drivers/infiniband/hw/mlx5/odp.c

   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 #include <linux/kernel.h>
  36
  37 #include "mlx5_ib.h"
  38 #include "cmd.h"
  39 #include "qp.h"
  40
  41 #include <linux/mlx5/eq.h>
  42
  43 /* Contains the details of a pagefault. */
  44 struct mlx5_pagefault {
  45         u32                     bytes_committed;
  46         u32                     token;
  47         u8                      event_subtype;
  48         u8                      type;
  49         union {
  50                 /* Initiator or send message responder pagefault details. */
  51                 struct {
  52                         /* Received packet size, only valid for responders. */
  53                         u32     packet_size;
  54                         /*
  55                          * Number of resource holding WQE, depends on type.
  56                          */
  57                         u32     wq_num;
  58                         /*
  59                          * WQE index. Refers to either the send queue or
  60                          * receive queue, according to event_subtype.
  61                          */
  62                         u16     wqe_index;
  63                 } wqe;
  64                 /* RDMA responder pagefault details */
  65                 struct {
  66                         u32     r_key;
  67                         /*
  68                          * Received packet size, minimal size page fault
  69                          * resolution required for forward progress.
  70                          */
  71                         u32     packet_size;
  72                         u32     rdma_op_len;
  73                         u64     rdma_va;
  74                 } rdma;
  75         };
  76
  77         struct mlx5_ib_pf_eq    *eq;
  78         struct work_struct      work;
  79 };
  80
  81 #define MAX_PREFETCH_LEN (4*1024*1024U)
  82
  83 /* Timeout in ms to wait for an active mmu notifier to complete when handling
  84  * a pagefault. */
  85 #define MMU_NOTIFIER_TIMEOUT 1000
  86
  87 #define MLX5_IMR_MTT_BITS (30 - PAGE_SHIFT)
  88 #define MLX5_IMR_MTT_SHIFT (MLX5_IMR_MTT_BITS + PAGE_SHIFT)
  89 #define MLX5_IMR_MTT_ENTRIES BIT_ULL(MLX5_IMR_MTT_BITS)
  90 #define MLX5_IMR_MTT_SIZE BIT_ULL(MLX5_IMR_MTT_SHIFT)
  91 #define MLX5_IMR_MTT_MASK (~(MLX5_IMR_MTT_SIZE - 1))
  92
  93 #define MLX5_KSM_PAGE_SHIFT MLX5_IMR_MTT_SHIFT
  94
  95 static u64 mlx5_imr_ksm_entries;
  96
  97 static void populate_klm(struct mlx5_klm *pklm, size_t idx, size_t nentries,
  98                         struct mlx5_ib_mr *imr, int flags)
  99 {
 100         struct mlx5_klm *end = pklm + nentries;
 101
 102         if (flags & MLX5_IB_UPD_XLT_ZAP) {
 103                 for (; pklm != end; pklm++, idx++) {
 104                         pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
 105                         pklm->key = cpu_to_be32(imr->dev->null_mkey);
 106                         pklm->va = 0;
 107                 }
 108                 return;
 109         }
 110
 111         /*
 112          * The locking here is pretty subtle. Ideally the implicit_children
 113          * xarray would be protected by the umem_mutex, however that is not
 114          * possible. Instead this uses a weaker update-then-lock pattern:
 115          *
 116          *  srcu_read_lock()
 117          *    xa_store()
 118          *    mutex_lock(umem_mutex)
 119          *     mlx5_ib_update_xlt()
 120          *    mutex_unlock(umem_mutex)
 121          *    destroy lkey
 122          *
 123          * ie any change the xarray must be followed by the locked update_xlt
 124          * before destroying.
 125          *
 126          * The umem_mutex provides the acquire/release semantic needed to make
 127          * the xa_store() visible to a racing thread. While SRCU is not
 128          * technically required, using it gives consistent use of the SRCU
 129          * locking around the xarray.
 130          */
 131         lockdep_assert_held(&to_ib_umem_odp(imr->umem)->umem_mutex);
 132         lockdep_assert_held(&imr->dev->odp_srcu);
 133
 134         for (; pklm != end; pklm++, idx++) {
 135                 struct mlx5_ib_mr *mtt = xa_load(&imr->implicit_children, idx);
 136
 137                 pklm->bcount = cpu_to_be32(MLX5_IMR_MTT_SIZE);
 138                 if (mtt) {
 139                         pklm->key = cpu_to_be32(mtt->ibmr.lkey);
 140                         pklm->va = cpu_to_be64(idx * MLX5_IMR_MTT_SIZE);
 141                 } else {
 142                         pklm->key = cpu_to_be32(imr->dev->null_mkey);
 143                         pklm->va = 0;
 144                 }
 145         }
 146 }
 147
 148 static u64 umem_dma_to_mtt(dma_addr_t umem_dma)
 149 {
 150         u64 mtt_entry = umem_dma & ODP_DMA_ADDR_MASK;
 151
 152         if (umem_dma & ODP_READ_ALLOWED_BIT)
 153                 mtt_entry |= MLX5_IB_MTT_READ;
 154         if (umem_dma & ODP_WRITE_ALLOWED_BIT)
 155                 mtt_entry |= MLX5_IB_MTT_WRITE;
 156
 157         return mtt_entry;
 158 }
 159
 160 static void populate_mtt(__be64 *pas, size_t idx, size_t nentries,
 161                          struct mlx5_ib_mr *mr, int flags)
 162 {
 163         struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 164         dma_addr_t pa;
 165         size_t i;
 166
 167         if (flags & MLX5_IB_UPD_XLT_ZAP)
 168                 return;
 169
 170         for (i = 0; i < nentries; i++) {
 171                 pa = odp->dma_list[idx + i];
 172                 pas[i] = cpu_to_be64(umem_dma_to_mtt(pa));
 173         }
 174 }
 175
 176 void mlx5_odp_populate_xlt(void *xlt, size_t idx, size_t nentries,
 177                            struct mlx5_ib_mr *mr, int flags)
 178 {
 179         if (flags & MLX5_IB_UPD_XLT_INDIRECT) {
 180                 populate_klm(xlt, idx, nentries, mr, flags);
 181         } else {
 182                 populate_mtt(xlt, idx, nentries, mr, flags);
 183         }
 184 }
 185
 186 static void dma_fence_odp_mr(struct mlx5_ib_mr *mr)
 187 {
 188         struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 189
 190         /* Ensure mlx5_ib_invalidate_range() will not touch the MR any more */
 191         mutex_lock(&odp->umem_mutex);
 192         if (odp->npages) {
 193                 mlx5_mr_cache_invalidate(mr);
 194                 ib_umem_odp_unmap_dma_pages(odp, ib_umem_start(odp),
 195                                             ib_umem_end(odp));
 196                 WARN_ON(odp->npages);
 197         }
 198         odp->private = NULL;
 199         mutex_unlock(&odp->umem_mutex);
 200
 201         if (!mr->cache_ent) {
 202                 mlx5_core_destroy_mkey(mr->dev->mdev, &mr->mmkey);
 203                 WARN_ON(mr->descs);
 204         }
 205 }
 206
 207 /*
 208  * This must be called after the mr has been removed from implicit_children
 209  * and the SRCU synchronized.  NOTE: The MR does not necessarily have to be
 210  * empty here, parallel page faults could have raced with the free process and
 211  * added pages to it.
 212  */
 213 static void free_implicit_child_mr(struct mlx5_ib_mr *mr, bool need_imr_xlt)
 214 {
 215         struct mlx5_ib_mr *imr = mr->parent;
 216         struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem);
 217         struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 218         unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT;
 219         int srcu_key;
 220
 221         /* implicit_child_mr's are not allowed to have deferred work */
 222         WARN_ON(atomic_read(&mr->num_deferred_work));
 223
 224         if (need_imr_xlt) {
 225                 srcu_key = srcu_read_lock(&mr->dev->odp_srcu);
 226                 mutex_lock(&odp_imr->umem_mutex);
 227                 mlx5_ib_update_xlt(mr->parent, idx, 1, 0,
 228                                    MLX5_IB_UPD_XLT_INDIRECT |
 229                                    MLX5_IB_UPD_XLT_ATOMIC);
 230                 mutex_unlock(&odp_imr->umem_mutex);
 231                 srcu_read_unlock(&mr->dev->odp_srcu, srcu_key);
 232         }
 233
 234         dma_fence_odp_mr(mr);
 235
 236         mr->parent = NULL;
 237         mlx5_mr_cache_free(mr->dev, mr);
 238         ib_umem_odp_release(odp);
 239         if (atomic_dec_and_test(&imr->num_deferred_work))
 240                 wake_up(&imr->q_deferred_work);
 241 }
 242
 243 static void free_implicit_child_mr_work(struct work_struct *work)
 244 {
 245         struct mlx5_ib_mr *mr =
 246                 container_of(work, struct mlx5_ib_mr, odp_destroy.work);
 247
 248         free_implicit_child_mr(mr, true);
 249 }
 250
 251 static void free_implicit_child_mr_rcu(struct rcu_head *head)
 252 {
 253         struct mlx5_ib_mr *mr =
 254                 container_of(head, struct mlx5_ib_mr, odp_destroy.rcu);
 255
 256         /* Freeing a MR is a sleeping operation, so bounce to a work queue */
 257         INIT_WORK(&mr->odp_destroy.work, free_implicit_child_mr_work);
 258         queue_work(system_unbound_wq, &mr->odp_destroy.work);
 259 }
 260
 261 static void destroy_unused_implicit_child_mr(struct mlx5_ib_mr *mr)
 262 {
 263         struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 264         unsigned long idx = ib_umem_start(odp) >> MLX5_IMR_MTT_SHIFT;
 265         struct mlx5_ib_mr *imr = mr->parent;
 266
 267         xa_lock(&imr->implicit_children);
 268         /*
 269          * This can race with mlx5_ib_free_implicit_mr(), the first one to
 270          * reach the xa lock wins the race and destroys the MR.
 271          */
 272         if (__xa_cmpxchg(&imr->implicit_children, idx, mr, NULL, GFP_ATOMIC) !=
 273             mr)
 274                 goto out_unlock;
 275
 276         atomic_inc(&imr->num_deferred_work);
 277         call_srcu(&mr->dev->odp_srcu, &mr->odp_destroy.rcu,
 278                   free_implicit_child_mr_rcu);
 279
 280 out_unlock:
 281         xa_unlock(&imr->implicit_children);
 282 }
 283
 284 static bool mlx5_ib_invalidate_range(struct mmu_interval_notifier *mni,
 285                                      const struct mmu_notifier_range *range,
 286                                      unsigned long cur_seq)
 287 {
 288         struct ib_umem_odp *umem_odp =
 289                 container_of(mni, struct ib_umem_odp, notifier);
 290         struct mlx5_ib_mr *mr;
 291         const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT /
 292                                     sizeof(struct mlx5_mtt)) - 1;
 293         u64 idx = 0, blk_start_idx = 0;
 294         u64 invalidations = 0;
 295         unsigned long start;
 296         unsigned long end;
 297         int in_block = 0;
 298         u64 addr;
 299
 300         if (!mmu_notifier_range_blockable(range))
 301                 return false;
 302
 303         mutex_lock(&umem_odp->umem_mutex);
 304         mmu_interval_set_seq(mni, cur_seq);
 305         /*
 306          * If npages is zero then umem_odp->private may not be setup yet. This
 307          * does not complete until after the first page is mapped for DMA.
 308          */
 309         if (!umem_odp->npages)
 310                 goto out;
 311         mr = umem_odp->private;
 312
 313         start = max_t(u64, ib_umem_start(umem_odp), range->start);
 314         end = min_t(u64, ib_umem_end(umem_odp), range->end);
 315
 316         /*
 317          * Iteration one - zap the HW's MTTs. The notifiers_count ensures that
 318          * while we are doing the invalidation, no page fault will attempt to
 319          * overwrite the same MTTs.  Concurent invalidations might race us,
 320          * but they will write 0s as well, so no difference in the end result.
 321          */
 322         for (addr = start; addr < end; addr += BIT(umem_odp->page_shift)) {
 323                 idx = (addr - ib_umem_start(umem_odp)) >> umem_odp->page_shift;
 324                 /*
 325                  * Strive to write the MTTs in chunks, but avoid overwriting
 326                  * non-existing MTTs. The huristic here can be improved to
 327                  * estimate the cost of another UMR vs. the cost of bigger
 328                  * UMR.
 329                  */
 330                 if (umem_odp->dma_list[idx] &
 331                     (ODP_READ_ALLOWED_BIT | ODP_WRITE_ALLOWED_BIT)) {
 332                         if (!in_block) {
 333                                 blk_start_idx = idx;
 334                                 in_block = 1;
 335                         }
 336
 337                         /* Count page invalidations */
 338                         invalidations += idx - blk_start_idx + 1;
 339                 } else {
 340                         u64 umr_offset = idx & umr_block_mask;
 341
 342                         if (in_block && umr_offset == 0) {
 343                                 mlx5_ib_update_xlt(mr, blk_start_idx,
 344                                                    idx - blk_start_idx, 0,
 345                                                    MLX5_IB_UPD_XLT_ZAP |
 346                                                    MLX5_IB_UPD_XLT_ATOMIC);
 347                                 in_block = 0;
 348                         }
 349                 }
 350         }
 351         if (in_block)
 352                 mlx5_ib_update_xlt(mr, blk_start_idx,
 353                                    idx - blk_start_idx + 1, 0,
 354                                    MLX5_IB_UPD_XLT_ZAP |
 355                                    MLX5_IB_UPD_XLT_ATOMIC);
 356
 357         mlx5_update_odp_stats(mr, invalidations, invalidations);
 358
 359         /*
 360          * We are now sure that the device will not access the
 361          * memory. We can safely unmap it, and mark it as dirty if
 362          * needed.
 363          */
 364
 365         ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
 366
 367         if (unlikely(!umem_odp->npages && mr->parent))
 368                 destroy_unused_implicit_child_mr(mr);
 369 out:
 370         mutex_unlock(&umem_odp->umem_mutex);
 371         return true;
 372 }
 373
 374 const struct mmu_interval_notifier_ops mlx5_mn_ops = {
 375         .invalidate = mlx5_ib_invalidate_range,
 376 };
 377
 378 void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
 379 {
 380         struct ib_odp_caps *caps = &dev->odp_caps;
 381
 382         memset(caps, 0, sizeof(*caps));
 383
 384         if (!MLX5_CAP_GEN(dev->mdev, pg) ||
 385             !mlx5_ib_can_use_umr(dev, true, 0))
 386                 return;
 387
 388         caps->general_caps = IB_ODP_SUPPORT;
 389
 390         if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
 391                 dev->odp_max_size = U64_MAX;
 392         else
 393                 dev->odp_max_size = BIT_ULL(MLX5_MAX_UMR_SHIFT + PAGE_SHIFT);
 394
 395         if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.send))
 396                 caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SEND;
 397
 398         if (MLX5_CAP_ODP(dev->mdev, ud_odp_caps.srq_receive))
 399                 caps->per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 400
 401         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.send))
 402                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SEND;
 403
 404         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.receive))
 405                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_RECV;
 406
 407         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.write))
 408                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_WRITE;
 409
 410         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.read))
 411                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_READ;
 412
 413         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.atomic))
 414                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
 415
 416         if (MLX5_CAP_ODP(dev->mdev, rc_odp_caps.srq_receive))
 417                 caps->per_transport_caps.rc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 418
 419         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.send))
 420                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SEND;
 421
 422         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.receive))
 423                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_RECV;
 424
 425         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.write))
 426                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_WRITE;
 427
 428         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.read))
 429                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_READ;
 430
 431         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.atomic))
 432                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_ATOMIC;
 433
 434         if (MLX5_CAP_ODP(dev->mdev, xrc_odp_caps.srq_receive))
 435                 caps->per_transport_caps.xrc_odp_caps |= IB_ODP_SUPPORT_SRQ_RECV;
 436
 437         if (MLX5_CAP_GEN(dev->mdev, fixed_buffer_size) &&
 438             MLX5_CAP_GEN(dev->mdev, null_mkey) &&
 439             MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset) &&
 440             !MLX5_CAP_GEN(dev->mdev, umr_indirect_mkey_disabled))
 441                 caps->general_caps |= IB_ODP_SUPPORT_IMPLICIT;
 442 }
 443
 444 static void mlx5_ib_page_fault_resume(struct mlx5_ib_dev *dev,
 445                                       struct mlx5_pagefault *pfault,
 446                                       int error)
 447 {
 448         int wq_num = pfault->event_subtype == MLX5_PFAULT_SUBTYPE_WQE ?
 449                      pfault->wqe.wq_num : pfault->token;
 450         u32 in[MLX5_ST_SZ_DW(page_fault_resume_in)] = {};
 451         int err;
 452
 453         MLX5_SET(page_fault_resume_in, in, opcode, MLX5_CMD_OP_PAGE_FAULT_RESUME);
 454         MLX5_SET(page_fault_resume_in, in, page_fault_type, pfault->type);
 455         MLX5_SET(page_fault_resume_in, in, token, pfault->token);
 456         MLX5_SET(page_fault_resume_in, in, wq_number, wq_num);
 457         MLX5_SET(page_fault_resume_in, in, error, !!error);
 458
 459         err = mlx5_cmd_exec_in(dev->mdev, page_fault_resume, in);
 460         if (err)
 461                 mlx5_ib_err(dev, "Failed to resolve the page fault on WQ 0x%x err %d\n",
 462                             wq_num, err);
 463 }
 464
 465 static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr,
 466                                                 unsigned long idx)
 467 {
 468         struct ib_umem_odp *odp;
 469         struct mlx5_ib_mr *mr;
 470         struct mlx5_ib_mr *ret;
 471         int err;
 472
 473         odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem),
 474                                       idx * MLX5_IMR_MTT_SIZE,
 475                                       MLX5_IMR_MTT_SIZE, &mlx5_mn_ops);
 476         if (IS_ERR(odp))
 477                 return ERR_CAST(odp);
 478
 479         ret = mr = mlx5_mr_cache_alloc(imr->dev, MLX5_IMR_MTT_CACHE_ENTRY);
 480         if (IS_ERR(mr))
 481                 goto out_umem;
 482
 483         mr->ibmr.pd = imr->ibmr.pd;
 484         mr->access_flags = imr->access_flags;
 485         mr->umem = &odp->umem;
 486         mr->ibmr.lkey = mr->mmkey.key;
 487         mr->ibmr.rkey = mr->mmkey.key;
 488         mr->mmkey.iova = idx * MLX5_IMR_MTT_SIZE;
 489         mr->parent = imr;
 490         odp->private = mr;
 491
 492         err = mlx5_ib_update_xlt(mr, 0,
 493                                  MLX5_IMR_MTT_ENTRIES,
 494                                  PAGE_SHIFT,
 495                                  MLX5_IB_UPD_XLT_ZAP |
 496                                  MLX5_IB_UPD_XLT_ENABLE);
 497         if (err) {
 498                 ret = ERR_PTR(err);
 499                 goto out_mr;
 500         }
 501
 502         /*
 503          * Once the store to either xarray completes any error unwind has to
 504          * use synchronize_srcu(). Avoid this with xa_reserve()
 505          */
 506         ret = xa_cmpxchg(&imr->implicit_children, idx, NULL, mr,
 507                          GFP_KERNEL);
 508         if (unlikely(ret)) {
 509                 if (xa_is_err(ret)) {
 510                         ret = ERR_PTR(xa_err(ret));
 511                         goto out_mr;
 512                 }
 513                 /*
 514                  * Another thread beat us to creating the child mr, use
 515                  * theirs.
 516                  */
 517                 goto out_mr;
 518         }
 519
 520         mlx5_ib_dbg(imr->dev, "key %x mr %p\n", mr->mmkey.key, mr);
 521         return mr;
 522
 523 out_mr:
 524         mlx5_mr_cache_free(imr->dev, mr);
 525 out_umem:
 526         ib_umem_odp_release(odp);
 527         return ret;
 528 }
 529
 530 struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
 531                                              struct ib_udata *udata,
 532                                              int access_flags)
 533 {
 534         struct mlx5_ib_dev *dev = to_mdev(pd->ibpd.device);
 535         struct ib_umem_odp *umem_odp;
 536         struct mlx5_ib_mr *imr;
 537         int err;
 538
 539         umem_odp = ib_umem_odp_alloc_implicit(&dev->ib_dev, access_flags);
 540         if (IS_ERR(umem_odp))
 541                 return ERR_CAST(umem_odp);
 542
 543         imr = mlx5_mr_cache_alloc(dev, MLX5_IMR_KSM_CACHE_ENTRY);
 544         if (IS_ERR(imr)) {
 545                 err = PTR_ERR(imr);
 546                 goto out_umem;
 547         }
 548
 549         imr->ibmr.pd = &pd->ibpd;
 550         imr->access_flags = access_flags;
 551         imr->mmkey.iova = 0;
 552         imr->umem = &umem_odp->umem;
 553         imr->ibmr.lkey = imr->mmkey.key;
 554         imr->ibmr.rkey = imr->mmkey.key;
 555         imr->umem = &umem_odp->umem;
 556         imr->is_odp_implicit = true;
 557         atomic_set(&imr->num_deferred_work, 0);
 558         init_waitqueue_head(&imr->q_deferred_work);
 559         xa_init(&imr->implicit_children);
 560
 561         err = mlx5_ib_update_xlt(imr, 0,
 562                                  mlx5_imr_ksm_entries,
 563                                  MLX5_KSM_PAGE_SHIFT,
 564                                  MLX5_IB_UPD_XLT_INDIRECT |
 565                                  MLX5_IB_UPD_XLT_ZAP |
 566                                  MLX5_IB_UPD_XLT_ENABLE);
 567         if (err)
 568                 goto out_mr;
 569
 570         err = xa_err(xa_store(&dev->odp_mkeys, mlx5_base_mkey(imr->mmkey.key),
 571                               &imr->mmkey, GFP_KERNEL));
 572         if (err)
 573                 goto out_mr;
 574
 575         mlx5_ib_dbg(dev, "key %x mr %p\n", imr->mmkey.key, imr);
 576         return imr;
 577 out_mr:
 578         mlx5_ib_err(dev, "Failed to register MKEY %d\n", err);
 579         mlx5_mr_cache_free(dev, imr);
 580 out_umem:
 581         ib_umem_odp_release(umem_odp);
 582         return ERR_PTR(err);
 583 }
 584
 585 void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr)
 586 {
 587         struct ib_umem_odp *odp_imr = to_ib_umem_odp(imr->umem);
 588         struct mlx5_ib_dev *dev = imr->dev;
 589         struct list_head destroy_list;
 590         struct mlx5_ib_mr *mtt;
 591         struct mlx5_ib_mr *tmp;
 592         unsigned long idx;
 593
 594         INIT_LIST_HEAD(&destroy_list);
 595
 596         xa_erase(&dev->odp_mkeys, mlx5_base_mkey(imr->mmkey.key));
 597         /*
 598          * This stops the SRCU protected page fault path from touching either
 599          * the imr or any children. The page fault path can only reach the
 600          * children xarray via the imr.
 601          */
 602         synchronize_srcu(&dev->odp_srcu);
 603
 604         /*
 605          * All work on the prefetch list must be completed, xa_erase() prevented
 606          * new work from being created.
 607          */
 608         wait_event(imr->q_deferred_work, !atomic_read(&imr->num_deferred_work));
 609
 610         /*
 611          * At this point it is forbidden for any other thread to enter
 612          * pagefault_mr() on this imr. It is already forbidden to call
 613          * pagefault_mr() on an implicit child. Due to this additions to
 614          * implicit_children are prevented.
 615          */
 616
 617         /*
 618          * Block destroy_unused_implicit_child_mr() from incrementing
 619          * num_deferred_work.
 620          */
 621         xa_lock(&imr->implicit_children);
 622         xa_for_each (&imr->implicit_children, idx, mtt) {
 623                 __xa_erase(&imr->implicit_children, idx);
 624                 list_add(&mtt->odp_destroy.elm, &destroy_list);
 625         }
 626         xa_unlock(&imr->implicit_children);
 627
 628         /*
 629          * Wait for any concurrent destroy_unused_implicit_child_mr() to
 630          * complete.
 631          */
 632         wait_event(imr->q_deferred_work, !atomic_read(&imr->num_deferred_work));
 633
 634         /*
 635          * Fence the imr before we destroy the children. This allows us to
 636          * skip updating the XLT of the imr during destroy of the child mkey
 637          * the imr points to.
 638          */
 639         mlx5_mr_cache_invalidate(imr);
 640
 641         list_for_each_entry_safe (mtt, tmp, &destroy_list, odp_destroy.elm)
 642                 free_implicit_child_mr(mtt, false);
 643
 644         mlx5_mr_cache_free(dev, imr);
 645         ib_umem_odp_release(odp_imr);
 646 }
 647
 648 /**
 649  * mlx5_ib_fence_odp_mr - Stop all access to the ODP MR
 650  * @mr: to fence
 651  *
 652  * On return no parallel threads will be touching this MR and no DMA will be
 653  * active.
 654  */
 655 void mlx5_ib_fence_odp_mr(struct mlx5_ib_mr *mr)
 656 {
 657         /* Prevent new page faults and prefetch requests from succeeding */
 658         xa_erase(&mr->dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key));
 659
 660         /* Wait for all running page-fault handlers to finish. */
 661         synchronize_srcu(&mr->dev->odp_srcu);
 662
 663         wait_event(mr->q_deferred_work, !atomic_read(&mr->num_deferred_work));
 664
 665         dma_fence_odp_mr(mr);
 666 }
 667
 668 #define MLX5_PF_FLAGS_DOWNGRADE BIT(1)
 669 static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
 670                              u64 user_va, size_t bcnt, u32 *bytes_mapped,
 671                              u32 flags)
 672 {
 673         int page_shift, ret, np;
 674         bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE;
 675         unsigned long current_seq;
 676         u64 access_mask;
 677         u64 start_idx;
 678
 679         page_shift = odp->page_shift;
 680         start_idx = (user_va - ib_umem_start(odp)) >> page_shift;
 681         access_mask = ODP_READ_ALLOWED_BIT;
 682
 683         if (odp->umem.writable && !downgrade)
 684                 access_mask |= ODP_WRITE_ALLOWED_BIT;
 685
 686         current_seq = mmu_interval_read_begin(&odp->notifier);
 687
 688         np = ib_umem_odp_map_dma_pages(odp, user_va, bcnt, access_mask,
 689                                        current_seq);
 690         if (np < 0)
 691                 return np;
 692
 693         mutex_lock(&odp->umem_mutex);
 694         if (!mmu_interval_read_retry(&odp->notifier, current_seq)) {
 695                 /*
 696                  * No need to check whether the MTTs really belong to
 697                  * this MR, since ib_umem_odp_map_dma_pages already
 698                  * checks this.
 699                  */
 700                 ret = mlx5_ib_update_xlt(mr, start_idx, np,
 701                                          page_shift, MLX5_IB_UPD_XLT_ATOMIC);
 702         } else {
 703                 ret = -EAGAIN;
 704         }
 705         mutex_unlock(&odp->umem_mutex);
 706
 707         if (ret < 0) {
 708                 if (ret != -EAGAIN)
 709                         mlx5_ib_err(mr->dev,
 710                                     "Failed to update mkey page tables\n");
 711                 goto out;
 712         }
 713
 714         if (bytes_mapped) {
 715                 u32 new_mappings = (np << page_shift) -
 716                         (user_va - round_down(user_va, 1 << page_shift));
 717
 718                 *bytes_mapped += min_t(u32, new_mappings, bcnt);
 719         }
 720
 721         return np << (page_shift - PAGE_SHIFT);
 722
 723 out:
 724         return ret;
 725 }
 726
 727 static int pagefault_implicit_mr(struct mlx5_ib_mr *imr,
 728                                  struct ib_umem_odp *odp_imr, u64 user_va,
 729                                  size_t bcnt, u32 *bytes_mapped, u32 flags)
 730 {
 731         unsigned long end_idx = (user_va + bcnt - 1) >> MLX5_IMR_MTT_SHIFT;
 732         unsigned long upd_start_idx = end_idx + 1;
 733         unsigned long upd_len = 0;
 734         unsigned long npages = 0;
 735         int err;
 736         int ret;
 737
 738         if (unlikely(user_va >= mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE ||
 739                      mlx5_imr_ksm_entries * MLX5_IMR_MTT_SIZE - user_va < bcnt))
 740                 return -EFAULT;
 741
 742         /* Fault each child mr that intersects with our interval. */
 743         while (bcnt) {
 744                 unsigned long idx = user_va >> MLX5_IMR_MTT_SHIFT;
 745                 struct ib_umem_odp *umem_odp;
 746                 struct mlx5_ib_mr *mtt;
 747                 u64 len;
 748
 749                 mtt = xa_load(&imr->implicit_children, idx);
 750                 if (unlikely(!mtt)) {
 751                         mtt = implicit_get_child_mr(imr, idx);
 752                         if (IS_ERR(mtt)) {
 753                                 ret = PTR_ERR(mtt);
 754                                 goto out;
 755                         }
 756                         upd_start_idx = min(upd_start_idx, idx);
 757                         upd_len = idx - upd_start_idx + 1;
 758                 }
 759
 760                 umem_odp = to_ib_umem_odp(mtt->umem);
 761                 len = min_t(u64, user_va + bcnt, ib_umem_end(umem_odp)) -
 762                       user_va;
 763
 764                 ret = pagefault_real_mr(mtt, umem_odp, user_va, len,
 765                                         bytes_mapped, flags);
 766                 if (ret < 0)
 767                         goto out;
 768                 user_va += len;
 769                 bcnt -= len;
 770                 npages += ret;
 771         }
 772
 773         ret = npages;
 774
 775         /*
 776          * Any time the implicit_children are changed we must perform an
 777          * update of the xlt before exiting to ensure the HW and the
 778          * implicit_children remains synchronized.
 779          */
 780 out:
 781         if (likely(!upd_len))
 782                 return ret;
 783
 784         /*
 785          * Notice this is not strictly ordered right, the KSM is updated after
 786          * the implicit_children is updated, so a parallel page fault could
 787          * see a MR that is not yet visible in the KSM.  This is similar to a
 788          * parallel page fault seeing a MR that is being concurrently removed
 789          * from the KSM. Both of these improbable situations are resolved
 790          * safely by resuming the HW and then taking another page fault. The
 791          * next pagefault handler will see the new information.
 792          */
 793         mutex_lock(&odp_imr->umem_mutex);
 794         err = mlx5_ib_update_xlt(imr, upd_start_idx, upd_len, 0,
 795                                  MLX5_IB_UPD_XLT_INDIRECT |
 796                                          MLX5_IB_UPD_XLT_ATOMIC);
 797         mutex_unlock(&odp_imr->umem_mutex);
 798         if (err) {
 799                 mlx5_ib_err(imr->dev, "Failed to update PAS\n");
 800                 return err;
 801         }
 802         return ret;
 803 }
 804
 805 /*
 806  * Returns:
 807  *  -EFAULT: The io_virt->bcnt is not within the MR, it covers pages that are
 808  *           not accessible, or the MR is no longer valid.
 809  *  -EAGAIN/-ENOMEM: The operation should be retried
 810  *
 811  *  -EINVAL/others: General internal malfunction
 812  *  >0: Number of pages mapped
 813  */
 814 static int pagefault_mr(struct mlx5_ib_mr *mr, u64 io_virt, size_t bcnt,
 815                         u32 *bytes_mapped, u32 flags)
 816 {
 817         struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
 818
 819         if (unlikely(io_virt < mr->mmkey.iova))
 820                 return -EFAULT;
 821
 822         if (!odp->is_implicit_odp) {
 823                 u64 user_va;
 824
 825                 if (check_add_overflow(io_virt - mr->mmkey.iova,
 826                                        (u64)odp->umem.address, &user_va))
 827                         return -EFAULT;
 828                 if (unlikely(user_va >= ib_umem_end(odp) ||
 829                              ib_umem_end(odp) - user_va < bcnt))
 830                         return -EFAULT;
 831                 return pagefault_real_mr(mr, odp, user_va, bcnt, bytes_mapped,
 832                                          flags);
 833         }
 834         return pagefault_implicit_mr(mr, odp, io_virt, bcnt, bytes_mapped,
 835                                      flags);
 836 }
 837
 838 struct pf_frame {
 839         struct pf_frame *next;
 840         u32 key;
 841         u64 io_virt;
 842         size_t bcnt;
 843         int depth;
 844 };
 845
 846 static bool mkey_is_eq(struct mlx5_core_mkey *mmkey, u32 key)
 847 {
 848         if (!mmkey)
 849                 return false;
 850         if (mmkey->type == MLX5_MKEY_MW)
 851                 return mlx5_base_mkey(mmkey->key) == mlx5_base_mkey(key);
 852         return mmkey->key == key;
 853 }
 854
 855 static int get_indirect_num_descs(struct mlx5_core_mkey *mmkey)
 856 {
 857         struct mlx5_ib_mw *mw;
 858         struct mlx5_ib_devx_mr *devx_mr;
 859
 860         if (mmkey->type == MLX5_MKEY_MW) {
 861                 mw = container_of(mmkey, struct mlx5_ib_mw, mmkey);
 862                 return mw->ndescs;
 863         }
 864
 865         devx_mr = container_of(mmkey, struct mlx5_ib_devx_mr,
 866                                mmkey);
 867         return devx_mr->ndescs;
 868 }
 869
 870 /*
 871  * Handle a single data segment in a page-fault WQE or RDMA region.
 872  *
 873  * Returns number of OS pages retrieved on success. The caller may continue to
 874  * the next data segment.
 875  * Can return the following error codes:
 876  * -EAGAIN to designate a temporary error. The caller will abort handling the
 877  *  page fault and resolve it.
 878  * -EFAULT when there's an error mapping the requested pages. The caller will
 879  *  abort the page fault handling.
 880  */
 881 static int pagefault_single_data_segment(struct mlx5_ib_dev *dev,
 882                                          struct ib_pd *pd, u32 key,
 883                                          u64 io_virt, size_t bcnt,
 884                                          u32 *bytes_committed,
 885                                          u32 *bytes_mapped)
 886 {
 887         int npages = 0, srcu_key, ret, i, outlen, cur_outlen = 0, depth = 0;
 888         struct pf_frame *head = NULL, *frame;
 889         struct mlx5_core_mkey *mmkey;
 890         struct mlx5_ib_mr *mr;
 891         struct mlx5_klm *pklm;
 892         u32 *out = NULL;
 893         size_t offset;
 894         int ndescs;
 895
 896         srcu_key = srcu_read_lock(&dev->odp_srcu);
 897
 898         io_virt += *bytes_committed;
 899         bcnt -= *bytes_committed;
 900
 901 next_mr:
 902         mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(key));
 903         if (!mmkey) {
 904                 mlx5_ib_dbg(
 905                         dev,
 906                         "skipping non ODP MR (lkey=0x%06x) in page fault handler.\n",
 907                         key);
 908                 if (bytes_mapped)
 909                         *bytes_mapped += bcnt;
 910                 /*
 911                  * The user could specify a SGL with multiple lkeys and only
 912                  * some of them are ODP. Treat the non-ODP ones as fully
 913                  * faulted.
 914                  */
 915                 ret = 0;
 916                 goto srcu_unlock;
 917         }
 918         if (!mkey_is_eq(mmkey, key)) {
 919                 mlx5_ib_dbg(dev, "failed to find mkey %x\n", key);
 920                 ret = -EFAULT;
 921                 goto srcu_unlock;
 922         }
 923
 924         switch (mmkey->type) {
 925         case MLX5_MKEY_MR:
 926                 mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
 927
 928                 ret = pagefault_mr(mr, io_virt, bcnt, bytes_mapped, 0);
 929                 if (ret < 0)
 930                         goto srcu_unlock;
 931
 932                 /*
 933                  * When prefetching a page, page fault is generated
 934                  * in order to bring the page to the main memory.
 935                  * In the current flow, page faults are being counted.
 936                  */
 937                 mlx5_update_odp_stats(mr, faults, ret);
 938
 939                 npages += ret;
 940                 ret = 0;
 941                 break;
 942
 943         case MLX5_MKEY_MW:
 944         case MLX5_MKEY_INDIRECT_DEVX:
 945                 ndescs = get_indirect_num_descs(mmkey);
 946
 947                 if (depth >= MLX5_CAP_GEN(dev->mdev, max_indirection)) {
 948                         mlx5_ib_dbg(dev, "indirection level exceeded\n");
 949                         ret = -EFAULT;
 950                         goto srcu_unlock;
 951                 }
 952
 953                 outlen = MLX5_ST_SZ_BYTES(query_mkey_out) +
 954                         sizeof(*pklm) * (ndescs - 2);
 955
 956                 if (outlen > cur_outlen) {
 957                         kfree(out);
 958                         out = kzalloc(outlen, GFP_KERNEL);
 959                         if (!out) {
 960                                 ret = -ENOMEM;
 961                                 goto srcu_unlock;
 962                         }
 963                         cur_outlen = outlen;
 964                 }
 965
 966                 pklm = (struct mlx5_klm *)MLX5_ADDR_OF(query_mkey_out, out,
 967                                                        bsf0_klm0_pas_mtt0_1);
 968
 969                 ret = mlx5_core_query_mkey(dev->mdev, mmkey, out, outlen);
 970                 if (ret)
 971                         goto srcu_unlock;
 972
 973                 offset = io_virt - MLX5_GET64(query_mkey_out, out,
 974                                               memory_key_mkey_entry.start_addr);
 975
 976                 for (i = 0; bcnt && i < ndescs; i++, pklm++) {
 977                         if (offset >= be32_to_cpu(pklm->bcount)) {
 978                                 offset -= be32_to_cpu(pklm->bcount);
 979                                 continue;
 980                         }
 981
 982                         frame = kzalloc(sizeof(*frame), GFP_KERNEL);
 983                         if (!frame) {
 984                                 ret = -ENOMEM;
 985                                 goto srcu_unlock;
 986                         }
 987
 988                         frame->key = be32_to_cpu(pklm->key);
 989                         frame->io_virt = be64_to_cpu(pklm->va) + offset;
 990                         frame->bcnt = min_t(size_t, bcnt,
 991                                             be32_to_cpu(pklm->bcount) - offset);
 992                         frame->depth = depth + 1;
 993                         frame->next = head;
 994                         head = frame;
 995
 996                         bcnt -= frame->bcnt;
 997                         offset = 0;
 998                 }
 999                 break;
1000
1001         default:
1002                 mlx5_ib_dbg(dev, "wrong mkey type %d\n", mmkey->type);
1003                 ret = -EFAULT;
1004                 goto srcu_unlock;
1005         }
1006
1007         if (head) {
1008                 frame = head;
1009                 head = frame->next;
1010
1011                 key = frame->key;
1012                 io_virt = frame->io_virt;
1013                 bcnt = frame->bcnt;
1014                 depth = frame->depth;
1015                 kfree(frame);
1016
1017                 goto next_mr;
1018         }
1019
1020 srcu_unlock:
1021         while (head) {
1022                 frame = head;
1023                 head = frame->next;
1024                 kfree(frame);
1025         }
1026         kfree(out);
1027
1028         srcu_read_unlock(&dev->odp_srcu, srcu_key);
1029         *bytes_committed = 0;
1030         return ret ? ret : npages;
1031 }
1032
1033 /**
1034  * Parse a series of data segments for page fault handling.
1035  *
1036  * @pfault contains page fault information.
1037  * @wqe points at the first data segment in the WQE.
1038  * @wqe_end points after the end of the WQE.
1039  * @bytes_mapped receives the number of bytes that the function was able to
1040  *               map. This allows the caller to decide intelligently whether
1041  *               enough memory was mapped to resolve the page fault
1042  *               successfully (e.g. enough for the next MTU, or the entire
1043  *               WQE).
1044  * @total_wqe_bytes receives the total data size of this WQE in bytes (minus
1045  *                  the committed bytes).
1046  *
1047  * Returns the number of pages loaded if positive, zero for an empty WQE, or a
1048  * negative error code.
1049  */
1050 static int pagefault_data_segments(struct mlx5_ib_dev *dev,
1051                                    struct mlx5_pagefault *pfault,
1052                                    void *wqe,
1053                                    void *wqe_end, u32 *bytes_mapped,
1054                                    u32 *total_wqe_bytes, bool receive_queue)
1055 {
1056         int ret = 0, npages = 0;
1057         u64 io_virt;
1058         u32 key;
1059         u32 byte_count;
1060         size_t bcnt;
1061         int inline_segment;
1062
1063         if (bytes_mapped)
1064                 *bytes_mapped = 0;
1065         if (total_wqe_bytes)
1066                 *total_wqe_bytes = 0;
1067
1068         while (wqe < wqe_end) {
1069                 struct mlx5_wqe_data_seg *dseg = wqe;
1070
1071                 io_virt = be64_to_cpu(dseg->addr);
1072                 key = be32_to_cpu(dseg->lkey);
1073                 byte_count = be32_to_cpu(dseg->byte_count);
1074                 inline_segment = !!(byte_count &  MLX5_INLINE_SEG);
1075                 bcnt           = byte_count & ~MLX5_INLINE_SEG;
1076
1077                 if (inline_segment) {
1078                         bcnt = bcnt & MLX5_WQE_INLINE_SEG_BYTE_COUNT_MASK;
1079                         wqe += ALIGN(sizeof(struct mlx5_wqe_inline_seg) + bcnt,
1080                                      16);
1081                 } else {
1082                         wqe += sizeof(*dseg);
1083                 }
1084
1085                 /* receive WQE end of sg list. */
1086                 if (receive_queue && bcnt == 0 && key == MLX5_INVALID_LKEY &&
1087                     io_virt == 0)
1088                         break;
1089
1090                 if (!inline_segment && total_wqe_bytes) {
1091                         *total_wqe_bytes += bcnt - min_t(size_t, bcnt,
1092                                         pfault->bytes_committed);
1093                 }
1094
1095                 /* A zero length data segment designates a length of 2GB. */
1096                 if (bcnt == 0)
1097                         bcnt = 1U << 31;
1098
1099                 if (inline_segment || bcnt <= pfault->bytes_committed) {
1100                         pfault->bytes_committed -=
1101                                 min_t(size_t, bcnt,
1102                                       pfault->bytes_committed);
1103                         continue;
1104                 }
1105
1106                 ret = pagefault_single_data_segment(dev, NULL, key,
1107                                                     io_virt, bcnt,
1108                                                     &pfault->bytes_committed,
1109                                                     bytes_mapped);
1110                 if (ret < 0)
1111                         break;
1112                 npages += ret;
1113         }
1114
1115         return ret < 0 ? ret : npages;
1116 }
1117
1118 /*
1119  * Parse initiator WQE. Advances the wqe pointer to point at the
1120  * scatter-gather list, and set wqe_end to the end of the WQE.
1121  */
1122 static int mlx5_ib_mr_initiator_pfault_handler(
1123         struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault,
1124         struct mlx5_ib_qp *qp, void **wqe, void **wqe_end, int wqe_length)
1125 {
1126         struct mlx5_wqe_ctrl_seg *ctrl = *wqe;
1127         u16 wqe_index = pfault->wqe.wqe_index;
1128         struct mlx5_base_av *av;
1129         unsigned ds, opcode;
1130         u32 qpn = qp->trans_qp.base.mqp.qpn;
1131
1132         ds = be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_DS_MASK;
1133         if (ds * MLX5_WQE_DS_UNITS > wqe_length) {
1134                 mlx5_ib_err(dev, "Unable to read the complete WQE. ds = 0x%x, ret = 0x%x\n",
1135                             ds, wqe_length);
1136                 return -EFAULT;
1137         }
1138
1139         if (ds == 0) {
1140                 mlx5_ib_err(dev, "Got WQE with zero DS. wqe_index=%x, qpn=%x\n",
1141                             wqe_index, qpn);
1142                 return -EFAULT;
1143         }
1144
1145         *wqe_end = *wqe + ds * MLX5_WQE_DS_UNITS;
1146         *wqe += sizeof(*ctrl);
1147
1148         opcode = be32_to_cpu(ctrl->opmod_idx_opcode) &
1149                  MLX5_WQE_CTRL_OPCODE_MASK;
1150
1151         if (qp->ibqp.qp_type == IB_QPT_XRC_INI)
1152                 *wqe += sizeof(struct mlx5_wqe_xrc_seg);
1153
1154         if (qp->type == IB_QPT_UD || qp->type == MLX5_IB_QPT_DCI) {
1155                 av = *wqe;
1156                 if (av->dqp_dct & cpu_to_be32(MLX5_EXTENDED_UD_AV))
1157                         *wqe += sizeof(struct mlx5_av);
1158                 else
1159                         *wqe += sizeof(struct mlx5_base_av);
1160         }
1161
1162         switch (opcode) {
1163         case MLX5_OPCODE_RDMA_WRITE:
1164         case MLX5_OPCODE_RDMA_WRITE_IMM:
1165         case MLX5_OPCODE_RDMA_READ:
1166                 *wqe += sizeof(struct mlx5_wqe_raddr_seg);
1167                 break;
1168         case MLX5_OPCODE_ATOMIC_CS:
1169         case MLX5_OPCODE_ATOMIC_FA:
1170                 *wqe += sizeof(struct mlx5_wqe_raddr_seg);
1171                 *wqe += sizeof(struct mlx5_wqe_atomic_seg);
1172                 break;
1173         }
1174
1175         return 0;
1176 }
1177
1178 /*
1179  * Parse responder WQE and set wqe_end to the end of the WQE.
1180  */
1181 static int mlx5_ib_mr_responder_pfault_handler_srq(struct mlx5_ib_dev *dev,
1182                                                    struct mlx5_ib_srq *srq,
1183                                                    void **wqe, void **wqe_end,
1184                                                    int wqe_length)
1185 {
1186         int wqe_size = 1 << srq->msrq.wqe_shift;
1187
1188         if (wqe_size > wqe_length) {
1189                 mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
1190                 return -EFAULT;
1191         }
1192
1193         *wqe_end = *wqe + wqe_size;
1194         *wqe += sizeof(struct mlx5_wqe_srq_next_seg);
1195
1196         return 0;
1197 }
1198
1199 static int mlx5_ib_mr_responder_pfault_handler_rq(struct mlx5_ib_dev *dev,
1200                                                   struct mlx5_ib_qp *qp,
1201                                                   void *wqe, void **wqe_end,
1202                                                   int wqe_length)
1203 {
1204         struct mlx5_ib_wq *wq = &qp->rq;
1205         int wqe_size = 1 << wq->wqe_shift;
1206
1207         if (qp->flags_en & MLX5_QP_FLAG_SIGNATURE) {
1208                 mlx5_ib_err(dev, "ODP fault with WQE signatures is not supported\n");
1209                 return -EFAULT;
1210         }
1211
1212         if (wqe_size > wqe_length) {
1213                 mlx5_ib_err(dev, "Couldn't read all of the receive WQE's content\n");
1214                 return -EFAULT;
1215         }
1216
1217         *wqe_end = wqe + wqe_size;
1218
1219         return 0;
1220 }
1221
1222 static inline struct mlx5_core_rsc_common *odp_get_rsc(struct mlx5_ib_dev *dev,
1223                                                        u32 wq_num, int pf_type)
1224 {
1225         struct mlx5_core_rsc_common *common = NULL;
1226         struct mlx5_core_srq *srq;
1227
1228         switch (pf_type) {
1229         case MLX5_WQE_PF_TYPE_RMP:
1230                 srq = mlx5_cmd_get_srq(dev, wq_num);
1231                 if (srq)
1232                         common = &srq->common;
1233                 break;
1234         case MLX5_WQE_PF_TYPE_REQ_SEND_OR_WRITE:
1235         case MLX5_WQE_PF_TYPE_RESP:
1236         case MLX5_WQE_PF_TYPE_REQ_READ_OR_ATOMIC:
1237                 common = mlx5_core_res_hold(dev, wq_num, MLX5_RES_QP);
1238                 break;
1239         default:
1240                 break;
1241         }
1242
1243         return common;
1244 }
1245
1246 static inline struct mlx5_ib_qp *res_to_qp(struct mlx5_core_rsc_common *res)
1247 {
1248         struct mlx5_core_qp *mqp = (struct mlx5_core_qp *)res;
1249
1250         return to_mibqp(mqp);
1251 }
1252
1253 static inline struct mlx5_ib_srq *res_to_srq(struct mlx5_core_rsc_common *res)
1254 {
1255         struct mlx5_core_srq *msrq =
1256                 container_of(res, struct mlx5_core_srq, common);
1257
1258         return to_mibsrq(msrq);
1259 }
1260
1261 static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
1262                                           struct mlx5_pagefault *pfault)
1263 {
1264         bool sq = pfault->type & MLX5_PFAULT_REQUESTOR;
1265         u16 wqe_index = pfault->wqe.wqe_index;
1266         void *wqe, *wqe_start = NULL, *wqe_end = NULL;
1267         u32 bytes_mapped, total_wqe_bytes;
1268         struct mlx5_core_rsc_common *res;
1269         int resume_with_error = 1;
1270         struct mlx5_ib_qp *qp;
1271         size_t bytes_copied;
1272         int ret = 0;
1273
1274         res = odp_get_rsc(dev, pfault->wqe.wq_num, pfault->type);
1275         if (!res) {
1276                 mlx5_ib_dbg(dev, "wqe page fault for missing resource %d\n", pfault->wqe.wq_num);
1277                 return;
1278         }
1279
1280         if (res->res != MLX5_RES_QP && res->res != MLX5_RES_SRQ &&
1281             res->res != MLX5_RES_XSRQ) {
1282                 mlx5_ib_err(dev, "wqe page fault for unsupported type %d\n",
1283                             pfault->type);
1284                 goto resolve_page_fault;
1285         }
1286
1287         wqe_start = (void *)__get_free_page(GFP_KERNEL);
1288         if (!wqe_start) {
1289                 mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
1290                 goto resolve_page_fault;
1291         }
1292
1293         wqe = wqe_start;
1294         qp = (res->res == MLX5_RES_QP) ? res_to_qp(res) : NULL;
1295         if (qp && sq) {
1296                 ret = mlx5_ib_read_wqe_sq(qp, wqe_index, wqe, PAGE_SIZE,
1297                                           &bytes_copied);
1298                 if (ret)
1299                         goto read_user;
1300                 ret = mlx5_ib_mr_initiator_pfault_handler(
1301                         dev, pfault, qp, &wqe, &wqe_end, bytes_copied);
1302         } else if (qp && !sq) {
1303                 ret = mlx5_ib_read_wqe_rq(qp, wqe_index, wqe, PAGE_SIZE,
1304                                           &bytes_copied);
1305                 if (ret)
1306                         goto read_user;
1307                 ret = mlx5_ib_mr_responder_pfault_handler_rq(
1308                         dev, qp, wqe, &wqe_end, bytes_copied);
1309         } else if (!qp) {
1310                 struct mlx5_ib_srq *srq = res_to_srq(res);
1311
1312                 ret = mlx5_ib_read_wqe_srq(srq, wqe_index, wqe, PAGE_SIZE,
1313                                            &bytes_copied);
1314                 if (ret)
1315                         goto read_user;
1316                 ret = mlx5_ib_mr_responder_pfault_handler_srq(
1317                         dev, srq, &wqe, &wqe_end, bytes_copied);
1318         }
1319
1320         if (ret < 0 || wqe >= wqe_end)
1321                 goto resolve_page_fault;
1322
1323         ret = pagefault_data_segments(dev, pfault, wqe, wqe_end, &bytes_mapped,
1324                                       &total_wqe_bytes, !sq);
1325         if (ret == -EAGAIN)
1326                 goto out;
1327
1328         if (ret < 0 || total_wqe_bytes > bytes_mapped)
1329                 goto resolve_page_fault;
1330
1331 out:
1332         ret = 0;
1333         resume_with_error = 0;
1334
1335 read_user:
1336         if (ret)
1337                 mlx5_ib_err(
1338                         dev,
1339                         "Failed reading a WQE following page fault, error %d, wqe_index %x, qpn %x\n",
1340                         ret, wqe_index, pfault->token);
1341
1342 resolve_page_fault:
1343         mlx5_ib_page_fault_resume(dev, pfault, resume_with_error);
1344         mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x resume_with_error=%d, type: 0x%x\n",
1345                     pfault->wqe.wq_num, resume_with_error,
1346                     pfault->type);
1347         mlx5_core_res_put(res);
1348         free_page((unsigned long)wqe_start);
1349 }
1350
1351 static int pages_in_range(u64 address, u32 length)
1352 {
1353         return (ALIGN(address + length, PAGE_SIZE) -
1354                 (address & PAGE_MASK)) >> PAGE_SHIFT;
1355 }
1356
1357 static void mlx5_ib_mr_rdma_pfault_handler(struct mlx5_ib_dev *dev,
1358                                            struct mlx5_pagefault *pfault)
1359 {
1360         u64 address;
1361         u32 length;
1362         u32 prefetch_len = pfault->bytes_committed;
1363         int prefetch_activated = 0;
1364         u32 rkey = pfault->rdma.r_key;
1365         int ret;
1366
1367         /* The RDMA responder handler handles the page fault in two parts.
1368          * First it brings the necessary pages for the current packet
1369          * (and uses the pfault context), and then (after resuming the QP)
1370          * prefetches more pages. The second operation cannot use the pfault
1371          * context and therefore uses the dummy_pfault context allocated on
1372          * the stack */
1373         pfault->rdma.rdma_va += pfault->bytes_committed;
1374         pfault->rdma.rdma_op_len -= min(pfault->bytes_committed,
1375                                          pfault->rdma.rdma_op_len);
1376         pfault->bytes_committed = 0;
1377
1378         address = pfault->rdma.rdma_va;
1379         length  = pfault->rdma.rdma_op_len;
1380
1381         /* For some operations, the hardware cannot tell the exact message
1382          * length, and in those cases it reports zero. Use prefetch
1383          * logic. */
1384         if (length == 0) {
1385                 prefetch_activated = 1;
1386                 length = pfault->rdma.packet_size;
1387                 prefetch_len = min(MAX_PREFETCH_LEN, prefetch_len);
1388         }
1389
1390         ret = pagefault_single_data_segment(dev, NULL, rkey, address, length,
1391                                             &pfault->bytes_committed, NULL);
1392         if (ret == -EAGAIN) {
1393                 /* We're racing with an invalidation, don't prefetch */
1394                 prefetch_activated = 0;
1395         } else if (ret < 0 || pages_in_range(address, length) > ret) {
1396                 mlx5_ib_page_fault_resume(dev, pfault, 1);
1397                 if (ret != -ENOENT)
1398                         mlx5_ib_dbg(dev, "PAGE FAULT error %d. QP 0x%x, type: 0x%x\n",
1399                                     ret, pfault->token, pfault->type);
1400                 return;
1401         }
1402
1403         mlx5_ib_page_fault_resume(dev, pfault, 0);
1404         mlx5_ib_dbg(dev, "PAGE FAULT completed. QP 0x%x, type: 0x%x, prefetch_activated: %d\n",
1405                     pfault->token, pfault->type,
1406                     prefetch_activated);
1407
1408         /* At this point, there might be a new pagefault already arriving in
1409          * the eq, switch to the dummy pagefault for the rest of the
1410          * processing. We're still OK with the objects being alive as the
1411          * work-queue is being fenced. */
1412
1413         if (prefetch_activated) {
1414                 u32 bytes_committed = 0;
1415
1416                 ret = pagefault_single_data_segment(dev, NULL, rkey, address,
1417                                                     prefetch_len,
1418                                                     &bytes_committed, NULL);
1419                 if (ret < 0 && ret != -EAGAIN) {
1420                         mlx5_ib_dbg(dev, "Prefetch failed. ret: %d, QP 0x%x, address: 0x%.16llx, length = 0x%.16x\n",
1421                                     ret, pfault->token, address, prefetch_len);
1422                 }
1423         }
1424 }
1425
1426 static void mlx5_ib_pfault(struct mlx5_ib_dev *dev, struct mlx5_pagefault *pfault)
1427 {
1428         u8 event_subtype = pfault->event_subtype;
1429
1430         switch (event_subtype) {
1431         case MLX5_PFAULT_SUBTYPE_WQE:
1432                 mlx5_ib_mr_wqe_pfault_handler(dev, pfault);
1433                 break;
1434         case MLX5_PFAULT_SUBTYPE_RDMA:
1435                 mlx5_ib_mr_rdma_pfault_handler(dev, pfault);
1436                 break;
1437         default:
1438                 mlx5_ib_err(dev, "Invalid page fault event subtype: 0x%x\n",
1439                             event_subtype);
1440                 mlx5_ib_page_fault_resume(dev, pfault, 1);
1441         }
1442 }
1443
1444 static void mlx5_ib_eqe_pf_action(struct work_struct *work)
1445 {
1446         struct mlx5_pagefault *pfault = container_of(work,
1447                                                      struct mlx5_pagefault,
1448                                                      work);
1449         struct mlx5_ib_pf_eq *eq = pfault->eq;
1450
1451         mlx5_ib_pfault(eq->dev, pfault);
1452         mempool_free(pfault, eq->pool);
1453 }
1454
1455 static void mlx5_ib_eq_pf_process(struct mlx5_ib_pf_eq *eq)
1456 {
1457         struct mlx5_eqe_page_fault *pf_eqe;
1458         struct mlx5_pagefault *pfault;
1459         struct mlx5_eqe *eqe;
1460         int cc = 0;
1461
1462         while ((eqe = mlx5_eq_get_eqe(eq->core, cc))) {
1463                 pfault = mempool_alloc(eq->pool, GFP_ATOMIC);
1464                 if (!pfault) {
1465                         schedule_work(&eq->work);
1466                         break;
1467                 }
1468
1469                 pf_eqe = &eqe->data.page_fault;
1470                 pfault->event_subtype = eqe->sub_type;
1471                 pfault->bytes_committed = be32_to_cpu(pf_eqe->bytes_committed);
1472
1473                 mlx5_ib_dbg(eq->dev,
1474                             "PAGE_FAULT: subtype: 0x%02x, bytes_committed: 0x%06x\n",
1475                             eqe->sub_type, pfault->bytes_committed);
1476
1477                 switch (eqe->sub_type) {
1478                 case MLX5_PFAULT_SUBTYPE_RDMA:
1479                         /* RDMA based event */
1480                         pfault->type =
1481                                 be32_to_cpu(pf_eqe->rdma.pftype_token) >> 24;
1482                         pfault->token =
1483                                 be32_to_cpu(pf_eqe->rdma.pftype_token) &
1484                                 MLX5_24BIT_MASK;
1485                         pfault->rdma.r_key =
1486                                 be32_to_cpu(pf_eqe->rdma.r_key);
1487                         pfault->rdma.packet_size =
1488                                 be16_to_cpu(pf_eqe->rdma.packet_length);
1489                         pfault->rdma.rdma_op_len =
1490                                 be32_to_cpu(pf_eqe->rdma.rdma_op_len);
1491                         pfault->rdma.rdma_va =
1492                                 be64_to_cpu(pf_eqe->rdma.rdma_va);
1493                         mlx5_ib_dbg(eq->dev,
1494                                     "PAGE_FAULT: type:0x%x, token: 0x%06x, r_key: 0x%08x\n",
1495                                     pfault->type, pfault->token,
1496                                     pfault->rdma.r_key);
1497                         mlx5_ib_dbg(eq->dev,
1498                                     "PAGE_FAULT: rdma_op_len: 0x%08x, rdma_va: 0x%016llx\n",
1499                                     pfault->rdma.rdma_op_len,
1500                                     pfault->rdma.rdma_va);
1501                         break;
1502
1503                 case MLX5_PFAULT_SUBTYPE_WQE:
1504                         /* WQE based event */
1505                         pfault->type =
1506                                 (be32_to_cpu(pf_eqe->wqe.pftype_wq) >> 24) & 0x7;
1507                         pfault->token =
1508                                 be32_to_cpu(pf_eqe->wqe.token);
1509                         pfault->wqe.wq_num =
1510                                 be32_to_cpu(pf_eqe->wqe.pftype_wq) &
1511                                 MLX5_24BIT_MASK;
1512                         pfault->wqe.wqe_index =
1513                                 be16_to_cpu(pf_eqe->wqe.wqe_index);
1514                         pfault->wqe.packet_size =
1515                                 be16_to_cpu(pf_eqe->wqe.packet_length);
1516                         mlx5_ib_dbg(eq->dev,
1517                                     "PAGE_FAULT: type:0x%x, token: 0x%06x, wq_num: 0x%06x, wqe_index: 0x%04x\n",
1518                                     pfault->type, pfault->token,
1519                                     pfault->wqe.wq_num,
1520                                     pfault->wqe.wqe_index);
1521                         break;
1522
1523                 default:
1524                         mlx5_ib_warn(eq->dev,
1525                                      "Unsupported page fault event sub-type: 0x%02hhx\n",
1526                                      eqe->sub_type);
1527                         /* Unsupported page faults should still be
1528                          * resolved by the page fault handler
1529                          */
1530                 }
1531
1532                 pfault->eq = eq;
1533                 INIT_WORK(&pfault->work, mlx5_ib_eqe_pf_action);
1534                 queue_work(eq->wq, &pfault->work);
1535
1536                 cc = mlx5_eq_update_cc(eq->core, ++cc);
1537         }
1538
1539         mlx5_eq_update_ci(eq->core, cc, 1);
1540 }
1541
1542 static int mlx5_ib_eq_pf_int(struct notifier_block *nb, unsigned long type,
1543                              void *data)
1544 {
1545         struct mlx5_ib_pf_eq *eq =
1546                 container_of(nb, struct mlx5_ib_pf_eq, irq_nb);
1547         unsigned long flags;
1548
1549         if (spin_trylock_irqsave(&eq->lock, flags)) {
1550                 mlx5_ib_eq_pf_process(eq);
1551                 spin_unlock_irqrestore(&eq->lock, flags);
1552         } else {
1553                 schedule_work(&eq->work);
1554         }
1555
1556         return IRQ_HANDLED;
1557 }
1558
1559 /* mempool_refill() was proposed but unfortunately wasn't accepted
1560  * http://lkml.iu.edu/hypermail/linux/kernel/1512.1/05073.html
1561  * Cheap workaround.
1562  */
1563 static void mempool_refill(mempool_t *pool)
1564 {
1565         while (pool->curr_nr < pool->min_nr)
1566                 mempool_free(mempool_alloc(pool, GFP_KERNEL), pool);
1567 }
1568
1569 static void mlx5_ib_eq_pf_action(struct work_struct *work)
1570 {
1571         struct mlx5_ib_pf_eq *eq =
1572                 container_of(work, struct mlx5_ib_pf_eq, work);
1573
1574         mempool_refill(eq->pool);
1575
1576         spin_lock_irq(&eq->lock);
1577         mlx5_ib_eq_pf_process(eq);
1578         spin_unlock_irq(&eq->lock);
1579 }
1580
1581 enum {
1582         MLX5_IB_NUM_PF_EQE      = 0x1000,
1583         MLX5_IB_NUM_PF_DRAIN    = 64,
1584 };
1585
1586 static int
1587 mlx5_ib_create_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
1588 {
1589         struct mlx5_eq_param param = {};
1590         int err;
1591
1592         INIT_WORK(&eq->work, mlx5_ib_eq_pf_action);
1593         spin_lock_init(&eq->lock);
1594         eq->dev = dev;
1595
1596         eq->pool = mempool_create_kmalloc_pool(MLX5_IB_NUM_PF_DRAIN,
1597                                                sizeof(struct mlx5_pagefault));
1598         if (!eq->pool)
1599                 return -ENOMEM;
1600
1601         eq->wq = alloc_workqueue("mlx5_ib_page_fault",
1602                                  WQ_HIGHPRI | WQ_UNBOUND | WQ_MEM_RECLAIM,
1603                                  MLX5_NUM_CMD_EQE);
1604         if (!eq->wq) {
1605                 err = -ENOMEM;
1606                 goto err_mempool;
1607         }
1608
1609         eq->irq_nb.notifier_call = mlx5_ib_eq_pf_int;
1610         param = (struct mlx5_eq_param) {
1611                 .irq_index = 0,
1612                 .nent = MLX5_IB_NUM_PF_EQE,
1613         };
1614         param.mask[0] = 1ull << MLX5_EVENT_TYPE_PAGE_FAULT;
1615         eq->core = mlx5_eq_create_generic(dev->mdev, &param);
1616         if (IS_ERR(eq->core)) {
1617                 err = PTR_ERR(eq->core);
1618                 goto err_wq;
1619         }
1620         err = mlx5_eq_enable(dev->mdev, eq->core, &eq->irq_nb);
1621         if (err) {
1622                 mlx5_ib_err(dev, "failed to enable odp EQ %d\n", err);
1623                 goto err_eq;
1624         }
1625
1626         return 0;
1627 err_eq:
1628         mlx5_eq_destroy_generic(dev->mdev, eq->core);
1629 err_wq:
1630         destroy_workqueue(eq->wq);
1631 err_mempool:
1632         mempool_destroy(eq->pool);
1633         return err;
1634 }
1635
1636 static int
1637 mlx5_ib_destroy_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
1638 {
1639         int err;
1640
1641         mlx5_eq_disable(dev->mdev, eq->core, &eq->irq_nb);
1642         err = mlx5_eq_destroy_generic(dev->mdev, eq->core);
1643         cancel_work_sync(&eq->work);
1644         destroy_workqueue(eq->wq);
1645         mempool_destroy(eq->pool);
1646
1647         return err;
1648 }
1649
1650 void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent)
1651 {
1652         if (!(ent->dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
1653                 return;
1654
1655         switch (ent->order - 2) {
1656         case MLX5_IMR_MTT_CACHE_ENTRY:
1657                 ent->page = PAGE_SHIFT;
1658                 ent->xlt = MLX5_IMR_MTT_ENTRIES *
1659                            sizeof(struct mlx5_mtt) /
1660                            MLX5_IB_UMR_OCTOWORD;
1661                 ent->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
1662                 ent->limit = 0;
1663                 break;
1664
1665         case MLX5_IMR_KSM_CACHE_ENTRY:
1666                 ent->page = MLX5_KSM_PAGE_SHIFT;
1667                 ent->xlt = mlx5_imr_ksm_entries *
1668                            sizeof(struct mlx5_klm) /
1669                            MLX5_IB_UMR_OCTOWORD;
1670                 ent->access_mode = MLX5_MKC_ACCESS_MODE_KSM;
1671                 ent->limit = 0;
1672                 break;
1673         }
1674 }
1675
1676 static const struct ib_device_ops mlx5_ib_dev_odp_ops = {
1677         .advise_mr = mlx5_ib_advise_mr,
1678 };
1679
1680 int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
1681 {
1682         int ret = 0;
1683
1684         if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
1685                 return ret;
1686
1687         ib_set_device_ops(&dev->ib_dev, &mlx5_ib_dev_odp_ops);
1688
1689         if (dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT) {
1690                 ret = mlx5_cmd_null_mkey(dev->mdev, &dev->null_mkey);
1691                 if (ret) {
1692                         mlx5_ib_err(dev, "Error getting null_mkey %d\n", ret);
1693                         return ret;
1694                 }
1695         }
1696
1697         ret = mlx5_ib_create_pf_eq(dev, &dev->odp_pf_eq);
1698
1699         return ret;
1700 }
1701
1702 void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *dev)
1703 {
1704         if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
1705                 return;
1706
1707         mlx5_ib_destroy_pf_eq(dev, &dev->odp_pf_eq);
1708 }
1709
1710 int mlx5_ib_odp_init(void)
1711 {
1712         mlx5_imr_ksm_entries = BIT_ULL(get_order(TASK_SIZE) -
1713                                        MLX5_IMR_MTT_BITS);
1714
1715         return 0;
1716 }
1717
1718 struct prefetch_mr_work {
1719         struct work_struct work;
1720         u32 pf_flags;
1721         u32 num_sge;
1722         struct {
1723                 u64 io_virt;
1724                 struct mlx5_ib_mr *mr;
1725                 size_t length;
1726         } frags[];
1727 };
1728
1729 static void destroy_prefetch_work(struct prefetch_mr_work *work)
1730 {
1731         u32 i;
1732
1733         for (i = 0; i < work->num_sge; ++i)
1734                 if (atomic_dec_and_test(&work->frags[i].mr->num_deferred_work))
1735                         wake_up(&work->frags[i].mr->q_deferred_work);
1736         kvfree(work);
1737 }
1738
1739 static struct mlx5_ib_mr *
1740 get_prefetchable_mr(struct ib_pd *pd, enum ib_uverbs_advise_mr_advice advice,
1741                     u32 lkey)
1742 {
1743         struct mlx5_ib_dev *dev = to_mdev(pd->device);
1744         struct mlx5_core_mkey *mmkey;
1745         struct ib_umem_odp *odp;
1746         struct mlx5_ib_mr *mr;
1747
1748         lockdep_assert_held(&dev->odp_srcu);
1749
1750         mmkey = xa_load(&dev->odp_mkeys, mlx5_base_mkey(lkey));
1751         if (!mmkey || mmkey->key != lkey || mmkey->type != MLX5_MKEY_MR)
1752                 return NULL;
1753
1754         mr = container_of(mmkey, struct mlx5_ib_mr, mmkey);
1755
1756         if (mr->ibmr.pd != pd)
1757                 return NULL;
1758
1759         odp = to_ib_umem_odp(mr->umem);
1760
1761         /* prefetch with write-access must be supported by the MR */
1762         if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE &&
1763             !odp->umem.writable)
1764                 return NULL;
1765
1766         return mr;
1767 }
1768
1769 static void mlx5_ib_prefetch_mr_work(struct work_struct *w)
1770 {
1771         struct prefetch_mr_work *work =
1772                 container_of(w, struct prefetch_mr_work, work);
1773         u32 bytes_mapped = 0;
1774         u32 i;
1775
1776         for (i = 0; i < work->num_sge; ++i)
1777                 pagefault_mr(work->frags[i].mr, work->frags[i].io_virt,
1778                              work->frags[i].length, &bytes_mapped,
1779                              work->pf_flags);
1780
1781         destroy_prefetch_work(work);
1782 }
1783
1784 static bool init_prefetch_work(struct ib_pd *pd,
1785                                enum ib_uverbs_advise_mr_advice advice,
1786                                u32 pf_flags, struct prefetch_mr_work *work,
1787                                struct ib_sge *sg_list, u32 num_sge)
1788 {
1789         u32 i;
1790
1791         INIT_WORK(&work->work, mlx5_ib_prefetch_mr_work);
1792         work->pf_flags = pf_flags;
1793
1794         for (i = 0; i < num_sge; ++i) {
1795                 work->frags[i].io_virt = sg_list[i].addr;
1796                 work->frags[i].length = sg_list[i].length;
1797                 work->frags[i].mr =
1798                         get_prefetchable_mr(pd, advice, sg_list[i].lkey);
1799                 if (!work->frags[i].mr) {
1800                         work->num_sge = i;
1801                         return false;
1802                 }
1803
1804                 /* Keep the MR pointer will valid outside the SRCU */
1805                 atomic_inc(&work->frags[i].mr->num_deferred_work);
1806         }
1807         work->num_sge = num_sge;
1808         return true;
1809 }
1810
1811 static int mlx5_ib_prefetch_sg_list(struct ib_pd *pd,
1812                                     enum ib_uverbs_advise_mr_advice advice,
1813                                     u32 pf_flags, struct ib_sge *sg_list,
1814                                     u32 num_sge)
1815 {
1816         struct mlx5_ib_dev *dev = to_mdev(pd->device);
1817         u32 bytes_mapped = 0;
1818         int srcu_key;
1819         int ret = 0;
1820         u32 i;
1821
1822         srcu_key = srcu_read_lock(&dev->odp_srcu);
1823         for (i = 0; i < num_sge; ++i) {
1824                 struct mlx5_ib_mr *mr;
1825
1826                 mr = get_prefetchable_mr(pd, advice, sg_list[i].lkey);
1827                 if (!mr) {
1828                         ret = -ENOENT;
1829                         goto out;
1830                 }
1831                 ret = pagefault_mr(mr, sg_list[i].addr, sg_list[i].length,
1832                                    &bytes_mapped, pf_flags);
1833                 if (ret < 0)
1834                         goto out;
1835         }
1836         ret = 0;
1837
1838 out:
1839         srcu_read_unlock(&dev->odp_srcu, srcu_key);
1840         return ret;
1841 }
1842
1843 int mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
1844                                enum ib_uverbs_advise_mr_advice advice,
1845                                u32 flags, struct ib_sge *sg_list, u32 num_sge)
1846 {
1847         struct mlx5_ib_dev *dev = to_mdev(pd->device);
1848         u32 pf_flags = 0;
1849         struct prefetch_mr_work *work;
1850         int srcu_key;
1851
1852         if (advice == IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH)
1853                 pf_flags |= MLX5_PF_FLAGS_DOWNGRADE;
1854
1855         if (flags & IB_UVERBS_ADVISE_MR_FLAG_FLUSH)
1856                 return mlx5_ib_prefetch_sg_list(pd, advice, pf_flags, sg_list,
1857                                                 num_sge);
1858
1859         work = kvzalloc(struct_size(work, frags, num_sge), GFP_KERNEL);
1860         if (!work)
1861                 return -ENOMEM;
1862
1863         srcu_key = srcu_read_lock(&dev->odp_srcu);
1864         if (!init_prefetch_work(pd, advice, pf_flags, work, sg_list, num_sge)) {
1865                 srcu_read_unlock(&dev->odp_srcu, srcu_key);
1866                 destroy_prefetch_work(work);
1867                 return -EINVAL;
1868         }
1869         queue_work(system_unbound_wq, &work->work);
1870         srcu_read_unlock(&dev->odp_srcu, srcu_key);
1871         return 0;
1872 }