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         fd->entry_to_rb = kcalloc(uctxt->expected_count,
  91                                   sizeof(struct rb_node *),
  92                                   GFP_KERNEL);
  93         if (!fd->entry_to_rb)
  94                 return -ENOMEM;
  95
  96         if (!HFI1_CAP_UGET_MASK(uctxt->flags, TID_UNMAP)) {
  97                 fd->invalid_tid_idx = 0;
  98                 fd->invalid_tids = kcalloc(uctxt->expected_count,
  99                                            sizeof(*fd->invalid_tids),
 100                                            GFP_KERNEL);
 101                 if (!fd->invalid_tids) {
 102                         kfree(fd->entry_to_rb);
 103                         fd->entry_to_rb = NULL;
 104                         return -ENOMEM;
 105                 }
 106                 fd->use_mn = true;
 107         }
 108
 109         /*
 110          * PSM does not have a good way to separate, count, and
 111          * effectively enforce a limit on RcvArray entries used by
 112          * subctxts (when context sharing is used) when TID caching
 113          * is enabled. To help with that, we calculate a per-process
 114          * RcvArray entry share and enforce that.
 115          * If TID caching is not in use, PSM deals with usage on its
 116          * own. In that case, we allow any subctxt to take all of the
 117          * entries.
 118          *
 119          * Make sure that we set the tid counts only after successful
 120          * init.
 121          */
 122         spin_lock(&fd->tid_lock);
 123         if (uctxt->subctxt_cnt && fd->use_mn) {
 124                 u16 remainder;
 125
 126                 fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
 127                 remainder = uctxt->expected_count % uctxt->subctxt_cnt;
 128                 if (remainder && fd->subctxt < remainder)
 129                         fd->tid_limit++;
 130         } else {
 131                 fd->tid_limit = uctxt->expected_count;
 132         }
 133         spin_unlock(&fd->tid_lock);
 134
 135         return ret;
 136 }
 137
 138 void hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
 139 {
 140         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 141
 142         mutex_lock(&uctxt->exp_mutex);
 143         if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
 144                 unlock_exp_tids(uctxt, &uctxt->tid_full_list, fd);
 145         if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
 146                 unlock_exp_tids(uctxt, &uctxt->tid_used_list, fd);
 147         mutex_unlock(&uctxt->exp_mutex);
 148
 149         kfree(fd->invalid_tids);
 150         fd->invalid_tids = NULL;
 151
 152         kfree(fd->entry_to_rb);
 153         fd->entry_to_rb = NULL;
 154 }
 155
 156 /**
 157  * Release pinned receive buffer pages.
 158  *
 159  * @mapped - true if the pages have been DMA mapped. false otherwise.
 160  * @idx - Index of the first page to unpin.
 161  * @npages - No of pages to unpin.
 162  *
 163  * If the pages have been DMA mapped (indicated by mapped parameter), their
 164  * info will be passed via a struct tid_rb_node. If they haven't been mapped,
 165  * their info will be passed via a struct tid_user_buf.
 166  */
 167 static void unpin_rcv_pages(struct hfi1_filedata *fd,
 168                             struct tid_user_buf *tidbuf,
 169                             struct tid_rb_node *node,
 170                             unsigned int idx,
 171                             unsigned int npages,
 172                             bool mapped)
 173 {
 174         struct page **pages;
 175         struct hfi1_devdata *dd = fd->uctxt->dd;
 176
 177         if (mapped) {
 178                 pci_unmap_single(dd->pcidev, node->dma_addr,
 179                                  node->npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 180                 pages = &node->pages[idx];
 181         } else {
 182                 pages = &tidbuf->pages[idx];
 183         }
 184         hfi1_release_user_pages(fd->mm, pages, npages, mapped);
 185         fd->tid_n_pinned -= npages;
 186 }
 187
 188 /**
 189  * Pin receive buffer pages.
 190  */
 191 static int pin_rcv_pages(struct hfi1_filedata *fd, struct tid_user_buf *tidbuf)
 192 {
 193         int pinned;
 194         unsigned int npages;
 195         unsigned long vaddr = tidbuf->vaddr;
 196         struct page **pages = NULL;
 197         struct hfi1_devdata *dd = fd->uctxt->dd;
 198
 199         /* Get the number of pages the user buffer spans */
 200         npages = num_user_pages(vaddr, tidbuf->length);
 201         if (!npages)
 202                 return -EINVAL;
 203
 204         if (npages > fd->uctxt->expected_count) {
 205                 dd_dev_err(dd, "Expected buffer too big\n");
 206                 return -EINVAL;
 207         }
 208
 209         /* Verify that access is OK for the user buffer */
 210         if (!access_ok((void __user *)vaddr,
 211                        npages * PAGE_SIZE)) {
 212                 dd_dev_err(dd, "Fail vaddr %p, %u pages, !access_ok\n",
 213                            (void *)vaddr, npages);
 214                 return -EFAULT;
 215         }
 216         /* Allocate the array of struct page pointers needed for pinning */
 217         pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
 218         if (!pages)
 219                 return -ENOMEM;
 220
 221         /*
 222          * Pin all the pages of the user buffer. If we can't pin all the
 223          * pages, accept the amount pinned so far and program only that.
 224          * User space knows how to deal with partially programmed buffers.
 225          */
 226         if (!hfi1_can_pin_pages(dd, fd->mm, fd->tid_n_pinned, npages)) {
 227                 kfree(pages);
 228                 return -ENOMEM;
 229         }
 230
 231         pinned = hfi1_acquire_user_pages(fd->mm, vaddr, npages, true, pages);
 232         if (pinned <= 0) {
 233                 kfree(pages);
 234                 return pinned;
 235         }
 236         tidbuf->pages = pages;
 237         tidbuf->npages = npages;
 238         fd->tid_n_pinned += pinned;
 239         return pinned;
 240 }
 241
 242 /*
 243  * RcvArray entry allocation for Expected Receives is done by the
 244  * following algorithm:
 245  *
 246  * The context keeps 3 lists of groups of RcvArray entries:
 247  *   1. List of empty groups - tid_group_list
 248  *      This list is created during user context creation and
 249  *      contains elements which describe sets (of 8) of empty
 250  *      RcvArray entries.
 251  *   2. List of partially used groups - tid_used_list
 252  *      This list contains sets of RcvArray entries which are
 253  *      not completely used up. Another mapping request could
 254  *      use some of all of the remaining entries.
 255  *   3. List of full groups - tid_full_list
 256  *      This is the list where sets that are completely used
 257  *      up go.
 258  *
 259  * An attempt to optimize the usage of RcvArray entries is
 260  * made by finding all sets of physically contiguous pages in a
 261  * user's buffer.
 262  * These physically contiguous sets are further split into
 263  * sizes supported by the receive engine of the HFI. The
 264  * resulting sets of pages are stored in struct tid_pageset,
 265  * which describes the sets as:
 266  *    * .count - number of pages in this set
 267  *    * .idx - starting index into struct page ** array
 268  *                    of this set
 269  *
 270  * From this point on, the algorithm deals with the page sets
 271  * described above. The number of pagesets is divided by the
 272  * RcvArray group size to produce the number of full groups
 273  * needed.
 274  *
 275  * Groups from the 3 lists are manipulated using the following
 276  * rules:
 277  *   1. For each set of 8 pagesets, a complete group from
 278  *      tid_group_list is taken, programmed, and moved to
 279  *      the tid_full_list list.
 280  *   2. For all remaining pagesets:
 281  *      2.1 If the tid_used_list is empty and the tid_group_list
 282  *          is empty, stop processing pageset and return only
 283  *          what has been programmed up to this point.
 284  *      2.2 If the tid_used_list is empty and the tid_group_list
 285  *          is not empty, move a group from tid_group_list to
 286  *          tid_used_list.
 287  *      2.3 For each group is tid_used_group, program as much as
 288  *          can fit into the group. If the group becomes fully
 289  *          used, move it to tid_full_list.
 290  */
 291 int hfi1_user_exp_rcv_setup(struct hfi1_filedata *fd,
 292                             struct hfi1_tid_info *tinfo)
 293 {
 294         int ret = 0, need_group = 0, pinned;
 295         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 296         struct hfi1_devdata *dd = uctxt->dd;
 297         unsigned int ngroups, pageidx = 0, pageset_count,
 298                 tididx = 0, mapped, mapped_pages = 0;
 299         u32 *tidlist = NULL;
 300         struct tid_user_buf *tidbuf;
 301
 302         if (!PAGE_ALIGNED(tinfo->vaddr))
 303                 return -EINVAL;
 304
 305         tidbuf = kzalloc(sizeof(*tidbuf), GFP_KERNEL);
 306         if (!tidbuf)
 307                 return -ENOMEM;
 308
 309         tidbuf->vaddr = tinfo->vaddr;
 310         tidbuf->length = tinfo->length;
 311         tidbuf->psets = kcalloc(uctxt->expected_count, sizeof(*tidbuf->psets),
 312                                 GFP_KERNEL);
 313         if (!tidbuf->psets) {
 314                 kfree(tidbuf);
 315                 return -ENOMEM;
 316         }
 317
 318         pinned = pin_rcv_pages(fd, tidbuf);
 319         if (pinned <= 0) {
 320                 kfree(tidbuf->psets);
 321                 kfree(tidbuf);
 322                 return pinned;
 323         }
 324
 325         /* Find sets of physically contiguous pages */
 326         tidbuf->n_psets = find_phys_blocks(tidbuf, pinned);
 327
 328         /*
 329          * We don't need to access this under a lock since tid_used is per
 330          * process and the same process cannot be in hfi1_user_exp_rcv_clear()
 331          * and hfi1_user_exp_rcv_setup() at the same time.
 332          */
 333         spin_lock(&fd->tid_lock);
 334         if (fd->tid_used + tidbuf->n_psets > fd->tid_limit)
 335                 pageset_count = fd->tid_limit - fd->tid_used;
 336         else
 337                 pageset_count = tidbuf->n_psets;
 338         spin_unlock(&fd->tid_lock);
 339
 340         if (!pageset_count)
 341                 goto bail;
 342
 343         ngroups = pageset_count / dd->rcv_entries.group_size;
 344         tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
 345         if (!tidlist) {
 346                 ret = -ENOMEM;
 347                 goto nomem;
 348         }
 349
 350         tididx = 0;
 351
 352         /*
 353          * From this point on, we are going to be using shared (between master
 354          * and subcontexts) context resources. We need to take the lock.
 355          */
 356         mutex_lock(&uctxt->exp_mutex);
 357         /*
 358          * The first step is to program the RcvArray entries which are complete
 359          * groups.
 360          */
 361         while (ngroups && uctxt->tid_group_list.count) {
 362                 struct tid_group *grp =
 363                         tid_group_pop(&uctxt->tid_group_list);
 364
 365                 ret = program_rcvarray(fd, tidbuf, grp,
 366                                        pageidx, dd->rcv_entries.group_size,
 367                                        tidlist, &tididx, &mapped);
 368                 /*
 369                  * If there was a failure to program the RcvArray
 370                  * entries for the entire group, reset the grp fields
 371                  * and add the grp back to the free group list.
 372                  */
 373                 if (ret <= 0) {
 374                         tid_group_add_tail(grp, &uctxt->tid_group_list);
 375                         hfi1_cdbg(TID,
 376                                   "Failed to program RcvArray group %d", ret);
 377                         goto unlock;
 378                 }
 379
 380                 tid_group_add_tail(grp, &uctxt->tid_full_list);
 381                 ngroups--;
 382                 pageidx += ret;
 383                 mapped_pages += mapped;
 384         }
 385
 386         while (pageidx < pageset_count) {
 387                 struct tid_group *grp, *ptr;
 388                 /*
 389                  * If we don't have any partially used tid groups, check
 390                  * if we have empty groups. If so, take one from there and
 391                  * put in the partially used list.
 392                  */
 393                 if (!uctxt->tid_used_list.count || need_group) {
 394                         if (!uctxt->tid_group_list.count)
 395                                 goto unlock;
 396
 397                         grp = tid_group_pop(&uctxt->tid_group_list);
 398                         tid_group_add_tail(grp, &uctxt->tid_used_list);
 399                         need_group = 0;
 400                 }
 401                 /*
 402                  * There is an optimization opportunity here - instead of
 403                  * fitting as many page sets as we can, check for a group
 404                  * later on in the list that could fit all of them.
 405                  */
 406                 list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
 407                                          list) {
 408                         unsigned use = min_t(unsigned, pageset_count - pageidx,
 409                                              grp->size - grp->used);
 410
 411                         ret = program_rcvarray(fd, tidbuf, grp,
 412                                                pageidx, use, tidlist,
 413                                                &tididx, &mapped);
 414                         if (ret < 0) {
 415                                 hfi1_cdbg(TID,
 416                                           "Failed to program RcvArray entries %d",
 417                                           ret);
 418                                 goto unlock;
 419                         } else if (ret > 0) {
 420                                 if (grp->used == grp->size)
 421                                         tid_group_move(grp,
 422                                                        &uctxt->tid_used_list,
 423                                                        &uctxt->tid_full_list);
 424                                 pageidx += ret;
 425                                 mapped_pages += mapped;
 426                                 need_group = 0;
 427                                 /* Check if we are done so we break out early */
 428                                 if (pageidx >= pageset_count)
 429                                         break;
 430                         } else if (WARN_ON(ret == 0)) {
 431                                 /*
 432                                  * If ret is 0, we did not program any entries
 433                                  * into this group, which can only happen if
 434                                  * we've screwed up the accounting somewhere.
 435                                  * Warn and try to continue.
 436                                  */
 437                                 need_group = 1;
 438                         }
 439                 }
 440         }
 441 unlock:
 442         mutex_unlock(&uctxt->exp_mutex);
 443 nomem:
 444         hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
 445                   mapped_pages, ret);
 446         if (tididx) {
 447                 spin_lock(&fd->tid_lock);
 448                 fd->tid_used += tididx;
 449                 spin_unlock(&fd->tid_lock);
 450                 tinfo->tidcnt = tididx;
 451                 tinfo->length = mapped_pages * PAGE_SIZE;
 452
 453                 if (copy_to_user(u64_to_user_ptr(tinfo->tidlist),
 454                                  tidlist, sizeof(tidlist[0]) * tididx)) {
 455                         /*
 456                          * On failure to copy to the user level, we need to undo
 457                          * everything done so far so we don't leak resources.
 458                          */
 459                         tinfo->tidlist = (unsigned long)&tidlist;
 460                         hfi1_user_exp_rcv_clear(fd, tinfo);
 461                         tinfo->tidlist = 0;
 462                         ret = -EFAULT;
 463                         goto bail;
 464                 }
 465         }
 466
 467         /*
 468          * If not everything was mapped (due to insufficient RcvArray entries,
 469          * for example), unpin all unmapped pages so we can pin them nex time.
 470          */
 471         if (mapped_pages != pinned)
 472                 unpin_rcv_pages(fd, tidbuf, NULL, mapped_pages,
 473                                 (pinned - mapped_pages), false);
 474 bail:
 475         kfree(tidbuf->psets);
 476         kfree(tidlist);
 477         kfree(tidbuf->pages);
 478         kfree(tidbuf);
 479         return ret > 0 ? 0 : ret;
 480 }
 481
 482 int hfi1_user_exp_rcv_clear(struct hfi1_filedata *fd,
 483                             struct hfi1_tid_info *tinfo)
 484 {
 485         int ret = 0;
 486         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 487         u32 *tidinfo;
 488         unsigned tididx;
 489
 490         if (unlikely(tinfo->tidcnt > fd->tid_used))
 491                 return -EINVAL;
 492
 493         tidinfo = memdup_user(u64_to_user_ptr(tinfo->tidlist),
 494                               sizeof(tidinfo[0]) * tinfo->tidcnt);
 495         if (IS_ERR(tidinfo))
 496                 return PTR_ERR(tidinfo);
 497
 498         mutex_lock(&uctxt->exp_mutex);
 499         for (tididx = 0; tididx < tinfo->tidcnt; tididx++) {
 500                 ret = unprogram_rcvarray(fd, tidinfo[tididx], NULL);
 501                 if (ret) {
 502                         hfi1_cdbg(TID, "Failed to unprogram rcv array %d",
 503                                   ret);
 504                         break;
 505                 }
 506         }
 507         spin_lock(&fd->tid_lock);
 508         fd->tid_used -= tididx;
 509         spin_unlock(&fd->tid_lock);
 510         tinfo->tidcnt = tididx;
 511         mutex_unlock(&uctxt->exp_mutex);
 512
 513         kfree(tidinfo);
 514         return ret;
 515 }
 516
 517 int hfi1_user_exp_rcv_invalid(struct hfi1_filedata *fd,
 518                               struct hfi1_tid_info *tinfo)
 519 {
 520         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 521         unsigned long *ev = uctxt->dd->events +
 522                 (uctxt_offset(uctxt) + fd->subctxt);
 523         u32 *array;
 524         int ret = 0;
 525
 526         /*
 527          * copy_to_user() can sleep, which will leave the invalid_lock
 528          * locked and cause the MMU notifier to be blocked on the lock
 529          * for a long time.
 530          * Copy the data to a local buffer so we can release the lock.
 531          */
 532         array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
 533         if (!array)
 534                 return -EFAULT;
 535
 536         spin_lock(&fd->invalid_lock);
 537         if (fd->invalid_tid_idx) {
 538                 memcpy(array, fd->invalid_tids, sizeof(*array) *
 539                        fd->invalid_tid_idx);
 540                 memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
 541                        fd->invalid_tid_idx);
 542                 tinfo->tidcnt = fd->invalid_tid_idx;
 543                 fd->invalid_tid_idx = 0;
 544                 /*
 545                  * Reset the user flag while still holding the lock.
 546                  * Otherwise, PSM can miss events.
 547                  */
 548                 clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 549         } else {
 550                 tinfo->tidcnt = 0;
 551         }
 552         spin_unlock(&fd->invalid_lock);
 553
 554         if (tinfo->tidcnt) {
 555                 if (copy_to_user((void __user *)tinfo->tidlist,
 556                                  array, sizeof(*array) * tinfo->tidcnt))
 557                         ret = -EFAULT;
 558         }
 559         kfree(array);
 560
 561         return ret;
 562 }
 563
 564 static u32 find_phys_blocks(struct tid_user_buf *tidbuf, unsigned int npages)
 565 {
 566         unsigned pagecount, pageidx, setcount = 0, i;
 567         unsigned long pfn, this_pfn;
 568         struct page **pages = tidbuf->pages;
 569         struct tid_pageset *list = tidbuf->psets;
 570
 571         if (!npages)
 572                 return 0;
 573
 574         /*
 575          * Look for sets of physically contiguous pages in the user buffer.
 576          * This will allow us to optimize Expected RcvArray entry usage by
 577          * using the bigger supported sizes.
 578          */
 579         pfn = page_to_pfn(pages[0]);
 580         for (pageidx = 0, pagecount = 1, i = 1; i <= npages; i++) {
 581                 this_pfn = i < npages ? page_to_pfn(pages[i]) : 0;
 582
 583                 /*
 584                  * If the pfn's are not sequential, pages are not physically
 585                  * contiguous.
 586                  */
 587                 if (this_pfn != ++pfn) {
 588                         /*
 589                          * At this point we have to loop over the set of
 590                          * physically contiguous pages and break them down it
 591                          * sizes supported by the HW.
 592                          * There are two main constraints:
 593                          *     1. The max buffer size is MAX_EXPECTED_BUFFER.
 594                          *        If the total set size is bigger than that
 595                          *        program only a MAX_EXPECTED_BUFFER chunk.
 596                          *     2. The buffer size has to be a power of two. If
 597                          *        it is not, round down to the closes power of
 598                          *        2 and program that size.
 599                          */
 600                         while (pagecount) {
 601                                 int maxpages = pagecount;
 602                                 u32 bufsize = pagecount * PAGE_SIZE;
 603
 604                                 if (bufsize > MAX_EXPECTED_BUFFER)
 605                                         maxpages =
 606                                                 MAX_EXPECTED_BUFFER >>
 607                                                 PAGE_SHIFT;
 608                                 else if (!is_power_of_2(bufsize))
 609                                         maxpages =
 610                                                 rounddown_pow_of_two(bufsize) >>
 611                                                 PAGE_SHIFT;
 612
 613                                 list[setcount].idx = pageidx;
 614                                 list[setcount].count = maxpages;
 615                                 pagecount -= maxpages;
 616                                 pageidx += maxpages;
 617                                 setcount++;
 618                         }
 619                         pageidx = i;
 620                         pagecount = 1;
 621                         pfn = this_pfn;
 622                 } else {
 623                         pagecount++;
 624                 }
 625         }
 626         return setcount;
 627 }
 628
 629 /**
 630  * program_rcvarray() - program an RcvArray group with receive buffers
 631  * @fd: filedata pointer
 632  * @tbuf: pointer to struct tid_user_buf that has the user buffer starting
 633  *        virtual address, buffer length, page pointers, pagesets (array of
 634  *        struct tid_pageset holding information on physically contiguous
 635  *        chunks from the user buffer), and other fields.
 636  * @grp: RcvArray group
 637  * @start: starting index into sets array
 638  * @count: number of struct tid_pageset's to program
 639  * @tidlist: the array of u32 elements when the information about the
 640  *           programmed RcvArray entries is to be encoded.
 641  * @tididx: starting offset into tidlist
 642  * @pmapped: (output parameter) number of pages programmed into the RcvArray
 643  *           entries.
 644  *
 645  * This function will program up to 'count' number of RcvArray entries from the
 646  * group 'grp'. To make best use of write-combining writes, the function will
 647  * perform writes to the unused RcvArray entries which will be ignored by the
 648  * HW. Each RcvArray entry will be programmed with a physically contiguous
 649  * buffer chunk from the user's virtual buffer.
 650  *
 651  * Return:
 652  * -EINVAL if the requested count is larger than the size of the group,
 653  * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
 654  * number of RcvArray entries programmed.
 655  */
 656 static int program_rcvarray(struct hfi1_filedata *fd, struct tid_user_buf *tbuf,
 657                             struct tid_group *grp,
 658                             unsigned int start, u16 count,
 659                             u32 *tidlist, unsigned int *tididx,
 660                             unsigned int *pmapped)
 661 {
 662         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 663         struct hfi1_devdata *dd = uctxt->dd;
 664         u16 idx;
 665         u32 tidinfo = 0, rcventry, useidx = 0;
 666         int mapped = 0;
 667
 668         /* Count should never be larger than the group size */
 669         if (count > grp->size)
 670                 return -EINVAL;
 671
 672         /* Find the first unused entry in the group */
 673         for (idx = 0; idx < grp->size; idx++) {
 674                 if (!(grp->map & (1 << idx))) {
 675                         useidx = idx;
 676                         break;
 677                 }
 678                 rcv_array_wc_fill(dd, grp->base + idx);
 679         }
 680
 681         idx = 0;
 682         while (idx < count) {
 683                 u16 npages, pageidx, setidx = start + idx;
 684                 int ret = 0;
 685
 686                 /*
 687                  * If this entry in the group is used, move to the next one.
 688                  * If we go past the end of the group, exit the loop.
 689                  */
 690                 if (useidx >= grp->size) {
 691                         break;
 692                 } else if (grp->map & (1 << useidx)) {
 693                         rcv_array_wc_fill(dd, grp->base + useidx);
 694                         useidx++;
 695                         continue;
 696                 }
 697
 698                 rcventry = grp->base + useidx;
 699                 npages = tbuf->psets[setidx].count;
 700                 pageidx = tbuf->psets[setidx].idx;
 701
 702                 ret = set_rcvarray_entry(fd, tbuf,
 703                                          rcventry, grp, pageidx,
 704                                          npages);
 705                 if (ret)
 706                         return ret;
 707                 mapped += npages;
 708
 709                 tidinfo = rcventry2tidinfo(rcventry - uctxt->expected_base) |
 710                         EXP_TID_SET(LEN, npages);
 711                 tidlist[(*tididx)++] = tidinfo;
 712                 grp->used++;
 713                 grp->map |= 1 << useidx++;
 714                 idx++;
 715         }
 716
 717         /* Fill the rest of the group with "blank" writes */
 718         for (; useidx < grp->size; useidx++)
 719                 rcv_array_wc_fill(dd, grp->base + useidx);
 720         *pmapped = mapped;
 721         return idx;
 722 }
 723
 724 static int set_rcvarray_entry(struct hfi1_filedata *fd,
 725                               struct tid_user_buf *tbuf,
 726                               u32 rcventry, struct tid_group *grp,
 727                               u16 pageidx, unsigned int npages)
 728 {
 729         int ret;
 730         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 731         struct tid_rb_node *node;
 732         struct hfi1_devdata *dd = uctxt->dd;
 733         dma_addr_t phys;
 734         struct page **pages = tbuf->pages + pageidx;
 735
 736         /*
 737          * Allocate the node first so we can handle a potential
 738          * failure before we've programmed anything.
 739          */
 740         node = kzalloc(sizeof(*node) + (sizeof(struct page *) * npages),
 741                        GFP_KERNEL);
 742         if (!node)
 743                 return -ENOMEM;
 744
 745         phys = pci_map_single(dd->pcidev,
 746                               __va(page_to_phys(pages[0])),
 747                               npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
 748         if (dma_mapping_error(&dd->pcidev->dev, phys)) {
 749                 dd_dev_err(dd, "Failed to DMA map Exp Rcv pages 0x%llx\n",
 750                            phys);
 751                 kfree(node);
 752                 return -EFAULT;
 753         }
 754
 755         node->fdata = fd;
 756         node->phys = page_to_phys(pages[0]);
 757         node->npages = npages;
 758         node->rcventry = rcventry;
 759         node->dma_addr = phys;
 760         node->grp = grp;
 761         node->freed = false;
 762         memcpy(node->pages, pages, sizeof(struct page *) * npages);
 763
 764         if (fd->use_mn) {
 765                 ret = mmu_interval_notifier_insert(
 766                         &node->notifier, fd->mm,
 767                         tbuf->vaddr + (pageidx * PAGE_SIZE), npages * PAGE_SIZE,
 768                         &tid_mn_ops);
 769                 if (ret)
 770                         goto out_unmap;
 771                 /*
 772                  * FIXME: This is in the wrong order, the notifier should be
 773                  * established before the pages are pinned by pin_rcv_pages.
 774                  */
 775                 mmu_interval_read_begin(&node->notifier);
 776         }
 777         fd->entry_to_rb[node->rcventry - uctxt->expected_base] = node;
 778
 779         hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
 780         trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
 781                                node->notifier.interval_tree.start, node->phys,
 782                                phys);
 783         return 0;
 784
 785 out_unmap:
 786         hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
 787                   node->rcventry, node->notifier.interval_tree.start,
 788                   node->phys, ret);
 789         pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
 790                          PCI_DMA_FROMDEVICE);
 791         kfree(node);
 792         return -EFAULT;
 793 }
 794
 795 static int unprogram_rcvarray(struct hfi1_filedata *fd, u32 tidinfo,
 796                               struct tid_group **grp)
 797 {
 798         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 799         struct hfi1_devdata *dd = uctxt->dd;
 800         struct tid_rb_node *node;
 801         u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
 802         u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
 803
 804         if (tididx >= uctxt->expected_count) {
 805                 dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
 806                            tididx, uctxt->ctxt);
 807                 return -EINVAL;
 808         }
 809
 810         if (tidctrl == 0x3)
 811                 return -EINVAL;
 812
 813         rcventry = tididx + (tidctrl - 1);
 814
 815         node = fd->entry_to_rb[rcventry];
 816         if (!node || node->rcventry != (uctxt->expected_base + rcventry))
 817                 return -EBADF;
 818
 819         if (grp)
 820                 *grp = node->grp;
 821
 822         if (fd->use_mn)
 823                 mmu_interval_notifier_remove(&node->notifier);
 824         cacheless_tid_rb_remove(fd, node);
 825
 826         return 0;
 827 }
 828
 829 static void clear_tid_node(struct hfi1_filedata *fd, struct tid_rb_node *node)
 830 {
 831         struct hfi1_ctxtdata *uctxt = fd->uctxt;
 832         struct hfi1_devdata *dd = uctxt->dd;
 833
 834         trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
 835                                  node->npages,
 836                                  node->notifier.interval_tree.start, node->phys,
 837                                  node->dma_addr);
 838
 839         /*
 840          * Make sure device has seen the write before we unpin the
 841          * pages.
 842          */
 843         hfi1_put_tid(dd, node->rcventry, PT_INVALID_FLUSH, 0, 0);
 844
 845         unpin_rcv_pages(fd, NULL, node, 0, node->npages, true);
 846
 847         node->grp->used--;
 848         node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
 849
 850         if (node->grp->used == node->grp->size - 1)
 851                 tid_group_move(node->grp, &uctxt->tid_full_list,
 852                                &uctxt->tid_used_list);
 853         else if (!node->grp->used)
 854                 tid_group_move(node->grp, &uctxt->tid_used_list,
 855                                &uctxt->tid_group_list);
 856         kfree(node);
 857 }
 858
 859 /*
 860  * As a simple helper for hfi1_user_exp_rcv_free, this function deals with
 861  * clearing nodes in the non-cached case.
 862  */
 863 static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
 864                             struct exp_tid_set *set,
 865                             struct hfi1_filedata *fd)
 866 {
 867         struct tid_group *grp, *ptr;
 868         int i;
 869
 870         list_for_each_entry_safe(grp, ptr, &set->list, list) {
 871                 list_del_init(&grp->list);
 872
 873                 for (i = 0; i < grp->size; i++) {
 874                         if (grp->map & (1 << i)) {
 875                                 u16 rcventry = grp->base + i;
 876                                 struct tid_rb_node *node;
 877
 878                                 node = fd->entry_to_rb[rcventry -
 879                                                           uctxt->expected_base];
 880                                 if (!node || node->rcventry != rcventry)
 881                                         continue;
 882
 883                                 if (fd->use_mn)
 884                                         mmu_interval_notifier_remove(
 885                                                 &node->notifier);
 886                                 cacheless_tid_rb_remove(fd, node);
 887                         }
 888                 }
 889         }
 890 }
 891
 892 static bool tid_rb_invalidate(struct mmu_interval_notifier *mni,
 893                               const struct mmu_notifier_range *range,
 894                               unsigned long cur_seq)
 895 {
 896         struct tid_rb_node *node =
 897                 container_of(mni, struct tid_rb_node, notifier);
 898         struct hfi1_filedata *fdata = node->fdata;
 899         struct hfi1_ctxtdata *uctxt = fdata->uctxt;
 900
 901         if (node->freed)
 902                 return true;
 903
 904         trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt,
 905                                  node->notifier.interval_tree.start,
 906                                  node->rcventry, node->npages, node->dma_addr);
 907         node->freed = true;
 908
 909         spin_lock(&fdata->invalid_lock);
 910         if (fdata->invalid_tid_idx < uctxt->expected_count) {
 911                 fdata->invalid_tids[fdata->invalid_tid_idx] =
 912                         rcventry2tidinfo(node->rcventry - uctxt->expected_base);
 913                 fdata->invalid_tids[fdata->invalid_tid_idx] |=
 914                         EXP_TID_SET(LEN, node->npages);
 915                 if (!fdata->invalid_tid_idx) {
 916                         unsigned long *ev;
 917
 918                         /*
 919                          * hfi1_set_uevent_bits() sets a user event flag
 920                          * for all processes. Because calling into the
 921                          * driver to process TID cache invalidations is
 922                          * expensive and TID cache invalidations are
 923                          * handled on a per-process basis, we can
 924                          * optimize this to set the flag only for the
 925                          * process in question.
 926                          */
 927                         ev = uctxt->dd->events +
 928                                 (uctxt_offset(uctxt) + fdata->subctxt);
 929                         set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
 930                 }
 931                 fdata->invalid_tid_idx++;
 932         }
 933         spin_unlock(&fdata->invalid_lock);
 934         return true;
 935 }
 936
 937 static void cacheless_tid_rb_remove(struct hfi1_filedata *fdata,
 938                                     struct tid_rb_node *tnode)
 939 {
 940         u32 base = fdata->uctxt->expected_base;
 941
 942         fdata->entry_to_rb[tnode->rcventry - base] = NULL;
 943         clear_tid_node(fdata, tnode);
 944 }