xref: /openbmc/linux/drivers/infiniband/hw/mlx5/odp.c (revision 7211ec63)
1 /*
2  * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <rdma/ib_umem.h>
34 #include <rdma/ib_umem_odp.h>
35 
36 #include "mlx5_ib.h"
37 #include "cmd.h"
38 
39 #define MAX_PREFETCH_LEN (4*1024*1024U)
40 
41 /* Timeout in ms to wait for an active mmu notifier to complete when handling
42  * a pagefault. */
43 #define MMU_NOTIFIER_TIMEOUT 1000
44 
45 #define MLX5_IMR_MTT_BITS (30 - PAGE_SHIFT)
46 #define MLX5_IMR_MTT_SHIFT (MLX5_IMR_MTT_BITS + PAGE_SHIFT)
47 #define MLX5_IMR_MTT_ENTRIES BIT_ULL(MLX5_IMR_MTT_BITS)
48 #define MLX5_IMR_MTT_SIZE BIT_ULL(MLX5_IMR_MTT_SHIFT)
49 #define MLX5_IMR_MTT_MASK (~(MLX5_IMR_MTT_SIZE - 1))
50 
51 #define MLX5_KSM_PAGE_SHIFT MLX5_IMR_MTT_SHIFT
52 
53 static u64 mlx5_imr_ksm_entries;
54 
55 static int check_parent(struct ib_umem_odp *odp,
56 			       struct mlx5_ib_mr *parent)
57 {
58 	struct mlx5_ib_mr *mr = odp->private;
59 
60 	return mr && mr->parent == parent && !odp->dying;
61 }
62 
63 static struct ib_umem_odp *odp_next(struct ib_umem_odp *odp)
64 {
65 	struct mlx5_ib_mr *mr = odp->private, *parent = mr->parent;
66 	struct ib_ucontext *ctx = odp->umem->context;
67 	struct rb_node *rb;
68 
69 	down_read(&ctx->umem_rwsem);
70 	while (1) {
71 		rb = rb_next(&odp->interval_tree.rb);
72 		if (!rb)
73 			goto not_found;
74 		odp = rb_entry(rb, struct ib_umem_odp, interval_tree.rb);
75 		if (check_parent(odp, parent))
76 			goto end;
77 	}
78 not_found:
79 	odp = NULL;
80 end:
81 	up_read(&ctx->umem_rwsem);
82 	return odp;
83 }
84 
85 static struct ib_umem_odp *odp_lookup(struct ib_ucontext *ctx,
86 				      u64 start, u64 length,
87 				      struct mlx5_ib_mr *parent)
88 {
89 	struct ib_umem_odp *odp;
90 	struct rb_node *rb;
91 
92 	down_read(&ctx->umem_rwsem);
93 	odp = rbt_ib_umem_lookup(&ctx->umem_tree, start, length);
94 	if (!odp)
95 		goto end;
96 
97 	while (1) {
98 		if (check_parent(odp, parent))
99 			goto end;
100 		rb = rb_next(&odp->interval_tree.rb);
101 		if (!rb)
102 			goto not_found;
103 		odp = rb_entry(rb, struct ib_umem_odp, interval_tree.rb);
104 		if (ib_umem_start(odp->umem) > start + length)
105 			goto not_found;
106 	}
107 not_found:
108 	odp = NULL;
109 end:
110 	up_read(&ctx->umem_rwsem);
111 	return odp;
112 }
113 
114 void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset,
115 			   size_t nentries, struct mlx5_ib_mr *mr, int flags)
116 {
117 	struct ib_pd *pd = mr->ibmr.pd;
118 	struct ib_ucontext *ctx = pd->uobject->context;
119 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
120 	struct ib_umem_odp *odp;
121 	unsigned long va;
122 	int i;
123 
124 	if (flags & MLX5_IB_UPD_XLT_ZAP) {
125 		for (i = 0; i < nentries; i++, pklm++) {
126 			pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
127 			pklm->key = cpu_to_be32(dev->null_mkey);
128 			pklm->va = 0;
129 		}
130 		return;
131 	}
132 
133 	odp = odp_lookup(ctx, offset * MLX5_IMR_MTT_SIZE,
134 			     nentries * MLX5_IMR_MTT_SIZE, mr);
135 
136 	for (i = 0; i < nentries; i++, pklm++) {
137 		pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
138 		va = (offset + i) * MLX5_IMR_MTT_SIZE;
139 		if (odp && odp->umem->address == va) {
140 			struct mlx5_ib_mr *mtt = odp->private;
141 
142 			pklm->key = cpu_to_be32(mtt->ibmr.lkey);
143 			odp = odp_next(odp);
144 		} else {
145 			pklm->key = cpu_to_be32(dev->null_mkey);
146 		}
147 		mlx5_ib_dbg(dev, "[%d] va %lx key %x\n",
148 			    i, va, be32_to_cpu(pklm->key));
149 	}
150 }
151 
152 static void mr_leaf_free_action(struct work_struct *work)
153 {
154 	struct ib_umem_odp *odp = container_of(work, struct ib_umem_odp, work);
155 	int idx = ib_umem_start(odp->umem) >> MLX5_IMR_MTT_SHIFT;
156 	struct mlx5_ib_mr *mr = odp->private, *imr = mr->parent;
157 
158 	mr->parent = NULL;
159 	synchronize_srcu(&mr->dev->mr_srcu);
160 
161 	ib_umem_release(odp->umem);
162 	if (imr->live)
163 		mlx5_ib_update_xlt(imr, idx, 1, 0,
164 				   MLX5_IB_UPD_XLT_INDIRECT |
165 				   MLX5_IB_UPD_XLT_ATOMIC);
166 	mlx5_mr_cache_free(mr->dev, mr);
167 
168 	if (atomic_dec_and_test(&imr->num_leaf_free))
169 		wake_up(&imr->q_leaf_free);
170 }
171 
172 void mlx5_ib_invalidate_range(struct ib_umem *umem, unsigned long start,
173 			      unsigned long end)
174 {
175 	struct mlx5_ib_mr *mr;
176 	const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT /
177 				    sizeof(struct mlx5_mtt)) - 1;
178 	u64 idx = 0, blk_start_idx = 0;
179 	int in_block = 0;
180 	u64 addr;
181 
182 	if (!umem || !umem->odp_data) {
183 		pr_err("invalidation called on NULL umem or non-ODP umem\n");
184 		return;
185 	}
186 
187 	mr = umem->odp_data->private;
188 
189 	if (!mr || !mr->ibmr.pd)
190 		return;
191 
192 	start = max_t(u64, ib_umem_start(umem), start);
193 	end = min_t(u64, ib_umem_end(umem), end);
194 
195 	/*
196 	 * Iteration one - zap the HW's MTTs. The notifiers_count ensures that
197 	 * while we are doing the invalidation, no page fault will attempt to
198 	 * overwrite the same MTTs.  Concurent invalidations might race us,
199 	 * but they will write 0s as well, so no difference in the end result.
200 	 */
201 
202 	for (addr = start; addr < end; addr += BIT(umem->page_shift)) {
203 		idx = (addr - ib_umem_start(umem)) >> umem->page_shift;
204 		/*
205 		 * Strive to write the MTTs in chunks, but avoid overwriting
206 		 * non-existing MTTs. The huristic here can be improved to
207 		 * estimate the cost of another UMR vs. the cost of bigger
208 		 * UMR.
209 		 */
210 		if (umem->odp_data->dma_list[idx] &
211 		    (ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) {
212 			if (!in_block) {
213 				blk_start_idx = idx;
214 				in_block = 1;
215 			}
216 		} else {
217 			u64 umr_offset = idx & umr_block_mask;
218 
219 			if (in_block && umr_offset == 0) {
220 				mlx5_ib_update_xlt(mr, blk_start_idx,
221 						   idx - blk_start_idx, 0,
222 						   MLX5_IB_UPD_XLT_ZAP |
223 						   MLX5_IB_UPD_XLT_ATOMIC);
224 				in_block = 0;
225 			}
226 		}
227 	}
228 	if (in_block)
229 		mlx5_ib_update_xlt(mr, blk_start_idx,
230 				   idx - blk_start_idx + 1, 0,
231 				   MLX5_IB_UPD_XLT_ZAP |
232 				   MLX5_IB_UPD_XLT_ATOMIC);
233 	/*
234 	 * We are now sure that the device will not access the
235 	 * memory. We can safely unmap it, and mark it as dirty if
236 	 * needed.
237 	 */
238 
239 	ib_umem_odp_unmap_dma_pages(umem, start, end);
240 
241 	if (unlikely(!umem->npages && mr->parent &&
242 		     !umem->odp_data->dying)) {
243 		WRITE_ONCE(umem->odp_data->dying, 1);
244 		atomic_inc(&mr->parent->num_leaf_free);
245 		schedule_work(&umem->odp_data->work);
246 	}
247 }
248 
249 void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
250 {
251 	struct ib_odp_caps *caps = &dev->odp_caps;
252 
253 	memset(caps, 0, sizeof(*caps));
254 
255 	if (!MLX5_CAP_GEN(dev->mdev, pg))
256 		return;
257 
258 	caps->general_caps = IB_ODP_SUPPORT;
259 
260 	if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
261 		dev->odp_max_size = U64_MAX;
262 	else
263 		dev->odp_max_size = BIT_ULL(MLX5_MAX_UMR_SHIFT + PAGE_SHIFT);
264 
265 	if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.send))
266 		caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SEND;
267 
268 	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.send))
269 		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SEND;
270 
271 	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.receive))
272 		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_RECV;
273 
274 	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.write))
275 		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_WRITE;
276 
277 	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.read))
278 		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_READ;
279 
280 	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.atomic))
281 		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
282 
283 	if (MLX5_CAP_GEN(dev->mdev, fixed_buffer_size) &&
284 	    MLX5_CAP_GEN(dev->mdev, null_mkey) &&
285 	    MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
286 		caps->general_caps |= IB_ODP_SUPPORT_IMPLICIT;
287 
288 	return;
289 }
290 
291 static void mlx5_ib_page_fault_resume(struct mlx5_ib_dev *dev,
292 				      struct mlx5_pagefault *pfault,
293 				      int error)
294 {
295 	int wq_num = pfault->event_subtype == MLX5_PFAULT_SUBTYPE_WQE ?
296 		     pfault->wqe.wq_num : pfault->token;
297 	int ret = mlx5_core_page_fault_resume(dev->mdev,
298 					      pfault->token,
299 					      wq_num,
300 					      pfault->type,
301 					      error);
302 	if (ret)
303 		mlx5_ib_err(dev, "Failed to resolve the page fault on WQ 0x%x\n",
304 			    wq_num);
305 }
306 
307 static struct mlx5_ib_mr *implicit_mr_alloc(struct ib_pd *pd,
308 					    struct ib_umem *umem,
309 					    bool ksm, int access_flags)
310 {
311 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
312 	struct mlx5_ib_mr *mr;
313 	int err;
314 
315 	mr = mlx5_mr_cache_alloc(dev, ksm ? MLX5_IMR_KSM_CACHE_ENTRY :
316 					    MLX5_IMR_MTT_CACHE_ENTRY);
317 
318 	if (IS_ERR(mr))
319 		return mr;
320 
321 	mr->ibmr.pd = pd;
322 
323 	mr->dev = dev;
324 	mr->access_flags = access_flags;
325 	mr->mmkey.iova = 0;
326 	mr->umem = umem;
327 
328 	if (ksm) {
329 		err = mlx5_ib_update_xlt(mr, 0,
330 					 mlx5_imr_ksm_entries,
331 					 MLX5_KSM_PAGE_SHIFT,
332 					 MLX5_IB_UPD_XLT_INDIRECT |
333 					 MLX5_IB_UPD_XLT_ZAP |
334 					 MLX5_IB_UPD_XLT_ENABLE);
335 
336 	} else {
337 		err = mlx5_ib_update_xlt(mr, 0,
338 					 MLX5_IMR_MTT_ENTRIES,
339 					 PAGE_SHIFT,
340 					 MLX5_IB_UPD_XLT_ZAP |
341 					 MLX5_IB_UPD_XLT_ENABLE |
342 					 MLX5_IB_UPD_XLT_ATOMIC);
343 	}
344 
345 	if (err)
346 		goto fail;
347 
348 	mr->ibmr.lkey = mr->mmkey.key;
349 	mr->ibmr.rkey = mr->mmkey.key;
350 
351 	mr->live = 1;
352 
353 	mlx5_ib_dbg(dev, "key %x dev %p mr %p\n",
354 		    mr->mmkey.key, dev->mdev, mr);
355 
356 	return mr;
357 
358 fail:
359 	mlx5_ib_err(dev, "Failed to register MKEY %d\n", err);
360 	mlx5_mr_cache_free(dev, mr);
361 
362 	return ERR_PTR(err);
363 }
364 
365 static struct ib_umem_odp *implicit_mr_get_data(struct mlx5_ib_mr *mr,
366 						u64 io_virt, size_t bcnt)
367 {
368 	struct ib_ucontext *ctx = mr->ibmr.pd->uobject->context;
369 	struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.pd->device);
370 	struct ib_umem_odp *odp, *result = NULL;
371 	u64 addr = io_virt & MLX5_IMR_MTT_MASK;
372 	int nentries = 0, start_idx = 0, ret;
373 	struct mlx5_ib_mr *mtt;
374 	struct ib_umem *umem;
375 
376 	mutex_lock(&mr->umem->odp_data->umem_mutex);
377 	odp = odp_lookup(ctx, addr, 1, mr);
378 
379 	mlx5_ib_dbg(dev, "io_virt:%llx bcnt:%zx addr:%llx odp:%p\n",
380 		    io_virt, bcnt, addr, odp);
381 
382 next_mr:
383 	if (likely(odp)) {
384 		if (nentries)
385 			nentries++;
386 	} else {
387 		umem = ib_alloc_odp_umem(ctx, addr, MLX5_IMR_MTT_SIZE);
388 		if (IS_ERR(umem)) {
389 			mutex_unlock(&mr->umem->odp_data->umem_mutex);
390 			return ERR_CAST(umem);
391 		}
392 
393 		mtt = implicit_mr_alloc(mr->ibmr.pd, umem, 0, mr->access_flags);
394 		if (IS_ERR(mtt)) {
395 			mutex_unlock(&mr->umem->odp_data->umem_mutex);
396 			ib_umem_release(umem);
397 			return ERR_CAST(mtt);
398 		}
399 
400 		odp = umem->odp_data;
401 		odp->private = mtt;
402 		mtt->umem = umem;
403 		mtt->mmkey.iova = addr;
404 		mtt->parent = mr;
405 		INIT_WORK(&odp->work, mr_leaf_free_action);
406 
407 		if (!nentries)
408 			start_idx = addr >> MLX5_IMR_MTT_SHIFT;
409 		nentries++;
410 	}
411 
412 	/* Return first odp if region not covered by single one */
413 	if (likely(!result))
414 		result = odp;
415 
416 	addr += MLX5_IMR_MTT_SIZE;
417 	if (unlikely(addr < io_virt + bcnt)) {
418 		odp = odp_next(odp);
419 		if (odp && odp->umem->address != addr)
420 			odp = NULL;
421 		goto next_mr;
422 	}
423 
424 	if (unlikely(nentries)) {
425 		ret = mlx5_ib_update_xlt(mr, start_idx, nentries, 0,
426 					 MLX5_IB_UPD_XLT_INDIRECT |
427 					 MLX5_IB_UPD_XLT_ATOMIC);
428 		if (ret) {
429 			mlx5_ib_err(dev, "Failed to update PAS\n");
430 			result = ERR_PTR(ret);
431 		}
432 	}
433 
434 	mutex_unlock(&mr->umem->odp_data->umem_mutex);
435 	return result;
436 }
437 
438 struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
439 					     int access_flags)
440 {
441 	struct ib_ucontext *ctx = pd->ibpd.uobject->context;
442 	struct mlx5_ib_mr *imr;
443 	struct ib_umem *umem;
444 
445 	umem = ib_umem_get(ctx, 0, 0, IB_ACCESS_ON_DEMAND, 0);
446 	if (IS_ERR(umem))
447 		return ERR_CAST(umem);
448 
449 	imr = implicit_mr_alloc(&pd->ibpd, umem, 1, access_flags);
450 	if (IS_ERR(imr)) {
451 		ib_umem_release(umem);
452 		return ERR_CAST(imr);
453 	}
454 
455 	imr->umem = umem;
456 	init_waitqueue_head(&imr->q_leaf_free);
457 	atomic_set(&imr->num_leaf_free, 0);
458 
459 	return imr;
460 }
461 
462 static int mr_leaf_free(struct ib_umem *umem, u64 start,
463 			u64 end, void *cookie)
464 {
465 	struct mlx5_ib_mr *mr = umem->odp_data->private, *imr = cookie;
466 
467 	if (mr->parent != imr)
468 		return 0;
469 
470 	ib_umem_odp_unmap_dma_pages(umem,
471 				    ib_umem_start(umem),
472 				    ib_umem_end(umem));
473 
474 	if (umem->odp_data->dying)
475 		return 0;
476 
477 	WRITE_ONCE(umem->odp_data->dying, 1);
478 	atomic_inc(&imr->num_leaf_free);
479 	schedule_work(&umem->odp_data->work);
480 
481 	return 0;
482 }
483 
484 void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr)
485 {
486 	struct ib_ucontext *ctx = imr->ibmr.pd->uobject->context;
487 
488 	down_read(&ctx->umem_rwsem);
489 	rbt_ib_umem_for_each_in_range(&ctx->umem_tree, 0, ULLONG_MAX,
490 				      mr_leaf_free, imr);
491 	up_read(&ctx->umem_rwsem);
492 
493 	wait_event(imr->q_leaf_free, !atomic_read(&imr->num_leaf_free));
494 }
495 
496 static int pagefault_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr,
497 			u64 io_virt, size_t bcnt, u32 *bytes_mapped)
498 {
499 	u64 access_mask = ODP_READ_ALLOWED_BIT;
500 	int npages = 0, page_shift, np;
501 	u64 start_idx, page_mask;
502 	struct ib_umem_odp *odp;
503 	int current_seq;
504 	size_t size;
505 	int ret;
506 
507 	if (!mr->umem->odp_data->page_list) {
508 		odp = implicit_mr_get_data(mr, io_virt, bcnt);
509 
510 		if (IS_ERR(odp))
511 			return PTR_ERR(odp);
512 		mr = odp->private;
513 
514 	} else {
515 		odp = mr->umem->odp_data;
516 	}
517 
518 next_mr:
519 	size = min_t(size_t, bcnt, ib_umem_end(odp->umem) - io_virt);
520 
521 	page_shift = mr->umem->page_shift;
522 	page_mask = ~(BIT(page_shift) - 1);
523 	start_idx = (io_virt - (mr->mmkey.iova & page_mask)) >> page_shift;
524 
525 	if (mr->umem->writable)
526 		access_mask |= ODP_WRITE_ALLOWED_BIT;
527 
528 	current_seq = READ_ONCE(odp->notifiers_seq);
529 	/*
530 	 * Ensure the sequence number is valid for some time before we call
531 	 * gup.
532 	 */
533 	smp_rmb();
534 
535 	ret = ib_umem_odp_map_dma_pages(mr->umem, io_virt, size,
536 					access_mask, current_seq);
537 
538 	if (ret < 0)
539 		goto out;
540 
541 	np = ret;
542 
543 	mutex_lock(&odp->umem_mutex);
544 	if (!ib_umem_mmu_notifier_retry(mr->umem, current_seq)) {
545 		/*
546 		 * No need to check whether the MTTs really belong to
547 		 * this MR, since ib_umem_odp_map_dma_pages already
548 		 * checks this.
549 		 */
550 		ret = mlx5_ib_update_xlt(mr, start_idx, np,
551 					 page_shift, MLX5_IB_UPD_XLT_ATOMIC);
552 	} else {
553 		ret = -EAGAIN;
554 	}
555 	mutex_unlock(&odp->umem_mutex);
556 
557 	if (ret < 0) {
558 		if (ret != -EAGAIN)
559 			mlx5_ib_err(dev, "Failed to update mkey page tables\n");
560 		goto out;
561 	}
562 
563 	if (bytes_mapped) {
564 		u32 new_mappings = (np << page_shift) -
565 			(io_virt - round_down(io_virt, 1 << page_shift));
566 		*bytes_mapped += min_t(u32, new_mappings, size);
567 	}
568 
569 	npages += np << (page_shift - PAGE_SHIFT);
570 	bcnt -= size;
571 
572 	if (unlikely(bcnt)) {
573 		struct ib_umem_odp *next;
574 
575 		io_virt += size;
576 		next = odp_next(odp);
577 		if (unlikely(!next || next->umem->address != io_virt)) {
578 			mlx5_ib_dbg(dev, "next implicit leaf removed at 0x%llx. got %p\n",
579 				    io_virt, next);
580 			return -EAGAIN;
581 		}
582 		odp = next;
583 		mr = odp->private;
584 		goto next_mr;
585 	}
586 
587 	return npages;
588 
589 out:
590 	if (ret == -EAGAIN) {
591 		if (mr->parent || !odp->dying) {
592 			unsigned long timeout =
593 				msecs_to_jiffies(MMU_NOTIFIER_TIMEOUT);
594 
595 			if (!wait_for_completion_timeout(
596 					&odp->notifier_completion,
597 					timeout)) {
598 				mlx5_ib_warn(dev, "timeout waiting for mmu notifier. seq %d against %d\n",
599 					     current_seq, odp->notifiers_seq);
600 			}
601 		} else {
602 			/* The MR is being killed, kill the QP as well. */
603 			ret = -EFAULT;
604 		}
605 	}
606 
607 	return ret;
608 }
609 
610 struct pf_frame {
611 	struct pf_frame *next;
612 	u32 key;
613 	u64 io_virt;
614 	size_t bcnt;
615 	int depth;
616 };
617 
618 /*
619  * Handle a single data segment in a page-fault WQE or RDMA region.
620  *
621  * Returns number of OS pages retrieved on success. The caller may continue to
622  * the next data segment.
623  * Can return the following error codes:
624  * -EAGAIN to designate a temporary error. The caller will abort handling the
625  *  page fault and resolve it.
626  * -EFAULT when there's an error mapping the requested pages. The caller will
627  *  abort the page fault handling.
628  */
629 static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
630 					 u32 key, u64 io_virt, size_t bcnt,
631 					 u32 *bytes_committed,
632 					 u32 *bytes_mapped)
633 {
634 	int npages = 0, srcu_key, ret, i, outlen, cur_outlen = 0, depth = 0;
635 	struct pf_frame *head = NULL, *frame;
636 	struct mlx5_core_mkey *mmkey;
637 	struct mlx5_ib_mw *mw;
638 	struct mlx5_ib_mr *mr;
639 	struct mlx5_klm *pklm;
640 	u32 *out = NULL;
641 	size_t offset;
642 
643 	srcu_key = srcu_read_lock(&dev->mr_srcu);
644 
645 	io_virt += *bytes_committed;
646 	bcnt -= *bytes_committed;
647 
648 next_mr:
649 	mmkey = __mlx5_mr_lookup(dev->mdev, mlx5_base_mkey(key));
650 	if (!mmkey || mmkey->key != key) {
651 		mlx5_ib_dbg(dev, "failed to find mkey %x\n", key);
652 		ret = -EFAULT;
653 		goto srcu_unlock;
654 	}
655 
656 	switch (mmkey->type) {
657 	case MLX5_MKEY_MR:
658 		mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
659 		if (!mr->live || !mr->ibmr.pd) {
660 			mlx5_ib_dbg(dev, "got dead MR\n");
661 			ret = -EFAULT;
662 			goto srcu_unlock;
663 		}
664 
665 		ret = pagefault_mr(dev, mr, io_virt, bcnt, bytes_mapped);
666 		if (ret < 0)
667 			goto srcu_unlock;
668 
669 		npages += ret;
670 		ret = 0;
671 		break;
672 
673 	case MLX5_MKEY_MW:
674 		mw = container_of(mmkey, struct mlx5_ib_mw, mmkey);
675 
676 		if (depth >= MLX5_CAP_GEN(dev->mdev, max_indirection)) {
677 			mlx5_ib_dbg(dev, "indirection level exceeded\n");
678 			ret = -EFAULT;
679 			goto srcu_unlock;
680 		}
681 
682 		outlen = MLX5_ST_SZ_BYTES(query_mkey_out) +
683 			sizeof(*pklm) * (mw->ndescs - 2);
684 
685 		if (outlen > cur_outlen) {
686 			kfree(out);
687 			out = kzalloc(outlen, GFP_KERNEL);
688 			if (!out) {
689 				ret = -ENOMEM;
690 				goto srcu_unlock;
691 			}
692 			cur_outlen = outlen;
693 		}
694 
695 		pklm = (struct mlx5_klm *)MLX5_ADDR_OF(query_mkey_out, out,
696 						       bsf0_klm0_pas_mtt0_1);
697 
698 		ret = mlx5_core_query_mkey(dev->mdev, &mw->mmkey, out, outlen);
699 		if (ret)
700 			goto srcu_unlock;
701 
702 		offset = io_virt - MLX5_GET64(query_mkey_out, out,
703 					      memory_key_mkey_entry.start_addr);
704 
705 		for (i = 0; bcnt && i < mw->ndescs; i++, pklm++) {
706 			if (offset >= be32_to_cpu(pklm->bcount)) {
707 				offset -= be32_to_cpu(pklm->bcount);
708 				continue;
709 			}
710 
711 			frame = kzalloc(sizeof(*frame), GFP_KERNEL);
712 			if (!frame) {
713 				ret = -ENOMEM;
714 				goto srcu_unlock;
715 			}
716 
717 			frame->key = be32_to_cpu(pklm->key);
718 			frame->io_virt = be64_to_cpu(pklm->va) + offset;
719 			frame->bcnt = min_t(size_t, bcnt,
720 					    be32_to_cpu(pklm->bcount) - offset);
721 			frame->depth = depth + 1;
722 			frame->next = head;
723 			head = frame;
724 
725 			bcnt -= frame->bcnt;
726 		}
727 		break;
728 
729 	default:
730 		mlx5_ib_dbg(dev, "wrong mkey type %d\n", mmkey->type);
731 		ret = -EFAULT;
732 		goto srcu_unlock;
733 	}
734 
735 	if (head) {
736 		frame = head;
737 		head = frame->next;
738 
739 		key = frame->key;
740 		io_virt = frame->io_virt;
741 		bcnt = frame->bcnt;
742 		depth = frame->depth;
743 		kfree(frame);
744 
745 		goto next_mr;
746 	}
747 
748 srcu_unlock:
749 	while (head) {
750 		frame = head;
751 		head = frame->next;
752 		kfree(frame);
753 	}
754 	kfree(out);
755 
756 	srcu_read_unlock(&dev->mr_srcu, srcu_key);
757 	*bytes_committed = 0;
758 	return ret ? ret : npages;
759 }
760 
761 /**
762  * Parse a series of data segments for page fault handling.
763  *
764  * @qp the QP on which the fault occurred.
765  * @pfault contains page fault information.
766  * @wqe points at the first data segment in the WQE.
767  * @wqe_end points after the end of the WQE.
768  * @bytes_mapped receives the number of bytes that the function was able to
769  *               map. This allows the caller to decide intelligently whether
770  *               enough memory was mapped to resolve the page fault
771  *               successfully (e.g. enough for the next MTU, or the entire
772  *               WQE).
773  * @total_wqe_bytes receives the total data size of this WQE in bytes (minus
774  *                  the committed bytes).
775  *
776  * Returns the number of pages loaded if positive, zero for an empty WQE, or a
777  * negative error code.
778  */
779 static int pagefault_data_segments(struct mlx5_ib_dev *dev,
780 				   struct mlx5_pagefault *pfault,
781 				   struct mlx5_ib_qp *qp, void *wqe,
782 				   void *wqe_end, u32 *bytes_mapped,
783 				   u32 *total_wqe_bytes, int receive_queue)
784 {
785 	int ret = 0, npages = 0;
786 	u64 io_virt;
787 	u32 key;
788 	u32 byte_count;
789 	size_t bcnt;
790 	int inline_segment;
791 
792 	/* Skip SRQ next-WQE segment. */
793 	if (receive_queue && qp->ibqp.srq)
794 		wqe += sizeof(struct mlx5_wqe_srq_next_seg);
795 
796 	if (bytes_mapped)
797 		*bytes_mapped = 0;
798 	if (total_wqe_bytes)
799 		*total_wqe_bytes = 0;
800 
801 	while (wqe < wqe_end) {
802 		struct mlx5_wqe_data_seg *dseg = wqe;
803 
804 		io_virt = be64_to_cpu(dseg->addr);
805 		key = be32_to_cpu(dseg->lkey);
806 		byte_count = be32_to_cpu(dseg->byte_count);
807 		inline_segment = !!(byte_count &  MLX5_INLINE_SEG);
808 		bcnt	       = byte_count & ~MLX5_INLINE_SEG;
809 
810 		if (inline_segment) {
811 			bcnt = bcnt & MLX5_WQE_INLINE_SEG_BYTE_COUNT_MASK;
812 			wqe += ALIGN(sizeof(struct mlx5_wqe_inline_seg) + bcnt,
813 				     16);
814 		} else {
815 			wqe += sizeof(*dseg);
816 		}
817 
818 		/* receive WQE end of sg list. */
819 		if (receive_queue && bcnt == 0 && key == MLX5_INVALID_LKEY &&
820 		    io_virt == 0)
821 			break;
822 
823 		if (!inline_segment && total_wqe_bytes) {
824 			*total_wqe_bytes += bcnt - min_t(size_t, bcnt,
825 					pfault->bytes_committed);
826 		}
827 
828 		/* A zero length data segment designates a length of 2GB. */
829 		if (bcnt == 0)
830 			bcnt = 1U << 31;
831 
832 		if (inline_segment || bcnt <= pfault->bytes_committed) {
833 			pfault->bytes_committed -=
834 				min_t(size_t, bcnt,
835 				      pfault->bytes_committed);
836 			continue;
837 		}
838 
839 		ret = pagefault_single_data_segment(dev, key, io_virt, bcnt,
840 						    &pfault->bytes_committed,
841 						    bytes_mapped);
842 		if (ret < 0)
843 			break;
844 		npages += ret;
845 	}
846 
847 	return ret < 0 ? ret : npages;
848 }
849 
850 static const u32 mlx5_ib_odp_opcode_cap[] = {
851 	[MLX5_OPCODE_SEND]	       = IB_ODP_SUPPORT_SEND,
852 	[MLX5_OPCODE_SEND_IMM]	       = IB_ODP_SUPPORT_SEND,
853 	[MLX5_OPCODE_SEND_INVAL]       = IB_ODP_SUPPORT_SEND,
854 	[MLX5_OPCODE_RDMA_WRITE]       = IB_ODP_SUPPORT_WRITE,
855 	[MLX5_OPCODE_RDMA_WRITE_IMM]   = IB_ODP_SUPPORT_WRITE,
856 	[MLX5_OPCODE_RDMA_READ]	       = IB_ODP_SUPPORT_READ,
857 	[MLX5_OPCODE_ATOMIC_CS]	       = IB_ODP_SUPPORT_ATOMIC,
858 	[MLX5_OPCODE_ATOMIC_FA]	       = IB_ODP_SUPPORT_ATOMIC,
859 };
860 
861 /*
862  * Parse initiator WQE. Advances the wqe pointer to point at the
863  * scatter-gather list, and set wqe_end to the end of the WQE.
864  */
865 static int mlx5_ib_mr_initiator_pfault_handler(
866 	struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
867 	struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
868 {
869 	struct mlx5_wqe_ctrl_seg *ctrl = *wqe;
870 	u16 wqe_index = pfault->wqe.wqe_index;
871 	u32 transport_caps;
872 	struct mlx5_base_av *av;
873 	unsigned ds, opcode;
874 #if defined(DEBUG)
875 	u32 ctrl_wqe_index, ctrl_qpn;
876 #endif
877 	u32 qpn = qp->trans_qp.base.mqp.qpn;
878 
879 	ds = be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_DS_MASK;
880 	if (ds * MLX5_WQE_DS_UNITS > wqe_length) {
881 		mlx5_ib_err(dev, "Unable to read the complete WQE. ds = 0x%x, ret = 0x%x\n",
882 			    ds, wqe_length);
883 		return -EFAULT;
884 	}
885 
886 	if (ds == 0) {
887 		mlx5_ib_err(dev, "Got WQE with zero DS. wqe_index=%x, qpn=%x\n",
888 			    wqe_index, qpn);
889 		return -EFAULT;
890 	}
891 
892 #if defined(DEBUG)
893 	ctrl_wqe_index = (be32_to_cpu(ctrl->opmod_idx_opcode) &
894 			MLX5_WQE_CTRL_WQE_INDEX_MASK) >>
895 			MLX5_WQE_CTRL_WQE_INDEX_SHIFT;
896 	if (wqe_index != ctrl_wqe_index) {
897 		mlx5_ib_err(dev, "Got WQE with invalid wqe_index. wqe_index=0x%x, qpn=0x%x ctrl->wqe_index=0x%x\n",
898 			    wqe_index, qpn,
899 			    ctrl_wqe_index);
900 		return -EFAULT;
901 	}
902 
903 	ctrl_qpn = (be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_QPN_MASK) >>
904 		MLX5_WQE_CTRL_QPN_SHIFT;
905 	if (qpn != ctrl_qpn) {
906 		mlx5_ib_err(dev, "Got WQE with incorrect QP number. wqe_index=0x%x, qpn=0x%x ctrl->qpn=0x%x\n",
907 			    wqe_index, qpn,
908 			    ctrl_qpn);
909 		return -EFAULT;
910 	}
911 #endif /* DEBUG */
912 
913 	*wqe_end = *wqe + ds * MLX5_WQE_DS_UNITS;
914 	*wqe += sizeof(*ctrl);
915 
916 	opcode = be32_to_cpu(ctrl->opmod_idx_opcode) &
917 		 MLX5_WQE_CTRL_OPCODE_MASK;
918 
919 	switch (qp->ibqp.qp_type) {
920 	case IB_QPT_RC:
921 		transport_caps = dev->odp_caps.per_transport_caps.rc_odp_caps;
922 		break;
923 	case IB_QPT_UD:
924 		transport_caps = dev->odp_caps.per_transport_caps.ud_odp_caps;
925 		break;
926 	default:
927 		mlx5_ib_err(dev, "ODP fault on QP of an unsupported transport 0x%x\n",
928 			    qp->ibqp.qp_type);
929 		return -EFAULT;
930 	}
931 
932 	if (unlikely(opcode >= sizeof(mlx5_ib_odp_opcode_cap) /
933 	    sizeof(mlx5_ib_odp_opcode_cap[0]) ||
934 	    !(transport_caps & mlx5_ib_odp_opcode_cap[opcode]))) {
935 		mlx5_ib_err(dev, "ODP fault on QP of an unsupported opcode 0x%x\n",
936 			    opcode);
937 		return -EFAULT;
938 	}
939 
940 	if (qp->ibqp.qp_type != IB_QPT_RC) {
941 		av = *wqe;
942 		if (av->dqp_dct & cpu_to_be32(MLX5_EXTENDED_UD_AV))
943 			*wqe += sizeof(struct mlx5_av);
944 		else
945 			*wqe += sizeof(struct mlx5_base_av);
946 	}
947 
948 	switch (opcode) {
949 	case MLX5_OPCODE_RDMA_WRITE:
950 	case MLX5_OPCODE_RDMA_WRITE_IMM:
951 	case MLX5_OPCODE_RDMA_READ:
952 		*wqe += sizeof(struct mlx5_wqe_raddr_seg);
953 		break;
954 	case MLX5_OPCODE_ATOMIC_CS:
955 	case MLX5_OPCODE_ATOMIC_FA:
956 		*wqe += sizeof(struct mlx5_wqe_raddr_seg);
957 		*wqe += sizeof(struct mlx5_wqe_atomic_seg);
958 		break;
959 	}
960 
961 	return 0;
962 }
963 
964 /*
965  * Parse responder WQE. Advances the wqe pointer to point at the
966  * scatter-gather list, and set wqe_end to the end of the WQE.
967  */
968 static int mlx5_ib_mr_responder_pfault_handler(
969 	struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
970 	struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
971 {
972 	struct mlx5_ib_wq *wq = &qp->rq;
973 	int wqe_size = 1 << wq->wqe_shift;
974 
975 	if (qp->ibqp.srq) {
976 		mlx5_ib_err(dev, "ODP fault on SRQ is not supported\n");
977 		return -EFAULT;
978 	}
979 
980 	if (qp->wq_sig) {
981 		mlx5_ib_err(dev, "ODP fault with WQE signatures is not supported\n");
982 		return -EFAULT;
983 	}
984 
985 	if (wqe_size > wqe_length) {
986 		mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
987 		return -EFAULT;
988 	}
989 
990 	switch (qp->ibqp.qp_type) {
991 	case IB_QPT_RC:
992 		if (!(dev->odp_caps.per_transport_caps.rc_odp_caps &
993 		      IB_ODP_SUPPORT_RECV))
994 			goto invalid_transport_or_opcode;
995 		break;
996 	default:
997 invalid_transport_or_opcode:
998 		mlx5_ib_err(dev, "ODP fault on QP of an unsupported transport. transport: 0x%x\n",
999 			    qp->ibqp.qp_type);
1000 		return -EFAULT;
1001 	}
1002 
1003 	*wqe_end = *wqe + wqe_size;
1004 
1005 	return 0;
1006 }
1007 
1008 static struct mlx5_ib_qp *mlx5_ib_odp_find_qp(struct mlx5_ib_dev *dev,
1009 					      u32 wq_num)
1010 {
1011 	struct mlx5_core_qp *mqp = __mlx5_qp_lookup(dev->mdev, wq_num);
1012 
1013 	if (!mqp) {
1014 		mlx5_ib_err(dev, "QPN 0x%6x not found\n", wq_num);
1015 		return NULL;
1016 	}
1017 
1018 	return to_mibqp(mqp);
1019 }
1020 
1021 static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
1022 					  struct mlx5_pagefault *pfault)
1023 {
1024 	int ret;
1025 	void *wqe, *wqe_end;
1026 	u32 bytes_mapped, total_wqe_bytes;
1027 	char *buffer = NULL;
1028 	int resume_with_error = 1;
1029 	u16 wqe_index = pfault->wqe.wqe_index;
1030 	int requestor = pfault->type & MLX5_PFAULT_REQUESTOR;
1031 	struct mlx5_ib_qp *qp;
1032 
1033 	buffer = (char *)__get_free_page(GFP_KERNEL);
1034 	if (!buffer) {
1035 		mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
1036 		goto resolve_page_fault;
1037 	}
1038 
1039 	qp = mlx5_ib_odp_find_qp(dev, pfault->wqe.wq_num);
1040 	if (!qp)
1041 		goto resolve_page_fault;
1042 
1043 	ret = mlx5_ib_read_user_wqe(qp, requestor, wqe_index, buffer,
1044 				    PAGE_SIZE, &qp->trans_qp.base);
1045 	if (ret < 0) {
1046 		mlx5_ib_err(dev, "Failed reading a WQE following page fault, error=%d, wqe_index=%x, qpn=%x\n",
1047 			    ret, wqe_index, pfault->token);
1048 		goto resolve_page_fault;
1049 	}
1050 
1051 	wqe = buffer;
1052 	if (requestor)
1053 		ret = mlx5_ib_mr_initiator_pfault_handler(dev, pfault, qp, &wqe,
1054 							  &wqe_end, ret);
1055 	else
1056 		ret = mlx5_ib_mr_responder_pfault_handler(dev, pfault, qp, &wqe,
1057 							  &wqe_end, ret);
1058 	if (ret < 0)
1059 		goto resolve_page_fault;
1060 
1061 	if (wqe >= wqe_end) {
1062 		mlx5_ib_err(dev, "ODP fault on invalid WQE.\n");
1063 		goto resolve_page_fault;
1064 	}
1065 
1066 	ret = pagefault_data_segments(dev, pfault, qp, wqe, wqe_end,
1067 				      &bytes_mapped, &total_wqe_bytes,
1068 				      !requestor);
1069 	if (ret == -EAGAIN) {
1070 		resume_with_error = 0;
1071 		goto resolve_page_fault;
1072 	} else if (ret < 0 || total_wqe_bytes > bytes_mapped) {
1073 		goto resolve_page_fault;
1074 	}
1075 
1076 	resume_with_error = 0;
1077 resolve_page_fault:
1078 	mlx5_ib_page_fault_resume(dev, pfault, resume_with_error);
1079 	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, type: 0x%x\n",
1080 		    pfault->wqe.wq_num, resume_with_error,
1081 		    pfault->type);
1082 	free_page((unsigned long)buffer);
1083 }
1084 
1085 static int pages_in_range(u64 address, u32 length)
1086 {
1087 	return (ALIGN(address + length, PAGE_SIZE) -
1088 		(address & PAGE_MASK)) >> PAGE_SHIFT;
1089 }
1090 
1091 static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_dev *dev,
1092 					   struct mlx5_pagefault *pfault)
1093 {
1094 	u64 address;
1095 	u32 length;
1096 	u32 prefetch_len = pfault->bytes_committed;
1097 	int prefetch_activated = 0;
1098 	u32 rkey = pfault->rdma.r_key;
1099 	int ret;
1100 
1101 	/* The RDMA responder handler handles the page fault in two parts.
1102 	 * First it brings the necessary pages for the current packet
1103 	 * (and uses the pfault context), and then (after resuming the QP)
1104 	 * prefetches more pages. The second operation cannot use the pfault
1105 	 * context and therefore uses the dummy_pfault context allocated on
1106 	 * the stack */
1107 	pfault->rdma.rdma_va += pfault->bytes_committed;
1108 	pfault->rdma.rdma_op_len -= min(pfault->bytes_committed,
1109 					 pfault->rdma.rdma_op_len);
1110 	pfault->bytes_committed = 0;
1111 
1112 	address = pfault->rdma.rdma_va;
1113 	length  = pfault->rdma.rdma_op_len;
1114 
1115 	/* For some operations, the hardware cannot tell the exact message
1116 	 * length, and in those cases it reports zero. Use prefetch
1117 	 * logic. */
1118 	if (length == 0) {
1119 		prefetch_activated = 1;
1120 		length = pfault->rdma.packet_size;
1121 		prefetch_len = min(MAX_PREFETCH_LEN, prefetch_len);
1122 	}
1123 
1124 	ret = pagefault_single_data_segment(dev, rkey, address, length,
1125 					    &pfault->bytes_committed, NULL);
1126 	if (ret == -EAGAIN) {
1127 		/* We're racing with an invalidation, don't prefetch */
1128 		prefetch_activated = 0;
1129 	} else if (ret < 0 || pages_in_range(address, length) > ret) {
1130 		mlx5_ib_page_fault_resume(dev, pfault, 1);
1131 		if (ret != -ENOENT)
1132 			mlx5_ib_dbg(dev, "PAGE FAULT error %d. QP 0x%x, type: 0x%x\n",
1133 				    ret, pfault->token, pfault->type);
1134 		return;
1135 	}
1136 
1137 	mlx5_ib_page_fault_resume(dev, pfault, 0);
1138 	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x, type: 0x%x, prefetch_activated: %d\n",
1139 		    pfault->token, pfault->type,
1140 		    prefetch_activated);
1141 
1142 	/* At this point, there might be a new pagefault already arriving in
1143 	 * the eq, switch to the dummy pagefault for the rest of the
1144 	 * processing. We're still OK with the objects being alive as the
1145 	 * work-queue is being fenced. */
1146 
1147 	if (prefetch_activated) {
1148 		u32 bytes_committed = 0;
1149 
1150 		ret = pagefault_single_data_segment(dev, rkey, address,
1151 						    prefetch_len,
1152 						    &bytes_committed, NULL);
1153 		if (ret < 0 && ret != -EAGAIN) {
1154 			mlx5_ib_dbg(dev, "Prefetch failed. ret: %d, QP 0x%x, address: 0x%.16llx, length = 0x%.16x\n",
1155 				    ret, pfault->token, address, prefetch_len);
1156 		}
1157 	}
1158 }
1159 
1160 void mlx5_ib_pfault(struct mlx5_core_dev *mdev, void *context,
1161 		    struct mlx5_pagefault *pfault)
1162 {
1163 	struct mlx5_ib_dev *dev = context;
1164 	u8 event_subtype = pfault->event_subtype;
1165 
1166 	switch (event_subtype) {
1167 	case MLX5_PFAULT_SUBTYPE_WQE:
1168 		mlx5_ib_mr_wqe_pfault_handler(dev, pfault);
1169 		break;
1170 	case MLX5_PFAULT_SUBTYPE_RDMA:
1171 		mlx5_ib_mr_rdma_pfault_handler(dev, pfault);
1172 		break;
1173 	default:
1174 		mlx5_ib_err(dev, "Invalid page fault event subtype: 0x%x\n",
1175 			    event_subtype);
1176 		mlx5_ib_page_fault_resume(dev, pfault, 1);
1177 	}
1178 }
1179 
1180 void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent)
1181 {
1182 	if (!(ent->dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
1183 		return;
1184 
1185 	switch (ent->order - 2) {
1186 	case MLX5_IMR_MTT_CACHE_ENTRY:
1187 		ent->page = PAGE_SHIFT;
1188 		ent->xlt = MLX5_IMR_MTT_ENTRIES *
1189 			   sizeof(struct mlx5_mtt) /
1190 			   MLX5_IB_UMR_OCTOWORD;
1191 		ent->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
1192 		ent->limit = 0;
1193 		break;
1194 
1195 	case MLX5_IMR_KSM_CACHE_ENTRY:
1196 		ent->page = MLX5_KSM_PAGE_SHIFT;
1197 		ent->xlt = mlx5_imr_ksm_entries *
1198 			   sizeof(struct mlx5_klm) /
1199 			   MLX5_IB_UMR_OCTOWORD;
1200 		ent->access_mode = MLX5_MKC_ACCESS_MODE_KSM;
1201 		ent->limit = 0;
1202 		break;
1203 	}
1204 }
1205 
1206 int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
1207 {
1208 	int ret;
1209 
1210 	ret = init_srcu_struct(&dev->mr_srcu);
1211 	if (ret)
1212 		return ret;
1213 
1214 	if (dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT) {
1215 		ret = mlx5_cmd_null_mkey(dev->mdev, &dev->null_mkey);
1216 		if (ret) {
1217 			mlx5_ib_err(dev, "Error getting null_mkey %d\n", ret);
1218 			return ret;
1219 		}
1220 	}
1221 
1222 	return 0;
1223 }
1224 
1225 void mlx5_ib_odp_remove_one(struct mlx5_ib_dev *dev)
1226 {
1227 	cleanup_srcu_struct(&dev->mr_srcu);
1228 }
1229 
1230 int mlx5_ib_odp_init(void)
1231 {
1232 	mlx5_imr_ksm_entries = BIT_ULL(get_order(TASK_SIZE) -
1233 				       MLX5_IMR_MTT_BITS);
1234 
1235 	return 0;
1236 }
1237 
1238