linux/drivers/infiniband/hw/mthca/mthca_memfree.c
<<
>>
Prefs
   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
  35#include <linux/mm.h>
  36#include <linux/scatterlist.h>
  37#include <linux/sched.h>
  38#include <linux/slab.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 */
  50enum {
  51        MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
  52        MTHCA_TABLE_CHUNK_SIZE = 1 << 18
  53};
  54
  55struct 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
  64static 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(sg_page(&chunk->mem[i]),
  74                             get_order(chunk->mem[i].length));
  75}
  76
  77static 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(sg_page(&chunk->mem[i])),
  84                                  sg_dma_address(&chunk->mem[i]));
  85        }
  86}
  87
  88void 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
 107static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
 108{
 109        struct page *page;
 110
 111        /*
 112         * Use __GFP_ZERO because buggy firmware assumes ICM pages are
 113         * cleared, and subtle failures are seen if they aren't.
 114         */
 115        page = alloc_pages(gfp_mask | __GFP_ZERO, order);
 116        if (!page)
 117                return -ENOMEM;
 118
 119        sg_set_page(mem, page, PAGE_SIZE << order, 0);
 120        return 0;
 121}
 122
 123static int mthca_alloc_icm_coherent(struct device *dev, struct scatterlist *mem,
 124                                    int order, gfp_t gfp_mask)
 125{
 126        void *buf = dma_alloc_coherent(dev, PAGE_SIZE << order, &sg_dma_address(mem),
 127                                       gfp_mask);
 128        if (!buf)
 129                return -ENOMEM;
 130
 131        sg_set_buf(mem, buf, PAGE_SIZE << order);
 132        BUG_ON(mem->offset);
 133        sg_dma_len(mem) = PAGE_SIZE << order;
 134        return 0;
 135}
 136
 137struct mthca_icm *mthca_alloc_icm(struct mthca_dev *dev, int npages,
 138                                  gfp_t gfp_mask, int coherent)
 139{
 140        struct mthca_icm *icm;
 141        struct mthca_icm_chunk *chunk = NULL;
 142        int cur_order;
 143        int ret;
 144
 145        /* We use sg_set_buf for coherent allocs, which assumes low memory */
 146        BUG_ON(coherent && (gfp_mask & __GFP_HIGHMEM));
 147
 148        icm = kmalloc(sizeof *icm, gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 149        if (!icm)
 150                return icm;
 151
 152        icm->refcount = 0;
 153        INIT_LIST_HEAD(&icm->chunk_list);
 154
 155        cur_order = get_order(MTHCA_ICM_ALLOC_SIZE);
 156
 157        while (npages > 0) {
 158                if (!chunk) {
 159                        chunk = kmalloc(sizeof *chunk,
 160                                        gfp_mask & ~(__GFP_HIGHMEM | __GFP_NOWARN));
 161                        if (!chunk)
 162                                goto fail;
 163
 164                        sg_init_table(chunk->mem, MTHCA_ICM_CHUNK_LEN);
 165                        chunk->npages = 0;
 166                        chunk->nsg    = 0;
 167                        list_add_tail(&chunk->list, &icm->chunk_list);
 168                }
 169
 170                while (1 << cur_order > npages)
 171                        --cur_order;
 172
 173                if (coherent)
 174                        ret = mthca_alloc_icm_coherent(&dev->pdev->dev,
 175                                                       &chunk->mem[chunk->npages],
 176                                                       cur_order, gfp_mask);
 177                else
 178                        ret = mthca_alloc_icm_pages(&chunk->mem[chunk->npages],
 179                                                    cur_order, gfp_mask);
 180
 181                if (!ret) {
 182                        ++chunk->npages;
 183
 184                        if (coherent)
 185                                ++chunk->nsg;
 186                        else if (chunk->npages == MTHCA_ICM_CHUNK_LEN) {
 187                                chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 188                                                        chunk->npages,
 189                                                        PCI_DMA_BIDIRECTIONAL);
 190
 191                                if (chunk->nsg <= 0)
 192                                        goto fail;
 193                        }
 194
 195                        if (chunk->npages == MTHCA_ICM_CHUNK_LEN)
 196                                chunk = NULL;
 197
 198                        npages -= 1 << cur_order;
 199                } else {
 200                        --cur_order;
 201                        if (cur_order < 0)
 202                                goto fail;
 203                }
 204        }
 205
 206        if (!coherent && chunk) {
 207                chunk->nsg = pci_map_sg(dev->pdev, chunk->mem,
 208                                        chunk->npages,
 209                                        PCI_DMA_BIDIRECTIONAL);
 210
 211                if (chunk->nsg <= 0)
 212                        goto fail;
 213        }
 214
 215        return icm;
 216
 217fail:
 218        mthca_free_icm(dev, icm, coherent);
 219        return NULL;
 220}
 221
 222int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 223{
 224        int i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 225        int ret = 0;
 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],
 243                          table->virt + i * MTHCA_TABLE_CHUNK_SIZE)) {
 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
 252out:
 253        mutex_unlock(&table->mutex);
 254        return ret;
 255}
 256
 257void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj)
 258{
 259        int i;
 260
 261        if (!mthca_is_memfree(dev))
 262                return;
 263
 264        i = (obj & (table->num_obj - 1)) * table->obj_size / MTHCA_TABLE_CHUNK_SIZE;
 265
 266        mutex_lock(&table->mutex);
 267
 268        if (--table->icm[i]->refcount == 0) {
 269                mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 270                                MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
 271                mthca_free_icm(dev, table->icm[i], table->coherent);
 272                table->icm[i] = NULL;
 273        }
 274
 275        mutex_unlock(&table->mutex);
 276}
 277
 278void *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
 316out:
 317        mutex_unlock(&table->mutex);
 318        return page ? lowmem_page_address(page) + offset : NULL;
 319}
 320
 321int 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
 335fail:
 336        while (i > start) {
 337                i -= inc;
 338                mthca_table_put(dev, table, i);
 339        }
 340
 341        return err;
 342}
 343
 344void 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
 356struct 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 obj_per_chunk;
 363        int num_icm;
 364        unsigned chunk_size;
 365        int i;
 366
 367        obj_per_chunk = MTHCA_TABLE_CHUNK_SIZE / obj_size;
 368        num_icm = DIV_ROUND_UP(nobj, obj_per_chunk);
 369
 370        table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 371        if (!table)
 372                return NULL;
 373
 374        table->virt     = virt;
 375        table->num_icm  = num_icm;
 376        table->num_obj  = nobj;
 377        table->obj_size = obj_size;
 378        table->lowmem   = use_lowmem;
 379        table->coherent = use_coherent;
 380        mutex_init(&table->mutex);
 381
 382        for (i = 0; i < num_icm; ++i)
 383                table->icm[i] = NULL;
 384
 385        for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 386                chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 387                if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 388                        chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 389
 390                table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 391                                                (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 392                                                __GFP_NOWARN, use_coherent);
 393                if (!table->icm[i])
 394                        goto err;
 395                if (mthca_MAP_ICM(dev, table->icm[i],
 396                                  virt + i * MTHCA_TABLE_CHUNK_SIZE)) {
 397                        mthca_free_icm(dev, table->icm[i], table->coherent);
 398                        table->icm[i] = NULL;
 399                        goto err;
 400                }
 401
 402                /*
 403                 * Add a reference to this ICM chunk so that it never
 404                 * gets freed (since it contains reserved firmware objects).
 405                 */
 406                ++table->icm[i]->refcount;
 407        }
 408
 409        return table;
 410
 411err:
 412        for (i = 0; i < num_icm; ++i)
 413                if (table->icm[i]) {
 414                        mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 415                                        MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
 416                        mthca_free_icm(dev, table->icm[i], table->coherent);
 417                }
 418
 419        kfree(table);
 420
 421        return NULL;
 422}
 423
 424void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 425{
 426        int i;
 427
 428        for (i = 0; i < table->num_icm; ++i)
 429                if (table->icm[i]) {
 430                        mthca_UNMAP_ICM(dev,
 431                                        table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 432                                        MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE);
 433                        mthca_free_icm(dev, table->icm[i], table->coherent);
 434                }
 435
 436        kfree(table);
 437}
 438
 439static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 440{
 441        return dev->uar_table.uarc_base +
 442                uar->index * dev->uar_table.uarc_size +
 443                page * MTHCA_ICM_PAGE_SIZE;
 444}
 445
 446int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 447                      struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 448{
 449        struct page *pages[1];
 450        int ret = 0;
 451        int i;
 452
 453        if (!mthca_is_memfree(dev))
 454                return 0;
 455
 456        if (index < 0 || index > dev->uar_table.uarc_size / 8)
 457                return -EINVAL;
 458
 459        mutex_lock(&db_tab->mutex);
 460
 461        i = index / MTHCA_DB_REC_PER_PAGE;
 462
 463        if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 464            (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 465            (uaddr & 4095)) {
 466                ret = -EINVAL;
 467                goto out;
 468        }
 469
 470        if (db_tab->page[i].refcount) {
 471                ++db_tab->page[i].refcount;
 472                goto out;
 473        }
 474
 475        ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 476                             pages, NULL);
 477        if (ret < 0)
 478                goto out;
 479
 480        sg_set_page(&db_tab->page[i].mem, pages[0], MTHCA_ICM_PAGE_SIZE,
 481                        uaddr & ~PAGE_MASK);
 482
 483        ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 484        if (ret < 0) {
 485                put_page(pages[0]);
 486                goto out;
 487        }
 488
 489        ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 490                                 mthca_uarc_virt(dev, uar, i));
 491        if (ret) {
 492                pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 493                put_page(sg_page(&db_tab->page[i].mem));
 494                goto out;
 495        }
 496
 497        db_tab->page[i].uvirt    = uaddr;
 498        db_tab->page[i].refcount = 1;
 499
 500out:
 501        mutex_unlock(&db_tab->mutex);
 502        return ret;
 503}
 504
 505void 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
 523struct 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                sg_init_table(&db_tab->page[i].mem, 1);
 542        }
 543
 544        return db_tab;
 545}
 546
 547void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 548                               struct mthca_user_db_table *db_tab)
 549{
 550        int i;
 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);
 558                        pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 559                        put_page(sg_page(&db_tab->page[i].mem));
 560                }
 561        }
 562
 563        kfree(db_tab);
 564}
 565
 566int 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
 575        mutex_lock(&dev->db_tab->mutex);
 576
 577        switch (type) {
 578        case MTHCA_DB_TYPE_CQ_ARM:
 579        case MTHCA_DB_TYPE_SQ:
 580                group = 0;
 581                start = 0;
 582                end   = dev->db_tab->max_group1;
 583                dir   = 1;
 584                break;
 585
 586        case MTHCA_DB_TYPE_CQ_SET_CI:
 587        case MTHCA_DB_TYPE_RQ:
 588        case MTHCA_DB_TYPE_SRQ:
 589                group = 1;
 590                start = dev->db_tab->npages - 1;
 591                end   = dev->db_tab->min_group2;
 592                dir   = -1;
 593                break;
 594
 595        default:
 596                ret = -EINVAL;
 597                goto out;
 598        }
 599
 600        for (i = start; i != end; i += dir)
 601                if (dev->db_tab->page[i].db_rec &&
 602                    !bitmap_full(dev->db_tab->page[i].used,
 603                                 MTHCA_DB_REC_PER_PAGE)) {
 604                        page = dev->db_tab->page + i;
 605                        goto found;
 606                }
 607
 608        for (i = start; i != end; i += dir)
 609                if (!dev->db_tab->page[i].db_rec) {
 610                        page = dev->db_tab->page + i;
 611                        goto alloc;
 612                }
 613
 614        if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 615                ret = -ENOMEM;
 616                goto out;
 617        }
 618
 619        if (group == 0)
 620                ++dev->db_tab->max_group1;
 621        else
 622                --dev->db_tab->min_group2;
 623
 624        page = dev->db_tab->page + end;
 625
 626alloc:
 627        page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 628                                          &page->mapping, GFP_KERNEL);
 629        if (!page->db_rec) {
 630                ret = -ENOMEM;
 631                goto out;
 632        }
 633        memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 634
 635        ret = mthca_MAP_ICM_page(dev, page->mapping,
 636                                 mthca_uarc_virt(dev, &dev->driver_uar, i));
 637        if (ret) {
 638                dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 639                                  page->db_rec, page->mapping);
 640                goto out;
 641        }
 642
 643        bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 644
 645found:
 646        j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 647        set_bit(j, page->used);
 648
 649        if (group == 1)
 650                j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 651
 652        ret = i * MTHCA_DB_REC_PER_PAGE + j;
 653
 654        page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 655
 656        *db = (__be32 *) &page->db_rec[j];
 657
 658out:
 659        mutex_unlock(&dev->db_tab->mutex);
 660
 661        return ret;
 662}
 663
 664void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 665{
 666        int i, j;
 667        struct mthca_db_page *page;
 668
 669        i = db_index / MTHCA_DB_REC_PER_PAGE;
 670        j = db_index % MTHCA_DB_REC_PER_PAGE;
 671
 672        page = dev->db_tab->page + i;
 673
 674        mutex_lock(&dev->db_tab->mutex);
 675
 676        page->db_rec[j] = 0;
 677        if (i >= dev->db_tab->min_group2)
 678                j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 679        clear_bit(j, page->used);
 680
 681        if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 682            i >= dev->db_tab->max_group1 - 1) {
 683                mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1);
 684
 685                dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 686                                  page->db_rec, page->mapping);
 687                page->db_rec = NULL;
 688
 689                if (i == dev->db_tab->max_group1) {
 690                        --dev->db_tab->max_group1;
 691                        /* XXX may be able to unmap more pages now */
 692                }
 693                if (i == dev->db_tab->min_group2)
 694                        ++dev->db_tab->min_group2;
 695        }
 696
 697        mutex_unlock(&dev->db_tab->mutex);
 698}
 699
 700int mthca_init_db_tab(struct mthca_dev *dev)
 701{
 702        int i;
 703
 704        if (!mthca_is_memfree(dev))
 705                return 0;
 706
 707        dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 708        if (!dev->db_tab)
 709                return -ENOMEM;
 710
 711        mutex_init(&dev->db_tab->mutex);
 712
 713        dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 714        dev->db_tab->max_group1 = 0;
 715        dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 716
 717        dev->db_tab->page = kmalloc(dev->db_tab->npages *
 718                                    sizeof *dev->db_tab->page,
 719                                    GFP_KERNEL);
 720        if (!dev->db_tab->page) {
 721                kfree(dev->db_tab);
 722                return -ENOMEM;
 723        }
 724
 725        for (i = 0; i < dev->db_tab->npages; ++i)
 726                dev->db_tab->page[i].db_rec = NULL;
 727
 728        return 0;
 729}
 730
 731void mthca_cleanup_db_tab(struct mthca_dev *dev)
 732{
 733        int i;
 734
 735        if (!mthca_is_memfree(dev))
 736                return;
 737
 738        /*
 739         * Because we don't always free our UARC pages when they
 740         * become empty to make mthca_free_db() simpler we need to
 741         * make a sweep through the doorbell pages and free any
 742         * leftover pages now.
 743         */
 744        for (i = 0; i < dev->db_tab->npages; ++i) {
 745                if (!dev->db_tab->page[i].db_rec)
 746                        continue;
 747
 748                if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 749                        mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 750
 751                mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1);
 752
 753                dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 754                                  dev->db_tab->page[i].db_rec,
 755                                  dev->db_tab->page[i].mapping);
 756        }
 757
 758        kfree(dev->db_tab->page);
 759        kfree(dev->db_tab);
 760}
 761