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);
 117         mem->length = PAGE_SIZE << order;
 118         mem->offset = 0;
 119         return 0;
 120 }
 121
 122 static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
 123                                     int order, gfp_t gfp_mask)
 124 {
 125         void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
 126                                        gfp_mask);
 127         if (!buf)
 128                 return -ENOMEM;
 129
 130         sg_set_buf(mem, buf, PAGE_SIZE << order);
 131         BUG_ON(mem->offset);
 132         sg_dma_len(mem) = PAGE_SIZE << order;
 133         return 0;
 134 }
 135
 136 struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 137                                   gfp_t gfp_mask, int coherent)
 138 {
 139         struct mthca_icm *icm;
 140         struct mthca_icm_chunk *chunk = NULL;
 141         int cur_order;
 142         int ret;
 143
 144         /* We use sg_set_buf for coherent allocs, which assumes low memory */
 145         BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
 146
 147         icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 148         if (!icm)
 149                 return icm;
 150
 151         icm->refcount = 0;
 152         INIT_LIST_HEAD(&icm->chunk_list);
 153
 154         cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
 155
 156         while (npages > 0) {
 157                 if (!chunk) {
 158                         chunk = kmalloc(sizeof *chunk,
 159                                         gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 160                         if (!chunk)
 161                                 goto fail;
 162
 163                         sg_init_table(chunk->mem, MTHCA_ICM_CHUNK_LEN);
 164                         chunk->npages = 0;
 165                         chunk->nsg    = 0;
 166                         list_add_tail(&chunk->list, &icm->chunk_list);
 167                 }
 168
 169                 while (1 << cur_order > npages)
 170                         --cur_order;
 171
 172                 if (coherent)
 173                         ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
 174                                                        &chunk->mem[chunk->npages],
 175                                                        cur_order, gfp_mask);
 176                 else
 177                         ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
 178                                                     cur_order, gfp_mask);
 179
 180                 if (!ret) {
 181                         ++chunk->npages;
 182
 183                         if (coherent)
 184                                 ++chunk->nsg;
 185                         else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
 186                                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 187                                                         chunk->npages,
 188                                                         PCI_DMA_BIDIRECTIONAL);
 189
 190                                 if (chunk->nsg <= 0)
 191                                         goto fail;
 192                         }
 193
 194                         if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
 195                                 chunk = NULL;
 196
 197                         npages -= 1 << cur_order;
 198                 } else {
 199                         --cur_order;
 200                         if (cur_order < 0)
 201                                 goto fail;
 202                 }
 203         }
 204
 205         if (!coherent && chunk) {
 206                 chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 207                                         chunk->npages,
 208                                         PCI_DMA_BIDIRECTIONAL);
 209
 210                 if (chunk->nsg <= 0)
 211                         goto fail;
 212         }
 213
 214         return icm;
 215
 216 fail:
 217         mthca_free_icm(dev, icm, coherent);
 218         return NULL;
 219 }
 220
 221 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 222 {
 223         int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 224         int ret = 0;
 225         u8 status;
 226
 227         mutex_lock(&table->mutex);
 228
 229         if (table->icm[i]) {
 230                 ++table->icm[i]->refcount;
 231                 goto out;
 232         }
 233
 234         table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
 235                                         (table->lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 236                                         __GFP_NOWARN, table->coherent);
 237         if (!table->icm[i]) {
 238                 ret = -ENOMEM;
 239                 goto out;
 240         }
 241
 242         if (mthca_MAP_ICM(dev, table->icm[i], table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 243                           &status) || status) {
 244                 mthca_free_icm(dev, table->icm[i], table->coherent);
 245                 table->icm[i] = NULL;
 246                 ret = -ENOMEM;
 247                 goto out;
 248         }
 249
 250         ++table->icm[i]->refcount;
 251
 252 out:
 253         mutex_unlock(&table->mutex);
 254         return ret;
 255 }
 256
 257 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 258 {
 259         int i;
 260         u8 status;
 261
 262         if (!mthca_is_memfree(dev))
 263                 return;
 264
 265         i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 266
 267         mutex_lock(&table->mutex);
 268
 269         if (--table->icm[i]->refcount == 0) {
 270                 mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 271                                 MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 272                                 &status);
 273                 mthca_free_icm(dev, table->icm[i], table->coherent);
 274                 table->icm[i] = NULL;
 275         }
 276
 277         mutex_unlock(&table->mutex);
 278 }
 279
 280 void *mthca_table_find(struct mthca_icm_table *table, int obj, dma_addr_t *dma_handle)
 281 {
 282         int idx, offset, dma_offset, i;
 283         struct mthca_icm_chunk *chunk;
 284         struct mthca_icm *icm;
 285         struct page *page = NULL;
 286
 287         if (!table->lowmem)
 288                 return NULL;
 289
 290         mutex_lock(&table->mutex);
 291
 292         idx = (obj & (table->num_obj - 1)) * table->obj_size;
 293         icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
 294         dma_offset = offset = idx % MTHCA_TABLE_CHUNK_SIZE;
 295
 296         if (!icm)
 297                 goto out;
 298
 299         list_for_each_entry(chunk, &icm->chunk_list, list) {
 300                 for (i = 0; i < chunk->npages; ++i) {
 301                         if (dma_handle && dma_offset >= 0) {
 302                                 if (sg_dma_len(&chunk->mem[i]) > dma_offset)
 303                                         *dma_handle = sg_dma_address(&chunk->mem[i]) +
 304                                                 dma_offset;
 305                                 dma_offset -= sg_dma_len(&chunk->mem[i]);
 306                         }
 307                         /* DMA mapping can merge pages but not split them,
 308                          * so if we found the page, dma_handle has already
 309                          * been assigned to. */
 310                         if (chunk->mem[i].length > offset) {
 311                                 page = sg_page(&chunk->mem[i]);
 312                                 goto out;
 313                         }
 314                         offset -= chunk->mem[i].length;
 315                 }
 316         }
 317
 318 out:
 319         mutex_unlock(&table->mutex);
 320         return page ? lowmem_page_address(page) + offset : NULL;
 321 }
 322
 323 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 324                           int start, int end)
 325 {
 326         int inc = MTHCA_TABLE_CHUNK_SIZE / table->obj_size;
 327         int i, err;
 328
 329         for (i = start; i <= end; i += inc) {
 330                 err = mthca_table_get(dev, table, i);
 331                 if (err)
 332                         goto fail;
 333         }
 334
 335         return 0;
 336
 337 fail:
 338         while (i > start) {
 339                 i -= inc;
 340                 mthca_table_put(dev, table, i);
 341         }
 342
 343         return err;
 344 }
 345
 346 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,
 347                            int start, int end)
 348 {
 349         int i;
 350
 351         if (!mthca_is_memfree(dev))
 352                 return;
 353
 354         for (i = start; i <= end; i += MTHCA_TABLE_CHUNK_SIZE / table->obj_size)
 355                 mthca_table_put(dev, table, i);
 356 }
 357
 358 struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 359                                               u64 virt, int obj_size,
 360                                               int nobj, int reserved,
 361                                               int use_lowmem, int use_coherent)
 362 {
 363         struct mthca_icm_table *table;
 364         int num_icm;
 365         unsigned chunk_size;
 366         int i;
 367         u8 status;
 368
 369         num_icm = (obj_size * nobj + MTHCA_TABLE_CHUNK_SIZE - 1) / MTHCA_TABLE_CHUNK_SIZE;
 370
 371         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 372         if (!table)
 373                 return NULL;
 374
 375         table->virt     = virt;
 376         table->num_icm  = num_icm;
 377         table->num_obj  = nobj;
 378         table->obj_size = obj_size;
 379         table->lowmem   = use_lowmem;
 380         table->coherent = use_coherent;
 381         mutex_init(&table->mutex);
 382
 383         for (i = 0; i < num_icm; ++i)
 384                 table->icm[i] = NULL;
 385
 386         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 387                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 388                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 389                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 390
 391                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 392                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 393                                                 __GFP_NOWARN, use_coherent);
 394                 if (!table->icm[i])
 395                         goto err;
 396                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 397                                   &status) || status) {
 398                         mthca_free_icm(dev, table->icm[i], table->coherent);
 399                         table->icm[i] = NULL;
 400                         goto err;
 401                 }
 402
 403                 /*
 404                  * Add a reference to this ICM chunk so that it never
 405                  * gets freed (since it contains reserved firmware objects).
 406                  */
 407                 ++table->icm[i]->refcount;
 408         }
 409
 410         return table;
 411
 412 err:
 413         for (i = 0; i < num_icm; ++i)
 414                 if (table->icm[i]) {
 415                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 416                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 417                                         &status);
 418                         mthca_free_icm(dev, table->icm[i], table->coherent);
 419                 }
 420
 421         kfree(table);
 422
 423         return NULL;
 424 }
 425
 426 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 427 {
 428         int i;
 429         u8 status;
 430
 431         for (i = 0; i < table->num_icm; ++i)
 432                 if (table->icm[i]) {
 433                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 434                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 435                                         &status);
 436                         mthca_free_icm(dev, table->icm[i], table->coherent);
 437                 }
 438
 439         kfree(table);
 440 }
 441
 442 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 443 {
 444         return dev->uar_table.uarc_base +
 445                 uar->index * dev->uar_table.uarc_size +
 446                 page * MTHCA_ICM_PAGE_SIZE;
 447 }
 448
 449 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 450                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 451 {
 452         struct page *pages[1];
 453         int ret = 0;
 454         u8 status;
 455         int i;
 456
 457         if (!mthca_is_memfree(dev))
 458                 return 0;
 459
 460         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 461                 return -EINVAL;
 462
 463         mutex_lock(&db_tab->mutex);
 464
 465         i = index / MTHCA_DB_REC_PER_PAGE;
 466
 467         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 468             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 469             (uaddr & 4095)) {
 470                 ret = -EINVAL;
 471                 goto out;
 472         }
 473
 474         if (db_tab->page[i].refcount) {
 475                 ++db_tab->page[i].refcount;
 476                 goto out;
 477         }
 478
 479         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 480                              pages, NULL);
 481         if (ret < 0)
 482                 goto out;
 483
 484         sg_set_page(&db_tab->page[i].mem, pages[0]);
 485         db_tab->page[i].mem.length = MTHCA_ICM_PAGE_SIZE;
 486         db_tab->page[i].mem.offset = uaddr & ~PAGE_MASK;
 487
 488         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 489         if (ret < 0) {
 490                 put_page(pages[0]);
 491                 goto out;
 492         }
 493
 494         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 495                                  mthca_uarc_virt(dev, uar, i), &status);
 496         if (!ret && status)
 497                 ret = -EINVAL;
 498         if (ret) {
 499                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 500                 put_page(sg_page(&db_tab->page[i].mem));
 501                 goto out;
 502         }
 503
 504         db_tab->page[i].uvirt    = uaddr;
 505         db_tab->page[i].refcount = 1;
 506
 507 out:
 508         mutex_unlock(&db_tab->mutex);
 509         return ret;
 510 }
 511
 512 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 513                          struct mthca_user_db_table *db_tab, int index)
 514 {
 515         if (!mthca_is_memfree(dev))
 516                 return;
 517
 518         /*
 519          * To make our bookkeeping simpler, we don't unmap DB
 520          * pages until we clean up the whole db table.
 521          */
 522
 523         mutex_lock(&db_tab->mutex);
 524
 525         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 526
 527         mutex_unlock(&db_tab->mutex);
 528 }
 529
 530 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 531 {
 532         struct mthca_user_db_table *db_tab;
 533         int npages;
 534         int i;
 535
 536         if (!mthca_is_memfree(dev))
 537                 return NULL;
 538
 539         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 540         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 541         if (!db_tab)
 542                 return ERR_PTR(-ENOMEM);
 543
 544         mutex_init(&db_tab->mutex);
 545         for (i = 0; i < npages; ++i) {
 546                 db_tab->page[i].refcount = 0;
 547                 db_tab->page[i].uvirt    = 0;
 548         }
 549
 550         return db_tab;
 551 }
 552
 553 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 554                                struct mthca_user_db_table *db_tab)
 555 {
 556         int i;
 557         u8 status;
 558
 559         if (!mthca_is_memfree(dev))
 560                 return;
 561
 562         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
 563                 if (db_tab->page[i].uvirt) {
 564                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 565                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 566                         put_page(sg_page(&db_tab->page[i].mem));
 567                 }
 568         }
 569
 570         kfree(db_tab);
 571 }
 572
 573 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 574                    u32 qn, __be32 **db)
 575 {
 576         int group;
 577         int start, end, dir;
 578         int i, j;
 579         struct mthca_db_page *page;
 580         int ret = 0;
 581         u8 status;
 582
 583         mutex_lock(&dev->db_tab->mutex);
 584
 585         switch (type) {
 586         case MTHCA_DB_TYPE_CQ_ARM:
 587         case MTHCA_DB_TYPE_SQ:
 588                 group = 0;
 589                 start = 0;
 590                 end   = dev->db_tab->max_group1;
 591                 dir   = 1;
 592                 break;
 593
 594         case MTHCA_DB_TYPE_CQ_SET_CI:
 595         case MTHCA_DB_TYPE_RQ:
 596         case MTHCA_DB_TYPE_SRQ:
 597                 group = 1;
 598                 start = dev->db_tab->npages - 1;
 599                 end   = dev->db_tab->min_group2;
 600                 dir   = -1;
 601                 break;
 602
 603         default:
 604                 ret = -EINVAL;
 605                 goto out;
 606         }
 607
 608         for (i = start; i != end; i += dir)
 609                 if (dev->db_tab->page[i].db_rec &&
 610                     !bitmap_full(dev->db_tab->page[i].used,
 611                                  MTHCA_DB_REC_PER_PAGE)) {
 612                         page = dev->db_tab->page + i;
 613                         goto found;
 614                 }
 615
 616         for (i = start; i != end; i += dir)
 617                 if (!dev->db_tab->page[i].db_rec) {
 618                         page = dev->db_tab->page + i;
 619                         goto alloc;
 620                 }
 621
 622         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 623                 ret = -ENOMEM;
 624                 goto out;
 625         }
 626
 627         if (group == 0)
 628                 ++dev->db_tab->max_group1;
 629         else
 630                 --dev->db_tab->min_group2;
 631
 632         page = dev->db_tab->page + end;
 633
 634 alloc:
 635         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 636                                           &page->mapping, GFP_KERNEL);
 637         if (!page->db_rec) {
 638                 ret = -ENOMEM;
 639                 goto out;
 640         }
 641         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 642
 643         ret = mthca_MAP_ICM_page(dev, page->mapping,
 644                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 645         if (!ret && status)
 646                 ret = -EINVAL;
 647         if (ret) {
 648                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 649                                   page->db_rec, page->mapping);
 650                 goto out;
 651         }
 652
 653         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 654
 655 found:
 656         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 657         set_bit(j, page->used);
 658
 659         if (group == 1)
 660                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 661
 662         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 663
 664         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 665
 666         *db = (__be32 *) &page->db_rec[j];
 667
 668 out:
 669         mutex_unlock(&dev->db_tab->mutex);
 670
 671         return ret;
 672 }
 673
 674 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 675 {
 676         int i, j;
 677         struct mthca_db_page *page;
 678         u8 status;
 679
 680         i = db_index / MTHCA_DB_REC_PER_PAGE;
 681         j = db_index % MTHCA_DB_REC_PER_PAGE;
 682
 683         page = dev->db_tab->page + i;
 684
 685         mutex_lock(&dev->db_tab->mutex);
 686
 687         page->db_rec[j] = 0;
 688         if (i >= dev->db_tab->min_group2)
 689                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 690         clear_bit(j, page->used);
 691
 692         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 693             i >= dev->db_tab->max_group1 - 1) {
 694                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 695
 696                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 697                                   page->db_rec, page->mapping);
 698                 page->db_rec = NULL;
 699
 700                 if (i == dev->db_tab->max_group1) {
 701                         --dev->db_tab->max_group1;
 702                         /* XXX may be able to unmap more pages now */
 703                 }
 704                 if (i == dev->db_tab->min_group2)
 705                         ++dev->db_tab->min_group2;
 706         }
 707
 708         mutex_unlock(&dev->db_tab->mutex);
 709 }
 710
 711 int mthca_init_db_tab(struct mthca_dev *dev)
 712 {
 713         int i;
 714
 715         if (!mthca_is_memfree(dev))
 716                 return 0;
 717
 718         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 719         if (!dev->db_tab)
 720                 return -ENOMEM;
 721
 722         mutex_init(&dev->db_tab->mutex);
 723
 724         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 725         dev->db_tab->max_group1 = 0;
 726         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 727
 728         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 729                                     sizeof *dev->db_tab->page,
 730                                     GFP_KERNEL);
 731         if (!dev->db_tab->page) {
 732                 kfree(dev->db_tab);
 733                 return -ENOMEM;
 734         }
 735
 736         for (i = 0; i < dev->db_tab->npages; ++i)
 737                 dev->db_tab->page[i].db_rec = NULL;
 738
 739         return 0;
 740 }
 741
 742 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 743 {
 744         int i;
 745         u8 status;
 746
 747         if (!mthca_is_memfree(dev))
 748                 return;
 749
 750         /*
 751          * Because we don't always free our UARC pages when they
 752          * become empty to make mthca_free_db() simpler we need to
 753          * make a sweep through the doorbell pages and free any
 754          * leftover pages now.
 755          */
 756         for (i = 0; i < dev->db_tab->npages; ++i) {
 757                 if (!dev->db_tab->page[i].db_rec)
 758                         continue;
 759
 760                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 761                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 762
 763                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 764
 765                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 766                                   dev->db_tab->page[i].db_rec,
 767                                   dev->db_tab->page[i].mapping);
 768         }
 769
 770         kfree(dev->db_tab->page);
 771         kfree(dev->db_tab);
 772 }