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, entity: &adev->mman.high_pr,
68 AMDGPU_FENCE_OWNER_UNDEFINED,
69 size: num_dw * 4 + num_bytes,
70 pool_type: AMDGPU_IB_POOL_DELAYED,
71 job: &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(bo: 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, offset: 0, pages: npages, dma_addr: addr, flags: pte_flags, dst: 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, addr: *vram);
143 r = svm_migrate_gart_map(ring, npages: size, addr: sys, gart_addr: &gart_d, flags: 0);
144
145 } else if (direction == FROM_RAM_TO_VRAM) {
146 r = svm_migrate_gart_map(ring, npages: size, addr: sys, gart_addr: &gart_s,
147 KFD_IOCTL_SVM_FLAG_GPU_RO);
148 gart_d = svm_migrate_direct_mapping_addr(adev, addr: *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, src_offset: gart_s, dst_offset: gart_d, byte_count: size * PAGE_SIZE,
156 NULL, fence: &next, direct_submit: false, vm_needs_flush: true, tmz: 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(fence: *mfence);
163 *mfence = next;
164 npages -= size;
165 if (npages) {
166 sys += size;
167 vram += size;
168 }
169 }
170
171out_unlock:
172 mutex_unlock(lock: &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(fence: mfence, intr: false);
199 dma_fence_put(fence: 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.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(svm_bo: 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.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_unsuccessful_pages(struct migrate_vma *migrate)
264{
265 unsigned long upages = 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 upages++;
272 }
273 return upages;
274}
275
276static int
277svm_migrate_copy_to_vram(struct kfd_node *node, struct svm_range *prange,
278 struct migrate_vma *migrate, struct dma_fence **mfence,
279 dma_addr_t *scratch, uint64_t ttm_res_offset)
280{
281 uint64_t npages = migrate->cpages;
282 struct amdgpu_device *adev = node->adev;
283 struct device *dev = adev->dev;
284 struct amdgpu_res_cursor cursor;
285 dma_addr_t *src;
286 uint64_t *dst;
287 uint64_t i, j;
288 int r;
289
290 pr_debug("svms 0x%p [0x%lx 0x%lx 0x%llx]\n", prange->svms, prange->start,
291 prange->last, ttm_res_offset);
292
293 src = scratch;
294 dst = (uint64_t *)(scratch + npages);
295
296 amdgpu_res_first(res: prange->ttm_res, start: ttm_res_offset,
297 size: npages << PAGE_SHIFT, cur: &cursor);
298 for (i = j = 0; i < npages; i++) {
299 struct page *spage;
300
301 dst[i] = cursor.start + (j << PAGE_SHIFT);
302 migrate->dst[i] = svm_migrate_addr_to_pfn(adev, addr: dst[i]);
303 svm_migrate_get_vram_page(prange, pfn: migrate->dst[i]);
304 migrate->dst[i] = migrate_pfn(pfn: migrate->dst[i]);
305
306 spage = migrate_pfn_to_page(mpfn: migrate->src[i]);
307 if (spage && !is_zone_device_page(page: spage)) {
308 src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
309 DMA_TO_DEVICE);
310 r = dma_mapping_error(dev, dma_addr: src[i]);
311 if (r) {
312 dev_err(dev, "%s: fail %d dma_map_page\n",
313 __func__, r);
314 goto out_free_vram_pages;
315 }
316 } else {
317 if (j) {
318 r = svm_migrate_copy_memory_gart(
319 adev, sys: src + i - j,
320 vram: dst + i - j, npages: j,
321 direction: FROM_RAM_TO_VRAM,
322 mfence);
323 if (r)
324 goto out_free_vram_pages;
325 amdgpu_res_next(cur: &cursor, size: (j + 1) << PAGE_SHIFT);
326 j = 0;
327 } else {
328 amdgpu_res_next(cur: &cursor, PAGE_SIZE);
329 }
330 continue;
331 }
332
333 pr_debug_ratelimited("dma mapping src to 0x%llx, pfn 0x%lx\n",
334 src[i] >> PAGE_SHIFT, page_to_pfn(spage));
335
336 if (j >= (cursor.size >> PAGE_SHIFT) - 1 && i < npages - 1) {
337 r = svm_migrate_copy_memory_gart(adev, sys: src + i - j,
338 vram: dst + i - j, npages: j + 1,
339 direction: FROM_RAM_TO_VRAM,
340 mfence);
341 if (r)
342 goto out_free_vram_pages;
343 amdgpu_res_next(cur: &cursor, size: (j + 1) * PAGE_SIZE);
344 j = 0;
345 } else {
346 j++;
347 }
348 }
349
350 r = svm_migrate_copy_memory_gart(adev, sys: src + i - j, vram: dst + i - j, npages: j,
351 direction: FROM_RAM_TO_VRAM, mfence);
352
353out_free_vram_pages:
354 if (r) {
355 pr_debug("failed %d to copy memory to vram\n", r);
356 while (i--) {
357 svm_migrate_put_vram_page(adev, addr: dst[i]);
358 migrate->dst[i] = 0;
359 }
360 }
361
362#ifdef DEBUG_FORCE_MIXED_DOMAINS
363 for (i = 0, j = 0; i < npages; i += 4, j++) {
364 if (j & 1)
365 continue;
366 svm_migrate_put_vram_page(adev, dst[i]);
367 migrate->dst[i] = 0;
368 svm_migrate_put_vram_page(adev, dst[i + 1]);
369 migrate->dst[i + 1] = 0;
370 svm_migrate_put_vram_page(adev, dst[i + 2]);
371 migrate->dst[i + 2] = 0;
372 svm_migrate_put_vram_page(adev, dst[i + 3]);
373 migrate->dst[i + 3] = 0;
374 }
375#endif
376
377 return r;
378}
379
380static long
381svm_migrate_vma_to_vram(struct kfd_node *node, struct svm_range *prange,
382 struct vm_area_struct *vma, uint64_t start,
383 uint64_t end, uint32_t trigger, uint64_t ttm_res_offset)
384{
385 struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
386 uint64_t npages = (end - start) >> PAGE_SHIFT;
387 struct amdgpu_device *adev = node->adev;
388 struct kfd_process_device *pdd;
389 struct dma_fence *mfence = NULL;
390 struct migrate_vma migrate = { 0 };
391 unsigned long cpages = 0;
392 unsigned long mpages = 0;
393 dma_addr_t *scratch;
394 void *buf;
395 int r = -ENOMEM;
396
397 memset(&migrate, 0, sizeof(migrate));
398 migrate.vma = vma;
399 migrate.start = start;
400 migrate.end = end;
401 migrate.flags = MIGRATE_VMA_SELECT_SYSTEM;
402 migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
403
404 buf = kvcalloc(n: npages,
405 size: 2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
406 GFP_KERNEL);
407 if (!buf)
408 goto out;
409
410 migrate.src = buf;
411 migrate.dst = migrate.src + npages;
412 scratch = (dma_addr_t *)(migrate.dst + npages);
413
414 kfd_smi_event_migration_start(node, pid: p->lead_thread->pid,
415 start: start >> PAGE_SHIFT, end: end >> PAGE_SHIFT,
416 from: 0, to: node->id, prefetch_loc: prange->prefetch_loc,
417 preferred_loc: prange->preferred_loc, trigger);
418
419 r = migrate_vma_setup(args: &migrate);
420 if (r) {
421 dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
422 __func__, r, prange->start, prange->last);
423 goto out_free;
424 }
425
426 cpages = migrate.cpages;
427 if (!cpages) {
428 pr_debug("failed collect migrate sys pages [0x%lx 0x%lx]\n",
429 prange->start, prange->last);
430 goto out_free;
431 }
432 if (cpages != npages)
433 pr_debug("partial migration, 0x%lx/0x%llx pages collected\n",
434 cpages, npages);
435 else
436 pr_debug("0x%lx pages collected\n", cpages);
437
438 r = svm_migrate_copy_to_vram(node, prange, migrate: &migrate, mfence: &mfence, scratch, ttm_res_offset);
439 migrate_vma_pages(migrate: &migrate);
440
441 svm_migrate_copy_done(adev, mfence);
442 migrate_vma_finalize(migrate: &migrate);
443
444 mpages = cpages - svm_migrate_unsuccessful_pages(migrate: &migrate);
445 pr_debug("successful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
446 mpages, cpages, migrate.npages);
447
448 kfd_smi_event_migration_end(node, pid: p->lead_thread->pid,
449 start: start >> PAGE_SHIFT, end: end >> PAGE_SHIFT,
450 from: 0, to: node->id, trigger);
451
452 svm_range_dma_unmap_dev(dev: adev->dev, dma_addr: scratch, offset: 0, npages);
453
454out_free:
455 kvfree(addr: buf);
456out:
457 if (!r && mpages) {
458 pdd = svm_range_get_pdd_by_node(prange, node);
459 if (pdd)
460 WRITE_ONCE(pdd->page_in, pdd->page_in + mpages);
461
462 return mpages;
463 }
464 return r;
465}
466
467/**
468 * svm_migrate_ram_to_vram - migrate svm range from system to device
469 * @prange: range structure
470 * @best_loc: the device to migrate to
471 * @start_mgr: start page to migrate
472 * @last_mgr: last page to migrate
473 * @mm: the process mm structure
474 * @trigger: reason of migration
475 *
476 * Context: Process context, caller hold mmap read lock, svms lock, prange lock
477 *
478 * Return:
479 * 0 - OK, otherwise error code
480 */
481static int
482svm_migrate_ram_to_vram(struct svm_range *prange, uint32_t best_loc,
483 unsigned long start_mgr, unsigned long last_mgr,
484 struct mm_struct *mm, uint32_t trigger)
485{
486 unsigned long addr, start, end;
487 struct vm_area_struct *vma;
488 uint64_t ttm_res_offset;
489 struct kfd_node *node;
490 unsigned long mpages = 0;
491 long r = 0;
492
493 if (start_mgr < prange->start || last_mgr > prange->last) {
494 pr_debug("range [0x%lx 0x%lx] out prange [0x%lx 0x%lx]\n",
495 start_mgr, last_mgr, prange->start, prange->last);
496 return -EFAULT;
497 }
498
499 node = svm_range_get_node_by_id(prange, gpu_id: best_loc);
500 if (!node) {
501 pr_debug("failed to get kfd node by id 0x%x\n", best_loc);
502 return -ENODEV;
503 }
504
505 pr_debug("svms 0x%p [0x%lx 0x%lx] in [0x%lx 0x%lx] to gpu 0x%x\n",
506 prange->svms, start_mgr, last_mgr, prange->start, prange->last,
507 best_loc);
508
509 start = start_mgr << PAGE_SHIFT;
510 end = (last_mgr + 1) << PAGE_SHIFT;
511
512 r = svm_range_vram_node_new(node, prange, clear: true);
513 if (r) {
514 dev_dbg(node->adev->dev, "fail %ld to alloc vram\n", r);
515 return r;
516 }
517 ttm_res_offset = (start_mgr - prange->start + prange->offset) << PAGE_SHIFT;
518
519 for (addr = start; addr < end;) {
520 unsigned long next;
521
522 vma = vma_lookup(mm, addr);
523 if (!vma)
524 break;
525
526 next = min(vma->vm_end, end);
527 r = svm_migrate_vma_to_vram(node, prange, vma, start: addr, end: next, trigger, ttm_res_offset);
528 if (r < 0) {
529 pr_debug("failed %ld to migrate\n", r);
530 break;
531 } else {
532 mpages += r;
533 }
534 ttm_res_offset += next - addr;
535 addr = next;
536 }
537
538 if (mpages) {
539 prange->actual_loc = best_loc;
540 prange->vram_pages += mpages;
541 } else if (!prange->actual_loc) {
542 /* if no page migrated and all pages from prange are at
543 * sys ram drop svm_bo got from svm_range_vram_node_new
544 */
545 svm_range_vram_node_free(prange);
546 }
547
548 return r < 0 ? r : 0;
549}
550
551static void svm_migrate_page_free(struct page *page)
552{
553 struct svm_range_bo *svm_bo = page->zone_device_data;
554
555 if (svm_bo) {
556 pr_debug_ratelimited("ref: %d\n", kref_read(&svm_bo->kref));
557 svm_range_bo_unref_async(svm_bo);
558 }
559}
560
561static int
562svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
563 struct migrate_vma *migrate, struct dma_fence **mfence,
564 dma_addr_t *scratch, uint64_t npages)
565{
566 struct device *dev = adev->dev;
567 uint64_t *src;
568 dma_addr_t *dst;
569 struct page *dpage;
570 uint64_t i = 0, j;
571 uint64_t addr;
572 int r = 0;
573
574 pr_debug("svms 0x%p [0x%lx 0x%lx]\n", prange->svms, prange->start,
575 prange->last);
576
577 addr = migrate->start;
578
579 src = (uint64_t *)(scratch + npages);
580 dst = scratch;
581
582 for (i = 0, j = 0; i < npages; i++, addr += PAGE_SIZE) {
583 struct page *spage;
584
585 spage = migrate_pfn_to_page(mpfn: migrate->src[i]);
586 if (!spage || !is_zone_device_page(page: spage)) {
587 pr_debug("invalid page. Could be in CPU already svms 0x%p [0x%lx 0x%lx]\n",
588 prange->svms, prange->start, prange->last);
589 if (j) {
590 r = svm_migrate_copy_memory_gart(adev, sys: dst + i - j,
591 vram: src + i - j, npages: j,
592 direction: FROM_VRAM_TO_RAM,
593 mfence);
594 if (r)
595 goto out_oom;
596 j = 0;
597 }
598 continue;
599 }
600 src[i] = svm_migrate_addr(adev, page: spage);
601 if (j > 0 && src[i] != src[i - 1] + PAGE_SIZE) {
602 r = svm_migrate_copy_memory_gart(adev, sys: dst + i - j,
603 vram: src + i - j, npages: j,
604 direction: FROM_VRAM_TO_RAM,
605 mfence);
606 if (r)
607 goto out_oom;
608 j = 0;
609 }
610
611 dpage = svm_migrate_get_sys_page(vma: migrate->vma, addr);
612 if (!dpage) {
613 pr_debug("failed get page svms 0x%p [0x%lx 0x%lx]\n",
614 prange->svms, prange->start, prange->last);
615 r = -ENOMEM;
616 goto out_oom;
617 }
618
619 dst[i] = dma_map_page(dev, dpage, 0, PAGE_SIZE, DMA_FROM_DEVICE);
620 r = dma_mapping_error(dev, dma_addr: dst[i]);
621 if (r) {
622 dev_err(adev->dev, "%s: fail %d dma_map_page\n", __func__, r);
623 goto out_oom;
624 }
625
626 pr_debug_ratelimited("dma mapping dst to 0x%llx, pfn 0x%lx\n",
627 dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
628
629 migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
630 j++;
631 }
632
633 r = svm_migrate_copy_memory_gart(adev, sys: dst + i - j, vram: src + i - j, npages: j,
634 direction: FROM_VRAM_TO_RAM, mfence);
635
636out_oom:
637 if (r) {
638 pr_debug("failed %d copy to ram\n", r);
639 while (i--) {
640 svm_migrate_put_sys_page(addr: dst[i]);
641 migrate->dst[i] = 0;
642 }
643 }
644
645 return r;
646}
647
648/**
649 * svm_migrate_vma_to_ram - migrate range inside one vma from device to system
650 *
651 * @prange: svm range structure
652 * @vma: vm_area_struct that range [start, end] belongs to
653 * @start: range start virtual address in pages
654 * @end: range end virtual address in pages
655 * @node: kfd node device to migrate from
656 * @trigger: reason of migration
657 * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
658 *
659 * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
660 *
661 * Return:
662 * negative values - indicate error
663 * positive values or zero - number of pages got migrated
664 */
665static long
666svm_migrate_vma_to_ram(struct kfd_node *node, struct svm_range *prange,
667 struct vm_area_struct *vma, uint64_t start, uint64_t end,
668 uint32_t trigger, struct page *fault_page)
669{
670 struct kfd_process *p = container_of(prange->svms, struct kfd_process, svms);
671 uint64_t npages = (end - start) >> PAGE_SHIFT;
672 unsigned long upages = npages;
673 unsigned long cpages = 0;
674 unsigned long mpages = 0;
675 struct amdgpu_device *adev = node->adev;
676 struct kfd_process_device *pdd;
677 struct dma_fence *mfence = NULL;
678 struct migrate_vma migrate = { 0 };
679 dma_addr_t *scratch;
680 void *buf;
681 int r = -ENOMEM;
682
683 memset(&migrate, 0, sizeof(migrate));
684 migrate.vma = vma;
685 migrate.start = start;
686 migrate.end = end;
687 migrate.pgmap_owner = SVM_ADEV_PGMAP_OWNER(adev);
688 if (adev->gmc.xgmi.connected_to_cpu)
689 migrate.flags = MIGRATE_VMA_SELECT_DEVICE_COHERENT;
690 else
691 migrate.flags = MIGRATE_VMA_SELECT_DEVICE_PRIVATE;
692
693 buf = kvcalloc(n: npages,
694 size: 2 * sizeof(*migrate.src) + sizeof(uint64_t) + sizeof(dma_addr_t),
695 GFP_KERNEL);
696 if (!buf)
697 goto out;
698
699 migrate.src = buf;
700 migrate.dst = migrate.src + npages;
701 migrate.fault_page = fault_page;
702 scratch = (dma_addr_t *)(migrate.dst + npages);
703
704 kfd_smi_event_migration_start(node, pid: p->lead_thread->pid,
705 start: start >> PAGE_SHIFT, end: end >> PAGE_SHIFT,
706 from: node->id, to: 0, prefetch_loc: prange->prefetch_loc,
707 preferred_loc: prange->preferred_loc, trigger);
708
709 r = migrate_vma_setup(args: &migrate);
710 if (r) {
711 dev_err(adev->dev, "%s: vma setup fail %d range [0x%lx 0x%lx]\n",
712 __func__, r, prange->start, prange->last);
713 goto out_free;
714 }
715
716 cpages = migrate.cpages;
717 if (!cpages) {
718 pr_debug("failed collect migrate device pages [0x%lx 0x%lx]\n",
719 prange->start, prange->last);
720 upages = svm_migrate_unsuccessful_pages(migrate: &migrate);
721 goto out_free;
722 }
723 if (cpages != npages)
724 pr_debug("partial migration, 0x%lx/0x%llx pages collected\n",
725 cpages, npages);
726 else
727 pr_debug("0x%lx pages collected\n", cpages);
728
729 r = svm_migrate_copy_to_ram(adev, prange, migrate: &migrate, mfence: &mfence,
730 scratch, npages);
731 migrate_vma_pages(migrate: &migrate);
732
733 upages = svm_migrate_unsuccessful_pages(migrate: &migrate);
734 pr_debug("unsuccessful/cpages/npages 0x%lx/0x%lx/0x%lx\n",
735 upages, cpages, migrate.npages);
736
737 svm_migrate_copy_done(adev, mfence);
738 migrate_vma_finalize(migrate: &migrate);
739
740 kfd_smi_event_migration_end(node, pid: p->lead_thread->pid,
741 start: start >> PAGE_SHIFT, end: end >> PAGE_SHIFT,
742 from: node->id, to: 0, trigger);
743
744 svm_range_dma_unmap_dev(dev: adev->dev, dma_addr: scratch, offset: 0, npages);
745
746out_free:
747 kvfree(addr: buf);
748out:
749 if (!r && cpages) {
750 mpages = cpages - upages;
751 pdd = svm_range_get_pdd_by_node(prange, node);
752 if (pdd)
753 WRITE_ONCE(pdd->page_out, pdd->page_out + mpages);
754 }
755
756 return r ? r : mpages;
757}
758
759/**
760 * svm_migrate_vram_to_ram - migrate svm range from device to system
761 * @prange: range structure
762 * @mm: process mm, use current->mm if NULL
763 * @start_mgr: start page need be migrated to sys ram
764 * @last_mgr: last page need be migrated to sys ram
765 * @trigger: reason of migration
766 * @fault_page: is from vmf->page, svm_migrate_to_ram(), this is CPU page fault callback
767 *
768 * Context: Process context, caller hold mmap read lock, prange->migrate_mutex
769 *
770 * Return:
771 * 0 - OK, otherwise error code
772 */
773int svm_migrate_vram_to_ram(struct svm_range *prange, struct mm_struct *mm,
774 unsigned long start_mgr, unsigned long last_mgr,
775 uint32_t trigger, struct page *fault_page)
776{
777 struct kfd_node *node;
778 struct vm_area_struct *vma;
779 unsigned long addr;
780 unsigned long start;
781 unsigned long end;
782 unsigned long mpages = 0;
783 long r = 0;
784
785 /* this pragne has no any vram page to migrate to sys ram */
786 if (!prange->actual_loc) {
787 pr_debug("[0x%lx 0x%lx] already migrated to ram\n",
788 prange->start, prange->last);
789 return 0;
790 }
791
792 if (start_mgr < prange->start || last_mgr > prange->last) {
793 pr_debug("range [0x%lx 0x%lx] out prange [0x%lx 0x%lx]\n",
794 start_mgr, last_mgr, prange->start, prange->last);
795 return -EFAULT;
796 }
797
798 node = svm_range_get_node_by_id(prange, gpu_id: prange->actual_loc);
799 if (!node) {
800 pr_debug("failed to get kfd node by id 0x%x\n", prange->actual_loc);
801 return -ENODEV;
802 }
803 pr_debug("svms 0x%p prange 0x%p [0x%lx 0x%lx] from gpu 0x%x to ram\n",
804 prange->svms, prange, start_mgr, last_mgr,
805 prange->actual_loc);
806
807 start = start_mgr << PAGE_SHIFT;
808 end = (last_mgr + 1) << PAGE_SHIFT;
809
810 for (addr = start; addr < end;) {
811 unsigned long next;
812
813 vma = vma_lookup(mm, addr);
814 if (!vma) {
815 pr_debug("failed to find vma for prange %p\n", prange);
816 r = -EFAULT;
817 break;
818 }
819
820 next = min(vma->vm_end, end);
821 r = svm_migrate_vma_to_ram(node, prange, vma, start: addr, end: next, trigger,
822 fault_page);
823 if (r < 0) {
824 pr_debug("failed %ld to migrate prange %p\n", r, prange);
825 break;
826 } else {
827 mpages += r;
828 }
829 addr = next;
830 }
831
832 if (r >= 0) {
833 prange->vram_pages -= mpages;
834
835 /* prange does not have vram page set its actual_loc to system
836 * and drop its svm_bo ref
837 */
838 if (prange->vram_pages == 0 && prange->ttm_res) {
839 prange->actual_loc = 0;
840 svm_range_vram_node_free(prange);
841 }
842 }
843
844 return r < 0 ? r : 0;
845}
846
847/**
848 * svm_migrate_vram_to_vram - migrate svm range from device to device
849 * @prange: range structure
850 * @best_loc: the device to migrate to
851 * @start: start page need be migrated to sys ram
852 * @last: last page need be migrated to sys ram
853 * @mm: process mm, use current->mm if NULL
854 * @trigger: reason of migration
855 *
856 * Context: Process context, caller hold mmap read lock, svms lock, prange lock
857 *
858 * migrate all vram pages in prange to sys ram, then migrate
859 * [start, last] pages from sys ram to gpu node best_loc.
860 *
861 * Return:
862 * 0 - OK, otherwise error code
863 */
864static int
865svm_migrate_vram_to_vram(struct svm_range *prange, uint32_t best_loc,
866 unsigned long start, unsigned long last,
867 struct mm_struct *mm, uint32_t trigger)
868{
869 int r, retries = 3;
870
871 /*
872 * TODO: for both devices with PCIe large bar or on same xgmi hive, skip
873 * system memory as migration bridge
874 */
875
876 pr_debug("from gpu 0x%x to gpu 0x%x\n", prange->actual_loc, best_loc);
877
878 do {
879 r = svm_migrate_vram_to_ram(prange, mm, start_mgr: prange->start, last_mgr: prange->last,
880 trigger, NULL);
881 if (r)
882 return r;
883 } while (prange->actual_loc && --retries);
884
885 if (prange->actual_loc)
886 return -EDEADLK;
887
888 return svm_migrate_ram_to_vram(prange, best_loc, start_mgr: start, last_mgr: last, mm, trigger);
889}
890
891int
892svm_migrate_to_vram(struct svm_range *prange, uint32_t best_loc,
893 unsigned long start, unsigned long last,
894 struct mm_struct *mm, uint32_t trigger)
895{
896 if (!prange->actual_loc || prange->actual_loc == best_loc)
897 return svm_migrate_ram_to_vram(prange, best_loc, start_mgr: start, last_mgr: last,
898 mm, trigger);
899
900 else
901 return svm_migrate_vram_to_vram(prange, best_loc, start, last,
902 mm, trigger);
903
904}
905
906/**
907 * svm_migrate_to_ram - CPU page fault handler
908 * @vmf: CPU vm fault vma, address
909 *
910 * Context: vm fault handler, caller holds the mmap read lock
911 *
912 * Return:
913 * 0 - OK
914 * VM_FAULT_SIGBUS - notice application to have SIGBUS page fault
915 */
916static vm_fault_t svm_migrate_to_ram(struct vm_fault *vmf)
917{
918 unsigned long start, last, size;
919 unsigned long addr = vmf->address;
920 struct svm_range_bo *svm_bo;
921 struct svm_range *prange;
922 struct kfd_process *p;
923 struct mm_struct *mm;
924 int r = 0;
925
926 svm_bo = vmf->page->zone_device_data;
927 if (!svm_bo) {
928 pr_debug("failed get device page at addr 0x%lx\n", addr);
929 return VM_FAULT_SIGBUS;
930 }
931 if (!mmget_not_zero(mm: svm_bo->eviction_fence->mm)) {
932 pr_debug("addr 0x%lx of process mm is destroyed\n", addr);
933 return VM_FAULT_SIGBUS;
934 }
935
936 mm = svm_bo->eviction_fence->mm;
937 if (mm != vmf->vma->vm_mm)
938 pr_debug("addr 0x%lx is COW mapping in child process\n", addr);
939
940 p = kfd_lookup_process_by_mm(mm);
941 if (!p) {
942 pr_debug("failed find process at fault address 0x%lx\n", addr);
943 r = VM_FAULT_SIGBUS;
944 goto out_mmput;
945 }
946 if (READ_ONCE(p->svms.faulting_task) == current) {
947 pr_debug("skipping ram migration\n");
948 r = 0;
949 goto out_unref_process;
950 }
951
952 pr_debug("CPU page fault svms 0x%p address 0x%lx\n", &p->svms, addr);
953 addr >>= PAGE_SHIFT;
954
955 mutex_lock(&p->svms.lock);
956
957 prange = svm_range_from_addr(svms: &p->svms, addr, NULL);
958 if (!prange) {
959 pr_debug("failed get range svms 0x%p addr 0x%lx\n", &p->svms, addr);
960 r = -EFAULT;
961 goto out_unlock_svms;
962 }
963
964 mutex_lock(&prange->migrate_mutex);
965
966 if (!prange->actual_loc)
967 goto out_unlock_prange;
968
969 /* Align migration range start and size to granularity size */
970 size = 1UL << prange->granularity;
971 start = max(ALIGN_DOWN(addr, size), prange->start);
972 last = min(ALIGN(addr + 1, size) - 1, prange->last);
973
974 r = svm_migrate_vram_to_ram(prange, mm: vmf->vma->vm_mm, start_mgr: start, last_mgr: last,
975 trigger: KFD_MIGRATE_TRIGGER_PAGEFAULT_CPU, fault_page: vmf->page);
976 if (r)
977 pr_debug("failed %d migrate svms 0x%p range 0x%p [0x%lx 0x%lx]\n",
978 r, prange->svms, prange, start, last);
979
980out_unlock_prange:
981 mutex_unlock(lock: &prange->migrate_mutex);
982out_unlock_svms:
983 mutex_unlock(lock: &p->svms.lock);
984out_unref_process:
985 pr_debug("CPU fault svms 0x%p address 0x%lx done\n", &p->svms, addr);
986 kfd_unref_process(p);
987out_mmput:
988 mmput(mm);
989 return r ? VM_FAULT_SIGBUS : 0;
990}
991
992static const struct dev_pagemap_ops svm_migrate_pgmap_ops = {
993 .page_free = svm_migrate_page_free,
994 .migrate_to_ram = svm_migrate_to_ram,
995};
996
997/* Each VRAM page uses sizeof(struct page) on system memory */
998#define SVM_HMM_PAGE_STRUCT_SIZE(size) ((size)/PAGE_SIZE * sizeof(struct page))
999
1000int kgd2kfd_init_zone_device(struct amdgpu_device *adev)
1001{
1002 struct amdgpu_kfd_dev *kfddev = &adev->kfd;
1003 struct dev_pagemap *pgmap;
1004 struct resource *res = NULL;
1005 unsigned long size;
1006 void *r;
1007
1008 /* Page migration works on gfx9 or newer */
1009 if (amdgpu_ip_version(adev, ip: GC_HWIP, inst: 0) < IP_VERSION(9, 0, 1))
1010 return -EINVAL;
1011
1012 if (adev->gmc.is_app_apu)
1013 return 0;
1014
1015 pgmap = &kfddev->pgmap;
1016 memset(pgmap, 0, sizeof(*pgmap));
1017
1018 /* TODO: register all vram to HMM for now.
1019 * should remove reserved size
1020 */
1021 size = ALIGN(adev->gmc.real_vram_size, 2ULL << 20);
1022 if (adev->gmc.xgmi.connected_to_cpu) {
1023 pgmap->range.start = adev->gmc.aper_base;
1024 pgmap->range.end = adev->gmc.aper_base + adev->gmc.aper_size - 1;
1025 pgmap->type = MEMORY_DEVICE_COHERENT;
1026 } else {
1027 res = devm_request_free_mem_region(dev: adev->dev, base: &iomem_resource, size);
1028 if (IS_ERR(ptr: res))
1029 return PTR_ERR(ptr: res);
1030 pgmap->range.start = res->start;
1031 pgmap->range.end = res->end;
1032 pgmap->type = MEMORY_DEVICE_PRIVATE;
1033 }
1034
1035 pgmap->nr_range = 1;
1036 pgmap->ops = &svm_migrate_pgmap_ops;
1037 pgmap->owner = SVM_ADEV_PGMAP_OWNER(adev);
1038 pgmap->flags = 0;
1039 /* Device manager releases device-specific resources, memory region and
1040 * pgmap when driver disconnects from device.
1041 */
1042 r = devm_memremap_pages(dev: adev->dev, pgmap);
1043 if (IS_ERR(ptr: r)) {
1044 pr_err("failed to register HMM device memory\n");
1045 if (pgmap->type == MEMORY_DEVICE_PRIVATE)
1046 devm_release_mem_region(adev->dev, res->start, resource_size(res));
1047 /* Disable SVM support capability */
1048 pgmap->type = 0;
1049 return PTR_ERR(ptr: r);
1050 }
1051
1052 pr_debug("reserve %ldMB system memory for VRAM pages struct\n",
1053 SVM_HMM_PAGE_STRUCT_SIZE(size) >> 20);
1054
1055 amdgpu_amdkfd_reserve_system_mem(SVM_HMM_PAGE_STRUCT_SIZE(size));
1056
1057 pr_info("HMM registered %ldMB device memory\n", size >> 20);
1058
1059 return 0;
1060}
1061

source code of linux/drivers/gpu/drm/amd/amdkfd/kfd_migrate.c