drivers/infiniband/hw/hfi1/user_exp_rcv.c

   1 /*
   2  * Copyright(c) 2015-2017 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 int tid_rb_insert(void *arg, struct mmu_rb_node *node);
  63 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
  64                                     struct tid_rb_node *tnode);
  65 static void tid_rb_remove(void *arg, struct mmu_rb_node *node);
  66 static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode);
  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 struct mmu_rb_ops tid_rb_ops = {
  77         .insert = tid_rb_insert,
  78         .remove = tid_rb_remove,
  79         .invalidate = tid_rb_invalidate
  80 };
  81
  82 /*
  83  * Initialize context and file private data needed for Expected
  84  * receive caching. This needs to be done after the context has
  85  * been configured with the eager/expected RcvEntry counts.
  86  */
  87 int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
  88                            struct hfi1_ctxtdata *uctxt)
  89 {
  90         struct hfi1_devdata *dd = uctxt->dd;
  91         int ret = 0;
  92
  93         spin_lock_init(&fd->tid_lock);
  94         spin_lock_init(&fd->invalid_lock);
  95
  96         fd->entry_to_rb = kcalloc(uctxt->expected_count,
  97                                   sizeof(struct rb_node *),
  98                                   GFP_KERNEL);
  99         if (!fd->entry_to_rb)
 100                 return -ENOMEM;
 101
 102         if (!HFI1_CAP_UGET_MASK(uctxt->flags, TID_UNMAP)) {
 103                 fd->invalid_tid_idx = 0;
 104                 fd->invalid_tids = kcalloc(uctxt->expected_count,
 105                                            sizeof(*fd->invalid_tids),
 106                                            GFP_KERNEL);
 107                 if (!fd->invalid_tids) {
 108                         kfree(fd->entry_to_rb);
 109                         fd->entry_to_rb = NULL;
 110                         return -ENOMEM;
 111                 }
 112
 113                 /*
 114                  * Register MMU notifier callbacks. If the registration
 115                  * fails, continue without TID caching for this context.
 116                  */
 117                 ret = hfi1_mmu_rb_register(fd, fd->mm, &tid_rb_ops,
 118                                            dd->pport->hfi1_wq,
 119                                            &fd->handler);
 120                 if (ret) {
 121                         dd_dev_info(dd,
 122                                     "Failed MMU notifier registration %d\n",
 123                                     ret);
 124                         ret = 0;
 125                 }
 126         }
 127
 128         /*
 129          * PSM does not have a good way to separate, count, and
 130          * effectively enforce a limit on RcvArray entries used by
 131          * subctxts (when context sharing is used) when TID caching
 132          * is enabled. To help with that, we calculate a per-process
 133          * RcvArray entry share and enforce that.
 134          * If TID caching is not in use, PSM deals with usage on its
 135          * own. In that case, we allow any subctxt to take all of the
 136          * entries.
 137          *
 138          * Make sure that we set the tid counts only after successful
 139          * init.
 140          */
 141         spin_lock(&fd->tid_lock);
 142         if (uctxt->subctxt_cnt && fd->handler) {
 143                 u16 remainder;
 144
 145                 fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
 146                 remainder = uctxt->expected_count % uctxt->subctxt_cnt;
 147                 if (remainder && fd->subctxt < remainder)
 148                         fd->tid_limit++;
 149         } else {
 150                 fd->tid_limit = uctxt->expected_count;
 151         }
 152         spin_unlock(&fd->tid_lock);
 153
 154         return ret;
 155 }
 156
 157 void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 158 {
 159         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 160
 161         /*
 162          * The notifier would have been removed when the process'es mm
 163          * was freed.
 164          */
 165         if (fd->handler) {
 166                 hfi1_mmu_rb_unregister(fd->handler);
 167         } else {
 168                 if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
 169                         unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
 170                 if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
 171                         unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 172         }
 173
 174         kfree(fd->invalid_tids);
 175         fd->invalid_tids = NULL;
 176
 177         kfree(fd->entry_to_rb);
 178         fd->entry_to_rb = NULL;
 179 }
 180
 181 /**
 182  * Release pinned receive buffer pages.
 183  *
 184  * @mapped - true if the pages have been DMA mapped. false otherwise.
 185  * @idx - Index of the first page to unpin.
 186  * @npages - No of pages to unpin.
 187  *
 188  * If the pages have been DMA mapped (indicated by mapped parameter), their
 189  * info will be passed via a struct tid_rb_node. If they haven't been mapped,
 190  * their info will be passed via a struct tid_user_buf.
 191  */
 192 static void unpin_rcv_pages(struct hfi1_filedata *fd,
 193                             struct tid_user_buf *tidbuf,
 194                             struct tid_rb_node *node,
 195                             unsigned int idx,
 196                             unsigned int npages,
 197                             bool mapped)
 198 {
 199         struct page **pages;
 200         struct hfi1_devdata *dd = fd->uctxt->dd;
 201
 202         if (mapped) {
 203                 pci_unmap_single(dd->pcidev, node->dma_addr,
 204                                  node->mmu.len, PCI_DMA_FROMDEVICE);
 205                 pages = &node->pages[idx];
 206         } else {
 207                 pages = &tidbuf->pages[idx];
 208         }
 209         hfi1_release_user_pages(fd->mm, pages, npages, mapped);
 210         fd->tid_n_pinned -= npages;
 211 }
 212
 213 /**
 214  * Pin receive buffer pages.
 215  */
 216 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 217 {
 218         int pinned;
 219         unsigned int npages;
 220         unsigned long vaddr = tidbuf->vaddr;
 221         struct page **pages = NULL;
 222         struct hfi1_devdata *dd = fd->uctxt->dd;
 223
 224         /* Get the number of pages the user buffer spans */
 225         npages = num_user_pages(vaddr, tidbuf->length);
 226         if (!npages)
 227                 return -EINVAL;
 228
 229         if (npages > fd->uctxt->expected_count) {
 230                 dd_dev_err(dd, "Expected buffer too big\n");
 231                 return -EINVAL;
 232         }
 233
 234         /* Verify that access is OK for the user buffer */
 235         if (!access_ok(VERIFY_WRITE, (void __user *)vaddr,
 236                        npages * PAGE_SIZE)) {
 237                 dd_dev_err(dd, "Fail vaddr %p, %u pages, !access_ok\n",
 238                            (void *)vaddr, npages);
 239                 return -EFAULT;
 240         }
 241         /* Allocate the array of struct page pointers needed for pinning */
 242         pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
 243         if (!pages)
 244                 return -ENOMEM;
 245
 246         /*
 247          * Pin all the pages of the user buffer. If we can't pin all the
 248          * pages, accept the amount pinned so far and program only that.
 249          * User space knows how to deal with partially programmed buffers.
 250          */
 251         if (!hfi1_can_pin_pages(dd, fd->mm, fd->tid_n_pinned, npages)) {
 252                 kfree(pages);
 253                 return -ENOMEM;
 254         }
 255
 256         pinned = hfi1_acquire_user_pages(fd->mm, vaddr, npages, true, pages);
 257         if (pinned <= 0) {
 258                 kfree(pages);
 259                 return pinned;
 260         }
 261         tidbuf->pages = pages;
 262         tidbuf->npages = npages;
 263         fd->tid_n_pinned += pinned;
 264         return pinned;
 265 }
 266
 267 /*
 268  * RcvArray entry allocation for Expected Receives is done by the
 269  * following algorithm:
 270  *
 271  * The context keeps 3 lists of groups of RcvArray entries:
 272  *   1. List of empty groups - tid_group_list
 273  *      This list is created during user context creation and
 274  *      contains elements which describe sets (of 8) of empty
 275  *      RcvArray entries.
 276  *   2. List of partially used groups - tid_used_list
 277  *      This list contains sets of RcvArray entries which are
 278  *      not completely used up. Another mapping request could
 279  *      use some of all of the remaining entries.
 280  *   3. List of full groups - tid_full_list
 281  *      This is the list where sets that are completely used
 282  *      up go.
 283  *
 284  * An attempt to optimize the usage of RcvArray entries is
 285  * made by finding all sets of physically contiguous pages in a
 286  * user's buffer.
 287  * These physically contiguous sets are further split into
 288  * sizes supported by the receive engine of the HFI. The
 289  * resulting sets of pages are stored in struct tid_pageset,
 290  * which describes the sets as:
 291  *    * .count - number of pages in this set
 292  *    * .idx - starting index into struct page ** array
 293  *                    of this set
 294  *
 295  * From this point on, the algorithm deals with the page sets
 296  * described above. The number of pagesets is divided by the
 297  * RcvArray group size to produce the number of full groups
 298  * needed.
 299  *
 300  * Groups from the 3 lists are manipulated using the following
 301  * rules:
 302  *   1. For each set of 8 pagesets, a complete group from
 303  *      tid_group_list is taken, programmed, and moved to
 304  *      the tid_full_list list.
 305  *   2. For all remaining pagesets:
 306  *      2.1 If the tid_used_list is empty and the tid_group_list
 307  *          is empty, stop processing pageset and return only
 308  *          what has been programmed up to this point.
 309  *      2.2 If the tid_used_list is empty and the tid_group_list
 310  *          is not empty, move a group from tid_group_list to
 311  *          tid_used_list.
 312  *      2.3 For each group is tid_used_group, program as much as
 313  *          can fit into the group. If the group becomes fully
 314  *          used, move it to tid_full_list.
 315  */
 316 int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 317                             struct hfi1_tid_info *tinfo)
 318 {
 319         int ret = 0, need_group = 0, pinned;
 320         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 321         struct hfi1_devdata *dd = uctxt->dd;
 322         unsigned int ngroups, pageidx = 0, pageset_count,
 323                 tididx = 0, mapped, mapped_pages = 0;
 324         u32 *tidlist = NULL;
 325         struct tid_user_buf *tidbuf;
 326
 327         tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 328         if (!tidbuf)
 329                 return -ENOMEM;
 330
 331         tidbuf->vaddr = tinfo->vaddr;
 332         tidbuf->length = tinfo->length;
 333         tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 334                                 GFP_KERNEL);
 335         if (!tidbuf->psets) {
 336                 kfree(tidbuf);
 337                 return -ENOMEM;
 338         }
 339
 340         pinned = pin_rcv_pages(fd, tidbuf);
 341         if (pinned <= 0) {
 342                 kfree(tidbuf->psets);
 343                 kfree(tidbuf);
 344                 return pinned;
 345         }
 346
 347         /* Find sets of physically contiguous pages */
 348         tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 349
 350         /*
 351          * We don't need to access this under a lock since tid_used is per
 352          * process and the same process cannot be in hfi1_user_exp_rcv_clear()
 353          * and hfi1_user_exp_rcv_setup() at the same time.
 354          */
 355         spin_lock(&fd->tid_lock);
 356         if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 357                 pageset_count = fd->tid_limit - fd->tid_used;
 358         else
 359                 pageset_count = tidbuf->n_psets;
 360         spin_unlock(&fd->tid_lock);
 361
 362         if (!pageset_count)
 363                 goto bail;
 364
 365         ngroups = pageset_count / dd->rcv_entries.group_size;
 366         tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 367         if (!tidlist) {
 368                 ret = -ENOMEM;
 369                 goto nomem;
 370         }
 371
 372         tididx = 0;
 373
 374         /*
 375          * From this point on, we are going to be using shared (between master
 376          * and subcontexts) context resources. We need to take the lock.
 377          */
 378         mutex_lock(&uctxt->exp_lock);
 379         /*
 380          * The first step is to program the RcvArray entries which are complete
 381          * groups.
 382          */
 383         while (ngroups && uctxt->tid_group_list.count) {
 384                 struct tid_group *grp =
 385                         tid_group_pop(&uctxt->tid_group_list);
 386
 387                 ret = program_rcvarray(fd, tidbuf, grp,
 388                                        pageidx, dd->rcv_entries.group_size,
 389                                        tidlist, &tididx, &mapped);
 390                 /*
 391                  * If there was a failure to program the RcvArray
 392                  * entries for the entire group, reset the grp fields
 393                  * and add the grp back to the free group list.
 394                  */
 395                 if (ret <= 0) {
 396                         tid_group_add_tail(grp, &uctxt->tid_group_list);
 397                         hfi1_cdbg(TID,
 398                                   "Failed to program RcvArray group %d", ret);
 399                         goto unlock;
 400                 }
 401
 402                 tid_group_add_tail(grp, &uctxt->tid_full_list);
 403                 ngroups--;
 404                 pageidx += ret;
 405                 mapped_pages += mapped;
 406         }
 407
 408         while (pageidx < pageset_count) {
 409                 struct tid_group *grp, *ptr;
 410                 /*
 411                  * If we don't have any partially used tid groups, check
 412                  * if we have empty groups. If so, take one from there and
 413                  * put in the partially used list.
 414                  */
 415                 if (!uctxt->tid_used_list.count || need_group) {
 416                         if (!uctxt->tid_group_list.count)
 417                                 goto unlock;
 418
 419                         grp = tid_group_pop(&uctxt->tid_group_list);
 420                         tid_group_add_tail(grp, &uctxt->tid_used_list);
 421                         need_group = 0;
 422                 }
 423                 /*
 424                  * There is an optimization opportunity here - instead of
 425                  * fitting as many page sets as we can, check for a group
 426                  * later on in the list that could fit all of them.
 427                  */
 428                 list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
 429                                          list) {
 430                         unsigned use = min_t(unsigned, pageset_count - pageidx,
 431                                              grp->size - grp->used);
 432
 433                         ret = program_rcvarray(fd, tidbuf, grp,
 434                                                pageidx, use, tidlist,
 435                                                &tididx, &mapped);
 436                         if (ret < 0) {
 437                                 hfi1_cdbg(TID,
 438                                           "Failed to program RcvArray entries %d",
 439                                           ret);
 440                                 ret = -EFAULT;
 441                                 goto unlock;
 442                         } else if (ret > 0) {
 443                                 if (grp->used == grp->size)
 444                                         tid_group_move(grp,
 445                                                        &uctxt->tid_used_list,
 446                                                        &uctxt->tid_full_list);
 447                                 pageidx += ret;
 448                                 mapped_pages += mapped;
 449                                 need_group = 0;
 450                                 /* Check if we are done so we break out early */
 451                                 if (pageidx >= pageset_count)
 452                                         break;
 453                         } else if (WARN_ON(ret == 0)) {
 454                                 /*
 455                                  * If ret is 0, we did not program any entries
 456                                  * into this group, which can only happen if
 457                                  * we've screwed up the accounting somewhere.
 458                                  * Warn and try to continue.
 459                                  */
 460                                 need_group = 1;
 461                         }
 462                 }
 463         }
 464 unlock:
 465         mutex_unlock(&uctxt->exp_lock);
 466 nomem:
 467         hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 468                   mapped_pages, ret);
 469         if (tididx) {
 470                 spin_lock(&fd->tid_lock);
 471                 fd->tid_used += tididx;
 472                 spin_unlock(&fd->tid_lock);
 473                 tinfo->tidcnt = tididx;
 474                 tinfo->length = mapped_pages * PAGE_SIZE;
 475
 476                 if (copy_to_user((void __user *)(unsigned long)tinfo->tidlist,
 477                                  tidlist, sizeof(tidlist[0]) * tididx)) {
 478                         /*
 479                          * On failure to copy to the user level, we need to undo
 480                          * everything done so far so we don't leak resources.
 481                          */
 482                         tinfo->tidlist = (unsigned long)&tidlist;
 483                         hfi1_user_exp_rcv_clear(fd, tinfo);
 484                         tinfo->tidlist = 0;
 485                         ret = -EFAULT;
 486                         goto bail;
 487                 }
 488         }
 489
 490         /*
 491          * If not everything was mapped (due to insufficient RcvArray entries,
 492          * for example), unpin all unmapped pages so we can pin them nex time.
 493          */
 494         if (mapped_pages != pinned)
 495                 unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages,
 496                                 (pinned - mapped_pages), false);
 497 bail:
 498         kfree(tidbuf->psets);
 499         kfree(tidlist);
 500         kfree(tidbuf->pages);
 501         kfree(tidbuf);
 502         return ret > 0 ? 0 : ret;
 503 }
 504
 505 int hfi1_user_exp_rcv_clear(struct hfi1_filedata *fd,
 506                             struct hfi1_tid_info *tinfo)
 507 {
 508         int ret = 0;
 509         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 510         u32 *tidinfo;
 511         unsigned tididx;
 512
 513         if (unlikely(tinfo->tidcnt > fd->tid_used))
 514                 return -EINVAL;
 515
 516         tidinfo = memdup_user((void __user *)(unsigned long)tinfo->tidlist,
 517                               sizeof(tidinfo[0]) * tinfo->tidcnt);
 518         if (IS_ERR(tidinfo))
 519                 return PTR_ERR(tidinfo);
 520
 521         mutex_lock(&uctxt->exp_lock);
 522         for (tididx = 0; tididx < tinfo->tidcnt; tididx++) {
 523                 ret = unprogram_rcvarray(fd, tidinfo[tididx], NULL);
 524                 if (ret) {
 525                         hfi1_cdbg(TID, "Failed to unprogram rcv array %d",
 526                                   ret);
 527                         break;
 528                 }
 529         }
 530         spin_lock(&fd->tid_lock);
 531         fd->tid_used -= tididx;
 532         spin_unlock(&fd->tid_lock);
 533         tinfo->tidcnt = tididx;
 534         mutex_unlock(&uctxt->exp_lock);
 535
 536         kfree(tidinfo);
 537         return ret;
 538 }
 539
 540 int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd,
 541                               struct hfi1_tid_info *tinfo)
 542 {
 543         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 544         unsigned long *ev = uctxt->dd->events +
 545                 (uctxt_offset(uctxt) + fd->subctxt);
 546         u32 *array;
 547         int ret = 0;
 548
 549         /*
 550          * copy_to_user() can sleep, which will leave the invalid_lock
 551          * locked and cause the MMU notifier to be blocked on the lock
 552          * for a long time.
 553          * Copy the data to a local buffer so we can release the lock.
 554          */
 555         array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
 556         if (!array)
 557                 return -EFAULT;
 558
 559         spin_lock(&fd->invalid_lock);
 560         if (fd->invalid_tid_idx) {
 561                 memcpy(array, fd->invalid_tids, sizeof(*array) *
 562                        fd->invalid_tid_idx);
 563                 memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
 564                        fd->invalid_tid_idx);
 565                 tinfo->tidcnt = fd->invalid_tid_idx;
 566                 fd->invalid_tid_idx = 0;
 567                 /*
 568                  * Reset the user flag while still holding the lock.
 569                  * Otherwise, PSM can miss events.
 570                  */
 571                 clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 572         } else {
 573                 tinfo->tidcnt = 0;
 574         }
 575         spin_unlock(&fd->invalid_lock);
 576
 577         if (tinfo->tidcnt) {
 578                 if (copy_to_user((void __user *)tinfo->tidlist,
 579                                  array, sizeof(*array) * tinfo->tidcnt))
 580                         ret = -EFAULT;
 581         }
 582         kfree(array);
 583
 584         return ret;
 585 }
 586
 587 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages)
 588 {
 589         unsigned pagecount, pageidx, setcount = 0, i;
 590         unsigned long pfn, this_pfn;
 591         struct page **pages = tidbuf->pages;
 592         struct tid_pageset *list = tidbuf->psets;
 593
 594         if (!npages)
 595                 return 0;
 596
 597         /*
 598          * Look for sets of physically contiguous pages in the user buffer.
 599          * This will allow us to optimize Expected RcvArray entry usage by
 600          * using the bigger supported sizes.
 601          */
 602         pfn = page_to_pfn(pages[0]);
 603         for (pageidx = 0, pagecount = 1, i = 1; i <= npages; i++) {
 604                 this_pfn = i < npages ? page_to_pfn(pages[i]) : 0;
 605
 606                 /*
 607                  * If the pfn's are not sequential, pages are not physically
 608                  * contiguous.
 609                  */
 610                 if (this_pfn != ++pfn) {
 611                         /*
 612                          * At this point we have to loop over the set of
 613                          * physically contiguous pages and break them down it
 614                          * sizes supported by the HW.
 615                          * There are two main constraints:
 616                          *     1. The max buffer size is MAX_EXPECTED_BUFFER.
 617                          *        If the total set size is bigger than that
 618                          *        program only a MAX_EXPECTED_BUFFER chunk.
 619                          *     2. The buffer size has to be a power of two. If
 620                          *        it is not, round down to the closes power of
 621                          *        2 and program that size.
 622                          */
 623                         while (pagecount) {
 624                                 int maxpages = pagecount;
 625                                 u32 bufsize = pagecount * PAGE_SIZE;
 626
 627                                 if (bufsize > MAX_EXPECTED_BUFFER)
 628                                         maxpages =
 629                                                 MAX_EXPECTED_BUFFER >>
 630                                                 PAGE_SHIFT;
 631                                 else if (!is_power_of_2(bufsize))
 632                                         maxpages =
 633                                                 rounddown_pow_of_two(bufsize) >>
 634                                                 PAGE_SHIFT;
 635
 636                                 list[setcount].idx = pageidx;
 637                                 list[setcount].count = maxpages;
 638                                 pagecount -= maxpages;
 639                                 pageidx += maxpages;
 640                                 setcount++;
 641                         }
 642                         pageidx = i;
 643                         pagecount = 1;
 644                         pfn = this_pfn;
 645                 } else {
 646                         pagecount++;
 647                 }
 648         }
 649         return setcount;
 650 }
 651
 652 /**
 653  * program_rcvarray() - program an RcvArray group with receive buffers
 654  * @fd: filedata pointer
 655  * @tbuf: pointer to struct tid_user_buf that has the user buffer starting
 656  *        virtual address, buffer length, page pointers, pagesets (array of
 657  *        struct tid_pageset holding information on physically contiguous
 658  *        chunks from the user buffer), and other fields.
 659  * @grp: RcvArray group
 660  * @start: starting index into sets array
 661  * @count: number of struct tid_pageset's to program
 662  * @tidlist: the array of u32 elements when the information about the
 663  *           programmed RcvArray entries is to be encoded.
 664  * @tididx: starting offset into tidlist
 665  * @pmapped: (output parameter) number of pages programmed into the RcvArray
 666  *           entries.
 667  *
 668  * This function will program up to 'count' number of RcvArray entries from the
 669  * group 'grp'. To make best use of write-combining writes, the function will
 670  * perform writes to the unused RcvArray entries which will be ignored by the
 671  * HW. Each RcvArray entry will be programmed with a physically contiguous
 672  * buffer chunk from the user's virtual buffer.
 673  *
 674  * Return:
 675  * -EINVAL if the requested count is larger than the size of the group,
 676  * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
 677  * number of RcvArray entries programmed.
 678  */
 679 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *tbuf,
 680                             struct tid_group *grp,
 681                             unsigned int start, u16 count,
 682                             u32 *tidlist, unsigned int *tididx,
 683                             unsigned int *pmapped)
 684 {
 685         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 686         struct hfi1_devdata *dd = uctxt->dd;
 687         u16 idx;
 688         u32 tidinfo = 0, rcventry, useidx = 0;
 689         int mapped = 0;
 690
 691         /* Count should never be larger than the group size */
 692         if (count > grp->size)
 693                 return -EINVAL;
 694
 695         /* Find the first unused entry in the group */
 696         for (idx = 0; idx < grp->size; idx++) {
 697                 if (!(grp->map & (1 << idx))) {
 698                         useidx = idx;
 699                         break;
 700                 }
 701                 rcv_array_wc_fill(dd, grp->base + idx);
 702         }
 703
 704         idx = 0;
 705         while (idx < count) {
 706                 u16 npages, pageidx, setidx = start + idx;
 707                 int ret = 0;
 708
 709                 /*
 710                  * If this entry in the group is used, move to the next one.
 711                  * If we go past the end of the group, exit the loop.
 712                  */
 713                 if (useidx >= grp->size) {
 714                         break;
 715                 } else if (grp->map & (1 << useidx)) {
 716                         rcv_array_wc_fill(dd, grp->base + useidx);
 717                         useidx++;
 718                         continue;
 719                 }
 720
 721                 rcventry = grp->base + useidx;
 722                 npages = tbuf->psets[setidx].count;
 723                 pageidx = tbuf->psets[setidx].idx;
 724
 725                 ret = set_rcvarray_entry(fd, tbuf,
 726                                          rcventry, grp, pageidx,
 727                                          npages);
 728                 if (ret)
 729                         return ret;
 730                 mapped += npages;
 731
 732                 tidinfo = rcventry2tidinfo(rcventry - uctxt->expected_base) |
 733                         EXP_TID_SET(LEN, npages);
 734                 tidlist[(*tididx)++] = tidinfo;
 735                 grp->used++;
 736                 grp->map |= 1 << useidx++;
 737                 idx++;
 738         }
 739
 740         /* Fill the rest of the group with "blank" writes */
 741         for (; useidx < grp->size; useidx++)
 742                 rcv_array_wc_fill(dd, grp->base + useidx);
 743         *pmapped = mapped;
 744         return idx;
 745 }
 746
 747 static int set_rcvarray_entry(struct hfi1_filedata *fd,
 748                               struct tid_user_buf *tbuf,
 749                               u32 rcventry, struct tid_group *grp,
 750                               u16 pageidx, unsigned int npages)
 751 {
 752         int ret;
 753         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 754         struct tid_rb_node *node;
 755         struct hfi1_devdata *dd = uctxt->dd;
 756         dma_addr_t phys;
 757         struct page **pages = tbuf->pages + pageidx;
 758
 759         /*
 760          * Allocate the node first so we can handle a potential
 761          * failure before we've programmed anything.
 762          */
 763         node = kzalloc(sizeof(*node) + (sizeof(struct page *) * npages),
 764                        GFP_KERNEL);
 765         if (!node)
 766                 return -ENOMEM;
 767
 768         phys = pci_map_single(dd->pcidev,
 769                               __va(page_to_phys(pages[0])),
 770                               npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 771         if (dma_mapping_error(&dd->pcidev->dev, phys)) {
 772                 dd_dev_err(dd, "Failed to DMA map Exp Rcv pages 0x%llx\n",
 773                            phys);
 774                 kfree(node);
 775                 return -EFAULT;
 776         }
 777
 778         node->mmu.addr = tbuf->vaddr + (pageidx * PAGE_SIZE);
 779         node->mmu.len = npages * PAGE_SIZE;
 780         node->phys = page_to_phys(pages[0]);
 781         node->npages = npages;
 782         node->rcventry = rcventry;
 783         node->dma_addr = phys;
 784         node->grp = grp;
 785         node->freed = false;
 786         memcpy(node->pages, pages, sizeof(struct page *) * npages);
 787
 788         if (!fd->handler)
 789                 ret = tid_rb_insert(fd, &node->mmu);
 790         else
 791                 ret = hfi1_mmu_rb_insert(fd->handler, &node->mmu);
 792
 793         if (ret) {
 794                 hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
 795                           node->rcventry, node->mmu.addr, node->phys, ret);
 796                 pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
 797                                  PCI_DMA_FROMDEVICE);
 798                 kfree(node);
 799                 return -EFAULT;
 800         }
 801         hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
 802         trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
 803                                node->mmu.addr, node->phys, phys);
 804         return 0;
 805 }
 806
 807 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
 808                               struct tid_group **grp)
 809 {
 810         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 811         struct hfi1_devdata *dd = uctxt->dd;
 812         struct tid_rb_node *node;
 813         u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 814         u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 815
 816         if (tididx >= uctxt->expected_count) {
 817                 dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
 818                            tididx, uctxt->ctxt);
 819                 return -EINVAL;
 820         }
 821
 822         if (tidctrl == 0x3)
 823                 return -EINVAL;
 824
 825         rcventry = tididx + (tidctrl - 1);
 826
 827         node = fd->entry_to_rb[rcventry];
 828         if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 829                 return -EBADF;
 830
 831         if (grp)
 832                 *grp = node->grp;
 833
 834         if (!fd->handler)
 835                 cacheless_tid_rb_remove(fd, node);
 836         else
 837                 hfi1_mmu_rb_remove(fd->handler, &node->mmu);
 838
 839         return 0;
 840 }
 841
 842 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 843 {
 844         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 845         struct hfi1_devdata *dd = uctxt->dd;
 846
 847         trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
 848                                  node->npages, node->mmu.addr, node->phys,
 849                                  node->dma_addr);
 850
 851         /*
 852          * Make sure device has seen the write before we unpin the
 853          * pages.
 854          */
 855         hfi1_put_tid(dd, node->rcventry, PT_INVALID_FLUSH, 0, 0);
 856
 857         unpin_rcv_pages(fd, NULL, node, 0, node->npages, true);
 858
 859         node->grp->used--;
 860         node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
 861
 862         if (node->grp->used == node->grp->size - 1)
 863                 tid_group_move(node->grp, &uctxt->tid_full_list,
 864                                &uctxt->tid_used_list);
 865         else if (!node->grp->used)
 866                 tid_group_move(node->grp, &uctxt->tid_used_list,
 867                                &uctxt->tid_group_list);
 868         kfree(node);
 869 }
 870
 871 /*
 872  * As a simple helper for hfi1_user_exp_rcv_free, this function deals with
 873  * clearing nodes in the non-cached case.
 874  */
 875 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 876                             struct exp_tid_set *set,
 877                             struct hfi1_filedata *fd)
 878 {
 879         struct tid_group *grp, *ptr;
 880         int i;
 881
 882         list_for_each_entry_safe(grp, ptr, &set->list, list) {
 883                 list_del_init(&grp->list);
 884
 885                 for (i = 0; i < grp->size; i++) {
 886                         if (grp->map & (1 << i)) {
 887                                 u16 rcventry = grp->base + i;
 888                                 struct tid_rb_node *node;
 889
 890                                 node = fd->entry_to_rb[rcventry -
 891                                                           uctxt->expected_base];
 892                                 if (!node || node->rcventry != rcventry)
 893                                         continue;
 894
 895                                 cacheless_tid_rb_remove(fd, node);
 896                         }
 897                 }
 898         }
 899 }
 900
 901 /*
 902  * Always return 0 from this function.  A non-zero return indicates that the
 903  * remove operation will be called and that memory should be unpinned.
 904  * However, the driver cannot unpin out from under PSM.  Instead, retain the
 905  * memory (by returning 0) and inform PSM that the memory is going away.  PSM
 906  * will call back later when it has removed the memory from its list.
 907  */
 908 static int tid_rb_invalidate(void *arg, struct mmu_rb_node *mnode)
 909 {
 910         struct hfi1_filedata *fdata = arg;
 911         struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 912         struct tid_rb_node *node =
 913                 container_of(mnode, struct tid_rb_node, mmu);
 914
 915         if (node->freed)
 916                 return 0;
 917
 918         trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt, node->mmu.addr,
 919                                  node->rcventry, node->npages, node->dma_addr);
 920         node->freed = true;
 921
 922         spin_lock(&fdata->invalid_lock);
 923         if (fdata->invalid_tid_idx < uctxt->expected_count) {
 924                 fdata->invalid_tids[fdata->invalid_tid_idx] =
 925                         rcventry2tidinfo(node->rcventry - uctxt->expected_base);
 926                 fdata->invalid_tids[fdata->invalid_tid_idx] |=
 927                         EXP_TID_SET(LEN, node->npages);
 928                 if (!fdata->invalid_tid_idx) {
 929                         unsigned long *ev;
 930
 931                         /*
 932                          * hfi1_set_uevent_bits() sets a user event flag
 933                          * for all processes. Because calling into the
 934                          * driver to process TID cache invalidations is
 935                          * expensive and TID cache invalidations are
 936                          * handled on a per-process basis, we can
 937                          * optimize this to set the flag only for the
 938                          * process in question.
 939                          */
 940                         ev = uctxt->dd->events +
 941                                 (uctxt_offset(uctxt) + fdata->subctxt);
 942                         set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 943                 }
 944                 fdata->invalid_tid_idx++;
 945         }
 946         spin_unlock(&fdata->invalid_lock);
 947         return 0;
 948 }
 949
 950 static int tid_rb_insert(void *arg, struct mmu_rb_node *node)
 951 {
 952         struct hfi1_filedata *fdata = arg;
 953         struct tid_rb_node *tnode =
 954                 container_of(node, struct tid_rb_node, mmu);
 955         u32 base = fdata->uctxt->expected_base;
 956
 957         fdata->entry_to_rb[tnode->rcventry - base] = tnode;
 958         return 0;
 959 }
 960
 961 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
 962                                     struct tid_rb_node *tnode)
 963 {
 964         u32 base = fdata->uctxt->expected_base;
 965
 966         fdata->entry_to_rb[tnode->rcventry - base] = NULL;
 967         clear_tid_node(fdata, tnode);
 968 }
 969
 970 static void tid_rb_remove(void *arg, struct mmu_rb_node *node)
 971 {
 972         struct hfi1_filedata *fdata = arg;
 973         struct tid_rb_node *tnode =
 974                 container_of(node, struct tid_rb_node, mmu);
 975
 976         cacheless_tid_rb_remove(fdata, tnode);
 977 }