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