drivers/infiniband/hw/hfi1/user_exp_rcv.c

   1 /*
   2  * Copyright(c) 2020 Cornelis Networks, Inc.
   3  * Copyright(c) 2015-2018 Intel Corporation.
   4  *
   5  * This file is provided under a dual BSD/GPLv2 license.  When using or
   6  * redistributing this file, you may do so under either license.
   7  *
   8  * GPL LICENSE SUMMARY
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of version 2 of the GNU General Public License as
  12  * published by the Free Software Foundation.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * BSD LICENSE
  20  *
  21  * Redistribution and use in source and binary forms, with or without
  22  * modification, are permitted provided that the following conditions
  23  * are met:
  24  *
  25  *  - Redistributions of source code must retain the above copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  *  - Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in
  29  *    the documentation and/or other materials provided with the
  30  *    distribution.
  31  *  - Neither the name of Intel Corporation nor the names of its
  32  *    contributors may be used to endorse or promote products derived
  33  *    from this software without specific prior written permission.
  34  *
  35  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  36  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  37  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  38  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  39  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  41  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  42  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  43  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  44  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  45  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  46  *
  47  */
  48 #include <asm/page.h>
  49 #include <linux/string.h>
  50
  51 #include "mmu_rb.h"
  52 #include "user_exp_rcv.h"
  53 #include "trace.h"
  54
  55 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
  56                             struct exp_tid_set *set,
  57                             struct hfi1_filedata *fd);
  58 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages);
  59 static int set_rcvarray_entry(struct hfi1_filedata *fd,
  60                               struct tid_user_buf *tbuf,
  61                               u32 rcventry, struct tid_group *grp,
  62                               u16 pageidx, unsigned int npages);
  63 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
  64                                     struct tid_rb_node *tnode);
  65 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
  66                               const struct mmu_notifier_range *range,
  67                               unsigned long cur_seq);
  68 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *,
  69                             struct tid_group *grp,
  70                             unsigned int start, u16 count,
  71                             u32 *tidlist, unsigned int *tididx,
  72                             unsigned int *pmapped);
  73 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
  74                               struct tid_group **grp);
  75 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node);
  76
  77 static const struct mmu_interval_notifier_ops tid_mn_ops = {
  78         .invalidate = tid_rb_invalidate,
  79 };
  80
  81 /*
  82  * Initialize context and file private data needed for Expected
  83  * receive caching. This needs to be done after the context has
  84  * been configured with the eager/expected RcvEntry counts.
  85  */
  86 int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
  87                            struct hfi1_ctxtdata *uctxt)
  88 {
  89         int ret = 0;
  90
  91         fd->entry_to_rb = kcalloc(uctxt->expected_count,
  92                                   sizeof(struct rb_node *),
  93                                   GFP_KERNEL);
  94         if (!fd->entry_to_rb)
  95                 return -ENOMEM;
  96
  97         if (!HFI1_CAP_UGET_MASK(uctxt->flags, TID_UNMAP)) {
  98                 fd->invalid_tid_idx = 0;
  99                 fd->invalid_tids = kcalloc(uctxt->expected_count,
 100                                            sizeof(*fd->invalid_tids),
 101                                            GFP_KERNEL);
 102                 if (!fd->invalid_tids) {
 103                         kfree(fd->entry_to_rb);
 104                         fd->entry_to_rb = NULL;
 105                         return -ENOMEM;
 106                 }
 107                 fd->use_mn = true;
 108         }
 109
 110         /*
 111          * PSM does not have a good way to separate, count, and
 112          * effectively enforce a limit on RcvArray entries used by
 113          * subctxts (when context sharing is used) when TID caching
 114          * is enabled. To help with that, we calculate a per-process
 115          * RcvArray entry share and enforce that.
 116          * If TID caching is not in use, PSM deals with usage on its
 117          * own. In that case, we allow any subctxt to take all of the
 118          * entries.
 119          *
 120          * Make sure that we set the tid counts only after successful
 121          * init.
 122          */
 123         spin_lock(&fd->tid_lock);
 124         if (uctxt->subctxt_cnt && fd->use_mn) {
 125                 u16 remainder;
 126
 127                 fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
 128                 remainder = uctxt->expected_count % uctxt->subctxt_cnt;
 129                 if (remainder && fd->subctxt < remainder)
 130                         fd->tid_limit++;
 131         } else {
 132                 fd->tid_limit = uctxt->expected_count;
 133         }
 134         spin_unlock(&fd->tid_lock);
 135
 136         return ret;
 137 }
 138
 139 void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 140 {
 141         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 142
 143         mutex_lock(&uctxt->exp_mutex);
 144         if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
 145                 unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
 146         if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
 147                 unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 148         mutex_unlock(&uctxt->exp_mutex);
 149
 150         kfree(fd->invalid_tids);
 151         fd->invalid_tids = NULL;
 152
 153         kfree(fd->entry_to_rb);
 154         fd->entry_to_rb = NULL;
 155 }
 156
 157 /*
 158  * Release pinned receive buffer pages.
 159  *
 160  * @mapped: true if the pages have been DMA mapped. false otherwise.
 161  * @idx: Index of the first page to unpin.
 162  * @npages: No of pages to unpin.
 163  *
 164  * If the pages have been DMA mapped (indicated by mapped parameter), their
 165  * info will be passed via a struct tid_rb_node. If they haven't been mapped,
 166  * their info will be passed via a struct tid_user_buf.
 167  */
 168 static void unpin_rcv_pages(struct hfi1_filedata *fd,
 169                             struct tid_user_buf *tidbuf,
 170                             struct tid_rb_node *node,
 171                             unsigned int idx,
 172                             unsigned int npages,
 173                             bool mapped)
 174 {
 175         struct page **pages;
 176         struct hfi1_devdata *dd = fd->uctxt->dd;
 177         struct mm_struct *mm;
 178
 179         if (mapped) {
 180                 pci_unmap_single(dd->pcidev, node->dma_addr,
 181                                  node->npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 182                 pages = &node->pages[idx];
 183                 mm = mm_from_tid_node(node);
 184         } else {
 185                 pages = &tidbuf->pages[idx];
 186                 mm = current->mm;
 187         }
 188         hfi1_release_user_pages(mm, pages, npages, mapped);
 189         fd->tid_n_pinned -= npages;
 190 }
 191
 192 /*
 193  * Pin receive buffer pages.
 194  */
 195 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 196 {
 197         int pinned;
 198         unsigned int npages;
 199         unsigned long vaddr = tidbuf->vaddr;
 200         struct page **pages = NULL;
 201         struct hfi1_devdata *dd = fd->uctxt->dd;
 202
 203         /* Get the number of pages the user buffer spans */
 204         npages = num_user_pages(vaddr, tidbuf->length);
 205         if (!npages)
 206                 return -EINVAL;
 207
 208         if (npages > fd->uctxt->expected_count) {
 209                 dd_dev_err(dd, "Expected buffer too big\n");
 210                 return -EINVAL;
 211         }
 212
 213         /* Allocate the array of struct page pointers needed for pinning */
 214         pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
 215         if (!pages)
 216                 return -ENOMEM;
 217
 218         /*
 219          * Pin all the pages of the user buffer. If we can't pin all the
 220          * pages, accept the amount pinned so far and program only that.
 221          * User space knows how to deal with partially programmed buffers.
 222          */
 223         if (!hfi1_can_pin_pages(dd, current->mm, fd->tid_n_pinned, npages)) {
 224                 kfree(pages);
 225                 return -ENOMEM;
 226         }
 227
 228         pinned = hfi1_acquire_user_pages(current->mm, vaddr, npages, true, pages);
 229         if (pinned <= 0) {
 230                 kfree(pages);
 231                 return pinned;
 232         }
 233         tidbuf->pages = pages;
 234         tidbuf->npages = npages;
 235         fd->tid_n_pinned += pinned;
 236         return pinned;
 237 }
 238
 239 /*
 240  * RcvArray entry allocation for Expected Receives is done by the
 241  * following algorithm:
 242  *
 243  * The context keeps 3 lists of groups of RcvArray entries:
 244  *   1. List of empty groups - tid_group_list
 245  *      This list is created during user context creation and
 246  *      contains elements which describe sets (of 8) of empty
 247  *      RcvArray entries.
 248  *   2. List of partially used groups - tid_used_list
 249  *      This list contains sets of RcvArray entries which are
 250  *      not completely used up. Another mapping request could
 251  *      use some of all of the remaining entries.
 252  *   3. List of full groups - tid_full_list
 253  *      This is the list where sets that are completely used
 254  *      up go.
 255  *
 256  * An attempt to optimize the usage of RcvArray entries is
 257  * made by finding all sets of physically contiguous pages in a
 258  * user's buffer.
 259  * These physically contiguous sets are further split into
 260  * sizes supported by the receive engine of the HFI. The
 261  * resulting sets of pages are stored in struct tid_pageset,
 262  * which describes the sets as:
 263  *    * .count - number of pages in this set
 264  *    * .idx - starting index into struct page ** array
 265  *                    of this set
 266  *
 267  * From this point on, the algorithm deals with the page sets
 268  * described above. The number of pagesets is divided by the
 269  * RcvArray group size to produce the number of full groups
 270  * needed.
 271  *
 272  * Groups from the 3 lists are manipulated using the following
 273  * rules:
 274  *   1. For each set of 8 pagesets, a complete group from
 275  *      tid_group_list is taken, programmed, and moved to
 276  *      the tid_full_list list.
 277  *   2. For all remaining pagesets:
 278  *      2.1 If the tid_used_list is empty and the tid_group_list
 279  *          is empty, stop processing pageset and return only
 280  *          what has been programmed up to this point.
 281  *      2.2 If the tid_used_list is empty and the tid_group_list
 282  *          is not empty, move a group from tid_group_list to
 283  *          tid_used_list.
 284  *      2.3 For each group is tid_used_group, program as much as
 285  *          can fit into the group. If the group becomes fully
 286  *          used, move it to tid_full_list.
 287  */
 288 int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 289                             struct hfi1_tid_info *tinfo)
 290 {
 291         int ret = 0, need_group = 0, pinned;
 292         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 293         struct hfi1_devdata *dd = uctxt->dd;
 294         unsigned int ngroups, pageidx = 0, pageset_count,
 295                 tididx = 0, mapped, mapped_pages = 0;
 296         u32 *tidlist = NULL;
 297         struct tid_user_buf *tidbuf;
 298
 299         if (!PAGE_ALIGNED(tinfo->vaddr))
 300                 return -EINVAL;
 301
 302         tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 303         if (!tidbuf)
 304                 return -ENOMEM;
 305
 306         tidbuf->vaddr = tinfo->vaddr;
 307         tidbuf->length = tinfo->length;
 308         tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 309                                 GFP_KERNEL);
 310         if (!tidbuf->psets) {
 311                 kfree(tidbuf);
 312                 return -ENOMEM;
 313         }
 314
 315         pinned = pin_rcv_pages(fd, tidbuf);
 316         if (pinned <= 0) {
 317                 kfree(tidbuf->psets);
 318                 kfree(tidbuf);
 319                 return pinned;
 320         }
 321
 322         /* Find sets of physically contiguous pages */
 323         tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 324
 325         /*
 326          * We don't need to access this under a lock since tid_used is per
 327          * process and the same process cannot be in hfi1_user_exp_rcv_clear()
 328          * and hfi1_user_exp_rcv_setup() at the same time.
 329          */
 330         spin_lock(&fd->tid_lock);
 331         if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 332                 pageset_count = fd->tid_limit - fd->tid_used;
 333         else
 334                 pageset_count = tidbuf->n_psets;
 335         spin_unlock(&fd->tid_lock);
 336
 337         if (!pageset_count)
 338                 goto bail;
 339
 340         ngroups = pageset_count / dd->rcv_entries.group_size;
 341         tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 342         if (!tidlist) {
 343                 ret = -ENOMEM;
 344                 goto nomem;
 345         }
 346
 347         tididx = 0;
 348
 349         /*
 350          * From this point on, we are going to be using shared (between master
 351          * and subcontexts) context resources. We need to take the lock.
 352          */
 353         mutex_lock(&uctxt->exp_mutex);
 354         /*
 355          * The first step is to program the RcvArray entries which are complete
 356          * groups.
 357          */
 358         while (ngroups && uctxt->tid_group_list.count) {
 359                 struct tid_group *grp =
 360                         tid_group_pop(&uctxt->tid_group_list);
 361
 362                 ret = program_rcvarray(fd, tidbuf, grp,
 363                                        pageidx, dd->rcv_entries.group_size,
 364                                        tidlist, &tididx, &mapped);
 365                 /*
 366                  * If there was a failure to program the RcvArray
 367                  * entries for the entire group, reset the grp fields
 368                  * and add the grp back to the free group list.
 369                  */
 370                 if (ret <= 0) {
 371                         tid_group_add_tail(grp, &uctxt->tid_group_list);
 372                         hfi1_cdbg(TID,
 373                                   "Failed to program RcvArray group %d", ret);
 374                         goto unlock;
 375                 }
 376
 377                 tid_group_add_tail(grp, &uctxt->tid_full_list);
 378                 ngroups--;
 379                 pageidx += ret;
 380                 mapped_pages += mapped;
 381         }
 382
 383         while (pageidx < pageset_count) {
 384                 struct tid_group *grp, *ptr;
 385                 /*
 386                  * If we don't have any partially used tid groups, check
 387                  * if we have empty groups. If so, take one from there and
 388                  * put in the partially used list.
 389                  */
 390                 if (!uctxt->tid_used_list.count || need_group) {
 391                         if (!uctxt->tid_group_list.count)
 392                                 goto unlock;
 393
 394                         grp = tid_group_pop(&uctxt->tid_group_list);
 395                         tid_group_add_tail(grp, &uctxt->tid_used_list);
 396                         need_group = 0;
 397                 }
 398                 /*
 399                  * There is an optimization opportunity here - instead of
 400                  * fitting as many page sets as we can, check for a group
 401                  * later on in the list that could fit all of them.
 402                  */
 403                 list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
 404                                          list) {
 405                         unsigned use = min_t(unsigned, pageset_count - pageidx,
 406                                              grp->size - grp->used);
 407
 408                         ret = program_rcvarray(fd, tidbuf, grp,
 409                                                pageidx, use, tidlist,
 410                                                &tididx, &mapped);
 411                         if (ret < 0) {
 412                                 hfi1_cdbg(TID,
 413                                           "Failed to program RcvArray entries %d",
 414                                           ret);
 415                                 goto unlock;
 416                         } else if (ret > 0) {
 417                                 if (grp->used == grp->size)
 418                                         tid_group_move(grp,
 419                                                        &uctxt->tid_used_list,
 420                                                        &uctxt->tid_full_list);
 421                                 pageidx += ret;
 422                                 mapped_pages += mapped;
 423                                 need_group = 0;
 424                                 /* Check if we are done so we break out early */
 425                                 if (pageidx >= pageset_count)
 426                                         break;
 427                         } else if (WARN_ON(ret == 0)) {
 428                                 /*
 429                                  * If ret is 0, we did not program any entries
 430                                  * into this group, which can only happen if
 431                                  * we've screwed up the accounting somewhere.
 432                                  * Warn and try to continue.
 433                                  */
 434                                 need_group = 1;
 435                         }
 436                 }
 437         }
 438 unlock:
 439         mutex_unlock(&uctxt->exp_mutex);
 440 nomem:
 441         hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 442                   mapped_pages, ret);
 443         if (tididx) {
 444                 spin_lock(&fd->tid_lock);
 445                 fd->tid_used += tididx;
 446                 spin_unlock(&fd->tid_lock);
 447                 tinfo->tidcnt = tididx;
 448                 tinfo->length = mapped_pages * PAGE_SIZE;
 449
 450                 if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
 451                                  tidlist, sizeof(tidlist[0]) * tididx)) {
 452                         /*
 453                          * On failure to copy to the user level, we need to undo
 454                          * everything done so far so we don't leak resources.
 455                          */
 456                         tinfo->tidlist = (unsigned long)&tidlist;
 457                         hfi1_user_exp_rcv_clear(fd, tinfo);
 458                         tinfo->tidlist = 0;
 459                         ret = -EFAULT;
 460                         goto bail;
 461                 }
 462         }
 463
 464         /*
 465          * If not everything was mapped (due to insufficient RcvArray entries,
 466          * for example), unpin all unmapped pages so we can pin them nex time.
 467          */
 468         if (mapped_pages != pinned)
 469                 unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages,
 470                                 (pinned - mapped_pages), false);
 471 bail:
 472         kfree(tidbuf->psets);
 473         kfree(tidlist);
 474         kfree(tidbuf->pages);
 475         kfree(tidbuf);
 476         return ret > 0 ? 0 : ret;
 477 }
 478
 479 int hfi1_user_exp_rcv_clear(struct hfi1_filedata *fd,
 480                             struct hfi1_tid_info *tinfo)
 481 {
 482         int ret = 0;
 483         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 484         u32 *tidinfo;
 485         unsigned tididx;
 486
 487         if (unlikely(tinfo->tidcnt > fd->tid_used))
 488                 return -EINVAL;
 489
 490         tidinfo = memdup_user(u64_to_user_ptr(tinfo->tidlist),
 491                               sizeof(tidinfo[0]) * tinfo->tidcnt);
 492         if (IS_ERR(tidinfo))
 493                 return PTR_ERR(tidinfo);
 494
 495         mutex_lock(&uctxt->exp_mutex);
 496         for (tididx = 0; tididx < tinfo->tidcnt; tididx++) {
 497                 ret = unprogram_rcvarray(fd, tidinfo[tididx], NULL);
 498                 if (ret) {
 499                         hfi1_cdbg(TID, "Failed to unprogram rcv array %d",
 500                                   ret);
 501                         break;
 502                 }
 503         }
 504         spin_lock(&fd->tid_lock);
 505         fd->tid_used -= tididx;
 506         spin_unlock(&fd->tid_lock);
 507         tinfo->tidcnt = tididx;
 508         mutex_unlock(&uctxt->exp_mutex);
 509
 510         kfree(tidinfo);
 511         return ret;
 512 }
 513
 514 int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd,
 515                               struct hfi1_tid_info *tinfo)
 516 {
 517         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 518         unsigned long *ev = uctxt->dd->events +
 519                 (uctxt_offset(uctxt) + fd->subctxt);
 520         u32 *array;
 521         int ret = 0;
 522
 523         /*
 524          * copy_to_user() can sleep, which will leave the invalid_lock
 525          * locked and cause the MMU notifier to be blocked on the lock
 526          * for a long time.
 527          * Copy the data to a local buffer so we can release the lock.
 528          */
 529         array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
 530         if (!array)
 531                 return -EFAULT;
 532
 533         spin_lock(&fd->invalid_lock);
 534         if (fd->invalid_tid_idx) {
 535                 memcpy(array, fd->invalid_tids, sizeof(*array) *
 536                        fd->invalid_tid_idx);
 537                 memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
 538                        fd->invalid_tid_idx);
 539                 tinfo->tidcnt = fd->invalid_tid_idx;
 540                 fd->invalid_tid_idx = 0;
 541                 /*
 542                  * Reset the user flag while still holding the lock.
 543                  * Otherwise, PSM can miss events.
 544                  */
 545                 clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 546         } else {
 547                 tinfo->tidcnt = 0;
 548         }
 549         spin_unlock(&fd->invalid_lock);
 550
 551         if (tinfo->tidcnt) {
 552                 if (copy_to_user((void __user *)tinfo->tidlist,
 553                                  array, sizeof(*array) * tinfo->tidcnt))
 554                         ret = -EFAULT;
 555         }
 556         kfree(array);
 557
 558         return ret;
 559 }
 560
 561 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages)
 562 {
 563         unsigned pagecount, pageidx, setcount = 0, i;
 564         unsigned long pfn, this_pfn;
 565         struct page **pages = tidbuf->pages;
 566         struct tid_pageset *list = tidbuf->psets;
 567
 568         if (!npages)
 569                 return 0;
 570
 571         /*
 572          * Look for sets of physically contiguous pages in the user buffer.
 573          * This will allow us to optimize Expected RcvArray entry usage by
 574          * using the bigger supported sizes.
 575          */
 576         pfn = page_to_pfn(pages[0]);
 577         for (pageidx = 0, pagecount = 1, i = 1; i <= npages; i++) {
 578                 this_pfn = i < npages ? page_to_pfn(pages[i]) : 0;
 579
 580                 /*
 581                  * If the pfn's are not sequential, pages are not physically
 582                  * contiguous.
 583                  */
 584                 if (this_pfn != ++pfn) {
 585                         /*
 586                          * At this point we have to loop over the set of
 587                          * physically contiguous pages and break them down it
 588                          * sizes supported by the HW.
 589                          * There are two main constraints:
 590                          *     1. The max buffer size is MAX_EXPECTED_BUFFER.
 591                          *        If the total set size is bigger than that
 592                          *        program only a MAX_EXPECTED_BUFFER chunk.
 593                          *     2. The buffer size has to be a power of two. If
 594                          *        it is not, round down to the closes power of
 595                          *        2 and program that size.
 596                          */
 597                         while (pagecount) {
 598                                 int maxpages = pagecount;
 599                                 u32 bufsize = pagecount * PAGE_SIZE;
 600
 601                                 if (bufsize > MAX_EXPECTED_BUFFER)
 602                                         maxpages =
 603                                                 MAX_EXPECTED_BUFFER >>
 604                                                 PAGE_SHIFT;
 605                                 else if (!is_power_of_2(bufsize))
 606                                         maxpages =
 607                                                 rounddown_pow_of_two(bufsize) >>
 608                                                 PAGE_SHIFT;
 609
 610                                 list[setcount].idx = pageidx;
 611                                 list[setcount].count = maxpages;
 612                                 pagecount -= maxpages;
 613                                 pageidx += maxpages;
 614                                 setcount++;
 615                         }
 616                         pageidx = i;
 617                         pagecount = 1;
 618                         pfn = this_pfn;
 619                 } else {
 620                         pagecount++;
 621                 }
 622         }
 623         return setcount;
 624 }
 625
 626 /**
 627  * program_rcvarray() - program an RcvArray group with receive buffers
 628  * @fd: filedata pointer
 629  * @tbuf: pointer to struct tid_user_buf that has the user buffer starting
 630  *        virtual address, buffer length, page pointers, pagesets (array of
 631  *        struct tid_pageset holding information on physically contiguous
 632  *        chunks from the user buffer), and other fields.
 633  * @grp: RcvArray group
 634  * @start: starting index into sets array
 635  * @count: number of struct tid_pageset's to program
 636  * @tidlist: the array of u32 elements when the information about the
 637  *           programmed RcvArray entries is to be encoded.
 638  * @tididx: starting offset into tidlist
 639  * @pmapped: (output parameter) number of pages programmed into the RcvArray
 640  *           entries.
 641  *
 642  * This function will program up to 'count' number of RcvArray entries from the
 643  * group 'grp'. To make best use of write-combining writes, the function will
 644  * perform writes to the unused RcvArray entries which will be ignored by the
 645  * HW. Each RcvArray entry will be programmed with a physically contiguous
 646  * buffer chunk from the user's virtual buffer.
 647  *
 648  * Return:
 649  * -EINVAL if the requested count is larger than the size of the group,
 650  * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
 651  * number of RcvArray entries programmed.
 652  */
 653 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *tbuf,
 654                             struct tid_group *grp,
 655                             unsigned int start, u16 count,
 656                             u32 *tidlist, unsigned int *tididx,
 657                             unsigned int *pmapped)
 658 {
 659         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 660         struct hfi1_devdata *dd = uctxt->dd;
 661         u16 idx;
 662         u32 tidinfo = 0, rcventry, useidx = 0;
 663         int mapped = 0;
 664
 665         /* Count should never be larger than the group size */
 666         if (count > grp->size)
 667                 return -EINVAL;
 668
 669         /* Find the first unused entry in the group */
 670         for (idx = 0; idx < grp->size; idx++) {
 671                 if (!(grp->map & (1 << idx))) {
 672                         useidx = idx;
 673                         break;
 674                 }
 675                 rcv_array_wc_fill(dd, grp->base + idx);
 676         }
 677
 678         idx = 0;
 679         while (idx < count) {
 680                 u16 npages, pageidx, setidx = start + idx;
 681                 int ret = 0;
 682
 683                 /*
 684                  * If this entry in the group is used, move to the next one.
 685                  * If we go past the end of the group, exit the loop.
 686                  */
 687                 if (useidx >= grp->size) {
 688                         break;
 689                 } else if (grp->map & (1 << useidx)) {
 690                         rcv_array_wc_fill(dd, grp->base + useidx);
 691                         useidx++;
 692                         continue;
 693                 }
 694
 695                 rcventry = grp->base + useidx;
 696                 npages = tbuf->psets[setidx].count;
 697                 pageidx = tbuf->psets[setidx].idx;
 698
 699                 ret = set_rcvarray_entry(fd, tbuf,
 700                                          rcventry, grp, pageidx,
 701                                          npages);
 702                 if (ret)
 703                         return ret;
 704                 mapped += npages;
 705
 706                 tidinfo = rcventry2tidinfo(rcventry - uctxt->expected_base) |
 707                         EXP_TID_SET(LEN, npages);
 708                 tidlist[(*tididx)++] = tidinfo;
 709                 grp->used++;
 710                 grp->map |= 1 << useidx++;
 711                 idx++;
 712         }
 713
 714         /* Fill the rest of the group with "blank" writes */
 715         for (; useidx < grp->size; useidx++)
 716                 rcv_array_wc_fill(dd, grp->base + useidx);
 717         *pmapped = mapped;
 718         return idx;
 719 }
 720
 721 static int set_rcvarray_entry(struct hfi1_filedata *fd,
 722                               struct tid_user_buf *tbuf,
 723                               u32 rcventry, struct tid_group *grp,
 724                               u16 pageidx, unsigned int npages)
 725 {
 726         int ret;
 727         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 728         struct tid_rb_node *node;
 729         struct hfi1_devdata *dd = uctxt->dd;
 730         dma_addr_t phys;
 731         struct page **pages = tbuf->pages + pageidx;
 732
 733         /*
 734          * Allocate the node first so we can handle a potential
 735          * failure before we've programmed anything.
 736          */
 737         node = kzalloc(sizeof(*node) + (sizeof(struct page *) * npages),
 738                        GFP_KERNEL);
 739         if (!node)
 740                 return -ENOMEM;
 741
 742         phys = pci_map_single(dd->pcidev,
 743                               __va(page_to_phys(pages[0])),
 744                               npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 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         node->phys = page_to_phys(pages[0]);
 754         node->npages = npages;
 755         node->rcventry = rcventry;
 756         node->dma_addr = phys;
 757         node->grp = grp;
 758         node->freed = false;
 759         memcpy(node->pages, pages, sizeof(struct page *) * npages);
 760
 761         if (fd->use_mn) {
 762                 ret = mmu_interval_notifier_insert(
 763                         &node->notifier, current->mm,
 764                         tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
 765                         &tid_mn_ops);
 766                 if (ret)
 767                         goto out_unmap;
 768                 /*
 769                  * FIXME: This is in the wrong order, the notifier should be
 770                  * established before the pages are pinned by pin_rcv_pages.
 771                  */
 772                 mmu_interval_read_begin(&node->notifier);
 773         }
 774         fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
 775
 776         hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
 777         trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
 778                                node->notifier.interval_tree.start, node->phys,
 779                                phys);
 780         return 0;
 781
 782 out_unmap:
 783         hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
 784                   node->rcventry, node->notifier.interval_tree.start,
 785                   node->phys, ret);
 786         pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
 787                          PCI_DMA_FROMDEVICE);
 788         kfree(node);
 789         return -EFAULT;
 790 }
 791
 792 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
 793                               struct tid_group **grp)
 794 {
 795         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 796         struct hfi1_devdata *dd = uctxt->dd;
 797         struct tid_rb_node *node;
 798         u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 799         u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 800
 801         if (tididx >= uctxt->expected_count) {
 802                 dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
 803                            tididx, uctxt->ctxt);
 804                 return -EINVAL;
 805         }
 806
 807         if (tidctrl == 0x3)
 808                 return -EINVAL;
 809
 810         rcventry = tididx + (tidctrl - 1);
 811
 812         node = fd->entry_to_rb[rcventry];
 813         if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 814                 return -EBADF;
 815
 816         if (grp)
 817                 *grp = node->grp;
 818
 819         if (fd->use_mn)
 820                 mmu_interval_notifier_remove(&node->notifier);
 821         cacheless_tid_rb_remove(fd, node);
 822
 823         return 0;
 824 }
 825
 826 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 827 {
 828         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 829         struct hfi1_devdata *dd = uctxt->dd;
 830
 831         trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
 832                                  node->npages,
 833                                  node->notifier.interval_tree.start, node->phys,
 834                                  node->dma_addr);
 835
 836         /*
 837          * Make sure device has seen the write before we unpin the
 838          * pages.
 839          */
 840         hfi1_put_tid(dd, node->rcventry, PT_INVALID_FLUSH, 0, 0);
 841
 842         unpin_rcv_pages(fd, NULL, node, 0, node->npages, true);
 843
 844         node->grp->used--;
 845         node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
 846
 847         if (node->grp->used == node->grp->size - 1)
 848                 tid_group_move(node->grp, &uctxt->tid_full_list,
 849                                &uctxt->tid_used_list);
 850         else if (!node->grp->used)
 851                 tid_group_move(node->grp, &uctxt->tid_used_list,
 852                                &uctxt->tid_group_list);
 853         kfree(node);
 854 }
 855
 856 /*
 857  * As a simple helper for hfi1_user_exp_rcv_free, this function deals with
 858  * clearing nodes in the non-cached case.
 859  */
 860 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 861                             struct exp_tid_set *set,
 862                             struct hfi1_filedata *fd)
 863 {
 864         struct tid_group *grp, *ptr;
 865         int i;
 866
 867         list_for_each_entry_safe(grp, ptr, &set->list, list) {
 868                 list_del_init(&grp->list);
 869
 870                 for (i = 0; i < grp->size; i++) {
 871                         if (grp->map & (1 << i)) {
 872                                 u16 rcventry = grp->base + i;
 873                                 struct tid_rb_node *node;
 874
 875                                 node = fd->entry_to_rb[rcventry -
 876                                                           uctxt->expected_base];
 877                                 if (!node || node->rcventry != rcventry)
 878                                         continue;
 879
 880                                 if (fd->use_mn)
 881                                         mmu_interval_notifier_remove(
 882                                                 &node->notifier);
 883                                 cacheless_tid_rb_remove(fd, node);
 884                         }
 885                 }
 886         }
 887 }
 888
 889 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
 890                               const struct mmu_notifier_range *range,
 891                               unsigned long cur_seq)
 892 {
 893         struct tid_rb_node *node =
 894                 container_of(mni, struct tid_rb_node, notifier);
 895         struct hfi1_filedata *fdata = node->fdata;
 896         struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 897
 898         if (node->freed)
 899                 return true;
 900
 901         trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
 902                                  node->notifier.interval_tree.start,
 903                                  node->rcventry, node->npages, node->dma_addr);
 904         node->freed = true;
 905
 906         spin_lock(&fdata->invalid_lock);
 907         if (fdata->invalid_tid_idx < uctxt->expected_count) {
 908                 fdata->invalid_tids[fdata->invalid_tid_idx] =
 909                         rcventry2tidinfo(node->rcventry - uctxt->expected_base);
 910                 fdata->invalid_tids[fdata->invalid_tid_idx] |=
 911                         EXP_TID_SET(LEN, node->npages);
 912                 if (!fdata->invalid_tid_idx) {
 913                         unsigned long *ev;
 914
 915                         /*
 916                          * hfi1_set_uevent_bits() sets a user event flag
 917                          * for all processes. Because calling into the
 918                          * driver to process TID cache invalidations is
 919                          * expensive and TID cache invalidations are
 920                          * handled on a per-process basis, we can
 921                          * optimize this to set the flag only for the
 922                          * process in question.
 923                          */
 924                         ev = uctxt->dd->events +
 925                                 (uctxt_offset(uctxt) + fdata->subctxt);
 926                         set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 927                 }
 928                 fdata->invalid_tid_idx++;
 929         }
 930         spin_unlock(&fdata->invalid_lock);
 931         return true;
 932 }
 933
 934 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
 935                                     struct tid_rb_node *tnode)
 936 {
 937         u32 base = fdata->uctxt->expected_base;
 938
 939         fdata->entry_to_rb[tnode->rcventry - base] = NULL;
 940         clear_tid_node(fdata, tnode);
 941 }