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 mutex 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         mutex_lock(&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         mutex_unlock(&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         mutex_lock(&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 / MTHCA_ICM_PAGE_SIZE,
 206                                 &status);
 207                 mthca_free_icm(dev, table->icm[i]);
 208                 table->icm[i] = NULL;
 209         }
 210
 211         mutex_unlock(&table->mutex);
 212 }
 213
 214 void *mthca_table_find(struct mthca_icm_table *table, int obj)
 215 {
 216         int idx, offset, i;
 217         struct mthca_icm_chunk *chunk;
 218         struct mthca_icm *icm;
 219         struct page *page = NULL;
 220
 221         if (!table->lowmem)
 222                 return NULL;
 223
 224         mutex_lock(&table->mutex);
 225
 226         idx = (obj & (table->num_obj - 1)) * table->obj_size;
 227         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
 228         offset = idx % MTHCA_TABLE_CHUNK_SIZE;
 229
 230         if (!icm)
 231                 goto out;
 232
 233         list_for_each_entry(chunk, &icm->chunk_list, list) {
 234                 for (i = 0; i < chunk->npages; ++i) {
 235                         if (chunk->mem[i].length >= offset) {
 236                                 page = chunk->mem[i].page;
 237                                 goto out;
 238                         }
 239                         offset -= chunk->mem[i].length;
 240                 }
 241         }
 242
 243 out:
 244         mutex_unlock(&table->mutex);
 245         return page ? lowmem_page_address(page) + offset : NULL;
 246 }
 247
 248 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 249                           int start, int end)
 250 {
 251         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
 252         int i, err;
 253
 254         for (i = start; i <= end; i += inc) {
 255                 err = mthca_table_get(dev, table, i);
 256                 if (err)
 257                         goto fail;
 258         }
 259
 260         return 0;
 261
 262 fail:
 263         while (i > start) {
 264                 i -= inc;
 265                 mthca_table_put(dev, table, i);
 266         }
 267
 268         return err;
 269 }
 270
 271 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 272                            int start, int end)
 273 {
 274         int i;
 275
 276         if (!mthca_is_memfree(dev))
 277                 return;
 278
 279         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
 280                 mthca_table_put(dev, table, i);
 281 }
 282
 283 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 284                                               u64 virt, int obj_size,
 285                                               int nobj, int reserved,
 286                                               int use_lowmem)
 287 {
 288         struct mthca_icm_table *table;
 289         int num_icm;
 290         unsigned chunk_size;
 291         int i;
 292         u8 status;
 293
 294         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
 295
 296         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 297         if (!table)
 298                 return NULL;
 299
 300         table->virt     = virt;
 301         table->num_icm  = num_icm;
 302         table->num_obj  = nobj;
 303         table->obj_size = obj_size;
 304         table->lowmem   = use_lowmem;
 305         mutex_init(&table->mutex);
 306
 307         for (i = 0; i < num_icm; ++i)
 308                 table->icm[i] = NULL;
 309
 310         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 311                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 312                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 313                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 314
 315                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 316                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 317                                                 __GFP_NOWARN);
 318                 if (!table->icm[i])
 319                         goto err;
 320                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 321                                   &status) || status) {
 322                         mthca_free_icm(dev, table->icm[i]);
 323                         table->icm[i] = NULL;
 324                         goto err;
 325                 }
 326
 327                 /*
 328                  * Add a reference to this ICM chunk so that it never
 329                  * gets freed (since it contains reserved firmware objects).
 330                  */
 331                 ++table->icm[i]->refcount;
 332         }
 333
 334         return table;
 335
 336 err:
 337         for (i = 0; i < num_icm; ++i)
 338                 if (table->icm[i]) {
 339                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 340                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 341                                         &status);
 342                         mthca_free_icm(dev, table->icm[i]);
 343                 }
 344
 345         kfree(table);
 346
 347         return NULL;
 348 }
 349
 350 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 351 {
 352         int i;
 353         u8 status;
 354
 355         for (i = 0; i < table->num_icm; ++i)
 356                 if (table->icm[i]) {
 357                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 358                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 359                                         &status);
 360                         mthca_free_icm(dev, table->icm[i]);
 361                 }
 362
 363         kfree(table);
 364 }
 365
 366 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 367 {
 368         return dev->uar_table.uarc_base +
 369                 uar->index * dev->uar_table.uarc_size +
 370                 page * MTHCA_ICM_PAGE_SIZE;
 371 }
 372
 373 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 374                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 375 {
 376         int ret = 0;
 377         u8 status;
 378         int i;
 379
 380         if (!mthca_is_memfree(dev))
 381                 return 0;
 382
 383         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 384                 return -EINVAL;
 385
 386         mutex_lock(&db_tab->mutex);
 387
 388         i = index / MTHCA_DB_REC_PER_PAGE;
 389
 390         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 391             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 392             (uaddr & 4095)) {
 393                 ret = -EINVAL;
 394                 goto out;
 395         }
 396
 397         if (db_tab->page[i].refcount) {
 398                 ++db_tab->page[i].refcount;
 399                 goto out;
 400         }
 401
 402         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 403                              &db_tab->page[i].mem.page, NULL);
 404         if (ret < 0)
 405                 goto out;
 406
 407         db_tab->page[i].mem.length = MTHCA_ICM_PAGE_SIZE;
 408         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
 409
 410         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 411         if (ret < 0) {
 412                 put_page(db_tab->page[i].mem.page);
 413                 goto out;
 414         }
 415
 416         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 417                                  mthca_uarc_virt(dev, uar, i), &status);
 418         if (!ret && status)
 419                 ret = -EINVAL;
 420         if (ret) {
 421                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 422                 put_page(db_tab->page[i].mem.page);
 423                 goto out;
 424         }
 425
 426         db_tab->page[i].uvirt    = uaddr;
 427         db_tab->page[i].refcount = 1;
 428
 429 out:
 430         mutex_unlock(&db_tab->mutex);
 431         return ret;
 432 }
 433
 434 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 435                          struct mthca_user_db_table *db_tab, int index)
 436 {
 437         if (!mthca_is_memfree(dev))
 438                 return;
 439
 440         /*
 441          * To make our bookkeeping simpler, we don't unmap DB
 442          * pages until we clean up the whole db table.
 443          */
 444
 445         mutex_lock(&db_tab->mutex);
 446
 447         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 448
 449         mutex_unlock(&db_tab->mutex);
 450 }
 451
 452 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 453 {
 454         struct mthca_user_db_table *db_tab;
 455         int npages;
 456         int i;
 457
 458         if (!mthca_is_memfree(dev))
 459                 return NULL;
 460
 461         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 462         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 463         if (!db_tab)
 464                 return ERR_PTR(-ENOMEM);
 465
 466         mutex_init(&db_tab->mutex);
 467         for (i = 0; i < npages; ++i) {
 468                 db_tab->page[i].refcount = 0;
 469                 db_tab->page[i].uvirt    = 0;
 470         }
 471
 472         return db_tab;
 473 }
 474
 475 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 476                                struct mthca_user_db_table *db_tab)
 477 {
 478         int i;
 479         u8 status;
 480
 481         if (!mthca_is_memfree(dev))
 482                 return;
 483
 484         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
 485                 if (db_tab->page[i].uvirt) {
 486                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 487                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 488                         put_page(db_tab->page[i].mem.page);
 489                 }
 490         }
 491
 492         kfree(db_tab);
 493 }
 494
 495 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 496                    u32 qn, __be32 **db)
 497 {
 498         int group;
 499         int start, end, dir;
 500         int i, j;
 501         struct mthca_db_page *page;
 502         int ret = 0;
 503         u8 status;
 504
 505         mutex_lock(&dev->db_tab->mutex);
 506
 507         switch (type) {
 508         case MTHCA_DB_TYPE_CQ_ARM:
 509         case MTHCA_DB_TYPE_SQ:
 510                 group = 0;
 511                 start = 0;
 512                 end   = dev->db_tab->max_group1;
 513                 dir   = 1;
 514                 break;
 515
 516         case MTHCA_DB_TYPE_CQ_SET_CI:
 517         case MTHCA_DB_TYPE_RQ:
 518         case MTHCA_DB_TYPE_SRQ:
 519                 group = 1;
 520                 start = dev->db_tab->npages - 1;
 521                 end   = dev->db_tab->min_group2;
 522                 dir   = -1;
 523                 break;
 524
 525         default:
 526                 ret = -EINVAL;
 527                 goto out;
 528         }
 529
 530         for (i = start; i != end; i += dir)
 531                 if (dev->db_tab->page[i].db_rec &&
 532                     !bitmap_full(dev->db_tab->page[i].used,
 533                                  MTHCA_DB_REC_PER_PAGE)) {
 534                         page = dev->db_tab->page + i;
 535                         goto found;
 536                 }
 537
 538         for (i = start; i != end; i += dir)
 539                 if (!dev->db_tab->page[i].db_rec) {
 540                         page = dev->db_tab->page + i;
 541                         goto alloc;
 542                 }
 543
 544         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 545                 ret = -ENOMEM;
 546                 goto out;
 547         }
 548
 549         if (group == 0)
 550                 ++dev->db_tab->max_group1;
 551         else
 552                 --dev->db_tab->min_group2;
 553
 554         page = dev->db_tab->page + end;
 555
 556 alloc:
 557         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 558                                           &page->mapping, GFP_KERNEL);
 559         if (!page->db_rec) {
 560                 ret = -ENOMEM;
 561                 goto out;
 562         }
 563         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 564
 565         ret = mthca_MAP_ICM_page(dev, page->mapping,
 566                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 567         if (!ret && status)
 568                 ret = -EINVAL;
 569         if (ret) {
 570                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 571                                   page->db_rec, page->mapping);
 572                 goto out;
 573         }
 574
 575         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 576
 577 found:
 578         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 579         set_bit(j, page->used);
 580
 581         if (group == 1)
 582                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 583
 584         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 585
 586         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 587
 588         *db = (__be32 *) &page->db_rec[j];
 589
 590 out:
 591         mutex_unlock(&dev->db_tab->mutex);
 592
 593         return ret;
 594 }
 595
 596 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 597 {
 598         int i, j;
 599         struct mthca_db_page *page;
 600         u8 status;
 601
 602         i = db_index / MTHCA_DB_REC_PER_PAGE;
 603         j = db_index % MTHCA_DB_REC_PER_PAGE;
 604
 605         page = dev->db_tab->page + i;
 606
 607         mutex_lock(&dev->db_tab->mutex);
 608
 609         page->db_rec[j] = 0;
 610         if (i >= dev->db_tab->min_group2)
 611                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 612         clear_bit(j, page->used);
 613
 614         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 615             i >= dev->db_tab->max_group1 - 1) {
 616                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 617
 618                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 619                                   page->db_rec, page->mapping);
 620                 page->db_rec = NULL;
 621
 622                 if (i == dev->db_tab->max_group1) {
 623                         --dev->db_tab->max_group1;
 624                         /* XXX may be able to unmap more pages now */
 625                 }
 626                 if (i == dev->db_tab->min_group2)
 627                         ++dev->db_tab->min_group2;
 628         }
 629
 630         mutex_unlock(&dev->db_tab->mutex);
 631 }
 632
 633 int mthca_init_db_tab(struct mthca_dev *dev)
 634 {
 635         int i;
 636
 637         if (!mthca_is_memfree(dev))
 638                 return 0;
 639
 640         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 641         if (!dev->db_tab)
 642                 return -ENOMEM;
 643
 644         mutex_init(&dev->db_tab->mutex);
 645
 646         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 647         dev->db_tab->max_group1 = 0;
 648         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 649
 650         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 651                                     sizeof *dev->db_tab->page,
 652                                     GFP_KERNEL);
 653         if (!dev->db_tab->page) {
 654                 kfree(dev->db_tab);
 655                 return -ENOMEM;
 656         }
 657
 658         for (i = 0; i < dev->db_tab->npages; ++i)
 659                 dev->db_tab->page[i].db_rec = NULL;
 660
 661         return 0;
 662 }
 663
 664 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 665 {
 666         int i;
 667         u8 status;
 668
 669         if (!mthca_is_memfree(dev))
 670                 return;
 671
 672         /*
 673          * Because we don't always free our UARC pages when they
 674          * become empty to make mthca_free_db() simpler we need to
 675          * make a sweep through the doorbell pages and free any
 676          * leftover pages now.
 677          */
 678         for (i = 0; i < dev->db_tab->npages; ++i) {
 679                 if (!dev->db_tab->page[i].db_rec)
 680                         continue;
 681
 682                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 683                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 684
 685                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 686
 687                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 688                                   dev->db_tab->page[i].db_rec,
 689                                   dev->db_tab->page[i].mapping);
 690         }
 691
 692         kfree(dev->db_tab->page);
 693         kfree(dev->db_tab);
 694 }