drivers/infiniband/hw/hfi1/user_exp_rcv.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
   2 /*
   3  * Copyright(c) 2020 Cornelis Networks, Inc.
   4  * Copyright(c) 2015-2018 Intel Corporation.
   5  */
   6 #include <asm/page.h>
   7 #include <linux/string.h>
   8
   9 #include "mmu_rb.h"
  10 #include "user_exp_rcv.h"
  11 #include "trace.h"
  12
  13 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
  14                             struct exp_tid_set *set,
  15                             struct hfi1_filedata *fd);
  16 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages);
  17 static int set_rcvarray_entry(struct hfi1_filedata *fd,
  18                               struct tid_user_buf *tbuf,
  19                               u32 rcventry, struct tid_group *grp,
  20                               u16 pageidx, unsigned int npages);
  21 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
  22                                     struct tid_rb_node *tnode);
  23 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
  24                               const struct mmu_notifier_range *range,
  25                               unsigned long cur_seq);
  26 static bool tid_cover_invalidate(struct mmu_interval_notifier *mni,
  27                                  const struct mmu_notifier_range *range,
  28                                  unsigned long cur_seq);
  29 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *,
  30                             struct tid_group *grp, u16 count,
  31                             u32 *tidlist, unsigned int *tididx,
  32                             unsigned int *pmapped);
  33 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo);
  34 static void __clear_tid_node(struct hfi1_filedata *fd,
  35                              struct tid_rb_node *node);
  36 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node);
  37
  38 static const struct mmu_interval_notifier_ops tid_mn_ops = {
  39         .invalidate = tid_rb_invalidate,
  40 };
  41 static const struct mmu_interval_notifier_ops tid_cover_ops = {
  42         .invalidate = tid_cover_invalidate,
  43 };
  44
  45 /*
  46  * Initialize context and file private data needed for Expected
  47  * receive caching. This needs to be done after the context has
  48  * been configured with the eager/expected RcvEntry counts.
  49  */
  50 int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
  51                            struct hfi1_ctxtdata *uctxt)
  52 {
  53         int ret = 0;
  54
  55         fd->entry_to_rb = kcalloc(uctxt->expected_count,
  56                                   sizeof(struct rb_node *),
  57                                   GFP_KERNEL);
  58         if (!fd->entry_to_rb)
  59                 return -ENOMEM;
  60
  61         if (!HFI1_CAP_UGET_MASK(uctxt->flags, TID_UNMAP)) {
  62                 fd->invalid_tid_idx = 0;
  63                 fd->invalid_tids = kcalloc(uctxt->expected_count,
  64                                            sizeof(*fd->invalid_tids),
  65                                            GFP_KERNEL);
  66                 if (!fd->invalid_tids) {
  67                         kfree(fd->entry_to_rb);
  68                         fd->entry_to_rb = NULL;
  69                         return -ENOMEM;
  70                 }
  71                 fd->use_mn = true;
  72         }
  73
  74         /*
  75          * PSM does not have a good way to separate, count, and
  76          * effectively enforce a limit on RcvArray entries used by
  77          * subctxts (when context sharing is used) when TID caching
  78          * is enabled. To help with that, we calculate a per-process
  79          * RcvArray entry share and enforce that.
  80          * If TID caching is not in use, PSM deals with usage on its
  81          * own. In that case, we allow any subctxt to take all of the
  82          * entries.
  83          *
  84          * Make sure that we set the tid counts only after successful
  85          * init.
  86          */
  87         spin_lock(&fd->tid_lock);
  88         if (uctxt->subctxt_cnt && fd->use_mn) {
  89                 u16 remainder;
  90
  91                 fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
  92                 remainder = uctxt->expected_count % uctxt->subctxt_cnt;
  93                 if (remainder && fd->subctxt < remainder)
  94                         fd->tid_limit++;
  95         } else {
  96                 fd->tid_limit = uctxt->expected_count;
  97         }
  98         spin_unlock(&fd->tid_lock);
  99
 100         return ret;
 101 }
 102
 103 void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 104 {
 105         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 106
 107         mutex_lock(&uctxt->exp_mutex);
 108         if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
 109                 unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
 110         if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
 111                 unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 112         mutex_unlock(&uctxt->exp_mutex);
 113
 114         kfree(fd->invalid_tids);
 115         fd->invalid_tids = NULL;
 116
 117         kfree(fd->entry_to_rb);
 118         fd->entry_to_rb = NULL;
 119 }
 120
 121 /*
 122  * Release pinned receive buffer pages.
 123  *
 124  * @mapped: true if the pages have been DMA mapped. false otherwise.
 125  * @idx: Index of the first page to unpin.
 126  * @npages: No of pages to unpin.
 127  *
 128  * If the pages have been DMA mapped (indicated by mapped parameter), their
 129  * info will be passed via a struct tid_rb_node. If they haven't been mapped,
 130  * their info will be passed via a struct tid_user_buf.
 131  */
 132 static void unpin_rcv_pages(struct hfi1_filedata *fd,
 133                             struct tid_user_buf *tidbuf,
 134                             struct tid_rb_node *node,
 135                             unsigned int idx,
 136                             unsigned int npages,
 137                             bool mapped)
 138 {
 139         struct page **pages;
 140         struct hfi1_devdata *dd = fd->uctxt->dd;
 141         struct mm_struct *mm;
 142
 143         if (mapped) {
 144                 dma_unmap_single(&dd->pcidev->dev, node->dma_addr,
 145                                  node->npages * PAGE_SIZE, DMA_FROM_DEVICE);
 146                 pages = &node->pages[idx];
 147                 mm = mm_from_tid_node(node);
 148         } else {
 149                 pages = &tidbuf->pages[idx];
 150                 mm = current->mm;
 151         }
 152         hfi1_release_user_pages(mm, pages, npages, mapped);
 153         fd->tid_n_pinned -= npages;
 154 }
 155
 156 /*
 157  * Pin receive buffer pages.
 158  */
 159 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 160 {
 161         int pinned;
 162         unsigned int npages = tidbuf->npages;
 163         unsigned long vaddr = tidbuf->vaddr;
 164         struct page **pages = NULL;
 165         struct hfi1_devdata *dd = fd->uctxt->dd;
 166
 167         if (npages > fd->uctxt->expected_count) {
 168                 dd_dev_err(dd, "Expected buffer too big\n");
 169                 return -EINVAL;
 170         }
 171
 172         /* Allocate the array of struct page pointers needed for pinning */
 173         pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
 174         if (!pages)
 175                 return -ENOMEM;
 176
 177         /*
 178          * Pin all the pages of the user buffer. If we can't pin all the
 179          * pages, accept the amount pinned so far and program only that.
 180          * User space knows how to deal with partially programmed buffers.
 181          */
 182         if (!hfi1_can_pin_pages(dd, current->mm, fd->tid_n_pinned, npages)) {
 183                 kfree(pages);
 184                 return -ENOMEM;
 185         }
 186
 187         pinned = hfi1_acquire_user_pages(current->mm, vaddr, npages, true, pages);
 188         if (pinned <= 0) {
 189                 kfree(pages);
 190                 return pinned;
 191         }
 192         tidbuf->pages = pages;
 193         fd->tid_n_pinned += pinned;
 194         return pinned;
 195 }
 196
 197 /*
 198  * RcvArray entry allocation for Expected Receives is done by the
 199  * following algorithm:
 200  *
 201  * The context keeps 3 lists of groups of RcvArray entries:
 202  *   1. List of empty groups - tid_group_list
 203  *      This list is created during user context creation and
 204  *      contains elements which describe sets (of 8) of empty
 205  *      RcvArray entries.
 206  *   2. List of partially used groups - tid_used_list
 207  *      This list contains sets of RcvArray entries which are
 208  *      not completely used up. Another mapping request could
 209  *      use some of all of the remaining entries.
 210  *   3. List of full groups - tid_full_list
 211  *      This is the list where sets that are completely used
 212  *      up go.
 213  *
 214  * An attempt to optimize the usage of RcvArray entries is
 215  * made by finding all sets of physically contiguous pages in a
 216  * user's buffer.
 217  * These physically contiguous sets are further split into
 218  * sizes supported by the receive engine of the HFI. The
 219  * resulting sets of pages are stored in struct tid_pageset,
 220  * which describes the sets as:
 221  *    * .count - number of pages in this set
 222  *    * .idx - starting index into struct page ** array
 223  *                    of this set
 224  *
 225  * From this point on, the algorithm deals with the page sets
 226  * described above. The number of pagesets is divided by the
 227  * RcvArray group size to produce the number of full groups
 228  * needed.
 229  *
 230  * Groups from the 3 lists are manipulated using the following
 231  * rules:
 232  *   1. For each set of 8 pagesets, a complete group from
 233  *      tid_group_list is taken, programmed, and moved to
 234  *      the tid_full_list list.
 235  *   2. For all remaining pagesets:
 236  *      2.1 If the tid_used_list is empty and the tid_group_list
 237  *          is empty, stop processing pageset and return only
 238  *          what has been programmed up to this point.
 239  *      2.2 If the tid_used_list is empty and the tid_group_list
 240  *          is not empty, move a group from tid_group_list to
 241  *          tid_used_list.
 242  *      2.3 For each group is tid_used_group, program as much as
 243  *          can fit into the group. If the group becomes fully
 244  *          used, move it to tid_full_list.
 245  */
 246 int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 247                             struct hfi1_tid_info *tinfo)
 248 {
 249         int ret = 0, need_group = 0, pinned;
 250         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 251         struct hfi1_devdata *dd = uctxt->dd;
 252         unsigned int ngroups, pageset_count,
 253                 tididx = 0, mapped, mapped_pages = 0;
 254         u32 *tidlist = NULL;
 255         struct tid_user_buf *tidbuf;
 256         unsigned long mmu_seq = 0;
 257
 258         if (!PAGE_ALIGNED(tinfo->vaddr))
 259                 return -EINVAL;
 260         if (tinfo->length == 0)
 261                 return -EINVAL;
 262
 263         tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 264         if (!tidbuf)
 265                 return -ENOMEM;
 266
 267         mutex_init(&tidbuf->cover_mutex);
 268         tidbuf->vaddr = tinfo->vaddr;
 269         tidbuf->length = tinfo->length;
 270         tidbuf->npages = num_user_pages(tidbuf->vaddr, tidbuf->length);
 271         tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 272                                 GFP_KERNEL);
 273         if (!tidbuf->psets) {
 274                 ret = -ENOMEM;
 275                 goto fail_release_mem;
 276         }
 277
 278         if (fd->use_mn) {
 279                 ret = mmu_interval_notifier_insert(
 280                         &tidbuf->notifier, current->mm,
 281                         tidbuf->vaddr, tidbuf->npages * PAGE_SIZE,
 282                         &tid_cover_ops);
 283                 if (ret)
 284                         goto fail_release_mem;
 285                 mmu_seq = mmu_interval_read_begin(&tidbuf->notifier);
 286         }
 287
 288         pinned = pin_rcv_pages(fd, tidbuf);
 289         if (pinned <= 0) {
 290                 ret = (pinned < 0) ? pinned : -ENOSPC;
 291                 goto fail_unpin;
 292         }
 293
 294         /* Find sets of physically contiguous pages */
 295         tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 296
 297         /* Reserve the number of expected tids to be used. */
 298         spin_lock(&fd->tid_lock);
 299         if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 300                 pageset_count = fd->tid_limit - fd->tid_used;
 301         else
 302                 pageset_count = tidbuf->n_psets;
 303         fd->tid_used += pageset_count;
 304         spin_unlock(&fd->tid_lock);
 305
 306         if (!pageset_count) {
 307                 ret = -ENOSPC;
 308                 goto fail_unreserve;
 309         }
 310
 311         ngroups = pageset_count / dd->rcv_entries.group_size;
 312         tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 313         if (!tidlist) {
 314                 ret = -ENOMEM;
 315                 goto fail_unreserve;
 316         }
 317
 318         tididx = 0;
 319
 320         /*
 321          * From this point on, we are going to be using shared (between master
 322          * and subcontexts) context resources. We need to take the lock.
 323          */
 324         mutex_lock(&uctxt->exp_mutex);
 325         /*
 326          * The first step is to program the RcvArray entries which are complete
 327          * groups.
 328          */
 329         while (ngroups && uctxt->tid_group_list.count) {
 330                 struct tid_group *grp =
 331                         tid_group_pop(&uctxt->tid_group_list);
 332
 333                 ret = program_rcvarray(fd, tidbuf, grp,
 334                                        dd->rcv_entries.group_size,
 335                                        tidlist, &tididx, &mapped);
 336                 /*
 337                  * If there was a failure to program the RcvArray
 338                  * entries for the entire group, reset the grp fields
 339                  * and add the grp back to the free group list.
 340                  */
 341                 if (ret <= 0) {
 342                         tid_group_add_tail(grp, &uctxt->tid_group_list);
 343                         hfi1_cdbg(TID,
 344                                   "Failed to program RcvArray group %d", ret);
 345                         goto unlock;
 346                 }
 347
 348                 tid_group_add_tail(grp, &uctxt->tid_full_list);
 349                 ngroups--;
 350                 mapped_pages += mapped;
 351         }
 352
 353         while (tididx < pageset_count) {
 354                 struct tid_group *grp, *ptr;
 355                 /*
 356                  * If we don't have any partially used tid groups, check
 357                  * if we have empty groups. If so, take one from there and
 358                  * put in the partially used list.
 359                  */
 360                 if (!uctxt->tid_used_list.count || need_group) {
 361                         if (!uctxt->tid_group_list.count)
 362                                 goto unlock;
 363
 364                         grp = tid_group_pop(&uctxt->tid_group_list);
 365                         tid_group_add_tail(grp, &uctxt->tid_used_list);
 366                         need_group = 0;
 367                 }
 368                 /*
 369                  * There is an optimization opportunity here - instead of
 370                  * fitting as many page sets as we can, check for a group
 371                  * later on in the list that could fit all of them.
 372                  */
 373                 list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
 374                                          list) {
 375                         unsigned use = min_t(unsigned, pageset_count - tididx,
 376                                              grp->size - grp->used);
 377
 378                         ret = program_rcvarray(fd, tidbuf, grp,
 379                                                use, tidlist,
 380                                                &tididx, &mapped);
 381                         if (ret < 0) {
 382                                 hfi1_cdbg(TID,
 383                                           "Failed to program RcvArray entries %d",
 384                                           ret);
 385                                 goto unlock;
 386                         } else if (ret > 0) {
 387                                 if (grp->used == grp->size)
 388                                         tid_group_move(grp,
 389                                                        &uctxt->tid_used_list,
 390                                                        &uctxt->tid_full_list);
 391                                 mapped_pages += mapped;
 392                                 need_group = 0;
 393                                 /* Check if we are done so we break out early */
 394                                 if (tididx >= pageset_count)
 395                                         break;
 396                         } else if (WARN_ON(ret == 0)) {
 397                                 /*
 398                                  * If ret is 0, we did not program any entries
 399                                  * into this group, which can only happen if
 400                                  * we've screwed up the accounting somewhere.
 401                                  * Warn and try to continue.
 402                                  */
 403                                 need_group = 1;
 404                         }
 405                 }
 406         }
 407 unlock:
 408         mutex_unlock(&uctxt->exp_mutex);
 409         hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 410                   mapped_pages, ret);
 411
 412         /* fail if nothing was programmed, set error if none provided */
 413         if (tididx == 0) {
 414                 if (ret >= 0)
 415                         ret = -ENOSPC;
 416                 goto fail_unreserve;
 417         }
 418
 419         /* adjust reserved tid_used to actual count */
 420         spin_lock(&fd->tid_lock);
 421         fd->tid_used -= pageset_count - tididx;
 422         spin_unlock(&fd->tid_lock);
 423
 424         /* unpin all pages not covered by a TID */
 425         unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages, pinned - mapped_pages,
 426                         false);
 427
 428         if (fd->use_mn) {
 429                 /* check for an invalidate during setup */
 430                 bool fail = false;
 431
 432                 mutex_lock(&tidbuf->cover_mutex);
 433                 fail = mmu_interval_read_retry(&tidbuf->notifier, mmu_seq);
 434                 mutex_unlock(&tidbuf->cover_mutex);
 435
 436                 if (fail) {
 437                         ret = -EBUSY;
 438                         goto fail_unprogram;
 439                 }
 440         }
 441
 442         tinfo->tidcnt = tididx;
 443         tinfo->length = mapped_pages * PAGE_SIZE;
 444
 445         if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
 446                          tidlist, sizeof(tidlist[0]) * tididx)) {
 447                 ret = -EFAULT;
 448                 goto fail_unprogram;
 449         }
 450
 451         if (fd->use_mn)
 452                 mmu_interval_notifier_remove(&tidbuf->notifier);
 453         kfree(tidbuf->pages);
 454         kfree(tidbuf->psets);
 455         kfree(tidbuf);
 456         kfree(tidlist);
 457         return 0;
 458
 459 fail_unprogram:
 460         /* unprogram, unmap, and unpin all allocated TIDs */
 461         tinfo->tidlist = (unsigned long)tidlist;
 462         hfi1_user_exp_rcv_clear(fd, tinfo);
 463         tinfo->tidlist = 0;
 464         pinned = 0;             /* nothing left to unpin */
 465         pageset_count = 0;      /* nothing left reserved */
 466 fail_unreserve:
 467         spin_lock(&fd->tid_lock);
 468         fd->tid_used -= pageset_count;
 469         spin_unlock(&fd->tid_lock);
 470 fail_unpin:
 471         if (fd->use_mn)
 472                 mmu_interval_notifier_remove(&tidbuf->notifier);
 473         if (pinned > 0)
 474                 unpin_rcv_pages(fd, tidbuf, NULL, 0, pinned, false);
 475 fail_release_mem:
 476         kfree(tidbuf->pages);
 477         kfree(tidbuf->psets);
 478         kfree(tidbuf);
 479         kfree(tidlist);
 480         return ret;
 481 }
 482
 483 int hfi1_user_exp_rcv_clear(struct hfi1_filedata *fd,
 484                             struct hfi1_tid_info *tinfo)
 485 {
 486         int ret = 0;
 487         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 488         u32 *tidinfo;
 489         unsigned tididx;
 490
 491         if (unlikely(tinfo->tidcnt > fd->tid_used))
 492                 return -EINVAL;
 493
 494         tidinfo = memdup_array_user(u64_to_user_ptr(tinfo->tidlist),
 495                                     tinfo->tidcnt, sizeof(tidinfo[0]));
 496         if (IS_ERR(tidinfo))
 497                 return PTR_ERR(tidinfo);
 498
 499         mutex_lock(&uctxt->exp_mutex);
 500         for (tididx = 0; tididx < tinfo->tidcnt; tididx++) {
 501                 ret = unprogram_rcvarray(fd, tidinfo[tididx]);
 502                 if (ret) {
 503                         hfi1_cdbg(TID, "Failed to unprogram rcv array %d",
 504                                   ret);
 505                         break;
 506                 }
 507         }
 508         spin_lock(&fd->tid_lock);
 509         fd->tid_used -= tididx;
 510         spin_unlock(&fd->tid_lock);
 511         tinfo->tidcnt = tididx;
 512         mutex_unlock(&uctxt->exp_mutex);
 513
 514         kfree(tidinfo);
 515         return ret;
 516 }
 517
 518 int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd,
 519                               struct hfi1_tid_info *tinfo)
 520 {
 521         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 522         unsigned long *ev = uctxt->dd->events +
 523                 (uctxt_offset(uctxt) + fd->subctxt);
 524         u32 *array;
 525         int ret = 0;
 526
 527         /*
 528          * copy_to_user() can sleep, which will leave the invalid_lock
 529          * locked and cause the MMU notifier to be blocked on the lock
 530          * for a long time.
 531          * Copy the data to a local buffer so we can release the lock.
 532          */
 533         array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
 534         if (!array)
 535                 return -EFAULT;
 536
 537         spin_lock(&fd->invalid_lock);
 538         if (fd->invalid_tid_idx) {
 539                 memcpy(array, fd->invalid_tids, sizeof(*array) *
 540                        fd->invalid_tid_idx);
 541                 memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
 542                        fd->invalid_tid_idx);
 543                 tinfo->tidcnt = fd->invalid_tid_idx;
 544                 fd->invalid_tid_idx = 0;
 545                 /*
 546                  * Reset the user flag while still holding the lock.
 547                  * Otherwise, PSM can miss events.
 548                  */
 549                 clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 550         } else {
 551                 tinfo->tidcnt = 0;
 552         }
 553         spin_unlock(&fd->invalid_lock);
 554
 555         if (tinfo->tidcnt) {
 556                 if (copy_to_user((void __user *)tinfo->tidlist,
 557                                  array, sizeof(*array) * tinfo->tidcnt))
 558                         ret = -EFAULT;
 559         }
 560         kfree(array);
 561
 562         return ret;
 563 }
 564
 565 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages)
 566 {
 567         unsigned pagecount, pageidx, setcount = 0, i;
 568         unsigned long pfn, this_pfn;
 569         struct page **pages = tidbuf->pages;
 570         struct tid_pageset *list = tidbuf->psets;
 571
 572         if (!npages)
 573                 return 0;
 574
 575         /*
 576          * Look for sets of physically contiguous pages in the user buffer.
 577          * This will allow us to optimize Expected RcvArray entry usage by
 578          * using the bigger supported sizes.
 579          */
 580         pfn = page_to_pfn(pages[0]);
 581         for (pageidx = 0, pagecount = 1, i = 1; i <= npages; i++) {
 582                 this_pfn = i < npages ? page_to_pfn(pages[i]) : 0;
 583
 584                 /*
 585                  * If the pfn's are not sequential, pages are not physically
 586                  * contiguous.
 587                  */
 588                 if (this_pfn != ++pfn) {
 589                         /*
 590                          * At this point we have to loop over the set of
 591                          * physically contiguous pages and break them down it
 592                          * sizes supported by the HW.
 593                          * There are two main constraints:
 594                          *     1. The max buffer size is MAX_EXPECTED_BUFFER.
 595                          *        If the total set size is bigger than that
 596                          *        program only a MAX_EXPECTED_BUFFER chunk.
 597                          *     2. The buffer size has to be a power of two. If
 598                          *        it is not, round down to the closes power of
 599                          *        2 and program that size.
 600                          */
 601                         while (pagecount) {
 602                                 int maxpages = pagecount;
 603                                 u32 bufsize = pagecount * PAGE_SIZE;
 604
 605                                 if (bufsize > MAX_EXPECTED_BUFFER)
 606                                         maxpages =
 607                                                 MAX_EXPECTED_BUFFER >>
 608                                                 PAGE_SHIFT;
 609                                 else if (!is_power_of_2(bufsize))
 610                                         maxpages =
 611                                                 rounddown_pow_of_two(bufsize) >>
 612                                                 PAGE_SHIFT;
 613
 614                                 list[setcount].idx = pageidx;
 615                                 list[setcount].count = maxpages;
 616                                 pagecount -= maxpages;
 617                                 pageidx += maxpages;
 618                                 setcount++;
 619                         }
 620                         pageidx = i;
 621                         pagecount = 1;
 622                         pfn = this_pfn;
 623                 } else {
 624                         pagecount++;
 625                 }
 626         }
 627         return setcount;
 628 }
 629
 630 /**
 631  * program_rcvarray() - program an RcvArray group with receive buffers
 632  * @fd: filedata pointer
 633  * @tbuf: pointer to struct tid_user_buf that has the user buffer starting
 634  *        virtual address, buffer length, page pointers, pagesets (array of
 635  *        struct tid_pageset holding information on physically contiguous
 636  *        chunks from the user buffer), and other fields.
 637  * @grp: RcvArray group
 638  * @count: number of struct tid_pageset's to program
 639  * @tidlist: the array of u32 elements when the information about the
 640  *           programmed RcvArray entries is to be encoded.
 641  * @tididx: starting offset into tidlist
 642  * @pmapped: (output parameter) number of pages programmed into the RcvArray
 643  *           entries.
 644  *
 645  * This function will program up to 'count' number of RcvArray entries from the
 646  * group 'grp'. To make best use of write-combining writes, the function will
 647  * perform writes to the unused RcvArray entries which will be ignored by the
 648  * HW. Each RcvArray entry will be programmed with a physically contiguous
 649  * buffer chunk from the user's virtual buffer.
 650  *
 651  * Return:
 652  * -EINVAL if the requested count is larger than the size of the group,
 653  * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
 654  * number of RcvArray entries programmed.
 655  */
 656 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *tbuf,
 657                             struct tid_group *grp, u16 count,
 658                             u32 *tidlist, unsigned int *tididx,
 659                             unsigned int *pmapped)
 660 {
 661         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 662         struct hfi1_devdata *dd = uctxt->dd;
 663         u16 idx;
 664         unsigned int start = *tididx;
 665         u32 tidinfo = 0, rcventry, useidx = 0;
 666         int mapped = 0;
 667
 668         /* Count should never be larger than the group size */
 669         if (count > grp->size)
 670                 return -EINVAL;
 671
 672         /* Find the first unused entry in the group */
 673         for (idx = 0; idx < grp->size; idx++) {
 674                 if (!(grp->map & (1 << idx))) {
 675                         useidx = idx;
 676                         break;
 677                 }
 678                 rcv_array_wc_fill(dd, grp->base + idx);
 679         }
 680
 681         idx = 0;
 682         while (idx < count) {
 683                 u16 npages, pageidx, setidx = start + idx;
 684                 int ret = 0;
 685
 686                 /*
 687                  * If this entry in the group is used, move to the next one.
 688                  * If we go past the end of the group, exit the loop.
 689                  */
 690                 if (useidx >= grp->size) {
 691                         break;
 692                 } else if (grp->map & (1 << useidx)) {
 693                         rcv_array_wc_fill(dd, grp->base + useidx);
 694                         useidx++;
 695                         continue;
 696                 }
 697
 698                 rcventry = grp->base + useidx;
 699                 npages = tbuf->psets[setidx].count;
 700                 pageidx = tbuf->psets[setidx].idx;
 701
 702                 ret = set_rcvarray_entry(fd, tbuf,
 703                                          rcventry, grp, pageidx,
 704                                          npages);
 705                 if (ret)
 706                         return ret;
 707                 mapped += npages;
 708
 709                 tidinfo = create_tid(rcventry - uctxt->expected_base, npages);
 710                 tidlist[(*tididx)++] = tidinfo;
 711                 grp->used++;
 712                 grp->map |= 1 << useidx++;
 713                 idx++;
 714         }
 715
 716         /* Fill the rest of the group with "blank" writes */
 717         for (; useidx < grp->size; useidx++)
 718                 rcv_array_wc_fill(dd, grp->base + useidx);
 719         *pmapped = mapped;
 720         return idx;
 721 }
 722
 723 static int set_rcvarray_entry(struct hfi1_filedata *fd,
 724                               struct tid_user_buf *tbuf,
 725                               u32 rcventry, struct tid_group *grp,
 726                               u16 pageidx, unsigned int npages)
 727 {
 728         int ret;
 729         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 730         struct tid_rb_node *node;
 731         struct hfi1_devdata *dd = uctxt->dd;
 732         dma_addr_t phys;
 733         struct page **pages = tbuf->pages + pageidx;
 734
 735         /*
 736          * Allocate the node first so we can handle a potential
 737          * failure before we've programmed anything.
 738          */
 739         node = kzalloc(struct_size(node, pages, npages), GFP_KERNEL);
 740         if (!node)
 741                 return -ENOMEM;
 742
 743         phys = dma_map_single(&dd->pcidev->dev, __va(page_to_phys(pages[0])),
 744                               npages * PAGE_SIZE, DMA_FROM_DEVICE);
 745         if (dma_mapping_error(&dd->pcidev->dev, phys)) {
 746                 dd_dev_err(dd, "Failed to DMA map Exp Rcv pages 0x%llx\n",
 747                            phys);
 748                 kfree(node);
 749                 return -EFAULT;
 750         }
 751
 752         node->fdata = fd;
 753         mutex_init(&node->invalidate_mutex);
 754         node->phys = page_to_phys(pages[0]);
 755         node->npages = npages;
 756         node->rcventry = rcventry;
 757         node->dma_addr = phys;
 758         node->grp = grp;
 759         node->freed = false;
 760         memcpy(node->pages, pages, flex_array_size(node, pages, npages));
 761
 762         if (fd->use_mn) {
 763                 ret = mmu_interval_notifier_insert(
 764                         &node->notifier, current->mm,
 765                         tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
 766                         &tid_mn_ops);
 767                 if (ret)
 768                         goto out_unmap;
 769         }
 770         fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
 771
 772         hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
 773         trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
 774                                node->notifier.interval_tree.start, node->phys,
 775                                phys);
 776         return 0;
 777
 778 out_unmap:
 779         hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
 780                   node->rcventry, node->notifier.interval_tree.start,
 781                   node->phys, ret);
 782         dma_unmap_single(&dd->pcidev->dev, phys, npages * PAGE_SIZE,
 783                          DMA_FROM_DEVICE);
 784         kfree(node);
 785         return -EFAULT;
 786 }
 787
 788 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo)
 789 {
 790         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 791         struct hfi1_devdata *dd = uctxt->dd;
 792         struct tid_rb_node *node;
 793         u32 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 794         u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 795
 796         if (tidctrl == 0x3 || tidctrl == 0x0)
 797                 return -EINVAL;
 798
 799         rcventry = tididx + (tidctrl - 1);
 800
 801         if (rcventry >= uctxt->expected_count) {
 802                 dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
 803                            rcventry, uctxt->ctxt);
 804                 return -EINVAL;
 805         }
 806
 807         node = fd->entry_to_rb[rcventry];
 808         if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 809                 return -EBADF;
 810
 811         if (fd->use_mn)
 812                 mmu_interval_notifier_remove(&node->notifier);
 813         cacheless_tid_rb_remove(fd, node);
 814
 815         return 0;
 816 }
 817
 818 static void __clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 819 {
 820         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 821         struct hfi1_devdata *dd = uctxt->dd;
 822
 823         mutex_lock(&node->invalidate_mutex);
 824         if (node->freed)
 825                 goto done;
 826         node->freed = true;
 827
 828         trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
 829                                  node->npages,
 830                                  node->notifier.interval_tree.start, node->phys,
 831                                  node->dma_addr);
 832
 833         /* Make sure device has seen the write before pages are unpinned */
 834         hfi1_put_tid(dd, node->rcventry, PT_INVALID_FLUSH, 0, 0);
 835
 836         unpin_rcv_pages(fd, NULL, node, 0, node->npages, true);
 837 done:
 838         mutex_unlock(&node->invalidate_mutex);
 839 }
 840
 841 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 842 {
 843         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 844
 845         __clear_tid_node(fd, node);
 846
 847         node->grp->used--;
 848         node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
 849
 850         if (node->grp->used == node->grp->size - 1)
 851                 tid_group_move(node->grp, &uctxt->tid_full_list,
 852                                &uctxt->tid_used_list);
 853         else if (!node->grp->used)
 854                 tid_group_move(node->grp, &uctxt->tid_used_list,
 855                                &uctxt->tid_group_list);
 856         kfree(node);
 857 }
 858
 859 /*
 860  * As a simple helper for hfi1_user_exp_rcv_free, this function deals with
 861  * clearing nodes in the non-cached case.
 862  */
 863 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 864                             struct exp_tid_set *set,
 865                             struct hfi1_filedata *fd)
 866 {
 867         struct tid_group *grp, *ptr;
 868         int i;
 869
 870         list_for_each_entry_safe(grp, ptr, &set->list, list) {
 871                 list_del_init(&grp->list);
 872
 873                 for (i = 0; i < grp->size; i++) {
 874                         if (grp->map & (1 << i)) {
 875                                 u16 rcventry = grp->base + i;
 876                                 struct tid_rb_node *node;
 877
 878                                 node = fd->entry_to_rb[rcventry -
 879                                                           uctxt->expected_base];
 880                                 if (!node || node->rcventry != rcventry)
 881                                         continue;
 882
 883                                 if (fd->use_mn)
 884                                         mmu_interval_notifier_remove(
 885                                                 &node->notifier);
 886                                 cacheless_tid_rb_remove(fd, node);
 887                         }
 888                 }
 889         }
 890 }
 891
 892 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
 893                               const struct mmu_notifier_range *range,
 894                               unsigned long cur_seq)
 895 {
 896         struct tid_rb_node *node =
 897                 container_of(mni, struct tid_rb_node, notifier);
 898         struct hfi1_filedata *fdata = node->fdata;
 899         struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 900
 901         if (node->freed)
 902                 return true;
 903
 904         /* take action only if unmapping */
 905         if (range->event != MMU_NOTIFY_UNMAP)
 906                 return true;
 907
 908         trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
 909                                  node->notifier.interval_tree.start,
 910                                  node->rcventry, node->npages, node->dma_addr);
 911
 912         /* clear the hardware rcvarray entry */
 913         __clear_tid_node(fdata, node);
 914
 915         spin_lock(&fdata->invalid_lock);
 916         if (fdata->invalid_tid_idx < uctxt->expected_count) {
 917                 fdata->invalid_tids[fdata->invalid_tid_idx] =
 918                         create_tid(node->rcventry - uctxt->expected_base,
 919                                    node->npages);
 920                 if (!fdata->invalid_tid_idx) {
 921                         unsigned long *ev;
 922
 923                         /*
 924                          * hfi1_set_uevent_bits() sets a user event flag
 925                          * for all processes. Because calling into the
 926                          * driver to process TID cache invalidations is
 927                          * expensive and TID cache invalidations are
 928                          * handled on a per-process basis, we can
 929                          * optimize this to set the flag only for the
 930                          * process in question.
 931                          */
 932                         ev = uctxt->dd->events +
 933                                 (uctxt_offset(uctxt) + fdata->subctxt);
 934                         set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 935                 }
 936                 fdata->invalid_tid_idx++;
 937         }
 938         spin_unlock(&fdata->invalid_lock);
 939         return true;
 940 }
 941
 942 static bool tid_cover_invalidate(struct mmu_interval_notifier *mni,
 943                                  const struct mmu_notifier_range *range,
 944                                  unsigned long cur_seq)
 945 {
 946         struct tid_user_buf *tidbuf =
 947                 container_of(mni, struct tid_user_buf, notifier);
 948
 949         /* take action only if unmapping */
 950         if (range->event == MMU_NOTIFY_UNMAP) {
 951                 mutex_lock(&tidbuf->cover_mutex);
 952                 mmu_interval_set_seq(mni, cur_seq);
 953                 mutex_unlock(&tidbuf->cover_mutex);
 954         }
 955
 956         return true;
 957 }
 958
 959 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
 960                                     struct tid_rb_node *tnode)
 961 {
 962         u32 base = fdata->uctxt->expected_base;
 963
 964         fdata->entry_to_rb[tnode->rcventry - base] = NULL;
 965         clear_tid_node(fdata, tnode);
 966 }