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_odp.h>
  34#include <linux/kernel.h>
  35#include <linux/dma-buf.h>
  36#include <linux/dma-resv.h>
  37
  38#include "mlx5_ib.h"
  39#include "cmd.h"
  40#include "umr.h"
  41#include "qp.h"
  42
  43#include <linux/mlx5/eq.h>
  44
  45/* Contains the details of a pagefault. */
  46struct mlx5_pagefault {
  47	u32			bytes_committed;
  48	u32			token;
  49	u8			event_subtype;
  50	u8			type;
  51	union {
  52		/* Initiator or send message responder pagefault details. */
  53		struct {
  54			/* Received packet size, only valid for responders. */
  55			u32	packet_size;
  56			/*
  57			 * Number of resource holding WQE, depends on type.
  58			 */
  59			u32	wq_num;
  60			/*
  61			 * WQE index. Refers to either the send queue or
  62			 * receive queue, according to event_subtype.
  63			 */
  64			u16	wqe_index;
  65		} wqe;
  66		/* RDMA responder pagefault details */
  67		struct {
  68			u32	r_key;
  69			/*
  70			 * Received packet size, minimal size page fault
  71			 * resolution required for forward progress.
  72			 */
  73			u32	packet_size;
  74			u32	rdma_op_len;
  75			u64	rdma_va;
  76		} rdma;
  77	};
  78
  79	struct mlx5_ib_pf_eq	*eq;
  80	struct work_struct	work;
  81};
  82
  83#define MAX_PREFETCH_LEN (4*1024*1024U)
  84
  85/* Timeout in ms to wait for an active mmu notifier to complete when handling
  86 * a pagefault. */
  87#define MMU_NOTIFIER_TIMEOUT 1000
  88
  89#define MLX5_IMR_MTT_BITS (30 - PAGE_SHIFT)
  90#define MLX5_IMR_MTT_SHIFT (MLX5_IMR_MTT_BITS + PAGE_SHIFT)
  91#define MLX5_IMR_MTT_ENTRIES BIT_ULL(MLX5_IMR_MTT_BITS)
  92#define MLX5_IMR_MTT_SIZE BIT_ULL(MLX5_IMR_MTT_SHIFT)
  93#define MLX5_IMR_MTT_MASK (~(MLX5_IMR_MTT_SIZE - 1))
  94
  95#define MLX5_KSM_PAGE_SHIFT MLX5_IMR_MTT_SHIFT
  96
  97static u64 mlx5_imr_ksm_entries;
  98
  99static void populate_klm(struct mlx5_klm *pklm, size_t idx, size_t nentries,
 100			struct mlx5_ib_mr *imr, int flags)
 101{
 102	struct mlx5_klm *end = pklm + nentries;
 103
 104	if (flags & MLX5_IB_UPD_XLT_ZAP) {
 105		for (; pklm != end; pklm++, idx++) {
 106			pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
 107			pklm->key = mr_to_mdev(imr)->mkeys.null_mkey;
 108			pklm->va = 0;
 109		}
 110		return;
 111	}
 112
 113	/*
 114	 * The locking here is pretty subtle. Ideally the implicit_children
 115	 * xarray would be protected by the umem_mutex, however that is not
 116	 * possible. Instead this uses a weaker update-then-lock pattern:
 117	 *
 118	 *    xa_store()
 119	 *    mutex_lock(umem_mutex)
 120	 *     mlx5r_umr_update_xlt()
 121	 *    mutex_unlock(umem_mutex)
 122	 *    destroy lkey
 123	 *
 124	 * ie any change the xarray must be followed by the locked update_xlt
 125	 * before destroying.
 126	 *
 127	 * The umem_mutex provides the acquire/release semantic needed to make
 128	 * the xa_store() visible to a racing thread.
 129	 */
 130	lockdep_assert_held(&to_ib_umem_odp(imr->umem)->umem_mutex);
 131
 132	for (; pklm != end; pklm++, idx++) {
 133		struct mlx5_ib_mr *mtt = xa_load(&imr->implicit_children, idx);
 134
 135		pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
 136		if (mtt) {
 137			pklm->key = cpu_to_be32(mtt->ibmr.lkey);
 138			pklm->va = cpu_to_be64(idx * MLX5_IMR_MTT_SIZE);
 139		} else {
 140			pklm->key = mr_to_mdev(imr)->mkeys.null_mkey;
 141			pklm->va = 0;
 142		}
 143	}
 144}
 145
 146static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
 147{
 148	u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
 149
 150	if (umem_dma & ODP_READ_ALLOWED_BIT)
 151		mtt_entry |= MLX5_IB_MTT_READ;
 152	if (umem_dma & ODP_WRITE_ALLOWED_BIT)
 153		mtt_entry |= MLX5_IB_MTT_WRITE;
 154
 155	return mtt_entry;
 156}
 157
 158static void populate_mtt(__be64 *pas, size_t idx, size_t nentries,
 159			 struct mlx5_ib_mr *mr, int flags)
 160{
 161	struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 162	dma_addr_t pa;
 163	size_t i;
 164
 165	if (flags & MLX5_IB_UPD_XLT_ZAP)
 166		return;
 167
 168	for (i = 0; i < nentries; i++) {
 169		pa = odp->dma_list[idx + i];
 170		pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
 171	}
 172}
 173
 174void mlx5_odp_populate_xlt(void *xlt, size_t idx, size_t nentries,
 175			   struct mlx5_ib_mr *mr, int flags)
 176{
 177	if (flags & MLX5_IB_UPD_XLT_INDIRECT) {
 178		populate_klm(xlt, idx, nentries, mr, flags);
 179	} else {
 180		populate_mtt(xlt, idx, nentries, mr, flags);
 181	}
 182}
 183
 184/*
 185 * This must be called after the mr has been removed from implicit_children.
 186 * NOTE: The MR does not necessarily have to be
 187 * empty here, parallel page faults could have raced with the free process and
 188 * added pages to it.
 189 */
 190static void free_implicit_child_mr_work(struct work_struct *work)
 191{
 192	struct mlx5_ib_mr *mr =
 193		container_of(work, struct mlx5_ib_mr, odp_destroy.work);
 194	struct mlx5_ib_mr *imr = mr->parent;
 195	struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem);
 196	struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 197
 198	mlx5r_deref_wait_odp_mkey(&mr->mmkey);
 199
 200	mutex_lock(&odp_imr->umem_mutex);
 201	mlx5r_umr_update_xlt(mr->parent,
 202			     ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT, 1, 0,
 203			     MLX5_IB_UPD_XLT_INDIRECT | MLX5_IB_UPD_XLT_ATOMIC);
 204	mutex_unlock(&odp_imr->umem_mutex);
 205	mlx5_ib_dereg_mr(&mr->ibmr, NULL);
 206
 207	mlx5r_deref_odp_mkey(&imr->mmkey);
 208}
 209
 210static void destroy_unused_implicit_child_mr(struct mlx5_ib_mr *mr)
 211{
 212	struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 213	unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT;
 214	struct mlx5_ib_mr *imr = mr->parent;
 215
 216	if (!refcount_inc_not_zero(&imr->mmkey.usecount))
 217		return;
 218
 219	xa_erase(&imr->implicit_children, idx);
 220
 221	/* Freeing a MR is a sleeping operation, so bounce to a work queue */
 222	INIT_WORK(&mr->odp_destroy.work, free_implicit_child_mr_work);
 223	queue_work(system_unbound_wq, &mr->odp_destroy.work);
 224}
 225
 226static bool mlx5_ib_invalidate_range(struct mmu_interval_notifier *mni,
 227				     const struct mmu_notifier_range *range,
 228				     unsigned long cur_seq)
 229{
 230	struct ib_umem_odp *umem_odp =
 231		container_of(mni, struct ib_umem_odp, notifier);
 232	struct mlx5_ib_mr *mr;
 233	const u64 umr_block_mask = MLX5_UMR_MTT_NUM_ENTRIES_ALIGNMENT - 1;
 234	u64 idx = 0, blk_start_idx = 0;
 235	u64 invalidations = 0;
 236	unsigned long start;
 237	unsigned long end;
 238	int in_block = 0;
 239	u64 addr;
 240
 241	if (!mmu_notifier_range_blockable(range))
 242		return false;
 243
 244	mutex_lock(&umem_odp->umem_mutex);
 245	mmu_interval_set_seq(mni, cur_seq);
 246	/*
 247	 * If npages is zero then umem_odp->private may not be setup yet. This
 248	 * does not complete until after the first page is mapped for DMA.
 249	 */
 250	if (!umem_odp->npages)
 251		goto out;
 252	mr = umem_odp->private;
 253
 254	start = max_t(u64, ib_umem_start(umem_odp), range->start);
 255	end = min_t(u64, ib_umem_end(umem_odp), range->end);
 256
 257	/*
 258	 * Iteration one - zap the HW's MTTs. The notifiers_count ensures that
 259	 * while we are doing the invalidation, no page fault will attempt to
 260	 * overwrite the same MTTs.  Concurent invalidations might race us,
 261	 * but they will write 0s as well, so no difference in the end result.
 262	 */
 263	for (addr = start; addr < end; addr += BIT(umem_odp->page_shift)) {
 264		idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift;
 265		/*
 266		 * Strive to write the MTTs in chunks, but avoid overwriting
 267		 * non-existing MTTs. The huristic here can be improved to
 268		 * estimate the cost of another UMR vs. the cost of bigger
 269		 * UMR.
 270		 */
 271		if (umem_odp->dma_list[idx] &
 272		    (ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) {
 273			if (!in_block) {
 274				blk_start_idx = idx;
 275				in_block = 1;
 276			}
 277
 278			/* Count page invalidations */
 279			invalidations += idx - blk_start_idx + 1;
 280		} else {
 281			u64 umr_offset = idx & umr_block_mask;
 282
 283			if (in_block && umr_offset == 0) {
 284				mlx5r_umr_update_xlt(mr, blk_start_idx,
 285						     idx - blk_start_idx, 0,
 286						     MLX5_IB_UPD_XLT_ZAP |
 287						     MLX5_IB_UPD_XLT_ATOMIC);
 288				in_block = 0;
 289			}
 290		}
 291	}
 292	if (in_block)
 293		mlx5r_umr_update_xlt(mr, blk_start_idx,
 294				     idx - blk_start_idx + 1, 0,
 295				     MLX5_IB_UPD_XLT_ZAP |
 296				     MLX5_IB_UPD_XLT_ATOMIC);
 297
 298	mlx5_update_odp_stats(mr, invalidations, invalidations);
 299
 300	/*
 301	 * We are now sure that the device will not access the
 302	 * memory. We can safely unmap it, and mark it as dirty if
 303	 * needed.
 304	 */
 305
 306	ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
 307
 308	if (unlikely(!umem_odp->npages && mr->parent))
 309		destroy_unused_implicit_child_mr(mr);
 310out:
 311	mutex_unlock(&umem_odp->umem_mutex);
 312	return true;
 313}
 314
 315const struct mmu_interval_notifier_ops mlx5_mn_ops = {
 316	.invalidate = mlx5_ib_invalidate_range,
 317};
 318
 319static void internal_fill_odp_caps(struct mlx5_ib_dev *dev)
 320{
 321	struct ib_odp_caps *caps = &dev->odp_caps;
 322
 323	memset(caps, 0, sizeof(*caps));
 324
 325	if (!MLX5_CAP_GEN(dev->mdev, pg) || !mlx5r_umr_can_load_pas(dev, 0))
 326		return;
 327
 328	caps->general_caps = IB_ODP_SUPPORT;
 329
 330	if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
 331		dev->odp_max_size = U64_MAX;
 332	else
 333		dev->odp_max_size = BIT_ULL(MLX5_MAX_UMR_SHIFT + PAGE_SHIFT);
 334
 335	if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.send))
 336		caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SEND;
 337
 338	if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.srq_receive))
 339		caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 340
 341	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.send))
 342		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SEND;
 343
 344	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.receive))
 345		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_RECV;
 346
 347	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.write))
 348		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_WRITE;
 349
 350	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.read))
 351		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_READ;
 352
 353	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.atomic))
 354		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
 355
 356	if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.srq_receive))
 357		caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 358
 359	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.send))
 360		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SEND;
 361
 362	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.receive))
 363		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_RECV;
 364
 365	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.write))
 366		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_WRITE;
 367
 368	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.read))
 369		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_READ;
 370
 371	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.atomic))
 372		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
 373
 374	if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.srq_receive))
 375		caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 376
 377	if (MLX5_CAP_GEN(dev->mdev, fixed_buffer_size) &&
 378	    MLX5_CAP_GEN(dev->mdev, null_mkey) &&
 379	    MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset) &&
 380	    !MLX5_CAP_GEN(dev->mdev, umr_indirect_mkey_disabled))
 381		caps->general_caps |= IB_ODP_SUPPORT_IMPLICIT;
 382}
 383
 384static void mlx5_ib_page_fault_resume(struct mlx5_ib_dev *dev,
 385				      struct mlx5_pagefault *pfault,
 386				      int error)
 387{
 388	int wq_num = pfault->event_subtype == MLX5_PFAULT_SUBTYPE_WQE ?
 389		     pfault->wqe.wq_num : pfault->token;
 390	u32 in[MLX5_ST_SZ_DW(page_fault_resume_in)] = {};
 391	int err;
 392
 393	MLX5_SET(page_fault_resume_in, in, opcode, MLX5_CMD_OP_PAGE_FAULT_RESUME);
 394	MLX5_SET(page_fault_resume_in, in, page_fault_type, pfault->type);
 395	MLX5_SET(page_fault_resume_in, in, token, pfault->token);
 396	MLX5_SET(page_fault_resume_in, in, wq_number, wq_num);
 397	MLX5_SET(page_fault_resume_in, in, error, !!error);
 398
 399	err = mlx5_cmd_exec_in(dev->mdev, page_fault_resume, in);
 400	if (err)
 401		mlx5_ib_err(dev, "Failed to resolve the page fault on WQ 0x%x err %d\n",
 402			    wq_num, err);
 403}
 404
 405static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr,
 406						unsigned long idx)
 407{
 408	struct mlx5_ib_dev *dev = mr_to_mdev(imr);
 409	struct ib_umem_odp *odp;
 410	struct mlx5_ib_mr *mr;
 411	struct mlx5_ib_mr *ret;
 412	int err;
 413
 414	odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem),
 415				      idx * MLX5_IMR_MTT_SIZE,
 416				      MLX5_IMR_MTT_SIZE, &mlx5_mn_ops);
 417	if (IS_ERR(odp))
 418		return ERR_CAST(odp);
 419
 420	mr = mlx5_mr_cache_alloc(dev, imr->access_flags,
 421				 MLX5_MKC_ACCESS_MODE_MTT,
 422				 MLX5_IMR_MTT_ENTRIES);
 423	if (IS_ERR(mr)) {
 424		ib_umem_odp_release(odp);
 425		return mr;
 426	}
 427
 428	mr->access_flags = imr->access_flags;
 429	mr->ibmr.pd = imr->ibmr.pd;
 430	mr->ibmr.device = &mr_to_mdev(imr)->ib_dev;
 431	mr->umem = &odp->umem;
 432	mr->ibmr.lkey = mr->mmkey.key;
 433	mr->ibmr.rkey = mr->mmkey.key;
 434	mr->ibmr.iova = idx * MLX5_IMR_MTT_SIZE;
 435	mr->parent = imr;
 436	odp->private = mr;
 437
 438	/*
 439	 * First refcount is owned by the xarray and second refconut
 440	 * is returned to the caller.
 441	 */
 442	refcount_set(&mr->mmkey.usecount, 2);
 443
 444	err = mlx5r_umr_update_xlt(mr, 0,
 445				   MLX5_IMR_MTT_ENTRIES,
 446				   PAGE_SHIFT,
 447				   MLX5_IB_UPD_XLT_ZAP |
 448				   MLX5_IB_UPD_XLT_ENABLE);
 449	if (err) {
 450		ret = ERR_PTR(err);
 451		goto out_mr;
 452	}
 453
 454	xa_lock(&imr->implicit_children);
 455	ret = __xa_cmpxchg(&imr->implicit_children, idx, NULL, mr,
 456			   GFP_KERNEL);
 457	if (unlikely(ret)) {
 458		if (xa_is_err(ret)) {
 459			ret = ERR_PTR(xa_err(ret));
 460			goto out_lock;
 461		}
 462		/*
 463		 * Another thread beat us to creating the child mr, use
 464		 * theirs.
 465		 */
 466		refcount_inc(&ret->mmkey.usecount);
 467		goto out_lock;
 468	}
 469	xa_unlock(&imr->implicit_children);
 470
 471	mlx5_ib_dbg(mr_to_mdev(imr), "key %x mr %p\n", mr->mmkey.key, mr);
 472	return mr;
 473
 474out_lock:
 475	xa_unlock(&imr->implicit_children);
 476out_mr:
 477	mlx5_ib_dereg_mr(&mr->ibmr, NULL);
 478	return ret;
 479}
 480
 481struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
 482					     int access_flags)
 483{
 484	struct mlx5_ib_dev *dev = to_mdev(pd->ibpd.device);
 485	struct ib_umem_odp *umem_odp;
 486	struct mlx5_ib_mr *imr;
 487	int err;
 488
 489	if (!mlx5r_umr_can_load_pas(dev, MLX5_IMR_MTT_ENTRIES * PAGE_SIZE))
 490		return ERR_PTR(-EOPNOTSUPP);
 491
 492	umem_odp = ib_umem_odp_alloc_implicit(&dev->ib_dev, access_flags);
 493	if (IS_ERR(umem_odp))
 494		return ERR_CAST(umem_odp);
 495
 496	imr = mlx5_mr_cache_alloc(dev, access_flags, MLX5_MKC_ACCESS_MODE_KSM,
 497				  mlx5_imr_ksm_entries);
 
 498	if (IS_ERR(imr)) {
 499		ib_umem_odp_release(umem_odp);
 500		return imr;
 501	}
 502
 503	imr->access_flags = access_flags;
 504	imr->ibmr.pd = &pd->ibpd;
 505	imr->ibmr.iova = 0;
 506	imr->umem = &umem_odp->umem;
 507	imr->ibmr.lkey = imr->mmkey.key;
 508	imr->ibmr.rkey = imr->mmkey.key;
 509	imr->ibmr.device = &dev->ib_dev;
 510	imr->is_odp_implicit = true;
 511	xa_init(&imr->implicit_children);
 512
 513	err = mlx5r_umr_update_xlt(imr, 0,
 514				   mlx5_imr_ksm_entries,
 515				   MLX5_KSM_PAGE_SHIFT,
 516				   MLX5_IB_UPD_XLT_INDIRECT |
 517				   MLX5_IB_UPD_XLT_ZAP |
 518				   MLX5_IB_UPD_XLT_ENABLE);
 519	if (err)
 520		goto out_mr;
 521
 522	err = mlx5r_store_odp_mkey(dev, &imr->mmkey);
 523	if (err)
 524		goto out_mr;
 525
 526	mlx5_ib_dbg(dev, "key %x mr %p\n", imr->mmkey.key, imr);
 527	return imr;
 528out_mr:
 529	mlx5_ib_err(dev, "Failed to register MKEY %d\n", err);
 530	mlx5_ib_dereg_mr(&imr->ibmr, NULL);
 531	return ERR_PTR(err);
 532}
 533
 534void mlx5_ib_free_odp_mr(struct mlx5_ib_mr *mr)
 535{
 536	struct mlx5_ib_mr *mtt;
 537	unsigned long idx;
 538
 539	/*
 540	 * If this is an implicit MR it is already invalidated so we can just
 541	 * delete the children mkeys.
 542	 */
 543	xa_for_each(&mr->implicit_children, idx, mtt) {
 544		xa_erase(&mr->implicit_children, idx);
 545		mlx5_ib_dereg_mr(&mtt->ibmr, NULL);
 546	}
 547}
 548
 549#define MLX5_PF_FLAGS_DOWNGRADE BIT(1)
 550#define MLX5_PF_FLAGS_SNAPSHOT BIT(2)
 551#define MLX5_PF_FLAGS_ENABLE BIT(3)
 552static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
 553			     u64 user_va, size_t bcnt, u32 *bytes_mapped,
 554			     u32 flags)
 555{
 556	int page_shift, ret, np;
 557	bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE;
 558	u64 access_mask;
 559	u64 start_idx;
 560	bool fault = !(flags & MLX5_PF_FLAGS_SNAPSHOT);
 561	u32 xlt_flags = MLX5_IB_UPD_XLT_ATOMIC;
 562
 563	if (flags & MLX5_PF_FLAGS_ENABLE)
 564		xlt_flags |= MLX5_IB_UPD_XLT_ENABLE;
 565
 566	page_shift = odp->page_shift;
 567	start_idx = (user_va - ib_umem_start(odp)) >> page_shift;
 568	access_mask = ODP_READ_ALLOWED_BIT;
 569
 570	if (odp->umem.writable && !downgrade)
 571		access_mask |= ODP_WRITE_ALLOWED_BIT;
 572
 573	np = ib_umem_odp_map_dma_and_lock(odp, user_va, bcnt, access_mask, fault);
 574	if (np < 0)
 575		return np;
 576
 577	/*
 578	 * No need to check whether the MTTs really belong to this MR, since
 579	 * ib_umem_odp_map_dma_and_lock already checks this.
 580	 */
 581	ret = mlx5r_umr_update_xlt(mr, start_idx, np, page_shift, xlt_flags);
 582	mutex_unlock(&odp->umem_mutex);
 583
 584	if (ret < 0) {
 585		if (ret != -EAGAIN)
 586			mlx5_ib_err(mr_to_mdev(mr),
 587				    "Failed to update mkey page tables\n");
 588		goto out;
 589	}
 590
 591	if (bytes_mapped) {
 592		u32 new_mappings = (np << page_shift) -
 593			(user_va - round_down(user_va, 1 << page_shift));
 594
 595		*bytes_mapped += min_t(u32, new_mappings, bcnt);
 596	}
 597
 598	return np << (page_shift - PAGE_SHIFT);
 599
 600out:
 601	return ret;
 602}
 603
 604static int pagefault_implicit_mr(struct mlx5_ib_mr *imr,
 605				 struct ib_umem_odp *odp_imr, u64 user_va,
 606				 size_t bcnt, u32 *bytes_mapped, u32 flags)
 607{
 608	unsigned long end_idx = (user_va + bcnt - 1) >> MLX5_IMR_MTT_SHIFT;
 609	unsigned long upd_start_idx = end_idx + 1;
 610	unsigned long upd_len = 0;
 611	unsigned long npages = 0;
 612	int err;
 613	int ret;
 614
 615	if (unlikely(user_va >= mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE ||
 616		     mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE - user_va < bcnt))
 617		return -EFAULT;
 618
 619	/* Fault each child mr that intersects with our interval. */
 620	while (bcnt) {
 621		unsigned long idx = user_va >> MLX5_IMR_MTT_SHIFT;
 622		struct ib_umem_odp *umem_odp;
 623		struct mlx5_ib_mr *mtt;
 624		u64 len;
 625
 626		xa_lock(&imr->implicit_children);
 627		mtt = xa_load(&imr->implicit_children, idx);
 628		if (unlikely(!mtt)) {
 629			xa_unlock(&imr->implicit_children);
 630			mtt = implicit_get_child_mr(imr, idx);
 631			if (IS_ERR(mtt)) {
 632				ret = PTR_ERR(mtt);
 633				goto out;
 634			}
 635			upd_start_idx = min(upd_start_idx, idx);
 636			upd_len = idx - upd_start_idx + 1;
 637		} else {
 638			refcount_inc(&mtt->mmkey.usecount);
 639			xa_unlock(&imr->implicit_children);
 640		}
 641
 642		umem_odp = to_ib_umem_odp(mtt->umem);
 643		len = min_t(u64, user_va + bcnt, ib_umem_end(umem_odp)) -
 644		      user_va;
 645
 646		ret = pagefault_real_mr(mtt, umem_odp, user_va, len,
 647					bytes_mapped, flags);
 648
 649		mlx5r_deref_odp_mkey(&mtt->mmkey);
 650
 651		if (ret < 0)
 652			goto out;
 653		user_va += len;
 654		bcnt -= len;
 655		npages += ret;
 656	}
 657
 658	ret = npages;
 659
 660	/*
 661	 * Any time the implicit_children are changed we must perform an
 662	 * update of the xlt before exiting to ensure the HW and the
 663	 * implicit_children remains synchronized.
 664	 */
 665out:
 666	if (likely(!upd_len))
 667		return ret;
 668
 669	/*
 670	 * Notice this is not strictly ordered right, the KSM is updated after
 671	 * the implicit_children is updated, so a parallel page fault could
 672	 * see a MR that is not yet visible in the KSM.  This is similar to a
 673	 * parallel page fault seeing a MR that is being concurrently removed
 674	 * from the KSM. Both of these improbable situations are resolved
 675	 * safely by resuming the HW and then taking another page fault. The
 676	 * next pagefault handler will see the new information.
 677	 */
 678	mutex_lock(&odp_imr->umem_mutex);
 679	err = mlx5r_umr_update_xlt(imr, upd_start_idx, upd_len, 0,
 680				   MLX5_IB_UPD_XLT_INDIRECT |
 681					  MLX5_IB_UPD_XLT_ATOMIC);
 682	mutex_unlock(&odp_imr->umem_mutex);
 683	if (err) {
 684		mlx5_ib_err(mr_to_mdev(imr), "Failed to update PAS\n");
 685		return err;
 686	}
 687	return ret;
 688}
 689
 690static int pagefault_dmabuf_mr(struct mlx5_ib_mr *mr, size_t bcnt,
 691			       u32 *bytes_mapped, u32 flags)
 692{
 693	struct ib_umem_dmabuf *umem_dmabuf = to_ib_umem_dmabuf(mr->umem);
 694	u32 xlt_flags = 0;
 695	int err;
 696	unsigned int page_size;
 697
 698	if (flags & MLX5_PF_FLAGS_ENABLE)
 699		xlt_flags |= MLX5_IB_UPD_XLT_ENABLE;
 700
 701	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);
 702	err = ib_umem_dmabuf_map_pages(umem_dmabuf);
 703	if (err) {
 704		dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
 705		return err;
 706	}
 707
 708	page_size = mlx5_umem_find_best_pgsz(&umem_dmabuf->umem, mkc,
 709					     log_page_size, 0,
 710					     umem_dmabuf->umem.iova);
 711	if (unlikely(page_size < PAGE_SIZE)) {
 712		ib_umem_dmabuf_unmap_pages(umem_dmabuf);
 713		err = -EINVAL;
 714	} else {
 715		err = mlx5r_umr_update_mr_pas(mr, xlt_flags);
 716	}
 717	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);
 718
 719	if (err)
 720		return err;
 721
 722	if (bytes_mapped)
 723		*bytes_mapped += bcnt;
 724
 725	return ib_umem_num_pages(mr->umem);
 726}
 727
 728/*
 729 * Returns:
 730 *  -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are
 731 *           not accessible, or the MR is no longer valid.
 732 *  -EAGAIN/-ENOMEM: The operation should be retried
 733 *
 734 *  -EINVAL/others: General internal malfunction
 735 *  >0: Number of pages mapped
 736 */
 737static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
 738			u32 *bytes_mapped, u32 flags)
 739{
 740	struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 741
 742	if (unlikely(io_virt < mr->ibmr.iova))
 743		return -EFAULT;
 744
 745	if (mr->umem->is_dmabuf)
 746		return pagefault_dmabuf_mr(mr, bcnt, bytes_mapped, flags);
 747
 748	if (!odp->is_implicit_odp) {
 749		u64 user_va;
 750
 751		if (check_add_overflow(io_virt - mr->ibmr.iova,
 752				       (u64)odp->umem.address, &user_va))
 753			return -EFAULT;
 754		if (unlikely(user_va >= ib_umem_end(odp) ||
 755			     ib_umem_end(odp) - user_va < bcnt))
 756			return -EFAULT;
 757		return pagefault_real_mr(mr, odp, user_va, bcnt, bytes_mapped,
 758					 flags);
 759	}
 760	return pagefault_implicit_mr(mr, odp, io_virt, bcnt, bytes_mapped,
 761				     flags);
 762}
 763
 764int mlx5_ib_init_odp_mr(struct mlx5_ib_mr *mr)
 765{
 766	int ret;
 767
 768	ret = pagefault_real_mr(mr, to_ib_umem_odp(mr->umem), mr->umem->address,
 769				mr->umem->length, NULL,
 770				MLX5_PF_FLAGS_SNAPSHOT | MLX5_PF_FLAGS_ENABLE);
 771	return ret >= 0 ? 0 : ret;
 772}
 773
 774int mlx5_ib_init_dmabuf_mr(struct mlx5_ib_mr *mr)
 775{
 776	int ret;
 777
 778	ret = pagefault_dmabuf_mr(mr, mr->umem->length, NULL,
 779				  MLX5_PF_FLAGS_ENABLE);
 780
 781	return ret >= 0 ? 0 : ret;
 782}
 783
 784struct pf_frame {
 785	struct pf_frame *next;
 786	u32 key;
 787	u64 io_virt;
 788	size_t bcnt;
 789	int depth;
 790};
 791
 792static bool mkey_is_eq(struct mlx5_ib_mkey *mmkey, u32 key)
 793{
 794	if (!mmkey)
 795		return false;
 796	if (mmkey->type == MLX5_MKEY_MW ||
 797	    mmkey->type == MLX5_MKEY_INDIRECT_DEVX)
 798		return mlx5_base_mkey(mmkey->key) == mlx5_base_mkey(key);
 799	return mmkey->key == key;
 800}
 801
 802/*
 803 * Handle a single data segment in a page-fault WQE or RDMA region.
 804 *
 805 * Returns number of OS pages retrieved on success. The caller may continue to
 806 * the next data segment.
 807 * Can return the following error codes:
 808 * -EAGAIN to designate a temporary error. The caller will abort handling the
 809 *  page fault and resolve it.
 810 * -EFAULT when there's an error mapping the requested pages. The caller will
 811 *  abort the page fault handling.
 812 */
 813static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
 814					 struct ib_pd *pd, u32 key,
 815					 u64 io_virt, size_t bcnt,
 816					 u32 *bytes_committed,
 817					 u32 *bytes_mapped)
 818{
 819	int npages = 0, ret, i, outlen, cur_outlen = 0, depth = 0;
 820	struct pf_frame *head = NULL, *frame;
 821	struct mlx5_ib_mkey *mmkey;
 822	struct mlx5_ib_mr *mr;
 823	struct mlx5_klm *pklm;
 824	u32 *out = NULL;
 825	size_t offset;
 826
 827	io_virt += *bytes_committed;
 828	bcnt -= *bytes_committed;
 829
 830next_mr:
 831	xa_lock(&dev->odp_mkeys);
 832	mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(key));
 833	if (!mmkey) {
 834		xa_unlock(&dev->odp_mkeys);
 835		mlx5_ib_dbg(
 836			dev,
 837			"skipping non ODP MR (lkey=0x%06x) in page fault handler.\n",
 838			key);
 839		if (bytes_mapped)
 840			*bytes_mapped += bcnt;
 841		/*
 842		 * The user could specify a SGL with multiple lkeys and only
 843		 * some of them are ODP. Treat the non-ODP ones as fully
 844		 * faulted.
 845		 */
 846		ret = 0;
 847		goto end;
 848	}
 849	refcount_inc(&mmkey->usecount);
 850	xa_unlock(&dev->odp_mkeys);
 851
 852	if (!mkey_is_eq(mmkey, key)) {
 853		mlx5_ib_dbg(dev, "failed to find mkey %x\n", key);
 854		ret = -EFAULT;
 855		goto end;
 856	}
 857
 858	switch (mmkey->type) {
 859	case MLX5_MKEY_MR:
 860		mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
 861
 862		ret = pagefault_mr(mr, io_virt, bcnt, bytes_mapped, 0);
 863		if (ret < 0)
 864			goto end;
 865
 866		mlx5_update_odp_stats(mr, faults, ret);
 867
 868		npages += ret;
 869		ret = 0;
 870		break;
 871
 872	case MLX5_MKEY_MW:
 873	case MLX5_MKEY_INDIRECT_DEVX:
 874		if (depth >= MLX5_CAP_GEN(dev->mdev, max_indirection)) {
 875			mlx5_ib_dbg(dev, "indirection level exceeded\n");
 876			ret = -EFAULT;
 877			goto end;
 878		}
 879
 880		outlen = MLX5_ST_SZ_BYTES(query_mkey_out) +
 881			sizeof(*pklm) * (mmkey->ndescs - 2);
 882
 883		if (outlen > cur_outlen) {
 884			kfree(out);
 885			out = kzalloc(outlen, GFP_KERNEL);
 886			if (!out) {
 887				ret = -ENOMEM;
 888				goto end;
 889			}
 890			cur_outlen = outlen;
 891		}
 892
 893		pklm = (struct mlx5_klm *)MLX5_ADDR_OF(query_mkey_out, out,
 894						       bsf0_klm0_pas_mtt0_1);
 895
 896		ret = mlx5_core_query_mkey(dev->mdev, mmkey->key, out, outlen);
 897		if (ret)
 898			goto end;
 899
 900		offset = io_virt - MLX5_GET64(query_mkey_out, out,
 901					      memory_key_mkey_entry.start_addr);
 902
 903		for (i = 0; bcnt && i < mmkey->ndescs; i++, pklm++) {
 904			if (offset >= be32_to_cpu(pklm->bcount)) {
 905				offset -= be32_to_cpu(pklm->bcount);
 906				continue;
 907			}
 908
 909			frame = kzalloc(sizeof(*frame), GFP_KERNEL);
 910			if (!frame) {
 911				ret = -ENOMEM;
 912				goto end;
 913			}
 914
 915			frame->key = be32_to_cpu(pklm->key);
 916			frame->io_virt = be64_to_cpu(pklm->va) + offset;
 917			frame->bcnt = min_t(size_t, bcnt,
 918					    be32_to_cpu(pklm->bcount) - offset);
 919			frame->depth = depth + 1;
 920			frame->next = head;
 921			head = frame;
 922
 923			bcnt -= frame->bcnt;
 924			offset = 0;
 925		}
 926		break;
 927
 928	default:
 929		mlx5_ib_dbg(dev, "wrong mkey type %d\n", mmkey->type);
 930		ret = -EFAULT;
 931		goto end;
 932	}
 933
 934	if (head) {
 935		frame = head;
 936		head = frame->next;
 937
 938		key = frame->key;
 939		io_virt = frame->io_virt;
 940		bcnt = frame->bcnt;
 941		depth = frame->depth;
 942		kfree(frame);
 943
 944		mlx5r_deref_odp_mkey(mmkey);
 945		goto next_mr;
 946	}
 947
 948end:
 949	if (mmkey)
 950		mlx5r_deref_odp_mkey(mmkey);
 951	while (head) {
 952		frame = head;
 953		head = frame->next;
 954		kfree(frame);
 955	}
 956	kfree(out);
 957
 958	*bytes_committed = 0;
 959	return ret ? ret : npages;
 960}
 961
 962/*
 963 * Parse a series of data segments for page fault handling.
 964 *
 965 * @dev:  Pointer to mlx5 IB device
 966 * @pfault: contains page fault information.
 967 * @wqe: points at the first data segment in the WQE.
 968 * @wqe_end: points after the end of the WQE.
 969 * @bytes_mapped: receives the number of bytes that the function was able to
 970 *                map. This allows the caller to decide intelligently whether
 971 *                enough memory was mapped to resolve the page fault
 972 *                successfully (e.g. enough for the next MTU, or the entire
 973 *                WQE).
 974 * @total_wqe_bytes: receives the total data size of this WQE in bytes (minus
 975 *                   the committed bytes).
 976 * @receive_queue: receive WQE end of sg list
 977 *
 978 * Returns the number of pages loaded if positive, zero for an empty WQE, or a
 979 * negative error code.
 980 */
 981static int pagefault_data_segments(struct mlx5_ib_dev *dev,
 982				   struct mlx5_pagefault *pfault,
 983				   void *wqe,
 984				   void *wqe_end, u32 *bytes_mapped,
 985				   u32 *total_wqe_bytes, bool receive_queue)
 986{
 987	int ret = 0, npages = 0;
 988	u64 io_virt;
 989	__be32 key;
 990	u32 byte_count;
 991	size_t bcnt;
 992	int inline_segment;
 993
 994	if (bytes_mapped)
 995		*bytes_mapped = 0;
 996	if (total_wqe_bytes)
 997		*total_wqe_bytes = 0;
 998
 999	while (wqe < wqe_end) {
1000		struct mlx5_wqe_data_seg *dseg = wqe;
1001
1002		io_virt = be64_to_cpu(dseg->addr);
1003		key = dseg->lkey;
1004		byte_count = be32_to_cpu(dseg->byte_count);
1005		inline_segment = !!(byte_count &  MLX5_INLINE_SEG);
1006		bcnt	       = byte_count & ~MLX5_INLINE_SEG;
1007
1008		if (inline_segment) {
1009			bcnt = bcnt & MLX5_WQE_INLINE_SEG_BYTE_COUNT_MASK;
1010			wqe += ALIGN(sizeof(struct mlx5_wqe_inline_seg) + bcnt,
1011				     16);
1012		} else {
1013			wqe += sizeof(*dseg);
1014		}
1015
1016		/* receive WQE end of sg list. */
1017		if (receive_queue && bcnt == 0 &&
1018		    key == dev->mkeys.terminate_scatter_list_mkey &&
1019		    io_virt == 0)
1020			break;
1021
1022		if (!inline_segment && total_wqe_bytes) {
1023			*total_wqe_bytes += bcnt - min_t(size_t, bcnt,
1024					pfault->bytes_committed);
1025		}
1026
1027		/* A zero length data segment designates a length of 2GB. */
1028		if (bcnt == 0)
1029			bcnt = 1U << 31;
1030
1031		if (inline_segment || bcnt <= pfault->bytes_committed) {
1032			pfault->bytes_committed -=
1033				min_t(size_t, bcnt,
1034				      pfault->bytes_committed);
1035			continue;
1036		}
1037
1038		ret = pagefault_single_data_segment(dev, NULL, be32_to_cpu(key),
1039						    io_virt, bcnt,
1040						    &pfault->bytes_committed,
1041						    bytes_mapped);
1042		if (ret < 0)
1043			break;
1044		npages += ret;
1045	}
1046
1047	return ret < 0 ? ret : npages;
1048}
1049
1050/*
1051 * Parse initiator WQE. Advances the wqe pointer to point at the
1052 * scatter-gather list, and set wqe_end to the end of the WQE.
1053 */
1054static int mlx5_ib_mr_initiator_pfault_handler(
1055	struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
1056	struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
1057{
1058	struct mlx5_wqe_ctrl_seg *ctrl = *wqe;
1059	u16 wqe_index = pfault->wqe.wqe_index;
1060	struct mlx5_base_av *av;
1061	unsigned ds, opcode;
1062	u32 qpn = qp->trans_qp.base.mqp.qpn;
1063
1064	ds = be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_DS_MASK;
1065	if (ds * MLX5_WQE_DS_UNITS > wqe_length) {
1066		mlx5_ib_err(dev, "Unable to read the complete WQE. ds = 0x%x, ret = 0x%x\n",
1067			    ds, wqe_length);
1068		return -EFAULT;
1069	}
1070
1071	if (ds == 0) {
1072		mlx5_ib_err(dev, "Got WQE with zero DS. wqe_index=%x, qpn=%x\n",
1073			    wqe_index, qpn);
1074		return -EFAULT;
1075	}
1076
1077	*wqe_end = *wqe + ds * MLX5_WQE_DS_UNITS;
1078	*wqe += sizeof(*ctrl);
1079
1080	opcode = be32_to_cpu(ctrl->opmod_idx_opcode) &
1081		 MLX5_WQE_CTRL_OPCODE_MASK;
1082
1083	if (qp->type == IB_QPT_XRC_INI)
1084		*wqe += sizeof(struct mlx5_wqe_xrc_seg);
1085
1086	if (qp->type == IB_QPT_UD || qp->type == MLX5_IB_QPT_DCI) {
1087		av = *wqe;
1088		if (av->dqp_dct & cpu_to_be32(MLX5_EXTENDED_UD_AV))
1089			*wqe += sizeof(struct mlx5_av);
1090		else
1091			*wqe += sizeof(struct mlx5_base_av);
1092	}
1093
1094	switch (opcode) {
1095	case MLX5_OPCODE_RDMA_WRITE:
1096	case MLX5_OPCODE_RDMA_WRITE_IMM:
1097	case MLX5_OPCODE_RDMA_READ:
1098		*wqe += sizeof(struct mlx5_wqe_raddr_seg);
1099		break;
1100	case MLX5_OPCODE_ATOMIC_CS:
1101	case MLX5_OPCODE_ATOMIC_FA:
1102		*wqe += sizeof(struct mlx5_wqe_raddr_seg);
1103		*wqe += sizeof(struct mlx5_wqe_atomic_seg);
1104		break;
1105	}
1106
1107	return 0;
1108}
1109
1110/*
1111 * Parse responder WQE and set wqe_end to the end of the WQE.
1112 */
1113static int mlx5_ib_mr_responder_pfault_handler_srq(struct mlx5_ib_dev *dev,
1114						   struct mlx5_ib_srq *srq,
1115						   void **wqe, void **wqe_end,
1116						   int wqe_length)
1117{
1118	int wqe_size = 1 << srq->msrq.wqe_shift;
1119
1120	if (wqe_size > wqe_length) {
1121		mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
1122		return -EFAULT;
1123	}
1124
1125	*wqe_end = *wqe + wqe_size;
1126	*wqe += sizeof(struct mlx5_wqe_srq_next_seg);
1127
1128	return 0;
1129}
1130
1131static int mlx5_ib_mr_responder_pfault_handler_rq(struct mlx5_ib_dev *dev,
1132						  struct mlx5_ib_qp *qp,
1133						  void *wqe, void **wqe_end,
1134						  int wqe_length)
1135{
1136	struct mlx5_ib_wq *wq = &qp->rq;
1137	int wqe_size = 1 << wq->wqe_shift;
1138
1139	if (qp->flags_en & MLX5_QP_FLAG_SIGNATURE) {
1140		mlx5_ib_err(dev, "ODP fault with WQE signatures is not supported\n");
1141		return -EFAULT;
1142	}
1143
1144	if (wqe_size > wqe_length) {
1145		mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
1146		return -EFAULT;
1147	}
1148
1149	*wqe_end = wqe + wqe_size;
1150
1151	return 0;
1152}
1153
1154static inline struct mlx5_core_rsc_common *odp_get_rsc(struct mlx5_ib_dev *dev,
1155						       u32 wq_num, int pf_type)
1156{
1157	struct mlx5_core_rsc_common *common = NULL;
1158	struct mlx5_core_srq *srq;
1159
1160	switch (pf_type) {
1161	case MLX5_WQE_PF_TYPE_RMP:
1162		srq = mlx5_cmd_get_srq(dev, wq_num);
1163		if (srq)
1164			common = &srq->common;
1165		break;
1166	case MLX5_WQE_PF_TYPE_REQ_SEND_OR_WRITE:
1167	case MLX5_WQE_PF_TYPE_RESP:
1168	case MLX5_WQE_PF_TYPE_REQ_READ_OR_ATOMIC:
1169		common = mlx5_core_res_hold(dev, wq_num, MLX5_RES_QP);
1170		break;
1171	default:
1172		break;
1173	}
1174
1175	return common;
1176}
1177
1178static inline struct mlx5_ib_qp *res_to_qp(struct mlx5_core_rsc_common *res)
1179{
1180	struct mlx5_core_qp *mqp = (struct mlx5_core_qp *)res;
1181
1182	return to_mibqp(mqp);
1183}
1184
1185static inline struct mlx5_ib_srq *res_to_srq(struct mlx5_core_rsc_common *res)
1186{
1187	struct mlx5_core_srq *msrq =
1188		container_of(res, struct mlx5_core_srq, common);
1189
1190	return to_mibsrq(msrq);
1191}
1192
1193static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
1194					  struct mlx5_pagefault *pfault)
1195{
1196	bool sq = pfault->type & MLX5_PFAULT_REQUESTOR;
1197	u16 wqe_index = pfault->wqe.wqe_index;
1198	void *wqe, *wqe_start = NULL, *wqe_end = NULL;
1199	u32 bytes_mapped, total_wqe_bytes;
1200	struct mlx5_core_rsc_common *res;
1201	int resume_with_error = 1;
1202	struct mlx5_ib_qp *qp;
1203	size_t bytes_copied;
1204	int ret = 0;
1205
1206	res = odp_get_rsc(dev, pfault->wqe.wq_num, pfault->type);
1207	if (!res) {
1208		mlx5_ib_dbg(dev, "wqe page fault for missing resource %d\n", pfault->wqe.wq_num);
1209		return;
1210	}
1211
1212	if (res->res != MLX5_RES_QP && res->res != MLX5_RES_SRQ &&
1213	    res->res != MLX5_RES_XSRQ) {
1214		mlx5_ib_err(dev, "wqe page fault for unsupported type %d\n",
1215			    pfault->type);
1216		goto resolve_page_fault;
1217	}
1218
1219	wqe_start = (void *)__get_free_page(GFP_KERNEL);
1220	if (!wqe_start) {
1221		mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
1222		goto resolve_page_fault;
1223	}
1224
1225	wqe = wqe_start;
1226	qp = (res->res == MLX5_RES_QP) ? res_to_qp(res) : NULL;
1227	if (qp && sq) {
1228		ret = mlx5_ib_read_wqe_sq(qp, wqe_index, wqe, PAGE_SIZE,
1229					  &bytes_copied);
1230		if (ret)
1231			goto read_user;
1232		ret = mlx5_ib_mr_initiator_pfault_handler(
1233			dev, pfault, qp, &wqe, &wqe_end, bytes_copied);
1234	} else if (qp && !sq) {
1235		ret = mlx5_ib_read_wqe_rq(qp, wqe_index, wqe, PAGE_SIZE,
1236					  &bytes_copied);
1237		if (ret)
1238			goto read_user;
1239		ret = mlx5_ib_mr_responder_pfault_handler_rq(
1240			dev, qp, wqe, &wqe_end, bytes_copied);
1241	} else if (!qp) {
1242		struct mlx5_ib_srq *srq = res_to_srq(res);
1243
1244		ret = mlx5_ib_read_wqe_srq(srq, wqe_index, wqe, PAGE_SIZE,
1245					   &bytes_copied);
1246		if (ret)
1247			goto read_user;
1248		ret = mlx5_ib_mr_responder_pfault_handler_srq(
1249			dev, srq, &wqe, &wqe_end, bytes_copied);
1250	}
1251
1252	if (ret < 0 || wqe >= wqe_end)
1253		goto resolve_page_fault;
1254
1255	ret = pagefault_data_segments(dev, pfault, wqe, wqe_end, &bytes_mapped,
1256				      &total_wqe_bytes, !sq);
1257	if (ret == -EAGAIN)
1258		goto out;
1259
1260	if (ret < 0 || total_wqe_bytes > bytes_mapped)
1261		goto resolve_page_fault;
1262
1263out:
1264	ret = 0;
1265	resume_with_error = 0;
1266
1267read_user:
1268	if (ret)
1269		mlx5_ib_err(
1270			dev,
1271			"Failed reading a WQE following page fault, error %d, wqe_index %x, qpn %x\n",
1272			ret, wqe_index, pfault->token);
1273
1274resolve_page_fault:
1275	mlx5_ib_page_fault_resume(dev, pfault, resume_with_error);
1276	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, type: 0x%x\n",
1277		    pfault->wqe.wq_num, resume_with_error,
1278		    pfault->type);
1279	mlx5_core_res_put(res);
1280	free_page((unsigned long)wqe_start);
1281}
1282
1283static int pages_in_range(u64 address, u32 length)
1284{
1285	return (ALIGN(address + length, PAGE_SIZE) -
1286		(address & PAGE_MASK)) >> PAGE_SHIFT;
1287}
1288
1289static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_dev *dev,
1290					   struct mlx5_pagefault *pfault)
1291{
1292	u64 address;
1293	u32 length;
1294	u32 prefetch_len = pfault->bytes_committed;
1295	int prefetch_activated = 0;
1296	u32 rkey = pfault->rdma.r_key;
1297	int ret;
1298
1299	/* The RDMA responder handler handles the page fault in two parts.
1300	 * First it brings the necessary pages for the current packet
1301	 * (and uses the pfault context), and then (after resuming the QP)
1302	 * prefetches more pages. The second operation cannot use the pfault
1303	 * context and therefore uses the dummy_pfault context allocated on
1304	 * the stack */
1305	pfault->rdma.rdma_va += pfault->bytes_committed;
1306	pfault->rdma.rdma_op_len -= min(pfault->bytes_committed,
1307					 pfault->rdma.rdma_op_len);
1308	pfault->bytes_committed = 0;
1309
1310	address = pfault->rdma.rdma_va;
1311	length  = pfault->rdma.rdma_op_len;
1312
1313	/* For some operations, the hardware cannot tell the exact message
1314	 * length, and in those cases it reports zero. Use prefetch
1315	 * logic. */
1316	if (length == 0) {
1317		prefetch_activated = 1;
1318		length = pfault->rdma.packet_size;
1319		prefetch_len = min(MAX_PREFETCH_LEN, prefetch_len);
1320	}
1321
1322	ret = pagefault_single_data_segment(dev, NULL, rkey, address, length,
1323					    &pfault->bytes_committed, NULL);
1324	if (ret == -EAGAIN) {
1325		/* We're racing with an invalidation, don't prefetch */
1326		prefetch_activated = 0;
1327	} else if (ret < 0 || pages_in_range(address, length) > ret) {
1328		mlx5_ib_page_fault_resume(dev, pfault, 1);
1329		if (ret != -ENOENT)
1330			mlx5_ib_dbg(dev, "PAGE FAULT error %d. QP 0x%x, type: 0x%x\n",
1331				    ret, pfault->token, pfault->type);
1332		return;
1333	}
1334
1335	mlx5_ib_page_fault_resume(dev, pfault, 0);
1336	mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x, type: 0x%x, prefetch_activated: %d\n",
1337		    pfault->token, pfault->type,
1338		    prefetch_activated);
1339
1340	/* At this point, there might be a new pagefault already arriving in
1341	 * the eq, switch to the dummy pagefault for the rest of the
1342	 * processing. We're still OK with the objects being alive as the
1343	 * work-queue is being fenced. */
1344
1345	if (prefetch_activated) {
1346		u32 bytes_committed = 0;
1347
1348		ret = pagefault_single_data_segment(dev, NULL, rkey, address,
1349						    prefetch_len,
1350						    &bytes_committed, NULL);
1351		if (ret < 0 && ret != -EAGAIN) {
1352			mlx5_ib_dbg(dev, "Prefetch failed. ret: %d, QP 0x%x, address: 0x%.16llx, length = 0x%.16x\n",
1353				    ret, pfault->token, address, prefetch_len);
1354		}
1355	}
1356}
1357
1358static void mlx5_ib_pfault(struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault)
1359{
1360	u8 event_subtype = pfault->event_subtype;
1361
1362	switch (event_subtype) {
1363	case MLX5_PFAULT_SUBTYPE_WQE:
1364		mlx5_ib_mr_wqe_pfault_handler(dev, pfault);
1365		break;
1366	case MLX5_PFAULT_SUBTYPE_RDMA:
1367		mlx5_ib_mr_rdma_pfault_handler(dev, pfault);
1368		break;
1369	default:
1370		mlx5_ib_err(dev, "Invalid page fault event subtype: 0x%x\n",
1371			    event_subtype);
1372		mlx5_ib_page_fault_resume(dev, pfault, 1);
1373	}
1374}
1375
1376static void mlx5_ib_eqe_pf_action(struct work_struct *work)
1377{
1378	struct mlx5_pagefault *pfault = container_of(work,
1379						     struct mlx5_pagefault,
1380						     work);
1381	struct mlx5_ib_pf_eq *eq = pfault->eq;
1382
1383	mlx5_ib_pfault(eq->dev, pfault);
1384	mempool_free(pfault, eq->pool);
1385}
1386
1387static void mlx5_ib_eq_pf_process(struct mlx5_ib_pf_eq *eq)
1388{
1389	struct mlx5_eqe_page_fault *pf_eqe;
1390	struct mlx5_pagefault *pfault;
1391	struct mlx5_eqe *eqe;
1392	int cc = 0;
1393
1394	while ((eqe = mlx5_eq_get_eqe(eq->core, cc))) {
1395		pfault = mempool_alloc(eq->pool, GFP_ATOMIC);
1396		if (!pfault) {
1397			schedule_work(&eq->work);
1398			break;
1399		}
1400
1401		pf_eqe = &eqe->data.page_fault;
1402		pfault->event_subtype = eqe->sub_type;
1403		pfault->bytes_committed = be32_to_cpu(pf_eqe->bytes_committed);
1404
1405		mlx5_ib_dbg(eq->dev,
1406			    "PAGE_FAULT: subtype: 0x%02x, bytes_committed: 0x%06x\n",
1407			    eqe->sub_type, pfault->bytes_committed);
1408
1409		switch (eqe->sub_type) {
1410		case MLX5_PFAULT_SUBTYPE_RDMA:
1411			/* RDMA based event */
1412			pfault->type =
1413				be32_to_cpu(pf_eqe->rdma.pftype_token) >> 24;
1414			pfault->token =
1415				be32_to_cpu(pf_eqe->rdma.pftype_token) &
1416				MLX5_24BIT_MASK;
1417			pfault->rdma.r_key =
1418				be32_to_cpu(pf_eqe->rdma.r_key);
1419			pfault->rdma.packet_size =
1420				be16_to_cpu(pf_eqe->rdma.packet_length);
1421			pfault->rdma.rdma_op_len =
1422				be32_to_cpu(pf_eqe->rdma.rdma_op_len);
1423			pfault->rdma.rdma_va =
1424				be64_to_cpu(pf_eqe->rdma.rdma_va);
1425			mlx5_ib_dbg(eq->dev,
1426				    "PAGE_FAULT: type:0x%x, token: 0x%06x, r_key: 0x%08x\n",
1427				    pfault->type, pfault->token,
1428				    pfault->rdma.r_key);
1429			mlx5_ib_dbg(eq->dev,
1430				    "PAGE_FAULT: rdma_op_len: 0x%08x, rdma_va: 0x%016llx\n",
1431				    pfault->rdma.rdma_op_len,
1432				    pfault->rdma.rdma_va);
1433			break;
1434
1435		case MLX5_PFAULT_SUBTYPE_WQE:
1436			/* WQE based event */
1437			pfault->type =
1438				(be32_to_cpu(pf_eqe->wqe.pftype_wq) >> 24) & 0x7;
1439			pfault->token =
1440				be32_to_cpu(pf_eqe->wqe.token);
1441			pfault->wqe.wq_num =
1442				be32_to_cpu(pf_eqe->wqe.pftype_wq) &
1443				MLX5_24BIT_MASK;
1444			pfault->wqe.wqe_index =
1445				be16_to_cpu(pf_eqe->wqe.wqe_index);
1446			pfault->wqe.packet_size =
1447				be16_to_cpu(pf_eqe->wqe.packet_length);
1448			mlx5_ib_dbg(eq->dev,
1449				    "PAGE_FAULT: type:0x%x, token: 0x%06x, wq_num: 0x%06x, wqe_index: 0x%04x\n",
1450				    pfault->type, pfault->token,
1451				    pfault->wqe.wq_num,
1452				    pfault->wqe.wqe_index);
1453			break;
1454
1455		default:
1456			mlx5_ib_warn(eq->dev,
1457				     "Unsupported page fault event sub-type: 0x%02hhx\n",
1458				     eqe->sub_type);
1459			/* Unsupported page faults should still be
1460			 * resolved by the page fault handler
1461			 */
1462		}
1463
1464		pfault->eq = eq;
1465		INIT_WORK(&pfault->work, mlx5_ib_eqe_pf_action);
1466		queue_work(eq->wq, &pfault->work);
1467
1468		cc = mlx5_eq_update_cc(eq->core, ++cc);
1469	}
1470
1471	mlx5_eq_update_ci(eq->core, cc, 1);
1472}
1473
1474static int mlx5_ib_eq_pf_int(struct notifier_block *nb, unsigned long type,
1475			     void *data)
1476{
1477	struct mlx5_ib_pf_eq *eq =
1478		container_of(nb, struct mlx5_ib_pf_eq, irq_nb);
1479	unsigned long flags;
1480
1481	if (spin_trylock_irqsave(&eq->lock, flags)) {
1482		mlx5_ib_eq_pf_process(eq);
1483		spin_unlock_irqrestore(&eq->lock, flags);
1484	} else {
1485		schedule_work(&eq->work);
1486	}
1487
1488	return IRQ_HANDLED;
1489}
1490
1491/* mempool_refill() was proposed but unfortunately wasn't accepted
1492 * http://lkml.iu.edu/hypermail/linux/kernel/1512.1/05073.html
1493 * Cheap workaround.
1494 */
1495static void mempool_refill(mempool_t *pool)
1496{
1497	while (pool->curr_nr < pool->min_nr)
1498		mempool_free(mempool_alloc(pool, GFP_KERNEL), pool);
1499}
1500
1501static void mlx5_ib_eq_pf_action(struct work_struct *work)
1502{
1503	struct mlx5_ib_pf_eq *eq =
1504		container_of(work, struct mlx5_ib_pf_eq, work);
1505
1506	mempool_refill(eq->pool);
1507
1508	spin_lock_irq(&eq->lock);
1509	mlx5_ib_eq_pf_process(eq);
1510	spin_unlock_irq(&eq->lock);
1511}
1512
1513enum {
1514	MLX5_IB_NUM_PF_EQE	= 0x1000,
1515	MLX5_IB_NUM_PF_DRAIN	= 64,
1516};
1517
1518int mlx5r_odp_create_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
1519{
1520	struct mlx5_eq_param param = {};
1521	int err = 0;
1522
1523	mutex_lock(&dev->odp_eq_mutex);
1524	if (eq->core)
1525		goto unlock;
1526	INIT_WORK(&eq->work, mlx5_ib_eq_pf_action);
1527	spin_lock_init(&eq->lock);
1528	eq->dev = dev;
1529
1530	eq->pool = mempool_create_kmalloc_pool(MLX5_IB_NUM_PF_DRAIN,
1531					       sizeof(struct mlx5_pagefault));
1532	if (!eq->pool) {
1533		err = -ENOMEM;
1534		goto unlock;
1535	}
1536
1537	eq->wq = alloc_workqueue("mlx5_ib_page_fault",
1538				 WQ_HIGHPRI | WQ_UNBOUND | WQ_MEM_RECLAIM,
1539				 MLX5_NUM_CMD_EQE);
1540	if (!eq->wq) {
1541		err = -ENOMEM;
1542		goto err_mempool;
1543	}
1544
1545	eq->irq_nb.notifier_call = mlx5_ib_eq_pf_int;
1546	param = (struct mlx5_eq_param) {
1547		.nent = MLX5_IB_NUM_PF_EQE,
1548	};
1549	param.mask[0] = 1ull << MLX5_EVENT_TYPE_PAGE_FAULT;
1550	eq->core = mlx5_eq_create_generic(dev->mdev, &param);
1551	if (IS_ERR(eq->core)) {
1552		err = PTR_ERR(eq->core);
1553		goto err_wq;
1554	}
1555	err = mlx5_eq_enable(dev->mdev, eq->core, &eq->irq_nb);
1556	if (err) {
1557		mlx5_ib_err(dev, "failed to enable odp EQ %d\n", err);
1558		goto err_eq;
1559	}
1560
1561	mutex_unlock(&dev->odp_eq_mutex);
1562	return 0;
1563err_eq:
1564	mlx5_eq_destroy_generic(dev->mdev, eq->core);
1565err_wq:
1566	eq->core = NULL;
1567	destroy_workqueue(eq->wq);
1568err_mempool:
1569	mempool_destroy(eq->pool);
1570unlock:
1571	mutex_unlock(&dev->odp_eq_mutex);
1572	return err;
1573}
1574
1575static int
1576mlx5_ib_odp_destroy_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
1577{
1578	int err;
1579
1580	if (!eq->core)
1581		return 0;
1582	mlx5_eq_disable(dev->mdev, eq->core, &eq->irq_nb);
1583	err = mlx5_eq_destroy_generic(dev->mdev, eq->core);
1584	cancel_work_sync(&eq->work);
1585	destroy_workqueue(eq->wq);
1586	mempool_destroy(eq->pool);
1587
1588	return err;
1589}
1590
1591int mlx5_odp_init_mkey_cache(struct mlx5_ib_dev *dev)
1592{
1593	struct mlx5r_cache_rb_key rb_key = {
1594		.access_mode = MLX5_MKC_ACCESS_MODE_KSM,
1595		.ndescs = mlx5_imr_ksm_entries,
1596	};
1597	struct mlx5_cache_ent *ent;
1598
1599	if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
1600		return 0;
1601
1602	ent = mlx5r_cache_create_ent_locked(dev, rb_key, true);
1603	if (IS_ERR(ent))
1604		return PTR_ERR(ent);
 
 
 
 
1605
1606	return 0;
 
 
 
 
 
 
1607}
1608
1609static const struct ib_device_ops mlx5_ib_dev_odp_ops = {
1610	.advise_mr = mlx5_ib_advise_mr,
1611};
1612
1613int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
1614{
 
 
1615	internal_fill_odp_caps(dev);
1616
1617	if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
1618		return 0;
1619
1620	ib_set_device_ops(&dev->ib_dev, &mlx5_ib_dev_odp_ops);
1621
 
 
 
 
 
 
 
 
1622	mutex_init(&dev->odp_eq_mutex);
1623	return 0;
1624}
1625
1626void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *dev)
1627{
1628	if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
1629		return;
1630
1631	mlx5_ib_odp_destroy_eq(dev, &dev->odp_pf_eq);
1632}
1633
1634int mlx5_ib_odp_init(void)
1635{
1636	mlx5_imr_ksm_entries = BIT_ULL(get_order(TASK_SIZE) -
1637				       MLX5_IMR_MTT_BITS);
1638
1639	return 0;
1640}
1641
1642struct prefetch_mr_work {
1643	struct work_struct work;
1644	u32 pf_flags;
1645	u32 num_sge;
1646	struct {
1647		u64 io_virt;
1648		struct mlx5_ib_mr *mr;
1649		size_t length;
1650	} frags[];
1651};
1652
1653static void destroy_prefetch_work(struct prefetch_mr_work *work)
1654{
1655	u32 i;
1656
1657	for (i = 0; i < work->num_sge; ++i)
1658		mlx5r_deref_odp_mkey(&work->frags[i].mr->mmkey);
1659
1660	kvfree(work);
1661}
1662
1663static struct mlx5_ib_mr *
1664get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice,
1665		    u32 lkey)
1666{
1667	struct mlx5_ib_dev *dev = to_mdev(pd->device);
1668	struct mlx5_ib_mr *mr = NULL;
1669	struct mlx5_ib_mkey *mmkey;
1670
1671	xa_lock(&dev->odp_mkeys);
1672	mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(lkey));
1673	if (!mmkey || mmkey->key != lkey) {
1674		mr = ERR_PTR(-ENOENT);
1675		goto end;
1676	}
1677	if (mmkey->type != MLX5_MKEY_MR) {
1678		mr = ERR_PTR(-EINVAL);
1679		goto end;
1680	}
1681
1682	mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
1683
1684	if (mr->ibmr.pd != pd) {
1685		mr = ERR_PTR(-EPERM);
1686		goto end;
1687	}
1688
1689	/* prefetch with write-access must be supported by the MR */
1690	if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
1691	    !mr->umem->writable) {
1692		mr = ERR_PTR(-EPERM);
1693		goto end;
1694	}
1695
1696	refcount_inc(&mmkey->usecount);
1697end:
1698	xa_unlock(&dev->odp_mkeys);
1699	return mr;
1700}
1701
1702static void mlx5_ib_prefetch_mr_work(struct work_struct *w)
1703{
1704	struct prefetch_mr_work *work =
1705		container_of(w, struct prefetch_mr_work, work);
1706	u32 bytes_mapped = 0;
1707	int ret;
1708	u32 i;
1709
1710	/* We rely on IB/core that work is executed if we have num_sge != 0 only. */
1711	WARN_ON(!work->num_sge);
1712	for (i = 0; i < work->num_sge; ++i) {
1713		ret = pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
1714				   work->frags[i].length, &bytes_mapped,
1715				   work->pf_flags);
1716		if (ret <= 0)
1717			continue;
1718		mlx5_update_odp_stats(work->frags[i].mr, prefetch, ret);
1719	}
1720
1721	destroy_prefetch_work(work);
1722}
1723
1724static int init_prefetch_work(struct ib_pd *pd,
1725			       enum ib_uverbs_advise_mr_advice advice,
1726			       u32 pf_flags, struct prefetch_mr_work *work,
1727			       struct ib_sge *sg_list, u32 num_sge)
1728{
1729	u32 i;
1730
1731	INIT_WORK(&work->work, mlx5_ib_prefetch_mr_work);
1732	work->pf_flags = pf_flags;
1733
1734	for (i = 0; i < num_sge; ++i) {
1735		struct mlx5_ib_mr *mr;
1736
1737		mr = get_prefetchable_mr(pd, advice, sg_list[i].lkey);
1738		if (IS_ERR(mr)) {
1739			work->num_sge = i;
1740			return PTR_ERR(mr);
1741		}
1742		work->frags[i].io_virt = sg_list[i].addr;
1743		work->frags[i].length = sg_list[i].length;
1744		work->frags[i].mr = mr;
1745	}
1746	work->num_sge = num_sge;
1747	return 0;
1748}
1749
1750static int mlx5_ib_prefetch_sg_list(struct ib_pd *pd,
1751				    enum ib_uverbs_advise_mr_advice advice,
1752				    u32 pf_flags, struct ib_sge *sg_list,
1753				    u32 num_sge)
1754{
1755	u32 bytes_mapped = 0;
1756	int ret = 0;
1757	u32 i;
1758
1759	for (i = 0; i < num_sge; ++i) {
1760		struct mlx5_ib_mr *mr;
1761
1762		mr = get_prefetchable_mr(pd, advice, sg_list[i].lkey);
1763		if (IS_ERR(mr))
1764			return PTR_ERR(mr);
1765		ret = pagefault_mr(mr, sg_list[i].addr, sg_list[i].length,
1766				   &bytes_mapped, pf_flags);
1767		if (ret < 0) {
1768			mlx5r_deref_odp_mkey(&mr->mmkey);
1769			return ret;
1770		}
1771		mlx5_update_odp_stats(mr, prefetch, ret);
1772		mlx5r_deref_odp_mkey(&mr->mmkey);
1773	}
1774
1775	return 0;
1776}
1777
1778int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
1779			       enum ib_uverbs_advise_mr_advice advice,
1780			       u32 flags, struct ib_sge *sg_list, u32 num_sge)
1781{
1782	u32 pf_flags = 0;
1783	struct prefetch_mr_work *work;
1784	int rc;
1785
1786	if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH)
1787		pf_flags |= MLX5_PF_FLAGS_DOWNGRADE;
1788
1789	if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_NO_FAULT)
1790		pf_flags |= MLX5_PF_FLAGS_SNAPSHOT;
1791
1792	if (flags & IB_UVERBS_ADVISE_MR_FLAG_FLUSH)
1793		return mlx5_ib_prefetch_sg_list(pd, advice, pf_flags, sg_list,
1794						num_sge);
1795
1796	work = kvzalloc(struct_size(work, frags, num_sge), GFP_KERNEL);
1797	if (!work)
1798		return -ENOMEM;
1799
1800	rc = init_prefetch_work(pd, advice, pf_flags, work, sg_list, num_sge);
1801	if (rc) {
1802		destroy_prefetch_work(work);
1803		return rc;
1804	}
1805	queue_work(system_unbound_wq, &work->work);
1806	return 0;
1807}