git.oblomov.eu Git - linux-2.6/blob - 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 #include <linux/scatterlist.h>
  39
  40 #include <asm/page.h>
  41
  42 #include "mthca_memfree.h"
  43 #include "mthca_dev.h"
  44 #include "mthca_cmd.h"
  45
  46 /*
  47  * We allocate in as big chunks as we can, up to a maximum of 256 KB
  48  * per chunk.
  49  */
  50 enum {
  51         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
  52         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
  53 };
  54
  55 struct mthca_user_db_table {
  56         struct mutex mutex;
  57         struct {
  58                 u64                uvirt;
  59                 struct scatterlist mem;
  60                 int                refcount;
  61         }                page[0];
  62 };
  63
  64 static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  65 {
  66         int i;
  67
  68         if (chunk->nsg > 0)
  69                 pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
  70                              PCI_DMA_BIDIRECTIONAL);
  71
  72         for (i = 0; i < chunk->npages; ++i)
  73                 __free_pages(chunk->mem[i].page,
  74                              get_order(chunk->mem[i].length));
  75 }
  76
  77 static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  78 {
  79         int i;
  80
  81         for (i = 0; i < chunk->npages; ++i) {
  82                 dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
  83                                   lowmem_page_address(chunk->mem[i].page),
  84                                   sg_dma_address(&chunk->mem[i]));
  85         }
  86 }
  87
  88 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
  89 {
  90         struct mthca_icm_chunk *chunk, *tmp;
  91
  92         if (!icm)
  93                 return;
  94
  95         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
  96                 if (coherent)
  97                         mthca_free_icm_coherent(dev, chunk);
  98                 else
  99                         mthca_free_icm_pages(dev, chunk);
 100
 101                 kfree(chunk);
 102         }
 103
 104         kfree(icm);
 105 }
 106
 107 static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
 108 {
 109         mem->page = alloc_pages(gfp_mask, order);
 110         if (!mem->page)
 111                 return -ENOMEM;
 112
 113         mem->length = PAGE_SIZE << order;
 114         mem->offset = 0;
 115         return 0;
 116 }
 117
 118 static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
 119                                     int order, gfp_t gfp_mask)
 120 {
 121         void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
 122                                        gfp_mask);
 123         if (!buf)
 124                 return -ENOMEM;
 125
 126         sg_set_buf(mem, buf, PAGE_SIZE << order);
 127         BUG_ON(mem->offset);
 128         sg_dma_len(mem) = PAGE_SIZE << order;
 129         return 0;
 130 }
 131
 132 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 133                                   gfp_t gfp_mask, int coherent)
 134 {
 135         struct mthca_icm *icm;
 136         struct mthca_icm_chunk *chunk = NULL;
 137         int cur_order;
 138         int ret;
 139
 140         /* We use sg_set_buf for coherent allocs, which assumes low memory */
 141         BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
 142
 143         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 144         if (!icm)
 145                 return icm;
 146
 147         icm->refcount = 0;
 148         INIT_LIST_HEAD(&icm->chunk_list);
 149
 150         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
 151
 152         while (npages > 0) {
 153                 if (!chunk) {
 154                         chunk = kmalloc(sizeof *chunk,
 155                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 156                         if (!chunk)
 157                                 goto fail;
 158
 159                         chunk->npages = 0;
 160                         chunk->nsg    = 0;
 161                         list_add_tail(&chunk->list, &icm->chunk_list);
 162                 }
 163
 164                 while (1 << cur_order > npages)
 165                         --cur_order;
 166
 167                 if (coherent)
 168                         ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
 169                                                        &chunk->mem[chunk->npages],
 170                                                        cur_order, gfp_mask);
 171                 else
 172                         ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
 173                                                     cur_order, gfp_mask);
 174
 175                 if (!ret) {
 176                         ++chunk->npages;
 177
 178                         if (coherent)
 179                                 ++chunk->nsg;
 180                         else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
 181                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 182                                                         chunk->npages,
 183                                                         PCI_DMA_BIDIRECTIONAL);
 184
 185                                 if (chunk->nsg <= 0)
 186                                         goto fail;
 187                         }
 188
 189                         if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
 190                                 chunk = NULL;
 191
 192                         npages -= 1 << cur_order;
 193                 } else {
 194                         --cur_order;
 195                         if (cur_order < 0)
 196                                 goto fail;
 197                 }
 198         }
 199
 200         if (!coherent && chunk) {
 201                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 202                                         chunk->npages,
 203                                         PCI_DMA_BIDIRECTIONAL);
 204
 205                 if (chunk->nsg <= 0)
 206                         goto fail;
 207         }
 208
 209         return icm;
 210
 211 fail:
 212         mthca_free_icm(dev, icm, coherent);
 213         return NULL;
 214 }
 215
 216 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 217 {
 218         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 219         int ret = 0;
 220         u8 status;
 221
 222         mutex_lock(&table->mutex);
 223
 224         if (table->icm[i]) {
 225                 ++table->icm[i]->refcount;
 226                 goto out;
 227         }
 228
 229         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
 230                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 231                                         __GFP_NOWARN, table->coherent);
 232         if (!table->icm[i]) {
 233                 ret = -ENOMEM;
 234                 goto out;
 235         }
 236
 237         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 238                           &status) || status) {
 239                 mthca_free_icm(dev, table->icm[i], table->coherent);
 240                 table->icm[i] = NULL;
 241                 ret = -ENOMEM;
 242                 goto out;
 243         }
 244
 245         ++table->icm[i]->refcount;
 246
 247 out:
 248         mutex_unlock(&table->mutex);
 249         return ret;
 250 }
 251
 252 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 253 {
 254         int i;
 255         u8 status;
 256
 257         if (!mthca_is_memfree(dev))
 258                 return;
 259
 260         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 261
 262         mutex_lock(&table->mutex);
 263
 264         if (--table->icm[i]->refcount == 0) {
 265                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 266                                 MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 267                                 &status);
 268                 mthca_free_icm(dev, table->icm[i], table->coherent);
 269                 table->icm[i] = NULL;
 270         }
 271
 272         mutex_unlock(&table->mutex);
 273 }
 274
 275 void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
 276 {
 277         int idx, offset, dma_offset, i;
 278         struct mthca_icm_chunk *chunk;
 279         struct mthca_icm *icm;
 280         struct page *page = NULL;
 281
 282         if (!table->lowmem)
 283                 return NULL;
 284
 285         mutex_lock(&table->mutex);
 286
 287         idx = (obj & (table->num_obj - 1)) * table->obj_size;
 288         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
 289         dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;
 290
 291         if (!icm)
 292                 goto out;
 293
 294         list_for_each_entry(chunk, &icm->chunk_list, list) {
 295                 for (i = 0; i < chunk->npages; ++i) {
 296                         if (dma_handle && dma_offset >= 0) {
 297                                 if (sg_dma_len(&chunk->mem[i]) > dma_offset)
 298                                         *dma_handle = sg_dma_address(&chunk->mem[i]) +
 299                                                 dma_offset;
 300                                 dma_offset -= sg_dma_len(&chunk->mem[i]);
 301                         }
 302                         /* DMA mapping can merge pages but not split them,
 303                          * so if we found the page, dma_handle has already
 304                          * been assigned to. */
 305                         if (chunk->mem[i].length > offset) {
 306                                 page = chunk->mem[i].page;
 307                                 goto out;
 308                         }
 309                         offset -= chunk->mem[i].length;
 310                 }
 311         }
 312
 313 out:
 314         mutex_unlock(&table->mutex);
 315         return page ? lowmem_page_address(page) + offset : NULL;
 316 }
 317
 318 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 319                           int start, int end)
 320 {
 321         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
 322         int i, err;
 323
 324         for (i = start; i <= end; i += inc) {
 325                 err = mthca_table_get(dev, table, i);
 326                 if (err)
 327                         goto fail;
 328         }
 329
 330         return 0;
 331
 332 fail:
 333         while (i > start) {
 334                 i -= inc;
 335                 mthca_table_put(dev, table, i);
 336         }
 337
 338         return err;
 339 }
 340
 341 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 342                            int start, int end)
 343 {
 344         int i;
 345
 346         if (!mthca_is_memfree(dev))
 347                 return;
 348
 349         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
 350                 mthca_table_put(dev, table, i);
 351 }
 352
 353 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 354                                               u64 virt, int obj_size,
 355                                               int nobj, int reserved,
 356                                               int use_lowmem, int use_coherent)
 357 {
 358         struct mthca_icm_table *table;
 359         int num_icm;
 360         unsigned chunk_size;
 361         int i;
 362         u8 status;
 363
 364         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
 365
 366         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 367         if (!table)
 368                 return NULL;
 369
 370         table->virt     = virt;
 371         table->num_icm  = num_icm;
 372         table->num_obj  = nobj;
 373         table->obj_size = obj_size;
 374         table->lowmem   = use_lowmem;
 375         table->coherent = use_coherent;
 376         mutex_init(&table->mutex);
 377
 378         for (i = 0; i < num_icm; ++i)
 379                 table->icm[i] = NULL;
 380
 381         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 382                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 383                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 384                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 385
 386                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 387                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 388                                                 __GFP_NOWARN, use_coherent);
 389                 if (!table->icm[i])
 390                         goto err;
 391                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 392                                   &status) || status) {
 393                         mthca_free_icm(dev, table->icm[i], table->coherent);
 394                         table->icm[i] = NULL;
 395                         goto err;
 396                 }
 397
 398                 /*
 399                  * Add a reference to this ICM chunk so that it never
 400                  * gets freed (since it contains reserved firmware objects).
 401                  */
 402                 ++table->icm[i]->refcount;
 403         }
 404
 405         return table;
 406
 407 err:
 408         for (i = 0; i < num_icm; ++i)
 409                 if (table->icm[i]) {
 410                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 411                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 412                                         &status);
 413                         mthca_free_icm(dev, table->icm[i], table->coherent);
 414                 }
 415
 416         kfree(table);
 417
 418         return NULL;
 419 }
 420
 421 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 422 {
 423         int i;
 424         u8 status;
 425
 426         for (i = 0; i < table->num_icm; ++i)
 427                 if (table->icm[i]) {
 428                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 429                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 430                                         &status);
 431                         mthca_free_icm(dev, table->icm[i], table->coherent);
 432                 }
 433
 434         kfree(table);
 435 }
 436
 437 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 438 {
 439         return dev->uar_table.uarc_base +
 440                 uar->index * dev->uar_table.uarc_size +
 441                 page * MTHCA_ICM_PAGE_SIZE;
 442 }
 443
 444 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 445                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 446 {
 447         int ret = 0;
 448         u8 status;
 449         int i;
 450
 451         if (!mthca_is_memfree(dev))
 452                 return 0;
 453
 454         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 455                 return -EINVAL;
 456
 457         mutex_lock(&db_tab->mutex);
 458
 459         i = index / MTHCA_DB_REC_PER_PAGE;
 460
 461         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 462             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 463             (uaddr & 4095)) {
 464                 ret = -EINVAL;
 465                 goto out;
 466         }
 467
 468         if (db_tab->page[i].refcount) {
 469                 ++db_tab->page[i].refcount;
 470                 goto out;
 471         }
 472
 473         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 474                              &db_tab->page[i].mem.page, NULL);
 475         if (ret < 0)
 476                 goto out;
 477
 478         db_tab->page[i].mem.length = MTHCA_ICM_PAGE_SIZE;
 479         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
 480
 481         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 482         if (ret < 0) {
 483                 put_page(db_tab->page[i].mem.page);
 484                 goto out;
 485         }
 486
 487         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 488                                  mthca_uarc_virt(dev, uar, i), &status);
 489         if (!ret && status)
 490                 ret = -EINVAL;
 491         if (ret) {
 492                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 493                 put_page(db_tab->page[i].mem.page);
 494                 goto out;
 495         }
 496
 497         db_tab->page[i].uvirt    = uaddr;
 498         db_tab->page[i].refcount = 1;
 499
 500 out:
 501         mutex_unlock(&db_tab->mutex);
 502         return ret;
 503 }
 504
 505 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 506                          struct mthca_user_db_table *db_tab, int index)
 507 {
 508         if (!mthca_is_memfree(dev))
 509                 return;
 510
 511         /*
 512          * To make our bookkeeping simpler, we don't unmap DB
 513          * pages until we clean up the whole db table.
 514          */
 515
 516         mutex_lock(&db_tab->mutex);
 517
 518         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 519
 520         mutex_unlock(&db_tab->mutex);
 521 }
 522
 523 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 524 {
 525         struct mthca_user_db_table *db_tab;
 526         int npages;
 527         int i;
 528
 529         if (!mthca_is_memfree(dev))
 530                 return NULL;
 531
 532         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 533         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 534         if (!db_tab)
 535                 return ERR_PTR(-ENOMEM);
 536
 537         mutex_init(&db_tab->mutex);
 538         for (i = 0; i < npages; ++i) {
 539                 db_tab->page[i].refcount = 0;
 540                 db_tab->page[i].uvirt    = 0;
 541         }
 542
 543         return db_tab;
 544 }
 545
 546 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 547                                struct mthca_user_db_table *db_tab)
 548 {
 549         int i;
 550         u8 status;
 551
 552         if (!mthca_is_memfree(dev))
 553                 return;
 554
 555         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
 556                 if (db_tab->page[i].uvirt) {
 557                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 558                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 559                         put_page(db_tab->page[i].mem.page);
 560                 }
 561         }
 562
 563         kfree(db_tab);
 564 }
 565
 566 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 567                    u32 qn, __be32 **db)
 568 {
 569         int group;
 570         int start, end, dir;
 571         int i, j;
 572         struct mthca_db_page *page;
 573         int ret = 0;
 574         u8 status;
 575
 576         mutex_lock(&dev->db_tab->mutex);
 577
 578         switch (type) {
 579         case MTHCA_DB_TYPE_CQ_ARM:
 580         case MTHCA_DB_TYPE_SQ:
 581                 group = 0;
 582                 start = 0;
 583                 end   = dev->db_tab->max_group1;
 584                 dir   = 1;
 585                 break;
 586
 587         case MTHCA_DB_TYPE_CQ_SET_CI:
 588         case MTHCA_DB_TYPE_RQ:
 589         case MTHCA_DB_TYPE_SRQ:
 590                 group = 1;
 591                 start = dev->db_tab->npages - 1;
 592                 end   = dev->db_tab->min_group2;
 593                 dir   = -1;
 594                 break;
 595
 596         default:
 597                 ret = -EINVAL;
 598                 goto out;
 599         }
 600
 601         for (i = start; i != end; i += dir)
 602                 if (dev->db_tab->page[i].db_rec &&
 603                     !bitmap_full(dev->db_tab->page[i].used,
 604                                  MTHCA_DB_REC_PER_PAGE)) {
 605                         page = dev->db_tab->page + i;
 606                         goto found;
 607                 }
 608
 609         for (i = start; i != end; i += dir)
 610                 if (!dev->db_tab->page[i].db_rec) {
 611                         page = dev->db_tab->page + i;
 612                         goto alloc;
 613                 }
 614
 615         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 616                 ret = -ENOMEM;
 617                 goto out;
 618         }
 619
 620         if (group == 0)
 621                 ++dev->db_tab->max_group1;
 622         else
 623                 --dev->db_tab->min_group2;
 624
 625         page = dev->db_tab->page + end;
 626
 627 alloc:
 628         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 629                                           &page->mapping, GFP_KERNEL);
 630         if (!page->db_rec) {
 631                 ret = -ENOMEM;
 632                 goto out;
 633         }
 634         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 635
 636         ret = mthca_MAP_ICM_page(dev, page->mapping,
 637                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 638         if (!ret && status)
 639                 ret = -EINVAL;
 640         if (ret) {
 641                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 642                                   page->db_rec, page->mapping);
 643                 goto out;
 644         }
 645
 646         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 647
 648 found:
 649         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 650         set_bit(j, page->used);
 651
 652         if (group == 1)
 653                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 654
 655         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 656
 657         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 658
 659         *db = (__be32 *) &page->db_rec[j];
 660
 661 out:
 662         mutex_unlock(&dev->db_tab->mutex);
 663
 664         return ret;
 665 }
 666
 667 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 668 {
 669         int i, j;
 670         struct mthca_db_page *page;
 671         u8 status;
 672
 673         i = db_index / MTHCA_DB_REC_PER_PAGE;
 674         j = db_index % MTHCA_DB_REC_PER_PAGE;
 675
 676         page = dev->db_tab->page + i;
 677
 678         mutex_lock(&dev->db_tab->mutex);
 679
 680         page->db_rec[j] = 0;
 681         if (i >= dev->db_tab->min_group2)
 682                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 683         clear_bit(j, page->used);
 684
 685         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 686             i >= dev->db_tab->max_group1 - 1) {
 687                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 688
 689                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 690                                   page->db_rec, page->mapping);
 691                 page->db_rec = NULL;
 692
 693                 if (i == dev->db_tab->max_group1) {
 694                         --dev->db_tab->max_group1;
 695                         /* XXX may be able to unmap more pages now */
 696                 }
 697                 if (i == dev->db_tab->min_group2)
 698                         ++dev->db_tab->min_group2;
 699         }
 700
 701         mutex_unlock(&dev->db_tab->mutex);
 702 }
 703
 704 int mthca_init_db_tab(struct mthca_dev *dev)
 705 {
 706         int i;
 707
 708         if (!mthca_is_memfree(dev))
 709                 return 0;
 710
 711         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 712         if (!dev->db_tab)
 713                 return -ENOMEM;
 714
 715         mutex_init(&dev->db_tab->mutex);
 716
 717         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 718         dev->db_tab->max_group1 = 0;
 719         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 720
 721         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 722                                     sizeof *dev->db_tab->page,
 723                                     GFP_KERNEL);
 724         if (!dev->db_tab->page) {
 725                 kfree(dev->db_tab);
 726                 return -ENOMEM;
 727         }
 728
 729         for (i = 0; i < dev->db_tab->npages; ++i)
 730                 dev->db_tab->page[i].db_rec = NULL;
 731
 732         return 0;
 733 }
 734
 735 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 736 {
 737         int i;
 738         u8 status;
 739
 740         if (!mthca_is_memfree(dev))
 741                 return;
 742
 743         /*
 744          * Because we don't always free our UARC pages when they
 745          * become empty to make mthca_free_db() simpler we need to
 746          * make a sweep through the doorbell pages and free any
 747          * leftover pages now.
 748          */
 749         for (i = 0; i < dev->db_tab->npages; ++i) {
 750                 if (!dev->db_tab->page[i].db_rec)
 751                         continue;
 752
 753                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 754                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 755
 756                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 757
 758                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 759                                   dev->db_tab->page[i].db_rec,
 760                                   dev->db_tab->page[i].mapping);
 761         }
 762
 763         kfree(dev->db_tab->page);
 764         kfree(dev->db_tab);
 765 }