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                                   unsigned int 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                                 break;
 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         int i;
 290         u8 status;
 291
 292         num_icm = obj_size * nobj / MTHCA_TABLE_CHUNK_SIZE;
 293
 294         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 295         if (!table)
 296                 return NULL;
 297
 298         table->virt     = virt;
 299         table->num_icm  = num_icm;
 300         table->num_obj  = nobj;
 301         table->obj_size = obj_size;
 302         table->lowmem   = use_lowmem;
 303         init_MUTEX(&table->mutex);
 304
 305         for (i = 0; i < num_icm; ++i)
 306                 table->icm[i] = NULL;
 307
 308         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 309                 table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
 310                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 311                                                 __GFP_NOWARN);
 312                 if (!table->icm[i])
 313                         goto err;
 314                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 315                                   &status) || status) {
 316                         mthca_free_icm(dev, table->icm[i]);
 317                         table->icm[i] = NULL;
 318                         goto err;
 319                 }
 320
 321                 /*
 322                  * Add a reference to this ICM chunk so that it never
 323                  * gets freed (since it contains reserved firmware objects).
 324                  */
 325                 ++table->icm[i]->refcount;
 326         }
 327
 328         return table;
 329
 330 err:
 331         for (i = 0; i < num_icm; ++i)
 332                 if (table->icm[i]) {
 333                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 334                                         MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
 335                         mthca_free_icm(dev, table->icm[i]);
 336                 }
 337
 338         kfree(table);
 339
 340         return NULL;
 341 }
 342
 343 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 344 {
 345         int i;
 346         u8 status;
 347
 348         for (i = 0; i < table->num_icm; ++i)
 349                 if (table->icm[i]) {
 350                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 351                                         MTHCA_TABLE_CHUNK_SIZE >> 12, &status);
 352                         mthca_free_icm(dev, table->icm[i]);
 353                 }
 354
 355         kfree(table);
 356 }
 357
 358 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 359 {
 360         return dev->uar_table.uarc_base +
 361                 uar->index * dev->uar_table.uarc_size +
 362                 page * 4096;
 363 }
 364
 365 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 366                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 367 {
 368         int ret = 0;
 369         u8 status;
 370         int i;
 371
 372         if (!mthca_is_memfree(dev))
 373                 return 0;
 374
 375         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 376                 return -EINVAL;
 377
 378         down(&db_tab->mutex);
 379
 380         i = index / MTHCA_DB_REC_PER_PAGE;
 381
 382         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 383             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 384             (uaddr & 4095)) {
 385                 ret = -EINVAL;
 386                 goto out;
 387         }
 388
 389         if (db_tab->page[i].refcount) {
 390                 ++db_tab->page[i].refcount;
 391                 goto out;
 392         }
 393
 394         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 395                              &db_tab->page[i].mem.page, NULL);
 396         if (ret < 0)
 397                 goto out;
 398
 399         db_tab->page[i].mem.length = 4096;
 400         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
 401
 402         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 403         if (ret < 0) {
 404                 put_page(db_tab->page[i].mem.page);
 405                 goto out;
 406         }
 407
 408         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 409                                  mthca_uarc_virt(dev, uar, i), &status);
 410         if (!ret && status)
 411                 ret = -EINVAL;
 412         if (ret) {
 413                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 414                 put_page(db_tab->page[i].mem.page);
 415                 goto out;
 416         }
 417
 418         db_tab->page[i].uvirt    = uaddr;
 419         db_tab->page[i].refcount = 1;
 420
 421 out:
 422         up(&db_tab->mutex);
 423         return ret;
 424 }
 425
 426 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 427                          struct mthca_user_db_table *db_tab, int index)
 428 {
 429         if (!mthca_is_memfree(dev))
 430                 return;
 431
 432         /*
 433          * To make our bookkeeping simpler, we don't unmap DB
 434          * pages until we clean up the whole db table.
 435          */
 436
 437         down(&db_tab->mutex);
 438
 439         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 440
 441         up(&db_tab->mutex);
 442 }
 443
 444 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 445 {
 446         struct mthca_user_db_table *db_tab;
 447         int npages;
 448         int i;
 449
 450         if (!mthca_is_memfree(dev))
 451                 return NULL;
 452
 453         npages = dev->uar_table.uarc_size / 4096;
 454         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 455         if (!db_tab)
 456                 return ERR_PTR(-ENOMEM);
 457
 458         init_MUTEX(&db_tab->mutex);
 459         for (i = 0; i < npages; ++i) {
 460                 db_tab->page[i].refcount = 0;
 461                 db_tab->page[i].uvirt    = 0;
 462         }
 463
 464         return db_tab;
 465 }
 466
 467 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 468                                struct mthca_user_db_table *db_tab)
 469 {
 470         int i;
 471         u8 status;
 472
 473         if (!mthca_is_memfree(dev))
 474                 return;
 475
 476         for (i = 0; i < dev->uar_table.uarc_size / 4096; ++i) {
 477                 if (db_tab->page[i].uvirt) {
 478                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 479                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 480                         put_page(db_tab->page[i].mem.page);
 481                 }
 482         }
 483 }
 484
 485 int mthca_alloc_db(struct mthca_dev *dev, int type, u32 qn, __be32 **db)
 486 {
 487         int group;
 488         int start, end, dir;
 489         int i, j;
 490         struct mthca_db_page *page;
 491         int ret = 0;
 492         u8 status;
 493
 494         down(&dev->db_tab->mutex);
 495
 496         switch (type) {
 497         case MTHCA_DB_TYPE_CQ_ARM:
 498         case MTHCA_DB_TYPE_SQ:
 499                 group = 0;
 500                 start = 0;
 501                 end   = dev->db_tab->max_group1;
 502                 dir   = 1;
 503                 break;
 504
 505         case MTHCA_DB_TYPE_CQ_SET_CI:
 506         case MTHCA_DB_TYPE_RQ:
 507         case MTHCA_DB_TYPE_SRQ:
 508                 group = 1;
 509                 start = dev->db_tab->npages - 1;
 510                 end   = dev->db_tab->min_group2;
 511                 dir   = -1;
 512                 break;
 513
 514         default:
 515                 ret = -EINVAL;
 516                 goto out;
 517         }
 518
 519         for (i = start; i != end; i += dir)
 520                 if (dev->db_tab->page[i].db_rec &&
 521                     !bitmap_full(dev->db_tab->page[i].used,
 522                                  MTHCA_DB_REC_PER_PAGE)) {
 523                         page = dev->db_tab->page + i;
 524                         goto found;
 525                 }
 526
 527         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 528                 ret = -ENOMEM;
 529                 goto out;
 530         }
 531
 532         page = dev->db_tab->page + end;
 533         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, 4096,
 534                                           &page->mapping, GFP_KERNEL);
 535         if (!page->db_rec) {
 536                 ret = -ENOMEM;
 537                 goto out;
 538         }
 539         memset(page->db_rec, 0, 4096);
 540
 541         ret = mthca_MAP_ICM_page(dev, page->mapping,
 542                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 543         if (!ret && status)
 544                 ret = -EINVAL;
 545         if (ret) {
 546                 dma_free_coherent(&dev->pdev->dev, 4096,
 547                                   page->db_rec, page->mapping);
 548                 goto out;
 549         }
 550
 551         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 552         if (group == 0)
 553                 ++dev->db_tab->max_group1;
 554         else
 555                 --dev->db_tab->min_group2;
 556
 557 found:
 558         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 559         set_bit(j, page->used);
 560
 561         if (group == 1)
 562                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 563
 564         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 565
 566         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 567
 568         *db = (__be32 *) &page->db_rec[j];
 569
 570 out:
 571         up(&dev->db_tab->mutex);
 572
 573         return ret;
 574 }
 575
 576 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 577 {
 578         int i, j;
 579         struct mthca_db_page *page;
 580         u8 status;
 581
 582         i = db_index / MTHCA_DB_REC_PER_PAGE;
 583         j = db_index % MTHCA_DB_REC_PER_PAGE;
 584
 585         page = dev->db_tab->page + i;
 586
 587         down(&dev->db_tab->mutex);
 588
 589         page->db_rec[j] = 0;
 590         if (i >= dev->db_tab->min_group2)
 591                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 592         clear_bit(j, page->used);
 593
 594         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 595             i >= dev->db_tab->max_group1 - 1) {
 596                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 597
 598                 dma_free_coherent(&dev->pdev->dev, 4096,
 599                                   page->db_rec, page->mapping);
 600                 page->db_rec = NULL;
 601
 602                 if (i == dev->db_tab->max_group1) {
 603                         --dev->db_tab->max_group1;
 604                         /* XXX may be able to unmap more pages now */
 605                 }
 606                 if (i == dev->db_tab->min_group2)
 607                         ++dev->db_tab->min_group2;
 608         }
 609
 610         up(&dev->db_tab->mutex);
 611 }
 612
 613 int mthca_init_db_tab(struct mthca_dev *dev)
 614 {
 615         int i;
 616
 617         if (!mthca_is_memfree(dev))
 618                 return 0;
 619
 620         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 621         if (!dev->db_tab)
 622                 return -ENOMEM;
 623
 624         init_MUTEX(&dev->db_tab->mutex);
 625
 626         dev->db_tab->npages     = dev->uar_table.uarc_size / 4096;
 627         dev->db_tab->max_group1 = 0;
 628         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 629
 630         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 631                                     sizeof *dev->db_tab->page,
 632                                     GFP_KERNEL);
 633         if (!dev->db_tab->page) {
 634                 kfree(dev->db_tab);
 635                 return -ENOMEM;
 636         }
 637
 638         for (i = 0; i < dev->db_tab->npages; ++i)
 639                 dev->db_tab->page[i].db_rec = NULL;
 640
 641         return 0;
 642 }
 643
 644 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 645 {
 646         int i;
 647         u8 status;
 648
 649         if (!mthca_is_memfree(dev))
 650                 return;
 651
 652         /*
 653          * Because we don't always free our UARC pages when they
 654          * become empty to make mthca_free_db() simpler we need to
 655          * make a sweep through the doorbell pages and free any
 656          * leftover pages now.
 657          */
 658         for (i = 0; i < dev->db_tab->npages; ++i) {
 659                 if (!dev->db_tab->page[i].db_rec)
 660                         continue;
 661
 662                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 663                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 664
 665                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 666
 667                 dma_free_coherent(&dev->pdev->dev, 4096,
 668                                   dev->db_tab->page[i].db_rec,
 669                                   dev->db_tab->page[i].mapping);
 670         }
 671
 672         kfree(dev->db_tab->page);
 673         kfree(dev->db_tab);
 674 }