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 #include <linux/sched.h>
  40
  41 #include <asm/page.h>
  42
  43 #include "mthca_memfree.h"
  44 #include "mthca_dev.h"
  45 #include "mthca_cmd.h"
  46
  47 /*
  48  * We allocate in as big chunks as we can, up to a maximum of 256 KB
  49  * per chunk.
  50  */
  51 enum {
  52         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
  53         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
  54 };
  55
  56 struct mthca_user_db_table {
  57         struct mutex mutex;
  58         struct {
  59                 u64                uvirt;
  60                 struct scatterlist mem;
  61                 int                refcount;
  62         }                page[0];
  63 };
  64
  65 static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  66 {
  67         int i;
  68
  69         if (chunk->nsg > 0)
  70                 pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
  71                              PCI_DMA_BIDIRECTIONAL);
  72
  73         for (i = 0; i < chunk->npages; ++i)
  74                 __free_pages(sg_page(&chunk->mem[i]),
  75                              get_order(chunk->mem[i].length));
  76 }
  77
  78 static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  79 {
  80         int i;
  81
  82         for (i = 0; i < chunk->npages; ++i) {
  83                 dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
  84                                   lowmem_page_address(sg_page(&chunk->mem[i])),
  85                                   sg_dma_address(&chunk->mem[i]));
  86         }
  87 }
  88
  89 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
  90 {
  91         struct mthca_icm_chunk *chunk, *tmp;
  92
  93         if (!icm)
  94                 return;
  95
  96         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
  97                 if (coherent)
  98                         mthca_free_icm_coherent(dev, chunk);
  99                 else
 100                         mthca_free_icm_pages(dev, chunk);
 101
 102                 kfree(chunk);
 103         }
 104
 105         kfree(icm);
 106 }
 107
 108 static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
 109 {
 110         struct page *page;
 111
 112         page = alloc_pages(gfp_mask, order);
 113         if (!page)
 114                 return -ENOMEM;
 115
 116         sg_set_page(mem, page, PAGE_SIZE << order, 0);
 117         return 0;
 118 }
 119
 120 static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
 121                                     int order, gfp_t gfp_mask)
 122 {
 123         void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
 124                                        gfp_mask);
 125         if (!buf)
 126                 return -ENOMEM;
 127
 128         sg_set_buf(mem, buf, PAGE_SIZE << order);
 129         BUG_ON(mem->offset);
 130         sg_dma_len(mem) = PAGE_SIZE << order;
 131         return 0;
 132 }
 133
 134 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 135                                   gfp_t gfp_mask, int coherent)
 136 {
 137         struct mthca_icm *icm;
 138         struct mthca_icm_chunk *chunk = NULL;
 139         int cur_order;
 140         int ret;
 141
 142         /* We use sg_set_buf for coherent allocs, which assumes low memory */
 143         BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
 144
 145         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 146         if (!icm)
 147                 return icm;
 148
 149         icm->refcount = 0;
 150         INIT_LIST_HEAD(&icm->chunk_list);
 151
 152         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
 153
 154         while (npages > 0) {
 155                 if (!chunk) {
 156                         chunk = kmalloc(sizeof *chunk,
 157                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 158                         if (!chunk)
 159                                 goto fail;
 160
 161                         sg_init_table(chunk->mem, MTHCA_ICM_CHUNK_LEN);
 162                         chunk->npages = 0;
 163                         chunk->nsg    = 0;
 164                         list_add_tail(&chunk->list, &icm->chunk_list);
 165                 }
 166
 167                 while (1 << cur_order > npages)
 168                         --cur_order;
 169
 170                 if (coherent)
 171                         ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
 172                                                        &chunk->mem[chunk->npages],
 173                                                        cur_order, gfp_mask);
 174                 else
 175                         ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
 176                                                     cur_order, gfp_mask);
 177
 178                 if (!ret) {
 179                         ++chunk->npages;
 180
 181                         if (coherent)
 182                                 ++chunk->nsg;
 183                         else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
 184                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 185                                                         chunk->npages,
 186                                                         PCI_DMA_BIDIRECTIONAL);
 187
 188                                 if (chunk->nsg <= 0)
 189                                         goto fail;
 190                         }
 191
 192                         if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
 193                                 chunk = NULL;
 194
 195                         npages -= 1 << cur_order;
 196                 } else {
 197                         --cur_order;
 198                         if (cur_order < 0)
 199                                 goto fail;
 200                 }
 201         }
 202
 203         if (!coherent && chunk) {
 204                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 205                                         chunk->npages,
 206                                         PCI_DMA_BIDIRECTIONAL);
 207
 208                 if (chunk->nsg <= 0)
 209                         goto fail;
 210         }
 211
 212         return icm;
 213
 214 fail:
 215         mthca_free_icm(dev, icm, coherent);
 216         return NULL;
 217 }
 218
 219 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 220 {
 221         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 222         int ret = 0;
 223         u8 status;
 224
 225         mutex_lock(&table->mutex);
 226
 227         if (table->icm[i]) {
 228                 ++table->icm[i]->refcount;
 229                 goto out;
 230         }
 231
 232         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
 233                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 234                                         __GFP_NOWARN, table->coherent);
 235         if (!table->icm[i]) {
 236                 ret = -ENOMEM;
 237                 goto out;
 238         }
 239
 240         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 241                           &status) || status) {
 242                 mthca_free_icm(dev, table->icm[i], table->coherent);
 243                 table->icm[i] = NULL;
 244                 ret = -ENOMEM;
 245                 goto out;
 246         }
 247
 248         ++table->icm[i]->refcount;
 249
 250 out:
 251         mutex_unlock(&table->mutex);
 252         return ret;
 253 }
 254
 255 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 256 {
 257         int i;
 258         u8 status;
 259
 260         if (!mthca_is_memfree(dev))
 261                 return;
 262
 263         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 264
 265         mutex_lock(&table->mutex);
 266
 267         if (--table->icm[i]->refcount == 0) {
 268                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 269                                 MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 270                                 &status);
 271                 mthca_free_icm(dev, table->icm[i], table->coherent);
 272                 table->icm[i] = NULL;
 273         }
 274
 275         mutex_unlock(&table->mutex);
 276 }
 277
 278 void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
 279 {
 280         int idx, offset, dma_offset, i;
 281         struct mthca_icm_chunk *chunk;
 282         struct mthca_icm *icm;
 283         struct page *page = NULL;
 284
 285         if (!table->lowmem)
 286                 return NULL;
 287
 288         mutex_lock(&table->mutex);
 289
 290         idx = (obj & (table->num_obj - 1)) * table->obj_size;
 291         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
 292         dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;
 293
 294         if (!icm)
 295                 goto out;
 296
 297         list_for_each_entry(chunk, &icm->chunk_list, list) {
 298                 for (i = 0; i < chunk->npages; ++i) {
 299                         if (dma_handle && dma_offset >= 0) {
 300                                 if (sg_dma_len(&chunk->mem[i]) > dma_offset)
 301                                         *dma_handle = sg_dma_address(&chunk->mem[i]) +
 302                                                 dma_offset;
 303                                 dma_offset -= sg_dma_len(&chunk->mem[i]);
 304                         }
 305                         /* DMA mapping can merge pages but not split them,
 306                          * so if we found the page, dma_handle has already
 307                          * been assigned to. */
 308                         if (chunk->mem[i].length > offset) {
 309                                 page = sg_page(&chunk->mem[i]);
 310                                 goto out;
 311                         }
 312                         offset -= chunk->mem[i].length;
 313                 }
 314         }
 315
 316 out:
 317         mutex_unlock(&table->mutex);
 318         return page ? lowmem_page_address(page) + offset : NULL;
 319 }
 320
 321 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 322                           int start, int end)
 323 {
 324         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
 325         int i, err;
 326
 327         for (i = start; i <= end; i += inc) {
 328                 err = mthca_table_get(dev, table, i);
 329                 if (err)
 330                         goto fail;
 331         }
 332
 333         return 0;
 334
 335 fail:
 336         while (i > start) {
 337                 i -= inc;
 338                 mthca_table_put(dev, table, i);
 339         }
 340
 341         return err;
 342 }
 343
 344 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 345                            int start, int end)
 346 {
 347         int i;
 348
 349         if (!mthca_is_memfree(dev))
 350                 return;
 351
 352         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
 353                 mthca_table_put(dev, table, i);
 354 }
 355
 356 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 357                                               u64 virt, int obj_size,
 358                                               int nobj, int reserved,
 359                                               int use_lowmem, int use_coherent)
 360 {
 361         struct mthca_icm_table *table;
 362         int num_icm;
 363         unsigned chunk_size;
 364         int i;
 365         u8 status;
 366
 367         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
 368
 369         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 370         if (!table)
 371                 return NULL;
 372
 373         table->virt     = virt;
 374         table->num_icm  = num_icm;
 375         table->num_obj  = nobj;
 376         table->obj_size = obj_size;
 377         table->lowmem   = use_lowmem;
 378         table->coherent = use_coherent;
 379         mutex_init(&table->mutex);
 380
 381         for (i = 0; i < num_icm; ++i)
 382                 table->icm[i] = NULL;
 383
 384         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 385                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 386                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 387                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 388
 389                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 390                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 391                                                 __GFP_NOWARN, use_coherent);
 392                 if (!table->icm[i])
 393                         goto err;
 394                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 395                                   &status) || status) {
 396                         mthca_free_icm(dev, table->icm[i], table->coherent);
 397                         table->icm[i] = NULL;
 398                         goto err;
 399                 }
 400
 401                 /*
 402                  * Add a reference to this ICM chunk so that it never
 403                  * gets freed (since it contains reserved firmware objects).
 404                  */
 405                 ++table->icm[i]->refcount;
 406         }
 407
 408         return table;
 409
 410 err:
 411         for (i = 0; i < num_icm; ++i)
 412                 if (table->icm[i]) {
 413                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 414                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 415                                         &status);
 416                         mthca_free_icm(dev, table->icm[i], table->coherent);
 417                 }
 418
 419         kfree(table);
 420
 421         return NULL;
 422 }
 423
 424 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 425 {
 426         int i;
 427         u8 status;
 428
 429         for (i = 0; i < table->num_icm; ++i)
 430                 if (table->icm[i]) {
 431                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 432                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 433                                         &status);
 434                         mthca_free_icm(dev, table->icm[i], table->coherent);
 435                 }
 436
 437         kfree(table);
 438 }
 439
 440 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 441 {
 442         return dev->uar_table.uarc_base +
 443                 uar->index * dev->uar_table.uarc_size +
 444                 page * MTHCA_ICM_PAGE_SIZE;
 445 }
 446
 447 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 448                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 449 {
 450         struct page *pages[1];
 451         int ret = 0;
 452         u8 status;
 453         int i;
 454
 455         if (!mthca_is_memfree(dev))
 456                 return 0;
 457
 458         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 459                 return -EINVAL;
 460
 461         mutex_lock(&db_tab->mutex);
 462
 463         i = index / MTHCA_DB_REC_PER_PAGE;
 464
 465         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 466             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 467             (uaddr & 4095)) {
 468                 ret = -EINVAL;
 469                 goto out;
 470         }
 471
 472         if (db_tab->page[i].refcount) {
 473                 ++db_tab->page[i].refcount;
 474                 goto out;
 475         }
 476
 477         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 478                              pages, NULL);
 479         if (ret < 0)
 480                 goto out;
 481
 482         sg_set_page(&db_tab->page[i].mem, pages[0], MTHCA_ICM_PAGE_SIZE,
 483                         uaddr & ~PAGE_MASK);
 484
 485         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 486         if (ret < 0) {
 487                 put_page(pages[0]);
 488                 goto out;
 489         }
 490
 491         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 492                                  mthca_uarc_virt(dev, uar, i), &status);
 493         if (!ret && status)
 494                 ret = -EINVAL;
 495         if (ret) {
 496                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 497                 put_page(sg_page(&db_tab->page[i].mem));
 498                 goto out;
 499         }
 500
 501         db_tab->page[i].uvirt    = uaddr;
 502         db_tab->page[i].refcount = 1;
 503
 504 out:
 505         mutex_unlock(&db_tab->mutex);
 506         return ret;
 507 }
 508
 509 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 510                          struct mthca_user_db_table *db_tab, int index)
 511 {
 512         if (!mthca_is_memfree(dev))
 513                 return;
 514
 515         /*
 516          * To make our bookkeeping simpler, we don't unmap DB
 517          * pages until we clean up the whole db table.
 518          */
 519
 520         mutex_lock(&db_tab->mutex);
 521
 522         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 523
 524         mutex_unlock(&db_tab->mutex);
 525 }
 526
 527 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 528 {
 529         struct mthca_user_db_table *db_tab;
 530         int npages;
 531         int i;
 532
 533         if (!mthca_is_memfree(dev))
 534                 return NULL;
 535
 536         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 537         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 538         if (!db_tab)
 539                 return ERR_PTR(-ENOMEM);
 540
 541         mutex_init(&db_tab->mutex);
 542         for (i = 0; i < npages; ++i) {
 543                 db_tab->page[i].refcount = 0;
 544                 db_tab->page[i].uvirt    = 0;
 545                 sg_init_table(&db_tab->page[i].mem, 1);
 546         }
 547
 548         return db_tab;
 549 }
 550
 551 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 552                                struct mthca_user_db_table *db_tab)
 553 {
 554         int i;
 555         u8 status;
 556
 557         if (!mthca_is_memfree(dev))
 558                 return;
 559
 560         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
 561                 if (db_tab->page[i].uvirt) {
 562                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 563                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 564                         put_page(sg_page(&db_tab->page[i].mem));
 565                 }
 566         }
 567
 568         kfree(db_tab);
 569 }
 570
 571 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 572                    u32 qn, __be32 **db)
 573 {
 574         int group;
 575         int start, end, dir;
 576         int i, j;
 577         struct mthca_db_page *page;
 578         int ret = 0;
 579         u8 status;
 580
 581         mutex_lock(&dev->db_tab->mutex);
 582
 583         switch (type) {
 584         case MTHCA_DB_TYPE_CQ_ARM:
 585         case MTHCA_DB_TYPE_SQ:
 586                 group = 0;
 587                 start = 0;
 588                 end   = dev->db_tab->max_group1;
 589                 dir   = 1;
 590                 break;
 591
 592         case MTHCA_DB_TYPE_CQ_SET_CI:
 593         case MTHCA_DB_TYPE_RQ:
 594         case MTHCA_DB_TYPE_SRQ:
 595                 group = 1;
 596                 start = dev->db_tab->npages - 1;
 597                 end   = dev->db_tab->min_group2;
 598                 dir   = -1;
 599                 break;
 600
 601         default:
 602                 ret = -EINVAL;
 603                 goto out;
 604         }
 605
 606         for (i = start; i != end; i += dir)
 607                 if (dev->db_tab->page[i].db_rec &&
 608                     !bitmap_full(dev->db_tab->page[i].used,
 609                                  MTHCA_DB_REC_PER_PAGE)) {
 610                         page = dev->db_tab->page + i;
 611                         goto found;
 612                 }
 613
 614         for (i = start; i != end; i += dir)
 615                 if (!dev->db_tab->page[i].db_rec) {
 616                         page = dev->db_tab->page + i;
 617                         goto alloc;
 618                 }
 619
 620         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 621                 ret = -ENOMEM;
 622                 goto out;
 623         }
 624
 625         if (group == 0)
 626                 ++dev->db_tab->max_group1;
 627         else
 628                 --dev->db_tab->min_group2;
 629
 630         page = dev->db_tab->page + end;
 631
 632 alloc:
 633         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 634                                           &page->mapping, GFP_KERNEL);
 635         if (!page->db_rec) {
 636                 ret = -ENOMEM;
 637                 goto out;
 638         }
 639         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 640
 641         ret = mthca_MAP_ICM_page(dev, page->mapping,
 642                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 643         if (!ret && status)
 644                 ret = -EINVAL;
 645         if (ret) {
 646                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 647                                   page->db_rec, page->mapping);
 648                 goto out;
 649         }
 650
 651         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 652
 653 found:
 654         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 655         set_bit(j, page->used);
 656
 657         if (group == 1)
 658                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 659
 660         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 661
 662         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 663
 664         *db = (__be32 *) &page->db_rec[j];
 665
 666 out:
 667         mutex_unlock(&dev->db_tab->mutex);
 668
 669         return ret;
 670 }
 671
 672 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 673 {
 674         int i, j;
 675         struct mthca_db_page *page;
 676         u8 status;
 677
 678         i = db_index / MTHCA_DB_REC_PER_PAGE;
 679         j = db_index % MTHCA_DB_REC_PER_PAGE;
 680
 681         page = dev->db_tab->page + i;
 682
 683         mutex_lock(&dev->db_tab->mutex);
 684
 685         page->db_rec[j] = 0;
 686         if (i >= dev->db_tab->min_group2)
 687                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 688         clear_bit(j, page->used);
 689
 690         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 691             i >= dev->db_tab->max_group1 - 1) {
 692                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 693
 694                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 695                                   page->db_rec, page->mapping);
 696                 page->db_rec = NULL;
 697
 698                 if (i == dev->db_tab->max_group1) {
 699                         --dev->db_tab->max_group1;
 700                         /* XXX may be able to unmap more pages now */
 701                 }
 702                 if (i == dev->db_tab->min_group2)
 703                         ++dev->db_tab->min_group2;
 704         }
 705
 706         mutex_unlock(&dev->db_tab->mutex);
 707 }
 708
 709 int mthca_init_db_tab(struct mthca_dev *dev)
 710 {
 711         int i;
 712
 713         if (!mthca_is_memfree(dev))
 714                 return 0;
 715
 716         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 717         if (!dev->db_tab)
 718                 return -ENOMEM;
 719
 720         mutex_init(&dev->db_tab->mutex);
 721
 722         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 723         dev->db_tab->max_group1 = 0;
 724         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 725
 726         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 727                                     sizeof *dev->db_tab->page,
 728                                     GFP_KERNEL);
 729         if (!dev->db_tab->page) {
 730                 kfree(dev->db_tab);
 731                 return -ENOMEM;
 732         }
 733
 734         for (i = 0; i < dev->db_tab->npages; ++i)
 735                 dev->db_tab->page[i].db_rec = NULL;
 736
 737         return 0;
 738 }
 739
 740 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 741 {
 742         int i;
 743         u8 status;
 744
 745         if (!mthca_is_memfree(dev))
 746                 return;
 747
 748         /*
 749          * Because we don't always free our UARC pages when they
 750          * become empty to make mthca_free_db() simpler we need to
 751          * make a sweep through the doorbell pages and free any
 752          * leftover pages now.
 753          */
 754         for (i = 0; i < dev->db_tab->npages; ++i) {
 755                 if (!dev->db_tab->page[i].db_rec)
 756                         continue;
 757
 758                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 759                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 760
 761                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 762
 763                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 764                                   dev->db_tab->page[i].db_rec,
 765                                   dev->db_tab->page[i].mapping);
 766         }
 767
 768         kfree(dev->db_tab->page);
 769         kfree(dev->db_tab);
 770 }