drivers/infiniband/hw/hfi1/user_exp_rcv.c

   1 /*
   2  * Copyright(c) 2015-2018 Intel Corporation.
   3  *
   4  * This file is provided under a dual BSD/GPLv2 license.  When using or
   5  * redistributing this file, you may do so under either license.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * BSD LICENSE
  19  *
  20  * Redistribution and use in source and binary forms, with or without
  21  * modification, are permitted provided that the following conditions
  22  * are met:
  23  *
  24  *  - Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  *  - Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in
  28  *    the documentation and/or other materials provided with the
  29  *    distribution.
  30  *  - Neither the name of Intel Corporation nor the names of its
  31  *    contributors may be used to endorse or promote products derived
  32  *    from this software without specific prior written permission.
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  35  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  36  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  37  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  38  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  39  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  40  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  41  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  42  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  43  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  44  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  *
  46  */
  47 #include <asm/page.h>
  48 #include <linux/string.h>
  49
  50 #include "mmu_rb.h"
  51 #include "user_exp_rcv.h"
  52 #include "trace.h"
  53
  54 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
  55                             struct exp_tid_set *set,
  56                             struct hfi1_filedata *fd);
  57 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages);
  58 static int set_rcvarray_entry(struct hfi1_filedata *fd,
  59                               struct tid_user_buf *tbuf,
  60                               u32 rcventry, struct tid_group *grp,
  61                               u16 pageidx, unsigned int npages);
  62 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
  63                                     struct tid_rb_node *tnode);
  64 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
  65                               const struct mmu_notifier_range *range,
  66                               unsigned long cur_seq);
  67 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *,
  68                             struct tid_group *grp,
  69                             unsigned int start, u16 count,
  70                             u32 *tidlist, unsigned int *tididx,
  71                             unsigned int *pmapped);
  72 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
  73                               struct tid_group **grp);
  74 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node);
  75
  76 static const struct mmu_interval_notifier_ops tid_mn_ops = {
  77         .invalidate = tid_rb_invalidate,
  78 };
  79
  80 /*
  81  * Initialize context and file private data needed for Expected
  82  * receive caching. This needs to be done after the context has
  83  * been configured with the eager/expected RcvEntry counts.
  84  */
  85 int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
  86                            struct hfi1_ctxtdata *uctxt)
  87 {
  88         int ret = 0;
  89
  90         spin_lock_init(&fd->tid_lock);
  91         spin_lock_init(&fd->invalid_lock);
  92
  93         fd->entry_to_rb = kcalloc(uctxt->expected_count,
  94                                   sizeof(struct rb_node *),
  95                                   GFP_KERNEL);
  96         if (!fd->entry_to_rb)
  97                 return -ENOMEM;
  98
  99         if (!HFI1_CAP_UGET_MASK(uctxt->flags, TID_UNMAP)) {
 100                 fd->invalid_tid_idx = 0;
 101                 fd->invalid_tids = kcalloc(uctxt->expected_count,
 102                                            sizeof(*fd->invalid_tids),
 103                                            GFP_KERNEL);
 104                 if (!fd->invalid_tids) {
 105                         kfree(fd->entry_to_rb);
 106                         fd->entry_to_rb = NULL;
 107                         return -ENOMEM;
 108                 }
 109                 fd->use_mn = true;
 110         }
 111
 112         /*
 113          * PSM does not have a good way to separate, count, and
 114          * effectively enforce a limit on RcvArray entries used by
 115          * subctxts (when context sharing is used) when TID caching
 116          * is enabled. To help with that, we calculate a per-process
 117          * RcvArray entry share and enforce that.
 118          * If TID caching is not in use, PSM deals with usage on its
 119          * own. In that case, we allow any subctxt to take all of the
 120          * entries.
 121          *
 122          * Make sure that we set the tid counts only after successful
 123          * init.
 124          */
 125         spin_lock(&fd->tid_lock);
 126         if (uctxt->subctxt_cnt && fd->use_mn) {
 127                 u16 remainder;
 128
 129                 fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
 130                 remainder = uctxt->expected_count % uctxt->subctxt_cnt;
 131                 if (remainder && fd->subctxt < remainder)
 132                         fd->tid_limit++;
 133         } else {
 134                 fd->tid_limit = uctxt->expected_count;
 135         }
 136         spin_unlock(&fd->tid_lock);
 137
 138         return ret;
 139 }
 140
 141 void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 142 {
 143         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 144
 145         if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
 146                 unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
 147         if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
 148                 unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 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
 178         if (mapped) {
 179                 pci_unmap_single(dd->pcidev, node->dma_addr,
 180                                  node->npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 181                 pages = &node->pages[idx];
 182         } else {
 183                 pages = &tidbuf->pages[idx];
 184         }
 185         hfi1_release_user_pages(fd->mm, pages, npages, mapped);
 186         fd->tid_n_pinned -= npages;
 187 }
 188
 189 /**
 190  * Pin receive buffer pages.
 191  */
 192 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 193 {
 194         int pinned;
 195         unsigned int npages;
 196         unsigned long vaddr = tidbuf->vaddr;
 197         struct page **pages = NULL;
 198         struct hfi1_devdata *dd = fd->uctxt->dd;
 199
 200         /* Get the number of pages the user buffer spans */
 201         npages = num_user_pages(vaddr, tidbuf->length);
 202         if (!npages)
 203                 return -EINVAL;
 204
 205         if (npages > fd->uctxt->expected_count) {
 206                 dd_dev_err(dd, "Expected buffer too big\n");
 207                 return -EINVAL;
 208         }
 209
 210         /* Verify that access is OK for the user buffer */
 211         if (!access_ok((void __user *)vaddr,
 212                        npages * PAGE_SIZE)) {
 213                 dd_dev_err(dd, "Fail vaddr %p, %u pages, !access_ok\n",
 214                            (void *)vaddr, npages);
 215                 return -EFAULT;
 216         }
 217         /* Allocate the array of struct page pointers needed for pinning */
 218         pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
 219         if (!pages)
 220                 return -ENOMEM;
 221
 222         /*
 223          * Pin all the pages of the user buffer. If we can't pin all the
 224          * pages, accept the amount pinned so far and program only that.
 225          * User space knows how to deal with partially programmed buffers.
 226          */
 227         if (!hfi1_can_pin_pages(dd, fd->mm, fd->tid_n_pinned, npages)) {
 228                 kfree(pages);
 229                 return -ENOMEM;
 230         }
 231
 232         pinned = hfi1_acquire_user_pages(fd->mm, vaddr, npages, true, pages);
 233         if (pinned <= 0) {
 234                 kfree(pages);
 235                 return pinned;
 236         }
 237         tidbuf->pages = pages;
 238         tidbuf->npages = npages;
 239         fd->tid_n_pinned += pinned;
 240         return pinned;
 241 }
 242
 243 /*
 244  * RcvArray entry allocation for Expected Receives is done by the
 245  * following algorithm:
 246  *
 247  * The context keeps 3 lists of groups of RcvArray entries:
 248  *   1. List of empty groups - tid_group_list
 249  *      This list is created during user context creation and
 250  *      contains elements which describe sets (of 8) of empty
 251  *      RcvArray entries.
 252  *   2. List of partially used groups - tid_used_list
 253  *      This list contains sets of RcvArray entries which are
 254  *      not completely used up. Another mapping request could
 255  *      use some of all of the remaining entries.
 256  *   3. List of full groups - tid_full_list
 257  *      This is the list where sets that are completely used
 258  *      up go.
 259  *
 260  * An attempt to optimize the usage of RcvArray entries is
 261  * made by finding all sets of physically contiguous pages in a
 262  * user's buffer.
 263  * These physically contiguous sets are further split into
 264  * sizes supported by the receive engine of the HFI. The
 265  * resulting sets of pages are stored in struct tid_pageset,
 266  * which describes the sets as:
 267  *    * .count - number of pages in this set
 268  *    * .idx - starting index into struct page ** array
 269  *                    of this set
 270  *
 271  * From this point on, the algorithm deals with the page sets
 272  * described above. The number of pagesets is divided by the
 273  * RcvArray group size to produce the number of full groups
 274  * needed.
 275  *
 276  * Groups from the 3 lists are manipulated using the following
 277  * rules:
 278  *   1. For each set of 8 pagesets, a complete group from
 279  *      tid_group_list is taken, programmed, and moved to
 280  *      the tid_full_list list.
 281  *   2. For all remaining pagesets:
 282  *      2.1 If the tid_used_list is empty and the tid_group_list
 283  *          is empty, stop processing pageset and return only
 284  *          what has been programmed up to this point.
 285  *      2.2 If the tid_used_list is empty and the tid_group_list
 286  *          is not empty, move a group from tid_group_list to
 287  *          tid_used_list.
 288  *      2.3 For each group is tid_used_group, program as much as
 289  *          can fit into the group. If the group becomes fully
 290  *          used, move it to tid_full_list.
 291  */
 292 int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 293                             struct hfi1_tid_info *tinfo)
 294 {
 295         int ret = 0, need_group = 0, pinned;
 296         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 297         struct hfi1_devdata *dd = uctxt->dd;
 298         unsigned int ngroups, pageidx = 0, pageset_count,
 299                 tididx = 0, mapped, mapped_pages = 0;
 300         u32 *tidlist = NULL;
 301         struct tid_user_buf *tidbuf;
 302
 303         if (!PAGE_ALIGNED(tinfo->vaddr))
 304                 return -EINVAL;
 305
 306         tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 307         if (!tidbuf)
 308                 return -ENOMEM;
 309
 310         tidbuf->vaddr = tinfo->vaddr;
 311         tidbuf->length = tinfo->length;
 312         tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 313                                 GFP_KERNEL);
 314         if (!tidbuf->psets) {
 315                 kfree(tidbuf);
 316                 return -ENOMEM;
 317         }
 318
 319         pinned = pin_rcv_pages(fd, tidbuf);
 320         if (pinned <= 0) {
 321                 kfree(tidbuf->psets);
 322                 kfree(tidbuf);
 323                 return pinned;
 324         }
 325
 326         /* Find sets of physically contiguous pages */
 327         tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 328
 329         /*
 330          * We don't need to access this under a lock since tid_used is per
 331          * process and the same process cannot be in hfi1_user_exp_rcv_clear()
 332          * and hfi1_user_exp_rcv_setup() at the same time.
 333          */
 334         spin_lock(&fd->tid_lock);
 335         if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 336                 pageset_count = fd->tid_limit - fd->tid_used;
 337         else
 338                 pageset_count = tidbuf->n_psets;
 339         spin_unlock(&fd->tid_lock);
 340
 341         if (!pageset_count)
 342                 goto bail;
 343
 344         ngroups = pageset_count / dd->rcv_entries.group_size;
 345         tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 346         if (!tidlist) {
 347                 ret = -ENOMEM;
 348                 goto nomem;
 349         }
 350
 351         tididx = 0;
 352
 353         /*
 354          * From this point on, we are going to be using shared (between master
 355          * and subcontexts) context resources. We need to take the lock.
 356          */
 357         mutex_lock(&uctxt->exp_mutex);
 358         /*
 359          * The first step is to program the RcvArray entries which are complete
 360          * groups.
 361          */
 362         while (ngroups && uctxt->tid_group_list.count) {
 363                 struct tid_group *grp =
 364                         tid_group_pop(&uctxt->tid_group_list);
 365
 366                 ret = program_rcvarray(fd, tidbuf, grp,
 367                                        pageidx, dd->rcv_entries.group_size,
 368                                        tidlist, &tididx, &mapped);
 369                 /*
 370                  * If there was a failure to program the RcvArray
 371                  * entries for the entire group, reset the grp fields
 372                  * and add the grp back to the free group list.
 373                  */
 374                 if (ret <= 0) {
 375                         tid_group_add_tail(grp, &uctxt->tid_group_list);
 376                         hfi1_cdbg(TID,
 377                                   "Failed to program RcvArray group %d", ret);
 378                         goto unlock;
 379                 }
 380
 381                 tid_group_add_tail(grp, &uctxt->tid_full_list);
 382                 ngroups--;
 383                 pageidx += ret;
 384                 mapped_pages += mapped;
 385         }
 386
 387         while (pageidx < pageset_count) {
 388                 struct tid_group *grp, *ptr;
 389                 /*
 390                  * If we don't have any partially used tid groups, check
 391                  * if we have empty groups. If so, take one from there and
 392                  * put in the partially used list.
 393                  */
 394                 if (!uctxt->tid_used_list.count || need_group) {
 395                         if (!uctxt->tid_group_list.count)
 396                                 goto unlock;
 397
 398                         grp = tid_group_pop(&uctxt->tid_group_list);
 399                         tid_group_add_tail(grp, &uctxt->tid_used_list);
 400                         need_group = 0;
 401                 }
 402                 /*
 403                  * There is an optimization opportunity here - instead of
 404                  * fitting as many page sets as we can, check for a group
 405                  * later on in the list that could fit all of them.
 406                  */
 407                 list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
 408                                          list) {
 409                         unsigned use = min_t(unsigned, pageset_count - pageidx,
 410                                              grp->size - grp->used);
 411
 412                         ret = program_rcvarray(fd, tidbuf, grp,
 413                                                pageidx, use, tidlist,
 414                                                &tididx, &mapped);
 415                         if (ret < 0) {
 416                                 hfi1_cdbg(TID,
 417                                           "Failed to program RcvArray entries %d",
 418                                           ret);
 419                                 goto unlock;
 420                         } else if (ret > 0) {
 421                                 if (grp->used == grp->size)
 422                                         tid_group_move(grp,
 423                                                        &uctxt->tid_used_list,
 424                                                        &uctxt->tid_full_list);
 425                                 pageidx += ret;
 426                                 mapped_pages += mapped;
 427                                 need_group = 0;
 428                                 /* Check if we are done so we break out early */
 429                                 if (pageidx >= pageset_count)
 430                                         break;
 431                         } else if (WARN_ON(ret == 0)) {
 432                                 /*
 433                                  * If ret is 0, we did not program any entries
 434                                  * into this group, which can only happen if
 435                                  * we've screwed up the accounting somewhere.
 436                                  * Warn and try to continue.
 437                                  */
 438                                 need_group = 1;
 439                         }
 440                 }
 441         }
 442 unlock:
 443         mutex_unlock(&uctxt->exp_mutex);
 444 nomem:
 445         hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 446                   mapped_pages, ret);
 447         if (tididx) {
 448                 spin_lock(&fd->tid_lock);
 449                 fd->tid_used += tididx;
 450                 spin_unlock(&fd->tid_lock);
 451                 tinfo->tidcnt = tididx;
 452                 tinfo->length = mapped_pages * PAGE_SIZE;
 453
 454                 if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
 455                                  tidlist, sizeof(tidlist[0]) * tididx)) {
 456                         /*
 457                          * On failure to copy to the user level, we need to undo
 458                          * everything done so far so we don't leak resources.
 459                          */
 460                         tinfo->tidlist = (unsigned long)&tidlist;
 461                         hfi1_user_exp_rcv_clear(fd, tinfo);
 462                         tinfo->tidlist = 0;
 463                         ret = -EFAULT;
 464                         goto bail;
 465                 }
 466         }
 467
 468         /*
 469          * If not everything was mapped (due to insufficient RcvArray entries,
 470          * for example), unpin all unmapped pages so we can pin them nex time.
 471          */
 472         if (mapped_pages != pinned)
 473                 unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages,
 474                                 (pinned - mapped_pages), false);
 475 bail:
 476         kfree(tidbuf->psets);
 477         kfree(tidlist);
 478         kfree(tidbuf->pages);
 479         kfree(tidbuf);
 480         return ret > 0 ? 0 : 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_user(u64_to_user_ptr(tinfo->tidlist),
 495                               sizeof(tidinfo[0]) * tinfo->tidcnt);
 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], NULL);
 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  * @start: starting index into sets array
 639  * @count: number of struct tid_pageset's to program
 640  * @tidlist: the array of u32 elements when the information about the
 641  *           programmed RcvArray entries is to be encoded.
 642  * @tididx: starting offset into tidlist
 643  * @pmapped: (output parameter) number of pages programmed into the RcvArray
 644  *           entries.
 645  *
 646  * This function will program up to 'count' number of RcvArray entries from the
 647  * group 'grp'. To make best use of write-combining writes, the function will
 648  * perform writes to the unused RcvArray entries which will be ignored by the
 649  * HW. Each RcvArray entry will be programmed with a physically contiguous
 650  * buffer chunk from the user's virtual buffer.
 651  *
 652  * Return:
 653  * -EINVAL if the requested count is larger than the size of the group,
 654  * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
 655  * number of RcvArray entries programmed.
 656  */
 657 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *tbuf,
 658                             struct tid_group *grp,
 659                             unsigned int start, u16 count,
 660                             u32 *tidlist, unsigned int *tididx,
 661                             unsigned int *pmapped)
 662 {
 663         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 664         struct hfi1_devdata *dd = uctxt->dd;
 665         u16 idx;
 666         u32 tidinfo = 0, rcventry, useidx = 0;
 667         int mapped = 0;
 668
 669         /* Count should never be larger than the group size */
 670         if (count > grp->size)
 671                 return -EINVAL;
 672
 673         /* Find the first unused entry in the group */
 674         for (idx = 0; idx < grp->size; idx++) {
 675                 if (!(grp->map & (1 << idx))) {
 676                         useidx = idx;
 677                         break;
 678                 }
 679                 rcv_array_wc_fill(dd, grp->base + idx);
 680         }
 681
 682         idx = 0;
 683         while (idx < count) {
 684                 u16 npages, pageidx, setidx = start + idx;
 685                 int ret = 0;
 686
 687                 /*
 688                  * If this entry in the group is used, move to the next one.
 689                  * If we go past the end of the group, exit the loop.
 690                  */
 691                 if (useidx >= grp->size) {
 692                         break;
 693                 } else if (grp->map & (1 << useidx)) {
 694                         rcv_array_wc_fill(dd, grp->base + useidx);
 695                         useidx++;
 696                         continue;
 697                 }
 698
 699                 rcventry = grp->base + useidx;
 700                 npages = tbuf->psets[setidx].count;
 701                 pageidx = tbuf->psets[setidx].idx;
 702
 703                 ret = set_rcvarray_entry(fd, tbuf,
 704                                          rcventry, grp, pageidx,
 705                                          npages);
 706                 if (ret)
 707                         return ret;
 708                 mapped += npages;
 709
 710                 tidinfo = rcventry2tidinfo(rcventry - uctxt->expected_base) |
 711                         EXP_TID_SET(LEN, npages);
 712                 tidlist[(*tididx)++] = tidinfo;
 713                 grp->used++;
 714                 grp->map |= 1 << useidx++;
 715                 idx++;
 716         }
 717
 718         /* Fill the rest of the group with "blank" writes */
 719         for (; useidx < grp->size; useidx++)
 720                 rcv_array_wc_fill(dd, grp->base + useidx);
 721         *pmapped = mapped;
 722         return idx;
 723 }
 724
 725 static int set_rcvarray_entry(struct hfi1_filedata *fd,
 726                               struct tid_user_buf *tbuf,
 727                               u32 rcventry, struct tid_group *grp,
 728                               u16 pageidx, unsigned int npages)
 729 {
 730         int ret;
 731         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 732         struct tid_rb_node *node;
 733         struct hfi1_devdata *dd = uctxt->dd;
 734         dma_addr_t phys;
 735         struct page **pages = tbuf->pages + pageidx;
 736
 737         /*
 738          * Allocate the node first so we can handle a potential
 739          * failure before we've programmed anything.
 740          */
 741         node = kzalloc(sizeof(*node) + (sizeof(struct page *) * npages),
 742                        GFP_KERNEL);
 743         if (!node)
 744                 return -ENOMEM;
 745
 746         phys = pci_map_single(dd->pcidev,
 747                               __va(page_to_phys(pages[0])),
 748                               npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 749         if (dma_mapping_error(&dd->pcidev->dev, phys)) {
 750                 dd_dev_err(dd, "Failed to DMA map Exp Rcv pages 0x%llx\n",
 751                            phys);
 752                 kfree(node);
 753                 return -EFAULT;
 754         }
 755
 756         node->fdata = fd;
 757         node->phys = page_to_phys(pages[0]);
 758         node->npages = npages;
 759         node->rcventry = rcventry;
 760         node->dma_addr = phys;
 761         node->grp = grp;
 762         node->freed = false;
 763         memcpy(node->pages, pages, sizeof(struct page *) * npages);
 764
 765         if (fd->use_mn) {
 766                 ret = mmu_interval_notifier_insert(
 767                         &node->notifier, fd->mm,
 768                         tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
 769                         &tid_mn_ops);
 770                 if (ret)
 771                         goto out_unmap;
 772                 /*
 773                  * FIXME: This is in the wrong order, the notifier should be
 774                  * established before the pages are pinned by pin_rcv_pages.
 775                  */
 776                 mmu_interval_read_begin(&node->notifier);
 777         }
 778         fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
 779
 780         hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
 781         trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
 782                                node->notifier.interval_tree.start, node->phys,
 783                                phys);
 784         return 0;
 785
 786 out_unmap:
 787         hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
 788                   node->rcventry, node->notifier.interval_tree.start,
 789                   node->phys, ret);
 790         pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
 791                          PCI_DMA_FROMDEVICE);
 792         kfree(node);
 793         return -EFAULT;
 794 }
 795
 796 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
 797                               struct tid_group **grp)
 798 {
 799         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 800         struct hfi1_devdata *dd = uctxt->dd;
 801         struct tid_rb_node *node;
 802         u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 803         u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 804
 805         if (tididx >= uctxt->expected_count) {
 806                 dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
 807                            tididx, uctxt->ctxt);
 808                 return -EINVAL;
 809         }
 810
 811         if (tidctrl == 0x3)
 812                 return -EINVAL;
 813
 814         rcventry = tididx + (tidctrl - 1);
 815
 816         node = fd->entry_to_rb[rcventry];
 817         if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 818                 return -EBADF;
 819
 820         if (grp)
 821                 *grp = node->grp;
 822
 823         if (fd->use_mn)
 824                 mmu_interval_notifier_remove(&node->notifier);
 825         cacheless_tid_rb_remove(fd, node);
 826
 827         return 0;
 828 }
 829
 830 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 831 {
 832         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 833         struct hfi1_devdata *dd = uctxt->dd;
 834
 835         trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
 836                                  node->npages,
 837                                  node->notifier.interval_tree.start, node->phys,
 838                                  node->dma_addr);
 839
 840         /*
 841          * Make sure device has seen the write before we unpin the
 842          * pages.
 843          */
 844         hfi1_put_tid(dd, node->rcventry, PT_INVALID_FLUSH, 0, 0);
 845
 846         unpin_rcv_pages(fd, NULL, node, 0, node->npages, true);
 847
 848         node->grp->used--;
 849         node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
 850
 851         if (node->grp->used == node->grp->size - 1)
 852                 tid_group_move(node->grp, &uctxt->tid_full_list,
 853                                &uctxt->tid_used_list);
 854         else if (!node->grp->used)
 855                 tid_group_move(node->grp, &uctxt->tid_used_list,
 856                                &uctxt->tid_group_list);
 857         kfree(node);
 858 }
 859
 860 /*
 861  * As a simple helper for hfi1_user_exp_rcv_free, this function deals with
 862  * clearing nodes in the non-cached case.
 863  */
 864 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 865                             struct exp_tid_set *set,
 866                             struct hfi1_filedata *fd)
 867 {
 868         struct tid_group *grp, *ptr;
 869         int i;
 870
 871         list_for_each_entry_safe(grp, ptr, &set->list, list) {
 872                 list_del_init(&grp->list);
 873
 874                 for (i = 0; i < grp->size; i++) {
 875                         if (grp->map & (1 << i)) {
 876                                 u16 rcventry = grp->base + i;
 877                                 struct tid_rb_node *node;
 878
 879                                 node = fd->entry_to_rb[rcventry -
 880                                                           uctxt->expected_base];
 881                                 if (!node || node->rcventry != rcventry)
 882                                         continue;
 883
 884                                 if (fd->use_mn)
 885                                         mmu_interval_notifier_remove(
 886                                                 &node->notifier);
 887                                 cacheless_tid_rb_remove(fd, node);
 888                         }
 889                 }
 890         }
 891 }
 892
 893 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
 894                               const struct mmu_notifier_range *range,
 895                               unsigned long cur_seq)
 896 {
 897         struct tid_rb_node *node =
 898                 container_of(mni, struct tid_rb_node, notifier);
 899         struct hfi1_filedata *fdata = node->fdata;
 900         struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 901
 902         if (node->freed)
 903                 return true;
 904
 905         trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
 906                                  node->notifier.interval_tree.start,
 907                                  node->rcventry, node->npages, node->dma_addr);
 908         node->freed = true;
 909
 910         spin_lock(&fdata->invalid_lock);
 911         if (fdata->invalid_tid_idx < uctxt->expected_count) {
 912                 fdata->invalid_tids[fdata->invalid_tid_idx] =
 913                         rcventry2tidinfo(node->rcventry - uctxt->expected_base);
 914                 fdata->invalid_tids[fdata->invalid_tid_idx] |=
 915                         EXP_TID_SET(LEN, node->npages);
 916                 if (!fdata->invalid_tid_idx) {
 917                         unsigned long *ev;
 918
 919                         /*
 920                          * hfi1_set_uevent_bits() sets a user event flag
 921                          * for all processes. Because calling into the
 922                          * driver to process TID cache invalidations is
 923                          * expensive and TID cache invalidations are
 924                          * handled on a per-process basis, we can
 925                          * optimize this to set the flag only for the
 926                          * process in question.
 927                          */
 928                         ev = uctxt->dd->events +
 929                                 (uctxt_offset(uctxt) + fdata->subctxt);
 930                         set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 931                 }
 932                 fdata->invalid_tid_idx++;
 933         }
 934         spin_unlock(&fdata->invalid_lock);
 935         return true;
 936 }
 937
 938 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
 939                                     struct tid_rb_node *tnode)
 940 {
 941         u32 base = fdata->uctxt->expected_base;
 942
 943         fdata->entry_to_rb[tnode->rcventry - base] = NULL;
 944         clear_tid_node(fdata, tnode);
 945 }