drivers/infiniband/hw/mthca/mthca_memfree.c

   1 /*
   2  * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
   3  * Copyright (c) 2005 Cisco Systems.  All rights reserved.
   4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
   5  *
   6  * This software is available to you under a choice of one of two
   7  * licenses.  You may choose to be licensed under the terms of the GNU
   8  * General Public License (GPL) Version 2, available from the file
   9  * COPYING in the main directory of this source tree, or the
  10  * OpenIB.org BSD license below:
  11  *
  12  *     Redistribution and use in source and binary forms, with or
  13  *     without modification, are permitted provided that the following
  14  *     conditions are met:
  15  *
  16  *      - Redistributions of source code must retain the above
  17  *        copyright notice, this list of conditions and the following
  18  *        disclaimer.
  19  *
  20  *      - Redistributions in binary form must reproduce the above
  21  *        copyright notice, this list of conditions and the following
  22  *        disclaimer in the documentation and/or other materials
  23  *        provided with the distribution.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  32  * SOFTWARE.
  33  *
  34  * $Id$
  35  */
  36
  37 #include <linux/mm.h>
  38
  39 #include "mthca_memfree.h"
  40 #include "mthca_dev.h"
  41 #include "mthca_cmd.h"
  42
  43 /*
  44  * We allocate in as big chunks as we can, up to a maximum of 256 KB
  45  * per chunk.
  46  */
  47 enum {
  48         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
  49         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
  50 };
  51
  52 struct mthca_user_db_table {
  53         struct semaphore mutex;
  54         struct {
  55                 u64                uvirt;
  56                 struct scatterlist mem;
  57                 int                refcount;
  58         }                page[0];
  59 };
  60
  61 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm)
  62 {
  63         struct mthca_icm_chunk *chunk, *tmp;
  64         int i;
  65
  66         if (!icm)
  67                 return;
  68
  69         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
  70                 if (chunk->nsg > 0)
  71                         pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
  72                                      PCI_DMA_BIDIRECTIONAL);
  73
  74                 for (i = 0; i < chunk->npages; ++i)
  75                         __free_pages(chunk->mem[i].page,
  76                                      get_order(chunk->mem[i].length));
  77
  78                 kfree(chunk);
  79         }
  80
  81         kfree(icm);
  82 }
  83
  84 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
  85                                   gfp_t gfp_mask)
  86 {
  87         struct mthca_icm *icm;
  88         struct mthca_icm_chunk *chunk = NULL;
  89         int cur_order;
  90
  91         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
  92         if (!icm)
  93                 return icm;
  94
  95         icm->refcount = 0;
  96         INIT_LIST_HEAD(&icm->chunk_list);
  97
  98         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
  99
 100         while (npages > 0) {
 101                 if (!chunk) {
 102                         chunk = kmalloc(sizeof *chunk,
 103                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 104                         if (!chunk)
 105                                 goto fail;
 106
 107                         chunk->npages = 0;
 108                         chunk->nsg    = 0;
 109                         list_add_tail(&chunk->list, &icm->chunk_list);
 110                 }
 111
 112                 while (1 << cur_order > npages)
 113                         --cur_order;
 114
 115                 chunk->mem[chunk->npages].page = alloc_pages(gfp_mask, cur_order);
 116                 if (chunk->mem[chunk->npages].page) {
 117                         chunk->mem[chunk->npages].length = PAGE_SIZE << cur_order;
 118                         chunk->mem[chunk->npages].offset = 0;
 119
 120                         if (++chunk->npages == MTHCA_ICM_CHUNK_LEN) {
 121                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 122                                                         chunk->npages,
 123                                                         PCI_DMA_BIDIRECTIONAL);
 124
 125                                 if (chunk->nsg <= 0)
 126                                         goto fail;
 127
 128                                 chunk = NULL;
 129                         }
 130
 131                         npages -= 1 << cur_order;
 132                 } else {
 133                         --cur_order;
 134                         if (cur_order < 0)
 135                                 goto fail;
 136                 }
 137         }
 138
 139         if (chunk) {
 140                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 141                                         chunk->npages,
 142                                         PCI_DMA_BIDIRECTIONAL);
 143
 144                 if (chunk->nsg <= 0)
 145                         goto fail;
 146         }
 147
 148         return icm;
 149
 150 fail:
 151         mthca_free_icm(dev, icm);
 152         return NULL;
 153 }
 154
 155 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 156 {
 157         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 158         int ret = 0;
 159         u8 status;
 160
 161         down(&table->mutex);
 162
 163         if (table->icm[i]) {
 164                 ++table->icm[i]->refcount;
 165                 goto out;
 166         }
 167
 168         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
 169                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 170                                         __GFP_NOWARN);
 171         if (!table->icm[i]) {
 172                 ret = -ENOMEM;
 173                 goto out;
 174         }
 175
 176         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 177                           &status) || status) {
 178                 mthca_free_icm(dev, table->icm[i]);
 179                 table->icm[i] = NULL;
 180                 ret = -ENOMEM;
 181                 goto out;
 182         }
 183
 184         ++table->icm[i]->refcount;
 185
 186 out:
 187         up(&table->mutex);
 188         return ret;
 189 }
 190
 191 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 192 {
 193         int i;
 194         u8 status;
 195
 196         if (!mthca_is_memfree(dev))
 197                 return;
 198
 199         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 200
 201         down(&table->mutex);
 202
 203         if (--table->icm[i]->refcount == 0) {
 204                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 205                                 MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
 206                 mthca_free_icm(dev, table->icm[i]);
 207                 table->icm[i] = NULL;
 208         }
 209
 210         up(&table->mutex);
 211 }
 212
 213 void *mthca_table_find(struct mthca_icm_table *table, int obj)
 214 {
 215         int idx, offset, i;
 216         struct mthca_icm_chunk *chunk;
 217         struct mthca_icm *icm;
 218         struct page *page = NULL;
 219
 220         if (!table->lowmem)
 221                 return NULL;
 222
 223         down(&table->mutex);
 224
 225         idx = (obj & (table->num_obj - 1)) * table->obj_size;
 226         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
 227         offset = idx % MTHCA_TABLE_CHUNK_SIZE;
 228
 229         if (!icm)
 230                 goto out;
 231
 232         list_for_each_entry(chunk, &icm->chunk_list, list) {
 233                 for (i = 0; i < chunk->npages; ++i) {
 234                         if (chunk->mem[i].length >= offset) {
 235                                 page = chunk->mem[i].page;
 236                                 goto out;
 237                         }
 238                         offset -= chunk->mem[i].length;
 239                 }
 240         }
 241
 242 out:
 243         up(&table->mutex);
 244         return page ? lowmem_page_address(page) + offset : NULL;
 245 }
 246
 247 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 248                           int start, int end)
 249 {
 250         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
 251         int i, err;
 252
 253         for (i = start; i <= end; i += inc) {
 254                 err = mthca_table_get(dev, table, i);
 255                 if (err)
 256                         goto fail;
 257         }
 258
 259         return 0;
 260
 261 fail:
 262         while (i > start) {
 263                 i -= inc;
 264                 mthca_table_put(dev, table, i);
 265         }
 266
 267         return err;
 268 }
 269
 270 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 271                            int start, int end)
 272 {
 273         int i;
 274
 275         if (!mthca_is_memfree(dev))
 276                 return;
 277
 278         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
 279                 mthca_table_put(dev, table, i);
 280 }
 281
 282 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 283                                               u64 virt, int obj_size,
 284                                               int nobj, int reserved,
 285                                               int use_lowmem)
 286 {
 287         struct mthca_icm_table *table;
 288         int num_icm;
 289         unsigned chunk_size;
 290         int i;
 291         u8 status;
 292
 293         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
 294
 295         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 296         if (!table)
 297                 return NULL;
 298
 299         table->virt     = virt;
 300         table->num_icm  = num_icm;
 301         table->num_obj  = nobj;
 302         table->obj_size = obj_size;
 303         table->lowmem   = use_lowmem;
 304         init_MUTEX(&table->mutex);
 305
 306         for (i = 0; i < num_icm; ++i)
 307                 table->icm[i] = NULL;
 308
 309         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 310                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 311                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 312                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 313
 314                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 315                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 316                                                 __GFP_NOWARN);
 317                 if (!table->icm[i])
 318                         goto err;
 319                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 320                                   &status) || status) {
 321                         mthca_free_icm(dev, table->icm[i]);
 322                         table->icm[i] = NULL;
 323                         goto err;
 324                 }
 325
 326                 /*
 327                  * Add a reference to this ICM chunk so that it never
 328                  * gets freed (since it contains reserved firmware objects).
 329                  */
 330                 ++table->icm[i]->refcount;
 331         }
 332
 333         return table;
 334
 335 err:
 336         for (i = 0; i < num_icm; ++i)
 337                 if (table->icm[i]) {
 338                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 339                                         MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
 340                         mthca_free_icm(dev, table->icm[i]);
 341                 }
 342
 343         kfree(table);
 344
 345         return NULL;
 346 }
 347
 348 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 349 {
 350         int i;
 351         u8 status;
 352
 353         for (i = 0; i < table->num_icm; ++i)
 354                 if (table->icm[i]) {
 355                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 356                                         MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
 357                         mthca_free_icm(dev, table->icm[i]);
 358                 }
 359
 360         kfree(table);
 361 }
 362
 363 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 364 {
 365         return dev->uar_table.uarc_base +
 366                 uar->index * dev->uar_table.uarc_size +
 367                 page * 4096;
 368 }
 369
 370 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 371                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 372 {
 373         int ret = 0;
 374         u8 status;
 375         int i;
 376
 377         if (!mthca_is_memfree(dev))
 378                 return 0;
 379
 380         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 381                 return -EINVAL;
 382
 383         down(&db_tab->mutex);
 384
 385         i = index / MTHCA_DB_REC_PER_PAGE;
 386
 387         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 388             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 389             (uaddr & 4095)) {
 390                 ret = -EINVAL;
 391                 goto out;
 392         }
 393
 394         if (db_tab->page[i].refcount) {
 395                 ++db_tab->page[i].refcount;
 396                 goto out;
 397         }
 398
 399         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 400                              &db_tab->page[i].mem.page, NULL);
 401         if (ret < 0)
 402                 goto out;
 403
 404         db_tab->page[i].mem.length = 4096;
 405         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
 406
 407         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 408         if (ret < 0) {
 409                 put_page(db_tab->page[i].mem.page);
 410                 goto out;
 411         }
 412
 413         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 414                                  mthca_uarc_virt(dev, uar, i), &status);
 415         if (!ret && status)
 416                 ret = -EINVAL;
 417         if (ret) {
 418                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 419                 put_page(db_tab->page[i].mem.page);
 420                 goto out;
 421         }
 422
 423         db_tab->page[i].uvirt    = uaddr;
 424         db_tab->page[i].refcount = 1;
 425
 426 out:
 427         up(&db_tab->mutex);
 428         return ret;
 429 }
 430
 431 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 432                          struct mthca_user_db_table *db_tab, int index)
 433 {
 434         if (!mthca_is_memfree(dev))
 435                 return;
 436
 437         /*
 438          * To make our bookkeeping simpler, we don't unmap DB
 439          * pages until we clean up the whole db table.
 440          */
 441
 442         down(&db_tab->mutex);
 443
 444         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 445
 446         up(&db_tab->mutex);
 447 }
 448
 449 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 450 {
 451         struct mthca_user_db_table *db_tab;
 452         int npages;
 453         int i;
 454
 455         if (!mthca_is_memfree(dev))
 456                 return NULL;
 457
 458         npages = dev->uar_table.uarc_size / 4096;
 459         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 460         if (!db_tab)
 461                 return ERR_PTR(-ENOMEM);
 462
 463         init_MUTEX(&db_tab->mutex);
 464         for (i = 0; i < npages; ++i) {
 465                 db_tab->page[i].refcount = 0;
 466                 db_tab->page[i].uvirt    = 0;
 467         }
 468
 469         return db_tab;
 470 }
 471
 472 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 473                                struct mthca_user_db_table *db_tab)
 474 {
 475         int i;
 476         u8 status;
 477
 478         if (!mthca_is_memfree(dev))
 479                 return;
 480
 481         for (i = 0; i < dev->uar_table.uarc_size / 4096; ++i) {
 482                 if (db_tab->page[i].uvirt) {
 483                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 484                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 485                         put_page(db_tab->page[i].mem.page);
 486                 }
 487         }
 488
 489         kfree(db_tab);
 490 }
 491
 492 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 493                    u32 qn, __be32 **db)
 494 {
 495         int group;
 496         int start, end, dir;
 497         int i, j;
 498         struct mthca_db_page *page;
 499         int ret = 0;
 500         u8 status;
 501
 502         down(&dev->db_tab->mutex);
 503
 504         switch (type) {
 505         case MTHCA_DB_TYPE_CQ_ARM:
 506         case MTHCA_DB_TYPE_SQ:
 507                 group = 0;
 508                 start = 0;
 509                 end   = dev->db_tab->max_group1;
 510                 dir   = 1;
 511                 break;
 512
 513         case MTHCA_DB_TYPE_CQ_SET_CI:
 514         case MTHCA_DB_TYPE_RQ:
 515         case MTHCA_DB_TYPE_SRQ:
 516                 group = 1;
 517                 start = dev->db_tab->npages - 1;
 518                 end   = dev->db_tab->min_group2;
 519                 dir   = -1;
 520                 break;
 521
 522         default:
 523                 ret = -EINVAL;
 524                 goto out;
 525         }
 526
 527         for (i = start; i != end; i += dir)
 528                 if (dev->db_tab->page[i].db_rec &&
 529                     !bitmap_full(dev->db_tab->page[i].used,
 530                                  MTHCA_DB_REC_PER_PAGE)) {
 531                         page = dev->db_tab->page + i;
 532                         goto found;
 533                 }
 534
 535         for (i = start; i != end; i += dir)
 536                 if (!dev->db_tab->page[i].db_rec) {
 537                         page = dev->db_tab->page + i;
 538                         goto alloc;
 539                 }
 540
 541         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 542                 ret = -ENOMEM;
 543                 goto out;
 544         }
 545
 546         if (group == 0)
 547                 ++dev->db_tab->max_group1;
 548         else
 549                 --dev->db_tab->min_group2;
 550
 551         page = dev->db_tab->page + end;
 552
 553 alloc:
 554         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, 4096,
 555                                           &page->mapping, GFP_KERNEL);
 556         if (!page->db_rec) {
 557                 ret = -ENOMEM;
 558                 goto out;
 559         }
 560         memset(page->db_rec, 0, 4096);
 561
 562         ret = mthca_MAP_ICM_page(dev, page->mapping,
 563                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 564         if (!ret && status)
 565                 ret = -EINVAL;
 566         if (ret) {
 567                 dma_free_coherent(&dev->pdev->dev, 4096,
 568                                   page->db_rec, page->mapping);
 569                 goto out;
 570         }
 571
 572         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 573
 574 found:
 575         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 576         set_bit(j, page->used);
 577
 578         if (group == 1)
 579                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 580
 581         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 582
 583         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 584
 585         *db = (__be32 *) &page->db_rec[j];
 586
 587 out:
 588         up(&dev->db_tab->mutex);
 589
 590         return ret;
 591 }
 592
 593 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 594 {
 595         int i, j;
 596         struct mthca_db_page *page;
 597         u8 status;
 598
 599         i = db_index / MTHCA_DB_REC_PER_PAGE;
 600         j = db_index % MTHCA_DB_REC_PER_PAGE;
 601
 602         page = dev->db_tab->page + i;
 603
 604         down(&dev->db_tab->mutex);
 605
 606         page->db_rec[j] = 0;
 607         if (i >= dev->db_tab->min_group2)
 608                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 609         clear_bit(j, page->used);
 610
 611         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 612             i >= dev->db_tab->max_group1 - 1) {
 613                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 614
 615                 dma_free_coherent(&dev->pdev->dev, 4096,
 616                                   page->db_rec, page->mapping);
 617                 page->db_rec = NULL;
 618
 619                 if (i == dev->db_tab->max_group1) {
 620                         --dev->db_tab->max_group1;
 621                         /* XXX may be able to unmap more pages now */
 622                 }
 623                 if (i == dev->db_tab->min_group2)
 624                         ++dev->db_tab->min_group2;
 625         }
 626
 627         up(&dev->db_tab->mutex);
 628 }
 629
 630 int mthca_init_db_tab(struct mthca_dev *dev)
 631 {
 632         int i;
 633
 634         if (!mthca_is_memfree(dev))
 635                 return 0;
 636
 637         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 638         if (!dev->db_tab)
 639                 return -ENOMEM;
 640
 641         init_MUTEX(&dev->db_tab->mutex);
 642
 643         dev->db_tab->npages     = dev->uar_table.uarc_size / 4096;
 644         dev->db_tab->max_group1 = 0;
 645         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 646
 647         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 648                                     sizeof *dev->db_tab->page,
 649                                     GFP_KERNEL);
 650         if (!dev->db_tab->page) {
 651                 kfree(dev->db_tab);
 652                 return -ENOMEM;
 653         }
 654
 655         for (i = 0; i < dev->db_tab->npages; ++i)
 656                 dev->db_tab->page[i].db_rec = NULL;
 657
 658         return 0;
 659 }
 660
 661 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 662 {
 663         int i;
 664         u8 status;
 665
 666         if (!mthca_is_memfree(dev))
 667                 return;
 668
 669         /*
 670          * Because we don't always free our UARC pages when they
 671          * become empty to make mthca_free_db() simpler we need to
 672          * make a sweep through the doorbell pages and free any
 673          * leftover pages now.
 674          */
 675         for (i = 0; i < dev->db_tab->npages; ++i) {
 676                 if (!dev->db_tab->page[i].db_rec)
 677                         continue;
 678
 679                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 680                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 681
 682                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 683
 684                 dma_free_coherent(&dev->pdev->dev, 4096,
 685                                   dev->db_tab->page[i].db_rec,
 686                                   dev->db_tab->page[i].mapping);
 687         }
 688
 689         kfree(dev->db_tab->page);
 690         kfree(dev->db_tab);
 691 }