf = kvcalloc(npages,
 421		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
 422		       GFP_KERNEL);
 423	if (!buf)
 424		goto out;
 425
 426	migrate.src = buf;
 427	migrate.dst = migrate.src + npages;
 428	scratch = (dma_addr_t *)(migrate.dst + npages);
 429
 430	kfd_smi_event_migration_start(adev->kfd.dev, p->lead_thread->pid,
 431				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 432				      0, adev->kfd.dev->id, prange->prefetch_loc,
 433				      prange->preferred_loc, trigger);
 434
 435	r = migrate_vma_setup(&migrate);
 436	if (r) {
 437		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
 438			__func__, r, prange->start, prange->last);
 439		goto out_free;
 440	}
 441
 442	cpages = migrate.cpages;
 443	if (!cpages) {
 444		pr_debug("failed collect migrate sys pages [0x%lx 0x%lx]\n",
 445			 prange->start, prange->last);
 446		goto out_free;
 447	}
 448	if (cpages != npages)
 449		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
 450			 cpages, npages);
 451	else
 452		pr_debug("0x%lx pages migrated\n", cpages);
 453
 454	r = svm_migrate_copy_to_vram(adev, prange, &migrate, &mfence, scratch);
 455	migrate_vma_pages(&migrate);
 456
 457	pr_debug("successful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
 458		svm_migrate_successful_pages(&migrate), cpages, migrate.npages);
 459
 460	svm_migrate_copy_done(adev, mfence);
 461	migrate_vma_finalize(&migrate);
 462
 463	kfd_smi_event_migration_end(adev->kfd.dev, p->lead_thread->pid,
 464				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 465				    0, adev->kfd.dev->id, trigger);
 466
 467	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
 468	svm_range_free_dma_mappings(prange);
 469
 470out_free:
 471	kvfree(buf);
 472out:
 473	if (!r && cpages) {
 474		pdd = svm_range_get_pdd_by_adev(prange, adev);
 475		if (pdd)
 476			WRITE_ONCE(pdd->page_in, pdd->page_in + cpages);
 477
 478		return cpages;
 479	}
 480	return r;
 481}
 482
 483/**
 484 * svm_migrate_ram_to_vram - migrate svm range from system to device
 485 * @prange: range structure
 486 * @best_loc: the device to migrate to
 487 * @mm: the process mm structure
 488 * @trigger: reason of migration
 489 *
 490 * Context: Process context, caller hold mmap read lock, svms lock, prange lock
 491 *
 492 * Return:
 493 * 0 - OK, otherwise error code
 494 */
 495static int
 496svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
 497			struct mm_struct *mm, uint32_t trigger)
 498{
 499	unsigned long addr, start, end;
 500	struct vm_area_struct *vma;
 501	struct amdgpu_device *adev;
 502	unsigned long cpages = 0;
 503	long r = 0;
 504
 505	if (prange->actual_loc == best_loc) {
 506		pr_debug("svms 0x%p [0x%lx 0x%lx] already on best_loc 0x%x\n",
 507			 prange->svms, prange->start, prange->last, best_loc);
 508		return 0;
 509	}
 510
 511	adev = svm_range_get_adev_by_id(prange, best_loc);
 512	if (!adev) {
 513		pr_debug("failed to get device by id 0x%x\n", best_loc);
 514		return -ENODEV;
 515	}
 516
 517	pr_debug("svms 0x%p [0x%lx 0x%lx] to gpu 0x%x\n", prange->svms,
 518		 prange->start, prange->last, best_loc);
 519
 520	start = prange->start << PAGE_SHIFT;
 521	end = (prange->last + 1) << PAGE_SHIFT;
 522
 523	for (addr = start; addr < end;) {
 524		unsigned long next;
 525
 526		vma = vma_lookup(mm, addr);
 527		if (!vma)
 528			break;
 529
 530		next = min(vma->vm_end, end);
 531		r = svm_migrate_vma_to_vram(adev, prange, vma, addr, next, trigger);
 532		if (r < 0) {
 533			pr_debug("failed %ld to migrate\n", r);
 534			break;
 535		} else {
 536			cpages += r;
 537		}
 538		addr = next;
 539	}
 540
 541	if (cpages)
 542		prange->actual_loc = best_loc;
 543
 544	return r < 0 ? r : 0;
 545}
 546
 547static void svm_migrate_page_free(struct page *page)
 548{
 549	struct svm_range_bo *svm_bo = page->zone_device_data;
 550
 551	if (svm_bo) {
 552		pr_debug_ratelimited("ref: %d\n", kref_read(&svm_bo->kref));
 553		svm_range_bo_unref_async(svm_bo);
 554	}
 555}
 556
 557static int
 558svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
 559			struct migrate_vma *migrate, struct dma_fence **mfence,
 560			dma_addr_t *scratch, uint64_t npages)
 561{
 562	struct device *dev = adev->dev;
 563	uint64_t *src;
 564	dma_addr_t *dst;
 565	struct page *dpage;
 566	uint64_t i = 0, j;
 567	uint64_t addr;
 568	int r = 0;
 569
 570	pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
 571		 prange->last);
 572
 573	addr = prange->start << PAGE_SHIFT;
 574
 575	src = (uint64_t *)(scratch + npages);
 576	dst = scratch;
 577
 578	for (i = 0, j = 0; i < npages; i++, addr += PAGE_SIZE) {
 579		struct page *spage;
 580
 581		spage = migrate_pfn_to_page(migrate->src[i]);
 582		if (!spage || !is_zone_device_page(spage)) {
 583			pr_debug("invalid page. Could be in CPU already svms 0x%p [0x%lx 0x%lx]\n",
 584				 prange->svms, prange->start, prange->last);
 585			if (j) {
 586				r = svm_migrate_copy_memory_gart(adev, dst + i - j,
 587								 src + i - j, j,
 588								 FROM_VRAM_TO_RAM,
 589								 mfence);
 590				if (r)
 591					goto out_oom;
 592				j = 0;
 593			}
 594			continue;
 595		}
 596		src[i] = svm_migrate_addr(adev, spage);
 597		if (j > 0 && src[i] != src[i - 1] + PAGE_SIZE) {
 598			r = svm_migrate_copy_memory_gart(adev, dst + i - j,
 599							 src + i - j, j,
 600							 FROM_VRAM_TO_RAM,
 601							 mfence);
 602			if (r)
 603				goto out_oom;
 604			j = 0;
 605		}
 606
 607		dpage = svm_migrate_get_sys_page(migrate->vma, addr);
 608		if (!dpage) {
 609			pr_debug("failed get page svms 0x%p [0x%lx 0x%lx]\n",
 610				 prange->svms, prange->start, prange->last);
 611			r = -ENOMEM;
 612			goto out_oom;
 613		}
 614
 615		dst[i] = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_FROM_DEVICE);
 616		r = dma_mapping_error(dev, dst[i]);
 617		if (r) {
 618			dev_err(adev->dev, "%s: fail %d dma_map_page\n", __func__, r);
 619			goto out_oom;
 620		}
 621
 622		pr_debug_ratelimited("dma mapping dst to 0x%llx, pfn 0x%lx\n",
 623				     dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
 624
 625		migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
 626		j++;
 627	}
 628
 629	r = svm_migrate_copy_memory_gart(adev, dst + i - j, src + i - j, j,
 630					 FROM_VRAM_TO_RAM, mfence);
 631
 632out_oom:
 633	if (r) {
 634		pr_debug("failed %d copy to ram\n", r);
 635		while (i--) {
 636			svm_migrate_put_sys_page(dst[i]);
 637			migrate->dst[i] = 0;
 638		}
 639	}
 640
 641	return r;
 642}
 643
 644/**
 645 * svm_migrate_vma_to_ram - migrate range inside one vma from device to system
 646 *
 647 * @adev: amdgpu device to migrate from
 648 * @prange: svm range structure
 649 * @vma: vm_area_struct that range [start, end] belongs to
 650 * @start: range start virtual address in pages
 651 * @end: range end virtual address in pages
 652 *
 653 * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
 654 *
 655 * Return:
 656 *   0 - success with all pages migrated
 657 *   negative values - indicate error
 658 *   positive values - partial migration, number of pages not migrated
 659 */
 660static long
 661svm_migrate_vma_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
 662		       struct vm_area_struct *vma, uint64_t start, uint64_t end,
 663		       uint32_t trigger, struct page *fault_page)
 664{
 665	struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
 666	uint64_t npages = (end - start) >> PAGE_SHIFT;
 667	unsigned long upages = npages;
 668	unsigned long cpages = 0;
 669	struct kfd_process_device *pdd;
 670	struct dma_fence *mfence = NULL;
 671	struct migrate_vma migrate = { 0 };
 672	dma_addr_t *scratch;
 673	void *buf;
 674	int r = -ENOMEM;
 675
 676	memset(&migrate, 0, sizeof(migrate));
 677	migrate.vma = vma;
 678	migrate.start = start;
 679	migrate.end = end;
 680	migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
 681	if (adev->gmc.xgmi.connected_to_cpu)
 682		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_COHERENT;
 683	else
 684		migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
 685
 686	buf = kvcalloc(npages,
 687		       2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
 688		       GFP_KERNEL);
 689	if (!buf)
 690		goto out;
 691
 692	migrate.src = buf;
 693	migrate.dst = migrate.src + npages;
 694	migrate.fault_page = fault_page;
 695	scratch = (dma_addr_t *)(migrate.dst + npages);
 696
 697	kfd_smi_event_migration_start(adev->kfd.dev, p->lead_thread->pid,
 698				      start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 699				      adev->kfd.dev->id, 0, prange->prefetch_loc,
 700				      prange->preferred_loc, trigger);
 701
 702	r = migrate_vma_setup(&migrate);
 703	if (r) {
 704		dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
 705			__func__, r, prange->start, prange->last);
 706		goto out_free;
 707	}
 708
 709	cpages = migrate.cpages;
 710	if (!cpages) {
 711		pr_debug("failed collect migrate device pages [0x%lx 0x%lx]\n",
 712			 prange->start, prange->last);
 713		upages = svm_migrate_unsuccessful_pages(&migrate);
 714		goto out_free;
 715	}
 716	if (cpages != npages)
 717		pr_debug("partial migration, 0x%lx/0x%llx pages migrated\n",
 718			 cpages, npages);
 719	else
 720		pr_debug("0x%lx pages migrated\n", cpages);
 721
 722	r = svm_migrate_copy_to_ram(adev, prange, &migrate, &mfence,
 723				    scratch, npages);
 724	migrate_vma_pages(&migrate);
 725
 726	upages = svm_migrate_unsuccessful_pages(&migrate);
 727	pr_debug("unsuccessful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
 728		 upages, cpages, migrate.npages);
 729
 730	svm_migrate_copy_done(adev, mfence);
 731	migrate_vma_finalize(&migrate);
 732
 733	kfd_smi_event_migration_end(adev->kfd.dev, p->lead_thread->pid,
 734				    start >> PAGE_SHIFT, end >> PAGE_SHIFT,
 735				    adev->kfd.dev->id, 0, trigger);
 736
 737	svm_range_dma_unmap(adev->dev, scratch, 0, npages);
 738
 739out_free:
 740	kvfree(buf);
 741out:
 742	if (!r && cpages) {
 743		pdd = svm_range_get_pdd_by_adev(prange, adev);
 744		if (pdd)
 745			WRITE_ONCE(pdd->page_out, pdd->page_out + cpages);
 746	}
 747	return r ? r : upages;
 748}
 749
 750/**
 751 * svm_migrate_vram_to_ram - migrate svm range from device to system
 752 * @prange: range structure
 753 * @mm: process mm, use current->mm if NULL
 754 * @trigger: reason of migration
 755 *
 756 * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
 757 *
 758 * Return:
 759 * 0 - OK, otherwise error code
 760 */
 761int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm,
 762			    uint32_t trigger, struct page *fault_page)
 763{
 764	struct amdgpu_device *adev;
 765	struct vm_area_struct *vma;
 766	unsigned long addr;
 767	unsigned long start;
 768	unsigned long end;
 769	unsigned long upages = 0;
 770	long r = 0;
 771
 772	if (!prange->actual_loc) {
 773		pr_debug("[0x%lx 0x%lx] already migrated to ram\n",
 774			 prange->start, prange->last);
 775		return 0;
 776	}
 777
 778	adev = svm_range_get_adev_by_id(prange, prange->actual_loc);
 779	if (!adev) {
 780		pr_debug("failed to get device by id 0x%x\n",
 781			 prange->actual_loc);
 782		return -ENODEV;
 783	}
 784
 785	pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] from gpu 0x%x to ram\n",
 786		 prange->svms, prange, prange->start, prange->last,
 787		 prange->actual_loc);
 788
 789	start = prange->start << PAGE_SHIFT;
 790	end = (prange->last + 1) << PAGE_SHIFT;
 791
 792	for (addr = start; addr < end;) {
 793		unsigned long next;
 794
 795		vma = vma_lookup(mm, addr);
 796		if (!vma) {
 797			pr_debug("failed to find vma for prange %p\n", prange);
 798			r = -EFAULT;
 799			break;
 800		}
 801
 802		next = min(vma->vm_end, end);
 803		r = svm_migrate_vma_to_ram(adev, prange, vma, addr, next, trigger,
 804			fault_page);
 805		if (r < 0) {
 806			pr_debug("failed %ld to migrate prange %p\n", r, prange);
 807			break;
 808		} else {
 809			upages += r;
 810		}
 811		addr = next;
 812	}
 813
 814	if (r >= 0 && !upages) {
 815		svm_range_vram_node_free(prange);
 816		prange->actual_loc = 0;
 817	}
 818
 819	return r < 0 ? r : 0;
 820}
 821
 822/**
 823 * svm_migrate_vram_to_vram - migrate svm range from device to device
 824 * @prange: range structure
 825 * @best_loc: the device to migrate to
 826 * @mm: process mm, use current->mm if NULL
 827 * @trigger: reason of migration
 828 *
 829 * Context: Process context, caller hold mmap read lock, svms lock, prange lock
 830 *
 831 * Return:
 832 * 0 - OK, otherwise error code
 833 */
 834static int
 835svm_migrate_vram_to_vram(struct svm_range *prange, uint32_t best_loc,
 836			 struct mm_struct *mm, uint32_t trigger)
 837{
 838	int r, retries = 3;
 839
 840	/*
 841	 * TODO: for both devices with PCIe large bar or on same xgmi hive, skip
 842	 * system memory as migration bridge
 843	 */
 844
 845	pr_debug("from gpu 0x%x to gpu 0x%x\n", prange->actual_loc, best_loc);
 846
 847	do {
 848		r = svm_migrate_vram_to_ram(prange, mm, trigger, NULL);
 849		if (r)
 850			return r;
 851	} while (prange->actual_loc && --retries);
 852
 853	if (prange->actual_loc)
 854		return -EDEADLK;
 855
 856	return svm_migrate_ram_to_vram(prange, best_loc, mm, trigger);
 857}
 858
 859int
 860svm_migrate_to_vram(struct svm_range *prange, uint32_t best_loc,
 861		    struct mm_struct *mm, uint32_t trigger)
 862{
 863	if  (!prange->actual_loc)
 864		return svm_migrate_ram_to_vram(prange, best_loc, mm, trigger);
 865	else
 866		return svm_migrate_vram_to_vram(prange, best_loc, mm, trigger);
 867
 868}
 869
 870/**
 871 * svm_migrate_to_ram - CPU page fault handler
 872 * @vmf: CPU vm fault vma, address
 873 *
 874 * Context: vm fault handler, caller holds the mmap read lock
 875 *
 876 * Return:
 877 * 0 - OK
 878 * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
 879 */
 880static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
 881{
 882	unsigned long addr = vmf->address;
 883	struct svm_range_bo *svm_bo;
 884	enum svm_work_list_ops op;
 885	struct svm_range *parent;
 886	struct svm_range *prange;
 887	struct kfd_process *p;
 888	struct mm_struct *mm;
 889	int r = 0;
 890
 891	svm_bo = vmf->page->zone_device_data;
 892	if (!svm_bo) {
 893		pr_debug("failed get device page at addr 0x%lx\n", addr);
 894		return VM_FAULT_SIGBUS;
 895	}
 896	if (!mmget_not_zero(svm_bo->eviction_fence->mm)) {
 897		pr_debug("addr 0x%lx of process mm is destroyed\n", addr);
 898		return VM_FAULT_SIGBUS;
 899	}
 900
 901	mm = svm_bo->eviction_fence->mm;
 902	if (mm != vmf->vma->vm_mm)
 903		pr_debug("addr 0x%lx is COW mapping in child process\n", addr);
 904
 905	p = kfd_lookup_process_by_mm(mm);
 906	if (!p) {
 907		pr_debug("failed find process at fault address 0x%lx\n", addr);
 908		r = VM_FAULT_SIGBUS;
 909		goto out_mmput;
 910	}
 911	if (READ_ONCE(p->svms.faulting_task) == current) {
 912		pr_debug("skipping ram migration\n");
 913		r = 0;
 914		goto out_unref_process;
 915	}
 916
 917	pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr);
 918	addr >>= PAGE_SHIFT;
 919
 920	mutex_lock(&p->svms.lock);
 921
 922	prange = svm_range_from_addr(&p->svms, addr, &parent);
 923	if (!prange) {
 924		pr_debug("failed get range svms 0x%p addr 0x%lx\n", &p->svms, addr);
 925		r = -EFAULT;
 926		goto out_unlock_svms;
 927	}
 928
 929	mutex_lock(&parent->migrate_mutex);
 930	if (prange != parent)
 931		mutex_lock_nested(&prange->migrate_mutex, 1);
 932
 933	if (!prange->actual_loc)
 934		goto out_unlock_prange;
 935
 936	svm_range_lock(parent);
 937	if (prange != parent)
 938		mutex_lock_nested(&prange->lock, 1);
 939	r = svm_range_split_by_granularity(p, mm, addr, parent, prange);
 940	if (prange != parent)
 941		mutex_unlock(&prange->lock);
 942	svm_range_unlock(parent);
 943	if (r) {
 944		pr_debug("failed %d to split range by granularity\n", r);
 945		goto out_unlock_prange;
 946	}
 947
 948	r = svm_migrate_vram_to_ram(prange, vmf->vma->vm_mm,
 949				    KFD_MIGRATE_TRIGGER_PAGEFAULT_CPU,
 950				    vmf->page);
 951	if (r)
 952		pr_debug("failed %d migrate svms 0x%p range 0x%p [0x%lx 0x%lx]\n",
 953			 r, prange->svms, prange, prange->start, prange->last);
 954
 955	/* xnack on, update mapping on GPUs with ACCESS_IN_PLACE */
 956	if (p->xnack_enabled && parent == prange)
 957		op = SVM_OP_UPDATE_RANGE_NOTIFIER_AND_MAP;
 958	else
 959		op = SVM_OP_UPDATE_RANGE_NOTIFIER;
 960	svm_range_add_list_work(&p->svms, parent, mm, op);
 961	schedule_deferred_list_work(&p->svms);
 962
 963out_unlock_prange:
 964	if (prange != parent)
 965		mutex_unlock(&prange->migrate_mutex);
 966	mutex_unlock(&parent->migrate_mutex);
 967out_unlock_svms:
 968	mutex_unlock(&p->svms.lock);
 969out_unref_process:
 970	pr_debug("CPU fault svms 0x%p address 0x%lx done\n", &p->svms, addr);
 971	kfd_unref_process(p);
 972out_mmput:
 973	mmput(mm);
 974	return r ? VM_FAULT_SIGBUS : 0;
 975}
 976
 977static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
 978	.page_free		= svm_migrate_page_free,
 979	.migrate_to_ram		= svm_migrate_to_ram,
 980};
 981
 982/* Each VRAM page uses sizeof(struct page) on system memory */
 983#define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
 984
 985int svm_migrate_init(struct amdgpu_device *adev)
 986{
 987	struct kfd_dev *kfddev = adev->kfd.dev;
 988	struct dev_pagemap *pgmap;
 989	struct resource *res = NULL;
 990	unsigned long size;
 991	void *r;
 992
 993	/* Page migration works on Vega10 or newer */
 994	if (!KFD_IS_SOC15(kfddev))
 995		return -EINVAL;
 996
 997	pgmap = &kfddev->pgmap;
 998	memset(pgmap, 0, sizeof(*pgmap));
 999
1000	/* TODO: register all vram to HMM for now.
1001	 * should remove reserved size
1002	 */
1003	size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
1004	if (adev->gmc.xgmi.connected_to_cpu) {
1005		pgmap->range.start = adev->gmc.aper_base;
1006		pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
1007		pgmap->type = MEMORY_DEVICE_COHERENT;
1008	} else {
1009		res = devm_request_free_mem_region(adev->dev, &iomem_resource, size);
1010		if (IS_ERR(res))
1011			return -ENOMEM;
1012		pgmap->range.start = res->start;
1013		pgmap->range.end = res->end;
1014		pgmap->type = MEMORY_DEVICE_PRIVATE;
1015	}
1016
1017	pgmap->nr_range = 1;
1018	pgmap->ops = &svm_migrate_pgmap_ops;
1019	pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
1020	pgmap->flags = 0;
1021	/* Device manager releases device-specific resources, memory region and
1022	 * pgmap when driver disconnects from device.
1023	 */
1024	r = devm_memremap_pages(adev->dev, pgmap);
1025	if (IS_ERR(r)) {
1026		pr_err("failed to register HMM device memory\n");
1027		/* Disable SVM support capability */
1028		pgmap->type = 0;
1029		if (pgmap->type == MEMORY_DEVICE_PRIVATE)
1030			devm_release_mem_region(adev->dev, res->start,
1031						res->end - res->start + 1);
1032		return PTR_ERR(r);
1033	}
1034
1035	pr_debug("reserve %ldMB system memory for VRAM pages struct\n",
1036		 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);
1037
1038	amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));
1039
1040	svm_range_set_max_pages(adev);
1041
1042	pr_info("HMM registered %ldMB device memory\n", size >> 20);
1043
1044	return 0;
1045}